FIELD

This disclosure relates to ethylene interpolymer products manufactured in a continuous solution polymerization process utilizing at least two reactors employing at least one single-site catalyst formulation and at least one heterogeneous catalyst formulation to produce ethylene interpolymer products having improved properties.

BACKGROUND

Solution polymerization processes are typically carried out at temperatures above the melting point of the ethylene interpolymer being synthesized. In a typical solution polymerization process, catalyst components, solvent, monomers and hydrogen are fed under pressure to one or more reactors.

For ethylene homo polymerization, or ethylene copolymerization, reactor temperatures can range from about 80° C. to about 300° C. while pressures generally range from about 3 MPag to about 45 MPag and the ethylene interpolymer produced is dissolved in a solvent. The residence time of the solvent in the reactor is relatively short, for example, from about 1 second to about 20 minutes. The solution process can be operated under a wide range of process conditions that allow the production of a wide variety of ethylene interpolymers. Post reactor, the polymerization reaction is quenched to prevent further polymerization, by adding a catalyst deactivator, and passivated, by adding an acid scavenger. Once passivated, the polymer solution is forwarded to a polymer recovery operation where the ethylene interpolymer product is separated from process solvent, unreacted residual ethylene and unreacted optional α-olefin(s).

The polymer industry is in constant need of improved ethylene interpolymer products in flexible film applications, non-limiting examples include food packaging, shrink and stretch films. The inventive ethylene interpolymer products disclosed herein have performance attributes that are advantageous in many film applications. Elaborating, relative to competitive polyethylenes of similar density and melt index, some embodiments of the disclosed ethylene interpolymers after converting into films have one or more of: higher stiffness (e.g., tensile and/or flex modulus); higher toughness properties (e.g. impact and puncture); higher heat deflection temperatures; higher Vicat softening point; improved color (WI and YI); higher melt strength, and; improved heat sealing properties (e.g., heat sealing and hot tack). These recited performance attributes are not to be construed as limiting.

The polymer industry is also in need of improved ethylene interpolymer products for rigid applications; non-limiting examples include containers, lids, caps and toys, etc. The inventive ethylene interpolymer products disclosed herein have performance attributes that are advantageous in many rigid applications. Elaborating, relative to competitive polyethylenes of similar density and melt index, some embodiments of the disclosed ethylene interpolymers have one or more of: higher stiffness (e.g. flexural modulus); higher toughness properties (e.g., ESCR, PENT, IZOD impact, arm impact, Dynatup impact or Charpy impact resistance); higher melt strength, higher heat deflection temperature; higher Vicat softening temperatures, improved color (WI and YI), and; faster crystallization rates (recited performance attributes are not to be construed as limiting).

Further, the polymerization process and catalyst formulations disclosed herein allow the production of ethylene interpolymer products that can be converted into flexible or rigid manufactured articles that have a unique balance of physical properties (i.e., several end-use properties can be balanced (as desired) through multidimensional optimization); relative to comparative polyethylenes of comparable density and melt index.

SUMMARY OF DISCLOSURE

This Application claims priority to Canadian Patent Application No. CA 2,868,640, filed Oct. 21, 2014 and entitled “SOLUTION POLYMERIZATION PROCESS”.

One embodiment of this disclosure is an ethylene interpolymer product comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has a Dilution Index, Y_d, greater than 0.

One embodiment of this disclosure is an ethylene interpolymer product comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer has ≥0.03 terminal vinyl unsaturations per 100 carbon atoms.

One embodiment of this disclosure is an ethylene interpolymer product comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has ≥3 parts per million (ppm) of a total catalytic metal.

Further embodiments of this disclosure include ethylene interpolymer products comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has a Dilution Index, Y_d, greater than 0 and ≥0.03 terminal vinyl unsaturations per 100 carbon atoms or ≥3 parts per million (ppm) of a total catalytic metal or a Dimensionless Modulus, X_d, >0.

Further embodiments of this disclosure include ethylene interpolymer products comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has ≥0.03 terminal vinyl unsaturations per 100 carbon atoms and ≥3 parts per million (ppm) of a total catalytic metal or a Dimensionless Modulus, X_d, >0.

One embodiments of this disclosure includes and ethylene interpolymer product comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has ≥3 parts per million (ppm) of a total catalytic metal and a Dimensionless Modulus, X_d, >0.

Further embodiments of this disclosure include ethylene interpolymer products comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has a Dilution Index, Y_d, greater than 0 and ≥0.03 terminal vinyl unsaturations per 100 carbon atoms and ≥3 parts per million (ppm) of a total catalytic metal or a Dimensionless Modulus, X_d, >0.

Additional embodiments of this disclosure include ethylene interpolymer products comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has a Dimensionless Modulus, X_d, >0 and ≥3 parts per million (ppm) of a total catalytic metal and a Dilution Index, Y_d, greater than 0 or ≥0.03 terminal vinyl unsaturations per 100 carbon atoms

One embodiment of this disclosure includes ethylene interpolymer products comprising: (i) a first ethylene interpolymer; (ii) a second ethylene interpolymer, and; (iii) optionally a third ethylene interpolymer; where the ethylene interpolymer product has a Dilution Index, Y_d, greater than 0, a Dimensionless Modulus, X_d, >0, ≥3 parts per million (ppm) of a total catalytic metal and ≥0.03 terminal vinyl unsaturations per 100 carbon atoms.

Additional embodiments include ethylene interpolymer product having a melt index from about 0.3 to about 500 dg/minute, a density from about 0.869 to about 0.975 g/cm³, a M_w/M_nfrom about 2 to about 25 and a CDBI₅₀from about 20% to about 98%; where melt index is measured according to ASTM D1238 (2.16 kg load and 190° C.) and density is measured according to ASTM D792.

Further embodiments include ethylene interpolymer products comprising: (i) from about 15 to about 60 weight percent of a first ethylene interpolymer having a melt index from about 0.01 to about 200 dg/minute and a density from about 0.855 g/cm³to about 0.975 g/cm³; (ii) from about 30 to about 85 weight percent of a second ethylene interpolymer having a melt index from about 0.3 to about 1000 dg/minute and a density from about 0.89 g/cm³to about 0.975 g/cm³, and; (iii) optionally from about 0 to about 30 weight percent of a third ethylene interpolymer having a melt index from about 0.5 to about 2000 dg/minute and a density from about 0.89 to about 0.975 g/cm³; where weight percent is the weight of the first, second or third ethylene polymer divided by the weight of ethylene interpolymer product.

Embodiments of this disclosure include ethylene interpolymer products synthesized in a solution polymerization process. Embodiments of this disclosure include ethylene interpolymer products comprising from 0 to about 10 mole percent of one or more α-olefins.

Further embodiments ethylene interpolymer products where the first ethylene interpolymer is synthesized using a single-site catalyst formulation. In other embodiments the second ethylene interpolymer is synthesized using a first heterogeneous catalyst formulation. Embodiments also include ethylene interpolymers where the third ethylene interpolymer is synthesized using a first heterogeneous catalyst formulation or a second heterogeneous catalyst formulation. The second ethylene interpolymer may also be synthesized using a first in-line Ziegler Natta catalyst formulation or a first batch Ziegler-Natta catalyst formulation; optionally, the third ethylene interpolymer is synthesized using the first in-line Ziegler Natta catalyst formulation or the first batch Ziegler-Natta catalyst formulation. The optional third ethylene interpolymer may be synthesized using a second in-line Ziegler Natta catalyst formulation or a second batch Ziegler-Natta catalyst formulation.

Embodiments of this disclosure include ethylene interpolymer products having ≤1 part per million (ppm) of a metal A; where metal A originates from the single-site catalyst formulation; non-limiting examples of metal A include titanium, zirconium or hafnium.

Further embodiments of this disclosure include ethylene interpolymer products comprising a metal B and optionally a metal C; where the total amount of metal B and metal C is from about 3 to about 11 parts per million (ppm); where metal B originates from a first heterogeneous catalyst formulation and metal C form an optional second heterogeneous catalyst formation. Metals B and C are independently selected from the following non-limiting examples: titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium or osmium.

Additional embodiments of the ethylene interpolymer products of this disclosure comprise a first ethylene interpolymer having a first M_w/M_n, a second ethylene interpolymer having a second M_w/M_nand an optional third ethylene having a third M_w/M_n; where the first M_w/M_nis lower than the second M_w/M_nand the third M_w/M_n. Embodiments include ethylene interpolymer products where the blending of the second ethylene interpolymer and the third ethylene interpolymer form an ethylene interpolymer blend having a fourth M_w/M_n; where the fourth M_w/M_nis not broader than the second M_w/M_n. Additional ethylene interpolymer product embodiments are characterized as having both the second M_w/M_nand the third M_w/M_nless than about 4.0.

Embodiments include ethylene interpolymer products where the first ethylene interpolymer has a first CDBI₅₀from about 70 to about 98%, the second ethylene interpolymer has a second CDBI₅₀from about 45 to about 98% and the optional third ethylene interpolymer has a third CDBI₅₀from about 35 to about 98%. Additional embodiments include ethylene interpolymer products where the first CDBI₅₀is higher than the second CDBI₅₀; optionally the first CDBI₅₀is higher than the third CDBI₅₀.

DESCRIPTION OF FIGURES

The following Figures are presented for the purpose of illustrating selected embodiments of this disclosure; it being understood, that the embodiments shown do not limit this disclosure.

FIG. 1 illustrates a continuous solution polymerization process where an in-line heterogeneous catalyst formulation is employed.

FIG. 2 illustrates a continuous solution polymerization process where a batch heterogeneous catalyst formulation is employed.

FIG. 3 is a plot of Dilution Index (Y_d) (Y_dhas dimensions of degrees (°)) and Dimensionless Modulus (X_d) for:

- Comparative S (open triangle, Y_d=X_d=0) is an ethylene interpolymer comprising an ethylene interpolymer synthesized using an in-line Ziegler-Natta catalyst in a solution process (rheological reference);
- Examples 6, 101, 102, 103, 110, 115, 200, 201 (solid circle, Y_d>0 and X_d<0) are ethylene interpolymer products as described in this disclosure comprising a first ethylene interpolymer synthesized using a single-site catalyst formulation and a second ethylene interpolymer synthesized using an in-line Ziegler-Natta catalyst formulation in a solution process;
- Examples 120, 130 and 131 (solid square, Y_d>0, X_d>0) are ethylene interpolymer products as described in this disclosure;
- Comparatives D and E (open diamond, Y_d<0, X_d>0) are ethylene interpolymers comprising a first ethylene interpolymer synthesized using a single-site catalyst formation and a second ethylene interpolymer synthesized using a batch Ziegler-Natta catalyst formulation in a solution process, and;
- Comparative A (open square, Y_d>0 and X_d<0) is an ethylene interpolymer comprising a first and second ethylene interpolymer synthesized using a single-site catalyst formation in a solution process.

FIG. 4 illustrates a typical Van Gurp Palmen (VGP) plot of phase angle [°] versus complex modulus [kPa].

FIG. 5 plots the Storage modulus (G′) and loss modulus (G″) showing the cross over frequency Ox and the two decade shift in phase angle to reach ω_c(ω_c=0.01 ω_x).

FIG. 6 compares the amount of terminal vinyl unsaturations per 100 carbon atoms (terminal vinyl/100 C) in the ethylene interpolymer products of this disclosure (solid circles) with Comparatives B, C, E, E2, G, H, H2, I and J (open triangles).

FIG. 7 compares the amount of total catalytic metal (ppm) in the ethylene interpolymer products of this disclosure (solid circles) with Comparatives B, C, E, E2, G, H, H2, I and J (open triangles).

DEFINITION OF TERMS

Other than in the examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, extrusion conditions, etc., used in the specification and claims are to be understood as modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties that the various embodiments desire to obtain. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. The numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

It should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10; that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10. Because the disclosed numerical ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.

All compositional ranges expressed herein are limited in total to and do not exceed 100 percent (volume percent or weight percent) in practice. Where multiple components can be present in a composition, the sum of the maximum amounts of each component can exceed 100 percent, with the understanding that, and as those skilled in the art readily understand, that the amounts of the components actually used will conform to the maximum of 100 percent.

In order to form a more complete understanding of this disclosure the following terms are defined and should be used with the accompanying figures and the description of the various embodiments throughout.

The term “Dilution Index (Y_d)” and “Dimensionless Modulus (X_d)” are based on rheological measurements and are fully described in this disclosure.

As used herein, the term “monomer” refers to a small molecule that may chemically react and become chemically bonded with itself or other monomers to form a polymer.

As used herein, the term “α-olefin” is used to describe a monomer having a linear hydrocarbon chain containing from 3 to 20 carbon atoms having a double bond at one end of the chain.

As used herein, the term “ethylene polymer”, refers to macromolecules produced from ethylene monomers and optionally one or more additional monomers; regardless of the specific catalyst or specific process used to make the ethylene polymer. In the polyethylene art, the one or more additional monomers are called “comonomer(s)” and often include α-olefins. The term “homopolymer” refers to a polymer that contains only one type of monomer. Common ethylene polymers include high density polyethylene (HDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), ultralow density polyethylene (ULDPE), plastomer and elastomers. The term ethylene polymer also includes polymers produced in a high pressure polymerization processes; non-limiting examples include low density polyethylene (LDPE), ethylene vinyl acetate copolymers (EVA), ethylene alkyl acrylate copolymers, ethylene acrylic acid copolymers and metal salts of ethylene acrylic acid (commonly referred to as ionomers). The term ethylene polymer also includes block copolymers which may include 2 to 4 comonomers. The term ethylene polymer also includes combinations of, or blends of, the ethylene polymers described above.

The term “ethylene interpolymer” refers to a subset of polymers within the “ethylene polymer” group that excludes polymers produced in high pressure polymerization processes; non-limiting examples of polymers produced in high pressure processes include LDPE and EVA (the latter is a copolymer of ethylene and vinyl acetate).

The term “heterogeneous ethylene interpolymers” refers to a subset of polymers in the ethylene interpolymer group that are produced using a heterogeneous catalyst formulation; non-limiting examples of which include Ziegler-Natta or chromium catalysts.

The term “homogeneous ethylene interpolymer” refers to a subset of polymers in the ethylene interpolymer group that are produced using metallocene or single-site catalysts. Typically, homogeneous ethylene interpolymers have narrow molecular weight distributions, for example gel permeation chromatography (GPC) M_w/M_nvalues of less than 2.8; M_wand M_nrefer to weight and number average molecular weights, respectively. In contrast, the M_w/M_nof heterogeneous ethylene interpolymers are typically greater than the M_w/M_nof homogeneous ethylene interpolymers. In general, homogeneous ethylene interpolymers also have a narrow comonomer distribution, i.e., each macromolecule within the molecular weight distribution has a similar comonomer content. Frequently, the composition distribution breadth index “CDBI” is used to quantify how the comonomer is distributed within an ethylene interpolymer, as well as to differentiate ethylene interpolymers produced with different catalysts or processes. The “CDBI₅₀” is defined as the percent of ethylene interpolymer whose composition is within 50% of the median comonomer composition; this definition is consistent with that described in U.S. Pat. No. 5,206,075 assigned to Exxon Chemical Patents Inc. The CDBI₅₀of an ethylene interpolymer can be calculated from TREF curves (Temperature Rising Elution Fractionation); the TREF method is described in Wild, et al., J. Polym. Sci., Part B, Polym. Phys., Vol. 20 (3), pages 441-455. Typically the CDBI₅₀of homogeneous ethylene interpolymers are greater than about 70%. In contrast, the CDBI₅₀of α-olefin containing heterogeneous ethylene interpolymers are generally lower than the CDBI₅₀of homogeneous ethylene interpolymers.

It is well known to those skilled in the art, that homogeneous ethylene interpolymers are frequently further subdivided into “linear homogeneous ethylene interpolymers” and “substantially linear homogeneous ethylene interpolymers”. These two subgroups differ in the amount of long chain branching: more specifically, linear homogeneous ethylene interpolymers have less than about 0.01 long chain branches per 1000 carbon atoms; while substantially linear ethylene interpolymers have greater than about 0.01 to about 3.0 long chain branches per 1000 carbon atoms. A long chain branch is macromolecular in nature, i.e., similar in length to the macromolecule that the long chain branch is attached to. Hereafter, in this disclosure, the term “homogeneous ethylene interpolymer” refers to both linear homogeneous ethylene interpolymers and substantially linear homogeneous ethylene interpolymers.

Herein, the term “polyolefin” includes ethylene polymers and propylene polymers; non-limiting examples of propylene polymers include isotactic, syndiotactic and atactic propylene homopolymers, random propylene copolymers containing at least one comonomer and impact polypropylene copolymers or heterophasic polypropylene copolymers.

The term “thermoplastic” refers to a polymer that becomes liquid when heated, will flow under pressure and solidify when cooled. Thermoplastic polymers include ethylene polymers as well as other polymers commonly used in the plastic industry; non-limiting examples of other polymers commonly used in film applications include barrier resins (EVOH), tie resins, polyethylene terephthalate (PET), polyamides and the like.

As used herein the term “monolayer film” refers to a film containing a single layer of one or more thermoplastics.

As used herein, the terms “hydrocarbyl”, “hydrocarbyl radical” or “hydrocarbyl group” refers to linear or cyclic, aliphatic, olefinic, acetylenic and aryl (aromatic) radicals comprising hydrogen and carbon that are deficient by one hydrogen.

As used herein, an “alkyl radical” includes linear, branched and cyclic paraffin radicals that are deficient by one hydrogen radical; non-limiting examples include methyl (—CH₃) and ethyl (−CH₂CH₃) radicals. The term “alkenyl radical” refers to linear, branched and cyclic hydrocarbons containing at least one carbon-carbon double bond that is deficient by one hydrogen radical.

As used herein, the term “aryl” group includes phenyl, naphthyl, pyridyl and other radicals whose molecules have an aromatic ring structure; non-limiting examples include naphthylene, phenanthrene and anthracene. An “arylalkyl” group is an alkyl group having an aryl group pendant there from; non-limiting examples include benzyl, phenethyl and tolylmethyl; an “alkylaryl” is an aryl group having one or more alkyl groups pendant there from; non-limiting examples include tolyl, xylyl, mesityl and cumyl.

As used herein, the phrase “heteroatom” includes any atom other than carbon and hydrogen that can be bound to carbon. A “heteroatom-containing group” is a hydrocarbon radical that contains a heteroatom and may contain one or more of the same or different heteroatoms. In one embodiment, a heteroatom-containing group is a hydrocarbyl group containing from 1 to 3 atoms selected from the group consisting of boron, aluminum, silicon, germanium, nitrogen, phosphorous, oxygen and sulfur. Non-limiting examples of heteroatom-containing groups include radicals of imines, amines, oxides, phosphines, ethers, ketones, oxoazolines heterocyclics, oxazolines, thioethers, and the like. The term “heterocyclic” refers to ring systems having a carbon backbone that comprise from 1 to 3 atoms selected from the group consisting of boron, aluminum, silicon, germanium, nitrogen, phosphorous, oxygen and sulfur.

As used herein the term “unsubstituted” means that hydrogen radicals are bounded to the molecular group that follows the term unsubstituted. The term “substituted” means that the group following this term possesses one or more moieties that have replaced one or more hydrogen radicals in any position within the group; non-limiting examples of moieties include halogen radicals (F, Cl, Br), hydroxyl groups, carbonyl groups, carboxyl groups, amine groups, phosphine groups, alkoxy groups, phenyl groups, naphthyl groups, C₁to C₁₀alkyl groups, C₂to C₁₀alkenyl groups, and combinations thereof. Non-limiting examples of substituted alkyls and aryls include: acyl radicals, alkylamino radicals, alkoxy radicals, aryloxy radicals, alkylthio radicals, dialkylamino radicals, alkoxycarbonyl radicals, aryloxycarbonyl radicals, carbomoyl radicals, alkyl- and dialkyl-carbamoyl radicals, acyloxy radicals, acylamino radicals, arylamino radicals and combinations thereof.

Herein the term “R1” and its superscript form “^R1” refers to a first reactor in a continuous solution polymerization process; it being understood that R1 is distinctly different from the symbol R¹; the latter is used in chemical formula, e.g. representing a hydrocarbyl group. Similarly, the term “R2” and it's superscript form “^R2” refers to a second reactor, and; the term “R3” and it's superscript form “^R3” refers to a third reactor.

As used herein, the term “oligomers” refers to an ethylene polymer of low molecular weight, e.g., an ethylene polymer with a weight average molecular weight (Mw) of about 2000 to 3000 daltons. Other commonly used terms for oligomers include “wax” or “grease”. As used herein, the term “light-end impurities” refers to chemical compounds with relatively low boiling points that may be present in the various vessels and process streams within a continuous solution polymerization process; non-limiting examples include, methane, ethane, propane, butane, nitrogen, CO₂, chloroethane, HCl, etc.

DETAILED DESCRIPTION
Catalysts

Organometallic catalyst formulations that are efficient in polymerizing olefins are well known in the art. In the embodiments disclosed herein, at least two catalyst formulations are employed in a continuous solution polymerization process. One of the catalyst formulations comprises at least one single-site catalyst formulation that produces a homogeneous first ethylene interpolymer. The other catalyst formulation comprises at least one heterogeneous catalyst formulation that produces a heterogeneous second ethylene interpolymer. Optionally a third ethylene interpolymer may be produced using the heterogeneous catalyst formulation that was used to produce the second ethylene interpolymer, or a different heterogeneous catalyst formulation may be used to produce the third ethylene interpolymer. In the continuous solution process, the at least one homogeneous ethylene interpolymer and the at least one heterogeneous ethylene interpolymer are solution blended and an ethylene interpolymer product is produced.

Single Site Catalyst Formulation

The catalyst components which make up the single site catalyst formulation are not particularly limited, i.e., a wide variety of catalyst components can be used. One non-limiting embodiment of a single site catalyst formulation comprises the following three or four components: a bulky ligand-metal complex; an alumoxane co-catalyst; an ionic activator and optionally a hindered phenol. In Tables 1A, 2A, 3A and 4A of this disclosure: “(i)” refers to the amount of “component (i)”, i.e., the bulky ligand-metal complex added to R1; “(ii)” refers to “component (ii)”, i.e., the alumoxane co-catalyst; “(iii)” refers to “component (iii)” i.e., the ionic activator, and; “(iv)” refers to “component (iv)”, i.e., the optional hindered phenol.

Non-limiting examples of component (i) are represented by formula (I):

(L^A)_aM(PI)_b(Q)_n (I)

wherein (L^A) represents a bulky ligand; M represents a metal atom; PI represents a phosphinimine ligand; Q represents a leaving group; a is 0 or 1; b is 1 or 2; (a+b)=2; n is 1 or 2, and; the sum of (a+b+n) equals the valance of the metal M.

Non-limiting examples of the bulky ligand L^Ain formula (I) include unsubstituted or substituted cyclopentadienyl ligands or cyclopentadienyl-type ligands, heteroatom substituted and/or heteroatom containing cyclopentadienyl-type ligands. Additional non-limiting examples include, cyclopenta-phenanthreneyl ligands, unsubstituted or substituted indenyl ligands, benzindenyl ligands, unsubstituted or substituted fluorenyl ligands, octahydrofluorenyl ligands, cyclooctatetraendiyl ligands, cyclopentacyclododecene ligands, azenyl ligands, azulene ligands, pentalene ligands, phosphoyl ligands, phosphinimine, pyrrolyl ligands, pyrozolyl ligands, carbazolyl ligands, borabenzene ligands and the like, including hydrogenated versions thereof, for example tetrahydroindenyl ligands. In other embodiments, L^Amay be any other ligand structure capable of q-bonding to the metal M, such embodiments include both η³-bonding and η⁵-bonding to the metal M. In other embodiments, L^Amay comprise one or more heteroatoms, for example, nitrogen, silicon, boron, germanium, sulfur and phosphorous, in combination with carbon atoms to form an open, acyclic, or a fused ring, or ring system, for example, a heterocyclopentadienyl ancillary ligand. Other non-limiting embodiments for L^Ainclude bulky amides, phosphides, alkoxides, aryloxides, imides, carbolides, borollides, porphyrins, phthalocyanines, corrins and other polyazomacrocycles.

Non-limiting examples of metal M in formula (I) include Group 4 metals, titanium, zirconium and hafnium.

The phosphinimine ligand, PI, is defined by formula (II):

(R^p)₃P=N— (II)

wherein the R^pgroups are independently selected from: a hydrogen atom; a halogen atom; C_1-20hydrocarbyl radicals which are unsubstituted or substituted with one or more halogen atom(s); a C_1-8alkoxy radical; a C_6-10aryl radical; a C_6-10aryloxy radical; an amido radical; a silyl radical of formula —Si(R^s)₃, wherein the R^sgroups are independently selected from, a hydrogen atom, a C_1-8alkyl or alkoxy radical, a C_6-10aryl radical, a C_6-10aryloxy radical, or a germanyl radical of formula —Ge(R^G)₃, wherein the R^Ggroups are defined as R^sis defined in this paragraph.

The leaving group Q is any ligand that can be abstracted from formula (I) forming a catalyst species capable of polymerizing one or more olefin(s). An equivalent term for Q is an “activatable ligand”, i.e., equivalent to the term “leaving group”. In some embodiments, Q is a monoanionic labile ligand having a sigma bond to M. Depending on the oxidation state of the metal, the value for n is 1 or 2 such that formula (I) represents a neutral bulky ligand-metal complex. Non-limiting examples of Q ligands include a hydrogen atom, halogens, C_1-20hydrocarbyl radicals, C_1-20alkoxy radicals, C_5-10aryl oxide radicals; these radicals may be linear, branched or cyclic or further substituted by halogen atoms, C_1-10alkyl radicals, C_1-10alkoxy radicals, C_6-10arly or aryloxy radicals. Further non-limiting examples of Q ligands include weak bases such as amines, phosphines, ethers, carboxylates, dienes, hydrocarbyl radicals having from 1 to 20 carbon atoms. In another embodiment, two Q ligands may form part of a fused ring or ring system.

Further embodiments of component (i) of the single site catalyst formulation include structural, optical or enantiomeric isomers (meso and racemic isomers) and mixtures thereof of the bulky ligand-metal complexes described in formula (I) above.

The second single site catalyst component, component (ii), is an alumoxane co-catalyst that activates component (i) to a cationic complex. An equivalent term for “alumoxane” is “aluminoxane”; although the exact structure of this co-catalyst is uncertain, subject matter experts generally agree that it is an oligomeric species that contain repeating units of the general formula (III):

(R)₂AlO—(Al(R)—O)_n—Al(R)₂ (III)

where the R groups may be the same or different linear, branched or cyclic hydrocarbyl radicals containing 1 to 20 carbon atoms and n is from 0 to about 50. A non-limiting example of an alumoxane is methyl aluminoxane (or MAO) wherein each R group in formula (III) is a methyl radical.

The third catalyst component (iii) of the single site catalyst formation is an ionic activator. In general, ionic activators are comprised of a cation and a bulky anion; wherein the latter is substantially non-coordinating. Non-limiting examples of ionic activators are boron ionic activators that are four coordinate with four ligands bonded to the boron atom. Non-limiting examples of boron ionic activators include the following formulas (IV) and (V) shown below;

[R⁵]⁺[B(R⁷)₄]⁻ (IV)

where B represents a boron atom, R⁵is an aromatic hydrocarbyl (e.g. triphenyl methyl cation) and each R⁷is independently selected from phenyl radicals which are unsubstituted or substituted with from 3 to 5 substituents selected from fluorine atoms, C_1-4alkyl or alkoxy radicals which are unsubstituted or substituted by fluorine atoms; and a silyl radical of formula —Si(R⁹)₃, where each R⁹is independently selected from hydrogen atoms and C_1-4alkyl radicals, and; compounds of formula (V);

[(R⁸)_tZH]⁺[B(R⁷)₄]⁻ (V)

where B is a boron atom, H is a hydrogen atom, Z is a nitrogen or phosphorus atom, t is 2 or 3 and R⁸is selected from C_1-8alkyl radicals, phenyl radicals which are unsubstituted or substituted by up to three C_1-4alkyl radicals, or one R⁸taken together with the nitrogen atom may form an anilinium radical and R⁷is as defined above in formula (IV).

In both formula (IV) and (V), a non-limiting example of R⁷is a pentafluorophenyl radical. In general, boron ionic activators may be described as salts of tetra(perfluorophenyl) boron; non-limiting examples include anilinium, carbonium, oxonium, phosphonium and sulfonium salts of tetra(perfluoro-phenyl)boron with anilinium and trityl (or triphenylmethylium). Additional non-limiting examples of ionic activators include: triethylammonium tetra(phenyl)-boron, tripropylammonium tetra(phenyl)boron, tri(n-butyl)ammonium tetra(phenyl)boron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o-tolyl)boron, tributylammonium tetra(pentafluorophenyl)boron, tripropylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(m,m-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetra(pentafluorophenyl)boron, tri(n-butyl)ammonium tetra(o-tolyl)boron, N,N-dimethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl)n-butylboron, N,N-2,4,6-pentamethylanilinium tetra(phenyl)boron, di-(isopropyl)ammonium tetra(penta-fluorophenyl)boron, dicyclohexylammonium tetra(phenyl)boron, triphenyl-phosphonium tetra(phenyl)boron, tri(methylphenyl)phosphonium tetra(phenyl)-boron, tri(dimethylphenyl)phosphonium tetra(phenyl)boron, tropillium tetrakispentafluorophenyl borate, triphenylmethylium tetrakispentafluorophenyl borate, benzene(diazonium)tetrakispentafluorophenyl borate, tropillium tetrakis(2,3,5,6-tetrafluorophenyl)borate, triphenylmethylium tetrakis(2,3,5,6-tetrafluorophenyl)borate, benzene(diazonium) tetrakis(3,4,5-trifluorophenyl)-borate, tropillium tetrakis(3,4,5-trifluorophenyl)borate, benzene(diazonium) tetrakis(3,4,5-trifluorophenyl)borate, tropillium tetrakis(1,2,2-trifluoroethenyl)-borate, triphenylmethylium tetrakis(1,2,2-trifluoroethenyl)borate, benzene(diazonium) tetrakis(1,2,2-trifluoroethenyl)borate, tropillium tetrakis(2,3,4,5-tetrafluorophenyl)borate, triphenylmethylium tetrakis(2,3,4,5-tetrafluorophenyl)borate, and benzene(diazonium) tetrakis(2,3,4,5 tetrafluorophenyl)borate. Readily available commercial ionic activators include N,N-dimethylanilinium tetrakispentafluorophenyl borate, and triphenylmethylium tetrakispentafluorophenyl borate.

The optional fourth catalyst component of the single site catalyst formation is a hindered phenol, component (iv). Non-limiting example of hindered phenols include butylated phenolic antioxidants, butylated hydroxytoluene, 2,4-di-tertiarybutyl-6-ethyl phenol, 4,4′-methylenebis (2,6-di-tertiary-butylphenol), 1,3, 5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene and octadecyl-3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl) propionate.

To produce an active single site catalyst formulation the quantity and mole ratios of the three or four components, (i) through (iv) are optimized as described below.

Heterogeneous Catalyst Formulations

A number of heterogeneous catalyst formulations are well known to those skilled in the art, including, as non-limiting examples, Ziegler-Natta and chromium catalyst formulations.

In this disclosure, embodiments include an in-line Ziegler-Natta catalyst formulation and a batch Ziegler-Natta catalyst formation. The term “in-line Ziegler-Natta catalyst formulation” refers to the continuous synthesis of a small quantity of active Ziegler-Natta catalyst and immediately injecting this catalyst into at least one continuously operating reactor, wherein the catalyst polymerizes ethylene and one or more optional α-olefins to form an ethylene interpolymer. The terms “batch Ziegler-Natta catalyst formulation” or “batch Ziegler-Natta procatalyst” refer to the synthesis of a much larger quantity of catalyst or procatalyst in one or more mixing vessels that are external to, or isolated from, the continuously operating solution polymerization process. Once prepared, the batch Ziegler-Natta catalyst formulation, or batch Ziegler-Natta procatalyst, is transferred to a catalyst storage tank. The term “procatalyst” refers to an inactive catalyst formulation (inactive with respect to ethylene polymerization); the procatalyst is converted into an active catalyst by adding an alkyl aluminum co-catalyst. As needed, the procatalyst is pumped from the storage tank to at least one continuously operating reactor, where an active catalyst is formed and polymerizes ethylene and one or more optional α-olefins to form an ethylene interpolymer. The procatalyst may be converted into an active catalyst in the reactor or external to the reactor.

A wide variety of chemical compounds can be used to synthesize an active Ziegler-Natta catalyst formulation. The following describes various chemical compounds that may be combined to produce an active Ziegler-Natta catalyst formulation. Those skilled in the art will understand that the embodiments in this disclosure are not limited to the specific chemical compound disclosed.

An active Ziegler-Natta catalyst formulation may be formed from: a magnesium compound, a chloride compound, a metal compound, an alkyl aluminum co-catalyst and an aluminum alkyl. In Table 1A, 2A, 3A and 4A of this disclosure: “(v)” refers to “component (v)” the magnesium compound; the term “(vi)” refers to the “component (vi)” the chloride compound; “(vii)” refers to “component (vii)” the metal compound; “(viii)” refers to “component (viii)” alkyl aluminum co-catalyst, and; “(ix)” refers to “component (ix)” the aluminum alkyl. As will be appreciated by those skilled in the art, Ziegler-Natta catalyst formulations may contain additional components; a non-limiting example of an additional component is an electron donor, e.g., amines or ethers.

A non-limiting example of an active in-line Ziegler-Natta catalyst formulation can be prepared as follows. In the first step, a solution of a magnesium compound (component (v)) is reacted with a solution of the chloride compound (component (vi)) to form a magnesium chloride support suspended in solution. Non-limiting examples of magnesium compounds include Mg(R¹)₂; wherein the R¹groups may be the same or different, linear, branched or cyclic hydrocarbyl radicals containing 1 to 10 carbon atoms. Non-limiting examples of chloride compounds include R²Cl; wherein R²represents a hydrogen atom, or a linear, branched or cyclic hydrocarbyl radical containing 1 to 10 carbon atoms. In the first step, the solution of magnesium compound may also contain an aluminum alkyl (component (ix)). Non-limiting examples of aluminum alkyl include Al(R³)₃, wherein the R³groups may be the same or different, linear, branched or cyclic hydrocarbyl radicals containing from 1 to 10 carbon atoms. In the second step a solution of the metal compound (component (vii)) is added to the solution of magnesium chloride and the metal compound is supported on the magnesium chloride. Non-limiting examples of suitable metal compounds include M(X)_nor MO(X)_n; where M represents a metal selected from Group 4 through Group 8 of the Periodic Table, or mixtures of metals selected from Group 4 through Group 8; O represents oxygen, and; X represents chloride or bromide; n is an integer from 3 to 6 that satisfies the oxidation state of the metal. Additional non-limiting examples of suitable metal compounds include Group 4 to Group 8 metal alkyls, metal alkoxides (which may be prepared by reacting a metal alkyl with an alcohol) and mixed-ligand metal compounds that contain a mixture of halide, alkyl and alkoxide ligands. In the third step a solution of an alkyl aluminum co-catalyst (component (viii)) is added to the metal compound supported on the magnesium chloride. A wide variety of alkyl aluminum co-catalysts are suitable, as expressed by formula (VI):

Al(R⁴)_p(OR⁵)_q(X)_r (VI)

wherein the R⁴groups may be the same or different, hydrocarbyl groups having from 1 to 10 carbon atoms; the OR⁵groups may be the same or different, alkoxy or aryloxy groups wherein R⁵is a hydrocarbyl group having from 1 to 10 carbon atoms bonded to oxygen; X is chloride or bromide, and; (p+q+r)=3, with the proviso that p is greater than 0. Non-limiting examples of commonly used alkyl aluminum co-catalysts include trimethyl aluminum, triethyl aluminum, tributyl aluminum, dimethyl aluminum methoxide, diethyl aluminum ethoxide, dibutyl aluminum butoxide, dimethyl aluminum chloride or bromide, diethyl aluminum chloride or bromide, dibutyl aluminum chloride or bromide and ethyl aluminum dichloride or dibromide.

The process described in the paragraph above, to synthesize an active in-line Ziegler-Natta catalyst formulation, can be carried out in a variety of solvents; non-limiting examples of solvents include linear or branched C₅to C₁₂alkanes or mixtures thereof. To produce an active in-line Ziegler-Natta catalyst formulation the quantity and mole ratios of the five components, (v) through (ix), are optimized as described below.

Additional embodiments of heterogeneous catalyst formulations include formulations where the “metal compound” is a chromium compound; non-limiting examples include silyl chromate, chromium oxide and chromocene. In some embodiments, the chromium compound is supported on a metal oxide such as silica or alumina. Heterogeneous catalyst formulations containing chromium may also include co-catalysts; non-limiting examples of co-catalysts include trialkylaluminum, alkylaluminoxane and dialkoxyalkylaluminum compounds and the like.

Solution Polymerization Process: In-Line Heterogeneous Catalyst Formulation

In a continuous solution polymerization process, process solvent, monomer(s) and a catalyst formulation are continuously fed to a reactor where the ethylene interpolymer is formed in solution. In FIG. 1, process solvent 1, ethylene 2 and optional α-olefin 3 are combined to produce reactor feed stream RF1 which flows into reactor 11a. In FIG. 1 optional streams, or optional embodiments, are denoted with dotted lines. It is not particularly important that combined reactor feed stream RF1 be formed; i.e. reactor feed streams can be combined in all possible combinations, including an embodiment where streams 1 through 3 are independently injected into reactor 11a. Optionally hydrogen may be injected into reactor 11a through stream 4; hydrogen is generally added to control the molecular weight of the first ethylene interpolymer produced in reactor 11a. Reactor 11a is continuously stirred by stirring assembly 11b which includes a motor external to the reactor and an agitator within the reactor. In the art, such a reactor is frequently called a CSTR (Continuously Stirred Tank Reactor).

A single site catalyst formulation is injected into reactor 11a through stream 5e. Single site catalyst component streams 5d, 5c, 5b and optional 5a refer to the ionic activator (component (iii)), the bulky ligand-metal complex (component (i)), the alumoxane co-catalyst (component (ii)) and optional hindered phenol (component (iv)), respectively. Single site catalyst component streams can be arranged in all possible configurations, including an embodiment where streams 5a through 5d are independently injected into reactor 11a. Each single site catalyst component is dissolved in a catalyst component solvent. Catalyst component solvents, for component (i) through (iv), may be the same or different. Catalyst component solvents are selected such that the combination of catalyst components does not produce a precipitate in any process stream; for example, precipitation of a single site catalyst component in stream 5e. The optimization of the single site catalyst formulation is described below.

Reactor 11a produces a first exit stream, stream 11c, containing the first ethylene interpolymer dissolved in process solvent, as well as unreacted ethylene, unreacted α-olefins (if present), unreacted hydrogen (if present), active single site catalyst, deactivated single site catalyst, residual catalyst components and other impurities (if present). Melt index ranges and density ranges of the first ethylene interpolymer produced are described below.

The continuous solution polymerization process shown in FIG. 1 includes two embodiments where reactors 11a and 12a can be operated in series or parallel modes. In series mode 100% of stream 11c (the first exit stream) passes through flow controller 11d forming stream 11e which enters reactor 12a. In contrast, in parallel mode 100% of stream 11c passes through flow controller 11f forming stream 11g. Stream 11g by-passes reactor 12a and is combined with stream 12c (the second exit stream) forming stream 12d (the third exit stream).

Fresh reactor feed streams are injected into reactor 12a; process solvent 6, ethylene 7 and optional α-olefin 8 are combined to produce reactor feed stream RF2. It is not important that stream RF2 is formed; i.e. reactor feed streams can be combined in all possible combinations, including independently injecting each stream into the reactor. Optionally hydrogen may be injected into reactor 12a through stream 9 to control the molecular weight of the second ethylene interpolymer. Reactor 12a is continuously stirred by stirring assembly 12b which includes a motor external to the reactor and an agitator within the reactor.

An in-line heterogeneous catalyst formulation is injected into reactor 12a through stream 10f and a second ethylene interpolymer is formed in reactor 12a. The components that comprise the in-line heterogeneous catalyst formulation are introduced through streams 10a, 10b, 10c and 10d. A first heterogeneous catalyst assembly, defined by the conduits and flow controllers associated with streams 10a-10h, is operated as described below. In the case of a Ziegler-Natta catalyst, the first heterogeneous catalyst assembly produces an efficient in-line Ziegler-Natta catalyst formulation by optimizing the following molar ratios: (aluminum alkyl)/(magnesium compound) or (ix)/(v); (chloride compound)/(magnesium compound) or (vi)/(v); (alkyl aluminum co-catalyst)/(metal compound) or (viii)/(vii), and; (aluminum alkyl)/(metal compound) or (ix)/(vii); as well as the time these compounds have to react and equilibrate.

Stream 10a (stream S1) contains a binary blend of a magnesium compound, component (v) and an aluminum alkyl, component (ix), in process solvent. The upper limit on the (aluminum alkyl)/(magnesium compound) molar ratio in stream 10a may be about 70, in some cases about 50 and is other cases about 30. The lower limit on the (aluminum alkyl)/(magnesium compound) molar ratio may be about 3.0, in some cases about 5.0 and in other cases about 10. Stream 10b (stream S2) contains a solution of a chloride compound, component (vi), in process solvent. Stream 10b is combined with stream 10a and the intermixing of streams 10a and 10b produces a magnesium chloride catalyst support. To produce an efficient in-line Ziegler-Natta catalyst (efficient in olefin polymerization), the (chloride compound)/(magnesium compound) molar ratio is optimized. The upper limit on the (chloride compound)/(magnesium compound) molar ratio may be about 4, in some cases about 3.5 and is other cases about 3.0. The lower limit on the (chloride compound)/(magnesium compound) molar ratio may be about 1.0, in some cases about 1.5 and in other cases about 1.9. The time between the addition of the chloride compound and the addition of the metal compound (component (vii)) via stream 10c (stream S3) is controlled; hereafter HUT-1 (the first Hold-Up-Time). HUT-1 is the time for streams 10a (stream S1) and 10b (stream S2) to equilibrate and form a magnesium chloride support. The upper limit on HUT-1 may be about 70 seconds, in some cases about 60 seconds and is other cases about 50 seconds. The lower limit on HUT-1 may be about 5 seconds, in some cases about 10 seconds and in other cases about 20 seconds. HUT-1 is controlled by adjusting the length of the conduit between stream 10b injection port and stream 10c injection port, as well as controlling the flow rates of streams 10a and 10b. The time between the addition of component (vii) and the addition of the alkyl aluminum co-catalyst, component (viii), via stream 10d (stream S4) is controlled; hereafter HUT-2 (the second Hold-Up-Time). HUT-2 is the time for the magnesium chloride support and stream 10c to react and equilibrate. The upper limit on HUT-2 may be about 50 seconds, in some cases about 35 seconds and is other cases about 25 seconds. The lower limit on HUT-2 may be about 2 seconds, in some cases about 6 seconds and in other cases about 10 seconds. HUT-2 is controlled by adjusting the length of the conduit between stream 10c injection port and stream 10d injection port, as well as controlling the flow rates of streams 10a, 10b and 10c. The quantity of the alkyl aluminum co-catalyst added is optimized to produce an efficient catalyst; this is accomplished by adjusting the (alkyl aluminum co-catalyst)/(metal compound) molar ratio, or (viii)/(vii) molar ratio. The upper limit on the (alkyl aluminum co-catalyst)/(metal compound) molar ratio may be about 10, in some cases about 7.5 and is other cases about 6.0. The lower limit on the (alkyl aluminum co-catalyst)/(metal compound) molar ratio may be 0, in some cases about 1.0 and in other cases about 2.0. In addition, the time between the addition of the alkyl aluminum co-catalyst (stream S4) and the injection of the in-line Ziegler-Natta catalyst formulation into reactor 12a is controlled; hereafter HUT-3 (the third Hold-Up-Time). HUT-3 is the time for stream 10d to intermix and equilibrate to form the in-line Ziegler Natta catalyst formulation. The upper limit on HUT-3 may be about 15 seconds, in some cases about 10 seconds and is other cases about 8 seconds. The lower limit on HUT-3 may be about 0.5 seconds, in some cases about 1 seconds and in other cases about 2 seconds. HUT-3 is controlled by adjusting the length of the conduit between stream 10d injection port and the catalyst injection port in reactor 12a, and by controlling the flow rates of streams 10a through 10d. As shown in FIG. 1, optionally, 100% of stream 10d, the alkyl aluminum co-catalyst, may be injected directly into reactor 12a via stream 10h. Optionally, a portion of stream 10d may be injected directly into reactor 12a via stream 10h and the remaining portion of stream 10d injected into reactor 12a via stream 10f.

As previously indicated, an equivalent term for reactor 12a is “R2”. The quantity of in-line heterogeneous catalyst formulation added to R2 is expressed as the parts-per-million (ppm) of metal compound (component (vii)) in the reactor solution, hereafter “R2 (vii) (ppm)”. The upper limit on R2 (vii) (ppm) may be about 10 ppm, in some cases about 8 ppm and in other cases about 6 ppm. The lower limit on R2 (vii) (ppm) in some cases may be about 0.5 ppm, in other cases about 1 ppm and in still other cases about 2 ppm. The (aluminum alkyl)/(metal compound) molar ratio in reactor 12a, or the (ix)/(vii) molar ratio, is also controlled. The upper limit on the (aluminum alkyl)/(metal compound) molar ratio in the reactor may be about 2, in some cases about 1.5 and is other cases about 1.0. The lower limit on the (aluminum alkyl)/(metal compound) molar ratio may be about 0.05, in some cases about 0.075 and in other cases about 0.1.

Any combination of the streams employed to prepare and deliver the in-line heterogeneous catalyst formulation to R2 may be heated or cooled, i.e., streams 10a through 10h (including stream 10g (optional R3 delivery) which is discussed below); in some cases the upper temperature limit of streams 10a through 10g may be about 90° C., in other cases about 80° C. and in still other cases about 70° C. and; in some cases the lower temperature limit may be about 20° C.; in other cases about 35° C. and in still other cases about 50° C.

Injection of the in-line heterogeneous catalyst formulation into reactor 12a produces a second ethylene interpolymer and a second exit stream 12c.

If reactors 11a and 12a are operated in a series mode, the second exit stream 12c contains the second ethylene interpolymer and the first ethylene interpolymer dissolved in process solvent; as well as unreacted ethylene, unreacted α-olefins (if present), unreacted hydrogen (if present), active catalysts, deactivated catalysts, catalyst components and other impurities (if present). Optionally the second exit stream 12c is deactivated by adding a catalyst deactivator A from catalyst deactivator tank 18A forming a deactivated solution A, stream 12e; in this case, FIG. 1 defaults to a dual reactor solution process. If the second exit stream 12c is not deactivated the second exit stream enters tubular reactor 17. Catalyst deactivator A is discussed below.

If reactors 11a and 12a are operated in parallel mode, the second exit stream 12c contains the second ethylene interpolymer dissolved in process solvent. The second exit stream 12c is combined with stream 11g forming a third exit stream 12d, the latter contains the second ethylene interpolymer and the first ethylene interpolymer dissolved in process solvent; as well as unreacted ethylene, unreacted α-olefins (if present), unreacted hydrogen (if present), active catalyst, deactivated catalyst, catalyst components and other impurities (if present). Optionally the third exit stream 12d is deactivated by adding catalyst deactivator A from catalyst deactivator tank 18A forming deactivated solution A, stream 12e; in this case, FIG. 1 defaults to a dual reactor solution process. If the third exit stream 12d is not deactivated the third exit stream 12d enters tubular reactor 17.

The term “tubular reactor” is meant to convey its conventional meaning, namely a simple tube; wherein the length/diameter (L/D) ratio is at least 10/1. Optionally, one or more of the following reactor feed streams may be injected into tubular reactor 17; process solvent 13, ethylene 14 and α-olefin 15. As shown in FIG. 1, streams 13, 14 and 15 may be combined forming reactor feed stream RF3 and the latter is injected into reactor 17. It is not particularly important that stream RF3 be formed; i.e., reactor feed streams can be combined in all possible combinations. Optionally hydrogen may be injected into reactor 17 through stream 16. Optionally, the in-line heterogeneous catalyst formulation may be injected into reactor 17 via catalyst stream 10g; i.e., a portion of the in-line heterogeneous catalyst enters reactor 12a through stream 10f and the remaining portion of the in-line heterogeneous catalyst enters reactor 17 through stream 10g.

FIG. 1 shows an additional embodiment where reactor 17 is supplied with a second heterogeneous catalyst formulation produced in a second heterogeneous catalyst assembly. The second heterogeneous catalyst assembly refers to the combination of conduits and flow controllers that include streams 34a-34e and 34h. The chemical composition of the first and second heterogeneous catalyst formulations may be the same, or different. In the case of a Ziegler-Natta catalyst, the second heterogeneous catalyst assembly produces a second in-line Ziegler-Natta catalyst formulation. For example, the catalyst components ((v) through (ix)), mole ratios and hold-up-times may differ in the first and second heterogeneous catalyst assemblies. Relative to the first heterogeneous catalyst assembly, the second heterogeneous catalyst assembly is operated in a similar manner, i.e., the second heterogeneous catalyst assembly generates an efficient catalyst by optimizing hold-up-times and the following molar ratios: (aluminum alkyl)/(magnesium compound), (chloride compound)/(magnesium compound), (alkyl aluminum co-catalyst/(metal compound, and (aluminum alkyl)/(metal compound). To be clear: stream 34a contains a binary blend of magnesium compound (component (v)) and aluminum alkyl (component (ix)) in process solvent; stream 34b contains a chloride compound (component (vi)) in process solvent; stream 34c contains a metal compound (component (vii)) in process solvent, and; stream 34d contains an alkyl aluminum co-catalyst (component (viii)) in process solvent. Once prepared, the in-line Ziegler-Natta catalyst is injected into reactor 17 through stream 34e; optionally, additional alkyl aluminum co-catalyst is injected into reactor 17 through stream 34h. As shown in FIG. 1, optionally, 100% of stream 34d, the alkyl aluminum co-catalyst, may be injected directly into reactor 17 via stream 34h. Optionally, a portion of stream 34d may be injected directly into reactor 17 via stream 34h and the remaining portion of stream 34d injected into reactor 17 via stream 34e. In FIG. 1, the first or the second heterogeneous catalyst assembly supplies 100% of the catalyst to reactor 17. Any combination of the streams that comprise the second heterogeneous catalyst assembly may be heated or cooled, i.e. streams 34a-34e and 34h; in some cases the upper temperature limit of streams 34a-34e and 34h may be about 90° C., in other cases about 80° C. and in still other cases about 70° C. and; in some cases the lower temperature limit may be about 20° C.; in other cases about 35° C. and in still other cases about 50° C.

In reactor 17 a third ethylene interpolymer may, or may not, form. A third ethylene interpolymer will not form if catalyst deactivator A is added upstream of reactor 17 via catalyst deactivator tank 18A. A third ethylene interpolymer will be formed if catalyst deactivator B is added downstream of reactor 17 via catalyst deactivator tank 18B.

The optional third ethylene interpolymer produced in reactor 17 may be formed using a variety of operational modes; with the proviso that catalyst deactivator A is not added upstream of reactor 17. Non-limiting examples of operational modes include: (a) residual ethylene, residual optional α-olefin and residual active catalyst entering reactor 17 react to form the optional third ethylene interpolymer, or; (b) fresh process solvent 13, fresh ethylene 14 and optionally fresh α-olefin 15 are added to reactor 17 and the residual active catalyst entering reactor 17 forms the optional third ethylene interpolymer, or; (c) the fresh second in-line heterogeneous catalyst formulation is added to reactor 17 via stream 10g or stream 34e to polymerize residual ethylene and residual optional α-olefin to form the optional third ethylene interpolymer, or; (d) fresh process solvent 13, ethylene 14, optional α-olefin 15 and fresh second in-line heterogeneous catalyst formulation (10g or 34e) are added to reactor 17 to form the optional third ethylene interpolymer. Optionally, 100% of the alkyl aluminum co-catalyst may be added to reactor 17 via stream 34h, or a portion of the alkyl aluminum co-catalyst may be added to reactor 17 via stream 10g or 34h and the remaining portion added via stream 34h. Optionally fresh hydrogen 16 may be added to reduce the molecular weight of the optional third optional ethylene interpolymer.

In series mode, Reactor 17 produces a third exit stream 17b containing the first ethylene interpolymer, the second ethylene interpolymer and optionally a third ethylene interpolymer. As shown in FIG. 1, catalyst deactivator B may be added to the third exit stream 17b via catalyst deactivator tank 18B producing a deactivated solution B, stream 19; with the proviso that catalyst deactivator B is not added if catalyst deactivator A was added upstream of reactor 17. Deactivated solution B may also contain unreacted ethylene, unreacted optional α-olefin, unreacted optional hydrogen and impurities if present. As indicated above, if catalyst deactivator A was added, deactivated solution A (stream 12e) exits tubular reactor 17 as shown in FIG. 1.

In parallel mode operation, reactor 17 produces a fourth exit stream 17b containing the first ethylene interpolymer, the second ethylene interpolymer and optionally a third ethylene interpolymer. As indicated above, in parallel mode, stream 12d is the third exit stream. As shown in FIG. 1, in parallel mode, catalyst deactivator B is added to the fourth exit stream 17b via catalyst deactivator tank 18B producing a deactivated solution B, stream 19; with the proviso that catalyst deactivator B is not added if catalyst deactivator A was added upstream of reactor 17.

In FIG. 1, deactivated solution A (stream 12e) or B (stream 19) passes through pressure let down device 20, heat exchanger 21 and a passivator is added via tank 22 forming a passivated solution 23; the passivator is described below. The passivated solution passes through pressure let down device 24 and enters a first vapor/liquid separator 25. Hereafter, “V/L” is equivalent to vapor/liquid. Two streams are formed in the first V/L separator: a first bottom stream 27 comprising a solution that is rich in ethylene interpolymers and also contains residual ethylene, residual optional α-olefins and catalyst residues, and; a first gaseous overhead stream 26 comprising ethylene, process solvent, optional α-olefins, optional hydrogen, oligomers and light-end impurities if present.

The first bottom stream enters a second V/L separator 28. In the second V/L separator two streams are formed: a second bottom stream 30 comprising a solution that is richer in ethylene interpolymer and leaner in process solvent relative to the first bottom stream 27, and; a second gaseous overhead stream 29 comprising process solvent, optional α-olefins, ethylene, oligomers and light-end impurities if present.

The second bottom stream 30 flows into a third V/L separator 31. In the third V/L separator two streams are formed: a product stream 33 comprising an ethylene interpolymer product, deactivated catalyst residues and less than 5 weight % of residual process solvent, and; a third gaseous overhead stream 32 comprised essentially of process solvent, optional α-olefins and light-end impurities if present.

Product stream 33 proceeds to polymer recovery operations. Non-limiting examples of polymer recovery operations include one or more gear pump, single screw extruder or twin screw extruder that forces the molten ethylene interpolymer product through a pelletizer. A devolatilizing extruder may be used to remove small amounts of residual process solvent and optional α-olefin, if present. Once pelletized the solidified ethylene interpolymer product is typically dried and transported to a product silo.

The first, second and third gaseous overhead streams shown in FIG. 1 (streams 26, 29 and 32, respectively) are sent to a distillation column where solvent, ethylene and optional α-olefin are separated for recycling, or; the first, second and third gaseous overhead streams are recycled to the reactors, or; a portion of the first, second and third gaseous overhead streams are recycled to the reactors and the remaining portion is sent to a distillation column. Solution Polymerization Process: Batch Heterogeneous Catalyst Formulation

In FIG. 2 a first batch heterogeneous catalyst assembly (vessels and streams 60a through 60h) and an optional second batch heterogeneous catalyst assembly (vessels and streams 90a through 90f) are employed. For the sake of clarity and avoid any confusion, many of the vessels and streams shown in FIG. 2 are equivalent to the respective vessel and stream shown in FIG. 1; equivalence is indicated through the use of a consistent vessel or stream label, i.e., number. For the avoidance of doubt, referring to FIG. 2, process solvent is injected into CSTR reactor 11a, CSTR reactor 12a and tubular reactor 17 via streams 1, 6 and 13. Ethylene is injected into reactors 11a, 12a and 17 via streams 2, 7 and 14. Optional α-olefin is injected into reactors 11a, 12a and 17 via streams 3, 8 and 15. Optional hydrogen is injected into reactors 11a, 12a and 17 via streams 4, 9 and 16. A single-site catalyst formulation is injected into reactor 11a, producing the first ethylene interpolymer. Single-site catalyst component streams (5a through 5e) were described above. A batch Ziegler-Natta catalyst formulation or a batch Ziegler-Natta procatalyst is injected into reactor 12a via stream 60e and the second ethylene interpolymer is formed. Reactors 11a and 12a shown in FIG. 2 may be operated in series or parallel modes, as described in FIG. 1 above.

Processes to prepare batch heterogeneous procatalysts and in batch Ziegler-Natta procatalysts are well known to those skilled in the art. A non-limiting formulation useful in the continuous solution polymerization process may be prepared as follows. A batch Ziegler-Natta procatalyst may be prepared by sequentially added the following components to a stirred mixing vessel: (a) a solution of a magnesium compound (an equivalent term for the magnesium compound is “component (v)”); (b) a solution of a chloride compound (an equivalent term for the chloride compound is “component (vi)”; (c) optionally a solution of an aluminum alkyl halide, and; (d) a solution of a metal compound (an equivalent term for the metal compound is “component (vii)”). Suitable, non-limiting examples of aluminum alkyl halides are defined by the formula (R⁶)_vAlX_3-v; wherein the R⁶groups may be the same or different hydrocarbyl group having from 1 to 10 carbon atoms, X represents chloride or bromide, and; v is 1 or 2. Suitable, non-limiting examples of the magnesium compound, the chloride compound and the metal compound were described earlier in this disclosure. Suitable solvents within which to prepare the procatalyst include linear or branched C₅to C₁₂alkanes or mixtures thereof. Individual mixing times and mixing temperatures may be used in each of steps (a) through (d). The upper limit on mixing temperatures for steps (a) through (d) in some case may be 160° C., in other cases 130° C. and in still other cases 100° C. The lower limit on mixing temperatures for steps (a) through (d) in some cases may be 10° C., in other cases 20° C. and in still other cases 30° C. The upper limit on mixing time for steps (a) through (d) in some case may be 6 hours, in other cases 3 hours and in still other cases 1 hour. The lower limit on mixing times for steps (a) through (d) in some cases may be 1 minute, in other cases 10 minutes and in still other cases 30 minutes.

Batch Ziegler-Natta procatalyst can have various catalyst component mole ratios. The upper limit on the (chloride compound)/(magnesium compound) molar ratio in some cases may be about 3, in other cases about 2.7 and is still other cases about 2.5; the lower limit in some cases may be about 2.0, in other cases about 2.1 and in still other cases about 2.2. The upper limit on the (magnesium compound)/(metal compound) molar ratio in some cases may be about 10, in other cases about 9 and in still other cases about 8; the lower limit in some cases may be about 5, in other cases about 6 and in still other cases about 7. The upper limit on the (aluminum alkyl halide)/(magnesium compound) molar ratio in some cases may be about 0.5, in other cases about 0.4 and in still other cases about 0.3; the lower limit in some cases may be 0, in other cases about 0.1 and in still other cases about 0.2. An active batch Ziegler-Natta catalyst formulation is formed when the procatalyst is combined with an alkyl aluminum co-catalyst. Suitable co-catalysts were described earlier in this disclosure. The procatalyst may be activated external to the reactor or in the reactor; in the latter case, the procatalyst and an appropriate amount of alkyl aluminum co-catalyst are independently injected R2 and optionally R3.

Once prepared the batch Ziegler-Natta procatalyst is pumped to procatalyst storage tank 60a shown in FIG. 2. Tank 60a may, or may not, be agitated. Storage tank 60c contains an alkyl aluminum co-catalyst; non-limiting examples of suitable alkyl aluminum co-catalysts were described earlier in this disclosure. A batch Ziegler Natta catalyst formulation stream 60e, that is efficient in converting olefins to polyolefins, is formed by combining batch Ziegler Natta procatalyst stream 60b (stream S5) with alkyl aluminum co-catalyst stream 60d (stream S4). Stream 60e is injected into reactor 12a where the second ethylene interpolymer is formed. Operationally, the following options may be employed: (a) 100% of the alkyl aluminum co-catalyst may be injected into reactor 12a through stream 60g, i.e., the batch Ziegler-Natta procatalyst is injected into reactor 12a through stream 60e, or; (b) a portion of the alkyl aluminum co-catalyst is injected into reactor 12a via stream 60g and the remaining portion passes through stream 60d where it combines with stream 60b forming the batch Ziegler-Natta catalyst formulation which is injected into reactor 12a via stream 60e.

Additional optional embodiments, where a batch heterogeneous catalyst formulation is employed, are shown in FIG. 2 where: (a) a batch Ziegler-Natta procatalyst is injected into tubular reactor 17 through stream 60f, or; (b) a batch Ziegler-Natta catalyst formulation is injected into tubular reactor 17 through stream 60f. In the case of option (a), 100% of the alkyl aluminum co-catalyst is injected directly into reactor 17 via stream 60h. An additional embodiment exists where a portion of the alkyl aluminum co-catalyst flows through stream 60f and the remaining portion flows through stream 60h. Any combination of tanks or streams 60a through 60h may be heated or cooled.

FIG. 2 includes additional embodiments where a second batch heterogeneous catalyst assembly, which is defined by vessels and streams 90a through 90f, may be used to optionally inject a second batch Ziegler-Natta catalyst formulation or a second batch Ziegler-Natta procatalyst into reactor 17. Once prepared the second batch Ziegler-Natta procatalyst is pumped to procatalyst storage tank 90a shown in FIG. 2. Tank 90a may, or may not, be agitated. Storage tank 90c contains an alkyl aluminum co-catalyst. A batch Ziegler Natta catalyst formulation stream 90e, that is efficient in converting olefins to polyolefins, is formed by combining the second batch Ziegler Natta procatalyst stream 90b (stream S6) with alkyl aluminum co-catalyst stream 90d (optionally stream). Stream 90e is optionally injected into reactor 17, wherein an optional third ethylene interpolymer may be formed. FIG. 2 includes additional embodiments where: (a) the batch Ziegler-Natta procatalyst is injected directly into reactor 17 through stream 90e and the procatalyst is activated inside reactor 17 by injecting 100% of the aluminum co-catalyst directly into rector 17 via stream 90f, or; (b) a portion of the aluminum co-catalyst may flow through stream 90e with the remaining portion flowing through stream 90f. Any combination of tanks or streams 90a through 90f may be heated or cooled.

The time between the addition of the alkyl aluminum co-catalyst (stream S4) and the injection of the batch Ziegler-Natta catalyst formulation into reactor 12a is controlled; hereafter HUT-4 (the fourth Hold-Up-Time). Referring to FIG. 2, HUT-4 is the time for stream 60d (stream S4) to intermix and equilibrate with stream 60b (batch Ziegler-Natta procatalyst) to form the batch Ziegler Natta catalyst formulation prior to injection into reactor 12a via in stream 60e. Optionally, HUT-4 is the time for stream 60d to intermix and equilibrate with stream 60b to from the batch Ziegler-Natta catalyst formulation prior to injection into the optional third reactor 17 via stream 60f, or; HUT-4 is the time for stream 90d to intermix and equilibrate with stream 90b to form the batch Ziegler-Natta catalyst formulation prior to injection into reactor 17 via stream 90e. The upper limit on HUT-4 may be about 300 seconds, in some cases about 200 seconds and in other cases about 100 seconds. The lower limit on HUT-4 may be about 0.1 seconds, in some cases about 1 seconds and in other cases about 10 seconds.

The quantity of batch Ziegler-Natta procatalyst produced and/or the size to procatalyst storage tanks 60a or 90a is not particularly important with respect to this disclosure. However, the large quantity of procatalyst produced allows one to operate the continuous solution polymerization plant for an extended period of time: the upper limit on this time in some cases may be about 3 months, in other cases for about 2 months and in still other cases for about 1 month; the lower limit on this time in some cases may be about 1 day, in other cases about 1 week and in still other cases about 2 weeks.

The quantity of batch Ziegler-Natta procatalyst or batch Ziegler-Natta catalyst formulation added to reactor 12a is expressed as “R2 (vii) (ppm)”, i.e., the parts-per-million (ppm) of metal compound (component (vii)) in the reactor solution. The upper limit on R2 (vii) (ppm) may be about 10 ppm, in some cases about 8 ppm and in other cases about 6 ppm. The lower limit on R2 (vii) (ppm) may be about 0.5 ppm, in some cases about 1 ppm and in other cases about 2 ppm. The quantity of the alkyl aluminum co-catalyst added to reactor 12a is optimized to produce an efficient catalyst; this is accomplished by adjusting the (alkyl aluminum co-catalyst)/(metal compound) molar ratio. The upper limit on the (alkyl aluminum co-catalyst)/(metal compound) molar ratio may be about 10, in some cases about 8.0 and is other cases about 6.0. The lower limit on the (alkyl aluminum co-catalyst)/(metal compound) molar ratio may be 0.5, in some cases about 0.75 and in other cases about 1.

Referring to FIG. 2, where the heterogeneous catalyst formulation is a batch Ziegler-Natta catalyst formulation, a third ethylene interpolymer may optionally be formed in reactor 17 by: (a) injecting the first batch Ziegler-Natta catalyst formulation or the first batch Ziegler-Natta procatalyst into reactor 17 through stream 60f, or; (b) injecting a chemically distinct second batch Ziegler-Natta catalyst formulation or second batch Ziegler-Natta procatalyst into reactor 17 through stream 90e. As shown in FIG. 2, the first batch Ziegler-Natta catalyst formulation may be deactivated upstream of reactor 17 by adding catalyst deactivator A via deactivator tank 18A to form a deactivated solution A (stream 12e), or; the first batch Ziegler-Natta catalyst formulation and optionally the second batch Ziegler-Natta catalyst formulation may be deactivated downstream of reactor 17 by adding catalyst deactivator B via deactivator tank 18B to form a deactivated solution B (stream 19). Deactivated solution A or B then pass through pressure let down device 20, heat exchange 21 and a passivator may be added via tank 22 forming passivated solution 23. The remaining vessels (24, 25, 28 and 31) and streams (26, 27, 29, 39, 32 and 33) and process conditions have been described previously. The ethylene interpolymer product stream 33 proceeds to polymer recovery. The first, second and third gaseous overhead streams shown in FIG. 2 (streams 26, 29 and 32, respectively) are sent to a distillation column where solvent, ethylene and optional α-olefin are separated for later use, or; the first, second and third gaseous overhead streams are recycled to the reactors, or; a portion of the first, second and third gaseous overhead streams are recycled to the reactors and the remaining portion is sent to a distillation column.

Optimization of the Single Site Catalyst Formulation

Referring to the embodiments shown in FIGS. 1 and 2; an active single site catalyst formulation is produced by optimizing the proportion of each of the four single site catalyst components, (i) through (iv). The term “active” means the single site catalyst formulation is very efficient in converting olefins to polyolefins; in practice the optimization objective is to maximize the following ratio: (pounds of ethylene interpolymer product produced)/(pounds of catalyst consumed). The quantity of bulky ligand metal complex, component (i), added to R1 is expressed as the parts per million (ppm) of component (i) in the total mass of the solution in R1; hereafter “R1 (i) (ppm)”. The upper limit on R1 (i) (ppm) may be about 5, in some cases about 3 and is other cases about 2. The lower limit on R1 (i) (ppm) may be about 0.02, in some cases about 0.05 and in other cases about 0.1.

The proportion of catalyst component (iii), the ionic activator, added to R1 is optimized by controlling the (ionic activator)/(bulky ligand-metal complex) molar ratio in the R1 solution; hereafter “R1 (iii)/(i)”. The upper limit on R1 (iii)/(i) may be about 10, in some cases about 5 and in other cases about 2. The lower limit on R1 (iii)/(i) may be about 0.1, in some cases about 0.5 and in other cases about 1.0. The proportion of catalyst component (ii) is optimized by controlling the (alumoxane)/(bulky ligand-metal complex) molar ratio in the R1 solution; hereafter “R1 (ii)/(i)”. The alumoxane co-catalyst is generally added in a molar excess relative to the bulky ligand-metal complex. The upper limit on R1 (ii)/(i) may be about 1000, in some cases about 500 and is other cases about 200. The lower limit on R1 (ii)/(i) may be about 1, in some cases about 10 and in other cases about 30.

The addition of catalyst component (iv), the hindered phenol, to R1 is optional in the embodiments shown in FIGS. 1-2. If added, the proportion of component (iv) is optimized by controlling the (hindered phenol)/(alumoxane) molar ratio in R1; hereafter “R1 (iv)/(ii)”. The upper limit on R1 (iv)/(ii) may be about 10, in some cases about 5 and in other cases about 2. The lower limit on R1 (iv)/(ii) may be 0.0, in some cases about 0.1 and in other cases about 0.2.

Any combination of the single site catalyst component streams in FIGS. 1 and 2 (streams 5a-5e) may, or may not, be heated or cooled. The upper limit on catalyst component stream temperatures may be about 70° C.; in other cases about 60° C. and in still other cases about 50° C. The lower limit on catalyst component stream temperatures may be about 0° C.; in other cases about 20° C. and in still other cases about 40° C.

Additional Solution Polymerization Process Parameters

In the continuous solution processes embodiments shown in FIGS. 1 and 2, a variety of solvents may be used as the process solvent; non-limiting examples include linear, branched or cyclic C₅to C₁₂alkanes. Non-limiting examples of α-olefins include 1-propene, 1-butene, 1-pentene, 1-hexene and 1-octene. Suitable catalyst component solvents include aliphatic and aromatic hydrocarbons. Non-limiting examples of aliphatic catalyst component solvents include linear, branched or cyclic C_5-12aliphatic hydrocarbons, e.g. pentane, methyl pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, hydrogenated naphtha or combinations thereof. Non-limiting examples of aromatic catalyst component solvents include benzene, toluene (methylbenzene), ethylbenzene, o-xylene (1,2-dimethylbenzene), m-xylene (1,3-dimethylbenzene), p-xylene (1,4-dimethylbenzene), mixtures of xylene isomers, hemellitene (1,2,3-trimethylbenzene), pseudocumene (1,2,4-trimethylbenzene), mesitylene (1,3,5-trimethylbenzene), mixtures of trimethylbenzene isomers, prehenitene (1,2,3,4-tetramethylbenzene), durene (1,2,3,5-tetramethylbenzene), mixtures of tetramethylbenzene isomers, pentamethylbenzene, hexamethylbenzene and combinations thereof.

It is well known to individuals experienced in the art that reactor feed streams (solvent, monomer, α-olefin, hydrogen, catalyst formulation etc.) must be essentially free of catalyst deactivating poisons; non-limiting examples of poisons include trace amounts of oxygenates such as water, fatty acids, alcohols, ketones and aldehydes. Such poisons are removed from reactor feed streams using standard purification practices; non-limiting examples include molecular sieve beds, alumina beds and oxygen removal catalysts for the purification of solvents, ethylene and α-olefins, etc.

Referring to the first and second reactors in FIGS. 1 and 2 any combination of the CSTR reactor feed streams may be heated or cooled: more specifically, streams 1-4 (reactor 11a) and streams 6-9 (reactor 12a). The upper limit on reactor feed stream temperatures may be about 90° C.; in other cases about 80° C. and in still other cases about 70° C. The lower limit on reactor feed stream temperatures may be about 0° C.; in other cases about 10° C. and in still other cases about 20° C.

Any combination of the streams feeding the tubular reactor may be heated or cooled; specifically, streams 13-16 in FIGS. 1 and 2. In some cases, tubular reactor feed streams are tempered, i.e., the tubular reactor feed streams are heated to at least above ambient temperature. The upper temperature limit on the tubular reactor feed streams in some cases are about 200° C., in other cases about 170° C. and in still other cases about 140° C.; the lower temperature limit on the tubular reactor feed streams in some cases are about 60° C., in other cases about 90° C. and in still other cases about 120° C.; with the proviso that the temperature of the tubular reactor feed streams are lower than the temperature of the process stream that enters the tubular reactor.

In the embodiments shown in FIGS. 1 and 2 the operating temperatures of the solution polymerization reactors (vessels 11a (R1) and 12a (R2)) can vary over a wide range. For example, the upper limit on reactor temperatures in some cases may be about 300° C., in other cases about 280° C. and in still other cases about 260° C.; and the lower limit in some cases may be about 80° C., in other cases about 100° C. and in still other cases about 125° C. The second reactor, reactor 12a (R2), is operated at a higher temperature than the first reactor 11a (R1). The maximum temperature difference between these two reactors (T^R2−T^R1) in some cases is about 120° C., in other cases about 100° C. and in still other cases about 80° C.; the minimum (T^R2−T^R1) in some cases is about 1° C., in other cases about 5° C. and in still other cases about 10° C. The optional tubular reactor, reactor 17 (R3), may be operated in some cases about 100° C. higher than R2; in other cases about 60° C. higher than R2, in still other cases about 10° C. higher than R2 and in alternative cases 0° C. higher, i.e. the same temperature as R2. The temperature within optional R3 may increase along its length. The maximum temperature difference between the inlet and outlet of R3 in some cases is about 100° C., in other cases about 60° C. and in still other cases about 40° C. The minimum temperature difference between the inlet and outlet of R3 is in some cases may be 0° C., in other cases about 3° C. and in still other cases about 10° C. In some cases R3 is operated an adiabatic fashion and in other cases R3 is heated.

The pressure in the polymerization reactors should be high enough to maintain the polymerization solution as a single phase solution and to provide the upstream pressure to force the polymer solution from the reactors through a heat exchanger and on to polymer recovery operations. Referring to the embodiments shown in FIGS. 1 and 2, the operating pressure of the solution polymerization reactors can vary over a wide range. For example, the upper limit on reactor pressure in some cases may be about 45 MPag, in other cases about 30 MPag and in still other cases about 20 MPag; and the lower limit in some cases may be about 3 MPag, in other some cases about 5 MPag and in still other cases about 7 MPag.

Referring to the embodiments shown in FIGS. 1 and 2, prior to entering the first V/L separator, the passivated solution (stream 23) may have a maximum temperature in some cases of about 300° C., in other cases about 290° C. and in still other cases about 280° C.; the minimum temperature may be in some cases about 150° C., in other cases about 200° C. and in still other cases about 220° C. Immediately prior to entering the first V/L separator the passivated solution in some cases may have a maximum pressure of about 40 MPag, in other cases about 25 MPag and in still cases about 15 MPag; the minimum pressure in some cases may be about 1.5 MPag, in other cases about 5 MPag and in still other cases about 6 MPag.

The first V/L separator (vessel 25 in FIGS. 1 and 2) may be operated over a relatively broad range of temperatures and pressures. For example, the maximum operating temperature of the first V/L separator in some cases may be about 300° C., in other cases about 285° C. and in still other cases about 270° C.; the minimum operating temperature in some cases may be about 100° C., in other cases about 140° C. and in still other cases 170° C. The maximum operating pressure of the first V/L separator in some cases may be about 20 MPag, in other cases about 10 MPag and in still other cases about 5 MPag; the minimum operating pressure in some cases may be about 1 MPag, in other cases about 2 MPag and in still other cases about 3 MPag.

The second V/L separator (vessel 28 in FIGS. 1 and 2) may be operated over a relatively broad range of temperatures and pressures. For example, the maximum operating temperature of the second V/L separator in some cases may be about 300° C., in other cases about 250° C. and in still other cases about 200° C.; the minimum operating temperature in some cases may be about 100° C., in other cases about 125° C. and in still other cases about 150° C. The maximum operating pressure of the second V/L separator in some cases may be about 1000 kPag, in other cases about 900 kPag and in still other cases about 800 kPag; the minimum operating pressure in some cases may be about 10 kPag, in other cases about 20 kPag and in still other cases about 30 kPag.

The third V/L separator (vessel 31 in FIGS. 1 and 2) may be operated over a relatively broad range of temperatures and pressures. For example, the maximum operating temperature of the third V/L separator in some cases may be about 300° C., in other cases about 250° C., and in still other cases about 200° C.; the minimum operating temperature in some cases may be about 100° C., in other cases about 125° C. and in still other cases about 150° C. The maximum operating pressure of the third V/L separator in some cases may be about 500 kPag, in other cases about 150 kPag and in still other cases about 100 kPag; the minimum operating pressure in some cases may be about 1 kPag, in other cases about 10 kPag and in still other cases about 25 kPag.

Embodiments of the continuous solution polymerization process shown in FIGS. 1 and 2 show three V/L separators. However, continuous solution polymerization embodiments may include configurations comprising at least one V/L separator.

The ethylene interpolymer products having improved color produced in the continuous solution polymerization process may be recovered using conventional devolatilization systems that are well known to persons skilled in the art, non-limiting examples include flash devolatilization systems and devolatilizing extruders.

Any reactor shape or design may be used for reactor 11a (R1) and reactor 12a (R2) in FIGS. 1 and 2; non-limiting examples include unstirred or stirred spherical, cylindrical or tank-like vessels, as well as tubular reactors or recirculating loop reactors. At commercial scale the maximum volume of R1 in some cases may be about 20,000 gallons (about 75,710 L), in other cases about 10,000 gallons (about 37,850 L) and in still other cases about 5,000 gallons (about 18,930 L). At commercial scale the minimum volume of R1 in some cases may be about 100 gallons (about 379 L), in other cases about 500 gallons (about 1,893 L) and in still other cases about 1,000 gallons (about 3,785 L). At pilot plant scales reactor volumes are typically much smaller, for example the volume of R1 at pilot scale could be less than about 2 gallons (less than about 7.6 L). In this disclosure the volume of reactor R2 is expressed as a percent of the volume of reactor R1. The upper limit on the volume of R2 in some cases may be about 600% of R1, in other cases about 400% of R1 and in still other cases about 200% of R1. For clarity, if the volume of R1 is 5,000 gallons and R2 is 200% the volume of R1, then R2 has a volume of 10,000 gallons. The lower limit on the volume of R2 in some cases may be about 50% of R1, in other cases about 100% of R1 and in still other cases about 150% of R1. In the case of continuously stirred tank reactors the stirring rate can vary over a wide range; in some cases from about 10 rpm to about 2000 rpm, in other cases from about 100 to about 1500 rpm and in still other cases from about 200 to about 1300 rpm. In this disclosure the volume of R3, the tubular reactor, is expressed as a percent of the volume of reactor R2. The upper limit on the volume of R3 in some cases may be about 500% of R2, in other cases about 300% of R2 and in still other cases about 100% of R2. The lower limit on the volume of R3 in some cases may be about 3% of R2, in other cases about 10% of R2 and in still other cases about 50% of R2.

The “average reactor residence time”, a commonly used parameter in the chemical engineering art, is defined by the first moment of the reactor residence time distribution; the reactor residence time distribution is a probability distribution function that describes the amount of time that a fluid element spends inside the reactor. The average reactor residence time can vary widely depending on process flow rates and reactor mixing, design and capacity. The upper limit on the average reactor residence time of the solution in R1 in some cases may be about 600 seconds, in other cases about 360 seconds and in still other cases about 180 seconds. The lower limit on the average reactor residence time of the solution in R1 in some cases may be about 10 seconds, in other cases about 20 seconds and in still other cases about 40 seconds. The upper limit on the average reactor residence time of the solution in R2 in some cases may be about 720 seconds, in other cases about 480 seconds and in still other cases about 240 seconds. The lower limit on the average reactor residence time of the solution in R2 in some cases may be about 10 seconds, in other cases about 30 seconds and in still other cases about 60 seconds. The upper limit on the average reactor residence time of the solution in R3 in some cases may be about 600 seconds, in other cases about 360 seconds and in still other cases about 180 seconds. The lower limit on the average reactor residence time of the solution in R3 in some cases may be about 1 second, in other cases about 5 seconds and in still other cases about 10 seconds.

Optionally, additional reactors (e.g., CSTRs, loops or tubes, etc.) could be added to the continuous solution polymerization process embodiments shown in FIGS. 1 and 2. In this disclosure, the number of reactors is not particularly important; with the proviso that the continuous solution polymerization process comprises at least two reactors that employ at least one single-site catalyst formulation and at least one heterogeneous catalyst formulation.

In operating the continuous solution polymerization process embodiments shown in FIGS. 1 and 2 the total amount of ethylene supplied to the process can be portioned or split between the three reactors R1, R2 and R3. This operational variable is referred to as the Ethylene Split (ES), i.e. “ES^R1” “ES^R2” and “ES^R3” refer to the weight percent of ethylene injected in R1, R2 and R3, respectively; with the proviso that ES^R1+ES^R2+ES^R3=100%. This is accomplished by adjusting the ethylene flow rates in the following streams: stream 2 (R1), stream 7 (R2) and stream 14 (R3). The upper limit on ES^R1in some cases is about 60%, in other cases about 55% and in still other cases about 50%; the lower limit on ES^R1in some cases is about 10%, in other cases about 15% and in still other cases about 20%. The upper limit on ES^R2in some cases is about 90%, in other cases about 80% and in still other cases about 70%; the lower limit on ES^R2in some cases is about 20%, in other cases about 30% and in still other cases about 40%. The upper limit on ES^R3in some cases is about 30%, in other cases about 25% and in still other cases about 20%; the lower limit on ES^R3in some cases is 0%, in other cases about 5% and in still other cases about 10%.

In operating the continuous solution polymerization process embodiments shown in FIGS. 1 and 2 the ethylene concentration in each reactor is also controlled. The R1 ethylene concentration is defined as the weight of ethylene in reactor 1 divided by the total weight of everything added to reactor 1; the R2 ethylene concentration (wt %) and R3 ethylene concentration (wt %) are defined similarly. Ethylene concentrations in the reactors in some cases may vary from about 7 weight percent (wt %) to about 25 wt %, in other cases from about 8 wt % to about 20 wt % and in still other cases from about 9 wt % to about 17 wt %.

In operating the continuous solution polymerization process embodiments shown in FIGS. 1 and 2 that produce ethylene interpolymers having improved color, the total amount of ethylene converted in each reactor is monitored. The term “Q^R1” refers to the percent of the ethylene added to R1 that is converted into an ethylene interpolymer by the catalyst formulation. Similarly Q^R2and Q^R3represent the percent of the ethylene added to R2 and R3 that was converted into ethylene interpolymer, in the respective reactor. Ethylene conversions can vary significantly depending on a variety of process conditions, e.g. catalyst concentration, catalyst formulation, impurities and poisons. The upper limit on both Q^R1and Q^R2in some cases is about 99%, in other cases about 95% and in still other cases about 90%; the lower limit on both Q^R1and Q^R2in some cases is about 65%, in other cases about 70% and in still other cases about 75%. The upper limit on Q^R3in some cases is about 99%, in other cases about 95% and in still other cases about 90%; the lower limit on Q^R3in some cases is 0%, in other cases about 5% and in still other cases about 10%. The term “Q^T” represents the total or overall ethylene conversion across the entire continuous solution polymerization plant; i.e. Q^T=100×[weight of ethylene in the interpolymer product]/([weight of ethylene in the interpolymer product]+[weight of unreacted ethylene]). The upper limit on Q^Tin some cases is about 99%, in other cases about 95% and in still other cases about 90%; the lower limit on Q^Tin some cases is about 75%, in other cases about 80% and in still other cases about 85%.

Optionally, α-olefin may be added to the continuous solution polymerization process. If added, α-olefin may be proportioned or split between R1, R2 and R3. This operational variable is referred to as the Comonomer Split (CS), i.e. “CS^R1”, “CS^R2” and “CS^R3” refer to the weight percent of α-olefin comonomer that is injected in R1, R2 and R3, respectively; with the proviso that CS^R1+CS^R2+CS^R3=100%. This is accomplished by adjusting α-olefin flow rates in the following streams: stream 3 (R1), stream 8 (R2) and stream 15 (R3). The upper limit on CS^R1in some cases is 100% (i.e. 100% of the α-olefin is injected into R1), in other cases about 95% and in still other cases about 90%. The lower limit on CS^R1in some cases is 0% (ethylene homopolymer produced in R1), in other cases about 5% and in still other cases about 10%. The upper limit on CS^R2in some cases is about 100% (i.e., 100% of the α-olefin is injected into reactor 2), in other cases about 95% and in still other cases about 90%. The lower limit on CS^R2in some cases is 0%, in other cases about 5% and in still other cases about 10%. The upper limit on CS^R3in some cases is 100%, in other cases about 95% and in still other cases about 90%. The lower limit on CS^R3in some cases is 0%, in other cases about 5% and in still other cases about 10%.

Catalyst Deactivation

In the continuous polymerization processes described in this disclosure, polymerization is terminated by adding a catalyst deactivator. Embodiments in FIGS. 1 and 2 show catalyst deactivation occurring either: (a) upstream of the tubular reactor by adding a catalyst deactivator A from catalyst deactivator tank 18A, or; (b) downstream of the tubular reactor by adding a catalyst deactivator B from catalyst deactivator tank 18B. Catalyst deactivator tanks 18A and 18B may contain neat (100%) catalyst deactivator, a solution of catalyst deactivator in a solvent, or a slurry of catalyst deactivator in a solvent. The chemical composition of catalyst deactivator A and B may be the same, or different. Non-limiting examples of suitable solvents include linear or branched C₅to C₁₂alkanes. In this disclosure, how the catalyst deactivator is added is not particularly important. Once added, the catalyst deactivator substantially stops the polymerization reaction by changing active catalyst species to inactive forms. Suitable deactivators are well known in the art, non-limiting examples include: amines (e.g. U.S. Pat. No. 4,803,259 to Zboril et al.); alkali or alkaline earth metal salts of carboxylic acid (e.g., U.S. Pat. No. 4,105,609 to Machan et al.); water (e.g., U.S. Pat. No. 4,731,438 to Bernier et al.); hydrotalcites, alcohols and carboxylic acids (e.g., U.S. Pat. No. 4,379,882 to Miyata); or a combination thereof (U.S. Pat. No. 6,180,730 to Sibtain et al.). In this disclosure the quantify of catalyst deactivator added was determined by the following catalyst deactivator molar ratio: 0.3≤(catalyst deactivator)/((total catalytic metal)+(alkyl aluminum co-catalyst)+(aluminum alkyl))≤2.0; where the catalytic metal is the total moles of (metal A+metal B+optional metal C). The upper limit on the catalyst deactivator molar ratio may be about 2, in some cases about 1.5 and in other cases about 0.75. The lower limit on the catalyst deactivator molar ratio may be about 0.3, in some cases about 0.35 and in still other cases about 0.4. In general, the catalyst deactivator is added in a minimal amount such that the catalyst is deactivated and the polymerization reaction is quenched.

Solution Passivation

Referring to the embodiments shown in FIGS. 1 and 2; prior to entering the first V/L separator, a passivator or acid scavenger is added to deactivated solution A or B to form a passivated solution, i.e. passivated solution stream 23. Passivator tank 22 may contain neat (100%) passivator, a solution of passivator in a solvent, or a slurry of passivator in a solvent. Non-limiting examples of suitable solvents include linear or branched C₅to C₁₂alkanes. In this disclosure, how the passivator is added is not particularly important. Suitable passivators are well known in the art, non-limiting examples include alkali or alkaline earth metal salts of carboxylic acids or hydrotalcites. The quantity of passivator added can vary over a wide range. In this disclosure the molar quantity of passivator added was determined by the total moles of chloride compounds added to the solution process, i.e. the chloride compound “component (vi)” plus the metal compound “compound (vii)”. Optionally, a first and second chloride compound and a first and second metal compound may be used, i.e. to form the first and second heterogeneous catalyst formulations; in this case the amount of passivator added is determined by the total moles all chloride containing compounds. The upper limit on passivator mole ratio (moles passivator)/(total chlorides) molar ratio may be 20, in some cases 15 and in other cases 10. The lower limit on the (passivator)/(total chlorides) molar ratio may be about 5, in some cases about 7 and in still other cases about 9. In general, the passivator is added in the minimal amount to substantially passivate the deactivated solution.

First Ethylene Interpolymer

The first ethylene interpolymer is produced with a single-site catalyst formulation. Referring to the embodiments shown in FIGS. 1 and 2, if the optional α-olefin is not added to reactor 1 (R1), then the ethylene interpolymer produced in R1 is an ethylene homopolymer. If an α-olefin is added, the following weight ratio is one parameter to control the density of the first ethylene interpolymer: ((α-olefin)/(ethylene))^R1. The upper limit on ((α-olefin)/(ethylene))^R1may be about 3; in other cases about 2 and in still other cases about 1. The lower limit on ((α-olefin)/(ethylene))^R1may be 0; in other cases about 0.25 and in still other cases about 0.5. Hereafter, the symbol “σ¹” refers to the density of the first ethylene interpolymer produced in R1. The upper limit on σ¹may be about 0.975 g/cm³; in some cases about 0.965 g/cm³and; in other cases about 0.955 g/cm³. The lower limit on σ¹may be about 0.855 g/cm³, in some cases about 0.865 g/cm³, and; in other cases about 0.875 g/cm³.

Methods to determine the CDBI₅₀(Composition Distribution Branching Index) of an ethylene interpolymer are well known to those skilled in the art. The CDBI₅₀, expressed as a percent, is defined as the percent of the ethylene interpolymer whose comonomer composition is within 50% of the median comonomer composition. It is also well known to those skilled in the art that the CDBI₅₀of ethylene interpolymers produced with single-site catalyst formulations are higher relative to the CDBI₅₀of α-olefin containing ethylene interpolymers produced with heterogeneous catalyst formulations. The upper limit on the CDBI₅₀of the first ethylene interpolymer (produced with a single-site catalyst formulation) may be about 98%, in other cases about 95% and in still other cases about 90%. The lower limit on the CDBI₅₀of the first ethylene interpolymer may be about 70%, in other cases about 75% and in still other cases about 80%.

As is well known to those skilled in the art the M_w/M_nof ethylene interpolymers produced with single site catalyst formulations are lower relative to ethylene interpolymers produced with heterogeneous catalyst formulations. Thus, in the embodiments disclosed, the first ethylene interpolymer has a lower M_w/M_nrelative to the second ethylene interpolymer; where the second ethylene interpolymer is produced with a heterogeneous catalyst formulation. The upper limit on the M_w/M_nof the first ethylene interpolymer may be about 2.8, in other cases about 2.5 and in still other cases about 2.2. The lower limit on the M_w/M_nthe first ethylene interpolymer may be about 1.7, in other cases about 1.8 and in still other cases about 1.9.

The first ethylene interpolymer contains catalyst residues that reflect the chemical composition of the single-site catalyst formulation used. Those skilled in the art will understand that catalyst residues are typically quantified by the parts per million of catalytic metal in the first ethylene interpolymer, where metal refers to the metal in component (i), i.e. the metal in the “bulky ligand-metal complex”; hereafter this metal will be referred to “metal A”. As recited earlier in this disclosure, non-limiting examples of metal A include Group 4 metals, titanium, zirconium and hafnium. The upper limit on the ppm of metal A in the first ethylene interpolymer may be about 1.0 ppm, in other cases about 0.9 ppm and in still other cases about 0.8 ppm. The lower limit on the ppm of metal A in the first ethylene interpolymer may be about 0.01 ppm, in other cases about 0.1 ppm and in still other cases about 0.2 ppm.

The amount of hydrogen added to R1 can vary over a wide range allowing the continuous solution process to produce first ethylene interpolymers that differ greatly in melt index, hereafter I₂¹(melt index is measured at 190° C. using a 2.16 kg load following the procedures outlined in ASTM D1238). This is accomplished by adjusting the hydrogen flow rate in stream 4 (as shown in FIGS. 1 and 2). The quantity of hydrogen added to R1 is expressed as the parts-per-million (ppm) of hydrogen in R1 relative to the total mass in reactor R1; hereafter H₂^R1(ppm). In some cases H₂^R1(ppm) ranges from about 100 ppm to 0 ppm, in other cases from about 50 ppm to 0 ppm, in alternative cases from about 20 to 0 and in still other cases from about 2 ppm to 0 ppm. The upper limit on I₂¹may be about 200 dg/min, in some cases about 100 dg/min; in other cases about 50 dg/min, and; in still other cases about 1 dg/min. The lower limit on I₂¹may be about 0.01 dg/min, in some cases about 0.05 dg/min; in other cases about 0.1 dg/min, and; in still other cases about 0.5 dg/min.

The upper limit on the weight percent (wt %) of the first ethylene interpolymer in the ethylene interpolymer product may be about 60 wt %, in other cases about 55 wt % and in still other cases about 50 wt %. The lower limit on the wt % of the first ethylene interpolymer in the ethylene interpolymer product may be about 15 wt %; in other cases about 25 wt % and in still other cases about 30 wt %.

Second Ethylene Interpolymer

Referring to the embodiments shown in FIG. 1, if optional α-olefin is not added to reactor 12a (R2) either through fresh α-olefin stream 8 or carried over from reactor 11a (R1) in stream 11e (in series mode), then the ethylene interpolymer produced in reactor 12a (R2) is an ethylene homopolymer. If an optional α-olefin is present in R2, the following weight ratio is one parameter to control the density of the second ethylene interpolymer produced in R2: ((α-olefin)/(ethylene))^R2. The upper limit on ((α-olefin)/(ethylene))^R2may be about 3; in other cases about 2 and in still other cases about 1. The lower limit on ((α-olefin)/(ethylene))^R2may be 0; in other cases about 0.25 and in still other cases about 0.5. Hereafter, the symbol “σ²” refers to the density of the ethylene interpolymer produced in R2. The upper limit on σ²may be about 0.975 g/cm³; in some cases about 0.965 g/cm³and; in other cases about 0.955 g/cm³. Depending on the heterogeneous catalyst formulation used, the lower limit on σ²may be about 0.89 g/cm³, in some cases about 0.90 g/cm³, and; in other cases about 0.91 g/cm³. The ranges disclosed in this paragraph also apply to the embodiments shown in FIG. 2.

A heterogeneous catalyst formulation is used to produce the second ethylene interpolymer. If the second ethylene interpolymer contains an α-olefin, the CDBI₅₀of the second ethylene interpolymer is lower relative to the CDBI₅₀of the first ethylene interpolymer that was produced with a single-site catalyst formulation. In an embodiment of this disclosure, the upper limit on the CDBI₅₀of the second ethylene interpolymer (that contains an α-olefin) may be about 70%, in other cases about 65% and in still other cases about 60%. In an embodiment of this disclosure, the lower limit on the CDBI₅₀of the second ethylene interpolymer (that contains an α-olefin) may be about 45%, in other cases about 50% and in still other cases about 55%. If an α-olefin is not added to the continuous solution polymerization process the second ethylene interpolymer is an ethylene homopolymer. In the case of a homopolymer, which does not contain α-olefin, one can still measure a CDBI₅₀using TREF. In the case of a homopolymer, the upper limit on the CDBI₅₀of the second ethylene interpolymer may be about 98%, in other cases about 96% and in still other cases about 95%, and; the lower limit on the CDBI₅₀may be about 88%, in other cases about 89% and in still other cases about 90%. It is well known to those skilled in the art that as the α-olefin content in the second ethylene interpolymer approaches zero, there is a smooth transition between the recited CDBI₅₀limits for the second ethylene interpolymers (that contain an α-olefin) and the recited CDBI₅₀limits for the second ethylene interpolymers that are ethylene homopolymers. Typically, the CDBI₅₀of the first ethylene interpolymer is higher than the CDBI₅₀of the second ethylene interpolymer.

The M_w/M_nof second ethylene interpolymer is higher than the M_w/M_nof the first ethylene interpolymer. The upper limit on the M_w/M_nof the second ethylene interpolymer may be about 4.4, in other cases about 4.2 and in still other cases about 4.0. The lower limit on the M_w/M_nof the second ethylene interpolymer may be about 2.2. M_w/M_n's of 2.2 are observed when the melt index of the second ethylene interpolymer is high, or when the melt index of the ethylene interpolymer product is high, e.g., greater than 10 dg/minute. In other cases the lower limit on the M_w/M_nof the second ethylene interpolymer may be about 2.4 and in still other cases about 2.6.

The second ethylene interpolymer contains catalyst residues that reflect the chemical composition of the heterogeneous catalyst formulation. Those skilled in the art with understand that heterogeneous catalyst residues are typically quantified by the parts per million of catalytic metal in the second ethylene interpolymer, where the metal refers to the metal originating from “component (vii)”, i.e., the metal compound; hereafter this metal will be referred to as “metal B”. As recited earlier in this disclosure, non-limiting examples of metal B include metals selected from Group 4 through Group 8 of the Periodic Table, or mixtures of metals selected from Group 4 through Group 8. The upper limit on the ppm of metal B in the second ethylene interpolymer may be about 12 ppm, in other cases about 10 ppm and in still other cases about 8 ppm. The lower limit on the ppm of metal B in the second ethylene interpolymer may be about 2 ppm, in other cases about 3 ppm and in still other cases about 4 ppm. While not wishing to be bound by any particular theory, in series mode of operation it is believed that the chemical environment within the second reactor deactivates the single site catalyst formulation, or; in parallel mode of operation the chemical environment within stream 12d deactivates the single site catalyst formation.

Referring to the embodiments shown in FIGS. 1 and 2, the amount of hydrogen added to R2 can vary over a wide range which allows the continuous solution process to produce second ethylene interpolymers that differ greatly in melt index, hereafter I₂². This is accomplished by adjusting the hydrogen flow rate in stream 9. The quantity of hydrogen added is expressed as the parts-per-million (ppm) of hydrogen in R2 relative to the total mass in reactor R2; hereafter H₂^R2(ppm). In some cases H₂^R2(ppm) ranges from about 50 ppm to 0 ppm, in some cases from about 25 ppm to 0 ppm, in other cases from about 10 to 0 and in still other cases from about 2 ppm to 0 ppm. The upper limit on I₂²may be about 1000 dg/min; in some cases about 750 dg/min; in other cases about 500 dg/min, and; in still other cases about 200 dg/min. The lower limit on I₂²may be about 0.3 dg/min, in some cases about 0.4 dg/min, in other cases about 0.5 dg/min, and; in still other cases about 0.6 dg/min.

The upper limit on the weight percent (wt %) of the second ethylene interpolymer in the ethylene interpolymer product may be about 85 wt %, in other cases about 80 wt % and in still other cases about 70 wt %. The lower limit on the wt % of the second ethylene interpolymer in the ethylene interpolymer product may be about 30 wt %; in other cases about 40 wt % and in still other cases about 50 wt %.

Third Ethylene Interpolymer

Referring to the embodiments shown in FIG. 1 a third ethylene interpolymer is not produced in reactor 17 (R3) if catalyst deactivator A is added upstream of reactor 17 via catalyst deactivator tank 18A. If catalyst deactivator A is not added and optional α-olefin is not added to reactor 17 either through fresh α-olefin stream 15 or carried over from reactor 12a (R2) in stream 12c (series mode) or stream 12d (parallel mode) then the ethylene interpolymer produced in reactor 17 is an ethylene homopolymer. If catalyst deactivator A is not added and optional α-olefin is present in R3, the following weight ratio determines the density of the third ethylene interpolymer: ((α-olefin)/(ethylene))^R3. In the continuous solution polymerization process ((α-olefin)/(ethylene))^R3is one of the control parameter used to produce a third ethylene interpolymer with a desired density. The upper limit on ((α-olefin)/(ethylene))^R3may be about 3; in other cases about 2 and in still other cases about 1. The lower limit on ((α-olefin)/(ethylene))^R3may be 0; in other cases about 0.25 and in still other cases about 0.5. Hereafter, the symbol “03” refers to the density of the ethylene interpolymer produced in R3. The upper limit on σ³may be about 0.975 g/cm³; in some cases about 0.965 g/cm³and; in other cases about 0.955 g/cm³. Depending on the heterogeneous catalyst formulations used, the lower limit on σ³may be about 0.89 g/cm³, in some cases about 0.90 g/cm³, and; in other cases about 0.91 g/cm³. Optionally, a second heterogeneous catalyst formulation may be added to R3. The ranges disclosed in this paragraph also apply to the embodiments shown in FIG. 2.

Typically, the upper limit on the CDBI₅₀of the optional third ethylene interpolymer (containing an α-olefin) may be about 65%, in other cases about 60% and in still other cases about 55%. The CDBI₅₀of an α-olefin containing optional third ethylene interpolymer will be lower than the CDBI₅₀of the first ethylene interpolymer produced with the single-site catalyst formulation. Typically, the lower limit on the CDBI₅₀of the optional third ethylene interpolymer (containing an α-olefin) may be about 35%, in other cases about 40% and in still other cases about 45%. If an α-olefin is not added to the continuous solution polymerization process the optional third ethylene interpolymer is an ethylene homopolymer. In the case of an ethylene homopolymer the upper limit on the CDBI₅₀may be about 98%, in other cases about 96% and in still other cases about 95%, and; the lower limit on the CDBI₅₀may be about 88%, in other cases about 89% and in still other cases about 90%. Typically, the CDBI₅₀of the first ethylene interpolymer is higher than the CDBI₅₀of the third ethylene interpolymer and second ethylene interpolymer.

The upper limit on the M_w/M_nof the optional third ethylene interpolymer may be about 5.0, in other cases about 4.8 and in still other cases about 4.5. The lower limit on the M_w/M_nof the optional third ethylene interpolymer may be about 2.2, in other cases about 2.4 and in still other cases about 2.6. The M_w/M_nof the optional third ethylene interpolymer is higher than the M_w/M_nof the first ethylene interpolymer. When blended together, the second and third ethylene interpolymer have a fourth M_w/M_nwhich is not broader than the M_w/M_nof the second ethylene interpolymer.

The catalyst residues in the optional third ethylene interpolymer reflect the chemical composition of the heterogeneous catalyst formulation(s) used, i.e. the first and optionally a second heterogeneous catalyst formulation. The chemical compositions of the first and second heterogeneous catalyst formulations may be the same or different; for example, a first component (vii) and a second component (vii) may be used to synthesize the first and second heterogeneous catalyst formulation. As recited above, “metal B” refers to the metal that originates from the first component (vii). Hereafter, “metal C” refers to the metal that originates from the second component (vii). Metal B and optional metal C may be the same, or different. Non-limiting examples of metal B and metal C include metals selected from Group 4 through Group 8 of the Periodic Table, or mixtures of metals selected from Group 4 through Group 8. The upper limit on the ppm of (metal B+metal C) in the optional third ethylene interpolymer may be about 12 ppm, in other cases about 10 ppm and in still other cases about 8 ppm. The lower limit on the ppm of (metal B+metal C) in the optional third ethylene interpolymer may be about 2 ppm, in other cases about 3 ppm and in still other cases about 4 ppm.

Referring to the embodiments shown in FIGS. 1 and 2, optional hydrogen may be added to the tubular reactor (R3) via stream 16. The amount of hydrogen added to R3 may vary over a wide range. Adjusting the amount of hydrogen in R3, hereafter H₂^R3(ppm), allows the continuous solution process to produce optional third ethylene interpolymers that differ widely in melt index, hereafter I₂³. The amount of optional hydrogen added to R3 ranges from about 50 ppm to 0 ppm, in some cases from about 25 ppm to 0 ppm, in other cases from about 10 to 0 and in still other cases from about 2 ppm to 0 ppm. The upper limit on I₂³may be about 2000 dg/min; in some cases about 1500 dg/min; in other cases about 1000 dg/min, and; in still other cases about 500 dg/min. The lower limit on I₂³may be about 0.5 dg/min, in some cases about 0.6 dg/min, in other cases about 0.7 dg/min, and; in still other cases about 0.8 dg/min.

The upper limit on the weight percent (wt %) of the optional third ethylene interpolymer in the ethylene interpolymer product may be about 30 wt %, in other cases about 25 wt % and in still other cases about 20 wt %. The lower limit on the wt % of the optional third ethylene interpolymer in the ethylene interpolymer product may be 0 wt %; in other cases about 5 wt % and in still other cases about 10 wt %.

Ethylene Interpolymer Product

The upper limit on the density of the ethylene interpolymer product may be about 0.975 g/cm³; in some cases about 0.965 g/cm³and; in other cases about 0.955 g/cm³. The lower limit on the density of the ethylene interpolymer product may be about 0.869 g/cm³, in some cases about 0.879 g/cm³, and; in other cases about 0.889 g/cm³.

The upper limit on the CDBI₅₀of the ethylene interpolymer product may be about 97%, in other cases about 90% and in still other cases about 85%. An ethylene interpolymer product with a CDBI₅₀of 97% may result if an α-olefin is not added to the continuous solution polymerization process; in this case, the ethylene interpolymer product is an ethylene homopolymer. The lower limit on the CDBI₅₀of an ethylene interpolymer may be about 20%, in other cases about 40% and in still other cases about 60%.

The upper limit on the M_w/M_nof the ethylene interpolymer product may be about 25, in other cases about 15 and in still other cases about 9. The lower limit on the M_w/M_nof the ethylene interpolymer product may be 2.0, in other cases about 2.2 and in still other cases about 2.4.

The catalyst residues in the ethylene interpolymer product reflect the chemical compositions of: the single-site catalyst formulation employed in R1; the first heterogeneous catalyst formulation employed in R2, and; optionally the first or optionally the first and second heterogeneous catalyst formulation employed in R3. In this disclosure, catalyst residues were quantified by measuring the parts per million of catalytic metal in the ethylene interpolymer products. In addition, the elemental quantities (ppm) of magnesium, chlorine and aluminum were quantified. Catalytic metals originate from two or optionally three sources, specifically: 1) “metal A” that originates from component (i) that was used to form the single-site catalyst formulation; (2) “metal B” that originates from the first component (vii) that was used to form the first heterogeneous catalyst formulation, and; (3) optionally “metal C” that originates from the second component (vii) that was used to form the optional second heterogeneous catalyst formulation. Metals A, B and C may be the same or different. In this disclosure the term “total catalytic metal” is equivalent to the sum of catalytic metals A+B+C. Further, in this disclosure the terms “first total catalytic metal” and “second total catalyst metal” are used to differentiate between the amount of catalytic metal in the first and second ethylene interpolymer.

The upper limit on the ppm of metal A in the ethylene interpolymer product may be about 0.6 ppm, in other cases about 0.5 ppm and in still other cases about 0.4 ppm. The lower limit on the ppm of metal A in the ethylene interpolymer product may be about 0.001 ppm, in other cases about 0.01 ppm and in still other cases about 0.03 ppm. The upper limit on the ppm of (metal B+metal C) in the ethylene interpolymer product may be about 11 ppm, in other cases about 9 ppm and in still other cases about 7 ppm. The lower limit on the ppm of (metal B+metal C) in the ethylene interpolymer product may be about 2 ppm, in other cases about 3 ppm and in still other cases about 4 ppm.

In some embodiments, ethylene interpolymers may be produced where the catalytic metals (metals A, B and C) are the same metal; a non-limiting example would be titanium. In such embodiments, the ppm of (metal B+metal C) in the ethylene interpolymer product is calculated using equation (VII):

ppm^(B+C)=((ppm^(A+B+C)−(f^A×ppm^A))/(1−f^A) (VII)

where: ppm^(B+C)is the calculated ppm of (metal B+metal C) in the ethylene interpolymer product; ppm^(A+B+C)is the total ppm of catalyst residue in the ethylene interpolymer product as measured experimentally, i.e. (metal A ppm+metal B ppm+metal C ppm); f^Arepresents the weight fraction of the first ethylene interpolymer in the ethylene interpolymer product, f^Amay vary from about 0.15 to about 0.6, and; ppm^Arepresents the ppm of metal A in the first ethylene interpolymer. In equation (VII) ppm^Ais assumed to be 0.35 ppm.

Embodiments of the ethylene interpolymer products disclosed herein have lower catalyst residues relative to the polyethylene polymers described in U.S. Pat. No. 6,277,931. Higher catalyst residues in U.S. Pat. No. 6,277,931 increase the complexity of the continuous solution polymerization process; an example of increased complexity includes additional purification steps to remove catalyst residues from the polymer. In contrast, in the present disclosure, catalyst residues are not removed. In this disclosure, the upper limit on the “total catalytic metal”, i.e., the total ppm of (metal A ppm+metal B ppm+optional metal C ppm) in the ethylene interpolymer product may be about 11 ppm, in other cases about 9 ppm and in still other cases about 7, and; the lower limit on the total ppm of catalyst residuals (metal A+metal B+optional metal C) in the ethylene interpolymer product may be about 2 ppm, in other cases about 3 ppm and in still other cases about 4 ppm.

The upper limit on melt index of the ethylene interpolymer product may be about 500 dg/min, in some cases about 400 dg/min; in other cases about 300 dg/min, and; in still other cases about 200 dg/min. The lower limit on the melt index of the ethylene interpolymer product may be about 0.3 dg/min, in some cases about 0.4 dg/min; in other cases about 0.5 dg/min, and; in still other cases about 0.6 dg/min.

A computer generated ethylene interpolymer product is illustrated in Table 3; this simulations was based on fundamental kinetic models (with kinetic constants specific for each catalyst formulation) as well as feed and reactor conditions. The simulation was based on the configuration of the solution pilot plant described below; which was used to produce the examples of ethylene interpolymer products disclosed herein. Simulated Example 13 was synthesized using a single-site catalyst formulation (PIC-1) in R1 and an in-line Ziegler-Natta catalyst formulation in R2 and R3. Table 7 discloses a non-limiting example of the density, melt index and molecular weights of the first, second and third ethylene interpolymers produced in the three reactors (R1, R2 and R3); these three interpolymers are combined to produce Simulated Example 13 (the ethylene polymer product). As shown in Table 7, the Simulated Example 13 product has a density of 0.9169 g/cm³, a melt index of 1.0 dg/min, a branch frequency of 12.1 (the number of C₆-branches per 1000 carbon atoms (1-octene comonomer)) and a M_w/M_nof 3.11. Simulated Example 13 comprises: a first, second and third ethylene interpolymer having a first, second and third melt index of 0.31 dg/min, 1.92 dg/min and 4.7 dg/min, respectively; a first, second and third density of 0.9087 g/cm³, 0.9206 g/cm³and 0.9154 g/cm³, respectively; a first, second and third M_w/M_nof 2.03 M_w/M_n, 3.29 M_w/M_nand 3.28 M_w/M_n, respectively, and; a first, second and third CDBI₅₀of 90 to 95%, 55 to 60% and 45 to 55%, respectively. The simulated production rate of Simulated Example 13 was 90.9 kg/hr and the R3 exit temperature was 217.1° C.

Ethylene Interpolymer Product Examples

Tables 1A through 1C summarize solution process conditions used to produce ethylene interpolymer products Example 6 and 7, as well as Comparative Example 3; the target melt index and density targets of these samples were 0.60 dg/min and 0.915 g/cm³. Example 6 and 7 were produced using a single-site catalyst in R1 and an in-line Ziegler-Natta catalyst in R2. In contrast, Comparative Example 3 was produced using a single-site catalyst in both reactors R1 and R2. Table 1A-1C show higher production rates (kg/h) for Examples 6 and 7, relative to Comparative Example 3. In Examples 6 and 7 ethylene interpolymer products were produced at 85.2 and 94 kg/h, respectively; 13% and 24% higher, respectively, relative to Comparative Example 3 at 75.6 kg/h.

Examples 6 and 7 are two non-limiting embodiments of this disclosure; selected physical properties of Examples 6 and 7 are summarized in Table 2.

Example 6 is an ethylene interpolymer product that has a Dilution Index (Y_d) of 4.69; a Dimensionless Modulus (X_d) of −0.08; 5.2 ppm of total catalytic metal (titanium), and; 0.038 terminal vinyls/100 carbon atoms. The Dilution Index (Y_d) and Dimensionless Modulus (X_d) are fully described in the next section of this disclosure.

Dilution Index (Y_d) of Ethylene Interpolymer Products

In FIG. 3 the Dilution Index (Y_d, having dimensions of ° (degrees)) and Dimensionless Modulus (X_d) are plotted for several embodiments of the ethylene interpolymer products disclosed herein (the solid symbols), as well as comparative ethylene interpolymer products, i.e., Comparative A, D, E and S. Further, FIG. 3 defines the following three quadrants:

- Type I: Y_d>0 and X_d<0;
- Type II: Y_d>0 and X_d>0, and;
- Type II: Y_d<0 and X_d>0.

The data plotted in FIG. 3 is also tabulated in Table 4. In FIG. 3, Comparative S (open triangle) was used as the rheological reference in the Dilution Index test protocol. Comparative S is an ethylene interpolymer product comprising an ethylene interpolymer synthesized using an in-line Ziegler-Natta catalyst in one solution reactor, i.e. SCLAIR® FP120-C which is an ethylene/1-octene interpolymer available from NOVA Chemicals Company (Calgary, Alberta, Canada). Comparatives D and E (open diamonds, Y_d<0, X_d>0) are ethylene interpolymer products comprising a first ethylene interpolymer synthesized using a single-site catalyst formation and a second ethylene interpolymer synthesized using a batch Ziegler-Natta catalyst formulation employing a dual reactor solution process, i.e. Elite® 5100G and Elite® 5400G, respectively, both ethylene/1-octene interpolymers available from The Dow Chemical Company (Midland, Mich., USA). Comparative A (open square, Y_d>0 and X_d<0) was an ethylene interpolymer product comprising a first and second ethylene interpolymer synthesized using a single-site catalyst formation in a dual reactor solution process, i.e., SURPASS® FPs117-C which is an ethylene/1-octene interpolymer available from NOVA Chemicals Company (Calgary, Alberta, Canada).

The following defines the Dilution Index (Y_d) and Dimensionless Modulus (X_d). In addition to having molecular weights, molecular weight distributions and branching structures, blends of ethylene interpolymers may exhibit a hierarchical structure in the melt phase. In other words, the ethylene interpolymer components may be, or may not be, homogeneous down to the molecular level depending on interpolymer miscibility and the physical history of the blend. Such hierarchical physical structure in the melt is expected to have a strong impact on flow and hence on processing and converting; as well as the end-use properties of manufactured articles. The nature of this hierarchical physical structure between interpolymers can be characterized.

The hierarchical physical structure of ethylene interpolymers can be characterized using melt rheology. A convenient method can be based on the small amplitude frequency sweep tests. Such rheology results are expressed as the phase angle δ as a function of complex modulus G*, referred to as van Gurp-Palmen plots (as described in M. Van Gurp, J. Palmen, Rheol. Bull. (1998) 67(1): 5-8, and; Dealy J, Plazek D. Rheol. Bull. (2009) 78(2): 16-31). For a typical ethylene interpolymer, the phase angle S increases toward its upper bound of 90° with G* becoming sufficiently low. A typical VGP plot is shown in FIG. 4. The VGP plots are a signature of resin architecture. The rise of δ toward 90° is monotonic for an ideally linear, monodisperse interpolymer. The S(G*) for a branched interpolymer or a blend containing a branched interpolymer may show an inflection point that reflects the topology of the branched interpolymer (see S. Trinkle, P. Walter, C. Friedrich, Rheo. Acta (2002) 41: 103-113). The deviation of the phase angle δ from the monotonic rise may indicate a deviation from the ideal linear interpolymer either due to presence of long chain branching if the inflection point is low (e.g., δ≤20°) or a blend containing at least two interpolymers having dissimilar branching structure if the inflection point is high (e.g., δ≥70θ).

For commercially available linear low density polyethylenes, inflection points are not observed; with the exception of some commercial polyethylenes that contain a small amount of long chain branching (LCB). To use the VGP plots regardless of presence of LCB, an alternative is to use the point where the frequency ω_cis two decades below the cross-over frequency ω_c, i.e., ω_c=0.01ω_x. The cross-over point is taken as the reference as it is known to be a characteristic point that correlates with MI, density and other specifications of an ethylene interpolymer. The cross-over modulus is related to the plateau modulus for a given molecular weight distribution (see S. Wu. J Polym Sci, Polym Phys Ed (1989) 27:723; M. R. Nobile, F. Cocchini. Rheol Acta (2001) 40:111). The two decade shift in phase angle δ is to find the comparable points where the individual viscoelastic responses of constituents could be detected; to be more clear, this two decade shift is shown in FIG. 5. The complex modulus G_c* for this point is normalized to the cross-over modulus, G_x*/(√{square root over (2)}), as (√{square root over (2)})G_c*/G_x*, to minimize the variation due to overall molecular weight, molecular weight distribution and the short chain branching. As a result, the coordinates on VGP plots for this low frequency point at ω_c=0.01ω_x, namely (√{square root over (2)})G_c*/G_x* and δ_c, characterize the contribution due to blending. Similar to the inflection points, the closer the ((√{square root over (2)})G_c*/G_x*, δ_c) point is toward the 90° upper bound, the more the blend behaves as if it were an ideal single component.

As an alternative way to avoid interference due to the molecular weight, molecular weight distribution and the short branching of the ethylene δ_cinterpolymer ingredients, the coordinates (G_c*, δ_c) are compared to a reference sample of interest to form the following two parameters:

“Dilution Index (Y_d)”

Y_d=δ_c−(C₀−C₁e^C²^{ln G}^c^*)

“Dimensionless Modulus (X_d)”

X_d=G_0.01ω_c*/G_r*

The constants C₀, C₁, and C₂are determined by fitting the VGP data δ(G*) of the reference sample to the following equation:

δ=C₀−C₁e^C²^{ln G*}

G_r* is the complex modulus of this reference sample at its δ_c=δ(0.01ω_x). When an ethylene interpolymer, synthesized with an in-line Ziegler-Natta catalyst employing one solution reactor, having a density of 0.920 g/cm³and a melt index (MI or I₂) of 1.0 dg/min is taken as a reference sample, the constants are:

C₀=93.43°

C₁=1.316°

C₂=0.2945

G_r*=9432 Pa.

The values of these constants can be different if the rheology test protocol differs from that specified herein.

These regrouped coordinates (X_d, Y_d) from (G_c*, δ_c) allows comparison between ethylene interpolymer products disclosed herein with Comparative examples. The Dilution Index (Y_d) reflects whether the blend behaves like a simple blend of linear ethylene interpolymers (lacking hierarchical structure in the melt) or shows a distinctive response that reflects a hierarchical physical structure within the melt. The lower the Y_d, the more the sample shows separate responses from the ethylene interpolymers that comprise the blend; the higher the Y_dthe more the sample behaves like a single component, or single ethylene interpolymer.

Returning to FIG. 3: Type I (upper left quadrant) ethylene interpolymer products of this disclosure (solid symbols) have Y_d>0; in contrast, Type III (lower right quadrant) comparative ethylene interpolymers, Comparative D and E have Y_d<0. In the case of Type I ethylene interpolymer products (solid circles), the first ethylene interpolymer (single-site catalyst) and the second ethylene interpolymer (in-line Ziegler Natta catalyst) behave as a simple blend of two ethylene interpolymers and a hierarchical structure within the melt does not exist. However, in the case of Comparatives D and E (open diamonds), the melt comprising a first ethylene interpolymer (single-site catalyst) and a second ethylene interpolymer (batch Ziegler Natta catalyst) possesses a hierarchical structure.

The ethylene interpolymer products of this disclosure fall into one of two quadrants: Type I with X_d<0, or; Type II with X_d>0. The Dimensionless Modulus (X_d), reflects differences (relative to the reference sample) that are related to the overall molecular weight, molecular weight distribution (M_w/M_n) and short chain branching. Not wishing to be bound by theory, conceptually, the Dimensionless Modulus (X_d) may be considered to be related to the M_w/M_nand the radius of gyration (<R_g>2) of the ethylene interpolymer in the melt; conceptually, increasing X_dhas similar effects as increasing M_w/M_nand/or <R_g>2, without the risk of including lower molecular weight fraction and sacrificing certain related properties.

Relative to Comparative A (recall that Comparative A comprises a first and second ethylene interpolymer synthesized with a single-site catalyst) the solution process disclosed herein enables the manufacture of ethylene interpolymer products having higher X_d. Not wishing to be bound by theory, as X_dincreases the macromolecular coils of higher molecular weight fraction are more expanded (conceptually higher <R_g>2) and upon crystallization the probability of tie chain formation is increased resulting in higher toughness properties; the polyethylene art is replete with disclosures that correlate higher toughness (higher dart impact in film applications and improved ESCR and/or PENT in molding applications) with an increasing probability of tie chain formation.

In the Dilution Index testing protocol, the upper limit on Y_dmay be about 20, in some cases about 15 and is other cases about 13. The lower limit on Y_dmay be about −30, in some cases −25, in other cases −20 and in still other cases −15.

In the Dilution Index testing protocol, the upper limit on X_dis 1.0, in some cases about 0.95 and in other cases about 0.9. The lower limit on X_dis −2, in some cases −1.5 and in still other cases −1.0.

Terminal Vinyl Unsaturation of Ethylene Interpolymer Products

The ethylene interpolymer products of this disclosure are further characterized by a terminal vinyl unsaturation greater than or equal to 0.03 terminal vinyl groups per 100 carbon atoms (≥0.03 terminal vinyls/100 C); as determine via Fourier Transform Infrared (FTIR) spectroscopy according to ASTM ASTM D3124-98 and ASTM D6248-98.

FIG. 6 compares the terminal vinyl/100 C content of the ethylene interpolymers of this disclosure with several Comparatives. The data shown in FIG. 6 is also tabulated in Tables 5A and 5B. All of the comparatives in FIG. 6 and Tables 5A and 5B are Elite® products available from The Dow Chemical Company (Midland, Mich., USA); Elite products are ethylene interpolymers produced in a dual reactor solution process and comprise an interpolymer synthesized using a single-site catalyst and an interpolymer synthesized using a batch Ziegler-Natta catalyst: Comparative B is Elite 5401G; Comparative C is Elite 5400G; Comparative E and E2 are Elite 5500G; Comparative G is Elite 5960; Comparative H and H2 are Elite 5100G; Comparative I is Elite 5940G, and; Comparative J is Elite 5230G.

As shown in FIG. 6 the average terminal vinyl content in the ethylene interpolymer of this disclosure was 0.045 terminal vinyls/100 C; in contrast, the average terminal vinyl content in the Comparative samples was 0.023 terminal vinyls/100 C. Statistically, at the 99.999% confidence level, the ethylene interpolymers of this disclosure are significantly different from the Comparatives; i.e. a t-Test assuming equal variances shows that the means of the two populations (0.045 and 0.023 terminal vinyls/100 C) are significantly different at the 99.999% confidence level (t(obs)=12.891>3.510 t(crit two tail); or p-value=4.84×10⁻¹⁷<0.001 α (99.999% confidence)).

Catalyst Residues (Total Catalytic Metal)

The ethylene interpolymer products of this disclosure are further characterized by having ≥3 parts per million (ppm) of total catalytic metal (Ti); where the quantity of catalytic metal was determined by Neutron Activation Analysis (N.A.A.) as specified herein.

FIG. 7 compares the total catalytic metal content of the disclosed ethylene interpolymers with several Comparatives; FIG. 7 data is also tabulated in Tables 6A and 6B. All of the comparatives in FIG. 7 and Tables 6A and 6B are Elite® products available from The Dow Chemical Company (Midland, Mich., USA), for additional detail see the section above.

As shown in FIG. 7 the average total catalytic metal content in the ethylene interpolymers of this disclosure was 7.02 ppm of titanium; in contrast, the average total catalytic metal content in the Comparative samples was 1.63 ppm of titanium. Statistically, at the 99.999% confidence level, the ethylene interpolymers of this disclosure are significantly different from the Comparatives, i.e., a t-Test assuming equal variances shows that the means of the two populations (7.02 and 1.63 ppm titanium) are significantly different at the 99.999% confidence level, i.e. (t(obs)=12.71>3.520 t(crit two tail); or p-value=1.69×10⁻¹⁶<0.001 α (99.999% confidence)).

Flexible Manufactured Articles

Ethylene interpolymer products disclosed herein may be converted into a wide variety of flexible manufactured articles. Non-limiting examples include monolayer or multilayer films. Such films are well known to those of ordinary sill in the art. Non-limiting examples of processes to prepare such films include blown film and cast film processes.

Depending on the end-use application, the disclosed ethylene interpolymer products may be converted into films that span a wide range of thicknesses. Non-limiting examples include, food packaging films where thicknesses may range from about 0.5 mil (13 μm) to about 4 mil (102 μm), and; in heavy duty sack applications film thickness may range from about 2 mil (51 μm) to about 10 mil (254 μm).

The disclosed ethylene interpolymer products may be used in monolayer films; where the monolayer comprises one or more of the disclosed ethylene interpolymer products and optionally additional thermoplastics; non-limiting examples of thermoplastics include ethylene polymers and propylene polymers. The lower limit on the weight percent of the ethylene interpolymer product in a monolayer film may be about 3 wt %, in other cases about 10 wt % and in still other cases about 30 wt %. The upper limit on the weight percent of the ethylene interpolymer product in the monolayer film may be 100 wt %, in other cases about 90 wt % and in still other cases about 70 wt %.

The ethylene interpolymer products disclosed herein may also be used in one or more layers of a multilayer film; non-limiting examples of multilayer films include three, five, seven, nine, eleven or more layers. The thickness of a specific layer (containing one or more ethylene interpolymer product(s)) within the multilayer film may be about 5%, in other cases about 15% and in still other cases about 30% of the total multilayer film thickness. In other embodiments, the thickness of a specific layer (containing one or more ethylene interpolymer product(s)) within the multilayer film may be about 95%, in other cases about 80% and in still other cases about 65% of the total multilayer film thickness. Each individual layer of a multilayer film may contain more than one ethylene interpolymer product and/or additional thermoplastics.

Additional embodiments include laminations and coatings, wherein mono or multilayer films containing the disclosed ethylene interpolymer products are extrusion laminated or adhesively laminated or extrusion coated. In extrusion lamination or adhesive lamination, two or more substrates are bonded together with a thermoplastic or an adhesive, respectively. In extrusion coating, a thermoplastic is applied to the surface of a substrate. These processes are well known to those of ordinary experience in the art.

The ethylene interpolymer products disclosed herein can be used in a wide range of manufactured articles comprising one or more films (monolayer or multilayer). Non-limiting examples of such manufactured articles include: food packaging films (fresh and frozen foods, liquids and granular foods), stand-up pouches, retortable packaging and bag-in-box packaging; barrier films (oxygen, moisture, aroma, oil, etc.) and modified atmosphere packaging; light and heavy duty shrink films and wraps, collation shrink film, pallet shrink film, shrink bags, shrink bundling and shrink shrouds; light and heavy duty stretch films, hand stretch wrap, machine stretch wrap and stretch hood films; high clarity films; heavy-duty sacks; household wrap, overwrap films and sandwich bags; industrial and institutional films, trash bags, can liners, magazine overwrap, newspaper bags, mail bags, sacks and envelopes, bubble wrap, carpet film, furniture bags, garment bags, coin bags, auto panel films; medical applications such as gowns, draping and surgical garb; construction films and sheeting, asphalt films, insulation bags, masking film, landscaping film and bags; geomembrane liners for municipal waste disposal and mining applications; batch inclusion bags; agricultural films, mulch film and green house films; in-store packaging, self-service bags, boutique bags, grocery bags, carry-out sacks and t-shirt bags; oriented films, machine direction and biaxially oriented films and functional film layers in oriented polypropylene (OPP) films, e.g., sealant and/or toughness layers. Additional manufactured articles comprising one or more films containing at least one ethylene interpolymer product include laminates and/or multilayer films; sealants and tie layers in multilayer films and composites; laminations with paper; aluminum foil laminates or laminates containing vacuum deposited aluminum; polyamide laminates; polyester laminates; extrusion coated laminates, and; hot-melt adhesive formulations. The manufactured articles summarized in this paragraph contain at least one film (monolayer or multilayer) comprising at least one embodiment of the disclosed ethylene interpolymer products.

The disclosed ethylene interpolymer products have performance attributes that are advantageous in many flexible applications. The performance attribute(s) required depends on how the film will be used, i.e., the specific film application the film is employed in. The disclosed ethylene interpolymer products have a desirable balance of properties. Elaborating, relative to competitive polyethylenes of similar density and melt index, the disclosed ethylene interpolymers have one or more of: higher stiffness (e.g. tensile and/or flex modulus); higher toughness properties (e.g., impact and puncture); higher heat deflection temperatures; higher Vicat softening point; improved color (WI and YI); higher melt strength, and; improved heat sealing properties (e.g., heat sealing and hot tack). The recited performance attributes, in the previous sentence, are not to be construed as limiting. Further, the polymerization process and catalyst formulations disclosed herein allow the production of ethylene interpolymer products that can be converted into flexible manufactured articles that have a unique balance of physical properties (i.e., a several end-use properties can be balanced (as desired) in a multidimensional optimization); relative to comparative polyethylenes of comparable density and melt index.

Rigid Manufactured Articles

The disclosed ethylene interpolymer products may be converted into a wide variety of rigid manufactured articles, non-limiting examples include: deli containers, margarine tubs, drink cups and produce trays, bottle cap liners and bottle caps (for carbonated or non-carbonated fluids), closures (including closures with living hinge functionality), household and industrial containers, cups, bottles, pails, crates, tanks, drums, bumpers, lids, industrial bulk containers, industrial vessels, material handling containers, toys, bins, playground equipment, recreational equipment, boats, marine equipment, safety equipment (helmets), wire and cable applications such as power cables, communication cables and conduits, flexible tubing and hoses, pipe applications including both pressure pipe and non-pressure pipe markets (e.g., natural gas distribution, water mains, interior plumbing, storm sewer, sanitary sewer, corrugated pipes and conduit), foamed articles manufactured from foamed sheet or bun foam, military packaging (equipment and ready meals), personal care packaging, diapers and sanitary products, cosmetic/pharmaceutical/medical packaging, truck bed liners, pallets and automotive dunnage.

The rigid manufactured articles summarized above contain one or more of the disclosed ethylene interpolymer products or a blend of at least one ethylene interpolymer product with at least one other thermoplastic. Further, the rigid manufactured articles summarized above may be multilayer, comprising at least one layer comprising one or more ethylene interpolymer product or a blend of at least one ethylene interpolymer product with at least one other thermoplastic. Such rigid manufactured articles may be fabricated using the following non-limiting processes: injection molding, compression molding, blow molding, rotomolding, profile extrusion, pipe extrusion, sheet thermoforming and foaming processes employing chemical or physical blowing agents.

The disclosed ethylene interpolymer products have performance attributes that are advantageous in many rigid applications. The specific performance attribute required depends on how the article will be used, i.e., the specific application. The disclosed ethylene interpolymer products have a desirable balance of properties. Elaborating, relative to competitive polyethylenes of similar density and melt index, the disclosed ethylene interpolymers have one or more of: higher stiffness (e.g., flexural modulus); higher toughness properties (e.g., ESCR, PENT, IZOD impact, arm impact, Dynatup impact or Charpy impact resistance); higher melt strength, higher heat deflection temperature; higher Vicat softening temperatures, improved color (WI and YI), and; faster crystallization rates. The recited performance attributes, in the previous sentence, are not to be construed as limiting. Further, the polymerization process and catalyst formulations disclosed herein allow the production of ethylene interpolymer products that can be converted into rigid manufactured articles that have a unique balance of physical properties (i.e., several end-use properties can be balanced (as desired) through multidimensional optimization); relative to comparative polyethylenes of comparable density and melt index.

Additives and Adjuvants

The disclosed ethylene interpolymer products used to manufacture articles described above may optionally include, depending on its intended use, additives and adjuvants. Non-limiting examples of additives and adjuvants include, anti-blocking agents, antioxidants, heat stabilizers, slip agents, processing aids, anti-static additives, colorants, dyes, filler materials, light stabilizers, heat stabilizers, light absorbers, lubricants, pigments, plasticizers, nucleating agents and combinations thereof. Non-limiting examples of suitable primary antioxidants include Irganox 1010 [CAS Reg. No. 6683-19-8] and Irganox 1076 [CAS Reg. No. 2082-79-3]; both available from BASF Corporation, Florham Park, N.J., U.S.A. Non-limiting examples of suitable secondary antioxidants include Irgafos 168 [CAS Reg. No. 31570-04-4], available from BASF Corporation, Florham Park, N.J., U.S.A.; Weston 705 [CAS Reg. No. 939402-02-5], available from Addivant, Danbury Conn., U.S.A. and; Doverphos Igp-11 [CAS Reg. No. 1227937-46-3] available form Dover Chemical Corporation, Dover Ohio, U.S.A.

Testing Methods

Prior to testing, each specimen was conditioned for at least 24 hours at 23±2C and 50±10% relative humidity and subsequent testing was conducted at 23±2° C. and 50±10% relative humidity. Herein, the term “ASTM conditions” refers to a laboratory that is maintained at 23±2C and 50±10% relative humidity; and specimens to be tested were conditioned for at least 24 hours in this laboratory prior to testing. ASTM refers to the American Society for Testing and Materials.

Density

Ethylene interpolymer product densities were determined using ASTM D792-13 (Nov. 1, 2013).

Melt Index

Ethylene interpolymer product melt index was determined using ASTM D1238 (Aug. 1, 2013). Melt indexes, I₂, I₆, I₁₀and I₂₁were measured at 190° C., using weights of 2.16 kg, 6.48 kg, 10 kg and a 21.6 kg respectively. Melt index is commonly report with units of g/10 minute or dg/minute; these units are equivalent and the latter was used in this disclosure. Herein, the term “stress exponent” or its acronym “S.Ex.”, is defined by the following relationship:

S.Ex.=log(I₆/I₂)/log(6480/2160)

wherein I₆and I₂are the melt flow rates measured at 190° C. using 6.48 kg and 2.16 kg loads, respectively. In this disclosure, melt index was expressed using the units of g/10 minute or g/10 min or dg/minute or dg/min; these units are equivalent.

Gel Permeation Chromatography (GPC)

Ethylene interpolymer product molecular weights, M_n, M_wand M_z, as well the as the polydispersity (M_w/M_n), were determined using ASTM D6474-12 (Dec. 15, 2012). This method illuminates the molecular weight distributions of ethylene interpolymer products by high temperature gel permeation chromatography (GPC). The method uses commercially available polystyrene standards to calibrate the GPC.

Unsaturation Content

The quantity of unsaturated groups, i.e. double bonds, in an ethylene interpolymer product was determined according to ASTM D3124-98 (vinylidene unsaturation, published March 2011) and ASTM D6248-98 (vinyl and trans unsaturation, published July 2012). An ethylene interpolymer sample was: a) first subjected to a carbon disulfide extraction to remove additives that may interfere with the analysis; b) the sample (pellet, film or granular form) was pressed into a plaque of uniform thickness (0.5 mm), and; c) the plaque was analyzed by FTIR.

Comonomer Content

The quantity of comonomer in an ethylene interpolymer product was determined by FTIR (Fourier Transform Infrared spectroscopy) according to ASTM D6645-01 (published January 2010).

Composition Distribution Branching Index (CDBI)

The “Composition Distribution Branching Index” or “CDBI” of the disclosed Examples and Comparative Examples were determined using a crystal-TREF unit commercially available form Polymer ChAR (Valencia, Spain). The acronym “TREF” refers to Temperature Rising Elution Fractionation. A sample of ethylene interpolymer product (80 to 100 mg) was placed in the reactor of the Polymer ChAR crystal-TREF unit, the reactor was filled with 35 ml of 1,2,4-trichlorobenzene (TCB), heated to 150° C. and held at this temperature for 2 hours to dissolve the sample. An aliquot of the TCB solution (1.5 mL) was then loaded into the Polymer ChAR TREF column filled with stainless steel beads and the column was equilibrated for 45 minutes at 110° C. The ethylene interpolymer product was then crystallized from the TCB solution, in the TREF column, by slowly cooling the column from 110° C. to 30° C. using a cooling rate of 0.09° C. per minute. The TREF column was then equilibrated at 30° C. for 30 minutes. The crystallized ethylene interpolymer product was then eluted from the TREF column by passing pure TCB solvent through the column at a flow rate of 0.75 mL/minute as the temperature of the column was slowly increased from 30° C. to 120° C. using a heating rate of 0.25° C. per minute. Using Polymer ChAR software a TREF distribution curve was generated as the ethylene interpolymer product was eluted from the TREF column, i.e., a TREF distribution curve is a plot of the quantity (or intensity) of ethylene interpolymer eluting from the column as a function of TREF elution temperature. A CDBI₅₀was calculated from the TREF distribution curve for each ethylene interpolymer product analyzed. The “CDBI₅₀” is defined as the percent of ethylene interpolymer whose composition is within 50% of the median comonomer composition (25% on each side of the median comonomer composition); it is calculated from the TREF composition distribution curve and the normalized cumulative integral of the TREF composition distribution curve. Those skilled in the art will understand that a calibration curve is required to convert a TREF elution temperature to comonomer content, i.e. the amount of comonomer in the ethylene interpolymer fraction that elutes at a specific temperature. The generation of such calibration curves are described in the prior art, e.g., Wild, et al., J. Polym. Sci., Part B, Polym. Phys., Vol. 20 (3), pages 441-455: hereby fully incorporated by reference.

Neutron Activation Analysis (NAA)

Neutron Activation Analysis, hereafter NAA, was used to determine catalyst residues in ethylene interpolymers and was performed as follows. A radiation vial (composed of ultrapure polyethylene, 7 mL internal volume) was filled with an ethylene interpolymer product sample and the sample weight was recorded. Using a pneumatic transfer system the sample was placed inside a SLOWPOKE™ nuclear reactor (Atomic Energy of Canada Limited, Ottawa, Ontario, Canada) and irradiated for 30 to 600 seconds for short half-life elements (e.g., Ti, V, Al, Mg, and Cl) or 3 to 5 hours for long half-life elements (e.g., Zr, Hf, Cr, Fe and Ni). The average thermal neutron flux within the reactor was 5×10¹¹/cm²/s. After irradiation, samples were withdrawn from the reactor and aged, allowing the radioactivity to decay; short half-life elements were aged for 300 seconds or long half-life elements were aged for several days. After aging, the gamma-ray spectrum of the sample was recorded using a germanium semiconductor gamma-ray detector (Ortec model GEM55185, Advanced Measurement Technology Inc., Oak Ridge, Tenn., USA) and a multichannel analyzer (Ortec model DSPEC Pro). The amount of each element in the sample was calculated from the gamma-ray spectrum and recorded in parts per million relative to the total weight of the ethylene interpolymer sample. The N.A.A. system was calibrated with Specpure standards (1000 ppm solutions of the desired element (greater than 99% pure)). One mL of solutions (elements of interest) were pipetted onto a 15 mm×800 mm rectangular paper filter and air dried. The filter paper was then placed in a 1.4 mL polyethylene irradiation vial and analyzed by the N.A.A. system. Standards are used to determine the sensitivity of the N.A.A. procedure (in counts/μg).

Dilution Index (Y_d) Measurements

A series of small amplitude frequency sweep tests were run on each sample using an Anton Paar MCR501 Rotational Rheometer equipped with the “TruGap™ Parallel Plate measuring system”. A gap of 1.5 mm and a strain amplitude of 10% were used throughout the tests. The frequency sweeps were from 0.05 to 100 rad/s at the intervals of seven points per decade. The test temperatures were 170°, 190°, 210° and 230° C. Master curves at 190° C. were constructed for each sample using the Rheoplus/32 V3.40 software through the Standard TTS (time-temperature superposition) procedure, with both horizontal and vertical shift enabled.

The Y_dand X_ddata generated are summarized in Table 4. The flow properties of the ethylene interpolymer products, e.g., the melt strength and melt flow ratio (MFR) are well characterized by the Dilution Index (Y_d) and the Dimensionless Modulus (X_d) as detailed below. In both cases, the flow property is a strong function of Y_dand X_din addition a dependence on the zero-shear viscosity. For example, the melt strength (hereafter MS) values of the disclosed Examples and the Comparative Examples were found to follow the same equation, confirming that the characteristic VGP point ((√{square root over (2)})G_c*/G_x*, δ_c) and the derived regrouped coordinates (X_d, Y_d) represent the structure well:

MS=a₀₀+a₁₀log η₀−a₂₀(90−δ_c)−a₃₀((√{square root over (2)})G_c*/G_x*)−a₄₀(90−δ_c)((√{square root over (2)})G_c*/G_x*)

where

a₀₀=−33.33; a₁₀=9.529; a₂₀=0.03517; a₃₀=0.894; a₄₀=0.02969

and r²=0.984 and the average relative standard deviation was 0.85%.

Further, this relation can be expressed in terms of the Dilution Index (Y_d) and the Dimensionless Modulus (X_d):

MS=a₀+a₁log η₀+a₂Y_d+a₃X_d+a₄Y_dX_d

where

a₀=33.34; a₁=9.794; a₂=0.02589; a₃=0.1126; a₄=0.03307 and

r²=0.989 and the average relative standard deviation was 0.89%.

The MFR of the disclosed Examples and the Comparative samples were found to follow a similar equation, further confirming that the dilution parameters Y_dand X_dshow that the flow properties of the disclosed Examples differ from the reference and Comparative Examples:

MFR=b₀−b₁log η₀−b₂Y_d−b₃X_d

where

- b₀=53.27; b₁=6.107; b₂=1.384; b₃=20.34

and

r²=0.889 and the average relative standard deviation and 3.3%.

Further, the polymerization process and catalyst formulations disclosed herein allow the production of ethylene interpolymer products that can be converted into flexible manufactured articles that have a unique balance of physical properties (i.e. several end-use properties can be balanced (as desired) through multidimensional optimization); relative to comparative polyethylenes of comparable density and melt index.

EXAMPLES
Polymerization

The following examples are presented for the purpose of illustrating selected embodiments of this disclosure; it being understood, that the examples presented do not limit the claims presented.

Examples of the disclosed ethylene interpolymer products were produced in a continuous solution polymerization pilot plant comprising reactors arranged in series configuration. Methylpentane was used as the process solvent (a commercial blend of methylpentane isomers). The volume of the first CSTR reactor (R1) was 3.2 gallons (12 L), the volume of the second CSTR reactor (R2) was 5.8 gallons (22 L) and the volume of the tubular reactor (R3) was 4.8 gallons (18 L). Examples of ethylene interpolymer products were produced using an R1 pressure from about 14 MPa to about 18 MPa; R2 was operated at a lower pressure to facilitate continuous flow from R1 to R2. R1 and R2 were operated in series mode, wherein the first exit stream from R1 flows directly into R2. Both CSTR's were agitated to give conditions in which the reactor contents were well mixed. The process was operated continuously by feeding fresh process solvent, ethylene, 1-octene and hydrogen to the reactors.

The single site catalyst components used were: component (i), cyclopentadienyl tri(tertiary butyl)phosphinimine titanium dichloride, (Cp[(t-Bu)₃PN]TiCl₂), hereafter PIC-1; component (ii), methylaluminoxane (MAO-07); component (iii), trityl tetrakis(pentafluoro-phenyl)borate, and; component (iv), 2,6-di-tert-butyl-4-ethylphenol. The single site catalyst component solvents used were methylpentane for components (ii) and (iv) and xylene for components (i) and (iii). The quantity of PIC-1 added to R1, “R1 (i) (ppm)” is shown in Table 1A; to be clear, in Example 6 in Table 1A, the solution in R1 contained 0.09 ppm of component (i), i.e., PIC-1. The mole ratios of the single site catalyst components employed to produce Example 6 were: R1 (ii)/(i) mole ratio=100, i.e., [(MAO-07)/(PIC-1)]; R1 (iv)/(ii) mole ratio=0, i.e., [(2,6-di-tert-butyl-4-ethylphenol)/(MAO-07)], and; R1 (iii)/(i) mole ratio=1.1, i.e., [(trityl tetrakis(pentafluoro-phenyl)borate)/(PIC-1)]. The single site catalyst formulation was injected into R1 using process solvent, the flow rate of this catalyst containing solvent was about 30 kg/hr.

The in-line Ziegler-Natta catalyst formulation was prepared from the following components: component (v), butyl ethyl magnesium; component (vi), tertiary butyl chloride; component (vii), titanium tetrachloride; component (viii), diethyl aluminum ethoxide, and; component (ix), triethyl aluminum. Methylpentane was used as the catalyst component solvent. The in-line Ziegler-Natta catalyst formulation was prepared using the following steps. In step one, a solution of triethylaluminum and dibutylmagnesium ((triethylaluminum)/(dibutylmagnesium) molar ratio of 20) was combined with a solution of tertiary butyl chloride and allowed to react for about 30 seconds (HUT-1); in step two, a solution of titanium tetrachloride was added to the mixture formed in step one and allowed to react for about 14 seconds (HUT-2), and; in step three, the mixture formed in step two was allowed to reactor for an additional 3 seconds (HUT-3) prior to injection into R2. The in-line Ziegler-Natta procatalyst formulation was injected into R2 using process solvent, the flow rate of the catalyst containing solvent was about 49 kg/hr. The in-line Ziegler-Natta catalyst formulation was formed in R2 by injecting a solution of diethyl aluminum ethoxide into R2. The quantity of titanium tetrachloride “R2 (vii) (ppm)” added to reactor 2 (R2) is shown in Table 1A; to be clear in Example 6 the solution in R2 contained 3.2 ppm of TiCl₄. The mole ratios of the in-line Ziegler-Natta catalyst components are also shown in Table 1A, specifically: R2 (vi)/(v) mole ratio, i.e., [(tertiary butyl chloride)/(butyl ethyl magnesium)]; R2 (viii)/(vii) mole ratio, i.e., [(diethyl aluminum ethoxide)/(titanium tetrachloride)], and; R2 (ix)/(vii) mole ratio, i.e., [(triethyl aluminum)/(titanium tetrachloride)]. To be clear, in Example 6, the following mole ratios were used to synthesize the in-line Ziegler-Natta catalyst: R2 (vi)/(v) mole ratio=1.98; R2 (viii)/(vii) mole ratio=1.35, and; R2 (ix)/(vii) mole ratio=0.35. Referring to FIG. 1, in all of the Examples disclosed, 100% of the diethyl aluminum ethoxide in stream 10d, component (viii), was added to reactor 12a via stream 10h.

In Comparative Example 3, a single site catalyst formulation was employed in both reactor 1 and reactor 2. Relative to Comparative Example 6, the maximum ethylene interpolymer product production rates (kg/h) of Examples 6 and 7, in which a single-site catalyst formulation was used in R1 and an in-line Ziegler Natta catalyst formulation was used in R2, were 19% higher (on average). For example, in Example 6 (single-site catalyst formulation in R1+in-line Ziegler-Natta catalyst in R2) the ethylene interpolymer product was produced at a production rate of 85.2 kg/h; in contrast, in Comparative Example 3 (single-site catalyst formulation in both R1 and R2) the maximum production rate of the comparative ethylene interpolymer product was 75.6 kg/h.

Average residence time of the solvent in a reactor is primarily influenced by the amount of solvent flowing through each reactor and the total amount of solvent flowing through the solution process, the following are representative or typical values for the examples shown in Tables 1A-1C: average reactor residence times were: about 61 seconds in R1, about 73 seconds in R2 and about 50 seconds in R3 (the volume of R3 was about 4.8 gallons (18 L)).

Polymerization in the continuous solution polymerization process was terminated by adding a catalyst deactivator to the third exit stream exiting the tubular reactor (R3). The catalyst deactivator used was octanoic acid (caprylic acid), commercially available from P&G Chemicals, Cincinnati, Ohio, U.S.A. The catalyst deactivator was added such that the moles of fatty acid added were 50% of the total molar amount of titanium and aluminum added to the polymerization process; to be clear, the moles of octanoic acid added=0.5×(moles titanium+moles aluminum); this mole ratio was consistently used in all examples.

A two-stage devolitizing process was employed to recover the ethylene interpolymer product from the process solvent, i.e., two vapor/liquid separators were used and the second bottom stream (from the second V/L separator) was passed through a gear pump/pelletizer combination. DHT-4V (hydrotalcite), supplied by Kyowa Chemical Industry Co. LTD, Tokyo, Japan was used as a passivator, or acid scavenger, in the continuous solution process. A slurry of DHT-4V in process solvent was added prior to the first V/L separator. The molar amount of DHT-4V added was about 10-fold higher than the molar amount of chlorides added to the process; the chlorides added were titanium tetrachloride and tertiary butyl chloride.

Prior to pelletization the ethylene interpolymer product was stabilized by adding about 500 ppm of Irganox 1076 (a primary antioxidant) and about 500 ppm of Irgafos 168 (a secondary antioxidant), based on weight of the ethylene interpolymer product. Antioxidants were dissolved in process solvent and added between the first and second V/L separators.

Tables 1B and 1C disclose additional solution process parameters, e.g. ethylene and 1-octene splits between the reactors, reactor temperatures and ethylene conversions, etc. recorded during the production of Examples 6 and 7 and Comparative Example 3. In Tables 1A-1C the targeted ethylene interpolymer product was 0.6 melt index (I₂) (ASTM D1239, 2.16 kg load, 190° C.) and 0.915 g/cm³(ASTM D792). In Comparative Example 3, the single-site catalyst formulation was injected into both reactor R1 and R2 and ES^R1was 50%. In Example 7, the single site catalyst formulation was injected into R1, the in-line Ziegler-Natta catalyst formulation was injected into R2 and ES^R1was 47%.

FTIR, N.A.A. and Dilution Index analysis was performed on Example 6 with the following results: 0.038 terminal vinyls/100 C; 5.2 ppm Ti; 4.69 Y_d(Dilution Index), and; −0.08 X_d(Dimensionless Modulus). FTIR and N.A.A. was performed on Example 7 with the following results: 0.042 terminal vinyls/100 C, and; 7.7 ppm Ti (Example 7 was not submitted for Dilution Index testing).

TABLE 1A

Continuous solution process catalyst parameters for:

Examples 6 and 7 and Comparative Example 3, targeting

ethylene interpolymer products at 0.60 melt index

(I₂(dg/min)) and a density of 0.915 g/cm³.

Com-

Exam-
Exam-
parative

Process Parameter
ple 6
ple 7
Example 3

R1 Catalyst
PIC-1
PIC-1
PIC-1

R2 Catalyst
ZN
ZN
PIC-1

R1 (i) (ppm)
0.09
0.1
0.07

R1 (ii)/(i) mole ratio
100
100
100

R1 (iv)/(ii) mole ratio
0
0
0.3

R1 (iii)/(i) mole ratio
1.1
1.1
1.2

R2 (i) (ppm)
0
0
0.14

R2 (ii)/(i) mole ratio
0
0
25

R2 (iv)/(ii) mole ratio
0
0
0.3

R2 (iii)/(i) mole ratio
0
0
1.27

R2 (vii) (ppm)
3.2
4.8
0

R2 (vi)/(v) mole ratio
1.98
1.98
0

R2 (viii)/(vii) mole ratio
1.35
1.35
0

R2 (ix)/(vii) mole ratio
0.35
0.35
0

Prod. Rate (kg/h)
85.2
94
75.6

Increase in Production Rate
12.7
24.3

(%)

TABLE 1B

Additional solution process parameters

for Examples 6-8 and Comparative Examples 3 and 4.

Exam-
Exam-
Comparative

Process Parameter
ple 6
ple 7
Example 3

R3 volume (L)
18
18
2.2

ES^R1(%)
40
47
50

ES^R2(%)
60
53
50

ES^R3(%)
0
0
0

R1 ethylene concentration (wt %)
10.3
10.3
10.3

R2 ethylene concentration (wt %)
13.7
14.9
12.7

R3 ethylene concentration (wt %)
13.7
14.9
12.7

((1-octene)/(ethylene))^R1(wt %)
0.63
0.66
0.81

OS^R1(%)
100
100
83.3

OS^R2(%)
0
0
16.7

OS^R3(%)
0
0
0

H₂^R1(ppm)
0.2
0.2
1.3

H₂^R2(ppm)
1
1
0.8

H₂^R3(ppm)
0
0
0

Prod. Rate (kg/h)
85.2
94
75.6

Increase in Production Rate (%)
12.7
24.3

TABLE 1C

Additional solution process parameters for

Examples 6-8 and Comparative

Examples 3 and 4.

Exam-
Exam-
Comparative

Process Parameter
ple 6
ple 7
Example 3

R1 total solution rate (kg/h)
319.9
409.1
369.9

R2 total solution rate (kg/h)
280.1
190.9
230.1

R3 solution rate (kg/h)
0
0
0

Overall total solution rate (kg/h)
600
600
600

R1 inlet temp (° C.)
30
30
30

R2 inlet temp (° C.)
30
30
30

R3 inlet temp(° C.)
130
130
130

R1 Mean temp (° C.)
140.3
140.1
140.2

R2 Mean temp (° C.)
187.8
202.5
185.7

R3 exit temp (actual) (° C.)
198.4
212.1
186

R3 exit temp (calc) (° C.)
200.4
215.3
187.6

Q^R1(%)
78.2
78.2
78.2

Q^R2(%)
80
80
81

Q^R2+R3 (%)
92
92.5
83.7

Q^R3(%)
60
62.4
14.1

Q^T(%)
94.5
95.2
90.1

Prod. Rate (kg/h)
85.2
94
75.6

Increase in Production Rate (%)
12.7
24.3

TABLE 2

Physical properties of Examples 6 and 7 and Comparative Example 3.

Comparative

Property
Example 6
Example 7
Example 3

Density (g/cm³)
0.9152
0.9155
0.9150

Melt Index I₂(dg/min)
0.67
0.70
0.58

Stress Exponent
1.23
1.24
1.27

M_w
113893
114401
112210

M_w/M_n
2.87
3.88
2.79

CDBI₅₀
69.0
65.7
74.0

TABLE 3

Computer generated Simulated Example 13: single-site

catalyst formulation in R1 (PIC-1) and an in-line Ziegler-

Natta catalyst formulation in R2 and R3.

Reactor
Reactor
Reactor

1 (R1)
2 (R2)
3 (R3)

Simulated
First
Second
Third
Simulated

Physical
Ethylene
Ethylene
Ethylene
Example

Property
Interpolymer
Interpolymer
Interpolymer
13

Weight
36.2
56.3
7.5
100

Percent (%)

M_n
63806
25653
20520
31963

M_w
129354
84516
67281
99434

M_z
195677
198218
162400
195074

Polydispersity
2.03
3.29
3.28
3.11

(M_w/M_n)

Branch Frequency
12.6
11.4
15.6
12.1

(C₆Branches

per 1000C)

CDBI₅₀(%)
90 to 95
55 to 60
45 to 55
65 to 70

(range)

Density (g/cm³)
0.9087
0.9206
0.9154
0.9169

Melt Index
0.31
1.92
4.7
1.0

(dg/min)

TABLE 4

Dilution Index (Y_d) and Dimensionless Modulus Data (X_d) for selected embodiments of

ethylene interpolymers of this disclosure (Examples), relative to Comparative S, A, D and

E. (MFR = melt flow rate (I₂₁/I₂); MS = melt strength)

Sample
Density
MI

MS
η₀
G⁰N
G*_c
δ_c

Code
[g/cm³]
[dg/min]
MFR
[cN]
[kPa · s]
[MPa]
[kPa]
[°]
X_d
Y_d

Comp. S
0.9176
0.86
29.2
6.46
11.5
1.50
9.43
74.0
0.00
0.02

Comp. A
0.9199
0.96
29.6
5.99
10.6
1.17
5.89
80.1
−0.20
3.66

Example 6
0.9152
0.67
23.7
7.05
12.9
1.57
7.89
79.6
−0.08
4.69

Example
0.9173
0.95
26.3
5.73
9.67
0.84
7.64
79.0
−0.09
3.93

101

Example
0.9176
0.97
22.6
5.65
9.38
1.46
7.46
79.5
−0.10
4.29

102

Example
0.9172
0.96
25.3
5.68
9.38
1.44
7.81
79.3
−0.08
4.29

103

Example
0.9252
0.98
23.9
5.57
9.41
1.64
8.90
78.1
−0.03
3.8

110

Example
0.9171
0.75
23.4
6.83
12.4
1.48
8.18
79.2
−0.06
4.44

115

Example
0.9250
1.04
24.2
5.33
8.81
0.97
8.97
78.9
−0.02
4.65

200

Example
0.9165
1.01
27.1
5.43
8.75
0.85
6.75
79.7
−0.15
3.91

201

Example
0.9204
1.00
24.0
5.99
10.2
1.45
13.5
73.6
0.16
1.82

120

Example
0.9232
0.94
22.1
6.21
10.4
0.97
11.6
75.7
0.09
3.02

130

Example
0.9242
0.95
22.1
6.24
10.7
1.02
11.6
75.3
0.09
2.59

131

Comp. D
0.9204
0.82
30.6
7.61
15.4
1.58
10.8
70.4
0.06
−2.77

Comp. E
0.9161
1.00
30.5
7.06
13.8
1.42
10.4
70.5
0.04
−2.91

TABLE 5A

Unsaturation data of several embodiments of the disclosed ethylene interpolymers,

as well as Comparative B, C, E, E2, G, H, H2, I and J; as determined by ASTM

D3124-98 and ASTM D6248-98.

Melt

Density
Index I₂
Melt Flow
Stress
Unsaturations per 100 C.

Sample Code
(g/cm³)
(dg/min)
Ratio (I₂₁/I₂)
Exponent
Internal
Side Chain
Terminal

Example 11
0.9113
0.91
24.8
1.24
0.009
0.004
0.037

Example 6
0.9152
0.67
23.7
1.23
0.008
0.004
0.038

Example 4
0.9154
0.97
37.1
1.33
0.009
0.004
0.047

Example 7
0.9155
0.70
25.7
1.24
0.008
0.005
0.042

Example 2
0.9160
1.04
27.0
1.26
0.009
0.005
0.048

Example 5
0.9163
1.04
25.9
1.23
0.008
0.005
0.042

Example 3
0.9164
0.9
29.2
1.27
0.009
0.004
0.049

Example 53
0.9164
0.9
29.2
1.27
0.009
0.004
0.049

Example 51
0.9165
1.01
28.0
1.26
0.009
0.003
0.049

Example 201
0.9165
1.01
27.1
1.22
0.008
0.007
0.048

Example 1
0.9169
0.88
23.4
1.23
0.008
0.005
0.044

Example 52
0.9169
0.85
29.4
1.28
0.008
0.002
0.049

Example 55
0.9170
0.91
29.8
1.29
0.009
0.004
0.050

Example 115
0.9171
0.75
23.4
1.22
0.007
0.003
0.041

Example 43
0.9174
1.08
24.2
1.23
0.007
0.007
0.046

Comparative E2
0.9138
1.56
24.1
1.26
0.006
0.007
0.019

Comparative E
0.9144
1.49
25.6
1.29
0.004
0.005
0.024

Comparative J
0.9151
4.2
21.8
1.2
0.006
0.002
0.024

Comparative C
0.9161
1
30.5
1.35
0.004
0.004
0.030

Comparative B
0.9179
1.01
30.2
1.33
0.004
0.002
0.025

Comparative H2
0.9189
0.89
30.6
1.36
0.004
0.002
0.021

Comparative H
0.9191
0.9
29.6
1.34
0.004
0.003
0.020

Comparative I
0.9415
0.87
62
1.61
0.002
0.000
0.025

Comparative G
0.9612
0.89
49
1.58
0.000
0.000
0.023

TABLE 5B

Additional unsaturation data of several embodiments of the disclosed

ethylene interpolymers; as determined by ASTM D3124-98 and ASTM D6248-98.

Density
Melt Index
Melt Flow

Unsaturations per 100 C.

Sample Code
(g/cm³)
I₂(dg/min)
Ratio (I₂₁/I₂)
S. Ex.
Internal
Side Chain
Terminal

Example 8
0.9176
4.64
27.2
1.25
0.009
0.001
0.048

Example 42
0.9176
0.99
23.9
1.23
0.007
0.006
0.046

Example 102
0.9176
0.97
22.6
1.24
0.007
0.005
0.044

Example 54
0.9176
0.94
29.9
1.29
0.009
0.002
0.049

Example 41
0.9178
0.93
23.8
1.23
0.007
0.006
0.046

Example 44
0.9179
0.93
23.4
1.23
0.007
0.007
0.045

Example 9
0.9190
0.91
40.3
1.38
0.008
0.003
0.052

Example 200
0.9250
1.04
24.2
1.24
0.006
0.005
0.050

Example 60
0.9381
4.57
22.2
1.23
0.005
0.002
0.053

Example 61
0.9396
4.82
20.2
1.23
0.002
0.002
0.053

Example 62
0.9426
3.5
25.4
1.26
0.002
0.002
0.052

Example 70
0.9468
1.9
32.3
1.34
0.001
0.002
0.042

Example 71
0.9470
1.61
34.8
1.35
0.001
0.001
0.048

Example 72
0.9471
1.51
31.4
1.34
0.001
0.002
0.043

Example 73
0.9472
1.51
31.6
1.35
0.001
0.002
0.047

Example 80
0.9528
1.53
41.1
1.38
0.002
0.000
0.035

Example 81
0.9533
1.61
50
1.43
0.002
0.000
0.044

Example 82
0.9546
1.6
59.6
1.5
0.001
0.000
0.045

Example 90
0.9588
7.51
29
1.28
0.001
0.000
0.042

Example 91
0.9589
6.72
30.4
1.29
0.002
0.000
0.041

Example 20
0.9596
1.21
31.3
1.35
0.002
0.001
0.036

Example 21
0.9618
1.31
38.3
1.39
0.002
0.001
0.037

Example 22
0.9620
1.3
51
1.49
0.002
0.001
0.041

Example 23
0.9621
0.63
78.9
1.68
0.002
0.001
0.042

Example 24
0.9646
1.98
83
1.79
0.001
0.001
0.052

TABLE 6A

Neutron Activation Analysis (NAA) catalyst residues in several

embodiments of the disclosed ethylene interpolymers, as well as

Comparatives G, I, J, B, C, E, E2, H and H2.

N.A.A. Elemental

Density
Melt Index I₂
Analysis (ppm)

Sample Code
(g/cm³)
(dg/min)
Ti
Mg
Cl
Al

Example 60
0.9381
4.57
9.0
140
284
127

Example 62
0.9426
3.50
9.2
179
358
94

Example 70
0.9468
1.90
6.2
148
299
99

Example 71
0.9470
1.61
6.8
168
348
87

Example 72
0.9471
1.51
5.8
178
365
88

Example 73
0.9472
1.51
7.2
142
281
66

Example 80
0.9528
1.53
4.3
141
288
82

Example 81
0.9533
1.61
6.4
163
332
82

Example 82
0.9546
1.60
5.8
132
250
95

Example 90
0.9588
7.51
6.7
143
286
94

Example 91
0.9589
6.72
6.7
231
85
112

Example 1
0.9169
0.88
6.1
199
99
97

Example 2
0.9160
1.04
7.4
229
104
112

Example 3
0.9164
0.90
7.3
268
137
129

Comparative G
0.9612
0.89
1.6
17.2
53
11

Comparative I
0.9415
0.87
2.3
102
24
53

Comparative J
0.9151
4.20
1.4
<2
0.6
7.9

Comparative B
0.9179
1.01
0.3
13.7
47
9.3

Comparative C
0.9161
1.00
2.0
9.0
25
5.4

Comparative E2
0.9138
1.56
1.2
9.8
32.2
6.8

Comparative E
0.9144
1.49
1.3
14.6
48.8
11.3

Comparative H
0.9191
0.90
2.2
14.6
48.8
11.3

Comparative H2
0.9189
0.89
2.2
253
122
130

TABLE 6B

Additional Neutron Activation Analysis (NAA) catalyst residues

in several embodiments of the disclosed ethylene interpolymers.

N.A.A. Elemental

Density
Melt Index I₂
Analysis (ppm)

Sample Code
(g/cm³)
(dg/min)
Ti
Mg
Cl
Al

Example 4
0.9154
0.97
9.6
287
45
140

Example 5
0.9163
1.04
6.7
261
70
131

Example 6
0.9152
0.67
5.2
245
48
119

Example 7
0.9155
0.70
7.7
365
102
177

Example 8
0.9176
4.64
7.6
234
86
117

Example 9
0.9190
0.91
6.4
199
78
99

Example 51
0.9165
1.01
5.9
207
73
106

Example 52
0.9169
0.85
5.2
229
104
112

Example 53
0.9164
0.90
7.3
347
101
167

Example 54
0.9176
0.94
7.5
295
100
146

Example 55
0.9170
0.91
7.1
189
101
90

Example 41
0.9178
0.93
7.2
199
103
92

Example 42
0.9176
0.99
7.5
188
104
86

Example 43
0.9174
1.08
7.4
192
101
91

Example 44
0.9179
0.93
7.2
230
121
110

Example 102
0.9176
0.97
9.5
239
60
117

Example 115
0.9171
0.75
5.1
258
115
130

Example 61
0.9396
4.82
8.3
352
96
179

Example 10
0.9168
0.94
7.8
333
91
170

Example 120
0.9204
1.00
7.3
284
75
149

Example 130
0.9232
0.94
5.8
292
114
147

Example 131
0.9242
0.95
8.6
81.4
173
94

Example 200
0.9250
1.04
6.3
90.1
190
104