For convenient description, standard golf illumination is defined herein as illumination associated with common outdoor playing conditions in natural lighting, i.e., full sun, partial sun, partial shade, full shade, and overcast conditions at times a few hours after sunrise and a few hours before sunset.

In certain embodiments, a golf ball surface may have at least a first color or a second color having a CIELab lightness (L) of 0 to 100, more particularly 0 to 30, 30 to 60, or 60 to 90, a CIELab “a” value of −100 to 100, more particularly −90 to −20, −20 to 20, or 20 to 90, and a CIELab b value of −100 to 100, more particularly 40 to 90, −40 to 40, or −40 to −90. The first or second color may be a white blue, green yellow, orange, pink, red, purple, blue, or turquoise

In certain embodiments, a golf ball surface may have at least a first contrasting color and a second contrasting color wherein the absolute value difference between CIELab L values for the first contrasting color and the second contrasting color is at between 1 and 15, between 3 and 12, between 4 and 11, between 5 and 10, between 30 and 90, between 40 and 80, between 50 and 70, between 55 and 65, 25 and 75, between 30 and 70, between 40 and 60, or between 45 and 55. In certain embodiments, a golf ball surface may have at least a first contrasting color and a second contrasting color wherein the absolute value difference between CIELab “a” values for the first contrasting color and the second contrasting color is at between 0.1 and 10, between 0.2 and 7, between 0.3 and 5, between 3 and 20, between 5 and 18, between 10 and 15, between 20 and 60, between 30 and 50, or between 35 and 45. In certain embodiments, a golf ball surface may have at least a first contrasting color and a second contrasting color wherein the absolute value difference between CIELab b values for the first contrasting color and the second contrasting color is between 3 and 12, between 4 and 11, between 5 and 10 between 50 and 100, between 60 and 95, between 70 and 95, between 5 and 50, between 10 and 40, or between 15 and 30.

In one embodiment, predominant white color of the golf ball has a CIELab lightness (L) of between 80 to 100, more particularly between 85 to 99, or between 90 to 99, a CIELab “a” value of between −5 to 0, more particularly between −4 to 0, and a CIELab b value of between −10 to 0, more particularly between −9 to 0, or between −8 to −2. The base color or predominant color may be white, black, red, yellow, blue, green, orange, purple, or any primary, secondary, or tertiary color or combination of any of the above.

In certain embodiments, the first color or second color may have a CIELab lightness (L) of 15 to 35, more particularly 20 to 30 or 25 to 30, a CIELab “a” value of −2.9 to 3, more particularly −2.5 to 1, and a CIELab b value of −1 to 10, more particularly 0 to 5 or 0 to 3. In another embodiment, the first or a second color may have a CIELab lightness (L) of 60 to 100, more particularly 70 to 90, or 75 to 85, a CIELab “a” value of 5 to 15, more particularly 8 to 12, or 9 to 11, and a CIELab b value of 60 to 100, more particularly 70 to 90, or 75 to 85. In yet another embodiment, the first or second color may have a CIELab lightness (L) of 30 to 50, more particularly 36 to 45, or 38 to 42, a CIELab “a” value of 30 to 50, more particularly 35 to 45, or 38 to 42, and a CIELab b value of 10 to 20, more particularly 12 to 18 or 13 to 15.

In certain embodiments, the first and second color may be a first contrasting color and a second contrasting color wherein the absolute value difference between CIELab L values for the first contrasting color and the second contrasting color is at between 5 to 70, between 10 to 60, or more particularly between 10 to 55. In certain embodiments, the first contrasting color and a second contrasting color can have an absolute value difference between CIELab “a” values for the first non-white or contrasting color and the second non-white or contrasting color is at between 3 and 50, between 5 and 45, or more particularly between 6 and 42. In certain embodiments, the first color and second color may be a first contrasting color and a second contrasting color wherein the absolute value difference between CIELab b values for the first contrasting color and the second contrasting color is between 5 and 90, between 10 and 85, or more particularly between 10 and 80.

In one embodiment, the ΔE*ab values are measured from the first color which can be a dominant white color of the golf ball or a base color that can be white or non-white. In another embodiment, the ΔE*ab is calculated for the second color utilizing the first color as the target color or specimen.

The value of ΔE*ab is calculated according the below equation in Eq. 1:

ΔE*ab=√(ΔL)2+(Δa)2+(Δb)2 Eq.1

Where

- ΔL is the lightness difference between the first color and the specimen having the second color being evaluated; and
- Δa, Δb are differences of the CIE 1976 a*and b*co-ordinates, respectively.

The ΔE*ab values for the second color can be either Black 3C or Black C relative to the first color of the golf ball. In one embodiment, the ΔE*ab of the second color relative to the first color is between 40 and 80, between 50 and 70, or between 55 and 65.

In one embodiment, the ΔE*ab value of the second color is between 70 and 110, between 80 and 100 or between 85 and 95 relative to the first color. In yet another embodiment, the ΔE*ab value of the second color is between 80 and 110, between 85 and 105, or between 90 and 100 when the target color is the first color.

In one embodiment, the ΔE*ab value of the second color is between 50 and 90, between 60 and 80 or between 65 and 75 relative to the first color. In yet another embodiment, the ΔE*ab value of a third color is between 25 and 55, between 30 and 50, or between 35 and 45 when the target color is the first color. In yet another embodiment, the ΔE*ab value of the third color is between 65 and 95, between 70 and 90, or between 75 and 85 when the target color is the second color.

In one embodiment where the ball has a base first color and at least two stripes containing a second color and a third color, the ΔE*ab values of the second and third color relative to the first color of the ball are between 40 and 100, between 50 and 95, or between 60 and 95. In one embodiment, the ΔE*ab values of the second and third color relative to the first color of the ball are between 30 and 110, between 35 and 98, or between 40 and 97. In some embodiments, where the golf ball has two colors or more, such as two to ten colors, or three to ten colors, the ΔE*ab values of all the image colors relative to the base color of the ball are between 40 and 100, between 50 and 95, or between 60 and 95.

The multi-color cover layer facilitates visibility of the ball. For example, a first color may enhance ball visibility in low visibility playing light, a second color may enhance ball visibility in medium visibility playing light, a third color may enhance ball visibility in high visibility playing light.

In the embodiments shown in FIG. 1, the boundary between first surface area portion, and the second surface area portion provide enhanced putting feedback by providing the golfer with a contrasting line of color to align with alignment aides located on the golf club. Similarly, in the embodiments shown in FIGS. 2A-2C and 3A-3D, the circumferential stripe(s) provide enhanced putting feedback by allowing the golfer to align such stripes with similar or identical markings located on the golf club.

The circumferential stripe(s) also functions as a contrasting alignment feature allowing the golfer to more easily align the ball prior to impact with a golf club. For example, in the embodiment shown in FIG. 3D the center circumferential stripe can be aligned with an alignment mark provided on a putter head. In some embodiments, the alignment color and line width and spacing between the lines on the golf ball is identical to the alignment color, line width and spacing between the lines on the putter head.

Castable Polyurethane or Polyurea Compositions, and Methods of Making, for the Multi-Color Cover Layer

In certain embodiments, the cast polyurethane or polyurea cover composition is a thermoset polyurethane or polyurea or a thermoplastic polyurethane or polyurea. In certain embodiments, the cast polyurethane or polyurea is the only polymer present in the cover layer.

Polyurethanes or polyureas typically are prepared by reacting a diisocyanate with a polyol (in the case of polyurethanes) or with a polyamine (in the case of a polyurea). Thermoplastic polyurethanes or polyureas may consist solely of this initial mixture or may be further combined with a chain extender to vary properties such as hardness of the thermoplastic. Thermoset polyurethanes or polyureas typically are formed by the reaction of a diisocyanate and a polyol or polyamine respectively, and an additional crosslinking agent to crosslink or cure the material to result in a thermoset.

A two-step process may occur in which the first step involves reacting the diisocyanate and the polyol (in the case of polyurethane) or the polyamine (in the case of a polyurea) to form a so-called prepolymer, to which can then be added either the chain extender or the curing agent. This procedure is known as the prepolymer process.

In addition, although depicted as discrete component packages as above, it is also possible to control the degree of crosslinking, and hence the degree of thermoplastic or thermoset properties in a final composition, by varying the stoichiometry not only of the diisocyanate-to-chain extender or curing agent ratio, but also the initial diisocyanate-to-polyol or polyamine ratio. Of course in the prepolymer process, the initial diisocyanate-to-polyol or polyamine ratio is fixed on selection of the required prepolymer.

In certain embodiments, the cast thermoset polyurethane cover composition is made by reacting together at least one polyurethane prepolymer, at least one diol or polyol, at least one diamine chain extender, at least one curing catalyst, and at least one color additive. Optional ingredients for inclusion in the composition include at least one UV inhibitor.

The amount of polyurethane prepolymer included in the castable cover composition may range from 50 to 95%, more particularly 70% to 92%.

The amount of diol or polyol included in the castable cover composition may range between 0% to 30%, more particularly between 0% to 10%.

The amount of diamine included in the castable cover composition may range from 5% to 30%, more particularly 6% to 20%.

The amount of UV inhibitor included in the castable cover composition may range from between 0% to 5%, more particularly between 0.5% to 3%.

The amount of curing catalyst included in the castable cover composition may range from between 0% to 5%, more particularly between 0.5% to 3%.

In certain embodiments, the color additive(s) may be included in a liquid color concentrate that includes at least one ingredient in addition to the color additive. The additional ingredient may be, for example, a plasticizer and/or polyol, pigment(s), surfactants, solvents, functional additives, thickeners, and UV stabilizers. The color concentrate may be added to any of the ingredient(s) of the castable composition prior to, or during, casting. The amount of color concentrate in the cover composition may range from between 0 to 5%, more particularly between 1% to 4%, or more particularly between 2% to 3%.

Illustrative polyurethane prepolymers include those made by reacting an isocyanate and a diol or polyol.

Isocyanates include, but are not limited to, aliphatic, cycloaliphatic, aromatic aliphatic, aromatic, any derivatives thereof, and combinations of these compounds having two or more isocyanate (NCO) groups per molecule. As used herein, aromatic aliphatic compounds should be understood as those containing an aromatic ring, wherein the isocyanate group is not directly bonded to the ring. One example of an aromatic aliphatic compound is a tetramethylene diisocyanate (TMXDI). The isocyanates may be organic polyisocyanate-terminated prepolymers, low free isocyanate prepolymer, and mixtures thereof. The isocyanate-containing reactable component also may include any isocyanate-functional monomer, dimer, trimer, or polymeric adduct thereof, prepolymer, quasi-prepolymer, or mixtures thereof. Isocyanate-functional compounds may include monoisocyanates or polyisocyanates that include any isocyanate functionality of two or more.

Suitable isocyanate-containing components include diisocyanates having the generic structure: O═C═N—R—N═C═O, where R preferably is a cyclic, aromatic, or linear or branched hydrocarbon moiety containing from about 1 to about 50 carbon atoms. The isocyanate also may contain one or more cyclic groups or one or more phenyl groups. When multiple cyclic or aromatic groups are present, linear and/or branched hydrocarbons containing from about 1 to about 10 carbon atoms can be present as spacers between the cyclic or aromatic groups. In some cases, the cyclic or aromatic group(s) may be substituted at the 2-, 3-, and/or 4-positions, or at the ortho-, meta-, and/or para-positions, respectively. Substituted groups may include, but are not limited to, halogens, primary, secondary, or tertiary hydrocarbon groups, or a mixture thereof.

Examples of isocyanates that can be used with the present invention include, but are not limited to, substituted and isomeric mixtures including 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate (MDI); 3,3′-dimethyl-4,4′-biphenylene diisocyanate (TODI); toluene diisocyanate (TDI); polymeric MDI; carbodiimide-modified liquid 4,4′-diphenylmethane diisocyanate; para-phenylene diisocyanate (PPDI); meta-phenylene diisocyanate (MPDI); triphenyl methane-4,4′- and triphenyl methane-4,4″-triisocyanate; naphthylene-1,5-diisocyanate; 2,4′-, 4,4′-, and 2,2-biphenyl diisocyanate; polyphenylene polymethylene polyisocyanate (PMDI) (also known as polymeric PMDI); mixtures of MDI and PMDI; mixtures of PMDI and TDI; ethylene diisocyanate; propylene-1,2-diisocyanate; trimethylene diisocyanate; butylenes diisocyanate; bitolylene diisocyanate; toluidine diisocyanate; tetramethylene-1,2-diisocyanate; tetramethylene-1,3-diisocyanate; tetramethylene-1,4-diisocyanate; pentamethylene diisocyanate; 1,6-hexamethylene diisocyanate (HDI); octamethylene diisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; diethylidene diisocyanate; methylcyclohexylene diisocyanate (HTDI); 2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate; 1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexane diisocyanate; 4,4′-bis(isocyanatomethyl) dicyclohexane; 2,4′-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate (IPDI); dimeryl diisocyanate, dodecane-1,12-diisocyanate, 1,10-decamethylene diisocyanate, cyclohexylene-1,2-diisocyanate, 1,10-decamethylene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, furfurylidene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,3-cyclobutane diisocyanate, 1,4-cyclohexane diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), 4,4′-methylenebis(phenyl isocyanate), 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis (isocyanato-methyl)cyclohexane, 1,6-diisocyanato-2,2,4,4-tetra-methylhexane, 1,6-diisocyanato-2,4,4-tetra-trimethylhexane, trans-cyclohexane-1,4-diisocyanate, 3-isocyanato-methyl-3,5,5-trimethylcyclo-hexyl isocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclohexyl isocyanate, dicyclohexylmethane 4,4′-diisocyanate, 1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate, m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylene diisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, metaxylene diisocyanate, 2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate, 4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 1, 3-xylylene diisocyanate, 1,4-naphthylene diisocyanate, azobenzene-4,4′-diisocyanate, diphenyl sulfone-4,4′-diisocyanate, triphenylmethane 4,4′,4″-triisocyanate, isocyanatoethyl methacrylate, 3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylene diisocyanate, ω,ω′-diisocyanato-1,4-diethylbenzene, polymethylene polyphenylene polyisocyanate, isocyanurate modified compounds, and carbodiimide modified compounds, as well as biuret modified compounds of the above polyisocyanates. These isocyanates may be used either alone or in combination. These combination isocyanates include triisocyanates, such as biuret of hexamethylene diisocyanate and triphenylmethane triisocyanates, and polyisocyanates, such as polymeric diphenylmethane diisocyanate.triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate (TMDI); 4,4′-dicyclohexylmethane diisocyanate (H₁₂MDI); 2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate; 1,2-, 1,3-, and 1,4-phenylene diisocyanate; aromatic aliphatic isocyanate, such as 1,2-, 1,3-, and 1,4-xylene diisocyanate; meta-tetramethylxylene diisocyanate (m-TMXDI); para-tetramethylxylene diisocyanate (p-TMXDI); trimerized isocyanurate of any polyisocyanate, such as isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, trimer of tetramethylxylene diisocyanate, isocyanurate of hexamethylene diisocyanate, and mixtures thereof, dimerized uretdione of any polyisocyanate, such as uretdione of toluene diisocyanate, uretdione of hexamethylene diisocyanate, and mixtures thereof; modified polyisocyanate derived from the above isocyanates and polyisocyanates; and mixtures thereof.

In certain embodiments, the isocyanate is toluene diisocyanate.

Polyols used for making the polyurethane in the copolymer include polyester polyols, polyether polyols, polycarbonate polyols and polybutadiene polyols. Polyester polyols are prepared by condensation or step-growth polymerization utilizing diacids. Primary diacids for polyester polyols are adipic acid and isomeric phthalic acids. Adipic acid is used for materials requiring added flexibility, whereas phthalic anhydride is used for those requiring rigidity. Some examples of polyester polyols include poly(ethylene adipate) (PEA), poly(diethylene adipate) (PDA), poly(propylene adipate) (PPA), poly(tetramethylene adipate) (PBA), poly(hexamethylene adipate) (PHA), poly(neopentylene adipate) (PNA), polyols composed of 3-methyl-1,5-pentanediol and adipic acid, random copolymer of PEA and PDA, random copolymer of PEA and PPA, random copolymer of PEA and PBA, random copolymer of PHA and PNA, caprolactone polyol obtained by the ring-opening polymerization of ε-caprolactone, and polyol obtained by opening the ring of β-methyl-δ-valerolactone with ethylene glycol can be used either alone or in a combination thereof. Additionally, polyester polyol may be composed of a copolymer of at least one of the following acids and at least one of the following glycols. The acids include terephthalic acid, isophthalic acid, phthalic anhydride, oxalic acid, malonic acid, succinic acid, pentanedioic acid, hexanedioic acid, octanedioic acid, nonanedioic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (a mixture), ρ-hydroxybenzoate, trimellitic anhydride, ε-caprolactone, and β-methyl-δ-valerolactone. The glycols include ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylene glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexane dimethanol, pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening addition polymerization of an alkylene oxide (e.g. ethylene oxide and propylene oxide) with an initiator of a polyhydric alcohol (e.g. diethylene glycol), which is an active hydride. Specifically, polypropylene glycol (PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxide copolymer can be obtained. Polytetramethylene ether glycol (PTMG) is prepared by the ring-opening polymerization of tetrahydrofuran, produced by dehydration of 1,4-butanediol or hydrogenation of furan. Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically, tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethylene oxide copolymer can be formed. A polyether polyol may be used either alone or in a mixture.

Polycarbonate polyol is obtained by the condensation of a known polyol (polyhydric alcohol) with phosgene, chloroformic acid ester, dialkyl carbonate or diallyl carbonate. A particularly preferred polycarbonate polyol contains a polyol component using 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentylglycol or 1,5-pentanediol. A polycarbonate polyol can be used either alone or in a mixture.

Polybutadiene polyol includes liquid diene polymer containing hydroxyl groups, and an average of at least 1.7 functional groups, and may be composed of diene polymer or diene copolymer having 4 to 12 carbon atoms, or a copolymer of such diene with addition to polymerizable α-olefin monomer having 2 to 2.2 carbon atoms. Specific examples include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethyl hexyl acrylate copolymer, and butadiene-n-octadecyl acrylate copolymer. These liquid diene polymers can be obtained, for example, by heating a conjugated diene monomer in the presence of hydrogen peroxide in a liquid reactant. A polybutadiene polyol can be used either alone or in a mixture.

Diisocyanate and polyol or polyamine components may be combined to form a prepolymer prior to reaction with a chain extender or curing agent. Any such prepolymer combination is suitable for use in the present invention. Commercially available prepolymers include LFH580, LFH120, LFH710, LFH1570, LF930A, LF950A, LF601D, LF751D, LFG963A, LFG640D.

One preferred prepolymer is a toluene diisocyanate prepolymer with polypropylene glycol. Such polypropylene glycol terminated toluene diisocyanate prepolymers are available from Uniroyal Chemical Company of Middlebury, Conn., under the trade name ADIPRENE® LFG963A and LFG640D. Most preferred prepolymers are the polytetramethylene ether glycol terminated toluene diisocyanate prepolymers including those available from Uniroyal Chemical Company of Middlebury, Conn., under the trade name ADIPRENE® LF930A, LF950A, LF601D, and LF751D.

In one embodiment, the number of free NCO groups in the urethane or urea prepolymer may be less than about 14 percent. Preferably the urethane or urea prepolymer has from about 3 percent to about 11 percent, more preferably from about 4 to about 9.5 percent, and even more preferably from about 3 percent to about 9 percent, free NCO on an equivalent weight basis.

The polyurethane also may incorporate chain extenders. Non-limiting examples of these extenders include polyols, polyamine compounds, and mixtures of these. Polyol extenders may be primary, secondary, or tertiary polyols. Specific examples of monomers of these polyols include: trimethylolpropane (TMP), ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, and 2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

Suitable polyamines that may be used as chain extenders include primary, secondary and tertiary amines; polyamines have two or more amines as functional groups. Examples of these include: aliphatic diamines, such as tetramethylenediamine, pentamethylenediamine, hexamethylenediamine; alicyclic diamines, such as 3,3′-dimethyl-4,4′-diamino-dicyclohexyl methane; or aromatic diamines, such as 4,4′-methylene bis-2-chloroaniline, 2,2′,3,3′-tetrachloro-4,4′-diaminophenyl methane, p,p′-methylenedianiline, p-phenylenediamine or 4,4′-diaminodiphenyl; and 2,4,6-tris(dimethylaminomethyl) phenol. Aromatic diamines have a tendency to provide a stiffer product than aliphatic or cycloaliphatic diamines. A chain extender may be used either alone or in a mixture.

In certain embodiments, a diamine chain extender and a diol chain extender are both included in the composition.

In certain embodiments, the diamine is 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, or a mixture thereof. In certain embodiments, the diol is 1,4-butanediol.

The color additive may be a pigment or a dye. Illustrative color additives include materials that include at least one metal-containing ingredient. In certain embodiments the metal-containing ingredient is or includes a transition metal element, a post transition metal element, a metalloid element, or a mixture thereof. Illustrative transition elements include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Hf, Ta, W, Re, Os, Ir, Pt, Au and Hg. Illustrative post transition elements include Al, Ga, Ge, In, Sn, Sb, Tl, Pb, Bi, and Po. Illustrative metalloid elements include B, Si, Ge, As, Sb, Te, and to a lesser extent C, Se, Po, At. In certain embodiments, the metal-containing ingredient is a transition metal oxide, transition metal halide, transition metal hydrate or transition metal phosphate. In certain embodiments, the post transition metal compound is a post transition metal oxide, post transition metal halide, post transition metal hydrate or post transition metal phosphate. Particularly preferred metal-containing ingredients include titanium dioxide, manganese oxide (Mn₂O₃), iron (III) oxide, zinc oxide, aluminum oxide (Al₂O₃), bismuth aluminate hydrate and aluminum phosphate.

In certain embodiments the metal-containing ingredient is mixed metal oxide. The mixed metal oxide may be a mixed metal oxide pigment. Mixed metal oxide pigments are compounds comprised of a group of two or more metals and oxygen. The most common crystal structures are rutile (MeO₂) hematite (Me₂O₃) or spinel (Me₃O₄). Metals commonly present include: cobalt, iron, trivalent chrome, tin, antimony, titanium, manganese and aluminum.

Depending on their chemical structure, curing agents may be slow- or fast-reacting polyamines or polyols. As described in U.S. Pat. Nos. 6,793,864, 6,719,646 and copending U.S. Patent Publication No. 2004/0201133 A1, (the contents of all of which are hereby incorporated herein by reference), slow-reacting polyamines are diamines having amine groups that are sterically and/or electronically hindered by electron withdrawing groups or bulky groups situated proximate to the amine reaction sites. The spacing of the amine reaction sites will also affect the reactivity speed of the polyamines.

Suitable curatives for use in the present invention are selected from the slow-reacting polyamine group include, but are not limited to, 3,5-dimethylthio-2,4-toluenediamine; 3,5-dimethylthio-2,6-toluenediamine; N,N′-dialkyldiamino diphenyl methane; trimethylene-glycol-di-p-aminobenzoate; polytetramethyleneoxide-di-p-aminobenzoate, and mixtures thereof. Of these, 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine are isomers and are sold under the trade name ETHACURE® 300 by Ethyl Corporation. Trimethylene glycol-di-p-aminobenzoate is sold under the trade name POLACURE 740M and polytetramethyleneoxide-di-p-aminobenzoates are sold under the trade name POLAMINES by Polaroid Corporation. N,N′-dialkyldiamino diphenyl methane is sold under the trade name UNILINK® by UOP.

When slow-reacting polyamines are used as the chain extender, a catalyst is typically needed to promote the reaction between the urethane prepolymer and the chain extender. Specific suitable catalysts include TEDA (1) dissolved in di-propylene glycol (such as TEDA L33 available from Witco Corp. Greenwich, Conn., and DABCO 33 LV available from Air Products and Chemicals Inc.). Catalysts are added at suitable effective amounts, such as from about 2% to about 5%, and (2) more preferably TEDA dissolved in 1,4-butane diol from about 2% to about 5%. Another suitable catalyst includes a blend of 0.5% 33LV or TEDA L33 (above) with 0.1% dibutyl tin dilaurate (available from Witco Corp. or Air Products and Chemicals, Inc.) which is added to a curative such as VIBRACURE® A250. Unfortunately, as is well known in the art, the use of a catalyst can have a significant effect on the ability to control the reaction and thus, on the overall processability.

To eliminate the need for a catalyst, a fast-reacting curing agent, or agents, can be used that does not have electron withdrawing groups or bulky groups that interfere with the reaction groups. However, the problem with lack of control associated with the use of catalysts is not completely eliminated since fast-reacting curing agents also are relatively difficult to control.

Preferred curing agent blends include using dicyandiamide in combination with fast curing agents such as diethyl-2,4-toluenediamine, 4,4″-methylenebis-(3-chloro,2,6-diethyl)-aniline (available from Air Products and Chemicals Inc., of Allentown, Pa., under the trade name LONZACURE®), 3,3′-dichlorobenzidene; 3,3′-dichloro-4,4′-diaminodiphenyl methane (MOCA); N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine and Curalon L, a trade name for a mixture of aromatic diamines sold by Uniroyal, Inc. or any and all combinations thereof. A preferred fast-reacting curing agent is diethyl-2,4-toluene diamine, which has two commercial grades names, Ethacure® 100 and Ethacure® 100LC commercial grade has lower color and less by-product. In other words, it is considered a cleaner product to those skilled in the art.

Advantageously, the use of the Ethacure® 100LC commercial grade results in a golf ball that is less susceptible to yellowing when exposed to UV light conditions. A player appreciates this desirable aesthetic effect although it should be noted that the instant invention may use either of these two commercial grades for the curing agent diethyl-2,4-toluenediamine.

If a reduced-yellowing post curable composition is required, the chain extender or curing agent can further comprise a peroxide or peroxide mixture. Before the composition is exposed to sufficient thermal energy to reach the activation temperature of the peroxide, the composition of (a) and (b) behaves as a thermoplastic material. Therefore, it can readily be formed into golf ball layers using injection molding. However, when sufficient thermal energy is applied to bring the composition above the peroxide activation temperature, crosslinking occurs, and the thermoplastic polyurethane is converted into crosslinked polyurethane.

Examples of suitable peroxides for use in compositions within the scope of the present invention include aliphatic peroxides, aromatic peroxides, cyclic peroxides, or mixtures of these. Primary, secondary, or tertiary peroxides can be used, with tertiary peroxides most preferred. Also, peroxides containing more than one peroxy group can be used, such as 2,5-bis-(tert-butylperoxy)-2,5-dimethyl hexane and 1,4-bis-(tert-butylperoxy-isopropyl)-benzene. Also, peroxides that are either symmetrical or asymmetric can be used, such as tert-butylperbenzoate and tert-butylcumylperoxide. Additionally, peroxides having carboxy groups also can be used. Decomposition of peroxides used in compositions within the scope of the present invention can be brought about by applying thermal energy, shear, reactions with other chemical ingredients, or a combination of these. Homolytically decomposed peroxide, heterolytically decomposed peroxide, or a mixture of those can be used to promote crosslinking reactions in compositions within the scope of this invention. Examples of suitable aliphatic peroxides and aromatic peroxides include diacetylperoxide, di-tert-butylperoxide, dibenzoylperoxide, dicumylperoxide, 2,5-bis-(t-butylperoxy)-2,5-dimethyl hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(butylperoxy)-3-hexyne, n-butyl-4,4-bis(t-butylperoxyl) valerate, 1,4-bis-(t-butylperoxyisopropyl)-benzene, t-butyl peroxybenzoate, 1,1-bis-(t-butylperoxy)-3,3,5 tri-methylcyclohexane, and di(2,4-dichloro-benzoyl). Peroxides for use within the scope of this invention may be acquired from Akzo Nobel Polymer Chemicals of Chicago, Illinois, Atofina of Philadelphia, Pennsylvania and Akrochem of Akron, Ohio. Further details of this post curable system are disclosed in U.S. Pat. No. 6,924,337, the entire contents of which are hereby incorporated by reference.

Casting (also called “cast-molding”) is performed in a ball cavity formed by bringing together two mold halves that define respective hemispherical cavities. Casting is especially suitable for forming the cover of a thermoset material. A precise amount of liquid thermoset resin is introduced into the hemispherical cavities and partially cured (“gelled”). The core is placed in the hemispherical cavity of one mold half and supported by the partially cured resin. The second mold half is placed relative to the first mold half to enclose the core and resin in the resulting ball cavity. As the mold halves are brought together, the resin flows around the core and forms the cover. The mold body is heated briefly to cure the resin, and then cooled for removal of the ball from the mold body. Advantages of casting are that it achieves substantial uniformity of cover thickness without having to use centering pins, and it can be performed at a much lower pressure inside the mold than injection molding or compression molding. In one embodiment, a multi-colored ball is produced using co-injection molding with a hot runner process.

In one embodiment having a color contrast between the two halves in the finished golf ball (see, for example, the embodiment shown in FIG. 1), a first color-containing composition is dispensed in the hemispherical cavity of a first mold half, the first color-containing composition is partially cured, the core is placed in the hemispherical cavity of the first mold half and supported by the partially cured resin. A second color-containing composition is dispensed in the hemispherical cavity of a second mold half, and the mold halves are brought together. The mold body is heated to cure the both of the color-containing compositions, and then cooled for removal of the ball from the mold body. The ball will have one half that presents the first color and a second half that presents the second color. Dispensing the substantially different color urethane halves can be achieved with two separate dispensers which would each include a mixing section where the prepolymer and curative come together prior to dispensing into the cavity half. Since the same prepolymer is used in the first and second ball halves and the color is typically added on the curative side a single dispenser option is a possible alternative. An electro-mechanical Y-valve on the curative side prior to the mixing section would enable two curatives with different colors to be used and dispense the first color and the second color at predetermined sequences.

Printing Processes

In certain embodiments, it is possible that the parting line between the first color and the second color won't be precise and linear because there may be a small amount of mixing between the two colors at the parting line/seam, or if a seamless dimple design is used. To create a linear intersection between the two colors another high contrast color or visible marking can be placed on the ball as shown, for example, in FIGS. 2A-2C. This can be accomplished with a paint-and-mask process, but preferably a printing process is used. To achieve an even linear marking the ball may be set in a fixture using positioning equipment so the marking would be applied to the parting line. To achieve the appearance of a continuous line, a series of images can be applied using the pad printing process and rotating the golf ball between the application of each stamp. Another option is rotary pad printing where a rotating pad and golf ball come together and the image is applied to the golf ball continuously. Yet another option is single pass inkjet technology where the oriented golf ball passes under or next to a printing head and rotates at a predetermined speed to apply a continuous image at the parting line.

With single pass industrial inkjet printers, a golf product passes below or adjacent to a series of print heads only once, producing high throughput speeds for mass production. In one embodiment, single pass inkjet systems are able to run at extremely high speeds, up to 50 inches per second and higher.

In order to increase resolution of a printed image in the lateral sense, it is possible to add additional print heads in the print direction and offset them by a certain number of pixels to double or triple the DPI in the in track while running at maximum speed. The print width can also be increased by adding print heads in the cross track to increase the print swath by a factor of the print head width.

In one embodiment, the single pass inkjet printers consist of WW+CYMK. It is also possible to vastly expand the color gamut with the addition of print heads having Orange, Green, and Violet.

In one embodiment, the item being printed upon can be pre-treated with a means to apply a charge to the surface to improve ink adhesion. Some examples of pretreatment methods include corona discharge, flame, or plasma pretreatment.

Golf articles other than golf balls can be printed upon using the single pass printing processes disclosed herein. Other golf articles include, but are not limited to: metal/wood golf clubs, iron golf clubs, putter golf clubs, golf club face inserts, golf club sole plates, alignment aides, custom colors on the golf club head, rangefinders, hats, golf bags, steel shafts, composite shafts, shaft regions located near the club head, golf grips, golf headcovers, golf face plates or face polymer coatings, golf club topline alignment peels, golf club weights, thermoplastic or thermoset components such as club inserts, metal ring components to a golf club head, golf club badges on irons or metal/woods, hybrid clubs, composites, metals, plastics, or golf club wedges. Logos, trademarks, technology names, face scorelines, custom images, club numbers or other indicia located on the club can be printed using the methods described herein.

FIG. 4 illustrates a single pass printer head 402 and a golf ball 400 located in a ball holder 416 having a printed area 404. The ball holder 416 is connected to a digital encoder 420 that tracks the precise orientation of the golf ball 400 during rotation 412. In one example, the ball can be held by a top cup (not shown) in addition to the ball holder 416. The golf ball 400 rotates 412 about a vertical rotation axis 406 at a rate of rotation while ink droplets 408 are emitted from the printer head 402. The throw distance 410 is defined as the distance between the closest point 414 on the golf ball 404 and the closest point on the printer head 402. In other words, with a relatively flat printer head 402 and a spherical-like ball 400, the throw distance 410 is the minimum distance between the golf ball 400 and the printer head 402. In one embodiment, the throw distance 410 is between 0 mm to 10 mm, between 0.5 mm and 1.5 mm, between 0.1 mm to 7 mm, or between 0.1 and 5 mm.

In one embodiment, the distance the ink droplets travel between the ball and the printer head 402 increases at a second reference point 424 that is located away from the closest point 414. As a result of having a further distance to travel, the ink dispersion may be less accurate at the second reference point 424 when compared to the accuracy of the ink image at the closest point 414. In such circumstances, software modifications may be necessary to the image to accommodate for image distortions at locations on the golf ball 400 located near the second reference point 424. In one embodiment, the second reference point 424 is about 12.7 mm away from the closest point 414 as measured along the vertical rotation axis 406.

In another embodiment, a zone of distortion has been identified as a region of the ball that has significant image distortion due to the distance of the ball 400 being further from the printer head 402. In one example, the upper zone of distortion border 426 and lower zone of distortion border 428 begins after an upper boundary distance 430 and lower boundary distance 428, respectively, as measured along the vertical rotation axis 406 away from a center plane 434. The center plane 434 passes through the closest point 414 and the center of the ball 400. The upper zone of distortion 426 begins after the upper boundary distance 430 and continues until the upper most point of the ball. The lower zone of distortion 428 begins at the after the lower boundary distance 432 and continues until the lower most point of the ball. In one embodiment, the upper boundary distance 430 and lower boundary distance 432 is 5 mm away from the center plane 434. The intended printing image may need to be adjusted in the software programs utilized for printing for image portions located in the upper zone of distortion 426 and lower zone of distortion 428. In other embodiments, the lower boundary distance 432 and upper boundary distance 430 may be 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm away from the center plane 434. The term “distortion” as used herein shall refer to the ink on an object being applied in a manner that the printed image is noticeably different from an intended image design. In simple terms, if an intended image design is superimposed on a printed image, areas of distortion can be identified.

The ball rotation rate of the golf ball 400 as it rotates 412 about the vertical rotation axis 406 is between 1 to 7 revolutions per second (rps) or between 60 revolutions per minute to 420 revolutions per minute (rpm). In one embodiment, the revolutions per second can be 2 to 3 rps or as low as between 0.1 rps to 1 rps, or even 0.2 rps to 0.5 rps. In one embodiment, the ball rotation rate can vary between 1 rpm to 400 rpm, between 10 rpm to 300 rpm, between 50 rpm to 320 rpm, 80 rpm to 180 rpm, 120 rpm to 180 rpm. The ball rotation rates defined herein are based on a ball circumference of about 13.4 cm and a ball diameter between 1.678 inches to 1.688 inches. In one example, the ball diameter is 1.683 inches with a plus or minus tolerance of 0.005 inches.

In one embodiment, the print rate or scan rate of the printer head 402 is between 10 cm/s and 100 cm/s, between 60 cm/s and 90 cm/s, or between 75 cm/s and 85 cm/s. The print rate or scan rate is how quickly the printer head 402 can print an image on a surface without seeing significant distortions in the image. In addition, the dispense rate is defined as the rate of ink being dispensed from the printer head 402. In one embodiment, the dispense rate or the velocity of the ink droplet is between 2 m/s and 10 m/s, between 3 m/s and 9 m/s, between 4 m/s and 8 m/s, or between 5 m/s and 7 m/s. In one embodiment, the volume of a single ink droplet is between 6 to 160 picoliters, between 0 to 200 picoliters, between 50 to 150 picoliters between 6 to 42 picoliters, between 12 to 84 picoliters, between 40 to 160 picoliters, or between 75 to 125 picoliters.

The resolution of the printed area 404 on the golf ball 400 can vary between 100 to 1400 dots per inch (dpi), between 200 dpi and 400 dpi, between 300 dpi and 400 dpi, between 320 dpi and 390 dpi, between 1000 dpi and 1300 dpi, or between 350 dpi and 370 dpi. The typical firing frequency of the printer heads can be between 6 to 12 kHz. In one embodiment, the print swathe width is between 1 mm to 25 mm, 3 mm to 20 mm, 4 mm to 15 mm, 5 mm to 10 mm, 25 mm to 200 mm, between 500 to 100 mm, or between 60 to 80 mm.

In some embodiment, a plurality of printer heads 402 are utilized for each color. For example, a black, red, and blue printed area 404 would require at least three printer heads 402 located in a serial arrangement so as to apply each color in successive stages of printing. The printer heads 402 are capable of printing in at least five colors including cyan, magenta, yellow, black, and white. It is possible to print in any number of colors beyond the CMYK inks depending on how many printer heads 402 are available.

FIG. 5 illustrates a top view of the golf ball 400 as it moves along a linear direction 436 and passes through a first printer head 402A at a first printer station to apply a first color. After the first color is applied, the golf ball 400 passes through a first ink curing station 418A before proceeding to the second printer head 402B at a second printer station to apply a second color. After the second color is applied to the golf ball 400, the ball 400 is cured at a second ink curing station 418B. The second ink curing station 418B can be a UV pinning operation where low power level UV light is applied or the second ink curing station can be a final curing station where a higher power level of UV light (when compared to the UV pinning operation) is applied to cure all the ink applied to the golf ball 400. This process can be repeated for as many colors as required for printing a certain image. In one embodiment, there are between 1 and 20 printer heads and between 1 and 20 curing stations. In some embodiments, there can be two or more printer heads per printer station applying at least two or more different colors on the golf ball 400 simultaneously.

As shown in FIG. 9, in one embodiment, the first printer head 402A is located at a “rotational” printing station, meaning that the object or golf ball 400 to be printed is rotated along an axis 406 of the golf ball 400 relative to the first printer head 402A. The first printer head 402A prints at least a first image on the golf ball 400. Additionally, a second printer head 402B can be connected in the manufacturing process to be located after the rotational printing station. The second printer head 402B can be located at a “linear” printing station where the second printer head 402B is primarily stationary and the golf ball 400 is moved without rotation and linearly, or at least in one direction, past the second printer head 402B to have at least a second image printed on the golf ball 400.

In another embodiment, the first printer head 402A may be located at a linear printing station and the second printer head 402B can be located at a rotational printing station.

In yet another embodiment, the first printer head 402A and the second printer head 402B can both be rotational printing stations.

In yet another embodiment, the first printer head 402A and the second printer head 402B can both be linear printing stations and having a reorientation mechanism located between the first printer head 402A and the second printer head 402B to rotate the golf ball 400 by about 90 degrees, or between 45 degrees and 135 degrees along a horizontal axis 438 that is perpendicular to the axis of rotation 406.

In yet another embodiment, the first printer head 402A may be located at a rotational printing station and a plurality of printer heads, such as at least two, three, four, or five or more subsequent printer heads may be located at linear printing stations.

In one embodiment, the digital encoder 420 can rotate the golf ball 400 by between forty-five degrees to about ninety degrees about the vertical axis of rotation 406 between the first printer head 402A and the second printer head 402B in order to print four images on a golf ball 400 at first distinct locations on the ball. These four images can also be printed at linear printing stations. Additionally, the golf ball 400 can be rotated along the horizontal axis 438 in between printing stations 402A,402B to allow for the rotation of the golf ball along a horizontal axis 438 that is perpendicular to the vertical axis of rotation 406. The rotation of the golf ball 400 about the horizontal axis 438 can be accomplished by a ball rotation mechanism 440 located between the printing stations 402A,402B which can be a mechanical mechanism with an encoder/decoder, a mechanical arm, a friction based contact member, or any other mechanical, electrical, or pneumatic device utilized to rotate a golf ball about the horizontal axis 438.

In FIG. 9, the ball printing heads are located on the right hand side of the linear directional movement 436, however, at any of the printing stations described herein, the printer head may be located on the left side of the ball movement 436, above the ball, behind the ball, in front of the ball, or below the ball. In one embodiment, the speed at which the ball 400 moves along the linear direction 436 can be 14 inches/sec for a 360 dpi printer resolution. If a 540 dpi printer resolution is utilized, the speed of the ball movement can be at 10 to 12 inches/sec. In one embodiment, the ratio of the printer resolution divided by the linear direction speed can be between 10 dpi/(inches/sec) and 100 dpi/(inches/sec), or preferably between 20 dip/(inches/sec) and 50 dpi/(inches/sec). The speed at which balls are printed can be between 20 and 300 balls per minute, or between 100 and 250 balls per minute.

In one embodiment, each linear printing station will require at least four printing heads for each image printed at the station. However, at the rotational printing station, the four printing heads can be utilized to print multiple images.

In one embodiment, the curing stations 418 include a UV pinning operation having lamps with a power rating of between 0 and 20 watts or between 1.5 watts and 7.5 watts to partially cure the ink applied in the previous printing station. In some embodiments, the UV curing can be accomplished by mercury arc UV curing lamps or LED curing lamps. In one embodiment, a UV pinning operation is used having lamps of a lower wattage than a final UV curing lamp. For example, the pinning lamps may have a power rating of 5 W or less while the final UV curing has a power rating of more than 5 W or 5 W to 15 W. In certain embodiments, photo initiators can be present in the ink to narrow the wavelength of light in which curing occurs and thereby reducing ambient light contamination during the curing process. In one embodiment, the energy density of the curing lamp is between 100 mJ/cm²and 5000 mJ/cm², or between 150 mJ/cm²and 3000 mJ/cm². In one embodiment, the pinning lamps have an energy density that is less than the final curing lamps. For example, the pinning lamps may have an energy density of between 50 mJ/cm²to 200 mJ/cm²while the final UV curing lamps are between 1 J/cm²and 5 J/cm².

FIG. 6 illustrates the same elements of FIG. 4 except that the printer head has a curved surface 422 that provides a contour more closely matching the general curvature of the golf ball 400. In some embodiments, the printer head curved surface has a radius of about 0.84″ in order to match the radius of the golf ball 400 (excluding dimple depth variations). The curved surface of the printer allows for the ink droplets 408 to travel a more uniform distance between the golf ball 400 and the printer head. A more uniform distance between the ink dispensing surface and the surface of the golf ball can result in more consistent and higher quality images. FIG. 6 shows the trajectory of ink droplets 408 is roughly perpendicular or orthogonal to the surface of the ball (excluding dimple depth variation) so that upper and lower distortion zones are effectively eliminated so that an intended image does not need to be modified in the printing software to accommodate for varying distances between the ball 400 and printer head 402.

FIG. 7 illustrates a putter assembly 700 of a grip 726, a shaft 704, head 706, heel 708, toe 710, and sole 712. The shaft 704 has a shaft axis 714 and a fluted section length 724. The grip 726 has a grip length 720. A printer head 702 is located adjacent to the shaft 704. The printer head 702 may be configured to be a single pass printer head or a multiple pass printer head. If a multiple pass printer head is utilized, all the parameters of printing and curing described in this application apply equally in each pass of the multiple pass printer application. A multiple pass printer head 702 needs to make multiple movements across an object to completely print a desired image or pattern. In one embodiment, the printer head 702 prints a solid color, pattern, or image in the fluted section located within the fluted section length. In one embodiment, the printer head 702 moves in a direction parallel to the surface of the shaft that is being printed where the printer head 702 is angled by an angle between 0 and 10 degrees, 1 and 8 degrees, or 2 and 7 degrees relative to the shaft axis 714. In another embodiment, the printer head 702 moves parallel to the shaft axis 714. In one embodiment, the printer head 702 moves in a first direction 718 toward the grip and second direction 716 toward the club head 706. In one embodiment, the printing of ink on the shaft 704 is applied while the printer head is moving in the first direction 718 only and the printer head 702 is reset without printing while moving in the second direction 716. In another embodiment, the printer head 702 is moving in the second direction 716 while the ink is applied to the shaft and reset without any printing while moving in the first direction 718.

In yet another embodiment, the printer head 702 has a UV curing light 728 connected to or located on the printer head 702 so that the ink is pre-cured in a UV pinning operation after each application of ink is applied to the shaft 704. The UV pinning lamp parameters can be identical to those described previously. The UV curing light 728 can be a final UV cure or a pre-cure UV pinning operation that occurs before a final cure.

FIG. 8 illustrates a cross-sectional view take along section lines 8-8 of FIG. 7. As shown in FIG. 8, there are six flutes 800 located in the shaft 704. Flutes 800 are indentations or recessed regions in the shaft that extend longitudinally along the shaft axis 714. Each flute 800 is relatively parallel with the adjacent flutes. In one embodiment, the number of flutes can be 1 to 20, 2 to 10, 3 to 7, or 4 to 6 located on the shaft 704. The shaft 704 can be metal, composite, or plastic. In one embodiment, only the flutes 800 have ink applied to the surface while the unpainted regions 802 are located between each of the printed flutes 800. In one embodiment, the unprinted region 802 located between the printed flutes 800 has a surface area that is less than the printed flutes 800 surface area. In one embodiment, the unprinted region 802 within the cross-sectional view has a first outer surface contour length 806 (measured two dimensionally as shown in the FIG. 8 and in a plane perpendicular to the shaft axis 714) that is less than a second outer surface contour length 804 of the flutes 800. In determining where the unprinted region 802 first outer contour length 806 ends and the second outer contour length 804 in the flutes 800 begins when measuring the contour length, a transition point having a radius of 5 mm ore more can be the point of separation between unprinted region 802 and flutes 800 when trying to determine the first and second outer contour length. In one embodiment, a first outer contour length divided by a second outer contour is a Contour Ratio. The Contour Ratio can be less than 1, between 0.1 and 0.9, between 0.2 and 0.8, between 0.3 and 0.7, or between 0.4 and 0.6.

In one embodiment, the fluted section length 724 can be between 1 mm and 375 mm, between 2 mm and 300 mm, between 5 mm and 290 mm, between 20 mm and 280 mm or between 25 mm and 200 mm. In one embodiment, the fluted section length 724 can be shorter than the grip length 720. In another embodiment, the fluted section length 724 can be longer than the grip length 720. In one embodiment, the ratio between the fluted section length 724 and the grip length 720 is between 0.05 and 1, between 0.1 and 0.9, between 0.2 and 0.8, between 0.3 and 0.7, or between 0.4 and 0.6.

The printing can occur before the shaft 704 of the putter is assembled and attached to the putter head 706. The shaft can be placed on a flat bed roller and the shaft can be rolled in a direction perpendicular to the shaft axis as the printer head 702 makes multiple passes to print swathes of ink within the flutes 800. In one embodiment, the print swathes are the same width as the flute 800 lengths.

In another embodiment, a single polyurethane or polyurea composition may be utilized rather than a first color-containing composition and a second color-containing composition as described above. In particular, a single color-containing polyurethane composition may be being used in combination with secondary application of either paint or ink for creating the circumferential stripes. The terms “paint” and “ink” are used interchangeably throughout this specification. In instances where the term “ink” is used, it is understood that the term “paint” can also be substituted and visa versa. In general, “paint” is considered a dispersion of insoluble opaque particles suspended in a clear medium such as oil or water based mediums. In general, “ink” is a colored organic compound that is dissolved in a solvent or water. In one embodiment, a urethane material is preferred over an ionomer cover material due to an increase in greenside spin of about 15%, higher durability due to the shear resistance of the urethane thereby producing a higher quality colored golf ball.

For example, in the embodiment shown in FIG. 3A, a red polyurethane cover golf ball may be formed using the casting process outlined above. A wide white circumferential stripe is placed on the golf ball using one of the stamping processes outlined above. A second black circumferential stripe is applied centered on top of the white circumferential stripe using similar stamping processes. If having the base urethane color in place of the black stripe is preferred, during the white stripe stamping application a center portion of the stamping area could be left out to stamp two parallel white stripes during the same application.

In the embodiment shown in FIG. 3D, a white polyurethane cover ball is formed using the casting process outlined above. A center black circumferential stripe can be applied using any of the stamping processes outlined above. The ball could then be rotated 90° from the original axis of rotation and a blue circle be applied with the stamping process. The ball would rotate 180° on the same axis of rotation and a second blue circle could be stamped.

The embodiments shown in FIGS. 3A-3D can alternatively be made with a first color-containing composition and a second color-containing composition as described above.

A series of clear coats, with or without additives, are applied to the golf ball for durability and to achieve a gloss finish. Matte clear is also an option. The printed images can be either under or over the clear coat. In some embodiments, the circumferential stripes can be stamped or printed over the clear coat layer.

The image, pole stamp, or pole marking ink may be UV curable compositions. For example, the image ink may be a UV curable epoxy. Alternatively, the image, pole stamp, or pole marking ink may be curable by another mechanism such as heat. A clear coat (e.g., a UV curable composition) may be applied onto the cover layer surface and the images. In one exemplary embodiment, a paint can be applied to the cover layer surface of any color suitable for alignment.

Additional Golf Ball Components

The multi-color cover layers disclosed herein can be used on any golf ball. In certain embodiments, the golf ball has a core and a cover layer surrounding the core. In certain embodiments, the golf ball has a core, at least one mantle layer, and a cover layer. The golf ball may be a two-piece ball, a three-piece ball, a four-piece ball, a five-piece ball, or a six-piece ball.

The term “core” is intended to mean the elastic center of a golf ball. The core may be a unitary core having a center it may have one or more “core layers” of elastic material, which are usually made of rubbery material such as diene rubbers.

The term “cover layer” is intended to mean the outermost layer of the golf ball; this is the layer that is directly in contact with paint and/or ink on the surface of the golf ball. If the cover consists of two or more layers, only the outermost layer is designated the cover layer, and the remaining layers (excluding the outermost layer) are commonly designated intermediate layers as herein defined. The term “outer cover layer” as used herein is used interchangeably with the term “cover layer.”

The term “mantle layer” may be used interchangeably herein with the terms “intermediate layer” and is intended to mean any layer(s) in a golf ball disposed between the core and the outer cover layer. Should a ball have more than one mantle layer, these may be distinguished as “inner intermediate layer” or “inner mantle layer” which terms may be used interchangeably to refer to the intermediate layer nearest the core and furthest from the outer cover, as opposed to the “outer intermediate layer” or “outer mantle layer” which terms may also be used interchangeably to refer to the intermediate layer furthest from the core and closest to the outer cover, and if there are three intermediate layers, these may be distinguished as “inner intermediate layer” or “inner mantle layer” which terms are used interchangeably to refer to the intermediate or mantle layer nearest the core and furthest from the outer cover, as opposed to the “outer intermediate layer” or “outer mantle layer” which terms are also used interchangeably to refer to the intermediate layer further from the core and closer to the outer cover, and as opposed to the “intermediate layer” or “intermediate mantle layer” which terms are also used interchangeably to refer to the intermediate layer between the inner intermediate layer and the outer intermediate layer.

The cover layer can be used with golf balls of any desired size. “The Rules of Golf” by the USGA dictate that the size of a competition golf ball must be at least 1.680 inches in diameter; however, golf balls of any size can be used for leisure golf play. The preferred diameter of the golf balls is from about 1.680 inches to about 1.800 inches. The more preferred diameter is from about 1.680 inches to about 1.760 inches. A diameter of from about 1.680 inches to about 1.740 inches is most preferred; however, diameters anywhere in the range of from 1.70 to about 2.0 inches can be used. Oversize golf balls with diameters above about 1.760 inches to as big as 2.75 inches are also within the scope of the invention.

Each of the mantle layers of the golf balls may have a thickness of less than 0.080 inch, more particularly less than 0.065 inch, and most particularly less than 0.055 inch.

In certain embodiments the inner mantle may have a material Shore D hardness of 15 to 65, particularly 25 to 60, and more particularly 30 to 58. The inner mantle may have a flexural modulus of 2 to 35, particularly 10 to 30, and more particularly 15 to 35, kpsi. The intermediate mantle may have a flexural modulus of 10 to 50, particularly 25 to 50, and most particularly 25 to 40, kpsi, and a material Shore D hardness of 40 to 70, more particularly from 45 to 65, and most particularly from 50 to 60. The outer mantle may have a material Shore D hardness of 55 to 75, particularly 58 to 70, and more particularly 60 to 68. The outer mantle material may have a flexural modulus of 30 to 80, particularly 40 to 80, and most particularly 50 to 75, kpsi. The core and mantle layer(s) may each include one or more of the following polymers.

Such polymers include synthetic and natural rubbers, thermoset polymers such as thermoset polyurethanes and thermoset polyureas, as well as thermoplastic polymers including thermoplastic elastomers such as unimodal ethylene/carboxylic acid copolymers, unimodal ethylene/carboxylic acid/carboxylate terpolymers, bimodal ethylene/carboxylic acid copolymers, bimodal ethylene/carboxylic acid/carboxylate terpolymers, unimodal ionomers, bimodal ionomers, modified unimodal ionomers, modified bimodal ionomers, thermoplastic polyurethanes, thermoplastic polyureas, polyesters, copolyesters, polyamides, copolyamides, polycarbonates, polyolefins, polyphenylene oxide, polyphenylene sulfide, diallyl phthalate polymer, polyimides, polyvinyl chloride, polyamide-ionomer, polyurethane-ionomer, polyvinyl alcohol, polyarylate, polyacrylate, polyphenylene ether, impact-modified polyphenylene ether, polystyrene, high impact polystyrene, acrylonitrile-butadiene-styrene copolymer styrene-acrylonitrile (SAN), acrylonitrile-styrene-acrylonitrile, styrene-maleic anhydride (S/MA) polymer, styrenic copolymer, functionalized styrenic copolymer, functionalized styrenic terpolymer, styrenic terpolymer, cellulose polymer, liquid crystal polymer (LCP), ethylene-propylene-diene terpolymer (EPDM), ethylene-vinyl acetate copolymers (EVA), ethylene-propylene copolymer, ethylene vinyl acetate, polyurea, and polysiloxane and any and all combinations thereof. One example is Paraloid EXL 2691A which is a methacrylate-butadiene-styrene (MBS) impact modifier available from Rohm & Haas Co.

More particularly, the synthetic and natural rubber polymers may include the traditional rubber components used in golf ball applications including, both natural and synthetic rubbers, such as cis-1,4-polybutadiene, trans-1,4-polybutadiene, 1,2-polybutadiene, cis-polyisoprene, trans-polyisoprene, polychloroprene, polybutylene, styrene-butadiene rubber, styrene-butadiene-styrene block copolymer and partially and fully hydrogenated equivalents, styrene-isoprene-styrene block copolymer and partially and fully hydrogenated equivalents, nitrile rubber, silicone rubber, and polyurethane, as well as mixtures of these. Polybutadiene rubbers, especially 1,4-polybutadiene rubbers containing at least 40 mol %, and more preferably 80 to 100 mol % of cis-1,4 bonds, are preferred because of their high rebound resilience, moldability, and high strength after vulcanization. The polybutadiene component may be synthesized by using rare earth-based catalysts, nickel-based catalysts, or cobalt-based catalysts, conventionally used in this field. Polybutadiene obtained by using lanthanum rare earth-based catalysts usually employ a combination of a lanthanum rare earth (atomic number of 57 to 71)-compound, but particularly preferred is a neodymium compound.

The 1,4-polybutadiene rubbers have a molecular weight distribution (Mw/Mn) of from about 1.2 to about 4.0, preferably from about 1.7 to about 3.7, even more preferably from about 2.0 to about 3.5, most preferably from about 2.2 to about 3.2. The polybutadiene rubbers have a Mooney viscosity (ML₁₊₄(100° C.)) of from about 20 to about 80, preferably from about 30 to about 70, even more preferably from about 30 to about 60, most preferably from about 35 to about 50. The term “Mooney viscosity” used herein refers in each case to an industrial index of viscosity as measured with a Mooney viscometer, which is a type of rotary plastometer (see JIS K6300). This value is represented by the symbol ML₁₊₄(100° C.), wherein “M” stands for Mooney viscosity, “L” stands for large rotor (L-type), “1+4” stands for a pre-heating time of 1 minute and a rotor rotation time of 4 minutes, and “100° C.” indicates that measurement was carried out at a temperature of 100° C.

Examples of 1,2-polybutadienes having differing tacticity, all of which are suitable as unsaturated polymers for use in the presently disclosed compositions, are atactic 1,2-polybutadiene, isotactic 1,2-polybutadiene, and syndiotactic 1,2-polybutadiene. Syndiotactic 1,2-polybutadiene having crystallinity suitable for use as an unsaturated polymer in the presently disclosed compositions are polymerized from a 1,2-addition of butadiene. The presently disclosed golf balls may include syndiotactic 1,2-polybutadiene having crystallinity and greater than about 70% of 1,2-bonds, more preferably greater than about 80% of 1,2-bonds, and most preferably greater than about 90% of 1,2-bonds. Also, the 1,2-polybutadiene may have a mean molecular weight between about 10,000 and about 350,000, more preferably between about 50,000 and about 300,000, more preferably between about 80,000 and about 200,000, and most preferably between about 10,000 and about 150,000. Examples of suitable syndiotactic 1,2-polybutadienes having crystallinity suitable for use in golf balls are sold under the trade names RB810, RB820, and RB830 by JSR Corporation of Tokyo, Japan. These have more than 90% of 1,2 bonds, a mean molecular weight of approximately 120,000, and crystallinity between about 15% and about 30%.

Examples of olefinic thermoplastic elastomers include metallocene-catalyzed polyolefins, ethylene-octene copolymer, ethylene-butene copolymer, and ethylene-propylene copolymers all with or without controlled tacticity as well as blends of polyolefins having ethyl-propylene-non-conjugated diene terpolymer, rubber-based copolymer, and dynamically vulcanized rubber-based copolymer. Examples of these include products sold under the trade names SANTOPRENE, DYTRON, VISAFLEX, and VYRAM by Advanced Elastomeric Systems of Houston, Texas, and SARLINK by DSM of Haarlen, the Netherlands.

Examples of rubber-based thermoplastic elastomers include multiblock rubber-based copolymers, particularly those in which the rubber block component is based on butadiene, isoprene, or ethylene/butylene. The non-rubber repeating units of the copolymer may be derived from any suitable monomers, including meth(acrylate) esters, such as methyl methacrylate and cyclohexylmethacrylate, and vinyl arylenes, such as styrene. Examples of styrenic copolymers are resins manufactured by Kraton Polymers (formerly of Shell Chemicals) under the trade names KRATON D (for styrene-butadiene-styrene and styrene-isoprene-styrene types) and KRATON G (for styrene-ethylene-butylene-styrene and styrene-ethylene-propylene-styrene types) and Kuraray under the trade name SEPTON. Examples of randomly distributed styrenic polymers include paramethylstyrene-isobutylene (isobutene) copolymers developed by ExxonMobil Chemical Corporation and styrene-butadiene random copolymers developed by Chevron Phillips Chemical Corp.

Examples of copolyester thermoplastic elastomers include polyether ester block copolymers, polylactone ester block copolymers, and aliphatic and aromatic dicarboxylic acid copolymerized polyesters. Polyether ester block copolymers are copolymers comprising polyester hard segments polymerized from a dicarboxylic acid and a low molecular weight diol, and polyether soft segments polymerized from an alkylene glycol having 2 to 10 atoms. Polylactone ester block copolymers are copolymers having polylactone chains instead of polyether as the soft segments discussed above for polyether ester block copolymers. Aliphatic and aromatic dicarboxylic copolymerized polyesters are copolymers of an acid component selected from aromatic dicarboxylic acids, such as terephthalic acid and isophthalic acid, and aliphatic acids having 2 to 10 carbon atoms with at least one diol component, selected from aliphatic and alicyclic diols having 2 to 10 carbon atoms. Blends of aromatic polyester and aliphatic polyester also may be used for these. Examples of these include products marketed under the trade names HYTREL by E.I. DuPont de Nemours & Company, and SKYPEL by S.K. Chemicals of Seoul, South Korea.

Examples of other thermoplastic elastomers suitable as additional polymer components include those having functional groups, such as carboxylic acid, maleic anhydride, glycidyl, norbornene, and hydroxyl functionalities. An example of these includes a block polymer having at least one polymer block A comprising an aromatic vinyl compound and at least one polymer block B comprising a conjugated diene compound, and having a hydroxyl group at the terminal block copolymer, or its hydrogenated product. An example of this polymer is sold under the trade name SEPTON HG-252 by Kuraray Company of Kurashiki, Japan. Other examples of these include: maleic anhydride functionalized triblock copolymer consisting of polystyrene end blocks and poly(ethylene/butylene), sold under the trade name KRATON FG 1901X by Shell Chemical Company; maleic anhydride modified ethylene-vinyl acetate copolymer, sold under the trade name FUSABOND by E.I. DuPont de Nemours & Company; ethylene-isobutyl acrylate-methacrylic acid terpolymer, sold under the trade name NUCREL by E.I. DuPont de Nemours & Company; ethylene-ethyl acrylate-methacrylic anhydride terpolymer, sold under the trade name BONDINE AX 8390 and 8060 by Sumitomo Chemical Industries; brominated styrene-isobutylene copolymers sold under the trade name BROMO XP-50 by Exxon Mobil Corporation; and resins having glycidyl or maleic anhydride functional groups sold under the trade name LOTADER by Elf Atochem of Puteaux, France.

Another example of a polymer for making any of the mantle layers or cover layer is blend of a polyamide (which may be a polyamide as described above) with a functional polymer modifier of the polyamide. The functional polymer modifier of the polyamide can include copolymers or terpolymers having a glycidyl group, hydroxyl group, maleic anhydride group or carboxylic group, collectively referred to as functionalized polymers. These copolymers and terpolymers may comprise an α-olefin. Examples of suitable α-olefins include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-petene, 3-methyl-1-pentene, 1-octene, 1-decene-, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, 1-dococene, 1-tetracocene, 1-hexacocene, 1-octacocene, and 1-triacontene. One or more of these α-olefins may be used.

Examples of suitable glycidyl groups in copolymers or terpolymers in the polymeric modifier include esters and ethers of aliphatic glycidyl, such as allylglycidylether, vinylglycidylether, glycidyl maleate and itaconatem glycidyl acrylate and methacrylate, and also alicyclic glycidyl esters and ethers, such as 2-cyclohexene-1-glycidylether, cyclohexene-4,5 diglyxidylcarboxylate, cyclohexene-4-glycidyl carboxylate, 5-norboenene-2-methyl-2-glycidyl carboxylate, and endocis-bicyclo(2,2,1)-5-heptene-2,3-diglycidyl dicarboxylate. These polymers having a glycidyl group may comprise other monomers, such as esters of unsaturated carboxylic acid, for example, alkyl(meth)acrylates or vinyl esters of unsaturated carboxylic acids. Polymers having a glycidyl group can be obtained by copolymerization or graft polymerization with homopolymers or copolymers.

Examples of suitable terpolymers having a glycidyl group include LOTADER AX8900 and AX8920, marketed by Atofina Chemicals, ELVALOY marketed by E.I. Du Pont de Nemours & Co., and REXPEARL marketed by Nippon Petrochemicals Co., Ltd. Additional examples of copolymers comprising epoxy monomers and which are suitable for use within the scope of the present invention include styrene-butadiene-styrene block copolymers in which the polybutadiene block contains epoxy group, and styrene-isoprene-styrene block copolymers in which the polyisoprene block contains epoxy. Commercially available examples of these epoxy functional copolymers include ESBS A1005, ESBS A1010, ESBS A1020, ESBS AT018, and ESBS AT019, marketed by Daicel Chemical Industries, Ltd.

Examples of polymers or terpolymers incorporating a maleic anhydride group suitable for use within the scope of the present invention include maleic anhydride-modified ethylene-propylene copolymers, maleic anhydride-modified ethylene-propylene-diene terpolymers, maleic anhydride-modified polyethylenes, maleic anhydride-modified polypropylenes, ethylene-ethylacrylate-maleic anhydride terpolymers, and maleic anhydride-indene-styrene-cumarone polymers. Examples of commercially available copolymers incorporating maleic anhydride include: BONDINE, marketed by Sumitomo Chemical Co., such as BONDINE AX8390, an ethylene-ethyl acrylate-maleic anhydride terpolymer having a combined ethylene acrylate and maleic anhydride content of 32% by weight, and BONDINE TX TX8030, an ethylene-ethyl acrylate-maleic anhydride terpolymer having a combined ethylene acrylate and maleic anhydride content of 15% by weight and a maleic anhydride content of 1% to 4% by weight; maleic anhydride-containing LOTADER 3200, 3210, 6200, 8200, 3300, 3400, 3410, 7500, 5500, 4720, and 4700, marketed by Atofina Chemicals; EXXELOR VA1803, a maleic anhydride-modified ethylene-propylene copolymer having a maleic anhydride content of 0.7% by weight, marketed by Exxon Chemical Co.; and KRATON FG 1901X, a maleic anhydride functionalized triblock copolymer having polystyrene endblocks and poly(ethylene/butylene) midblocks, marketed by Shell Chemical.

Preferably the functional polymer component for blending with a polyamide is a maleic anhydride grafted polymers preferably maleic anhydride grafted polyolefins (for example, Exxellor VA1803).

Styrenic block copolymers are copolymers of styrene with butadiene, isoprene, or a mixture of the two. Additional unsaturated monomers may be added to the structure of the styrenic block copolymer as needed for property modification of the resulting SBC/urethane copolymer. The styrenic block copolymer can be a diblock or a triblock styrenic polymer. Examples of such styrenic block copolymers are described in, for example, U.S. Pat. No. 5,436,295 to Nishikawa et al. The styrenic block copolymer can have any known molecular weight for such polymers, and it can possess a linear, branched, star, dendrimeric or combination molecular structure. The styrenic block copolymer can be unmodified by functional groups, or it can be modified by hydroxyl group, carboxyl group, or other functional groups, either in its chain structure or at one or more terminus. The styrenic block copolymer can be obtained using any common process for manufacture of such polymers. The styrenic block copolymers also may be hydrogenated using well-known methods to obtain a partially or fully saturated diene monomer block.

Other preferred materials suitable for use as additional polymers in the presently disclosed compositions include polyester thermoplastic elastomers marketed under the tradename SKYPEL™ by SK Chemicals of South Korea, or diblock or triblock copolymers marketed under the tradename SEPTON™ by Kuraray Corporation of Kurashiki, Japan, and KRATON™ by Kraton Polymers Group of Companies of Chester, United Kingdom. For example, SEPTON HG 252 is a triblock copolymer, which has polystyrene end blocks and a hydrogenated polyisoprene midblock and has hydroxyl groups at the end of the polystyrene blocks. HG-252 is commercially available from Kuraray America Inc. (Houston, Texas).

Additional other polymer components include polyalkenamers as described, for example, in US-2006-0166762-A1, which is incorporated herein by reference in its entirety. Examples of suitable polyalkenamer rubbers are polypentenamer rubber, polyheptenamer rubber, polyoctenamer rubber, polydecenamer rubber and polydodecenamer rubber. For further details concerning polyalkenamer rubber, see Rubber Chem. & Tech., Vol. 47, page 511-596, 1974, which is incorporated herein by reference. Polyoctenamer rubbers are commercially available from Huls AG of Marl, Germany, and through its distributor in the U.S., Creanova Inc. of Somerset, N.J., and sold under the trademark VESTENAMER®. Two grades of the VESTENAMER® trans-polyoctenamer are commercially available: VESTENAMER 8012 designates a material having a trans-content of approximately 80% (and a cis-content of 20%) with a melting point of approximately 54° C.; and VESTENAMER 6213 designates a material having a trans-content of approximately 60% (cis-content of 40%) with a melting point of approximately 30° C. Both of these polymers have a double bond at every eighth carbon atom in the ring.

If a polyalkenamer rubber is present, the polyalkenamer rubber preferably contains from about 50 to about 99, preferably from about 60 to about 99, more preferably from about 65 to about 99, even more preferably from about 70 to about 90 percent of its double bonds in the trans-configuration. The preferred form of the polyalkenamer has a trans content of approximately 80%, however, compounds having other ratios of the cis- and trans-isomeric forms of the polyalkenamer can also be obtained by blending available products for use in making the composition.

The polyalkenamer rubber has a molecular weight (as measured by GPC) from about 10,000 to about 300,000, preferably from about 20,000 to about 250,000, more preferably from about 30,000 to about 200,000, even more preferably from about 50,000 to about 150,000.

The polyalkenamer rubber has a degree of crystallization (as measured by DSC secondary fusion) from about 5 to about 70, preferably from about 6 to about 50, more preferably from about from 6.5 to about 50%, even more preferably from about from 7 to about 45%.

More preferably, the polyalkenamer rubber is a polymer prepared by polymerization of cyclooctene to form a trans-polyoctenamer rubber as a mixture of linear and cyclic macromolecules.

A further example of a polymer is a specialty propylene elastomer as described, for example, in US 2007/0238552 A1, and incorporated herein by reference in its entirety. A specialty propylene elastomer includes a thermoplastic propylene-ethylene copolymer composed of a majority amount of propylene and a minority amount of ethylene. These copolymers have at least partial crystallinity due to adjacent isotactic propylene units. Although not bound by any theory, it is believed that the crystalline segments are physical crosslinking sites at room temperature, and at high temperature (i.e., about the melting point), the physical crosslinking is removed and the copolymer is easy to process. According to one embodiment, a specialty propylene elastomer includes at least about 50 mole % propylene co-monomer. Specialty propylene elastomers can also include functional groups such as maleic anhydride, glycidyl, hydroxyl, and/or carboxylic acid. Suitable specialty propylene elastomers include propylene-ethylene copolymers produced in the presence of a metallocene catalyst. More specific examples of specialty propylene elastomers are illustrated below. Specialty propylene elastomers are commercially available under the tradename VISTAMAXX from ExxonMobil Chemical.

Another example of an additional polymer component includes the thermoplastic polyurethanes, which are the reaction product of a diol or polyol and an isocyanate, with or without a chain extender. Isocyanates used for making the urethanes encompass diisocyanates and polyisocyanates. Examples of suitable isocyanates include the following: trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, ethylene diisocyanate, diethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, bitolylene diisocyanate, tolidine isocyanate, isophorone diisocyanate, dimeryl diisocyanate, dodecane-1,12-diisocyanate, 1,10-decamethylene diisocyanate, cyclohexylene-1,2-diisocyanate, 1-chlorobenzene-2,4-diisocyanate, furfurylidene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,3cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,3-cyclobutane diisocyanate, 1,4-cyclohexane diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), 4,4′-methylenebis(phenyl isocyanate), 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis (isocyanato-methyl)cyclohexane, 1,6-diisocyanato-2,2,4,4-tetra-methylhexane, 1,6-diisocyanato-2,4,4-tetra-trimethylhexane, trans-cyclohexane-1,4-diisocyanate, 3-isocyanato-methyl-3,5,5-trimethylcyclohexyl isocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclohexyl isocyanate, dicyclohexylmethane 4,4′-diisocyanate, 1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate, m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylene diisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, metaxylene diisocyanate, 2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate, 4,4′-toluidine diisocyanate, dianisidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 1, 3-xylylene diisocyanate, 1,4-naphthylene diisocyanate, azobenzene-4,4′-diisocyanate, diphenyl sulfone-4,4′-diisocyanate, triphenylmethane 4,4′,4″-triisocyanate, isocyanatoethyl methacrylate, 3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylene diisocyanate, ω,ω′-diisocyanato-1,4-diethylbenzene, polymethylene polyphenylene polyisocyanate, polybutylene diisocyanate, isocyanurate modified compounds, and carbodiimide modified compounds, as well as biuret modified compounds of the above polyisocyanates. Each isocyanate may be used either alone or in combination with one or more other isocyanates. These isocyanate mixtures can include triisocyanates, such as biuret of hexamethylene diisocyanate and triphenylmethane triisocyanate, and polyisocyanates, such as polymeric diphenylmethane diisocyanate.

Polyols used for making the polyurethane in the copolymer include polyester polyols, polyether polyols, polycarbonate polyols and polybutadiene polyols. Polyester polyols are prepared by condensation or step-growth polymerization utilizing diacids. Primary diacids for polyester polyols are adipic acid and isomeric phthalic acids. Adipic acid is used for materials requiring added flexibility, whereas phthalic anhydride is used for those requiring rigidity. Some examples of polyester polyols include poly(ethylene adipate) (PEA), poly(diethylene adipate) (PDA), poly(propylene adipate) (PPA), poly(tetramethylene adipate) (PBA), poly(hexamethylene adipate) (PHA), poly(neopentylene adipate) (PNA), polyols composed of 3-methyl-1,5-pentanediol and adipic acid, random copolymer of PEA and PDA, random copolymer of PEA and PPA, random copolymer of PEA and PBA, random copolymer of PHA and PNA, caprolactone polyol obtained by the ring-opening polymerization of F-caprolactone, and polyol obtained by opening the ring of β-methyl-6-valerolactone with ethylene glycol can be used either alone or in a combination thereof. Additionally, polyester polyol may be composed of a copolymer of at least one of the following acids and at least one of the following glycols. The acids include terephthalic acid, isophthalic acid, phthalic anhydride, oxalic acid, malonic acid, succinic acid, pentanedioic acid, hexanedioic acid, octanedioic acid, nonanedioic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (a mixture), p-hydroxybenzoate, trimellitic anhydride, ε-caprolactone, and β-methyl-δ-valerolactone. The glycols include ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylene glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexane dimethanol, pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening addition polymerization of an alkylene oxide (e.g. ethylene oxide and propylene oxide) with an initiator of a polyhydric alcohol (e.g. diethylene glycol), which is an active hydride. Specifically, polypropylene glycol (PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxide copolymer can be obtained. Polytetramethylene ether glycol (PTMG) is prepared by the ring-opening polymerization of tetrahydrofuran, produced by dehydration of 1,4-butanediol or hydrogenation of furan. Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically, tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethylene oxide copolymer can be formed. A polyether polyol may be used either alone or in a mixture.

Polycarbonate polyol is obtained by the condensation of a known polyol (polyhydric alcohol) with phosgene, chloroformic acid ester, dialkyl carbonate or diallyl carbonate. A particularly preferred polycarbonate polyol contains a polyol component using 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentylglycol or 1,5-pentanediol. A polycarbonate polyol can be used either alone or in a mixture.

Polybutadiene polyol includes liquid diene polymer containing hydroxyl groups, and an average of at least 1.7 functional groups, and may be composed of diene polymer or diene copolymer having 4 to 12 carbon atoms, or a copolymer of such diene with addition to polymerizable α-olefin monomer having 2 to 2.2 carbon atoms. Specific examples include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethyl hexyl acrylate copolymer, and butadiene-n-octadecyl acrylate copolymer. These liquid diene polymers can be obtained, for example, by heating a conjugated diene monomer in the presence of hydrogen peroxide in a liquid reactant. A polybutadiene polyol can be used either alone or in a mixture.

As stated above, the urethane also may incorporate chain extenders. Non-limiting examples of these extenders include polyols, polyamine compounds, and mixtures of these. Polyol extenders may be primary, secondary, or tertiary polyols. Specific examples of monomers of these polyols include: trimethylolpropane (TMP), ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, and 2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

Suitable polyamines that may be used as chain extenders include primary, secondary and tertiary amines; polyamines have two or more amines as functional groups. Examples of these include: aliphatic diamines, such as tetramethylenediamine, pentamethylenediamine, hexamethylenediamine; alicyclic diamines, such as 3,3′-dimethyl-4,4′-diamino-dicyclohexyl methane; or aromatic diamines, such as 4,4′-methylene bis-2-chloroaniline, 2,2′,3,3′-tetrachloro-4,4′-diaminophenyl methane, p,p′-methylenedianiline, p-phenylenediamine or 4,4′-diaminodiphenyl; and 2,4,6-tris(dimethylaminomethyl) phenol. Aromatic diamines have a tendency to provide a stiffer product than aliphatic or cycloaliphatic diamines. A chain extender may be used either alone or in a mixture.

Polyurethanes or polyureas typically are prepared by reacting a diisocyanate with a polyol (in the case of polyurethanes) or with a polyamine (in the case of a polyurea). Thermoplastic polyurethanes or polyureas may consist solely of this initial mixture or may be further combined with a chain extender to vary properties such as hardness of the thermoplastic. Thermoset polyurethanes or polyureas typically are formed by the reaction of a diisocyanate and a polyol or polyamine respectively, and an additional crosslinking agent to crosslink or cure the material to result in a thermoset.

In what is known as a one-shot process, the three reactants, diisocyanate, polyol or polyamine, and optionally a chain extender or a curing agent, are combined in one step. Alternatively, a two-step process may occur in which the first step involves reacting the diisocyanate and the polyol (in the case of polyurethane) or the polyamine (in the case of a polyurea) to form a so-called prepolymer, to which can then be added either the chain extender or the curing agent. This procedure is known as the prepolymer process.

In addition, although depicted as discrete component packages as above, it is also possible to control the degree of crosslinking, and hence the degree of thermoplastic or thermoset properties in a final composition, by varying the stoichiometry not only of the diisocyanate-to-chain extender or curing agent ratio, but also the initial diisocyanate-to-polyol or polyamine ratio. Of course in the prepolymer process, the initial diisocyanate-to-polyol or polyamine ratio is fixed on selection of the required prepolymer.

Finally, in addition to discrete thermoplastic or thermoset materials, it also is possible to modify a thermoplastic polyurethane or polyurea composition by introducing materials in the composition that undergo subsequent curing after molding the thermoplastic to provide properties similar to those of a thermoset. For example, Kim in U.S. Pat. No. 6,924,337, the entire contents of which are hereby incorporated by reference, discloses a thermoplastic urethane or urea composition optionally comprising chain extenders and further comprising a peroxide or peroxide mixture, which can then undergo post curing to result in a thermoset.

Also, Kim et al. in U.S. Pat. No. 6,939,924, the entire contents of which are hereby incorporated by reference, discloses a thermoplastic urethane or urea composition, optionally also comprising chain extenders, that is prepared from a diisocyanate and a modified or blocked diisocyanate which unblocks and induces further cross-linking post extrusion. The modified isocyanate preferably is selected from the group consisting of: isophorone diisocyanate (IPDI)-based uretdione-type crosslinker; a combination of a uretdione adduct of IPDI and a partially e-caprolactam-modified IPDI; a combination of isocyanate adducts modified by e-caprolactam and a carboxylic acid functional group; a caprolactam-modified Desmodur diisocyanate; a Desmodur diisocyanate having a 3,5-dimethyl pyrazole modified isocyanate; or mixtures of these.

Finally, Kim et al. in U.S. Pat. No. 7,037,985 B2, the entire contents of which are hereby incorporated by reference, discloses thermoplastic urethane or urea compositions further comprising a reaction product of a nitroso compound and a diisocyanate or a polyisocyanate. The nitroso reaction product has a characteristic temperature at which it decomposes to regenerate the nitroso compound and diisocyanate or polyisocyanate. Thus, by judicious choice of the post-processing temperature, further crosslinking can be induced in the originally thermoplastic composition to provide thermoset-like properties.

Any isocyanate available to one of ordinary skill in the art is suitable for use according to the invention. Isocyanates for use with the present invention include, but are not limited to, aliphatic, cycloaliphatic, aromatic aliphatic, aromatic, any derivatives thereof, and combinations of these compounds having two or more isocyanate (NCO) groups per molecule. As used herein, aromatic aliphatic compounds should be understood as those containing an aromatic ring, wherein the isocyanate group is not directly bonded to the ring. One example of an aromatic aliphatic compound is a tetramethylene diisocyanate (TMXDI). The isocyanates may be organic polyisocyanate-terminated prepolymers, low free isocyanate prepolymer, and mixtures thereof. The isocyanate-containing reactable component also may include any isocyanate-functional monomer, dimer, trimer, or polymeric adduct thereof, prepolymer, quasi-prepolymer, or mixtures thereof. Isocyanate-functional compounds may include monoisocyanates or polyisocyanates that include any isocyanate functionality of two or more.

Suitable isocyanate-containing components include diisocyanates having the generic structure: O═C═N—R—N═C═O, where R preferably is a cyclic, aromatic, or linear or branched hydrocarbon moiety containing from about 1 to about 50 carbon atoms. The isocyanate also may contain one or more cyclic groups or one or more phenyl groups. When multiple cyclic or aromatic groups are present, linear and/or branched hydrocarbons containing from about 1 to about 10 carbon atoms can be present as spacers between the cyclic or aromatic groups. In some cases, the cyclic or aromatic group(s) may be substituted at the 2-, 3-, and/or 4-positions, or at the ortho-, meta-, and/or para-positions, respectively. Substituted groups may include, but are not limited to, halogens, primary, secondary, or tertiary hydrocarbon groups, or a mixture thereof.

Examples of isocyanates that can be used with the present invention include, but are not limited to, substituted and isomeric mixtures including 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate (MDI); 3,3′-dimethyl-4,4′-biphenylene diisocyanate (TODI); toluene diisocyanate (TDI); polymeric MDI; carbodiimide-modified liquid 4,4′-diphenylmethane diisocyanate; para-phenylene diisocyanate (PPDI); meta-phenylene diisocyanate (MPDI); triphenyl methane-4,4′- and triphenyl methane-4,4″-triisocyanate; naphthylene-1,5-diisocyanate; 2,4′-, 4,4′-, and 2,2-biphenyl diisocyanate; polyphenylene polymethylene polyisocyanate (PMDI) (also known as polymeric PMDI); mixtures of MDI and PMDI; mixtures of PMDI and TDI; ethylene diisocyanate; propylene-1,2-diisocyanate; trimethylene diisocyanate; butylenes diisocyanate; bitolylene diisocyanate; toluidine diisocyanate; tetramethylene-1,2-diisocyanate; tetramethylene-1,3-diisocyanate; tetramethylene-1,4-diisocyanate; pentamethylene diisocyanate; 1,6-hexamethylene diisocyanate (HDI); octamethylene diisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; diethylidene diisocyanate; methylcyclohexylene diisocyanate (HTDI); 2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate; 4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate; 1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexane diisocyanate; 4,4′-bis(isocyanatomethyl) dicyclohexane; 2,4′-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate (IPDI); dimeryl diisocyanate, dodecane-1,12-diisocyanate, 1,10-decamethylene diisocyanate, cyclohexylene-1,2-diisocyanate, 1,10-decamethylene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, furfurylidene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,3-cyclobutane diisocyanate, 1,4-cyclohexane diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), 4,4′-methylenebis(phenyl isocyanate), 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis (isocyanato-methyl)cyclohexane, 1,6-diisocyanato-2,2,4,4-tetra-methylhexane, 1,6-diisocyanato-2,4,4-tetra-trimethylhexane, trans-cyclohexane-1,4-diisocyanate, 3-isocyanato-methyl-3,5,5-trimethylcyclo-hexyl isocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclohexyl isocyanate, dicyclohexylmethane 4,4′-diisocyanate, 1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate, m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylene diisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, metaxylene diisocyanate, 2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate, 4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 1, 3-xylylene diisocyanate, 1,4-naphthylene diisocyanate, azobenzene-4,4′-diisocyanate, diphenyl sulfone-4,4′-diisocyanate, triphenylmethane 4,4′,4″-triisocyanate, isocyanatoethyl methacrylate, 3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylene diisocyanate, ω,ω′-diisocyanato-1,4-diethylbenzene, polymethylene polyphenylene polyisocyanate, isocyanurate modified compounds, and carbodiimide modified compounds, as well as biuret modified compounds of the above polyisocyanates. These isocyanates may be used either alone or in combination. These combination isocyanates include triisocyanates, such as biuret of hexamethylene diisocyanate and triphenylmethane triisocyanates, and polyisocyanates, such as polymeric diphenylmethane diisocyanate.triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate (TMDI); 4,4′-dicyclohexylmethane diisocyanate (H₁₂MDI); 2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate; 1,2-, 1,3-, and 1,4-phenylene diisocyanate; aromatic aliphatic isocyanate, such as 1,2-, 1,3-, and 1,4-xylene diisocyanate; meta-tetramethylxylene diisocyanate (m-TMXDI); para-tetramethylxylene diisocyanate (p-TMXDI); trimerized isocyanurate of any polyisocyanate, such as isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, trimer of tetramethylxylene diisocyanate, isocyanurate of hexamethylene diisocyanate, and mixtures thereof, dimerized uretdione of any polyisocyanate, such as uretdione of toluene diisocyanate, uretdione of hexamethylene diisocyanate, and mixtures thereof; modified polyisocyanate derived from the above isocyanates and polyisocyanates; and mixtures thereof.

In view of the advantages of injection molding versus the more complex casting process, under some circumstances it is advantageous to have formulations capable of curing as a thermoset but only within a specified temperature range above that of the typical injection molding process. This allows parts, such as golf ball cover layers, to be initially injection molded, followed by subsequent processing at higher temperatures and pressures to induce further crosslinking and curing, resulting in thermoset properties in the final part. Such an initially injection moldable composition is thus called a post curable urethane or urea composition. In one exemplary embodiment, a post curable urethane or rea can be sued for the multi-color cover layer.

If a post curable urethane composition is required, a modified or blocked diisocyanate which subsequently unblocks and induces further cross-linking post extrusion may be included in the diisocyanate starting material. Modified isocyanates used for making the polyurethanes of the present invention generally are defined as chemical compounds containing isocyanate groups that are not reactive at room temperature, but that become reactive once they reach a characteristic temperature. The resulting isocyanates can act as crosslinking agents or chain extenders to form crosslinked polyurethanes. The degree of crosslinking is governed by type and concentration of modified isocyanate presented in the composition. The modified isocyanate used in the composition preferably is selected, in part, to have a characteristic temperature sufficiently high such that the urethane in the composition will retain its thermoplastic behavior during initial processing (such as injection molding). If a characteristic temperature is too low, the composition crosslinks before processing is completed, leading to process difficulties. The modified isocyanate preferably is selected from isophorone diisocyanate (IPDI)-based uretdione-type crosslinker; a combination of a uretdione adduct of IPDI and a partially e-caprolactam-modified IPDI; a combination of isocyanate adducts modified by e-caprolactam and a carboxylic acid functional group; a caprolactam-modified Desmodur diisocyanate; a Desmodur diisocyanate having a 3,5-dimethyl pyrazole modified isocyanate; or mixtures of these. Particular preferred examples of modified isocyanates include those marketed under the trade name CRELAN by Bayer Corporation. Examples of these include: CRELAN TP LS 2147; CRELAN NI 2; isophorone diisocyanate (IPDI)-based uretdione-type crosslinker, such as CRELAN VP LS 2347; a combination of a uretdione adduct of IPDI and a partially e-caprolactam-modified IPDI, such as CRELAN VP LS 2386; a combination of isocyanate adducts modified by e-caprolactam and a carboxylic acid functional group, such as CRELAN VP LS 2181/1; a caprolactam-modified Desmodur diisocyanate, such as CRELAN NW5; and a Desmodur diisocyanate having a 3,5-dimethyl pyrazole modified isocyanate, such as CRELAN XP 7180. These modified isocyanates may be used either alone or in combination. Such modified diisocyanates are described in more detail in U.S. Pat. No. 6,939,924, the entire contents of which are hereby incorporated by reference.

As an alternative if a post curable polyurethane or polyurea composition is required, the diisocyanate may further comprise reaction product of a nitroso compound and a diisocyanate or a polyisocyanate. The reaction product has a characteristic temperature at which it decomposes regenerating the nitroso compound and diisocyanate or polyisocyanate, which can, by judicious choice of the post processing temperature, in turn induce further crosslinking in the originally thermoplastic composition resulting in thermoset-like properties. Such nitroso compounds are described in more detail in U.S. Pat. No. 7,037,985 B2, the entire contents of which are hereby incorporated by reference.

Any polyol now known or hereafter developed is suitable for use according to the invention. Polyols suitable for use in the present invention include, but are not limited to, polyester polyols, polyether polyols, polycarbonate polyols and polydiene polyols such as polybutadiene polyols.

Polyester polyols are prepared by condensation or step-growth polymerization utilizing diacids. Primary diacids for polyester polyols are adipic acid and isomeric phthalic acids. Adipic acid is used for materials requiring added flexibility, whereas phthalic anhydride is used for those requiring rigidity. Some examples of polyester polyols include poly(ethylene adipate) (PEA), poly(diethylene adipate) (PDA), poly(propylene adipate) (PPA), poly(tetramethylene adipate) (PBA), poly(hexamethylene adipate) (PHA), poly(neopentylene adipate) (PNA), polyols composed of 3-methyl-1,5-pentanediol and adipic acid, random copolymer of PEA and PDA, random copolymer of PEA and PPA, random copolymer of PEA and PBA, random copolymer of PHA and PNA, caprolactone polyol obtained by the ring-opening polymerization of ε-caprolactone, and polyol obtained by opening the ring of β-methyl-δ-valerolactone with ethylene glycol can be used either alone or in a combination thereof. Additionally, polyester polyol may be composed of a copolymer of at least one of the following acids and at least one of the following glycols. The acids include terephthalic acid, isophthalic acid, phthalic anhydride, oxalic acid, malonic acid, succinic acid, pentanedioic acid, hexanedioic acid, octanedioic acid, nonanedioic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (a mixture), p-hydroxybenzoate, trimellitic anhydride, ε-caprolactone, and β-methyl-δ-valerolactone. The glycols includes ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylene glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexane dimethanol, pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening addition polymerization of an alkylene oxide (e.g. ethylene oxide and propylene oxide) with an initiator of a polyhydric alcohol (e.g. diethylene glycol), which is an active hydride. Specifically, polypropylene glycol (PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxide copolymer can be obtained. Polytetramethylene ether glycol (PTMG) is prepared by the ring-opening polymerization of tetrahydrofuran, produced by dehydration of 1,4-butanediol or hydrogenation of furan. Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically, tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethylene oxide copolymer can be formed. The polyether polyol may be used either alone or in a combination.

Polycarbonate polyol is obtained by the condensation of a known polyol (polyhydric alcohol) with phosgene, chloroformic acid ester, dialkyl carbonate or diallyl carbonate. Particularly preferred polycarbonate polyols contain a polyol component using 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentylglycol or 1,5-pentanediol. Polycarbonate polyols can be used either alone or in a combination with other polyols.

Polydiene polyols include liquid diene polymer containing hydroxyl groups having an average of at least 1.7 functional groups, and may comprise diene polymers or diene copolymers having from about 4 to about 12 carbon atoms, or a copolymer of such diene with addition to polymerizable α-olefin monomer having 2 to 2.2 carbon atoms. Specific examples include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethyl hexyl acrylate copolymer, and butadiene-n-octadecyl acrylate copolymer. These liquid diene polymers can be obtained, for example, by heating a conjugated diene monomer in the presence of hydrogen peroxide in a liquid reactant.

Polybutadiene polyol includes liquid diene polymer containing hydroxyl groups having an average of at least 1.7 functional groups, and may be composed of diene polymer or diene copolymer having 4 to 12 carbon atoms, or a copolymer of such diene with addition to polymerizable α-olefin monomer having 2 to 2.2 carbon atoms. Specific examples include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethyl hexyl acrylate copolymer, and butadiene-n-octadecyl acrylate copolymer. These liquid diene polymers can be obtained, for example, by heating a conjugated diene monomer in the presence of hydrogen peroxide in a liquid reactant

Any polyamine available to one of ordinary skill in the polyurethane art is suitable for use according to the disclosure herein. Polyamines suitable for use include, but are not limited to, amine-terminated compounds typically are selected from amine-terminated hydrocarbons, amine-terminated polyethers, amine-terminated polyesters, amine-terminated polycaprolactones, amine-terminated polycarbonates, amine-terminated polyamides, and mixtures thereof. The amine-terminated compound may be a polyether amine selected from polytetramethylene ether diamines, polyoxypropylene diamines, poly(ethylene oxide capped oxypropylene) ether diamines, triethyleneglycoldiamines, propylene oxide-based triamines, trimethylolpropane-based triamines, glycerin-based triamines, and mixtures thereof.

Diisocyanate and polyol or polyamine components may be combined to form a prepolymer prior to reaction with a chain extender or curing agent. Any such prepolymer combination is suitable for use in the present invention. Commercially available prepolymers include LFH580, LFH120, LFH710, LFH1570, LF930A, LF950A, LF601D, LF751D, LFG963A, LFG640D.

One preferred prepolymer is a toluene diisocyanate prepolymer with polypropylene glycol. Such polypropylene glycol terminated toluene diisocyanate prepolymers are available from Uniroyal Chemical Company of Middlebury, Conn., under the trade name ADIPRENE® LFG963A and LFG640D. Most preferred prepolymers are the polytetramethylene ether glycol terminated toluene diisocyanate prepolymers including those available from Uniroyal Chemical Company of Middlebury, Conn., under the trade name ADIPRENE® LF930A, LF950A, LF601D, and LF751D.

In one embodiment, the number of free NCO groups in the urethane or urea prepolymer may be less than about 14 percent. Preferably the urethane or urea prepolymer has from about 3 percent to about 11 percent, more preferably from about 4 to about 9.5 percent, and even more preferably from about 3 percent to about 9 percent, free NCO on an equivalent weight basis.

Polyol chain extenders or curing agents may be primary, secondary, or tertiary polyols. Non-limiting examples of monomers of these polyols include: trimethylolpropane (TMP), ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, and 2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

Diamines and other suitable polyamines may be added to the compositions to function as chain extenders or curing agents. These include primary, secondary and tertiary amines having two or more amines as functional groups. Exemplary diamines include aliphatic diamines, such as tetramethylenediamine, pentamethylenediamine, hexamethylenediamine; alicyclic diamines, such as 3,3′-dimethyl-4,4′-diamino-dicyclohexyl methane; or aromatic diamines, such as diethyl-2,4-toluenediamine, 4,4″-methylenebis-(3-chloro,2,6-diethyl)-aniline (available from Air Products and Chemicals Inc., of Allentown, Pa., under the trade name LONZACURE®), 3,3′-dichlorobenzidene; 3,3′-dichloro-4,4′-diaminodiphenyl methane (MOCA); N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine, 3,5-dimethylthio-2,4-toluenediamine; 3,5-dimethylthio-2,6-toluenediamine; N,N′-dialkyldiamino diphenyl methane; trimethylene-glycol-di-p-aminobenzoate; polytetramethyleneoxide-di-p-aminobenzoate, 4,4′-methylene bis-2-chloroaniline, 2,2′,3,3′-tetrachloro-4,4′-diamino-phenyl methane, p,p′-methylenedianiline, p-phenylenediamine or 4,4′-diaminodiphenyl; and 2,4,6-tris(dimethylaminomethyl) phenol.

Further examples include ethylene diamine; 1-methyl-2,6-cyclohexyl diamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine; 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,4-bis-(sec-butylamino)-cyclohexane; 1,2-bis-(sec-butylamino)-cyclohexane; derivatives of 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethane diamine; 1,4-cyclohexane-bis-(methylamine); 1,3-cyclohexane-bis-(methylamine); diethylene glycol bis-(aminopropyl) ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylene triamine; triethylene tetramine; tetraethylene pentamine; propylene diamine; 1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine; imido-(bis-propylamine); monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine, diisopropanolamine; isophoronediamine; and mixtures thereof.

Aromatic diamines have a tendency to provide a stiffer (i.e., having a higher Mooney viscosity) product than aliphatic or cycloaliphatic diamines.

Depending on their chemical structure, curing agents may be slow- or fast-reacting polyamines or polyols. As described in U.S. Pat. Nos. 6,793,864, 6,719,646 and copending U.S. Patent Publication No. 2004/0201133 A1, (the contents of all of which are hereby incorporated herein by reference), slow-reacting polyamines are diamines having amine groups that are sterically and/or electronically hindered by electron withdrawing groups or bulky groups situated proximate to the amine reaction sites. The spacing of the amine reaction sites will also affect the reactivity speed of the polyamines.

Suitable curatives for use in the present invention are selected from the slow-reacting polyamine group include, but are not limited to, 3,5-dimethylthio-2,4-toluenediamine; 3,5-dimethylthio-2,6-toluenediamine; N,N′-dialkyldiamino diphenyl methane; trimethylene-glycol-di-p-aminobenzoate; polytetramethyleneoxide-di-p-aminobenzoate, and mixtures thereof. Of these, 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine are isomers and are sold under the trade name ETHACURE® 300 by Ethyl Corporation. Trimethylene glycol-di-p-aminobenzoate is sold under the trade name POLACURE 740M and polytetramethyleneoxide-di-p-aminobenzoates are sold under the trade name POLAMINES by Polaroid Corporation. N,N′-dialkyldiamino diphenyl methane is sold under the trade name UNILINK® by UOP.

When slow-reacting polyamines are used as the curing agent to produce urethane elastomers, a catalyst is typically needed to promote the reaction between the urethane prepolymer and the curing agent. Specific suitable catalysts include TEDA (1) dissolved in di-propylene glycol (such as TEDA L33 available from Witco Corp. Greenwich, Conn., and DABCO 33 LV available from Air Products and Chemicals Inc.). Catalysts are added at suitable effective amounts, such as from about 2% to about 5%, and (2) more preferably TEDA dissolved in 1,4-butane diol from about 2% to about 5%. Another suitable catalyst includes a blend of 0.5% 33LV or TEDA L33 (above) with 0.1% dibutyl tin dilaurate (available from Witco Corp. or Air Products and Chemicals, Inc.) which is added to a curative such as VIBRACURE® A250. Unfortunately, as is well known in the art, the use of a catalyst can have a significant effect on the ability to control the reaction and thus, on the overall processability.

To eliminate the need for a catalyst, a fast-reacting curing agent, or agents, can be used that does not have electron withdrawing groups or bulky groups that interfere with the reaction groups. However, the problem with lack of control associated with the use of catalysts is not completely eliminated since fast-reacting curing agents also are relatively difficult to control.

Preferred curing agent blends include using dicyandiamide in combination with fast curing agents such as diethyl-2,4-toluenediamine, 4,4″-methylenebis-(3-chloro,2,6-diethyl)-aniline (available from Air Products and Chemicals Inc., of Allentown, Pa., under the trade name LONZACURE®), 3,3′-dichlorobenzidene; 3,3′-dichloro-4,4′-diaminodiphenyl methane (MOCA); N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine and Curalon L, a trade name for a mixture of aromatic diamines sold by Uniroyal, Inc. or any and all combinations thereof. A preferred fast-reacting curing agent is diethyl-2,4-toluene diamine, which has two commercial grades names, Ethacure® 100 and Ethacure® 100LC commercial grade has lower color and less by-product. In other words, it is considered a cleaner product to those skilled in the art.

Advantageously, the use of the Ethacure® 100LC commercial grade results in a golf ball that is less susceptible to yellowing when exposed to UV light conditions. A player appreciates this desirable aesthetic effect although it should be noted that the instant invention may use either of these two commercial grades for the curing agent diethyl-2,4-toluenediamine.

If a reduced-yellowing post curable composition is required, the chain extender or curing agent can further comprise a peroxide or peroxide mixture. Before the composition is exposed to sufficient thermal energy to reach the activation temperature of the peroxide, the composition of (a) and (b) behaves as a thermoplastic material. Therefore, it can readily be formed into golf ball layers using injection molding. However, when sufficient thermal energy is applied to bring the composition above the peroxide activation temperature, crosslinking occurs, and the thermoplastic polyurethane is converted into crosslinked polyurethane.

Examples of suitable peroxides for use in compositions within the scope of the present invention include aliphatic peroxides, aromatic peroxides, cyclic peroxides, or mixtures of these. Primary, secondary, or tertiary peroxides can be used, with tertiary peroxides most preferred. Also, peroxides containing more than one peroxy group can be used, such as 2,5-bis-(tert-butylperoxy)-2,5-dimethyl hexane and 1,4-bis-(tert-butylperoxy-isopropyl)-benzene. Also, peroxides that are either symmetrical or asymmetric can be used, such as tert-butylperbenzoate and tert-butylcumylperoxide. Additionally, peroxides having carboxy groups also can be used. Decomposition of peroxides used in compositions within the scope of the present invention can be brought about by applying thermal energy, shear, reactions with other chemical ingredients, or a combination of these. Homolytically decomposed peroxide, heterolytically decomposed peroxide, or a mixture of those can be used to promote crosslinking reactions in compositions within the scope of this invention. Examples of suitable aliphatic peroxides and aromatic peroxides include diacetylperoxide, di-tert-butylperoxide, dibenzoylperoxide, dicumylperoxide, 2,5-bis-(t-butylperoxy)-2,5-dimethyl hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(butylperoxy)-3-hexyne, n-butyl-4,4-bis(t-butylperoxyl) valerate, 1,4-bis-(t-butylperoxyisopropyl)-benzene, t-butyl peroxybenzoate, 1,1-bis-(t-butylperoxy)-3,3,5 tri-methylcyclohexane, and di(2,4-dichloro-benzoyl). Peroxides for use within the scope of this invention may be acquired from Akzo Nobel Polymer Chemicals of Chicago, Illinois, Atofina of Philadelphia, Pennsylvania and Akrochem of Akron, Ohio. Further details of this post curable system are disclosed in U.S. Pat. No. 6,924,337, the entire contents of which are hereby incorporated by reference.

The core and/or one or more mantle layers may comprise one or more ionomer resins. One family of such resins was developed in the mid-1960's, by E.I. DuPont de Nemours and Co., and sold under the trademark SURLYN®. Preparation of such ionomers is well known, for example see U.S. Pat. No. 3,264,272. Generally speaking, most commercial ionomers are unimodal and consist of a polymer of a mono-olefin, e.g., an alkene, with an unsaturated mono- or dicarboxylic acids having 3 to 12 carbon atoms. An additional monomer in the form of a mono- or dicarboxylic acid ester may also be incorporated in the formulation as a so-called “softening comonomer”. The incorporated carboxylic acid groups are then neutralized by a basic metal ion salt, to form the ionomer. The metal cations of the basic metal ion salt used for neutralization include Li⁺, Na⁺, K⁺, Zn²⁺, Ca²⁺, Co²⁺, Ni²⁺, Cu²⁺, Pb²⁺, and Mg²⁺, with the Li⁺, Na⁺, Ca²⁺, Zn²⁺, and Mg²⁺ being preferred. The basic metal ion salts include those of for example formic acid, acetic acid, nitric acid, and carbonic acid, hydrogen carbonate salts, oxides, hydroxides, and alkoxides.

The first commercially available ionomer resins contained up to 16 weight percent acrylic or methacrylic acid, although it was also well known at that time that, as a general rule, the hardness of these cover materials could be increased with increasing acid content. Hence, in Research Disclosure 29703, published in January 1989, DuPont disclosed ionomers based on ethylene/acrylic acid or ethylene/methacrylic acid containing acid contents of greater than 15 weight percent. In this same disclosure, DuPont also taught that such so called “high acid ionomers” had significantly improved stiffness and hardness and thus could be advantageously used in golf ball construction, when used either singly or in a blend with other ionomers.

More recently, high acid ionomers can be ionomer resins with acrylic or methacrylic acid units present from 16 wt. % to about 35 wt. % in the polymer. Generally, such a high acid ionomer will have a flexural modulus from about 50,000 psi to about 125,000 psi.

Ionomer resins further comprising a softening comonomer, present from about 10 wt. % to about 50 wt. % in the polymer, have a flexural modulus from about 2,000 psi to about 10,000 psi, and are sometimes referred to as “soft” or “very low modulus” ionomers. Typical softening comonomers include n-butyl acrylate, iso-butyl acrylate, n-butyl methacrylate, methyl acrylate and methyl methacrylate.

Today, there are a wide variety of commercially available ionomer resins based both on copolymers of ethylene and (meth)acrylic acid or terpolymers of ethylene and (meth)acrylic acid and (meth)acrylate, all of which can be used as a golf ball component. The properties of these ionomer resins can vary widely due to variations in acid content, softening comonomer content, the degree of neutralization, and the type of metal ion used in the neutralization. The full range commercially available typically includes ionomers of polymers of general formula, E/X/Y polymer, wherein E is ethylene, X is a C₃to C₈α,β ethylenically unsaturated carboxylic acid, such as acrylic or methacrylic acid, and is present in an amount from about 0 wt. % to about 50 wt. %, particularly about 2 to about 30 weight %, of the E/X/Y copolymer, and Y is a softening comonomer selected from the group consisting of alkyl acrylate and alkyl methacrylate, such as methyl acrylate or methyl methacrylate, and wherein the alkyl groups have from 1-8 carbon atoms, Y is in the range of 0 to about 50 weight %, particularly about 5 wt. % to about 35 wt. %, of the E/X/Y copolymer, and wherein the acid groups present in said ionomeric polymer are partially (e.g., about 1% to about 90%) neutralized with a metal selected from the group consisting of lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc or aluminum, or a combination of such cations.

The ionomer may also be a so-called bimodal ionomer as described in U.S. Pat. No. 6,562,906 (the entire contents of which are herein incorporated by reference). These ionomers are bimodal as they are prepared from blends comprising polymers of different molecular weights. Specifically, they include bimodal polymer blend compositions comprising:

- a) a high molecular weight component having weight average molecular weight (M_W) of about 80,000 to about 500,000 and comprising one or more ethylene/α, β-ethylenically unsaturated C_3-8carboxylic acid copolymers and/or one or more ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers; said high molecular weight component being partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and a mixture of any these; and
- b) a low molecular weight component having a weight average molecular weight (M_W) of about from about 2,000 to about 30,000 and comprising one or more ethylene/α, β-ethylenically unsaturated C_3-8carboxylic acid copolymers and/or one or more ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers; said low molecular weight component being partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and a mixture of any these.

In addition to the unimodal and bimodal ionomers, also included are the so-called “modified ionomers” examples of which are described in U.S. Pat. Nos. 6,100,321, 6,329,458 and 6,616,552 and U.S. Patent Publication No. US 2003/0158312 A1, the entire contents of all of which are herein incorporated by reference.

The modified unimodal ionomers may be prepared by mixing:

- a) an ionomeric polymer comprising ethylene, from 5 to 25 weight percent (meth)acrylic acid, and from 0 to 40 weight percent of a (meth)acrylate monomer, said ionomeric polymer neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and a mixture of any of these; and
- b) from about 5 to about 40 weight percent (based on the total weight of said modified ionomeric polymer) of one or more fatty acids or metal salts of said fatty acid, the metal selected from the group consisting of calcium, sodium, zinc, potassium, and lithium, barium and magnesium and the fatty acid preferably being stearic acid.

The modified bimodal ionomers, which are ionomers derived from the earlier described bimodal ethylene/carboxylic acid polymers (as described in U.S. Pat. No. 6,562,906, the entire contents of which are herein incorporated by reference), are prepared by mixing;

- a) a high molecular weight component having weight average molecular weight (M_W) of about 80,000 to about 500,000 and comprising one or more ethylene/α, β-ethylenically unsaturated C_3-8carboxylic acid copolymers and/or one or more ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers; said high molecular weight component being partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, potassium, magnesium, and a mixture of any of these; and
- b) a low molecular weight component having a weight average molecular weight (M_W) of about from about 2,000 to about 30,000 and comprising one or more ethylene/α, β-ethylenically unsaturated C_3-8carboxylic acid copolymers and/or one or more ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers; said low molecular weight component being partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, potassium, magnesium, and a mixture of any of these; and
- c) from about 5 to about 40 weight percent (based on the total weight of said modified ionomeric polymer) of one or more fatty acids or metal salts of said fatty acid, the metal selected from the group consisting of calcium, sodium, zinc, potassium and lithium, barium and magnesium and the fatty acid preferably being stearic acid.

The fatty or waxy acid salts utilized in the various modified ionomers are composed of a chain of alkyl groups containing from about 4 to 75 carbon atoms (usually even numbered) and characterized by a —COOH terminal group. The generic formula for all fatty and waxy acids above acetic acid is CH₃(CH₂)_XCOOH, wherein the carbon atom count includes the carboxyl group. The fatty or waxy acids utilized to produce the fatty or waxy acid salts modifiers may be saturated or unsaturated, and they may be present in solid, semi-solid or liquid form.

Examples of suitable saturated fatty acids, i.e., fatty acids in which the carbon atoms of the alkyl chain are connected by single bonds, include but are not limited to stearic acid (C₁₈, i.e., CH₃(CH₂)₁₆COOH), palmitic acid (C₁₆, i.e., CH₃(CH₂)₁₄COOH), pelargonic acid (C₉, i.e., CH₃(CH₂)₇COOH) and lauric acid (C₁₂, i.e., CH₃(CH₂)₁₀OCOOH). Examples of suitable unsaturated fatty acids, i.e., a fatty acid in which there are one or more double bonds between the carbon atoms in the alkyl chain, include but are not limited to oleic acid (C₁₃, i.e., CH₃(CH₂)₇CH:CH(CH₂)₇COOH).

The source of the metal ions used to produce the metal salts of the fatty or waxy acid salts used in the various modified ionomers are generally various metal salts which provide the metal ions capable of neutralizing, to various extents, the carboxylic acid groups of the fatty acids. These include the sulfate, carbonate, acetate and hydroxylate salts of zinc, barium, calcium and magnesium.

Since the fatty acid salts modifiers comprise various combinations of fatty acids neutralized with a large number of different metal ions, several different types of fatty acid salts may be utilized in the invention, including metal stearates, laureates, oleates, and palmitates, with calcium, zinc, sodium, lithium, potassium and magnesium stearate being preferred, and calcium and sodium stearate being most preferred.

The fatty or waxy acid or metal salt of said fatty or waxy acid is present in the modified ionomeric polymers in an amount of from about 5 to about 40, preferably from about 7 to about 35, more preferably from about 8 to about 20 weight percent (based on the total weight of said modified ionomeric polymer).

As a result of the addition of the one or more metal salts of a fatty or waxy acid, from about 40 to 100, preferably from about 50 to 100, more preferably from about 70 to 100 percent of the acidic groups in the final modified ionomeric polymer composition are neutralized by a metal ion.

An example of such a modified ionomer polymer is DuPont® HPF-1000 available from E. I. DuPont de Nemours and Co. Inc.

A preferred ionomer composition may be prepared by blending one or more of the unimodal ionomers, bimodal ionomers, or modified unimodal or bimodal ionomeric polymers as described herein, and further blended with a zinc neutralized ionomer of a polymer of general formula E/X/Y where E is ethylene, X is a softening comonomer such as acrylate or methacrylate and is present in an amount of from 0 to about 50, preferably 0 to about 25, most preferably 0, and Y is acrylic or methacrylic acid and is present in an amount from about 5 wt. % to about 25, preferably from about 10 to about 25, and most preferably about 10 to about 20 wt. % of the total composition.

In particular embodiment, blends used to make the core, intermediate and/or cover layers may include about 5 to about 95 wt. %, particularly about 5 to about 75 wt. %, preferably about 5 to about 55 wt. %, of a specialty propylene elastomer(s) and about 95 to about 5 wt. %, particularly about 95 to about 25 wt. %, preferably about 95 to about 45 wt. %, of at least one ionomer, especially a high-acid ionomer.

In yet another embodiment, a blend of an ionomer and a block copolymer can be included in the composition. An example of a block copolymer is a functionalized styrenic block copolymer, the block copolymer incorporating a first polymer block having an aromatic vinyl compound, a second polymer block having a conjugated diene compound, and a hydroxyl group located at a block copolymer, or its hydrogenation product, in which the ratio of block copolymer to ionomer ranges from 5:95 to 95:5 by weight, more preferably from about 10:90 to about 90:10 by weight, more preferably from about 20:80 to about 80:20 by weight, more preferably from about 30:70 to about 70:30 by weight and most preferably from about 35:65 to about 65:35 by weight. A preferred block copolymer is SEPTON HG-252. Such blends are described in more detail in commonly-assigned U.S. Pat. No. 6,861,474 and U.S. Patent Publication No. 2003/0224871 both of which are incorporated herein by reference in their entireties.

In a further embodiment, the core, mantle and/or cover layers (and particularly a mantle layer) can comprise a composition prepared by blending together at least three materials, identified as Components A, B, and C, and melt-processing these components to form in-situ a polymer blend composition incorporating a pseudo-crosslinked polymer network. Such blends are described in more detail in commonly-assigned U.S. Pat. No. 6,930,150, which is incorporated by reference herein in its entirety. Component A is a monomer, oligomer, prepolymer or polymer that incorporates at least five percent by weight of at least one type of an anionic functional group, and more preferably between about 5% and 50% by weight. Component B is a monomer, oligomer, or polymer that incorporates less by weight of anionic functional groups than does Component A, Component B preferably incorporates less than about 25% by weight of anionic functional groups, more preferably less than about 20% by weight, more preferably less than about 10% by weight, and most preferably Component B is free of anionic functional groups. Component C incorporates a metal cation, preferably as a metal salt. The pseudo-crosslinked network structure is formed in-situ, not by covalent bonds, but instead by ionic clustering of the reacted functional groups of Component A. The method can incorporate blending together more than one of any of Components A, B, or C.

The polymer blend can include either Component A or B dispersed in a phase of the other. Preferably, blend compositions comprises between about 1% and about 99% by weight of Component A based on the combined weight of Components A and B, more preferably between about 10% and about 90%, more preferably between about 20% and about 80%, and most preferably, between about 30% and about 70%. Component C is present in a quantity sufficient to produce the preferred amount of reaction of the anionic functional groups of Component A after sufficient melt-processing. Preferably, after melt-processing at least about 5% of the anionic functional groups in the chemical structure of Component A have been consumed, more preferably between about 10% and about 90%, more preferably between about 10% and about 80%, and most preferably between about 10% and about 70%.

The composition preferably is prepared by mixing the above materials into each other thoroughly, either by using a dispersive mixing mechanism, a distributive mixing mechanism, or a combination of these. These mixing methods are well known in the manufacture of polymer blends. As a result of this mixing, the anionic functional group of Component A is dispersed evenly throughout the mixture. Next, reaction is made to take place in-situ at the site of the anionic functional groups of Component A with Component C in the presence of Component B. This reaction is prompted by addition of heat to the mixture. The reaction results in the formation of ionic clusters in Component A and formation of a pseudo-crosslinked structure of Component A in the presence of Component B. Depending upon the structure of Component B, this pseudo-crosslinked Component A can combine with Component B to form a variety of interpenetrating network structures. For example, the materials can form a pseudo-crosslinked network of Component A dispersed in the phase of Component B, or Component B can be dispersed in the phase of the pseudo-crosslinked network of Component A. Component B may or may not also form a network, depending upon its structure, resulting in either: a fully-interpenetrating network, i.e., two independent networks of Components A and B penetrating each other, but not covalently bonded to each other; or, a semi-interpenetrating network of Components A and B, in which Component B forms a linear, grafted, or branched polymer interspersed in the network of Component A. For example, a reactive functional group or an unsaturation in Component B can be reacted to form a crosslinked structure in the presence of the in-situ-formed, pseudo-crosslinked structure of Component A, leading to formation of a fully-interpenetrating network. Any anionic functional groups in Component B also can be reacted with the metal cation of Component C, resulting in pseudo-crosslinking via ionic cluster attraction of Component A to Component B.

The level of in-situ-formed pseudo-crosslinking in the compositions formed by the present methods can be controlled as desired by selection and ratio of Components A and B, amount and type of anionic functional group, amount and type of metal cation in Component C, type and degree of chemical reaction in Component B, and degree of pseudo-crosslinking produced of Components A and B.

As discussed above, the mechanical and thermal properties of the polymer blend for the inner mantle layer and/or the outer mantle layer can be controlled as required by a modifying any of a number of factors, including: chemical structure of Components A and B, particularly the amount and type of anionic functional groups; mean molecular weight and molecular weight distribution of Components A and B; linearity and crystallinity of Components A and B; type of metal cation in Component C; degree of reaction achieved between the anionic functional groups and the metal cation; mix ratio of Component A to Component B; type and degree of chemical reaction in Component B; presence of chemical reaction, such as a crosslinking reaction, between Components A and B; and the particular mixing methods and conditions used.

As discussed above, Component A can be any monomer, oligomer, prepolymer, or polymer incorporating at least 5% by weight of anionic functional groups. Those anionic functional groups can be incorporated into monomeric, oligomeric, prepolymeric, or polymeric structures during the synthesis of Component A, or they can be incorporated into a pre-existing monomer, oligomer, prepolymer, or polymer through sulfonation, phosphonation, or carboxylation to produce Component A.

Preferred, but non-limiting, examples of suitable copolymers and terpolymers include copolymers or terpolymers of: ethylene/acrylic acid, ethylene/methacrylic acid, ethylene/itaconic acid, ethylene/methyl hydrogen maleate, ethylene/maleic acid, ethylene/methacrylic acid/ethylacrylate, ethylene/itaconic acid/methyl methacrylate, ethylene/methyl hydrogen maleate/ethyl acrylate, ethylene/methacrylic acid/vinyl acetate, ethylene/acrylic acid/vinyl alcohol, ethylene/propylene/acrylic acid, ethylene/styrene/acrylic acid, ethylene/methacrylic acid/acrylonitrile, ethylene/fumaric acid/vinyl methyl ether, ethylene/vinyl chloride/acrylic acid, ethylene/vinyldiene chloride/acrylic acid, ethylene/vinyl fluoride/methacrylic acid, and ethylene/chlorotrifluoroethylene/methacrylic acid, or any metallocene-catalyzed polymers of the above-listed species.

Another family of thermoplastic elastomers for use in the golf balls are polymers of i) ethylene and/or an alpha olefin; and ii) an α, β-ethylenically unsaturated C₃-C₂₀carboxylic acid or anhydride, or an α, β-ethylenically unsaturated C₃-C₂₀sulfonic acid or anhydride or an α, β-ethylenically unsaturated C₃-C₂₀phosphoric acid or anhydride and, optionally iii) a C₁-C₁₀ester of an α, β-ethylenically unsaturated C₃-C₂₀carboxylic acid or a C₁-C₁₀ester of an α, β-ethylenically unsaturated C₃-C₂₀sulfonic acid or a C₁-C₁₀ester of an α, β-ethylenically unsaturated C₃-C₂₀phosphoric acid.

Preferably, the alpha-olefin has from 2 to 10 carbon atoms and is preferably ethylene, and the unsaturated carboxylic acid is a carboxylic acid having from about 3 to 8 carbons. Examples of such acids include acrylic acid, methacrylic acid, ethacrylic acid, chloroacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, with acrylic acid being preferred. Preferably, the carboxylic acid ester if present may be selected from the group consisting of vinyl esters of aliphatic carboxylic acids wherein the acids have 2 to 10 carbon atoms and vinyl ethers wherein the alkyl groups contain 1 to 10 carbon atoms.

Examples of such polymers suitable for use include, but are not limited to, an ethylene/acrylic acid copolymer, an ethylene/methacrylic acid copolymer, an ethylene/itaconic acid copolymer, an ethylene/maleic acid copolymer, an ethylene/methacrylic acid/vinyl acetate copolymer, an ethylene/acrylic acid/vinyl alcohol copolymer, and the like.

Most preferred are ethylene/(meth)acrylic acid copolymers and ethylene/(meth)acrylic acid/alkyl (meth)acrylate terpolymers, or ethylene and/or propylene maleic anhydride copolymers and terpolymers.

The acid content of the polymer may contain anywhere from 1 to 30 percent by weight acid. In some instances, it is preferable to utilize a high acid copolymer (i.e., a copolymer containing greater than 16% by weight acid, preferably from about 17 to about 25 weight percent acid, and more preferably about 20 weight percent acid).

Examples of such polymers which are commercially available include, but are not limited to, the Escor® 5000, 5001, 5020, 5050, 5070, 5100, 5110 and 5200 series of ethylene-acrylic acid copolymers sold by Exxon and the PRIMACOR® 1321, 1410, 1410-XT, 1420, 1430, 2912, 3150, 3330, 3340, 3440, 3460, 4311, 4608 and 5980 series of ethylene-acrylic acid copolymers sold by The Dow Chemical Company, Midland, Michigan.

Also included are the bimodal ethylene/carboxylic acid polymers as described in U.S. Pat. No. 6,562,906. These polymers comprise ethylene/α, β-ethylenically unsaturated C_3-8carboxylic acid high copolymers, particularly ethylene (meth)acrylic acid copolymers and ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers, having molecular weights of about 80,000 to about 500,000 which are melt blended with ethylene/α, β-ethylenically unsaturated C_3-8carboxylic acid copolymers, particularly ethylene/(meth)acrylic acid copolymers having molecular weights of about 2,000 to about 30,000.

As discussed above, Component B can be any monomer, oligomer, or polymer, preferably having a lower weight percentage of anionic functional groups than that present in Component A in the weight ranges discussed above, and most preferably free of such functional groups. Examples of suitable materials for Component B include, but are not limited to, the following: thermoplastic elastomer, thermoset elastomer, synthetic rubber, thermoplastic vulcanizate, copolymeric ionomer, terpolymeric ionomer, polycarbonate, polyolefin, polyamide, copolymeric polyamide, polyesters, polyvinyl alcohols, acrylonitrile-butadiene-styrene copolymers, polyurethane, polyarylate, polyacrylate, polyphenyl ether, modified-polyphenyl ether, high-impact polystyrene, diallyl phthalate polymer, metallocene catalyzed polymers, acrylonitrile-styrene-butadiene (ABS), styrene-acrylonitrile (SAN) (including olefin-modified SAN and acrylonitrile styrene acrylonitrile), styrene-maleic anhydride (S/MA) polymer, styrenic copolymer, functionalized styrenic copolymer, functionalized styrenic terpolymer, styrenic terpolymer, cellulose polymer, liquid crystal polymer (LCP), ethylene-propylene-diene terpolymer (EPDM), ethylene-propylene copolymer, ethylene vinyl acetate, polyurea, and polysiloxane or any metallocene-catalyzed polymers of these species. Particularly suitable polymers for use as Component B include polyethylene-terephthalate, polybutyleneterephthalate, polytrimethylene-terephthalate, ethylene-carbon monoxide copolymer, polyvinyl-diene fluorides, polyphenylenesulfide, polypropyleneoxide, polyphenyloxide, polypropylene, functionalized polypropylene, polyethylene, ethylene-octene copolymer, ethylene-methyl acrylate, ethylene-butyl acrylate, polycarbonate, polysiloxane, functionalized polysiloxane, copolymeric ionomer, terpolymeric ionomer, polyetherester elastomer, polyesterester elastomer, polyetheramide elastomer, propylene-butadiene copolymer, modified copolymer of ethylene and propylene, styrenic copolymer (including styrenic block copolymer and randomly distributed styrenic copolymer, such as styrene-isobutylene copolymer and styrene-butadiene copolymer), partially or fully hydrogenated styrene-butadiene-styrene block copolymers such as styrene-(ethylene-propylene)-styrene or styrene-(ethylene-butylene)-styrene block copolymers, partially or fully hydrogenated styrene-butadiene-styrene block copolymers with functional group, polymers based on ethylene-propylene-(diene), polymers based on functionalized ethylene-propylene-diene), dynamically vulcanized polypropylene/ethylene-propylene-diene-copolymer, thermoplastic vulcanizates based on ethylene-propylene-(diene), thermoplastic polyetherurethane, thermoplastic polyesterurethane, compositions for making thermoset polyurethane, thermoset polyurethane, natural rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber, fluorocarbon rubber, butyl rubber, acrylic rubber, silicone rubber, chlorosulfonated polyethylene, polyisobutylene, alfin rubber, polyester rubber, epichlorohydrin rubber, chlorinated isobutylene-isoprene rubber, nitrile-isobutylene rubber, 1,2-polybutadiene, 1,4-polybutadiene, cis-polyisoprene, trans-polyisoprene, and polybutylene-octene.

Preferred materials for use as Component B include polyester elastomers marketed under the name PEBAX and LOTADER marketed by ATOFINA Chemicals of Philadelphia, Pennsylvania; HYTREL, FUSABOND, and NUCREL marketed by E.I. DuPont de Nemours & Co. of Wilmington, Delaware; SKYPEL and SKYTHANE by S.K. Chemicals of Seoul, South Korea; SEPTON and HYBRAR marketed by Kuraray Company of Kurashiki, Japan; ESTHANE by Noveon; and KRATON marketed by Kraton Polymers. A most preferred material for use as Component B is SEPTON HG-252.

As stated above, Component C is a metal cation. These metals are from groups IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, VB, VIA, VIB, VIIB and VIIIB of the periodic table. Examples of these metals include lithium, sodium, magnesium, aluminum, potassium, calcium, manganese, tungsten, titanium, iron, cobalt, nickel, hafnium, copper, zinc, barium, zirconium, and tin. Suitable metal compounds for use as a source of Component C are, for example, metal salts, preferably metal hydroxides, metal carbonates, or metal acetates. In addition to Components A, B, and C, other materials commonly used in polymer blend compositions, can be incorporated into compositions prepared using these methods, including: crosslinking agents, co-crosslinking agents, accelerators, activators, UV-active chemicals such as UV initiators, EB-active chemicals, colorants, UV stabilizers, optical brighteners, antioxidants, processing aids, mold release agents, foaming agents, and organic, inorganic or metallic fillers or fibers, including fillers to adjust specific gravity.

Various known methods are suitable for preparation of polymer blends. For example, the three components can be premixed together in any type of suitable mixer, such as a V-blender, tumbler mixer, or blade mixer. This premix then can be melt-processed using an internal mixer, such as Banbury mixer, roll-mill or combination of these, to produce a reaction product of the anionic functional groups of Component A by Component C in the presence of Component B. Alternatively, the premix can be melt-processed using an extruder, such as single screw, co-rotating twin screw, or counter-rotating twin screw extruder, to produce the reaction product. The mixing methods discussed above can be used together to melt-mix the three components to prepare the compositions of the present invention. Also, the components can be fed into an extruder simultaneously or sequentially.

Most preferably, Components A and B are melt-mixed together without Component C, with or without the premixing discussed above, to produce a melt-mixture of the two components. Then, Component C separately is mixed into the blend of Components A and B. This mixture is melt-mixed to produce the reaction product. This two-step mixing can be performed in a single process, such as, for example, an extrusion process using a proper barrel length or screw configuration, along with a multiple feeding system. In this case, Components A and B can be fed into the extruder through a main hopper to be melted and well-mixed while flowing downstream through the extruder. Then Component C can be fed into the extruder to react with the mixture of Components A and B between the feeding port for Component C and the die head of the extruder. The final polymer composition then exits from the die. If desired, any extra steps of melt-mixing can be added to either approach of the method of the present invention to provide for improved mixing or completion of the reaction between Components A and C. Also, additional components discussed above can be incorporated either into a premix, or at any of the melt-mixing stages. Alternatively, Components A, B, and C can be melt-mixed simultaneously to form in-situ a pseudo-crosslinked structure of Component A in the presence of Component B, either as a fully or semi-interpenetrating network.

Illustrative polyamides for use in the compositions/golf balls disclosed include those obtained by: (1) polycondensation of (a) a dicarboxylic acid, such as oxalic acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, or 1,4-cyclohexanedicarboxylic acid, with (b) a diamine, such as ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine, 1,4-cyclohexyldiamine or m-xylylenediamine; (2) a ring-opening polymerization of cyclic lactam, such as ε-caprolactam or co-laurolactam; (3) polycondensation of an aminocarboxylic acid, such as 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid or 12-aminododecanoic acid; (4) copolymerization of a cyclic lactam with a dicarboxylic acid and a diamine; or any combination of (1)-(4). In certain examples, the dicarboxylic acid may be an aromatic dicarboxylic acid or a cycloaliphatic dicarboxylic acid. In certain examples, the diamine may be an aromatic diamine or a cycloaliphatic diamine. Specific examples of suitable polyamides include polyamide 6; polyamide 11; polyamide 12; polyamide 4,6; polyamide 6,6; polyamide 6,9; polyamide 6,10; polyamide 6,12; polyamide MXD6; PA12,CX; PA12, IT; PPA; PA6, IT; and PA6/PPE.

The polyamide may be any homopolyamide or copolyamide. One example of a group of suitable polyamides is thermoplastic polyamide elastomers. Thermoplastic polyamide elastomers typically are copolymers of a polyamide and polyester or polyether. For example, the thermoplastic polyamide elastomer can contain a polyamide (Nylon 6, Nylon 66, Nylon 11, Nylon 12 and the like) as a hard segment and a polyether or polyester as a soft segment. In one specific example, the thermoplastic polyamides are amorphous copolyamides based on polyamide (PA 12).

One class of copolyamide elastomers are polyether amide elastomers. Illustrative examples of polyether amide elastomers are those that result from the copolycondensation of polyamide blocks having reactive chain ends with polyether blocks having reactive chain ends, including:

- (1) polyamide blocks of diamine chain ends with polyoxyalkylene sequences of dicarboxylic chains;
- (2) polyamide blocks of dicarboxylic chain ends with polyoxyalkylene sequences of diamine chain ends obtained by cyanoethylation and hydrogenation of polyoxyalkylene alpha-omega dihydroxylated aliphatic sequences known as polyether diols; and
- (3) polyamide blocks of dicarboxylic chain ends with polyether diols, the products obtained, in this particular case, being polyetheresteramides.

More specifically, the polyamide elastomer can be prepared by polycondensation of the components (i) a diamine and a dicarboxylate, lactames or an amino dicarboxylic acid (PA component), (ii) a polyoxyalkylene glycol such as polyoxyethylene glycol, polyoxy propylene glycol (PG component) and (iii) a dicarboxylic acid.

The polyamide blocks of dicarboxylic chain ends come, for example, from the condensation of alpha-omega aminocarboxylic acids of lactam or of carboxylic diacids and diamines in the presence of a carboxylic diacid which limits the chain length. The molecular weight of the polyamide sequences is preferably between about 300 and 15,000, and more preferably between about 600 and 5,000. The molecular weight of the polyether sequences is preferably between about 100 and 6,000, and more preferably between about 200 and 3,000.

The amide block polyethers may also comprise randomly distributed units. These polymers may be prepared by the simultaneous reaction of polyether and precursor of polyamide blocks. For example, the polyether diol may react with a lactam (or alpha-omega amino acid) and a diacid which limits the chain in the presence of water. A polymer is obtained that has primarily polyether blocks and/or polyamide blocks of very variable length, but also the various reactive groups that have reacted in a random manner and which are distributed statistically along the polymer chain.

Suitable amide block polyethers include those as disclosed in U.S. Pat. Nos. 4,331,786; 4,115,475; 4,195,015; 4,839,441; 4,864,014; 4,230,848 and 4,332,920.

The polyether may be, for example, a polyethylene glycol (PEG), a polypropylene glycol (PPG), or a polytetramethylene glycol (PTMG), also designated as polytetrahydrofurane (PTHF). The polyether blocks may be along the polymer chain in the form of diols or diamines. However, for reasons of simplification, they are designated PEG blocks, or PPG blocks, or also PTMG blocks.

The polyether block comprises different units such as units which derive from ethylene glycol, propylene glycol, or tetramethylene glycol.

The amide block polyether comprises at least one type of polyamide block and one type of polyether block. Mixing of two or more polymers with polyamide blocks and polyether blocks may also be used. The amide block polyether also can comprise any amide structure made from the method described on the above.

Preferably, the amide block polyether is such that it represents the major component in weight, i.e., that the amount of polyamide which is under the block configuration and that which is eventually distributed statistically in the chain represents 50 weight percent or more of the amide block polyether. Advantageously, the amount of polyamide and the amount of polyether is in a ratio (polyamide/polyether) of 1/1 to 3/1.

One type of polyetherester elastomer is the family of Pebax, which are available from Elf-Atochem Company. Preferably, the choice can be made from among Pebax 2533, 3533, 4033, 1205, 7033 and 7233. Blends or combinations of Pebax 2533, 3533, 4033, 1205, 7033 and 7233 can also be prepared, as well. Pebax 2533 has a hardness of about 25 shore D (according to ASTM D-2240), a Flexural Modulus of 2.1 kpsi (according to ASTM D-790), and a Bayshore resilience of about 62% (according to ASTM D-2632). Pebax 3533 has a hardness of about 35 shore D (according to ASTM D-2240), a Flexural Modulus of 2.8 kpsi (according to ASTM D-790), and a Bayshore resilience of about 59% (according to ASTM D-2632). Pebax 7033 has a hardness of about 69 shore D (according to ASTM D-2240) and a Flexural Modulus of 67 kpsi (according to ASTM D-790). Pebax 7333 has a hardness of about 72 shore D (according to ASTM D-2240) and a Flexural Modulus of 107 kpsi (according to ASTM D-790).

Some examples of suitable polyamides for use include those commercially available under the tradenames PEBAX, CRISTAMID and RILSAN marketed by Atofina Chemicals of Philadelphia, Pennsylvania, GRIVORY and GRILAMID marketed by EMS Chemie of Sumter, South Carolina, TROGAMID and VESTAMID available from Degussa, and ZYTEL marketed by E.I. DuPont de Nemours & Co., of Wilmington, Delaware.

The layer or core compositions can also incorporate one or more fillers. Such fillers are typically in a finely divided form, for example, in a size generally less than about 20 mesh, preferably less than about 100 mesh U.S. standard size, except for fibers and flock, which are generally elongated. Flock and fiber sizes should be small enough to facilitate processing. Filler particle size will depend upon desired effect, cost, ease of addition, and dusting considerations. The appropriate amounts of filler required will vary depending on the application but typically can be readily determined without undue experimentation.

The filler preferably is selected from the group consisting of precipitated hydrated silica, limestone, clay, talc, asbestos, barytes, glass fibers, aramid fibers, mica, calcium metasilicate, barium sulfate, zinc sulfide, lithopone, silicates, silicon carbide, diatomaceous earth, carbonates such as calcium or magnesium or barium carbonate, sulfates such as calcium or magnesium or barium sulfate, metals, including tungsten steel copper, cobalt or iron, metal alloys, tungsten carbide, metal oxides, metal stearates, and other particulate carbonaceous materials, and any and all combinations thereof. Preferred examples of fillers include metal oxides, such as zinc oxide and magnesium oxide. In another preferred embodiment the filler comprises a continuous or non-continuous fiber. In another preferred embodiment the filler comprises one or more so called nanofillers, as described in U.S. Pat. No. 6,794,447 and U.S. Patent Publication No. 2004-0092336A1 published May 13, 2004 and U.S. Patent Publication No. 2005-0059756A1 published Mar. 17, 2005, the entire contents of each of which are herein incorporated by reference.

Inorganic nanofiller material generally is made of clay, such as hydrotalcite, phyllosilicate, saponite, hectorite, beidellite, stevensite, vermiculite, halloysite, mica, montmorillonite, micafluoride, or octosilicate. To facilitate incorporation of the nanofiller material into a polymer material, either in preparing nanocomposite materials or in preparing polymer-based golf ball compositions, the clay particles generally are coated or treated by a suitable compatibilizing agent. The compatibilizing agent allows for superior linkage between the inorganic and organic material, and it also can account for the hydrophilic nature of the inorganic nanofiller material and the possibly hydrophobic nature of the polymer. Compatibilizing agents may exhibit a variety of different structures depending upon the nature of both the inorganic nanofiller material and the target matrix polymer. Non-limiting examples include hydroxy-, thiol-, amino-, epoxy-, carboxylic acid-, ester-, amide-, and siloxy-group containing compounds, oligomers or polymers. The nanofiller materials can be incorporated into the polymer either by dispersion into the particular monomer or oligomer prior to polymerization, or by melt compounding of the particles into the matrix polymer. Examples of commercial nanofillers are various Cloisite grades including 10A, 15A, 20A, 25A, 30B, and NA+ of Southern Clay Products (Gonzales, Texas) and the Nanomer grades including 1.24TL and C.30EVA of Nanocor, Inc. (Arlington Heights, Illinois).

As mentioned above, the nanofiller particles have an aggregate structure with the aggregates particle sizes in the micron range and above. However, these aggregates have a stacked plate structure with the individual platelets being roughly 1 nanometer (nm) thick and 100 to 1000 nm across. As a result, nanofillers have extremely high surface area, resulting in high reinforcement efficiency to the material at low loading levels of the particles. The sub-micron-sized particles enhance the stiffness of the material, without increasing its weight or opacity and without reducing the material's low-temperature toughness.

Nanofillers when added into a matrix polymer, can be mixed in three ways. In one type of mixing there is dispersion of the aggregate structures within the matrix polymer, but on mixing no interaction of the matrix polymer with the aggregate platelet structure occurs, and thus the stacked platelet structure is essentially maintained. As used herein, this type of mixing is defined as “undispersed”.

However, if the nanofiller material is selected correctly, the matrix polymer chains can penetrate into the aggregates and separate the platelets, and thus when viewed by transmission electron microscopy or x-ray diffraction, the aggregates of platelets are expanded. At this point the nanofiller is said to be substantially evenly dispersed within and reacted into the structure of the matrix polymer. This level of expansion can occur to differing degrees. If small amounts of the matrix polymer are layered between the individual platelets then, as used herein, this type of mixing is known as “intercalation”.

In some cases, further penetration of the matrix polymer chains into the aggregate structure separates the platelets, and leads to a complete breaking up of the platelet's stacked structure in the aggregate and thus when viewed by transmission electron microscopy (TEM), the individual platelets are thoroughly mixed throughout the matrix polymer. As used herein, this type of mixing is known as “exfoliated”. An exfoliated nanofiller has the platelets fully dispersed throughout the polymer matrix; the platelets may be dispersed unevenly but preferably are dispersed evenly.

While not wishing to be limited to any theory, one possible explanation of the differing degrees of dispersion of such nanofillers within the matrix polymer structure is the effect of the compatibilizer surface coating on the interaction between the nanofiller platelet structure and the matrix polymer. By careful selection of the nanofiller it is possible to vary the penetration of the matrix polymer into the platelet structure of the nanofiller on mixing. Thus, the degree of interaction and intrusion of the polymer matrix into the nanofiller controls the separation and dispersion of the individual platelets of the nanofiller within the polymer matrix. This interaction of the polymer matrix and the platelet structure of the nanofiller is defined herein as the nanofiller “reacting into the structure of the polymer” and the subsequent dispersion of the platelets within the polymer matrix is defined herein as the nanofiller “being substantially evenly dispersed” within the structure of the polymer matrix.

If no compatibilizer is present on the surface of a filler such as a clay, or if the coating of the clay is attempted after its addition to the polymer matrix, then the penetration of the matrix polymer into the nanofiller is much less efficient, very little separation and no dispersion of the individual clay platelets occurs within the matrix polymer.

As used herein, a “nanocomposite” is defined as a polymer matrix having nanofiller intercalated or exfoliated within the matrix. Physical properties of the polymer will change with the addition of nanofiller and the physical properties of the polymer are expected to improve even more as the nanofiller is dispersed into the polymer matrix to form a nanocomposite.

Materials incorporating nanofiller materials can provide these property improvements at much lower densities than those incorporating conventional fillers. For example, a nylon-6 nanocomposite material manufactured by RTP Corporation of Wichita, Kansas uses a 3% to 5% clay loading and has a tensile strength of 11,800 psi and a specific gravity of 1.14, while a conventional 30% mineral-filled material has a tensile strength of 8,000 psi and a specific gravity of 1.36. Because use of nanocomposite materials with lower loadings of inorganic materials than conventional fillers provides the same properties, this use allows products to be lighter than those with conventional fillers, while maintaining those same properties.

Nanocomposite materials are materials incorporating from about 0.1% to about 20%, preferably from about 0.1% to about 15%, and most preferably from about 0.1% to about 10% of nanofiller reacted into and substantially dispersed through intercalation or exfoliation into the structure of an organic material, such as a polymer, to provide strength, temperature resistance, and other property improvements to the resulting composite. Descriptions of particular nanocomposite materials and their manufacture can be found in U.S. Pat. No. 5,962,553 to Ellsworth, U.S. Pat. No. 5,385,776 to Maxfield et al., and U.S. Pat. No. 4,894,411 to Okada et al. Examples of nanocomposite materials currently marketed include M1030D, manufactured by Unitika Limited, of Osaka, Japan, and 1015C2, manufactured by UBE America of New York, New York.

When nanocomposites are blended with other polymer systems, the nanocomposite may be considered a type of nanofiller concentrate. However, a nanofiller concentrate may be more generally a polymer into which nanofiller is mixed; a nanofiller concentrate does not require that the nanofiller has reacted and/or dispersed evenly into the carrier polymer.

Preferably the nanofiller material is added to the polymeric composition in an amount of from about 0.1% to about 20%, preferably from about 0.1% to about 15%, and most preferably from about 0.1% to about 10% by weight of nanofiller reacted into and substantially dispersed through intercalation or exfoliation into the structure of the polymeric composition.

If desired, the various polymer compositions used to prepare the golf balls can additionally contain other additives such as plasticizers, pigments, antioxidants, U.V. absorbers, optical brighteners, or any other additives generally employed in plastics formulation or the preparation of golf balls.

Another particularly well-suited additive for use in the presently disclosed compositions includes compounds having the general formula:

(R₂N)_m—R′—(X(O)_nOR_y)_m,

where R is hydrogen, or a C₁-C₂₀aliphatic, cycloaliphatic or aromatic systems; R′ is a bridging group comprising one or more C₁-C₂₀straight chain or branched aliphatic or alicyclic groups, or substituted straight chain or branched aliphatic or alicyclic groups, or aromatic group, or an oligomer of up to 12 repeating units including, but not limited to, polypeptides derived from an amino acid sequence of up to 12 amino acids; and X is C or S or P with the proviso that when X=C, n=1 and y=1 and when X=S, n=2 and y=1, and when X=P, n=2 and y=2. Also, m=1-3. These materials are more fully described in U.S. Provisional Patent Application No. 60/588,603, filed on Jul. 16, 2004, the entire contents of which are herein incorporated by reference. These materials include caprolactam, oenantholactam, decanolactam, undecanolactam, dodecanolactam, caproic 6-amino acid, 11-aminoundecanoicacid, 12-aminododecanoic acid, diamine hexamethylene salts of adipic acid, azeleic acid, sebacic acid and 1,12-dodecanoic acid and the diamine nonamethylene salt of adipic acid, 2-aminocinnamic acid, L-aspartic acid, 5-aminosalicylic acid, aminobutyric acid; aminocaproic acid; aminocapyryic acid; 1-(aminocarbonyl)-1-cyclopropanecarboxylic acid; aminocephalosporanic acid; aminobenzoic acid; aminochlorobenzoic acid; 2-(3-amino-4-chlorobenzoyl)benzoic acid; aminonaphtoic acid; aminonicotinic acid; aminonorbornanecarboxylic acid; aminoorotic acid; aminopenicillanic acid; aminopentenoic acid; (aminophenyl)butyric acid; aminophenyl propionic acid; aminophthalic acid; aminofolic acid; aminopyrazine carboxylic acid; aminopyrazole carboxylic acid; aminosalicylic acid; aminoterephthalic acid; aminovaleric acid; ammonium hydrogencitrate; anthranillic acid; aminobenzophenone carboxylic acid; aminosuccinamic acid, epsilon-caprolactam; omega-caprolactam, (carbamoylphenoxy)acetic acid, sodium salt; carbobenzyloxy aspartic acid; carbobenzyl glutamine; carbobenzyloxyglycine; 2-aminoethyl hydrogensulfate; aminonaphthalenesulfonic acid; aminotoluene sulfonic acid; 4,4′-methylene-bis-(cyclohexylamine)carbamate and ammonium carbamate.