In some embodiments, the set acoustic adhesive composition has a Tan δ height, as described above, of at least 1 in the frequency range of 0.1-10 kHz. For example, in various embodiments, the set acoustic adhesive composition has a Tan δ height of at least 1 in the frequency range of 0.1-8 kHz, or 0.1-6 kHz, or 0.1-4 kHz, or 0.2-8 kHz, or 0.2-6 kHz, or 0.2-4 kHz. For example, in various embodiments, the set acoustic adhesive composition has a Tan δ height of at least 1 in the frequency range of 1-10 kHz, or 1-8 kHz, or 1-6 kHz, or 1-4 kHz, or 2-8 kHz, or 2-6 kHz, or 2-4 kHz. In some embodiments, the set acoustic adhesive composition has a Tan δ height in the range of 1-2 in the frequency range of 0.1-10 kHz. For example, in various embodiments, the set acoustic adhesive composition has a Tan δ height in the range of 1-2 in the frequency range of 0.1-8 kHz, or 0.1-6 kHz, or 0.1-4 kHz, or 0.2-8 kHz, or 0.2-6 kHz, or 0.2-4 kHz. For example, in various embodiments, the set acoustic adhesive composition has a Tan δ height in the range of 1-2 in the frequency range of 1-8 kHz, or 1-6 kHz, or 1-4 kHz, or 2-8 kHz, or 2-6 kHz, or 2-4 kHz.

These viscoelastic properties of the set acoustic adhesive composition are determined by the components that make up the compositions. As described above, the set acoustic adhesive composition includes a continuous phase of a viscoelastic material present in an amount in the range of 60-95 wt % of the set acoustic adhesive composition. In some embodiments, the continuous phase of the viscoelastic material is present in an amount in the range of 65-95 wt % of the set acoustic adhesive composition. For example, in various embodiments, the continuous phase of the viscoelastic material is present in the range of 70-95 wt %, or 75-95 wt %, or 80-95 wt % of the set acoustic adhesive composition. In some embodiments, the continuous phase of the viscoelastic material is present in an amount in the range of 60-90 wt % of the set acoustic adhesive composition. For example, in various embodiments, the continuous phase of the viscoelastic material is present in the range of 65-90 wt %, or 70-90 wt %, or 75-90 wt %, or 80-90 wt % of the set acoustic adhesive composition. In some embodiments, the continuous phase of the viscoelastic material is present in an amount in the range of 60-85 wt % of the set acoustic adhesive composition. For example, in various embodiments, the continuous phase of the viscoelastic material is present in the range of 65-85 wt %, or 70-85 wt %, or 75-85 wt %, or 60-80 wt %, or 65-80 wt %, or 70-80 wt %, or 75-80 wt % of the set acoustic adhesive composition.

The continuous phase of viscoelastic material can be based on a variety of polymer systems. For example, the present inventors note that a variety of elastomeric polymers can be adapted for use in continuous phase of viscoelastic material. A variety of acrylic elastomers are known, e.g., available as aqueous emulsions under the trade name RHOPLEX from Dow. But other elastomeric materials can be used.

In various embodiments, the elastomeric (e.g., acrylic) polymer is present in an amount of at least 50 wt % of the continuous phase of the viscoelastic material. For example, in some embodiments, the elastomeric (e.g., acrylic) polymer is present in an amount of at least 80 wt % (e.g., at least 85 wt %, or at least 90 wt %) of the continuous phase of the viscoelastic material. In some embodiments, the elastomeric (e.g., acrylic) polymer is present in an amount in the range of 50-99 wt % of the continuous phase of the viscoelastic material, e.g., 80-99 wt %, or 85-99 wt %, or 90-99 wt %, or 50-98 wt %, or 80-98 wt %, or 85-98 wt %, or 90-98 wt %, or 50-95 wt %, or 80-95 wt %, or 85-95 wt %, or 50-90 wt %, or 80-90 wt %, or 50-80 wt %, or 50-70 wt %.

In some embodiments, the elastomeric polymer has a glass transition temperature (T_g) less than the continuous phase of the viscoelastic material, e.g., has a glass transition temperature of no greater than −10° C. For example, in various embodiments, the elastomeric polymer has a glass transition temperature (Tg) no greater than −20° C., or −25° C., or −30° C. In various embodiments, the acrylic polymer has a glass transition temperature in the range of −70 to −20° C., or −65 to −20° C., or −60 to −20° C., or −70 to −25° C., or −65 to −25° C., or −60 to −25° C., or −70 to −30° C., or −65 to −30° C., or −60 to −30° C.

A variety of other components may be present in the continuous phase of viscoelastic material, to adjust properties. For example, in various embodiments, the continuous phase further includes a tackifier. As the person of ordinary skill in the art will appreciate, a tackifier can be used to provide additional “tack,” or stickiness to the material, to provide it improved adhesive properties. This can be desirable for systems in which the composition adheres together two plaster layers to form a sound-dampening building board. In various embodiments, the tackifier is present in an amount in the range of 1-20 wt %, or 5-20 wt %, or 5-15 wt %, or 5-10 wt %, or 10-20 wt %, or 10-15 wt %, or 10-12 wt %, of the liquid acoustic adhesive formulation, on a dry solids basis. The tackifier may be selected from a variety of tackifiers and is not particularly limited. For example, in some embodiments, the tackifier is a low molecular weight solid. The tackifier may comprise a rosin resin. The resin can comprise a glycerol ester of wood resin, preferably abietic acid. For example, in some embodiments, the tackifier is a rosin ester based tackifier (e.g., Dermulsene RE1513 from DRT).

In various embodiments, the continuous phase of the viscoelastic material further comprises a rheology modifier, e.g., to modify the rheology properties especially of a liquid formulation from which the composition is formed. In various embodiments, the rheology modifier is present in an amount in the range of 1-20 wt %, or 5-20 wt %, or 5-15 wt %, or 5-10 wt %, or 10-20 wt %, or 10-15 wt %, or 10-12 wt % of the adhesive composition. The rheology modifier may be selected from a variety of rheology modifiers and is not particularly limited. The rheology modifier may be used to increase the viscosity of the acoustic adhesive composition. For example, in some embodiments, the rheology modifier is a hydrophobically-modified alkali-swellable associative thickener (e.g., Acrysol TT-615, from Dow). In some embodiments, the rheology modifier is a cellulosic thickener (e.g., Walocel MW40000PFV, from Dow). In some embodiments as described herein the continuous phase of the viscoelastic material includes both a hydrophobically-modified alkali-swellable associative thickener and a cellulosic thickener.

In various desirable embodiments of the disclosure, the continuous phase of viscoelastic material is not substantially crosslinked. The present inventors have found that a non-crosslinked continuous phase can provide good viscoelastic properties to the overall set acoustic adhesive composition.

The particulate polymer filler may be selected from a variety of polymers having the desired glass transition temperature and/or storage modulus, and other desirable properties, and is not otherwise particularly limited. The person of ordinary skill in the art would be able to select an appropriate particulate polymer filler that has the properties as described herein. For example, in some embodiments, the particulate polymer filler retains its rigid, particle like structure at ambient temperatures which helps it act as reinforcing filler to the softer continuous phase of the viscoelastic material. In some embodiments, the particulate polymer filler is non-polar. In some embodiments, the particulate polymer filler is a styrene-based polymer, an acrylic-based polymer or an epoxy-based polymer. Copolymers, e.g., of styrene/acrylic and styrene/butadiene can be used. Examples include STYRON DL 218NA (styrene/butadiene) and LIGOS A3411 (styrene/acrylic).

As described above, the set acoustic adhesive composition includes a particulate polymer filler in an amount in the range of 5-40 wt % of the set acoustic adhesive composition. For example, in various embodiments, the particulate polymer filler is present in an amount in the range of 5-35 wt % (e.g., in the range of 5-30 wt %, or 5-25 wt %, or 5-20 wt %) of the set acoustic adhesive composition. In various embodiments, the particulate polymer filler is present in an amount in the range of 10-40 wt % (e.g., in the range of 10-35 wt %, or 10-30 wt %, or 10-25 wt %, or 10-20 wt %) of the set acoustic adhesive composition. In various embodiments, the particulate polymer filler is present in an amount in the range of 15-40 wt % (e.g., in the range of 15-35 wt %, or 15-35 wt %, or 15-30 wt %, or 15-25 wt %) of the set acoustic adhesive composition. In various embodiments, the particulate polymer filler is present in an amount in the range of 20-40 wt % (e.g., in the range of 20-35 wt %, wo-30 wt %, or 20-25 wt %) of the set acoustic adhesive composition.

The present inventors have determined that use of small particle size particulate polymer fillers can be especially advantageous for use in the materials described herein. For example, in various embodiments, the particulate polymer filler has a d₅₀particle size of at least 50 nm (e.g., at least 75 nm, or at least 100 nm, or at least 125 nm). In various embodiments, the particulate polymer filler has a d₅₀particle size in the range of 50-500 nm (e.g., in the range of 50-450 nm, or 50-400 nm, or 50-350 nm, or 50-300 nm, or 100-500 nm, or 100-450 nm, or 100-400 nm, or 100-350 nm, or 100-300 nm, or 150-500 nm, or 150-450 nm, or 150-400 nm, or 150-350 nm, or 150-300 nm). In various such embodiments, the particulate polymer filler has d₁₀value of at least 10 nm (e.g., at least 25 nm, or at least 50 nm); and a d₉₀value of no more than 1000 nm (e.g., no more than 750 nm, or no more than 500 nm).

The present inventors have found that using a particulate polymer filler that has a similar density to that of the continuous phase of viscoelastic material can be particularly advantageous. In particular, by having densities that are similar, the particulate polymer filler may be evenly dispersed throughout the continuous phase and prevents the particulate polymer filler from sinking or floating in the continuous phase. For example, in various embodiments the particulate filler has a density at 20° C. that is within 20% (e.g., within 15%, or within 10%) of a density at 20° C. of the continuous phase of viscoelastic material.

A variety of polymeric materials can be used as the particular polymer filler. For example, in various embodiments as otherwise described herein, the particulate polymer filler is a particulate polystyrene filler. But the present inventors have identified other materials can be used, such as epoxy resins and poly(meth)acrylates such as poly(methyl methacrylate). The person of ordinary skill in the art can, based on the disclosure herein, select other appropriate materials.

As described above, the set adhesive composition includes the continuous phase of viscoelastic material as described herein and the particulate polymer filler as described herein. The set acoustic adhesive composition may mostly consist of the continuous phase of the viscoelastic material and the particulate polymer filler. For example, in some embodiments, the continuous phase of the viscoelastic material and the particulate polymer filler together make up at least 90 wt % of the set acoustic adhesive composition. In various embodiments, the continuous phase of the viscoelastic material and the particulate polymer filler together make up at least 92 wt %, or at least 95 wt %, or at least 99 wt %, of the set acoustic adhesive composition.

In particular, the present inventors have found that the set acoustic adhesive including a particulate polymer filler does not have some of the drawbacks associated with use of a mineral filler. Namely, in various embodiments, the particulate polymer filler does not settle in the acoustic adhesive composition during storage or during long-term use of the material. As such, it can be advantageous for the set acoustic adhesive to have a low amount of minerals present. For example, in various embodiments, the set acoustic adhesive composition includes no more than 15 wt %, or no more than 10 wt %, or no more than 5 wt %, or no more than 1 wt %, or no more than 1 wt %, of a mineral filler.

The present inventors have determined that liquid formulations, especially aqueous formulations based on latexes and other emulsions, can be used to prepare layers of the set acoustic adhesive compositions of the disclosure. The present inventors have noted that the use of aqueous formulations can provide a variety of advantages from the standpoint of cost, environmental concerns, and manufacturing safety. Accordingly, other aspect of the present disclosure provides a liquid adhesive acoustic adhesive formulation, e.g., that is suitable for providing a set acoustic adhesive composition as described herein. As described above, the liquid acoustic adhesive formulation comprises an aqueous dispersion of one or more components suitable to provide the continuous phase of the viscoelastic material of the set acoustic adhesive composition, present in an amount in the range of 60-95 wt % on a dry solids basis; and the particulate polymer filler, present in an amount in the range of 5-40 wt %.

The one or more components may be provided in a variety of forms so long as they are suitable to provide the continuous phase as described herein. For example, in some embodiments, the one or more components are provided as an aqueous dispersion suitable to provide the continuous phase of the viscoelastic material as described herein. In some embodiments, the one or more components are present in an amount suitable to provide a continuous phase of a viscoelastic material as described herein. For example, in various embodiments, the one or more components suitable to provide a continuous phase of a viscoelastic material are present in any amount as described above with respect to the continuous phase of the set acoustic adhesive composition, on a dry solids basis.

In some embodiments, the one or more components includes an elastomeric polymer, e.g., an acrylic polymer. The acrylic polymer may be provided as an aqueous dispersion (e.g., a so-called “latex” or another emulsion). In some embodiments, the acrylic polymer may be present in an amount of at least 50 wt % of the components that form the continuous phase of the viscoelastic material, on a dry solids basis. In various embodiments the acrylic polymer is present in an amount of at least 80 wt %, or at least 85 wt %, or at least 90 wt %, of the components that form the continuous phase of the viscoelastic material, on a dry solids basis. The acrylic polymer may be present in various amounts of the liquid acoustic adhesive composition. For example, in some embodiments, the acrylic polymer is present in an amount of 32-90 wt % (e.g., or 35-90 wt %, or 35-85 wt %, or 35-80 wt %, or 35-75 wt %, or 40-90 wt %, or 40-85 wt %, or 40-80 wt %, or 40-75 wt %, or 45-90 wt %, or 45-85 wt %, or 45-80 wt %, or 45-75 wt %) of the liquid acoustic adhesive formulation, on a dry solids basis.

In some embodiments, the one or more components suitable to provide the continuous phase of the viscoelastic material have a wet density of at least 8 lbs/gal. For example, in various embodiments, the one or more components suitable to provide the continuous phase of the viscoelastic material have a wet density of at least 9 lbs/gal, or 10 lbs/gal, or 11 lbs/gal, or 12 lbs/gal.

In some embodiments as described herein, the liquid acoustic adhesive formulation further comprises a tackifier as described herein. The tackifier may be selected from a variety of tackifiers and is not particularly limited. For example, in some embodiments, the tackifier is a low molecular weight solid. The tackifier may comprise a rosin resin. The resin can comprise a glycerol ester of wood resin, preferably abietic acid. For example, in some embodiments, the tackifier is a rosin ester based tackifier (e.g., Dermulsene RE1513 from DRT). The tackifier can be present in any amount described above with respect to the continuous phase, on a dry solids basis.

In some embodiments as described herein, the liquid acoustic adhesive formulation further comprises a rheology modifier as described herein. The rheology modifier may be selected from a variety of rheology modifiers and is not particularly limited. The rheology modifier may be used to increase the viscosity of the acoustic adhesive composition. For example, in some embodiments, the rheology modifier is a hydrophobically-modified alkali-swellable associative thickener (e.g., Acrysol TT-615, from Dow). In some embodiments, the rheology modifier is a cellulosic thickener (e.g., Walocel MW40000PFV, from Dow). In some embodiments as described herein the continuous phase of the viscoelastic material includes both a hydrophobically-modified alkali-swellable associative thickener and a cellulosic thickener. The rheology modifier can be present in any amount described above with respect to the continuous phase, on a dry solids basis.

As described above, the liquid acoustic adhesive formulation also includes a particulate polymer filler as described herein. The particulate polymer filler may be provided in a variety of forms, for example, the particulate polymer filler may be provided as an aqueous dispersion. In some embodiments, the particulate polymer filler is present in an amount as described above with respect to the set acoustic adhesive composition, on a dry solids basis.

As described above, the liquid acoustic adhesive formulation includes one or more components suitable to provide the continuous phase of viscoelastic material as described herein and the particulate polymer filler as described herein. The liquid acoustic adhesive formulation may be mostly the one or more components suitable to provide the continuous phase of the viscoelastic material and the particulate polymer filler. For example, in some embodiments, the one or more components suitable to provide the continuous phase of the viscoelastic material and the particulate polymer filler together make up at least 90 wt %, or at least 92 wt %, or at least 95 wt %, or at least 99 wt %, of the liquid acoustic adhesive formulation, on a dry solids basis.

In particular, the present inventors have found that the liquid acoustic adhesive formulation including a particulate polymer filler does not have some of the drawbacks associated with use of a mineral filler. Namely, in various embodiments the particulate polymer filler does not settle in the liquid acoustic adhesive formulation during storage. As such, it can be advantageous for the liquid acoustic adhesive formulation to have a low amount of minerals present. For example, in various embodiments, the liquid acoustic adhesive formulation includes no more than 15 wt %, or no more than 10 wt %, or no more than 5 wt %, or no more than 2 wt %, or no more than 1 wt %, on a dry solids basis, of a mineral filler.

The person of ordinary skill in the art will, based on the disclosure herein, select a suitable solids content for the formulation, balancing the desire to have relatively low water content with a desire to have a workable material. In some embodiments, the liquid acoustic adhesive formulation has a solids content in the range of 40-70 wt %. For example, in some embodiments of the disclosure as described herein, the liquid acoustic adhesive formulation has a solids content in the range of 45-70 wt %, or 50-70 wt %, or 55-70 wt %, or 40-65 wt %, or 45-65 wt %, or 50-65 wt %, or 55-65 wt %, or 40-60 wt %, or 45-60 wt %, or 50-60 wt %, or 55-60 wt %.

The liquid acoustic adhesive compositions of the disclosure desirably use water as the solvent. In various embodiments, water is the only solvent. In some embodiments a small proportion of volatile organic liquid (i.e., boiling point less than 200° C.) is present, but it is desirably no more than 5 wt % of the overall liquid acoustic adhesive composition, e.g., no more than 2 wt %, or no more than 1 wt %, or no more than 0.5 wt %.

In some embodiments, the liquid acoustic adhesive composition has a basic pH. For example, the liquid acoustic adhesive composition has a pH in the range of 7-12, or 7-11.5, or 7-11, or 7-10.5, or 7-10, 8-12, or 8-11.5, or 8-11, or 8-10.5, or 8-10, or 8.5-12, or 8.5-11.5, or 8.5-11, or 8.5-10.5, or 8.5-10, or 9-12, or 9-11.5, or 9-11, or 9-10.5, or 9-10. In some embodiments, the one or more components suitable to provide a continuous phase of the viscoelastic material further comprises a basic pH modifier. For example, in various embodiments, the basic pH modifier is selected from sodium bicarbonate, potassium bicarbonate, or calcium carbonate. Providing a liquid acoustic adhesive composition with a basic pH can be especially desirable when an associative thickener is used as a rheology modifier.

In some embodiments of the present disclosure as described herein, the liquid acoustic adhesive formulation has a viscosity of greater than 10 Pa-s over a shear rate of 0.1-100 s⁻¹. For example, in some embodiments, the liquid acoustic adhesive formulation has a viscosity in the range of 10-10,000 Pa-s over a shear rate of 0.1-100 s⁻¹.

The liquid formulations described herein are particularly useful in sound-damping building boards. For example, in some embodiments, the liquid formulation may be disposed onto a top surface of a first plaster layer, and a second plaster layer may be disposed onto the liquid formulation such that the liquid formulation is disposed between the top surface of the first plaster layer and the bottom surface of the second plaster layer. To set the liquid formulation within the sound-damping building board, in some embodiments, the board is exposed to a setting temperature for a setting time. In some embodiments, the setting temperature is in the range of 20-35° C. In some embodiments, the setting time is in the range of 3-10 days (e.g., in the range of 5-10 days, or 7-10 days). In some embodiments as described herein, during the setting process, a weight is applied to the sound-damping building board.

Another aspect of the present disclosure provides a sound-dampening building board comprising a first plaster layer having a top surface and a bottom surface; a second plaster layer board having a top surface and a bottom surface; and the set acoustic adhesive composition as described herein disposed between the top surface of the first plaster layer and the bottom surface of the second plaster layer. Such an embodiment is shown in FIG. 1, which illustrates a plaster layer board (100) including a first plaster layer (102) having a top surface (122) and a bottom surface (112); a second plaster layer (104) having a top surface (124) and a bottom surface (114); and the set acoustic adhesive composition (101) as described herein disposed between the top surface (122) of the first plaster layer (102) and the bottom surface (114) of the second plaster layer (104).

As the person of ordinary skill in the art will appreciate, the plaster layers can be formed of a variety of materials. Gypsum is a typical material for plaster layers in building boards, but other materials can be used. For example, various plaster materials including stucco, lime, and Portland cement may be used.

In various embodiments, the first plaster layer has a thickness in the range of ¼″ ½″. In various embodiments, the second plaster layer has a thickness in the range of ¼″ ½″. In some embodiments, the thickness of the first plaster layer is equal to the thickness of the second plaster layer d. In some embodiments, the thickness of the first plaster layer is not equal to the thickness of the second plaster layer.

In some embodiments, the set acoustic adhesive composition has a thickness of in the range of 100 to 500 μm. For example, in some embodiments of the disclosure a described herein, the set acoustic adhesive composition has a thickness in the range or 150 to 500 μm, or 150 to 450 μm, or 150 to 400 μm, or 150 to 350 μm, or 150 to 300 μm, or 200 to 500 μm, or 200 to 450 μm, or 200 to 400 μm, or 200 to 350 μm, or 200 to 300 μm.

In some embodiments, the sound-dampening building board has a thickness in the range of ⅜″ to 1″.

Moreover, each plaster layer can comprise one or more liners disposed at the top surface and/or the bottom surface, e.g., made of paper, fiberglass, or plastic. The liners can in some embodiments be present only on the outer surfaces of the building board (i.e., at the bottom surface of the first plaster layer and at the top surface of the second plaster layer). But in some embodiments, one or more liners can be present inside the building board, i.e., at the top surface of the first plaster layer and/or the bottom surface of the second plaster layer).

Such an embodiment is shown in FIG. 2, which illustrates a sound-dampening building board (200) including a first plaster layer (202) having a top surface (222) and a bottom surface (212); a second plaster layer (204) having a top surface (224) and a bottom surface (214); and the set acoustic adhesive composition (201) as described herein disposed between the top surface (222) of the first plaster layer (202) and the bottom surface (214) of the second plaster layer (204). Here, the first plaster layer 202 includes a liner (230) disposed at the bottom surface (212) of the first plaster layer (202) and a liner (231) disposed at the top surface (222) of the first plaster layer (202) and a liner (232) disposed at the bottom surface (214) of the second plaster layer (204) and a liner (233) disposed at the top surface (224) of the second plaster layer (204).

The sound dampening building boards of the present disclosure reduce acoustic noise. As would be understood by the person of ordinary skill in the art, mechanical impedance testing may be used to calculate acoustic performance indicators, such as the sound transmission loss (STL) curve and the loss factor. To perform the mechanical impedance testing, gypsum sample boards are cut into beams of approximate size 300 mm×22 mm. The beam size is measured precisely with a caliber and weighed. A screw button is glued with superglue in the center of one of the paper face of the beam. After the glue is cured, the sample is ready for testing. The mechanical impedance device is composed of a vertical shaker that can vibrate at different frequencies. The sample beam was screwed on top of the shaker. While the shaker screens a wide range of frequencies, sensors record the force and velocity of the beam so that the mechanical impedance of the beam can be plotted as a function of time. The composite loss factor and the STL curve of the sample could be calculated from this curve, the board dimensions, and weight. Such measurements are consistent with ASTM E756-05. For example, in some embodiments, the sound dampening building board has a loss factor of at least 10% at a frequency in the range of 175-225 Hz. In some embodiments, the sound dampening building board has a loss factor in the range of 10-18% at a frequency in the range of 175-225 Hz. For example, in some embodiments, the sound dampening building board has a loss factor of at least 12% at a frequency in the range of 800-1000 Hz. In some embodiments, the sound dampening building board has a loss factor in the range of 12-20% at a frequency in the range of 800-1000 Hz. For example, in some embodiments, the sound dampening building board has a loss factor of at least 16% at a frequency in the range of 2000-2500 Hz. In some embodiments, the sound dampening building board has a loss factor in the range of 16-24% at a frequency in the range of 2000-2400 Hz. In some embodiments, the sound dampening building board has a loss factor of at least 12% at a frequency in the range of 800-1000 Hz, and has a loss factor of at least 16% at a frequency in the range of 2000-2500 Hz. In some embodiments, the sound dampening building board has a loss factor in the range of 10-18% at a frequency in the range of 175-225 Hz, a loss factor in the range of 12-20% at a frequency in the range of 800-1000 Hz, and a loss factor in the range of 16-24% at a frequency in the range of 2000-2400 Hz.

Another aspect of the present disclosure provides a method for making the sound dampening building board as described herein. The method includes providing a first plaster layer having a top surface and a bottom surface and a second plaster layer having a top surface and a bottom surface; disposing the liquid acoustic adhesive formulation as described herein between the top surface of the first plaster layer and the bottom surface of the second plaster layer; and allowing the liquid acoustic adhesive formulation to set to provide the set acoustic adhesive composition. Disposing the liquid acoustic adhesive composition may be accomplished by any means as known in the art.

The liquid acoustic adhesive formulation can be allowed to set in a number of ways. For example, a heating step can be performed for a time and at a temperature sufficient to provide a set acoustic adhesive composition as described herein. For example, in various embodiments, the heating occurs at a temperature in the range of 50-350° C., or 50-325° C., or 50-300° C. In various embodiments, the curing occurs at a temperature in the range of 100-350° C., or 100-325° C., or 100-300° C., or 150-350° C., or 150-325° C., or 150-300° C., or 200-350° C., or 200-325° C., or 200-300° C. In some embodiments, the heating occurs for a time in the range of 30 minutes to 3 hours (e.g., 1-3 hours, or 2-3 hours).

EXAMPLES

The Examples that follow are illustrative of specific embodiments of the compositions, products, methods of the disclosure, and various uses thereof. They are set forth for explanatory purposes only, and are not to be taken as limiting the scope of the disclosure.

Example 1. Evaluation of Continuous Phase of Viscoelastic Material

A variety of waterborne latex materials were evaluated for their acoustic rheology properties. No additional material was added to the latex. To provide test samples, each material was spread on a sheet of PET film at a thickness of approximately 2 mm and allowed to dry for 24 hours at ambient conditions. The samples were then placed in a convection oven at 70° C. for 12-18 hours to accelerate aging.

To evaluate the sound-dampening properties of the dried sample, the mechanical responses of the polymer samples were measured in a parallel plate rheometer using an 8 mm parallel plate geometry with a Discovery Series Hybrid Rheometer (DHR) from TA Instruments. Frequency sweeps, from 0.1 to 100 rad/s were performed at 10° C. increments from 40° C. to −30° C. the frequency sweeps obtained at each temperature were then shifted using the Williams-Landel-Ferry (WLF) model to obtain a master curve showing G′, G″, and the Tan δ over a broad range of frequencies using the time-temperature superposition principle. The resulting Tan δ and storage modulus (G′) of the late samples tested are shown in FIGS. 3A and 3B, respectively. Table 1 reports the Tan δ height and Tan δ location for each latex samples tested.

TABLE 1

Tan δ Location

Latex
Supplier
Tan δ Height
(kHz)

Commercial
Saint-Gobain
1.46
11.8

Reference

Rhoplex EC-1791
Dow
1.95
9.4

Rhoplex 440
Dow
2.21
16.4

Encor 9215
Arkema
2.41
1.8

Encor 9466
Arkema
2.03
4.4

Robond PS-2000
Dow
2.10
26.3

Robond PS-7860
Dow
1.74
13.8

While the Tan δ peak location is in the desired range and the Tan δ peak height is of the desired value, the storage modulus values of these latexes are not stiff enough to provide the desired storage modulus to the overall material.

Example 2. Evaluation of Particulate Polymer-Filled Continuous Phase

To increase the overall stiffness of the composition, a particulate polymer filler was added to the Rhoplex EC-1791 latex tested in Example 1. Rhoplex EC-1791 was chosen as it is cost-effective and has a starting pH of approximately 9, which can be beneficial when using associative thickeners. A styrene/butadiene particulate polymer (LIGOS A3411, d₅₀˜157 nm) was used as the polymer filler because it is one of the cheapest, non-polar, commercially available polymer dispersions. Additionally, to some formulations, a rosin ester tackifier (Dermulsene RE1513 from DRT) was added to adjust the location of the Tan δ.

To make the formulations, the latex was added to a container and placed underneath an overhead stirrer equipped with a blade (paddle, cowls, or pitch) with an RPM of approximately 300. Then, the reminder of the formulation was added one at a time while maintaining a vortex (RPM of approximately 600-1200). Once all the ingredients were added to the formulation, it was allowed to stir for 30 minutes. Samples of each formulation were then dried on PET films and tested for their damping properties, as described in Example 1. The resulting Tan δ and storage modulus (G′) are shown in FIGS. 4A and 4B, respectively. Table 2 reports the formulations (in parts per hundred rubber (PHR) on a dry solids basis) and the Tan δ height and Tan δ location for each formulation tested, and compares them to Commercial Reference and the Rhoplex EC-1791 latex.

TABLE 2

Rhoplex
Poly-
Dermulsene

Tan δ

Formula-
EC-1791
styrene
RE1513
Tan δ
Location

tion
(PHR)
(PHR)
(PHR)
Height
(kHz)

Commercial
—
—
—
1.46
11.8

Reference

Rhoplex
100
0
0
1.95
9.42

EC-1791

1
100
20
0
1.36
5.47

2
100
25
10
1.08
2.58

3
100
20
12
1.31
2.28

Without intending to be bound by theory, the present inventors surmise that the tackifier breaks up polymer chain entanglements to increase chain mobility at low frequency. At high frequency, the rigid structure of the tackifier increases the modulus, therefore shifting peak position and slightly increasing the peak height. The initial loading of 25 parts polystyrene to 10 parts of tackifier in formulation 2 resulted in a dampened Tan δ peak height and a stiff storage modulus compared to Commercial Reference. Therefore, the loading of the polystyrene was reduced and the tackifier loading was increased (formulation 3).

The viscosity of the wet formulations (as mixed) listed in Table 2 were also tested using a DHR rheometer with 25 mm parallel plates with a 1 mm gap. Sheer sweeps were performed from 100 to 0.1 s⁻¹. However, the viscosity of the formulation 3 needed to be adjusted to be useful in a plaster board. In order to increase the viscosity, a hydrophobically modified, alkaline soluble emulsion (HASE) thickener (Acrysol TT-615) was added to formulation 3. The pH of the mixture was measured to be approximately 9, which is within the range required to add the associative thickener. If the pH of the mixture is not basic, then sodium carbonate (or bicarbonate) can be added to increase the pH. 1 part solids of Acrysol TT-615, from Dow, was added to the polymer mixture at a rate of ˜4 drops per minute while mixing at 1000 rpm with a Heidolph overhead mixer equipped with a 1.5″ Cowles blade. If added to the polymer mixture too quickly, the Acrysol can form spherical aggregates. These aggregates could be broken apart by increasing the mixing speed and letting it mix for up to 30 minutes. The resulting increase in the viscosity profile is shown in FIG. 5.

Example 3. Evaluation of Additional Particulate Polymer Filled Formulations

Latexes, tackifiers, and other polymer fillers, such as polymethylmethacrylate (PMMA) were also evaluated. The dried samples of the formulations were made and the damping properties were evaluated as described in Example 1. Table 3 reports the formulations (in parts per hundred rubber (PHR)) and Table 4 reports the Tan δ height and Tan δ location for each formulation tested, and compares them to Commercial Reference and formulation 3. The resulting Tan δ and storage modulus (G′) are shown in FIGS. 6A, 6B, and 6C, respectively.

TABLE 3

Latex
Polymer
Polymer

Tackifier

Formulation
Latex
(PHR)
Filler
Filler (PHR)
Tackifier
(PHR)

4
Encor
100
LIGOS A3411
20
Dermulsene
12

9215

RE 1513

5
Encor
100
LIGOS A3411
20
Dermulsene
12

9466

RE 1513

6
Rhoplex
100
LIGOS A3411
20
Tacolyn
12

EC-1791

3100

7
Rhoplex
100
LIGOS A3411
20
Tacolyn
12

EC-1791

1070

8
Rhoplex
100
Rhoplex GL-720
20
Dermulsene
12

EC-1791

Polymethylmethacrylate

RE 1513

11
Rhoplex
100
Olin Epoxy
20
Tacolyn
12

EC-1791

Dispersion

1070

TABLE 4

Formulation
Tan δ Height
Tan δ Location (kHz)

Commercial Reference
1.46
11.8

3
1.31
2.28

4
1.55
0.41

5
1.39
2.11

6
1.38
0.89

7
1.48
1.64

8
1.56
1.80

11
1.05
11.02

The modified 3 formulation using PMMA (i.e., formulation 8) resulted in acceptable criteria. This demonstrates the flexibility of the formulation structure and ability to use a variety of high T_gpolymers.

Example 4. Evaluation of Addition of Mineral Filler to Particulate Polymer Filled Formulations

To further evaluate the polymer filled formulation, an additional mineral filler was added and the results formulation was evaluated for its damping properties. The addition of mineral to the formulation is preferred for two reasons; to increase the rheology of the formulation without adding the HASE modifier and to reduce the cost of the final product.

A combination of clay and a methyl hydroxyethyl cellulosic thickener were chosen as a mineral filler as it delivered the required rheology. Specifically, Burgess #40 clay and Walocel MW40000PFV cellulosic thickener were mixed together in a ratio of 95% clay to 5% Walocel MW40000PFV. To mix the clay and cellulosic thickener, the two components were placed in a FlackTek speed mixer for 2 minutes at 2000 RPM to ensure sufficient incorporation. The clay and cellulosic mixture were then added to formulation 7 (described in Table 3) at both 15% (formulation 9) and 20% (formulation 10) solids. The speed of mixing the clay and cellulosic mixture and the formulation 7 was increased to 1200 RPM.

Dried samples of the formulations were made and the damping properties were evaluated as described in Example 1. FIGS. 7A, 7B, 7C, and 7D report the viscosity of these wet formulations, the Tan δ of the dried samples, the storage modulus of the dried samples, and the loss modulus of the dried samples, respectively. Table 5 reports the Tan δ height and Tan δ location for each formulation tested with the mineral addition and compares them to Commercial Reference and formulation 7.

TABLE 5

Formulation
Tan δ height
Tan δ location (kHz)

Weber
1.46
11.84

7
1.48
1.64

9, no acrysol, 15% clay:mhec
1.46
1.60

10, no acrysol, 20% clay:mhec
1.26
3.02

The viscosity of formulations 9 and 10, with 15% and 20% mineral filler, respectively, are slightly higher than both Weber and the original 7 formulation. One possible issue with mineral addition is settling in the final product. This is an advantage that the polymer filled formulation has over the mineral formulation.

Example 5. Mechanical Testing

The formulations 2 and 7, as discussed above, were tested for their mechanical properties. Specifically, the tests performed were a mechanical impedance measurement test (MIM), differential mechanical analysis (DMA), and a Z-pull test, as described in more detail below.

Mechanical Impedance Measurement (MIM)

The MIM test is used to collect information about the sound transmission loss (STL) curve of a product including the acoustic adhesive formulation applied to two blank pieces of gypsum and measures the mechanical impedance of such a product over a wide range of frequencies. From this measurement, acoustic performance indicators can be calculated, such as the sound transmission loss curve and the loss factor. The MIM test was used to validate the acoustic properties of formulation 2 by comparison to a computer simulation. Gypsum sample boards were cut into beams of approximate size 300 mm×22 mm. The beam size was measured precisely with a caliber and weighted. A screw button was glued with superglue in the center of one of the paper face of the beam. After the glue is cured, the sample was ready for testing.

The MIM device was composed of a vertical shaker that can vibrate at different frequencies. The sample beam was screwed on top of the shaker. While the shaker screens a wide range of frequencies, sensors record the force and velocity of the beam so that the mechanical impedance of the beam can be plotted as a function of time. The composite loss factor and the STL curve of the sample are then calculated from this curve and the board dimensions and weight.

The MIM testing results for formulation 2 are shown in FIG. 8 and are compared to Commercial Reference. The loss factor of formulation 2 is comparable to Commercial Reference for each frequency mode tested and meets the desired acoustic criteria.

Differential Mechanical Analysis

The “score & snap” test of the inline laminate is an important experimental screening method to determine crack path in the end use product. The crack path of the sandwiched board is strongly dependent on the acoustic glue storage modulus (E′). However, the quality of the “score & snap” test is subjective as the results are dependent on human observation. A qualitative method to measure the storage modulus (E′) of viscoelastic glues was developed. The storage modulus for a given thickness of material is measured using Differential Mechanical Analysis (DMA).

For the differential mechanical analysis, RSA G2 by TA Instruments was used to measure the tensile storage modulus of potential materials. A rectangular fixture was used to apply a sinusoidal tensile deformation of given frequency and amplitude to a rectangular piece of material. The initial gauge length was fixed at 15 mm and width at 5.6 mm, while thickness depended on the material and was measured before each measurement with a caliber. The test was conducted at room temperature. First, a strain sweep was performed at rad/s from 0.01% to 5%. Then a frequency sweep was programmed at 0.3% maximum strain, from 5 to 600 rad/s. Each material was run in 3 duplicates. To measure the modulus of formulation, a layer of liquid formulation was left to cure at 70° C. on a PTFE release liner. After 24 hours curing, one can peel a free-standing formulation film that is suitable for DMA.

Results for a variety of viscoelastic glues tested were used to construct a simulation curve that is dependent on the measured storage modulus at a defined thickness. FIG. 9A depicts this simulation curve. The results of the elastic modulus measured using the DMA for Commercial Reference and formulation 7 are plotted on the simulation curve in FIG. 9B. The storage modulus for formulation 7 is located in the “desired zone” above the simulation limit line indicating that the developed formulation is likely to give a desirable, straight path crack propagation in “score & snap testing”.

Z-Pull Testing

Z-pull testing is used to test the adhesion properties of the formulations as described herein when used in a sandwiched board. This method has been used to evaluate the adhesion strength of formulations 2 and 7. A 2″×2″ square piece of board was cut with a tile saw. Two plywood boards were then epoxy glued on each face of the square's paper side. An Instron was used to separate the two gypsum layers and monitor the associated force with pulling speed at 2 mm/s and the load cell at 1000 N. The test would stop after rupture of the board or the paper. The peak load at failure (N) and the type of failure were recorded.

In addition to testing formulation 2 and 7 for adhesion, formulation 11 was also tested. Formulation 11 is based on formulation 2, but does not have a tackifier. The results of the adhesion (Z-Pull) testing are shown in FIG. 10. All versions of the adhesive formulation pass the Z-Pull desired criteria, indicating that the formulations with and without a tackifier have a comparable adhesion to Commercial Reference.

Various aspects and embodiments of the disclosure are provided by the following enumerated embodiments, which can be combined in any number and in any combination not technically or logically inconsistent.

- Embodiment 1. A set acoustic adhesive composition having a storage modulus at 20° C. of at least 2.0 MPa at 20° C. over a frequency of 1-10 kHz, the set acoustic adhesive composition comprising:
  - a continuous phase of a viscoelastic material having a glass transition temperature (T_g) no greater than 0° C. present in an amount in the range of 60-95 wt % of the set acoustic adhesive composition; and
  - dispersed in the continuous phase, a particulate polymer filler having a glass transition temperature (T_g) of at least 60° C. present in an amount in the range of 5-40 wt % of the set acoustic adhesive composition.
- Embodiment 2. The set acoustic adhesive composition of Embodiment 1, wherein the continuous phase of the viscoelastic material has a glass transition temperature (T_g) no greater than −10° C. (e.g. no greater than −15° C., or no greater than −20° C.).
- Embodiment 3. The set acoustic adhesive composition of Embodiment 1, wherein the continuous phase of the viscoelastic material has a glass transition temperature (T_g) in the range of −60 to 0° C. (e.g., e.g., in the range of −60 to −10° C., or −60 to −15° C., or −60 to −20° C., or −50 to 0° C., or −50 to 10° C., or −50 to −15° C., or −50 to −20° C., or −40 to 0° C., or −40 to −10° C., or −40 to −15° C., or −40 to −20° C.).
- Embodiment 4. The set acoustic adhesive composition of any of Embodiments 1-3, wherein the continuous phase of the viscoelastic material lacks a glass transition temperature in excess of 20° C.
- Embodiment 5. The set adhesive composition of any of Embodiments 1-4, wherein the particulate polymer filler has a glass transition temperature (T_g) of at least 70° C., e.g., at least 80° C., or at least 90° C.
- Embodiment 6. The set adhesive composition of any of Embodiments 1-4, wherein the particulate polymer filler has a glass transition temperature (T_g) in the range of 60-175° C., e.g., 70-175° C., or 80-175° C., or 90-175° C., or 60-150° C., or 70-150° C., or 80-150° C., or 90-150° C., or 60-125° C., or 70-125° C., or 80-125° C., or 90-125° C.
- Embodiment 7. The set acoustic adhesive composition of any of Embodiments 1-6, wherein the particulate polymer filler lacks a glass transition temperature (T_g) of less than 40° C.
- Embodiment 8. The set adhesive composition of any of Embodiments 1-7, wherein the particulate polymer filler has a storage modulus at 20° C. over a frequency of 1-10 kHz of at least 50 times a storage modulus at 20° C. of the continuous phase at 20° C. over a frequency of 1-10 kHz.
- Embodiment 9. A set acoustic adhesive composition having a storage modulus at 20° C. of at least 2.0 MPa at 20° C. over a frequency of 1-10 kHz, the set acoustic adhesive composition comprising:
  - a continuous phase of a viscoelastic material present in an amount in the range of 60-95 wt % of the set acoustic adhesive composition; and
  - dispersed in the continuous phase, a particulate polymer filler present in an amount in the range of 5-40 wt % of the set acoustic adhesive composition,
  - wherein the particulate polymer filler has a storage modulus at 20° C. of at least 50 times a storage modulus at 20° C. of the continuous phase at 20° C., over a frequency of 1-10 kHz (e.g., over a frequency of 1-8 kHz, or 1-6 kHz, or 1-4 kHz).
- Embodiment 10. A set acoustic adhesive composition of any of Embodiments 1-9, wherein the particulate polymer filler has a storage modulus at 20° C. that is at least 100 times, e.g., at least 10³times, or at least 10⁴times a storage modulus at 20° C. over a frequency of 1-10 kHz of the continuous phase of the viscoelastic material, over a frequency of 1-10 kHz (e.g., over a frequency of 1-8 kHz, or 1-6 kHz, or 1-4 kHz).
- Embodiment 11. A set acoustic adhesive composition of any of Embodiments 1-10, wherein the particulate polymer filler has a storage modulus at 20° C. over a frequency of 1-10 kHz of at least 1000 MPa, e.g., at least 1500 MPa, over a frequency of 1-10 kHz (e.g., over a frequency of 1-8 kHz, or 1-6 kHz, or 1-4 kHz).
- Embodiment 12. A set acoustic adhesive composition of any of Embodiments 1-10, wherein the particulate polymer filler has a storage modulus at 20° C. over a frequency of 1-10 kHz in the range of 1000 to 5000 MPa, e.g., in the range of 1000 to 4000 MPa, or 1000 to 3000 MPa, or 1500 to 5000 MPa, or 1500 to 3000 MPa, over a frequency of 1-10 kHz (e.g., over a frequency of 1-8 kHz, or 1-6 kHz, or 1-4 kHz).
- Embodiment 13. A set acoustic adhesive composition of any of Embodiments 1-12, wherein the continuous phase of the viscoelastic material has a storage modulus at 20° C. of no more than 1 MPa, e.g., no more than 0.5 MPa or no more than 0.2 MPa, over a frequency of 1-10 kHz (e.g., over a frequency of 1-8 kHz, or 1-6 kHz, or 1-4 kHz).
- Embodiment 14. A set acoustic adhesive composition of any of Embodiments 1-12, wherein the continuous phase of the viscoelastic material has a storage modulus at 20° C. in the range of 0.01 to 1 MPa (e.g., in the range of 0.01 to 0.5 MPa, or 0.01 to 0.2 MPa, or 0.1 to 1 MPa, or 0.1 to 0.5 MPa, or 0.1 to 0.2 MPa), over a frequency of 1-10 kHz (e.g., over a frequency of 1-8 kHz, or 1-6 kHz, or 1-4 kHz).
- Embodiment 15. The set acoustic adhesive composition of any of Embodiments 1-14 having a storage modulus at 20° C. of at least 2.5 MPa (e.g., at least 3.0 MPa, or at least 3.5 MPa, or at least 4.0 MPa) over a frequency of 1-10 kHz.
- Embodiment 16. The set acoustic adhesive composition of any of Embodiments 1-14 having a storage modulus at 20° C. in the range of 2.0 MPa to 6.0 MPa (e.g., in the range of 2.5 MPa to 6.0 MPa, or 3.0 MPa to 6.0 MPa, or 3.5 MPa to 6.0 MPa, or 4.0 MPa to 6.0 MPa, or 2.0 MPa to 5.5 MPa, or 2.5 MPa to 5.5 MPa, or 3.0 MPa to 5.5 MPa, or 3.5 MPa to 5.5 MPa, or 4.0 MPa to 5.5 MPa, or 2.0 MPa to 5.0 MPa, or 2.5 MPa to 5.0 MPa, or 3.0 MPa to 5.0 MPa, or 3.5 MPa to 5.0 MPa, or 4.0 MPa to 5.0 MPa) over a frequency of 1-10 kHz.
- Embodiment 17. The set acoustic adhesive composition of any of Embodiments 1-16 having a loss modulus at 20° C. of at least 3.0 MPa (e.g., at least 3.5 MPa, or at least 4.0 MPa, or at least 4.5 MPa) over a frequency of 1-10 kHz.
- Embodiment 18. The set acoustic adhesive composition of any of Embodiments 1-16 having a loss modulus at 20° C. in the range of 3.0 MPa to 7.0 MPa (e.g., in the range of 3.5 MPa to 7.0 MPa, or 4.0 MPa to 7.0 MPa, or 4.5 MPa to 7.0 MPa, or 3.0 MPa to 6.5 MPa, or 3.5 MPa to 6.5 MPa, or 4.0 MPa to 6.5 MPa, or 4.5 MPa to 6.5 MPa, or 3.0 MPa to 6.0 MPa, or 3.5 MPa to 6.0 MPa, or 4.0 MPa to 6.0 MPa, or 4.5 MPa to 6.0 MPa) over a frequency of 1-10 kHz.
- Embodiment 19. The set acoustic adhesive composition of any of Embodiments 1-18, wherein the set acoustic adhesive composition has a Tan δ height of at least 1 in the frequency range of 0.1-10 kHz.
- Embodiment 20. The set acoustic adhesive composition of any of Embodiments 1-18, wherein the set acoustic adhesive composition has a Tan δ height of at least 1 in the frequency range of 1-8 kHz.
- Embodiment 21. The set acoustic adhesive composition of any of Embodiments 1-18, wherein the set acoustic adhesive composition has a Tan δ height of at least 1 in the frequency range of 1-4 kHz.
- Embodiment 22. The set acoustic adhesive composition of any of Embodiments 1-18, wherein the set acoustic adhesive composition has a Tan δ height in the range of 1-2 in the frequency range of 0.1-10 kHz.
- Embodiment 23. The set acoustic adhesive composition of any of Embodiments 1-18, wherein the set acoustic adhesive composition has a Tan δ height in the range of 1-2 in the frequency range of 1-8 kHz.
- Embodiment 24. The set acoustic adhesive composition of any of Embodiments 1-18, wherein the set acoustic adhesive composition has a Tan δ height in the range of 1-2 in the frequency range of 1-4 kHz.
- Embodiment 25. The set acoustic adhesive composition of any of Embodiments 1-24, wherein the continuous phase of the viscoelastic material is present in an amount in the range of 65-95 wt % (e.g., in the range of 70-95 wt %, or 75-95 wt %, or 80-95 wt %) of the set acoustic adhesive composition.
- Embodiment 26. The set acoustic adhesive composition of any of Embodiments 1-24, wherein the continuous phase of the viscoelastic material is present in an amount in the range of 60-90 wt % (e.g., in the range of 65-90 wt %, or 70-90 wt %, or 80-90 wt %) of the set acoustic adhesive composition.
- Embodiment 27. The set acoustic adhesive composition of any of Embodiments 1-24, wherein the continuous phase of the viscoelastic material is present in an amount in the range of 60-85 wt % (e.g., in the range of 65-85 wt %, or 70-85 wt %, or 75-85 wt %, or 60-80 wt %, or 65-80 wt %, or 70-80 wt %, or 75-80 wt %) of the set acoustic adhesive composition.
- Embodiment 28. The set acoustic adhesive composition of any of Embodiments 1-27, wherein the continuous phase of the viscoelastic material comprises a elastomeric polymer such as an acrylic polymer (e.g., derived from a latex).
- Embodiment 29. The set acoustic adhesive composition of Embodiment 28, wherein the elastomeric (e.g., acrylic) polymer is present in an amount of at least 50 wt % of the continuous phase of the viscoelastic material.
- Embodiment 30. The set acoustic adhesive composition of Embodiment 28, wherein the elastomeric (e.g., acrylic) polymer is present in an amount of at least 80 wt % (e.g., at least 85 wt %, or at least 90 wt %) of the continuous phase of the viscoelastic material.
- Embodiment 31. The set acoustic adhesive composition of Embodiment 28, wherein the elastomeric (e.g., acrylic) polymer is present in an amount in the range of 50-99 wt % of the continuous phase of the viscoelastic material, e.g., 80-99 wt %, or 85-99 wt %, or 90-99 wt %, or 50-98 wt %, or 80-98 wt %, or 85-98 wt %, or 90-98 wt %, or 50-95 wt %, or 80-95 wt %, or 85-95 wt %, or 50-90 wt %, or 80-90 wt %, or 50-80 wt %, or 50-70 wt %.
- Embodiment 32. The set acoustic adhesive composition of any of Embodiments 29-31, wherein the elastomeric (e.g., acrylic) polymer has a glass transition temperature of no greater than −10° C. (e.g., no greater than −20° C., no greater than 25° C., or no greater than −30° C.).
- Embodiment 33. The set acoustic adhesive composition of any of Embodiments 29-31, wherein the elastomeric (e.g., acrylic) polymer has a glass transition temperature in the range of −70 to −20° C. (e.g., in the range of −65 to −20° C., or −60 to −20° C., or −70 to −25° C., or −65 to −25° C., or −60 to −25° C., or −70 to −30° C., or −65 to −30° C., or −60 to −30° C.).
- Embodiment 34. The set acoustic adhesive composition of any of Embodiments 1-33, wherein the continuous phase of the viscoelastic material further comprises a tackifier.
- Embodiment 35. The set acoustic adhesive composition of Embodiment 34, wherein the tackifier is present in an amount in the range of 1-20 wt % (e.g., in the range of 1-15 wt %, or 1-10 wt %, or 5-20 wt %, or 5-15 wt %, or 5-10 wt %, or 10-20 wt %, or 10-15 wt %) of the set acoustic adhesive composition.
- Embodiment 36. The set acoustic adhesive composition of Embodiment 34 or Embodiment 35, wherein the tackifier is a rosin ester-based tackifier.
- Embodiment 37. The set acoustic adhesive composition of any of Embodiments 1-36, wherein the continuous phase of the viscoelastic material further comprises a rheology modifier.
- Embodiment 38. The set acoustic adhesive composition of Embodiment 37, wherein the rheology modifier is present in an amount in the range of 0.1-2 wt % (e.g., in the range of 0.2-2 wt %, or 0.2-1.5 wt %, or 0.2-1 wt %, 0.5-2 wt %, or 0.5-1.5 wt %, or 0.5-1 wt %) of the set acoustic adhesive composition.
- Embodiment 39. The set acoustic adhesive composition of Embodiment 37 or Embodiment 38, wherein the rheology modifier is a hydrophobically-modified alkali-swellable associative thickener and/or a cellulosic thickener.
- Embodiment 40. The set acoustic adhesive composition of any of Embodiments 1-39, wherein the continuous phase of viscoelastic material is not substantially crosslinked.
- Embodiment 41. The set acoustic adhesive composition of any of Embodiments 1-39, wherein the particulate polymer filler is present in an amount in the range of 5-35 wt % (e.g., in the range of 5-30 wt %, or 5-25 wt %, or 5-20 wt %) of the set acoustic adhesive composition.
- Embodiment 42. The set acoustic adhesive composition of any of Embodiments 1-39, wherein the particulate polymer filler is present in an amount in the range of 10-40 wt % (e.g., in the range of 10-35 wt %, or 10-30 wt %, or 10-25 wt %, or 10-20 wt % of the set acoustic adhesive composition.
- Embodiment 43. The set acoustic adhesive composition of any of Embodiments 1-39, wherein the particulate polymer filler is present in an amount in the range of 15-40 wt % (e.g., in the range of 15-35 wt %, or 15-35 wt %, or 15-30 wt %, or 15-25 wt %) of the set acoustic adhesive composition.
- Embodiment 44. The set acoustic adhesive composition of any of Embodiments 1-39, wherein the particulate polymer filler is present in an amount in the range of 20-40 wt % (e.g., in the range of 20-35 wt %, wo-30 wt %, or 20-25 wt %) of the set acoustic adhesive composition.
- Embodiment 45. The acoustic adhesive composition of any of Embodiment 1-44, wherein the particulate polymer filler has a d₅₀particle size of at least 50 nm (e.g., at least 75 nm, or at least 100 nm, or at least 125 nm).
- Embodiment 46. The set acoustic adhesive composition of any of Embodiments 1-45, wherein the particulate polymer filler has a d₅₀particle size in the range of 50-500 nm (e.g., in the range of 50-450 nm, or 50-400 nm, or 50-350 nm, or 50-300 nm, or 100-500 nm, or 100-450 nm, or 100-400 nm, or 100-350 nm, or 100-300 nm, or 150-500 nm, or 150-450 nm, or 150-400 nm, or 150-350 nm, or 150-300 nm).
- Embodiment 47. The set acoustic adhesive composition of any of Embodiments 1-46, wherein the particulate polymer filler has d₁₀value of at least 10 nm (e.g., at least 25 nm, or at least 50 nm); and a d₉₀value of no more than 1000 nm (e.g., no more than 750 nm, or no more than 500 nm).
- Embodiment 48. The set acoustic adhesive composition of any of Embodiments 1-47, wherein the particulate polymer filler has a density at 20° C. that is within 20% (e.g., within 15%, or within 10%) of a density at 20° C. of the continuous phase of viscoelastic material.
- Embodiment 49. The set acoustic adhesive composition of any of Embodiment 1-48, wherein the particulate polymer filler is a styrene-based polymer, an acrylic-based polymer or an epoxy-based polymer, e.g., a styrene/butadiene polymer or a styrene/acrylic polymer.
- Embodiment 50. The set acoustic adhesive composition of any of Embodiments 1-49, wherein the continuous phase of viscoelastic material and the particulate polymer filler together make up at least 90 wt % (e.g., at least 92 wt %, at least 95 wt %, or at least 99 wt %) of the set acoustic adhesive composition.
- Embodiment 51. The set acoustic adhesive composition of any of Embodiments 1-50 comprising no more than 15 wt % of mineral filler (e.g., no more than 10 wt %, or no more than 5 wt %, or no more than 2 wt %, or no more than 1 wt %).
- Embodiment 52. A liquid acoustic adhesive formulation, e.g., suitable for providing a set acoustic adhesive composition of any of Embodiments 1-51, the liquid acoustic adhesive formulation comprising an aqueous dispersion of:
  - one or more components suitable to provide the continuous phase of viscoelastic material of the set acoustic adhesive composition, present in an amount in the range of 60-95 wt % on a dry solids basis; and
  - the particulate polymer filler, in an amount in the range of 5-40 wt %, on a dry solids basis.
- Embodiment 53. The liquid acoustic adhesive formulation of Embodiment 52, wherein the one or more components suitable to provide a continuous phase of a viscoelastic material are present in an amount as described in any of Embodiments 12-14, on a dry solids basis.
- Embodiment 54. The liquid acoustic adhesive formulation of Embodiment 52 or Embodiment 53, wherein the continuous phase of viscoelastic material is as described in any of Embodiments 17-23.
- Embodiment 55. The liquid acoustic adhesive formulation of any of Embodiments 52-54, wherein the one or more components include an acrylic polymer, e.g., in the form of a latex.
- Embodiment 56. The liquid acoustic adhesive formulation of Embodiment 55, wherein the acrylic polymer is present in an amount of at least 80 wt % (e.g., at least 85 wt %, or at least 90 wt %) of the components that form the continuous phase of the viscoelastic material, on a dry solids basis.
- Embodiment 57. The liquid acoustic adhesive formulation of Embodiment 55 or Embodiment 56, wherein the acrylic polymer is present in an amount of 32-90 wt % of the liquid acoustic adhesive formulation, on a dry solids basis.
- Embodiment 58. The liquid acoustic adhesive formulation of any of Embodiments 52-57, further comprising a tackifier, for example, a rosin ester-based tackifier.
- Embodiment 59. The liquid acoustic adhesive formulation of Embodiment 58, wherein the tackifier is present in an amount as described above with respect to Embodiment 33, on a dry solids basis.
- Embodiment 60. The set acoustic adhesive formulation of any of Embodiments 52-59, further comprising a rheology modifier, for example, a hydrophobically-modified alkali-swellable associative thickener and/or a cellulosic thickener.
- Embodiment 61. The liquid acoustic adhesive formulation of Embodiment 60, wherein the rheology modifier is present in an amount as described above with respect to Embodiment 36, on a dry solids basis.
- Embodiment 62. The liquid acoustic adhesive formulation of any of Embodiments 52-58, wherein the particulate polymer filler is present in the liquid acoustic adhesive formulation in an amount as described in any of Embodiments 41-44, on a dry solids basis.
- Embodiment 63. The liquid acoustic adhesive formulation of any of Embodiments 52-62, wherein the particulate polymer filler is as described in any of Embodiments 45-50.
- Embodiment 64. The liquid acoustic adhesive formulation of any of Embodiments 52-63, wherein the one or more components suitable to provide the continuous phase of viscoelastic material and the particulate polymer filler together make up at least 90 wt % (e.g., at least 92 wt %, at least 95 wt %, or at least 99 wt %) of the liquid acoustic adhesive formulation, on a dry solids basis.
- Embodiment 65. The liquid acoustic adhesive formulation of any of Embodiments 52-64, comprising no more than 15 wt % of mineral filler (e.g., no more than 10 wt %, or no more than 5 wt %, or no more than 2 wt %, or no more than 1 wt %), on a dry solids basis.
- Embodiment 66. The liquid acoustic adhesive formulation of any of Embodiments 52-65, having a solids content in the range of 40-70 wt % (e.g., in the range of 45-70 wt %, or 50-70 wt %, or 55-70 wt %, or 40-65 wt %, or 45-65 wt %, or 50-65 wt %, or 55-65 wt %, or 40-60 wt %, or 45-60 wt %, or 50-60 wt %, or 55-60 wt %).
- Embodiment 67. The liquid acoustic adhesive formulation of any of Embodiments 52-66, wherein the one or more components suitable to provide the continuous phase of the viscoelastic material has a wet density of at least 8 lbs/gal (e.g., at least 9 lbs/gal, or at least 10 lbs/gal, or at least 11 lbs/gal, or at least 12 lbs/gal).
- Embodiment 68. The liquid acoustic adhesive formulation of any of Embodiments 52-67, comprising no more than 5 wt % of volatile organic liquid (e.g., no more than 2 wt %, no more than 1 wt %, or no more than 0.5 wt %).
- Embodiment 69. The liquid acoustic adhesive formulation of any of Embodiments 52-68, having a pH in the range of 7-12 (e.g., in the range of 7-11.5, or 7-11, or 7-10.5, or 7-10, or 8-12, or 8-11.5, or 8-11, or 8-10.5, or 8-10, or 8.5-12, or 8.5-11.5, or 8.5-11, or 8.5-10.5, or 8.5-10, or 9-12, or 9-11.5, or 9-11, or 9-10.5, or 9-10).
- Embodiment 70. The liquid acoustic adhesive formulation of any of Embodiments 52-69, wherein the one or more components suitable to provide the continuous phase of the viscoelastic material further comprises a basic pH modifier.
- Embodiment 71. The liquid acoustic adhesive formulation of Embodiment 70, wherein the basic pH modifier is selected from sodium bicarbonate, potassium bicarbonate, or calcium carbonate.
- Embodiment 72. The liquid acoustic adhesive formulation of any of Embodiments 52-71, wherein the liquid acoustic adhesive formulation has a viscosity of greater than 10 Pa-s over a shear rate of 0.1-100 s⁻¹.
- Embodiment 73. The liquid acoustic adhesive formulation of any of Embodiments 52-71, wherein the liquid acoustic adhesive formulation has a viscosity in the range of 10-10,000 Pa-s over a shear rate of 0.1-100 s⁻¹.
- Embodiment 74. A sound-dampening building board comprising: