Four-piece golf ball

• US 20060172823A1
• Filed: 01/31/2006
• Published: 08/03/2006
• Est. Priority Date: 02/01/2005
• Status: Active Grant

• Current Assignee: Taylor Made Golf Co., Inc.
• Original Assignee: Taylor Made Golf Co., Inc.
• Inventors: Loper, Eric, Kim, Hyun Jin, Snell, Dean
• Granted Patent: US 8,177,665 B2
• Time in Patent Office: Days
• US Class Current: 473/371
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0024 Materials other than ionomers or polyurethane
• CPC Class Codes: A63B 37/0031 Hardness
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0049 Flexural modulus; Bending stiffness
• CPC Class Codes: A63B 37/0054 Substantially rigid, e.g. metal
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0065 Deflection or compression
• CPC Class Codes: A63B 37/0069 Flexural modulus; Bending stiffness
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: C08L 23/0869 Acids or derivatives thereof
• CPC Class Codes: C08L 23/0876 Neutralised polymers, i.e. ionomers
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof

Abstract

A four-piece solid golf ball construction is disclosed, including one or more core layers, an inner mantle layer, an outer mantle layer, and one or more cover layers. The inner mantle layer has a Shore D hardness in the range of 20 to 60, and the outer mantle layer has a Shore D hardness in the range of 40 to 80 and exceeding that of the inner mantle layer by at least 3. The solid golf ball provides a high spin rate when struck not only by a full 8-iron, but also by a soft pitching wedge, for short shots near a putting green.

Claims

1. A golf ball comprising:

(a) one or more core layers having a flexural modulus (F1) less than 30 kpsi;

(b) an inner mantle layer surrounding the one or more core layers, wherein the inner mantle layer has a flexural modulus (F2) in the range of 15 to 60 kpsi;

(c) an outer mantle layer surrounding the inner mantle layers, wherein the outer mantle layer has a flexural modulus (F3) in the range of 30 to 120 kpsi; and

(d) one or more cover layers surrounding the outer mantle layer;

(e) wherein the flexural modulus (F2) of inner mantle layer is greater than the flexural modulus (F1) of the one or more core layers by at least by 3 kpsi;

(f) and wherein the flexural modulus (F3) of outer mantle layer is greater than the flexural modulus (F2) of inner mantle layer by at least by 3 kpsi.

2. The golf ball of claim 1, wherein the inner mantle layer and/or the outer mantle layer comprises ionomeric polymer comprising:

(a) an ionomeric polymer comprising one or more E/X/Y copolymers, wherein E is ethylene, X is a C₃ to C₈ α

,β

ethylenically unsaturated carboxylic acid, and Y is a softening comonomer selected from the group consisting of alkyl acrylate and alkyl methacrylate, wherein the alkyl groups have from 1 to 8 carbon atoms, or ionomers of such E/X/Y copolymers, wherein X is in the range of about 5 to about 35 weight % of the E/X/Y copolymer and Y is in the range of 0 to about 50 weight % of the E/X/Y copolymer, and wherein the acid groups present in the ionomeric polymer are partially neutralized with a metal selected from the group consisting of zinc, sodium, lithium, calcium, magnesium, and combinations thereof;

or

(b) a bimodal ionomeric polymer comprising;

(i) a high molecular weight component having a molecular weight in the range of about 80,000 to about 500,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the high molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof, and

(ii) a low molecular weight component having a molecular weight in the range of about 2,000 to about 30,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the low molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof;

or

(c) a modified ionomeric polymer comprising;

(i) a blend composition comprising;

(1) ethylene,

(2) 5 to 25 weight percent (meth)acrylic acid (based on the total weight of the modified ionomeric polymer), and

(3) 0 to 40 weight percent of a C₁ to C₈-alkyl acrylate (based on the total weight of the modified ionomeric polymer), and

(4) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer) of a fatty acid or one or more metal salts of a fatty acid, or

(ii) a bimodal polymer blend composition comprising;

(1) a high molecular weight component having a molecular weight in the range of about 80,000 to about 500,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the high molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof,

(2) a low molecular weight component having a molecular weight in the range of about 2,000 to about 30,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the low molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof, and

(3) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer) of a fatty acid or one or more metal salts of a fatty acid;

or

(d) a blend composition comprising the reaction product of;

(i) one or more ionomers, and

(ii) a compound having a general formula (R₂N)_m—

R′

—

(X(O)_nOR_y)_m,

wherein R is selected from the group consisting of

(1) hydrogen,

(2) one or more C₁-C₂₀ aliphatic systems,

(3) one or more cycloaliphatic systems,

(4) one or more aromatic systems, and

(5) combinations thereof,

wherein R′

is a bridging group comprising

(1) one or more unsubstituted C₁-C₂₀ straight chain or branched aliphatic or alicyclic groups, or

(2) one or more substituted straight chain or branched aliphatic or alicyclic groups, or

(3) one or more aromatic groups, or

(4) one or more oligomers each containing up to 12 repeating units,

wherein when X=C or S or P, m is 1-3,

wherein when X=C, n=1 and y=1,

wherein when X=S, n=2 and y=1, and

wherein when X=P, n=2 and y=2;

or

(e) combinations of (a), (b), (c), and (d).

3. The golf ball of claim 1, wherein the inner mantle layer and/or the outer mantle layer consists essentially of:

(a) one or more triblock copolymers;

or

(b) one or more hydrogenation products of the triblock copolymers;

or

(c) one or more hydrogenated diene block copolymers;

or

(d) mixtures thereof;

(e) wherein each triblock copolymer has

(i) a first polymer block comprising an aromatic vinyl compound,

(ii) a second polymer block comprising a conjugated diene compound, and

(iii) a hydroxyl group located at a block copolymer,

(f) wherein each hydrogenated diene block copolymer has a polystyrene-reduced number-average molecular weight of from 50,000 to 600,000 and is a hydrogenation product of

(i) an A-B block copolymer, in which A is an alkenyl aromatic compound polymer block, and B is either

(1) a conjugated diene homopolymer block, wherein the vinyl content of the conjugated diene portion is more than 60%, or

(2) an alkenyl aromatic compound-conjugated diene random copolymer block wherein the vinyl content of the conjugated diene portion is 15-60%, or

(ii) an A-B-C block copolymer, in which A and B are as defined above and C is an alkenyl aromatic compound-conjugated diene copolymer tapered block, wherein the proportion of the alkenyl aromatic compound increases gradually, or

(iii) an A-B-A block copolymer, in which A and B are as defined above;

(g) and wherein in each of the hydrogenated diene block copolymers, the weight proportion of the alkenyl aromatic compound to conjugated diene is from 5/95 to 60/40, the content of the bound alkenyl aromatic compound in at least one block A is at least 3% by weight, the total of the bound alkenyl aromatic compound contents in the two block A'"'"'s or the block A and the block C is 5% to 25% by weight based on the total monomers, and at least 80% of the double bond unsaturations of the conjugated diene portion is saturated by the hydrogenation.

4. The golf ball of claim 1, wherein the inner mantle layer and/or the outer mantle layer incorporates a block copolymer comprising:

(a) a first polymer block comprising an aromatic vinyl compound;

(b) a second polymer block comprising a conjugated diene compound; and

(c) a hydroxyl group, or its hydrogenation product;

(d) wherein the composition is essentially free of ionomer.

5. The golf ball of claim 4, wherein the inner mantle layer and/or the outer mantle layer further comprises, in addition to the block copolymer, a second polymer selected from the group consisting of polyamide, polyamide copolymer, polyacrylate, polycarbonate, polypropylene, polyarylate, polyolefin, polyphenyl ether, modified-polyphenyl ether, polystyrene, diallyl phthalmate polymer, styrene-acrylonitrile, styrene-maileic anhydride, liquid crystal polymer, cellulose polymer, polyurethane, polyester, and mixtures thereof.

6. The golf ball of claim 5, wherein the inner mantle layer and/or the outer mantle layer comprises from about 10% to about 90% by weight of the block copolymer.

7. The golf ball of claim 1, wherein the inner mantle layer and/or the outer mantle layer comprises ionomeric polymer comprising the reaction product of:

(a) at least one component A, comprising a monomer, oligomer, or prepolymer, or polymer comprising at least 5% by weight of at least one type of functional group;

(b) at least one component B, comprising a monomer, oligomer, prepolymer, or polymer comprising less by weight of anionic functional groups than the weight percentage of anionic functional groups of the at least one component A; and

(c) at least one component C, comprising a metal cation,

(d) wherein the reaction product comprises a pseudo-crosslinked network of the at least one component A in the presence of the at least one component B.

8. The golf ball of claim 1, wherein the inner mantle layer and/or the outer mantle layer comprises:

(a) a matrix polymer selected from the group consisting of thermoplastics, thermosets, and combinations thereof; and

(b) one or more nanofillers substantially dispersed in the matrix polymer.

9. The golf ball of claim 8, wherein the nanofiller is intercalated within the matrix polymer.

10. The golf ball of claim 8, wherein the nanofiller is exfoliated within the matrix polymer.

11. The golf ball of claim 1, wherein the inner mantle layer and/or the outer mantle layer comprises a polymer selected from the group consisting of thermoplastic resins, thermoset resins, polyurethane resins, polyester resins, polyamide elastomer resins, polyamide-ionomer, polyurethane ionomer, thermoplastic copolyetherester block copolymer, thermoplastic copolyesterester block copolymer, thermoplastic elastomer, thermoset elastomer, synthetic rubber, thermoplastic vulcanizate, copolymeric ionomer, terpolymeric ionomer, polyurethane ionomer, polyamide ionomer, polycarbonate, polyolefin, polyamide, copolymeric polyamide, polyester, polyvinyl alcohol, acrylonitrile-butadiene-styrene copolymer, polyarylate, polyacrylate, polyphenylene ether, impact-modified polyphenylene ether, high impact polystyrene, diallyl phthalate polymer, metallocene catalyzed polymer, 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-vinyl acetate copolymers (EVA), ethylene-propylene copolymer, ethylene vinyl acetate, polyurea, polysiloxane, and combinations thereof.

12. The golf ball of claim 1, wherein at least one of the one or more cover layers comprises a material selected from the group consisting of thermoset polyurethane, thermoplastic polyurethane, ionomer, and combinations thereof.

13. The golf ball of claim 1, wherein at least one of the one or more cover layer comprises ionomeric polymer comprises:

(a) an ionomeric polymer comprising one or more E/X/Y copolymers, wherein E is ethylene, X is a C₃ to C₈ α

,β

ethylenically unsaturated carboxylic acid, and Y is a softening comonomer selected from the group consisting of alkyl acrylate and alkyl methacrylate, wherein the alkyl groups have from 1 to 8 carbon atoms, or ionomers of such E/X/Y copolymers, wherein X is in the range of about 5 to about 35 weight % of the E/X/Y copolymer and Y is in the range of 0 to about 50 weight % of the E/X/Y copolymer, and wherein the acid groups present in the ionomeric polymer are partially neutralized with a metal selected from the group consisting of zinc, sodium, lithium, calcium, magnesium, and combinations thereof;

or

(b) a bimodal ionomeric polymer comprising;

(i) a high molecular weight component having a molecular weight in the range of about 80,000 to about 500,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the high molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof, and

(ii) a low molecular weight component having a molecular weight in the range of about 2,000 to about 30,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the low molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof;

or

(c) a modified ionomeric polymer comprising;

(i) a blend composition comprising;

(1) ethylene,

(2) 5 to 25 weight percent (meth)acrylic acid (based on the total weight of the modified ionomeric polymer), and

(3) 0 to 40 weight percent of a C₁ to C₈-alkyl acrylate (based on the total weight of the modified ionomeric polymer), and

(4) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer) of a fatty acid or one or more metal salts of a fatty acid, or

(ii) a bimodal polymer blend composition comprising;

(1) a high molecular weight component having a molecular weight in the range of about 80,000 to about 500,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the high molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof,

(2) a low molecular weight component having a molecular weight in the range of about 2,000 to about 30,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the low molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof, and

(3) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer) of a fatty acid or one or more metal salts of a fatty acid;

or

(d) a blend composition comprising the reaction product of;

(i) one or more ionomers, and

(ii) a compound having a general formula (R₂N)_m—

R′

—

(X(O)_nOR_y)_m,

(iii) wherein R is selected from the group consisting of

(1) hydrogen,

(2) one or more C₁-C₂₀ aliphatic systems,

(3) one or more cycloaliphatic systems,

(4) one or more aromatic systems, and

(5) combinations thereof,

(iv) wherein R′

is a bridging group comprising

(1) one or more unsubstituted C₁-C₂₀ straight chain or branched aliphatic or alicyclic groups, or

(2) one or more substituted straight chain or branched aliphatic or alicyclic groups, or

(3) one or more aromatic groups, or

(4) one or more oligomers each containing up to 12 repeating units,

(v) wherein when X=C or S or P, m is 1-3,

(vi) wherein when X=C, n=1 and y=1,

(vii) wherein when X=S, n=2 and y=1, and

(viii) wherein when X=P, n=2 and y=2;

or

(e) combinations of (a), (b), (c), and (d).

14. The golf ball of claim 1, wherein at least one of the one or more cover layers comprises an ionomer and a block copolymer, the block copolymer comprising a first polymer block comprising an aromatic vinyl compound, a second polymer block comprising a conjugated diene compound, and a hydroxyl group located at a block copolymer, or its hydrogenation product, wherein the ratio of block copolymer to ionomer is in the range of about 51:

49 to about 95;

5 by weight.

15. The golf ball of claim 14, wherein the one or more cover layers further comprises, in addition to the ionomer and the block copolymer, a second polymer selected from the group consisting of polyamide, polyamide copolymer, polyacrylate, polycarbonate, polypropylene, polyarylate, polyolefin, polyphenyl ether, modified-polyphenyl ether, polystyrene, diallyl phthalmate polymer, styrene-acrylonitrile, styrene-maileic anhydride, liquid crystal polymer, cellulose polymer, polyurethane, and polyester, and mixtures thereof.

16. The golf ball of claim 1, wherein at least one of the one or more cover layers comprises a polyamide and a block copolymer, the block copolymer comprising:

(a) a first polymer block comprising an aromatic vinyl compound;

(b) a second polymer block comprising a conjugated diene compound; and

(c) a hydroxyl group, or its hydrogenation product;

(d) wherein the cover is essentially free of ionomer;

(e) and wherein the cover comprises from about 10% to about 90% by weight of the block copolymer.

17. The golf ball of claim 1, wherein at least one of the one or more cover layers comprises:

(a) a matrix polymer selected from the group consisting of thermoplastics, thermosets and combinations thereof; and

(b) one or more nanofillers substantially dispersed in the matrix polymer.

18. The golf ball of claim 17, wherein the nanofiller is intercalated within the matrix polymer.

19. The golf ball of claim 17, wherein the nanofiller is exfoliated within the matrix polymer.

20. The golf ball of claim 1, wherein at least one of the one or more core layers comprises a modified ionomeric polymer comprising:

(a) an ionomeric polymer comprising one or more E/X/Y copolymers, wherein E is ethylene, X is a C₃ to C₈ α

,β

ethylenically unsaturated carboxylic acid, and Y is a softening comonomer selected from the group consisting of alkyl acrylate and alkyl methacrylate, wherein the alkyl groups have from 1 to 8 carbon atoms, or ionomers of such E/X/Y copolymers, wherein X is in the range of about 5 to about 35 weight % of the E/X/Y copolymer and Y is in the range of 0 to about 50 weight % of the E/X/Y copolymer, and wherein the acid groups present in the ionomeric polymer are partially neutralized with a metal selected from the group consisting of zinc, sodium, lithium, calcium, magnesium, and combinations thereof;

or

(b) a bimodal ionomeric polymer comprising;

(i) a high molecular weight component having a molecular weight in the range of about 80,000 to about 500,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the high molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof, and

(ii) a low molecular weight component having a molecular weight in the range of about 2,000 to about 30,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the low molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof, or

(c) a modified ionomeric polymer comprising;

(i) a blend composition comprising;

(1) ethylene,

(2) 5 to 25 weight percent (meth)acrylic acid (based on the total weight of the modified ionomeric polymer), and

(3) 0 to 40 weight percent of a C₁ to C₈-alkyl acrylate (based on the total weight of the modified ionomeric polymer), and

(4) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer) of a fatty acid or one or more metal salts of a fatty acid, or

(ii) a bimodal polymer blend composition comprising;

(1) a high molecular weight component having a molecular weight in the range of about 80,000 to about 500,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the high molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof,

(2) a low molecular weight component having a molecular weight in the range of about 2,000 to about 30,000 and comprising one or more ethylene/α

,β

-ethylenically unsaturated C_3-8 carboxylic acid copolymers and/or one or more ethylene, alkyl(meth)acrylate, (meth)acrylic acid terpolymers, wherein the low molecular weight component is partially neutralized with metal ions selected from the group consisting of lithium, sodium, zinc, calcium, magnesium, and combinations thereof, and

(3) about 5 to about 45 weight percent (based on the total weight of the modified ionomeric polymer) of a fatty acid or one or more metal salts of a fatty acid;

or

(d) a blend composition comprising the reaction product of;

(i) one or more ionomers, and

(ii) a compound having a general formula (R₂N)_m—

R′

—

(X(O)_nOR_y)_m,

(iii) wherein R is selected from the group consisting of

(1) hydrogen,

(2) one or more C₁-C₂₀ aliphatic systems,

(3) one or more cycloaliphatic systems,

(4) one or more aromatic systems, and

(5) combinations thereof,

(iv) wherein R′

is a bridging group comprising

(1) one or more unsubstituted C₁-C₂₀ straight chain or branched aliphatic or alicyclic groups, or

(2) one or more substituted straight chain or branched aliphatic or alicyclic groups, or

(3) one or more aromatic groups, or

(4) one or more oligomers each containing up to 12 repeating units,

(v) wherein when X=C or S or P, m is 1-3,

(vi) wherein when X=C, n=1 and y=1,

(vii) wherein when X=S, n=2 and y=1, and

(viii) wherein when X=P, n=2 and y=2;

or

(e) combinations of (a), (b), (c), and (d).

21. The golf ball of claim 1, wherein at least one of the one or more core layers comprises:

(a) at least one unsaturated polymers;

(b) at least one cross-linking agent;

(c) optionally, at least one co-cross-linking agent;

(d) optionally, at least one peptizer;

(e) optionally, at least one accelerator; and

(f) optionally, at least one filler.

22. The golf ball of claim 21, wherein:

(a) the unsaturated polymer has a Mooney viscosity (ML₁₊₄ (100°

C.)) of from about 20 to about 80 and is selected from the group consisting of 1,2-polybutadiene, cis-1,4-polybutadiene, trans-1,4-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, and combinations thereof;

(b) the cross-linking agent is present in an amount of from about 0.05 to about 5 parts by weight of the cross-linking agents per 100 parts by weight of the unsaturated polymer;

(c) the peptizer, if present, comprises

(i) an organic sulfur compound,

(ii) a metal salt of an organic sulfur compound,

(iii) a non-metal salt of an organic sulfur compound, or

(iv) combinations of (i), (ii), and/or (iii);

(d) the accelerator, if present, is present in an amount of from about 0.1 to about 10 parts by weight per 100 parts by weight of the unsaturated polymer; and

(e) the filler, if present, 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, other particulate carbonaceous materials, and combinations thereof.

23. The golf ball of claim 21, wherein:

(a) the unsaturated polymer is cis-1,4-polybutadiene and has a Mooney viscosity (ML₁₊₄ (100°

C.)) of from about 30 to about 60;

(b) the cross-linking agent is present in an amount of from about 0.2 to about 3 parts by weight per 100 parts by weight of the unsaturated polymer;

(c) the peptizer, if present, is

(i) present in an amount of from about 0.01 to about 10 parts by weight per 100 parts by weight of the unsaturated polymer, and

(ii) is selected from the group consisting of organic sulfur compounds, metal salts of an organic sulfur compound, non-metal salt of an organic sulfur compound, and combinations thereof; and

(d) the accelerator, if present, is present in an amount of from about from about 0.2 to about 5 parts by weight of the accelerator per 100 parts by weight of the unsaturated polymer.

24. The golf ball of claim 21, wherein:

(a) the unsaturated polymer is cis-14-polybutadiene and has a Mooney viscosity (ML₁₊₄ (100°

C.)) of from about 35 to about 50;

(b) the cross-linking agent is present in an amount of from about 0.2 to about 2 parts by weight per 100 parts by weight of the unsaturated polymer;

(c) the peptizer, if present, is

(i) present in an amount of from about 0.1 to about 7 parts by weight per 100 parts by weight of the unsaturated polymer component; and

(ii) selected from the group consisting of pentachlorothiophenol, dibenzamido diphenyldisulfide, a metal salt of pentachlorothiophenol, an ammonium salt of pentachlorothiophenol with the ammonium cation having the general formula [NR¹R²R³R⁴]⁺ where R¹, R², R³, and R⁴ is either hydrogen, or a C₁-C₂₀ aliphatic, cycloaliphatic or aromatic system, and combinations thereof, and

(d) the accelerator, if present, is present in an amount of from about 0.5 to about 1.5 parts by weight per 100 parts by weight of the unsaturated polymer and is selected from the group consisting of 2-mercaptobenzothiazole and a salt of 2-mercaptobenzothiazole.

25. The golf ball of claim 21, wherein the peptizer is present in an amount of from about 0.15 to about 5 parts by weight per 100 parts by weight of the unsaturated polymer component, and is selected from the group consisting of pentachlorothiophenol, the zinc salt of pentachlorothiophenol, the NH₄⁺ salt of pentachlorothiophenol, and combinations thereof.

26. The golf ball of claim 1, wherein at least one of the one or more core layers comprises:

(a) a first cross-linking agent, having a first characteristic decomposition temperature less than 150°

C. for a t_1/2 equal to 0.1 hour; and

(b) a second one cross-linking agent, having a second characteristic decomposition temperature greater than 150°

C. for a t_1/2 equal to 0.1 hour.

27. The golf ball of claim 26, wherein the composition weight ratio of the first cross-linking agent to the second cross-linking agent is in the range of 5:

95 to 95;

5.

28. The golf ball of claim 26, wherein the composition weight ratio of the first cross-linking agent to the second cross-linking agent is in the range of 10:

90 to 50;

50.

29. A four-piece golf ball comprising:

(a) one or more core layers having a diameter in the range of about 1.20 to about 1.52 inches and a PGA compression in the range of about 50 to about 80;

(b) an inner mantle layer surrounding the one or more core layers and having a thickness of less than 0.055 inches and a Shore D hardness in the range of about 40 to about 55;

(c) an outer mantle layer surrounding the inner mantle layer and having a thickness in the range of 0.025 to 0.065 inches and a Shore D hardness in the range of about 55 to about 70; and

(d) one or more cover layers surrounding the outer mantle layer;

(e) wherein the golf ball has a C.O.R. greater than about 0.790, at 125 ft/sec inbound velocity.

30. A method for making a golf ball mantle layer of a kind that comprises ionomeric polymer, comprising the steps of:

(a) blending together the following components to form a first composition

(i) at least one component A that is a monomer, oligomer, prepolymer, or polymer comprising at least 5% by weight of anionic functional groups,

(ii) at least one component B that is a monomer, oligomer, prepolymer, or polymer comprising less by weight of anionic functional groups than the weight percentage of anionic functional groups of the at least one component A, and

(iii) at least one component C that is a metal cation; and

(b) melt-processing the first composition to produce a reaction product of the anionic functional groups of the at least one component A and the at least one component C, to form a polymer blend composition, wherein the polymer blend composition incorporates an in-situ-formed pseudo-crosslinked network of the at least one component A in the presence of the at least one component B.