Three-layer-cover golf ball

1. A golf ball comprising:

a core; and

a cover comprising:

an inner cover layer having a thickness of 0.010 to 0.100 inches and comprising a non-ionomeric composition comprised of an acid copolymer or terpolymer having a formula of E/X/Y, where E is an olefin, Y is a carboxylic acid, and X is a softening comonomer;

an outer cover layer comprising: a light-stable polyurea or a copolymer of a polyurea; and

an intermediate cover layer disposed between the inner and outer cover layers comprising a fully-neutralized ionomer formed from a reaction between an ionomer having acid groups, a suitable cation source, and a salt of an organic acid, the cation source being present in an amount sufficient to neutralize the acid groups by at least 100%, wherein the organic acid is selected from the group consisting of caproic acid, caprylic acid, capric acid, lauric acid, stearic acid, behenic acid, erucic acid, oleic acid, and linoleic acid.

2. The golf ball of claim 1 , wherein the polyurea and the copolymer of the polyurea are prepared from an isocyanate comprising 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, toluene diisocyanate, polymeric diphenylmethane diisocyanates, carbodimide-modified liquid 4,4′-diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, triphenylmethane-4,4′-triisocyanate, and triphenylmethane-4,4″-triisocyanate, napthylene-1,5,-diisocyanate, 2,4′-, 4,4′-, and 2,2-biphenyl diisocyanate, polyphenyl polymethylene polyisocyanate, ethylene diisocyanate, propylene- 1,2-diisocyanate, tetramethylene diisocyanate, tetramethylene- 1,4-diisocyanate, 1,6-hexamethylene-diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodecane-1,12-disocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,2-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, methyl-cyclohexylene diisocyanate, 2,4-methylcyclohexane diisocyanate, 2,6-methylcyclohexane diisocyanate, 4,4′-dicyclohexyl diisocyanate, 2,4′-dicyclohexyl diisocyanate, 1,3,5-cyclohexane triisocyanate, isocyanatomethylcyclohexane isocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, isocyanatoethylcyclohexane isocyanate, bis(isocyanatomethyl)-cyclohexane diisocyanate, 4,4′-bis(isocyanatomethyl) dicyclohexane, 2,4′-bis(isocyanatomethyl) dicyclohexane, isophorone diisocyanate, triisocyanate of hexamethylene-diisocyanate, triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, 1,2-, 1,3-, and 1,4-xylene diisocyanate, m-tetramethylxylene diisocyanate, p-tetramethylxylene diisocyanate, trimerized isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, trimer of tetramethyixylene diisocyanate, isocyanurate of hexamethylene diisocyanate, isocyanurate of isophorone diisocyanate, dimerized uretdione of toluene diisocyanate, or uretdione of hexamethylene diisocyanate.

3. The golf ball of claim 1 , wherein the polyurea and the copolymer of the polyurea are prepared from a polyamine comprising 3,5-dimethylthio-2,4-toluenediamine; 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine; 4,4′-bis-(sec-butylamino)-diphenylmethane; 1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenyl methane; p,p′-methylene dianiline; m-phenylenediamine; 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(2,6-diethylaniline); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane; 2,2′, 3,3′-tetrachloro diamino diphenylmethane; 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); trimethylene glycol di-p-aminobenzoate; or a mixture thereof.

4. The golf ball of claim 1 , wherein the intermediate cover layer has a thickness of 0.005 to 0.050 inches.

5. The golf ball of claim 1 , wherein the outer cover layer has a material hardness of less than 60 Shore D, and the inner cover layer has a material hardness of greater than 60 Shore D.

6. The golf ball of claim 1 , wherein the olefin comprises ethylene, and the carboxylic acid comprises acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, or itaconic acid.

7. The golf ball of claim 1 , wherein the cation source comprises barium, lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium, strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium.

8. The golf ball of claim 1 , wherein the intermediate cover layer has a material hardness of 30 Shore D to 65 Shore D.

9. The golf ball of claim 1 , wherein the organic acid is non-volatile and non-migratory.

10. The golf ball of claim 1 , wherein the core comprises a fully neutralized ionomer being formed from a reaction between an ionomer having acid groups, a suitable cation source, and a salt of an organic acid, the cation source being present in an amount sufficient to neutralize the acid groups 100%.

11. A golf ball comprising:

a core; and

a cover comprising:

an inner cover layer comprising a fully-neutralized ionomer formed from a reaction between an ionomer having acid groups, a suitable cation source, and a salt of an organic acid, the cation source being present in an amount sufficient to neutralize the acid groups by at least 100%, wherein the organic acid is selected from the group consisting of caproic acid, caprylic acid, capric acid, lauric acid, stearic acid, behenic acid, erucic acid, oleic acid, and linoleic acid;

an outer cover layer comprising a light-stable polyurea or a copolymer of a polyurea; and

an intermediate cover layer disposed between the inner and outer cover layers comprising a non-ionomeric composition comprised of an acid copolymer or terpolymer having a formula of E/X/Y, where E is an olefin, Y is a carboxylic acid, and X is a softening comonomer.

12. The golf ball of claim 11 , wherein the polyurea and the copolymer of the polyurea are prepared from an isocyanate comprising 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, toluene diisocyanate, polymeric diphenylmethane diisocyanates, carbodimide-modified liquid 4,4′-diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, triphenylmethane-4,4′-triisocyanate, and triphenylmethane-4,4″-triisocyanate, napthylene-1,5,-diisocyanate, 2,4′-, 4,4′-, and 2,2-biphenyl diisocyanate, polyphenyl polymethylene polyisocyanate, ethylene diisocyanate, propylene-1,2-diisocyanate, tetramethylene diisocyanate, tetramethylene-1,4-diisocyanate, 1,6-hexamethylene-diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodecane-1,12-diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,2-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, methyl-cyclohexylene diisocyanate, 2,4-methylcyclohexane diisocyanate, 2,6-methylcyclohexane diisocyanate, 4,4′-dicyclohexyl diisoeyanate, 2,4′-dicyclohexyl diisocyanate, 1,3,5-cyclohexane triisocyanate, isocyanatomethylcyclohexane isocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, isocyanatoethylcyclohexane isocyanate, bis(isocyanatomethyl)-cyclohexane diisocyanate, 4,4′-bis(isocyanatomethyl) dicyclohexane, 2,4′-bis(isocyanatomethyl) dicyclohexane, isophorone diisocyanate, triisocyanate of hexamethylene-diisocyanate, triisocyanate of 2,2,4-trimethyl- 1,6-hexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, 1,2-, 1,3-, and 1,4-xylene diisocyanate, m-tetramethylxylene diisocyanate, p-tetramethylxylene diisocyanate, trimerized isocyanurate of toluene diisocyanate, trimer of diphenylmethane diisocyanate, timer of tetramethylxylene diisocyanate, isocyanurate of hexamethylene diisocyanate, isocyanurate of isophorone diisocyanate, dimerized uretdione of toluene diisocyanate, or uretdione of hexamethylene diisocyanate.

13. The golf ball of claim 11 , wherein the polyurea and the copolymer of the polyurea are prepared from a polyamine comprising 3,5-dimethylthio-2,4-toluenediamine; 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine; 4,4′-bis-(sec-butylamino)-diphenylmethane; 1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenyl methane; p,p′-methylene dianiline; m-phenylenediamine; 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(2,6-diethylaniline); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane; 2,2′, 3,3′-tetrachloro diamino diphenylmethane; 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); trimethylene glycol di-p-aminobenzoate; or a mixture thereof.

14. The golf ball of claim 11 , wherein the intermediate cover layer has a thickness of 0.005 to 0.050 inches.

15. The golf ball of claim 11 , wherein the outer cover layer has a material hardness of less than 60 Shore D, and the inner cover layer has a material hardness of greater than 60 Shore D.

16. The golf ball of claim 11 , wherein the olefin comprises ethylene, and the carboxylic acid comprises acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, or itaconic acid.

17. The golf ball of claim 11 , wherein the cation source comprises barium, lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium, strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium.

18. The golf ball of claim 11 , wherein the intermediate cover layer has a material hardness of 30 Shore D to 65 Shore D.

19. The golf ball of claim 11 , wherein the organic acid is non-volatile and non-migratory.

20. The golf ball of claim 11 , wherein the core comprises a fully neutralized ionomer being formed from a reaction between an ionomer having acid groups, a suitable cation source, and a salt of an organic acid, the cation source being present in an amount sufficient to neutralize the acid groups 100%.