Acid-functional polyurethane and polyurea compositions for golf balls

1. A golf ball comprising:

a core having a compression greater than about 55; and

an outer cover comprising an acid-functional polyurethane, polyurea, or copolymer thereof, the outer cover having a Shore D hardness of at least about 25, a thickness of from at least about 0.02 inches to about 0.03 inches, and a specific gravity of at least about 0.7.

2. The golf ball of claim 1 , wherein the acid-functional polyurethane or polyurea is formed from an acid-functional prepolymer comprising at least one of an acid-functional polyol, an acid-functional oligomer, or an acid-functional organic amine; and at least one of an isocyanate or an acid-functional isocyanate.

3. The golf ball of claim 2 , wherein the acid-functional prepolymer has the formula:

where A=a straight chain or branched aliphatic or alicyclic group, a substituted straight chain or branched aliphatic or alicyclic group, or an aromatic or substituted aromatic group; and B=R—Y, where R=a straight chain or branched aliphatic or alicyclic group, a substituted straight chain or branched aliphatic or alicyclic group, or an aromatic or substituted aromatic group, and Y=HSO 3 , HCO 2 , or H 2 PO 3 .

4. The golf ball of claim 2 , wherein the acid-functional polyol or acid-functional oligomer comprise carboxylated, sulfonated or phosphonated derivatives of polyester polyol; polyether polyol; polylactone polyol; polytetramethylene ether glycol; poly(oxypropylene)glycol; polybutadiene glycol; polyethylene adipate glycol; polyethylene propylene adipate glycol; polybutylene adipate glycol; diethylene glycol initiated caprolactone; 1,4-butanediol initiated caprolactone; trimethylol propane initiated caprolactone; neopentyl glycol initiated caprolactone; oligomers of dimethylol proprionic acid, or oligomers of isophthalic sulfonic acid.

5. The golf ball of claim 2 , wherein the acid-functional polyol or acid-functional oligomer has an acid number of from about 10 to about 150, a hydroxyl number of from about 10 to about 175, or a hydroxyl functionality of at least about 1.8.

6. The golf ball of claim 2 , wherein the acid-functional prepolymer has an isocyanate content of from about 2% to about 32% and the equivalent weight ratio of isocyanate to curing agent is about 0.80 to about 1.20.

7. The golf ball of claim 2 , wherein the isocyanate comprises 4,4′-diphenylmethane diisocyanate; 3,3′-dimethyl-4,4′-biphenylene diisocyanate; toluene diisocyanate; polymeric diphenylmethane diisocyanate; modified liquid 4,4′-diphenylmethane diisocyanate; hexamethylene-diisocyanate; 4,4′-dicyclohexylmethane diisocyanate; isophorone diisocyanate; m-tetramethylxylene diisocyanate; p-tetramethylxylene diisocyanate; p-phenylene diisocyanate; m-phenylene diisocyanate; or low-free isocyanate.

8. The golf ball of claim 2 , wherein the acid-functional polyurethane or polyurea further comprises a curing agent.

9. The golf ball of claim 8 , wherein the curing agent comprises an amine curing agent, a glycol curing agent, or a mixture thereof.

10. The golf ball of claim 9 , wherein the curing agent is an amine curing agent comprising 4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 1,4-bis-(sec-butylamino)-cyclohexane; 3,5-dimehtylthio-2,4(2,6)-toluenediamine; 3,5-diethyl-2,4(2,6)-toluenediamine; N,N′-dialkyldiamine diphenyl methane; trimethylene-glycol-di-p-aminobenzoate; or polytetramethyleneoxide-di-p-aminobenzoate with molecular weight ranging from about 250 to about 1000.

11. The golf ball of claim 9 , wherein the curing agent is a glycol curing agent comprising ethylene glycol; diethylene glycol; propylene glycol; 1,3-propane glycol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; or polytetramethylene ether glycol with molecular weight ranging from about 250 to about 1000.

12. The golf ball of claim 2 , wherein the acid-functional isocyanate comprises carboxylated, sulfonated or phosphonated derivatives of diphenylmethane-2,4′-diisocyanate; diphenylmethane-4,4′-diisocyanate; 3,3′-dimethyl-4,4′-biphenylene diisocyanate; 2,4-toluene diisocyanate; methylenebis-(4-cyclohexyl diisocyanate); phenylene-1,4-diisocyanate; diphenyl ether 4,4′-diisocyanate; naphthylene-1,5,-diisocyanate; p-phenylene diisocyanate; p,p′-diphenyl diisocyanate; hexahydrophenylene-1,3-diisocyanate; hexahydrophenylene-1,4-diisocyanate; triphenylmethane-4,4,4′,4″-triisocyanate; perhydrodiphenylmethane-2,4′-diisocyanate; perhydrodiphenylmethane-4,4′-diisocyanate; ethylene diisocyanate; propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; hexamethylene-1,6-diisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; or 1,3-xylene diisocyanate.

13. The golf ball of claim 2 , wherein the acid-functional organic amine comprises carboxylated, sulfonated or phosphonated derivatives of polyolamines; polymethylene-di-p-aminobenzoates; polyethyleneglycol-bis(4-aminobenzoates); polydimethylsiloxane-bis(4-aminobenzoates); polytetramethyleneetherglycol-di-p-aminobenzoates; polypropyleneglycol-di-p-aminobenzoates; N,N,N′,N′-tetramethyl-ethylenediamine; 1,4-diazobicyclo (2,2,2)-octane; N-methyl-N′-dimethylaminoethylpiperazine; N,N-dimethylbenzylamine; bis-(N,N-diethylaminoethyl)-adipate; N,N-diethylbenzylamine; pentamethyldiethylenetriamine; N,N-dimethylcyclohexylamine; N,N,N′,N′-tetramethyl-1,3-butanediamine; N,N-dimethyl-beta-phenylethylamine; 1,2-dimethylimidazole; or 2-methylimidazole.

14. The golf ball of claim 2 , wherein the prepolymer further comprises a co-polymer polyol comprising polytetramethylene ether glycol; poly(oxypropylene) glycol; poly(ethylene oxide capped oxypropylene) glycol; diethylene glycol initiated polycaprolactone; propylene glycol initiated polycaprolactone; 1,4-butanediol initiated polycaprolactone; trimethylol propane initiated polycaprolactone; neopentyl glycol initiated polycaprolactone; 1,5-pentanediol initiated polycaprolactone; 1,6-hexanediol initiated polycaprolactone; polytetramethylene ether glycol initiated polycaprolactone; polyethylene adipate glycol; polyethylene propylene adipate glycol; polybutylene adipate glycol; ortho-phthalate-1,6-hexanediol polyester polyol; polyethylene terephthalate polyester polyol; poly(hexamethylene adipate) glycol; poly(phthalate carbonate) glycol; poly(hexamethylene carbonate) glycol; polycarbonate glycols containing bisphenol A; hydroxy-terminated polybutadiene glycol; hydroxy-terminated liquid isoprene rubber; acrylic polyol; or p-dimer alcohols coverted from dimerized fatty acids.

15. The golf ball of claim 1 , further comprising an intermediate layer disposed between the core and the cover.

16. The golf ball of claim 15 , wherein the intermediate layer has a thickness of between about 0.02 inches and about 0.035 inches.

17. The golf ball of claim 1 , wherein the acid-functional polyurethane or polyurea comprises a thermoset or thermoplastic material.

18. A golf ball comprising:

a core;

an outer cover comprising an acid-functional polyurethane, polyurea, or copolymer thereof, the cover layer having a Shore D hardness of at least about 25 and a thickness of from at least about 0.02 inches to about 0.03 inches; and

an intermediate layer disposed between the core and the outer cover, the intermediate layer comprising an acid-functional polyurethane, polyurea, or copolymer thereof, the intermediate layer having a thickness of from at least about 0.02 inches to about 0.035 inches.

19. A golf ball comprising:

a core;

an outer cover comprising an acid-functional polyurethane, polyurea, or copolymer thereof, the cover layer having a Shore D hardness of at least about 25, a specific gravity of at least about 0.7, and a thickness of from at least about 0.02 inches to about 0.03 inches; and

an intermediate layer disposed between the core and the outer cover, the intermediate layer comprising a blend of an acid-functional polyurethane, polyurea, or copolymer thereof and at least one of non-anionic polyurethanes, epoxy resins, polyethylenes, polyamides, polyesters, acid copolymers or their ionomer derivatives, or mixtures thereof.