Multi-layer core golf ball
A golf ball comprising a core and a cover, wherein the core consists of: a solid inner core layer formed from a plasticized non-acid polymer composition PC p/N-A and having a diameter of 1.10 inch or less and a center Shore C hardness (H center ) of 50 or less, one or more optional intermediate core layers, and an outer core layer formed from at least one of a thermoset rubber composition TR and a thermoplastic composition TP and having a thickness of 0.200 inches or greater and an outer surface Shore C hardness (H outer surface ) of 70 or greater, wherein H outer surface >H center , and H outer surface −H center ≧40. In another embodiment, the center Shore C hardness (H center ) is 40 or less, the outer surface Shore C hardness (H outer surface ) is 85 or greater, and H outer surface −H center ≧45. In one embodiment, an intermediate layer is disposed between the outer core layer and the cover. The plasticized non-acid polymer composition PC p/N-A . may be formed from at least one non-acid polymer composition and at least one plasticizer.
1. A golf ball comprising a core and a cover, wherein the core consists of:
a solid inner core layer formed from a plasticized non-acid polymer composition PC p/N-A and having a diameter of 1.10 inch or less and a center Shore C hardness (H center ) of 15 or less,
an intermediate core layer, and
an outer core layer formed from at least one of a thermoset rubber composition TR and a thermoplastic composition TP and having a thickness of 0.40 inches or greater and an outer surface Shore C hardness (H outer surface ) of 70 or greater,
wherein H outer surface >H center , and H outer surface −H center ≧55.
2. The golf ball of claim 1 , wherein H outer surface −H center ≧65.
3. The golf ball of claim 1 , wherein H outer surface −H center ≧75.
4. The golf ball of claim 1 , wherein H outer surface −H center ≧80.
5. The golf ball of claim 1 , wherein H outer surface −H center ≧60.
6. The golf ball of claim 1 , wherein the inner core layer has an inner core interface Shore C hardness H inner core interface such that −5≦H inner core interface −H center ≦5.
7. The golf ball of claim 1 , wherein the outer core layer has an outer core interface Shore C hardness H outer core interface such that H outer core interface −H inner core interface ≦H outer surface −H center .
8. The golf ball of claim 1 , wherein the outer core layer has an outer core interface Shore C hardness H outer core interface such that H outer core interface −H inner core interface >H outer surface −H center .
9. The golf ball of claim 1 , wherein the plasticized non-acid polymer composition PC p/N-A , is formed from at least one non-acid polymer composition and at least one plasticizer.
10. The golf ball of claim 9 , wherein the non-acid polymer composition includes at least one of polyolefins, polyamides, polyesters, polyethers, polyurethanes, metallocene-catalyzed polymers, single-site catalyst polymerized polymers, ethylene propylene rubber, ethylene propylene diene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers, and functionalized derivatives thereof.
11. The golf ball of claim 9 , wherein the non-acid polymer composition includes an alkyl acrylate rubber selected from ethylene-alkyl acrylates and ethylene-alkyl methacrylates.
12. The golf ball of claim 11 , wherein the non-acid polymer composition contains ethylene-n-butyl acrylate, and the n-butyl-acrylate is present in an amount of 20 wt. % or greater, based on the total weight of the non-acid polymer composition.
13. The golf ball of claim 1 , wherein the outer core layer comprises at least one of natural rubber, polybutadiene, polyisoprene, ethylene propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber, butyl rubber, halobutyl rubber, polyurethane, polyurea, acrylonitrile butadiene rubber, polychloroprene, alkyl acrylate rubber, chlorinated isoprene rubber, acrylonitrile chlorinated isoprene rubber, polyalkenamer, phenol formaldehyde, melamine formaldehyde, polyepoxide, polysiloxane, polyester, alkyd, polyisocyanurate, polycyanurate, polyacrylate, and combinations thereof.
14. The golf ball of claim 1 , wherein the outer core layer comprises at least one of ionomers; highly neutralized ionomers; non-ionomeric acid polymers; polyurethanes, polyureas, and polyurethane-polyurea hybrids; polyester-based thermoplastic elastomers; polyamides, copolymers of ionomer and polyamide, polyamide-ethers, and polyamide-esters; ethylene-based homopolymers and copolymers; propylene-based homopolymers and copolymers; triblock copolymers based on styrene and ethylene/butylene; derivatives thereof that are compatibilized with at least one grafted or copolymerized functional group; and combinations thereof.
15. The golf ball of claim 1 , wherein the intermediate core layer comprises at least one of ionomers; highly neutralized ionomers; non-ionomeric acid polymers; polyurethanes, polyureas, and polyurethane-polyurea hybrids; polyester-based thermoplastic elastomers; polyamides, copolymers of ionomer and polyamide, polyamide-ethers, and polyamide-esters; ethylene-based homopolymers and copolymers; propylene-based homopolymers and copolymers; triblock copolymers based on styrene and ethylene/butylene; derivatives thereof that are compatibilized with at least one grafted or copolymerized functional group; and combinations thereof.
16. The golf ball of claim 1 , comprising an intermediate core layer formed from at least one of natural rubber, polybutadiene, polyisoprene, ethylene propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber, butyl rubber, halobutyl rubber, polyurethane, polyurea, acrylonitrile butadiene rubber, polychloroprene, alkyl acrylate rubber, chlorinated isoprene rubber, acrylonitrile chlorinated isoprene rubber, polyalkenamer, phenol formaldehyde, melamine formaldehyde, polyepoxide, polysiloxane, polyester, alkyd, polyisocyanurate, polycyanurate, polyacrylate, and combinations thereof.
17. The golf ball of claim 1 , the outer core layer has an outer surface Shore C hardness (H outer surface ) of 85 or greater, and wherein H outer surface >H center , and H outer surface −H center ≧70.
18. The golf ball of claim 1 , further comprising an intermediate layer disposed between the outer core layer and the cover.
19. The golf ball of claim 9 , wherein the at least one plasticizer is selected from the group consisting of fatty acid esters, carbonate esters, benzoate esters, or combinations thereof.
20. The golf ball of claim 19 , wherein the plasticizer is selected from the group consisting of methyl oleate, ethyl oleate, propylene carbonate, dipropylene glycol dibenzoate, or combinations thereof.