Golf ball cores with improved durability
View Patent ↗The present invention is directed toward more durable golf ball cores and more durable golf balls. The golf balls of this invention comprise a cover and a core wherein the core may further comprise a center and one or more layers of a mantle disposed between the center and the cover. The core, the mantle or the layers of the mantle, comprise a mixture of one or more thermoset rubber materials and at least one compatible, modified, non-ionic polyolefin. The non-ionic polyolefin that is modified may be a homopolymer, copolymer, terpolymer, block copolymer or a mixture thereof that is present at about 0.5 to about 10 parts per hundred of the thermoset rubber material used in the core or core layer.
1. A method of forming a golf ball, the method comprising:
providing at least one non-ionic modified polyolefin by polymerizing at least one compatibilizing monomer within or grafted to the polyolefin;
forming a blend comprising at least one rubber material and about 1.5 percent to about 3.5 percent of the at least one non-ionic modified based on the weight of the blend; and
forming a golf ball component from the blend.
2. The method of claim 1 , wherein the at least one compatibilizing monomer comprises acrylic acid, methacrylic acid, maleic anhydride, or mixtures thereof.
3. The method of claim 1 , wherein the non-ionic, modified polyolefin is selected from the group consisting of modified polybutadiene homopolymers, modified polystyrene homopolymers, modified copolymers of ethylene and ethyl acrylate, modified copolymers of ethylene and methyl acrylate, modified copolymers of ethylene and vinyl acetate, modified terpolymers of butadiene, modified terpolymers of styrene, rubber modified polystyrenes, olefin rubber modified polystyrenes, modified metallocene polymers, modified metallocene graft copolymers, and mixtures thereof.
4. The method of claim 1 , wherein the non-ionic, modified polyolefin is selected from the group consisting of modified polybutadiene homopolymers, modified polystyrene homopolymers, modified terpolymers of butadiene, modified terpolymers of styrene, rubber modified polystyrenes, olefin rubber modified polystyrenes, and mixtures thereof.
5. The method of claim 1 , wherein the blend further comprises a reinforcing component.
6. The method of claim 5 , wherein the reinforcing component comprises polybutadiene, polyisoprene, styrene-butadiene, styrene-propylene-diene rubber, or mixtures thereof.
7. The method of claim 1 , wherein the golf ball component is a core.
8. The method of claim 7 , further comprising the step of disposing a cover about the core.
9. The method of claim 8 , wherein the cover has a thickness of about 0.02 inches to about 0.08 inches.
10. A method of forming a golf ball, the method comprising:
forming a blend comprising about 60 percent to about 90 percent of at least one rubber material by weight of the blend, about 1.5 percent to about 3.5 percent of at least one non-ionic, modified polyolefin material by weight of the blend, and about 10 percent to about 30 percent at least one reinforcing component by weight of the blend;
forming a golf ball component from the blend; and
incorporating the golf ball component in a golf ball.
11. The method of claim 10 , wherein the step of forming a golf ball component comprises forming a core.
12. The method of claim 11 , further comprising forming a cover disposed about the core.
13. The method of claim 12 , wherein the cover has a thickness of about 0.02 inches to about 0.08 inches.
14. The method of claim 10 , wherein the step of forming a golf ball component comprises:
providing a center; and
forming an outer core layer disposed about the center, wherein the outer core layer is formed from the blend.
15. The method of claim 14 , further comprising forming a cover disposed about the outer core layer.
16. The method of claim 14 , wherein the outer core layer has a diameter of about 1.25 inches to about 1.65 inches.
17. The method of claim 10 , wherein the reinforcing component comprises polybutadiene, polyisoprene, styrene-butadiene, styrene-propylene-diene rubber, or mixtures thereof.
18. The method of claim 10 , wherein the non-ionic, modified polyolefin is selected from the group consisting of modified polybutadiene homopolymers, modified polystyrene homopolymers, modified copolymers of ethylene and ethyl acrylate, modified copolymers of ethylene and methyl acrylate, modified copolymers of ethylene and vinyl acetate, modified terpolymers of butadiene, modified terpolymers of styrene, rubber modified polystyrenes, olefin rubber modified polystyrenes, modified metallocene polymers, modified metallocene graft copolymers, and mixtures thereof.
19. A method of forming a golf ball, the method comprising:
forming a blend comprising at least one rubber material and at least one non-ionic, modified polyolefin material, wherein the non-ionic modified polyolefin material is added in an amount of about 1.5 to about 3.5 parts per hundred of the at least one rubber material;
forming a golf ball component from the blend; and
disposing a cover about the golf ball component.
20. The method of claim 19 , wherein the step of forming a golf ball component comprises forming a center.
21. The method of claim 19 , wherein the cover has a thickness of about 0.02 inches to about 0.08 inches.
22. The method of claim 19 , wherein the step of forming a golf ball component comprises:
forming a center; and
forming an outer core layer disposed about the center, wherein the outer core layer is formed from the blend.
23. The method of claim 19 , further comprising selecting the non-ionic, modified polyolefin material to have a melting point below about 170° C. and an Izod Impact Resistance of at least about 1 ft-lb/in.