Golf ball core compositions
Golf ball compositions including novel processing aids, e.g., metal salts of unsaturated fatty acids, high styrene resins, transpolyisoprene, and transpolybutadiene, for inclusion in rubber-based compositions that reduce safety risks, mixer down time, increase dispersion of the ingredients during processing, and increase component COR over that of a component formed with a conventional processing aid.
1. A core composition for a golf ball comprising:
a first base rubber; and
a crosslinker masterbatch comprising at least one crosslinker, a second base rubber, and at least one high styrene resin.
2. The core composition of claim 1 , wherein the at least one crosslinker comprises a blend of a crosslinking agent and a metal salt of a fatty acid.
3. The core composition of claim 1 , wherein the crosslinker masterbatch is present in an amount of about 25 pph to about 35 pph of the total core composition.
4. The core composition of claim 1 , wherein the second base rubber comprises polybutadiene.
5. The core composition of claim 1 , wherein the crosslinker masterbatch comprises about 60 percent to about 90 percent crosslinker, about 10 percent to about 30 percent base rubber, and about 1 percent to about 10 percent at least one high styrene resin.
6. The core composition of claim 5 , wherein the crosslinker masterbatch comprises about 75 percent to about 85 percent crosslinker, about 10 percent to about 25 percent base rubber, and about 1 percent to about 5 percent at least one high styrene resin.
7. The core composition of claim 6 , wherein the crosslinker masterbatch comprises about 80 percent crosslinker, about 17 percent base rubber, and about 3 percent at least one high styrene resin.
8. The core composition of claim 1 , further comprising a free radical initiator.
9. The core composition of claim 8 , wherein the free radical initiator comprises a peroxide.
10. The core composition of claim 1 , wherein the first base rubber and the second base rubber comprise polybutadiene, and wherein the crosslinker comprises zinc diacrylate.
11. The core composition of claim 10 , wherein the at least one high styrene resin is a styrene-butadiene copolymer.
12. The core composition of claim 1 , further comprising at least one of a density-adjusting filler or an antioxidant.
13. A composition for golf balls comprising:
a base rubber; and
a crosslinker pellet, wherein the pellet comprises about 50 percent to about 95 percent of at least one crosslinking agent and about 50 percent to about 5 percent of at least one high styrene resin.
14. The composition of claim 13 , wherein the pellet comprises about 60 percent or greater of the at least one crosslinking agent and about 40 percent or less of the at least one high styrene resin.
15. The composition of claim 13 , further comprising a free radical initiator.
16. The composition of claim 15 , wherein the free radical initiator is present in the composition in an amount of about 0.5 ph to about 2 pph.
17. The composition of claim 13 , wherein the crosslinking agent is selected from the group consisting of zinc acrylate, zinc diacrylate, zinc methacrylate, zinc dimethacrylate, and mixtures thereof.
18. A method of preparing a composition for golf balls comprising the steps of:
providing a crosslinking agent;
blending the crosslinking agent and styrene-butadiene copolymer in a mixer at a temperature of about 200° F. to about 225° F. to form a pellet;
providing a base rubber;
mixing the base rubber and the pellet; and
promoting crosslinking between the base rubber and the pellet with a free radical initiator.
19. The method of claim 18 , wherein the crosslinking agent is selected from the group consisting of zinc acrylate, zinc diacrylate, zinc methacrylate, zinc dimethacrylate, and mixtures thereof.