GOLF BALL COMPOSITIONS
Disclosed herein are soft and stiff compositions, i.e., compositions which have a flexural modulus that is greater than the value that is expected based on the composition's hardness. The compositions preferably have a hardness/modulus relationship represented by the formula H ≦11.889 Ln( M )+42, where H is the hardness of the composition, in JIS-C, and M is the flexural modulus of the composition, in ksi; or a softness/stiffness relationship represented by the formula if M <56, then H ≦8.5218 Ln( M )+26.5 if M ≧56, then H ≦8.5218 Ln( M )+28.5, where H is the hardness of the composition, in Shore D, and M is the flexural modulus of the composition, in ksi. The compositions preferably comprise an ionomer and a functionalized elastomer.
1 . A golf ball comprising at least one layer formed from a thermoplastic composition, the thermoplastic composition comprising an ionomer and a functionalized elastomer, the thermoplastic composition having a JIS-C hardness (H) and a flexural modulus in ksi (M) wherein H≦11.889 Ln(M)+42, and wherein M>6 ksi.
2 . The golf ball of claim 1 , wherein H≦9.45 Ln(−0.0105M 2 +3.95M−14)+40.
3 . The golf ball of claim 1 , wherein H≦87 JIS-C.
4 . The golf ball of claim 1 , wherein the functionalized elastomer is present in an amount of 20 wt % or greater, based on the combined weight of the ionomer and the functionalized elastomer.
5 . The golf ball of claim 1 , wherein the functionalized elastomer is present in an amount of 25 wt % or greater, based on the combined weight of the ionomer and the functionalized elastomer.
6 . The golf ball of claim 1 , wherein the functionalized elastomer is present in an amount of 30 wt % or greater, based on the combined weight of the ionomer and the functionalized elastomer.
7 . The golf ball of claim 6 , wherein H≦9.45 Ln(−0.0105M 2 +3.95M−14)+40.
8 . The golf ball of claim 1 , wherein the elastomer is selected from the group consisting of styrenic block copolymers, ethylene propylene diene rubbers, ethylene acrylic ester copolymers, and ethylene vinyl acetate copolymers.
9 . The golf ball of claim 1 , wherein the functionalized elastomer is a maleic anhydride functionalized styrenic block copolymer.
10 . The golf ball of claim 9 , wherein the functionalized elastomer has a Shore A hardness of 70 or less.
11 . The golf ball of claim 1 , wherein the ionomer is a high acid ionomer partially neutralized with a sodium cation source and the functionalized elastomer is a maleic anhydride functionalized elastomer selected from the group consisting of styrenic block copolymers, ethylene propylene diene rubbers, ethylene acrylic ester copolymers, and ethylene vinyl acetate copolymers.
12 . A golf ball comprising at least one layer formed from a thermoplastic composition, the thermoplastic composition comprising an ionomer and 20 wt % or greater of a functionalized styrenic block copolymer, based on the combined weight of the ionomer and the functionalized styrenic block copolymer, the thermoplastic composition having a JIS-C hardness (H) and a flexural modulus in ksi (M) wherein H≦11.889 Ln(M)+42, and wherein M>6 ksi.
13 . The golf ball of claim 12 , wherein the functionalized styrenic block copolymer has a Shore A hardness of 70 or less.
14 . The golf ball of claim 13 , wherein the functionalized styrenic block copolymer is present in the thermoplastic composition in an amount of 25 wt % or greater, based on the combined weight of the ionomer and the functionalized styrenic block copolymer.
15 . The golf ball of claim 13 , wherein the functionalized styrenic block copolymer is present in the thermoplastic composition in an amount of 30 wt % or greater, based on the combined weight of the ionomer and the functionalized styrenic block copolymer.
16 . The golf ball of claim 15 , wherein H≦9.45 Ln(−0.0105M 2 +3.95M−14)+40.
17 . A golf ball comprising at least one layer formed from a thermoplastic composition, the thermoplastic composition comprising an ionomer and 20 wt % or greater of a functionalized ethylene propylene diene rubber, based on the combined weight of the ionomer and the functionalized rubber, the thermoplastic composition having a JIS-C hardness (H) and a flexural modulus in ksi (M) wherein H≦11.889 Ln(M)+42, and wherein M>6 ksi.
18 . The golf ball of claim 17 , wherein the functionalized rubber is present in the thermoplastic composition in an amount of 25 wt % or greater, based on the combined weight of the ionomer and the functionalized rubber.
19 . The golf ball of claim 17 , wherein the functionalized rubber is present in the thermoplastic composition in an amount of 30 wt % or greater, based on the combined weight of the ionomer and the functionalized rubber.
20 . The golf ball of claim 19 , wherein H≦9.45 Ln(−0.0105M 2 +3.95M−14)+40.