GOLF BALL COMPOSITIONS
Disclosed herein are hard and flexible compositions, i.e., compositions which have a flexural modulus that is less 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 )+47, 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 <110, then H ≧8.5218 Ln( M )+32.5 if M ≧110, then H ≧72.5, where H is the hardness of the composition, in Shore D, and M is the flexural modulus of the composition, in ksi.
1 . A golf ball comprising:
a core having an outer surface and a geometric center and being formed from a substantially homogeneous formulation; and
a cover layer;
wherein the difference between the Shore C hardness of the outer surface of the core and the Shore C hardness of the center of the core is 8 or less;
and wherein the cover layer is formed from a polymer blend composition having a JIS-C hardness (H) and a flexural modulus in ksi (M) wherein H≧11.889 Ln(M)+47.
2 . The golf ball of claim 1 , wherein H≧11.889 Ln(M)+48.
3 . The golf ball of claim 1 , wherein H≧11.889 Ln(M)+49.
4 . A golf ball comprising:
an inner core layer having an outer surface and a geometric center and being formed from a first substantially homogeneous formulation;
an outer core layer having an outer surface and an inner surface and being formed from a second substantially homogeneous formulation; and
a cover layer;
wherein the difference between the Shore C hardness of the outer surface of the inner core layer and the Shore C hardness of the center of the inner core layer is 8 or less;
and wherein the cover layer is formed from a polymer blend composition having a JIS-C hardness (H) and a flexural modulus in ksi (M) wherein H≧11.889 Ln(M)+47.
5 . The golf ball of claim 4 , wherein the difference between the Shore C hardness of the outer surface of the outer core layer and the Shore C hardness of the inner surface of the outer core layer is 8 or less.
6 . The golf ball of claim 4 , wherein H≧11.889 Ln(M)+48.
7 . The golf ball of claim 4 , wherein H≧11.889 Ln(M)+49.
8 . A golf ball comprising:
a core having an outer surface and a geometric center and being formed from a substantially homogeneous formulation;
an intermediate layer; and
a cover layer;
wherein the difference between the Shore C hardness of the outer surface of the core and the Shore C hardness of the center of the core is 8 or less;
and wherein the intermediate layer is formed from a polymer blend composition having a JIS-C hardness (H) and a flexural modulus in ksi (M) wherein H≧11.889 Ln(M)+47.
9 . The golf ball of claim 8 , wherein H≧11.889 Ln(M)+48.
10 . The golf ball of claim 8 , wherein H≧11.889 Ln(M)+49.
11 . A golf ball comprising:
an inner core layer having an outer surface and a geometric center and being formed from a first substantially homogeneous formulation;
an outer core layer having an outer surface and an inner surface and being formed from a second substantially homogeneous formulation;
an intermediate layer; and
a cover layer;
wherein the difference between the Shore C hardness of the outer surface of the inner core layer and the Shore C hardness of the center of the inner core layer is 8 or less;
and wherein the intermediate layer is formed from a polymer blend composition having a JIS-C hardness (H) and a flexural modulus in ksi (M) wherein H≧11.889 Ln(M)+47.
12 . The golf ball of claim 11 , wherein the difference between the Shore C hardness of the outer surface of the outer core layer and the Shore C hardness of the inner surface of the outer core layer is 8 or less.
13 . The golf ball of claim 8 , wherein H≧11.889 Ln(M)+48.
14 . The golf ball of claim 8 , wherein H≧11.889 Ln(M)+49.