Thin-layer-covered golf ball with improved velocity
View Patent ↗A golf ball comprising a center comprising a polybutadiene having a molecular weight of greater than 200,000 and a resilience index of at least about 40; and a cover layer comprising a polyurethane composition formed from a prepolymer having no greater than 7.5 percent by weight unreacted isocyanate groups.
1. A golf ball comprising:
a center formed of a reaction product having a loss tangent of less than about 0.1 at −50° C. comprising:
polybutadiene having a molecular weight of greater than about 200,000;
a crosslinking material present in an amount of about 10 to about 40 parts per hundred of the reaction product;
a free radical source present in an amount of about 0.1 to about 15 parts per hundred of the reaction product;
a cis-to-trans catalyst present in an amount of about 0.1 to about 10 parts per hundred of the reaction product, wherein the cis-to-trans catalyst comprises a metal organosulfur compound; and
a cover comprising a thermoplastic or thermoset polyurethane.
2. The golf ball of claim 1 , wherein the loss tangent is less than about 0.07 at −50° C.
3. The golf ball of claim 1 , wherein the polybutadiene has a resilience index of about 40 or greater.
4. The golf ball of claim 3 , wherein the resilience index is greater than about 50.
5. The golf ball of claim 1 , wherein the molecular weight of the polybutadiene is greater than about 250,000.
6. The golf ball of claim 5 , wherein the molecular weight of the polybutadiene is from about 300,000 to about 500,000.
7. A golf ball comprising:
a center formed of a reaction product having a dynamic stiffness of less than about 50,000 N/m at −50° C. and a loss tangent of less than about 0.1 at −50° C., wherein the reaction product comprises:
polybutadiene having a molecular weight of greater than about 200,000;
a crosslinking material present in an amount of about 10 to about 40 parts per hundred of the reaction product;
a free radical source present in an amount of about 0.1 to about 15 parts per hundred of the reaction product;
a cis-to-trans catalyst present in an amount sufficient to produce at least about 32 percent trans-isomer in the reaction product; and
a cover comprising a castable reactive liquid material.
8. The golf ball of claim 7 , wherein the dynamic stiffness is about 10,000 N/m to about 40,000 N/m at −50° C.
9. The golf ball of claim 8 , wherein the dynamic stiffness is about 20,000 N/m to about 30,000 N/m at −50° C.
10. The golf ball of claim 7 , wherein the loss tangent is less than about 0.07 at −50° C.
11. The golf ball of claim 7 , wherein the castable reactive liquid material comprises polyurethane.
12. The golf ball of claim 7 , wherein the center has an outer diameter of about 1.55 inches or greater.
13. A golf ball comprising:
a center formed of a reaction product having a loss tangent of less than about 0.1 at −50° C. comprising:
polybutadiene having a molecular weight of greater than about 200,000;
a crosslinking material present in an amount of about 10 to about 40 parts per hundred of the reaction product;
a free radical source present in an amount of about 0.1 to about 15 parts per hundred of the reaction product;
a cis-to-trans catalyst present in an amount sufficient to produce a reaction product comprising at least about 32 percent trans-isomer; and
a cover comprising a thermoplastic or thermoset polyurethane.
14. The golf ball of claim 13 , wherein the cis-to-trans catalyst comprises at least one of an organosulfur compound, an aromatic organic compound, or a mixture thereof.
15. The golf ball of claim 13 , wherein the cis-to-trans catalyst is present in an amount of about 0.1 to about 10 parts per hundred of the reaction product.
16. The golf ball of claim 7 , wherein the cis-to-trans catalyst comprises at least one of an organosulfur compound, an aromatic organic compound, or a mixture thereof.
17. The golf ball of claim 16 , wherein the organosulfur compound comprises metal.
18. The golf ball of claim 16 , wherein the organosulfur compound is substantially free of metal.
19. The golf ball of claim 16 , wherein the aromatic organic compound comprises a hydroxy group, a metal salt of a hydroxyl, a mercapto group, a metal salt of a mercapto group, a carboxy group, a metal salt of a carboxyl, an acrylate, a metal salt of an acrylate, or a combination thereof.
20. The golf ball of claim 16 , wherein the aromatic organic compound is substantially free of metal.