Golf ball with rigid intermediate layer
View Patent ↗The invention relates to a golf ball comprising a core, an intermediate layer disposing around the core, and a cover including at least one layer that includes a polyurethane or polyurea polymer. The intermediate layer is preferably rigid and has a durometer hardness of greater than at least 80 Shore C or at least 55 Shore D. The intermediate layer preferably includes a diene polymer. Alternatively, the intermediate layer includes a cast or RIM thermoset polyurethane, polyurea, polyurethane-ionomer, epoxy or blends thereof.
1. A golf ball comprising:
a core having at least an inner layer having a diameter of at least 1.51 inches and comprised of a first polybutadiene composition having a resilience index of at least 50, a dynamic stiffness of less than 50,000 N/m at −50° C. and a loss tangent below 0.1 at −50° C. and an intermediate layer having an outer diameter of 1.55 to 1.67 inches, wherein the intermediate layer comprises a diene rubber composition having a Shore D hardness of at least about 55 which is harder than the core and the cover and a flexural modulus of between 60,000 and 140,000 psi; and
a cover disposed about the core, wherein the cover comprises an outer cover layer comprising at least one polyurethane or polyurea.
2. The golf ball of claim 1 , wherein the diene rubber composition comprises a cis-polybutadiene or trans-polybutadiene, 1,2-polybutadiene, a blend of two different types of polybutadienes, a blend of polybutadiene with at least one additional stiffening polymer, polychloroprene, poly(norbornene), polyoctenamer, polypentanamer, or metallocene catalyzed diene polymers.
3. The golf ball of claim 2 , wherein the diene rubber is a polybutadiene with at least one additional stiffening polymer, wherein the at least one additional stiffening polymer comprises styrene-butadiene rubber.
4. The golf ball of claim 1 , wherein the diene rubber composition comprises a cis-polyisoprene or trans-polyisoprene material, a blend of two different types of polyisoprenes, or a blend of polyisoprene with at least one additional stiffening polymer.
5. The golf ball of claim 4 , wherein the at least one additional polymer comprises styrene-butadiene rubber.
6. The golf ball of claim 1 , wherein the diene rubber comprises polybutadiene and greater than about 50 parts per hundred of polybutadiene of metal salt diacrylate, dimethacrylate or monomethacrylate reactive co-agent.
7. The golf ball of claim 6 , comprising greater than about 60 parts per hundred of polybutadiene of zinc diacrylate.
8. The golf ball of claim 1 , wherein the outer cover layer has a thickness of less than about 0.05 inches.
9. The golf ball of claim 1 , wherein the intermediate layer has a hardness of at least about 60 Shore D.
10. The golf ball of claim 1 , wherein the outer cover layer has a hardness of about 45 to about 60 Shore D when measured on the ball.
11. The golf ball of claim 1 , wherein the intermediate layer has a thickness of between about 0.02 and about 0.06 inch.
12. The golf ball of claim 1 , wherein the intermediate layer has a diameter of about 1.62 inches.
13. The golf ball of claim 1 , wherein the intermediate layer has specific gravity of about 0.9 to about 1.25.
14. The golf ball of claim 1 , wherein the specific gravity of the inner core, the intermediate layer and the cover is within 0.05 from each other.
15. The golf ball of claim 14 , wherein the specific gravity of the inner core the intermediate layer and the cover is within 0.02 from each other.
16. The golf ball of claim 1 , further comprising a barrier layer disposed between the intermediate layer and the cover, wherein the barrier layer having a water vapor transmission rate less than the cover and having a thickness of less than 0.01 inch.
17. The golf ball of claim 1 , wherein the intermediate layer comprises a barrier layer having a water vapor transmission rate less than the cover.
18. The golf ball of claim 1 , wherein the core has a coefficient of restitution of at least about 0.82.
19. The golf ball of claim 1 , wherein the inner layer has a Shore D hardness of less than 50.
20. A golf ball comprising:
an inner core having a first hardness and a diameter of at least 1.51 inches and comprising a first polymer having a resilience index of at least 50, a dynamic stiffness of less than 50,000 N/m at −50° C. and a loss tangent below 0.1 at −50° C.;
an outer cover layer having a second hardness and comprising a polyurethane or polyurea; and
an intermediate layer disposed between the inner core and the cover, the intermediate layer being comprised of the first polymer, a castable reactive liquid material or reaction product thereof, a polyurethane or a polyurea and having a third hardness that is greater than the first and second hardnesses.
21. The golf ball of claim 20 , wherein the core and the intermediate layer have a diameter of at least about 1.58 inches and the outer cover layer has a thickness of less than about 0.035 inch.
22. The golf ball of claim 20 , wherein the intermediate layer has a hardness of at least about 55 Shore D.
23. The golf ball of claim 22 , wherein the intermediate layer has a hardness of at least about 60 Shore D.
24. The golf ball of claim 20 , wherein to intermediate layer has a thickness of between about 0.02 and 0.06 inch.
25. The golf ball of claim 20 , wherein the intermediate layer has a specific gravity of between about 0.09 and about 1.25.
26. The golf ball of claim 20 , wherein the intermediate layer comprises cis-polyisoprene, trans-polyisoprene, polychloroprene, poly(norbornene), polyoctenamer, polypentanamer, or metallocene catalyzed diene polymers, or blends thereof.