Perimeter weighted golf ball
View Patent ↗A perimeter weighted golf ball with a low compression core is provided. The core preferably comprises a diene polymer that has low cross-link density or not cross-linked with a reactive co-agent. This core has low compression and low specific gravity. The low specific gravity core is encased within a thin dense layer positioned outside of the centroid radius to provide the ball with a high moment of inertia. The same core can be encased within a plurality of intermediate layers having either increasing hardness or decreasing hardness to provide selective golf balls for either low swing speed players or advanced players. Alternatively, a thin layer of diene polymer highly cross-linked with reactive a co-agent may be incorporated into the ball to increase the hardness of the ball.
1. A golf ball comprising:
a core comprising a core layer comprising:
an elastomeric composition,
a reactive co-agent present by less than about 10 phr by weight of the elastomeric composition, and
a cross-linking agent;
a thin dense layer encasing the core, the thin dense layer being positioned at a radial distance outside a centroid radius of the golf ball, and having:
an inner diameter of at least about 38.4 mm,
a specific gravity of greater than about 1.2, and
a thickness from about 0.127 mm to about 0.76 mm; and
a cover encasing the thin dense layer.
2. The golf ball of claim 1 , wherein the elastomeric composition comprises a diene polymer.
3. The golf ball of claim 2 , wherein the diene polymer is metallocene catalyzed.
4. The golf ball of claim 2 , wherein the cross-linking agent is a peroxide.
5. The golf ball of claim 4 , wherein the diene polymer is a polybutadiene.
6. The golf ball of claim 5 , wherein the polybutadiene is metallocene catalyzed.
7. The golf ball of claim 2 , wherein the cross-linking agent is sulfur.
8. The golf ball of claim 7 , wherein the diene polymer is an ethylene-propylene-diene polymer.
9. The golf ball of claim 8 , wherein the ethylene-propylene-diene polymer is metallocene catalyzed.
10. The golf ball of claim 8 , wherein the ethylene-propylene-diene polymer comprises about 70% to about 90% ethylene.
11. The golf ball of claim 10 , wherein the ethylene-propylene-diene polymer further comprises about 1% to about 5% ethylidene-2-norborene.
12. The golf ball of claim 1 , wherein the elastomeric composition comprises a material selected from a group consisting of metallocene catalyzed polymers, poly(styrene-butadiene-styrene), SEBS, SEPS block polymers, styrene-ethylene block copolymers, and polar group grafted or copolymerized polymers.
13. The golf ball of claim 12 , wherein the polar group grafted or copolymerized polymers comprise maleic anhydride or succinate modified metallocene catalyzed ethylene copolymers.
14. The golf ball of claim 1 , wherein the reactive co-agent is about 0 phr.
15. The golf ball of claim 1 , wherein the reactive co-agent comprises a metal salt of diacrylate, dimethacrylate, or monomethacrylate, or a non-metallic oligomer.
16. The golf ball of claim 15 , wherein the metal is selected from zinc, magnesium, calcium, barium, tin, aluminum, lithium, sodium, potassium, iron, zirconium, and bismuth.
17. The golf ball of claim 1 , wherein the core layer has an Atti compression of about 0 to about 70.
18. The golf ball of claim 17 , wherein the Atti compression of the core layer is about 10 to about 60.
19. The golf ball of claim 1 , wherein the core layer has a specific gravity of less than about 1.05.
20. The golf ball of claim 1 , wherein the core layer has a diameter of about 41.15 mm or less.
21. The golf ball of claim 1 , wherein the core further comprises an innermost core encased by the core layer.
22. The golf ball of claim 21 , wherein the innermost core comprises a diene polymer and about 10 phr to about 50 phr of a reactive co-agent.
23. The golf ball of claim 1 , wherein the specific gravity of the thin dense layer is greater than about 1.5.
24. The golf ball of claim 1 , wherein the specific gravity of the thin dense layer is greater than about 2.0.
25. The golf ball of claim 1 , wherein the thickness of the thin dense layer is about 0.25 mm to about 0.5 mm.
26. The golf ball of claim 1 , wherein the thin dense layer is made from a densified loaded film.
27. The golf ball of claim 1 , wherein the thin dense layer is made from a polymer loaded with a specific gravity increasing agent.
28. The golf ball of claim 1 , wherein the thin dense layer is made from a diene polymer with tungsten powder.
29. The golf ball of claim 1 , wherein the thin dense layer is applied to the core as a liquid solution.
30. A golf ball comprising:
a core comprising a core layer comprising
an elastomeric composition,
a reactive co-agent less than about 5 phr by weight of the
elastomeric composition, and
a cross-linking agent;
a thin dense layer encasing the core, the thin dense layer being positioned
at a radial distance outside a centroid radius of the golf ball, and having;
an inner diameter of at least about 38.4 mm,
a specific gravity of greater than about 1.27, and
a thickness from about 0.025 mm to about 1.27 mm; and
cover encasing the thin dense layer.
31. A golf ball comprising:
a core comprising an innermost core encased by a core layer comprising:
an elastomeric composition,
a reactive co-agent present by less than about 10 phr by weight of the elastomeric composition, and
a cross-linking agent:
a thin dense layer encasing the core, the thin dense layer being positioned at a radial distance outside a centroid radius of the golf ball, and having;
an inner diameter of at least about 38.4 mm,
a specific gravity of greater than about 1.2, and
a thickness from about 0.127 mm to about 0.76 mm; and
a cover encasing the thin dense layer;
wherein the innermost core comprises a diene polymer and at least about 50 phr of a reactive co-agent.