Polybutadiene rubber / ionomer blends for golf balls having dual cores and covers

Patent metadata

Field	Value
Publication number	US-8992342-B2
Application number	US-201113029835-A
Country	US
Kind code	B2
Filing date	Feb 17, 2011
Priority date	Nov 28, 2001
Publication date	Mar 31, 2015
Grant date	Mar 31, 2015

Abstract

A multi-piece golf ball comprising at least one component made of a polybutadiene rubber/ionomer resin blend is provided. The ball preferably contains a dual-core comprising a center and surrounding outer core layer. The polybutadiene rubber/ionomer resin blend is used preferably to form the outer core layer. The ball further includes a cover comprising inner and outer cover layers. The surface hardness of the outer core layer is preferably greater than the material hardness of the inner cover layer. The resulting ball has high resiliency and good impact durability.

First claim

We claim:

1. A multi-piece of ball, comprising:
a dual-core comprising an inner core and outer core layer, the inner core having an outer surface and geometric center and the outer core layer having an outer surface and inner surface; the outer core being formed from a first rubber composition comprising polybutadiene rubber and ionomer resin, and
a cover comprising an inner cover layer and outer cover layer, the cover being disposed about the outer core layer, wherein the outer core layer has an outer surface hardness greater than the material hardness of the outer and inner cover layers.

2. The golf ball of claim 1 , wherein the outer core layer has an outer surface hardness of 75 Shore C or greater.

3. The golf ball of claim 1 , wherein the outer core layer has an outer surface hardness of 85 Shore C or greater, and the inner cover has a material hardness of less than 85 Shore C.

4. The golf ball of claim 1 , wherein the outer core layer has an outer surface hardness in the range of 81 to 95 Shore C and the inner cover has a material hardness of 80 to 94 Shore C.

5. The golf ball of claim 1 , wherein the outer surface hardness of the outer core is at least 5 Shore C units greater than the material hardness of the inner cover layer.

6. The golf ball of claim 1 , wherein the ionomer resin contains greater than 5 weight percent acid groups.

7. The golf ball of claim 1 , wherein the ionomer resin contains greater than 11 weight percent add groups.

8. The golf ball of claim 6 or 7 wherein the add groups of the ionomer resin are neutralized greater than 70%.

9. The golf ball of claim 6 or 7 , wherein the add groups of the ionomer resin are neutralized greater than 90%.

10. The golf ball of claim 1 , wherein the ionomer resin is a E/X/Y copolymer, wherein E is ethylene; X is a C 3 to C 8 α,β-ethylenically unsaturated mono- or dicarboxylic add; and Y is a softening monomer.

11. The golf ball of claim 10 , wherein the copolymer is selected from the group consisting of ethylene/(meth)acrylic acid/n-butyl acrylate; ethylene/(meth)acrylic acid/ethyl acrylate; ethylene/(meth)acrylic acid/methyl acrylate; ethylene/(meth)acrylic acid/n-butyl acrylate; and ethylene/(meth)acrylic acid/isobutyl acrylate copolymers.

12. The golf ball of claim 1 , wherein the ionomer composition further comprises a fatty add or salt thereof.

13. The golf ball of claim 1 , wherein the first rubber composition further comprises a polymer selected from the group consisting of polyesters; polyamides; polyamide-ethers, polyamide-esters; polyurethanes, polyureas; fluoropolymers; polystyrenes; polypropylenes and polyethylenes; polyvinyl chlorides; polyvinyl acetates; polycarbonates; polyvinyl alcohols; polyethers; polyimides, polyetherketones, polyamideimides; and mixtures thereof.

14. The golf ball of claim 1 , wherein the inner core is formed from a second rubber composition comprising polybutadiene rubber.

15. The golf ball of claim 1 , wherein the inner core has a diameter of about 0.80 to about 1.40 inches.

16. The golf ball of claim 1 , wherein the overall diameter of the dual-core is from 1.51 to 1.62 inches.

17. The golf ball of claim 1 , wherein the inner core has an outer surface hardness of 55 Shore C to 70 Shore C.

18. The golf ball of claim 1 , wherein the inner core has an outer surface hardness of 70 Shore C or greater.

19. The golf ball of claim 1 , wherein the outer and inner cover layers are formed of a composition comprising a polymer selected from the group consisting of ionomers, polyesters; polyamides; polyamide-ethers, polyamide-esters; polyurethanes, polyureas; fluoropolymers; polystyrenes; polypropylenes and polyethylenes; polyvinyl chlorides; polyvinyl acetates; polycarbonates; polyvinyl alcohols; polyethers; polyimides, polyetherketones, polyamideimides; and mixtures thereof.

20. The golf ball of claim 1 , wherein the inner cover layer has a material hardness greater than the surface hardness of the outer cover layer.

21. The golf ball of claim 20 , wherein the inner cover layer has a material hardness in the range of 80 to 95 Shore C.

22. The golf ball of claim 20 , wherein the outer cover layer has a material hardness less than 80 Shore C.

Assignees

• Sullivan Michael J
• Ladd Derek A
• Acushnet Co

Inventors

• Sullivan Michael J
• Ladd Derek A

Classifications

• A63B37/02 Primary

  Special cores {(balls with finger holes A63B37/0001, golf ball cores A63B37/005)} · CPC title

• A63B37/0064

  Diameter · CPC title

• A63B37/0039

  characterised by the material · CPC title

• A63B37/0062

  Hardness · CPC title

• A63B37/0066

  Density; Specific gravity · CPC title