Multi-layer golf ball

• US 6,213,894 B1
• Filed: 03/18/1998
• Issued: 04/10/2001
• Est. Priority Date: 06/01/1993
• Status: Expired due to Fees

• Current Assignee: Callaway Golf Company
• Original Assignee: Spalding Sports Worldwide, Inc. (Berkshire Hathaway Incorporated)
• Inventors: Sullivan, Michael J., Nealon, John, Binette, Mark
• Primary Examiner(s): Graham, Mark S.
• Assistant Examiner(s): Gorden, Raeann
• Application Number:
  US09/040,456
• Time in Patent Office: 1,119 Days
• Field of Search: 473/374, 473/373, 473/377, 473/378
• US Class Current: 473/374
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/003 Coefficient of restitution
• CPC Class Codes: A63B 37/0031 Hardness
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0034 Deflection or compression
• CPC Class Codes: A63B 37/0037 Flexural modulus; Bending stiffness
• CPC Class Codes: A63B 37/0039 characterised by the material
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0052 Liquid cores
• CPC Class Codes: A63B 37/0053 Thread wound
• CPC Class Codes: A63B 37/0075 Three piece balls, i.e. cover, intermediate layer and core
• CPC Class Codes: A63B 37/0087 Deflection or compression
• CPC Class Codes: A63B 37/0096 Spin rate
• CPC Class Codes: A63B 37/02 Special cores balls with finger holes A63B37/0001, golf ball cores A63B37/005
• CPC Class Codes: C08L 23/08 Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0876 Neutralised polymers, i.e. ionomers
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/18 Polyesters or polycarbonates according to C08L67/00 - C08L69/00; Derivatives thereof
• CPC Class Codes: C08L 2666/20 : Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof
• CPC Class Codes: C08L 53/00 : Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 69/00 : Compositions of polycarbonates; Compositions of derivatives of polycarbonates
• CPC Class Codes: C08L 75/04 : Polyurethanes

Abstract

Disclosed herein is a multi-layer golf ball having a soft outer cover. The golf ball has an inner cover layer with a Shore D hardness of 60 or more, and an outer cover with a Shore D hardness of 55 or less, and more preferably 50 or less. In a particularly preferred form of the invention, the outer cover comprises at least 75% of a soft copolymer formed from a polyolefin, an unsaturated carboxylic acid, and a monomer of the acrylate ester class. The golf ball of the invention has exceptionally soft feel and high spin rates on short shots of 80 yards or less and, particularly, 40 yards or less, while maintaining good distance and average spin on full shots.

Claims

1. A golf ball, comprising:

a core;

a thermoplastic inner cover layer formed over the core, the inner cover layer having a Shore D hardness of at least 60 as measured on the curved surface thereof, and

an outer cover layer formed over the inner cover layer, the outer cover layer having a Shore D hardness of no more than 53 as measured on the curved surface thereof, the golf ball having a PGA compression of 100 or less and a coefficient of restitution of at least 0.750.

2. A golf ball according to claim 1, wherein the outer cover layer has a Shore D hardness of no more than 50.

3. A golf ball according to claim 2, wherein the ball has a PGA compression of 90 or less.

4. A golf ball according to claim 1, wherein the outer cover layer comprises a thermoplastic material.

5. A golf ball according to claim 1, wherein the inner cover layer comprises at least one member selected from the group consisting of polyphenylene ether/ionomer blends, ionomers, polyamides, polyurethanes, polyester elastomers, polyester amides, metallocene catalyzed polyolefins, and blends thereof.

6. A golf ball according to claim 5, wherein the inner cover layer comprises ionomer.

7. A golf ball according to claim 6, wherein the inner cover layer has a flex modulus of greater than 30,000 psi.

8. A golf ball according to claim 7, wherein the inner cover layer has a Shore D hardness of at least 65 as measured on the curved surface thereof.

9. A golf ball according to claim 7, wherein the inner cover layer has a Shore D hardness of 60-85 as measured on the curved surface thereof.

10. A golf ball according to claim 1, wherein the outer cover layer comprises at least one member selected from the group consisting of polyphenylene ether/ionomer blends, ionomers, polyamides, polyurethanes, polyester elastomers, polyester amides, metallocene catalyzed polyolefins, and blends thereof.

11. A golf ball according to claim 1, wherein the outer cover layer comprises ionomer.

12. A golf ball according to claim 11, wherein the outer cover layer has a flex modulus of 1,000-10,000 psi.

13. A golf ball according to claim 12, wherein the outer cover layer has a Shore D hardness of no more than 30.

14. A golf ball according to claim 13, wherein the outer cover layer has a Shore D hardness of 30-53.

15. A golf ball according to claim 10, wherein the inner cover layer comprises at least one member selected from the group consisting of polyphenylene ether/ionomer blends, ionomers, polyamides, polyurethanes, polyester elastomers, polyester amides, metallocene catalyzed polyolefins and blends thereof.

16. A golf ball according to claim 15, wherein the outer cover layer comprises an ionomeric resin, more than 75 wt % of the ionomeric resin consisting of one or more copolymers, each of which is formed from (a) an olefin having 2 to 8 carbon atoms, (b) an unsaturated monomer of the acrylate ester class having from 1 to 21 carbon atoms, and (c) an acid which includes at least one member selected from the group consisting of alpha, beta-ethylenically unsaturated mono- or dicarboxylic acids with a portion of the acid being neutralized with cations.

17. A golf ball according to claim 16, wherein the acid is at least one member selected from the group consisting of acrylic acid and methacrylic acid.

18. A golf ball according to claim 17, wherein the olefin is ethylene.

19. A golf ball according to claim 1, wherein the ball has a spin factor of at least 5.0.

20. A golf ball according to claim 1, wherein the ball has a spin factor of at least 8.0.

21. A golf ball according to claim 1, wherein the inner cover layer has a Shore D hardness of at least 65.

22. A golf ball according to claim 1, wherein the outer cover layer has a thickness of about 0.01-0.10 inches.

23. A golf ball according to claim 21, wherein the outer cover layer has a thickness of about 0.01-0.10 inches.

24. A golf ball according to claim 1, wherein the outer cover layer has a thickness of 0.03 inches to 0.07 inches.

25. A golf ball according to claim 1, wherein the inner cover layer has a thickness of 0.03 inches to 0.07 inches.

26. A golf ball according to claim 24, wherein the inner cover layer has a thickness of 0.03 inches to 0.07 inches.

27. A golf ball according to claim 1, wherei the outer cover layer has a Shore D hardness of 45-53 as measured on the curved surface thereof.

28. A golf ball according to claim 27, wherein the inner cover layer has a Shore D hardness of 60-85 as measured on the curved surface thereof.

29. A golf ball according to claim 1, wherein the core is solid or liquid filled.

30. A golf ball according to claim 15, wherein the core is solid or liquid filled.

31. A golf ball according to claim 29, wherein the core is wound.

32. A golf ball according to claim 10, wherein the core is wound.

33. A golf ball according to claim 15, wherein the core is wound.

34. A golf ball according to claim 1, wherein at least one of the inner and outer cover layers comprises a thermoplastic block polyester.

35. A golf ball according to claim 1, wherein at least one of the inner and outer cover layers comprises a thermoplastic block polyamide.

36. A golf ball comprising:

a core,

an inner cover layer formed from a composition which includes at least 75 weight % of at least one material selected from the group consisting of polyphenylene ether/ionomer blends, ionomers, polyamides, polyurethanes, polyester elastomers, polyester amides, metallocene catalyzed polyolefins, and blends thereof, and

an outer cover layer formed over the inner cover layer, the outer cover layer having a Shore D hardness of no more than 53 as measured on the curved surface thereof, the golf ball having a PGA compression of 100 or less and a coefficient of restitution of at least 0.750.

37. A golf ball according to claim 36, wherein said at least one material is thermoplastic.

38. A golf ball according to claim 36, wherein said at least one material is a thermoset.

39. A golf ball comprising:

a core,

an inner cover layer formed over the core, the inner cover layer having a Shore D hardness of at least 60 as measured on the curved surface thereof, and

a outer cover layer formed over the inner cover layer, the outer cover layer having a flex modulus of 1,000-10,000 psi, the golf ball having a PGA compression of 100 or less and a coefficient of restitution of at least 0.750.

40. A golf ball according to claim 39, wherein the inner cover layer has a flex modulus of at least 30,000 psi.

41. A golf ball according to claim 39, wherein the outer cover layer comprises an ionomeric resin, more than 75 wt % of the ionomeric resin consisting of one or more copolymers, each of which is formed from (a) an olefin having 2 to 8 carbon atoms, (b) an unsaturated monomer of the acrylate ester class having from 1 to 21 carbon atoms, and (c) an acid which includes at least one member selected from the group consisting of alpha, beta-ethylenically unsaturated mono- or dicarboxylic acids with a portion of the acid being neutralized with cations.

42. A golf ball according to claim 39, wherein the inner cover layer comprises at least one member selected from the group consisting of thermoset polyurethane and thermoset metallocene catalyzed polyolefin.