Solid golf ball

• US 6,334,820 B1
• Filed: 12/09/1999
• Issued: 01/01/2002
• Est. Priority Date: 12/24/1998
• Status: Expired due to Term

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: Sasaki, Takashi
• Primary Examiner(s): Graham, Mark S.
• Assistant Examiner(s): Gorden, Raeann
• Application Number:
  US09/457,362
• Time in Patent Office: 754 Days
• Field of Search: 473/374, 473/373, 473/378, 473/376, 473/377, 473/370, 525/93
• US Class Current: 473/374
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0062 Hardness
• CPC Class Codes: A63B 37/0069 Flexural modulus; Bending stiffness
• CPC Class Codes: A63B 37/0075 Three piece balls, i.e. cover, intermediate layer and core
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 23/08 Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0869 Acids or derivatives thereof
• 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 53/02 of vinyl-aromatic monomers and conjugated dienes

Abstract

The present invention provides a solid golf ball having the improved shot feeling without damaging the durability and good carry. The solid golf ball has an intermediate layer between a core and a cover layer. The intermediate layer is a cured body of a thermoplastic resin composition including components (a) and (b). The component (a) is selected from a group consisting of a first block copolymer including at least one polymer block A of an aromatic vinyl compound and at least one polymer block B of a conjugated diene compound, and a second block copolymer obtained by hydrogenating said first block copolymer. The component (b) consisting of ionomer.

Claims

1. The solid golf ball comprising:

a core,

a cover layer, and

an intermediate layer disposed between said core and said cover layer, wherein said intermediate layer comprises a thermoplastic resin composition including;

component (a) being at least one member selected from the group consisting of a first block copolymer which has at least one polymer block A of an aromatic vinyl compound and at least one polymer block B of a conjugated diene compound, and a second block copolymer obtained by hydrogenating said first block copolymer; and

component (b) comprising at least one hard ionomer having a flexural modulus of not less than 150 MPa and a Shore D hardness of not less than 57.

2. The solid golf ball according to claim 1, wherein said component (a) has a hydroxyl group bonded to its molecular terminal.

3. The solid golf ball according to claim 2, wherein said first block copolymer is polystyrene block—

polymer block of conjugated diene—

polystyrene block.

4. The solid golf ball according to claim 1, wherein the content ratio of said component (a) per said component (b) ranges from 10/90 to 80/20.

5. The solid golf ball according to claim 1, wherein said first block copolymer contains 5 to 75% by weight of said polymer block A.

6. The solid golf ball according to claim 1, wherein said component (a) has a number-average molecular weight of 30,000 to 1,000,000.

7. The solid golf ball according to claim 1, wherein said component (b) has a flexural modulus of not less than 200 MPa and a Shore D hardness of not less than 60.

8. The solid golf ball according to claim 1, wherein said intermediate layer has a thickness of 1 to 3 mm.

9. The solid golf ball according to claim 1, wherein said core is made of a vulcanized rubber composition containing a base rubber, a metal salt of α

,β

p-unsaturated carboxylic acid and a peroxide, and has an outer diameter of 32 to 38 mm and an amount of deformation of 3.0 to 6.0 mm when applied with a load from 10 kgf as an initial load to 130 kgf as a final load.

10. A solid golf ball according to claim 1, wherein said cover layer is made of a material having a Shore D hardness of 55 to 70.

11. The solid golf ball of claim 1, wherein component (b) further contains a soft ionomer, said hard ionomer being present in an amount of 50% or more by weight based on the total weight of component (b).