Multi-piece solid golf ball

Assignee: Bridgestone Sports Co., Ltd.

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Quick Facts

Patent No.: US 6,899,641
App. No.: 10/755,360
Granted: May 31, 2005
Kind: B2

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Abstract

A multi-piece solid golf ball comprising a core, an intermediate layer enclosing the core, and an outer layer enclosing the intermediate layer is characterized in that the intermediate layer is made of a thermoplastic resin composition, the intermediate layer on its surface has a Shore D hardness of at least 57, the intermediate layer has a specific gravity of 1.00-1.30 g/cm 3 , the outer layer has a specific gravity of at least 1.00 g/cm 3 , the core has a specific gravity of 1.05-1.20 g/cm 3 , the intermediate layer and the outer layer have a total gauge of up to 3.3 mm, [(core surface JIS-C hardness)−(core center JIS-C hardness)]≧16, [(intermediate layer surface JIS-C hardness)−(core surface JIS-C hardness)]≧0, and −18≦[(outer layer surface Shore D hardness)−(intermediate layer surface Shore D hardness)]<0.

Claims (34)

1. A multi-piece solid golf ball comprising a core, an intermediate layer enclosing the core, and an outer layer enclosing the intermediate layer, characterized in that

the intermediate layer is made of a thermoplastic resin composition,

the intermediate layer on its surface has a Shore D hardness of at least 57,

the intermediate layer has a specific gravity of 1.00 to 1.30 g/cm3, the outer layer has a specific gravity of at least 1.00 g/cm 3 , the core has a specific gravity of 1.05 to 1.20 g/cm 3 ,

the intermediate layer and the outer layer have a total gauge of up to 3.3 mm,

the core at its surface and center, the intermediate layer at its surface, and the outer layer at its surface have hardness satisfying: (core surface JIS-C hardness)−(core center JIS-C hardness)]≧16, [(intermediate layer surface JIS-C hardness)−(core surface JIS-C hardness)]≧0, and −18≦[(outer layer surface Shore D hardness)−(intermediate layer surface Shore D hardness)]<0;

wherein the outer layer is made of a polyurethane composition containing (C) a thermoplastic polyurethane and (D) an isocyanate mixture and said isocyanate mixture (D) is a mixture prepared by dispersing (d-1) a compound having as functional groups at least two isocyanate groups per molecule in (d-2) a thermoplastic resin that is substantially non-reactive with isocyanate.

2. The multi-piece solid golf ball of claim 1 wherein the core center has a JIS-C hardness of 54 to 66, and the core surface has a XIS-C hardness of 72 to 95.

3. The multi-piece solid golf ball of claim 1 wherein said thermoplastic resin composition comprises a thermoplastic resin and an inorganic particulate filler in a proportion of 100/5 to 100/25 by weight ratio.

4. The multi-piece solid golf ball of claim 3 wherein said thermoplastic resin composition comprises:

(A) an ionomer resin component which contains (a-1) an olefin/unsaturated carboxylic acid random bipolymer and/or a metal ion neutralization product of an olefin/unsaturated carboxylic acid random bipolymer and (a-2) an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester random terpolymer and/or a metal ion neutralization product of an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester random terpolymer, and

(B) a non-ionomer thermoplastic elastomer.

5. The multi-piece solid golf ball of claim 3 wherein said thermoplastic resin composition comprises:

(B) a non-ionomer thermoplastic elastomer in a proportion (A)/(B) of 100/0 to 50/50 by weight ratio.

6. The multi-piece solid golf ball of claim 1 wherein [(core surface JIS-C hardness)−(core center JIS-C hardness)]≧20.

7. The multi-piece solid golf ball of claim 1 wherein the core includes an organosulfur compound.

8. A multi-piece solid golf ball comprising a core, an intermediate layer enclosing the core, and an outer layer enclosing the intermediate layer, characterized in that

the intermediate layer is made of a thermoplastic resin composition,

the intermediate layer on its surface has a Shore D hardness of at least 57,

the intermediate layer has a specific gravity of 1.00 to 1.30 g/cm 3 , the outer layer has a specific gravity of at least 1.00 g/cm 3 , the core has a specific gravity of 1.05 to 1.20 g/cm 3 ,

the intermediate layer and the outer layer have a total gauge of up to 3.3 mm,

the core at its surface and center, the intermediate layer at its surface, and the outer layer at its surface have hardness satisfying: [(core surface JIS-C hardness)−(core center JIS-C hardness)]≧16, [(intermediate layer surface JIS-C hardness)−(core surface JIS-C hardness)]≧0, and −18≦([(outer layer surface Shore D hardness)−(intermediate layer surface Shore D hardness)]<0;

wherein said core has a two-layer structure.

9. The multi-piece solid golf ball of claim 8 wherein the core center has a JIS-C hardness of 54 to 66, and the core surface has a JIS-C hardness of 72 to 95.

10. The multi-piece solid golf ball of claim 8 wherein said thermoplastic resin composition comprises a thermoplastic resin and an inorganic particulate filler in a proportion of 100/5 to 100/25 by weight ratio.

11. The multi-piece solid golf ball of claim 10 wherein said thermoplastic resin composition comprises:

(B) a non-ionomer thermoplastic elastomer.

12. The multi-piece solid golf ball of claim 10 wherein said thermoplastic resin composition comprises:

(B) a non-ionomer thermoplastic elastomer in a proportion (A)/(B) of 100/0 to 50150 by weight ratio.

13. The multi-piece solid golf ball of claim 8 wherein [(core surface JIS-C hardness)−(core center JIS-C hardness)]≧20.

14. The multi-piece solid golf ball of claim 8 wherein the core includes an organosulfur compound.

Continuity (2)

Division 1023604400 · Sep 5, 2002

Related Publication 20040142770A1 · Jul 22, 2004