Golf ball

Patent metadata

Field	Value
Publication number	US-9975005-B2
Application number	US-201615381966-A
Country	US
Kind code	B2
Filing date	Dec 16, 2016
Priority date	Dec 18, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

An object of the present invention is to provide a golf ball travelling a great flight distance on driver shots, exhibiting an excellent spin performance on approach shots under a dry condition and a wet condition, and showing an excellent shot feeling and durability. The present invention provides a golf ball comprising a golf ball body having a spherical core, an intermediate layer and a cover, and a paint film composed of two or more layers, wherein a 10% elastic modulus difference (M in −M out ) between an innermost layer and an outermost layer of the paint film is 25 kgf/cm 2 or more.

First claim

The invention claimed is:

1. A golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body,
wherein the golf ball body comprises a spherical core, an intermediate layer covering the spherical core and a cover covering the intermediate layer, and the paint film has a multi-layered construction composed of two or more layers,
wherein a difference (M in −M out ) between a 10% elastic modulus (M in ) of an innermost layer of the paint film and a 10% elastic modulus (M out ) of an outermost layer of the paint film is 25 kgf/cm 2 or more, and
wherein the 10% elastic modulus (M in ) of the innermost layer of the paint film is 100 kgf/cm 2 or more.

2. The golf ball according to claim 1 , wherein the intermediate layer has a thickness Tm of 0.75 mm or more.

3. The golf ball according to claim 1 , wherein the cover has a material hardness Hc of 40 or less in Shore D hardness.

4. The golf ball according to claim 1 , wherein the intermediate layer has a material hardness Hm of 55 or more in Shore D hardness.

5. The golf ball according to claim 1 , wherein a hardness difference (surface hardness-center hardness) HDc (Shore C hardness) between a surface hardness and a center hardness of the spherical core, a material hardness Hm (Shore D hardness) of the intermediate layer, a thickness Tc (mm) of the cover, and a material hardness Hc (Shore D hardness) of the cover satisfy the following mathematical formula (1):
( HDc×Hm )/( Hc×Tc )>63  Mathematical formula (1).

6. The golf ball according to claim 1 , wherein a volume Vm (mm 3 ) and a material hardness Hm (Shore D hardness) of the intermediate layer, a phantom volume Vc (mm 3 ) and a material hardness Hc (Shore D hardness) of the cover satisfy the following mathematical formula (2):
3.0<( Vm×Hm )/( Vc×Hc )<7.5  Mathematical formula (2).

7. The golf ball according to claim 1 , wherein the 10% elastic modulus (M out ) of the outermost layer of the paint film is less than 100 kgf/cm 2 .

8. The golf ball according to claim 1 , wherein the innermost layer of the paint film has a thickness (T in ) ranging from 5 μm to 30 μm, and the outermost layer of the paint film has a thickness (T out ) ranging from 5 μm to 30 μm.

9. The golf ball according to claim 1 , wherein the intermediate layer has a thickness Tm of 0.8 mm or more.

10. The golf ball according to claim 5 , wherein the hardness difference HDc ranges from 15 to 40 in Shore C hardness.

11. The golf ball according to claim 5 , wherein the surface hardness of the spherical core ranges from 75 to 90 in Shore C hardness.

12. The golf ball according to claim 5 , wherein the center hardness of the spherical core ranges from 45 to 70 in Shore C hardness.

13. The golf ball according to claim 1 , wherein the spherical core is a dual-layered core composed of a spherical center and an outer core covering the spherical center.

14. The golf ball according to claim 6 , wherein the volume Vm of the intermediate layer ranges from 3900 mm 3 to 9500 mm 3 .

15. The golf ball according to claim 5 , wherein the thickness Tc of the cover ranges from 0.2 mm to 0.7 mm.

16. The golf ball according to claim 6 , wherein the phantom volume Vc of the cover ranges from 1100 mm 3 to 3900 mm 3 .

17. The golf ball according to claim 1 , wherein the 10% elastic modulus (M in ) of the innermost layer of the paint film is 500 kgf/cm 2 or less.

18. The golf ball according to claim 7 , wherein the 10% elastic modulus (M out ) of the outermost layer of the paint film is 5 kgf/cm 2 or more.

19. The golf ball according to claim 1 , wherein a base resin constituting the paint film includes a polyurethane resin.

20. The golf ball according to claim 1 , wherein
the intermediate layer has a thickness Tm of 0.75 mm or more;
the cover has a material hardness Hc of 40 or less in Shore D hardness;
a hardness difference (surface hardness-center hardness) HDc (Shore C hardness) between a surface hardness and a center hardness of the spherical core, a material hardness Hm (Shore D hardness) of the intermediate layer, a thickness Tc (mm) of the cover, and a material hardness Hc (Shore D hardness) of the cover satisfy the following mathematical formula (1); and
a volume Vm (mm 3 ) and a material hardness Hm (Shore D hardness) of the intermediate layer, a phantom volume Vc (mm 3 ) and a material hardness Hc (Shore D hardness) of the cover satisfy the following mathematical formula (2):
( HDc×Hm )/( Hc×Tc )>63  formula (1);

3.0<( Vm×Hm )/( Vc×Hc )<7.5  formula (2).

Assignees

• Dunlop Sports Co Ltd

Inventors

• Tachibana Kosuke
• Kamino Kazuya
• Tarao Toshiyuki
• Inoue Hidetaka

Classifications

• A63B37/0075

  Three piece balls, i.e. cover, intermediate layer and core · CPC title

• C09D175/00

  Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers · CPC title

• A63B37/0043

  Hardness · CPC title

• A63B37/0063

  Hardness gradient · CPC title

• C09D175/04

  Polyurethanes · CPC title