Golf ball

Patent metadata

Field	Value
Publication number	US-10046204-B2
Application number	US-201615374290-A
Country	US
Kind code	B2
Filing date	Dec 9, 2016
Priority date	Dec 11, 2015
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

An object of the present invention is to provide a golf ball showing an increased spin rate on approach shots under a wet condition while maintaining a spin rate on approach shots under a dry condition. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the paint film has a multi-layered construction composed of two or more layers, and a difference (Mout−Min) between a 10% elastic modulus (Mout) of an outermost layer of the paint film and a 10% elastic modulus (Min) of an innermost layer of the paint film is 25 kgf/cm2 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 paint film has a multi-layered construction composed of two or more layers, and a difference (M out −M in ) between a 10% elastic modulus (M out ) of an outermost layer of the paint film and a 10% elastic modulus (M in ) of an innermost layer of the paint film is 25 kgf/cm 2 or more, and the 10% elastic modulus (M out ) of the outermost layer of the paint film is 100 kgf/cm 2 or more.

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

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

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

5. The golf ball according to claim 4 , wherein a polyol composition constituting the polyurethane contains a urethane polyol, wherein the urethane polyol includes a polyether diol having a number average molecular weight in a range from 600 to 3000 as a constituent component.

6. The golf ball according to claim 5 , wherein the urethane polyol has a weight average molecular weight ranging from 5000 to 20000.

7. The golf ball according to claim 5 , wherein the urethane polyol has a hydroxyl value ranging from 10 mgKOH/g to 200 mgKOH/g.

8. The golf ball according to claim 5 , wherein the urethane polyol further includes a triol as a constituent component.

9. The golf ball according to claim 8 , wherein a mass ratio (triol/polyether diol) of the triol to the polyether diol ranges from 0.2 to 6.0.

10. The golf ball according to claim 5 , wherein a polyisocyanate composition constituting the polyurethane contains at least one selected from the group consisting of a biuret-modified product of hexamethylene diisocyanate, an isocyanurate of hexamethylene diisocyanate, and an isocyanurate of isophorone diisocyanate.

11. The golf ball according to claim 10 , wherein the biuret-modified product of hexamethylene diisocyanate and the isocyanurate of hexamethylene diisocyanate are used in combination, and a mass ratio (biuret-modified product/isocyanurate) of the biuret-modified product of hexamethylene diisocyanate to the isocyanurate of hexamethylene diisocyanate ranges from 20/40 to 40/20.

12. The golf ball according to claim 4 , wherein a polyol composition constituting the polyurethane contains a polyrotaxane, wherein the polyrotaxane has a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via —O—C 3 H 6 —O— group.

13. The golf ball according to claim 12 , wherein the polyol composition further contains a polycaprolactone polyol, and a mass ratio (polycaprolactone polyol/polyrotaxane) of the polycaprolactone polyol to the polyrotaxane ranges from 5/95 to 90/10.

14. The golf ball according to claim 12 , wherein the polyol composition further contains a hydroxyl group modified vinyl chloride-vinyl acetate copolymer, and an amount of the hydroxyl group modified vinyl chloride-vinyl acetate copolymer in a polyol component of the polyol composition ranges from 4 mass % to 50 mass %.

15. The golf ball according to claim 12 , wherein the polyol composition further contains a modified silicone.

16. The golf ball according to claim 12 , wherein a polyisocyanate composition constituting the polyurethane contains an isocyanurate of hexamethylene diisocyanate.

17. The golf ball according to claim 1 , wherein the golf ball body comprises a core and a cover covering the core, and the cover has a slab hardness of 60 or less in Shore D hardness.

18. The golf ball according to claim 1 , wherein the golf ball body comprises a core and a cover covering the core, and the cover has a 10% elastic modulus of less than 120 kgf/cm 2 .

19. The golf ball according to claim 1 , wherein the golf ball has a coefficient of friction ranging from 0.35 to 0.60 calculated using a contact force tester.

20. A golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the paint film has a multi-layered construction composed of two or more layers, and a difference (M out −M in ) between a 10% elastic modulus (M out ) of an outermost layer of the paint film and a 10% elastic modulus (M in ) of an innermost layer of the paint film is 25 kgf/cm 2 or more, and wherein a base resin constituting the paint film includes a polyurethane, and a polyol composition constituting the polyurethane contains a polyrotaxane,
wherein the polyrotaxane has a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via —O—C 3 H 6 —O— group.

21. The golf ball according to claim 20 , wherein the polyol composition further contains a polycaprolactone polyol, and a mass ratio (polycaprolactone polyol/polyrotaxane) of the polycaprolactone polyol to the polyrotaxane ranges from 5/95 to 90/10.

22. The golf ball according to claim 20 , wherein the polyol composition further contains a hydroxyl group modified vinyl chloride-vinyl acetate copolymer, and an amount of the hydroxyl group modified vinyl chloride-vinyl acetate copolymer in a polyol component of the polyol composition ranges from 4 mass % to 50 mass %.

23. The golf ball according to claim 20 , wherein the polyol composition further contains a modified silicone.

24. The golf ball according to claim 20 , wherein a polyisocyanate composition constituting the polyurethane contains an isocyanurate of hexamethylene diisocyanate.

Assignees

• Dunlop Sports Co Ltd
• Sumitomo Rubber Ind

Inventors

• Inoue Hidetaka
• Tarao Toshiyuki

Classifications

• A63B37/0037

  Flexural modulus; Bending stiffness · CPC title

• C08G18/792

  formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates · CPC title

• A63B37/0089

  Coefficient of drag · CPC title

• C08G18/725

  Combination of polyisocyanates of C08G18/78 with other polyisocyanates · CPC title

• C08G18/4063

  Mixtures of compounds of group C08G18/62 with other macromolecular compounds · CPC title