GOLF BALL

• US 20160184654A1
• Filed: 12/28/2015
• Published: 06/30/2016
• Est. Priority Date: 12/26/2014
• Status: Active Grant

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Dunlop Sports Co. Ltd. (Sumitomo Rubber Industries Limited)
• Inventors: MATSUYAMA, Yoshiko, TARAO, Toshiyuki
• Granted Patent: US 9,839,815 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A63B 37/00221 characterised by the material
• CPC Class Codes: A63B 37/0074 Two piece balls, i.e. cover and core
• CPC Class Codes: A63B 37/0096 Spin rate
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/246 containing also tin-carbon bonds
• CPC Class Codes: C08G 18/3206 aliphatic
• CPC Class Codes: C08G 18/4854 Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
• CPC Class Codes: C08G 18/5042 containing ureum groups
• CPC Class Codes: C08G 18/6677 having at least three hydroxy groups
• CPC Class Codes: C08G 18/722 Combination of two or more aliphatic and/or cycloaliphatic polyisocyanates
• CPC Class Codes: C08G 18/725 Combination of polyisocyanates of C08G18/78 with other polyisocyanates
• CPC Class Codes: C08G 18/7831 containing biuret groups
• CPC Class Codes: C08G 18/792 formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
• CPC Class Codes: C09D 175/08 from polyethers

Abstract

An object of the present invention is to provide a golf ball showing excellent shot feeling and stain resistance. 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 a base resin constituting the paint film includes a polyurethane obtained by a reaction between a polyol composition and a polyisocyanate composition, a molar ratio (NCO/OH) of an isocyanate group (NCO group) in the polyisocyanate composition to a hydroxyl group (OH group) in the polyol composition is 0.6 or more, and the paint film has an elastic modulus of 300 MPa or less.

Claims

1. A golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein a base resin constituting the paint film includes a polyurethane obtained by a reaction between a polyol composition and a polyisocyanate composition, a molar ratio (NCO/OH) of an isocyanate group (NCO group) of the polyisocyanate composition to a hydroxyl group (OH group) of the polyol composition is 0.6 or more, and the paint film has an elastic modulus of 300 MPa or less.

2. The golf ball according to claim 1, wherein the elastic modulus of the paint film ranges from 40 MPa to 250 MPa.

3. The golf ball according to claim 1, wherein the molar ratio (NCO/OH) ranges from 0.65 to 1.2.

4. The golf ball according to claim 1, wherein the polyol composition contains a urethane polyol including a polyether diol having a number average molecular weight ranging from 800 to 3,000 as a constituent component.

5. The golf ball according to claim 1, wherein the paint film is formed from a paint having a solid content ranging from 30 mass % to 45 mass %.

6. The golf ball according to claim 1, wherein the elastic modulus of the paint film and the molar ratio (NCO/OH) satisfy the following formula:

Y≦

960X−

470

in the formula, Y represents the elastic modulus (MPa) of the paint film, and X represents the molar ratio (NCO/OH).

7. The golf ball according to claim 1, wherein the polyol composition contains a urethane polyol including a triol and a diol as a constituent component.

8. The golf ball according to claim 7, wherein a mixing ratio (triol/diol) of the triol to the diol ranges from 0.2 to 6.0 in a mass ratio.

9. The golf ball according to claim 7, wherein the triol is trimethylolpropane, and the diol is a polyether diol having a number average molecular weight ranging from 800 to 3,000.

10. The golf ball according to claim 4, wherein a content of the polyether diol having a number average molecular weight ranging from 800 to 3,000 in the constituent component of the urethane polyol is 70 mass % or more.

11. The golf ball according to claim 4, wherein the urethane polyol has a weight average molecular weight ranging from 5,000 to 20,000.

12. The golf ball according to claim 4, wherein the urethane polyol has a hydroxyl value ranging from 10 mg KOH/g to 200 mg KOH/g.

13. The golf ball according to claim 1, wherein the polyisocyanate composition contains a triisocyanate.

14. The golf ball according to claim 1, wherein the polyisocyanate composition contains an isocyanurate product of hexamethylene diisocyanate, a biuret product of hexamethylene diisocyanate, and an isocyanurate product of isophorone diisocyanate.

15. The golf ball according to claim 14, wherein a mixing ratio (biuret product/isocyanurate product) of the biuret product of hexamethylene diisocyanate to the isocyanurate product of hexamethylene diisocyanate ranges from 20/40 to 40/20 in a mass ratio.

16. The golf ball according to claim 1, wherein the paint film has a thickness ranging from 5 μ

m to 50 μ

m.