Golf ball

Patent metadata

Field	Value
Publication number	US-2019217158-A1
Application number	US-201916365295-A
Country	US
Kind code	A1
Filing date	Mar 26, 2019
Priority date	May 25, 2016
Publication date	Jul 18, 2019
Grant date	—

Abstract

An object of the present invention is to provide a golf ball having excellent abrasion resistance and spin performance on driver shots. The present invention provides a golf ball having a spherical core and a cover covering the spherical core, wherein the cover contains a polyurethane, wherein the polyurethane comprises, as a constituent component, (A) a polyisocyanate component and (B) a polyol component containing (b1) a polyrotaxane, and wherein (b1) the polyrotaxane has a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and a blocking group 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—C3H6—O— group.

First claim

1 . A golf ball having a spherical core and a cover covering the spherical core, wherein the cover contains a polyurethane and the polyurethane comprises, as a constituent component, (A) a polyisocyanate component and (B) a polyol component containing (b1) a polyrotaxane and (b2) a polyol other than (b1) the polyrotaxane, and wherein (b1) 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, and (b2) the polyol includes two or more polyols.

2 . The golf ball according to claim 1 , wherein (b2) the polyol is a combination of two or more low molecular weight polyols, a combination of two or more high molecular weight polyols, or a combination of at least one low molecular weight polyol and at least one high molecular weight polyol.

3 . The golf ball according to claim 2 , wherein the low molecular weight polyol is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, propanediol, dipropylene glycol, butanediol, neopentyl glycol, pentanediol, hexanediol, heptanediol, octanediol, 1,4-cyclohexanedimethylol, aniline diol, bisphenol A type diol, glycerin, trimethylolpropane, hexanetriol, pentaerythritol and sorbitol.

4 . The golf ball according to claim 2 , wherein the high molecular weight polyol is selected from the group consisting of a polyether polyol, a condensed polyester polyol, a lactone polyester polyol, a polycarbonate polyol and an acrylic polyol.

5 . The golf ball according to claim 1 , wherein the linear molecule of (b1) the polyrotaxane is polyethylene glycol, and the blocking group of (b1) the polyrotaxane is an adamantyl group.

6 . The golf ball according to claim 1 , wherein the polyurethane contains (b1) the polyrotaxane component in an amount of less than 50 mass %.

7 . The golf ball according to claim 1 , wherein the polyurethane contains (b1) the polyrotaxane component in an amount of more than 10 mass % and less than 50 mass %.

8 . The golf ball according to claim 1 , wherein (A) the polyisocyanate component is 4,4′-dicyclohexylmethane diisocyanate.

9 . The golf ball according to claim 1 , wherein the cover has a loss modulus of elasticity E″ of 4.5×10 7 Pa or less.

10 . The golf ball according to claim 1 , wherein the cyclodextrin is an α-cyclodextrin.

11 . The golf ball according to claim 1 , wherein the linear molecule has a weight average molecular weight ranging from 5,000 to 100,000.

12 . The golf ball according to claim 1 , wherein (b1) the polyrotaxane has a hydroxyl value ranging from 10 mgKOH/g to 400 mgKOH/g.

13 . The golf ball according to claim 1 , wherein (b1) the polyrotaxane has a total molecular weight ranging from 30,000 to 3,000,000 in a weight average molecular weight.

14 . The golf ball according to claim 2 , wherein the low molecular weight polyol includes butanediol, and the high molecular weight polyol includes polyoxytetramethylene glycol.

15 . The golf ball according to claim 1 , wherein a molar ratio (NCO/OH) of an isocyanate group (NCO) in (A) the polyisocyanate component to a hydroxyl group (OH) in (B) the polyol component ranges from 0.7 to 1.0.

16 . The golf ball according to claim 1 , wherein a molar ratio (NCO/OH) of an isocyanate group (NCO) in (A) the polyisocyanate component to a hydroxyl group (OH) in (b2) the polyol ranges from 0.8 to 1.2.

17 . The golf ball according to claim 1 , wherein the cover composition has a pencil hardness ranging from H to 9H.

18 . The golf ball according to claim 1 , wherein the cover composition has a slab hardness ranging from 74 to 94 in Shore A hardness.

19 . The golf ball according to claim 1 , wherein the spherical core has a center hardness Ho ranging from 40 to 70 in Shore C hardness, and a surface hardness Hs ranging from 65 to 100 in Shore C hardness.

20 . The golf ball according to claim 1 , wherein the spherical core has a hardness difference (Hs-Ho) ranging from 10 to 40 in Shore C hardness between a surface hardness Hs and a center hardness Ho thereof.

Assignees

• Sumitomo Rubber Ind

Inventors

• Tanaka Mami
• Tarao Toshiyuki

Classifications

• A63B37/0029

  Physical properties · CPC title

• A63B37/0092

  Hardness distribution amongst different ball layers · CPC title

• A63B37/0074

  Two piece balls, i.e. cover and core · CPC title

• C08G83/007

  Polyrotaxanes; Polycatenanes · CPC title

• A63B37/0023 Primary

  Covers · CPC title