Patent ID: 7160940
Filing Date: 2007-01-09
Classification: A63B,C08K

Abstract:
1. A multi-piece solid golf ball comprising a solid core, a mantle of at least one layer, and a cover, wherein the solid core is made of a rubber composition comprising (A) 100 parts by weight of a base rubber that contains 60 to 100 wt % of a polybutadiene of at least 60% cis-1,4 structure and synthesized using a rare-earth catalyst, (B) 0.1 to 0.8 part by weight of an organic peroxide, (C) an unsaturated carboxylic acid or an unsaturated carboxylic acid metal salt or both, (D) an organic sulfur compound and (B) an inorganic filler, has a deflection when subjected to a load of 980 N (100 kgf) of 3.0 to 6.0 mm, and has a diameter of 30 to 40 mm; the mantle of at least one layer is made of a thermoplastic resin composition, has a thickness per layer of 0.5 to 2.0 mm, and includes an outermost layer which is in contact with the cover and has a Shore D hardness of 20 to 60; the cover is made primarily of (F) a thermoplastic polyurethane material, has a thickness of 0.5 to 2.5 mm and a Shore D hardness of 50 to 70, and satisfies the condition (Shore D hardness of mantle outermost layer)≦(Shore D hardness of cover); the golf ball has a deflection when subjected to a load of 980 N (100 kgf) of 3.0 to 5.0 mm; and the thermoplastic resin composition comprises: 100 parts by weight of resin components which include a base resin of (P) an olefin/unsaturated carboxylic acid binary random copolymer or a metal ion neutralization product of an olefin/unsaturated carboxylic acid binary random copolymer or both in admixture with (Q) an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester ternary random copolymer or a metal ion neutralization product of an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester ternary random copolymer or both in a weight ratio P/Q of 100:0 to 25:75, and (R) a non-ionomeric thermoplastic elastomer in a weight ratio (P+Q)/R of 100:0 to 50:50; (S) 5 to 80 parts by weight of a fatty acid or fatty acid derivative having a molecular weight of 280 to 1,500, or both; and (T) 0.1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing un-neutralized acid groups in the base resin and component S.