US 6,981,925 B2
Multi-piece solid golf ball
Yasumasa Shimizu, Chichibu (Japan); Junji Hayashi, Chichibu (Japan); Hiroshi Higuchi, Chichibu (Japan); Rinya Takesue, Chichibu (Japan); and Yasushi Ichikawa, Chichibu (Japan)
Assigned to Bridgestone Sports Co., Ltd., Tokyo (Japan)
Filed on Dec. 01, 2003, as Appl. No. 10/724,112.
Claims priority of application No. 2002-349726 (JP), filed on Dec. 02, 2002.
Prior Publication US 2005/0075196 A1, Apr. 07, 2005
This patent is subject to a terminal disclaimer.
Int. Cl. A63B 37/12 (2006.01)
U.S. Cl. 473—376 17 Claims
 
1. A multi-piece solid golf ball comprising a solid core, a mantle of at least one layer and a cover, wherein
the core is obtained by molding and vulcanizing a rubber composition comprising (A) 100 parts by weight of a base rubber which includes 60 to 100 wt % of a polybutadiene of at least 60 wt % cis-1,4 structure and synthesized using a rare-earth catalyst, (B) an unsaturated carboxylic acid or an unsaturated carboxylic acid metal salt or both, (C) one or more organic sulfur compounds selected from the group consisting of thiophenols, thionaphthols, halogenated thiophenols, and metal salts thereof, (D) an inorganic filler and (E) 0.1 to 0.8 parts by weight of organic peroxide, has a diameter of 30 to 40 mm and has a deflection when subjected to a load of 980 N (100 kg) of 2.5 to 6.0 mm;
the mantle is made primarily of a thermoplastic resin, has a thickness of at least 0.5 mm, has a Durometer D hardness of 30 to 70, and includes an outermost layer which is in contact with the cover and has a specific Durometer D hardness;
the cover is made primarily of a thermoplastic polyurethane, has a thickness of 0.5 to 2.5 mm and has a Durometer D hardness of 40 to 60 which is lower than the Durometer D hardness of the outermost layer of the mantle; and
the golf ball has a deflection when subjected to a load of 980 N (100 kg) of 2.0 to 4.0 mm.