Patent ID: 7390852

Claim:
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 (E) 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 58; 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 58, 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; the organic sulfur compound (D) is selected from the group consisting of thiophenols and metal salts thereof, thionaphthols and metal salts thereof, halogenated thiophenols and metal salts thereof, diphenylpolysulfides having 2 to 4 sulfurs, dibenzylpolysulfides having 2 to 4 sulfurs, dibenzoylpolysulfides having 2 to 4 sulfurs, dibenzothiazoylpolysulfides having 2 to 4 sulfurs, dithiobenzoylpolysulfides having 2 to 4 sulfurs, alkylphenyldisulfides, furan ring-bearing sulfur compounds and thiophene ring-bearing sulfur compounds; and the thickness of the mantle is larger than that of the cover.