| abstract |
The invention provides a solid golf ball having a solid core and a cover layer that encases the core and has an outermost layer on an outside surface of which are formed a plurality of dimples. The solid core is formed of a rubber composition composed of 100 parts by weight of a base rubber that includes from 60 to 100 parts by weight of a polybutadiene rubber having a cis-1,4 bond content of at least 60% and synthesized using a rare-earth catalyst, from 0.1 to 5 parts by weight of an organosulfur compound, an unsaturated carboxylic acid or a metal salt thereof, an inorganic filler, and an antioxidant. The solid core has a deformation, when compressed under a final load of 130 kgf from an initial load of 10 kgf, of from 2.0 to 4.0 mm, and has a specific hardness distribution. The cover layer is formed by injection molding a single resin blend composed primarily of (A) a polyurethane material and (B) a polyisocyanate compound, which resin blend includes a polyisocyanate compound in at least some portion of which all the isocyanate groups on a molecule remain in an unreacted state. The cover layer has a thickness of from 0.5 to 2.5 mm and a Shore D hardness at the surface of from 50 to 70. The golf ball has a deformation, when compressed under a final load of 130 kgf from an initial load of 10 kgf, of from 2.0 to 3.8 mm. The solid golf ball is advantageous overall in competitive use. |