| abstract |
A molded rubber material for golf balls which is obtained by molding and curing a rubber compound composed of base rubber and such ingredients as crosslinking agent, co-crosslinking agent, and vulcanization accelerator, wherein the base rubber is polybutadiene which results from polymerization with the help of a catalyst of rare earth element and has a stress relaxation time (T 80 ) no longer than 5 (measured according to ASTM D 1646-96), the vulcanization accelerator is hexamethylenetetramine, and the rubber compound contains an organosulfur compound. A method for producing the molded rubber material, and a golf ball having the molded rubber material as the solid core. The method permits efficient production of high-quality rubber molded material with high rebound resilience. |