Patent ID: 7294067

Claim:
A golf ball, comprising, as a constituent element, an article molded under heat from a rubber composition comprised of: (a) a base rubber containing polybutadiene having a stress relaxation time (T 80 ), defined as the time in seconds from the moment when rotor rotation is stopped immediately after measurement of the ML 1+4 (100° C.) value (the Mooney viscosity measured at 100° C. in accordance with ASTM D-1646-96) that is required for the ML 1+4 value to decrease 80%, of at most 3.5, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide, wherein the polybutadiene having a stress relaxation time (T 80 ) of at most 3.5 is a polybutadiene prepared using a rare-earth catalyst.