Patent ID: 6899640

Claim:
A one-piece golf ball formed by vulcanization from a rubber composition composed of 100 parts by weight of rubber base material, 10 to 40 parts by weight of unsaturated carboxylic acid, 10 to 60 parts by weight of metal oxide, and 0.9 to 5 parts by weight of organic peroxide, said rubber base material containing 60 to 100% by weight based on the weight of a polybutadiene which is synthesized with a catalyst of rare earth element, contains no less than 60% of cis-1,4-linkage, and has a Mooney viscosity (ML 1+4 (100° C.)) no less than 52, wherein the rubber base material contains, in addition to the polybutadiene, no more than 40% by weight of a second polybutadiene which is synthesized with a catalyst of Group VIII element and has a Mooney viscosity (ML 1+4 (100° C.)) less than 50.