Disclosed herein is 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 (ML1+4(100
C.)) no less than 40. This golf ball has good shot feeling and high rebound resilience
and is easy to produce by extrusion.
