Patent ID: 7524252

Claim:
A one-piece golf ball obtained by molding a rubber composition which comprises: (a) a base rubber containing a polybutadiene obtained by polymerizing butadiene in the presence of a catalyst containing a cobalt salen complex and methylaluminoxane; (b) a co-crosslinking agent; and (c) a crosslinking agent, and the polybutadiene contains 98% or more of cis-1,4-bond and 1% or less of trans-1,4-bond, and the one-piece golf ball having a compression deformation amount of 2.3 mm or more, and 3.0 mm or less when applying a load from 98 N as an initial toad to 1275 N as a final load, the difference of the hardness between the surface hardness and the center hardness being 15 or more, 30 or less in shore D hardness, the center hardness being 25 or more, 45 or less in shore D hardness, and the surface hardness being 45 or more, 70 or less in shore D hardness.