Patent ID: 7125346

Claim:
A solid golf ball comprising at least one layer of a core, and at least one layer of a cover formed on the core, wherein the core is formed from a rubber composition comprising a base rubber, a co-crosslinking agent, an organic peroxide and an organic sulfur compound, the base rubber comprises a polybutadiene synthesized using rare-earth element-containing catalyst in an amount of 100 parts by weight, based on 100 parts by weight of the base rubber, and the organic sulfur compound comprises a polysulfide compound having at least one bromo group, and the core has a center hardness in JIS-C hardness of 35 to 60, a surface hardness in JIS-C hardness of 60 to 90 and a hardness difference (b-a) in JIS-C hardness between a center hardness (a) and a surface hardness (b) of not less than 20.