| abstract |
A golf ball 2 includes a core 4 , a mid layer 6 positioned outside the core 4 , a reinforcing layer 8 positioned outside the mid layer 6 , and a cover 10 positioned outside the reinforcing layer 8 . The core 4 is obtained by a rubber composition being crosslinked. The rubber composition includes a base rubber, a co-crosslinking agent, a crosslinking initiator, and a carboxylate. The co-crosslinking agent is: (1) an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms; and/or (2) a metal salt of an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms. The amount of the carboxylate is equal to or greater than 1.0 parts by weight but less than 40 parts by weight per 100 parts by weight of the base rubber. A hardness of the mid layer 6 is greater than a hardness of the cover 10. |