| 摘要 |
A golf ball 2 includes a core 4, an inner cover 6, and an outer cover 8. The core 4 includes a center 10 and an envelope layer 12. The envelope layer 12 is formed by a rubber composition being crosslinked. The rubber composition includes a base rubber (a), a co-crosslinking agent (b), a crosslinking initiator (c), and an acid and/or a salt (d). The co-crosslinking agent (b) is (b1) an ±,²-unsaturated carboxylic acid having 3 to 8 carbon atoms; or (b2) a metal salt of an ±,²-unsaturated carboxylic acid having 3 to 8 carbon atoms. A hardness Hi of the inner cover 6 is greater than a hardness Hs at a surface of the core 4. A hardness Ho of the outer cover 8 is less than the hardness Hi. |
