A golf ball 2 includes a core 4, a mid layer 6, and a cover 10. The core 4 includes a center 16, a first envelope layer 18, and a second envelope layer 20. The first envelope layer 18 is formed by a first rubber composition being crosslinked. The second envelope layer 20 is formed by a second rubber composition being crosslinked. The first rubber composition and/or the second rubber composition include: a base rubber; a co-crosslinking agent; a crosslinking initiator; and an acid and/or a salt. 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.
高尔夫球 2 包括球芯 4、中层 6 和外层 10。球芯 4 包括中心 16、第一包胶层 18 和第二包胶层 20。第一包层 18 由交联的第一橡胶成分形成。第二包胶层 20 由交联的第二橡胶组合物形成。第一橡胶组合物和/或第二橡胶组合物包括:基础橡胶;共
交联剂;交联
引发剂;酸和/或盐。共
交联剂是(1)具有 3 至 8 个碳原子的 α,β-不饱和
羧酸;和/或(2)具有 3 至 8 个碳原子的 α,β-不饱和
羧酸的
金属盐。