| 摘要 |
PROBLEM TO BE SOLVED: To provide a golf ball having excellent flying performance and controllability.SOLUTION: A golf ball 2 includes a core 4, an inner cover 6, a mid cover 8, and an outer cover 10. The core 4 includes a center 12 and an envelope layer 14. The center 12 is formed by being crosslinked with a rubber composition. The envelope layer 14 is formed by being crosslinked with a rubber composition. At least one of the rubber composition of the center 12 and the rubber composition of the envelope layer 14 includes (a) base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) an acid and/or a salt. The co-crosslinking agent (b) is (b1) an α, &bgr;-unsaturated carboxylic acid having 3-8 carbon atoms; or (b2) a metal salt thereof. The JIS-C hardness Hi of the inner cover 6 is higher than JIS-C hardness Hs at a surface of the core 4, and a difference (Hi-Hs) is 1 or larger. The JIS-C hardness Ho of the outer cover 10 is higher than the hardness Hi. |
