| 摘要 |
PROBLEM TO BE SOLVED: To provide a golf ball 2 having excellent flying performance when being hit with a middle iron.SOLUTION: A golf ball 2 includes a core 4, an inner cover 8, a mid cover 10, and an outer cover 12. Nine points are determined by dividing a region from a central point to a surface of the core 4 at intervals of 12.5% of a radius of the core 4. When distances (%) of the nine points from a central point and hardnesses at the nine points are plotted in a graph, Rof a linear approximation curve obtained by a least-square method is equal to or greater than 0.95. A hardness Hi of the inner cover 8 is greater than a hardness Hs at the surface of the core 4. A hardness Ho of the outer cover 12 is greater than the hardness Hi. A difference (Hi-Hs) is 1 or greater. A difference (Ho-Hi) is 5 or greater but 30 or less. The core 4 is formed by a rubber composition being crosslinked. The rubber composition includes carboxylate. |
