| 摘要 |
PROBLEM TO BE SOLVED: To provide a golf ball travelling a great distance on driver shots.SOLUTION: A golf ball has a spherical core having an inner layer and an outer layer. A difference (H-H) between hardness (H) at a point located 1 mm radially outward from a boundary between the inner layer and the outer layer and hardness (H) at a point located 1 mm radially inward from the boundary between the inner layer and the outer layer of the spherical core is 0 or greater with respect to Shore C hardness. Surface hardness (H) of the spherical core exceeds 70 with respect to the Shore C hardness. An angle α of hardness gradient of the inner layer is 0° or greater, and a difference (α-β) between the angle α and an angle β of hardness gradient of the outer layer is 0° or greater. Among constituent members of the golf ball, a middle layer has highest hardness.SELECTED DRAWING: Figure 2 |
