| 摘要 |
PROBLEM TO BE SOLVED: To provide a golf ball that achieves satisfactory distances both on shots with drivers and on shots with middle irons used by professional golfers and skilled amateurs, and which also has an excellent durability to cracking when repeatedly struck.SOLUTION: A golf ball has a core and a cover of at least one layer. The cover includes an outermost layer and at least one intermediate layer interposed between the outermost layer and the core. The core has a cross-sectional hardness which, letting R (mm) be the radius of the core, A be the JIS-C hardness at the center of the core, B be the JIS-C hardness at a position R/3 mm from the core center, C be the JIS-C hardness at a position R/1.8 mm from the core center, D be the JIS-C hardness at a position R/1.5 mm from the core center, and E be the JIS-C hardness at the surface of the core, satisfies formulas (1) B-A<D-B, (2) C-A≤8, and (3) E-B≥15. The intermediate layer and the outermost layer have a hardness relationship therebetween which satisfies the formula "material hardness of intermediate layer<material hardness of outermost layer". The golf ball achieves satisfactory distances, both on shots with drivers and on shots with middle irons such as a number six iron (I#6) used by professional golfers and skilled amateurs, and also exhibits an improved durability to cracking when repeatedly struck. |
