| 主权项 |
1. A solid golf ball comprising a core of at least one layer and a cover of at least one layer, wherein at least one layer of the core is formed primarily of polybutadiene and includes at least 0.05 part by weight each of (I-a) a rubber powder obtained by granulating a rubber material containing methacrylic acid, (I-b) a rubber powder obtained by granulating a rubber material containing a metal salt of acrylic acid, and (II) a polyurethane resin powder per 100 parts by weight of rubber component, and at least one layer of the cover is formed primarily of a thermoplastic polyurethane elastomer; and
wherein the core has a hardness designed so as to gradually increase from a center of the core toward a surface of the core, and wherein the metal salt of acrylic acid in the rubber powder (I-b) is selected from the group consisting of zinc acrylate (ZDA), sodium acrylate, potassium acrylate, aluminum acrylate, and calcium acrylate, and wherein the polyurethane resin powder (II) is granulated by a granulator to an average particle size of not more than 1 mm. |
