Patent ID: 7740547
Filing Date: 2010-06-22
Classification: A63B

Abstract:
1. A multi-piece solid golf ball comprising a core which is obtained by molding under heat a rubber composition containing a base rubber, a filler, an organic peroxide, an antioxidant and an α,β-unsaturated carboxylic acid, and a cover of at least three layers which encases the core and in which the cover layers other than an outermost cover layer are formed primarily of a thermoplastic resin, wherein the core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load state of 98 N (10 kgf) of more than 3.2 mm; at least one intermediate cover layer situated between an innermost cover layer and the outermost cover layer has a higher hardness than the innermost cover layer and the outermost cover layer; the innermost cover layer and the core have a difference in specific gravity therebetween of 0.1 or less; the core has a center hardness (A) which satisfies the following condition with respect to the Shore D hardness (B) of the innermost cover layer: the cover has a hardest layer with a Shore D hardness of 58 or less; the cover layers have a combined thickness of at least 3.5 mm; and the innermost cover layer is made of a resin composition comprising: 100 parts by weight of one or a mixture of