Patent Number: 7,086,970

Title: Multi-piece golf ball

Abstract: A multi-piece golf ball includes a core 30 40 mm in diameter, an intermediate layer including an outermost layer 0.5 2.0 mm thick, and a cover 0.5 2.0 mm thick. The core is a rubber composition mainly containing polybutadiene. The outermost layer is a resin material containing an ionomer resin in an amount of 30% by weight or more. The cover material is obtained by dispersedly blending a silicone powder in a main resin containing an ionomer resin in an amount of 50% by weight or more. The hardness of the outermost layer is harder than the hardness of the core's a center portion. The hardness of the cover is harder than the hardness of the outermost layer. A difference in hardness between the cover and the center portion of the core satisfies a relation of 10.ltoreq.(Durometer D hardness of cover-Durometer D hardness of center portion of core.ltoreq.40.

Inventors: Hayashi; Junji (Chichibu, JP), Yamagishi; Hisashi (Chichibu, JP), Shimizu; Yasumasa (Chichibu, JP), Ichikawa; Yasushi (Chichibu, JP)

Assignee: Bridgestone Sports Co., Ltd.

International Classification: A63B 37/04 (20060101); A63B 37/06 (20060101); A63B 37/12 (20060101)

Expiration Date: 8/08/02018