Patent ID: 8932151
Filing Date: 2015-01-13
Classification: A63B,C08K

Abstract:
1. A solid golf ball comprising a core and a cover, wherein the core is formed of a rubber composition comprising a base rubber, a co-crosslinking agent, a crosslinking initiator and a metal oxide, the base rubber containing polybutadiene, a styrene-butadiene rubber and, optionally, an isoprene rubber, the co-crosslinking agent being methacrylic acid, and the rubber composition including from 0.05 to 60 parts by weight of powders, each of which has a particle size of not more than 3 mm and which consist of a combination of (I) a rubber powder and (II) a polyurethane resin powder per 100 parts by weight of the base rubber, where the rubber powder (I) is selected from among (I-a) a rubber powder obtained by granulating a rubber material containing methacrylic acid or a metal salt thereof and (I-b) a rubber powder obtained by granulating a rubber material containing acrylic acid or a metal salt of acrylic acid, and the polyurethane resin powder (II) is composed primarily of a thermoplastic polyurethane; the core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) of from 2.5 to 7.0 mm; the cover is formed of a resin material having a breaking strength of from 20 to 80 MPa and an elongation of from 150 to 600%; and the ball has formed on a surface thereof a plurality of dimples, each having a spatial volume below a flat plane circumscribed by an edge of the dimple, the sum of the dimple spatial volumes, expressed as a percentage (VR) of the volume of a hypothetical sphere were the ball to have no dimples on the surface thereof, being from 0.95 to 1.7.