Patent ID: 8846794

Claim:
A golf ball comprising a plurality of members which include: (I) a first member comprised of a material molded under heat from a rubber composition comprising (a) a base rubber composed primarily of a mixture of at least 60 wt % of a polybutadiene having a stress relaxation time (T 80 ), defined as the length of time it takes from the moment rotor rotation is stopped immediately after measurement of the ML 1+4 (100° C.) value (the Mooney viscosity measured at 100° C. in accordance with ASTM D-1646-96) for the ML 1+4 value to decrease 80%, of less than 4 seconds and up to 40 wt % of a polybutadiene having a stress relaxation time (T 80 ) of at least 4 seconds, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide; and (II) a second member formed primarily of a resin composition obtained by mixing 100 parts by weight of a base resin composed primarily of (A-I) an olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random terpolymer and/or a metal salt thereof, and/or (A-II) an olefin-unsaturated carboxylic acid random copolymer and/or a metal salt thereof, (B) from 100 to 170 parts by weight of a fatty acid or fatty acid ester having a molecular weight of from 280 to 1500, and (C) from 0.1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing acid groups in components A and B, wherein (i) the olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random terpolymer and/or a metal salt thereof serving as component A-I has a weight-average molecular weight (Mw) of at least 100,000 but not more than 200,000, and a weight-average molecular weight (Mw) to number-average molecular weight (Mn) ratio of at least 3 but not more than 7.0, and (ii) the olefin-unsaturated carboxylic acid random copolymer and/or a metal salt thereof serving as component A-II has a weight-average molecular weight (Mw) of at least 150,000 but not more than 200,000, and a weight-average molecular weight (Mw) to number-average molecular weight (Mn) ratio of at least 3 but not more than 7.0.