US 7,563,179 B2
Golf ball
Jun Shindo, Chichibu (Japan); Eiji Takehana, Chichibu (Japan); and Kae Yamazaki, Chichibu (Japan)
Assigned to Bridgestone Sports Co., Ltd., Tokyo (Japan)
Filed on Jul. 27, 2007, as Appl. No. 11/878,952.
Application 11/878952 is a continuation in part of application No. 11/324297, filed on Jan. 04, 2006, granted, now 7,294,067.
Claims priority of application No. 2007-173986 (JP), filed on Jul. 02, 2007.
Prior Publication US 2008/0076603 A1, Mar. 27, 2008
This patent is subject to a terminal disclaimer.
Int. Cl. A63B 37/00 (2006.01)
U.S. Cl. 473—351 10 Claims
 
1. A golf ball comprising a core and a cover of one or more layer, wherein the core is made of a material obtained by molding under heat a rubber composition comprising (a) a base rubber containing polybutadiene having a stress relaxation time (T80), defined as the time in seconds from the moment when rotation is stopped immediately after measurement of the ML1+4 (100° C.) value (the Mooney viscosity measured at 100° C. in accordance with ASTM D-1646-96) that is required for the ML1+4 value to decrease 80%, of 3.5 or less, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide, and wherein at least one layer of the cover is made of a material obtained by molding a mixture comprising (A) 100 parts by weight of a base resin and (B) 1 to 40 parts by weight of a branched saturated fatty acid or a derivative thereof.