Patent ID: 9586094
Date: 2017-03-07
CPC Classifications: A63B,B29C,B29K,B29L

Claim:
1. A method for manufacturing a golf ball that comprises a spherical core and at least one cover layer covering the spherical core, comprising the steps of: preparing a rubber composition containing a base rubber, an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, crosslinking initiator and a carboxylic acid and/or a salt thereof not including the α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or the metal salt thereof, provided that the rubber composition further contains a metal compound in the case of containing only the α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent; heat pressing the rubber composition at a press temperature ranging from t-40° C. to t-15° C. to mold the spherical core having a hardness difference (Hs−Ho) between a surface hardness Hs and a center hardness Ho thereof of 16 or more in JIS-C hardness, wherein t ° C. is a one-minute half-life temperature of the crosslinking initiator, provided that the heat press temperature is adjusted to satisfy said range relative to one-minute half-life temperatures of all of the crosslinking initiators in the case of blending two or more kinds of the crosslinking initiators in the rubber composition; and forming at least one cover layer covering the spherical core.