Patent ID: 9309350
Filing Date: 2016-04-12
CPC Classification: A63B,C08G

Claim Text:
1. A golf ball comprising a core composed of at least one layer and a cover covering the core, wherein at least one layer of the core is formed from a golf ball polyurethane composition comprising, as a resin component, a polyurethane elastomer formed from a polyisocyanate component of 4,4′-dicyclohexylmethane diisocyanate, a polyol component of polytetramethylene ether glycol having a number average molecular weight ranging from 2,000 to 3,000, and a chain extender component of 1,4-butanediol, the 4,4′-dicyclohexylmethane diisocyanate is in the form of its trans,trans-isomer in an amount of 50 mole % or more, and the polyurethane composition has a storage modulus E′ (Pa) and a loss modulus E″ (Pa) satisfying the following expression: when measured in a tensile mode using a dynamic viscoelasticity measuring apparatus, the polyurethane composition has a slab hardness of 53 or less in Shore D hardness and rebound resilience of 60% or more, and the polyurethane elastomer is produced by reacting the 4,4′-dicyclohexylmethane diisocyanate with the polytetramethylene ether glycol in a molar ratio (NCO/OH) of an isocyanate group (NCO) of the 4,4′-dicyclohexylmethane diisocyanate to a hydroxyl group (OH) of the polytetramethylene ether glycol ranging from 1 to 1.5 to obtain an isocyanate group terminated urethane prepolymer, and reacting the isocyanate group terminated urethane prepolymer with 1,4-butanediol in a molar ratio (NCO/OH) of an isocyanate group (NCO) of the isocyanate group terminated urethane prepolymer to a hydroxyl group (OH) of the 1,4-butanediol ranging from 0.9 to 1.1.