Patent ID: 6592470
Filing Date: 2003-07-15
Classification: A63B

Abstract:
A solid multi-piece golf ball comprising a solid elastic core, a cover composed of at least one layer enclosing the core, and an intermediate layer composed of a thermoplastic material between the core and the cover; whereinthe core, when subjected to a load of 1274 N (130 kgf) from an initial load of 98 N (10 kgf), undergoes a deformation of 3.2 to 6.5 mm; the cover has a Shore D hardness of 45 to 55 and the intermediate layer has a Shore D hardness in a range of 54 to 65 and higher than the Shore D hardness of the cover; the cover and the intermediate layer have a combined thickness, defined as (cover thickness+intermediate layer thickness), of 2.3 to 3.5 mm; and the cover and the intermediate layer have a thickness ratio, defined as (cover thickness)/(intermediate layer thickness), of 0.48 to 0.84, wherein the intermediate layer is made of a resin composition containing at least 30 parts by weight of ionomer resin, said resin composition including: (a) 100 parts by weight of an olefin/unsaturated carboxylic acid random copolymer, an olefin/unsaturated carboxylic acid/unsaturated carboxylic acid ester random copolymer, a metal ion neutralization product of either type of copolymer, or a mixture of any of the copolymers and the neutralization products thereof; (b) 5 to 80 parts by weight of a fatty acid having a molecular weight of at least 280 or a derivative thereof; and (c) 0.1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing the acid groups in components (a) and (b).