| 摘要 |
The present invention provides a golf ball composed of a core, an outermost cover layer and one or more intermediate layer therebetween. At least one intermediate layer includes a mixture composed of a base polymer made of, in a specific ratio, (a) a metal ion neutralization product of an olefin-unsaturated carboxylic acid random copolymer and/or a metal ion neutralization product of an olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random copolymer, (b) a thermoplastic elastomer selected from the group consisting of thermoplastic polyester elastomers, thermoplastic block copolymers and thermoplastic polyurethanes, and (c) a thermoplastic block copolymer containing end blocks modified by a functional group having reactivity with an ionomer resin, both end blocks being formed of different comonomers. The mixture also includes (e) an organic acid of 18 to 40 carbons or a derivative thereof, and (f) a metal ion source selected from the group consisting of alkali metals, alkaline earth metals and transition metals. The mixture has an optimized ratio between the melt viscosities of (b) and (a) as measured under a shear rate of 6,000 sec-1 and 240° C. in accordance with JIS K-7199. The golf ball of the invention has a flight and control performance acceptable for use by professional golfers and skilled amateurs, and also has an excellent durability to cracking under repeated impact.
|
