Golf ball

Abstract

The invention provides, in a golf ball having a core, an intermediate layer and a cover, a golf ball which combines an intermediate layer formed of an ionomer resin material having a high degree of neutralization with a cover formed of a material that includes a first ionomer resin having a high unsaturated carboxylic acid content and a second ionomer resin having a low unsaturated carboxylic acid content. The golf ball is able to achieve a lower spin rate on full shots with a driver (W#1) without reducing the spin performance on approach shots in the short game, provides high levels of both flight performance and controllability, and also has a good feel at impact.

1 . A golf ball comprising a core, at least one intermediate layer, and a cover having a plurality of dimples on an outside surface thereof, wherein the intermediate layer is formed of a material comprising:
 100 parts by weight of a resin component composed of, in admixture,
 (A) a base resin of (a-1) an olefin-unsaturated carboxylic acid random copolymer and/or a metal ion neutralization product of an olefin-unsaturated carboxylic acid random copolymer blended with (a-2) an olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random terpolymer and/or a metal ion neutralization product of an olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random terpolymer in a weight ratio of from 100:0 to 0:100, and 
 (B) a non-ionomeric thermoplastic elastomer in a weight ratio of from 100:0 to 50:50, 
   (C) from 5 to 150 parts by weight of a fatty acid and/or fatty acid derivative having a molecular weight of from 228 to 1500, and   (D) from 0.1 to 17 parts by weight of a basic inorganic metal compound capable of neutralizing un-neutralized acid groups in component A and component C; and the cover is formed of a material comprising a first ionomer resin having an unsaturated carboxylic acid content of at least 16 wt % and a second ionomer resin having an unsaturated carboxylic acid content of 12 wt % or less, which material has a Shore D hardness of not more than 61.   
     
     
         2 . The golf ball of  claim 1 , wherein the cover material has a first ionomer resin content, based on the total amount of the ionomer resin components, of 50 wt % or less. 
     
     
         3 . The golf ball of  claim 1 , wherein the intermediate layer material has a degree of neutralization of from 70 to 95 wt %. 
     
     
         4 . The golf ball of  claim 1  further comprising, between the core and the intermediate layer, an envelope layer which is formed of a material having a Shore D hardness of not more than 50. 
     
     
         5 . The golf ball of  claim 4 , wherein the envelope layer-forming material is a polyester resin.