Multiple-layer golf ball

Abstract

Disclosed herein is a multi-layer golf ball having a soft outer cover. The golf ball has an inner cover layer with a Shore D hardness of 60 or more, and an outer cover with a Shore D hardness of 55 or less, and more preferably 50 or less. In a particularly preferred form of the invention, the outer cover comprises one or more polyurethane materials. The golf ball of the invention has exceptionally soft feel and high spin rates on short shots of 80 yards or less, and particularly, 40 yards or less, while maintaining good distance and average spin on full shots.

1 . A golf ball comprising:
 a core;   an inner cover layer disposed on the core, the inner cover layer comprising a blend of ionomers, the blend of ionomers having at least one ionomer with an acid content by weight of 16% or less, and 10% to 100% neutralization of the acids by metal ions selected from the group consisting of zinc, sodium and magnesium;   and an outer cover layer disposed on the inner cover layer, the outer cover layer having a Shore D hardness of no more than 55 as measured on the curved surface thereof and comprising a composition including at least one material selected from the group consisting of polyphenylene ether/ionomer blends, ionomers, polyamides, polyurethanes, polyester elastomers, polyester amides, metallocene catalyzed polyolefins, and blends thereof;   wherein the golf ball exhibits a PGA compression of 100 or less and a coefficient of restitution of at least 0.770.   
     
     
         2 . The golf ball of  claim 1 , wherein the core and inner cover layer form an inner ball having a coefficient of restitution of 0.790 or more and a diameter of 1.48 inches to 1.66 inches 
     
     
         3 . The golf ball of  claim 1 , wherein the inner cover layer has a Shore D hardness of at least 60. 
     
     
         4 . The golf ball of  claim 1 , wherein the outer cover layer has a Shore D hardness of from about 30 to about 53. 
     
     
         5 . The golf ball of  claim 1 , wherein the outer cover layer comprises polyurethane. 
     
     
         6 . The golf ball of  claim 5 , wherein the polyurethane is composed of thermoplastic polyester polyurethane. 
     
     
         7 . The golf ball of  claim 1 , wherein the outer cover layer comprises an ionomer. 
     
     
         8 . The golf ball of  claim 7 , wherein the ionomer has an acid content by weight of 16% or less. 
     
     
         9 . The golf ball of  claim 7 , wherein the ionomer is composed of at least 75 weight % of an acrylate ester-containing ionic copolymer or blend of acrylate ester-containing ionic copolymers. 
     
     
         10 . The golf ball of  claim 1 , wherein the outer cover layer comprises a metallocene catalyzed polyolefin material. 
     
     
         11 . The golf ball of  claim 1 , wherein the blend of ionomers comprises at least two ionomer resins with an acid content by weight of 16% or less. 
     
     
         12 . The golf ball of  claim 1 , wherein the blend of ionomers further comprises at least one ionomer with an acid content by weight of 17% to 25%. 
     
     
         13 . The golf ball of  claim 1 , wherein the inner cover layer further comprises a metal fatty acid salt. 
     
     
         14 . The golf ball of  claim 13 , wherein the metal fatty acid salt is a metal stearate. 
     
     
         15 . The golf ball of  claim 14 , wherein the metal stearate comprises a metal selected from the group consisting of zinc, sodium and magnesium. 
     
     
         16 . The golf ball of  claim 1 , wherein the core is solid and is composed of a polybutadiene mixture. 
     
     
         17 . The golf ball of  claim 1 , wherein the core is solid and is formed from materials comprising at least one polybutadiene and an ethylenically unsaturated carboxylic acid selected from the group consisting of zinc diacrylate, zinc acrylate and zinc methacrylate. 
     
     
         18 . The golf ball of  claim 1 , wherein the core is solid and is formed from materials comprising at least one polybutadiene, zinc oxide and an ethylenically unsaturated carboxylic acid selected from the group consisting of zinc diacrylate, zinc acrylate and zinc methacrylate 
     
     
         19 . The golf ball of  claim 18 , wherein the ethylenically unsaturated carboxylic acid is zinc diacrylate. 
     
     
         20 . The golf ball of  claim 1 , wherein the core is a thread wound core having a liquid filled center.