Multilayer golf ball

Abstract

Multilayer golf balls comprising a thermoplastic or thermoset cover disposed about four or more thermoplastic layers are disclosed.

What is claimed is: 
     
         1 . A golf ball comprising:
 a thermoplastic core having a diameter of from 0.900 inches to 1.550 inches and a compression of 90 or less;   a first thermoplastic intermediate layer having a thickness of from 0.025 inches to 0.125 inches and a material hardness of 65 Shore D or less;   a second thermoplastic intermediate layer having a thickness of from 0.010 inches to 0. 070 inches and a material hardness of from 60 Shore D to 80 Shore D;   a third thermoplastic intermediate layer having a thickness of from 0.010 inches to 0.070 inches and a material hardness of from 60 Shore D to 80 Shore D; and   a cover;   wherein the material hardness of the third thermoplastic intermediate layer is greater than the material hardness of the second thermoplastic intermediate layer; and   wherein the material hardness of the second thermoplastic intermediate layer is greater than the material hardness of the first thermoplastic intermediate layer.   
     
     
         2 . The golf ball of  claim 1 , wherein the first intermediate layer is formed from a highly-neutralized thermoplastic composition comprising an E/X/Y-type copolymer, wherein E is ethylene, X is a C 3 -C 8  α,β-ethylenically unsaturated carboxylic acid present in an amount of from 10 to 20 wt %, based on the total weight of the copolymer, and Y is an acrylate selected from alkyl acrylates and aryl acrylates present in an amount of from 0 wt % to 50 wt %, based on the total weight of the copolymer, wherein 80% or greater of the acids present in the composition are neutralized with a metal ion source. 
     
     
         3 . The golf ball of  claim 1 , wherein the second intermediate layer and the third intermediate layer are each formed from a thermoplastic composition independently selected from partially-neutralized ionomer compositions comprising an E/X/Y-type copolymer, wherein E is ethylene, X is a C 3 -C 8  α,β-ethylenically unsaturated carboxylic acid present in an amount of from 10 to 20 wt %, based on the total weight of the copolymer, and Y is an acrylate selected from alkyl acrylates and aryl acrylates present in an amount of from 0 wt % to 50 wt %, based on the total weight of the copolymer, wherein less than 80% of the acids present in the composition are neutralized with a metal ion source. 
     
     
         4 . The golf ball of  claim 1 , wherein the core is a solid, single-layer core. 
     
     
         5 . The golf ball of  claim 4 , wherein the core has a compression of 60 or less. 
     
     
         6 . The golf ball of  claim 1 , wherein the core comprises an inner core layer formed from a first thermoplastic core composition and an outer core layer formed from a second thermoplastic core composition. 
     
     
         7 . The golf ball of  claim 6 , wherein the overall core has a compression of 60 or less. 
     
     
         8 . The golf ball of  claim 1 , wherein the thickness of the first intermediate core layer is greater than the thickness of the second thermoplastic intermediate layer and the thickness of the third thermoplastic intermediate layer. 
     
     
         9 . The golf ball of  claim 8 , wherein the thickness of the first thermoplastic intermediate layer is from 0.035 inches to 0.075 inches, the thickness of the second thermoplastic intermediate layer is from 0.025 inches to 0.040 inches, and the thickness of the second thermoplastic intermediate layer is from 0.025 inches to 0.040 inches. 
     
     
         10 . The golf ball of  claim 1 , wherein the surface hardness of the third thermoplastic intermediate layer is greater than the surface hardness of the second thermoplastic intermediate layer, and wherein the surface hardness of the second thermoplastic intermediate layer is greater than the surface hardness of the first thermoplastic intermediate layer.