Isophthalic acid polyamide polymer for use in golf ball covers or mantles

Abstract

Disclosed herein is a golf ball with a cover or mantle, or both, formed from an isophthalic acid polyamide composition and a method of making the same. In one embodiment, the golf ball has a cover which contains a combination of an isophthalic acid polyamide component and an ionomeric component or a non-ionomeric terpolymer component. The cover composition has excellent durability and resistance to cracking, even at cold temperatures. The nylon-ionomer blend is a useful substitute for an ionomer golf ball cover, particularly when a low spin golf ball is desired.

What is claimed is:  
     
         1 . A golf ball having a cover and a core centrally disposed within said cover, said cover including a combination of a first component and a second component, wherein 
 said first component comprises an isophthalic acid polyamide formed from reacting an agent including at least one of phthalic acid, isophthalic acid, and terephthalic acid; and    said second component comprises an ionomer.    
     
     
         2 . The golf ball according to  claim 1 , wherein said first component further comprises at least one member selected from the group consisting of a polyamide homopolymer and a polyamide copolymer.  
     
     
         3 . The golf ball according to  claim 1 , wherein said combination of said first component and said second component is a reaction product.  
     
     
         4 . The golf ball according to  claim 1 , wherein said first component is present in a mixture with said second component.  
     
     
         5 . The golf ball according to  claim 1 , wherein said first component constitutes from about 10% to about 80% by weight of said cover.  
     
     
         6 . The golf ball according to  claim 1 , wherein said second component constitutes from about 90% to about 40% by weight of said cover.  
     
     
         7 . The golf ball according to  claim 1 , wherein said cover includes from about 10% to about 60% by weight of said first component and from about 90% to about 40% by weight of said second component.  
     
     
         8 . The golf ball according to  claim 1 , wherein said golf ball exhibits a coefficient of restitution of at least 0.750.  
     
     
         9 . The golf ball according to  claim 1 , wherein said golf ball exhibits a coefficient of restitution of at least 0.800.  
     
     
         10 . The golf ball according to  claim 1 , wherein said golf ball exhibits a Riehle compression of less than about 75.  
     
     
         11 . The golf ball according to  claim 1 , wherein said combination further includes an ester component.  
     
     
         12 . The golf ball according to  claim 11 , wherein said ester component is an olefin ester component.  
     
     
         13 . The golf ball according to  claim 12 , wherein said combination is a reaction product of said first component, said second component and said olefin ester component.  
     
     
         14 . The golf ball according to  claim 1 , wherein said second component further comprises an alkyl acrylate.  
     
     
         15 . The golf ball according to  claim 1 , wherein said polyamide of said first component is a polyphthalamide and said ionomer of said second component is an ionomeric copolymer of two types of monomers.  
     
     
         16 . The golf ball according to  claim 1 , wherein said first component is a polyphthalamide homopolymer and said second component is an ionomeric terpolymer.  
     
     
         17 . The golf ball according to  claim 11 , wherein said ionomer of said second component is a zinc-neutralized copolymer of ethylene and methacrylic acid, and said ester component is a copolymer of ethylene and ethylacrylate.  
     
     
         18 . A golf ball comprising: 
 a core; and    a cover layer disposed about said core, said cover layer including an isophthalic acid polyamide.    
     
     
         19 . The golf ball of  claim 18  wherein said isophthalic acid polyamide is formed from at least one of phthalic acid, isophthalic acid, and terephthalic acid.  
     
     
         20 . The golf ball of  claim 18  wherein said isophthalic acid polyamide exhibits a melting point of about 590° F.  
     
     
         21 . The golf ball of  claim 18  wherein said isophthalic acid polyamide has a specific gravity of about 1.15.  
     
     
         22 . The golf ball of  claim 18  wherein said cover layer includes from about 10% to about 60% of said isophthalic acid polyamide based upon the weight of said cover layer.  
     
     
         23 . The golf ball of  claim 22  wherein said cover layer includes from about 15% to about 50% of said isophthalic acid polyamide based upon the weight of said cover layer.  
     
     
         24 . The golf ball of  claim 23  wherein said cover layer includes from about 20% to about 40% of said isophthalic acid polyamide based upon the weight of said cover layer.  
     
     
         25 . The golf ball of  claim 18  wherein said golf ball exhibits a coefficient of restitution of at least 0.750.  
     
     
         26 . The golf ball of  claim 25  wherein said golf ball exhibits a coefficient of restitution of at least 0.800.  
     
     
         27 . The golf ball of  claim 18  wherein said golf ball exhibits a Riehle compression of less than 75.  
     
     
         28 . The golf ball of  claim 27  wherein said golf ball exhibits a Riehle compression of less than 71.  
     
     
         29 . A golf ball comprising: 
 a core;    a mantle layer disposed about said core; and    a cover layer disposed on said mantle; wherein said mantle layer comprises an isophthalic acid polyamide.    
     
     
         30 . The golf ball of  claim 29  wherein said mantle layer comprises polyphthalamide.  
     
     
         31 . A method of making a golf ball, comprising the steps of: 
 obtaining a golf ball core, and    forming a cover layer over the core, said cover layer having a resin composition comprising a combination of an isophthalic acid polyamide component and an ionomeric component, the amount of said isophthalic acid polyamide component being at least 10 wt. % of said resin composition.