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 consisting essentially of a first component and a second component, wherein 
 said first component comprises a phthalic acid polyamide formed from reacting an agent including at least one of phthalic acid, and isophthalic 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.  
     
     
         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 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 consisting essentially of (i) a phthalic acid polyamide formed from at least one of phthalic acid and isophthalic acid, and (ii) an olefin/alkyl (meth)acrylate/carboxylic acid terpolymer.    
     
     
         19 . The golf ball of  claim 18  wherein said phthalic acid polyamide is formed from isophthalic acid.  
     
     
         20 . The golf ball of  claim 18  wherein said phthalic acid polyamide exhibits a melting point of about 590° F.  
     
     
         21 . The golf ball of  claim 18  wherein said phthalic 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 phthalic 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 phthalic 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 phthalic 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 solid golf ball comprising: 
 a core;    a mantle layer disposed about said core; and    a cover layer disposed on said mantle;    wherein said mantle layer consists essentially of (i) a phthalic acid polyamide formed from at least one of phthalic acid and isophthalic acid, and (ii) an ionomer.    
     
     
         30 . The golf ball of  claim 29  wherein said mantle layer comprises polyphthalamide, an ionomer and an acrylate.  
     
     
         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 consisting essentially of a combination of (i) a phthalic acid polyamide component formed from at least one of phthalic acid and isophthalic acid, and (ii) an ionomeric component, the amount of said isophthalic acid polyamide component being at least 10 wt. % of said resin composition.