Thermoplastic Multi-Layer Golf Ball

Abstract

A thermoplastic multi-layer golf ball has a core center having a shell from about 1-6 mm thick defining an interior space about 12-24 mm in diameter, a core layer at least about 5 mm thick outward from the core center, and a cover. The shell includes a first thermoplastic material with first flexural modulus less than about 15,000 psi. The core layer includes a second thermoplastic material with second flexural modulus up to about 15,000 psi and greater than the first flexural modulus and a specific gravity of at least about 1.5 g/cm 3 . The cover includes a third thermoplastic material with a third flexural modulus that in a first embodiment is up to about 5,000 psi and less than the first flexural modulus and in a second embodiment is least about 40,000 psi.

1 . A golf ball, comprising:
 a core center comprising a shell with a thickness of from about 1 mm to about 6 mm defining an interior space from about 12 mm to about 24 mm in diameter, wherein the shell comprises a first thermoplastic material having a first flexural modulus less than about 15,000 psi;   a core layer disposed radially outward from the core center, wherein the core layer has a thickness of at least about 5 mm and comprises a second thermoplastic material having a second flexural modulus up to about 15,000 psi and a specific gravity of at least about 1.5 g/cm 3 ; and   a cover disposed radially outward of the core layer and forming an outermost layer of the golf ball, wherein the cover comprises a third thermoplastic material having a third flexural modulus up to about 5,000 psi;   wherein the second flexural modulus is greater than the first flexural modulus and the first flexural modulus is greater than the third flexural modulus.   
     
     
         2 . A golf ball according to  claim 1 , wherein one of the first thermoplastic material and the second thermoplastic material comprises an ionomer resin. 
     
     
         3 . A golf ball according to  claim 2 , wherein the ionomer resin comprises a monomeric organic acid or salt thereof and wherein the ionomer resin is neutralized from at least about 40 to about 100%. 
     
     
         4 . A golf ball according to  claim 2 , wherein the thermoplastic material comprising the ionomer resin further comprises a polyolefin elastomer. 
     
     
         5 - 11 . (canceled) 
     
     
         12 . A golf ball, comprising:
 a core center comprising a shell with a thickness of from about 1 mm to about 6 mm defining an interior space from about 12 mm to about 24 mm in diameter, wherein the shell comprises a first thermoplastic material having a first flexural modulus less than about 15,000 psi;   a core layer disposed radially outward from the core center, wherein the core layer has a thickness of at least about 5 mm and comprises a second thermoplastic material having a second flexural modulus up to about 15,000 psi and a specific gravity of at least about 1.5 g/cm 3 ; and   a cover disposed radially outward of the core layer, wherein the cover comprises a third thermoplastic material having a third flexural modulus of at least about 40,000 psi;   wherein the second flexural modulus is greater than the first flexural modulus.   
     
     
         13 . A golf ball according to  claim 12 , wherein one of the first thermoplastic material, the second thermoplastic material, and the third thermoplastic material comprises an ionomer resin. 
     
     
         14 . A golf ball according to  claim 13 , wherein the ionomer resin comprises a monomeric organic acid or salt thereof and wherein the ionomer resin is neutralized from at least about 40 to about 100%. 
     
     
         15 . A golf ball according to  claim 13  or  claim 14 , wherein the one of the first thermoplastic material or the second thermoplastic material comprises the ionomer resin and further comprises a polyolefin elastomer. 
     
     
         16 . A golf ball according to  claim 12 , wherein each of the first thermoplastic material and the second thermoplastic material independently comprises an ionomer resin comprising an organic acid or a salt of organic acid wherein the ionomer resin is neutralized to a level of at least about 90% and wherein the third thermoplastic material comprises an ionomer resin with from about 4 weight percent to about 35 weight percent of a carboxylic acid monomer that is neutralized from at least about 40 to about 100%. 
     
     
         17 - 22 . (canceled)