Thermoplastic Multi-Layer Golf Ball

Abstract

A thermoplastic multi-layer golf ball has a thermoplastic core center with first flexural modulus and diameter from about 21-29 mm; a thermoplastic core layer radially outward with second flexural modulus; and a thermoplastic cover radially outward with third flexural modulus of up to about 5,000-6000. The second flexural modulus is greater than the third flexural modulus. The core layer and core center specific gravities differ by at least about 0.1 g/cm 3 . The first flexural modulus is up to about 15,000 psi and greater than the second flexural modulus, which is up to about 9700, or the second flexural modulus is up to about 15,000 psi and is greater than the first flexural modulus, which is up to about 9700, with the first thermoplastic material including an ionomer resin and a polyolefin elastomer and having a 10-130 kg compression deformation of at least about 4 mm.

What is claimed is: 
     
         1 . A golf ball, comprising:
 a core center having a diameter from about 21 mm to about 29 mm and comprising a first thermoplastic material having a first flexural modulus of up to 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 4 mm and comprises a second thermoplastic material having a second flexural modulus of up to about 9700 psi; and   a cover disposed radially outward from the core layer, wherein the cover comprises a third thermoplastic material having a third flexural modulus of up to about 6,000 psi;   wherein the first flexural modulus is greater than the second flexural modulus, the second flexural modulus is greater than the third flexural modulus, and the specific gravity of the core layer and the specific gravity of the core center differ by at least about 0.1 g/cm 3 .   
     
     
         2 . A golf ball according to  claim 1 , wherein the third flexural modulus is up to about 5,000 psi. 
     
     
         3 . A golf ball according to  claim 1 , wherein the specific gravity of the core layer is at least about 0.1 g/cm 3  greater than the specific gravity of the core center. 
     
     
         4 . A golf ball according to  claim 1 , wherein the specific gravity of the core center is at least about 0.1 g/cm 3  greater than the specific gravity of the core layer. 
     
     
         5 - 8 . (canceled) 
     
     
         9 . A golf ball, comprising:
 a core center having a diameter from about 21 mm to about 29 mm and comprising a first thermoplastic material comprising an ionomer resin and a polyolefin elastomer and having a 10-130 kg compression deformation of at least about 4 mm and a first flexural modulus of up to about 9700 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 of up to about 15,000 psi; and   a cover disposed radially outward from the core layer, wherein the cover comprises a third thermoplastic material having a third flexural modulus of up to about 5,000 psi; wherein the second flexural modulus is greater than the first flexural modulus, the second flexural modulus is at least about 10,000 psi greater than the third flexural modulus, and the specific gravity of the core layer and the specific gravity of the core center differ by at least about 0.1 g/cm 3 .   
     
     
         10 . A golf ball according to  claim 9 , wherein the specific gravity of the core layer is at least about 0.1 g/cm 3  greater than the specific gravity of the core center. 
     
     
         11 . A golf ball according to  claim 9 , wherein the specific gravity of the core center is at least about 0.1 g/cm 3  greater than the specific gravity of the core layer. 
     
     
         12 . A golf ball according to  claim 9 , any one of  claim 9 , wherein the third flexural modulus is up to about 2,000 psi. 
     
     
         13 - 15 . (canceled)