Golf ball of unitary molded construction

Abstract

The invention herein disclosed is, in one embodiment, directed to a golf ball of unitary molded construction, wherein the golf ball is foamed from a composition that comprises an ethylene-vinyl acetate copolymer, a thermoplastic elastomer, and a blowing agent, and wherein the golf ball has (i) a diameter that ranges from about 1.6 to about 2.4 inches, (ii) a weight that ranges from about 10 to about 28 grams, and (iii) a coefficient of restitution value that ranges from about 0.30 to about 0.45. In another embodiment, the present invention is directed to a golf ball of unitary molded construction, wherein the golf ball is foamed from a composition comprising: a major amount by weight of an ethylene-vinyl acetate copolymer; a minor amount by weight of a thermoplastic elastomer material, wherein the thermoplastic elastomer material is one or more of (i) a thermoplastic elastomer based on a dynamically vulcanized elastomer-thermoplastic blend, (ii) a styrene tri-block copolymer thermoplastic elastomer, and (iii) an ethylene-α-olefin copolymer thermoplastic elastomer; and a blowing agent.

What is claimed is:  
     
         1 . A golf ball of unitary molded construction, wherein the entire golf ball is foamed from a composition that comprises an ethylene-vinyl acetate copolymer, a thermoplastic elastomer, and a blowing agent.  
     
     
         2 . The golf ball of  claim 1  wherein the golf ball has (i) a diameter that ranges from about 1.6 to about 2.4 inches, (ii) a weight that ranges from about 10 to about 28 grams, and (iii) a coefficient of restitution value that ranges from about 0.30 to about 0.45.  
     
     
         3 . The golf ball of  claim 1  wherein the ethylene-vinyl acetate copolymer ranges from about 0 to about 99 weight percent of the composition.  
     
     
         4 . The golf ball of  claim 1  wherein the thermoplastic elastomer ranges from about 0 to about 99 weight percent of the composition.  
     
     
         5 . The golf ball of  claim 1  wherein the blowing agent ranges from about 1 to about 10 weight percent of the composition.  
     
     
         6 . The golf ball of  claim 1  wherein the ethylene-vinyl acetate copolymer has vinyl acetate content that by weight ranges from about 15% to about 18%.  
     
     
         7 . The golf ball of  claim 1  wherein the thermoplastic elastomer has a Shore Hardness ranging from about 40 to about 90.  
     
     
         8 . The golf ball of  claim 1  wherein the thermoplastic elastomer is one or more of (i) a thermoplastic elastomer based on a dynamically vulcanized elastomer-thermoplastic blend, (ii) a styrene tri-block copolymer thermoplastic elastomer, and (iii) an ethylene-α-olefin copolymer thermoplastic elastomer.  
     
     
         9 . The golf ball of  claim 1  wherein the thermoplastic elastomer is a styrene tri-block copolymer thermoplastic elastomer.  
     
     
         10 . The golf ball of  claim 9  wherein the styrene tri-block copolymer thermoplastic elastomer is a styrene-butadiene-styrene block copolymer, a styrene-ethylene/butylene-styrene block copolymer, or a combination thereof.  
     
     
         11 . The golf ball of  claim 9  wherein the styrene tri-block copolymer thermoplastic elastomer is a styrene-ethylene/butylene-styrene block copolymer.  
     
     
         12 . The golf ball of  claim 1 , further comprising polypropylene.  
     
     
         13 . The golf ball of  claim 12  wherein the polypropylene ranges from about 1.5 to about 10 weight percent of the composition.  
     
     
         14 . The golf ball of  claim 1 , further comprising polyethylene.  
     
     
         15 . The golf ball of  claim 14  wherein the polyethylene ranges from about 1.5 to about 10 weight percent of the composition.  
     
     
         16 . A method of making a golf ball of unitary molded construction comprising at least the following steps: 
 compounding a polymeric composition from the ingredients comprising an ethylene-vinyl acetate copolymer and a thermoplastic elastomer;    combining the polymeric composition with a blowing agent to yield a feedstock;    injecting the feedstock into a mold having a substantially spherical shape; and    cooling the mold to form the golf ball.    
     
     
         17 . The method of making a golf ball in accordance with  claim 16  further comprising the step of quenching the golf ball in an agitated water bath.  
     
     
         18 . The method of making a golf ball in accordance with  claim 16  wherein the ethylene-vinyl acetate copolymer ranges from about 0 to about 99 weight percent of the composition.  
     
     
         19 . The method of making a golf ball in accordance with  claim 16  wherein the thermoplastic elastomer ranges from about 0 to about 99 weight percent of the composition.  
     
     
         20 . A golf ball of unitary molded construction made in accordance with the method of  claim 16.