Thin-layer-covered multilayer golf ball

Abstract

A golf ball comprising a core and a cover disposed about the core, wherein the core comprises a center and at least one outer core layer adjacent the center, and the cover comprises at least one inner cover layer and an outer cover layer; wherein the center has an outer diameter of 0.375 inches to 1.4 inches; the outer core layer has an outer diameter of 1.4 inches to 1.62 inches; the inner cover layer has an outer diameter of 1.58 inches or greater and a material hardness of 72 Shore D or less; and the outer cover layer has a material hardness of 55 Shore D or less; and wherein the center has a first hardness, the outer core layer has a second hardness greater than the first, and the inner cover layer has a third hardness greater than the second.

1 . A golf ball comprising a core and a cover disposed about the core, wherein the core comprises a center and at least one outer core layer adjacent the center, and the cover comprises at least one inner cover layer and an outer cover layer; 
 wherein the center has an outer diameter of 0.375 inches to 1.4 inches;    the outer core layer has an outer diameter of 1.4 inches to 1.62 inches;    the inner cover layer has an outer diameter of 1.58 inches or greater and a material hardness of 72 Shore D or less; and    the outer cover layer has a material hardness of 55 Shore D or less;    and wherein the center has a first hardness, the outer core layer has a second hardness greater than the first, and the inner cover layer has a third hardness greater than the second.    
     
     
         2 . The golf ball of  claim 1 , wherein the center is formed from a composition comprising at least one base rubber having a first loss tangent measured at 10 cpm and a second loss tangent measured at 1000 cpm, the difference between the first and second loss tangents, divided by a frequency span of 990 cpm, and normalized by 100,000, being 40 or greater.  
     
     
         3 . The golf ball of  claim 1 , wherein the outer cover material hardness is 50 Shore D or less.  
     
     
         4 . The golf ball of  claim 1 , wherein the inner cover layer material hardness is from 60 to 70 Shore D.  
     
     
         5 . The golf ball of  claim 4 , wherein the inner cover layer material hardness is from 60 to 65 Shore D.  
     
     
         6 . The golf ball of  claim 1 , wherein the inner cover layer outer diameter is from 1.59 inches to 1.66 inches.  
     
     
         7 . The golf ball of  claim 6 , wherein the inner cover layer outer diameter is from 1.6 inches to 1.64 inches.  
     
     
         8 . The golf ball of  claim 1 , wherein the center outer diameter is from 0.5 inches to 1.25 inches.  
     
     
         9 . The golf ball of  claim 8 , wherein the center outer diameter from 0.9 inches to 1.2 inches.  
     
     
         10 . The golf ball of  claim 1 , wherein the outer core layer outer diameter is from 1.52 inches to 1.59 inches.  
     
     
         11 . The golf ball of  claim 10 , wherein the outer core layer outer diameter is from 1.535 inches to 1.58 inches.  
     
     
         12 . The golf ball of  claim 1 , wherein the ball has a moment of inertia of 83 g·cm 2  or less.  
     
     
         13 . The golf ball of  claim 1 , wherein the outer cover layer has a fourth hardness less than the third hardness.  
     
     
         14 . The golf ball of  claim 1 , wherein the center has a first specific gravity and the outer core layer has a second specific gravity that differ by 0.1 or less.  
     
     
         15 . The golf ball of  claim 1 , wherein the center is solid.  
     
     
         16 . The golf ball of  claim 1 , wherein the outer cover comprises a polyurethane material resulting from the reaction product of an isocyanate and a polyol or polyamine compound.  
     
     
         17 . The golf ball of  claim 16 , wherein the polyurethane material further comprises a second isocyanate present in an amount sufficient to form a thermoset polyurethane.  
     
     
         18 . The golf ball of  claim 16 , wherein the isocyanate is 4,4′-dicyclohexylmethane diisocyanate.  
     
     
         19 . The golf ball of  claim 16 , wherein the polyurethane material is thermoset or castable thermoplastic.  
     
     
         20 . The golf ball of  claim 16 , wherein the polyurethane material is castable or a reactive liquid.