Castable liquid rubber compositions for golf balls

Abstract

A golf ball comprising a layer made from a liquid rubber composition is disclosed. A castable liquid polybutadiene is the preferred principal rubber component. The molecular weight of the castable liquid polybutadiene is at least about 1,000 and the castable liquid polybutadiene is in a liquid state at room temperature. The castable liquid rubber layer can be a cover layer, a casing layer, an intermediate layer or a core layer.

1 . A golf ball comprising:
 a solid golf ball core having a diameter of 1.55 inches to 1.60 inches;   a cast layer having a thickness of 0.010 inch to 0.050 inch cast over said golf ball core, said cast layer comprises a rubber composition, wherein said rubber composition comprises a functionalized castable liquid polybutadiene as the principal rubber component and wherein the molecular weight of the castable liquid polybutadiene is at least 1,000 and wherein the castable liquid polybutadiene is in a liquid state at room temperature.   
   
   
       2 . The golf ball of  claim 1 , wherein the castable liquid polybutadiene comprises less than 30% by weight of vinyl-1,2 isomer. 
   
   
       3 . The golf ball of  claim 1 , wherein the molecular weight of castable liquid polybutadiene is at least 2,000. 
   
   
       4 . The golf ball of  claim 3 , wherein the molecular weight of castable liquid polybutadiene is at least 5,000. 
   
   
       5 . The golf ball of  claim 1 , wherein the castable liquid polybutadiene is functionalized with a group consisting of epoxy, (meth)acrylate, hydroxyl, vinyl, isocyanate, ester, carboxyl and carbonyl groups. 
   
   
       6 . The golf ball of  claim 1 , wherein the rubber composition further comprises a reactive co-agent. 
   
   
       7 . The golf ball of  claim 6 , wherein the reactive co-agent comprises an unsaturated carboxylic acid. 
   
   
       8 . The golf ball of  claim 7 , wherein the reactive co-agent comprises an unsaturated vinyl compound. 
   
   
       9 . The golf ball of  claim 8 , wherein the unsaturated vinyl compound is trimethylolpropane trimethacrylate. 
   
   
       10 . The golf ball of  claim 1 , wherein the rubber compound further comprises a cross-linking agent. 
   
   
       11 . The golf ball of  claim 10 , wherein the crosslinking agent comprises one or more metallic salts of unsaturated fatty acids or monocarboxylic acids. 
   
   
       12 . The golf ball of  claim 10 , wherein the crosslinking agent is selected from a group consisting of zinc, aluminum, sodium, lithium, nickel, calcium, magnesium, acrylate salt and mixtures thereof. 
   
   
       13 . The golf ball of  claim 12 , wherein the acrylate salt is selected from a group consisting of zinc acrylate, zinc diacrylate, zinc methacrylate, zinc dimethacrylate, and mixtures thereof. 
   
   
       14 . The golf ball of  claim 1 , wherein the rubber composition further comprises a molecular weight adjusting compound. 
   
   
       15 . The golf ball of  claim 14 , wherein the molecular weight adjusting compound comprises an organosulfur. 
   
   
       16 . The golf ball of  claim 1 , wherein the cast layer is an intermediate layer and the golf ball further comprises a cover layer cast over said intermediate layer. 
   
   
       17 . The golf ball of  claim 16 , wherein the thickness is in the range of 0.02 inch to 0.04 inch. 
   
   
       18 . The golf ball of  claim 1 , wherein the cast layer is an outer cover. 
   
   
       19 . The golf ball of  claim 18 , wherein the outer cover has a thickness of 0.03 inch to 0.05 inch.