Rubber Composition for golf ball

Abstract

The present invention provides a rubber composition for obtaining golf ball having excellent rebound characteristics and excellent durability, and showing good workability when producing. The present invention relates to a rubber composition for golf ball comprising a base rubber, a co-crosslinking agent, an organic peroxide and an inorganic filler, wherein the base rubber comprises a polybutadiene (a) containing a cis-1,4 bond of not less than 80%, having a Mooney viscosity of not less than 30 to less than 50 ML 1+4 (100° C.) and a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 3.0 to 6.0, synthesized using lanthanide-containing catalyst.

What is claimed is:  
     
         1 . A rubber composition for golf ball comprising a base rubber, a co-crosslinking agent, an organic peroxide and an inorganic filler, wherein the base rubber comprises a polybutadiene (a) containing a cis-1,4 bond of not less than 80%, having a Mooney viscosity of not less than 30 to less than 50 ML 1+4 (100° C.) and a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 3.0 to 6.0, synthesized using lanthanide-containing catalyst.  
     
     
         2 . The rubber composition for golf ball according to  claim 1 , wherein the base rubber is a polybutadiene mixture consisting of the polybutadiene (a) and a polybutadiene (b) containing a cis-1,4 bond of not less than 40%, having a Mooney viscosity of not less than 55 to less than 70 ML 1+4 (100° C.), synthesized using lanthanide-containing catalyst, 
 a weight ratio (a)/(b) being 30/70 to 90/10.  
 
     
     
         3 . The rubber composition for golf ball according to  claim 1 , wherein the base rubber is a polybutadiene mixture consisting of the polybutadiene (a) and 
 a polybutadiene (c) containing a cis-1,4 bond of not less than 40%, having a Mooney viscosity of not less than 30 to less than 50 ML 1+4 (100° C.) and a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 3.6 to 8.0, synthesized using cobalt-containing catalyst and/or nickel-containing catalyst,    a weight ratio (a)/(c) being 86/14 to 90/10.    
     
     
         4 . The rubber composition for golf ball according to  claim 1 , wherein the base rubber is a polybutadiene mixture consisting of the polybutadiene (a) and 
 a polybutadiene (d) containing a cis-1,4 bond of not less than 40%, having a Mooney viscosity of not less than 50 ML 1+4 (100° C.) and a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of not less than 2.0 to less than 4.0, synthesized using cobalt-containing catalyst,    a weight ratio (a)/(d) being 30/70 to 90/10.    
     
     
         5 . The rubber composition for golf ball according to  claim 2 , wherein the polybutadiene (b) has a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 1.0 to 3.0.  
     
     
         6 . A one-piece solid golf ball formed from the rubber composition according to anyone of  claims 1  to  4 .  
     
     
         7 . A solid golf ball composed of at least one layer of a rubber material, wherein the rubber material is formed from the rubber composition according to anyone of  claims 1  to  4 .