Golf ball

Abstract

The invention provides a golf ball endowed with an improved distance and durability. The ball has a core and a cover, the core being formed of a rubber composition containing a base rubber, a co-crosslinking agent, a crosslinking initiator, a metal oxide and an organosulfur compound. The co-crosslinking agent is methacrylic acid, the metal oxide is zinc oxide, and the rubber composition contains the crosslinking initiator in an amount of from 1.2 to 5 parts by weight per 100 parts by weight of the base rubber. The finished ball has an initial velocity of at least 74.3 m/s.

1 . A golf ball comprising a core and a cover, wherein the core is formed of a rubber composition comprising a base rubber, a co-crosslinking agent, a crosslinking initiator, a metal oxide and an organosulfur compound, the co-crosslinking agent being methacrylic acid, the metal oxide being zinc oxide, and the rubber composition containing the crosslinking initiator in an amount of from 1.2 to 5 parts by weight per 100 parts by weight of the base rubber, and wherein the ball as a finished product has an initial velocity of at least 74.3 m/s. 
     
     
         2 . The golf ball of  claim 1 , wherein the organosulfur compound is included in an amount of from 0.01 to 3 parts by weight per 100 parts by weight of the base rubber. 
     
     
         3 . The golf ball of  claim 1 , wherein the rubber composition further includes a fatty acid metal salt. 
     
     
         4 . The golf ball of  claim 3 , wherein the fatty acid metal salt is zinc stearate. 
     
     
         5 . The golf ball of  claim 3 , wherein the fatty acid metal salt is included in an amount of from 0.1 to 5 parts by weight per 100 parts by weight of the base rubber. 
     
     
         6 . The golf ball of  claim 1 , wherein the cover is formed of a resin material which has a breaking strength of from 20 to 80 MPa and an elongation of from 150 to 6000. 
     
     
         7 . The golf ball of  claim 1 , wherein the core has a deflection (CH), when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf), of from 2.0 to 7.0 mm.