Golf ball

Abstract

The invention provides a golf ball having a core and a cover of at least one layer. The core has a cross-sectional hardness which, letting D (mm) be the radius of the core, O be the JIS-C hardness at a center of the core, P be the JIS-C hardness at a position 25% of D from the core center, Q be the JIS-C hardness at a position 55% of D mm from the core center, and T be the JIS-C hardness at a position 85% of D from the core center, satisfies the formulas (1) P−O≦4, (2) Q−O≦5, and (3) T−Q≧10.

1 . A golf ball comprising a core and a cover of at least one layer, wherein the core has a cross-sectional hardness which, letting D (mm) be a radius of the core, O be a JIS-C hardness at a center of the core, P be a JIS-C hardness at a position 25% of D from the core center, Q be a JIS-C hardness at a position 55% of D mm from the core center, and T be a JIS-C hardness at a position 85% of D from the core center, satisfies the formulas (1), (2) and (3) below:
     P−O≦ 4  (1)
       Q−O≦ 5  (2)
       T−Q≧ 10.  (3)
   
     
     
         2 . The golf ball of  claim 1 , wherein the ball has a deflection, when compressed under a final load of 5,880 N (600 kgf) from an initial load state of 98 N (10 kgf), of from 7 to 10 mm. 
     
     
         3 . The golf ball of  claim 1 , wherein the core is formed of a rubber composition which includes an organic peroxide having a one-minute half-life temperature of from about 165° C. to about 185° C. and sulfur. 
     
     
         4 . The golf ball of  claim 1 , wherein the core has a diameter of from 32 to 41 mm. 
     
     
         5 . The golf ball of  claim 1 , wherein the core is composed of a single layer. 
     
     
         6 . The golf ball of  claim 1 , wherein (T−Q)÷(Q−O)≧1.