Golf ball

Abstract

The invention provides a golf ball which includes a core and a cover encasing the core, wherein the cover has a thickness of at least 1.3 mm but not more than 1.8 mm and a material hardness, expressed as the Shore D hardness, of not more than 58, the core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load state of 98 N (10 kgf) of at least 4.1 mm, the ball has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load state of 98 N (10 kgf) of at least 3.8 mm, and the ratio of the core deflection to the ball deflection (core/ball) is at least 0.8 but not more than 1.2. The ball of the invention can be sufficiently deformed on shots with a driver, even when played by a low head speed golfer, allowing a good ball rebound to be obtained and thus resulting in an increased distance. The ball also has a good feel when played and a satisfactory durability.

1 . A golf ball comprising a core and a cover encasing the core, wherein the cover has a thickness of at least 1.3 mm but not more than 1.8 mm and a material hardness, expressed as the Shore D hardness, of not more than 58, the core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load state of 98 N (10 kgf) of at least 4.1 mm, the ball has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load state of 98 N (10 kgf) of at least 3.8 mm, and the ratio of the core deflection to the ball deflection (core/ball) is at least 0.8 but not more than 1.2. 
     
     
         2 . The golf ball of  claim 1 , wherein the cover is formed of a resin composition which is composed primarily of an ionomer and which has a melt flow rate of at least 4. 
     
     
         3 . The golf ball of  claim 2 , wherein an ethylene-methacrylic acid-methacrylic acid ester copolymer resin accounts for between 10 and 80 wt % of the polymer components included in the ionomer composition. 
     
     
         4 . The golf ball of  claim 1 , wherein the cover is formed of a resin composition which is composed primarily of polyurethane and which has a melt flow rate of at least 16.