Multi-piece solid golf ball

Abstract

A multi-piece solid golf ball includes a solid core, at least one intermediate layer, and a cover having at least one cover layer. The solid core has a compression deflection of 3.0 mm or more, the intermediate layer is mainly made from a thermoplastic resin and has a Shore D hardness of 45 to 55 and a specific gravity of 1.2 or less, and the cover has a Shore D hardness of 60 or more and a thickness of 1.6 to 2.3 mm. The golf ball further comprises a ratio of the compression deflection of a sphere composed of the solid core covered with the intermediate layer to the compression deflection of the solid core is more than 0.900 and less than 0.970; and a difference in JIS-C hardness between the surface and the center of the solid core is equal to or less than 5.

1. A multi-piece solid golf ball comprising: a solid core; at least one intermediate layer for covering said solid core; and a cover having at least one cover layer for covering said intermediate layer;
 wherein said solid core has a comparison deflection of 3.0 mm or more when a load range of initial 10 kgf to final 130 kgf is applied, said intermediate layer is mainly made from a thermoplastic resin and has a Shore D hardness of 45 to 55 and a specific gravity of 1.2 or less and less than a specific gravity of said solid core, and said cover has a Shore D hardness of 60 or more and a thickness of 1.6 to 2.3 mm;  
 a ratio of the compression deflection of a sphere composed of said intermediate layer and said solid core covered therewith to the compression deflection of said solid core is more than 0.900 and less than 0.970 [0.900<( compression deflection of sphere/compression deflection of solid core ) < 0 . 970 ] ; and  
 a difference in JIS-C hardness (specified under JIS K6301-1996) between the surface and the center of said solid core is equal to or less  greater than 5 [5≦( surface hardness - center hardness )].  
 
     
     
       2. A multi-piece solid golf ball according to  claim 1 , wherein the gage of said intermediate layer is equal to or less than 2.0 mm. 
     
     
       3. A multi- piece solid golf ball according to    claim 1   , wherein said difference in JIS - C hardness between the surface and the center of said solid core is equal to or less than  22 .   
     
     
       4. A multi- piece solid golf ball according to    claim 1   , wherein said ratio of the compression deflection of said sphere composed of said intermediate layer and said solid core covered therewith to the compression deflection of the solid core is more than  0 . 910  and less than  0 . 960 .   
     
     
       5. A multi- piece solid golf ball comprising: a solid core; at least one intermediate layer for covering said solid core; and a cover having at least one cover layer for covering said intermediate layer;      wherein said solid core has a compression deflection of  3 . 0  mm or more when a load range of initial  10  kgf to final  130  kgf is applied, said intermediate layer is mainly made from a thermoplastic resin and has a Shore D hardness of  45  to  55  and a specific gravity of  1 . 2  or less and less than a specific gravity of said solid core, and said cover has a Shore D hardness of  60  or more;        a ratio of the compression deflection of a sphere composed of said intermediate layer and said solid core covered therewith to the compression deflection of said solid core is more than  0 . 900  and less than  0 . 970 ; and        a difference in JIS - C hardness  ( specified under JIS K 6301   -   1996   )  between the surface and the center of said solid core is equal to or greater than  5  [ 5 ≦ ( surface hardness - center hardness )].