Three-piece solid golf ball

Abstract

The present invention provides a three-piece solid golf ball having both excellent hit feeling and large flying distance. The three-piece solid golf ball comprises a core 1 and a cover 2 covering the core 1, and the core 1 has a two-layer structure comprising a center 1 a and an outer shell 1 b. The center 1 a contains an α,β-unsaturated carboxylic acid metallic salt in an amount of 13 to 28 parts by weight based on 100 parts by weight of a base rubber and the outer shell 1 b contains an α,β-unsaturated carboxylic acid metallic salt in an amount of 28 to 35 parts by weight based on 100 parts by weight of an base rubber. A surface hardness (measured by JIS-C type hardness tester) of the core 1 is 75 to 88 and a compression deformation amount of the core 1 is 2.7 to 5.0 mm.

What is claimed is:  
     
       1. A three-piece solid golf ball comprising a core  1  and a cover covering said core  1 , said core  1  having a two-layer structure composed of a center  1 a and an outer shell  1 b, wherein the center  1 a is prepared from an α,β-unsaturated carboxylic acid metallic salt in an amount of 13  20 to 28 parts by weight based on 100 parts by weight of a base rubber and the outer shell  1 b is prepared from an α,β-unsaturated carboxylic acid metallic salt in an amount of 28 to 35  33 parts by weight based on 100 parts by weight of a base rubber and wherein a surface hardness (measured by JIS-C type hardness tester) of the core  1  is 75 to 88 and a compression deformation amount of the core  1  is 2.7 to 5.0 mm . 
     
     
       2. The three-piece solid golf ball according to  claim 1 , wherein a diameter of the center  1 a is 22 to 32 mm. 
     
     
       3. The three-piece solid golf ball according to  claim 1  wherein said center  1 a is formed by molding a rubber composition which comprises 100 parts by weight of a base rubber, 13 to 28 parts by weight of an α,β-unsaturated carboxylic acid metallic salt, 0.5 to 3 parts by weight of a crosslinking initiator and 4 to 136 parts by weight of a filler. 
     
     
       4. The three-piece solid golf ball according to  claim 3  wherein said base rubber is a butadiene rubber having not less than 85% of 1,4-structure. 
     
     
       5. The three-piece solid golf ball according to  claim 3  wherein said α,β-unsaturated carboxylic acid metallic salt is zinc acrylate or zinc methacrylate. 
     
     
       6. The three-piece solid golf ball according to  claim 3  wherein said crosslinking initiator is an organic peroxide. 
     
     
       7. The three-piece solid golf ball according to  claim 6  wherein said organic peroxide is dicumyl peroxide. 
     
     
       8. The three-piece solid golf ball according to  claim 1  wherein said outer shell  1 b is formed by molding a rubber composition which comprises 100 parts by weight of a base rubber, 28 to 35 parts by weight of an α,β-unsaturated carboxylic acid metallic salt, 0.5 to 3 parts by weight of a crosslinking initiator and 1 to 106 parts by weight of a filler. 
     
     
       9. The three-piece solid golf ball according to  claim 8  wherein said base rubber is a butadiene rubber having not less than 85% of 1,4-structure. 
     
     
       10. The three-piece solid golf ball according to  claim 8  wherein said α,β-unsaturated carboxylic acid metallic salt is zinc acrylate or zinc methacrylate. 
     
     
       11. The three-piece solid golf ball according to  claim 8  wherein said crosslinking initiator is an organic peroxide. 
     
     
       12. The three-piece solid golf ball according to  claim 11  wherein said organic peroxide is dicumyl peroxide. 
     
     
       13. The three- piece solid golf ball according to    claim 1   , wherein the content of α, β - unsaturated carboxylic acid metallic salt in the center  1 a is smaller than the content of α, β - unsaturated carboxylic acid metallic salt in the outer shell  1 b and the center  1 a is softer than the outer shell  1 b.   
     
     
       14. The three- piece solid golf ball according to    claim 1   , wherein a compression deformation amount of the core  1  is  2 . 7  to  5 . 0  mm.