| 摘要 |
Golf ball 2 has a core 4 , a mid layer 6 , a reinforcing layer 8 and a cover 10 . Base polymer of the mid layer 6 includes an ionomer resin as a principal component. The mid layer 6 has a hardness Hm as measured with a Shore D type hardness scale of equal to or greater than 55. Base polymer of the reinforcing layer 8 is a thermosetting resin. Base polymer of the cover 10 includes a thermoplastic polyurethane elastomer as a principal component. The cover 10 has a nominal thickness Tc of equal to or less than 0.6 mm. The cover 10 has a hardness Hc as measured with a Shore D type hardness scale of equal to or less than 54. Ratio (Tr/Tc) of the thickness Tr of the reinforcing layer to the nominal thickness Tc of the cover is 0.005 or greater and 3.0 or less. This golf ball 2 includes dimples 12 having a depth Dp. Thickness Td of the cover 10 immediately below the deepest site of one or more of the dimples 12 is greater than (Tc-Dp). |
