| abstract |
A first golf ball 2 includes a core 4 , a mid-layer 6 , and a cover 8 . The core 4 includes a center 10 and an envelope layer 12 . The mid-layer 6 includes a metal ion source (C) that can neutralize an ionomer resin. The mid-layer 6 has a melt flow rate (at 190° C. and 2.16 kg) of 4 g/10 minute or greater. The difference (H 3 -H 1 ) between the JIS-C hardness H 3 of the cover 8 and the JIS-C central hardness H 1 of the center 10 is equal to or greater than 45. A second golf ball 22 includes a core 24 , a mid-layer 28 , and a cover 30 . The mid-layer 28 has a melt flow rate (at 190° C. and 2.16 kg) of 4 g/10 minute or greater. Preferably, the mid-layer 28 includes a high melt viscosity resin (A), a low melt viscosity ionomer resin (B), and a metal ion source (C 1 ). |