| abstract |
A golf ball includes a hot-molded product of a rubber composition comprising a base rubber composed of (a) 20-100 wt % of a polybutadiene having a high cis-1,4 content, a minimal 1,2 vinyl content, and a viscosity η of up to 600 mPa·s at 25° C. as a 5 wt % toluene solution, and satisfying a certain relationship between Mooney viscosity and polydispersity index Mw/Mn, in combination with (b) 0-80 wt % of another diene rubber, (c) an unsaturated carboxylic acid, (d) an organosulfur compound, (e) an inorganic filler, (f) an organic peroxide, and optionally, (g) an antioxidant. The hot-molded product has a difference in JIS-C hardness between the center and surface thereof of up to 15 units. The composition and hardness characteristics of the hot-molded product provide the golf ball with a solid comfortable feel upon impact and an excellent rebound. |