| abstract |
(A) A polybutadiene having not less than 60% of cis 1,4 bonds and not more than 2% of 1,2 vinyl bonds, and having a mass of 5% at 25 ° C. % Toluene solution has a viscosity η (mPa · s) of 600 or less, its Mooney viscosity (ML 1 + 4 (100 ° C.)) as A, and its weight average molecular weight (Mw) and number average molecular weight (Mn). When the ratio (Mw / Mn) is B, 10 × B + 5 ≦ A Polybutadiene 20 that satisfies the relationship of ≦ 10 × B + 60 To 100% by mass of a base rubber containing 0 to 80% by mass of (b) a diene rubber other than the component (a), and a predetermined amount of (c) an unsaturated carboxylic acid and / or Alternatively, there is provided a golf ball which is a heat molded product formed of a rubber composition containing a metal salt thereof, (d) an organic sulfur compound, (e) an inorganic filler, and (f) an organic peroxide. [Effect] The golf ball has a firm and comfortable hit feeling and has extremely excellent resilience. |