GOLF BALL

文件类型：PDF文档
文件大小：76K
PROBLEM TO BE SOLVED : To provide a goof ball with soft feeling of hitting and extremely excellent resilience. SOLUTION : The golf ball includes a core formed of a hot molded product of a rubber composition, wherein the difference between the central hardness and the surface hardness is >15 to ≤18, and an extent of flexibility is 2.0-6.0 mm. The rubber composition is obtained by blending (c) unsaturated carboxylic acid and/or its metallic salt, (d) organic sulfur compound, (e) inorganic filler, (f) organic peroxide, and (g) antioxidant, into the base rubber comprising the followings : (a) polybutadiene synthesized using a rare earth element-based catalyst having ≥60% of cis-1, 4 bond, and ≤2% of 1, 2 vinyl bond, wherein viscosity of 5 mass% toluene solution is ≤600 at 25°C, and an equation 10×B+5≤A≤10×B+60 is satisfied when Mooney viscosity is represented by A and a ratio of weight-average molecular weight against number-average molecular weight is satisfied by B; and (b) diene based rubber other than the (a) component. COPYRIGHT : (C)2009, JPO&INPIT