| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a golf ball having a polyurethane cover and being satisfactory in repellency and controllability. SOLUTION: The polyurethane cover is constituted of a cured material made by curing an isocyanate-terminated urethane-prepolymer composed mainly of a reaction product of 4,4'-diphenylmethane-diisocyanete and polyoxy- tetramethylene-glycol with an amine type hardener represented by the following general formula. The stoichiometric ratio (NH2 /NCO) of the amino group in the amine type hardener to the isocyanate group in the urethane prepolymer is 1.05 to 1.35, the polyurethane cover is 0.5 to 1.5 mm in thickness and the surface of the golf ball has the Shore D Hardness of 35 to 55. [Chemical Formula 2] ('n' is an integer of 2 to 6, and 'N' is an integer of 1 to 4).</p> |
