NYLON COPOLYMER/IONOMER TERPOLYMER BLEND FOR GOLF BALL COVER COMPOUND

摘要

PROBLEM TO BE SOLVED: To provide a high durability golf ball by making the content of plyamide component not less than a specified amount of resin compound, and making a resuming coefficient of a golf ball not less than a specified value. SOLUTION: The component of polyamide in a golf ball is made not less than 23wt.% so that it has a resuming coefficient being not less than 0.750. The durability thereof is measured by shooting it in a pentagonal container whose wall surfaces are made of steel plate. The container has therein an insertion plate and at its central part quadilateral grooves extending in a horizontal plane for the aim to simulate a face of a golf club with quadilateral grooves formed thereon. The groove has a width of 0.033 inch and a depth of 0.100 inch, and each width is separated by a planar part 34 with a width of 0.130 inch. The ball is shot 70 times or more so that the destruction is inspected. When minute cracks are generated in the ball, the shooting speed is changed and it is alarmed to an operator. The operator, then, inspects the ball by eyes.