| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve restoring coefficient without bothering easier play by applying a mixture of a hard ionomer resin and a ionomer resin having very low elasticity. SOLUTION: A mixture of the hard ionomer resin and the ionomer resin having very low elasticity neutralized by magnesium ion is applied to form a cover 12 of a golf ball composed of a core 11 and the cover 12. The hard ionomer resin made from a copolymer of olefin and an alpha, beta-ethylenic unsaturated carboxylic acid is prepared to keep a bending elasticity 40,000-100,000psi and Shore D hardness higher than 65. While, the ionomer resin having very low elasticity should be a terpolymer of olefin, an alpha, beta- ethylenic unsaturated carboxylic acid and an acrylate ester, of which 10-90% of carboxyl groups are neutralized by magnesium ion to keep a bending elasticity of 3,000-10,000psi and Shore D hardness of 30-55.</p> |
