| 摘要 |
<p>PURPOSE: To obtain a golf ball covered with baryta rubber having a brittleness proof and desired hitting characteristics by mixing a (hard) ionomer having a high flexibility coefficient and a (soft) ionomer having a low flexibility coefficient. CONSTITUTION: An ionomer having a high flexibility coefficient has such a flexibility coefficient as about 30000-55000 p.s.i. and it is an ionic copolymer of a sodium salt or a zinc salt of a reaction product between an olefin with 2-8 carbon atoms and an unsaturated monocarboxylic acid with 3-8 carbon atoms. An ionomer having a low flexibility coefficient has such a flexibility coefficient as about 3000-7000 p.s.i. and it is a sodium salt or a zinc salt of a terpolymer of an olefin with 2-8 carbon atoms, an unsaturated monocarboxylic acid with 3-8 carbon atoms and an unsaturated monomer of acrylic esters having 2-22 carbons. The basic ionomer mixture is used for making an excellent golf ball cover and thus an excellent golf ball made of about 25-75 parts of an ionomer with a lower flexibility coefficient and about 75-25 parts of an ionomer with a high flexibility coefficient.</p> |
