| 摘要 |
<p>A practice golf ball has a core and a cover. The core is made of a rubber composition which includes a base rubber, a co-crosslinking agent, a crosslinking initiator and a metal oxide. The base rubber is a mixture of polybutadiene with styrene-butadiene rubber and/or isoprene rubber, and the co-crosslinking agent is methacrylic acid. The core has a specific deflection under a specific load, and the ball has a specific initial velocity. The dimples on the surface of the ball have a volume ratio VR of from 0.95 to 1.7.</p> |
