| 摘要 |
<p>A golf ball includes four layers. The first, third, and fourth layers are made from thermoplastic materials and the second is made of a thermoset material. The third layer is the hardest and is at least 10 Shore D harder than the fourth layer. The flexural modulus of the third layer is greater than that of the first layer, and the flexural modulus of the first layer is greater than that of the fourth layer.</p> |
