| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a golf ball which enables us to judge easily how much heat record a stored golf ball has received. SOLUTION: A temperature record mark by a temperature-indicating paint of irreversibility or semi-irreversibility is painted on the surface of the ball. And a paint film of a clear paint is applied on top of it in order to protect the temperature record mark.</p> |
