| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal racket frame in which vibration damping characteristics are largely improved by providing a rubber layer around the outer periphery and/or the inner periphery of a metal core material. SOLUTION: This racket frame 10 comprises a frame 10a, a shaft 10b, and a york 10c which are made of a hollow metal core material 11 and a rubber layer 12 covering the outer periphery of the metal core material 11. The metal core material 11 is made of, for example, aluminum and is a hollow pipe having the diameter smaller than that of the racket frame 10 by, for example, 0.3mm. The outer surface of the metal core material 11 is formed as a satin finished surface by glass particle shot blasting. After degreasing by toluene, the surface is processed with a silane coupling agent. Subsequently, the metal core material 11 is dipped in a coagulating agent of calcium nitrate liquid of, for example, density of 20% and is dried, for instance, at 50 deg.C. After that, the metal core material 11 is dipped in a pre-cured natural rubber latex and is heated and cured. The metal core material 11 is leached in water at an ordinary temperature and is dried. |
