PURPOSE: To improve the impact resistance of the shaft of a golf club without lowering the flying distance of a ball when prepreg is used as said shaft, while the mechanical strength of the shaft is heightened by a method in which in the carbon fiber arranged in one direction, organic fiber and the fiber of of different kinds are arranged in the same direction as that of the carbon fiber, thereby producing a hybrid prepreg.
CONSTITUTION: As the fiber 8 of different kinds, glass fiber or e.g. the inorganic fiber such as boron fiber is used, and a plurality of kinds may be also used. As organic fiber 6, polyacrylate fiber, aramid fiber or polyethylene fiber, etc., is used. Since the diameters of the organic fiber and the glass fiber are small, the fiber is used as the fiber bundle in which n pieces of monofilaments are bundled. The converted diameter D0 obtained from the formula of D0=n.d is set at 30-500μm. The organic fiber 6 and the fiber 8 of different kinds are arranged at prescribed distance in the same direction as that of the carbon fiber between two prepregs reinforced with the carbon fiber in one direction and are integrally formed by pressing and/or heating, thereby producing the highly bred prepreg 1 remarkably preferably. As a matrix resin, thermosetting resin such as epoxy resin may be used, and curing agent and other addition agent are suitably added thereto.
MIYAO KANJI
INOUE HIROSHI
