| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a tubular molding which is excellent in various kinds of strength, is light in weight and is applied to shafts for club clubs made of FRP, rods for fishing rods, etc. by providing the molding with a layer consisting of a fiber reinforced composite material comprising a resin material of a specific value or above in frame toughness value when formed as cured matter as a matrix resin. SOLUTION: The fiber reinforced composite material layer used for the tubular molding is formed of reinforcing fibers, such as carbon fibers, and the matrix resin, such as epoxy resin, which exhibits the required fracture toughness value. The matrix resin is set at >=400 J/m2 in the mode I fracture toughness value GIC in the initial period of crack progression when the resin is formed as the cured matter. The measurement of the fracture toughness value GIC is executed by first subjecting the resin to be measured to a heat treatment, etc. to form the planar cured matter, then working a notch 12 pin mounting holes 14 in the cured matter to form a sample 10, fixing these pin mounting holes 14 by means of pins, tearing the cured matter at the notch 12, measuring the fracture load and calculating the fracture toughness value in accordance with the prescribed equation.</p> |
