| 摘要 |
PROBLEM TO BE SOLVED: To obtain a prepreg which is sufficiently curable by heating even at low temperature and free form problem as to life, tack and draping properties, by using as the constituents an epoxy resin containing a tetraglycidylamine- type epoxy resin, a dicyandiamide curing agent, a cure accelerator and carbon fibers having a specified tensile strength. SOLUTION: The low-temperature heating conditions necessary for curing comprise at 130 deg.C for about 2 hr. The tetraglycidylamine-type epoxy resin (having an epoxy equivalent of 90 to 180) used preferably comprises tetraglycidylaminediphenylmethane. Other than this compound, cresol novolak, phenolic novolak, and dicyclopentadiene type epoxy resins are also suitably used. The epoxy resin is used in an amount of at least 50 pts.wt. based on 100 pts.wt. total of epoxy resins. The dicyandiamide curing agent preferably has a mean particle diameter of at most 10μm. The cure accelerator used preferably comprises a urea compound, although imidazole compounds, etc., can also be used. The carbon fibers used comprise those having a tensile strength of at least 4,000 MPa and preferably having a degree of sectional deformation of at most 1.1 and a hook drop value of at most 10 cm.
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