PURPOSE: The title intermediate having improved adhesivity and interlaminar shear strength, comprising a thermosetting resin as a matrix consisting of an unsaturated alkyd resin, a specific allyl ester prepolymer and monomer as main components and a catalyst.
CONSTITUTION: 1W10pts.wt. of a polymerization catalyst (e.g., t-butyl perbenzoate) is added to a resin consisting of 100pts.wt. of an unsaturated alkyd resin (e.g., unsaturated polyester resin) and/or an aryl ester prepolymer (e.g., diarylphthalate) having two or more allyloxycarbonyl group and not more than 50wt. part of the above-mentioned allylester monomer. The resulting resin composition is impregnated into carbon fibers to give the desired intermediate. The use of carbon fibers sized with 0.3W6wt% of an epoxy resin gives preferably an interlaminar shear strength of not less than 8kg/mm 2 .