Fiber-base composite material having high tensile strength

A fiber-base composite material having high tensile strength, obtained by impregnating fibers with a composition containing at least one unsaturated epoxy resin having a double bond index within the range of 0.10 to 0.40, obtained by modifying a saturated epoxy resin by acrylic acid or methacrylic acid, at least a first ethylenically unsaturated monomer selected from the group consisting of vinyl-pyrrolidone, 2-vinyl-pyridine, 4-vinyl-pyridine, 2-vinyl-5-methyl-pyridine, methylamino-ethyl methacrylate, methoxy-ethyl acrylate, butoxy-ethyl acrylate, at least a second ethylenically unsaturated monomer selected from the group consisting of butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, at least one ethylenically polyunsaturated monomer selected from the group consisting of hexane-diol diacrylate, diethyleneglycol diacrylate, tetraethyleneglycol, diacrylate, polyethylene-glycol diacrylate, pentaerythritol tetraacrylate, a photoinitiator and an organic peroxide, said composition comprising 30-60% by weight of said unsaturated epoxy resin, 5-30% by weight of said first monomer, 5-40% by weight of said second monomer, 5-25% by weight of said polyunsaturated monomer, 1-5% by weight of said photoinitiator and 1-5% by weight of said organic peroxide, by prepolymerizing said composition by means of ultraviolet rays in a first step, and then cross-linking said composition in a second step.