Fibrous material including fibers, bundles of fibers, strands, roving, flakes and beads have a dried residue of a chemical treating composition for improved solvent resistance of polymers the fibrous materials reinforced. The chemical treated composition has at least one crosslinkable polyurethane, at least one organofunctional silane coupling agent, and acrylic copolymer with at least one addition polymerizable acrylic-type monomer and at least one monomer that is addition polymerizable and matrix resin miscible and reactable and a carrier. In addition, the chemical treating composition can have a polyurethane crosslinking agent in an effective amount to produce a dried residue of limited swellability from the chemical treatment, where the residue is a thin film on a substantial portion of the surface of the fibrous materials. Optionally, there may be present at least one low temperature antioxidant such as alkali metal and alkaline earth metal hypo or hydrogen phosphites. Also, there may be present in addition or in lieu of the first antioxidant a high temperature antioxidant such as: alkali metal or alkaline earth metal phenylphosphonates, thioethers like dialkyl thioalkylionate and processing aids such as epoxy polyester polymers.

Chemically treated fibers of glass, carbon or polyamide have a treatment incorporating a copolymer or terpolymer with (vinylpyrrolidone-acrylate or acrylic moieties. In addition the treatment can have at least one film forming polymer, at least one organic/inorganic coupling agent, at least one fiber lubricant and water all in effective amounts to perform their stated functions. In one aspect of the invention the fibers are glass fibers which have a chemical treatment which is a dried residue of an aqueous chemical treating composition comprising at least one epoxy polymer, emulsion or dispersion in a predominant amount on a nonaqueous basis of the dried components amount of the aqueous chemical treating composition, at least one amino organofunctional silane coupling agent in an effective coupling agent amount, at least one cationic fiber lubricant in an effective lubricating amount and water. In this aspect the ratio of the epoxy to copolymer should be less than around 60 to 1.