A process for the preparation of the unsaturated polyester resin prepreg, tack-free, the reinforcing sheet form materials.

摘要

Manufacture of sheet-formed reinforcing material impregnated with an unsatd. polyester resin comprising unsatd. alkyld resin, ethylenically unsatd. monomer and catalyst for polymerising reaction between unsatd. groups in the resin, is characterised in that the alkyd resin, monomer, catalyst and polyfunctional isocyanate are added to the reinforcing material before the alkyd resin and the isocyanate have undergone reaction, and then the alkyd resin and isocyanate are allowe d to react to a substantial degree without the unsatd. groups in the alkyd resin and monomer reacting with each other to any great degree so that they are available for reaction when the impregnated material is used in the manufacture of a moulded product.