Epoxy!-imide! resin compsn. for circuit board mfr. - comprising non-amide solvent, reaction prod. of epoxy! resin and bis:maleimide, and di:amine curing agent

Compsn. comprises a mixt. of 20-80 wt.% of a non-amide solvent (I) and 80-20 wt.% of a reaction prod. of an epoxy resin (II), and a bismaleimide (III), the (II) and (III) being reacted at 115-135 deg.C for 0.5-2 hours and the prod. being contacted with a diamine H2N-R'-NH2 (IV) to form the reaction prod. R' is an aromatic or (cycle)aliphatic gp. and the mol. ratio (III):(IV) is less than 1. The epoxy resin(II) is a cpd. in which R is 1-4C alkylene, n is a positive whole number and the resin has an epoxide equiv. of 150-1000, or an epoxy-novolac resin in which n is a positive whole number and the resin has an epoxide equiv. of 150-300, opt. mixed with a brominated epoxy resin of formula (VII) in which n is a positive whole number sufficient to give a viscosity of 250-4000 centipoises at 25 deg.C and an epoxide equiv. of 300-800. The prods. are useful as laminating resins for impregnating glass fibre in the prodn. of copper clad laminated circuit boards having good heat resistance, electrical properties, and low thermal expansion. The boards have a high performance approaching that of polyimide based materials but are considerably cheaper than these. L'INVENTION SE RAPPORTE AUX COMPOSITIONS DE RESINES SYNTHETIQUES.ELLE CONCERNE UNE COMPOSITION COMPRENANT, EN POIDS: A.20-80 DU PRODUIT DE REACTION OBTENU EN FAISANT REAGIR UNE RESINE EPOXY OU UNE RESINE EPOXYNOVOLAQUE APPROPRIEE AVEC UNE BIS-MALEIMIDE, PUIS AVEC UN DURCISSEUR CONSTITUE D'UNE DIAMINE; ET B.80-20 D'UN SOLVANT CONVENABLE QUI N'EST PAS UN AMIDE.UTILISATION DANS LA FABRICATION DE PLAQUETTES OU PANNEAUX POUR CIRCUITS IMPRIMES.