Compositions containing: (a) a liquid epoxy resin; (b) an aliphatic or cycloaliphatic primary monoamine and/or an aliphatic or cycloaliphatic disecondary diamine; (c) a latent curing agent for the epoxy resin (a) which does not react until temperatures above 70.degree. C. (measured by means of DSC at a heating rate of 10.degree. C./min); (d) a photopolymerizable compound; and (e) a photoinitiator; the ratio of the number of equivalents of epoxy groups to that of photopolymerizable groups being 1:0.01 to 1:0.7, are suitable as impregnating resins.