Curable resin composition

Claim 1

A curable resin composition which comprises (I) an epoxy compound having at least two epoxy groups, said epoxy compound being a member selected from the group consisting of polyglycidyl ethers of di- or more polyhydric phenol, polyglycidyl ethers of di- or more polyhydric alcohol, polyglycidyl esters of di- or more polyvalent carboxylic acid, polyglycidyl ethers which are obtained by substituting an active hydrogen combined to a nitrogen atom of aniline or isocyanuric acid, alicyclic polyepoxy compound, and aminopolyepoxy compound, (II) a component selected from the group consisting of a photopolymerizable compound having from one to three carboxyl groups in the molecule, and a mixture of not less than 10% by weight of said photopolymerizable compound and at least one other photopolymerizable compound, said photopolymerizable compound having from one to three carboxyl groups in the molecule being a compound of the formula: ##STR2## in which R 1 is hydrogen or methyl group, R 2 and R 3 are each aliphatic, aromatic or alicyclic hydrocarbon residues A is on ester bond, m and n are each a positive integer of 1 to 3, and (III) a photosensitizer, said epoxy compound (I) and component (II) being incorporated in a weight ratio range of 10:90 to 90:10 and in an equivalent ratio range of epoxy group: carboxyl group of 1:3 to 33:1, said photosensitizer being incorporated into the resin mixture in an amount of 0.05 to 20% by weight, based on the total weight of the epoxy compound and the photopolymerisable compound, said composition being adapted to be subjected to active beam irradiation to polymerize component (II) to form a carboxyl group-containing polymer and thereafter to be subjected to heating to effect reaction of a carboxyl group in the resultant carboxyl group-containing polymer with an epoxy group in the epoxy compound (I) to effect complete curing.