Photocurable epoxy compositions containing group Va onium salts

Claim 1

Photocurable compositions consisting essentially of A. an epoxy resin polymerizable to a higher molecular weight state, and B. an effective amount of a photodecomposable aromatic onium salt of a Group Va element capable of effecting the cure of (A) when exposed to radiant energy where the photodecomposable aromatic onium salt of a Group Va element has the formula, [(R).sub.a (R.sup.1).sub.b (R.sup.2).sub.c X].sup.+.sub.d [MQ.sub.e ].sup.-(e-f), where R is a monovalent aromatic organic radical selected from carbocyclic radicals and heterocyclic radicals, R 1 is a monovalent organic aliphatic radical selected from alkyl, alkoxy, cycloalkyl and substituted derivatives thereof, R 2 is a polyvalent organic radical forming an aromatic heterocyclic or fused ring structure with X, X is a Group Va element selected from N, P, As, Sb and Bi, M is a metal or metalloid, Q is a halogen radical, a is a whole number equal to 0 to 4 inclusive, b is a whole number equal to 0 to 2 inclusive, c is a whole number equal to 0 to 2 inclusive, and the sum of a + b + c is a value equal to 4 or the valence of X, d = e - f f = valence of M and is an integer equal to from 2 to 7 inclusive e is > f and is an integer having a value up to 8.