Heat curable cationically polymerizable compositions and method of curing same with onium salts and reducing agents

A method which comprises heating a curable composition to a temperature in the range of between 25.degree. C. to 250.degree. C. comprising

• (A) a cationically polymerizable organic material,
• (B) from 0.1 to 15% by weight of an aromatic onium salt of the formula,
• [Y].sup.+ [J],
• (C) from 0.5% to 25% by weight of a compound, or polymer having a molecular weight in the range of from about 80 to 2000 and consisting of at least two or more chemically combined atoms selected from the class consisting of C, H, O, S, Si, halogen atoms, transition metals and metals selected from Groups III, IV, V and VI metals, which compound or polymer is capable of lowering, or reducing the charge of the hetero arom of an aromatic onium salt initiator selected from aromatic halonium salts, aromatic Group Va onium salts and aromatic Group VIa onium salts,
• where J is a counterion selected from teh class consisting of MQ.sub.d anions, where M is a metal or metalloid, Q is a halogen radical, and d is an integer from 4-6 inclusive, perchlorate, CF.sub.3 SO.sub.3.sup.-, C.sub.6 H.sub.4 SO.sub.3.sup.-, Cl.sup.-, Br.sup.-, F.sup.-, nitrate and phosphate, Y is a cation selected from the class consisting of an aromatic halonium cation,
• [(R).sub.a (R.sup.1).sub.b D],
• an aromatic Group Va cation,
• [(R).sub.f (R.sup.2).sub.g (R.sup.3).sub.h E],
• and an aromatic Group VIa cation,
• [(R).sub.j (R.sup.4).sub.k (R.sup.5).sub.m G],
• where R is a monovalent aromatic organic radical, R.sup.1 is a divalent aromatic organic radical, R.sup.2 and R.sup.4 are monovalent organic aliphatic radicals selected from alkyl, cyclo alkyl and substituted alkyl, R.sup.3 and R.sup.5 are polyvalent organic radicals forming a heterocyclic or fused ring structure selected from aliphatic radicals and aromatic radicals with E or G, D is a halogen radical, E is a Group Va element selected from N, P, As, Sb and Bi, G is a Group VIa element selected from S, Se and Te,
• "a" is a whole number equal to 0 or 2,
• "b" is a whole number equal to 0 or 1,
• and the sum of "a"+"b" is equal to 2 or the valence of D,
• "f" is a whole number equal to 0 to 4 inclusive,
• "g" is a whole number equal to 0 to 2 inclusive,
• "h" is a whole number equal to 0 to 2 inclusive,
• and the sum of "f"+"g"+"h" is a value equal to 4 or the valence of E,
• "j" is a whole number equal to 0 to 3 inclusive,
• "k" is a whole number equal to 0 to 2 inclusive,
• "m" is a whole number equal to 0 or 1,
• where the sum of "j"+"k"+"m" is a value equal to 3 or the valence of G.