Heat curable epoxy resin compositions

Claim 2

A heat curable epoxy resin composition which contains (a) an epoxy compound or an epoxy resin containing on average more than one epoxide group per molecule, (b) a catalytic amount of an aromatic onium salt, (c) a catalytic amount of an organic copper compound, wherein the copper is complexed, as co-catalyst, and (d) from 0.05 to 2 parts, based on 100 parts of epoxy resin, of a light stabilizer selected from the group consisting of the 2-hydroxybenzophenones, the 2-hydroxyphenylbenzotriazoles, 2,4-dibenzoylresorcinol, the arylsubstituted acrylates and the salicylates.

Claim 3

A composition according to claim 1 which contains (a) an aromatic, aliphatic or cycloaliphatic epoxy compound containing at least two epoxide groups per molecule, (b) an aromatic onium salt of formula I [Ar.sub.m Q]+·[MX.sub.n ]- (I), wherein each Ar is an aromatic radical, Q is iodine, sulfur or selenium, M is a metal or metalloid, X is halogen, m is 2 or 3 and greater by one than the valency of Q, and n is 4, 5 or 6 and greater by one than the valency of M, (c) an organic copper complex compound, and (d) from 0.05 to 2 parts, based on 100 parts of epoxy resin, of a light stabilizer selected from the group consisting of the 2-hydroxybenzophenones, the 2-hydroxyphenylbenzotriazoles, 2,4-dibenzoylresorcinol, the arylsubstituted acrylates and the salicylates.

Claim 4

A composition according to claim 1, wherein component (a) is a di- or polyglycidyl ether or a di- or polyglycidyl ester.

Claim 5

A composition according to claim 1, wherein component (a) is a di- or polyglycidyl ether of a diphenol or polyphenol.

Claim 6

A composition according to claim 1, wherein component (b) is an iodonium salt or a sulfonium salt.

Claim 7

A composition according to claim 2, wherein component (b) is an onium salt of the formula I, wherein each Ar independently is phenyl, naphthyl, or phenyl which is substituted by C 1 -C 4 alkyl, phenyl, phenoxy, halogen, nitro or C 1 -C 4 alkoxy, or two symbols Ar together are a divalent radical of the formula II ##STR2## wherein Y is a direct bond, --O--, --S-- or --CH 2 --, and each R 1 is hydrogen, C 1 --C 4 alkyl, halogen, nitro or C 1 -C 4 alkoxy, M is a metal or metalloid atom selected from the series consisting of B, P, As, Sb, Sn, Bi and Fe, X is fluorine or chlorine, and m and n are as defined for formula I.

Claim 8

A composition according to claim 2, wherein component (b) is a compound of the formula I, in which the anion [MX n ] - is one of the anions BF 4 - , PF 6 - , AsF 6 - , SbCl 6 - or SbF 6 - .

Claim 9

A composition according to claim 1, wherein component (c) is a copper complex in which the complex forming ligand is acetylacetone or a homolog thereof.

Claim 10

A composition according to claim 1 wherein component (d) is 2-[2-hydroxy-3,5-di(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole.