Stabilized cationically-curable compositions

An energy polymerizable composition comprising

• a) at least one cationically curable monomer selected from the group consisting of epoxy monomers and vinyl ether-containing monomers,
• b) a two-component initiator comprising
• (1) at least one salt of an organometallic complex cation wherein said cation contains at least one carbon atom bonded to a transition metal atom, and
• (2) at least one stabilizing additive, or an active portion thereof, selected from the group consisting of classes 1 to 5:
• wherein
• Class 1 comprises compounds represented by formula III
• R.sup.1 --Z.sup.1 --R.sup.1 (III)
• where Z.sup.1 is a diradical moiety selected from the group consisting of ##STR29## and each R.sup.1 independently is a group selected from C.sub.1 to C.sub.10 alkyl groups and groups having 1 to 4 fused or unfused aromatic rings, and the R.sup.1 s together can form a heterocyclic ring having 5 to 7 ring atoms;
• Class 2 comprises macrocyclic compounds represented by formula IV ##STR30## wherein Z.sup.2 is a diradical --O--, --S--, or --NH--;
• wherein each R.sup.2 independently can be hydrogen or it can be R.sup.1 as previously defined, or two R.sup.2 s together can form at least one ring which is saturated or unsaturated and the ring can be substituted or unsubstituted with alkyl, alkenyl or alkynyl groups containing from 1 to 30 carbon atoms;
• the carbon atoms can be interrupted with up to 10 individual, non-catenated heteroatoms selected from O, S, and N;
• x is 1 or 2, and bis an integer from 3 to 10;
• Class 3 is represented by compounds having formulae V and VI, ##STR31## wherein each R.sup.2 independently is as previously defined;
• and a class of tripyridyltriazines ##STR32## wherein each R.sup.2 independently is as previously defined;
• Class 4 is described by compounds of formula VII:
• ##STR33## where Z.sup.3 is nitrogen, phosphorus, arsenic or antimony;
• where each R.sup.1 independently is as defined above, and R.sup.3 can be R.sup.1 or a difunctional group selected from alkylene and phenylene groups, wherein c is either 1 or 2;
• Class 5 describes Schiff bases and can be represented by compounds of formula VIII:
• ##STR34## wherein R.sup.2 and R.sup.3 independently are as previously defined, and wherein d is 1 or 2.