Energy-induced curable compositions

Claim 1

A polymerizable composition consisting essentially of (a) polyurethane precursors comprising at least one monomer comprising at least two isocyanate groups and at least one monomer having at least two isocyanate-reactive hydrogen atoms, and (b) a curing agent comprising (i) an organometallic compound, said organometallic compound having the formula, L.sup.1 L.sup.2 L.sup.3 M wherein L 1 represents none, or 1 to 12 ligands contributing pi-electrons that can be the same or different ligand selected from substituted and unsubstituted acyclic and cyclic unsaturated compounds and groups and substituted and unsubstituted carbocyclic aromatic and heterocyclic aromatic compounds, each capable of contributing 2 to 24 pi-electrons to the valence shell of M; L 2 represents none, or 1 to 24 ligands that can be the same or different contributing an even number of sigma-electrons selected from mono-, di-, and tri-dentate ligands, each donating 2, 4, or 6 sigma-electrons to the valence shell of M; L 3 represents none, or 1 to 12 ligands that can be the same or different, each contributing no more than one sigma-electron each to the valence shell of each M; Ligands L 1 , L 2 , and L 3 can be bridging or non-bridging ligands; M represents 1 to 4 of the same or different transition metal atom selected from the elements of Periodic Groups IVB, VB, VIB, VIIB, and VIIB; with the proviso that said organometallic compound contains at least one of a metal-metal sigma bond and L 3 ; and with the proviso that L 1 , L 2 , L 3 , and M are chosen so as to achieve a stable configuration, and (2) an onium salt selected from the group consisting of salts of halonium compounds and compounds of hypervalent Group VIA elements.