Patent ID: 8344038

Claim:
A liquid radiation curable composition comprising: a photoinitiating system consisting of: one or more photoinitiators selected from the group consisting of non-polymeric di- or multifunctional initiators, oligomeric or polymeric initiators, and polymerizable initiators; and one or more polymerizable co-initiators; wherein at least one of the polymerizable co-initiators is a co-initiator according to Formula (I): wherein, R 1 and R 2 are independently selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group, and a heteroaryl group; R 3 to R 6 are independently selected from the group consisting of hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an acyl group, a thioalkyl group, an alkoxy group, a halogen, an aralkyl group, an alkaryl group, an aryl group, and a heteroaryl group; R 7 is selected from the group consisting of hydrogen, an aldehyde group, a ketone group, an ester group, an amide group, an acyl group, a thioalkyl group, an alkoxy group, a halogen, a nitrile group, a sulphonate group, a sulphonamide group, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group, and a heteroaryl group; R 1 and R 2 , R 1 and R 3 , R 2 and R 5 , R 3 and R 4 , R 4 and R 7 , R 5 and R 6 , and R 6 and R 7 may represent the necessary atoms to form a 5 to 8 membered ring; and with the proviso that the aromatic amine has at least one alpha hydrogen; at least one of R 1 to R 7 includes a polymerizable ethylenically unsaturated functional group; if R 1 to R 6 includes the polymerizable ethylenically unsaturated functional group, then the polymerizable ethylenically unsaturated functional group is selected from the group consisting of acrylate, substituted acrylate, methacrylate, styrene, acrylamide, methacrylamide, allyl ester, allyl ether, vinyl ester, vinyl ether, fumarate, maleate, maleimide, and vinyl nitrile; and if R 7 includes the polymerizable ethylenically unsaturated functional group, then the polymerizable ethylenically unsaturated functional group is selected from the group consisting of acrylate, substituted acrylate, methacrylate, styrene, acrylamide, methacrylamide, fumarate, maleate, maleimide, and vinyl nitrile.