Patent ID: 8536217

Claim:
A polymerizable Norrish Type II photoinitiator according to Formula (I): wherein A represents a Norrish Type II initiating group selected from the group consisting of an optionally substituted benzophenone group and an optionally substituted thioxanthone group; L represents a divalent linking group which positions the Norrish Type II initiator moiety A and the C═O-group in a 1 to X position, where position 1 is defined as the atom in an aromatic ring of A to which L is covalently bonded and position X is defined as a carbon atom of the C═O-group; n represents 0 or 1; m represents 0 or 1, with the proviso that n is equal to 0 when m is equal to 0, and with the proviso that if A represents an optionally substituted thioxanthone group that n and m are both equal to 1; X represents an integer from 3 to 7; R1 is selected from the group consisting of hydrogen, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted aralkyl group, an optionally substituted alkaryl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, and an acyl group; R2 is selected from the group consisting of an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted alkynyl group, an optionally substituted aralkyl group, an optionally substituted alkaryl group, an optionally substituted aryl group, and an optionally substituted heteroaryl group; with the proviso that at least one of R1 and R2 is an ethylenically unsaturated polymerizable group selected from the group consisting of an acrylate group and a methacrylate group; and the linking group L is selected from the group consisting of —O—CH 2 —, —S—CH 2 —, —O—CH(CH 3 )—, and —O—CH(butyl)-.