Lithographic printing plate precursors with oligomeric or polymeric sensitizers

Abstract

Lithographic printing plate precursor comprising (a) a lithographic substrate with a hydrophilic surface and (b) a radiation-sensitive coating on the hydrophilic surface comprising (i) one or more types of monomers and/or oligomers and/or polymers, each comprising at least one ethylenically unsaturated group accessible to a free radical polymerization, (ii) at least one sensitizer, and at least one coinitiator capable of forming free radicals together with the sensitizer (ii); characterized in that the at least one sensitizer is an oligomeric or polymeric compound comprising the following structural unit (Formula (I)), wherein π1 is an aromatic or heteroaromatic unit or a combination of the two so that a conjugated n-system is present between the two groups Z in structure (I), each Z independently represents a heteroatom, each R1 and R2 is independently selected from a halogen atom, an alkyl, aryl, alkylaryl or aralkyl group, a group —NR3R4 and a group —OR5, each R3, R4 and R5 is independently selected from an alkyl, aryl, alkylaryl and aralkyl group, a and b independently represent 0 or an integer from 1 to 4, n has a value of >1 and AS is an aliphatic spacer.

Dependencies are inferred from the claim text.