Patent ID: 7923193

Claim:
A lithographic printing plate precursor comprising: a photopolymerizable composition, the composition including a binder, a polymerizable compound, a sensitizer, a photoinitiator, and a polythiol compound; wherein the composition includes, with respect to its total solid weight, at least about 0.01 wt. % of the polythiol compound and the polythiol compound is selected from one of the following formulae (I) or (II): wherein X 1 means O, S, Se, or NR 5 ; L 1 means a linking group or a single bond; R 1 to R 5 mutually independent mean H, a non-metal atom substituent, or L 1 ; m is an integer from 1 to 100; and for the case that m is 1, L 1 includes at least one additional thiol group; wherein X 2 represents O, S, Se, or NR 6 ; Y 1 , Y 2 mutually independent mean N or CR 7 ; L 2 means a linking group or a single bond; R 6 , R 7 mutually independent mean H, a non-metal atom substituent, or L 2 ; n is an integer from 2 to 100; the thiol groups of formulae (I) or (II) may also be present in their tautomeric thione form; and L 1 , L 2 mutually independent mean alkylene, alkyleneoxy, alkylenethio, oxygen, sulfur, amino, alkylamino, amido, alkylamido, sulphonyl, acyloxy, or alkylsiloxane; or an alkylene chain containing acyloxy, ether, carbonate, thioether, hydroxy, phenyl, heterocylic, amino, thiol sulphonyl, amido, glycerol monoether, urethane, or urea functions.