Abstract: A photopolymerizable composition comprising an addition polymerizable compound having at least one ethylenically unsaturated double bond and a photopolymerization initiator system, wherein the photopolymerization initiator system comprises:(a) a sensitizer of the formula (I) ##STR1## wherein -A is ##STR2## wherein each of R.sup.1 and R.sup.2 is a hydrogen atom, an alkyl group, an aryl group or a halogen atom, each of R.sup.3 and R.sup.4 is an alkyl group which may have substituents, each of R.sup.5 to R.sup.8 is a hydrogen atom, an alkyl group or an alkoxy group, or R.sup.3 and R.sup.4, R.sup.3 and R.sup.5 and/or R.sup.4 and R.sup.6 bond to each other to form a ring structure, and n is 0, 1 or 2; and each of X.sup.1 and X.sup.

Abstract: A photopolymerizable composition comprising at least an addition polymerizable compound having at least one ethylenically unsaturated double bond and a photopolymerization initiator system, which system comprises (a) a sensitizer of the formula (I): ##STR1## wherein each of R.sup.1 to R.sup.6 is hydrogen, halogen, alkyl, aryl, aralkyl, acyl, alkoxycarbonyl, optionally substituted hydrocarbon ring, optionally substituted heterocyclic residue or --SO.sub.3 --R.sup.8, wherein R.sup.8 is hydrogen, alkyl, aryl, aralkyl, alkali metal, or quaternary ammonium, R.sup.7 is hydrogen, alkyl, aryl, aralkyl, optionally substituted hydrocarbon ring, or optionally substituted heterocyclic group, each of X.sup.1 and X.sup.2 is halogen, alkyl, aryl, aralkyl, optionally substituted hydrocarbon ring, or optionally substituted heterocyclic group, and (b) a titanocene compound.

Abstract: A light-sensitive coating liquid, comprising, as an organic solvent, at least one substance represented by the formulae (I) to (III) shown below: ##STR1## wherein R.sub.1 represents an alkyl group having 1 to 4 carbon atoms, R.sub.2 to R.sub.7 each represent hydrogen atom or an alkyl group having 1 to 3 carbon atoms, with the proviso that at least one of R.sub.2 to R.sub.7 is an alkyl group. The light-sensitive coating liquid of this invention is improved in odor, low in toxicity and yet excellent in storability, and is also suitable for preparation of a light-sensitive lithographic printing plate improved in press life and dye remaining.