Abstract: A lithographic printing plate precursor comprises a substrate, a free radical polymerizable photosensitive layer comprising a light-sensitive composition on the substrate, and a water-soluble overcoat layer on the photosensitive layer, wherein the overcoat layer comprises polyvinyl alcohol, and a further component that is not amphoteric and is poly(1-vinylimidazole) or a copolymer of 1-vinylimidazole and at least one further monomer. The photosensitive layer comprises a free radical polymerizable component and a photoinitiator.

Abstract: The invention relates to water-soluble layers which in addition to polyvinyl alcohol comprise poly(1-vinylimidazole) or a copolymer of 1-vinylimidazole and at least one further monomer as a further component. These layers can be used as an overcoat on the light-sensitive layer of printing plates.

Abstract: A photosensitive composition having a photoreactive component, selected from a diazonium polycondensation product or a free radical polymerizable system of photoinitiators and unsaturated compounds or a hybrid system and a binder formed by reacting a carboxyl group containing a polymer of formulaP--(--X--COOH).sub.n (I),wherein P is a polymer, n is an integer and X is a single bond or a spacer group, with a 2-oxazoline of the formula ##STR1## wherein R is an alkyl-, aryl-, aralkyl-, alkoxy-, aryloxy- or aralkyloxy group and R' and R" are independently a hydrogen, alkyl- or aryl groups.