Method for the production of printing plates using photosensitive compositions

Claim 1

A process for the production of printing plates using a photosensitive composition consisting essentially of an intimate blend of A. 40 to 97% by weight, with reference to the whole blend A + B, of a mixture of A.1. 15 to 80% by weight, with reference to A, of a water-soluble linear N-vinylpyrrolidone polymer having a molecular weight of at least 1000, and A.2. 20 to 85% by weight, with reference to A, of a polymer or copolymer of an olefinically unsaturated carboxylic acid having 3-6 carbon atoms which is soluble or swellable in water or aqueous alkali and has a molecular weight of at least 500, the content of carboxyl groups therein being at least 5% by weight based on the polymeric polycarboxylic acid, and B. 3 to 60% by weight, with reference to the whole blend A + B, of olefinically unsaturated monomers which are compatible with mixture A (A.1 + A.2), which do not boil below 100°C at atmospheric pressure, and of which the portion having more than one photo polymerizable olefinically unsaturated double bond predominates, which comprises applying a thin layer of said composition to supports and exposing said layer through an at least partially transparent negative or positive without subsequent development processing.