HARDENABLE PHOTOSENSITIVE MIXTURE SUITABLE AS POSITIVE TYPE RECORDING MATERIAL

A curable photosensitive mixture which is suitable as a positive-working recording material contains (a) one or more polymers which have a molecular weight of >500, contain not less than 5% by weight, based on the molecular weight of the polymer, of aromatic and/or heteroaromatic o-nitrocarbinol ester groups and also contain two or more further reactive functional groups which are available for reaction with a thermal crosslinking agent, (b) one or more compounds which effect crosslinking and are capable of reacting with the further reactive functional groups of the polymer (a) under the action of heat, at temperatures substantially above room temperature, and (c) a filler, with or without (d) other conventional additives and/or assistants. The photosensitive mixture is particularly useful as a positive-working recording material for optical information fixing, principally for the production of thermally stable relief images or resist images and, particularly advantageously, of soldering masks.