Radiation-sensitive composition containing both a vinyl pyrrolidone polymer and an unsaturated polyester and use thereof in lithographic printing plates

摘要

Radiation-sensitive compositions which are especially useful in the production of negative-working lithographic printing plates comprise a photocrosslinkable polymer containing the photosensitive group <IMAGE> as an integral part of the polymer backbone and, in an amount sufficient to improve the properties of the composition, both a polymer of vinyl pyrrolidone and an unsaturated polyester such as a polyester derived from fumaric acid and a 4,4'-isopropylidine-diphenol. The combination of a polymer of vinyl pyrrolidone and an unsaturated polyester improves the properties of the radiation-sensitive composition in regard to such factors as shelf life, image contrast, developability and ink receptivity and thereby provides a superior lithographic printing plate.