Water-soluble photoresins based on polymeric azo compounds

Abstract

Polymeric azosulfonates lose their water solubility when exposed to UV light due to decomposition of the azo function. This effect can be used in water-based photoprinting processes. Water-soluble copolymers of azosulfonate containing repeat units and methyl methacrylate have been alternatively synthesized by a polymer-analogous reaction [1,2] and by direct copolymerization [3]. Both polymer types have been evaluated for application as photoresins in offset printing processes. The polymer made by copolymerization is superior and shows excellent results for photosensitivity, resolution, film-forming properties, and development in water, as well as for thermal and moisture storage stability.