BENZANTHRONE POLYMERIZATION GATE IN PHOTOPOLYMERIZABLE COMPOSITIONS

摘要

A light sensitive composition which is capable of photopolymerization which includes a photopolymerizable compound a free radical generating component and a benzanthrone or substituted benzanthrone which substantially prevents photopolymerization when the light sensitive composition is exposed to actinic radiation below a threshold amount but permits photopolymerization when the light sensitive composition is exposed to actinic radiation above a threshold amount. This achieves a gate effect which eliminates or decreases unwanted partial exposure in the nonimage areas and hence improves reproduction quality.