Transition Metal-Carbonyl Derivatives as Photopolymerization Initiators and Photocrosslinking Agents in Photoresists

Abstract

Transition metal carbonyls are used in two photochemical processes which can be applied to the formulation of photoresists and presensitized lithographic plates. Benzene chromium tricarbonyl, together with a perhalo compound, will on exposure to actinic radiation yield free radicals, which initiate polymerization. This process can be dye sensitized. In the second type of reaction it is thought that a transient species, formed on exposure of benzene chromium tricarbonyl, participates in oxidative ligand exchange to crosslink polymers carrying a variety of nucleophilic functional groups.