Radiation-polymerizable composition

Abstract From the Canadian patent

This invention relates to a photopolymerizable composition for use in a photographic element such as a lithographic printing plate comprising in admixture, a) a polymeric binder; b) a photoinitiator;, c) a diazonium salt; and d) a polymerizable mixture of, i) an acrylic monomer having from 3 to 6 unsaturated groups; and, ii) an oligomer which is prepared by reacting one molar equivalent of a substantially linear polymeric compound having an active hydrogen group at each end thereof with at least two molar equivalents of a diisocyanate compound so as to form a prepolymer having an isocyanate group at each end thereof; and subsequently reacting said prepolymer with at least two equivalents of …