Abstract: Release of a resin mold from a photopolymeric mold is enhanced by using an unsaturated fatty acid ester release agent in the photopolymeric composition. In addition to providing quick release of the resin mold, the incorporation of the unsaturated fatty acid ester improves the flexibility of the photopolymeric mold without sacrificing tensile strength or hardness. The resin mold is used to fabricate rubber plates for ink printing.

Abstract: A urethane polymer having free acidic groups on the backbone of the polymer and terminal (meth)acrylate groups is prepared by (1) reacting a mixture comprising an aliphatic diol and a diol having acidic functionality with an excess of an aliphatic, cycloaliphatic or aromatic diisocyanate in the presence of a catalyst to produce an isocyanate-terminated urethane polymer and (2) reacting the terminal isocyanate groups of the product of step (1) with a mono- or dihydroxy (meth)acrylate. The diol comprises greater than 50% of the reaction mixture, based on the total weight of reactants. The polymer can be used in photopolymerizable compositions for making low tack flexographic printing plates and photopolymer masters.

Abstract: Disclosed is an aqueous developable, photopolymerizable composition having increased flexibility and reduced cold flow comprising a unique mixture of a siliceous material and a plasticizer in combination with known photopolymerizable monomers, polymeric binders, thermal polymerization inhibitors, and photoinitiators.