Abstract: A photopolymerizable material is provided that is suitable for use in the production of coatings or resists on printed circuit boards, for example The material is an ethylenically unsaturated polymerizable reaction product of a polyepoxide and a mixture of (i) a major proportion of an ethylenically unsaturated carboxylic acid and (ii) a minor. proportion of a saturated aliphatic or aromatic carboxylic acid, the reaction product being further modified by reaction with a dicarboxylic acid or anhydride thereof.

Abstract: A process for the formation of a patterned resist of a photocurable material on a circuit board, the uncured portion of which is water soluble. The process includes the steps of forming a layer of an aqueous emulsion of a photocurable material upon the circuit board, drying the layer to a substantially dry and non-tacky state, imagewise exposing the layer to radiation to cure portions of the layer exposed to the radiation, and removing unexposed portions of the layer by washing with water. In a preferred embodiment, the photocurable material is an organic solvent solution of an epoxy acrylate derived from an epoxy novolac resin which has been carboxylated to render it alkali-developable.

Abstract: A two-part system for the preparation of a thermally curable coating composition, in which one-pack contains a thermally curable material and the other contains a curing system potentially reactive therewith, at least one of the packs having water as the principal liquid carrier.