Abstract: Screen emulsions in accordance with the present invention include a poly vinyl alcohol and poly vinyl acetate or a poly vinyl acetate copolymer emulsified in water along with appropriate amounts of diacetone acrylamide and an acrylic monomer. The emulsions preferably also include a cyclic amide, phthalate plasticizers, an initiator of monomer polymerization and a thermal stabilizer. The emulsions are intended to be admixed with a photosensitive free radical-generating compound that initiates cross-linking of the polymeric components and then applied to a mesh or screen. The screen is overlaid with an obliterating material, exposed to light and then washed to remove non-exposed emulsion. The resulting screen can be used without further hardening with both water- and solvent-based inks, and the film can be removed with emulsion-removing chemicals to permit reuse of the screen.

Abstract: Photopolymerizable screen printing inks comprising a hydroxyalkyl acrylate-type monomeric material, a polyester binder and a free-radical initiating system, such inks having a viscosity of from 5,000 to 200,000 centipoises, an acid number of from 0 to 120 and a thixotropic index of from 1 to 4. The process of using such inks to treat substrates, such as in making printed circuits, which includes the steps of screen printing the photopolymerizable ink on the substrate; exposing the ink to actinic radiation to cure the ink and to form a resist; and permanently modifying the exposed areas on the substrate. The resist may thereafter be removed by dissolving in aqueous dilute alkali or an organic solvent.

Abstract: Highly durable coatings are formed by the photopolymerization of screen printing inks containing aryloxyalkyl acrylate monomers or prepolymers, a polymerizable diluent and a free-radical initiating system, such inks having a viscosity of 5,000 to 200,000 centipoises and a thixotropic index of from 1 to 6. The photopolymerizable inks are useful for coating substrates, such as printed circuits, and serve as solder masks and resists for electroless plating, electroplating and etching.

Abstract: Highly durable coatings are formed by the photopolymerization of screen printing inks containing aryloxyalkyl acrylate monomers or prepolymers, a polymerizable diluent and a free-radical initiating system, such inks having a viscosity of 5,000 to 200,000 centipoises and a thixotropic index of from 1 to 6. The photopolymerizable inks are useful for coating substrates, such as printed circuits, and serve as solder masks and resists for electroless plating, electroplating and etching.

Abstract: Photopolymerizable screen printing inks comprising a hydroxyalkyl acrylate-type monomeric material, a polyester binder and a free-radical initiating system, such inks having a viscosity of from 5,000 to 200,000 centipoises, an acid number of from 0 to 120 and a thixotropic index of from 1 to 4. The process of using such inks to treat substrates, such as in making printed circuits, which includes the steps of screen printing the photopolymerizable ink on the substrate; exposing the ink to actinic radiation to cure the ink and to form a resist; and permanently modifying the exposed areas on the substrate. The resist may thereafter be removed by dissolving in aqueous dilute alkali or an organic solvent.