Abstract: Dry-film, negative-acting photoresist layers are used in the formation of many articles such as circuit boards, printing plates and the like. Laminable monolayers of photoresist can suffer from slow speeds, brittleness, variable adhesive characteristics, and narrow processing latitude during development and exposure. The use of a crosslinked or crosslinkable integral thermoplastic adhesive laer on the dry-film, negative-acting photoresist layer improves the properties and performance of the photoresist.

Abstract: A photohardenable material is disclosed. The material is comprised of a copolymer (I') having ethylenically unsaturated bonds and having an acid value of about 5 to 180 and a molecular weight of about 1,500 to 100,000. The copolymer (I') is obtained by reacting carboxyl groups with a copolymer represented by the structural formula (I), as defined within the application. The material is further comprised of a copolymer (II) having a molecular weight of about 50,000 to 500,000. The copolymer (II) is comprised of three monomers whose structural formula is also defined within the application. The material is further comprised of a cross-linking agent having two or more ethylenically unsaturated bonds and a photoactivator. The copolymers (I') and (II) are present in a ratio of about 0.5 to 20.

Abstract: Aqueous compositions useful in making stencils for screen printing comprise one or more unsaturated monomers, a tertiary amino compound, a colloid, and a water-soluble, carboxy- or sulpho-alkyleneoxy-thioxanthone photoinitiator. When coated on to a suitable support sheet and dried, photosensitive sheets are obtained useful for making stencils for screen printing by the direct, indirect, or direct/indirect methods.