초록 ▼

A photosensitive plate suitable for preparation of a waterless lithographic printing plate, which comprises a support material and a photosensitive layer provided thereon, said photosensitive layer being made of a photosensitive composition comprising an emulsion polymerization product of an acrylic

A photosensitive plate suitable for preparation of a waterless lithographic printing plate, which comprises a support material and a photosensitive layer provided thereon, said photosensitive layer being made of a photosensitive composition comprising an emulsion polymerization product of an acrylic or methacrylic monomer having a perfluoroalkyl group in the side chain and a water-soluble photosensitive substance resin whose water-solubility is variable by irradiation of ultraviolet rays.

대표청구항 ▼

A method for preparing a waterless lithographic printing plate with a photosensitive printing plate comprising a support material and a photosensitive layer provided thereon, said photosensitive layer being made of a photosensitive composition comprising a mixture of (a) an emulsion polymerization p

A method for preparing a waterless lithographic printing plate with a photosensitive printing plate comprising a support material and a photosensitive layer provided thereon, said photosensitive layer being made of a photosensitive composition comprising a mixture of (a) an emulsion polymerization product of an acrylic or methacrylic monomer having a perfluoroalkyl group in the side chain with or without at least one of other polymerizable monomers, the content of the perfluoroalkyl group-bearing acrylic or methacrylic monomer being not less than 50% by weight, and (b) a film-forming, water-soluble photosensitive substance which is rendered water-insoluble by irradiation with ultra-violet rays in an aqueous medium, the weight proportion of the emulsion polymerization product (a) and the photosensitive substance (b) being 100:0.5-500 in terms of the solid components and the total content of the emulsion polymerization product (a) and the photosensitive substance (b) in the photosensitive composition being from 1 to 50% by weight in terms of the solid components, which comprises the steps of (1) placing an original image film on the photosensitive layer, (2) irradiating ultraviolet rays thereto, (3) separating the irradiated plate from the image film, (4) treating the separated plate with water for washing out the photosensitive composition at the non-exposed part to make the non-exposed part as imaged and the exposed part as non-imaged, thereby producing a positive type printing plate and (5) inking the surface of the printing plate with a lithographic ink so that the ink adheres to the substrate, but does not substantially adhere to the exposed non-image part; said film-forming substance (b) being used in such small amounts in the mixture relative to component (a) that the exposed portion acquires lithographic ink repellant properties when said lithographic ink is applied to the surface thereof. In a method for preparing a waterless lithographic printing plate with a photosensitive printing plate comprising a support material and a photosensitive layer provided thereon, said photosensitive layer being made of a photosensitive composition comprising a mixture of (a) an emulsion polymerization product of an acrylic or methacrylic monomer having a perfluoroalkyl group in the side chain with or without at least one of other polymerizable monomers, the content of the perfluoroalkyl group-bearing acrylic or methacrylic monomer being not less than 50% by weight, and (b) a film-forming, water-soluble photosensitive substance which is rendered water-insoluble by irradiation with ultra-violet rays in an aqueous medium, the weight proportion of the emulsion polymerization product (a) and the photosensitive substance (b) being 100:0.5-500 in terms of the solid components and the total content of the emulsion polymerization product (a) and the photosensitive substance (b) in the photosensitive composition being from 1 from 50% by weight in terms of the solid components, which comprises the steps of (1) placing an original image film on the photosensitive layer, (2) irradiating ultraviolet rays thereto, (3) separating the irradiated plate from the image film and (4′) treating the separated plate with water for extracting the photosensitive substance in the photosensitive composition at the non-exposed part to make the exposed part as imaged and the non-exposed part as non-imaged, thereby producing a negative type printing plate, said film-forming substance (b) being used in large amounts relative to component (a) such that the exposed portion becomes the lithographic ink accepting part, when a lithographic ink is applied to the surface thereof.