A positive-working radiation-sensitive mixture is described which is composed of a compound having at least one C--O--C bond which can be split by acid, a compound which forms a strong acid when irradiated, a binder which is insoluble in water and soluble in aqueous-alkaline solutions, and a resin having solubility properties which differ from those of the binder and which is selected from (1) a polyurethane resin obtained from an organic isocyanate and a polymer which contains hydroxyl groups, (2) a polyvinyl alkyl ether, (3) an alkyl acrylate polymer, or (4) a hydrogenated or partially hydrogenated derivative of colophony. As a result of the resin additives, photoresist layers are obtained which have good adhesion to the support, good flexibility, good latitude in developing and good resolution.

Positive-working radiation-sensitive mixture

A process for preparing a color proofing sheet is disclosed. The process comprises imagewise exposing a light-sensitive image-forming material comprising a transparent support having provided thereon a dye- or pigment-containing light-sensitive photoresist composition layer or both a dye- or pigment-containing colorant layer and a light-sensitive photoresist composition layer through a color separation mask, developing the material to form a color separation image, transferring the color separation image onto a photopolymerizable image-receiving layer, transferring in registration at least one more color separation image onto the same image-receiving layer to obtain a multicolored color proofing sheet on a single support, and totally exposing the image-receiving layer after the image transfer in an amount sufficient to induce photopolymerization thereof. A color proofing sheet realizing color reproduction essentially the same as actual print copies and has a good image strength and non-tackiness can be obtained by the process.

Process for preparing a color proofing sheet

A developing solution for a light-sensitive printing plate having an o-quinonediazide-containing light-sensitive layer is disclosed The developing solution is comprized of an aqueous solution of alkali silicate and a chelating agent By including the chelating agent within the developing solution it is possible to carry out development utilizing water which contains typical impurities such as insoluble calcium silicate or magnesium silicate for a long period of time which substantially has no formation of insoluble matter within the developing machine Use of the developing solution substantially eliminate the formation of any deposit within the spraying pipes and nozzles of the developing machine which it is used in connection with

Developing solution for light-sensitive printing plates

An image-forming method includes a reaction solution-applying step of applying a reaction solution containing a thickening agent and a colorant-aggregating component aggregating a colorant in ink to an intermediate transfer medium, a first ink-applying step of applying a first ink to the intermediate transfer medium provided with the reaction solution, a second ink-applying step of applying a second ink to the intermediate transfer medium provided with the first ink, and a transfer step of transferring an intermediate image formed on the intermediate transfer medium provided with the second ink to a recording medium. An ink layer formed on the intermediate transfer medium by applying the first ink thereto has a yield value of 0.5 Pa or more.

Image-forming method

A photo-curable composite material used for preparing various stencils for screen printing, textile printing or the like, which comprises a flat, flexible and photo-transmitting thin film (A); a flat and flexible film (B); a liquid photo-curable resin and a flat screen material, said films (A) and (B) being air-tightly bonded to each other at the peripheral portion thereof to form a flat inner space therein, said liquid resin being filled in said inner space to form a layer and said screen material also being placed in the inner space substantially in parallel with the inner walls of the films (A) and (B).

Photo-curable composite containing a screen material in a liquid resin

A light-sensitive layer transfer material and such layer disposed on a carrier, for use in screen-printing stencils, printed circuit boards, integrated circuits, intaglio printing plates, relief printing plates, proof prints and the like, which comprises an alkali-soluble phenolic resin, such as phenol-formaldehyde novolacs, an ester or an amide of an o-naphthoquinone-diazide sulphonic acid, such as the p-cumyl phenyl ester of 1,2-naphthoquinone-2-diazide-4-sulphonic acid, etc., and an acrylic resin, such as a polymer of an alkyl ester of acrylic acid or methacrylic acid.

Barbara Wildenhain

Papers

Light sensitive o-quinone diazide containing transfer composition