Abstract:
The present invention relates to a positiive-working presensitized plate useful for preparing a lithographic printing plate comprising a positive-working photosensitive composition comprising at least one ester of 1,2-naphthoquinone-2-diazide-5-sulfonic acid, at least one ester of 1,2-naphthoquinone-2-diazide-4-sulfonic acid, and at least one polymer which is insoluble in water and soluble in an aqueous alkaline solution and which comprises at least one group or bond selected from sulfonamide group, urea bond or urethane bond. A lithographic printing plate prepared from the presensitized plate of the present invention shows improvement of chemical-resistance and printing durability, and good sensitivity, coupling property, adaptability to ball-point pen, shelf stability, and stability of sensitivity with time after exposure.
Abstract:
The present invention relates to(A) a photosensitive resin composition containing a high molecular compound having at least three specific constituting components as copolymer components, whereof the first one comprises a perfluoroalkyl group, and an o-quiononediazide compound; and(B) a photosensitive lithographic printing plate comprising a support having coated thereon a photosensitive layer containing the following components (a), (b) and (c),(a) an o-naphtoquinonediazide compound,(b) a resin soluble in an alkaline aqueous solution, and(c) a polymer having a (meth)acrylate monomer having two or three perfluoroalkyl groups having from 3 to 20 carbon atoms in the molecule as a polymer component.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for preparing a coating liquid for a plate making layer, with which a coating liquid for producing a negative lithographic printing plate material having superior stability at storage and high sensitivity is obtained, and to provide a method for producing a negative lithographic printing plate that uses the coating liquid for a plate making layer. SOLUTION: The method for preparing a coating liquid for a plate making layer comprises a first step of adjusting the pH of an acid-crosslinkable compound to be in a range of 2.5-6, and a second step of preparing a coating liquid for a plate making layer, by mixing the acid-crosslinkable compound of which the pH has been adjusted to above range, an alkali-soluble resin, an acid generator and an infrared absorber. The method for producing a lithographic printing material includes applying the coating liquid for a plate making layer onto a support to form a plate making layer. COPYRIGHT: (C)2008,JPO&INPIT