Method of making a positive photosensitive lithographic printing plate

• Main Authors: MURATA, AKIHISA, NAGASAKA, HIDEKI
• Format: Patent
• Language: English; French; German
• Published: 06.05.2015
• Subjects: APPARATUS SPECIALLY ADAPTED THEREFOR; BASIC ELECTRIC ELEMENTS; CINEMATOGRAPHY; COLOUR PRINTING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROGRAPHY; HOLOGRAPHY; LINING MACHINES; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING,INKING, DAMPING, OR THE LIKE; MATERIALS THEREFOR; ORIGINALS THEREFOR; PERFORMING OPERATIONS; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM; PRINTING; PRINTING PLATES OR FOILS; PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTINGSURFACES; SEMICONDUCTOR DEVICES; STAMPS; TRANSPORTING; TYPEWRITERS

A positive photosensitive lithographic printing plate which is capable of being operated under white light containing ultraviolet light, said printing plate comprising on a support a positive photosensitive composition which shows, upon scanning exposure to light in the wavelength range from 650 to 1300 nm, by a change other than a chemical change, a difference in solubility in an alkali developer between an exposed portion and a non-exposed portion, characterized in that said composition comprises (i) a dye which absorbs said light, (ii) an alkali-soluble resin and (iii) a solubility-surpressing agent which is capable of lowering the dissolution in an alkaline developer of a blend comprising the dye and the alkali-soluble resin, with the proviso that the solubility-surpressing agent is not selected from the group consisting of a quinolinium compound, a benzothiazolium compound, a pyridinium compound and an imidazoline compound.