Abstract: The present invention provides a dye solution for a photosensitive lithographic printing plate requiring no fountain solution comprising a photosensitive layer and a silicone rubber layer provided in this order on a support, which comprises at least one basic dye, at least one organic solvent having a water solubility of less than 10% at 20.degree. C., at least one hydrotrope agent, and at least one anionic surface active agent represented by the following general formula (I):R.sup.1 O--(CH.sub.2 CH.sub.2 O).sub.n --SO.sub.3 M.sup.1 (I)whereinR.sup.1 represents an alkyl, aryl, aralkyl, alkenyl or alkynyl group;M.sup.1 represents an alkaline metal, NH.sub.4, NH(C.sub.2 H.sub.4 OH).sub.3, NH.sub.2 (C.sub.2 H.sub.4 OH).sub.2 or NH.sub.3 (C.sub.2 H.sub.4 OH); andn represents an integer 1 to 100.

Abstract: A developer for a presensitized plate for use in making a lithographic printing plate requiring no dampening water comprises: (1) 1 to 39% by weight of at least one alcohol derivative selected from the group consisting of those represented by the following general formula (I): ##STR1## (wherein R.sup.1 represents an alkyl or alkenyl group having 4 to 12 carbon atoms; R.sup.2 represents a hydrogen atom or a methyl group; and n is an integer ranging from 1 to 6); (2) 1 to 39% by weight of at least one water-soluble organic solvent having a boiling point of not less than 100.degree. C.; and (3) 60 to 98% by weight of water. If this developer is used, foaming is hardly caused during the development processing a PS plate requiring no dampening water, it has excellent developing ability and half tone dot reproduction and can provide an excellent lithographic printing plate free of defects such as scratch marks.

Abstract: A water-less PS plate for use in making a water-less lithographic printing plate comprises, on a substrate, a photopolymerizable light-sensitive layer and a silicone rubber layer in this order, wherein the light-sensitive layer is formed from a photopolymerizable light-sensitive composition which contains an urea bond-containing polyurethane as a binder. According to the present invention, there is obtained a water-less PS plate having good resistance to scratch and high printing durability. Moreover, the resulting light-sensitive layer does not get sticky, the light-sensitive layer of the non-image portions is not peeled off during the printing operations, and the lithographic plate shows good dyeability and plate-examination property.

Abstract: A novel electrophotographic printing plate precursor and a novel photosensitive lithographic printing plate precursor are disclosed, in which a specific layer is formed on the end face thereof.

Abstract: A process of correcting a dry lithographic printing plate which comprises applying to an unwanted area of an ink-accepting area in the dry lithographic printing plate consisting of ink-repellent areas comprising a silicone rubber layer and ink-accepting area, a correcting solution comprising the following components:______________________________________ amount (parts by weight) ______________________________________ (a) Linear organopolysiloxane having three 100 alkoxy groups at both terminal ends (b) Titanium based condensation catalyst 0.1 to 5 (c) Organic solvent. 100 to 5,000 ______________________________________The plate surface retouching solution provides a coating which has a good adhesion to a light-sensitive layer and a good resistance to printing.

Abstract: The present invention relates to a presensitized plate for use in making a lithographic plate requiring no dampening water and comprising, on a support, a light-sensitive resin layer and a silicone rubber layer, in this order, wherein the silicone rubber layer is crosslinked by addition reaction of an .fwdarw.SiH group with a --CH.dbd.CH-- group and wherein the light-sensitive resin layer comprises: (1) a monomer or oligomer having at least one photopolymerizable or photo-crosslinkable and olefinically unsaturated double bond, (2) an organic solvent-soluble polyurethane resin having a glass transition temperature of 20.degree. C. or below and being capable of forming a film, and (3) a photopolymerization initiator. According to the present invention, the PS plate has excellent image-forming properties and printing properties.

Abstract: A dry PS plate comprises a substrate provided thereon with in order a primer layer, a light-sensitive layer and a silicone rubber layer wherein the primer layer comprises at least one compound selected from the group consisting of those having urethane or/and urea bonds and is adhered to the substrate with a functional group containing silane coupling agent represented by the following general formula: ##STR1## wherein n is an integer ranging from 1 to 3; X represents an alkyl group, a vinyl group or an organic group having a functional group showing affinity to or capable of being bonded to the compound included in the primer layer; R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and Y represents an organic group which generates a hydroxyl group through hydrolysis or a hydroxyl group.

Abstract: The present invention relates to a photosensitive lithographic plate necessitating no damping water, which plate has an excellent image reproducibility and stability in the lapse of time. The plate comprises, on a support, a photosensitive layer and a silicone rubber layer in this order, the silicone rubber layer being formed by addition reaction of an SiH group with a --CH.dbd.CH- group to cause crosslinking, and the photosensitive layer comprising:(1) a polymer comprising at least a structural formula (I): ##STR1## wherein R represents a hydrogen atom or a methyl group; R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.