Abstract: The present invention provides a photosensitive imaging element comprising on a support a two-phase layer, said two-phase layer comprising a disperse hydrophobic photopolymerizable. phase and a hydrophilic continuous phase, characterized in that the hydrophobic photopolymerizable phase comprises a multifunctional monomer with a perfluoroalkyl or perfluoroalkenyl group.

Abstract: A lithographic printing plate requiring no fountain solution comprising a substrate having thereon a silicone rubber layer, wherein the silicone rubber layer comprises (A) 100 parts by weight of a linear diorganopolysiloxane having a trialkoxysilyl group at least at both ends, and (B) 0.1 to 50 parts by weight of a condensation catalyst.

Abstract: A waterless or driographic printing plate which can be thermally imaged by an infrared laser is composed of a substrate; a thermal imaging layer containing a photothermal conversion material, such as an infrared absorbing material, and a thermoplastic polyurethane with pendent allyl groups; and a crosslinked silicone polymer top layer. It was discovered that when the imaging layer contains an allyl functional polyurethane mixed with an infrared absorbing dye or pigment, the polymeric layer will have enhanced solubility in certain solvents when exposed to infrared radiation. In addition, the polymeric layer continues to exhibit excellent adhesion to the silicone in unexposed areas so that the infrared absorbing layer can endure development with a suitable organic solvent, or a solvent mixture. Mild brushing or rubbing with the developing solvent readily removes laser-struck portions of the infrared imaging layer while unexposed areas remain firmly intact.

Abstract: A planographic original plate requiring no fountain solution, in which a layer allowing adhesion thereof with a silicone rubber layer to decrease through transforming a laser beam into heat and the silicone rubber layer of an addition type containing 10 to 20% by weight of organohydrogenpolysiloxane based on solid content are laminated to a support in this order, thereby providing a planographic original plate requiring no fountain solution which is capable of heat mode recording due to a laser beam and is excellent in image reproducibility and resistance to scratching.

Abstract: A lithographic printing plate precursor requiring no fountain solution possible to conduct heat mode recording by a laser beam and excellent in image reproducibility and scratch resistance, which comprises a support having provided thereon a light-heat conversion layer containing a compound converting a laser beam to heat and a silicone rubber layer in this order, wherein the light-heat conversion layer contains an addition polymer having a group capable of reacting with a silicone crosslinking agent at a side chain thereof, and the addition polymer reacts with a silicone crosslinking agent contained in the silicone rubber layer when the silicone rubber layer is formed by coating and drying.

Abstract: The present invention is a water-less lithographic printing plate, in which a photosensitive layer and a silicone rubber layer are laminated in this order on a substrate, characterized in that the photosensitive layer contains the reaction product between a compound with at least one each of phenolic hydroxyl groups and non-phenolic hydroxyl groups and a quinonediazide compound, or contains both the reaction product between a compound with at least one of phenolic hydroxyl groups and a quinonediazide compound, and the reaction product between a compound with at least one of non-phenolic hydroxyl groups and a quinonediazide compound.The water-less lithographic raw plate of the present invention is excellent in image reproducibility and printing durability, and so can be favorably and economically advantageously used also in the commercial web offset printing and the newspaper web offset printing where high printing durability is required.

Abstract: The present invention relates to a method of making a waterless lithographic printing plate having an image by which printing can be effected without using dampening water, comprising the steps of (1) providing a waterless lithographic fresh printing plate by layering on a substrate a first layer which converts laser light to heat and a second layer which has an ink-repellent surface, sequentially, (2) exposing the waterless lithographic fresh printing plate laser light by irradiating laser light which can be absorbed by the first layer, and (3) applying a liquid having a surface tension of 25-50 dyn/cm.sup.2 to the second layer, and abrading the surface of the second layer to remove the exposed portion of the second layer selectively so that an image enabling printing without using dampening water can be formed.

Abstract: The present invention relates to a water-less lithographic raw plate, in which a photosensitive layer and a silicone rubber layer are laminated in this order on a substrate, comprising: the peel bonding strength between the photosensitive layer and the silicone rubber layer being 5 to 100 g/cm, and the initial elastic modulus of the photosensitive layer after completion of exposure being 5 to 75 kgf/mm2. In the present invention, attention is paid to the peel bonding strength between the photosensitive layer and the silicone rubber layer before exposure, and it is intensified, while the photosensitive layer after completion of exposure is kept lower in elastic modulus, to provide a water-less lithographic printing plate excellent in printing durability and image reproducibility. Therefore, the water-less lithographic printing plate obtained is suitable for commercial web offset printing and newspaper web offset printing.

Abstract: A support is laminated with a light-sensitive layer and a silicone rubber layer in this order, wherein the light sensitive layer comprises (a) a resol resin, (b) a novolak resin, (c) an infrared absorber, and (d) a compound which generates an acid with heat, thereby providing a light-sensitive lithographic printing plate requiring no fountain solution for direct print-making, which can directly record digital date of computers, etc. with solid lasers or semiconductor lasers having light emitting regions from near infrared to infrared.

Abstract: According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing an imaging element having on a plastic film support in the order given (i) a uniform ink-repellant layer comprising a cross-linked hydrophilic binder and (ii) a photosensitive layer comprising a diazonium salt or a diazo resin;(2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and supplying an aqueous dampening liquid and/or ink to said photosensitive layer.

Abstract: According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing an imaging element having of a flexible film support in the order given (i) a uniform ink-repellant layer comprising a cross-linked hydrophilic binder and (ii) a photosensitive layer comprising a diazonium salt or a diazo resin;(2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and wiping it with a disposable absorbing tissue moistened with water or fountain solution.

Abstract: A radiation-sensitive recording material comprising:a base;a radiation-sensitive layer comprising a diazonium salt polycondensation product and 3 to 50% by weight, relative to the total weight of the radiation-sensitive layer, of a mineral acid; anda silicone layer.

Abstract: A method for forming a lithographic printing plate requiring no fountain solution, which comprises the steps of irradiating a lithographic printing plate precursor requiring no fountain solution comprising a support having a layer for converting a laser beam to heat (first layer) and a layer having an ink-repellent surface (second layer) provided thereon in this order with the laser beam absorbable by the first layer to conduct image exposure, pressing an adhesive sheet layer on the second layer, the sheet having a surface layer adhesive to a surface of the second layer, and thereafter separating the adhesive sheet, thereby forming an image which makes it possible to perform printing requiring no fountain solution.

Abstract: The present invention provides an image-forming material which comprises a support having thereon, in the following order, (1) a photosensitive composition layer comprising (a) an o-quinonediazide compound, and (b) an additive which reacts with a photoreaction product of the o-quinonediazide compound on heating to produce an alkali-insoluble matter, and (2) a water-soluble high molecular compound layer or a silicone rubber layer. The present invention also provides an image formation process which comprises exposing an entire surface of the image-forming material to light rays which render the o-quinonediazide compound soluble in an alkaline developer, imagewise heating the image-forming material, and then developing the image forming material with an alkaline developer to remove those areas which have not been heated.

Abstract: A presensitized plate for use in making a lithographic printing plate requiring no fountain solution excellent in scratch resistance and press life is disclosed, which comprises support and, formed thereon in order from support, a photosensitive layer and a silicone rubber layer, wherein the silicone rubber layer is a crosslinked and cured product obtained by addition reaction of (a) polysiloxane having alkenyl groups with (b) hydrogen polysiloxane having .tbd.Si--H groups so that the number of .tbd.Si--H groups in (b) is from 11 to 30 based on the number of alkenyl groups in (a), wherein polysiloxane (a) has at least two alkenyl groups directly bonded to silicon atoms per molecule, average repeating number x of --[Si(R.sup.1)(R.sup.2)--O].sub.x -- group of 100 .ltoreq.x.ltoreq.600 (wherein R.sup.1 and R.sup.2 each represents a alkyl group, aryl group, aralkyl group, alkenyl group, polydimethylsiloxane group or halogenated hydrocarbon group, provided that 70% or more of R.sup.1 and R.sup.

Abstract: A camera speed lithographic plate precursor composition is used for the preparation of waterless, imaged printing plates. The plates comprise a solid substrate with a first layer of a photopolymerizable, oleophilic coating; a second layer of silicone rubber; a third protective film layer; and a top or fourth layer comprising a silver halide emulsion containing polymeric binders or keying agents.

Abstract: A heat developable color light-sensitive material containing at least light-sensitive silver halide, a binder, and a dye-providing compound on a support, wherein at least one of the compounds represented by formula (1) is contained as the above dye-providing compound, and the amount of the above binder is 5 g/m.sup.2 or less: ##STR1## wherein variables in the above formula are defined in the specification. The heat developable color light-sensitive material which provides an excellent discrimination of an image and is less susceptible to an influence by a fluctuation in a development processing condition.

Abstract: A radiation-sensitive plate comprises a substrate coated with a radiation-sensitive composition including a component having groups imparting solubility in aqueous solutions and a component having functional groups capable of reacting with a silane compound. The surface of the composition is modified by reaction with a silane compound. The plate gives rise to images of improved ink receptivity and can be developed in aqueous developer liquids after image-wise exposure.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: The present invention provides a heat mode recording material comprising on a transparent support a recording layer containing a light to heat converting substance, an image forming substance and a binder characterised in that there is present a heat decomposable intermediate layer between said transparent support and said recording layer and said heat decomposable intermediate layer being contiguous to said recording layer. High density images practically free of fog are obtained. The images are suitable for use as masks in contact exposures of lithographic printing plate precursors.

Abstract: A camera speed lithographic plate precursor composition is used for the preparation of waterless, imaged printing plates. The plates comprise a solid substrate with a first layer of a photopolymerizable, oleophilic coating; a second layer of silicone rubber; a third protective film layer; and a top or fourth layer comprising a silver halide emulsion containing polymeric binders or keying agents.

Abstract: A photosensitive lithographic printing plate requiring no fountain solution, which comprises an aluminum base and, formed thereon in the following order, a primer layer, a photosensitive layer, and a silicone rubber layer, wherein the aluminum base has a roughened surface with an average roughness (R.sub.a) of from 0.2 .mu.m to 0.8 .mu.m and a whiteness of from 0.10 to 0.35, and the primer layer is a homogeneous layer comprising a binder as the main component. The lithographic printing plate requiring no fountain solution is excellent in tone reproducibility, suitability for plate inspection, suitability for plate scanner examination, and press life.

Abstract: A PS plate requiring no dampening water comprises a substrate provided thereon with, in order, a light-sensitive resin layer and a silicone rubber layer, wherein the light-sensitive resin layer is formed from a light-sensitive composition which comprises the following components:(i) at least one monomer represented by the following general formula (I): ##STR1## (wherein R.sup.1 represents, for instance, H or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; a to f each independently represents an integer; R.sup.2 and R.sup.3 each independently represents H or a methyl group); (ii) a photopolymerization initiator; and (iii) a polymeric compound having film-forming ability. The hardening properties of the silicone rubber layer is greatly improved and thus there can be obtained a PS plate exhibiting high sensitivity and hence lithographic printing plates having good printing durability.

Abstract: According to the present invention there is provided a laminate comprising a photosensitive layer and a silicone rubber layer both laminated successively onto a base substrate, in which a main component of the photosensitive layer is formed by an adduct obtained by an addition reaction of a photopolymerizable glycidyl (meth)acrylate and a monoglycidyl ether compound not having a photopolymerizable group with a diamine compound. Because of using a photosensitive layer having such a specific composition as mentioned above, the dry planographic printing plate obtained from the present invention is suitably employable in commercial web offset printing and newspaper web offset printing.

Abstract: The present invention provides a method for making a lithographic printing plate requiring no dampening liquid comprising the steps of:image-wise exposing using a laser beam a heat mode recording material comprising on a support having an oleophilic surface (i) a recording layer having a thickness of not more than 3 .mu.m and containing a substance capable of converting the laser beam radiation into heat and (ii) a cured oleophobic surface layer and wherein said recording layer and oleophobic surface layer may be the same layer;rubbing the exposed heat mode recording material thereby removing said oleophobic surface layer in the exposed areas so that the underlying oleophilic surface is exposed andavoiding the swelling of said oleophobic surface layer by carrying out said rubbing without the use of a liquid or with the use of a non-solvent for said oleophobic surface layer.

Abstract: The present invention features planographic plates fabricated with a silicone coating which produces economical and durable waterless plates when the coating is applied to imaged plates, cured and allowed to properly develop. Such a plate has a very high resolution and an excellent ink repellency in the non-print zones. The process of the invention applies the silicone coating directly onto a photo-imaged or a non-photo-imaged plate, curing the silicone, and then applying a solvent (developer) which penetrates through the silicone to the image. The imaging material is removed precisely, leaving a silicone stencil only in the desired, non-print areas. The silicone coating attaches chemically to the base metal (aluminum oxide), which produces a very durable coating.

Abstract: The present invention provides a heat mode recording material comprising on the same side of a non-conductive support a conductive recording layer and an elastomeric image forming layer being non-conductive characterised in that a peelable polymeric film is provided as an outermost layer on the side of said support containing said elastomeric image forming layer.

Abstract: A photopolymerizable composition comprising: (a) a compound obtained by reacting one mole of a polyamine represented by the following general formula (I) with at least 2 moles of a compound having a group capable of reacting with the polyamine and a polymerizable ethylenically unsaturated group: ##STR1## wherein n is an integer of not less than 1 and (b) a photopolymerization initiator.A dry PS plate comprises a substrate provided thereon with, in order, a light-sensitive resin layer and a silicone rubber layer wherein the light-sensitive resin layer comprises the photopolymerizable composition and a polymeric compound having film-forming ability.The photopolymerizable composition and the dry PS plate have very high sensitivity.

Abstract: Disclosed is a process for developing a presensitized plate which is used in making a lithographic printing plate requiring no dampening water and which comprises, on a substrate, a photopolymerizable adhesive layer and a silicone rubber layer in the order, said process comprising water as a main component and at least one ethylene glycol derivative represented by the following general formula (I):C.sub.m H.sub.2m+1 --(OCH.sub.2 CH.sub.2).sub.n --OH (I)(wherein m is an integer of 5 to 8 and n is 1 or 2). According to the present invention, the developer is excellent in safety, in developing ability and in half-tone dots reproduction.

Abstract: An improved method of making lithographic reproductions is disclosed. The method involves several improvements over prior processes, including (a) the combination of random plates and a waterless, dry press for halftone, duotone, tritone and four color separation halftone printing, and (b) the use, in duotone, tritone and four color separation halftone printing of random plates exclusively for all the plates involved in the multi-step printing process.

Abstract: A dry PS plate having a substrate provided thereon with a photopolymerizable light-sensitive layer and a silicone rubber layer in that order. The silicone rubber layer comprises a product obtained by crosslinking through addition reaction the following components:(a) an alkenylpolysiloxane having at least two alkenyl groups directly bonded to the silicon atoms in each molecule thereof; and(b) a hydrogen polysiloxane of the following general formula I: ##STR1## wherein R.sup.1 and R.sup.2 independently represent a hydrogen atom or methyl group, R.sup.3 and R.sup.4 independently represent a methyl, vinyl or phenyl group, m+n is 5 to 30 and m:n is 3:1 to 1:3. The dry PS plate provides a lithographic printing plate exhibiting excellent tone reproducibility and printing durability as well as not being subject to background contamination.

Abstract: Disclosed is a light-sensitive litho printing plate requiring no dampening water having a primer layer, a light-sensitive layer and a silicone rubber layer in this order on a support, characterized in that the above primer layer contains (1) an ethylenic unsaturated compound having a polymerizable unsaturated group and (2) a photopolymerization initiator, and has a tensile strength of 10 Kg/cm.sup.2 or more and a Vickers hardness of 70 or less.

Abstract: A method for preparing a lithographic printing plate not requiring dampening with water comprising the steps of imagewise exposing to light a presensitized plate for use in preparing a lithographic printing plate not requiring dampening with water which comprises a substrate provided thereon with a light-sensitive layer and a silicone rubber layer in that order and then spraying a pressurized liquid on the plate surface to remove the silicone rubber layer of the image areas. The method does not require the use of brush rolls or developing pads which directly come in contact with the plate surface and give rise to wear and/or bending. Therefore, the method always ensures excellent quality and uniformity of development. Further, the method may be carried out repeatedly with less maintenance of equipment since it is not necessary to use any developing pad or brush roll which must frequently be exchanged due to wear or bending.

Abstract: A dry PS plate comprises a substrate having provided thereon in order a primer layer, a light-sensitive layer and a silicone rubber layer wherein the primer layer comprises a film forming polyurethane resin and a diazonium salt polycondensate. The dry PS plate is excellent in the adhesion strength between the substrate and the light-sensitive layer. The adhesion is surely maintained even after imagewise exposure to light and the subsequent development. The dry PS plate shows excellent image reproduction and the resulting dry lithographic plate is excellent in printing durability as well as resistance to scratch.

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: Disclosed is a light-sensitive litho printing plate comprising:a support, a light-sensitive layer and a silicone rubber layer provided thereon,wherein said light-sensitive layer contains a substance,whereby said substance forms a color during developing or after developing.

Abstract: The invention relates to new mixed ester photosensitive compounds and photosensitizer compositions comprised thereof. The photosensitive compounds and photosensitizer compositions are prepared by condensing phenolic compounds with a 1,2-naphthoquinonediazide-4-sulfonic acid halide and an organic acid halide in specific ratios. Photoresist compositions comprising the photosensitive compounds and photosensitizer compositions are also disclosed. The photosensitizer compositions exhibit excellent solution stability and resistance to precipitation when formulated in alkali-soluble resin photoresist compositions. The photoresist compositions have improved shelf life.

Abstract: Polymers comprising perfluoroalkyl groups, reproduction layers containing these polymers and use thereof for waterless offset printing. The novel perfluoroalkyl group-containing polymers comprise polymers or polycondensates and have, in each case as substituents on different carbon atoms of benzene rings, phenolic OH groups and perfluoroalkyl groups which are optionally attached through intermediate members. In particular, at least 10% of the polymer units carry perfluoroalkyl groups. These polymers are either formed by condensation of substituted phenols (e.g., 4-hydroxybenzoic acid-perfluoroalkyl ester) with an aldehyde, a ketone, or a reactive bismethylene compound or by reacting polymers containing phenolic OH groups (e.g., hydroxypolystyrene) or polycondensates containing reactive OH groups (e.g., phenol-formaldehyde resins) with a perfluoroalkyl group-containing compound (e.g., 2,2-dihydroperfluorodecanoic acid chloride).

Abstract: A method of developing a waterless light-sensitive lithographic printing plate having a support and, provided thereon, a light-sensitive layer comprising a diazo resin and a silicone gum layer with a developer is disclosed. The developer comprises an organic carboxylic acid or salt thereof, water, and at least one of a sulfite and a surfactant.

Abstract: Polymerizable compounds comprising perfluoroalkyl groups, reproduction layers containing these compounds, and use of the reproduction layers for waterless offset printing. The novel polymerizable compounds comprise at least two acryloyl or methacryloyl groups and at least one perfluoroalkyl group which is linked to the molecule through a functional group, in particular, an ester or amide function. The compounds can be prepared, for example, from hydroxyl group-containing acrylates or methacrylates and perfluoroalkyl group-containing carboxylic acid chlorides, in the presence of an amine or from perfluoroalkyl group-containing carboxylic acid derivatives and reactive acryloyloxy or methacryloyloxy compounds. Oligomeric compounds can additionally be synthesized from the above-mentioned compounds by linking, for example, with diisocyanates.

Abstract: A planographic printing plate suitable for direct printing, which comprises a support comprised of a rubber layer, a photosensitive resin layer laminated on the support and a silicone rubber layer laminated on the photosensitive resin layer. Preferably, a barrier layer is formed between the support and the photosensitive resin layer.

Abstract: The invention relates to new mixed ester photosensitive compounds and photosensitizer compositions comprised thereof. The photosensitive compounds and photosensitizer compositions are prepared by condensing phenolic compounds with a 1,2-naphthoquinonediazide-4-sulfonic acid halide and an organic acid halide in specific ratios. Photoresist compositions comprising the photosensitive compounds and photosensitizer compositions are also disclosed. The photosensitiizer compositions exhibit excellent solution stability and resistance to precipitation when formulated in alkali-soluble resin photoresist compositions. The photoresist compositions have improved shelf life.

Abstract: A presensitized printing plate for waterless lithographic printing is described which is composed of a substrate, a printing ink-repellent crosslinked silicone elastomer coating situated thereon, an intermediate coating of amorphous silicic acid or of an exposed coating of a photosensitive organic halogen compound and a radiation-sensitive coating. The intermediate coating effects a better adhesion of the photosensitive coating to the silicone coating and, consequently, a better resistance to developer and better print run of the plate.

Abstract: Polymers comprising perfluoralkyl groups, reproduction layers containing these polymers and use thereof for waterless offset printing. The novel perfluoralkyl group-containing polymers comprise polymers or polycondensates and have, in each case as substituents on different carbon atoms of benzene rings, phenolic OH groups and perfluoroalkyl groups which are optionally attached through intermediate members. In particular, at least 10% of the polymer units carry perfluoroalkyl groups. These polymers are either formed by condensation of substituted phenols (e.g., 4-hydroxybenzoic acid-perfluoroalkyl ester) with an aldehyde, a ketone, or a reactive bismethylene compound or by reacting polymers containing phenolic OH groups (e.g., hydroxypolystyrene) or polycondensates containing reactive OH groups (e.g., phenol-formaldehyde resins) with a perfluoroalkyl group-containing compound (e.g., 2,2-dihydroperfluorodecanoic acid chloride).

Abstract: The invention provides a mixture suitable for treating a photographic composition which comprises from about 1 to about 10 parts by weight of a propylene glycol alkyl ether and from about 1 to about 10 parts by weight of a propylene glycol alkyl ether acetate.

Abstract: A developing method for printing plates employing waterless offset processes is disclosed. The plates comprise a support coated with a photosensitive layer based on a diazonium salt polycondensation product and a super-imposed ink-repellent, crosslinked silicone elastomer layer, whereby said developer is characterized in that it contains a predominant proportion of compounds of the general formula R--(O--CH.sub.2 --CH.sub.2 --).sub.n --O--R, where R denotes C.sub.m H.sub.2m+1, n denotes an integer from 1 to 25 and m denotes an integer from 1 to 5. The present invention is particularly suitable for developing printing plates where the photosensitive layer comprises a diazonium salt polycondensation product comprising recurrent A--N.sub.

Abstract: The present invention is concerned with a printing plate of which image formation is done by photoirradiation, having a front side covered waith a peelable or removable protective layer which contains a photofading material. The printing plate is safe against fogging to light and can be used under ordinary illumination.

Abstract: A photosensitive printing plate for waterless offset printing is described which comprises a support, a photosensitive layer and an overlying, printing ink-repellent silicone rubber layer. The photosensitive layer contains a diazonium salt polycondensation product, a compound which can be polymerized by means of free radicals, preferably a (meth)acrylate, a photopolymerization initiator and optionally a binder. The printing plate has higher photosensitivity than corresponding plates whose photosensitive layer contains only a photopolymerizable mixture or only a diazonium salt polycondensation product.

Abstract: A light-sensitive printing plate for waterless planographic printing is disclosed comprising a support, a superimposed light-sensitive layer, an outer, ink-repellent silicone rubber layer, and an inner, ink-repellent silicone layer between the light-sensitive layer and the outer silicone rubber layer, the outer silicone rubber layer having a higher degree of crosslinking than the inner layer. The printing plate is less sensitive to scratching and, at the same time, shows good developability and image resolution.

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.