Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared with a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic polymer having ionic moieties and a polymer grafted carbon as a photothermal conversion material. The heat-sensitive polymer and polymer grafted carbon can be formulated in water or water-miscible solvents without agglomeration. In the imaging member, the polymer reacts to provide increased hydrophobicity in areas exposed to energy that provides or generates heat. For example, heat can be supplied by laser irradiation in the IR region of the electromagnetic spectrum. The heat-sensitive polymer is considered “switchable” in response to heat, and provides a lithographic image without wet processing.

Abstract: This invention discloses an on-press developable lithographic plate comprising on a substrate a photosensitive layer and a top ultrathin ink and/or fountain solution soluble or dispersible overcoat with a coverage of 0.001 to 0.150 g/m2. The incorporation of such an ultrathin overcoat can provide excellent white light stability, high contrast, excellent ink receptivity, and fast on-press development.

Abstract: A heat-mode exposable imaging material is disclosed which is suitable for making a driographic printing master capable of accepting ink at exposed areas, said material comprising (i) a first layer containing more than 50% by weight of carbon or of an organic light absorbing compound, and (ii) an ink-abhesive second layer underlying said first layer, characterised in that said first layer is removable at non-exposed areas by starting a pressrun without substantially removing said second layer. In a preferred embodiment, the material comprises a support, a silicone coating and a surface coating which consists essentially of carbon, soot or graphite. After heat-mode exposure, the material is ink accepting at exposed areas and the surface coating is removed at non-exposed areas during the start of a pressrun, thereby revealing the silicone coating.

Abstract: A directly imageable planographic printing plates that is high in image productivity and easy to check is produced by using a directly imageable planographic printing plate that comprises at least a substrate, a thermo-sensitive layer and a ink-repelling layer in this order, wherein the thermo-sensitive layer in the printing area contains a dye that has an absorption maximum in the range of 400 nm to 700 nm, and the difference between the reflected absorption of the non-printing area and the reflected absorption of the printing area, observed at the absorption maximum wavelength of the dye, is not less than 0.3 and not more than 2.0.

Abstract: Provided is a media-fluid material set which comprises a media with a support that bears a hydrophilic receiving surface together with a fluid material comprising a liquid carrier medium and a reactive transition metal complex of a fluorinated organic acid. After application of the fluid material to the hydrophilic receiving surface, the reactive complex reacts to form an ink-releasing layer. Such a media-fluid material set can be advantageously used in preparing waterless lithographic printing plates with ink-releasing layers comprising such fluorinated reaction products. Also provided are imaged waterless lithographic printing plates with such ink-releasing layers made by an ink jet printing application or by laser-induced thermal ablation, and methods of making such waterless lithographic printing plates.

Abstract: This invention provides a directly imageable planographic printing plate precursor with excellent image reproducibility without requiring any complicated process after irradiation with a laser beam. To solve the above problem, this invention is constituted as describe below. A directly imageable waterless planographic printing plate precursor, in which at least an ink acceptable layer and a silcone rubber layer are laminated in this order on a substrate, wherein when the printing plate precursor is measured by TG-GC/MS in a hellium current at a heating rate of 10° C./min, a decomposition product is generated in a temperature range of 100° C. to 200° C. by 0.001 g/m2 to 1 g/m2 per plate area.

Abstract: A hydrophilic layer and an overcoat layer are provided in this order on a heat-sensitive layer having an ink receiving surface, so as to form an original (plate) for a lithographic printing plate. The overcoat layer can be removed during printing. A system capable of forming an inorganic hydrophilic matrix by sol-gel conversion is provided in the hydrophilic layer. Adhesion between the heat-sensitive layer and the hydrophilic layer decreases in a heated region through image processing. Emulsion ink is supplied to the plate surface during printing, whereby the overcoat layer and the hydrophilic layer at an image portion are removed with a hydrophilic component of the emulsion ink. Thus, with a heat-sensitive original that can be subjected to heat-mode prepress using laser exposure, good printed matter can be stably obtained, irrespective of balance between image and non-image portions, without using wetting water.

Abstract: A structure for pattern formation adapted for optically forming a pattern, characterized by comprising: a photocatalyst-containing layer provided on a substrate, the photocatalyst-containing layer containing a material of which the wettability is variable through photocatalytic action upon pattern-wise exposure.

Abstract: The effects of interfacial transition between organic and inorganic layers of a lithographic printing member are ameliorated by incorporating an inorganic component within the matrix of the organic layer. In a first aspect, a lithographic printing plate having adjacent organic and inorganic layers is fabricated by depositing a curable polymer, softening the polymer, and integrating an inorganic material therewith. The polymer is then cured to immobilize the integrated deposition material, and the desired inorganic layer is applied over the deposited inorganic material (and any exposed portions of the polymer). In a second aspect, a graded structure is built up on a substrate in successive deposition steps. Both polymer precursors and an inorganic filler material are deposited in stages, with each stage containing a desired ratio of polymer to filler.

Abstract: A printing system which uses a single layer printing member coated on to a cylinder is provided. For waterless offset application, the single layer printing member consists of an oleophobic imaging layer containing an oleophobic resin, coated on an oleophillic cylinder. For wet application, the single layer may either be hydrophilic, coated on a oleophillic cylinder; or vice versa. The single layer printing member is composed of a resin having either oleophobic, hydrophilic or oleophillic properties, to which an infra red absorbing component or components may be added.

Abstract: A waterless planographic printing plate precursor which has a support member, a light-to-heat conversion layer for converting laser light to heat, and a silicone rubber layer. The light-to-heat conversion layer is contains at least one kind of polyurethane having at least one carboxyl group, and at least one light-to-heat conversion substance.

Abstract: A structure for pattern formation adapted for optically forming a pattern, characterized by comprising: a photocatalyst-containing layer provided on a substrate, the photocatalyst-containing layer containing a material of which the wettability is variable through photocatalytic action upon pattern-wise exposure.

Abstract: A directly imageable waterless planographic printing plate, which has at least the heat sensitive layer and an ink repellent layer in this order on a substrate, having a high sensitivity and good image reproducibility and allowing a heat sensitive layer to remain even after development is produced by imagewisely irradiating a precursor of the printing plate with a laser beam, pre-treating the precursor by a pre-treatment liquid containing an amine compound by 0.1 to 30 wt % based on the weight of the entire pre-treatment liquid, and removing the ink repellent layer at the laser beam irradiated area, in this order, such that the heat sensitive layer is at least partially left on the printing plate after completion of the above steps.

Abstract: A recording material is provided, having, in this sequence, a support, a radiation-sensitive layer and a silicone layer. The radiation-sensitive layer contains, as a radiation-sensitive component, a diazonium salt polycondensation product and, as a binder, a homopolymer of (C1-C12) alkyl vinyl ether units and/or a copolymer including at least 5 mol-% of such units, and being free of aliphatic hydroxyl groups. In a process to produce a printing plate for driographic offset printing, this recording material is exposed imagewise and subsequently developed using water or an aqueous solution.

Abstract: A positive-working lithographic printing plate which is imageable by dual infrared lasers has a substrate which absorbs modulated, imaging infrared laser radiation of one wavelength to heat the substrate and an adjacent coating. The substrate has a coating which is a material which will react and form gaseous reaction products which ablate or propel the coating from the substrate upon reaching a threshold reaction temperature. The coating is transparent to the infrared radiation of the one wavelength and contains a dye which absorbs unmodulated, non-imaging infrared laser radiation of another wavelength to heat the coating. The unmodulated, non-imaging infrared laser radiation heats the coating in the imaged areas to a temperature below the threshold temperature and the heat from the substrate further heats the coating to a temperature above the threshold temperature and ablates the coating in the imaged areas.

Abstract: A radiant ray-sensitive lithographic printing plate precursor which comprises (a) material or material series which absorbs radiant rays, converts the absorbed radiant rays to heat, and enters into a self-exothermic reaction by the heat, and (b) material or material series which causes a chemical change or a physical change by the reaction heat generated as a result of the self-exothermic reaction.

Abstract: This patent describes on-press process of a lithographic plate comprising on a substrate a photosensitive layer and a top laser sensitive mask layer. The plate is exposed by first digitally exposing the plate with an infrared radiation to selectively remove or render transparent to an actinic radiation exposed areas of the mask layer and then overall exposing the plate with the actinic radiation to cause hardening or solubilization of the photosensitive layer in the infrared laser exposed areas. The exposed plate is processed on a printing press by contacting the plate with ink and/or fountain solution during initial press operation to remove the mask layer and develop the photosensitive layer. Optionally, an ink and/or fountain solution soluble or dispersible interlayer may be interposed between the mask layer and the photosensitive layer.

Abstract: This patent describes a method of imaging a printing plate comprising on a substrate a photosensitive layer and a top laser ablatable mask layer. The method includes imagewise exposing the plate with an infrared laser to remove the mask layer in the exposed areas, overall exposing the plate with an actinic light to harden or solubilize the photosensitive layer in the areas where the mask layer has been removed, and further exposing the plate with the infrared laser radiation in the laser non-exposed areas to remove the remaining mask layer. The fully exposed plate can be developed to bare the substrate in the non-hardened or solubilized areas of the photosensitive layer.

Abstract: There is described a method of preparing a water-less lithographic printing form using a precursor which includes a support having a coating thereon comprising a diazo salt formed from an aromatic diazonium compound and an abhesive counter anionic moiety, the method comprising heat mode imaging the precursor and processing the imaged percursor on press by the application of printing ink to remove the abhesive products of the imaging so that areas of the precursor which have been imaged are ink-accepting.

Abstract: This invention discloses a lithographic plate comprising on a roughened substrate a substantially conformal radiation-sensitive layer. The radiation-sensitive layer can be a photo hardenable or photo solubilizable layer, or can be a laser ablatable layer. The radiation-sensitive layer is substantially conformally coated on the roughened substrate surface in a way so that the surface of the radiation-sensitive layer has peaks and valleys substantially corresponding to the major peaks and valleys of the substrate microscopic surface. The lithographic plate of such a configuration can provide no or low tackiness and excellent block resistance, while allowing excellent press durability. For on-press developable lithographic plate, such a plate configuration also allows excellent on-press developability.

Abstract: A plate precursor for a lithographic printing plate requiring no development, which comprises a surface formed of a solid material of an inorganic compound comprising at least two kinds of elements selected from groups 13, 14 and 15 of the periodic table; a method for making a lithographic printing plate using the same; and a novel plate precursor for a lithographic printing plate in which an image can be formed and deleted.

Abstract: The effects of interfacial transition between organic and inorganic layers of a lithographic printing member are ameliorated by incorporating an inorganic component within the matrix of the organic layer. In a first aspect, a lithographic printing plate having adjacent organic and inorganic layers is fabricated by depositing a curable polymer, softening the polymer, and integrating an inorganic material therewith. The polymer is then cured to immobilize the integrated deposition material, and the desired inorganic layer is applied over the deposited inorganic material (and any exposed portions of the polymer). In a second aspect, a graded structure is built up on a substrate in successive deposition steps. Both polymer precursors and an inorganic filler material are deposited in stages, with each stage containing a desired ratio of polymer to filler.

Abstract: There is described a method of preparing a positive working water-less lithographic plate which comprises a support having an oleophilic surface, there being coated on the support a mixture which comprises as one component an ink-repellant and water-repellant polymer or a mixture of such polymers or polymer precursors, and as the other essential component of the mixture an infra-red or heat sensitive composition selected from (a) an organic solvent soluble diazo compound and an infra-red absorbing compound, (b) a photopolymer and an infra-red absorbing dye, or (c) a mixture of a free-radically polymerisable ethylenically unsaturated compound or compounds together with either a photoinitiator which is infra-red sensitive or an initiator which is heat sensitive together with an infra-red absorbing compound, the ratio of ink-repellant polymer to infra-red or heat sensitive composition (a), (b) or (c) in the mixture being from 20-80 ink repellant polymer to 80-20 infra-red or heat sensitive composition by weight,

Abstract: According to the present invention there is provided a heat-sensitive non-ablatable wasteless imaging element for providing a lithographic printing plate, having on a support as top layer an image forming layer comprising a heat-switchable binder, characterized in that said image forming layer becomes more hydrophobic under the influence of heat.

Abstract: According to the present invention there is provided a method for lithographic printing comprising the following steps:preparing a lithographic printing plate by image-wise laser exposing a heat-sensitive non-ablatable wasteless imaging element comprising a compound capable of transferring light into heat and having on a support as top layer a heat sensitive image forming layer comprising a heat-switchable binder which layer becomes more hydrophilic or more hydrophobic under the action of image-wise laser exposure;mounting said printing element on the press prior to or after the exposure; andapplying a fountain solution and ink, characterized in that said fountain solution comprises at least one water insoluble compound selected from the group consisting of silica, alumina, titanium oxide, tin oxyde, china clay, smectic clay and zirconium oxide.

Abstract: An imaging member is prepared by applying to a support a heat-sensitive imaging layer which comprises at least one heat-sensitive polymer capable of undergoing transformation from a hydrophilic to hydrophobic state or hydrophobic to hydrophilic state, wherein the transformation occurs such that the activation energy Ea and the Arrhenius pre-exponential factor A associated with the transformation simultaneously fulfill the relationships: ln (A).gtoreq.0.4 Ea+8.84 and ln (A).ltoreq.1.69 Ea-14.37. The imaging member is useful in processless thermal lithographic printing.

Abstract: A method for preparing a waterless lithographic plate is disclosed. A mixture that contains a water-repellant release material and a compound that becomes aqueous developable on heating is coated on a support, heated imagewise, and developed to produce the printing plate. Preferred water-repellant release materials are acrylic and methacrylic polymers with fluorinated side chains and silicone containing polymers, especially organo functional siloxanes. Preferred compounds that become aqueous developable on heating are phenolic resins as well as complexes of phenolic resins with quinolinium compounds, benzothiazolium compounds, pyridinium compounds, and imidazoline compounds.

Abstract: According to the present invention there is provided a heat sensitive recording material comprising a support and thereon a surface layer comprising an ink abhesive binder, characterized in that said binder is capable of being imagewise converted to an ink acceptive binder by exposure to heat or actinic irradiation.

Abstract: According to the present invention there is provided a method for making driographic printing plates comprising the image-wise exposure of a heat-sensitive recording material comprising on an ink-accepting support an image-forming layer containing nydrofobic thermoplastic polymer particles and a compound capable of converting light into heat, said compound being present in said image-forming layer or a layer adjacent thereto and a cured ink-repellant surface layer. After the exposure the printing plate is developed by wiping it with water or an aqueous solution before or after mounting it on the print cylinder of a printing press.

Abstract: Methods and apparatus for lithographic imaging without ablation function by irreversibly debonding intermediate printing-plate layers, thereby rendering at least the surface layer removable by cleaning to expose, in an imagewise pattern, an underlying layer having a different affinity for ink and/or an abhesive fluid for ink. In contrast to ablation-type systems, it is unnecessary to destroy a plate layer, thereby reducing power requirements and facilitating increased imaging speeds.

Abstract: Provided is a non-processed plate for waterless lithographic printing plates, which comprises a photosensitive layer, an ink-repellent layer and a protective layer as laminated in that order on a support and in which the photosensitive layer contains a polymerizable compound as obtained by reacting a glycidyl ether of a polyalcohol, such as hexitol or pentitol, with acrylic acid and/or methacrylic acid. The plate has good image reproducibility and good storage stability. Processing the plate gives waterless lithographic printing plates having good printing durability.

Abstract: A directly imageable raw plate for waterless planographic printing plate, in which a heat insulating layer, heat sensitive layer and ink repellent layer are formed in this order on a substrate, comprising physical properties of 5 to 100 kgf/mm.sup.2 in initial elastic modulus and 0.05 to 5 kgf/mm.sup.2 in 5% stress as tensile properties of the heat sensitive layer or the heat insulating layer or the laminate consisting of both the layers.It can be suitably used also for large printing presses and web offset printing presses requiring high printing durability, and makes it possible to obtain an economically advantageous printing plate.

Abstract: According to the present invention there is provided a heat sensitive recording material having on a support a recording layer containing a homogeneous ink accepting phase and an ink abhesive phase, characterized in that said ink abhesive phase comprises a silicon based polymer.

Abstract: A lithographic imaging member, such as a printing plate, has a support having thereon an ink-accepting melanophilic layer and an ink-rejecting siloxane surface melanophobic layer. Within the printing plate is a photothermal conversion material capable of converting irradiation, such as IR radiation, to heat in exposed regions. Also within one of the layers is a compound that upon imaging releases a moiety that facilitates degradation of the surface melanophobic layer. The released moiety can be fluoride ion or a fluoride ion-containing compound. In some imaging members, a barrier layer may be interposed between the two other layers. Such imaging members can be digitally imaged and used for printing without post-imaging processing.

Abstract: There is described a method of preparing a water-less lithographic plate by coating a positive working photosensitive composition onto an oleophilic base imagewise exposing the plate and developing it to remove the areas of the photosensitive composition which have been light exposed, coating overall the surface of the plate with a layer of a composition which is ink-releasing or when cured becomes ink releasing, then either as a separate step or as a combined step curing the ink-releasing composition or drying the ink-releasing composition and light exposing overall the plate, then redeveloping the plate to remove the photosensitive composition remaining after the first development and any ink-releasing composition overlying the photosensitive composition.

Abstract: There is described a water-less lithographic plate precursor which comprises on an aluminium plate a light-sensitive composition which comprises a polymer with hydroxy functional groups, an acid generator which when light exposed yields an acid together with a silyl ether of general formula (I), where Rf is a fluoroaliphatic group having 3 to 10 carbon atoms, Y is oxygen, SO.sub.2, carbonyl or a direct link, X is N R.sub.4 where R.sub.4 is hydrogen or lower alkyl having up to six carbon atoms or is a direct link, each of R.sub.1, R.sub.2 and R.sub.3 are lower alkyl groups having up to six carbon atoms and R.sub.5 is a lower alkyl group having up to six carbon atoms.

Abstract: The present invention provides a heat mode recording material comprising on a side of a support having an oleophilic surface (i) a recording layer containing a light-to-heat converting substance capable of converting radiation into heat and (ii) an oleophobic surface layer, wherein said oleophobic surface layer and said recording layer may be the same layer and on another side of the support a backing layer, characterized in that the maximum roughness depth R.sub.t of the surface layer is at least 0.65 .mu.m and/or the maximum roughness depth of the outer back layer is at least 1.20 .mu.m.

Abstract: The present invention relates to a precursor of waterless planographic printing plates, in which at least a photosensitive layer and a silicone rubber layer are laminated on a substrate in this order, characterized in that said photosensitive layer contains a quinonediazide group-containing polyurethane resin and furthermore, preferably, contains a light-heat converting material.The present invention can provide a precursor of waterless planographic printing plates, which is improved in both image reproducibility and printing durability, and which can be applied to both the method of obtaining a waterless planographic printing plate by ordinary image exposure and the method of obtaining a waterless planographic printing plate by laser irradiation.

Abstract: Printing plates for dry development wherein the plate is made up of a radiation absorbing layer positioned between a hydrophobic, substantially non-radiation absorbing film layer and a support. Such plates are typically exposed using a laser.

Abstract: Provided is a media-fluid material set which comprises a media with a support that bears a hydrophilic receiving surface together with a fluid material comprising a liquid carrier medium and a reactive transition metal complex of a fluorinated organic acid. After application of the fluid material to the hydrophilic receiving surface, the reactive complex reacts to form an ink-releasing layer. Such a media-fluid material set can be advantageously used in preparing waterless lithographic printing plates with ink-releasing layers comprising such fluorinated reaction products. Also provided are imaged waterless lithographic printing plates with such ink-releasing layers made by an ink jet printing application or by laser-induced thermal ablation, and methods of making such waterless lithographic printing plates.

Abstract: A negative waterless plate contains a sheet substrate; a radiation sensitive imaging layer composed of a diazido naphthaquinone ester or amide compound, such as diazido naphthaquinone sulfonate of a phenolic resin, and a polyurethane prepared by reacting a di-isocyanate and a diol; and a silicone layer. The planographic printing plate is imagewise exposed to actinic radiation through a negative original to form exposed areas of the imaged layer which are soluble or dispersible in a developer liquid. After imaging exposure, the developer liquid is applied which penetrates the silicone layer and dissolves the areas exposed to the radiation. The coating areas not exposed by the radiation remain intact. During this development procedure, areas of the silicone layer overlying the exposed areas are removed along with the underlying soluble areas to produce an imaged planographic printing plate having uncovered ink receptive areas and complimentary ink repellent areas of the silicone layer.

Abstract: A thermally imagable element suitable for use as a lithographic printing plate is disclosed. Imagable element contains an ink repellent, thermally sensitive surface layer on a substrate. The surface layer contains an ink repellent, thermally sensitive co-polymer which is both thermally sensitive and has the physical properties needed for handling and printing. The thermally sensitive co-polymer contains two types of segments: (a) soft silicone segments, which repel ink, and (b) hard segments, which provide physical integrity and impart thermal sensitivity to the co-polymer. The element can be imaged by imagewise expose either by infrared radiation or by heat. The process requires no wet development step and no wiping. Thermally labile crosslinked polymers are also disclosed.

Abstract: A printing plate material producing prints with inhibited background staining is provided by formation of a photosensitive layer comprising nitrocellulose, a black coloring agent, e.g. carbon black, and an organic binder and having (1) a surface roughness of not greater than Rmax. 2.0 .mu.m or (2) a surface tension equivalent to a wettability index of not greater than 36 dyn/cm on a support. The nitrocellulose has a nitrogen content of 11 to 12.5% and a solution viscosity of about 1 to 1/8 second. The organic binder includes polyester resins such as solvent-soluble, noncrystal-line, linear, oil-free aromatic polyesters. Based on 100 parts by weight of the organic binder, the amount of nitrocellulose is about 5 to 300 parts by weight and that of the black coloring agent is about 0.5 to 50 parts by weight. The photosensitive layer may contain a crosslinking agent, e.g. melamine resin, and/or a water repellent, e.g. a silicone compound or a fluorine-containing compound.

Abstract: A lithographic imaging member has a support having thereon a melanophobic silicone copolymer layer and a contiguous surface melanophilic layer composed of an inorganic or organic polymeric matrix. Either or both layers includes a photothermal conversion material capable of converting irradiation, such as IR radiation, to heat in exposed regions. The imaging member can include in one or more layers a material capable of promoting adhesion across the interface of the contiguous layers. This imaging member can be digitally imaged, for example using a laser, and used for printing without wet processing.

Abstract: There is disclosed an IR ablateable driographic printing plate (10) including a substrate (12), an IR absorbing layer (14) comprised substantially of a first water based emulsion and a top IR ablatable layer (16) comprised substantially of a second water based emulsion. The term water based is used herein to indicate the precursor materials from which each layer is being deposited are dissolvable in water and not in an organic solvent or solvents.

Abstract: There is described a method of preparing water-less lithographic plate which comprises imagewise exposing a lithographic plate coated with a photosensitive composition, processing the exposed plate in an aqueous based developing liquid to remove those areas of the photosensitive composition which are removable by the developing liquid, drying the plate and coating the plate with an ink releasing coating composition which adheres to those areas of the plate from which the photosensitive composition has been removed, but which does not adhere to those areas of the plate from which the photosensitive composition which has not been removed, further treating the plate to cure or fix the ink-releasing composition thus providing ink-receptive areas of the plate which are those areas of the plate from which the photosensitive composition which has not been removed in the developing liquid and ink-releasing areas of the plate which are covered with the cured ink-releasing composition.

Abstract: The present invention provides a heat mode recording material comprising on a flexible support having an oleophilic surface (i) a recording layer containing a light-to-heat converting substance capable of converting radiation into heat and (ii) an oleophobic surface layer, wherein said oleophobic surface layer and said recording layer may be the same layer, characterized in that the kinetic coefficient of friction (.mu..sub.k) of said material when sliding one side of said material over the other side of said material is not more than 2.6.

Abstract: A treating liquid for making a waterless planographic printing plate with a photosensitive layer and a silicone rubber layer laminated in this order on a substrate, comprising at least one amine compound with two or more amino groups and one or more hydroxyl groups in one molecule.A treating liquid for making a waterless planographic printing plate excellent in plate surface coatability and developability can be obtained.

Abstract: A waterless planographic printing plate, wherein the waterless planographic printing plate comprises a laser-light-sensitive layer which constitute a first layer provided on a support, containing a compound (A) generating an acid by irradiating an actinic light thereto, a compound (B) converting a laser light to heat and a polymer compound (C) which is decomposed by heat under an acidic condition; and a layer which constitutes a second layer having an ink repellent surface thereon. The entire surface of the waterless planographic printing plate is exposed with ultraviolet light. The printing plate is irradiated imagewisely with an infrared laser light to heat the portion irradiated with the laser light, and at least a layer having an ink repellent surface at the portion irradiated with the laser light is removed.

Abstract: A lithographic imaging member, such as a printing plate, has a support having thereon an ink-accepting melanophilic layer and an ink-rejecting siloxane surface melanophobic layer. Within the printing plate is a photothermal conversion material capable of converting irradiation, such as IR radiation, to heat in exposed regions. Also within one of the layers is a compound that upon imaging releases a moiety that facilitates degradation of the surface melanophobic layer. The released moiety can be fluoride ion or a fluoride ion-containing compound. In some imaging members, a barrier layer may be interposed between the two other layers. Such imaging members can be digitally imaged and used for printing without post-imaging processing.