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 method of preparing a planographic printing member is disclosed. In one embodiment, the method comprises forming a hydrophilic layer by thermally spraying a hydrophilic particulate material onto an ablatable layer. Typical hydrophilic materials are SiO2, Al2O3, Cr2O3, TiO2 and ZrO2. Spraying a plasma containing the hydrophilic material in an inert gas atmosphere is preferred method for forming the hydrophilic layer.

Abstract: A lithographic printing plate precursor which comprises a metal support having provided thereon a heat-insulating layer, a metal layer having a hydrophilic surface, and a lipophilic layer which is abraded by heating or whose solubility to alkali is transformed by heating, in this order from the support.

Abstract: According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer that is soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer that is IR-sensitive and unpenetrable for an alkaline developer; characterized in that at least one of the first layer and the top layer includes a surfactant.

Abstract: Provided is a lithographic printing plate comprising a support substrate having disposed thereon an ablative-absorbing layer and, optionally, a durable, ink-accepting surface layer that is not ablative-absorbing. The ablative-absorbing layer contains a high weight percent of an organic sulfonic acid component. The printing plate may further comprise a hydrophilic polymeric layer interposed between the ablative-absorbing layer and the substrate. The printing plate may also comprise a primer layer underlying the ablative-absorbing layer with an adhesion-promoting agent present in the primer layer. Also provided are methods of preparing such lithographic printing plates, and methods of preparing imaged lithographic printing plates from such lithographic printing plates by imagewise exposure to a laser and a subsequent cleaning step with water or with a cleaning solution.

Abstract: A presensitized printing plate intermediate having an image mask on a UV radiation transparent removable coating layer; and a printing plate produced directly by reactants which polymerize alone or in combination with other reactants precoated on the plate substrate to form a printable hard resin image. A method of digitally forming an image on said printing plate intermediate.

Abstract: Provided are methods of imaging a wet positive working lithographic printing member comprising the steps of providing a positive working printing member comprising a substrate, a hydrophilic layer, an infrared-absorbing layer, and, optionally, an ink-accepting surface layer; exposing the printing member to infrared radiation in an imagewise pattern removing by ablation greater than 10% by weight, and most preferably none of the infrared-absorbing layer and optional ink-accepting surface layer; and removing with water the laser-exposed areas of the infrared-absorbing layer and optional ink-accepting surface layer to reveal the underlying hydrophilic layer. These methods are advantageous in reducing airborne debris and vapors during laser imaging, in increasing the speed of laser imaging, and in providing excellent cleanability and image quality. The printing member may further comprise a primer layer underlying the infrared-absorbing layer with an adhesion-promoting agent present in the primer layer.

Abstract: Provided is a lithographic printing plate comprising a support substrate having disposed thereon an ablative-absorbing layer and, optionally, a durable, ink-accepting surface layer that is not ablative-absorbing. The ablative-absorbing layer may contain a high weight percent of an organic sulfonic acid component. The printing plate may further comprise a hydrophilic polymeric layer interposed between the ablative-absorbing layer and the substrate. The printing plate also comprises a primer layer underlying the ablative-absorbing layer with an adhesion-promoting agent, such as a zirconium compound, present in the primer layer. Also provided are methods of preparing such lithographic printing plates, and methods of preparing imaged lithographic printing plates from such lithographic printing plates by imagewise exposure to a laser and a subsequent cleaning step with water or with a cleaning solution.

Abstract: Provided is a positive working, wet lithographic printing member comprising a hydrophilic metal substrate having disposed thereon a hydrophilic layer, an ablative-absorbing, ink-accepting surface layer and, optionally, an ink-accepting overcoat layer that is not ablative-absorbing. Also provided are methods of preparing such lithographic printing plates, and methods of preparing imaged lithographic printing plates from such lithographic printing plates by imagewise exposure to a laser and a subsequent cleaning step to remove residual laser-induced debris and damaged areas from the hydrophilic layer.

Abstract: A lithoprinting plate comprising a support and a recording layer which comprises a polyvalent metal ion and a hydrophilic binder polymer having a Lewis base portion containing nitrogen, oxygen or sulfur and which has an oleophilic image area and a hydrophilic non-image area which are printed in a thermal mode, wherein the hydrophilic binder polymer in the hydrophilic non-image area is three-dimensionally cross-linked by the interaction between the polyvalent metal ion and the Lewis base portion.

Abstract: The present invention is directed to a heat mode imaging element for making a lithographic printing plate including on a lithographic base with a hydrophilic surface, a first layer including a polymer, soluble in an aqueous alkaline solution, and a top layer on the same side of the lithographic base as the first layer. The top layer is IR-sensitive and unpenetrable for an alkaline developer. The first layer and the top layer may be one and the same layer. The top layer is characterized in that it contains at least one compound containing epoxy units in an amount between 20 and 500 mg/m.sup.2 and a hardener.

Abstract: A metal substrate is treated with a plurality of rotating brushes and a slurry of particulate material such that the treated surface is capable of absorbing incident infrared laser radiation. The substrate is itself capable of being visibly imaged by selective writing with an infrared laser. The substrate is coated with an ablatable coating which is transparent to the imaging infrared laser radiation. Selective exposure to infrared laser radiation ablates this coating in the laser exposed areas as a result of the absorption of infrared radiation by the substrate. The substrate can be anodized after rotary brush graining and still retain its ability to be imaged and ablate a coating. The coated article can be imaged in a computer-to-plate infrared laser imaging device. Depending on the specific coating and substrate selection, the imaged article can be used in a conventional lithographic printing process or in a dryographic printing process.

Abstract: A precursor element for making a lithographic printing plate is composed of a support, an ink receptive thermal conversion inner layer and a sol-gel, ink repellent outer layer. The outer sol-gel layer containes crosslinked colloids derived from certain metal oxides or hydroxides. The plates produced from the ellements are long-running plates that require no post-imaging processing.

Abstract: The present invention provides a method for making a lithographic printing plate comprising the steps of:(1) mounting an imaging element comprising (i) on a hydrophilic surface of a lithographic base an image forming layer comprising hydrophobic thermoplastic polymer particles capable of coalescing under the influence of heat and dispersed in a hydrophilic binder and (ii) a compound capable of converting light to heat, said compound being comprised in said image forming layer or a layer adjacent thereto on a print cylinder of a printing press;(2) image-wise exposing said imaging element by means of a laser or LED;(3) and developing a thus obtained image-wise exposed imaging element by supplying an aqueous dampening liquid and/or ink to said image forming layer while rotating said print cylinder.

Abstract: A method for making a lithographic printing plate comprising exposing a support, a melonophilic layer and a melonophobic layer, the latter containing crosslinked colloids to a laser beam having an intensity greater than 0.1 mW/.mu..sup.2 for a time sufficient to give a total exposure of about 200 milliJoules/cm.sup.2 or greater. Good printing steps and long running plates are produced.

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: The present invention is directed to lithographic printing plates that are suitable for imaging by laser discharge using laser ablation. The lithographic printing plates according to the present invention comprise a vacuum deposited polymeric layer comprising polyvinylpyrrolidone having a thickness of up to about 6000 Angstroms, an absorbing layer underlying the first layer that absorbs infrared radiation and has a thickness in a range between about 100 and about 500 Angstroms, and a substrate underlying the absorbing layer. The polymeric layer and the substrate exhibit different affinities for at least one printing liquid selected from the group consisting of ink and an adhesive fluid for ink.

Abstract: A short run offset printing member is provided which includes a substrate layer that is substantially oleophilic to conventional hydrocarbon-based printing inks, with a second infra-red radiation ablatable and hydrophilic layer over it. The infra-red radiation ablatable layer is coupled with an infra-red radiation absorbing covering to permit ablation of the infra-red radiation ablatable layer.

Abstract: Lithographic printing members have protective layers formulated specifically for use with single-fluid inks, and which are removed from the printing member during the preparatory procedures that precede printing. The protective layer provides protection against handling and environmental damage, and also extends plate shelf life; performs a cleaning function, entraining debris and carrying it away as the layer itself is removed; acts as a debris-management barrier if the layer immediately beneath the protective layer is ablated during the imaging process, preventing the emergence of airborne debris that might interfere with unimaged areas and/or imaging optics; and exhibits hydrophilicity, actually accelerating plate roll-up.

Abstract: A lithographic printing plate, in which (1) the non-image area of a hydrophilic swellable layer is 1 to 50 g/m.sup.2 in water absorbability, and the water absorbability of the image area is less than that of the non-image area, (2) the non-image area of a hydrophilic swellable layer is 0.01 to 10 kg/mm.sup.2 in initial modulus, and the initial modulus of the image area is larger than that of the non-image area, (3) the non-image area of a hydrophilic swellable layer is 10 to 2000% in water swelling ratio, and the water swelling ratio of the image area is less than that of the non-image area, or (4) the hydrophilic swelling layer has a phase separated structure consisting of at least two phases; a phase mainly composed of a hydrophilic polymer and a phase mainly composed of a hydrophobic polymer, can be produced from a new photosensitive lithographic original plate simple in development treatment, highly repellent against ink even without being etched, and allowing the use of pure water as dampening water.

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: According to the present invention there is provided a method for making a lithographic printing plate comprising the image-wise exposure of a heat-sensitive imaging element with a laser and developing said imaging element by rinsing it with plain water or an aqueous solution. To improve ink-uptake the imaging element is exposed on an external drum recorder whereby the pixel dwell time of the laser is above 0.1 .mu.

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: An imaging member can be prepared by imagewise application of a fluid onto a water-soluble fluid-receiving layer coated on a hydrophilic support. Application is preferably accomplished by ink jet printing. The fluid is dried or cured to form an oleophilic image on the fluid-receiving layer. After removal of the non-imaged areas, the resulting imaging member can be used for lithographic printing. The fluid-receiving layer is designed to protect the resulting imaging member from fingerprints or other handling defects.

Abstract: Constructions useful as lithographic printing plates include metallic inorganic layers exhibiting both hydrophilicity and substantial durability at very thin application levels. These materials ablatively absorb imaging radiation, thereby facilitating direct imaging without chemical development. They can also be used to form optical interference structures which, in addition to providing color, likewise absorb imaging radiation and ablate in response to imaging pulses.

Abstract: Printing plates having a photoresist layer thereon that can be exposed by a computer controller laser have improved sensitivity and do not require a photomask step. We have found photoresists that include a film forming polymer, an organo azide and a photosensitive dye that absorbs light at the frequency of the patterning laser and converts it to heat energy. The heat energy in turn elevates the temperature of the organo azide above its dissociation temperature, destroying the azide in areas exposed to the light source, and solubilizing those regions. A post pattern exposure flood exposure with ultraviolet light hardens the unexposed resist, improving its resistance to etch solvents.

Abstract: Lithographic printing is accomplished using wet lithographic printing plates that include a protective layer providing protection against handling and environmental damage, extension of plate shelf life, and entrainment of debris generated by ablation. The layer washes away during the printing make-ready process, effectively cleaning the plate and disappearing without the need for a separate removal process.

Abstract: The present invention provides a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing to light an imaging element comprising (i) on a hydrophilic surface of a lithographic base an image forming layer comprising hydrophobic thermoplastic polymer particles capable of coalescing under the influence of heat and dispersed in a hydrophilic binder and (ii) a compound capable of converting light to heat, said compound being comprised in said image forming layer or a layer adjacent thereto;(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 image forming layer while rotating said print cylinder.

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: The present invention provides a process for the preparation of a hot-melt ink jet process printing plate capable of printing many sheets of printed matters having a sharp image quality free of background stain. The present invention concerns a novel process for the preparation of an ink jet process lithographic printing plate which comprises preparing a direct imaging lithographic printing plate precursor comprising a water-resistant support having an image-receiving layer containing an inorganic pigment and a hydrophilic binder resin as main components provided thereon, and then jetting through a nozzle ink droplets obtained by heating and melting a solid ink composition at ordinary temperatures onto the image-receiving layer to form an image thereon by a hot-melt ink jet process, characterized in that the image-receiving layer comprises as the inorganic pigments a particulate silica having an average grain diameter of from 1 to 6 .mu.

Abstract: A lithographic printing plate that works according to the silver salt diffusion transfer reversal process is disclosed. The lithographic properties of said plate can be improved by incorporating a hydrophilic amphoteric block copolymer, comprising a non-ionic block of acrylic units with pendant nitrile groups and an acrylamid(in)e block which comprises units with pendant basic and acidic groups. The hydrophilic amphoteric block copolymer is preferentially present in the image receiving layer of the lithographic printing plate. In an alternative embodiment, said block copolymer may be present in a treating solution used for processing said plate or applied onto said plate while printing. The hydrophilicity of the printing plate's surface is improved without deteriorating the ink-acceptance in the printing areas.

Abstract: A substrate is coated with a first material which is soluble in a first solvent, whereupon a second material which is strongly adherent to the first material and insoluble in the first solvent is selectively applied by an ink jet printer. The substrate is then developed in the first solvent to establish the image. In a preferred embodiment the substrate is hydrophilic, the first material is a negative working photosensitive material, and the second material is a transparent adhesive, which permits curing the first material by exposure to actinic light after the development step. The adhesive is then removed. In an embodiment directed to a waterless plate the substrate includes a surface coating of silicone, and the first material is a primer which promotes adhesion of a second material in the form of an oleophilic adhesive which is selectively applied. The primer is then developed to expose the silicone on the non-image areas.

Abstract: A lithographic printing plate made by coating a support web with a coextensive hydrophilic layer of a crosslinked polymeric matrix containing a member of the group consisting of colloids of beryllium, magnesium, aluminum, silicon, gadolinium, germanium, arsenic, indium, tin, antimony, tellurium, lead, bismuth and the transition metal oxides, along with a photothermal conversion material capable of accepting ink when exposed to high intensity radiation.

Abstract: The present invention provides a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing to light an imaging element comprising (i) on a hydrophilic surface of a lithographic base an image forming layer comprising hydrophobic thermoplastic polymer particles dispersed in a hydrophilic binder and (ii) a compound capable of converting light to heat, said compound being comprised in said image forming layer or a layer adjacent thereto;(2) and developing a thus obtained image-wise exposed imaging element by rinsing it with plain water or an aqueous liquid.

Abstract: The performance-limiting effects of thermal breakdown on ablation-type lithographic printing plates are overcome by rendering the ink-accepting surface largely impervious to the effects of debris originating with the surface layer of the printing member, or by discouraging the formation of harmful debris altogether. In one approach, the ink-accepting surface is a highly crosslinked polymer. The resulting cured matrix exhibits a sufficient degree of three-dimensional bonding to resist melting, softening, or chemical degradation as a result of the imaging process. Alternatively, an intervening layer, disposed between the imaging layer and the surface layer, prevents the surface layer from undergoing significant thermal degradation in response to imaging radiation or ablation of the underlying imaging layer, and is also formulated to produce little debris or debris having an affinity for ink and/or fountain solution similar to the affinity of the substrate--e.g.

Abstract: The traditional trade-off between performance and shelf-life of processless thermal printing plates can be eliminated by using reactive chemicals which are mixed during (or just prior to) application to the plate and imaged shortly thereafter. The utility of high power thermal exposure heads combined with the advantages of mixing two reactive chemicals, allows the generation of high performance processless thermal printing plates on-site, effectively eliminating the requirements of shelf-life and robustness. Furthermore, the process of mixing the reactive chemicals is ideally suited for on-press imaging.

Abstract: According to the present invention there is provided a polymer not comprising maleic acid derivatives having acid labile groups pendant from the polymer backbone, characterized in that said pendant groups are represented by--L--(C.dbd.O)--O--(C.dbd.O)--O--C--R.sup.1 R.sup.2 R.sup.3,wherein L represents a divalent linking group bonded to the polymer backbone, R.sup.1 represents an alkyl group of which the linking C atom comprises at least one hydrogen and R.sup.2 and R.sup.3 each independently represent a hydrogen or an alkyl group or R.sup.1 and R.sup.2 or R.sup.2 and R.sup.3 form together a ring compound still with the proviso that the linking C atom of R.sup.1 comprises at least one hydrogen.According to the present invention there is further provided a novel photosensitive composition comprising a latent Bronsted acid and a polymer having acid labile groups pendant from the polymer backbone as described above.

Abstract: A substrate is coated with a first material which is soluble in a first solvent, whereupon a second material which is strongly adherent to the first material and insoluble in the first solvent is selectively applied by an ink jet printer. The substrate is then developed in the first solvent to establish the image. In a preferred embodiment the substrate is hydrophilic, the first material is a negative working photosensitive material, and the second material is a transparent adhesive, which permits curing the first material by exposure to actinic light after the development step. The adhesive is then removed. In an embodiment directed to a waterless plate the substrate includes a surface coating of silicone, and the first material is a primer which promotes adhesion of a second material in the form of an oleophilic adhesive which is selectively applied. The primer is then developed to expose the silicone on the non-image areas.

Abstract: A sheet material suitable for imaging by laser radiation includes a substrate, an adhesive layer comprising a thermoplastic or elastomeric polymer coated onto the substrate, and a particle layer adhered to the adhesive layer and comprising a plurality of carbon or metal or mineral particles that are subject to laser ablation. The particle layer preferably contains alumina particles. The adhesive layer may be filled with particles and is preferably filled with titanium dioxide particles that are more sensitive to laser radiation than the thermoplastic or elastomeric polymer. Preferably, a silicone or silicate layer that is not subject to laser ablation overlies the particle layer.

Abstract: According to the present invention there is provided a heat mode imaging element comprising in the order given:i) a lithographic base,ii) a heat ablatable recording layer andiii) a top layer having an opposite affinity for ink or an ink abhesive fluid than the lithographic base,characterized in that the top layer comprises as main substance an inorganic-organic composite material wherein the inorganic phase is formed by controlled hydrolysis and polycondensation of a metal alkoxide and the organic phase is an organic polymer or copolymer linked to at least one inorganic atom.

Abstract: An imaging member is composed of a hydrophilic imaging layer having a hydrophilic heat-sensitive polymer containing heat-activatable thiosulfate groups, and optionally a photothermal conversion material. Upon application of energy that generates heat, such as from IR irradiation, the polymer is crosslinked and rendered more hydrophobic. The exposed imaging member can be contacted with a lithographic printing ink and a fountain solution and used for printing with or without post-imaging wet processing. This imaging member is particularly useful for direct write imaging using IR lasers or thermal printing heads.

Abstract: An imaging member can be prepared by imagewise application of a mixture of a sol precursor in a liquid to a suitable substrate. Application is preferably accomplished by ink jet printing. Upon removal of the liquid, such as by drying, an insoluble, crosslinked polymeric sol-gel matrix is formed that will accept a lithographic printing ink. The resulting imaging member can be used for lithographic printing.

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: A printing plate for use in lithographic printing has a thermally responsive recording material. A plate is fabricated with a photosensitive emulsion affixed to an upper surface of an aluminum substrate. The plate is first chemically processed so that it is capable of accepting ink (i.e., oleophilic). Thereafter, selected areas of the emulsion are thermally removed, preferably by exposure to a high power laser beam. The plate is ready for immersion into an aqueous ink solution.

Abstract: A laser imageable direct write printing member for use with a laser producing laser radiation comprising a flexible sheet of plastic having first and second surfaces serving as a film substrate. A vacuum-deposited laser ablative coating is carried by said first surface formed of a metal selected from a group consisting of titanium, zirconium, aluminum hafnium and alloys thereof.

Abstract: Long wearing lithographic imaging members are prepared from a zirconia ceramic layer having thereon a hydrophilic, non-crosslinked water-insoluble surface layer. This surface layer is ablatable using imaging apparatus such as a laser, and the surface energy differential between the non-removed hydrophilic layer and the exposed underlying zirconia ceramic is desirable to provide lithographic printing with improved image sharpness.

Abstract: The invention relates to a recording material having a plate- or sheet-like substrate, at least one IR-absorbing layer, which comprises at least one IR-absorbing component and at least one polymeric, organic binder and decomposes under the action of IR laser radiation or changes so that its adhesion to the silicone top layer decreases, and a top layer comprising a cured silicone rubber. The substrate comprises an oxidizable metal or one of its alloys and, at least on the side facing the IR-absorbing layer, is roughened and is covered with a layer of an oxide of the metal. The invention also relates to a process for the production of a waterless offset printing plate and to the printing plate itself which is produced from the recording material according to the invention and in which the hydrophilic surface of the oxide layer is ink-carrying and the oleophobic top layer is ink-repellent.

Abstract: Lithographic plate compositions and a method for their production have been discovered that are especially useful in conjunction with digitally controlled lasers to directly construct printable images on lithographic plates. The plates comprise a substrate and an ablatable polymeric coating on the substrate where the ablatable, imageable coating is prepared by in situ or solution polymerization of conjugated monomers deposited on the plate by vapor deposition or in solution. Examples of such monomers are thiophene, pyrrole and aniline.

Abstract: Apparatus and methods for rapid, efficient production of durable lithographic printing plates by a thermal-transfer process that does not involve ablation. In response to an imaging pulse, a transfer material reduces in viscosity to a flowable state. The material exhibits a higher melt adhesion for a plate substrate than for the carrier sheet to which it is initially bound, so that in a flowable state it transfers completely to the substrate. Following transfer, the carrier sheet, along with untransferred material, is removed from the substrate.

Abstract: The present invention provides a method for developing a lithographic plate on a printing press without the requirement of bath processing, the printing press equipped with means for delivering ink and aqueous fountain solutions to the plate, the preferred plate having in order (a) a substrate; and (b) a photoresist photohardenable upon imagewise exposure to actinic radiation, the photoresist comprising (i) a macromolecular organic binder; (ii) a photopolymerizable ethylenically unsaturated monomer having at least one terminal ethylenic group capable of forming a high polymer by chain-propagated polymerization, (iii) a polymerization initiator activatable by actinic radiation, and (iv) a disperse hydrophilic microgel. According to a product aspect, the present invention also provides a lithographic plate, configured as indicated, with the further combination therewith of an on-press removable polymeric overcoat.