Abstract: The present invention relates to a photosensitive flexographic printing element for the production of flexographic newspaper printing plates, comprising at least a flexible, metallic support, an adhesive layer applied thereto, a photopolymerizable layer which can be developed in organic media and which itself comprises at least one elastomeric binder, ethylenically unsaturated monomers, a photoinitiator or photoinitiator system and a plasticizer, a transparent substrate layer, and optionally a removable protective film, where the total thickness of the flexographic printing element is from 300 to 1000 ?m, the elastomeric binder has a weight average molecular weight Mw of from 80,000 to 150,000 g/mol and a Shore A hardness of from 50 to 80, and the amount of plasticizer is from 5 to 50% by weight, based on the amount of all constituents of the photopolymerizable layer, and to a process for the production of flexographic newspaper printing plates by imagewise exposure of the flexographic printing element to act

Abstract: An improved method of manufacturing a photosensitive printing element that minimizes relief variation and improves image fidelity. The method involves a step of pre-curing the first (floor layer) of photocurable material prior to depositing an additional layer or layers of photocurable material that may be imaged and developed to produce a desired relief image on the surface of the photosensitive printing element. The photosensitive printing element is then thermally developed by contacting the photosensitive printing element with at least one roll that is capable of moving over at least a portion of the imaged surface of the flexographic printing element to remove the softened or melted non-crosslinked photopolymer.

Abstract: A method for preparing lithographic printing plates is disclosed. Imaged positive-working, thermally imageable, multi-layer imageable elements useful as lithographic printing plate precursors are developed using solvent based developers. Development may be carried out by immersing the imaged imageable element in the developer.

Abstract: Disclosed is a printing plate material comprising a surface roughened aluminum support, and provided thereon, an image formation layer containing a heat-curable polymer having a main chain polymer in the main chain, and an acryloyl group or a methacryloyl group in the side chain, a glass transition temperature Tg of the main chain polymer being from 0 to 100° C., wherein the printing plate material is capable of being developed on a printing press.

Abstract: A lithographic printing plate material is disclosed, comprising a flexible support having thereon a hydrophilic layer and an image forming layer, wherein the flexible support having the hydrophilic layer exhibits a transmission density of 0.5 to 1.2, and the outermost surface of an unexposed area of the image forming layer exhibiting a glossiness of 0.1 to 10. A printing method is also disclosed.

Abstract: A method for making a photosensitive resin printing plate which comprises at least (1) the exposure step of forming a latent image in an aqueous-developable photosensitive resin layer of a printing plate material by irradiating the printing plate material with a ray of active light, (2) the development step of forming a relief image from the latent image by dissolving or dispersing the photosensitive resin layer that forms the latent image into a developer that contains water as a main component, and (3) the drying step of removing the developer from the printing plate having the relief image, the method being characterized in that a photosensitive resin layer component-dissolved or dispersed developer produced in the development step is subjected to a reduced pressure distillation, and is therefore reused as a developer, and a residue produced by the reduced pressure distillation is solidified.

Abstract: Systems and methods are described for improved yield and line width performance for liquid polymers and other materials. A method for minimizing precipitation of developing reactant by lowering a sudden change in pH includes: developing at least a portion of a polymer layer on a substrate with an initial charge of a developer fluid; then rinsing the polymer with an additional charge of the developer fluid so as to controllably minimize a subsequent sudden change in pH; and then rinsing the polymer with a charge of another fluid. An apparatus for minimizing fluid impingement force on a polymer layer to be developed on a substrate includes: a nozzle including: a developer manifold adapted to supply a developer fluid; a plurality of developer fluid conduits coupled to the developer manifold; a rinse manifold adapted to supply a rinse fluid; and a plurality of rinse fluid conduits coupled to the developer manifold.

Abstract: A method for preparation of a lithographic printing plate, which comprises the steps of: imagewise recording on a lithographic printing plate precursor comprising a support having a hydrophilic surface and a thermosensitive layer, the thermosensitive layer comprising at least one of polymer particles and a microcapsule encapsulating an oleophilic compound therein; and rubbing the printing plate precursor by a rubbing member in the presence of a processing liquid to remove the thermosensitive layer of non-image portions.

Abstract: A positive-working, heat-sensitive material for making a lithographic printing plate by direct-to-plate recording is disclosed. The material comprises a hydrophobized grained and anodized aluminum support and a layer comprising a compound capable of converting light into heat provided onto said support, said support being obtainable by RF plasma treatment of a grained and anodized aluminum support in the presence of a fluorine containing gas.

Abstract: Disclosed is a process of preparing a planographic printing plate from a light sensitive planographic printing plate material comprising a hydrophilic support and provided thereon, an image formation layer containing (A) a polymerization initiator selected from an arene-iron complex and a tribromoacetyl compound, (B) a polymerizable ethylenically unsaturated compound, and (C) an alkali soluble resin with an acid value of 5 to 200, the process comprising the steps of imagewise exposing the light sensitive planographic printing plate material to ultraviolet light using an exposure device comprising a digital mirror device (DMD), and removing an image formation layer at non-exposed portions with an aqueous alkali solution to form an image.

Abstract: Disclosed is a process for manufacturing an aluminum support for a planographic printing plate material, the process comprising the steps of electrolytically surface-roughening an aluminum plate in an electrolytic solution, employing a sinewave alternating current; and anodizing the surface-roughened aluminum plate, the electrolytically surface-roughening step comprising a first stage of electrolytically surface-roughening the aluminum plate in a first electrolytic solution containing hydrochloric acid as a main component at a current density of D1 for t1 at a quantity of electricity of Q1 and a second stage of electrolytically surface-roughening the aluminum plate in a second electrolytic solution containing hydrochloric acid as a main component at a current density of D2 for t2 at a quantity of electricity of Q2.

Abstract: A method of manufacturing a light sensitive planographic printing plate which has an image forming layer containing (A) a coloring material having an absorption in a wavelength range of 700 nm through 1200 nm and (B) a radical generator on a support and is exposed by a laser beam with a light emission wavelength in a wavelength range of 700 nm through 1200 nm, the method comprising: at least coating process, dry process, cutting process, and inspection/sorting process, wherein either of the coating process, the dry process, the cutting process, or the inspection/sorting process is carried out under light of a light source comprising a light-emitting diode with an emission wavelength maximum in a range of 400 nm through 500 nm and a fluorescent phosphor to emit an yellow light by absorbing a light emission of the light-emitting diode.

Abstract: The present invention provides an imageable element including a lithographic substrate and an imageable layer disposed on the substrate. The imageable layer includes a radically polymerizable component, an initiator system, and a polymeric binder. The imageable element further includes a tetraarylborate salt. The presence of the tetraarylborate salt may provide improved imaging speed and may enhance press life due to better adhesion between the imageable layer and the substrate. The tetraarylborate salt may be present in the imageable layer, an interlayer, or a separate layer between the substrate and the imageable layer. The imageable element may be imaged and mounted on-press without a separate development step.

Abstract: The present invention provides an exposure processing method of a planographic printing plate comprising: providing an image recording layer containing a polymerizable compound which is solid at the room temperature, a polymerization initiator, and a light-to-heat converting agent, and a microcapsule encapsulating at least one of the monomer and the polymerization initiator, such that the light energy quantity absorbed in the lower part of the image recording layer is more than the light energy quantity absorbed in the upper and middle parts of the image recording layer; exposing the image recording layer, and thereafter post-heating the image recording layer at a temperature in a range equal to or above the melting point of the monomer and below the glass transition point of the wall of the microcapsule. As a result, the printing resistance of a planographic printing plate is enhanced.

Abstract: Disclosed is a manufacturing process of a printing plate material comprising a boehmite treated aluminum support, and provided thereon, an image formation layer containing water soluble resins or water dispersible resins, the process comprising the steps of surface roughening an aluminum plate, anodizing the surface roughened aluminum plate, boehmite treating the anodized aluminum plate to produce the boehmite treated aluminum support having boehmite protrusions with an average height of from 30 to 200 nm and an average base size of from 10 to 100 nm, coating a coating solution for the image formation layer on the resulting aluminum support to form a coated layer, and drying the coated layer to form the image formation layer on the aluminum support.

Abstract: Disclosed is a process of manufacturing a planographic printing plate from a planographic printing plate material comprising a support and provided thereon, at least one of an image formation layer and an ablation layer, the process comprising the steps of imagewise exposing the planographic printing plate material, and developing the exposed planographic printing plate material by supplying printing ink containing at least one of a polymerizable monomer and a polymerizable oligomer to the exposed planographic printing plate material.

Abstract: A manufacturing line for manufacturing a print belt comprising a support-forming strip and a photopolymerized resin forming printing characters, the line comprises spreader means adapted to spread the resin on the strip, photopolymerizer means adapted to solidify that portion of the resin that is to correspond to the printing characters, remover means adapted to remove the non-photopolymerized resin from the strip, and drive means adapted to drive the strip in translation in such a manner that each of its transverse sections passes in succession in register with the spreader means, the photopolymerizer means, and the remover means.

Abstract: This invention pertains to a system for thermally treating a photosensitive element to form a relief structure suitable for flexographic printing. The system of the invention comprises a plurality of consecutively arranged blotting stations for removing uncured photopolymer from the imaged surface of the photosensitive printing element. The flexographic plates produced in the apparatus of the invention are especially suited for use in printing newspapers and other publications.

Abstract: A process for manufacturing an aluminum support for a planographic printing plate material, the process containing the steps of: (a) electrolytically surface-roughening an aluminum plate in an electrolyte solution containing hydrochloric acid as a main component; and (b) anodizing the surface-roughened aluminum plate, wherein the step (a) contains: (i) a first stage which surface-roughens the aluminum plate employing a sine-wave alternating current; and (ii) a second stage which surface-roughens the aluminum plate employing a controlled sine-wave alternating current using a thyristor so that a current flow starts at a phase angle of 60 to 120 degree of an alternating current cycle.

Abstract: A negative-working CTP plate which is superior in resolution and printing resistance of the image area of a press plate is provided, which is obtained by forming a latent image on a heat-sensitive layer in a heat-sensitive lithographic printing plate comprising a substrate having a hydrophilic surface and a heat-sensitive layer made of an alkali-soluble polymer formed on the surface of the substrate, using heat generated upon irradiation with laser light, and developing the heat-sensitive layer using an alkaline developing solution. In the heat-sensitive lithographic printing plate comprising a substrate having a hydrophilic surface, and a heat-sensitive layer made of an alkali-soluble polymer formed on the surface of the substrate, an advancing contact angle (?f1) of the surface of the heat-sensitive layer with water at 25° C. is within a range from 70° to 110°, a receding contact angle (?b2) of the surface of the heat-sensitive layer with water at 25° C. after heating at 150° C.

Abstract: A printing plate material including: a plastic support; a hydrophilic layer on the plastic support; and a back layer on the plastic support, being provided on the opposite side to the hydrophilic layer, wherein the back layer includes a matting agent, and a distribution width of a projection amount of the matting agent is 1 to 20%.

Abstract: A photosensitive composition comprising, a polymerizable compound having an ethylenically unsaturated group, a metallic arene compound, and an acid generating agent, wherein, the polymerizable compound is a multifunctional acrylate compound containing an amide bond and a secondary or tertiary amine group in the molecule, and the acid generating agent is a compound containing a trihalomethyl group, a dihalomethyl group or a dihalomethylene group.

Abstract: Disclosed is a process of preparing a planographic printing plate from a light sensitive planographic printing plate material comprising a hydrophilic support and provided thereon, an image formation layer containing (a) an alkali soluble resin with an acid value of 5 to 200 having an acryloyl group or a methacryloyl group, the alkali soluble resin being obtained by reacting a vinyl copolymer having a monomer unit derived from acrylic acid or methacrylic acid with an epoxy compound having an acryloyl group or a methacryloyl group in the molecule, and (b) a diazo resin, the process comprising the steps of imagewise exposing the light sensitive planographic printing plate material to ultraviolet light using an exposure device comprising a digital mirror device (DMD), and removing an image formation layer at non-exposed portions with an aqueous alkali solution to form an image.

Abstract: The present invention provides a PS plate for use in making a lithographic printing plate, comprising an aluminum substrate provided thereon with a light-sensitive layer comprising a polyurethane resin binder, an addition polymerizable ethylenically unsaturated bond-containing compound and a photopolymerization initiator, wherein the polyurethane resin binder is one synthesized from at least the following compounds (i) to (iv): (i) at least one di-isocyanate compound; (ii) at least one diol compound having at least one carboxyl group; (iii) at least one diol compound whose log P value is less than 0; and (iv) at least one diol compound whose log P value is higher than 0.

Abstract: Disclosed is a planographic printing plate material comprising a hydrophilic support and provided thereon, a light sensitive layer and an overcoat layer in that order, wherein the light sensitive layer contains (a) an alkali soluble polymer, (b) a polymerizable compound having an ethylenically unsaturated bond, (c) a polymerization initiator, and (d) an anionic dye represented by the following formula (1),

Abstract: A method of printing is disclosed which comprises the steps of (i) providing a lithographic printing plate precursor comprising a support and a heat- or light-sensitive coating; (ii) image-wise exposure of the coating to heat or light; (iii) prior to step (ii) or (iv), mounting the lithographic printing plate precursor in a printing unit of a printing press, said printing unit comprising a dampening system and an inking system; (iv) development by supplying a processing liquid to the coating by means of the dampening system, thereby obtaining a lithographic printing plate; (v) printing by supplying single-fluid ink or driographic ink to the lithographic printing plate by means of the inking system. This method allows on-press processing of printing plate materials that require wet processing.

Abstract: A flexographic printing plate is prepared from a photosensitive element having a photopolymerizable elastomeric layer with specific rheological properties. The element is imagewise exposed and thermally treated to form a relief structure suitable for flexographic printing.

Abstract: A heat mode type negative image recording material is provided which comprises (A) a polymer compound that is insoluble in water but is soluble in an alkali aqueous solution and has at least one of groups represented by general formulae (1) to (3) on a side chain; (B) a photothermal conversion agent; and (C) an onium salt compound forming radicals by heat mode exposure with light that is capable of being absorbed by said photothermal conversion agent (B), said heat mode type negative image recording material being capable of recording an image by heat mode exposure. The general formulae are defined in the specification.

Abstract: An improved method of manufacturing a photosensitive printing element that minimizes relief variation and improves image fidelity. The method involves a step of pre-curing the first (floor layer) of photocurable material prior to depositing an additional layer or layers of photocurable material that may be imaged and developed to produce a desired relief image on the surface of the photosensitive printing element. The photosensitive printing element is then thermally developed by contacting the photosensitive printing element with at least one roll that is capable of moving over at least a portion of the imaged surface of the flexographic printing element to remove the softened or melted non-crosslinked photopolymer.

Abstract: A method of making a printing plate from a heat-sensitive PS plate of a positive-working mode for lithographic printing includes the steps of exposing the heat-sensitive PS plate to light and developing the PS plate using an alkaline developing solution containing at least one compound selected from the group consisting of cationic surfactants and compounds having three or more of an ethylene oxide-terminal group in the molecule thereof. The PS plate has a substrate and an image forming layer formed thereon, said image forming layer comprising a lower layer which is formed on the substrate and contains a water-insoluble and alkali-soluble resin and an upper heat-sensitive layer which is overlaid on the lower layer and contains a water-insoluble and alkali-soluble resin and an infrared absorption dye and exhibits an elevated solubility with respect to alkaline aqueous solutions when heated.

Abstract: A method for making a lithographic printing plate comprising the steps of: light-exposing to infrared radiation, a heat-sensitive presensitized plate of a positive-working mode for use in making a lithographic printing plate, said presensitized plate comprising a substrate and an image recording layer which is formed thereon and comprises a novolak resin containing xylenol as a monomer component and an infrared absorbing dye; and developing the light-exposed plate with an alkaline developing solution comprising at least one surfactant selected from the group consisting of anionic surfactants and amphoteric surfactants.

Abstract: An automated method of preventing edge curing of cut surfaces of photosensitive printing elements is disclosed. Once a photosensitive printing element is cut in a pattern of a desired size and shape, a portion of the coversheet on a periphery of the cut edges of the printing plate is removed, while leaving intact the layer of photocurable material and the optional ablation layer beneath the coversheet. Next, an edge cure prevention composition is applied to the optional ablation layer or the layer of photocurable material revealed by the removal of the portion of the coversheet. Once the edge cure prevention composition is dried, the remainder of the coversheet may be removed from the photosensitive printing element and the printing element may be mounted on a sleeve or cylindrical carrier for further processing. The method ensures that the edge cure prevention composition is applied only to areas where it is needed and does not affect imageable areas of the printing plate.

Abstract: The present invention provides a positive-working, thermally imageable element generally comprising a multi-layered imageable coating. The invention provides an imageable element comprising a substrate, an ink-receptive top layer, and an underlayer, the underlayer including a specific copolymer described herein. The copolymer can be a polymer comprising constitutional units derived from: a) a monomer having a cyclic urea group; b) a monomer comprising an N-substituted maleimide; c) a (meth)acrylamide or (meth)acrylate monomer; and d) a (meth)acrylic acid or vinyl benzoic acid monomer. In another embodiment, the copolymer can be a polymer comprising constitutional units derived from: a) a monomer having a cyclic urea group; b) a (meth)acrylic acid or vinyl benzoic acid monomer; c) and a (meth)acrylonitrile monomer. The imageable element may be used to prepare a lithographic printing plate that is resistant to press chemistry and can optionally be baked to increase press runlength.

Abstract: A method of graft polymerization which includes a step of forming a polymerization initiating layer in which a polymer having, on a side chain thereof, a crosslinking group and a functional group having polymerization initiating capability is immobilized on a support by a crosslinking reaction, and a step of conatacting a compound having a polymerizable functional group with the polymerization initiating layer, and then bonding the compound to the polymerization initiating layer supplying energy thereto, as well as a hydrophilic member, a printing plate precursor, a pattern forming material, a pattern forming method, a method of producing a particle-adsorbed material, and a method of producing a metal particle-dispersed thin layer film, to which the above-mentioned method of graft polymerization can be applied.

Abstract: A method for forming an image useful as a lithographic printing plate is disclosed. The imageable precursor comprises a water solubilized phenolic resin made up of an insoluble phenolic resin and a surfactant. The precursor can be imaged with an imaging solution, either off press or on press, using ink jet imaging techniques. The resulting imaged precursor can be developed using an aqueous liquid, such as water or a fountain solution, either off press or on press.

Abstract: Multilayer, positive working, thermally imageable, bakeable imageable elements are disclosed. The elements have a substrate, an underlayer, and a top layer. The underlayer comprises a resin or resins having activated methylol and/or activated alkylated methylol groups, such as a resole resin, and a polymeric material that comprises, in polymerized form about 5 mol % to about 30 mol % of methacrylic acid; about 20 mol % to about 75 mol % of N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, or a mixture thereof; optionally, about 5 mol % to about 50 mol % of methacrylamide; and about 3 mol % to about 50 mol % of a compound represented by the formula: CH2C(R2)C(O)NHCH2OR1, in which R1 is C1 to C12 alkyl, phenyl, C1 to C12 substituted phenyl, C1 to C12 aralkyl, or Si(CH3)3; and R2 is H or methyl. The elements produce bakeable lithographic printing plates that are resistant to press chemistries.

Abstract: A method for forming images useful as lithographic printing plate precursors is disclosed. An imageable element in which the imageable layer comprises an acid generator, a crosslinking agent, and a binder is imaged with ultraviolet radiation and developed with a solvent based developer. The acid generator is an iodonium, sulfonium, or diazonium salt in which the anion is an organic sulfate or thiosulfate anion. The binder comprises a copolymer that contains a reactive pendent group capable of undergoing acid crosslinking, in which the reactive pendent group is hydroxyl, carboxylic acid, sulfonamide, alkoxymethyl, or a mixture thereof. The method is especially suited for use with direct digital ultraviolet imaging devices. The resulting image is useful as a lithographic printing plate.

Abstract: An improved apparatus for thermally developing a flexographic printing element to reveal a relief image on the surface and a method of using the apparatus to expose and develop a flexographic printing element. The apparatus typically comprises means for softening or melting non-crosslinked photopolymer on the imaged and exposed surface of the flexographic printing element; at least one roll that is contactable with the imaged surface of the flexographic printing element and capable of moving over at least a portion of the imaged surface of the flexographic printing element to remove the softened or melted non-crosslinked photopolymer on the imaged and exposed surface of the flexographic printing element; and means for maintaining contact between the at least one roll and the imaged and exposed surface of the flexographic printing element.

Abstract: Disclosed are a printing plate material comprising a substrate and provided thereon, a component layer comprising a hydrophilic layer and an image formation layer, the hydrophilic layer being provided closer to the substrate than the image formation layer, wherein the hydrophilic layer contains an electron providing dye precursor, the image formation layer contains an organic electron accepting developing agent, and the component layer contains a light heat conversion material.

Abstract: A method of making a printing plate from a heat-sensitive PS plate of a positive-working mode for lithographic printing includes the steps of exposing the heat-sensitive PS plate to light and developing the PS plate using an alkaline developing solution containing at least one surfactant selected from the group consisting of anionic surfactants and ampholytic surfactants, and a salt selected from the group consisting of alkali metal salts and ammonium cation salts. The PS plate has a substrate and an image forming layer formed thereon, the image forming layer including a lower layer which is formed on the substrate and contains a water-insoluble and alkali-soluble resin and an upper heat-sensitive layer which is overlaid on the lower layer and contains a water-insoluble and alkali-soluble resin and an infrared absorption dye and exhibits an elevated solubility with respect to alkaline aqueous solutions when heated.

Abstract: Disclosed is a developing process on a press of a planographic printing plate material comprising a hydrophilic layer and an image formation layer, which is capable of being developed with water or capable of being developed on a press, the process comprising the steps of (a) supplying dampening water to the planographic printing plate material with a recorded image mounted on a plate cylinder of a press by bringing a dampening roller into contact with the planographic printing plate material while rotating the plate cylinder, and (b) then supplying ink to the planographic printing plate material by bringing an ink roller into contact with the planographic printing plate material to remove an image formation layer unnecessary for printing, wherein in the step (a), the supplied amount of the dampening water is varied.

Abstract: A method for structuring a surface includes, by an assigned modification device, creating a latent structure of at least a first layer of the surface, which has a polymer therein, so as to form hydrophilic and hydrophobic regions for producing a printing form for offset printing, by selectively applying a gaseous, readily volatile solvent as a modifying agent to at least one locally limited region of the surface over at least one exposure time interval. A device for performing the method, a printing form exposer, a printing unit and a printing machine including the surface-structuring device according to the invention, are also provided.

Abstract: A gravure printing element is fabricated using a negative-working thermally-imageable coating that is exposed using commercially available diode lasers, the coating being insensitive to ultraviolet light, daylight or visible light, and developable using aqueous media. A gravure etch mask is formed on a printing precursor by applying a coating of thermally-imageable material, curing the coating, imagewise illuminating the cured coating with a laser and removing with a developer the areas of the coating that were not illuminated. The masked precursor is then chemically etched to produce a gravure printing element.

Abstract: Thermally imageable elements useful as on-press developable lithographic printing plate precursors are disclosed. The elements comprise a substrate and a layer of an imageable composition over the substrate. The imageable composition comprises a photothermal conversion material, particles of a polyurethane polymer, and, optionally, a water soluble polymer. The polyurethane polymer comprises urethane linkages in the main chain, but does not comprise side chain urethane groups.

Abstract: A presensitized lithographic printing plate comprises a hydrophilic support and an image-forming layer. The image-forming layer contains microcapsules. The microcapsules consist of a shell and a core. The shell comprises a polymer. The polymer has a decomposition temperature in the range of 150 to 280° C. The core comprises a polymerizable compound.

Abstract: The present invention provides a thermally sensitive composition that may be coated as a water-borne material onto a substrate to yield a printing plate precursor having an imageable coating. The thermally sensitive composition comprises a sulfated phenolic resin. The sulfated phenolic resin may be a sulfated novolak resin or a sulfated resole resin, for example. The thermally sensitive composition may include a water-soluble binder, such as polyvinyl pyrrolidone, and a radiation-absorbing component. The invention also provides a printing plate precursor that is developed in water after imaging. The precursor does not require chemical development with a developing solution containing organic solvents or inorganic additives. The imaged precursor is on-press-developable when used with a fountain solution. Methods for making and using the precursor are also provided.

Abstract: The present invention provides a processless printing plate precursor including a thermally sensitive layer applied onto a substrate. The thermally sensitive layer includes polycyanoacrylate particles having a major dimension between about 50 and about 500 nm, and a mean major dimension of no greater than about 350 nm. The printing plate precursor may be exposed to radiation and may then be developed “on press” with a suitable fountain solution.

Abstract: A method for producing a pattern of hydrophilic (34) and hydrophobic (32) regions on a printing form (30) is presented which, in a first, essentially unpatterned state, features a polymer material containing imide groups, for example, polybenzene diimide or polyamide imide. The method includes a chemical treatment of the surface with an oxidizing agent subsequent in time to a locally selective exposure with UV light. Optionally, the locally selective exposure can be preceded by a large-area chemical treatment of the surface with a strong base. The printing form (30) can be restored to the first state by a large-area chemical treatment of the surface with a strong acid. The patterned printing form (30) is suitable for use in offset printing.

Abstract: A method for preparing a lithographic printing plate is disclosed, and said method comprises the steps of imagewise light-exposing to infrared radiation, a presensitized plate for use in making a lithographic printing plate, said presensitized plate having an image-forming layer which comprises an IR-absorbing agent, and developing the light-exposed plate with an alkaline liquid developer comprising a polyhydric alcohol-type alkylene oxide adduct.

Abstract: Infrared absorbing compounds that absorb at 800 nm±50 nm and at 1050 nm±50 nm, the two different regions of the infrared spectrum typically used for imaging, are disclosed. Thermally imageable elements that comprise these infrared absorbing compounds can be imaged with radiation in either of these two regions of the infrared spectrum. The elements are especially useful as lithographic printing plate precursors.