Abstract: A method for the preparation of a negative working lithographic printing plate by means of ink jet printing is disclosed. This method uses a lithographic printing plate precursor comprising a lithographic support and an image forming layer containing a polymeric binder soluble in an aqueous alkaline developer. The precursor is image-wise printed by an ink jet fluid comprising a compound capable of reducing the solubility of said binder in said aqueous alkaline developer. After development a negative working printing plate is obtained.

Abstract: An offset press is equipped with a printer and a regenerative platemaker. The printer includes a plate cylinder on which a printing plate is fitted, and a transfer cylinder to which an image on the printing plate is transferred. The regenerative platemaker is arranged near the printer and is used to write the image to the printing plate.

Abstract: An offset press is equipped with a printer and a writable regenerative platemaker. The printer includes a plate cylinder on which a printing plate is fitted, and a transfer cylinder to which an image on the printing plate is transferred. The regenerative platemaker is formed integrally with the printer and is used to write the image to the printing plate. The printing plate is constructed of a gapless printing plate. The printing plate can be removed from and fitted on the plate cylinder by being moved along the axial direction of the plate cylinder.

Abstract: The invention provides a lithographic printing for precursor having an imagable coating on an aluminum support, wherein the imagable coating comprises a polymeric substance comprising colorant groups, and wherein the aluminum support on which the coating is provided is anodized but not subsequently modified by means of a post-anodic treatment compound, and the coating does not comprise a colorant dye. The polymeric substance may also comprise pendent infra-red or developer dissolution inhibiting groups, and these groups may also be the colorant groups themselves.

Abstract: This patent describes on-press ink and/or fountain solution development of lithographic plates having on a substrate a thermosensitive layer capable of hardening or solubilization upon exposure to an infrared laser radiation. The plate can be imagewise exposed with an infrared laser and then on-press developed with ink and/or fountain solution by rotating the plate cylinder and engaging ink and/or fountain solution roller. The developed plate can then directly print images to the receiving sheets. The imagewise exposure can be performed off the press or with the plate being mounted on the plate cylinder of a lithographic press.

Abstract: A method for preparing a lithographic plate which can react with an imaging fluid to form an image, including providing a hydrophilic support; forming a fluid-receiving layer that includes a water-soluble material which is chemically reactive with the imaging fluid; imagewise applying the imaging fluid to the fluid-receiving layer; and drying or curing the applied fluid to form an image in the fluid-receiving layer.

Abstract: A printing plate is prepared by the method comprising: (a) providing a substrate; and (b) applying by ink jetting to the substrate a fluid composition comprising an acidic polymeric compound, in which the acid groups of the acidic polymeric compound are at least partially neutralized with base, providing a printing plate that is ready-to-use on a press without having to develop it. The printing plate of this invention is capable of extended press run length and advantageously avoids the need of chemical development.

Abstract: A method of making a printing plate in which the uncoated surface of a substrate is treated with a pre-treatment solution prior to the deposition of ink on the surface. The pre-treatment liquid comprises a polyvalent metal salt, and at least one of an organic swelling reagent and/or a coalescence reagent. The pre-treatment liquid is applied to form a thin, homogenous layer of approximately 4 &mgr;m to the entire upper surface of the recording plate. The swelling reagent and/or the coalescence reagent and the polyvalent metal cations are physically well localized in the porous structure of the plate's surface. After partial drying of the pretreated anodized aluminum plate, CTP liquid is deposited onto the surface to form an image. The CTP liquid solids react with the pre-treatment liquid and are, therefore, chemically bound to the surface. This allows all data to be deposited in a single pass of the inkjet head without the problem of clustering.

Abstract: According to the present invention there is provided a method for the preparation of a lithographic printing plate comprising the steps of exposing with IR light an imaging element comprising 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 which top layer is IR-sensitive and unpenetratable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer, said imaging element comprising a siloxane surfactant; developing said exposed imaging element with an alkaline solution; rinsing said developed imaging element with water or an aqueous solution; gumming said developed imaging element with a baking gum solution; subjecting said gummed imaging element to a thermal treatment at a temperature above 50° C.

Abstract: According to the present invention there is provided a method for preparing a lithographic printing plate, the method including the steps of (1) providing an imaging element including on a lithographic hydrophilic support as contiguous top layer a heat-sensitive coating including a compound capable of converting light to heat and a compound, which becomes more hydrophilic under the action of heat; (2) imagewise exposing the imaging heat-sensitive composition with a high intensity laser emitting a laser beam with an intensity at the surface of the heat-sensitive composition of tat least 2 mW/&mgr;m2 thereby at least partially removing the heat-sensitive composition to expose at least partially the lithographic support.

Abstract: A fluid composition suitable for ink jetting upon a substrate, which includes a copolymer having a low surface energy and a plurality of tertiary amine sites, where the tertiary amine sites are at least partially neutralized with an acid; a nonionic or cationic surfactant; and water. The fluid composition may be used to prepare a printable media comprised of a substrate and an ink receptive thermoplastic image layer supported on the substrate; where the ink receptive layer contains a copolymer having a low surface energy and a plurality of tertiary amine sites, the amine sites being at least partially neutralized with an acid.

Abstract: According to the present invention there is provided a method for the preparation of a lithographic printing plate comprising the steps of exposing with IR light an imaging element comprising 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 which top layer is IR-sensitive and unpenetratable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer, said imaging element comprising a siloxane surfactant; developing said exposed imaging element with an alkaline solution; gumming said developed imaging element with a baking gum solution; subjecting said gummed imaging element to a thermal treatment at a temperature above 50° C.

Abstract: A printing plate is prepared by the method comprising: (a) providing a substrate; and (b) applying by ink jetting to the substrate a fluid composition comprising a compound which comprises at least one nitrogen-containing heterocyclic moiety, providing a printing plate that is ready-to-use on a press without having to develop it. The printing plate of this invention is capable of extended press run length and advantageously avoids the need of chemical development.

Abstract: A method for preparing a lithographic plate which can react with an imaging fluid to form an image, including providing a hydrophilic support; forming a fluid-receiving layer that includes a water-soluble material which is chemically reactive with the imaging fluid; imagewise applying the imaging fluid to the fluid-receiving layer; and drying or curing the applied fluid to form an image in the fluid-receiving layer.

Abstract: A method for correcting mistakes and other imperfections in printing members is disclosed. Ink accepting areas of the printing member are rendered non-ink accepting by treatment with a deletion fluid. Deletion fluids include, for example, acids, alkalis, and oxidizing formulations. A preferred deletion fluid is concentrated sulfuric acid.

Abstract: A method of preparing a printing plate for printing comprises applying a fluid composition by ink jetting to a substrate, and thereafter curing the fluid applied to the substrate. The fluid composition is jetted onto the substrate at a jetting temperature T2. The substrate is at a temperature Ts. The viscosity of the fluid composition at temperature Ts is about at least 300 times greater than the fluid's viscosity at temperature T2. The invention minimizes the dot spreading which otherwise occurs when a substrate is imaged via ink jetting to prepare a printing plate.

Abstract: A process for the treatment of an erasable lithographic printing plate, includes treating a used or unused printing plate with an erasing composition to clean the printing plate, laser imaging the printing plate with a polymeric substance, and to provide an image thereon, and fixing the image on the printing plate. Further, the printing plane has applied thereto any one of a heat-curable and water-soluble substance, if desired, immediately after the laser imaging, or a water-soluble substance immediately after the laser imaging, or a heat-curable and water-soluble substance immediately after the laser imaging, followed by warming of the printing plate. The water-soluble substance or the heat-curable and water-soluble substance is washed off using a solution essentially consisting of water before printing.

Abstract: Disclosed are a printing plate precursor having an anodized titanium film layer on a surface thereof; a process for lithography which comprises image-wise exposing the surface of the printing plate precursor to an actinic light, bringing the exposed surface into contact with a printing ink to form a printing surface where the image areas have received the ink, and using the resultant printing plate to conduct printing; and the process for lithography described above which further comprises cleaning the surface of the printing plate after completion of the printing to remove the remaining ink from the surface, subsequently heating the printing plate precursor at 80 to 500° C., and then repeatedly using the printing plate precursor.

Abstract: A method is disclosed for removing ink accepting areas of a printing surface of a lithographic printing master by treatment with an atmospheric plasma. Preferably, the plasma is directed to the printing surface as a plasma jet while the printing master is mounted on the plate cylinder of a printing press. The method enables to clean a support of a printing master and then reuse the cleaned support for making another printing master. Preferably, all the following steps are performed on-press: (i) making an imaging material by providing a support with an image recording layer; (ii) making a printing master having a printing surface comprising ink accepting areas by image-wise exposing and optionally developing the imaging material; (iii) starting a pressrun; (iv) a cleaning step using an atmospheric plasma and then repeating steps (i) to (iv).

Abstract: A process for making lithographic sheet material suitable for imaging by laser radiation. A metal substrate is electrocoated in a bath containing a polymeric resin and laser-sensitive particles, thereby depositing a laser ablatable layer on a principal surface of the metal substrate. In one embodiment, the laser-ablatable layer is treated with a corona discharge for a time sufficient to render the layer non-ink wettable. In other preferred embodiments, the laser-ablatable layer is overcoated with an overlayer such as a non-ink wettable silicone layer or a water-wettable layer comprising an organophosphorus polymer, preferably a copolymer of acrylic acid and vinylphosphonic.

Abstract: A direct drawing lithographic printing plate precursor, which includes a water-resisting support having provided thereon an image-receiving layer, an image being formed on the image-receiving layer with an oil-based ink by an electrostatic ink jet system, wherein the water-resisting support has at least a resin coating layer on the side opposite to the side on which the image-receiving layer is provided, wherein the resin coating layer includes a mixture containing from 10 to 90 wt % of a low density polyethylene having a density of from 0.915 to 0.930 g/ml and a melt index of from 1.0 to 30.0 g/10 min., wherein the surface of the resin coating layer has a Bekk's smoothness of from 5 to 2,000 sec/10 ml, and wherein the water-resisting support has a conductive layer having a specific electric resistance value of 1010 &OHgr; cm or less on the image-receiving layer side surface thereof and on at least one end face thereof.

Abstract: According to the present invention there is provided a method for preparing a lithographic printing plate, comprising the step of dispensing in a predetermined pattern a hydrophobic or hydrophobizing composition onto a receiving element comprising on a support a layer comprising hydrophobic thermoplastic polymer particles dispersed in a hardened hydrophilic binder.

Abstract: A plate-making method comprising: forming an image directly on a plate material by an electrostatic ink jet method comprising ejecting an oil ink using electrostatic field based on signals of image data; and fixing said image to manufacture a printing plate, wherein said method uses: (1) an ink circulation line having the following members a, b and c: a. an ink jet ejection head, b. an ink transportation line comprising an ink feed line for feeding said oil ink to said ink jet ejection head and an ink recovery line for recovering said oil ink from said ink jet ejection head, and c.

Abstract: The printing form, such as a printing plate or the surface of a printing cylinder, has a semiconducting surface with defined hydrophobic and hydrophilic areas corresponding to a print image to be printed with the printing form. The wetting characteristics of the printing form can be altered. To this end, the surface of the printing form is first placed into an essentially uniform chemical state with a first wetting behavior. Parts of all of the areas of the semiconductor surface are then put into a second chemical state which has a second wetting property that is different from the first.

Abstract: An imaging device for forming an image on a printing form, includes an imaging head containing a multiplicity of mutually parallel conductive pins separated from one another by an insulating material, a voltage source for a high-frequency alternating voltage, and a multiplicity of electronic switches, respectively, connected at one end thereof to one of the conductive pins, and at the other end thereof to the voltage source. Also disclosed are a method of operating the imaging device, and a printing form whereon the imaging method is performed.

Abstract: A support for lithographic printing plate which is obtained by performing surface roughening treatments including electrolytic graining on an aluminum alloy plate containing Fe, Si, Cu. Ti, Mg and Ni in specified amounts, with the balance being Al and incidental impurities. The Ni content, Cu content and the average surface roughness of the roughened support surface satisfy a specified relationship. A lithographic printing plate prepared from the support have longer press life, higher resistance to staining and better surface quality.

Abstract: A process is provided for a printing form for wet offset printing. A printing style is formed on an ink-transferring surface of the printing form (12) by forming ink-absorbing and ink-repelling areas. For illustration, the ink-transferring surface is wetted with a moistening agent. The areas of the moistened surface that are to be made into ink-absorbing areas are dried in a specific manner, and a material that absorbs printing ink is uniformly applied to the ink-transferring surface with the still dry areas. It is also possible to uniformly apply to the ink-transferring surface first a flowable material that absorbs printing ink, to dry the areas to be made into ink-absorbing areas in a specific manner, and to remove it from the areas to be made into ink-repelling areas by means of moistening agent.

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 processing device in a printing apparatus includes a developer feed roller partly immersed in a developer stored in a developer tank, a fixer feed roller partly immersed in a fixer stored in a fixer tank, and a drive mechanism for rotating the developer feed roller and fixer feed roller. Each of the developer feed roller and fixer feed roller has positioning members mounted on opposite end portions thereof to position the surface of the roller at a slight distance from an image area of a printing plate. Thus, the developer feed roller feeds the developer to the image area without contacting the image area, while the fixer feed roller feeds the fixer to the image area without contacting the image area.

Abstract: A computer-to-cylinder recording type lithographic printing method comprising: mounting a printing plate precursor onto a plate cylinder; forming an image directly onto a surface of said printing plate precursor mounted on the plate cylinder, by an ink jet process which comprises ejecting an ink containing a lipophilic component onto said printing plate precursor surface from a recording head having a plurality of ejection channels according to signals of image data, to thereby prepare a printing plate, said image recording being carried out while rotating the plate cylinder to effect main scanning, and moving said recording head in a direction parallel to an axis of the plate cylinder to effect subsidiary scanning; and performing lithographic printing with said printing plate, wherein the number of the ejection channels of said recording head is (X·(N/K)+1) and wherein the subsidiary scanning movement of said ejection head is carried out continuously at a constant speed of (X·(N/K)+1)

Abstract: A method of making a printing plate comprising forming an image on a surface of a first image-holding body based on image data signals by an electrostatic inkjet process comprising ejecting an oil-based ink; and contact-transferring the image formed on said first image-holding body onto a second image-holding body. Also disclosed are plate making apparatuses suitable for the method.

Abstract: Disclosed is an ink jet printing process comprising: filtering an oil-based ink; forming an image directly on a printing medium by an ink jet method comprising ejecting said filtered oil-based ink using electrostatic field based on signals of image data; and fixing said formed image to obtain a printed matter. Also disclosed is a printing apparatus suitable for the process.

Abstract: An image forming apparatus comprises: an image forming body comprising a substrate and a self-assembling compound adsorbed to a surface of the substrate to form a self-assembling monomolecular film; a first desorbing device for selectively desorbing at least a part of the self-assembling compound forming the self-assembling monomolecular film from the surface of the image forming body, so as to provide the surface of the image forming body with a desorbed face and an undesorbed face which have wettabilities different from each other; a developing device for supplying the surface of the image forming body with ink which preferentially attaches to one of the desorbed face or undesorbed face; and a transfer device for transferring to a recording medium the ink attached to the surface of the image forming body. In this apparatus, a printing plate can easily be formed and erased, and the same printing plate can be used repeatedly.

Abstract: A printing machine includes a printing form, an optical imaging unit for directly imaging the printing form, and an inking unit for inking the printing form, the printing form having a surface formed of a material with wetting properties reversibly changeable between a state with a very small contact angle and a state with a relatively large contact angle, the state with a small contact angle being achievable by action of light having a wavelength shorter than a material-specific wavelength, and a cleaning device for cleaning the surface of the printing form; and a printing process performed with the printing machine.

Abstract: A process for imaging a lithographic printing plate having a coating containing diazo resins. An ink jet printer is used to apply micro drops of a basic chemical solution that insolubilizes the affected areas of the coating to a developing solution. The latent image may be cured by heating the plate for a short period, and is then developed. The process works with conventional, commercially available lithographic plates and developers.

Abstract: There is provided a lithographic plate material which can be desensitized by distilled water or a fountain solution used for other lithographic plates without desensitizing process using an etching solution and lowers generation of scumming in non-image portion of printed matters. The lithographic plate material has an image-receptive layer formed on a support consisting of at least polyvinyl alcohol cross-linked by tetra alkoxy silane hydrolysate, titanium oxide micropatricles, silica having an average particle size of not less than 1 nm and less than 100 nm. The image-receptive layer has a surface having an arithmetic mean roughness of not less than 0.40 &mgr;m and less than 1.20 &mgr;m and a contact angle of less than 50 degree to distilled water at room temperature, and is ink-receptive for hot-melt and lipophilic ink.

Abstract: A method for preparing a printing form and a method of printing are disclosed. A coating of a radiation sensitive ink on a lithographic support having a hydrophilic surface is imaged. The unexposed areas of the coating are removed to produce a printing form, which is used for printing. Preferably, the same radiation sensitive ink is used for printing as is used in the coating, and, preferably, the desired printing run length is predetermined and the thickness of the coating determined according to the desired run length.

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 printer includes a printer carrier having a surface for receiving ink for transfer printing onto a carrier material, such as paper. Areas of the surface print carrier are ink attracting and others are made ink repelling. The ink repelling areas are formed by providing the surface with a layer of a substance in a solid phase, such as water in the form of ice. The ice layer repels the ink as it is applied so that the ink is only held on the surface of the print carrier at the areas that are ice free. The ice layer is formed by cooling the surface using a cooling mechanism to form a coating of frost due to condensation. A surface tension reducer for water is coated on the surface prior to cooling the surface. A laser or other radiation emitter structures the ice layer to form the print image.

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 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 printing plate precursor for direct receipt of an image-wise applied ink receptive layer the precursor having a desorbable surfactant adsorbed on at least one surface in an amount effective to improve the resolution of the subsequently image-wise applied ink receptive layer. The printing plate precursor can be used to prepare a printing plate having improved resolution. The printing plate may be prepared by (a) applying a desorbable surfactant to at least one surface of a printing plate substrate, (b) removing non-adsorbed surfactant from the surface, (c) applying a fluid composition containing an ink receptive material onto at least a portion of the surface in the form of a desired image, thereby providing an ink receptive image layer; and (d) removing the desorbable surfactant from any area of the surface which does not form part of the desired image.

Abstract: A direct-to-plate method of lithographic printing is disclosed which enables to recycle the lithographic substrate of the printing master.

Abstract: The object of the present invention is to provide a printing system ensuring easy formation of a plate and regeneration of said plate, and a press plate thereof.

Abstract: A printer and a restoration method for a printing plate which can be reused, while coping with digitization of printing processes is provided. On a substrate serving as a hydrophilic surface mounted beforehand onto a plate cylinder, a toner image portion formed on the surface of a photosensitive material is adhered and fixed directly or via an intermediate body to thereby form an image area. In thus way, the substrate is divided into a hydrophobic image area having at least a 50° or higher contact angle with water and a non-image area having an ink repulsion property, to thereby form a printing plate. After completion of printing, the ink and wetting solution adhered to the surface of the printing plate are cleaned by a cleaning apparatus, and image area on the surface of the printing plate is then removed by a chemical treatment solution supply roller, to thereby restore the printing plate to the initial condition so that this can be reused.

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: Provided is an imaged wet lithographic printing plate which bears a hydrophilic layer and an oleophilic, water-insoluble layer in a desired imagewise pattern overlying the hydrophilic layer, wherein the oleophilic layer comprises a reaction product of a transition metal complex of an organic acid, preferably a chromium complex of an organic carboxylic acid. Also provided are methods of preparing such imaged wet lithographic plates by ink jet printing and by laser ablation imaging; methods of preparing positive working, wet lithographic printing plates imageable by laser radiation; positive working, wet lithographic printing plates prepared by such methods; and methods of imaging such positive working plates by laser ablation imaging.

Abstract: A method for forming a planographic printing member is disclosed. A hydrophilic layer is formed on a support by contacting the support with a silicate solution that contains a silicate and a particulate material. An image layer is provided over the hydrophilic layer. The hydrophilic layer is treated to ensure that the image layer is able to change color on exposure. The hydrophilic layer may be treated with an acid, with a buffer formulation, with a colloidal suspension, or with a salt. Preferably the hydrophilic layer is treated with aluminum sulphate.

Abstract: A planographic printing member comprising a substrate, an oleophilic layer, an infra-red sensitive/ablatable layer, and a hydrophilic layer. The hydrophilic layer is derived from a silicate solution, optionally containing particulate materials such as alumina and/or titania. The printing member may be exposed to radiation from a laser which ablates the infra-red sensitive/ablatable layer to reveal areas of the oleophilic layer. An exposed printing member may be used in wet lithographic printing.

Abstract: An oil-based ink for the preparation of a printing plate by an ink jet process comprising dropwise Supplying an oil-based ink comprising resin particles dispersed in a nonaqueous carrier liquid having an electric resistance of 10.sup.9 .OMEGA.cm or more and a dielectric constant of 3.5 or less on an image-receiving layer of a lithographic printing plate precursor comprising a water-resistant support and the image-receiving layer provided thereon which contains zinc oxide and a binder resin and whose surface has a contact angle with water of 30 degrees or more to form an image and subjecting the non-image area of the image-receiving layer to oil-desensitization upon a chemical reaction treatment to prepare a lithographic printing plate wherein the resin particles dispersed are copolymer resin particles obtained by polymerization granulation of a solution of at least one monofunctional monomer, at least one monofunctional macromonomer and at least one resin for dispersion stabilization.