Abstract: A process for making thermally imageable negative working compositions comprising the steps of: (1) providing a patterning composition layer on a substrate, said patterning composition comprising: (a) at least one thermal-generator acid generator, (b) at least one cross-linking resin or compound; (c) at least one binder resin comprising a polymer containing at least one reactive pendent group selected from the group, consisting of hydroxyl, carboxylic acid, sulfonamide, alkoxymethylamide and mixtures thereof; and (d) at least one infrared absorber; (2) subjecting the patterning composition layer to a two-stage radiation exposure; (a) one stage being a flood UV-exposure; and (b) the other stage being a imagewise infrared exposure stage; (3) treating the exposed patterning composition with heat energy; and (4) developing the heat treated, exposed patterning composition with an aqueous alkaline developer to remove the non-imaged areas of the patterning composition and leaving the imaged areas substanti

Abstract: A positive photosensitive printing plate is prepared wherein the photosensitivity is to near-infrared rays which do not induce a chemical change in a photosensitive component. The photosensitive material has an inclined structure from the viewpoint of dissolution of the irradiated portion in an alkali developer. The dissolution rate is such that it continuously increases from the upper, surface part of the photosensitive material to the lower part of the photosensitive material. This effect may be enhanced by diffusion of a material, preferably a polar compound, such as H2O, from the surface toward the inner lower part of the photosensitive material. Techniques for accomplishing the diffusion include contacting the surface of the photosensitive material with an atmosphere of high humidity or overlaying the photosensitive material with a layer of protective material (paper) containing moisture and heating the resultant composite.

Abstract: A lithographic printing method is disclosed which comprising the steps of providing an imaging material which comprises a support and an image-recording layer that is not removable with a single-fluid ink which comprises an ink phase and a polar phase; image-wise exposure of the image-recording layer to heat or light without substantially ablating said image-recording layer, thereby switching the affinity of the image-recording towards ink or an ink-abhesive fluid and thereby creating a printing master comprising a lithographic image which consists of unexposed areas that have affinity for one phase of said ink phase and polar phase and of exposed areas that have affinity for the other phase of said ink phase and polar phase; printing, wherein the single-fluid ink is supplied to the printing master.

Abstract: A printing plate element is disclosed, comprising a substrate and a component layer containing a first material which is water-insoluble or capable of varying from being water-soluble to being water-insoluble at a prescribed temperature of not less than 60° C. and a second material which is water-soluble and has a melting point of 60 to 300° C. A method of preparing a printing plate is also disclosed, comprising imagewise exposure of the printing plate element and removing an unexposed area of the printing plate element with aqueous solution.

Abstract: An offset plate sensitive to UV or visible light, prepared simply and imaged digitally therewith in a CTP method, and also processed in a simple manner. The plate is provided as a photopolymer plate with increased sensitivity, and is used in a simple imaging-on-press system, using the surface of a lithographic printing cylinder itself as a plate substrate.

Abstract: Multi-layer thermally imageable elements, useful as a lithographic printing plate precursors, are disclosed. The elements contain a top layer, an absorber layer that contains a photothermal conversion material and a hydrophilic substrate. An optional underlayer may also be present between the absorber layer and the hydrophilic substrate. The elements can be thermally imaged and processed with an aqueous alkaline developer.

Abstract: A method of producing a printing plate comprises: (a) providing a printing plate precursor comprising a topmost etchable first layer and a second layer located below the first layer, wherein the first and second layers have different affinities for at least one printing liquid; (b) imagewise providing atomized fluid particles in an interaction zone located above the surface of the first layer; and (c) imagewise directing laser energy into the interaction zone, wherein the laser energy has a wavelength which is substantially absorbed by the atomized fluid particles in the interaction zone, and the absorption of the laser energy causes the atomized fluid particles to imagewise impart kinetic energy to and etch the first layer. Lithographic and flexographic printing plates may be prepared according to this method, including waterless plates, negative-and positive-working plates, and processless plates.

Abstract: There is provided improvement of a light-heat conversion in a light-stimulated writing method. An image recording body includes an element, which absorbs light (electromagnetic wave), provided in a surface of a recording body 10, or in a recording layer formed on uppermost layer of the recording body having a material exhibiting thermal changeable character of wettability, or in a substrate or an intermediate layer of the recording body. After a liquid is on the recording body 10 by a liquid forming means 3, light-stimulated writing is carried out. When the light-stimulated writing is carried out with light (electromagnetic wave) from a light (electromagnetic wave) source according to image information, an efficiency of light-heat conversion can be enhanced by a light (electromagnetic wave)-absorbing element.

Abstract: A process for making thermally imageable negative working compositions comprising the steps of:

Abstract: Negative working thermally imageable elements useful as lithographic printing plate precursors and methods for their use are disclosed. The elements have a substrate, a layer of imageable composition over the substrate, and, optionally, an overcoat layer over the layer of imageable composition. The imageable composition has an allyl-functional polymeric binder. Optimum resolution and on-press performance can be attained without a post-exposure bake. The elements do not require a post-exposure bake and can be used in on-press development applications.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, comprises latex polymer-carbon black composite particles. Such imaging members can be prepared with a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic polymer having ionic moieties and the latex polymer-carbon black composite particles as a photothermal conversion material. The latex polymer-carbon black composite particles can be formulated in water or water-miscible solvents without agglomeration with other components such as charged polymers.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared with a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic charged polymer (ionomer) and an infrared radiation sensitive negatively-charged oxonol dye that has a &lgr;max of greater than 700 nm. The heat-sensitive polymer and IR dye can be formulated in water or water-miscible solvents to provide highly thermal sensitive imaging compositions. In the imaging member, the polymer reacts to provide increased hydrophobicity in areas exposed to energy that provides or generates heat. For example, heat can be supplied by laser irradiation in the IR region of the electromagnetic spectrum. The heat-sensitive polymer is considered “switchable” in response to heat, and provides a lithographic image without conventional alkaline processing.

Abstract: According to the present invention there is provided a heat-sensitive material for making lithographic plates comprising in the order given on a support an IR-sensitive oleophilic layer and an ablatable cross-linked hydrophilic layer comprising an inorganic pigment and a hardener, characterized in that the ratio of said inorganic pigment over the hardener is comprised between 95/5 and 75/25 by weight.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared with a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic charged polymer (ionomer) and an infrared radiation sensitive negatively-charged oxonol dye that has a &lgr;max of greater than 700 nm. The heat-sensitive polymer and IR dye can be formulated in water or water-miscible solvents to provide highly thermal sensitive imaging compositions. In the imaging member, the polymer reacts to provide increased hydrophobicity in areas exposed to energy that provides or generates heat. For example, heat can be supplied by laser irradiation in the IR region of the electromagnetic spectrum. The heat-sensitive polymer is considered “switchable” in response to heat, and provides a lithographic image without conventional alkaline processing.

Abstract: A lithographic printing plate precursor comprising a support having a hydrophilic surface containing hydrophilic graft polymer chains and a heat-sensitive layer containing at least either of fine particulate polymer and microcapsules, which is excellent in on press developing property, sensitivity and printing durability.

Abstract: A method for making a printing plate including a step of forming a hydrophobic image area on at least a part of a hydrophilic surface of a plate. The plate surface contains a photocatalyst and the image area is formed by using an organic compound which is decomposed and removed by the irradiation of light having a higher energy than the band gap energy of the photocatalyst.

Abstract: A variable data lithographic printing device comprises surrounding a printing cylinder a photosensitive layer coater, an exposure source, optionally a developer, an inking applicator, optionally a transfer system, and optionally an eraser. During printing operation, each surface areas of the rotating cylinder continuously undergo the cycle of coating, imagewise exposure, optionally developing, inking, printing of inked imaging to the receiving medium, and optionally erasing processes. The developing means can be omitted if an ink and/or fountain solution developable photosensitive layer is used. In an alternative design, the cylinder is replaced with a continuous supply of a ribbon with lithographic substrate surface. In another alternative design, the cylinder and the coater are replaced with a continuous supply of a pre-sensitized ribbon comprising on a substrate a photosensitive layer.

Abstract: A method for imaging a printing form in which the printing form is charged on its entire surface and is coated on its entire surface with particles, in particular toner particles, which bear the opposite charge. The layer formed by the particles is then fixed in accordance with the image by a beam, in particular a laser beam, and especially by infrared radiation, on the surface of the printing form or ablated in accordance with the image. Thereupon, the unfixed portions of the layer are removed or the non-ablated portions are fixed by full-surface heat treatment.

Abstract: An improved offset printing press has a single plate blanket image (PBI) cylinder for holding an image formed on a thin film printing plate affixed thereto. The plate may be from 0.5 to 25 microns thick and has a thin layer of ink repelling material coated thereon. The plate is imaged, after being affixed to the PBI cylinder, by ablating selective portions of the ink repelling coating. The PBI cylinder is constructed to hold the printing plate by vacuum techniques, and apparatus to load and unload the plate is associated with the PBI cylinder. Because of the thinness of the printing plate, the PBI cylinder is a compliant surface, capable of printing on an inelastic media covered impression cylinder. In addition, unique inking apparatus is provided to transfer ink to the imaged printing plate. Variations of the press include a four color press utilizing a single PBI cylinder.

Abstract: A developer composition for developing a lithographic printing plate having a negative recording layer on which an image is recorded via an infrared laser, the composition containing a nonionic surfactant, and a process for forming an image on a lithographic printing plate. The process comprises the steps of imagewise exposing a lithographic printing plate having a negative recording layer on which an image is recorded via an infrared ray and which contains an infrared ray absorbent, a radical generator and a radically polymerizable compound, and then developing the lithographic printing plate with the developer composition containing a nonionic surfactant.

Abstract: According to the present invention there is provided a heat-sensitive material for making lithographic plates comprising in the order given on a support an IR-sensitive oleophilic layer and a cross-linked hydrophilic layer comprising an inorganic pigment and a hardener, characterized in that the ratio of said inorganic pigment over the hardener is comprised between 75/25 and 25/75 by weight.

Abstract: According to the present invention there is provided a heat-sensitive material for making a negative working non-ablative lithographic printing plate including in a heat sensitive layer thermoplastic polymer beads and a compound capable of converting light into heat on a surface of a hydrophilic metal support, the layer being free of binder, and characterized in that the thermoplastic polymer beads have a diameter between 0.2 &mgr;m and 1.4 &mgr;m.

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: A printing press includes a plate cylinder, a plate making unit, and a detection unit. The plate cylinder is rotatably supported by a frame and has an outer surface on which a plate is mounted. The plate making unit is supported to be movable between an operative position where plate making is performed and a wait position to escape from the operative position to perform plate making for the plate. The plate making unit has an exposure unit and a support mechanism for supporting the exposure unit to be movable in an axial direction of the plate cylinder. The exposure unit has a head which irradiates the plate with a laser beam to print an image on the plate. The detection unit detects a position of the exposure unit with reference to the frame.

Abstract: A method of treating a process-free printing form fitted to a printing-form cylinder includes having an imaging unit act upon a coating of a printing form and produce printing areas and non-printing areas on the printing form, and after the imaging unit has acted upon the coating, operating the imaging unit at reduced power during a return pass into a starting position thereof.

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

Abstract: A coating fluid for printing plates which can be suitably used to make printing plates that permit images to be written in response to input digital data and that can be easily regenerated and reused. This coating fluid for printing plates comprises at least a carrier liquid, thermoplastic resin particles and an IR absorber, and the IR absorber has a decomposition starting temperature higher than the melt starting temperature of the thermoplastic resin particles.

Abstract: A printing form that can be used many times has a printing surface which is provided with a metallic titanium layer. For imaging, the printing form is selectively coated hydrophilically in point-by-point manner by supplying controlled energy. After the printing, the image on the printing form can be erased by supplying heat; a method for forming images on a printing form and for erasing them; and a printing unit and a printing press including the printing form.

Abstract: Provided is a lithographic printing machine comprising a plate cylinder for imaging, a blanket cylinder, an impression cylinder, and a film-coating unit, a film-hardening unit, an imaging unit and a cleaning unit each unit of which is adjacent to the plate cylinder for imaging, wherein an image-forming layer containing a polymer having a functional group which is crosslinked by light or heat before imaging and a functional group which is converted from hydrophilic to hydrophobic by the heat generated by infrared ray irradiation is formed by the coating unit. A lithographic printing method using the lithographic printing machine is also provided.

Abstract: There is provided improvement of a light-heat conversion in a light-stimulated writing method.

Abstract: A method of printing is disclosed which comprises the steps of

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: According to the present invention there is provided a heat-sensitive material for making lithographic printing plates comprising on a lithographic support an image-forming layer comprising a hydrophilic binder, a cross-linking agent for a hydrophilic binder and dispersed hydrophobic thermoplastic polymer particles, characterized in that said image-forming layer is covered with a layer comprising at least one organic compound comprising cationic groups.

Abstract: A printing plate for computer-to plate lithography having a metal substrate with an anodized surface portion. The anodized surface portion has a porous texture in which a radiation-absorbing composition, preferably a black dye, is deposited. The surface portion with the radiation-absorbing composition is covered with a hydrophilic polymer or a sealant both. Upon exposure to laser radiation, the underlying oleophilic anodized surface portion containing the radiation-absorbing composition is revealed. Alternatively, laser radiation of the polymer composition may cause the affinity of the polymer for water and ink to change so that an irradiated portion of the polymer becomes oleophilic while the non-irradiated portion remains hydrophilic.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, has an imaging layer comprised of a thermally sensitive ionomer (charged polymer) and a photothermal conversion material that is a bis(aminoaryl)polymethine dye that is soluble in water or a water-miscible organic solvent, and that has a &lgr;max greater than 700 nm as measured in water or the water-miscible organic solvent.

Abstract: Provided is a lithographic printing plate comprising a support substrate having disposed thereon a hydrophilic layer interposed between the substrate and an ink-accepting ablative-absorbing surface layer. The ink-accepting surface layer comprising a one or more polymers and a sensitizer characterized by absorption of laser radiation. The printing plate may also comprise a primer layer underlying the ink-accepting surface 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: 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 layer imaging in an imagewise pattern removing by ablation not 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: A direct-to-plate method of lithographic printing is disclosed which enables to recycle the lithographic substrate of the printing master. The method comprises the steps of (a) making a negative-working imaging material by coating on a hydrophilic substrate a coating solution comprising hydrophobic thermoplastic polymer particles and a hydrophilic binder; (b) making a printing master having ink-accepting areas by image-wise exposing the imaging material; (c) applying ink and fountain solution to the printing master; (d) removing the ink-accepting areas from the printing master by supplying an amide and preferably also an alkanolamine. The above steps are preferably carried out on-press.

Abstract: A lithographic printing plate precursor comprises an electrochemically grained aluminium substrate, the grained surface of which is coated with a layer of gel-like amorphous colloidal oxides and hydroxides of aluminium and their hydrates incorporating metallic aluminium and inter-metallic aluminium alloys—generally at a level of below 5%—this layer being produced during the electrochemical graining process. The layer is typically present in an amount of from 0.1-20 g/m2 and at a layer thickness of 0.1-4.0 &mgr;m, the particle sizes in the said layer generally falling in the range of from 10 to 2000 nm. Methods are disclosed for the preparation of said precursors via the electrochemical graining of aluminium substrates. The invention provides lithographic printing plate precursors which may be imagewise exposed by means of a high intensity laser beam to provide printing plates showing high durability on press and giving images which show good resolution and are free from background staining.

Abstract: A printing press includes a plate cylinder, a plate making unit, at least one first engaging member, a first regulating member, a second engaging member, and a second regulating member. The plate cylinder is rotatably supported by a frame and has an outer surface on which a plate is mounted. The plate making unit is supported to be movable between an operative position where plate making is performed and a wait position to escape from the operative position. The first engaging member is fixed to one of the frame and the plate making unit. The first regulating member is fixed to the other of the frame and the plate making unit to engage with the first engaging member, and the first regulating member has a recess extending in an axial direction of the plate cylinder. The second engaging member is fixed to one of the frame and the plate making unit, and the second regulating member is fixed to the other of the frame and the plate making unit to engage with the second engaging member.

Abstract: A direct-to-plate method of lithographic printing is disclosed which enables to recycle the lithographic substrate of the printing master. The method comprises the steps of (a) making a negative-working imaging material by coating on a hydrophilic substrate a coating solution comprising hydrophobic thermoplastic polymer particles and a hydrophilic binder; (b) making a printing master having ink-accepting areas by image-wise exposing the imaging material; (c) applying ink and fountain solution to the printing master; (d) removing the ink-accepting areas from the printing master by supplying a aliphatic or aromatic compound having a structure comprising at least 6 carbon atoms. The above steps are preferably carried out on-press.

Abstract: Lithographic plate constructions include imaging layers having dispersed therein a radiation-scattering material and a radiation-absorbing material, both of which cooperate to increase the overall absorption of radiation in that layer. The radiation-scattering material may be in particulate form, the particles reflecting the imaging radiation from their surfaces. The use of particulate scattering material within the imaging layer creates a highly porous matrix that favors deep penetration of the imaging radiation and mechanical locking of the imaging layer to one or both adjacent layers. The scattering material may also be chosen also for its ability to chemically bind with an adjacent layer to increase intercoat adhesion.

Abstract: A method of printing an image with a printing plate prepared from a printing plate precursor, which comprises a support having thereon an image forming layer A containing a water-soluble material, the method comprising the steps of: (a) imagewise exposing the layer A of the printing plate precursor so as to form an unexposed portion and an exposed portion; (b) supplying an emulsion ink containing an oil-based ink and water onto the layer A so that the unexposed portion is removed from the layer A so as to form a non image portion and the exposed portion remains in the layer A so as to form an image portion to give the printing plate, wherein the image portion is lyophilic and the non image portion is hydrophilic; and (c) printing the image on the printing plate to an image receiving material while further supplying the emulsion ink.

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: An improved offset printing press has a single plate blanket image (PBI) cylinder for holding an image formed on a thin film printing plate affixed thereto. The plate may be from 0.5 to 25 microns thick and has a thin layer of ink repelling material coated thereon. The plate is imaged, after being affixed to the PBI cylinder, by ablating selective portions of the ink repelling coating. The PBI cylinder is constructed to hold the printing plate by vacuum techniques, and apparatus to load and unload the plate is associated with the PBI cylinder. Because of the thinness of the printing plate, the PBI cylinder is a compliant surface, capable of printing on an inelastic media covered impression cylinder. In addition, unique inking apparatus is provided to transfer ink to the imaged printing plate. Variations of the press include a four color press utilizing a single PBI cylinder.

Abstract: The present invention provides a printing member having a single radiation-absorptive multiphase layer over a substrate layer that may be imaged with or without ablation.

Abstract: According to the present invention there is provided a heat ode imaging element for making a lithographic printing plate having n 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 unpenetrable or insoluble for an alkaline developer wherein said first layer and said top layer may be one and the same layer and said first layer and said top layer being the imaging layers; characterized in that said imaging layers have a glass transition temperature of at least 57° C.

Abstract: A direct drawing type lithographic printing plate precursor comprising a water-resistant support having provided thereon an image-receiving layer, the image-receiving layer containing: at least one metal oxide hydrate having an average particle size of from 0.01 to 5 pm and comprising a metal atom selected from Mg, Al, Zn, Ge, Ti, Co, Zr, Sn, Fe, Cu, Ni, Pb, Pd, Cd, Mo, Cr, Ga, Mn, V, Ce and La; and a binder resin containing a complex comprising: a resin containing a siloxane bond in which a silicon atom is connected with an oxygen atom; and an organic polymer containing a group capable of forming a hydrogen bond with the resin containing a siloxane bond.

Abstract: Provided is a planographic printing plate precursor having the advantages of good developability in printers, high sensitivity and a long press life. On a support having a hydrophilic surface with hydrophilic graft polymer chains existing therein, formed is a thermosensitive layer containing a polymer having, in the molecule, a functional group capable of interacting with the hydrophilic graft polymer and a functional group that undergoes hydrophilicity/hydrophobicity conversion through exposure to heat, acid or radiation to fabricate the planographic printing plate precursor.