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

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

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

Abstract: The present invention provide a planographic printing plate comprising a substrate having thereon a recording layer which comprises at least one of a polymer compound carrying on a side chain a functional group which generates sulfonic acid under influence of an acid, base or heating; and a photo acid-generating agent or acid-generating agent; thermal base-generating agent; or an infrared ray absorbing agent, and by this structure, a high sensitive positive type planographic printing plate which can be developed with water or requires no developing is provided.

Abstract: This invention discloses lithographic printing plates having a thin releasable interlayer interposed between a rough and/or porous substrate and a radiation-sensitive layer. The radiation-sensitive layer is bonded to the rough and/or porous substrate through mechanical interlocking. Insertion of a thin releasable interlayer in such a configuration minimizes cross-contamination between the substrate and the radiation-sensitive layer, protects the substrate from attack by environmental species and reduces ink scumming tendency of the plates while still allowing good bonding between the substrate and the radiation-sensitive layer.

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

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

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

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

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

Abstract: The invention relates to a printing process, such as lithographic printing, that requires a printing press and a colorant vehicle. To enable constituting and rapidly removing motifs to be transferred to a printing medium, a hardenable material having good affinity for the colorant vehicle is deposited automatically and directly onto a device that cannot be dismantled or detached from the press, i.e., is part of the press, and that is constituted of a material having an opposite affinity, so as to constitute the motifs to be transferred to the medium. The material constituting the device is such that the material can be removed rapidly when the motifs are to be changed, and is such that new motifs can be constituted there immediately after the removal of those preceding them.

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

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

Abstract: To delete undesired ink-receptive areas on a wet lithographic printing construction, an oleophobic material is applied to the hydrophilic surface of the plate that has suffered contamination and/or scratching, and allowed to cure. So long as the hydrophilic surface is capable of permanently bonding the oleophobic deletion agent, the areas to which that agent has been applied will not accept ink.

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

Abstract: A processless visible light insensitive, IR sensitive printing member, is provided together with a method for producing the printing member. The method includes the steps of providing a visible light sensitive printing member and the step of processing the visible light sensitive printing member so as to receive a visible light insensitive, IR radiation sensitive printing member therefrom. The processing step is carried out in a visible light free environment.

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

Abstract: An imagewise polarizable imaging member can be used to print the same or different images with an electrically responsive marking media. The imaging member includes a matrix-addressable microelectronic layer in proximate relationship with an imagewise polarizable ferroelectric layer. Imaging is accomplished by forming an imagewise electrical pattern in the ferroelectric layer using signals from the matrix-addressable microelectronic layer, and applying the electrically responsive marking media to the electrically polarized ferroelectric layer, creating thereon an identifiable image pattern. The marking media can then be transferred to a suitable receiver material to form the desired printed image.

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

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

Abstract: Long wearing and reusable lithographic printing members are prepared from a zirconium metal or alloy that has an anodized zirconium metal or alloy printing surface. In use, the anodized printing surface of the printing member is imagewise exposed to electromagnetic radiation which transforms it from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface which is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. Such inked areas can then be used to transfer an image to a suitable receiving material in lithographic printing. These printing members are directly laser-imageable as well as image erasable.

Abstract: According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing an imaging element having on a support in the order given (i) a uniform ink-repellant layer comprising a hydrophilic binder cross-linked by means of a hydrolysed tetra-alkylorthosilicate and (ii) a photosensitive layer comprising a diazonium salt or a diazo resin;(2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and supplying an aqueous dampening liquid and/or ink to said photosensitive layer.

Abstract: A circuit arrangement for a reversible image build-up of a surface matrix of a printing form for a printing machine, wherein the surface matrix has regions which are activatable and de-activatable by repeated triggering, includes a respective electrical circuit operatively associated with every region of the surface matrix activatable and de-activatable by the repeated triggering, at least one threshold value switch connected in each of the electrical circuits and having a switching state variable by the triggering for respectively activating and de-activating the region operatively associated therewith.

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

Abstract: Reusable lithographic printing members are prepared from a ceramic that is a composite of a zirconia alloy and .alpha.-alumina. In use, a printing surface of the zirconia-alumina composite ceramic is imagewise exposed to electromagnetic radiation such as from a laser under controlled conditions to provide localized "melting" of the zirconia alloy in the exposed areas. Those areas are transformed from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface that is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. Such inked areas can then be used to transfer an image to a suitable substrate in lithographic printing. The printing members are directly laser-imageable as well as image erasable, and can include printing plates, printing cylinders, printing tapes and printing sleeves.

Abstract: Lithographic printing constructions are removable from a permanent support, which may be a metal sheet affixable (usually by clamps) to a plate cylinder, or may instead be the permanent surface of such a cylinder. In this way, the traditional "plate" is replaced with a thin, easily manufactured printing member, which is separated from the support following its use.

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

Abstract: A plate imaging apparatus and method for imaging a seamless printing member preferably loaded onto a rotating plate cylinder. The plate imaging apparatus moves a writing head in fixed increments in an axial direction relative to the plate cylinder. With the writing head fixed at a first axial position, the imaging apparatus causes a circumferential swath to be imaged onto the seamless printing member commencing from a first starting point. With the plate cylinder still rotating, the imaging apparatus then steps the writing head to the next axial position, thereby defining a second starting point once the writing head is ready to resume imaging that is offset from the first starting point. The imaging apparatus then causes a second circumferential swath to be imaged onto the seamless printing member commencing from the second starting point.

Abstract: Rotary lithographic printing members are prepared from a non-porous zirconia ceramic that is an alloy of ZrO.sub.2 and a second oxide chosen from MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, a rare earth oxide or a combination of any of these. These printing members can be rotary printing cylinders having a zirconia alloy ceramic printing surface. Such cylinders can be composed of zirconia alloy ceramic throughout, or have a ceramic sleeve or shell mounted around a non-ceramic core. In use, the surface of the zirconia alloy ceramic printing member is imagewise exposed to infrared radiation which transforms it from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface which is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. These printing members are directly laser-imageable as well as image erasable.

Abstract: Reusable lithographic printing members are prepared from a zirconia ceramic that is an alloy of ZrO.sub.2 and a second oxide chosen from MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, a rare earth oxide or a combination of any of these. In use, a printing surface of the zirconia alloy ceramic is imagewise exposed to electromagnetic radiation such as from a laser under controlled conditions to provide localized "melting" of the zirconia in the exposed areas. Those areas are transformed from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface which is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. Such inked areas can then be used to transfer an image to a suitable substrate in lithographic printing. The printing members are directly laser-imageable as well as image erasable, and can include printing plates, printing cylinders, printing tapes and printing sleeves.

Abstract: Flexible and reusable lithographic printing tapes are prepared from a zirconia ceramic that is an alloy of ZrO.sub.2 and a second oxide chosen from MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, a rare earth oxide or a combination of any of these. These printing tapes have an average thickness of less than about 5 mm. In use, a surface of the zirconia alloy ceramic printing tape is imagewise exposed to electromagnetic radiation which transforms it from a lydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface which is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. Such inked areas can then be used to transfer an image to a suitable substrate in lithographic printing. These printing tapes are directly laser-imageable as well as image erasable.

Abstract: Reusable lithographic printing members are prepared from a ceramic that is a composite of a zirconia alloy and .alpha.-alumina. In use, a printing surface of the zirconia-alumina composite ceramic is imagewise exposed to electromagnetic radiation such as from a laser under controlled conditions to provide ablation of the zirconia alloy in the exposed areas. Those areas are transformed from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface that is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. Such inked areas can then be used to transfer an image to a suitable substrate in lithographic printing. The printing members are directly laser-imageable as well as image erasable, and can include printing plates, printing cylinders, printing tapes and printing sleeves.

Abstract: The lithographic affinity characteristics of a material, such as a polymer, are affected--and thereby selectively modulated--through implantation of one or more metallic materials, typically in the form of ions and/or atoms (or molecules). The desired characteristics are achieved by bulk chemical modification of the material rather than by texturing or deposition of a new surface layer. In the case of a polymer system, for example, the metal impregnates the matrix, penetrating to an observable depth without substantial surface accumulation.

Abstract: A web is punched with registration holes and imaged prior to cutting the web into individual imaged plates particularly for use as printing plates. The web with an imageable surface is serially punched, imaged and sheeted with the punched holes being utilized to assure registration and alignment in the imaging operation and in the subsequent use of the plates on a printing press. The punching and imaging may be performed at separate stations or at a single punching and imaging station. The web is preferably advanced under tension and tension and/or vacuum may be used to hold the web flat on the imaging platen.

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

Abstract: The present invention provides a method for making a lithographic printing plate wherein an imaging element is image-wise heated by means of a thermal head. The imaging element comprises on a flexible support (i) an ink-repellant layer containing a cross-linked hydrophilic binder and (ii) an image forming layer comprising hydrophobic thermoplastic polymer particles dispersed in a hydrophilic binder. Subsequent to image-wise heating, the imaging element is developed with water or an aqueous liquid. Development may also be carried out on-press. Moreover, image-wise heating and development can both be carried out on press.

Abstract: A plate-imaging system and a plate-cylinder support structure are coupled in a manner that achieves precise spacing between a writing head and the surface of a lithographic plate. The imaging unit is designed to permit the writing head undergo controlled advancement toward the plate cylinder, and includes a pair of rollers fixed with respect to the writing head and a spaced so as to facilitate rolling contact with peripheral segments of the cylinder. When the imaging unit is brought into contact with the structure containing the plate cylinder, the writing head is advanced toward the cylinder until the rollers make contact with the peripheral segments. The alignment between the rollers and the writing head is fixed such that rolling contact between the rollers and the peripheral cylinder segments ensures proper spacing between the writing head and a plate mounted to the plate cylinder.

Abstract: Wet lithographic printing plates include a protective layer that provides protection against handling and environmental damage, extends plate shelf life, and entrains debris generated by ablation. The layer washes away during the printing make-ready process, effectively cleaning the plate and disappearing without the need for a separate removal process.

Abstract: The present invention discloses a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing an imaging element having on a hydrophilic surface of a lithographic base a photosensitive layer comprising a photosensitive polymer containing aryl-diazosulfonate units;(2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and supplying an aqueous dampening liquid and/or ink to said photosensitive layer while rotating said print cylinder.Excellent printing results are obtained with a printing plate perpared according to the above described method. The lithographic base may be an anodized aluminium or a support provided with an ink-repellant layer containing a cross-linked hydrophilic binder.

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

Abstract: Lithographic printing is carried out by a novel process utilizing a zirconia ceramic as a printing plate. In this process, the surface of the zirconia ceramic printing plate is imagewise exposed to radiation which transforms it from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface which is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. The zirconia ceramic printing plate utilized in this process is capable of extremely long printing runs, is especially well adapted for direct digital laser imaging using images that are electronically captured and digitally stored, and can be reused by erasing the image from the ceramic surface by thermally-activated oxidation or laser-assisted oxidation.

Abstract: Provided is a media-ink jet fluid marking material set which comprises a media comprising a support with a hydrophilic receiving layer together with an ink jet fluid marking material which comprises a liquid carrier medium and at least one organic or transition metal complex reactive component. Upon ink jet printing and subsequent exposure to an energy source, an effective amount of an olcophilic, water-insoluble, and substantially non-metallic pattern is achieved on the hydrophilic media. Such a media-ink jet fluid marking material set can be advantageously used in the manufacture of lithographic printing plates, and provides many advantages in the manufacture of durable and water-insoluble imaging elements.

Abstract: A direct-to-press system using a seamless cylinder coated on the press with a curable polymer. After curing, the surface of the polymer is modified by selective laser radiation to change its affinity to printing ink. The cylinder is used in place of a plate cylinder in an offset press, either conventional or waterless. Since only the surface is selectively modified by the laser, coating thickness and uniformity are of little concern. After printing, the cylinder is cleaned on the press using a cleaning station similar to blanket washers used on presses. Cleaning does not have to be complete since the surface of the cylinder is never exposed to the ink. The system is compatible with existing press designs as it can be mounted in the space currently used to access the plate cylinder for plate changing.

Abstract: In a printing method, an electrically encoded image to be transferred to a printing substrate during a printing process is provided in an electronic memory. A flexible carrier web is attached under tension to a cutting cylinder identical in dimensions to a blanket or printing cylinder of a printing machine. The curing cylinder may be a blanket or printing cylinder in a printing machine or a dedicated support cylinder in a stand-alone cutting assembly. The carrier web is cut automatically in accordance with the electrically encoded image after attachment of the carrier web to the cutting cylinder. Subsequently, sections of the carrier web are removed therefrom along cut lines made in the carrier web during the cutting thereof.

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

Abstract: Imaging elements are prepared by a method in which an image is generated on a donor element and then transferred from the donor element to a receiver element by the steps of lamination and peeling. The donor element comprises a support, an image-forming layer and optional release and adhesive layers and the image is formed by imagewise laser-induced thermal ablation of the image-forming layer. The method is particularly useful for the preparation of lithographic printing plates as it avoids the need to employ alkaline developing solutions.

Abstract: A method for producing a printing plate which involves forming an image on the surface of a sheet having open cells by selectively applying a thermal exposure to the surface of the sheet. The sheet is a thermoplastic resin preferably having melting point between about 50.degree. to 150.degree. C. The resulting printing plate has a planar surface with no relief sections; instead there are porous and nonporous sections, with the porous sections being permeable to ink infused within the printing plate. A method of printing using the above plate is also disclosed.

Abstract: Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.

Abstract: Seamless, sleeve-shaped dry and wet lithographic printing members that can be recycled after use include a strong, durable, hollow cylinder or sleeve that is attached to the plate mandrel or cylinder jacket of an offset printing press or platemaking apparatus. In one version, the sleeve is surrounded by a photopolymer, which is itself surrounded by a mask coating opaque to radiation that is actinic with respect to the photopolymer. Subsequently, the imaged construction is exposed to actinic radiation, and the unexposed photopolymer, along with the overlying mask, is removed by ordinary chemical means. In another version, a thermally transferable material surrounds a cylinder, and is itself surrounded by a withdrawal layer. Exposure of the thermally transferable layer to laser radiation adheres the transferable layer to the cylinder, and the adhered layer exhibits an affinity for fountain solution and/or ink opposite to that exhibited by the cylinder.