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 photosensitive composition comprising: a titanocene compound; and at least one dye selected from: carbonyl compounds represented by formula (I): wherein Y represents a nonmetallic atom group for forming a nitrogen-containing heterocyclic ring together with the adjacent N and carbon atom, and X represents a monovalent nonmetallic atom group; and merocyanine compounds represented by formula (II): wherein A represents S atom or NR1, R1 represents an alkyl group or an aryl group, Y represents a nonmetallic atom group for forming a basic nucleus of the dye together with the adjacent A and carbon atom, X1 and X2 each independently represents a monovalent nonmetallic atom group, and X1 and X2 may be combined with each other to form the acidic nucleus of a dye. Also disclosed is a method for manufacturing a lithographic printing plate using the photosensitive composition.

Abstract: An elongated web of lithographic printing plate stock is intermittently fed to the drum of an external drum imaging device. The web is then cut to form the trailing end of an individual printing plate either before or after the leading end is clamped to the drum. The drum is then rotated such that the plate is wrapped around the drum and the trailing end is clamped to the drum.

Abstract: Phenolic resin compositions formulated for use in lithographic exposure processes are given a heat treatment at 40-90° C. for at least 4 hours shortly after their coating onto lithographic substrates, to produce lithographic printing forms. It is found that such a heat treatment improves later exposure processes, in particular by rendering the sensitivity of the compositions less variable, over time.

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 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 heat mode type lithographic printing plate precursor which can be directly mounted on a printing press without development processing after scanning exposure for a short time to conduct plate-making, has excellent press life and also gives few print stains onto a printed face, which comprises a substrate having provided thereon an image recording layer containing fine light-heat convertible particles which are coated with a hydrophilic material, the layer being made hydrophobic by the action of heat.

Abstract: A lithographic printing plate precursor is disclosed, comprising a support having thereon a photosensitive layer containing 6 wt % or more of an infrared absorbent which changes from hydrophilic to hydrophobic by heat, the support having a hydrophilic surface.

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: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared using a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic polymer that comprises recurring units comprising quaternary ammonium carboxylate groups. These quaternary ammonium carboxylate groups include at least one substituted-alkylene(C1-C3)-phenyl group. The imaging member can also include an infrared radiation sensitive material to provide added sensitivity to heat that can be supplied by laser irradiation in the IR region. The heat-sensitive polymer is considered “switchable” in response to heat, and provides a lithographic image without wet processing.

Abstract: According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer soluble in an aqueous alkaline solution, and a top layer on the same side of the lithographic base as the first layer that is IR-sensitive and unpenetrable for an aqueous alkaline developer wherein said first layer and said top layer may be one and the same layer; characterized in that the surface of said element upon exposure and treatment with an aqueous alkaline developer is such that a) the contact angle between the unexposed areas of the imaging element and the aqueous alkaline developer changes for at most 6° during the first minute of contact with said developer; b) the contact angle between the exposed areas of the imaging element and the aqueous alkaline developer changes more than 15° during the first minute of contact with said developer; c) the difference in contact angle betwe

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared using a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic polymer that comprises recurring units comprising quaternary ammonium carboxylate groups. The imaging member can also include an infrared radiation sensitive material to provide added sensitivity to heat that can be supplied by laser irradiation in the IR region. The heat-sensitive polymer is considered “switchable” in response to heat, and provides a lithographic image without wet processing.

Abstract: A positive-type photosensitive composition that has high sensitivity, good latitude in development, and good storage stability and is for use in a direct plate production process using an infrared laser and a novel anionic infrared-ray absorbing agent suitable therefor. This composition comprises (a) an anionic, infrared-ray absorbing agent represented by general formula (I) and (b) a polymeric compound that is insoluble in water but soluble in an aqueous alkaline solution so that the composition becomes soluble in the aqueous alkaline solution when irradiated with the infrared laser. In the general formula (I) given below, M represents a conjugated chain, Ga− represents an anionic substituent group, Gb represents a neutral substituent group, and Xm+ represents a cation including a portion, the cation having a valence of from 1 to m, wherein m represents an integer ranging from 1 to 6.

Abstract: Patterned photoresist layers formed on substrates have features with high aspect ratios. The photoresist layers can be formed as single layers with aspect ratios as high as about 4:1. In addition, the features in the photoresist layers can have a wide range of aspect ratios in a given single layer. The photoresist layers can be used in ink jet print heads and other devices to provide controlled fluid flow. The photoresist layers are formed using a contrast enhancement material that enables features having substantially vertical side walls and high aspect ratios to be formed.

Abstract: A planographic printing original plate which comprises an intermediate layer which contains a polymer including, as a monomer unit, at least a monomer having an acid group and a monomer having an onium group; and a photosensitive layer comprised of a positive-type photosensitive composition for an infrared laser which contains: (A) at least an alkali-soluble polymeric compound; (B) a compound which has a function to deteriorate the solubility of the alkali-soluble polymeric compound in an alkaline aqueous solution due to compatibility with the alkali-soluble polymeric compound, the function being deteriorated by compound (B) being heated; and (C) a compound which generates heat by absorbing light, the intermediate layer and the photosensitive layer being formed sequentially on a support which has been subjected to a hydrophilizing treatment.

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 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 wet processing.

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 of producing a lithographic printing plate which comprises subjecting a printing plate precursor comprising a support having a metallic compound layer which has a photo-catalytic property and a hydrophilic surface and bears light-heat convertible minute particles on the surface thereof to imagewise irradiation of heat mode to convert polarity of the metallic compound layer, thereby forming an imagewise hydrophobic region. The lithographic printing plate can be repeatedly employed.

Abstract: A planographic printing plate precursor is provided which includes a substrate having thereon an image recording layer containing a metal compound (I-a) which causes a decarboxylation reaction by heat and releases a polyvalent metal cation, and a hydrophilic polymer (I-b) which has two or more hydrophilic groups within the same molecule and can coordinate with the polyvalent cation. Also provided is a planographic printing plate precursor including a substrate having thereon an image recording layer containing a metal complex compound (II-a) and a hydrophilic polymer (II-b) which can coordinate with a metal generated from the metal complex compound by action of heat and which has two or more hydrophilic groups within the molecule and whose main chains are crosslinked.

Abstract: A method of producing a resist pattern on a substrate using a precursor which comprises a coating composition which includes a heat sensitive polymeric substance having functional groups Q thereon (wherein groups Q may be siloxane or optionally substituted fluoroalkyl groups) wherein groups Q cause the polymeric substance to have a reduced adhesive interaction with ink for use in waterless lithographic printing compared to aid polymeric substance in the absence of said groups, the method including the step of causing the patternwise application of heat to said coating composition and optional development thereby to define ink accepting areas in heat exposed areas and non-ink accepting areas in non-exposed areas.