Abstract: There is provided a method and apparatus for forming an image which includes providing a recording composition capable of changing its adhesivity corresponding to the polarity of a voltage applied thereto between a pair of electrodes. The recording composition has a transfer characteristic having a tendency to change by loss of at least one component of the recording composition. A voltage is applied between the pair of electrodes to attach the recording composition to one of the pair of electrodes to attach the recording composition to one of the pair of electrodes. Any such change in the transfer characteristic of the recording composition is detected during the process. In response to any change in the transfer characteristic additional component is added to the recording composition to compensate for that change.

Abstract: A direct-to-press imaging system for use in lithographic printing wherein a master-image printing cylinder is used with separate application of ink and water onto its surface to enable repetitive conveyance of image-formatted ink films onto substrates for printing purposes. The imaging system includes a master-image printing cylinder adapted for receiving a hydrophilic coating layer on its surface and a device for laying down a uniform layer of hydrophilic material on the surface of this cylinder. An apparatus is also provided for applying oleophilic material in image-formatted patterns on top of the layer of hydrophilic material on the master-image printing cylinder to form a printing structure having separate hydrophilic and oleophilic areas of the format to be printed.

Abstract: A dampening water composition for lithographic printing which comprises 0.1 to 5% by weight of at least one member selected from the group consisting of monoalcohols or diols of alkanes or alkenes having 5 to 11 carbon atoms, to which 1 to 10 moles of ethylene oxide and/or propylene oxide are added. The dampening water composition is not toxic, has not a possiblity of causing a fire and pollution of working atmosphere and, therefore, the use of a local exhaust installation is not necessary. Moreover, it is excellent in characteristics as dampening water such that it does not cause contamination of metering roll, has good bleeding properties, emulsifying properties and stability in continuous processing as well as low foaming properties. Thus, the composition makes printing operation quite stable.

Abstract: An image forming apparatus includes a master having a conductive portion and an insulating portion which form a pattern; an applicator for applying the ink material on the master wherein deposition of the ink material onto the master is different depending on a direction of electric current flowing through the ink material; an excessive ink material remover, contactable to the ink material applied on the master by the applicator, for removing excessive ink material with a voltage applied between the master and the excessive ink material remover.

Abstract: A single-phase homogeneous composition for the protection of lithographic printing plate surfaces is provided which comprises an aqueous solution of(a) a hydrophilic film forming compound which is essentially cold-water soluble,(b) a hydrophilizing agent(c) a wet film forming agent,(d) a nonionic surfactant,(e) a greasing agent,and(f) one or more desensitizing salts.

Abstract: A lipophobicating solution for an electrophotographic plate for offset printing is disclosed which comprises (a) phytic acid, (b) a diamine having the general formula NH.sub.2 --R--NH.sub.2 wherein R is an alkyl or aryl group having from 2 to 8 carbon atoms, and (c) water. The pH of the solution is in the range from about 3.0 to about 6.0. This lipophobicating solution does not cause scumming and allows an electrophotographic process to produce clean printed sheets.

Abstract: The invention is a composition for forming a surface on a suitable substrate comprising(a) a water soluble polymer crosslinkable into a water-insoluble form;(b) a pigment component;(c) silica; and(d) a crosslinking agent.In a preferred embodiment, the polymer is an organic colloid such as polyvinyl alcohol, the pigment component comprises a water dispersible pigment such as titanium dioxide and clay, silica particles have diameters smaller than that of the pigment, and the crosslinking agent comprises a water soluble organic compound containing both an acid and carbonyl group, a water soluble dicarbonyl compound, and a suitable polymerizable resin.

Abstract: A printer capable of simultaneously forming planographic printing surface and printing ink images. The printer comprises a control unit, a plate feeding unit for continuously feeding a printing plate formed by coating an oil-repellent sheet with a fusible lipophilic thermal film, a plate making unit having a thermal head for locally and selectively heating lipophilic thermal film according to electric signals to remove portions of the lipophilic thermal film to make a planographic printing surface having a printing area, an inking unit having an inking roller for applying a liquid ink to the planographic printing surface of the printing plate, a transfer unit comprising a platen roller for continuously feeding a recording medium, and a pressure roller for pressing the planographic printing surface of the printing plate against the recording medium to transfer the inked pattern of the printing area to the recording medium.

Abstract: The invention provides a cleaner for lithographic printing plates free of aromatic hydrocarbons consisting essentially of from about 3.0% to about 35.0% of a solvent component which is selected from the group consisting of ethoxylates and propoxylates of C.sub.1 to C.sub.4 alcohols; and from about 0.5% to about 7.0% sodium metasilicate; and from about 0.25% to about 6.0% of a non-ionic surfactant selected from the group consisting of polyoxy aryl ethers having a hydrophile-lipophile balance in the range of from about 10.5 to about 11.5; and from about 52.0% to about 96.25% water, wherein said percentages are by weight of the cleaner.

Abstract: A desensitizing gum comprising an aqueous solution of water-soluble and film-forming hydroxyalkylated starch, characterized in that the degree of etherification of the hydroxyalkylated starch is 0.03 to 0.08 and the gum further contains at least one member selected from the group consisting of anionic and nonionic surfactants.

Abstract: A moistening agent and method for its use in offset printing plates is described. The agent contains native soluble non-crosslinked collagen and/or non-crosslinked elastin as a water-soluble organic polymer.

Abstract: Method of making a processing-free planographic printing plate comprising irradiating a plate surface comprised of a hydrophobic organic compound capable of being converted, upon exposure to radiation, from hydrophobic to hydrophilic, in an image pattern and thereby selectively converting said surface, in the image pattern, from hydrophobic to hydrophilic. Alternatively, the image pattern is allowed to remain hydrophobic while the non-image areas are rendered hydrophilic.

Abstract: A desensitizing gum for a lithographic printing plate and a gumming up process thereof are disclosed. The gum is comprised of water having dispersed therein 5 to 35 wt %, based on the total weight of the gum, of a film-forming, water-soluble compound selected from the group consisting of enzyme-decomposed dextrine and enzyme-decomposed etherified dextrine. The desensitizing gum exerts a desensitizing action on non-image areas of a lithographic printing plate and does not cause image blinding of image areas even when the plate is stored for a long period of time.

Abstract: A cyan-free desensitizing solution for use in offset printing comprising as the effective ingredients:(a) at least one member selected from the group of an ammonium salt and amine salt of inositol hexaphosphate ester;(b) a water-soluble cationic polymer; and(c) a low molecular weight electrolyte.

Abstract: An improved process for restoring the hydrophilic property of stained non-image areas in a lithographic printing plate is described, which comprises treating said lithographic printing plate with a plate cleaner, wherein the improvement comprises using a plate cleaner comprising an aqueous solution containing a silicate and at least one surface active agent selected from the group consisting of cationic surface active agents and amphoteric surface active agents.

Abstract: The invention relates to a solution and a process for desensitizing lithographic printing forms based on light-hardened diazo compounds and which are ready for printing. The desensitizing solution of the invention is composed of a water-soluble, film-forming, high molecular weight organic compound, a compound which has a high light-absorption in the spectral region in which the photolysis of light-sensitive aromatic diazo compounds is initiated, and water as the solvent.The desensitizing solution protects the image stencil against the action of light and prevents any deterioration of the oleophilic character of the image stencil during storage.

Abstract: A process for desensitizing lithographic printing plates is described. The gum for the process comprises an aqueous solution containing a film-forming starch derivative modified with polyoxyethylene or a polyoxyethylene-polyoxypropylene copolymer. The gum reduces the number of spoiled copies printed and the amount of staining on non-image areas.

Abstract: A method of preparing a lithographic printing plate in which a toner image formed by electrophotographic process is transferred and fixed on a metal base lithographic printing plate having a thin insulating synthetic resin surface layer. Thereafter the synthetic resin layer on the non-image area is removed followed by removal of the toner to leave resin image areas.

Abstract: An aluminum alloy plate for printing is composed of 0.05-0.30% Mg, 0.05-0.30% Si, 0.15-0.30% Fe and the remainder Al and ordinary impurities. This printing plate is manufactured through the steps of subjecting an aluminum alloy ingot of this composition to a thermal soaking treatment; carrying out a hot rolling process; then carrying out a cold rolling process on the hot rolled alloy at least at a reduction of 70%; and carrying out low temperature annealing at a temperature of 150.degree.-250.degree. C. for at least one hour.

Abstract: An offset printing plate is provided comprising a carbon steel substrate with printing and non-printing areas on its surface. The printing areas are made of a light-sensitive top layer material based on derivatives of ortho-naphthoquinonediazide-sulphonic or carboxylic acids or a light-sensitive top layer material comprising a photopolymerizable composition. These printing areas form a relief over the plate surface. The non-printing areas are made of a hydrophilized metal of the substrate hydrophilized carbon steel.A process for making an offset printing plate comprises application, onto a carbon steel substrate, of a light sensitive top layer based on derivatives of ortho-naphthoquinonediazide-sulphonic or carboxylic acids or a light-sensitive top layer comprising a photopolymerizable composition. The thus-applied top layer is dried.

Abstract: A retouching agent for lithographic printing plate containing an admixture of (a) a lactone having 4 to 6 carbon atoms and (b) a glycol ether or ketone.

Abstract: An emulsion type protective agent for the surface of a lithographic printing plate comprising an aqueous phase having dissolved therein a hydrophilic high molecular weight compound and an oil phase containing an organic solvent, an alkylphenyl type nonionic surfactant having an HLB less than 14 and an anionic surfactant.

Abstract: Method for lithographic printing wherein a lithographic printing plate having oleophilic and hydrophilic areas on the printing surface of the plate is contacted with ink and an aqueous fountain solution during printing. An aqueous solution comprising an enzyme is used as the fountain solution.

Abstract: A method for desensitizing an offset printing plate which comprises applying an aqueous desensitizing composition consisting essentially of at least one complex to a non-image area of the offset printing plate having an oleophilic image formed thereon in an amount effective to desensitize said non-image area.

Abstract: There is provided a desensitizer used in a quick-drying desensitizing ink for no-carbon copy paper, which is a compound represented by the formula ##STR1## wherein R.sup.1 represents hydrogen atom or methyl group; R.sup.2 represents hydrogen atom, a methyl group, a phenyl group which may have as substituent an alkyl group having 1 to 12 carbon atoms, ##STR2## and l and m are integers of 1 or greater than 1, l+m being not greater than 46, and p is zero or an integer of 1, provided that when p is zero R.sup.

Abstract: Aqueous solutions are provided for treating image-bearing lithographic plates.

Abstract: The method of preparing a lithographic printing plate containing ink receptive printing image areas and water receptive non-printing background areas in which the plate consists of a substrate having on one side thereof in sequence an electrically conductive layer and a photoconductive layer consisting of fully crystalline inorganic photoconductive substance. The method comprises the steps of forming an electrostatic latent image on the surface of said photoconductive layer, developing the electrostatic latent image to define the ink receptive printing image areas on the surface, and applying to the surface an aqueous chromic acid solution.

Abstract: A method of preparing a lithographic printing plate, and the resulting printing plate, by applying an acidified oxidizing agent such as aqueous potassium permanganate solution to the toned electrostatic latent image on the photoconductive layer of an electrophotographic member to define water-receptive non-printing areas. The thus treated surface may be washed or further treated with conventional ferrocyanide ion containing fountain solutions or gum arabic, but only if desired.

Abstract: A waterless planographic printing plate having toner image areas of ink receptivity and non-image areas of ink releasability is provided, which plate has a substrate and an overlying layer coated on the substrate. The overlying layer is predominantly comprised of a reaction product of 50 to 99% by weight of a polymeric material having, on the average, at least two hydroxyl groups per molecule and exhibiting a high adhesion to the ink-receptive toner, and 1 to 50% by weight of an organopolysiloxane having hydroxyl end groups. The overlying layer preferably consists of a relatively thin surface layer substantially composed of the organopolysiloxane, and a relatively thick inner layer sandwiched between the surface layer and the substrate and having an islands-in-sea heterophase structure composed of the organopolysiloxane islands substantially uniformly dispersed in the sea of the polymeric material.

Abstract: A desensitizer for a lithographic printing plate, which contains:(i) at least one silicate represented by the general formulae (I), (II) and (III)M.sub.2 O.(SiO.sub.2).sub.n.qH.sub.2 O (I) ##STR1## wherein M represents an alkali metal atom; R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, each represents a hydrogen atom, an alkyl group or a hydroxyalkyl group; n represents a number of from 1 to 8.5; q represents a number of from 0 to 12; m represents a number of greater than 0 and up to 10; and p represents a number of from 4 to 5000;(ii) at least one wetting agent;(iii) a hydrophilic colloidal material; and(iv) water, anda process for preparing a lithographic printing plate using the desensitizer.

Abstract: An agent for protecting the surface of a lithographic printing plate which is an emulsion comprising an oil phase containing a plasticizer having a solidifying point of 15.degree. C. or less and a surfactant, and an aqueous phase having dissolved therein a hydrophilic high molecular weight compound.

Abstract: Original plates for producing dry planographic printing plates comprising (a) a support, and over and in contact with the support, (b) a light-sensitive adhesive layer made of a photopolymerizable composition comprising one or more photopolymerizable ethylenically unsaturated compounds and one or more photopolymerization initiators and overlying said light-sensitive adhesive layer, (c) a light-sensitive ink-repellent layer made of a silicone composition comprising one or more silicones, one or more photopolymerizable ethylenically unsaturated compounds and one or more photopolymerization initiators. Dry planographic printing plates can be produced from the original plates by image-wise exposing to actinic light and developing.

Abstract: A method for treating imaged lithographic printing plates with a solution comprising (1) water, (2) an active polymer component for rendering non-image areas of a lithographic printing plate hydrophilic, comprised of a polyacrylamide-based polymer or copolymer or a blend of polyacrylamide and polyacrylic acid, or the like, said polymer or copolymer or blend having an average molecular weight of from about 5,000 to about 10.sup.

Abstract: A liquid composition for treating surface of lithographic printing plates, especially etching liquid and dampening liquid which essentially consists of (a) phosphoric acids, (b) nitric acid or salts thereof and (c) nitrous acid or salts thereof and which has all characteristics required for treating liquids used for offset printing, has excellent ability of rendering the non-image areas oil-unreceptive and has rust resistance for all metals. This composition may additionally contain aminopolycarboxylates, polyol compounds and inorganic fine particles.

Abstract: Process for etching a nickel-polyester layered offset plate, which is made by electroless nickel-plating of polyester and subsequently coated on the nickel-layer by a photoresist layer. After exposure of the photoresist layer under a transparent master and development of the offset-plate, the offset-plate is etched by an aqueous etching solution containing copper(II) ions, as the only etching agent together with Cl.sup.- ions. An offset printing plate is prepared from the etched nickel-polyester layered plate. The nickel layer of the nickel-polyester layered plate is etched with the aqueous etching solution. The etching solution additionally contains:(a) a salt which is inert as against the nickel-polyester layered plate, or 10 to 40 weight percent of an organic solvent, which is miscible or nonmiscible with water and which is inert as against the nickel-polyester layered plate, and 60 to 90 weight percent of de-ionized water; and(b) a wetting agent or pyridine.

Abstract: A photosensitive lithographic printing plate having an excellent printing durability, which comprises a supporting layer, a hydrophilic layer formed on the supporting layer, a photosensitive layer formed on the hydrophilic layer surface and, optionally, a water-proof layer located between the supporting layer and the hydrophilic layer, the photosensitive layer being composed of a photosensitive diazo resin modified by a phenol compound and a water-soluble acrylic polymer compound, and the hydrophilic layer being composed of a resinous component comprising 5 to 40% by weight of a urea compound resin and 60 to 95% by weight of a polyamide resin, and a pigment component.

Abstract: The adherence of the oleophilic polymer printing surface of a lithographic printing plate to the support of the lithographic printing plate is improved by an anchoring layer formed from a hydrophobic oleophilic ester colloid which is capable of being rendered hydrophilic by treatment with an aqueous alkali solution. After an image-wise exposure of the photosensitive layer of the presensitized photosensitive sheet used to prepare the lithographic printing plate and removal of the non-polymerized (non-image) portions of the photosensitive layer the plate is contacted with an aqueous alkali solution to render those portions of the anchoring layer, which have been exposed by removal of the non-polymerized portions of the photosensitive layer, hydrophilic. Accordingly, the portions of the anchoring layer underlying the oleophilic hardened polymeric printing surface remain hydrophobic oleophilic and therefore can increase the number of satisfactory printings which can be made from the lithographic printing plate.

Abstract: A durable planographic driographic printing plate comprising a substrate having a highly abhesive layer thereon which is capable of repelling oleo ink when dry, and photobonded to the abhesive layer in image areas an oleo-ink receptive polymer layer. The photobonding occurs during imaging of the plate by including within the abhesive layer ethylenically unsaturated groups which are copolymerizable with a light-sensitive ethylenically unsaturated free radical initiated photopolymerizable material which provides the ink receptive image areas upon exposure.

Abstract: A photolithographic plate, method for preparation thereof, and salt compound useful in the preparation, the method involving the treatment of a metallic silver image on a substrate with a homogeneously stable acidic aqueous salt solution comprising a ferricyanide anion for oxidizing the metallic silver and an organic cation capable of forming a water-insoluble, inherently oleophilic complex with oxidized silver, the cation being derived from a protonatable nitrogen-substituted hydrocarbon compound containing a formal imine group therein which is in resonant association with adjacent groups within the hydrocarbon compound.

Abstract: Aqueous solutions are provided for treating image-bearing lithographic plates.

Abstract: Planographic printing plates are made by depositing on a support sheet an aqueous mixture comprising a hydroxyl group-containing polymer free from acid groups, an insolubilizing agent, a synthetic polymer containing acid groups and preferably a filler, and then drying the deposited layer.The process can be operated at near ambient temperature to give rapidly and reliably a durable water-insoluble hydrophilic layer.

Abstract: The present invention is intended to provide a cyanless treating liquid for use in offset printing which has an intense desensitizability, is capable of rapidly forming a firm hydrophilic film, is free from deterioration of the efficiency thereof when subjected to light or heat, and poses no problem of public nuisance.

Abstract: A flexible offset printing plate is formed from a directly imaged electrophotographic member comprising an inorganic coating of a photoconductive material on a polyester substrate. The photoconductive material is an oriented crystalline deposit about 3000 Angstroms thick which has been directly sputtered with radiofrequency energy in a process using a Langmuir sheath to produce a light sensitive, readily imaged abrasion-resistant, transparent coating. It is deposited on a sheet of dimensionally stable, transparent polyester film having a thickness of about 0.005 inch with an intervening sandwiched layer of ohmic material such as indium-tin oxide about 300 Angstroms thick. The transparency of the ohmic layer and the photoconductive coating on a transparent substrate result in a transparent plate.The electrophotographic member is imaged by charging, exposure and toning with a suitable toner.

Abstract: Aqueous solutions are provided for treating image-bearing lithographic plates.

Abstract: A composition for a recording material comprising a bismuth-sulfur series material or a bismuth-germanium-sulfur series material.

Abstract: Aqueous solutions are provided for treating imagebearing lithographic plates.

Abstract: An offset printing system and method wherein a plate cylinder, a blanket cylinder and ink applying means are arranged in cooperative relationship. The ink applying means applies ink to a plate removably carried by the plate cylinder and the ink applied to the plate is transferred as an image to an image receiving surface of a blanket secured to the blanket cylinder and having an image receiving surface comprising a solid fluoroelastomer. In the disclosed embodiment, the fluoroelastomer is a copolymer of vinylidene fluoride and hexafluoropropylene of a grade which remains solid and deforms elastically at temperatures in excess of 150.degree. F. The fluoroelastomer has a specific gravity between about 1.82 and 1.86 and the ink applying means may also be provided with a surface comprising a fluoroelastomer which remains solid and deforms elastically at temperatures in excess of 150.degree. F.

Abstract: A conversion solution for zinc oxide coated electrophotographic master printing plates is provided containing triethylenetetramine or ethylenediamine which replaces the normally used ferrocyanide in conventional EP master conversions solutions.

Abstract: A process for preparing a lithographic printing plate, which has excellent printability, durability and stability, which comprisingimagewise irradiating a lithographic printing plate material comprising a support having thereon a light-sensitive layer comprising, as essential components, (a) an inorganic material and (b) at least one member selected from the group consisting of a metal and a metal compound, both of which are in contact with each other and which, upon irradiation with electromagnetic radiation, react with each other forming a mutually diffused state and as a result, a difference in the hydrophilic property or in the oleophilic property occurs between the areas irradiated with the electromagnetic radiation and the non-irradiated areas, with electromagnetic radiation, andthen wetting the light-sensitive layer thereof with wetting solution containing (i) at least one compound selected from the group consisting of thiourea and a thiourea derivative and (ii) as an acid component, at least one compo

Abstract: A composition for finishing lithographic printing plates having an oil phase which preferentially adheres to the image areas and an aqueous phase which desensitizes the metal carrier and aids in maintaining its hydrophilic character upon storage.