Abstract: A support for a lithographic plate produced by a process which comprises:mechanically roughening the surface of an aluminum plate,chemically etching about 5 to 20 g/m.sup.2 of aluminum from the surface of the plate, andapplying an alternating wave-form electric current to the plate in an acidic aqueous solution such that the quantity of electricity generated with the plate as the anode is equal to or greater than the quantity of electricity generated with the plate as the cathode, electrolysis being carried out such that the current density when the plate is the anode is not less than about 20 A/dm.sup.2 and the quantity of electricity generated with the plate as the anode is about 200 coulombs/dm.sup.2 or less.

Abstract: An aluminum alloy support for a lithographic printing plate, comprising a cold rolled plate of aluminum alloy comprising, in % by weight:98.0% or more Al;Fe in an amount of from 0.15 to 1.2% as an alloying element; andimpurities, each of which is present in an amount of from 0.0% but less than or equal to 0.15%, wherein the cold rolled plate has a distribution of Al--Fe and Al--Fe--Si based intermetallic compounds formed from the alloy, having grain sizes of greater than 0 microns but less than or equal to 3 microns, which are positioned directly under an outer surface of the cold rolled plate and wherein the surface of the cold rolled plate is roughened by etching or electrochemical etching and anodically oxidized.

Abstract: An aluminum alloy, a lithographic printing plate support, a lithographic printing plate using the aluminum alloy are disclosed. The aluminum alloy is comprised of aluminum containing 0.20 to 1.0% Fe and 0.005 to 0.1% of elements selected from the group consisting of Sn, In, Ga and Zn. The support composed by the aluminum alloy can be chemically etched with an acid and/or an alkali solution and after undergoing etching the surface of the support is uniformly etched. The uniformly etched surface may be provided with a subbing layer or an anode oxidation film. The support is coated with a light-sensitive layer and utilized as a lithographic printing plate.

Abstract: A lithographic printing plate support and a process for producing it are disclosed. The plate is produced by providing an aluminum alloy material which is comprised of 0.20 to 1.0% Fe, 0.005 to 0.1% of an element selected from the group consisting of Sn, In, Ga and Zn and the remainder being aluminum. The alloy may further contain 0.1 to 2% Cu. After providing the aluminum material either or both of its surfaces are subjected to a chemical etching treatment in order to provide a uniform and dense grain structure on the surface forming primary pits in the surface having a particularly defined average size. The surface is then subjected to electrochemical etching treatment in an acidic electrolytic solution in order to provide secondary pits on the surface also having a particularly defined average size. The support base may be further treated to provide in additional coating thereon or directly coated with a light-sensitive layer in order to provide a light-sensitive lithographic printing plate.

Abstract: A method of replenishing a developer during the development of photosensitive plates in a conveyor-type automatic developing machine connected to a replenishing device in which the dissolution of the photosensitive layer in the non-image area of a photosensitive plate is measured with a sensor. The sensor is positioned at a certain point in the developing zone of the machine, and, when the measured dissolution reaches a certain level, the replenishing device is automatically actuated to supply a predetermined amount of replenisher to the developer.

Abstract: A support for a lithographic plate and process for producing a support for such a plate are described, which process comprises:mechanically roughening the surface of an aluminum plate,chemically etching about 5 to 20 g/m.sup.2 of aluminum from the surface of the plate, andapplying an alternating wave-form electric current to the plate in an acidic aqueous solution such that the quantity of electricity generated with the plate as the anode is equal to or greater than the quantity of electricity generated with the plate as the cathode, electrolysis being carried out such that the current density when the plate is the anode is not less than about 20 A/dm.sup.2 and the quantity of electricity generated with the plate as the anode is about 200 coulombs/dm.sup.2 or less.

Abstract: A support for a lithographic plate comprising an aluminum plate or an aluminum-alloy plate the surface of which has been grained such that the grain structure comprises pits and;(i) the distribution of pit diameter is such that the pits corresponding to 5% and 95% on a cumulative frequency curve for pit diameter are about 3.mu. or more and about 10.+-.1.mu. in diameter, respectively; and(ii) the center line average roughness (Ra) of said surface is on the range from about 0.6 to 1.0.mu.. A light-sensitive material for preparing a lithographic plate is also disclosed.

Abstract: A method for preparing a support for a planographic printing plate using an electrolytic surface treatment of an aluminum plate is disclosed, wherein an alternating charge voltage is applied to the aluminum plate in an acidic electrolyzing bath, and the wave form representing the voltage includes an intermission of zero voltage in at least one of the anode or the cathode phases, and is such that the electric quantity for the anode phase is larger than the electric quantity for the cathode phase.

Abstract: A light-sensitive printing plate having a matt layer, which is removable at development, on the surface thereof.

Abstract: A light-sensitive copying material comprising at least two organic coating layers on a support, at least one of the coating layers being a light-sensitive layer which comprises an O-quinone diazide compound whose alkali solubility is increased by irradiation with active rays.

Abstract: A light-sensitive copying material comprising at least two organic coating layers on a support, at least one of the coating layers being a light-sensitive layer which comprises an O-quinone diazide compound whose alkali solubility is increased by irradiation with active rays.

Abstract: A light-sensitive copying material comprising at least two organic coating layers on a support, at least one of the coating layers being a light-sensitive layer which comprises an O-quinone diazide compound whose alkali solubility is increased by irradiation with active rays.

Abstract: A light-sensitive printing plate having a matt layer, which is removable at development, on the surface thereof.

Abstract: A method of producing a support for a printing plate comprising treating an aluminum plate, which has been oxidized by anodizing and then etched, with hot water or with water vapor.