Abstract: An aluminum alloy substrate for presensitized plates for use in making lithographic printing plates comprises an aluminum alloy plate composed of not less than 0.05% by weight and less than 0.5% by weight of Si; 0.2 to 0.7% by weight of Fe; 0.3 to 1.5% by weight of Mn; less than 0.5% by weight of Cu; and the balance of aluminum and unavoidable impurities, the surface of the aluminum alloy plate being subjected to electrolytic graining treatment. The aluminum alloy substrates for PS plates are favorable for appropriate electrolytic graining treatment and show good printing properties and sufficient strength suitable for high-speed printing operation.

Abstract: An aluminum alloy substrate for a lithographic printing plate consisting essentially of an aluminum alloy plate containing 0.2 to 0.5% by weight of Si, 0.3 to 0.7% by weight of Fe, 0.004 to 0.02% by weight of Cu, 0.9 to 1.5% by weight of Mn, 0.05 to 0.3% by weight of Mg and 0.01 to 0.04% by weight of Ti and the balance of Al and impurities, in which the surface of said aluminum alloy plate is roughened electrolytically and anodized. The alluminum alloy substrate has high mechanical strength and can also rapidly print a large number of copies with less stain.

Abstract: An aluminum alloy support material for a lithographic printing plate which consists essentially, on a weight basis, of 0.5-2.0 % Mn, 0.05-1.0 % Si, 0.15-1.0 % Fe, 0-0.10 % Ti, and a balance of Al and inevitable impurities. The support material has a specific resistance satisfying the following inequality:Specific resistance (.mu..OMEGA.mm).ltoreq.14+16[% Ti] as measured in liquid nitrogen at 77 K, and a particular size distribution of precipitates therein. The support is produced from an ingot of an aluminum alloy having the above composition by homogenizing, hot rolling, cold rolling, intermediate annealing, and finish cold rolling under specific conditions followed by electrochemical graining. The support has fine, uniform pits formed by electrochemical graining and improved strength and printability.

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: A printing aluminum alloy material plate is described which provides good printing characteristics, that is, surface-treatment ability, burning ability and ink stain resistivity; the plate is obtained from an aluminum alloy material which is cold-rolled at a reduction rate of from 20 to 95% after being subjected to intermediate annealing at a temperature of 300.degree. to 550.degree. C. wherein the aluminum alloy material comprises 0.25 wt % or less Si, from 0.05 to 1.0 wt % Fe, 0.03 wt % or less Cu, 0.10 wt % or less Ti, and 0.03 wt % or less Mg and the balance of unavoidable impurities and Al.

Abstract: An aluminum alloy support for lithographic printing plate comprising 0.05 to 0.5 wt. % of Fe, 0.1 to 0.9 wt. % of Mg, 0.01 to 0.3 wt % of V and/or Ni, not more than 0.2 wt. % of Si, not more than 0.05 wt. % of Cu and the remainder of Al and inevitable impurities is disclosed. In addition, 0.01-0.3 wt. % of Zr and/or 0.05-2 wt. % of Mn may be contained.

Abstract: An aluminum alloy support for lithographic printing plates produced by cold rolling an aluminum alloy composed substantially of Mg 0.05 to 3 wt %, Si 0.05 to 0.7 wt %, Zr 0.01 to 0.25 wt %, and Fe 0.05 to 0.4 wt %, with the balance being Al and impurities, and imparting a grained surface to the plate surface has high mechanical strength, good heat softening resistance, excellent water retentive property, and long press life.

Abstract: An aluminum alloy support for a lithographic printing plate, suitable for an electrochemical roughening treatment and excellent in fatigue resistance, heat softening resistance and printability, is provided which comprises 0.05 to less than 1% by weight of Mn, at most 0.2% by weight of Si, at most 0.5% by weight of Fe and unavoidable amounts of impurities.

Abstract: A support for lithographic printing plates is disclosed which comprises a plate of an aluminum alloy containing 0.02 to 0.20% by weight zirconium. The aluminum alloy causes no recrystallization phenomenon at temperatures below 320.degree. C. There is also disclosed a photosensitive lithographic printing plate comprising such a support with a photosensitive layer thereon.

Abstract: A process for producing an aluminum support for a lithographic printing plate is described, comprising a step of electrolytically graining the surface of an aluminum plate in an aqueous solution of electrolyte comprising hydrochloric acid and nitric acid in a ratio by weight from 1/1 to 1/3.5 by applying an electric current having an asymmetrical alternating wave form.