Abstract: Aluminum-containing metal sheets can be electrochemically grained to provide a center line average roughness (Ra) of less than 0.60 ?m and an average maximum pit depth (Rv) of less than 4.5 ?m using a current density of at least 50 A/dm2 and a charge density less than or equal to 850 coulombs/dm2. This improved metal sheet can be used as substrates for imageable elements including lithographic printing plates that exhibit reduced blanket toning.

Abstract: The present invention includes a radiation-imageable element for lithographic printing having a hydrophilic anodized aluminum base with a surface having pores and a image-forming layer having polymer particles coated on the aluminum base. The ratio of the average pore diameter to the average particle diameter is from 0.4:1 to 10:1. The present invention further includes a method of producing the imaged element. The method includes the steps of imagewise exposing the radiation-imageable element to radiation to produce exposed and unexposed regions and contacting the imagewise exposed radiation-imageable element and a developer to remove the exposed or the unexposed regions.

Abstract: The present invention includes a radiation-imageable element for lithographic printing having a hydrophilic anodized aluminum base with a surface having pores and a image-forming layer having polymer particles coated on the aluminum base. The ratio of the average pore diameter to the average particle diameter is from 0.4:1 to 10:1. The present invention further includes a method of producing the imaged element. The method includes the steps of imagewise exposing the radiation-imageable element to radiation to produce exposed and unexposed regions and contacting the imagewise exposed radiation-imageable element and a developer to remove the exposed or the unexposed regions.

Abstract: A printing plate is prepared by the method comprising: (a) providing a substrate; and (b) applying by ink jetting to the substrate a fluid composition comprising a compound which comprises at least one nitrogen-containing heterocyclic moiety, providing a printing plate that is ready-to-use on a press without having to develop it. The printing plate of this invention is capable of extended press run length and advantageously avoids the need of chemical development.

Abstract: A process is disclosed to produce a fine honeycomb grain with matte finishing on an aluminum surface in alkaline solution with or without electrical treatment. To achieve the fine honeycomb, a passivation enhancement step is used prior to alkaline etching with or without electricity. The matte appearance with fine honeycomb topography on the aluminum surface is produced by silicating raw aluminum prior to alkaline etching.

Abstract: A method for producing aluminum sheets for lithographic plates by electrolytically etching the surface in an aqueous mineral acid electrolyte solution utilizing direct current with superimposed alternating current. The surface of aluminum plate sheets may be mechanically grained prior to the step of electrolytic etching.

Abstract: An all electrolytic method for quickly and efficiently producing a well roughened, substantially non-directional, fine honeycomb surface on an aluminum sheet which is characterized by excellent adhesion to coatings and therefore suitable for making lithographic printing plates. The method comprises graining said aluminum sheet with alternating current for less than about 10 seconds in a first aqueous electrolyte solution containing hydrochloric acid, washing and drying the resulting grained aluminum sheet, and then further graining said dried aluminum sheet with alternating current for less than about 10 seconds, preferably 5 to 10 seconds, in a second aqueous electrolyte solution containing nitric acid alone or admixed with hydrochloric acid to obtain the substantially non-directional, fine honeycomb surface on said aluminum sheet.

Abstract: A method of preparing an anodized aluminum printing plate comprising treating the aluminum support with aqueous solution of a condensed aryl sulfonic acid having a neutral pH, anodizing the support before or after the treating step, and coat, radiation expose through a mask, as well as develop a radiation-sensitive composition to produce the lithographic printing plate.

Abstract: An improved planographic printing plate comprised of a metal substrate, a sealing layer, an interlayer formed from a monomer or polymer of an organic compound having at least one cationic, quaternary substituted ammonium group, and a photosensitive layer on the surface of the interlayer. The printing plates are water developable and characterized by cleaner non-imaging areas during printing operations. The method of preparing such planographic printing plates is also described and illustrated.

Abstract: A method is provided for electrolytically graining an aluminum lithographic plate to produce a grained surface with a honeycomb topography, non-directional grain structure, and a substantially reduced production of smut. The reduction of smut is achieved by utilizing an alternating current of higher frequencies, generally in the range of approximately 140 to 400 Hz.

Abstract: The method of production of lithographic aluminum substrates which comprises first mechanically graining a surface of an aluminum sheet to obtain a pumice grained surface and then etching with a hot sulfuric acid (10-90%) solution.

Abstract: An improved planographic printing plate comprised of a metal substrate, a sealing layer, an interlayer formed from a monomer or polymer of an organic compound having at least one cationic, quaternary sustituted ammonium group, and a photosensitive layer on the surface of the interlayer. The printing plates are water developable and characterized by cleaner non-imaging areas during printing operations. The method of preparing such planographic printing plates is also described and illustrated.

Abstract: A method for the production of aluminum substrates useful in the production of lithographic printing plates which comprises first mechanically graining at least one surface of an aluminum sheet to obtain a pumice grained surface of the aluminum sheet, and then electrolytically etching said grained surface with alternating current.

Abstract: A planographic printing plate comprises an anodized metal substrate, an interlayer on the substrate and a photosensitive layer on the interlayer in which the interlayer is a hydroxy-substituted organic acid.

Abstract: An improved anodized support material comprising an anodized support material which has been treated with an alkali metal salt of a condensed aryl sulfonic acid following or during anodization; an improved radiation sensitive element comprising the above improved supports to which has been applied a radiation-sensitive composition and improved lithographic printing plates prepared from said elements.

Abstract: In the method of electrolytically treating a lithographic-grade aluminum web by liquid contact in a sulfuric acid electrolyte, the improvement which comprises carrying out said treatment in the presence of an iridium oxide plated titanium metal anode.

Abstract: A method for the production of aluminum substrates useful in the production of lithographic printing plates which comprises mechanically graining the surface of an aluminum sheet, subsequently finely graining the mechanically grained sheet in a saturated solution of an aluminum salt of a mineral acid to which up to 10% of a mineral acid has been added, with discretional electrolysis, and then optionally anodizing the sheet.

Abstract: A method for the production of aluminum substrates useful in the production of lithographic printing plates which comprises mechanically graining the surface of an aluminum sheet, subsequently finely graining the mechanically grained sheet in a saturated solution of an aluminum salt of a mineral acid to which up to 10% of a mineral acid has been added, with discretional electrolysis, and then optionally anodizing the sheet.

Abstract: A method for the production of aluminum substrates useful in the production of lithographic printing plates which comprises graining the surface of an aluminum sheet in a saturated solution of an aluminum salt of a mineral acid to which up to 10% of a mineral acid has been added, with optional electrolysis.

Abstract: A method for electrolytically graining the surface of aluminum sheets useful in the production of lithographic printing plates which comprises subjecting said aluminum sheets to the action of alternating electric current in an aqueous electrolytic solution containing, in combination, small but effective amounts of both hydrochloric and nitric acids.