Abstract: A presensitized plate adapted for use in lithography comprising a support member with a metal surface, e.g. aluminum metal, and overlying layer containing a diazo compound. In accordance with this invention, the relative exposure sensitivity of the diazo compound is improved by pretreatment to accelerate its reactivity in the presence of actinic light. One method of pretreatment involves preheating the diazo compound to a temperature above about 35.degree. C. up to about 120.degree. C. The improved lithographic plate and the process of preparing plate are claimed.

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 O-epoxyalklyated tetrakis (hydroxyphenyl) alkane resin or the esterified reaction product of about one equivalent thereof with less than one equivalent of an ethylentically unsaturated organic acid can be combined with an aqueous alkali- and radiation sensitive, negative acting substance which when coated on a substrate forms a radiation sensitive negative working element.

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: An O-epoxyalklyated tetrakis (hydroxyphenyl) alkane resin or the esterified reaction product of about one equivalent thereof with less than one equivalent of an ethylentically unsaturated organic acid can be combined with an aqueous alkali- and radiation sensitive, negative acting substance which when coated on a substrate forms a radiation sensitive negative working element.

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: A colored, positive-acting, radiation-sensitive composition whose color is extinguished or greatly decreased in intensity upon irradiation comprising at least one acid-free resin, at least one component which upon irradiation yields acidic and/or free radical products, at least one acid and/or free radical sensitive dyestuff and at least one positive-acting component; positive-acting elements comprising suitable support materials at least one surface of which has been coated with the above composition and lithographic printing plates comprising the above elements, wherein the support materials are lithographically suitable support materials, whch have been imagewise exposed to radiation whereby there is a high contrast, before development, between the colored image areas and less intensely colored or colorless non-image areas, the image areas of said plates being additionally highly stable against aqueous alkaline developers after development to remove the exposed non-image areas of the composition and more h

Abstract: Described is a lithographic element which may optionally be used as a positive working or a negative working element by minor changes in exposure and development parameters.

Abstract: Improved compositions comprising solvent-soluble, negative-acting or positive-acting light-sensitive diazonium compounds and solvent-soluble unsaturated monomers which are the products of about two equivalents of an organic diisocyanate with about one equivalent of an active hydrogen-containing organic compound, e.g., an alcohol or amine, preferably a polyol, which products are subsequently reacted with an unsaturated compound which contains an active-hydrogen, preferably in a hydroxyl group, available to react with the remaining isocyanate groups. The compositions can be coated onto suitable base sheet materials to form presensitized lithographic printing plates, proofs for multi-color printing, visual aids, printed circuits and the like.

Abstract: NEGATIVE WORKING LITHOGRAPHIC PRINTING PLATES WHOSE COATING COMPRISES THE ADMIXTURE OF ACRYLATED ESTERS OF EPOXY RESINS WITH NEGATIVE WORKING LITHOGRAPHIC SENSITIZERS ARE FORMED, WHEREBY THE NON-IMAGE AREAS ARE REMOVABLE BY AQUEOUS ALKALI DEVELOPERS.

Abstract: A method for producing an improved aluminum substrate for lithographic printing plates which comprises applying an interlayer bonding solution to the surface of an aluminum web, heating said interlayer solution on the surface of the said aluminum at an elevated temperature and removing any excess solution which has not reacted with the aluminum substrate.

Abstract: A developer composition for photosensitive coatings on substrates, particularly lithographic printing plates sensitized with substantially water-insoluble diazonium compounds, which is comprised of an aqueous solution of a substantially water-soluble organo-lithium salt, e.g., lithium naphthenate, lithium benzoate, lithium ricinoleate, etc. The novel developers quickly remove unexposed areas of the plate and yet do not detrimentally dissolve the exposed areas of the plate.

Abstract: A method for producing a water developable lithographic printing plate which comprises treating at least one surface of a metal sheet substrate with a layer of a lithographically suitable, light sensitive, water soluble substance and subsequently coating the thus treated base sheet with an upper layer of a water insoluble, ink receptive, lithographically suitable photosensitive composition. Said photosensitive layers must be either both positive working or both negative working. Upon imagewise exposure through a mask by standard methods the exposed areas of said upper photosensitive composition are alternatively characterized as either water permeable or water impermeable and the unexposed areas are alternatively water impermeable or water permeable as opposed to the exposed areas. Upon said imagewise exposure, the exposed lower level areas in a negative system are rendered water insoluble whereas the exposed lower level areas in a positive system are rendered more water soluble than the unexposed areas.

Abstract: Compositions comprising (I) solvent-soluble, negative-acting, light-sensitive reaction products of (a) water-soluble diazo condensation products with (b) water-insolubilizing inorganic compounds therefor and (II) synthetic, film-forming oleophilic resins, which compositions can be coated onto suitable base sheet materials to form presensitized lithographic printing plates, proofs for multi-color printing, visual aids, printed circuits and the like.

Abstract: A method for preparing aluminum based lithographic printing plates which comprises treating at least one surface of an aluminum base sheet with an interlayer composition, thereafter anodizing the thus treated aluminun surface, optionally retreating the coated, anodized aluminum plate with another stratum of the interlayer composition and then applying to said surface a suitable light sensitive composition to yield the desired photosensitive lithographic printing plate of improved characteristics.

Abstract: A method for preparing aluminum based lithographic printing plates which comprises coating at least one surface of an aluminum base sheet with a potassium zirconium fluoride solution, thereafter treating the coated, aluminum plate with a stratum of a sodium silicate solution and then applying to said surface a lithographically suitable light sensitive composition to yield the desired photosensitive lithographic printing plate of improved characteristics.

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.

Abstract: In the production of lithographic printing plates, the method of anodizing the surface of an aluminum web substrate which comprises subjecting said web to an anodization treatment in an electrolyte comprised of a combination of sulfuric acid and phosphoric acid, and thereafter applying a lithographically acceptable photosensitive coating to the web to obtain a presensitized lithographic printing plate.