Abstract: A method for producing polymers which are anhydride modifications of polymers containing hydroxyl groups, such as polyvinyl acetal polymers. Such modified polymers are useful as binders for photosensitive compositions used to prepare photographic elements such as lithographic printing plates, color proofing films and photoresists. The binder is the reaction product of an intramolecular anhydride of an organic polycarboxylic acid with a polymer containing hydroxyl groups, and which does not contain other functional groups which are capable of reaction with acid anhydrides. The reaction is conducted in a solvent composition free of hydroxyl containing solvents such as methyl ethyl ketone and ethylene glycol monomethyl ether.

Abstract: A color ant dispersion having a pigment, a solvent composition of a C1-C8 aliphatic alcohol, a mono- or di-C1-C8 alkylene glycol C1-C8 alkyl ether, or a cyclic ketone; and an aqueous alkaline soluble or swellable polymeric compound which is the reaction product of a hydroxy containing polymer and an anhydride in the presence of a catalytic amount of a tertiary amine catalyst. The pigment and the polymeric compound are present in a high relative weight ratio of from about 0.75:1.25 to about 1.25:0.75. An admixture of the dispersion, a light sensitive component diazonium compound or photopolymerizable composition and an aqueous alkaline soluble or swellable polymeric binder, when coated and dried onto a substrate, forms a photographic element, which when imagewise exposed and developed has an exceptionally high contrast between image and removed non-image areas.

Abstract: The present invention relates to supports for lithographic printing plates and to a process for producing the same. In particular, the invention relates to aluminum plates having an electrochemically grained and anodized surface which is has a smooth, shiny surface and hence greater image contrast when a lithographic image is formed thereon. The surface has a substantially uniform surface topography comprising peaks and valleys and surface roughness parameters wherein Ra ranges from about 0.10 to about 0.50 microns, Rz ranges from about 0.00 to about 5.00 microns, Rt ranges from about 0.00 to about 6.00 microns and Rp ranges from about 0.00 to about 4.00 microns. The surface preferably has tristimulus color coordinate values wherein L ranges from about 35.00 to about 75.00, a ranges from about -4.00 to about +4.00 and b ranges from about -4.00 to about +4.00.

Abstract: The present invention relates to supports for lithographic printing plates and to a process for producing the same. In particular, the invention relates to aluminum plates having an electrochemically grained and anodized surface which is has a smooth, shiny surface and hence greater image contrast when a lithographic image is formed thereon. The surface has a substantially uniform surface topography comprising peaks and valleys and surface roughness parameters wherein Ra ranges from about 0.10 to about 0.50 microns, Rz ranges from about 0.00 to about 5.00 microns, Rt ranges from about 0.00 to about 6.00 microns and Rp ranges from about 0.00 to about 4.00 microns. The surface preferably has tristimulus color coordinate values wherein L ranges from about 35.00 to about 75.00, a ranges from about -4.00 to about +4.00 and b ranges from about -4.00 to about +4.00.

Abstract: Provided herein is a brushgraining process to improve the quality of lithographic printing plate substrate surfaces. In the process, the surface is brushed in an aqueous slurry comprising a mixture of particulates of alumina and quartz in a weight ratio range 95:5 to 5:95, with the particulates being in the size range of 1-20 microns. Such a process surprisingly lessens the number of scratches produced on the substrate surface than when compared to using alumina alone or quartz alone or a mixture of alumina and quartz with particle sizes higher than the range disclosed.

Abstract: The invention is directed toward a base material for aluminum offset printing plates having improved heat stability comprising an aluminum alloy consisting of from about 0.2 to about 0.6% by weight of iron, less than about 0.25% by weight silicon and copper combined, from about 0.1 to about 0.3% by weight manganese and the remainder being aluminum and trace production impurities, said base material further characterized as containing secondary precipitates in the form of phases of the Al Mn Si: Al Fe: Al Mn type which bear a ratio to one another of from about 1:1:2 to about 1:1:3, the mean particle size being from about 0.25 to about 0.010 micron with a maximum particle size of less than about 0.3 micron and further containing a precipitation structure with a degree of dispersion of less than about 50 phases per cubic micron and a process for producing such material. The sheet material according to this invention may be uniformly roughened in either HCl or HNO.sub.

Abstract: The invention is directed toward a base material for aluminium offset printing plates having improved heat stability comprising an aluminum alloy consisting of from about 0.2 to about 0.6% by weight of iron, less than about 0.25% by weight silicon and copper combined, from about 0.1 to about 0.3% by weight manganese and the remainder being aluminum and trace production impurities, said base material further characterized as containing secondary precipitates in the form of phases of the Al Mn Si: Al Fe: Al Mn type which bear a ratio to one another of from about 1:1:2 to about 1:1:3, the mean particle size being from about 0.25 to about 0.010 micron with a maximum particle size of less than about 0.3 micron and further containing a precipitation structure with a degree of dispersion of less than about 50 phases per cubic micron and a process for producing such material. The sheet material according to this invention may be uniformly roughened in either HCl or HNO.sub.

Abstract: The process for manufacturing materials, in the form of sheets, foils or webs, comprised of chemically, mechanically and/or electrochemically roughened and anodically oxidized aluminum or an aluminum alloy, which process is performed with two hydrophilizing post-treatment steps. In post-treatment step (a) a supported aluminum oxide layer is treated with an aqueous alkali metal silicate solution which optionally contains alkaline earth metal ions, and in step (b) the aluminum oxide layer is separately treated with an aqueous solution containing at least one organic polymer comprised of vinylphosphonic acid and/or vinylmethylphosphinic acid monomers, such as polyvinylphosphonic acid. Treatment of the aluminum oxide layer is accomplished by means of immersion and/or electrochemically. Materials prepared by this process are particularly useful as supports for offset printing plates, showing an improved resistance to alkali and a reduced tendency to adsorb dyestuff.

Abstract: Disclosed is a sheet, foil or strip material comprising aluminum or an alloy thereof, which is first mechanically and then electrochemically roughened on one or both surfaces to produce the following parameters:(a) from about 60 to 90% of the surface comprise a basic structure, in which the arithmetic mean of the distribution of diameters D.sub.a1 of the pits is in the range from about 1 to 5 microns,(b) from about 10 to 40% of the surface comprise a superimposed structure formed of elevations having an average base F from about 100 to 1,500 microns.sup.2, in which the arithmetic mean of the distribution of diameters D.sub.a2 of the pits is in the range from about 0.1 to 1.0 micron,(c) the center line average roughnesses R.sub.a of the entire surface are at least 0.6 micron, and(d) the contact area t.sub.pmi of the entire surface is not more than about 20% at a stylus working depth of 0.125 micron and not more than about 70% at a stylus working depth of 0.4 micron.

Abstract: In the process for continuously anodically oxidizing one surface of strips of aluminum or an aluminum alloy, a direct current is caused to act on the strips, by at least one anode and at least one cathode, which are arranged in an aqueous electrolyte. The anode(s) and cathode(s) electrochemically act, from opposite sides and simultaneously, on the strip which moves past them and which is, in particular, substantially horizontally conveyed past the substantially horizontally arranged electrodes.A device for carrying out a process of this kind comprises (a) at least one treating bath (2) which is filled with an aqueous electrolyte (3), (b) at least one anode (5) each, which is arranged in the electrolyte, below the strip (1) to be treated, and (c) at least one cathode (4) each, which is arranged in the electrolyte, above the strip (1) to be treated.

Abstract: Disclosed is a process for the production of a material in the form of a plate, a foil or a strip, from aluminum or an alloy thereof, which has been chemically, mechanically and/or electrochemically roughened. The process comprises a two-stage oxidation involving a first stage (a) which is performed in an aqueous electrolyte having from about 60 to 180 g/l of phosphoric acid, at a temperature of the electrolyte bath of about 47.degree. to 70.degree. C. and at a voltage of about 36 to 80 V and a second stage (b) which is performed in an aqueous electrolyte having from about 60 to 300 g/l of sulfuric acid, at a temperature of the electrolyte bath of about 30.degree. to 65.degree. C. and at a voltage of about 15 to 35 V. Also disclosed is an offset-printing plate, having a radiation-sensitive coating and a support material produced by the process described above.

Abstract: The invention relates to a developer mixture for developing exposed, light-sensitive reproduction layers which contain a diazonium salt polycondensation product. The mixture comprises water, a salt of an alkanoic acid and a surfactant and contains 0.5 to 15 percent by weight, in particular 1 to 10 percent by weight, of at least one salt of an alkanoic acid having 8 to 13 carbon atoms and 0.5 to 20 percent by weight, in particular 1 to 12 percent by weight, of at least one low-foaming, nonionic surfactant. These surfactants preferably include optionally modified block polymers formed from ethylene oxide and propylene oxide.The invention also relates to a process for developing negative-working reproduction layers, of the composition indicated above, with the developer mixture according to the invention.

Abstract: This invention relates to a developer mixture for washing out light-sensitive copying layers previously exposed in imagewise manner and containing a polymer of an N-vinyl amine, of vinyl alcohol or of a vinyl alcohol derivative, an alcohol being water-soluble in an amount less than 10% by weight, and water as the main constituent, the mixture containing as said polymer a copolymer which is water-soluble or which can be dispersed in water to form a stable dispersion, composed of (a) hydrophilic units of the formula I: ##STR1## wherein A is O-R or ##STR2## R is a hydrogen atom or a methyl group; R.sub.1 is a hydrogen atom, an alkyl group or an alkoxy alkyl group having 1 to 10 carbon atoms each or an aryl group with 6 to 10 carbon atoms; R.sub.

Abstract: This invention relates to a light-sensitive copying material comprising a coating support and an optically homogeneous light-hardenable coating which contains a condensation product of an aromatic diazonium salt and a water-insoluble macromolecular polymer, wherein the coating is applied from a stable dispersion of the water-insoluble polymer under conditions such that after drying an optically homogeneous coating is formed. The invention also relates to a process for the manufacture of a light-sensitive copying material containing the optically homogeneous light-hardenable coating.