Abstract: A composition useful for the protection of actinic light-exposed presensitized lithographic printing plates. The composition contains an effective amount of the di-potassium salt of hydroxyethylidene diphosphonic acid dissolved in water. The composition is applied to the surface of the revealed substrate of the plates after they have been developed but before treatment to heat, to prevent surface contamination from the heat treatment.

Abstract: A persistent photoconductive coating composition contains a persistent photoconductor, photoinitiator, an acetate or phenolic hydroxyl containing resin and ketone dispersed in an inert coherent matrix.

Abstract: An electrophotographic imaging process. The process utilizes a disposable photoconductor and develops the photoconductor in fresh toner. The toner is packaged in a pod to protect its freshness and dispense a predetermined quantity of toner. The toner contains a one-shot application, but the process may be repeated for various colors. In the process, a charge plate is exposed to form a latent image, or a pre-exposed plate is charged to form a latent image. The latent image is contacted with toner released from the pod onto a development electrode. A cleanup electrode is provided for excess toner and the image is subsequently transferred to a substrate to produce a print, or the image is fixed on the photoconductor to make a lithographic, di-litho or letterpress plate.

Abstract: A process for preparing polyvinyl phosphonic acid by the steps of polymerizing bis(2-chloroethyl) vinyl phosphonate in the presence of a free radical initiator or catalyst, such as dicumyl peroxide. The resulting poly bis(2-chloroethyl) vinyl phosphonate is then subjected to acid hydrolysis to obtain high purity polyvinyl phosphonic acid having measurable and controllable molecular weight distribution.

Abstract: The invention features a new series of triazine compounds which are characterized by their ability to generate free radicals upon irradiation in a desired optical region, such that they are useful in the fabrication of lithographic plates having improved exposure speed, development, print-out, and contrast characteristics.

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: The invention features a lithographic composition fabricated from a process wherein an acidic novolak resin is neutralized in solution. The solution comprises a common compatible solvent with the other ingredients of the coating composition, such as a positive sensitizer, a color changing dye, and a light activated, acid-releasing compound.

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 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 water developable printing plate is provided with a photopolymerizable system as a latex comprising a water soluble diazopolymer reaction product of a diazoaryl amine and an aldehyde and an aqueous cationic or nonionic dispersion of a water insoluble polymer. The inclusion of a water miscible organic solvent improves the shelf-life of the photopolymerizable system and the printing plate especially under high humidity conditions.

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 method for the preparation of chromophore-substituted vinyl-halomethyl-s-triazines especially 2-(p-methoxystyryl)-4,6-bis-(trichloromethyl)-s-triazine. In the known preparation of these compounds, a two step procedure is utilized wherein an intermediate reaction product has to be isolated. This step of separating the intermediate is eliminated in the present process by dissolving the crude reaction product obtained in the first step in toluene, removing excess hydrogen chloride gas and catalysts by purging the reaction product solution with an inert gas, and then reacting p-anisaldehyde with the toluene solution of the reaction product mixture using piperidinium acetate catalyst to obtain 2-(p-methoxystyryl)-4,6-bis-(trichloromethyl)-s-triazine.As a further improvement of the art the Knoevenagel-type condensation is run until no further water is evolved. At this point the product formed is isolated by filtration and a like amount of catalyst as a second charge is added.

Abstract: The invention features an electrolytic process for producing lithographic plates. The plates are immersed in a bath and fed a shaped alternating wave having a multiplicity of zero voltage intermissions. The grain topography of the plate can be varied by changing the frequency and duration of the intermissions in the wave.

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: A non-silver, positive-working, essentially alkali-insoluble, radiation-sensitive composition, which becomes alkali-soluble on exposure to radiation, comprising a non-silver, positive-acting, essentially alkali-insoluble radiation-sensitive component a radiation absorbing component and an essentially alkali-soluble polymeric binder. A radiation-sensitive element comprising a transparent substrate overcoated with said radiation-sensitive composition. A duplicating film comprising the said element prepared by exposing said composition through the substrate and then image-wise exposing said composition through a mask in front of the composition followed by treatment with an alkaline developer to remove those areas of the composition subjected to both exposures.

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: 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.