Hoechst Aktiengesellschaft

Agfa-gevaert Ag

Wolfgang Wiedemann

Dieter Guenther

Michael Drexler

Juergen Fuerderer

Ernst Spietschka

Hans-Matthias Deger

Jurgen Rochlitz

Helmut Troester

A process for the treatment of a material having an aluminum oxide layer comprising (a) treating the aluminum oxide layer with an aqueous solution of a pure and crystalline alkali metal silicate, and (b) rinsing the treated aluminum oxide layer with ion-containing water. A substrate so produced is useful in offset printing.

Process for the aftertreatment of aluminum materials, substrates of such

Process for the aftertreatment of aluminum materials substrates of such

The invention described a multilayer recording medium for optical information for use in a single recording operation and the process for its production. The multilayer recording medium essentially comprises a support and a layer comprising an unsubstituted naphthalocyanine dye. A binder layer is disposed between the support and the dye layer or the dye layer carries a binder layer which, in turn, is coated with a dye layer. Moreover, the invention describes composite systems, in particular, adhesive-bonded systems constructed from these multilayer recording media. As compared to recording media of the prior art, the media and composite systems according to the present invention exhibit a high reflectivity and require a lower write-pulse energy, while maintaining a particular contrast ratio.

Multilayer recording medium for optical information

An electrophotographic recording material is described that comprises an electrically conducting base layer and a photoconductive system deposited thereon, which system comprises an optional insulating intermediate layer, a layer containing a charge-generating compound, and a layer containing a charge-transporting compound mixed with binders, along with any sensitizers, acceptors and usual additives. The photoconductive system contains, as acceptor additive, one or more monomeric or polymeric compounds that have electron-attracting substitutents (halogen, cyano, nitro groups) and that are selected from the group consisting of anthracene, acridine, the anhydrides of phthalic acid, maleic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and the polymers of vinyl chloride, vinylidine chloride and nitrocellulose, in a quantity of 0.2 to 10% by weight based on total coating weight. After erasure of the latent electrostatic image, the recording material has a low residual charge, even when operated cyclically. Background imaging is thereby avoided.

Electrophotographic recording material with mopomeril alleptor additive

An electrophotographic recording material is comprised of an electrically conducting film base, an optional, adhesion-promoting, insulating intermediate film and at least one binder-containing photoconductive film that also contains a charge-carrier generating compound and pyrazoline charge-transporting compound represented by the formula ##STR1## in which n denotes zero or 1 and

Electrophotographic recording material comprising a pyrazoline derivative

An electrophotographic recording material comprising an electrically conducting layer support, an optional insulating intermediate layer, a photoconductive layer comprising at least one dyestuff as charge carrier-generating compound, and a layer containing a binder and photoconductor as charge-transport compound contains, as dyestuff in the photoconductive layer, a benzo-benzimidazo[1,2a]-quinoline derivative, preferably one represented by the formula ##STR1## Use of the dyestuff, in combination with a wide variety of photoconductors and binders, yields materials with excellent electrophotographic properties.

Electrophotographic recording material

An electrophotographic recording material comprises an electrically conductive base material, an optional insulating intermediate layer and a photoconductive layer comprising at least one layer containing an asymmetrically substituted perylene-3,4,9,10-tetracarboxylic acid imide as charge carrier producing compound, a photoconductor as charge transport compound, binder and customary additives. The asymmetrically substituted perylene-3,4,9,10-tetracarboxylic acid imide can, for example, be represented by the formula ##STR1## where R denotes hydrogen, alkyl, hydroxyalky, alkoxyalkyl, aryl or aralkyl and A denotes phenylene, naphthylene or a more highly fused aromatic carbocylic or heterocyclic radical which can each be substituted by halogen, alkyl, cyano or nitro groups. This material is suitable in double-layer arrangement for highly light sensitive systems, and in a single layer for preparing printing forms or printed circuits.

Perylene tetracarboxylic acid imide pigments in an electrophotographic

The photoconductor of an electrophotographic recording material comprising an electrically conductive support, an optional insulating interlayer, and a photoconductive single layer containing a binder, a dye or pigment sensitizer and a pyrimido[5',4':5,6]pyrido[1,2-a]benzimidazole charge transporting compound represented by the formula ##STR1## wherein R.sub.1 and R.sub.2 are identical or different and are hydrogen or an R.sub.3,R.sub.4 N group; R.sub.3 and R.sub.4 are identical or different and are (C.sub.1 to C.sub.4)-alkyl, hydroxy-(C.sub.1 to C.sub.4)-alkyl, phenyl or benzyl which are unsubstituted or (C.sub.1 to C.sub.4)-alkyl-substituted, or, together with the N atom to which they are bonded, are an imidazolyl or triazolyl group; and R.sub.5 is a benzothiazole, a benzoxazole or a benzimidazole group, is photosensitive in the visible range around 430 to 500 nm and can be sensitized for the longer-wavelength region with dyes.

Electrophotographic material with pyrimido-pyridobenzimidazole compound

An electrophotographic recording material comprising an electrically conductive base material, an option insulating intermediate layer, and a photoconductive double layer comprised of a charge-generating and a charge-transporting layer employs a pyrimido[5' ,4':5,6]-pyrido-[1,2-a]-benzimidazole transport compound, along with a binder and a dye or pigment, in the charge transporting layer, which compound is represented by the formula I ##STR1## wherein R.sub.1 and R.sub.2 are identical or different and denote hydrogen or an R.sub.3 R.sub.4 N group; R.sub.3 and R.sub.4 are identical or different and denote (C.sub.1 to C.sub.4)-alkyl, hydroxy-(C.sub.1 to C.sub.4)-alkyl, optionally (C.sub.1 to C.sub.4)-alkyl-substituted phenyl or benzyl, or, together with the nitrogen atoms to which they are bonded, an imidazolyl or a triazolyl group; and R.sub.5 denotes a benzothiazole, a benzoxazole, a benzimidazole or a cyano group. Use of the transport compound makes it possible to adjust the photosensitivity of the recording material to different spectral regions when the material is subjected to electrostatic charging of different polarities.

Electrophotographic recording material containing benzimidazole

The present invention relates to an electrophotographic recording material composed of an electrically conducting coating support which is suitable, in particular, for the manufacture of printing forms or printed circuits, and a photoconductive insulating coating which contains a dye, in dispersion, which is a compound according to the general formula ##STR1## in which X is an oxygen atom, or a sulfur atom, or a CO group, and

Electrophotographic recording material for printing forms

An electrophotographic recording material comprised of an electrically conductive support, an optional insulating interlayer, a photoconductive system comprised of at least one layer of organic material containing a charge carrier-producing compound and a charge-transporting compound, and a radiation-cured, transparent protective layer, wherein the protective layer has been applied onto the surface of the photoconductive system with the aid of a removable auxiliary support and is comprised of an acrylated binder which is cured by irradiation with ultraviolet light. Also disclosed is a process for the production of the recording material.

Electrophotographic recording material having protective layer and

An electrophotographic recording material comprising an electrically conductive support, an optional insulating intermediate layer, at least one photoconductive layer comprising a charge carrier generating compound and a charge transporting compound, and a protective transparent cover layer made from a surface abrasion resistant binder composed of a polyurethane resin, polycarbonate resin, phenoxy resin, polyacrylate or polymethacrylate resin, polyurethane formed from a two-component system comprising a polyisocyanate and a hydroxyl group containing polyester or polyether, a polyisocyanate and a hydroxyl group containing acrylic or epoxy resin, polyurethane formed from a one-component system comprising a polyisocyanate prepolymer, or a polyisocyanate having temporarily masked isocyanate groups.

Electrophotographic recording material with abrasion resistant overcoat

This invention relates to an electrophotographic recording material consisting of an electroconductive support material and a photoconductive double layer of organic materials which consists of a homogeneous, opaque, charge carrier producing dyestuff layer from a more annealed quinone or the substitution product thereof, selected from the group consisting of dibenzopyrene quinone, anthanthrone, pyranthrone, dibenzanthrone, and flavanthrone, possible substituents being halogen, nitro, amino, hydroxy, alkoxy, mercapto or alkyl mercapto groups, and of a transparent top layer of insulating materials with at least one charge transporting compound.

Organic double layer electrophotographic recording material

This invention relates to an improvement in an electrophotographic recording material comprising an electrically conductive support, optionally an insulating intermediate layer, and a photoconductive layer composed of at least one layer comprising charge carrier-producing and charge transporting compounds, a binder, and conventional additives, the improvement that the recording material comprises a 75 to 250 .mu.m thick support and, in the form of a photoconductor web, is sufficiently flexible that it is not prone to the formation of hairline cracks when repeatedly conducted over rollers of at least 18 mm diameter, said binder being a cellulose acyl ester with an acetyl content of not more than 30 percent and a viscosity of more than 15 poises, measured by the ASTM methods D 817-65, Formula A, and D 1343-56.

Electrophotographic recording material with cellulose acyl ester binder

This invention relates to an improvement in an electrophotographic recording material comprising an electrically conductive support, optionally an insulating intermediate layer, and a photoconductive layer composed of at least one layer comprising charge carrier-producing and charge transporting compounds, a binder, and conventional additives, the improvement that the recording material comprises a 75 to 250 .mu.m thick support, and, in the form of a photoconductor web, is sufficiently flexible that it is not prone to the formation of hairline cracks when repeatedly conducted over rollers of at least 12 mm diameter, said binder being a cellulose nitrate with a viscosity of 400.+-.25 cPoises at concentrations between about 4 and 12 percent in a 5 percent aqueous acetone solution, according to DIN 53 179 (standard type 4-12).

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Geisenheim-Johannisberg, Germany

Wolfgang Wiedemann