Abstract: A photochromic system contains an oxidizable leuco dye and a photochemically activated initiator which converts the leuco dye to the dye, the initiator being a phenanthroimidazole derivative.The photochromic system is useful for the production of photochromic layers for photoresists and printing plates.

Abstract: In the production of resist images by application of a radiation-sensitive positive-working resist layer based on degradable polymers onto a substrate, imagewise exposure of the resist layer to actinic radiation and removal of the irradiated parts of the layer with development of the resist image, the radiation-sensitive resist layer used is composed of poly(diacetylenes), in particular soluble ones. Preferably, the radiation-sensitive resist layer based on the poly(diacetylenes) contains sensitizers which can be activated by actinic radiation and which, after being activated, induce or accelerate molecular degradation of the poly(diacetylenes). Dry film resists comprise a temporary dimensionally stable base and a radiation-sensitive resist layer which is applied on the base, can be degraded by exposure to actinic radiation and is based on poly(diacetylenes), in particular soluble ones, with or without a cover sheet on top of the said resist layer.

Abstract: An electrophotographic recording element consisting of an aluminum base, which is mechanically, chemically and/or electrochemically pretreated in a conventional manner, and a photoconductive layer which is applied to this base is produced by a process in which a thin layer which imparts hydrophilic properties and consists of a hydrolysis product or condensate of a silane is applied between the base and the photoconductive layer.These recording elements are particularly useful for electrophotographic offset printing.

Abstract: Phenanthroimidazole compounds, a process for their preparation, photopolymerizable coating and recording materials and lithographic layers produced using these.The novel phenanthroimidazole compounds are useful as photoinitiators for photopolymerizable coating and recording materials.

Abstract: An electrophotographic recording material contains, as charge carrier-transporting compounds in the photoconductor layer, a mixture of one or more compounds of the formula ##STR1## and one or more compounds of the formula ##STR2## in a ratio of from 9:1 to 0.6:1, preferably from 2.3:1 to 0.8:1. In the formulae, R.sup.1 and R.sup.2 independently of one another are each alkyl, allyl, phenylalkyl or unsubstituted or substituted phenyl, R.sup.3 and R.sup.4 independently of one another are each hydrogen, alkyl, alkoxy or halogen, and R.sup.6, R.sup.7, R.sup.8 and R.sup.9 independently of one another are each alkyl, phenylalkyl or cyclohexyl.When the mixture of (I) and (II) is present in an appropriate concentration, the recording materials are highly photosensitive, although the problems usually encounted in the case of high concentrations of charge carrier-transporting compounds do not arise.

Abstract: Mixtures which are curable by heating or irradiation with actinic light contain one or more cationically curable compounds, such as an epoxy, an olefinically unsaturated monomer, amino resin or phenolic resin, and as a cationically active curing catalyst one or more N-sulfonylamino-sulfonium salts of the formula ##STR1## such as N-p-toluenesulfonyl-N-methylaminodiphenylsulfonium hexafluorophosphate with or without quinones or peroxides are suitable, inter alia, for producing moldings, coatings, relief images and resist patterns.

Abstract: In the production of resist images by application of a radiation-sensitive positive-working resist layer based on degradable polymers onto a substrate, imagewise exposure of the resist layer to actinic radiation and removal of the irradiated parts of the layer with development of the resist image, the radiation-sensitive resist layer used is composed of poly(diacetylenes), in particular soluble ones. Preferably, the radiation-sensitive resist layer based on the poly(diacetylenes) contains sensitizers which can be activated by actinic radiation and which, after being activated, induce or accelerate molecular degradation of the poly(diacetylenes). Dry film resists comprise a temporary dimensionally stable base and a radiation-sensitive resist layer which is applied on the base, can be degraded by exposure to actinic radiation and is based on poly(diacetylenes), in particular soluble ones, with or without a cover sheet on top of the said resist layer.

Abstract: Molecular degradation of poly(diacetylenes), in particular with production of poly(diacetylenes) having selected molecular weights, is carried out by a process in which the poly(diacetylenes), for example in solution or as solid or liquid layers, are present as a homogeneous mixture with sensitizers or sensitizer systems which can be activated chemically, those which can be activated by heat and/or those which can be activated by actinic light, and degradation of the poly(diacetylenes) is induced, in particular via free radical reactions, by appropriate activation of these sensitizers or sensitizer systems.

Abstract: Photopolymerizable recording materials which are suitable for the production of photoresist layers, and contain one or more thermoplastic vinyl polymers as the binder, one or more low molecular weight, ethylenically unsaturated, photopolymerizable compounds and one or more photoinitiators, with or without other, conventional additives and/or assistants, have excellent adhesion to metallic substrate surfaces if the binder employed is a vinyl polymer which possesses amino and/or imino groups.

Abstract: To transfer a toner image from a toner-treated surface, a toner transfer film is employed, which comprises a transparent base carrying a transparent layer which is capable of picking up toner and has a temporary slight surface tack, the layer consisting of a mixture containing a polymeric and/or pre-polymeric binder, a polymerizable low molecular weight compound and a polymerization initiator. After transfer, the toner image can be permanently fixed to the toner transfer film by heating the film and/or exposing it to light.

Abstract: A curable photosensitive mixture which is suitable as a positive-working recording material contains (a) one or more polymers which have a molecular weight of >500, contain not less than 5% by weight, based on the molecular weight of the polymer, of aromatic and/or heteroaromatic o-nitrocarbinol ester groups and also contain two or more further reactive functional groups which are available for reaction with a thermal crosslinking agent, (b) one or more compounds which effect crosslinking and are capable of reacting with the further reactive functional groups of the polymer (a) under the action of heat, at temperatures substantially above room temperature, and (c) a filler, with or without (d) other conventional additives and/or assistants. The photosensitive mixture is particularly useful as a positive-working recording material for optical information fixing, principally for the production of thermally stable relief images or resist images and, particularly advantageously, of soldering masks.

Abstract: Gravure printing plates comprising a plastic printing layer applied on a printing plate base are produced by a method wherein a solid photosensitive layer (L) firmly bonded on the printing plate base is exposed imagewise to actinic light, and the exposed layer is washed out with a developer and then subjected to thermal hardening to form the plastic printing layer. In this process, the photosensitive layer (L) employed contains, as the photosensitive component, a compound possessing two or more aromatic and/or heteroaromatic o-nitrocarbinol ester groups, and a compound which effects crosslinking and possesses two or more reactive groups which are capable of reacting with --COOH groups under the action of heat to form a covalent chemical bond.

Abstract: An electrophotographic recording medium which consists essentially of an electrically conductive base and a photosemiconductive double layer which comprises a first layer containing charge carrier-producing dyes, and a second layer containing one or more compounds which are charge carrier-transporting when exposed to light, wherein the charge carrier-producing dyes are dark in color, possess substantially panchromatic absorption characteristics, and are of the general formula ##STR1## where R.sup.1 is propyl, 1-hydroxypropyl, 1-methoxypropyl or 1-phenylethyl, Z is p-phenylazoanilino, phenylthio or anilino, and n is 0-6, and a process for the production of this electrophotographic recording medium.

Abstract: An electrophotographic recording medium which consists essentially of an electrically conductive base and a photosemiconductive double layer which comprises a first layer containing charge carrier-producing dyes, and a second layer containing one or more compounds which are charge carrier-transporting when exposed to light, wherein the charge carrier-producing dyes are those of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each hydrogen or a non-ionic substituent, X and Y are each the radical of a methylene-active compound, or of an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic amine or hydrazine, and Z is hydrogen, methyl or phenyl, and the production of this recording medium.

Abstract: Relief images or resist images are produced by a negative-working process, using a photosensitive resist layer which is applied on a base and contains a compound possessing two or more aromatic and/or heteroaromatic o-nitrocarbinol ester groups as well as a crosslinking compound possessing two or more reactive groups which are capable, under the action of heat, of reacting with carboxyl groups to form a covalent chemical bond. To produce the relief images or resist images, the photosensitive resist layer is first exposed imagewise to actinic light, the exposed areas of this layer are subjected to selective thermal hardening and crosslinking and the resist layer is then post-exposed uniformly to actinic light and finally washed out with an aqueous developer.

Abstract: Relief images or resist images are produced by a positive-working process, using a solid photosensitive resist layer which is applied to a base and contains a compound possessing two or more aromatic and/or heteroaromatic o-nitrocarbinol ester groups and crosslinking compounds possessing two or more reactive groups which are capable, under the action of heat, of reacting with carboxyl groups to form a covalent chemical bond. To produce the relief images or resist images, the photosensitive resist layer is first exposed imagewise to actinic light, the exposed areas of this layer are then washed out with an aqueous developer, the remaining resist layer is post-exposed uniformly to actinic light and finally the post-exposed resist layer is thermally crosslinked and hardened.

Abstract: An electrophotographic recording medium which consists essentially of an electrically conductive base and a photosemiconductive double layer which comprises a first layer containing charge carrier-producing dyes, and a second layer containing one or more compounds which are charge carrier-transporting when exposed to light, wherein the charge carrier-producing dyes are those of the formula I ##STR1## or of the formula II ##STR2## where R.sup.1 is hydrogen, alkyl, aralkyl, alkyl or alkylaryl, and Z may be a a fused aromatic system, and the degree to which the aromatic skeleton is halogen-substituted is from 45 to 75% of the maximum possible, and a process for the production of this electrophotographic recording medium.

Abstract: An electrophotographic recording medium which consists essentially of an electrically conductive base and a photosemiconductive double layer which comprises a first layer containing charge carrier-producing dyes, and a second layer containing one or more compounds which are charge carrier-transporting when exposed to light, wherein perylene-3,4,9,10-tetracarboxylic acid N,N'-bis-(2',6'-dichlorophenyl)-diimide is employed as the charge carrier-producing dye, and the production of this recording medium.