Basf Aktiengesellschaft

Franz Feichtmayr

Klaus Grychtol

Hans-Juergen Degen

Peter Neumann

Herbert Naarmann

Joachim Paust

Reinhold J Leyrer

Gerhard Hoffmann

Udo Mayer

Heinz Eilingsfeld

Klaus Penzien

Peter Bauer

Dietrich Lach

Johannes Schlag

Rolf Streicher

Hellmut Kast

Albert Elzer

Albrecht Eckell

Horst Bruder

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.

Layered electrophotographic recording medium comprising heterocyclic

Compounds of the general formula I ##STR1## where the radicals A, A.sup.1 and B are identical or different and

Cationic dyes

A process for the preparation of an electrically conductive polyene, wherein a polyene which contains one or more chain members of the formula where R is hydrogen or methyl, and which contains a total of not less than seven aliphatic double bonds, is treated, in the absence of moisture and of oxygen, with a strong Lewis acid having a pk.sub.a of from -10 to +4, or with an alkali metal.

Preparation of electrically conductive carotenoids

A process for dyeing grain leather with anionic dyes under the conventional conditions for exhaustion methods, in the presence of two specific surfactants. The combined use of the two surfactants results, in the case of cationically tanned (essentially mineral-tanned) leather, in an improvement in the levelness and dye penetration and in the case of anionically tanned (synthetics-tanned or vegetable-tanned) or retanned leather, in an increase in depth of the color. The two surfactants are

Dyeing of grain leather

Methine dyes of the general formula ##STR1## where the groups A are identical or different aryl or hetaryl, A.sup..crclbar. is an anion, R is hydrogen, methyl or ethyl and X is a bridge member, and the methine groups are in the .alpha.- or .gamma.-position. The compounds are preferably used for dyeing paper.

Methine dyes for paper and amonically-modified fibers

Compounds of the general formula I ##STR1## where B is a bridge member,

Triphenylmethane dyes

The present invention relates to electrical insulating compositions based on olefin polymers and a specific azomethine containing a naphthalene nucleus and serving to increase the long-term dielectric strength. The insulating compositions of the invention are particularly suitable for cables, especially high-tension cables.

Growing community of inventors

Ludwigshafen, Germany

Franz Feichtmayr