Bayer Aktiengesellschaft

Hermann C. Starck Berlin Gmbh & Co Kg

Jurgen Scharschmidt

Hans-Josef Buysch

Christine Mendoza-Frohn

Gerhard Darsow

Gunter Buxbaum

Udo Birkenstock

Ulrich Notheis

Rudolf J Klee

Jurgen Wiese

Axel Westerhaus

Peter Kunert

Helmut Meinhardt

HaPaul

Paul Meier

Rainer Klotzbucher

A description is given of the preparation of hydroxybiphenyl by dehydrogenation of completely or partially hydrogenated precursors using a supported Rh catalyst which additionally contains chromium, manganese and alkali metal and can contain a sulphur compound. The Rh catalyst which can be used according to the invention is prepared from halide-free starting materials. The Rh catalyst is distinguished by a low dependence of the initial selectivity, with the selectivity in the run-in state and the running-in time on the conditions of the reductive pretreatment and requires only short running-in times to reach the optimum state.

Process for preparing hydroxybiphenyl

In the hydrogenation of phenol with H.sub.2 over Pd supported catalysts, the ratio of the products formed, cyclohexanone and cyclohexanol, can be predetermined by specific treatment of the catalysts during the initial activation and regeneration by O.sub.2 pretreatment and H.sub.2 treatment, the following time/temperature conditions being used:

Process for the preparation of a mixture of cyclohexanone and

In an advantageous process for producing powdered aluminium alloys which have a catalytic action or are capable of acting as precursors of catalysts, good results are obtained if the alloy is atomized with water and/or a gas at a temperature of 50.degree. to 500.degree. C. above its melting point and then cooled and dried.

Process for producing powdered aluminum alloys

Pigments for printing inks and magnetic toners are iron oxide pigments with a rhombic dodecahedral form and an average particle diameter of from 0.05 to 3.0 .mu.m with a standard deviation of the particle size distribution of .+-.30%.

Iron oxide pigments, a process for their preparation and their use

Growing community of inventors

Krefeld, Germany

Jurgen Scharschmidt