Basf Aktiengesellschaft

Basf Magnetics Gmbh

Bernd Hoppner

Ekkehard Schwab

Gerd Kaibel

Franz-Josef Mueller

Ronald J Veitch

Wolfgang Steiner

Gerhart Eigenberger

Emil Pfannebecker

Axel Anderlohr

Peter Blei

Schuster, Ludwig

Acicular cobalt-containing magnetic iron oxides having a high coercive force and a core/shell structure and hence low temperature dependence of the coercive force are prepared by a process in which, in a first stage, surface activation is effected by means of iron(II) and cobalt ions under alkaline conditions on the iron oxide core under an inert gas atmosphere and thereafter, in a second stage, an epitactic coating of cobalt ferrite is applied, which coating is formed oxidatively from iron (II) and cobalt (II) hydroxide, likewise under alkaline reaction conditions. The total amount of cobalt ions used for doping remains unchanged compared with the known doped iron oxides or is even smaller. In the second process stage, the achievable coercive force can be controlled by the proportion of air in the gas mixture during the formation of the epitactic coating.

Preparation of acicular cobalt-containing magnetic iron oxide

Ethanol is prepared by hydrogenating acetic acid under superatmospheric pressure and at elevated temperatures by a process wherein a predominantly cobalt-containing catalyst is used and acetic acid and hydrogen are passed through the reactor, at from 210.degree. to 330.degree. C. and under from 10 to 350 bar, under conditions such that a liquid phase in not formed during this procedure.

Continuous preparation of ethanol

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Neustadt, Germany

Bernd Hoppner