Hoechst Aktiengesellschaft

Gerhard Mietens

Michael Ahlgrim

Franz-Josef Dany

Joachim Kandler

Erich Schallus

Eberhard Preisler

Klaus Hestermann

Wilhelm Vogt

Alexander Maurer

Hermann Glaser

Eitel Goedicke

Johannes Holzem

Gerhard Nolte

Gunter Sorbe

Gregor Fucker

Herbert Beumling

Helga Zygmann

Friedrich Wilhelm Dorn

Jurgen Petrell

The present invention relates to a method for the preparation of electrolytic manganese dioxide in which flocculent nuclei of a manganese oxide hydrate is dispersed in the electrolyte.

Process for the preparation electrolytic manganese dioxide

The invention relates to a corrosion-inhibiting active pigment for use in the surface protection of iron and iron alloys. The pigment consists of a mixture of calcium hydrogen phosphate dihydrate, magnesium hydrogen phosphate trihydrate and zinc oxide. More specifically, the mixture contains 2 to 98 weight % of ZnO and 98 to 2 weight % of phosphate components. These in turn contain 3 to 97 weight % of CaHPO.sub.4 .multidot.2 H.sub.2 O and 97 to 3 weight % of MgHPO.sub.4 .multidot.3 H.sub.2 O. The active pigment is suitable for use in painting compositions or lacquers.

Corrosion-inhibiting pigment and paint composition

The invention relates to a long chain ammonium polyphosphate and its use as an effective additive in lubricants and/or coolants for metal working under extremely high pressures and temperatures. The polyphosphate chain preferably contains 50 to 1000 phosphorus atoms. Up to 20% of the ammonium groups are replaceable by hydrogen. The additive is preferably added to the lubricant/coolant in a proportion of 0.1 to 30 weight %.

Additive for use in metal working

Electrical power of high intensity is transmitted to a rotating electrode with the use of an apparatus, wherein a shaft is provided with a connecting joint which is rigidly connected to a cylindrical container serving as the rotating electrode. A trough filled with a low-melting alloy has a contact maker secured to it, and the latter has a flexible cable screwed thereto. A cover, which has the shaft passed through it, is insulatingly placed on the cover, and the shaft is provided with a disk, in the region of the cover.

Electrical power transmitting apparatus

Axially unsymmetrical articles are electropolished zonewise, or the inside and outside surfaces of articles are electropolished zonewise and simultaneously. To this end a cathode of which the geometrical configuration and surface area correspond to the surface to be electropolished is arranged opposite an anode; more particularly, the cathode is subdivided into a plurality of segments which are non-conductive with respect to one another, through which segments a current of the necessary density is alternately passed and discontinued, at intervals, for a period compatible with the production of the desired electropolishing effect.

Electropolishing process

Antistatic properties are imparted to plastics by blending a pulverulent plastics material and, if desired further addends, with conductive carbon black and making the resulting blend into a moulding composition. The plastics are more particularly blended with 4 to 12 weight % of conductive carbon black having a water absorption stiffness (AS-number) of 15 to 35, a specific electric resistance of 10.sup.-1 up to 10.sup.-3 ohms . cm under a moulding pressure of 100 to 180 atmospheres absolute, a bulk density of 100 to 180 g/liter, a BET-surface area of 100 to 1000 m.sup.2 /g. The carbon black is made by a process wherein an aqueous suspension of carbon black having an AS-number higher than 15 is intimately blended at temperatures within the range 5.degree. and 120.degree. C, under pressure within the range 1 and 20 atmospheres absolute, in liquid phase at a pH-value of 7 to 10, and for a period of 1 to 20 minutes, with vaporizable liquid aliphatic or cycloaliphatic hydrocarbons, the carbon black is separated from liquid matter, then heated and thereby freed from hydrocarbons and water, and finally annealed for 20 to 30 minutes at 200.degree. up to 2200.degree. C. The aqueous suspension is prepared by subjecting hydrocarbons, which are liquid at room temperature, to thermal conversion at 1200.degree. to 2000.degree. C, under pressures within the range 1 and 80 atmospheres absolute, and in the presence of oxygen or an oxygen-containing gas, and water scrubbing the resulting carbon black-containing reaction gas.

Process for imparting antistatic properties to plastics

Conductive carbon black for use in depolarization masses in dry batteries is produced. To this end, an aqueous suspension of carbon black having an AS-number higher than 15 and having been obtained by subjecting hydrocarbons, which are liquid at room temperature, to thermal conversion at 1200.degree.-2000.degree. C, under 1-80 atmospheres, and in the presence of oxygen or oxygen-containing gas and, if desired, steam, and water-scrubbing the resulting carbon black-containing reaction gas, is intimately mixed at 5.degree.-120.degree. C, under 1-20 atmospheres, in liquid phase and for 1-20 minutes with 0.5-10 g, per gram of carbon black, of vaporizable aliphatic or cycloaliphatic hydrocarbons, the resulting carbon black is separated from the liquid phase, heated and thereby freed from hydrocarbons and water, and the temperature is finally increased for 2-30 minutes to 1100.degree.-2200.degree. C.

Process of conductive carbon black for use in depolarization masses in

Apparatus adapted to receive one or more catalysts for the decontamination of exhaust gas of internal combustion engines. The apparatus, which includes a closed container for one or more beds of catalyst, is provided with an inlet for introducing exhaust gas thereinto and with an outlet for removing decontaminated exhaust gas therefrom. The catalyst beds are maintained in position by means of a spring-actuated clamping device which comprises a thrust rod, a mounting therefor and a spring element. The spring element, which bears against the mounting, urges the thrust rod into close contact with the catalyst beds.

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Hurth-Efferen, Germany

Gerhard Mietens