Degussa Aktiengesellschaft

Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Degussa Gmbh

Rudolf Schwarz

Peter K Kleinschmit

Roland Reuter

Gerhard Sextl

Sabine Schmidt

Siegfried Wolff

Hans Strack

Christa Liedtke

Wolfgang Weigert

Eugen Meyer-Simon

Ingo Pauli

Sabine Bartelt

Klaus Wilmes

Anh T Liu

Friedel Worch

Edgar Koberstein

Rainer Domesle

Bernd Engler

Rudolf Michel

Reinhold Brand

Werner Hartmann

Wolfgang Buder

Alexander Ruhs

Johannes Ohmer

Hans-Dieter Pletka

Ilona Sporys

Ilona Fuss

Gerhard Dusing

Martin Foerster

Sabine Gliem

Peter Kleihschmit

Powdered substances are compressed by a process wherein the powdered substances are enclosed in a flexible receptacle, the receptacle is enclosed in a pressure vessel and the space between the wall of the receptacle and the wall of the pressure vessel is pressurized with compressed gas.

Apparatus for the compression of powdered substances

Process for the compression of powdered substances

Heat insulator and method of making it

A preferably platelike form body for use as heat insulation, consisting of: a) a finely divided, powdery or fibrous material, b) a microporous casing and c) a gas and watertight casing. The form body is produced by optionally drying the powdery or fibrous material, optionally placing it into a microporous casing, optionally pressing it and then optionally drying it. Then, the powdery material is placed with the microporous casing into a gas and watertight casing. This gas and watertight casing is optionally evacuated and sealed.

Shaped articles for heat insulation

A shaped body, preferably plate-shaped, for use as heat insulation, formed of (a) a finely distributed, powdery or fibrous substance, (b) a microporous casing, and (c) a gastight and watertight, metal-free casing. The shaped body is produced by drying a powdery or fibrous substance if necessary, optionally placing it into a microporous casing, optionally pressing and then optionally drying. Thereafter, the powdery substance is placed with the microporous casing into a gastight and watertight, metal-free casing. This gastight and watertight casing is optionally evacuated and sealed. Furthermore, a shaped article, preferably plate-shaped, for use as heat insulation, produced from (a) a finely distributed, powdery or fibrous substance with a water absorption capacity of 4 to 50% by weight at 23.degree. C. and 85% relative humidity, (b) a casing of two parts with asymmetric design which contains this finely distributed, powdery or fibrous substance, the first part of the casing being metal-free and concave in such a manner that it is completely filled by the preferably plate-like shaped article and the second part being metal-free or metallic and planar and connected to the trough in such a manner that a gastight and water-vapor-tight seal is assured and both parts having water-vapor-permeabilities between 0 and 0.2 g/m.sup.2 /d at 23.degree. C. and 85% relative humidity and gas permeabilities for N.sub.2, O.sub.2 and CO.sub.2 of in sum 0 to 0.5 cm.sup.3 /m.sup.2 d/bar at 23.degree. C.; the shaped article having the property of absorbing water up to an amount of 2 to 15% by weight without its thermal conductivity deteriorating more than 25%.

Form body for heat insulation and vacuum insulation panel with

Heat insulator and method of making same

Titanium dioxide compacts are produced by intensively mixing pyrogenically produced titanium dioxide in the presence of deionized water with a wetting agent and/or with a base and/or optionally with a binder and/or optionally with an auxiliary deformation agent and/or optionally with a pore former, extruding the mass thus obtained at pressures between 5 and 100 bars to form shaped articles, drying the shaped articles at temperatures between 50.degree. and 120.degree. C. and subsequently calcining the shaped articles in the ambient air at temperatures of 400.degree. to 700.degree. C. for 1 to 5 hours.

Titanium dioxide compacts, method of their production and a catalyst

Zirconium-doped pseudoboehmite with the following properties: zirconium content of 0.5 to 10 mol % relative to Al water content of 20 to 35 weight percent total of the anionic impurities less than 0.5 weight percent. It is synthesized by a process wherein zirconium salt is added in calculated quantity to an aqueous aluminum sulfate solution, the resulting mixture is fed simultaneously with a sodium aluminate liquor into a water pool having a temperature of 50.degree. to 100.degree. C., thereby precipitating zirconium-doped alumina gel while a pH of 3.5 to 8 is maintained, the pH of the suspension is adjusted after addition of the aluminum sulfate solution to 8.5 to 10.5 by further addition of sodium aluminate liquor, the suspension is digested if necessary at the pH of 8.5 to 10.5 and the temperature of 50.degree. to 100.degree. C. for a period of up to 24 hours, the formed pseudoboehmite crystals are filtered off, the filter cake is redispersed with water and the suspension is sprayed-dried. By calcining at 700.degree. to 1100.degree. C., preferably at 850.degree. to 950.degree. C., the pseudoboehmite is further processed to zirconium-doped gamma-alumina suitable for automobile exhaust catalysts.

Process for producing zirconium-doped pseudoboehmite

X-ray amorphous, aluminum oxide which exhibits a specific surface area (BET) according to DIN 66 131 of &gt;10 m.sup.2 /g, an average particle size of .gtoreq.0.1 .mu.m and a water content of &gt;10%. The X-ray amorphous aluminum oxide can be produced by reacting water vapor and vaporous aluminum trichloride in a molar ratio of 1.5 to 10:1, preferably 7.+-.1:1=H.sub.2 O:alCl.sub.3 at a temperature of 200.degree. to 1000.degree. C., preferably 600.degree..+-.50.degree. C. and at a dwell time of &gt;1 sec., preferably 3.5.+-.1 sec. and a partial vacuum of 100.+-.10 mm H.sub.2 O column. By means of calcination thereof an aluminum oxide can be obtained which consists of .gtoreq.90% by weight of .alpha.-aluminum oxide and exhibits a specific surface area (BET) according to DIN 66 131 of &gt;5 m.sup.2 /g and an average particle size of .gtoreq.0.1 .mu.m.

Amorphous aluminum oxides, methods of production and uses

Zirconium-doped pseudobehmite, process for its production and use thereof

A spherical, hydrophilic silica consisting of compact, massive, non-crystalline particles without inner pores with a particle size of 0.5 to 10 .mu.m, preferably 0.5 to 4 .mu.m and especially 1 to 3 .mu.m with a BET surface of &lt;50 m.sup.2 /g, preferably of 1 to 10 m.sup.2 /g is prepared by heating water vapor and gaseous silicon tetrachloride separately to a temperature of 300.degree. to 400.degree. C., mixing them with each other in a molar ratio of 2:1 to 6.7:1 and reacting the mixture at a temperature of 600.degree. to 1200.degree. C.

Spherical, hydrophilic silica, method of its preparation and use

There is prepared an aqueous suspension which in addition to water, consists of 2 to 50 weight % of a mixture of bentonite and inorganic fibers, with the portion of inorganic fiber being 1 to 30 weight % and the portion of bentonite being 1 to 30 weight % and wherein the total amount of solids does not exceed 50 weight %. With the suspension there is attained an improvement of the mechanical properties of thermal insulating molded objects which are employed for thermal insulation and which for example, contain pyrogenically produced silica as a filler by delivery of this suspension on the thermal insulating plate. The suspension can also be delivered on thermal insulating molded bodies on which there is pressed a fiber net or a fiber felt. After applying the suspension several thermal insulating molded bodies can be joined together where the coating formed consisting of bentonite and inorganic fibers acts as binder. The heat insulating molded article in addition to this layer, can have one or more additional coatings based on organic or inorganic lacquer systems, silicone compositions or low melting glazes.

Aqueous suspension of bentonite and its use for coating thermal

Binder-free mixtures of heat-insulating material are mixed with substances showing a basic reaction in aqueous solution during the mixing process and are then press-molded to press-molded heat-insulating parts.

Process for the production of binder-free press-molded heat-insulating

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Alzenau-Wasserlos, Germany

Rudolf Schwarz