Degussa Aktiengesellschaft

Degussa - Huls Ag

Evonik Degussa Gmbh

Degussa Gmbh

Degussa-huels Aktiengesellschaft

Dieter Kerner

Helmut Mangold

Werner Hartmann

Peter K Kleinschmit

Manfred Ettlinger

Hans Deusser

Andreas Stubbe

Juergen Meyer

Klaus Deller

Kai Schumacher

Siegfried Wolff

Felix Schmidt

J&uuml;rgen Meyer

Alan Parkhouse

Adolf Wagner

Dietrich Bauer

Thomas Rudolph

Jürgen Meyer

Mario Scholz

Helmfried Krause

Rainer Golchert

Hans Klebe

Patrik Stenner

Uwe Diener

Stephanie Frahn

Juergen Flesch

Roland Schilling

Hans Lansink-Rotgerink

Josef Schmid

Hilmar Gilges

Manfred Nagel

Detlev Koth

Thomas Schiener

Gu/ Nther Michael

Manfred Schmid

Ju/ Rgen Meyer

Aymee Lisette Michel De Arevalo

Stefan Fiedler

De Arevalo Aymee Lisette Michel

Jürgen Flesch

Process for the phase transformation of substances and mixtures of substances, in which the substance or the mixture of substances is introduced into a plasma reactor, the substance or the mixture of substances is converted into the higher-energy phase and the product is removed in gaseous form from the plasma reactor. The process can be used for the sublimation of metal salts, metal nitrates and/or metal alkoxides and other vaporizable metal-organic compounds.

Process for the phase transformation of substances

Surface-modified, doped, pyrogenically produced oxides surface-modified with one or several compounds from the following groups: 

Surface-modified, doped, pyrogenically produced oxides

Pyrogenically produced silicon dioxide powder with a specific surface area of between 5 and 600 m/g and a carbon content of less than 500 ppm, which displays a specific dibutyl phthalate absorption of less than or equal to 1.2 g dibutyl phthalate/100 g SiO2 per mof specific surface area and a specific thickening action of less than 15 mPas/mof specific surface area. It is produced by supplying vaporous tetramethoxysilane and/or tetraethoxysilane together with air and separately hydrogen to a burner, and allowing the mixture of gases to react in a flame in a reaction chamber connected in series to the burner, and separating the solid reaction product from the gas stream by known means, the lambda value in the burner being between 0.95 and 1.5 and sufficient secondary air also being supplied to the reaction chamber that the lambda value in the reaction chamber is between 0.8 and 1.6. The invention also provides a dispersion containing the silicon dioxide powder and the use of the powder and of the dispersion.

Pyrogenic silicon dioxide powder and dispersion thereof

Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 200&#xb1;25 m/g, wherein the aggregates display an average surface area of 7000 to 12000 nm, an average equivalent circle diameter (ECD) of 80 to 100 nm and an average circumference of 850 to 1050 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a second silicon component comprising HSiCl, HSiCl, HSiCl, CHSiCl, (CH)SiCl, (CH)SiCl and/or (n-CH)SiClare mixed with primary air and a combustion gas and burnt into a reaction chamber, secondary air also being introduced into the reaction chamber, and the feed materials being chosen such that an adiabatic flame temperature of 1570 to 1630&#xb0; C. is obtained. It can be used as a filler.

Pyrogenically produced silicon dioxide powder

Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 150&#xb1;15 m/g, wherein the aggregates display an average surface area of 12000 to 20000 nm, an average equivalent circle diameter (ECD) of 90 to 120 nm and an average circumference of 1150 to 1700 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a second silicon component comprising HSiCl, HSiCl, HSiCl, CHSiCl, (CH)SiCl, (CH)SiCl and/or (n-CH)SiClare mixed with primary air and a combustion gas and burnt into a reaction chamber, secondary air also being introduced into the reaction chamber, and the feed materials being chosen such that an adiabatic flame temperature of 1670 to 1730&#xb0; C. is obtained. Silicone sealing compound containing the pyrogenically produced silicon dioxide powder.

Pyrogenically produced silicon dioxide powder and silicone sealing compound containing this powder

Functionalized silicas with 3-methacryloxypropylsilyl and/or glycidyloxypropylsilyl groups on the surface are prepared by mixing the silicas with the silane and heat-treating the mixture. The silicas are employed, for example, in solvent-containing coatings.

Functionalized silicas

A product obtained by treating surface-modified, pyrogenically produced titanium dioxide with at least one ammonium-functional silane, such as by spraying the pyrogenically produced titanium dioxide with the at least one silane, alone or in ethanol solution, and tempering, and useful in the field of cosmetics in sunblocks, in toner powders, in paints and varnishes, in silicone rubber, as abrasives and polishes, for example, in the field of CMP.

Surface-modified titanium dioxide

Pyrogenically, especially flame-hydrolytically produced zirconium dioxide powder with a specific surface area between 20 and 200 m /g, a primary particle size between 7 and 100 nm, a tamped density of the deacidified and non-deacidified zirconium dioxide between 40 and 150 g/l with Sears numbers of the deacidified and non-deacidified zirconium dioxide between 1 and 20 ml/2 g and with a chlorine content of the deacidified zirconium dioxide less than 0.6% by weight. These are produced by evaporating zirconium halides, mixing the vapors alone or together with a carrier gas in a burner with air, oxygen, nitrogen and hydrogen, causing the gases to react with each other in a flame in a closed burner chamber, cooling off the waste gases and the zirconium dioxide in a heat exchanger unit, separating the waste gases from the zirconium dioxide and removing any halide remnants adhering to the zirconium dioxide by a heat treatment with moistened air.

Zirconium dioxide powder, method of its production and use

A silicon-aluminum mixed oxide produced by flame hydrolysis and having a composition of from 1 to 99.999 wt. % Al O , the remainder being SiO , which mixed oxide exhibits an amorphous structure in the X-ray diffraction pattern and consists of intergrown primary particles, and in these primary particles crystallites are present. These crystallites having sizes of between one and 200 namometers and the specific surface of the powder being between 5 and 300 m /g. These products are produced by a process wherein silicon halide and aluminum halide are vaporized in a particular ratio to one another and are homogeneously mixed with air, oxygen and hydrogen in a mixing unit by means of any carrier gas, this mixture undergoes combustion in a burner of known construction and, after the separation of the solids from the vapour phase, any traces of halide possibly adhering to the product are separated off in a further processing step by means of moist air at elevated temperature. The silicon-aluminum mixed oxide produced by flame hydrolysis are used in the form of dispersions for polishing, in particular in the electronics industry (CMP).

Silicon-aluminum mixed oxide

Granules based on pyrogenic titanium dioxide and a process for preparing the granules

A titanium dioxide powder/iron oxide mixed oxide which is prepared from FeCl and TiCl using a pyrogenic, especially a flame hydrolytic method. A further possibility is to coat pyrogenically, especially flame hydrolytically prepared titanium dioxide with iron oxide in aqueous dispersion. Both of these titanium dioxide powders which contain iron oxide may be used as a UV absorber in sunscreens.

Titanium dioxide powder which contains iron oxide

A toner or a mixture of toners, comprises a pyrogenically synthesized alumina-silica mixed oxide as a component in combination with other components necessary to complete a toner formulation. The surface of the mixed alumina-silica oxide material.

Toners and/or toner mixtures

A boron oxide-silicon dioxide mixed oxide which has a BET surface of less than 100 m,g, and optionally containing oxides of aluminium, titanium or zirconium, is prepared pyrogenically by flame hydrolysis. The mixed oxide is used in glass making.

Boron oxide-silicon dioxide mixed oxide

A boron oxide-silicon dioxide mixed oxide which has a BET surface of less than 100 m.sup.2 g, and optionally containing oxides of aluminium, titanium or zirconium, is prepared pyrogenically by flame hydrolysis. The mixed oxide is used in glass making.

Growing community of inventors

Hanau, Germany

Dieter Kerner