Evonik Degussa Gmbh

Degussa Aktiengesellschaft

Evonik Operations Gmbh

Degussa Gmbh

Harald Alff

Kai Schumacher

Stipan Katusic

Peter Kress

Rudolf Michel

Helmut Roth

Thomas Goebel

Roland Schilling

Armin Wiegand

Josef Karl

Helmut Mangold

Steffen Hasenzahl

Rainer Golchert

Martin Moerters

Matthias Schmitt

Peter Albers

Matthias Rochnia

Juergen Flesch

Harald Herzog

Daniel Esken

Michael Hagemann

Franz Schmidt

Volker Hamm

Tobias Renger

Ryo Takata

Marcus Von Twistern

Marcel Herzog

Jürgen Flesch

Martin Mörters

A process for producing a metal oxide powder by flame spray pyrolysis where

Method for producing metal oxides by means of spray pyrolysis

Process for producing metal oxide powders by means of flame spray pyrolysis, in which an aerosol comprising a metal compound is introduced into a flame in a reactor and reacted therein, and the metal oxide powder obtained is separated from gaseous substances, wherein a) the flame is formed by the ignition of an oxygen-containing gas (1) with a fuel gas, b) the aerosol is obtained by joint atomization of a solution containing a metal compound and an atomization gas by means of one or more nozzles and c) the ratio of the spray area to the cross-sectional reactor area is at least 0.2.

Process for producing metal oxide powders by means of flame spray pyrolysis

Core-shell particles containing crystalline iron oxide in the core and amorphous silicon dioxide in the shell and in which

Iron-silicon oxide particles having an improved heating rate

Process for the production of doped metal oxide particles, wherein the doping component is present on the surface in the form of domains, wherein in a first reaction zone, an oxidizable and/or &#x2014;hydrolysable metal compound as dopant together with an atomization gas is atomized into a flow of metal oxide particles in a carrier gas, wherein the mass flow of the metal oxide particles und &#x2014;the mass flow of the dopant are selected such that the doped metal oxide particles contain 10 ppm to 10 wt. % of the doping component, where the quantity of dopant to be introduced is calculated as the corresponding oxide, and wherein the temperature in the first reaction zone is &#x2014;selected such that it is below the boiling temperature of the dopant under the prevailing reaction conditions, and then, in a second reaction zone, the flow from the first &#x2014;reaction zone and optionally at least as much oxygen and/or steam are &#x2014;introduced that the quantity of oxygen and/or steam at least suffices completely to convert the dopant, wherein the temperature is from 300 to 2000&#xb0; C., &#x2014;preferably 500 to 1000&#xb0; C., and the reaction mixture is then cooled or allowed to cool and the doped metal oxide particles are separated from the gaseous substances.

Process for the production of doped metal oxide particles

Aluminum oxide powder in the form of aggregates of primary-particles, which has a BET surface area of from 10 to 90 m2/g and comprises as crystalline phases, in addition to gamma-aluminum oxide and/or theta-aluminum oxide, at least 30% of delta-aluminum oxide. It is prepared by vaporizing aluminum chloride and burning the vapor together with hydrogen and air, the ratio of primary air/secondary air being 0.01 to 2, the exit speed vof the reaction mixture from the burner being at least 10 m/s, the lambda value being 1 to 4, the gamma value being 1 to 3 and the value of gamma*v/lambda being greater than or equal to 55. Dispersion comprising the aluminum oxide powder. Coating composition comprising the dispersion.

Aluminium oxide powder, dispersion and coating composition

Titanium-aluminium mixed oxide powder with a proportion of aluminium oxide of less than 1 wt. % or a proportion of titanium dioxide of less than 5 wt. %, wherein the sum of the proportions of titanium dioxide and aluminium oxide is at least 99.7 wt. %. It is produced by transferring a vaporous starting compound of the quantitatively greater component of the mixed oxide into a mixing chamber by means of primary air and a vaporous starting compound of the quantitatively smaller component of the mixed oxide by means of an inert gas, and burning the mixture mixed with hydrogen in a mixing chamber into a reaction chamber. It can be used as a catalyst support.

Titanium-aluminium mixed oxide powder

Metal oxide particles having a metal oxide core and a silicon dioxide coating have a low structure. The particle are produced by a base dissolved in water being added under agitation to a dispersion comprising a metal oxide, at least one compound of the type X Si(OR) , and water, the reaction product being separated out, optionally washed with water and dried. The metal oxide particles coated with silicon dioxide may be used in sun screening agents and in chemical-mechanical-polishing (CMP) applications.

Metal oxide particles coated with silicon dioxide

Aqueous emulsions are disclosed containing organosilicon compounds for the impregnation of inorganic materials, in particular building materials, containing alkoxysilanes and silane surfactants. The aqueous emulsions are storage stable and are adjusted to pH of from 3 to 5.5 just prior to use.

Process for impregnating a building material with an organosilicon

Aqueous emulsions are disclosed containing organosilicon compounds for the impregnation of inorganic materials, in particular building materials, containing alkoxysilanes and silane surfactants. The emulsions comprise 1-80% by weight of one alkoxy silane, ##STR1## X.dbd.H,cl,Br, I, NH.sub.2, SCN, CN, N.sub.3, NHR, NR, NR.sub.3, --S.sub.x --, aryl or alkenyl

Aqueous emulsions containing organosilicon compounds for the

Growing community of inventors

Kahl, Germany

Harald Alff