Abstract: Process for preparing a mixed metal oxide powder, in which oxidizable starting materials are evaporated and oxidized, the reaction mixture is cooled after the reaction and the pulverulent solids are removed from gaseous substances, wherein as starting materials, at least one pulverulent metal and at least one metal compound, the metal and the metal component of the metal compound being different and the proportion of metal being at least 80% by weight based on the sum of metal and metal component from metal compound, together with one or more combustion gases, are fed to an evaporation zone of a reactor, where metal and metal compound are evaporated completely under nonoxidizing conditions, subsequently, the mixture flowing out of the evaporation zone is reacted in the oxidation zone of this reactor with a stream of a supplied oxygen-containing gas whose oxygen content is at least sufficient to oxidize the starting materials and combustion gases completely.

Abstract: Fumed silicon dioxide powder with a BET surface area of 20 to 35 m2/g, characterized in that a) the number-based median particle diameter is 60 to 150 nm, and b) the proportion of particles with a diameter of 200 nm or more is at most 10%, and c) the proportion of particles with a diameter of up to 60 nm is at most 20%, based in each case on the total number of particles.

Abstract: Aqueous cerium oxide dispersion Aqueous cerium oxide dispersion, containing 5 to 60% by weight cerium oxide. It can be used to polish SiO2 in the semiconductor industry.

Abstract: Iron-silicon oxide particles with a core-shell structure, which have a) a BET-surface area of 10 to 80 m2/g, b) a thickness of the shell of 2 to 30 nm and c) a content of iron oxide of 60 to 90% by weight, of silicon dioxide of 10 to 40% by weight, based in each case on the enveloped particles, where d) the proportion of iron, silicon and oxygen is at least 99% by weight, based on the enveloped particles, and where e) the core is crystalline and the iron oxides comprise haematite, magnetite and maghemite, f) the shell consists of amorphous silicon dioxide and g) at least one compound or a plurality of compounds consisting of the elements silicon, iron and oxygen is/are present between shell and core.

Abstract: Process for the production of a metal oxide powder having a BET surface area of at least 20 m2/g by reacting an aerosol with oxygen in a reaction space at a reaction temperature of more than 700° C. and then separating the resulting powder from gaseous substances in the reaction space, wherein the aerosol is obtained by atomisation using a multi-component nozzle of at least one starting material, as such in liquid form or in solution, and at least one atomising gas, the volume-related mean drop diameter D30 of the aerosol is from 30 to 100 ?m and the number of aerosol drops larger than 100 ?m is up to 10%, based on the total number of drops, and metal oxide powder obtainable by this process.

Abstract: Surface-modified superparamagnetic oxidic particles, characterized by the following physicochemical characteristics: BET surface area 20 to 75 m2/g; Carbon content 0.5 to 6.0% by weight; Tamped density 150 to 500 g/l; Chlorine content 50 to 1000 ppm; Drying loss 0.1 to 4.0% by weight are prepared by contacting the oxides with the surface modifier either by spraying or vapour deposition and then heat-treating them. The surface-modified oxidic particles can be used as a filler in adhesives. Further fields of application are use for data carriers, as a contrast agent in imaging processes, for biochemical separation and analysis processes, for medical applications, as an abrasive, as a catalyst or as a catalyst support, as a thickener, for thermal insulation, as a dispersing assistant, as a flow assistant and in ferrofluids.

Abstract: Hydrophobized silicon-iron mixed oxide powder, characterized in that it has the following physicochemical characteristics: BET surface area 20 to 75 mVg; Carbon content 0.5 to 10% by weight; Tamped density 150 to 600 g/l; Chlorine content 0.1 to 3.0%; Drying loss 0.1 to 4% by weight; DVS isotherm (60%) 0.5 to 1.5% by weight; Heating rate (Is, 10%) 50 to 550° C./s; 90% range (number) 5 to 50 nm; 90% range (weight) 5 to 150 nm; Overall range 2 to 200 nm, is prepared by treating a silicon-iron mixed oxide powder with the surface modifier either in spray form or in vapour form, and then heat treating it. The surface-modified oxidic particles can be used as a filler in adhesives. Further fields of use are use for data carriers, as a contrast agent in imaging processes, for biochemical separation and analysis processes, for medical applications, as an abrasive, as a catalyst or as a catalyst support, as a thickener, for thermal insulation, as a dispersing aid, as a flow aid and in ferrofluids.

Abstract: Zirconium dioxide powder in the form of aggregated primary particles, having a BET surface area of 30 to 150 m2/g and a Berger whiteness of at least 88%. It is prepared by atomizing a solution which comprises an organic zirconium compound and mixing it with a combustion gas and air and allowing the mixture to burn in a flame into a reaction chamber surrounded by a casing, where the temperature in the reaction chamber and along the side of the wall of the casing facing the reaction chamber is at least 500° C. Dispersion comprising the zirconium dioxide powder. Use of the zirconium dioxide powder and of the dispersion for producing ceramics.

Abstract: Mixed oxide powder consisting of particles with the components zirconium dioxide, aluminium oxide and at least a third component selected from the group including yttrium oxide, magnesium oxide or calcium oxide, wherein mixed oxide powder has an aluminium oxide content 0.01 to 10 wt. % and is homogeneously distributed in the mixed oxide particles, the content of aluminium oxide, zirconium dioxide and yttrium oxide is at least 99.5 wt. %, based on the total quantity of the powder, and the BET surface area is 20 to 80 m2/g. It is obtained by atomising a solution containing at least one starting compound for each of aluminium oxide, zirconium dioxide and the third component, allowing the atomised solution to react with oxygen in a reaction chamber at a reaction temperature 700 to 15000° C., cooling the hot gases and the solid products and then separating the solid product from the gases. It can be used as a dental material.

Abstract: Nanoscale, pyrogenically produced zinc oxide having a BET surface area of 10 to 200 m2/g, which is in the form of aggregates of anisotropic primary particles and whereby the aggregates display an average diameter of 50 to 300 nm. It is obtained from zinc powder, which is converted to zinc oxide powder in the four successive reaction zones, evaporation zone, nucleation zone, oxidation zone and quench zone. It can be used in sunscreen formulations.

Abstract: Hydrophobic zinc oxide powder in the form of partially or completely coated aggregates of zinc oxide primary particles having a carbon content of from 0.4 to 1.5% by weight, based on the hydrophobic zinc oxide powder, and a BET surface area of from 25 to 100 m2/g, where the coated aggregates are present to 0 to <10% in a circular form, 15 to <30% in an ellipsoidal form, to <30% in a linear form, 40 to <70% in a branched form, and the sum of the different forms is 15 100% and the coating comprises chemically bonded linear and/or branched monoalkylsilyl groups Si-alkyl and/or dialkylsilyl groups Si-(alkyl)2 having 1 to 20 carbon atoms.

Abstract: Surface-modified zinc-silicon oxide particles which consist of a core, a first coating layer surrounding the core, and a second coating layer surrounding the first coating layer, where the core is crystalline and consists of aggregated zinc oxide primary particles having a primary particle diameter of from 10 to 75 nm, the first coating layer consists of one or more compounds containing the elements Zn, Si and O, the second coating layer comprises linear and/or branched alkylsilyl groups having 1 to 20 carbon atoms bonded chemically to the first coating layer, which have an average aggregate area of less than 40 000 nm2 and an average aggregate diameter (ECD) of less than 300 nm, a carbon content of from 0.4 to 1.5% by weight and a BET surface area of from 10 to 60 m2/g.

Abstract: Aqueous cerium oxide dispersion Aqueous cerium oxide dispersion, containing 5 to 60% by weight cerium oxide. It can be used to polish SiO2 in the semiconductor industry.

Abstract: Zinc silicon oxide particles with a core-shell structure which have a Zn/Si ratio of from 2 to 75, in atom %/atom %, whose fraction of Zn, Si and O is at least 99% by weight, based on the zinc silicon oxide particles, which have a BET surface area of from 10 to 60 m2/g, a weight-averaged primary particle diameter of from 10 to 75 nm an average aggregate area of less than 40 000 nm2 and an average aggregate diameter (ECD) of less than 200 nm, whose core is crystalline and consists of aggregated primary particles of zinc oxide and whose shell surrounds the aggregated zinc oxide primary particles and consists of one or more compounds containing the elements Si and O. Dispersion, coating composition and sunscreen formulation comprise the zinc silicon oxide particles.

Abstract: Process for preparing a metal oxide powder, in which starting materials are evaporated and oxidized, wherein a metal melt in the form of droplets and one or more combustion gases are fed to the evaporation zone of a reactor, where the metal melt is evaporated completely under nonoxidizing conditions, subsequently, the mixture flowing out of the evaporation zone is reacted in the oxidation zone of this reactor with a stream of a supplied oxygen-containing gas whose oxygen content is at least sufficient to oxidize the metal and the combustion gases completely.

Abstract: A process is described for producing mouldings from plastics by coating a moulding on one or more sides with a lacquer system, the lacquer system being composed of a binder or a binder mixture, optionally a solvent or solvent mixture, optionally other additives usual in lacquer systems and optionally a thickener, and use can be made here of polymeric thickeners at from 0 to 20% content and oligomeric thickeners at from 0 to 40% content, in each case based on dry film (components a, c, d, e), from 5 to 500 parts by weight, based on a), of an electrically conductive metal oxide powder with a median primary particle size of from 1 to 80 nm and a percentage degree of aggregation of from 0.01 to 99%, from 5 to 500 parts by weight, based on a), of inert nanoparticles coated [sic] in a manner known per se and the lacquer cured.

Abstract: Process for the production of a metal oxide powder having a BET surface area of at least 20 m2/g by reacting an aerosol with oxygen in a reaction space at a reaction temperature of more than 700° C. and then separating the resulting powder from gaseous substances in the reaction space, wherein the aerosol is obtained by atomisation using a multi-component nozzle of at least one starting material, as such in liquid form or in solution, and at least one atomising gas, the volume-related mean drop diameter D30 of the aerosol is from 30 to 100 ?m and the number of aerosol drops larger than 100 ?m is up to 10%, based on the total number of drops, and metal oxide powder obtainable by this process.

Abstract: Process for preparing mixed metal oxide powders Abstract Process for preparing a mixed metal oxide powder, in which oxidizable starting materials are evaporated in an evaporation zone of a reactor and oxidized in the vaporous state in an oxidation zone of this reactor, the reaction mixture is cooled after the reaction and the pulverulent solids are removed from gaseous substances, wherein at least one pulverulent metal, together with one or more combustion gases, is fed to the evaporation zone, the metal is evaporated completely in the evaporation zone under nonoxidizing conditions, an oxygen-containing gas and at least one metal compound are fed, separately or together, in the oxidation zone to the mixture flowing out of the evaporation zone, the oxygen content of the oxygen-containing gas being at least sufficient to oxidize the metal, the metal compound and the combustion gas completely.

Abstract: Cerium oxide powder having carbonate groups and made of crystalline primary particles containing cerium oxide and having carbonate groups on the surface and in a region close to the surface, and having a BET surface area of from 25 to 150 m2/g, a mean diameter of from 5 to 50 nm, a carbonate concentration in the region close to the surface decreasing inwardly from the surface, a carbon content due to carbonate groups on the surface of from 5 to 50% by area, a carbon content due to carbonate groups at a depth of about 5 nm in a region close to the surface of from 0 to 30% by area, a content of cerium oxide calculated as CeO2 and based on the powder of at least 99.5% by weight and a content of organic and inorganic carbon of from 0.01 to 0.3% by weight. A dispersion containing this powder.

Abstract: Nano-scale yttrium-zirconium mixed oxide powder in the form of aggregated primary particles having the following physico-chemical parameters:—BET surface area: from 40 to 100 m2/g,—da=from 3 to 30 nm, d,=mean, number-related primary particle diameter,—yttrium content, calculated as yttrium oxide Y2O3, determined by chemical analysis, from 5 to 15 wt. %, based on the mixed oxide powder,—yttrium contents of individual primary particles, calculated as yttrium oxide Y2O3 determined by TEM EDX, corresponding to the content in the powder+?10%,—content at room temperature, determined by X-ray diffraction and based on the mixed oxide powder—monoclinic zirconium oxide from <1 to 10 wt. %—tetragonal zirconium oxide from 10 to 95 wt. %—the content of monoclinic zirconium oxide after 2 hours' heating at 1300° C. being less than 1 wt. %,—carbon content less than 0.2 wt. %.