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: 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: Indium-tin mixed oxide powder which consists of primary particle aggregates and contains 50 to 90% by weight indium oxide, calculated as In2O3, and 10 to 50% by weight tin oxide, calculated as SnO2. It is produced by atomising a solution of an inorganic indium compound and an organic tin compound and burning it in a flame. It may be used for the production of electrically conductive paints and coatings, solar cells and IR and UV absorbers and in medical technology.

Abstract: Nanoscalar, pyrogenically produced yttrium-zirconium mixed oxide which has a BET surface area of between 1 and 600 m2/g, a total chloride content of less than 0.05 wt. % and does not exhibit a conversion into the monoclinic phase during storage is produced by atomizing yttrium compounds and zirconium compounds and reacting them in a flame. The mixed oxide can be used as ceramic raw material.

Abstract: Goldcatalyst Goldcatalyst comprising gold on a support of ceria or ceria-manganese oxide is used for the oxidation of CO in a H2 stream.

Abstract: Process for preparing pulverulent solids, in which one or more oxidizable and/or hydrolysable metal compounds are reacted in a high-temperature zone in the presence of oxygen and/or steam, the reaction mixture is cooled after the reaction, and the pulverulent solid is removed from gaseous substances, wherein at least one metal compound is introduced into the high-temperature zone in solid form and the evaporation temperature of the metal compound is below the temperature of the high-temperature zone.

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: Mixed oxide powder containing indium and tin, with a proportion of indium oxide of between 90 and 98 wt. % and a BET surface area of 40 to 120 m2/g, which is in the form of aggregates having an average circumference of less than 500 nm, consists of at least 95% of an indium oxide phase and displays an oxygen content that is lower than the content that theoretically results from In2O3 and SnO2. It is produced by mixing a solution of an indium compound with a solution of a tin compound, atomising this mixture of solutions, pyrolysing the atomised mixture of solutions in a first zone of a reactor and in a second zone of the reactor, following pyrolysis, adding reducing gases to the pyrolysed mixture at one or more points in a quantity such that overall a reducing atmosphere is established in this second zone, and separating the resulting solid from the waste gases in a further, third zone, in which a reducing atmosphere likewise still prevails.

Abstract: Pyrogenically prepared zinc oxide powder having a BET surface area of from 10 to 200 m2/g, which is in the form of aggregates, the aggregates being composed of particles having different morphologies, and 0-10% of the aggregates being in a circular form, 30-50% being in an ellipsoidal form, 30-50% being in a linear form and 20-30% being in a branched form. It is prepared by reacting a starting mixture containing zinc vapour, a combustible gas and steam or a mixture of steam and carbon dioxide in a flame with an oxygen-containing gas in an oxidation zone, cooling the hot reaction mixture in a quenching zone and separating the solid material from the gas stream, the amount of oxygen in the oxidation zone being greater than the amount necessary for the complete oxidation of the combustible gas and the zinc vapour. The zinc oxide powder can be used as a constituent of sun protection compositions for protection against UV radiation.

Abstract: A dispersion of pyrogenically produced cerium oxide, which does not contain any particles larger than 1 ?m, is produced by dispersing a pyrogenically produced cerium oxide in water by means of a dissolver, centrifuging it, separating the supernatant from the bottom product, and again dispersing the supernatant by means of ultrasound. The dispersion can be used for chemical-mechanical polishing (CMP).

Abstract: Polycrystalline cerium oxide powder in the form of aggregates of primary particles with a specific surface of between 70 and 150 m2/g, an average primary particle diameter of between 5 and 20 nm and an average, projected aggregate diameter of between 20 and 100 nm. It is produced in that an aerosol is reacted in a flame obtained from a hydrogen-containing combustible gas and primary air and the solid obtained is then separated from the gaseous substances.

Abstract: Nanoscale, pyrogenically produced oxides and/or mixed oxides having a BET surface area of between 1 m2/g and 600 m2/g and a chloride content of less than 0.05 wt. % are produced by converting organometallic and/or organometalloid substances into the oxides at temperatures of above 200° C. The oxides may be used as a polishing agent in the electronics industry (CMP).

Abstract: Zinc oxide powder is prepared by a process having the following steps a) generating of a zinc vapor-containing stream in a vaporization zone; b) oxidizing the zinc vapor by reaction with an oxygen-containing gas thereby forming zinc oxide powder in an oxidation zone; and c) cooling of the reaction mixture with water or an inert gas, and separation of the zinc oxide powder in a cooling/isolation zone, wherein aa) in the vaporization zone, a gas stream of an inert gas and a fuel gas is passed through a zinc melt which has a temperature of 450 to <900° C., thereby forming zinc vapor, the content of fuel gas being 1 to 50 vol. %, based on the sum of inert gas and fuel gas, and the molar quotient of zinc vapor to fuel gas being 0.01 to 50, and bb) in the oxidation zone, a second gas stream, which contains an oxygen-containing gas and steam, is added to the gas stream of zinc vapor, fuel gas and inert gas in an amount such that the temperature in the oxidation zone is from 500 to 1100° C.

Abstract: Composite particles useful for absorbing in the UV-A and UV-B regions contain a zinc oxide matrix and cerium oxide domains, wherein the domains are located in and on the matrix, wherein a fraction of zinc oxide is 80 to 98% by weight and a fraction of cerium oxide is 2 to 20% by weight, in each case based on the composite particles, and wherein a BET surface area of said composite particles is from 5 to 100 m2/g.

Abstract: Pyrogenically prepared, doped zinc oxide powder, wherein the doping component comprises at least one oxide from the group aluminum, gallium, indium, germanium, tin and is present in the doped zinc oxide powder in an amount of from 0.005 to 15 wt. %, and wherein the doped zinc oxide powder is in the form of aggregates of primary particles having a mean maximum diameter of from 30 to 400 nm. It is prepared by oxidation from zinc powder and at least one doping agent, wherein the process zones vaporisation, nucleation, oxidation and quenching are passed through and the doping agent is metered in in the nucleation zone, in which the temperature is below the boiling temperature of zinc. The doped zinc oxide powder can be used in electrically conductive lacquers and coatings.

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: Pyrogenically prepared zinc oxide powder having a BET surface area of from 10 to 200 m2/g, which is in the form of aggregates, the aggregates being composed of particles having different morphologies, and 0-10% of the aggregates being in a circular form, 30-50% being in an ellipsoidal form, 30-50% being in a linear form and 20-30% being in a branched form. It is prepared by reacting a starting mixture containing zinc vapour, a combustible gas and steam or a mixture of steam and carbon dioxide in a flame with an oxygen-containing gas in an oxidation zone, cooling the hot reaction mixture in a quenching zone and separating the solid material from the gas stream, the amount of oxygen in the oxidation zone being greater than the amount necessary for the complete oxidation of the combustible gas and the zinc vapour. The zinc oxide powder can be used as a constituent of sun protection compositions for protection against UV radiation.

Abstract: Mixed oxide powder containing indium and tin, with a proportion of indium oxide of between 90 and 98 wt. % and a BET surface area of 40 to 120 m2/g, which is in the form of aggregates having an average circumference of less than 500 nm, consists of at least 95% of an indium oxide phase and displays an oxygen content that is lower than the content that theoretically results from In2O3 and SnO2. It is produced by mixing a solution of an indium compound with a solution of a tin compound, atomising this mixture of solutions, pyrolysing the atomised mixture of solutions in a first zone of a reactor and in a second zone of the reactor, following pyrolysis, adding reducing gases to the pyrolysed mixture at one or more points in a quantity such that overall a reducing atmosphere is established in this second zone, and separating the resulting solid from the waste gases in a further, third zone, in which a reducing atmosphere likewise still prevails.

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: 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.