Abstract:
Titanium-zirconium mixed oxide powder in the form of aggregated primary particles, which powder has a content of titanium dioxide of from 40 to 97 wt . % and a content of zirconium dioxide of from 3 to 60 wt.%, wherein the sum of the contents of titanium dioxide and zirconium dioxide is at least 99.7 wt.% and wherein the contents are in each case based on the total amount of powder, and which exhibits reflections of titanium dioxide modifications and does not exhibit reflections of monoclinic, tetragonal and cubic zirconium dioxide in X-ray diffraction analysis. It is prepared by transporting into a mixing chamber a starting compound, in vapour form, for the first mixed oxide component by means of primary air and a starting compound, in vapour form, for the second mixed oxide component by means of an inert gas, mixing the mixture with hydrogen in a mixing chamber and burning it into a reaction chamber. It can be used as a catalyst support.
Abstract:
Aluminium oxide powder produced by flame hydrolysis and consisting of aggregates of primary particles, having a BET surface area of from 100 to 250 m /g, a dibutyl phthalate absorption of from 50 to 450 g/100 g of aluminium oxide powder, which powder shows only crystalline primary particles in high-resolution TEM pictures. It is prepared by vaporising aluminium chloride, transferring the vapour by means of a carrier gas to a mixing chamber and, separately therefrom, supplying hydrogen, air (primary air), which may optionally be enriched with oxygen and/or may optionally be pre-heated, to the mixing chamber, then igniting the mixture of aluminium chloride vapour, hydrogen, air in a burner and burning the flame into a reaction chamber that is separated from the surrounding air, subsequently separating the solid material from the gaseous substances and then treating the solid material with steam and optionally with air, the discharge rate of the reaction mixture from the mixing chamber into the reaction chamber being at least 10 m/s, and the lambda value being from 1 to 10 and the gamma value being from 1 to 15. It can be used as an ink-absorbing substance in ink-jet media.
Abstract:
Powder consisting of particles with a core of titanium dioxide and a coating of silicon dioxide, which powder has a content of silicon dioxide of between 0.5 and 40 wt.%, a BET surface of between 5 and 300 m /g, and which consists of primary particles that have a coating of silicon dioxide and a core of titanium dioxide. The powder is produced according to a process in which a vaporisable silicon compound and a vaporisable titanium compound are mixed corresponding to the subsequently desired ratio of SiO2 and TiO2 in the product, are vaporised at temperatures of 200°C or less, and conveyed by means of an inert gas stream together with hydrogen and air or with oxygen-enriched air to the central pipe (core) of a known burner, the reaction mixture is ignited at the mouth of the burner and introduced together with secondary air, is combusted in a cooled flame pipe, following which the titanium dioxide powder coated with silicon dioxide is separated from the gaseous reaction products and if necessary is freed in moist air from adhering hydrogen chloride, the ratio of primary air to secondary air being greater than 0.3, the ratio of core hydrogen to secondary air being greater than 1, and the ratio of titanium dioxide precursor to secondary air being greater than 0.5. Sunscreen agent containing the powder in an amount of between 0.01 and 25 wt.%.
Abstract:
Pyrogenically prepared oxides are compacted by mechanically moving the oxides in a stirred container by means of a stirring member and discharging said oxides from the stirred container.
Abstract:
Process for preparing metal oxide granules having a particle diameter of 200 to 1500 µm, characterized in that a pyrogenic metal oxide powder selected from the group consisting of the oxides of Al, B, Ce, Cs, Er, Fe, In, Ga, Ge, Ni, Pb, Sn, Ta, Zr and/or Zn with a tamped density of 10 to 1200 g/l is compacted to slugs which are subsequently crushed and optionally classified, the slug fragments having a tamped density of 210 to 2000 g/1.
Abstract:
Preparation containing at least one photocatalytically active metal oxide powder with a specific surface area of at least 20 m 2 /g at least one wetting agent. Use of the preparation for weed control.
Abstract:
SURFACE-MODIFIED SILICON DIOXIDE-TITANIUM DIOXIDE MIXED OXIDES PYROGENICALLY PREPARED SURFACE-MODIFIED SILICON DIOXIDE- TITANIUM DIOXIDE MIXED OXIDES ARE PREPARED BY SPRAYING PYROGENICALLY PREPARED SILICON DIOXIDE-TITANIUM DIOXIDE MIXED OXIDES WITH A SURFACE-MODIFYING AGENT. THE SURFACE-MODIFIED PYROGENICALLY PREPARED SILICON DIOXIDE- TITANIUM DIOXIDE MIXED OXIDES CAN BE USED IN SUN PROTECTION FORMULATION ( 02@
Abstract:
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 vB of 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*vB/lambda being greater than or equal to 55. Dispersion comprising the aluminum oxide powder. Coating composition comprising the dispersion.
Abstract:
The crystalline titanium dioxide powder has a aggregated primary particles form. The aggregated primary particles form has a Brunauer-Emmett-Teller surface area of 30-65 m 2>/g and a rutile content of 50-70%. An independent claim is also included for a method for preparing titanium dioxide powder, which involves introducing hydrogen, air or oxygen-enriched air into a mixing chamber, where a mixture of titanium tetrachloride vapour, hydrogen and primary air is subsequently ignited in a burner and the flame is burned into a reaction chamber, the solid is subsequently separated off from gaseous substances.