摘要:
Aluminium oxide powder produced by flame hydrolysis and consisting of aggregates of primary particles, having a BET surface area of from 100 to 250 m2/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.
摘要:
Aluminium oxide powder produced by flame hydrolysis and consisting of aggregates of primary particles, having a BET surface area of from 100 to 250 m2/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 vaporizing 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.
摘要:
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 m2/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. %.
摘要:
A powder containing particles with a core of titanium dioxide and a coating of silicon dioxide in an amount of between 0.5 and 40 wt. %, the particles have a BET surface of between 5 and 300 m2/g, and the particles are primary particles that have a coating of silicon dioxide and a core of titanium dioxide.
摘要:
The present invention relates to an aqueous dispersion containing a silicon dioxide powder coated with cerium oxide. In addition, the present invention provides a method of producing an aqueous dispersion containing a silicon dioxide powder coated with cerium oxide and methods of using this aqueous dispersion for chemical-mechanical polishing.
摘要:
Alkali metal oxide-metal oxide mixed oxide powder in the form of aggregates of pore-free primary particles, comprising from 0.005 to 5% by weight of at least one alkali metal oxide, which has a BET surface area of from 100 to 350 m2/g, has a specific DBP number, expressed as DBP number per square meter of specific surface area, greater than or equal to that of a powder which has only the metal oxide component, has the alkali metal oxide distributed in the core and on the surface of the primary particles. Silicone rubber comprising the alkali metal oxide-metal oxide mixed oxide powder.
摘要:
Provided is a crystalline TiO2 powder in the form of aggregated primary particles having a variable sintering stability at a BET surface area of 70-100 m2/g and a rutile content of greater than 10% but less than or equal to 40%, and a process for preparing the crystalline TiO2 powder, which involves: introducing a TiCl4 vapor and, separately therefrom, H2 and a primary air into a mixing chamber to produce a gaseous mixture; igniting the gaseous mixture in a burner to produce a flame, which is burned into a reaction chamber to produce the crystalline TiO2 powder and gaseous substances; and separating the crystalline TiO2 powder from the gaseous substances, wherein the relative amounts of TiCl4 vapor, H2 and primary air are selected to provide crystalline TiO2 powder having the aforementioned BET surface area and rutile content, with the proviso that factor A has a value of 0.1-0.4·105 g/m2 in accordance within the following formula: factor A=105{[(TiCl4 vapor×H2)/(primary air×gaseous mixture)]/BET]}.
摘要:
Carbon black with an OAN, measured on the beaded carbon black, of less than 120 ml/100 g. A process for the preparation of the carbon black is described, wherein a salt solution is converted into an aerosol and this is then introduced into the carbon black formation zone. The carbon black can be used in inks, paints, lacquers, printing inks and ink-jet inks, and for coloring plastics.
摘要:
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 - hydrolysable metal compound as dopant together with an atomization gas is atomised into a flow of metal oxide particles in a carrier gas, wherein the mass flow of the metal oxide particles und - 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 - 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 - reaction zone and optionally at least as much oxygen and/or steam are - 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° C., - preferably 500 to 1000° C., and the reaction mixture is then cooled or allowed to cool and the doped metal oxide particles are separated from the gaseous substances.
摘要:
Ternary, pyrogenically prepared, crystalline metal mixed oxide powder having the components titanium and silicon and a third component chosen from the group comprising aluminium, zirconium, zinc, tin, magnesium, yttrium, vanadium, tungsten, tantalum, cerium or boron. It is prepared by a procedure in which a vaporizable or atomizable silicon and titanium compound and a vaporizable or atomizable compound of a third mixed oxide component are mixed with hydrogen and primary air and the gas mixture is burned into a reaction chamber, and the powder formed is separated off from the gaseous reaction products. It can be employed in sunscreen formulations.