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:
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:
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:
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:
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:
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 XnSi(OR)4−n, 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.
摘要:
Pyrogenic silicon-titanium mixed oxide powder having • a BET surface area of 200 to 400 m2/g, • a DBP number/BET surface area ratio of 0.5 to 1.2, • a silicon dioxide content of 93.5 to 95.4% by weight and a titanium dioxide content of 4.6 to 6.5% by weight, where the sum of the contents is greater than 99.7% by weight. Dispersion comprising the pyrogenic silicon-titanium mixed oxide powder. Process for preparing a titanium-containing zeolite proceeding from powder or dispersion.
摘要:
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.
摘要:
Surface-modified zinc-titanium mixed oxides are produced by treating zinc-titanium mixed oxides with a surface-modifying agent. They may be used for the production of sunscreen preparations.
摘要:
Surface-modified metal oxide particles coated with silicon dioxide and having a low structure are produced by adding a base dissolved in water, with stirring, to a dispersion consisting of a metal oxide, at least one compound of the type XnSi(OR)4−n and water, separating off, optionally washing with water, drying and surface-modifying the reaction product. The surface-modified metal oxide particles coated with silicon dioxide can be used in sunscreens and in CMP applications.