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:
Silicon titanium mixed oxide powder having the following features: BET surface area of 5 to 300 m2/g, silica content, based on the total amount of the mixed oxide powder, of ≧0.1 to
摘要:
Aluminium 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- aluminium oxide and/or theta-aluminium oxide, at least 30% of delta-aluminium oxide. It is prepared by vaporizing aluminium chloride and burning the vapour 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 aluminium oxide powder. Coating composition comprising the dispersion.
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:
Pyrogenically produced silicon dioxide powder with a specific surface area of between 5 and 600 m2/g and a carbon content of less than 500 ppm, which displays a specific dibutyl phthalate absorption of less than or equal to 1.2 g dibutyl phthalate/100 g SiO2 per m2 of specific surface area and a specific thickening action of less than 15 mPas/m2 of specific surface area. It is produced by supplying vaporous tetramethoxysilane and/or tetraethoxysilane together with air and separately hydrogen to a burner, and allowing the mixture of gases to react in a flame in a reaction chamber connected in series to the burner, and separating the solid reaction product from the gas stream by known means, the lambda value in the burner being between 0.95 and 1.5 and sufficient secondary air also being supplied to the reaction chamber that the lambda value in the reaction chamber is between 0.8 and 1.6. The invention also provides a dispersion containing the silicon dioxide powder and the use of the powder and of the dispersion.
摘要翻译:比热表面积为5〜600m 2 / g,碳含量小于500ppm的热解生成二氧化硅粉末,其特征在于邻苯二甲酸二丁酯的吸收小于或等于1.2 g二丁基邻苯二甲酸酯/ 100g SiO 2 / m 2比表面积和特定增稠作用小于15mPas / m 2比表面积。 它是通过将空气四甲氧基硅烷和/或四乙氧基硅烷与空气和单独的氢气一起向燃烧器供应的,并且允许气体混合物在与燃烧器串联连接的反应室中的火焰中反应,并将固体反应产物从 通过已知方式的气流,燃烧器中的λ值在0.95和1.5之间,并且足够的二次空气也被供应到反应室,反应室中的λ值在0.8和1.6之间。 本发明还提供了含有二氧化硅粉末的分散体以及粉末和分散体的用途。
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:
Silicon titanium mixed oxide powder having the following features: BET surface area of 5 to 300 m2/g, silica content, based on the total amount of the mixed oxide powder, of ≧0.1 to
摘要:
Stable, aqueous dispersion containing silicon dioxide powder having a hydroxyl group density of 2.5 to 4.7 OH/nm2, which is obtained from a silicon dioxide powder produced by a flame hydrolysis process under acid conditions. The dispersion is produced by incorporating the silicon dioxide powder into an aqueous solution by means of a dispersing device. The dispersion can be used to produce glass articles.
摘要:
Surface-modified, pyrogenically prepared silica is prepared by subjecting the pyrogenically prepared silica, which is in the form of aggregates of primary particles and possesses a BET surface area of 150±15 m2/g, the aggregates having an average area of 12 000-20 000 nm2, an average equivalent circle diameter (ECD) of 90-120 nm and an average circumference of 1150-1700 nm, to surface-modification in a known way. It can be used as a filler for thickening liquid systems.