摘要:
Aqueous dispersion comprising silicon/titanium mixed oxide powder with a BET surface area of 5 to 500 m2/g which has been prepared by flame hydrolysis and has a titanium dioxide content of 0.5 to 20 wt. %, based on the powder, water and at least one pH-regulating substance which can be removed completely from the reaction mixture on heating, the aqueous dispersion having a solids content of between 40 and 80 wt. %. A green body produced therefrom with a green density of between 40 and 85%. A shaped glass article of optical quality with a coefficient of thermal expansion of not more than 0.5×10−6/K produced from the green body.
摘要:
A process for the preparation of doped, pyrogenically prepared titanium dioxide is described. The titanium dioxide is doped with zinc oxide, platinum oxide, magnesium oxide, or aluminium oxide, by injecting an aerosol of the oxide into the production stream. The doped titanium dioxide may be used as a photocatalyst or UV absorber.
摘要:
An ink jet recording material excellent in all characteristics including drying property, ink absorbency, water resistance and the like, is provided. The ink jet recording material has an ink-receiving layer comprising hydrophilic resin and inorganic pigment, the ink-receiving layer containing silica particles surface-doped with alumina as the inorganic pigment. The alumina-doped silica is prepared by a process employing flame hydrolysis techniques combined with pyrolysis. The ink-receiving layer preferably contains the alumina-doped silica in an amount ranging from 5 to 200 weight parts based on 100 weight parts of the hydrophilic resin.
摘要:
Moldings are disclosed for use as a catalyst or catalyst support for hydrating olefin, such as ethylene and propylene. The moldings are based on a pyrogenically produced mixed oxide having the following physicochemical parameters: External diameter 0.8-25 mm BET surface area 5-400 m2/g Pore volume 0.2-1.8 ml/g Fracture strength 5 to 350 N Composition At least two materials selected from the group of SiO2, Al2O3, TiO2 and ZrO2 in any desired combination, with the proviso that when the combination is a SiO2/Al2O3 mixed oxide, at least 75 wt. % of SiO2 is present based on the total weight of the mixed oxide. Other constituents
摘要:
A boron oxide-silicon dioxide mixed oxide which has a BET surface of less than 100 m.sup.2 g, and optionally containing oxides of aluminium, titanium or zirconium, is prepared pyrogenically by flame hydrolysis. The mixed oxide is used in glass making.
摘要:
Pyrogenic oxides having a BET surface area of between 30 and 150 m.sup.2 /g have a viscosity of less than 2,500 mPas in an aqueous suspension. They are prepared by setting the hydrogen ratio gamma and the oxygen ratio lambda to less than one in a high-temperature flame hydrolysis. The pyrogenic oxides are employed in the CMP application in the electronics industry.
摘要:
A finely-divided cerium metal/metalloid oxide mixture, containing pyrogenically produced metal/metalloid oxide and 0.001 to 95 wt. % cerium oxide, has a specific surface area between 10 and 400 m.sup.2 /g. The mixture is produced by mixing pyrogenically produced metal/metalloid oxide, having a specific surface area between 30 and 400 m.sup.2 /g, with a cerium compound decomposable to an oxide at elevated temperature, the cerium compound being thermally decomposed to the oxide. The cerium oxide-metal/metalloid oxide mixture can be used as a polishing agent or filler.
摘要:
Flame-hydrolytically produced titanium dioxide mixed oxide having a BET surface of 10 to 150 m.sup.2 /g and 1 to 30% by weight aluminum oxide or 1 to 30% by weight silicon dioxide is produced by evaporating aluminum chloride or silicon tetrachloride, transferring the evaporated aluminum chloride or silicon tetrachloride, together with an inert gas, into the mixing chamber of a burner, mixing them with hydrogen, air and gaseous titanium tetrachloride, burning the resulting 4-component mixture in the reaction chamber of the burner, and separating the titanium dioxide mixed oxide from the gaseous reaction products.
摘要:
Stable, pourable silicon dioxide dispersion, in which the average, number-related aggregate diameter of the silicon dioxide particles in dispersion is less than 200 nm, and which comprises at least 35 wt. % of a silicon dioxide powder, 3 to 35 wt. % of at least one polyol, 20 to 60 wt. % of water, 0 to 10 wt. % of an additive and a substance having an alkaline action in an amount such that a pH of 10
摘要:
Stable, pourable silicon dioxide dispersion, in which the average, number-related aggregate diameter of the silicon dioxide particles in dispersion is less than 200 nm, and which comprises at least 35 wt. % of a silicon dioxide powder, 3 to 35 wt. % of at least one polyol, 20 to 60 wt. % of water, 0 to 10 wt. % of an additive and a substance having an alkaline action in an amount such that a pH of 10