Abstract:
PROBLEM TO BE SOLVED: To provide a silicon dioxide powder displaying a good thickening action combined with a short incorporation time into polymers and good dispersibility in the polymers, particularly silicone polymers. SOLUTION: The silicon dioxide powder is pyrogenically produced in the form of aggregates of primary particles having a BET surface area of 150±15 m 2 /g, wherein the aggregates display an average surface area of 12,000 to 20,000 nm 2 , an average equivalent circle diameter (ECD) of 90 to 120 nm and an average circumference of 1,150 to 1,700 nm, and the powder is produced by a pyrogenic process. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide titanium dioxide powder having high sintering activity.SOLUTION: This invention relates to crystalline titanium dioxide powder in the form of aggregated primary particles having a BET surface area of 30-65 m/g and a rutile content of 50-70%. It is produced by introducing titanium tetrachloride vapor and, separately therefrom, hydrogen, air or oxygen-enriched air into a mixing chamber, subsequently igniting the mixture of titanium tetrachloride vapor, hydrogen and primary air in a burner and burning the flame into a reaction chamber and subsequently separating off the solid from gaseous substances, where the amounts used therefor are selected so as to satisfy following equation: A=A=10{[(TiCl×H)/(amount of air×total gas)]/BET}, [in the equation, A=6-12 is obeyed]. The titanium dioxide powder can be used in the ceramics industry.
Abstract:
PROBLEM TO BE SOLVED: To provide a silicon/titanium mixed oxide powder containing no dark-colored contaminants and a higher percentage of silicon dioxide or titanium dioxide than that by a conventional technology. SOLUTION: This silicon/titanium mixed oxide powder is manufactured by flame hydrolysis and comprises agglomerate of primary particles comprising an amorphous silicon dioxide, a crystalline titanium dioxide, or a silicon/titanium mixed oxide having an amorphous silicon dioxide part and a crystalline titanium dioxide part, and mainly comprising silicon/titanium mixed oxide primary particles, and the particle has a BET surface area of 20-200 m 2 /g and a titanium dioxide content of more than 10 mass% but less than 70 mass%, and its X-ray diffraction photograph shows a diffraction pattern of rutile-type and anatase-type, and the ratio of the rutile-type to the anatase-type is 2/98-98/2. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide powder overcoming defects characteristic of conventional technologies. SOLUTION: The silicon-titanium-mixed powder is manufactured by flame hydrolysis, where a silicon dioxide/titanium dioxide mass ratio at the surface of a primary particle is larger than that of whole primary particles. COPYRIGHT: (C)2003,JPO
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:
Process for preparing a dispersion of surface-modified silicon dioxide particles having an average particle diameter of not more than 100 nm by high-pressure milling of a preliminary dispersion comprising a) 10% to 50% by weight of surface-modified silicon dioxide particles, b) at least one glycol monoether of the general formula (A): H3C(CH2)m-O-(CH2)n-[O-(CH2)o]p-OH, c) at least one carboxylic ester of the general formula (B): H2x+1Cx-O-CH2-(CHR)-[O-CHR]y-O-C(=O)-CzH2z+1, d) the molar ratio A/B being 10:90 to 40:60 and m, n, o, p, x, y and z being independent of one another. Dispersion obtainable by this process. Process for producing granules of surface-modified silicon dioxide particles by separating off the liquid phase of the dispersion. Granules obtainable by this process. Use of dispersion and granules in coating materials.
Abstract:
Process for preparing surface-modified silicon dioxide particles with a mean particle diameter of at most 100 nm, comprising the steps of: a) providing a predispersion b) high-pressure grinding of the predispersion to form a dispersion c) removing the liquid phase of the dispersion, the predispersion comprising al) surface-modified silicon dioxide particles which are at least partly aggregated, are bonded to the surface-modifying component via Si-O-Si bonds and still have reactive groups on their surface, a2) one or more organosilicon compounds which have at least one silicon-carbon bond and at least one functional group which can react with the reactive groups to form a covalent Si-O-Si bond, and a3) one or more solvents. Redispersible, surface-modified silicon dioxide particles obtainable by this process. Use of these in toner powders, silicone rubber, adhesives and scratch-resistance surface coatings.
Abstract:
Metalloxidpartikel enthaltende Dispersion, bei der a) die Metalloxidpartikel a1) ausgewählt sind aus einem oder mehreren Oxiden der Gruppe bestehend Titandioxid, Ceroxid, Zinkoxid und Zirkondioxid a2) mit einem Anteil von wenigstens 25 Gew.-% in der Dispersion vorliegen, a3) einen mittleren Aggregatdurchmesser von 20 bis 120 nm aufweisen und b) die flüssige Phase b1) 90 bis 99,5 Gew.-% eines oder mehrerer Alkanole CnH2n+1OH mit n = 2 bis 4, b2) 0,5 bis 10 Gew.-% einer oder mehrerer α,&bgr;-ungesättigter Carbonsäuren mit 4 bis 12 C-Atomen, b3) 0 bis 2 Gew.-% eines oder mehrerer Alkandiole HO(CH2)xOH mit x = 2 bis 4, b4) maximal 5 Gew.-% ieradditive aus der Gruppe bestehend aus polyoxyethylenierten Alkyletherphosphaten, polyoxyethylenierten Aryletherphosphaten; Alkylolammoniumsalzen von Block-Copolymeren mit aciden Gruppen; Polyalkylenglykolen, Polyalkyleniminen, Polyalkylenalkoholen enthält. Verwendung der Dispersion zur Herstellung von Farbstoffsolarzellen.
Abstract:
Polvo de dióxido de silicio producido pirogénicamente, en forma de agregados de partículas primarias, caracterizado porque, - tiene una superficie BET de 150 ± 15 m2/g y los agregados - tienen una superficie media de 12.000-20.000 nm2, - tienen un diámetro circular medio equivalente (ECD = Equivalent Circle Diameter) de 90-120 nm y - tienen un perímetro medio de 1150-1700 nm.