Abstract: Fumed silica having a BET surface area of 200±15 m2/g, a grindometer value of less than 30 ?m and a median value by PCS of 65 to 85 nm is prepared by grinding a fumed silica having a surface area of 200±25 m2/g, and silicone rubber containing this silica.

Abstract: Fumed silica having a BET surface area of 200±15 m2/g, a grindometer value of less than 30 ?m and a median value by PCS of 65 to 85 nm is prepared by grinding a fumed silica having a surface area of 200±25 m2/g, and silicone rubber containing this silica.

Abstract: The present invention relates to innovative antifouling additives, to a process for producing them, to coating systems comprising the antifouling systems of the invention, to a process for producing the coating systems, and to the use of the antifouling additives and coating systems of the invention for preventing the underwater fouling of surfaces of objects which are in contact or come into contact with water.

Abstract: 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 atomized 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.

Abstract: The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a silicon oxide, purified by acidic precipitation from an aqueous solution of a silicon oxide dissolved in an aqueous phase, using one or more pure carbon sources, the purified silicon oxide being obtained, in particular, by the precipitation of a silicon oxide dissolved in an aqueous phase in an acidifier. The invention also relates to a formulation containing an activator and to a device for producing silicon, a reactor and electrodes.

Abstract: The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a purified silicon oxide using one or more pure carbon sources, the purified silicon oxide, which was purified as silicon oxide dissolved in an aqueous phase, having a content of other polyvalent metals or metal oxides, in relation to the silicon oxide, of less than or equal to 300 ppm, preferably less than 100 ppm, especially preferably less than 50 ppm and according to the invention less than 10 ppm of the other metals and being obtained advantageously by gel formation in alkaline conditions. The invention also relates to a formulation containing an activator and to the use of purified silicon oxide together with an activator for producing silicon.

Abstract: The present invention relates to innovative antifouling additives, to a process for producing them, to coating systems comprising the antifouling systems of the invention, to a process for producing the coating systems, and to the use of the antifouling additives and coating systems of the invention for preventing the underwater fouling of surfaces of objects which are in contact or come into contact with water.

Abstract: Provided is a pyrogenically prepared SiO2 powder in the form of aggregated primary particles having a statistical thickness surface area (STSA) of 10-500 m2/g, a thickening action based on the STSA of 4-8 mPas·g/m2, and a micropore volume of 0.03-0.

Abstract: Mixed oxide powder consisting of particles with the components zirconium dioxide, aluminium oxide and at least a third component selected from the group including yttrium oxide, magnesium oxide or calcium oxide, wherein mixed oxide powder has an aluminium oxide content 0.01 to 10 wt. % and is homogeneously distributed in the mixed oxide particles, the content of aluminium oxide, zirconium dioxide and yttrium oxide is at least 99.5 wt. %, based on the total quantity of the powder, and the BET surface area is 20 to 80 m2/g. It is obtained by atomising a solution containing at least one starting compound for each of aluminium oxide, zirconium dioxide and the third component, allowing the atomised solution to react with oxygen in a reaction chamber at a reaction temperature 700 to 15000° C., cooling the hot gases and the solid products and then separating the solid product from the gases. It can be used as a dental material.

Abstract: Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 90±15 m2/g, wherein the aggregates display an average surface area of 10000 to 20000 nm2, an average equivalent circle diameter (ECD) of 90 to 130 nm and an average circumference of 1000 to 1400 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a second silicon component comprising H3SiCl, H2SiCl2, HSiCl3, CH3SiCl3, (CH3)2SiCl2, (CH3)3SiCl and/or (n-C3H7)SiCl3 are mixed with primary air and a combustion gas and burnt into a reaction chamber, secondary air also being introduced into the reaction chamber, and the feed materials being chosen such that an adiabatic flame temperature of 1810 to 1890° C. is obtained. Dispersion containing the pyrogenically produced silicon dioxide powder.

Abstract: 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.

Abstract: Fumed silica having a BET surface area of 200±15 m2/g, a grindometer value of less than 30 ?m and a median value by PCS of 65 to 85 nm is prepared by grinding a fumed silica having a surface area of 200±25 m2/g, and silicone rubber containing this silica.

Abstract: Provided is a pyrogenically prepared SiO2 powder in the form of aggregated primary particles having a statistical thickness surface area (STSA) of 10-500 m2/g, a thickening action based on the STSA of 4-8 mPas·g/m2, and a micropore volume of 0.03-0.

Abstract: Mixed oxide powder consisting of particles with the components zirconium dioxide, aluminium oxide and at least a third component selected from the group including yttrium oxide, magnesium oxide or calcium oxide, wherein mixed oxide powder has an aluminium oxide content 0.01 to 10 wt. % and is homogeneously distributed in the mixed oxide particles, the content of aluminium oxide, zirconium dioxide and yttrium oxide is at least 99.5 wt. %, based on the total quantity of the powder, and the BET surface area is 20 to 80 m2/g. It is obtained by atomising a solution containing at least one starting compound for each of aluminium oxide, zirconium dioxide and the third component, allowing the atomised solution to react with oxygen in a reaction chamber at a reaction temperature 700 to 15000° C., cooling the hot gases and the solid products and then separating the solid product from the gases. It can be used as a dental material.

Abstract: Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 90±15 m2/g, wherein the aggregates display an average surface area of 10000 to 20000 nm2, an average equivalent circle diameter (ECD) of 90 to 130 nm and an average circumference of 1000 to 1400 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a second silicon component comprising H3SiCl, H2SiCl2, HSiCl3, CH3SiCl3, (CH3)2SiCl2, (CH3)3SiCl and/or (n-C3H7)SiCl3 are mixed with primary air and a combustion gas and burnt into a reaction chamber, secondary air also being introduced into the reaction chamber, and the feed materials being chosen such that an adiabatic flame temperature of 1810 to 1890° C. is obtained. Dispersion containing the pyrogenically produced silicon dioxide powder.

Abstract: A fumed silica powder having a BET specific surface area of between 10 and 600 m2/g, a thickening action of at least 3000 mPas, and a grindometer value of less than 40 &mgr;m is produced by mixing i) at least one fumed silica precursor in vapor form, ii) a free-oxygen-containing gas and iii) a combustion gas in a burner with a combustion chamber with attached cooled flame tube to obtain a gas mixture; introducing steam through a tube arranged centrally in the burner into the gas mixture, to obtain a reaction mixture; and reacting the reaction mixture in the combustion chamber; wherein the lambda value is between 1 and 2, the gamma value is between 1 and 2 and the beta value is between 2.2 and 3.2.