Abstract: Process for the phase transformation of substances and mixtures of substances, in which the substance or the mixture of substances is introduced into a plasma reactor, the substance or the mixture of substances is converted into the higher-energy phase and the product is removed in gaseous form from the plasma reactor. The process can be used for the sublimation of metal salts, metal nitrates and/or metal alkoxides and other vaporizable metal-organic compounds.

Abstract: Process for the phase transformation of substances and mixtures of substances, in which the substance or the mixture of substances is introduced into a plasma reactor, the substance or the mixture of substances is converted into the higher-energy phase and the product is removed in gaseous form from the plasma reactor. The process can be used for the sublimation of metal salts, metal nitrates and/or metal alkoxides and other vaporizable metal organic compounds.

Abstract: Surface-modified, doped, pyrogenically produced oxides surface-modified with one or several compounds from the following groups: a) Organosilanes of the type (RO)3Si(CnH2n+1), (RO)3Si(CnH2n?1) b) R?x(RO)ySi(CnH2n+1), (RO)3Si(CnH2n+1) c) X3Si(CnH2n+1), X3Si(CnH2n?1) d) X2(R?)Si(CnH2n+1), X2(R?)Si(CnH2n?1) e) X(R?)2Si(CnH2n+1), X(R?)2Si(CnH2n?1) f) (RO)3Si(CH2)m—R?, g) (R?)x(RO)ySi(CH2)m—R?, h) X3Si(CH2)m—R?, i) (R)X2Si(CH2)m—R?, j) (R)2XSi(CH2)m—R?, k) Silazanes of the type l) Cyclic polysiloxanes, m) Polysiloxanes or silicone oils.

Abstract: 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.

Abstract: Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 200±25 m2/g, wherein the aggregates display an average surface area of 7000 to 12000 nm2, an average equivalent circle diameter (ECD) of 80 to 100 nm and an average circumference of 850 to 1050 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 1570 to 1630° C. is obtained. It can be used as a filler.

Abstract: Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 150±15 m2/g, wherein the aggregates display an average surface area of 12000 to 20000 nm2, an average equivalent circle diameter (ECD) of 90 to 120 nm and an average circumference of 1150 to 1700 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 1670 to 1730° C. is obtained. Silicone sealing compound containing the pyrogenically produced silicon dioxide powder.

Abstract: Surface-modified, doped, pyrogenically produced oxides surface-modified with one or several compounds from the following groups: a) Organosilanes of the type (RO)3Si(CnH2n+1), (RO)3Si(CnH2n?1) b) R?x(RO)ySi(CnH2n+1), (RO)3Si(CnH2n+1) c) X3Si(CnH2n+1), X3Si(CnH2n?1) d) X2(R?)Si(CnH2n+1), X2(R?)Si(CnH2n?1) e) X(R?)2Si(CnH2n+1), X(R?)2Si(CnH2n?1) f) (RO)3Si(CH2)m—R?, g) (R?)x(RO)ySi(CH2)m—R?, h) X3Si(CH2)m—R?, i) (R)X2Si(CH2)m—R?, j) (R)2XSi(CH2)m—R?, k) Silazanes of the type l) Cyclic polysiloxanes, m) Polysiloxanes or silicone oils.

Abstract: Method for the homogenisation of nanoscale powders, in which mixtures of nanoscale powders having the same or different chemical composition and/or structure and in solid form are introduced in the presence of a regulable gas stream into a vessel, the gas stream being adjusted so that the nanoscale powders remain in suspension and are thoroughly mixed.

Abstract: 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.

Abstract: Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 150±15 m2/g, wherein the aggregates display an average surface area of 12000 to 20000 nm2, an average equivalent circle diameter (ECD) of 90 to 120 nm and an average circumference of 1150 to 1700 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 1670 to 1730° C. is obtained. Silicone sealing compound containing the pyrogenically produced silicon dioxide powder.

Abstract: Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 200±25 m2/g, wherein the aggregates display an average surface area of 7000 to 12000 nm2, an average equivalent circle diameter (ECD) of 80 to 100 nm and an average circumference of 850 to 1050 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 1570 to 1630° C. is obtained. It can be used as a filler.

Abstract: Functionalized silicas with 3-methacryloxypropylsilyl and/or glycidyloxypropylsilyl groups on the surface are prepared by mixing the silicas with the silane and heat-treating the mixture. The silicas are employed, for example, in solvent-containing coatings.

Abstract: A product obtained by treating surface-modified, pyrogenically produced titanium dioxide with at least one ammonium-functional silane, such as by spraying the pyrogenically produced titanium dioxide with the at least one silane, alone or in ethanol solution, and tempering, and useful in the field of cosmetics in sunblocks, in toner powders, in paints and varnishes, in silicone rubber, as abrasives and polishes, for example, in the field of CMP.

Abstract: A titanium dioxide powder/iron oxide mixed oxide which is prepared from FeCl3 and TiCl4 using a pyrogenic, especially a flame hydrolytic method. A further possibility is to coat pyrogenically, especially flame hydrolytically prepared titanium dioxide with iron oxide in aqueous dispersion. Both of these titanium dioxide powders which contain iron oxide may be used as a UV absorber in sunscreens.

Abstract: Pyrogenically, especially flame-hydrolytically produced zirconium dioxide powder with a specific surface area between 20 and 200 m2/g, a primary particle size between 7 and 100 nm, a tamped density of the deacidified and non-deacidified zirconium dioxide between 40 and 150 g/l with Sears numbers of the deacidified and non-deacidified zirconium dioxide between 1 and 20 ml/2 g and with a chlorine content of the deacidified zirconium dioxide less than 0.6% by weight. These are produced by evaporating zirconium halides, mixing the vapors alone or together with a carrier gas in a burner with air, oxygen, nitrogen and hydrogen, causing the gases to react with each other in a flame in a closed burner chamber, cooling off the waste gases and the zirconium dioxide in a heat exchanger unit, separating the waste gases from the zirconium dioxide and removing any halide remnants adhering to the zirconium dioxide by a heat treatment with moistened air.

Abstract: Surface-modified, doped, pyrogenically produced oxides surface-modified with one or several compounds from the following groups:

Abstract: A silicon-aluminum mixed oxide produced by flame hydrolysis and having a composition of from 1 to 99.999 wt. % Al2O3, the remainder being SiO2, which mixed oxide exhibits an amorphous structure in the X-ray diffraction pattern and consists of intergrown primary particles, and in these primary particles crystallites are present. These crystallites having sizes of between one and 200 namometers and the specific surface of the powder being between 5 and 300 m2/g. These products are produced by a process wherein silicon halide and aluminum halide are vaporized in a particular ratio to one another and are homogeneously mixed with air, oxygen and hydrogen in a mixing unit by means of any carrier gas, this mixture undergoes combustion in a burner of known construction and, after the separation of the solids from the vapour phase, any traces of halide possibly adhering to the product are separated off in a further processing step by means of moist air at elevated temperature.

Abstract: A titanium dioxide powder/iron oxide mixed oxide which is prepared from FeCl3 and TiCl4 using a pyrogenic, especially a flame hydrolytic method. A further possibility is to coat pyrogenically, especially flame hydrolytically prepared titanium dioxide with iron oxide in aqueous dispersion. Both of these titanium dioxide powders which contain iron oxide may be used as a UV absorber in sunscreens.

Abstract: Granules based on titanium dioxide with the characteristics: Average particle diameter: 10 to 150 &mgr;m BET surface area: 25 to 100 m2/g pH: 3 to 6 Compacted density: 400 to 1,200 g/l The granules are prepared by dispersing titanium dioxide in water, spray-drying and silanizing. In the silanized form, the granules have the following characteristics: Average particle diameter: 10 to 160 &mgr;m BET surface area: 15 to 100 m2/g pH: 3.0 to 9.0 Compacted density: 400 to 1,200 g/l Carbon content: 0.3 to 12.0 wt. % The granules are used, inter alia, as catalyst supports, in cosmetics, as sun screens, in silicone rubber, in toning powder, in lacquers and colorants, as grinding and polishing agents and as a raw material for producing glass and ceramics.

Abstract: A titanium dioxide powder/iron oxide mixed oxide which is prepared from FeCl3 and TiCl4 using a pyrogenic, especially a flame hydrolytic method. A further possibility is to coat pyrogenically, especially flame hydrolytically prepared titanium dioxide with iron oxide in aqueous dispersion. Both of these titanium dioxide powders which contain iron oxide may be used as a UV absorber in sunscreens.