Abstract: Aluminium oxide dispersion, which is stable in a pH range 5 from 5 to 9 and has an aluminium oxide content of at least 40 wt. %, obtainable by dispersing pyrogenically produced aluminium oxide particles in an aqueous phase, wherein one or several at least dibasic hydroxycarboxylic acids present dissolved in the dispersion and at least one salt of a 10 dialkali metal hydrogen phosphate and/or alkali metal dihydrogen phosphate are added to the aqueous phase each mutually independently in a quantity of 0.3?3×10?6 mol/m2 of aluminium oxide specific surface area.

Abstract: Process for preparing ultrafine powders based on polyamides by contacting polyamides having a relative solution viscosity ?rel in the range from 1.5 to 2.0, measured in 0.5% m-cresol solution at 25° C., with an alcoholic medium in the presence of inorganic particles under the action of pressure and/or temperature to generate an at least partial solution, and then precipitating the polyamide from the at least partial solution, characterized in that a suspension of the inorganic particles suspended in the alcoholic medium is used. The resulting ultrafine polyamide powders have a specific BET surface area in the range of 5-100 m2/g; a fineness d50 of less than 70 ?m; an apparent density AD in the range from 250 to 1000 g/l; and a particle content of 0.1 to 80% by weight of inorganic particles based on the total weight of the polyamide powder. They are equally suitable for coatings and for mouldings and components with improved mechanical properties.

Abstract: Aqueous dispersions comprising microfine metal oxide particles and dispersion auxiliaries, wherein, as dispersion auxiliaries, at least one of the compounds of the general formula (I) in which M is hydrogen, monovalent or divalent metal cation, ammonium ion, organic amine radical; a is 1, or where M is a divalent metal cation, is ½; X is likewise —OMa or —O—(CpH2pO)q—Rl where R1?H, aliphatic hydrocarbon radical having 1-20 carbon atoms, cycloaliphatic hydrocarbon radical having 5 to 8 carbon atoms, optionally substituted aryl radical having 6 to 14 carbon atoms, p=2 to 4, q=0 to 100, —NHR2 and/or —NR22 where R2?R1 or —CO—NH2; Y is O, NR2; A1 is ethylene radical, propylene radical, isopropylene radical, butylene radical; m is 10 to 30; n is 0 to 50; and k is 10 to 30, where the summ+k is in the range from 20 to 60, is co-used.

Abstract: An aqueous dispersion, having a silicon dioxide powder having a silicon dioxide content of 10 to 60 wt.%, wherein the aqueous dispersion is stable in the pH range of 2 to 6, the aqueous dispersion additionally contains at least one compound, which is at least partially soluble in aqueous solution in the pH range 2 to 6 in the form of polyvalent cations, these being stable in a silicate-like environment as an anionic component of the particle surface of the silicon dioxide powder, the quantity of cation-providing compound in relation to the surface of the silicon dioxide is 0.001 to 0.1 mg cation-providing compound/m2 silicon dioxide surface, the cation-providing compound being calculated as the oxide, and the zeta potential of the aqueous dispersion has values of less than or equal to zero.

Abstract: Aqueous dispersion obtainable by placing in water an aggregated titanium dioxide powder having a specific surface area of from 20 to 150 m2/g in such an amount that the desired dispersion comprises at least 20 wt. % titanium dioxide, and at least onc amino alcohol having from 1 to 6 carbon atoms, and at least one carboxylic acid from the group comprising dibasic carboxylic acids and/or hydroxycarboxylic acids having from 2 to 6 carbon atoms,—the amino alcohol being present in the dispersion in an amount of from 2.5 to 7.0 ?mol./m2 specific surface area TiO2 and the carboxylic acid being present in an amount of from 1.0 to 3.5 ?mol./m specific surface area TiO2,—producing a pre-dispersion by introducing energy in an amount of less than 200 kJ/m3 and then producing a dispersion in which the aggregated titanium dioxide powder has a mean, volume-related aggregate diameter of less than 150 nm by grinding the pre-dispersion by means of a high-energy mill at a pressure of at least 500 bar.

Abstract: A method and device for producing a finely divided dispersion of solids having a mean particle size of 10 nm to 10 µm, in which at least two flows of a predispersion are sprayed by means of pumps, preferably high-pressure pumps, through one nozzle each into a grinding chamber enclosed by a reactor housing onto a collision point, wherein the grinding chamber is flooded with the predispersion and the finaly divided dispersion is removed from the grinding chamber by the overpressure of the predispersion continuing to flow into the grinding chamber.

Abstract: A powder containing particles with a core of titanium dioxide and a coating of silicon dioxide in an amount of between 0.5 and 40 wt. %, the particles have a BET surface of between 5 and 300 m2/g, and the particles are primary particles that have a coating of silicon dioxide and a core of titanium dioxide.

Abstract: Aqueous dispersion which comprises hydrophobized silicon dioxide powder with a content of between 5 and 50 wt. % and which comprises at least one compound of the general formula R & supl; —COO—(CH2-CH(Ph)—O)a-(CnH2n-xR2xO)b-R3 (I). It is prepared by dispersing the hydrophobic silicon dioxide powder, dispersing agent and optionally pH-regulating substances and further additives in an aqueous medium. It can be employed as an additive to waterborne fillers in the automobile industry, as a coating constituent in can and coil coating processes, as an additive in water-based UV-curable formulations e.g. for wood preservation and as a constituent of protective lacquer films.

Abstract: Aluminium oxide powder produced by flame hydrolysis and consisting of aggregates of primary particles, having a BET surface area of from 100 to 250 m2/g, a dibutyl phthalate absorption of from 50 to 450 g/100 g of aluminium oxide powder, which powder shows only crystalline primary particles in high-resolution TEM pictures.

Abstract: Stable, aqueous dispersion containing powders A and B,—wherein powder A is an amorphous silicon dioxide powder having an average particle diameter of 0.05 to 0.7 ?m and a BET surface aa of 5 to 50 m2/g, and—wherein powder B is a metal oxide or non-metal oxide powder consisting of aggregates of intergrown primary particles and displays a primary particle size of 5 to 50 nm and a BET surface area of 50 to 400 m2/g. Coating slip to form an ink-absorptive coating using the dispersion and at least one hydrophilic binder. Absorptive medium using the coating slip and a support.

Abstract: Process for the production of an aqueous dispersion of pyrogenically produced metal oxide and metalloid oxide powders with a BET surface area of between 5 and 600 m2/g, with a metal oxide or metalloid oxide content in the dispersion of between 5 and 25 wt. %, comprising the following steps:—water, which is optionally adjusted to pH values of between 2 and 4 by adding acids, is circulated from a receiving vessel via a rotor/stator machine, and—metal oxide or metalloid oxide powder is introduced, using a feed device, into the shear zone between the slots in the rotor teeth and the stator slots, continuously or discontinuously and with the rotor/stator machine running, in a quantity such that a predispersion with a solids content of between 20 and 40 wt.

Abstract: A stable, aqueous dispersion, which includes: silicon dioxide mixed-oxide particles dispersed in at least one water-soluble cationic polymer having a mass average molar mass of less than 100,000 g/mol, said mixed-oxide including aluminum oxide or titanium dioxide, wherein said particles are produced by flame hydrolysis, wherein said particles have a BET specific surface area of 5 to 600 m2/g and a negative zeta potential, and wherein the dispersion has a positive zeta potential.

Abstract: Powder consisting of particles with a core of titanium dioxide and a coating of silicon dioxide, which powder has a content of silicon dioxide of between 0.5 and 40 wt. %, a BET surface of between 5 and 300 m2/g, and which consists of primary particles that have a coating of silicon dioxide and a core of titanium dioxide. The powder is produced according to a process in which a vaporisable silicon compound and a vaporisable titanium compound are mixed corresponding to the subsequently desired ratio of SiO2 and TiO2 in the product, are vaporised at temperatures of 200° C.

Abstract: A finely divided, stable dispersion of a solid is produced by: spraying at least two streams of a preliminary dispersion, each through a separate nozzle by pumps, onto a collision point in a reactor chamber enclosed by a reactor housing; passing water vapor through an opening into the reactor chamber so that a vaporous atmosphere consisting mainly of water vapor prevails in the reactor chamber; and removing the finely divided dispersion and a) vapor, b) partially condensed vapor consisting mainly of water or c) a combination of a) and b) from the reactor chamber by excess pressure of an incoming water vapor on the gas inlet side; wherein the solid has an average particle size of from 10 nm to 10 ?m.

Abstract: An aqueous dispersion containing pyrogenically prepared metal oxide particles and dispersants An aqueous dispersion containing pyrogenically prepared oxide particles of titanium, zinc, iron or cerium with an average particle size, expressed as the median, in the dispersion of less than 250 nm, that the particle sizes of the oxide particles in the dispersion are not distributed symmetrically and the dispersion contains, as a dispersant, at least one compound of the formula (I) and/or a maleic anhydride/acrylate copolymer of the general formula (IIa) and/or a maleate/acrylate copolymer of the general formula (IIb). It is prepared by dispersing a predispersion stream by means of a high energy mill. It can be used in sunscreen formulations.

Abstract: Aqueous dispersion containing pyrogenically produced oxide particles of titanium, zinc, iron or cerium having an average particle size, expressed as a median value, in the dispersion of less than 200 nm, the particle sizes of the oxide particles are not distributed symmetrically in the dispersion, the dispersion contains as dispersing agent at least one (poly)phosphate corresponding to the general formula I and has a pH of 4.5 to 7.5. It is prepared by dispersing a stream of a preliminary dispersion by means of a high-energy mill. It can be used in sunscreen formulations.

Abstract: An aqueous dispersion is used in the chemical mechanical polishing of surfaces, particularly oxidic surfaces, such as silicon dioxide. The aqueous dispersion contains a powder of pyrogenically produced silicon dioxide doped with 0.01 and 3 wt. % aluminium oxide, relative to the total amount of powder, said powder having an average particle diameter in the dispersion of not more than 0.1 ?m.

Abstract: Aluminium oxide doped with a divalent metal oxide, produced by flame hydrolysis and which has no spinell structures or alpha-aluminium detectable in an x-ray diffractogram. It is produced by a pyrogenic process in which, during the flame hydrolysis of aluminium halogenides, an aerosol, which contains an aqueous solution of a divalent metal salt is added to the gas mixture. The doped aluminium oxides can be used in aqueous dispersions for chemical-mechanical polishing.

Abstract: The present invention provides an aqueous dispersion containing at least two powder types selected from one or more metal oxide powders and/or one or more non-metal oxide powder. The present invention also provides a coating composition containing this dispersion, an inkjet recording medium containing the coating composition, and methods of making the same.

Abstract: The present invention relates to an aqueous dispersion containing a silicon dioxide powder coated with cerium oxide. In addition, the present invention provides a method of producing an aqueous dispersion containing a silicon dioxide powder coated with cerium oxide and methods of using this aqueous dispersion for chemical-mechanical polishing.