Process for the production of metal oxide and metalloid oxide dispersions

• Main Authors: BATZ-SOHN CHRISTOPH, LORTZ WOLFGANG, WILL WERNER, PERLET GABRIELE, SCHNEIDER GERRIT
• Format: Patent
• Language: English
• Published: 10.09.2013
• Subjects: ADHESIVES; CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM,CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THERARE-EARTH METALS; COMPOUNDS THEREOF; DYES; GLASS; GRINDING; INORGANIC CHEMISTRY; JOINING GLASS TO GLASS OR OTHER MATERIALS; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MINERAL OR SLAG WOOL; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; NON-METALLIC ELEMENTS; PAINTS; PERFORMING OPERATIONS; POLISHES; POLISHING; POLISHING COMPOSITIONS OTHER THAN FRENCH POLISH; PREPARATION OF CARBON BLACK; SKI WAXES; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS; TOOLS FOR GRINDING, BUFFING, OR SHARPENING; TRANSPORTING; TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS,TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES

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. % results, and, after all the metal oxide powder or metalloid oxide powder has been added, the feed device closes and shearing continues in such a way that the shear rate is in the range of between 10000 and 40000 s-1, and then, by dilution, the predispersion is adjusted to the desired solids content of the dispersion while maintaining the dispersing conditions.