Patents by Inventor Geoffrey J. Varga

Geoffrey J. Varga has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7718261
    Abstract: Nanoscale, pyrogenically produced zinc oxide having a BET surface area of 10 to 200 m2/g, which is in the form of aggregates of anisotropic primary particles and whereby the aggregates display an average diameter of 50 to 300 nm. It is obtained from zinc powder, which is converted to zinc oxide powder in the four successive reaction zones, evaporation zone, nucleation zone, oxidation zone and quench zone. It can be used in sunscreen formulations.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: May 18, 2010
    Assignee: Evonik Degussa GmbH
    Inventors: Stipan Katusic, Günther Michael, Peter Kress, Geoffrey J. Varga, Edwin Staab, Winfried Weber
  • Patent number: 7235298
    Abstract: Pyrogenically prepared, doped zinc oxide powder, wherein the doping component comprises at least one oxide from the group aluminum, gallium, indium, germanium, tin and is present in the doped zinc oxide powder in an amount of from 0.005 to 15 wt. %, and wherein the doped zinc oxide powder is in the form of aggregates of primary particles having a mean maximum diameter of from 30 to 400 nm. It is prepared by oxidation from zinc powder and at least one doping agent, wherein the process zones vaporisation, nucleation, oxidation and quenching are passed through and the doping agent is metered in in the nucleation zone, in which the temperature is below the boiling temperature of zinc. The doped zinc oxide powder can be used in electrically conductive lacquers and coatings.
    Type: Grant
    Filed: July 7, 2003
    Date of Patent: June 26, 2007
    Assignee: Degussa AG
    Inventors: Stipan Katusic, Guenther Michael, Peter Kress, Guido Zimmermann, Andreas Gutsch, Geoffrey J. Varga
  • Publication number: 20030206854
    Abstract: Nanoscale, pyrogenically produced oxides and/or mixed oxides having a BET surface area of between 1 m2/g and 600 m2/g and a chloride content of less than 0.05 wt. % are produced by converting organometallic and/or organometalloid substances into the oxides at temperatures of above 200° C. The oxides may be used as a polishing agent in the electronics industry (CMP).
    Type: Application
    Filed: April 17, 2003
    Publication date: November 6, 2003
    Applicant: Degussa AG
    Inventors: Andreas Gutsch, Thomas Hennig, Stipan Katusic, Michael Kramer, Gunther Michael, Geoffrey J. Varga
  • Publication number: 20010036437
    Abstract: Nanoscale, pyrogenically produced oxides and/or mixed oxides having a BET surface area of between 1 and 600 m2/g and a chloride content of less than 0.05 wt. % are produced by converting organometallic and/or organometalloid substances into the oxides at temperatures of above 200° C.
    Type: Application
    Filed: March 30, 2001
    Publication date: November 1, 2001
    Inventors: Andreas Gutsch, Thomas Hennig, Stipan Katusic, Michael Kramer, Gunther Michael, Geoffrey J. Varga
  • Patent number: 6000241
    Abstract: A precursor solution composition is provided for making highly pure, fine barium-containing silicate glass powders and specifically barium aluminoborosilicate (BABS) glass powders. An atomized precursor solution containing colloidal silica, a water soluble source of barium, boric acid, and aluminum nitrate is used to make the powders. After mixing, the liquid precursor solution is formed into fine droplets, classified for size, and pyrolyzed into fine powders. The resulting spherical particles of the BABS glass is in the 0.1 to 10 micrometer size range.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: December 14, 1999
    Assignee: Particle Technology, Inc.
    Inventors: Madhav B. Ranade, Rohitha K. Wijayatilleke, M. Kamal Akhtar, Geoffrey J. Varga
  • Patent number: 5928405
    Abstract: An economical process and associated hardware for commercial manufacture of controllable submicrometer size metallic powders for electronic and other applications. The method is based on the preparation of a stable high concentration precursor solution, production of a high density aerosol mist of the precursor solutions, selection of mist droplets with upper and lower size bounds, controlled drying of the droplets, their conversion to metallic powder in a high temperature gaseous atmosphere and the separation of the powders from carrier gases without significant loss inside the process hardware.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: July 27, 1999
    Assignees: Degussa Corporation, Particle Technology, Inc.
    Inventors: Madhav B. Ranade, Dan V. Goia, Geoffrey J. Varga, Bernard W. Gamson, John Bara