Patents Assigned to Axiva GmbH
  • On-line analysis of process gas during the production of ketene
    Patent number: 6284547
    Abstract: The invention relates to a process for the on-line analysis of a reactive gas mixture, in particular of a gas mixture comprising ketene and/or diketene and/or acetic anhydride and/or acetic acid, which gas mixture is situated in a vessel, which comprises expanding a portion of the gas mixture instantaneously into a sampling line via a probe which is integrated into the vessel and which has an orifice whose clear cross sectional area is less than or equal to 1 mm2 and feeding it to a mass-spectrometric analysis.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: September 4, 2001
    Assignee: Axiva GmbH
    Inventor: Thomas Schäfer
  • Optical brightening agent
    Patent number: 6187224
    Abstract: An optical brightener comprising one or more spiro compounds of the formula (I), where K1 and K2, which are identical or different, are conjugated systems, and &psgr; is C, Si, Ge, Sn or Pb, is notable for high fluorescence quantum yields and a high temperature stability.
    Type: Grant
    Filed: July 6, 1999
    Date of Patent: February 13, 2001
    Assignee: Axiva GmbH
    Inventors: Willi Kreuder, Josef Salbeck