Patents by Inventor Helmut Klappert

Helmut Klappert 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).

  • Evaporating solutions which contain phosgene in a vacuum liquid ring pump
    Patent number: 3954567
    Abstract: Solutions of phosgene, an organic solvent and nitrogen or oxygen compounds which have a higher boiling point than the solvent are evaporated in a vacuum which is produced by a liquid ring pump operated on a phosgene-containing solvent as working fluid, the used working fluid being subsequently returned to the process.
    Type: Grant
    Filed: August 28, 1973
    Date of Patent: May 4, 1976
    Assignee: Bayer Aktiengesellschaft
    Inventors: Peter Fischer, Wilhelm Hagen, Helmut Klappert, Walter Levin, Karl-Friedrich Zenner, Johannes Werneburg
  • Continuous prephosgenation process for the production of organic isocyanates
    Patent number: 3947484
    Abstract: A process for pre-phosgenating organic primary amines is provided wherein a phosgene solution and an amine solution are combined in the suction side of a multiple stage rotary pump.
    Type: Grant
    Filed: May 31, 1974
    Date of Patent: March 30, 1976
    Assignee: Bayer Aktiengesellschaft
    Inventors: Alexander Mitrowsky, Helmut Klappert, Karl-Friedrich Zenner, Wilhelm Hagen