Patents by Inventor Frank Döbert

Frank Döbert 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).

  • Continuous isothermal process for preparing mononitrotoluenes
    Patent number: 6583327
    Abstract: The present invention relates to a process for the continuous isothermal preparation of mononitrotoluenes with concentration of the resultant waste sulfuric acid and recycling of the concentrated waste sulfuric acid to the process.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: June 24, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Ralf Demuth, Frank Döbert, Harald Petersen, Georg Ronge, Hans-Martin Weber, Thomas Würminghausen, Eberhard Zirngiebl
  • Process for preparing trimethylol compounds and formic acid
    Patent number: 6441254
    Abstract: The present invention relates to a process for preparing trimethylol compounds and formic acid by reaction of formaldehyde and aldehydes in the presence of a nitrogen base and distillation of the resulting reaction mixture in the presence of an auxiliary.
    Type: Grant
    Filed: December 13, 2001
    Date of Patent: August 27, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Frank Döbert, Paul Wagner, Alexander Klausener, Wolfgang Eymann, Rolf Feller
  • Preparation and use of iminodisuccinic acid salts
    Patent number: 6207010
    Abstract: A process for the preparation of iminodisuccinic acid alkali metal salts by reaction of maleic acid and ammonia in an aqueous medium in the presence of alkali metal hydroxides and working up thereof.
    Type: Grant
    Filed: June 1, 2000
    Date of Patent: March 27, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Torsten Groth, Winfried Joentgen, Paul Wagner, Frank Döbert, Eckhard Wenderoth, Thomas Roick
  • Method for carrying out polycondensation reactions
    Patent number: 6187898
    Abstract: The invention relates to a method for carrying out polycondensation reactions, according to which the polycondensation of a monomeric starting material is carried out with external supply of heat in a reactor combination which has at least two stages and is composed of a pre-reactor and a high-viscosity reactor, where the low-molecular-weight elimination products produced are removed by evaporation. In the pre-reactor, the reaction product is concentrated to give a high-viscosity preliminary product. The high-viscosity preliminary product is then fed to the high-viscosity reactor, in which it reacts to completion with simultaneous introduction of thermal and mechanical energy and with a residence time of from 20 s to 60 min to give a polycondensation product.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: February 13, 2001
    Assignee: Bayer AG
    Inventors: Paul Wagner, Frank Döbert, Thomas Menzel, Torsten Groth, Winfried Joentgen, Ulrich Liesenfelder, Jörgen Weinschenck, Klaus-Peter Heise