Patents by Inventor Frank Doebert

Frank Doebert 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).

  • Process and apparatus for the preparation of polycarbonate
    Patent number: 8394912
    Abstract: The invention relates to a process for the pretreatment of material surfaces in order to minimize the interaction between polycarbonate and metal and, in the processing and synthesis of polycarbonate, to obtain a high-quality polymer which in particular does not become discolored and is free of insoluble constituents.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: March 12, 2013
    Assignee: Bayer MaterialScience AG
    Inventors: Frank Doebert, Andreas Stremmel, Christoph Biedron, Stephan Laue, Johann Rechner, Torsten Hagen, Frank Bruynseels, Frank Quaeyhaegens, Johan Decloedt, Paul Van Dorst, Uwe Arndt, Johan Vanden Eynde, Ursula Tracht, Thomas König, Ulrich Liesenfelder
  • PROCESS AND APPARATUS FOR THE PREPARATION OF POLYCARBONATE
    Publication number: 20110184144
    Abstract: The invention relates to a process for the pretreatment of material surfaces in order to minimize the interaction between polycarbonate and metal and, in the processing and synthesis of polycarbonate, to obtain a high-quality polymer which in particular does not become discoloured and is free of insoluble constituents.
    Type: Application
    Filed: December 20, 2010
    Publication date: July 28, 2011
    Applicant: Bayer MaterialScience AG
    Inventors: Frank Doebert, Andreas Stremmel, Christoph Biedron, Stephan Laue, Johann Rechner, Torsten Hagen, Frank Bruynseels, Frank Quaeyhaegens, Johan Decloedt, Paul Van Dorst, Uwe Arndt, Johan Vanden Eynde, Ursula Tracht, Thomas König, Ulrich Liesenfelder
  • 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
  • Continuous preparation of cyclohexene by partial hydrogenation of benzene
    Patent number: 6344593
    Abstract: Cyclohexene is prepared by partial hydrogenation of benzene with hydrogen in the presence of water and ruthenium catalyst at elevated temperature and superatmospheric pressure by a continuous process in which benzene is introduced in gaseous form and the resulting cyclohexene is discharged in gaseous form and the catalyst is present in solution or suspension in a liquid, aqueous phase.
    Type: Grant
    Filed: July 6, 1995
    Date of Patent: February 5, 2002
    Assignee: BASF Aktiengesellschaft
    Inventors: Johann Gaube, Frank Doebert
  • 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