Patents by Inventor Ralf Demuth

Ralf Demuth 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 for preparing monomer complexes
    Patent number: 7851584
    Abstract: Disclosed are processes for preparing monomer complexes that include contacting 2,3,5,6-tetraminopyridine free base in water with 2,5-dihydroxy terephthalic acid dipotassium salt to form an aqueous mixture, and adjusting the pH of the aqueous mixture to within the range of from about (3) to about (5) to precipitate the monomer complex. Processes of polymerizing the monomer complexes, polyareneazoles, filaments and yarns are also disclosed.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: December 14, 2010
    Assignees: E. I. du Pont de Nemours and Company, Magellan Systems International, LLC
    Inventors: Doetze Jakob Sikkema, David J Rodini, Hasan Dindi, James Arnold Schultz, Georg Valentin Martin, Ralf Demuth, Michael Schelhaas
  • Processes for increasing polymer inherent viscosity
    Patent number: 7683122
    Abstract: Disclosed are processes for preparing polyareneazole polymers including contacting a molar excess of a free base in water with a terephthalic acid salt to form an aqueous mixture, adjusting the pH to precipitate a monomer complex, contacting the monomer complex with metal powder, and polymerizing the monomer complex. Polyareneazoles, filaments and yarns are also disclosed.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: March 23, 2010
    Assignees: E. I. du Pont de Nemours and Company, Magellan Systems International, LLC
    Inventors: Doetze Jakob Sikkema, David J. Rodini, Qinghong Fu Adkins, Steven R. Allen, Georg Valentin Martin, Ralf Demuth, Michael Schelhaas
  • PROCESS FOR PREPARING MONOMER COMPLEXES
    Publication number: 20090215946
    Abstract: Disclosed are processes for preparing monomer complexes that include contacting 2,3,5,6-tetraaminopyridine free base in water with 2,5-dihydroxy terephthalic acid dipotassium salt to form an aqueous mixture, and adjusting the pH of the aqueous mixture to within the range of from about (3) to about (5) to precipitate the monomer complex. Processes of polymerizing the monomer complexes, polyareneazoles, filaments and yarns are also disclosed.
    Type: Application
    Filed: March 27, 2006
    Publication date: August 27, 2009
    Inventors: Doetze Jakob Sikkema, David J. Rodini, Hasan Dindi, James Arnold Schultz, Georg Valentin Martin, Ralf Demuth, Michael Schelhaas
  • Processes for increasing polymer inherent viscosity
    Publication number: 20070072993
    Abstract: Disclosed are processes for preparing polyareneazole polymers including contacting a molar excess of a free base in water with a terephthalic acid salt to form an aqueous mixture, adjusting the pH to precipitate a monomer complex, contacting the monomer complex with metal powder, and polymerizing the monomer complex. Polyareneazoles, filaments and yarns are also disclosed.
    Type: Application
    Filed: March 27, 2006
    Publication date: March 29, 2007
    Applicants: E. I. du Pont de Nemours and Company, Magellan Systems International, LLC
    Inventors: Doetze Sikkema, David Rodini, Qinghong Adkins, Steven Allen, Georg Martin, Ralf Demuth, Michael Schelhass
  • Continuous adiabatic process for nitrating chlorobenzene
    Patent number: 6794549
    Abstract: The present invention relates to a continuous adiabatic process for preparing nitrochlorobenzene in the presence of phosphoric acid. The waste acid produced during the practice of the process is reconcentrated and recycled into the nitration reaction.
    Type: Grant
    Filed: February 6, 2003
    Date of Patent: September 21, 2004
    Assignee: Bayer Aktiengesellschaft
    Inventors: Ralf Demuth, Matthias Gotta, Thomas Linn, Hans-Martin Weber, Eberhard Zirngiebl
  • Continuous isothermal process for preparing mononitrotoluenes in the presence of phosphoric acid
    Patent number: 6768032
    Abstract: The present invention relates to a continuous isothermal process for preparing mononitrotoluenes in the presence of a mixed acid component comprising mixtures of sulfuric acid and phosphoric acid with concentration of the resultant waste acid and recycling of the concentrated waste acid to the process.
    Type: Grant
    Filed: April 2, 2002
    Date of Patent: July 27, 2004
    Assignee: Bayer Chemicals AG
    Inventors: Matthias Gotta, Ralf Demuth, Eberhard Zirngiebl, Hans-Martin Weber, Georg Ronge
  • Continuous adiabatic process for nitrating chlorobenzene
    Publication number: 20030181771
    Abstract: The present invention relates to a continuous adiabatic process for preparing nitrochlorobenzene in the presence of phosphoric acid. The waste acid produced during the practice of the process is reconcentrated and recycled into the nitration reaction.
    Type: Application
    Filed: February 6, 2003
    Publication date: September 25, 2003
    Inventors: Ralf Demuth, Matthias Gotta, Thomas Linn, Hans-Martin Weber, Eberhard Zirngiebl
  • Continuous adiabatic process for preparing nitrochlorobenzene
    Patent number: 6586645
    Abstract: The present invention relates to a continuous adiabatic process for preparing nitrochlorobenzene, in which the waste sulfuric acid produced during the practice of the process is reconcentrated and recycled into the nitration reaction.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: July 1, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Ralf Demuth, Bernd-Michael König, Thomas Linn, Hans-Joachim Raatz, Hans-Martin Weber, Eberhard Zirngiebl, Ricarda Leiberich
  • 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
  • Tubular reactor for adiabatic nitration
    Publication number: 20030055300
    Abstract: The invention relates to an optimized tubular reactor for adiabatically mononitrating aromatics, halogenated aromatics and halogenated hydrocarbons, which tubular reactor is divided into from 4 to 12 chambers by plates which have openings and effect a pressure drop of from 0.5 to 4 bar per plate.
    Type: Application
    Filed: September 6, 2002
    Publication date: March 20, 2003
    Inventors: Andreas Chrisochoou, Ralf DeMuth, Thomas Linn, Paul Wagner, Knud Werner
  • Continuous adiabatic procss for preparing nitrochlorobenzene
    Publication number: 20020161269
    Abstract: The present invention relates to a continuous adiabatic process for preparing nitrochlorobenzene, in which the waste sulfuric acid produced during the practice of the process is reconcentrated and recycled into the nitration reaction.
    Type: Application
    Filed: February 19, 2002
    Publication date: October 31, 2002
    Inventors: Ralf Demuth, Bernd-Michael Konig, Thomas Linn, Hans-Joachim Raatz, Hans-Martin Weber, Eberhard Zirngiebl, Ricarda Leiberich
  • Continuous isothermal process for preparing mononitrotoluenes in the presence of phosphoric acid
    Publication number: 20020147372
    Abstract: The present invention relates to a continuous isothermal process for preparing mononitrotoluenes in the presence of a mixed acid component comprising mixtures of sulfuric acid and phosphoric acid with concentration of the resultant waste acid and recycling of the concentrated waste acid to the process.
    Type: Application
    Filed: April 2, 2002
    Publication date: October 10, 2002
    Inventors: Matthias Gotta, Ralf Demuth, Eberhard Zirngiebl, Hans-Martin Weber, Georg Ronge
  • Continuous isothermal process for preparing mononitrotoluenes
    Publication number: 20020091290
    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: Application
    Filed: October 26, 2001
    Publication date: July 11, 2002
    Inventors: Ralf Demuth, Frank Dobert, Harald Petersen, Georg Ronge, Hans-Martin Weber, Thomas Wurminghausen, Eberhard Zirngiebl