Patents by Inventor Walter Bieg

Walter Bieg 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).

  • Method for the continuous production of 1,3-dioxolan-2-ones
    Patent number: 6265592
    Abstract: A process for the continuous production of 1,3-dioxolan-2-ones such as ethylene carbonate or propylene carbonate by reacting a corresponding oxirane with carbon dioxide in the liquid phase in the presence of a catalyst comprises conducting the reaction in a two-part reactor in whose first part the reaction is taken with backmixing to a conversion of not less than 80% of the oxirane II and in whose second part the reaction is completed under nonbackmixing conditions, and passing the carbon dioxide in countercurrent to the oxirane II in the entire reactor.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: July 24, 2001
    Assignee: BASF Aktiengesellschaft
    Inventors: Stefan Birnbach, Toni Dockner, Jürgen Mohr, Regina Benfer, Walter Bieg, Jarren Peters, Bernd Ruge, Werner Weinle, Peter Zehner
  • Purification of indigo
    Patent number: 5116996
    Abstract: A process for purifying indigo comprises stripping the as-synthesized aqueous alkaline indoxylate solution before its oxidation to indigo of impurities in the absence of oxygen by distillation or by passing in steam or an inert gas and then treating the indigo precipitated on oxidation of the stripped indoxylate solution with dilute hydrogen peroxide solution.
    Type: Grant
    Filed: July 17, 1991
    Date of Patent: May 26, 1992
    Assignee: BASF Aktiengesellschaft
    Inventors: Reinhold Kohlhaupt, Walter Bieg, Ernst Lang
  • Purification of indigo
    Patent number: 5109137
    Abstract: A process for the preparation of purified indigo comprises extracting the aqueous alkaline indoxylate solution arising from the synthesis with an inert water-insoluble solvent in the absence of oxygen before oxidizing the indoxylate solution to give indigo.
    Type: Grant
    Filed: July 15, 1991
    Date of Patent: April 28, 1992
    Assignee: BASF Aktiengesellschaft
    Inventors: Reinhold Kohlhaupt, Manfred Gaeng, Lothar Haas, Guenter Engelhardt, Walter Bieg, Matthias Fankhaenel
  • Purification of indigo
    Patent number: 5075458
    Abstract: A process for the preparation of purified indigo comprises extracting the aqueous alkaline indoxylate solution arising from the synthesis with an inert water-insoluble solvent in the absence of oxygen before oxidizing the indoxylate solution to give indigo.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: December 24, 1991
    Assignee: BASF Aktiengesellschaft
    Inventors: Reinhold Kohlhaupt, Manfred Gaeng, Lothar Haas, Guenter Engelhardt, Walter Bieg, Matthias Fankhaenel