Patents by Inventor Renate Wilms

Renate Wilms 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).

  • Production and use of polyester carbonates
    Patent number: 6646099
    Abstract: A transesterification process for producing polyester is disclosed. In a first stage of the process there is heated, in an inert gas atmosphere, a first mixture containing at least one dihydroxy compound and at least one diaryl carbonate to form an oligocondensate. In a second stage there is added to the oligocondensate at least one dicarboxylic acid to form a second mixture. The second mixture is heated to a temperature not higher than 290° C. in the presence of a quaternary onium compound as catalyst to form polyester carbonate. Hydroxyaryl formed throughout the process is distilled-off under reduced pressure.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: November 11, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Silke Kratschmer, Lothar Bunzel, Wolfgang Alewelt, Renate Wilms
  • Production and use of polyester carbonates
    Publication number: 20030105272
    Abstract: A transesterification process for producing polyester is disclosed. In a first stage of the process there is heated, in an inert gas atmosphere, a first mixture containing at least one dihydroxy compound and at least one diaryl carbonate to form an oligocondensate. In a second stage there is added to the oligocondensate at least one dicarboxylic acid to form a second mixture. The second mixture is heated to a temperature not higher than 290° C. in the presence of a quaternary onium compound as catalyst to form polyester carbonate. Hydroxyaryl formed throughout the process is distilled-off under reduced pressure.
    Type: Application
    Filed: June 26, 2002
    Publication date: June 5, 2003
    Inventors: Silke Kratschmer, Lothar Bunzel, Wolfgang Alewelt, Renate Wilms