Patents by Inventor Emanuel W. Wirfel

Emanuel W. Wirfel 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).

  • Utilization of bisphenol-A from the alkaline phase generated in the production of polycarbonates
    Patent number: 4025489
    Abstract: This invention relates to polycarbonates and more particularly to recovering unreacted bisphenol-A from the alkaline phase generated in the production of polycarbonates, comprising reacting the alkaline phase with phosgene to convert the unreacted bisphenol-A to a low molecular weight polymer and returning a solvent solution of the low molecular weight polymer to the main reaction stream.
    Type: Grant
    Filed: January 27, 1975
    Date of Patent: May 24, 1977
    Assignee: Mobay Chemical Corporation
    Inventors: John V. Bailey, Thomas H. Cleveland, Emanuel W. Wirfel