Patents by Inventor Hans-Jürgen Dietrich

Hans-Jürgen Dietrich 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 of producing branched polyamides
    Patent number: 6566486
    Abstract: A process for the production of polyamides is disclosed. In a first reaction step, suitable monomers such as caprolactam or an aliphatic aminocarboxylic acid are reacted with polyfunctional amines, which contain at least one secondary amino group, and/or with salts containing such amines and dicarboxylic acids. The reaction product is in a further process step undergoes solid phase post-condensation.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: May 20, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Detlev Joachimi, Hans-Jürgen Dietrich, Heinrich Morhenn, Cliff Scherer, Andreas Gittinger, Friedrich-Karl Bruder
  • Method for producing highly viscous polyesters
    Patent number: 6515044
    Abstract: The present invention relates to a process for the preparation of high-viscosity polyesters with a reduced content of acid end groups, wherein a masterbatch of low-viscosity polyesters and oxazolines is prepared, this is then mixed with a higher-viscosity polyester and this mixture (dry blend) is further processed.
    Type: Grant
    Filed: April 9, 2001
    Date of Patent: February 4, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Karsten-Josef Idel, Hans-Jürgen Dietrich, Matthias Müller