Patents by Inventor Dieter Zimmerling

Dieter Zimmerling 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).

  • Obtaining very pure maleic anhydride from crude maleic anhydride
    Patent number: 4961827
    Abstract: Very pure maleic anhydride having a stable color is obtained by fractional distillation of crude maleic anhydride by a method in which the maleic anhydride vapor separated off from low boilers and high boilers is partially condensed so that from 0.5 to 15% by weight of the maleic anydride vapor is separated off from the vapor phase as a liquid precondensate, and the remaining very pure maleic anhydride vapor is then completely condensed.
    Type: Grant
    Filed: January 22, 1986
    Date of Patent: October 9, 1990
    Assignee: BASF Aktiengesellschaft
    Inventors: Dieter Zimmerling, Johannes E. Schmidt, Rolf Seubert, Karl Fischer, Friedrich Sauer
  • Isolation of methyl 4-pentenoate from mixtures containing this and methyl 3-pentenoate
    Patent number: 4561942
    Abstract: Methyl 4-pentenoate is isolated from mixtures containing this and methyl 3-pentenoate by a process in which from 0.25 to 0.4 part by weight of water is added per part by weight of methyl 4-pentenoate, and the azeotrope of methyl 4-pentenoate and water is distilled off.
    Type: Grant
    Filed: March 28, 1985
    Date of Patent: December 31, 1985
    Assignee: BASF Aktiengesellschaft
    Inventors: Heinz-Walter Schneider, Rudolf Kummer, Dieter Zimmerling