Patents by Inventor Piotr Zettinger

Piotr Zettinger 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).

  • Process for the production of ketene dimers
    Patent number: 5502218
    Abstract: A process for the production of ketene dimers from fatty acid halides by reaction with tertiary amines. The process is operated batchwise and the reaction is started in the presence of an initial reaction mixture containing ketene dimer and pre-prepared crystals of tertiary amine hydrogen halide and is carried out in the substantial absence of additional solvents.
    Type: Grant
    Filed: September 15, 1994
    Date of Patent: March 26, 1996
    Assignee: Eka Nobel AB
    Inventors: John F. Nicholass, Piotr Zettinger