Patents by Inventor Hans Ledwinka

Hans Ledwinka 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).

  • Patent number: 5629255
    Abstract: Highly active catalysts, for olefin polymerization, from tetraneophylzirconium and partly hydroxylated metal oxides from group IIa, IIIa, IVa or IVb of the Periodic Table, which are essentially free from by-products.
    Type: Grant
    Filed: September 21, 1995
    Date of Patent: May 13, 1997
    Assignee: PCD Polymere Gesellschaft m.b.H.
    Inventors: Norbert Hafner, Wilfried T oltsch, Hans Ledwinka, Wolfgang Neissl
  • Patent number: 5596076
    Abstract: Process for the preparation of elastomeric, non-agglomerated, powdery/crumbly polypropylene by polymerization of propylene, if appropriate together with other olefins as comonomers, in liquid propylene and subsequent precipitation of the polypropylenes formed with CO.sub.2 or a polar solvent of which the polar term "delta p" of the solubility parameter according to Hansen is greater than 5 and the total solubility parameter "delta" is less than 30.
    Type: Grant
    Filed: May 19, 1994
    Date of Patent: January 21, 1997
    Assignee: PCD Polymere Gesellschaft m.b.H.
    Inventors: Norbert Hafner, Friedrich Mitter, Hans Ledwinka, Elisabeth Bruckm uller, Josef Kurz