Patents by Inventor Bernhard Dorrer

Bernhard Dorrer 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 preparation of a polypropylene molding composition
    Patent number: 4576994
    Abstract: A polypropylene molding composition with a good hardness and good impact strength at low temperatures is formed by two-stage polymerization of propylene and ethylene in liquid propylene in the presence of a special supported catalyst.
    Type: Grant
    Filed: August 31, 1984
    Date of Patent: March 18, 1986
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Bernhard Dorrer, Helmut Strametz
  • Polypropylene molding composition and process for its preparation
    Patent number: 4473687
    Abstract: A polypropylene molding composition of polypropylene, ethylene-propylene copolymer and polyethylene having a high hardness and increased impact strength and homogeneity after processing is obtained by way of a continuous three-stage polymerization, when the melt viscosities of the polymer mixtures obtained in the individual stages are in a determined ratio of one to the other.
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: September 25, 1984
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Bernhard Dorrer, Friedrich Kloos, Horst Neumann, Helmut Strametz