Patents by Inventor Heiner Bromstrup

Heiner Bromstrup 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).

  • Pipe of polyethylene having improved mechanical properties
    Patent number: 5908679
    Abstract: The invention relates to a high strength pipe of ethylene polymer having a bimodal molecular weight distribution. Such pipe has a stress cracking resistance of .gtoreq.1400 h, a fracture toughness of .gtoreq.7 mJ/mm.sup.2 and a modulus of creep in flexure, measured according to DIN 54852-Z4, of .gtoreq.1100 N/mm.sup.2. The pipe according to the invention is produced from an ethylene polymer in which the ratio of weight of the low molecular weight fraction to the weight of the higher molecular weight fraction is in the range from 0.5 to 2.0 and which has a melt flow index MFI.sub.5/190.degree. C. of .ltoreq.0.35 g/10 min. It is particularly suitable for the transportation of gases and water.
    Type: Grant
    Filed: October 6, 1997
    Date of Patent: June 1, 1999
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Joachim Berthold, Ludwig Bohm, Werner Breuers, Johannes Friedrich Enderle, Manfred Fleissner, Rainer Lecht, Hartmut Luker, Ulrich Schulte, Heiner Bromstrup