Patents by Inventor Hans-Dieter Behrens

Hans-Dieter Behrens 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: 5283045
    Abstract: A carbon powder is disclosed with 40 to 75% by weight QI or more than 90% by weight TI, an optical anisotropy of less than 50% by volume, a start of softening between 200.degree. and 300.degree. C., and an oxygen content of more than 2% by weight, and which can be used for without binding agent the production of shaped carbon bodies. The carbon powder is produced by means of distillation from bituminous product at a maximum of 5 mbars and a final temperature of at least 400.degree. C., grinding of the distillation residue to a particle size of less than 30 .mu.m, and oxidation of the powder into the particle core.
    Type: Grant
    Filed: January 14, 1993
    Date of Patent: February 1, 1994
    Assignee: Rutgerswerke AG
    Inventors: Winfried Boenigk, Hans-Dieter Behrens, Andreas Niehoff, Hans Spengler
  • Patent number: 5262043
    Abstract: An isotropic coal tar pitch having a low content of carcinogenic compounds is prepared by distilling a coal tar pitch in an evaporator having a specific evaporator surface of from 330 to 10,000 m.sup.2 /m.sup.3, at a temperature in the range of from 300.degree. to 380.degree. C., under a pressure not exceeding 1 mbar, whereby the average stay period is from 2 to 10 minutes. The isotropic pitch thus obtained contains less that 50 ppm of benzo[a]pyrene and is suitable, optionally after adding an oil, resin or other modifying agents having a low benzo[a]pyrene content, for use as binding and impregnating agent and also as protecting agent in construction materials or as varnish (painting agent).
    Type: Grant
    Filed: April 17, 1992
    Date of Patent: November 16, 1993
    Assignee: Rutgerswerke AG
    Inventors: Winfried Boenigk, Hans-Dieter Behrens, Hans Spengler