Patents by Inventor Karlchristian Schilffarth

Karlchristian Schilffarth 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: 4477531
    Abstract: The present invention relates to a magnetic storage medium consisting of a non-magnetic layer support and, applied thereto, a binder-containing magnetic layer, the binder consisting of from 25 to 100% of a thermoplastic polyurethane substantially free from reactive terminal groups obtained by reacting a linear polyester of at least one dicarboxylic acid containing from 2 to 8 carbon atoms and/or hydroxy carboxylic acid containing from 4 to 6 carbon atoms and at least one glycol containing from 2 to 6 carbon atoms, the polyester having a molecular weight of from 1200 to 6000, at least one diisocyanate and a mixture of at least two glycols containing from 2 to 20 carbon atoms, the molar fraction of the individual components not exceeding 0.8. The polyurethane has a hardness of from 80 to 100 Shore A, a tensile strength of from 30 to 75 MPa and a breaking elongation of from 320 to 520%.
    Type: Grant
    Filed: July 8, 1982
    Date of Patent: October 16, 1984
    Assignee: Agfa-Gevaert AG
    Inventors: Robert Kohler, Burkhard Nippe, Heinrich Kober, Karlchristian Schilffarth, Walter Meckel, Bernd Quiring
  • Patent number: 4404253
    Abstract: Magnetic recording medium using water as dispersion medium. The magnetic layer comprises as binder an aqueous dispersion of polyurethane having functional groups capable of salt formation and a magnetic pigment. The volumetric ratio of magnetic pigment to polyurethane in terms of solids content is in the range of 0.7:1 to 1.4:1.
    Type: Grant
    Filed: February 25, 1982
    Date of Patent: September 13, 1983
    Assignee: Agfa-Gevaert Aktiengesellschaft
    Inventors: Robert Kohler, Karlchristian Schilffarth, Heinrich Kober, Burkhard Nippe