Patents by Inventor Rudi Lehnert

Rudi Lehnert 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).

  • Publication number: 20010026880
    Abstract: Tape-like magnetic recording media having a nonmagnetic substrate and at least one layer applied to the substrate having incorporated into at least one of these layers, an inorganic needle-shaped pigment which serves as a supporting pigment and has a ratio of the average length to the average diameter of the pigment of at least 3, and the mean modulus of elasticity of the layers is not less than 15 Gpa in the longitudinal direction of the tape-like recording media.
    Type: Application
    Filed: March 19, 2001
    Publication date: October 4, 2001
    Inventors: August Lehner, Helmut Jakusch, Volker Koch, Manfred Ohlinger, Albert Kohl, Werner Lenz, Norbert Schneider, Peter Heilmann, Werner Hubner, Erich Hoffmann, Ronald John Veitch, Rudi Lehnert, Harald Jachow
  • Patent number: 6231963
    Abstract: Described are tape-type magnetic recording media (I) including a non-magnetic substrate (III), at least one film applied to the substrate and, in at least one of these films, an inorganic acicular pigment (II) suitable for use as a supporting pigment, the ratio of the mean length to the mean diameter of the pigment (II) being at least 3 and the mean modulus of elasticity of the films being not less than 15 GPa in the longitudinal direction of the tape-type recording medium (I).
    Type: Grant
    Filed: March 17, 1998
    Date of Patent: May 15, 2001
    Assignee: EMTEC Magnetics GmbH
    Inventors: August Lehner, Helmut Jakusch, Volker Koch, Manfred Ohlinger, Albert Kohl, Werner Lenz, Norbert Schneider, Peter Heilmann, Werner Hübner, Erich Hoffmann, Ronald John Veitch, Rudi Lehnert, Harald Jachow
  • Patent number: 5569409
    Abstract: A finely divided acicular CrO.sub.2 modified with iron, tellurium and/or antimony and having a high coercive force possesses improved heat stability of the residual induction and a relatively narrow distribution of the particle size and of the coercive force. This CrO.sub.2 pigment is obtained by a method in which the iron compound used for the modification is iron oxalate, which is employed in an amount of 1-10% by weight, based on the theoretical CrO.sub.2 yield.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: October 29, 1996
    Assignee: BASF Magnetics GmbH
    Inventors: Harald Jachow, Reinhard K orner, Ronald J. Veitch, Ekkehard Schwab, Helmut Jakusch, Bernd H oppner, Rudi Lehnert, Manfred Ohlinger
  • Patent number: 5378383
    Abstract: A magnetic recording medium comprising a nonmagnetic substrate and at least one magnetic layer applied thereon and containing an acicular chromium dioxide uniformly distributed in a polymeric binder and additives and having a coercive force of at least 60 kA/m, a mean particle length of the chromium dioxide of less than 300 nm, whose factor HD according to the formula ##EQU1## where KT is the coercive force of the magnetic layer in [kA/m], measured in an external field of 380 kA/m, L is the mean particle length and .DELTA.L is the range of the particle size distribution, determined from the numerical distribution of the particle length, both measured in [nm], is greater than 1.85, and a process for the preparation of this chromium dioxide.
    Type: Grant
    Filed: August 20, 1993
    Date of Patent: January 3, 1995
    Assignee: BASF Magnetics GmbH
    Inventors: Harald Jachow, Ekkehard Schwab, Reinhard Koerner, Norbert Mueller, Rudi Lehnert, Manfred Ohlinger, Helmut Auweter, Helmut Jakusch, Ronald J. Veitch, Michael Bobrich
  • Patent number: 5030371
    Abstract: An acicular, ferromagnetic material which has a high coercive force and essentially consists of iron-containing chromium dioxide is prepared by thermal decomposition of hydrated chromium(III) chromate under superatmospheric pressure.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: July 9, 1991
    Assignee: BASF
    Inventors: Michael W. Mueller, Ekkehard Schwab, Helmut Auweter, Rainer Feser, Rudi Lehnert, Norbert Mueller, Manfred Ohlinger