Patents by Inventor Herbert Giesche

Herbert Giesche 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).

  • Spherical SIO.sub.2 particles
    Patent number: 4911903
    Abstract: Highly monodispersed nonporous spherical SiO.sub.2 particles are prepared having mean particle diameters between 0.05 and 10 .mu.m with a standard deviation of not more than 5% and a method for the preparation of such particles. The particles can be produced by a two step process wherein first a sol of primary particles is prepared by hydrolytic polycondensation of tetraalkoxysilanes in an aqueous/alcoholic ammoniacal medium. The SiO.sub.2 particles are then converted to the desired particle size by a continuous measured addition of tetraalkoxysilane or organotrialkoxysilane controlled by the extent of the reaction. The SiO.sub.2 particles produced by this process are particularly useful as sorption material in chromatography.
    Type: Grant
    Filed: July 12, 1988
    Date of Patent: March 27, 1990
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Klaus Unger, Herbert Giesche, Joachim Kinkel
  • Spherical SiO.sub.2 particles
    Patent number: 4775520
    Abstract: Highly monodispersed nonporous spherical SiO.sub.2 particles are prepared having mean particle diameters between 0.05 and 10 .mu.m with a standard deviation of not more than 5% and a method for the preparation of such particles. The particles can be produced by a two step process wherein first a sol of primary particles is prepared by hydrolytic polycondensation of tetraalkoxysilanes in an aqueous/alcoholic ammoniacal medium. The SiO.sub.2 particles are then converted to the desired particle size by a continuous measured addition of tetraalkoxysilane or organotrialkoxysilane controlled by the extent of the reaction. The SiO.sub.2 particles produced by this process are particularly useful as sorption material in chromatography.
    Type: Grant
    Filed: September 25, 1986
    Date of Patent: October 4, 1988
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Klaus Unger, Herbert Giesche, Joachim Kinkel