Patents by Inventor Avraham Metzer

Avraham Metzer 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).

  • Macrocrystalline aluminum oxide and method for its manufacture
    Patent number: 4308088
    Abstract: A method for producing hexagonal, laminar, alpha aluminum oxide monocrystals having a grain size of about 16 to about 250 microns, and a diameter to thickness ratio of about 3:1 to about 7:1. Aluminum hydroxide of particle size greater than 60 microns is calcined in the presence of a fluorine-containing mineralizer at a temperature of greater than 1200.degree. C. but no more than 1450.degree. C., and the desired grain size is separated from the calcinate.
    Type: Grant
    Filed: November 19, 1979
    Date of Patent: December 29, 1981
    Assignee: Giulini Chemi GmbH
    Inventors: Egon Cherdron, Heinz Hellinghausen, Alois Kramer, Horst Pohland, Avraham Metzer