Patents by Inventor Wolfgang Hoffmeister

Wolfgang Hoffmeister 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).

  • Method of purifying ammonium fluoride solutions
    Patent number: 4000251
    Abstract: Newly precipitated MnO(OH).sub.2 is either added to an NH.sub.4 F solution that has been made slightly basic or this compound is formed in the NH.sub.4 F solution by adding an Mn (II) and an Mn (VII) salt solution. MnO(OH).sub.2 absorbs As and noble metal ions. The purity obtained is 10.sup..sup.-8 per cent by weight (starting from .ltoreq.10.sup..sup.-5 per cent by weight) of NH.sub.4 F solution.
    Type: Grant
    Filed: November 7, 1974
    Date of Patent: December 28, 1976
    Assignee: International Business Machines Corporation
    Inventors: Marian Briska, Wolfgang Hoffmeister
  • Method of etching materials containing silicon
    Patent number: 3971683
    Abstract: The invention relates to a method of etching solid, chemically resistant materials containing silicon (Si) by means of a hot melt made up of Society phosphorus pentoxide (P.sub.2 O.sub.5) and phosphoric acid (H.sub.3 PO.sub.4) (anhydrous).
    Type: Grant
    Filed: April 21, 1975
    Date of Patent: July 27, 1976
    Assignee: International Business Machines Corporation
    Inventors: Marian Briska, Wolfgang Hoffmeister, Herbert Kuhlmey