Patents by Inventor Otto Zeller

Otto Zeller 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).

  • Process for preparing water-repellent articles from gypsum powder containing hydrophobic agents
    Patent number: 4851047
    Abstract: The present invention relates to gypsum powders containing a hydrophobic agent and to water-repellent articles which are prepared from gypsum containing powered hydrophobic agents, in which the hydropohobic agents are prepared by spray-drying a mixture containing at least water, an organopolysiloxane having Si-bonded hydrogen and a water-soluble, film-forming polymer having a turbidity point of from 35.degree. to 98.degree. C.
    Type: Grant
    Filed: January 11, 1988
    Date of Patent: July 25, 1989
    Assignee: Wacker-Chemie GmbH
    Inventors: Ulrich Demlehner, Herbert Eck, Heinrich Hopf, Erich Pilzweger, Otto Zeller