Patents by Inventor Ludwig K. Schuster

Ludwig K. Schuster 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).

  • Aqueous coating compositions for asbestos-cement and the like
    Patent number: 3947397
    Abstract: Pigmented, in situ reduced zinc dichromate coatings on asbestos-cement and similar surfaces are made more reproducible in color by including as at least a portion of the reducing agent a hexitol or pentitol such as sorbitol, or a low alkanolamine, or mixtures of these. An acid like phosphoric acid that forms a water-insoluble calcium salt but does not precipitate the zinc can also be added to the coating formulation.
    Type: Grant
    Filed: February 28, 1974
    Date of Patent: March 30, 1976
    Assignee: Pennwalt Corporation
    Inventors: Ludwig K. Schuster, Singkata Tongyai