Patents by Inventor Willi Birnstiel

Willi Birnstiel 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).

  • Acidic chromium containing coating solution for zinc or cadmium surfaces
    Patent number: 4705576
    Abstract: An aqueous acidic trivalent chromium and fluoride containing coating (passivating) solution for zinc, zinc alloy and cadmium surfaces contains one or more complex compounds of the formula[Cr(H.sub.2 O).sub.6-x F.sub.x ].sup.(3-x)+ A.sup.-wherein x is an integer of from 1 to 3 and A is an anion of the group selected from nitrate, sulfate, phosphate, chloride, bromide, fluoride and iodide. In particular the solution contains a soluble nitrate in an amount greater than the cromium(III)concentration and before application the solution is either heated to at least 60.degree. C. or treated with a catalyst at a temperature above 15.degree. C.
    Type: Grant
    Filed: November 3, 1986
    Date of Patent: November 10, 1987
    Assignee: Elektro-Brite GmbH
    Inventors: Klaus-Peter Klos, Karl-Heinz Lindemann, Willi Birnstiel