Patents by Inventor Lothar Kaul

Lothar Kaul 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 of forming phosphate coatings on metal surfaces
    Patent number: 5203930
    Abstract: A process for forming phosphate coatings on metal surfaces is provided which comprises the steps of contacting said metal surface with an Fe(II)-containing phosphating solution comprising0.4 to 30 g/l Zn4 to 30 g/l P.sub.2 O.sub.55 to 50 g/l NO.sub.3up to 10 g/l Fe(II) ; andup to 0.3 g/l (Fe(III)wherein the weight ratio of free P.sub.2 O.sub.5 to total P.sub.2 O.sub.5 is (0.04 to 0.50):1 and, replenishing said phosphating solution with Zn, NO.sub.3 and P.sub.2 O.sub.5 in a weight ratio ofZn:NO.sub. 3 P.sub.2 O.sub.5 =(0.60 to 0.30):(0.2 to 0.4):1.wherein the Fe(II) content is adjusted by oxidation with nitrate or nitrite derived from nitrate optionally employed with an oxygen-containing gas, H.sub.2 O.sub.
    Type: Grant
    Filed: August 21, 1990
    Date of Patent: April 20, 1993
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Georg Blumlhuber, Horst Gehmecker, Dieter Hauffe, Lothar Kaul, Thomas Nitschke, Werner Rausch, Hardy Wietzoreck