Patents by Inventor Herman J. J. M. Geurta

Herman J. J. M. Geurta 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).

  • Orthorhombic greenish-tinged lead chromate pigments
    Patent number: 4921541
    Abstract: Orthorhombic greenish-tinged lead chromate pigments containing lead chromate and lead sulfate in a weight ratio of 91:9 to 100:0 and distinguished by a tinctorial strength of 0.053 to 0.066 at a standard depth of color of 1/25 in accordance with DIN 53235 are obtainable by mixing an aqueous solution of a lead salt with an aqueous solution of a chromate and, if necessary, of a sulfate under high turbulence in the presence of an aluminium salt and in the absence of zinc salts.
    Type: Grant
    Filed: May 25, 1988
    Date of Patent: May 1, 1990
    Assignee: Ciba-Geigy Corporation
    Inventors: Leonardus J. H. Erkens, Herman J. J. M. Geurta, Jean L. G. M. Vandevenne, Gerben P. Algra