Patents by Inventor Steven L. Johnson

Steven L. Johnson 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).

  • Conditioning crude phthalocyanine pigments
    Patent number: 4448607
    Abstract: Crude phthalocyanine is converted from its crude state to its pigmentary form by (1) milling it with a phthalimidomethyl phthalocyanine derivative or a sulfonated phthalimidomethyl phthalocyanine derivative in the absence of any milling or grinding aid or by (2) grinding the crude phthalocyanine in the absence of any milling or grinding aid and then blending the ground material with a phthalimidomethyl phthalocyanine derivative or a sulfonated phthalimidomethyl phthalocyanine derivative. Without any additional conditioning or purification the pigment product is suitable for use in printing inks, paints, coating compositions, and the like.
    Type: Grant
    Filed: September 20, 1982
    Date of Patent: May 15, 1984
    Assignee: Sun Chemical Corporation
    Inventors: Steven L. Johnson, George McLaren, George H. Robertson