Patents by Inventor David H. Durham

David H. Durham 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).

  • Dyed hectorite pigments and applications
    Patent number: 5296284
    Abstract: A coloring pigment useful for coloring or tinting inks, paints, plastics and rubber comprises the reaction product of a cationic organic dye and a hectorite mineral, the hectorite mineral having a small average particle size and a high cation exchange capacity. The pigment has excellent color strength and does not bleed in water or oil and is easily dispersable in aqueous and organic media.
    Type: Grant
    Filed: September 29, 1992
    Date of Patent: March 22, 1994
    Assignee: J. M. Huber Corporation
    Inventor: David H. Durham
  • Organokaolin pigments in ink formulations
    Patent number: 5137568
    Abstract: Dispersibility of extender pigments in ink formulations is improved by using as the extender pigment, a quaternary ammonium treated kaolin clay.
    Type: Grant
    Filed: May 16, 1991
    Date of Patent: August 11, 1992
    Assignee: J.M. Huber Corporation
    Inventors: David H. Durham, Michael Pugliese