Patents by Inventor Doug R. Campbell

Doug R. Campbell 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).

  • Aqueous dye preparations
    Patent number: 5891227
    Abstract: Aqueous dye preparations useful for producing inks for the inkjet process or writing inks or for producing aqueous alcoholic coating or printing colors comprise, based on the weight of the preparation, from 0.1 to 15% by weight of a dye quantity comprising from 90 to 100% by weight of the dye of the formula I ##STR1## where Kat.sup..sym. is the equivalent of a metal or ammonium ion, from 1 to 40% by weight of carbon black and from 0.1 to 15% by weight of polyethylene glycol.
    Type: Grant
    Filed: August 14, 1997
    Date of Patent: April 6, 1999
    Assignee: BASF Aktiengesellschaft
    Inventors: Dietrich Hoffmann, Ulrike Schlosser, Erwin Czech, Walter Kurtz, Karin Heidrun Beck, Doug R. Campbell, Helmut Bellaire, Horst Belde