Patents by Inventor Willem W. Nijholt

Willem W. Nijholt 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).

  • Patent number: 4983591
    Abstract: A combination of pyrethrum and fatty acid salt materials has been formulated which produces a stable, commercially useful, and environmentally safe pesticide. The specific composition comprises an aqueous solution having a pH within the range of 7.5 to 8.8; an aqueous solution comprising at least about 0.5 percent by weight of monocarboxylic acids and their alkali metal salts, where the acid mixture is at least 70% oleic acid and 6% linoleic acid; a pyrethrum extract; a solvent for the pyrethrum, which is preferably a 2-6 carbon alcohol; a trace amount of an antioxidant. The composition is effective against insects of at least the orders Homoptera, Coleoptera, Dermaptera, Hemiptera, and Lepidoptera, and against crustacea of the order Isopoda.
    Type: Grant
    Filed: November 6, 1989
    Date of Patent: January 8, 1991
    Assignee: Safer, Ltd.
    Inventors: George S. Puritch, Gregory S. Salloum, Willem W. Nijholt
  • Patent number: 4904645
    Abstract: A combination of pyrethrum and fatty acid salt materials has been formulated which produces a stable, commercially useful, and environmentally safe pesticide. The specific composition comprises an aqueous solutioon having a pH within the range of 7.5 to 8.8; an aqueous solution comprising about 50% by weight of monocarboxylic acids and their alkali metal salts, where the acid mixture is at least 70% oleic acid and 6% linoleic acid; a pyrethrum extract; a solvent for the pyrethrum, which is preferably a 2-6 carbon alcohol; a trace amount of an antioxidant. The composition is effective against insects of at least the orders Homoptera, Coleoptera, Dermaptera, Hemiptera, and Lepidoptera, and against crustacea of the order Isopoda.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: February 27, 1990
    Assignee: Safer, Ltd.
    Inventors: George S. Puritch, Gregory S. Salloum, Willem W. Nijholt