Patents by Inventor Donald D. Buerkley

Donald D. Buerkley 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: 4232083
    Abstract: Color-forming precursor compositions comprising a metal-complexing compound having a plurality of ligand groups and color-activating compositions comprising transition metal salts of oleophilic, organic acids are combined to form dark, permanent images on substrates. The methods and compositions are particularly useful for providing permanent fingerprints and other dermographs.
    Type: Grant
    Filed: July 22, 1975
    Date of Patent: November 4, 1980
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Donald D. Buerkley, Norman P. Sweeny, Daniel N. Vivona
  • Patent number: 4098738
    Abstract: The disclosed moldable compositions contain a metal salt which is a coreactant for, preferably, one of the conventional iron/polyhydric phenol image-forming reactions. The metal salt is dissolved in a liquid plasticizer, and the liquid plasticizer is blended with solid waxes to form a solid, substantially non-toxic, non-hygroscopic, moldable waxy material which is non-softening under normal conditions but which can easily be shaped, hot-melt coated, or the like at temperatures above 60.degree. C. The composition is useful for making wax imaging crayons and sheet-like dispensing means for the metal salt imaging chemical.
    Type: Grant
    Filed: May 25, 1976
    Date of Patent: July 4, 1978
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Donald D. Buerkley, Richard S. Law