Patents by Inventor John Darrel Walker

John Darrel Walker 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).

  • Silanized titanium dioxide pigments resistant to discoloration when incorporated in polymers
    Patent number: 5707437
    Abstract: Titanium dioxide pigment particles with treatment of an organosilicon compound and boric acid and/or boron oxide is disclosed. The product has a greater resistance to becoming discolored upon exposure to ultraviolet light when incorporated in polymers, particularly polyolefins such as polyethylene.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: January 13, 1998
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Philipp Martin Niedenzu, John Darrel Walker, Laura Faye McClure