Patents by Inventor Richard Vandahm

Richard Vandahm 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).

  • Anthraquinone colorant compositions and methods for producing the same
    Publication number: 20060117499
    Abstract: This invention relates to compositions of N,N?-dialkyleneoxy-substituted 1,4-diaminoanthraquinone colorants which contain a low percentage of impurities, to a process to make the compositions, and also to the use of the compositions thus prepared for coloring consumer products.
    Type: Application
    Filed: December 8, 2004
    Publication date: June 8, 2006
    Inventors: X. Hong, Robert Mahaffey, Eric Stephens, Richard Vandahm