Patents by Inventor Derek S. H. Smith

Derek S. H. Smith 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).

  • Pigment compositions
    Patent number: 4304711
    Abstract: A colored synthetic plastics mass having incorporated therein the calcium salt of the dyestuff from diazotized 2-nitroaniline-4-sulphonic acid and acetoacet-o-chloroanilide.
    Type: Grant
    Filed: March 16, 1979
    Date of Patent: December 8, 1981
    Assignee: Ciba-Geigy Corporation
    Inventor: Derek S. H. Smith