Patents by Inventor Martin Alec Williamson

Martin Alec Williamson 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).

  • Composite pigmentary material
    Patent number: 5643974
    Abstract: A process for the production of a structured composite pigmentary material in the form of a dispersion comprises mixing an aqueous dispersion of inorganic pigmentary particles and an aqueous dispersion of polyvinyl chloride (PVC) particles. The inorganic pigment particles carry a positive surface charge and the PVC particles carry a negative surface charge and the particles in the composite are held in association as a result of these charges. The inorganic pigment particles and PVC particles are mixed in the presence of a surfactant system which provides both anionic and steric stabilisation.
    Type: Grant
    Filed: February 6, 1996
    Date of Patent: July 1, 1997
    Assignee: Tioxide Group Services Limited
    Inventors: Leslie Ainsley Simpson, Keith Robson, David Trevor Knight, Martin Alec Williamson