Patents by Inventor David S. Bignell

David S. Bignell 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).

  • Addition polymer particles
    Patent number: 5244737
    Abstract: Very small (100 nanometres maximum) non-ionically-stabilised core-sheath addition polymer particles, wherein the core is addition polymer and the sheath polyoxyalkylene chains, at least a portion of which chains are bonded to the core, there being present on each core sufficient chains such that the mass ratio of core to sheath is from 98:2 to 60:40. The particles are prepared by polymerisation in aqueous media initiated at under 40.degree. C. In a preferred embodiment, a seed-feed process is used. The dispersions exhibit excellent rheological characteristics and are useful, for example, as film-formers in coating compositions.
    Type: Grant
    Filed: June 10, 1992
    Date of Patent: September 14, 1993
    Assignee: ICI Australia Operations Proprietary Limited
    Inventors: Geoffrey B. Anderson, David S. Bignell, Iain B. Cook, Bruce Leary, Christopher J. Lyons
  • Addition polymer particles
    Patent number: 5141814
    Abstract: Very small (100 nanometers maximum) non-ionically-stabilized core-sheath addition polymer particles, wherein the core is addition polymer and the sheath polyoxylkylene chains, at least a portion of which chains are bonded to the core, there being present on each core sufficient chains such that the mass ratio of core to sheath is from 98:2 to 60:40. The particles are prepared by polymerization in aqueous media initiated at under 40.degree. C. In a preferred embodiment, a seed-feed process is used. The dispersions exhibit excellent rheological characteristics and are useful, for example, as film-formers in coating compositions.
    Type: Grant
    Filed: March 23, 1990
    Date of Patent: August 25, 1992
    Assignee: ICI Australia Operations Proprietary Ltd.
    Inventors: Geoffrey B. Anderson, David S. Bignell, Iain B. Cook, Bruce Leary, Christopher J. Lyons