Patents by Inventor David T. Williamson

David T. 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).

  • Publication number: 20080315453
    Abstract: A method for dispersing sepiolite-type clay particles in a polyester matrix by melt-compounding a mixture of: sepiolite-type clay, at least one linear polyester oligomer, and at least one polyester polymer to produce a nanocomposite composition; and, optionally, subjecting said nanocomposite composition to solid state polymerization to increase polyester molecular weight. Further described is a method for preparing a polyester nanocomposite composition from a masterbatch, comprising melt-compounding a mixture of: sepiolite-type clay, at least one polyester oligomer, and at least one polyester polymer to produce a nanocomposite composition containing a greater concentration of sepiolite-type clay than is desired in the final resin composition; optionally, subjecting said nanocomposite composition to solid state polymerization to increase the polyester molecular weight; and further melt compounding said nanocomposite composition with polyester polymer and, optionally, additional ingredients.
    Type: Application
    Filed: June 22, 2007
    Publication date: December 25, 2008
    Inventors: Michael Joseph Molitor, Mark Gary Weinberg, Mark David Wetzel, David T. Williamson
  • Publication number: 20080261062
    Abstract: Compositions of thermoplastic polyesters and sepiolite-type clay in which the clay is dispersed in the polyester as often fibrous particles whose smallest dimension is less than 100 nm are made by polymerizing the polyester precursors in the presence of the clay. The compositions have good physical properties and can be melt molded into various articles. Many of these articles may be coated (painted) and are especially useful for appearance parts such as visible exterior automotive body parts.
    Type: Application
    Filed: December 21, 2005
    Publication date: October 23, 2008
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: David T. Williamson, Thomas M. Herrod, William M. Simmons, Henry Max Schleinitz
  • Patent number: 6699941
    Abstract: The present invention relates to selectively hydrogenated block copolymers where one of the blocks is a random copolymer of a mono-alkenyl arene monomer, such as styrene, and a 1,3-cyclodiene monomer, such as 1,3-cyclohexadiene, and one of the other blocks is a hydrogenated polymer or copolymer of an acyclic conjugated diene, such as 1,3-butadiene or isoprene.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: March 2, 2004
    Assignee: Kraton Polymers U.S. LLC
    Inventors: Dale L. Handlin, David T. Williamson, Carl L. Willis