Patents by Inventor Charles Winfield Stewart

Charles Winfield Stewart 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).

  • In situ fluoropolymer polymerization into porous substrates
    Patent number: 6916549
    Abstract: The present invention relates to in situ polymerization of fluoropolymer into porous substrates, to improve resistance to degradation by wetting and staining, and wood, to improve resistance to degradation, staining and warping.
    Type: Grant
    Filed: March 5, 2003
    Date of Patent: July 12, 2005
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: John Russell Crompton, Jr., James M. Donatello, Kiu-Seung Lee, Charles Winfield Stewart, Robert Clayton Wheland
  • In situ fluoropolymer polymerization into porous substrates
    Publication number: 20030162030
    Abstract: The present invention relates to in situ polymerization of fluoropolymer into porous substrates, to improve resistance to degradation by wetting and staining, and wood, to improve resistance to degradation, staining and warping.
    Type: Application
    Filed: March 5, 2003
    Publication date: August 28, 2003
    Inventors: John Russell Crompton, James M. Donatello, Kiu-Seung Lee, Charles Winfield Stewart, Robert Clayton Wheland
  • Amorphous tetrafluoroethylene-hexafluoropropylene copolymers
    Patent number: 6486280
    Abstract: Disclosed herein are novel amorphous tetrafluoroethylene-hexafluoropropylene (TFE-HFP) dipolymers, and other copolymers containing TFE, HFP and a third monomer, many of which are more random than previous amorphous TFE-HFP copolymers, as well as a novel high productivity continuous process for making these polymers. The polymers are particularly useful in the form of coatings, films and encapsulants.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: November 26, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Colin Anolick, Viacheslav Alexandrovich Petrov, Bruce Edmund Smart, Charles Winfield Stewart, Robert Clayton Wheland, William Brown Farnham, Andrew Edward Feiring, Weiming Qiu
  • Amorphous tetrafluoroethylene-hexafluoropropylene copolymers
    Patent number: 6133389
    Abstract: Disclosed herein are novel amorphous tetrafluoroethylene-hexafluoropropylene (TFE-HFP) dipolymers, and other copolymers containing TFE, HFP and a third monomer, many of which are more random than previous amorphous TFE-HFP copolymers, as well as a novel high productivity continuous process for making these polymers. The polymers are particularly useful in the form of coatings, films and encapsulants.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: October 17, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Colin Anolick, Viacheslav Alexandrovich Petrov, Bruce Edmund Smart, Charles Winfield Stewart, Robert Clayton Wheland, William Brown Farnham, Andrew Edward Feiring, Weiming Qiu
  • Thermoplastic fluoropolymer containing elastomer and production process therefor
    Patent number: 6124403
    Abstract: Polymer compositions containing a mixture of an elastomer and a fluoropolymer can be made by diffusing fluorinated olefins and free radical initiators in preferably swollen elastomers and polymerizing the fluorinated olefins. The resulting compositions have useful properties, such as reduced sliding friction, which makes them useful for seals in contact with moving surfaces, and for other uses.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: September 26, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: John Russell Crompton, Jr., Charles Winfield Stewart, Sr., Robert Clayton Wheland
  • Extrusion foaming of fluoropolymers
    Patent number: 5821273
    Abstract: Fluoropolymer resin is extrusion foamed at low temperature using carbon dioxide as the foaming agent.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: October 13, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Sundar Kilnagar Venkataraman, Charles Winfield Stewart, Maurice Armand Baumann
  • Fluoropolymer nanocomposites
    Patent number: 5726247
    Abstract: This invention relates to a fluoropolymer nanocomposite comprising a fluoropolymer phase and an inorganic oxide phase dispersed throughout, said inorganic oxide phase having either no particles or particles substantially all of which have a particle size of less than about 75 nm which can be determined by small angle x-ray scattering and transmission electron microscopy techniques. These nanocomposites are useful as protective coatings.
    Type: Grant
    Filed: June 14, 1996
    Date of Patent: March 10, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Michael Joseph Michalczyk, Kenneth George Sharp, Charles Winfield Stewart
  • Processing aid system for polyolefins
    Patent number: 5707569
    Abstract: Polar-side-group-containing extrusion adjuvants, such as ethylene diamine tetraacetic acid or ionomer, that counteract the deleterious effect of certain additives such as zinc stearate, used in polyolefins on the performance of fluoropolymer processing aids in polyolefins are taught.
    Type: Grant
    Filed: February 15, 1994
    Date of Patent: January 13, 1998
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Donnan Edwin Priester, Charles Winfield Stewart