Patents by Inventor David G. S. Walton

David G. S. Walton 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).

  • Patent number: 8962214
    Abstract: Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.
    Type: Grant
    Filed: January 17, 2014
    Date of Patent: February 24, 2015
    Assignee: 3M Innovative Properties Company
    Inventors: Samantha D. Smith, Gene H. Shipman, Robert M. Floyd, Harold Todd Freemyer, Steven J. Hamrock, Michael A. Yandrasits, David G. S. Walton
  • Publication number: 20140134518
    Abstract: Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.
    Type: Application
    Filed: January 17, 2014
    Publication date: May 15, 2014
    Applicant: 3M INNOVATIVE PROPERTIES COMPANY
    Inventors: Samantha D. Smith, Gene H. Shipman, Robert M. Floyd, Harold Todd Freemyer, Steven J. Hamrock, Michael A. Yandrasits, David G. S. Walton
  • Patent number: 8663868
    Abstract: Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.
    Type: Grant
    Filed: January 15, 2008
    Date of Patent: March 4, 2014
    Assignee: 3M Innovative Properties Company
    Inventors: Samantha D. Smith, Gene H. Shipman, Robert M. Floyd, Harold Todd Freemyer, Steven J. Hamrock, Michael A. Yandrasits, David G. S. Walton
  • Patent number: 7338692
    Abstract: Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: March 4, 2008
    Assignee: 3M Innovative Properties Company
    Inventors: Samantha D. Smith, Gene H. Shipman, Robert M. Floyd, Harold Todd Freemyer, Steven J. Hamrock, Michael A. Yandrasits, David G. S. Walton