Patents by Inventor Ron W. Call

Ron W. Call 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).

  • Battery separators with reduced splitting propensity
    Patent number: 6602593
    Abstract: A split resistant microporous membrane is provided for use in preparing a battery separator. The microporous membrane has a TD tensile strength to MD tensile strength ratio of from about 0.12 to about 1.2, preferably from about 0.5 to about 1. The microporous membrane is made by a process which includes the steps of preparing a film precursor by blown film extrusion at a blow-up ratio of at least 1.5, annealing the film precursor, and stretching the resultant annealed film precursor to form the microporous membrane.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: August 5, 2003
    Assignee: Celgard Inc.
    Inventors: Robert W. Callahan, Ron W. Call, Ken J. Harleson, Ta-Hua Yu