Patents by Inventor Robert W. Callahan

Robert W. Callahan 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: 7119126
    Abstract: The polymer matrix material includes a polymerization product of one or more monomers selected from the group of water-soluble, ethylenically-unsaturated acids and acid derivatives, and a crosslinking agent. A quantity of water is used for polymerization, such that the polymer material is swelled to a defined volume upon curing. Optionally, a water-soluble or water-swellable polymer and/or a chemical polymerization initiator.
    Type: Grant
    Filed: April 5, 2004
    Date of Patent: October 10, 2006
    Assignee: eVionyx, Inc.
    Inventors: Robert W. Callahan, Mark G. Stevens, Muguo Chen
  • Patent number: 6849702
    Abstract: The polymer matrix material includes a polymerization product of one or more monomers selected from the group of water-soluble, ethylenically-unsaturated acids and acid derivatives, and a crosslinking agent. A quantity of water is used for polymerization, such that the polymer material is swelled to a defined volume upon curing. Optionally, a water-soluble or water-swellable polymer and/or a chemical polymerization initiator.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: February 1, 2005
    Inventors: Robert W. Callahan, Mark G. Stevens, Muguo Chen
  • Publication number: 20040266895
    Abstract: The polymer matrix material includes a polymerization product of one or more monomers selected from the group of water-soluble, ethylenically-unsaturated acids and acid derivatives, and a crosslinking agent. A quantity of water is used for polymerization, such that the polymer material is swelled to a defined volume upon curing. Optionally, a water-soluble or water-swellable polymer and/or a chemical polymerization initiator.
    Type: Application
    Filed: April 5, 2004
    Publication date: December 30, 2004
    Inventors: Robert W. Callahan, Mark G. Stevens, Muguo Chen
  • 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
  • Publication number: 20020012848
    Abstract: An electrochemical cell using a polymer matrix material includes a polymerization product of one or more monomers selected from the group of water-soluble, ethylenically-unsaturated acids and acid derivatives, and a crosslinking agent. A quantity of water is used for polymerization, such that the polymer material is swelled to a defined volume upon curing. Optionally, a water-soluble or water-swellable polymer and/or a chemical polymerization initiator.
    Type: Application
    Filed: August 30, 2001
    Publication date: January 31, 2002
    Inventors: Robert W. Callahan, Mark G. Stevens, Muguo Chen
  • Publication number: 20020010261
    Abstract: The polymer matrix material includes a polymerization product of one or more monomers selected from the group of water-soluble, ethylenically-unsaturated acids and acid derivatives, and a crosslinking agent. A quantity of water is used for polymerization, such that the polymer material is swelled to a defined volume upon curing. Optionally, a water-soluble or water-swellable polymer and/or a chemical polymerization initiator.
    Type: Application
    Filed: August 30, 2001
    Publication date: January 24, 2002
    Inventors: Robert W. Callahan, Mark G. Stevens, Muguo Chen
  • Patent number: 6287730
    Abstract: The present invention is directed to a hydrophilic polyolefin article comprising a polyolefin article having a coating containing a surfactant and an ethylene vinyl alcohol (EVOH) copolymer.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: September 11, 2001
    Assignee: Celgard Inc.
    Inventors: Robert W. Callahan, Khuy Van Nguyen
  • Patent number: 6057061
    Abstract: The present invention is directed to a battery separator being an oriented microporous film containing ethylene vinyl alcohol copolymer with a filler, and a battery containing that separator.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: May 2, 2000
    Assignee: Celgard Inc.
    Inventors: Robert W. Callahan, Hongkyu Kim
  • Patent number: 5102552
    Abstract: A composite membrane is disclosed having a microporous support which is coated with a UV curable polymer composition having a sufficiently high viscosity to prevent pore filling upon coating and curing. A process for making and a process for using the membrane is also disclosed.
    Type: Grant
    Filed: September 25, 1990
    Date of Patent: April 7, 1992
    Assignee: Hoechst Celanese Corporation
    Inventors: Robert W. Callahan, Richard D. Johnson
  • Patent number: 4976897
    Abstract: A composite membrane is disclosed having a microporous support which is coated with a UV curable polymer composition having a sufficiently high viscosity to prevent pore filling upon coating and curing. A process for making and a process for using the membrane is also disclosed.
    Type: Grant
    Filed: December 16, 1987
    Date of Patent: December 11, 1990
    Assignee: Hoechst Celanese Corporation
    Inventors: Robert W. Callahan, Richard D. Johnson
  • Patent number: 4976867
    Abstract: Systems and methods for predetermining maximum pressure differentials for particular microporous hollow fiber membranes and essentially immiscible feed and extractant liquids to be employed in liquid-liquid extractions include a test module having a number of such fibers formed into a loop between the opposing ends thereof. A tubular sleeve element encompasses these opposing ends, and a potting compound positionally retains the opposing ends within the tubular sleeve. The hollow fiber lumens are fluid-connected to a reservoir containing a pressurized feed liquid, and the loops of hollow fiber are immersed in an essentially unpressurized extractant liquid. The pressure of the feed liquid is continually increased until there is an incipient presence of the feed liquid in the extractant liquid. The pressure of the feed liquid at that incipient presence may therefore be used to calculate a maximum pressure differential tolerated by the microporous hollow fibers for the feed and extractant liquids used.
    Type: Grant
    Filed: April 5, 1989
    Date of Patent: December 11, 1990
    Assignee: Hoechst Celanese Corporation
    Inventors: Robert W. Callahan, Bradley W. Reed
  • Patent number: 4972317
    Abstract: A microprocessor chip which is capable of executing a specific subset of instructions on behalf of the main storage portion of a computer memory can be made to emulate direct execution instructions not in that specific subset while working on behalf a control storage portion of the computer memory in a manner which is transparent to the main storage portion by means of a novel set of operand space selection instructions in the control storage portion and a novel switching circuit on the microprocessor chip which controls the access of the chip to the control store portion and the main store portion.
    Type: Grant
    Filed: August 4, 1989
    Date of Patent: November 20, 1990
    Assignee: International Business Machines Corp.
    Inventors: Joseph P. Buonomo, Robert W. Callahan, Steven R. Houghtalen, Sivarama K. Kodukula, Raymond E. Losinger, Brion N. Shimamoto, Harry L. Tredennick, James W. Valashinas
  • Patent number: 4966707
    Abstract: The rate of mass transfer in liquid/liquid extractions can be increased by the appropriate selection of a solubilizing liquid to wet a microporous membrane. A solute is transferred between immiscible liquids across the membrane where and interface between the liquids is immobilized at a surface of the membrane.
    Type: Grant
    Filed: May 13, 1986
    Date of Patent: October 30, 1990
    Assignee: Celanese Corporation
    Inventors: Edward L. Cussler, Robert W. Callahan, Paul R. Alexander, Jr.