Patents by Inventor Howard J. Troffkin

Howard J. Troffkin 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 separator
    Patent number: 5281491
    Abstract: The present invention is directed to a multi-ply unfilled microporous sheet product composed of at least one first ply and at least one second ply which are, respectively, formed from polymeric compositions having different rheological properties and to a method of forming said sheet product.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: January 25, 1994
    Assignee: W. R. Grace & Co.
    Inventors: Burton M. Rein, Howard J. Troffkin, Robert M. Spotnitz, Richard T. Giovannoni, Yihong Guo
  • Process of making a battery separator
    Patent number: 5240655
    Abstract: A process of having a microporous multiply sheet product which is capable of becoming non-porous at a predetermined elevated transformation temperature is formed by first forming a non-porous, multiply initial sheet product having at least one first ply and at least one second ply, each with its own viscosity profile. The initial sheet product is then stretched and annealed to impart porosity to the sheet product.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: August 31, 1993
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Howard J. Troffkin, Burton M. Rein, Robert M. Spotnitz, Richard T. Giovannoni, Yihong Guo
  • Battery separator
    Patent number: 4731304
    Abstract: A multiply sheet product useful as a battery separator having at least two plies each in the form of a microporous sheet of predetermined length and breadth and a thickness of less than 10 mils wherein (a) at least one of said ply being a sheet capable of transforming to a substantially non-porous membrane at a temperature between about 80.degree. C. and 150.degree. C. while essentially maintaining its length and breadth dimensions and (b) at least one ply being a sheet capable of maintaining its dimensions and porosity at temperatures from ambient to at least about 10.degree. C. greater than the transformation temperature of sheet (a).
    Type: Grant
    Filed: December 3, 1986
    Date of Patent: March 15, 1988
    Assignee: W. R. Grace & Co.
    Inventors: Joseph T. Lundquist, Christian B. Lundsager, Nigel I. Palmer, Howard J. Troffkin
  • Battery separator
    Patent number: 4650730
    Abstract: A multiply sheet product useful as a battery separator having at least two plies each in the form of a microporous sheet of predetermined length and breadth and a thickness of less than 10 mils wherein (a) at least one of said ply being a sheet capable of transforming to a substantially non-porous membrane at a temperature between about 80.degree. and 150.degree. C. while essentially maintaining its length and breadth dimensions and (b) at least one ply being a sheet capable of maintaining its dimensions and porosity at temperatures from ambient to at least about 10.degree. C. greater than the transformation temperature of sheet (a).
    Type: Grant
    Filed: May 16, 1985
    Date of Patent: March 17, 1987
    Assignee: W. R. Grace & Co.
    Inventors: Joseph T. Lundquist, Christian B. Lundsager, Nigel I. Palmer, Howard J. Troffkin
  • Mortar topping with calcium nitrite
    Patent number: 4398959
    Abstract: Reinforced concrete structures often suffer corrosion damage. This damage is repaired by removing the layer of distressed concrete around the metal reinforcement and filling in the removed area with a high content calcium nitrite-containing cement based composition.
    Type: Grant
    Filed: February 25, 1982
    Date of Patent: August 16, 1983
    Assignee: W. R. Grace & Co.
    Inventors: Arnold M. Rosenberg, James M. Gaidis, Howard J. Troffkin
  • Gelled acrylic polymer
    Patent number: 4146368
    Abstract: The invention relates to a cross-linked composition of matter comprising acrylonitrile, (B) an acrylonitrile-soluble, carboxy group containing acrylic polymer capable of being cross-linked through the carboxy groups and (C) an acrylonitrile-soluble, carboxy group-reactive cross-linking agent. These compositions are fuel gels or flame agents which function over a wide spectrum of flame weapon applications including flame-throwers, shells and grenades.
    Type: Grant
    Filed: December 23, 1966
    Date of Patent: March 27, 1979
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Howard J. Troffkin, James J. Keavney