Patents by Inventor Paul F. Duffer

Paul F. Duffer 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).

  • Method of applying interleaving material to glass sheets
    Patent number: 4606946
    Abstract: A method is disclosed for applying a powdered interleaving material to a glass surface in the form of an aqueous composition comprising particulate interleaving material dispersed in atomized water.
    Type: Grant
    Filed: July 12, 1985
    Date of Patent: August 19, 1986
    Assignee: PPG Industries, Inc.
    Inventors: Paul F. Duffer, Joseph D. Kelly, Helmut Franz
  • Acidified powdered interleaving
    Patent number: 4568605
    Abstract: A method and composition utilizing porous particulate interleaving material treated with a strong organic acid are disclosed to reduce staining of stacked glass sheets.
    Type: Grant
    Filed: January 30, 1985
    Date of Patent: February 4, 1986
    Assignee: PPG Industries, Inc.
    Inventors: Paul F. Duffer, Helmut Franz, Joseph D. Kelly
  • Acidified powdered interleaving
    Patent number: 4530889
    Abstract: A method and composition utilizing porous particulate interleaving material treated with a strong organic acid are disclosed to reduce staining of stacked glass sheets.
    Type: Grant
    Filed: January 28, 1981
    Date of Patent: July 23, 1985
    Assignee: PPG Industries, Inc.
    Inventors: Paul F. Duffer, Helmut Franz, Joseph D. Kelly
  • Method of applying interleaving material to glass sheets
    Patent number: 4529648
    Abstract: A method is disclosed for applying a powdered interleaving material to a glass surface in the form of an aqueous slurry.
    Type: Grant
    Filed: January 28, 1981
    Date of Patent: July 16, 1985
    Assignee: PPG Industries, Inc.
    Inventors: Paul F. Duffer, Joseph D. Kelly, Helmut Franz
  • Two step interleaving method
    Patent number: 4489106
    Abstract: A method is disclosed for protecting glass surfaces in a stack of glass sheets by treating the surfaces with a stain-inhibiting organic hydroxy acid and separating adjacent surfaces with an interleaving material.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: December 18, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Paul F. Duffer, Helmut Franz, Joseph D. Kelly
  • Mixed acid stain inhibitor
    Patent number: 4487807
    Abstract: A method is disclosed for protecting glass surfaces in a stack of glass sheets by treating the surfaces with a mixture of stain-inhibiting organic acids which crystallize on the glass, and separating adjacent surfaces with an interleaving material.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: December 11, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Paul F. Duffer, Joseph D. Kelly, Helmut Franz
  • Organotin surface treatment and interleaving material for glass sheets
    Patent number: 4447496
    Abstract: A method is disclosed for protecting glass surfaces in a stack of glass sheets by treating the surfaces with an organotin compound and separating adjacent surfaces with an interleaving material.
    Type: Grant
    Filed: July 23, 1982
    Date of Patent: May 8, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Helmut Franz, Paul F. Duffer, Joseph D. Kelly
  • Organotin surface treatment and interleaving material for glass sheets
    Patent number: 4360544
    Abstract: A method is disclosed for protecting glass surfaces in a stack of glass sheets by treating the surfaces with an organotin compound and separating adjacent surfaces with an interleaving material.
    Type: Grant
    Filed: January 28, 1981
    Date of Patent: November 23, 1982
    Assignee: PPG Industries, Inc.
    Inventors: Helmut Franz, Paul F. Duffer, Joseph D. Kelly
  • Method for making dimethyltin difluoride
    Patent number: 4254046
    Abstract: A method is disclosed for making dimethyltin difluoride by reacting dimethyltin dichloride with an alkali metal or ammonium fluoride salt.
    Type: Grant
    Filed: February 5, 1979
    Date of Patent: March 3, 1981
    Assignee: PPG Industries, Inc.
    Inventors: Helmut Franz, Paul F. Duffer, James H. Hanlon