Patents by Inventor Mary B. Letscher

Mary B. Letscher 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).

  • Use of surfactants having an HLB less than 10 in the deinking of dry toner electrostatic printed wastepaper
    Patent number: 5200034
    Abstract: A method for deinking dry toner electrostatic printed wastepaper is disclosed. The method includes administering a sufficient amount of an ethoxylated surfactant, propoxylated surfactant, esterified surfactant or alkanolamide surfactant having an HLB value of less than 10.0 to a sample of electrostatic printed wastepaper for which treatment is desired.
    Type: Grant
    Filed: April 25, 1991
    Date of Patent: April 6, 1993
    Assignee: Betz PaperChem, Inc.
    Inventors: Sandra K. Richmann, Mary B. Letscher
  • Use of anionic surfactant/dispersant blends for the deinking of groundwood newsprint
    Patent number: 5094716
    Abstract: A composition and method for the improved deinking of groundwood newsprint is disclosed. The composition comprises an amount, effective for the intended purpose, of: 1) an anionic surfactant, e.g., the ammonium or sodium salts of a sulfated ethoxylate derived from a 12 to 14 carbon linear primary alcohol blend, and 2) a dispersant, e.g., naphthalene-formaldehyde condensates.The method comprises administering a sufficient amount of this combined treatment to a sample of groundwood newsprint for which treatment is desired.
    Type: Grant
    Filed: September 19, 1990
    Date of Patent: March 10, 1992
    Assignee: Betz PaperChem, Inc.
    Inventor: Mary B. Letscher