Patents by Inventor Felix J. DeRooy

Felix J. DeRooy 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).

  • Composition for accelerating the setting of calcined gypsum and the product formed thereby
    Patent number: 4059456
    Abstract: A composition for accelerating the setting of an aqueous calcined gypsum slurry, the composition comprising finely ground calcium sulfate dihydrate and a lignosulfonate. The composition, when added to an aqueous calcined gypsum slurry, accelerates the setting process and shortens the set time period as determined by the temperature rise set test procedure. The composition is useful for making gypsum wallboard.
    Type: Grant
    Filed: October 21, 1975
    Date of Patent: November 22, 1977
    Assignee: United States Gypsum Company
    Inventors: Felix J. DeRooy, Thell D. Daniel, Erle C. Annes, Billy G. Arnold