Patents by Inventor Frederic Levet

Frederic Levet 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).

  • Process for crystallizing an adduct of 2,2-di(4-hydroxyphenyl) propane and phenol
    Patent number: 4209646
    Abstract: 2,2-di(4-hydroxyphenyl) propane, i.e., diphenylolpropane, is purified by preparing a liquid mixture of raw diphenylolpropane, phenol and water and applying reduced pressure thereto corresponding to the vapor pressure of the mixture while simultaneously cooling same whereby an adduct of pure diphenylolpropane and phenol is crystallized.
    Type: Grant
    Filed: September 26, 1977
    Date of Patent: June 24, 1980
    Assignee: Rhone-Poulenc Industries
    Inventors: Robert Gac, Jean-Pierre Dal Pont, Frederic Levet