Patents by Inventor Paul Gesche

Paul Gesche 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).

  • Patent number: 5417908
    Abstract: Process for making a polyester having polyethylene terephthalate units including transesterifying a terephthalic acid ester with a glycol using a manganese salt as catalyst and then subjecting the product to a polycondensation reaction using a germanium-containing catalyst to form a polyester; adding phosphorous compounds to block 80 to 99% by weight of the active manganese salt thus leaving an unblocked portion of the manganese salt prior to the polycondensation; and adding 10 to 100 ppm of Ge at the end of a ethylene glycol stage of the polymerization so that the Ge and the unblocked portion of the manganese salts provide the germanium-containing catalyst for the polycondensation reaction. The P/Mn molar ratio being less than 1. The reaction mixture contains 10 to 100 ppm of manganese during the reaction.
    Type: Grant
    Filed: December 15, 1993
    Date of Patent: May 23, 1995
    Assignee: Rhone-Poulenc Viscosuisse SA
    Inventors: Josiane Enggasser, Roland Stahlin, Paul Gesche