Patents by Inventor J. R. Dees

J. R. Dees 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).

  • Poly(1,3-propylene terephthalate)
    Patent number: 5340909
    Abstract: A process for producing poly(1,3-propylene terephthalate) from the reaction of either terephthalic acid or a lower dialkyl ester of terephthalic acid and 1,3-propanediol and polymerization of the monomer produced therefrom using a novel catalyst system. The novel catalyst composition includes employing an effective catalytic amount tin in the polycondensation reaction. Using the catalyst system and Hostaperm.RTM. pigments allows for the production of poly(1,3-propylene terephthalate) having yellowness of less than 4 and an IV of at least 0.80 dl/g.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: August 23, 1994
    Assignee: Hoechst Celanese Corporation
    Inventors: Marvin L. Doerr, Joseph J. Hammer, J. R. Dees