Patents by Inventor Eckhard Seidel

Eckhard Seidel 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 of producing polytrimethylene terephthalate (PTT)
    Patent number: 6277947
    Abstract: Process of producing polytrimethylene terephthalate (PTT) by esterification of terephthalic acid (TPA) with trimethylene glycol (TMG) in the presence of a catalytic titanium compound, precondensation and polycondensation. The esterification is effected in at least two stages, where in the first stage a molar ratio of TMG to TPA of 1.15 to 2.5, a content of titanium of 0 to 40 ppm, a temperature of 240 to 275° C., and a pressure of 1 to 3.5 bar are used. In the at least one subsequent stage a content of titanium is adjusted which is higher than in the initial stage by 35 to 110 ppm.
    Type: Grant
    Filed: April 21, 2000
    Date of Patent: August 21, 2001
    Assignee: Shell Oil Company
    Inventors: Donald Ross Kelsey, Robert Lawrence Blackbourn, Robert Stephen Tomaskovic, Hans Reitz, Eckhard Seidel, Fritz Wilhelm