Patents by Inventor Bert J. Held

Bert J. Held 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).

  • Method for the continuous preparation of carbonate oligomers with loop reactor, static mixer and plug flow
    Patent number: 5210172
    Abstract: The invention relates to a method for the continuous preparation of carbonate oligomers by boundary face oligomerization of aromatic dihydroxy compounds with phosgene while adding base, in which the reaction is carried out in a loop-like reactor system in the absence of chain stopper and while using less than 200 ppm of catalyst related to the organic solvent using at least one static mixer and plug folw, optionally in combination with a stirred tank reactor.
    Type: Grant
    Filed: July 26, 1991
    Date of Patent: May 11, 1993
    Assignee: General Electric Company
    Inventors: Hendricus H. M. van Hout, Martin H. Oyevaar, Bert J. Held
  • Method for the continuous preparation of aromatic polycarbonate having a high molecular weight with static mixer and plug flow
    Patent number: 5182361
    Abstract: The invention relates to a method of preparing aromatic polycarbonate having a high molecular weight by boundary face condensation of carbonate oligomer in the presence of an aromatic monohydroxy compound as a chain stopper, base, water and organic solvent at a temperature of at most 70.degree. C., in which the components, among which the chain stopper, are mixed in static mixers to form a fine dispersion, reacting these in a residence zone with plug flow and repeating these steps at least once.
    Type: Grant
    Filed: July 29, 1991
    Date of Patent: January 26, 1993
    Assignee: General Electric Company
    Inventors: Hendricus H. Maria van Hout, Martin H. Oyevaar, Bert J. Held