Patents by Inventor Seung D. Cho

Seung D. Cho 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).

  • Polymerization method for preparing non-halogenated aromatic
    Patent number: 5506330
    Abstract: The present invention relates to a polymerization method for preparing non-halogenated aromatic polyesters by a standard interfacial polymerization except the addition of a phase-transfer catalyst to the organic phase. More specifically, the present invention offers a method for substantially reducing the polymerization time and improving the reaction yield, by introducing a specific phase transfer catalyst, tetrabutyl ammonium bromide, to the organic phase.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: April 9, 1996
    Assignee: Korea Kumbo Petrochemical Co., Ltd.
    Inventors: Young H. Ko, Byung C. Jeon, Seung D. Cho
  • Method for the production of phosphorus-containing aromatic polyester
    Patent number: 5399654
    Abstract: A phosphorus-containing wholly aromatic polyester is produced by an interfacial polymerization method which includes the step of reacting a phosphorus-containing bisphenol compound and a bisphenol compound with dicarboxylic acid chlorides. An organic layer containing the dicarboxylic acid chlorides and phase transfer catalyst is added into an alkaline aqueous layer which contains a bisphenol compound.
    Type: Grant
    Filed: October 21, 1993
    Date of Patent: March 21, 1995
    Assignee: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Young H. Ko, Seung D. Cho, Byung C. Jeon