Patents by Inventor Wei-Teh Wade Shang

Wei-Teh Wade Shang 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 and apparatus for preparing purified terephthalic acid
    Patent number: 5961935
    Abstract: A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: October 5, 1999
    Assignee: HFM International, Inc.
    Inventors: Fu-Ming Lee, Wei-Teh Wade Shang
  • Method and apparatus for preparing purified terephtalic acid
    Patent number: 5767311
    Abstract: A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 16, 1998
    Assignee: Glitsch International, Inc.
    Inventors: Fu-Ming Lee, Wei-Teh Wade Shang
  • Aromatic sulfide/sulfone polymer production
    Patent number: 5015725
    Abstract: A process is provided for the production of aromatic sulfide/sulfone polymers which comprises contacting under suitable polymerization reaction conditions: (1) at least one dihaloaromatic sulfone, (2) water, and (3) a complex comprising at least one alkali metal hydrosulfide.
    Type: Grant
    Filed: August 31, 1989
    Date of Patent: May 14, 1991
    Assignee: Phillips Petroleum Company
    Inventors: Lacey E. Scoggins, Kenneth C. Hoover, Wei-Teh Wade Shang