Patents by Inventor Yuan-Haun Lee

Yuan-Haun Lee 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).

  • Patent number: 5651950
    Abstract: Disclosed is a process for producing silicon carbide. The process includes the steps of (1) mixing .beta.-resin extracted from coal-tar pitch with .alpha.-resin and silica gel; (2) after being dried, grinding the mixture to powder; (3) heating the powder in an atmosphere of nitrogen with a temperature in the range from 300.degree. C. to 480.degree. C. until mesophase is cultured; and (4) proceeding the heat treatment with a higher temperature in the range from 900.degree. C. to 1200.degree. C. for a period in the range from 2 to 7 hours. By the process, the production of silicon carbide can be carried out at low temperatures so that it is cost-effective in energy consumption.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: July 29, 1997
    Assignee: Yee Fong Chemical & Ind. Co., Ltd.
    Inventors: Yuan-Haun Lee, Yu-Shiang Wu
  • Patent number: 5275797
    Abstract: A method is disclosed for producing barium carbonate by adding barium sulfate to coal tar pitch maintained at a temperature of about 350.degree. C. to about 450.degree. C., and thereafter heating the reactants to a temperature between 700.degree. C. to 950.degree. C. in a second stage. The second stage reaction product is reacted with an alkali metal carbonate.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: January 4, 1994
    Assignee: Yee Fong Chemical & Ind. Co., Ltd.
    Inventor: Yuan-Haun Lee