Patents by Inventor Thomas Z. Li

Thomas Z. Li 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 for improving stability of glycerin
    Patent number: 6784326
    Abstract: A process for inhibiting the oxidative degradation of glycerin involving adjusting the pH of glycerin to a range of either: (a) from about 3.5 to about 5.0; or (b) to from about 10.0 to about 12.0.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: August 31, 2004
    Assignee: Cognis Corporation
    Inventor: Thomas Z. Li
  • Process for the production of carboxylic amides using alkyltin catalysts
    Patent number: 4277410
    Abstract: An improved process is provided for the amidation of carboxylic acids. For the process a carboxylic acid is reacted with ammonia gas at an elevated temperature and at atmospheric pressure or above in the presence of an alkyltin catalyst, preferably an alkyltin compound containing both hydroxyl and halo groups. High conversions are achieved with the process and the resulting products have low nitrile contents.
    Type: Grant
    Filed: May 2, 1980
    Date of Patent: July 7, 1981
    Assignee: Emery Industries, Inc.
    Inventors: Thomas Z. Li, James Lamont