Patents by Inventor David Lei

David Lei 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 preparing alkali metal pyrithione and its polyvalent metal complexes from pyridine oxide
    Patent number: 9079857
    Abstract: The present invention generally relates to a novel process for preparing alkali metal pyrithione from pyridine N-oxide, using a sulfurination agent and a base agent. In particular, the present invention relates to an efficient process for preparing polyvalent metal complexes of sodium pyrithione from the alkali metal pyridine N-oxide described herein.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: July 14, 2015
    Assignee: Arch Chemicals, Inc.
    Inventors: Rahim Hani, John J. Jardas, Richard Dumas, David Lei
  • Process for Preparing Alkali Metal Pyrithione and its Polyvalent Metal Complexes from Pyridine Oxide
    Publication number: 20130261309
    Abstract: The present invention generally relates to a novel process for preparing alkali metal pyrithione from pyridine N-oxide, using a sulfurination agent and a base agent. In particular, the present invention relates to an efficient process for preparing polyvalent metal complexes of sodium pyrithione from the alkali metal pyridine N-oxide described herein.
    Type: Application
    Filed: March 15, 2013
    Publication date: October 3, 2013
    Applicant: Arch Chemicals, Inc.
    Inventors: Rahim Hani, John J. Jardas, Richard Dumas, David Lei