Patents by Inventor Robert Henry Campbell

Robert Henry Campbell 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).

  • Preparation of 2-mercaptoazoles
    Patent number: 3974170
    Abstract: A process is disclosed which comprises reacting hydrogen sulfide with azolesulfonates and sulfinates to give 2-mercaptoazoles. One embodiment of the invention describes removal of oxidized forms of 2-mercaptobenzothiazole including benzothiazole-2-sulfonates from effluent by treatment with hydrogen sulfide.
    Type: Grant
    Filed: August 26, 1974
    Date of Patent: August 10, 1976
    Assignee: Monsanto Company
    Inventors: Robert Henry Campbell, Alfred Bay Sullivan