Patents by Inventor Irvin S. Klaus

Irvin S. Klaus 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).

  • Purification of N-acetyl aminophenols
    Patent number: 4474985
    Abstract: A process for increasing the color-free shelf life of a crude N-acetyl aminophenol prepared by the acetylation of an aminophenol wherein the N-acetyl aminophenol contains color-forming impurities which are the products of oxidation of the aminophenol and other side reactions. The process comprises dissolving the crude N-acetyl aminophenol in a solvent containing a reducing agent, heating the solution at about the boiling point, crystallizing the N-acetyl aminophenol from the solution, washing the crystalline N-acetyl aminophenol with solvent containing reducing agent and thereafter separating and drying the crystalline N-acetyl aminophenol.
    Type: Grant
    Filed: January 31, 1983
    Date of Patent: October 2, 1984
    Assignee: Monsanto Company
    Inventors: Billy L. Keel, Irvin S. Klaus, Marvin L. Oftedahl