Patents by Inventor James R. Darwent

James R. Darwent 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).

  • Quaternary ammonium compounds for use in bleaching systems
    Patent number: 4904406
    Abstract: A quaternary ammonium-substituted peroxycarboxylic acid bleach precursor, its quaternary ammonium peroxycarboxylic acid derivative, and bleaching-detergent compositions containing these materials are disclosed herein. The bleach precursor structurally comprises a quaternized ammonium group linked to a carboxyl moiety having a leaving group via an aromatic or heterocyclic bridging group which, upon perhydrolysis in the presence of hydrogen peroxide, generates a highly effective, quaternary ammonium-substituted aromatic or heterocyclic peroxycarboxylic acid bleach.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: February 27, 1990
    Assignee: Lever Brothers Company
    Inventors: James R. Darwent, Keith C. Francis, John Oakes, David W. Thornthwaite