Patents by Inventor Josef S. Gratzl

Josef S. Gratzl 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).

  • Selective enzymatic oxidation of aromatic methyl groups to aldehydes by oxygen in the presence of a laccase-mediator catalyst
    Patent number: 5888787
    Abstract: A method for oxidation of a pendant methyl moiety on an aromatic ring to the pendant aldehyde moiety is presented. The reaction employs laccase and the diammonium salt of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), and is carried out in the presence of oxygen.
    Type: Grant
    Filed: July 2, 1996
    Date of Patent: March 30, 1999
    Assignee: North Carolina State University
    Inventors: Chen-Loung Chen, Josef S. Gratzl, Adrianna G. Kirkman, Antje Potthast, Thomas Rosenau
  • Two stage process for the oxygen delignification of lignocellulosic fibers with peroxide reinforcement in the first stage
    Patent number: 5011572
    Abstract: A process is provided for a two-stage oxygen delignification of chemical pulp in which 0.01% to 1% hydrogen peroxide is incorporated into the first and, optionally the second stage. The invention is particularly suitable when the pulp is subsequently bleached with at least one chlorine dioxide stage and at least one hydrogen peroxide stage.
    Type: Grant
    Filed: May 19, 1989
    Date of Patent: April 30, 1991
    Assignees: FMC Corporation, North Carolina State University
    Inventors: V. R. Parthasarathy, Meenaksi Sundaram, Hasan Jameel, Josef S. Gratzl, Ronald J. Klein
  • Process for delignification of cellulosic substances by pretreating with a complexing agent followed by peroxide prior to kraft digestion
    Patent number: 4826568
    Abstract: Process for the delignification of cellulosic substances comprising:a first stage of treatment of cellulosic substances with an acida second stage of treatment with hydrogen peroxide in an alkaline mediuma third stage of digestion in the presence of at least one chemical reactant chosen from sulphur-containing compounds and oxygen.The process applies to the treatment of wood fragments.
    Type: Grant
    Filed: March 2, 1987
    Date of Patent: May 2, 1989
    Assignee: Interox (Societe Anonyme)
    Inventor: Josef S. Gratzl
  • Process for the delignification of cellulosic substances by pretreating with a complexing agent followed by hydrogen peroxide
    Patent number: 4826567
    Abstract: Process for the delignification of cellulosic substances comprising:a first stage of treatment of cellulosic substances with an acida second stage of treatment with hydrogen peroxide in an alkaline mediuma third stage of digestion in the presence of at least one chemical reactant chosen from hydroxides of alkaline or alkaline-earth metals.The process applies to the treatment of wood fragments.
    Type: Grant
    Filed: March 27, 1987
    Date of Patent: May 2, 1989
    Assignee: Interox (Societe Anonyme)
    Inventor: Josef S. Gratzl