Patents by Inventor Dieter Herzog

Dieter Herzog 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 producing methyl hydroxyalkyl cellulose ethers
    Patent number: 5360902
    Abstract: The present invention relates to a process for producing methyl hydroxyalkyl cellulose ethers by alkalisation and etherification of celluloses, rinsing the methyl hydroxyalkyl cellulose ethers with water at higher temperatures and recovering the short-chain cellulose ethers that are soluble in the wash water, wherein the wash water containing sodium chloride and organic by-products is passed across a first stage of a membrane filtration having a molecular cut size of 200 to 150,000 Dalton, is concentrated during this process and passes across a second stage of a membrane filtration.
    Type: Grant
    Filed: December 15, 1992
    Date of Patent: November 1, 1994
    Assignee: Wolff Walsrode AG
    Inventors: Oke Brauer, Bernd Haase, Dieter Herzog, Lutz Riechardt, Gerd Sonnenberg, Dietrich Tegtmeier
  • Carboxymethylsulphoethyl celluloses and a process for their preparation
    Patent number: 5001232
    Abstract: Improved water soluble carboxymethylsulphoethyl celluloses may be obtained by suspending cellulose, adding compounds which transfer sulphoalkyl and carboxymethyl and then etherifying after alkalization.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: March 19, 1991
    Assignee: Wolff Walsrode AG
    Inventors: Dieter Herzog, Klaus Balser, Klaus Szablikowski
  • Sulfoethyl cellulose of high solution quality and a process for its production
    Patent number: 4990609
    Abstract: Sulfoethyl cellulose prepared by addition of an alkylating agent and subsequent addition of alkali shows particularly valuable properties.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: February 5, 1991
    Assignee: Wolff Walsrode AG
    Inventors: Dieter Herzog, Klaus Balser, Klaus Szablikowski
  • Use of cellulose derivatives in drilling fluids
    Patent number: 4972007
    Abstract: Cellulose derivatives which are substituted in a specified manner by both carboxyalkyl groups and sulphoalkyl groups which are suitable in drilling fluids.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: November 20, 1990
    Assignee: Wolff Walsrode AG
    Inventors: Dieter Herzog, Bernd Schriewer