Patents by Inventor Gerolf Weissach

Gerolf Weissach 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).

  • Patent number: 6891034
    Abstract: Described is a process of preparing alkylhydroxyalkyl cellulose, e.g., methylhydroxypropyl cellulose (MHPC). The process includes: (a) alkylating cellulose with an aqueous caustic solution containing from 1.5 to 5.5 equivalents of alkali metal hydroxide, e.g., NaOH, per anhydroglucose unit (AGU) of said cellulose, in the presence of a suspension agent, e.g., dimethyl ether, which contains alkyl halide, e.g., methyl chloride, in an amount of from (equivalents of alkali metal hydroxide per AGU minus 1.4) to (equivalents of alkali metal hydroxide per AGU plus 0.8); (b) reacting the alkalised cellulose of step (a) with one or more alkylene oxides, e.g., propylene oxide, at a temperature higher than 65° C., e.g., 85° C.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: May 10, 2005
    Assignee: Wolff Walsrode AG
    Inventors: Wolfgang Dannhorn, Hartwig Schlesiger, Jörn-Bernd Pannek, Gerolf Weissach
  • Publication number: 20020038018
    Abstract: Described is a process of preparing alkylhydroxyalkyl cellulose, e.g., methylhydroxypropyl cellulose (MHPC). The process includes: (a) alkylating cellulose with an aqueous caustic solution containing from 1.5 to 5.5 equivalents of alkali metal hydroxide, e.g., NaOH, per anhydroglucose unit (AGU) of said cellulose, in the presence of a suspension agent, e.g., dimethyl ether, which contains alkyl halide, e.g., methyl chloride, in an amount of from (equivalents of alkali metal hydroxide per AGU minus 1.4) to (equivalents of alkali metal hydroxide per AGU plus 0.8); (b) reacting the alkalised cellulose of step (a) with one or more alkylene oxides, e.g., propylene oxide, at a temperature higher than 65° C., e.g., 85° C.
    Type: Application
    Filed: August 3, 2001
    Publication date: March 28, 2002
    Inventors: Wolfgang Dannhorn, Hartwig Schlesiger, Jorn-Bernd Pannek, Gerolf Weissach