Patents by Inventor Ellen Kohn

Ellen Kohn 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: 5001191
    Abstract: A process for the dry cationization of polyvinyl alcohol (PVA) by reaction of alkylidene epoxides with PVA in alkaline medium in the presence of water, in which the reaction mixture contains 11 to 30 weight % of water, based on its total amount, and 1 to 4 weight % of an alkali metal or alkaline earth metal hydroxide or alkaline earth metal oxide, based on the quantity of PVA. As the cationizing agent there are used alkylidene epoxides or their mixtures having the general formula: ##STR1## wherein n=1, 2 or, 3, R.sup.1, R.sup.2 and R.sup.3 represent the same or different alkyl residues having 1 to 18 carbon atoms or R.sup.1 represents the benzyl or --C.sub.2 H.sub.4 OH, and X.sup.- denotes chloride, bromide, sulfate or acetate. Instead of alkylidene epoxides, the corresponding halohydrins, e.g. chlorohydrin or bromohydrin, can be used.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: March 19, 1991
    Assignee: Degussa Aktiengesellschaft
    Inventors: Reinhard Stober, Dietmar Bischoff, Ellen Kohn
  • Patent number: 4822851
    Abstract: A process for the preparation of cationized polyvinyl alcohol (PVA) by reaction of alkylidene epoxides with PVA in alkaline medium in the presence of water, in which the reaction mixture contains 11 to 30 weight % of water, based on its total amount, and 1 to 4 weight % of an alkali metal or alkaline earth metal hydroxide or alkaline earth metal oxide, based on the quantity of PVA. As the cationizing agent there are used alkylidene epoxides or their mixtures having the general formula ##STR1## wherein n - 1, 2 or 3, R.sub.1, R.sub.2 and R.sub.3 represent the same or different alkyl residues having 1 to 18 carbon atoms or R.sub.1 represents the benzyl or --C.sub.2 H.sub.4 OH, and X.sup.- denotes chloride, bromide, sulfate or acetate.
    Type: Grant
    Filed: December 29, 1986
    Date of Patent: April 18, 1989
    Assignee: Degussa Aktiengesellschaft
    Inventors: Reinhard Stober, Ellen Kohn, Dietmar Bischoff