Patents by Inventor Friedrich Lawitzki

Friedrich Lawitzki 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).

  • Dialyzing membrane with adsorbent layer
    Patent number: 4267047
    Abstract: A dialyzing membrane, especially for hemodialysis, formed as a hollow fiber, tubular foil or flat sheet by regeneration of cellulose from a cuprammonium solution, the membrane comprising at least two firmly adhered cellulosic layers including at least one dialyzing layer consisting essentially of a semipermeable regenerated cellulose and at least one adsorbent layer consisting of said regenerated cellulose containing embedded therein fine particles of an adsorbent material in an amount of up to 95% by weight with reference to the dry weight of the adsorbent layer, preferably 1 to 90% and especially 20 to 70% by weight, when the adsorbent layer is part of a hollow fiber structure.
    Type: Grant
    Filed: April 16, 1979
    Date of Patent: May 12, 1981
    Assignee: Akzo N.V. of Arnhem/Nederland
    Inventors: Werner Henne, Gustav Dunweg, Werner Schmitz, Raimund Pohle, Friedrich Lawitzki
  • Method of producing dialyzing membrane
    Patent number: 4164437
    Abstract: A dialyzing membrane, especially for hemodialysis, formed as a hollow fiber, tubular foil or flat sheet by regeneration of cellulose from a cuprammonium solution, the membrane comprising at least two firmly adhered cellulosic layers including at least one dialyzing layer consisting essentially of a semipermeable regenerated cellulose and at least one adsorbent layer consisting of said regenerated cellulose containing embedded therein fine particles of an adsorbent material in an amount of up to 95% by weight with reference to the dry weight of the adsorbent layer, preferably 1 to 90% and especially 20 to 70% by weight, when the adsorbent layer is part of a hollow fiber structure.
    Type: Grant
    Filed: June 23, 1977
    Date of Patent: August 14, 1979
    Assignee: Akzo N.V.
    Inventors: Werner Henne, Gustav Dunweg, Werner Schmitz, Raimund Pohle, Friedrich Lawitzki