Patents by Inventor Emil Schaefer

Emil Schaefer 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).

  • Water-soluble, crosslinked nitrogen-containing condensation products
    Patent number: 4224421
    Abstract: Water-soluble, crosslinked nitrogen-containing condensation products, the viscosity of which, in aqueous solution, increases with increasing temperature, are obtained by reacting a block copolymer of the formula: ##STR1## x is from 50 to 250, y is from 20 to 100, the ratio of x to y is from 6.5:1 to 1:15, with compounds having at least four basic NH groups in a weight ratio of from 0.8:1 to 30:1. The products are added to aqueous systems, e.g. polymer solutions and polymer dispersions, to improve the viscosity characteristics.
    Type: Grant
    Filed: July 3, 1978
    Date of Patent: September 23, 1980
    Assignee: BASF Aktiengesellschaft
    Inventors: Werner Streit, Rolf Fikentscher, Karl Gans, Gerhard Welzel, Klaus Glaser, Emil Schaefer