Patents by Inventor Ullrich Riegel

Ullrich Riegel 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).

  • Hydrophilic swellable graft polymers from maleic anhydride-alkylene substrate
    Patent number: 4931497
    Abstract: The present invention relates to hydrophilic swellable graft polymers which consist, in random distribution, to the extent of 0.5 to 20% by weight of radicals of the general formula I ##STR1## 79 to 99% by weight of radicals containing an acid group, of the general formula II ##STR2## and 0.1 to 2% by weight of crosslinking structures originating from monomers with at least two olefinically unsaturated double bonds, wherein the radicals R.sup.1 to R.sup.4 and n have the meanings given in claim 1, these graft polymers being used as absorbants for water and aqueous solutions.
    Type: Grant
    Filed: October 28, 1988
    Date of Patent: June 5, 1990
    Assignee: Cassella Aktiengesellschaft
    Inventors: Friedrich Engelhardt, Ullrich Riegel