Patents by Inventor Rudolf Gisler

Rudolf Gisler 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).

  • Carboxylic acid dianhydrides based on trimellitic anhydride
    Patent number: 4286097
    Abstract: Novel carboxylic acid dianhydrides are obtained by esterifying or trans-esterifying hydantoindiols, or diesters thereof, of the formula ##STR1## in which m and n are each a number from 1 to 4 and R.sub.1 and R.sub.2 are each an alkyl having 1 to 5 C atoms, or R.sub.1 and R.sub.2 together are the pentamethylene radical, R.sub.3 is a hydrogen atom or methyl and R.sub.4 is a hydrogen atom, acetyl or propionyl, with trimellitic anhydride.The novel dianhydrides are valuable curing agents for epoxide resins and are suitable for the preparation of polymers which are derived from carboxylic acid dianhydrides.
    Type: Grant
    Filed: July 16, 1979
    Date of Patent: August 25, 1981
    Assignee: Ciba-Geigy Corporation
    Inventors: Jurgen Habermeier, Eduard Knecht, Rudolf Gisler