Patents by Inventor Wilhelm Dunwald

Wilhelm Dunwald 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).

  • Polyisocyanates, a process for their preparation and their use in stoving lacquers
    Patent number: 5071938
    Abstract: This invention relates to polyisocyanates containing(i) 0.5 to 15% by weight of structural units incorporated by urea groups and corresponding to the formula ##STR1## (ii) 5 to 20% by weight of isocyanate groups (calculated as NCO) reversibly blocked with monofunctional blocking agents for isocyanate groups and(iii) 0 to 30% by weight of chemically incorporated urethane groups (calculated as NH--CO--O) other than urethane groups present in blocked isocyanate groups.The invention also relates to a process for the preparation of these polyisocyanates and to their use in combination with organic polyhydroxyl compounds as stoving compositions or for the preparation of stoving compositions for heat resistant substrates, in particular wire.
    Type: Grant
    Filed: September 21, 1990
    Date of Patent: December 10, 1991
    Assignee: Bayer Aktiengesellschaft
    Inventors: Reinhard Halpaap, Wilhelm Dunwald, Holger Casselmann, Hans Schlegel