Patents Assigned to Chemisch Werke Huls AG
  • Process for the preparation of blocked polyisocyanates
    Patent number: 4258186
    Abstract: A process for the preparation of blocked polyisocyanates which comprises reacting a polyisocyanate with a cyclic amidine of the formula: ##STR1## wherein R are the same or different substituents selected from the group consisting of hydrogen, alkyl, cycloalkyl, aralkyl and aryl, and wherein either R' and R or two R' taken together form a cycloaliphatic ring, and wherein the reaction is carried out at temperatures of 0.degree.-150.degree. C. Polyisocyanates blocked with 6-membered ring bicyclic amidines.
    Type: Grant
    Filed: November 17, 1978
    Date of Patent: March 24, 1981
    Assignee: Chemisch Werke Huls AG
    Inventors: Ansgar Schott, Rainer Gras, Elmar Wolf