Patents Assigned to Elprochine AG
  • Process for the preparation of polyaryl amines having methylene bridges
    Patent number: 4393239
    Abstract: A process has been invented for the preparation of polyaryl polyamines having methylene bridges by condensation of primary arylamines with formaldehyde in the presence of a catalyst. According to the invention, the amount of binuclear compounds and an improved viscosity can be obtained if one adds the remaining amount of primary arylamine immediately after the formaldehyde.
    Type: Grant
    Filed: April 16, 1980
    Date of Patent: July 12, 1983
    Assignee: Elprochine AG
    Inventor: Efim Biller