Method for making a polyamine

摘要

A process is provided for making an aromatic polyamine by condensing an aromatic amine with formaldehyde wherein the reaction mixture is maintained at a boiling temperature under reflux and formaldehyde is mixed with the stream of condensed vapors returning to the reactor from the reflux condenser. The process produces a diphenylmethane polyamine particularly well suited for phosgenation to form the corresponding polyisocyanate.