Verfahren zur Herstellung von Di(aminophenyl)methan

摘要

Di(aminophenyl)methane is produced by reacting 1 mole formaldehyde with 2 to 3 moles of aniline at 0 deg.-60 deg.C in the presence of HCl; the molar ratio acid: aniline is not higher than 1:1, Reaction is carried out until the presence of N-CH2-N (present in intermediaries) can no longer be detected. The product is pure and contains least 96% of the p,p'-isomer. It may be used as a curing agent for epoxy or polyurethane resins but in particular it may be directly phosgenated to give the diisocynate. This process fives diisocyanate which can be used directly for production of polyurethanes without purification.