Process for the preparation of polyamines from N-monoaryl-N',N'-dialkyl urea compounds and their use for the synthesis of polyurethanes

摘要

This invention relates to an improved process for the preparation of aromatic polyamines containing urethane and/or biuret and/or urea and/or isocyanurate groups and preferably also ether groups by the hydrolysis of poly-N-monoaryl-N',N'-dialkyl urea compounds (1-aryl-3,3-dialkyl ureas). The ureas are obtained by the reaction of secondary aliphatic, cycloaliphatic or saturated heterocyclic amines with divalent to tetravalent isocyanate compounds containing isocyanate end groups attached to aromatic residues. The ureas correspond to the general formula: <IMAGE> wherein R1, R2 denote alkyl or cycloalkyl groups, or together form a ring and A denotes a divalent to tetravalent residue attached to the ureas by aromatic groups. Hydrolysis is carried out in the presence of water and up to two equivalents of a base containing hydroxide ions and/or up to two equivalents of a compound containing tertiary amino groups, optionally in the presence of solvents. The use of the polyamines obtained by this process for the synthesis of polyurethanes is also described.