Aromatic diamines useful for prep of isocyanates as

摘要

New aromatic diamines have the formula: where R and R' are alike or different (cyclo)alkyl or aryl residues, or together form an alkylene residue. The diamines can be used to prepare isocyanates. By condensation with other divalent derivs. they yield polymers of high heat stability and increased solubility. They are hardeners for epoxy resins. They have better stability to air and light then corresponding known compounds in which only one of the positions ortho to each amino group is substituted. They do not darken on storage even when not pure.