摘要 |
A process for the preparation of organic mono- and polyisocyanates is described, in which a hydrogen chloride adduct of a trisubstituted urea is thermally decomposed to form the isocyanate. The hydrogen chloride adduct at minimum contains the stoichiometric amount of HCl, and at maximum a 10 mole-% excess. The process is carried out in a closed system at a temperature between about 80 DEG and 180 DEG C.; the reaction is effected either in a melt or in the presence of an inert organic solvent. |