| 摘要 |
The subject of the present invention is a method for preparing an isocyanate compound. The invention relates more particularly to the preparation of a diisocyanate compound from the corresponding diamine compound. The invention is directed preferentially towards the preparation of toluene diisocyanate, of hexamethylene diisocyanate and of isophorone diisocyanate. The method for preparing an isocyanate compound according to the invention, which comprises a stage of reacting an amine compound and phosgene, under pressure, in the presence of an organic solvent; a stage of reactive distillation under pressure, is characterized in that it comprises, at the end of the phosgenation operation, a stage of separating the reaction mixture (F1) resulting from the phosgenation stage into a gas stream (F3) and a liquid stream (F2) essentially comprising the isocyanate precursors in the organic solvent, and a stage of preheating the liquid stream (F2) to a temperature of between 100°C and 250°C, before being conveyed to the distillation operation. |
