METHOD FOR PRODUCING ISOCYANATES

The present invention relates to a process for preparing an isocyanate comprising the steps of (A) reacting an amine with a stoichiometric excess of phosgene using an aromatic solvent of formula C6H6-XClX, wherein X=1 or 2, (a) as a diluent during the reaction and/or (b) as a means for cooling the reaction mixture formed from the reaction of the amine with phosgene (so-called quench) to obtain (optionally after a decompression) a liquid product mixture comprising the isocyanate and the aromatic solvent employed and a gaseous product mixture containing phosgene and hydrogen chloride; followed by (B) isolating the isocyanate from the liquid product mixture obtained in step (A) comprising the step of a final distillation in which the isolated isocyanate is obtained as a product stream, wherein in the final distillation or in a distillation step upstream of the final distillation at least one stream comprising aromatic solvent of formula C6H6-YClY, wherein Y=X+1, is (at intervals or continuously) discharged such that the isolated isocyanate has a mass fraction, based on its total mass, of aromatic solvent of formula C6H6-YClY in the range from 0.0 ppm to 9.9 ppm, preferably 0.0 ppm to 5.0 ppm, particularly preferably 0.0 ppm to 3.0 ppm.