Process for reducing the chlorine content of low molecular weight isocyanates

摘要

The present invention relates to a process for purifying low molecular weight isocyanates or isocyanate mixtures from chlorine compounds by extractively treating the low molecular weight isocyanates or isocyanate mixtures with an extraction agent containing near-critical and/or super-critical fluids or fluid mixtures at a temperature of 10° C. to 200° C., a pressure of 10 bar to 1,000 bar and a weight ratio of the extraction agent to the isocyanate or isocyanate mixture of 1 to 200, and separating the chlorine compounds from the extraction agent by reduction in pressure.