Process for adjusting a certain amount of iron in diphenylmethane diisocyanate or in polyisocyanate mixtures of the diphenylmethane diisocyanate series

摘要

Method for restricting the iron content, in diphenylmethane diisocyanate or polyisocyanate mixts. derived from this series of cpds., to a mass proportion of 0.1-100 mg/kg, comprises treatment with a microporous adsorbent material having a min. internal surface area of 100 m2/g at 20-200 degrees C and 0.5-100 bar, opt. in the presence of an organic solvent.