VERFAHREN ZUR HERSTELLUNG VON WAERMEFARBBESTAENDIGEN ALIPHATISCHEN UND/ODER CYCLOALIPHATISCHEN DIISOCYANATEN UND IHRE VERWENDUNG ZUR HERSTELLUNG VON FARBVERBESSERTEN, MODIFIZIERTEN POLYISOCYANATEN

摘要

The present invention relates to a process for the production of aliphatic and/or cycloaliphatic diisocyanates which are color stable to heat, which is characterized in that a diisocyanate with aliphatically-and/or cycloaliphatically-bound isocyanate groups is heated in the presence of about 0.1 to 3% by weight, based on the diisocyanate, of at least one compound which is soluble in the diisocyanate and contains at least 3% by weight of structural units corresponding to the formula: for up to about 5 hours at a temperature of about 100 DEG to 220 DEG C. and the diisocyanate which has been treated in this way is subsequently purified by distillation. The present invention also relates to the use of the products of the present process for the production of modified polyisocyanates having improved coloration.