PROCESS FOR PRODUCING POLYISOCYANATE

摘要

A method for producing a polyisocyanate includes a purification step of purifying an unpurified polyisocyanate, the purification step including a tar ingredient removal step of removing tar ingredients from an unpurified polyisocyanate, and a distillation step of distilling the unpurified polyisocyanate from which tar ingredients have been removed through a dividing wall distillation column.