METHOD FOR PRODUCING POLYISOCYANATE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a polyisocyanate, which can be suitably used for producing a product polyisocyanate having slight discoloration and low acidity while reducing an energy consumption and purifying an unpurified polyisocyanate. SOLUTION: In the method for producing the polyisocyanate, comprising a purification process for purifying an unpurified polyisocyanate, the purification process comprises a tar component removal process of removing a tar component from the unpurified polyisocyanate and a distillation process of distilling the unpurified polyisocyanate from which the tar component is removed by a distillation column with a divider wall. COPYRIGHT: (C)2009,JPO&INPIT