METHOD FOR PRODUCING POLYCARBONATE POLYOLS, POLYURETHANE USING SAID POLYCARBONATE POLYOLS

摘要

A method for producing a polycarbonate polyol having a specific structure and specific physical properties, comprising performing a polycondensation reaction of a dihydroxy compound with a carbonic acid diester through a transesterification reaction therebetween in the presence of a catalyst, wherein at least one reactor is a reactor having an internal volume of 20 L or more and being equipped with a reflux condenser and a heating device for heating the reactor by using a heat medium, the difference between the temperature of the heat medium and the temperature of the reaction solution in the reactor is at least 5°C or more, and the total amount of monomers distilled out in all reaction steps is 15 wt% or less based on the gross weight of raw material monomers.