PROCESS FOR PRODUCING POLYURETHANE

摘要

A process for producing polyurethane useful as coating material, which comprises preparing dialkyl carbonate substantially without using phosgene, reacting the carbonate with a diamine to give a urethane, thermally decomposing it into a diisocyanate, and converting it into a polyurethane in the presence of a Lewis acid and/or a protonic acid. The reaction of a diisocyanate compound containing a reduced amount of chlorine is promoted by a Lewis acid and/or a protonic acid.