PRODUCTION METHOD OF POLYURETHANE, AND USE OF POLYURETHANE OBTAINED BY THE PRODUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To produce a polyurethane capable of forming an ink-coated membrane excellent in waterproof and adhesion to a substrate without using a step for removing an organic solvent and further to provide an aqueous ink by using the polyurethane. SOLUTION: (A) A polyol containing (a1) a polyethylene glycol and (a2) a diol having an ionizable leaving group is heated with no solvent to a temperature over the compatible temperature, and the heated polyol is reacted with (B) a polyisocyanate to provide the objective polyurethane.