MANUFACTURING METHOD OF IMIDAZOLE BLOCKED POLYURETHANE RESIN, IMIDAZOLE BLOCKED POLYURETHANE RESIN USING THE SAME AND PRE COATED AUTOMOTIVE METAL SHEE COMPRISING THE SAME

摘要

PURPOSE: An imidazole block polyurethane resin is provided to have excellent adhesion and collision resistance together with improving flexibility, thereby providing pigment with excellent adhesion to metal steel plate basis material. CONSTITUTION: A manufacturing method of an imidazole block polyurethane resin comprises: a step of adding an isocyanate compound to a polyester resin manufactured through a condensation-reaction of a glycol component and a carboxylic acid; a step of blocking a part of the isocyanate by adding an imidazole compound during addition-reaction at 40-70 °C. The hydroxyl value of the imidazole block polyurethane resin is 10-50 mgKOH/g, and the weight average molecular weight is 20,000-30,000.