AQUEOUS POLYURETHANE RESIN DISPERSION AND MANUFACTURING METHOD THEREOF

摘要

Disclosed is an aqueous polyurethane resin dispersion which can easily be reapplied after application to a substrate, and with which excess paint can be easily removed. Disclosed is an aqueous polyurethane resin dispersion in which a polyurethane resin, obtained by reacting (A) a polyurethane pre-polymer that is obtained by reacting (a) a polyisocyanate compound, (b) a polyol compound containing at least one polycarbonate polyol with a number average molecular weight of 400-3000, (c) a polyol compound that contains an acidic group, and (d) an isocyanate group blocking agent that dissociates at 80-180°C, with (B) a chain extender, is dispersed in a water based medium. The total of the urethane bond content ratio and the urea bond content ratio is 7-18% by weight, based on solid content, the carbonate bond content ratio is 15-40% by weight, based on solid content, and the content ratio of the isocyanate groups to which the aforementioned blocking agent has bonded is 0.2-3% by weight, based on solid content and isocyanate group equivalent.