WATERBORNE POLYURETHANE RESIN DISPERSION AND USE THEREOF

摘要

Provided is a waterborne polyurethane resin dispersion, which can form a coating film able to be reapplied even while having superior water resistance and solvent resistance, wherein a polyurethane resin obtained by reacting (B) a chain extender and (A) a polyurethane prepolymer obtained by reacting (a) a polyisocyanate compound, (b) a polyol compound containing a polycarbonate polyol having a number average molecular weight of 400-3000, (c) an acidic-group-containing polyol compound, and (d) a blocking agent is dispersed in an aqueous medium, the proportions contained by solid content are 7-15 wt% of the total of urethane bonds and urea bonds, 15-40 wt% of carbonate bonds, 0.5-5 wt% of ether bonds, and 0.2-2.0 wt% of isocyanato gropus to which the blocking agent has bonded, and the acid number is 10-16 mg KOH/g. Further provided are: a coating composition containing the waterborne polyurethane resin dispersion; and a polyurethane resin film obtained by heating/drying a composition containing same.