Aqueous polyurethane resin dispersion, preparation method of the same, and coating composition containing the same

摘要

Disclosed is an aqueous polyurethane resin dispersion which comprises a polyurethane resin which is obtained by reacting (A) a polyurethane prepolymer obtained by reacting (a) a polycarbonate polyol having an alicyclic structure in the main chain, (b) an acidic group-containing polyol compound and (d) a polyisocyanate, and (B) a chain-elongating agent, being dispersed in an aqueous medium, a carboxylic acid group content of the above-mentioned (A) polyurethane prepolymer based on a solid component of (A) the polyurethane prepolymer is 2.0 to 13.0% by weight, and a number of a hydroxyl equivalent of a mixture of the above-mentioned (a) polycarbonate polyol having an alicyclic structure in the main chain, the above-mentioned (b) acidic group-containing polyol compound, and, if necessary, (c) a polyol other than (a) and (b) is 70 to 270.