| abstract |
The present invention provides an aqueous polyurethane resin dispersion wherein a polyurethane resin is dispersed in an aqueous medium, wherein the polyurethane resin is obtained by reacting (A) a polyurethane prepolymer with (B) a chain extender, wherein (A) the polyurethane prepolymer is obtained by reacting (a) a polyisocyanate compound, (b) a polyol compound, (c) an acid group-containing polyol compound, with (d) a blocking agent for isocyanate group, wherein the total of the content of urethane bonds and the content of urea bonds in the aqueous polyurethane resin dispersion is 8 to 13 wt % based on a solid content, the content of carbonate bonds in the aqueous polyurethane resin dispersion is 15 to 40 wt % based on the solid content, and the content of isocyanate groups wherein the blocking agent is bonded thereto in the aqueous polyurethane resin dispersion is 0.3 to 2.0 wt %, wherein an alkanedioic dihydrazide is contained as the chain extender. |