Aqueous polyurethane-resin dispersion and uses thereof

Provided is an aqueous polyurethane-resin dispersion which comprises an aqueous medium and, dispersed therein, a polyurethane resin obtained by reacting at least polyols, an acidic-group-containing polyol, a polyisocyanate, and a chain extender, wherein the polyols comprise a high-molecular-weight diol having a number-average molecular weight of 1,000-30,000 and a high-molecular-weight triol having a number-average molecular weight of 300-30,000 and the chain extender comprises a compound having, in the molecule, three or more functional groups reactive with an isocyanato group. This aqueous polyurethane-resin dispersion is useful especially as a coating material for synthetic leathers. 提供种水性聚氨酯树脂分散体，该水性聚氨酯树脂分散体是聚氨酯树脂分散于水系介质中而得到的，该聚氨酯树脂是至少使多元醇、含有酸性基团的多元醇、多异氰酸酯和扩链剂反应而得到的，上述多元醇至少含有数均分子量为1000～30000的高分子量二醇和数均分子量为300～30000的高分子量三醇，上述扩链剂含有在个分子中具有3个以上与异氰酸酯基具有反应性的官能团的化合物。本发明的水性聚氨酯树脂分散体作为合成皮革用的涂布剂特别有用。