This is to provide an aqueous polyurethane resin dispersion which can form a tough coating film.
An aqueous polyurethane resin dispersion is obtained by dispersing an aqueous polyurethane resin, which is obtained by reacting (A) a polyurethane prepolymer obtained by reacting (a1) a polycarbonate polyol having no urethane bonding having an average molecular weight of 400 to 5000, and having 2.05 to 5 hydroxyl groups in average in one molecule, (b) a polyol compound having an acidic group and (c) a polyisocyanate, or obtained by reacting (a2) the polycarbonate polyol having no urethane bonding having an average molecular weight of 600 to 5000, and having 2.05 to 5 hydroxyl groups in average in one molecule, and having an acidic group, and (c) a polyisocyanate, and (B) a chain elongating agent having a reactivity with the isocyanate group of (A) the polyurethane prepolymer, being dispersed in an aqueous medium.
本发明提供了一种能够形成坚韧涂层膜的
水性聚
氨酯
树脂分散体。通过将
水性聚
氨酯
树脂分散在
水介质中得到。所述
水性聚
氨酯
树脂是通过反应得到的,反应物包括:(A)
聚氨酯预聚体,所述
聚氨酯预聚体是由以下反应物反应得到的:(a1)分子量为400到5000的聚
碳酸酯多元醇,其中每个分子平均具有2.05到5个羟基;(b)具有酸性基团的多元醇化合物;(c)多
异氰酸酯;或者是由以下反应物反应得到的:(a2)分子量为600到5000的聚
碳酸酯多元醇,其中每个分子平均具有2.05到5个羟基和一个酸性基团;(c)多
异氰酸酯;(B)链延长剂,其与(A)
聚氨酯预聚体的
异氰酸酯基团具有反应性。