An aqueous polyurethane resin dispersion is a dispersion of a polyurethane resin in an aqueous medium, the polyurethane resin being obtained by reacting (A) a polyurethane prepolymer obtained by reacting (a) a polyisocyanate compound, (b) a polyol compound including a polycarbonate polyol with a number average molecular weight of 400 to 3000, (c) an acidic group-containing polyol compound and (d) a blocking agent, with (B) a chain extender, the total content of urethane bonds and urea bonds being 7 to 15 wt%, the content of carbonate bonds being 15 to 40 wt%, the content of ether bonds being 0.5 to 5 wt%, the content of isocyanate groups bonded to the blocking agent being 0.2 to 2.0 wt%, each of these contents being based on solid contents, the acid value being 10 to 16 mg KOH/g. The aqueous polyurethane resin dispersion can form coating films which permit new application while exhibiting excellent water resistance and solvent resistance. A coating composition includes the dispersion. A polyurethane resin film is obtained by thermally drying a composition including the dispersion.
一种
水性聚
氨酯
树脂分散体是一种聚
氨酯
树脂在
水性介质中的分散体,该聚
氨酯
树脂是通过以下反应获得的:(A)聚
氨酯预聚物,该预聚物是通过以下反应获得的:(a)多
异氰酸酯化合物;(b)多元醇化合物,该多元醇化合物包括平均分子量为 400 至 3000 的聚
碳酸酯多元醇、(c) 含酸性基团的多元醇化合物和 (d) 封端剂,与 (B) 扩链剂反应,聚
氨酯键和
脲键的总含量为 7 至 15 wt%,
碳酸酯键的含量为 15 至 40 wt%,醚键的含量为 0.5 至 5 wt%,与封端剂结合的
异氰酸酯基团的含量为 0.2 至 2.0 wt%,上述各含量均基于固体含量,酸值为 10 至 16 mg KOH/g。
水性聚
氨酯
树脂分散体可以形成涂膜,允许新的应用,同时表现出优异的耐
水性和耐溶剂性。涂料组合物包括该分散体。通过热干燥包含该分散体的组合物,可获得聚
氨酯
树脂薄膜。