초록 ▼

characterized in that the molar ratio of polyol of the component a) to the sum of the polyols b) and d) is 1:1.5 to 1:4, preferably 1:2 to 1:3, the molar ratio of the sum of the polyols a), b) and d) to the polyisocyanate c) is 1:1.1 to 1:2.5, preferably 1:1.2 to 1:1.7, the OH functionality of the p

characterized in that the molar ratio of polyol of the component a) to the sum of the polyols b) and d) is 1:1.5 to 1:4, preferably 1:2 to 1:3, the molar ratio of the sum of the polyols a), b) and d) to the polyisocyanate c) is 1:1.1 to 1:2.5, preferably 1:1.2 to 1:1.7, the OH functionality of the polyurethane being 2 to 6, preferably 2 to 4, and the average molecular weight, determined as the number average, of the polyurethane being less than 15,000, preferably from 2500 to 10,000, in particular from 3000 to 7000, g/mol.

대표청구항 ▼

[ What is claimed is:] [1.]1. An aqueous polyurethane dispersion comprising a polyurethane having an OH functionality of 2 to 6 and a number average molecular weight of less than 15,000 prepared by reacting(a) at least one polyol having a number average molecular weight of 500 to 6000 g/mol,(b) at l

[ What is claimed is:] [1.]1. An aqueous polyurethane dispersion comprising a polyurethane having an OH functionality of 2 to 6 and a number average molecular weight of less than 15,000 prepared by reacting(a) at least one polyol having a number average molecular weight of 500 to 6000 g/mol,(b) at least one polyol having a molecular weight of less than 500 g/mol,(c) at least one aliphatic polyisocyanate,(d) at least one diol having a molecular weight of less than 450 g/mol and bearing one or more ionic groups and/or one or more potentially ionic groups,(e) at least one amine that is reactive towards NCO groups, bears hydroxyl groups, and has an OH functionality of 1 to 6,(f) water, and(g) a C.sub.1 -C.sub.10 aliphatic monoalcohol, rein the molar ratio of polyol (a) to the sum of polyol (b) and diol (d) is 1:1.5 to 1:4 and the molar ratio of the sum of polyol (a), polyol (b), and diol (d) to polyisocyanate (c) is 1:1.1 to 1:2.5.