Anionic modified polyurethane dispersions

Abstract

The present invention relates to an aqueous polyurethane urea dispersion comprising a polyurethane urea polymer comprising structural units of the formula (I) wherein Aromat represents a compound selected from the group consisting of phenylene, tolylene, xylylene, tetramethylxylylene and diphenylenemethane, and wherein the polyurethane urea is obtained from components comprising A) at least one aromatic diisocyanate, B) at least one polyether polyol having a number-average molecular weight of from 300 to 1500 Da, C) at least one compound having one to two isocyanate-reactive groups and at least one ionogenic group, D) at least one polyol having a number-average molecular weight of from 60 to 499 Da, and E) water, wherein the average overall functionality of compounds B) to D) is from 1.85 to 2.2 and wherein the sum of the amount of aromatic urea groups and the amount of urethane groups is 2700 to 5000 mmol per kg polyurethane urea polymer.

Dependencies are inferred from the claim text.