Aqueous polyurethane-polyurea dispersions

A process for coating a flexible sheet-like substrate comprising coating the substrate with an aqueous polyurethane-polyurea dispersion prepared by

• A) a NCO-containing polyurethane prepolymer, wherein the prepolymer is prepared by reacting
• A1) at least one polyisocyanate with
• A2) at least one polymeric polyol and/or polyamine having a number average molecular weight of more than 400 to 8000 g/mol,
• A3) optionally a low molecular weight compound having number average molecular weights of 17-400 g/mol selected from the group consisting of mono- and polyalcohols, mono- and polyamines and amino alcohols,
• A4) at least one isocyanate-reactive ionically or potentially ionically hydrophilizing compound and/or isocyanate-reactive nonionically hydrophilizing compound,
• A5) at least one isocyanate-reactive compound comprising at least one C7- to C24-alkyl or C7- to C24-alkenyl group, and
• A6) at least one isocyanate-reactive compound comprising at least one compound of formula (4)
• where
• X is O, S, NH or NR,
• A, B, B′ are each independently hydrocarbyl groups having 1 to 30 carbon atoms, which may optionally contain heteroatoms selected from the group consisting of N, O, P and/or S, and which are not isocyanate reactive,
• m is from 3 to 55,
• and wherein the polysiloxane groups introduced via component A6) are present as side chains, and
• B) the still free NCO groups of the prepolymer having been reacted with isocyanate-reactive monoamines, polyamines, hydrazine and/or hydrazides sufficient for an arithmetic ratio of the isocyanate-reactive NH groups to the NCO groups in the range from 0.7 to 1.2;
• wherein the substrate is leather or artificial leather:
• and
• wherein in the coating step the dispersion is not applied as a foam, and wherein the C7- to C24-alkyl or C7- to C24-alkeyl groups introduced via component A5) are present as side chains.