摘要 |
The invention relates to a method for producing aqueous polyurethane-polyurea dispersions, where A) first a polyurethane prepolymer containing NCO groups is produced by reacting A1) polyisocyanates with A2) polymeric polyols and/or polyamines having number-average molecular weights of more than 400 to 8,000 g/mol, A3) possibly low-molecular-weight compounds having number-average molecular weights of 17 - 400 g/mol selected from the group comprising mono- and polyalcohols, mono- and polyamines, and amino alcohols, A4) isocyanate-reactive, ionically or potentially ionically hydrophilic compounds and/or isocyanate-reactive non-ionically hydrophilic compounds, A5) isocyanate-reactive compounds, which contain at least one C<sub>7</sub> to C<sub>24</sub> alkyl group or C<sub>7</sub> to C<sub>24</sub> alkenyl group, and A6) isocyanate-reactive compounds, which contain at least one polysiloxane group, and B) the NCO groups of the prepolymer that are not yet free are reacted with isocyanate-reactive monoamines, polyamines, hydrazine, and/or hydrazides, dimensioned in such a way that a calculated ratio of the isocyanate-reactive NH groups to the NCO groups of 0.7 to 1.2 is achieved. |