| abstract |
The present invention relates to water-dispersible polyisocyanate mixtures which a) have an average isocyanate functionality of 1.8 to 4.2, b) contain 12.0 to 21.5% by weight of (cyclo)aliphatically bound isocyanate groups (calculated as NCO, molecular weight=42) and c) contain 2 to 20% by weight of ethylene oxide units (calculated as C2H4O, molecular weight=44) arranged within polyether chains, the polyether chains containing an average of 5.0 to 9.9 ethylene oxide units. The present invention also relates to the preparation of these polyisocyanate mixtures by reacting at an NCO/OH equivalent ratio of 4:1 to 120:1 A) a polyisocyanate component having an average isocyanate functionality of 2.1 to 4.4 and containing one or more polyisocyanates in which all the isocyanate groups are (cyclo)aliphatically bound with B) a monovalent polyalkylene oxide polyether alcohol containing an average of 5.0 to 9.9 ethylene oxide units. Finally, the present invention also relates to aqueous two-component compositions containing these polyisocyanate mixtures and aqueous resins having isocyanate-reactive groups. |