THE USE OF NONIONIC, WATER-DISPERSIBLE POLYISOCYANATES AS CONCRETE ADDITIVES

摘要

The present invention relates to a process for preparing mortar/concrete compositions by incorporating into the mortar/concrete compositions either befor e or during the mixing operation a water-dispersible polyisocyanate which a) has an average isocyanate functionality of 1.8 to 4.0, b) contains 4.0 to 25.0 wt.% of aliphatically and/or cycloaliphatically bound isocyanate groups (calculated as NCO; molecular weight = 42) and c) contains 5 to 80 wt.% of ethylene oxide units present within polyether chains (calculated as C2H4O; molecular weight = 44), in which d) the polyether chains contain an average of 5 to 50 ethylene oxide units.