Sprayable seal of building constructions based on coagulable polyurethane dispersions

摘要

Sprayable seal for waterproofing building works, contains (A) a dispersion of polyurethane (PU) and/or PU-urea based mainly on a polyether structure, with a Tg of not above 30 degrees C, a solids content of at least 40% and an emulsifier system integrated into the polymer, and (B) a coagulant-containing component which counteracts the emulsifier system in (A), resulting in precipitation of the dispersion particles with formation of a film. Also claimed is (i) a process for the production of a watertight membrane by mixing (A) and (B) in a nozzle or directly outside the nozzle(s) of a spray machine and applying the resulting mixture to the substrate, and (ii) a process for the production of the polymer in dispersion (A).