New polyester polyol with improved curing speed for waterborne 2C-PU-coatings

 
Water-borne 2K-PU-coatings are gaining market share for decades and replace solventborne alternatives with success. In general, water- and solventborne 2K-PU-coatings show comparable properties in terms of gloss, corrosion resistance and final hardness. One drawback of waterborne systems is related to the low curing speed compared to solventborne alternatives. This lack in performance is mainly driven by the poor selection of suitable catalysts that also promote side-reactions in aqueous media. Therefore, a new waterborne polyester polyol with higher cross-linking density and reactivity was developed. In addition, the influence of catalysts and cross linkers on curing speed and gloss was investigated. Characterization methods like drying time recorder, pendulum hardness and corrosion resistance confirm improved curing behavior by maintaining the advantages of gloss and processability.