System two layer coating water based, urethane-based, use and substrates coated with the same

aqueous clearcoat to produce a coating system two layers water-based, urethane-based, characterized in that it comprises - at least one secondary polyacrylate dispersion with a glass transition temperature of the polyacrylate Tg> = 20 ° C and - at least one hybrid polyurethane dispersion poliacrilato- - with a weight ratio of the proportion of secondary dispersion polyacrylate relative to the proportion of polyacrylate - polyurethane hybrid dispersion of 1: 1 to 4: 1, preferably 2: 1 to 3: 1, particularly preferably 2.25: 1 to 2.75: 1, and - as hardener, at least one low viscosity aminosulfonic polyisocyanate.