An aqueous highly cross-linked two-component polyurethane coating system is described with reduced hydrophilicity and improved resistance to chemicals which can be obtained by a) producing a binder component based on an aqueous solution or dispersion of low-molecular hydroxyfunctional and/or aminofunctional oligourethanes or polyurethanes and b) by subsequently reacting the binder component a) with a cross-linking component (H) in a ratio of 3:1 to 5:1, wherein water-dispersible polyisocyanates are used as the cross-linking component (H).