Aqueous coating dispersions and their use

摘要

Aqueous coating dispersions are disclosed which consist of a polyurethane resin, pigments and other conventional auxiliaries and additives; also disclosed is the use of these coating dispersions as a basecoat for the production of multicoat systems in the paint-processing industry, in particular for the coating of hard surfaces, and preferably for original finishes (OEM finishes). These coating dispersions are characterised by a specific polyester, which contains hydroxyl and carboxyl groups and which is used to prepare the polyurethane resin. Furthermore, this polyurethane resin is obtained as an aqueous dispersion by reacting said specific polyester with at least one diol and at least one diisocyanate, to give an intermediate product which contains terminal hydroxyl groups, then reacting this product with at least one polyisocyanate, and finally transferring the polyurethane resin to a predominantly aqueous phase.