Multilayer Coatings and Processes for the Multilayer Coating of Substrates

A process for the multilayer coating of substrates comprising the following steps:

• III) applying a base coat layer of a water-based colour- and/or special effect-imparting base coat composition onto an optionally pre-coated substrate,
• IV) optionally curing the base coat layer obtained in step I;
• V) applying a clear coat layer of a transparent clear coat composition onto the base coat layer and
• VI) curing the clear coat layer applied in step III, optionally together with the base coat layer,
• wherein the water-based colour- and/or special effect-imparting base coat composition is a water-based coating composition comprising
• A) at least one water-dilutable polyurethane binder,
• B) optionally at least one curing agent, and
• C) at least one pigment,
• characterised in that the at least one water-dilutable polyurethane binder is based on at least one polyhydroxyl compound, said polyhydroxyl compound comprises at least 50% by weight of at least one polycarbonate polyol, which is liquid at 20° C., the % by weight are based on the total amount of the polyhydroxyl compound.