| abstract |
The present invention relates to a novel method for producing a colour and/or effect-producing multi-layered coating, in which (1) a pigmented aqueous base coat containing at least one polyurethane resin (A) as a binder and at least one colour and/or effect-producing pigment, is applied to a substrate, (2) a polymer film is formed from the base coat that was applied in stage (1), (3) a clear coat is applied onto the base coat layer which was obtained in this manner, and then (4) the base coat layer is cured together with the clear coat that was applied in stage (3). The claimed method is characterized in that the pigmented aqueous base coat applied in stage (1) contains, in relation to the total amount of the pigmented aqueous base coat, 0.05 to 10 wt.% of an associative thickener (B) which differs from the polyurethane resin (A). Said associative thickener (B) consists of at least one compound of formula (I) with n=0-50, wherein R=(Ia) with m=0-10, R1=H or R2, R2=(Ib) with o=0-50, providing that, for no more than 50 wt.% of the compounds of formula (I), m=0 and R1=H apply. The subject matter of the present invention is also a pigmented aqueous base coat containing at least one polyurethane resin (A) as a binder, at least one colour and/or effect-producing pigment as well as, in relation to the total amount of the pigmented aqueous base coat, 0.05 to 10 wt.% of at least one associative thickener (B). Likewise, the subject matter of the present invention is a colour and/or effect-producing multi-layered coating that is produced according to the claimed method. |