Method of producing metal effect lacquerings and sheets treated with weather-resistant multicoat metal effect lacquerings

A method of producing metal effect lacquerings with improved weather-resistance by multicoat lacquering of substrates, using a clear lacquer as top coat and a lacquer containing metal pigments for producing the outer layer of the multicoat lacquering which is covered by the layer of clear lacquer, characterized in that the clear lacquer used is one in which the main binder is a two-component system of:

• (a) a polyol component consisting essentially of polyester polyols wherein the acid component of the polyester polyol contains not more than about 30% by weight of aromatic carboxylic acids and optionally polyacrylate polyols;
• and
• (b) a polyisocyanate component containing biuret and/or isocyanurate groups as well as cycloaliphatically-bound and/or aliphatically-bound isocyanate groups optionally blocked with blocking agents for isocyanate groups
• wherein components (a) and (b) are used in quantities sufficient to provide an NCO:OH equivalent ratio of about 0.8:1 to 2.5:1.