E.i. Dupont De Nemours and Company

Armin Goebel

Bettina Vogt-Birnbrich

Karl-Friedrich Doessel

Holger Schmidt

Werner Bosch

Marc Chilla

Frank Mueller

Manfred Stein

Kornelia Wetzel

A process for multi-layer coating by application of a base coat layer of a water-borne base coat to a substrate and subsequent application of a clear coat layer of a powder clear coat, followed by joint baking of both coating layers, wherein said water-borne base coat contains an effective amount, preferably 0.5 to 10 wt. %, of one or more water-insoluble cellulose esters, largely avoids the formation of blisters in the powder clear coat layer.

Process for the preparation of multi-layer coatings of the water-borne base coat/powder clear coat type

Water-borne base coats, the resin solid of which contain 40 to 90 wt-% of a water-dilutable polyester binder, 0 to 50 wt-% of one or more additional binders, 0 to 20 wt-% of one or more paste resins and 10 to 40 wt-% of one or more cross-linking agents, wherein the water-dilutable polyester binder has a weight average molecular mass of 5000 to 50000, an acid value of 10 to 50 mg KOH/g, a hydroxyl value of 30 to 100 mg KOH/g and an average hydroxyl-functionality of 2 to 3 and consists of 5 to 25 wt-% of structural units &mdash;O&mdash;R&mdash;O&mdash; derived from one or more macrodiols having a hydroxyl value of 25 to 120 mg KOH/g, wherein R represents residues located between the terminal hydroxyl groups of the one or more macrodiols, are suitable for preparing water-borne base coat/clear coat-two-layer coatings, in particular water-borne base coat/powder clear coat two-layer coatings.

Water-borne base coats and process for preparing water-borne base coat/clear coat-two-layer coatings

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Wetter, Germany

Armin Goebel