PROCESS FOR THE PRODUCTION OF MULTI-LAYER COATINGS

摘要

A process for the production of multi-layer coatings comprising the successive steps: 1) application of a 8 to 20 µm thick coating layer from an aqueous coating composition A onto a substrate provided with an EDC primer, 2) application of a base coat layer from an aqueous coating composition B in a film thickness, below its black/white opacity, of 5 to 10 µm onto the previously applied coating layer, 3) application of a clear coat layer onto the base coat layer, 4) joint curing of the three coating layers, wherein coating compositions A and B being different from each other, the coating composition A having a ratio by weight of pigment content to resin solids of 0.2 to 0.5 : 1, the pigment content consisting of 0 to 100 wt.% of at least one aluminium platelet pigment having a platelet thickness from 200 to 500 nm, 0 to 90 wt.% of at least one interference platelet pigment C selected from the group consisting of metal oxide-coated aluminum oxide platelet pigments, metal oxide-coated silicon dioxide platelet pigments and metal oxide-coated mica platelet pigments, 0 to 15 wt.% of at least one carbon black pigment, and 0 to 60 wt.% of at least one pigment other than aluminum platelet pigments, interference platelet pigments C and carbon black pigments, the sum of the wt.% being 100 wt.%, at least 40 wt.% of the pigment content being formed by the at least one aluminum platelet pigment and/or the at least one interference platelet pigment C, and a proportion of at least 20 wt.% of the at least one aluminum platelet pigment having a mean particle diameter from 6 to 15 µm.