Production method of the multilayer coating which includes with water system primer - surfacer layer and the topcoat which is applied to that

摘要

A process for producing multi-layer coatings comprising a waterborne primer-surfacer layer and a topcoat applied thereto on substrates, in which a waterborne primer-surfacer layer is applied from a waterborne primer-surfacer to substrates and baked and then a topcoat is applied, wherein the waterborne primer-surfacer has a binder solids content with a hydroxyl number of 100 to 250 mg KOH/g and contains free or blocked polyisocyanate as a curing agent (crosslinking agent) for the hydroxy-functional binder(s) in a molar ratio of OH/NCO of more than 2:1 to 5:1, and wherein, after it has been applied and before baking, the waterborne primer-surfacer layer is allowed to evaporate for 30 to 300 seconds at 15 to 40° C.