Patent ID: 7211182

Claim:
A process for the production of a CED (cathodic electrodeposition) coating with improved adhesion towards subsequent layers comprising the steps of a) cathodically electrodepositing a CED coating layer of a CED coating composition onto an electrically conductive substrate surface and b) thermally curing the CED coating layer by baking in an indirectly heated circulating air oven operated with a proportion of fresh air in the circulating air of the oven of 0 to 20 vol. %, wherein the CED coating composition used contains at least one water-soluble metal nitrate corresponding to a quantity of 1 to 10 mmol of nitrate per 100 g of resin solids content, wherein the metal is selected from the group consisting of metals of atomic numbers 20 to 83, with the exception of chromium, arsenic, rubidium, ruthenium, rhodium, palladium, cadmium, antimony, caesium, osmium, iridium, platinum, mercury, thallium and lead, and wherein the CED coating layer substrate surface is rinsed with ultrafiltrate obtained from the CED coating composition at least in an area visible to an observer and subsequently at most 50 area-% of the CED coating layer substrate surface is rinsed with water prior to thermal curing.