Multilayer coating process for automobile parts and bodies

摘要

A process for the production of a multi-layer coated automobile part or body is claimed. A sheet metal coil is coated on both sides with a primer coat (I) and baked followed by pressing and deep drawing processes and optionally assembly to form a motor vehicle body. A second coat is then applied by electrophoretic deposition followed by further coats. The primer coat (I) contains electrically conductive components that impart a sufficiently low electrical resistivity to the baked primer coat (I) to allow subsequent electrophoretic deposition to be carried out. (I) contains 55-80 wt.% polyester polyol, 2-10 wt.% aromatic epoxy resin, 0-20 wt.% aminoplast resin and 10-30 wt.% of a blocked polyisocyanate such that the sum of the solid resin components add up to 100 wt.%.