Multi-step method for electrodeposition

摘要

The subject matter of the present invention is a multi-step method for the anti-corrosive coating of metal components, in which a reaction rinse is used after a conversion treatment but before electrodeposition is carried out on the component. The conversion treatment includes first the deposition of a thin inorganic layer containing the elements Zr and/or Ti. The metal component is then treated with a reaction rinse containing a surface-active substance and is subsequently subjected to electrodeposition.

主权项

1. A method of anticorrosion coating of surfaces of a metal component, comprising:
a) subjecting a surface of a metal component to a conversion treatment by contacting the surfaces of the metal component with an acidic aqueous composition containing water-soluble compounds of the elements zirconium and/or titanium, thereby forming a conversion-treated surface of the metal component comprising a zirconium and/or titanium layer density of at least 10 mg/m2 created directly on the surface of the metal component; b) performing a reaction rinse following the conversion treatment, with or without an intermediate rinsing and/or drying step, by contacting the conversion-treated surface of the metal component with an aqueous composition, having a pH no lower than 8 and no higher than 10, and comprising at least one surface-active substance comprising at least one nonionic surfactant selected from alkoxylated alkyl alcohols, said at least one surface-active substance optionally further comprising at least one alkoxylated fatty amine; and c) following the reaction rinse of b), with or without an intermediate rinsing and/or drying step, treating the conversion-treated surface of the metal component by electro-dip coating.