Atotech Deutschland Gmbh

Nancy Born

Philipp Wachter

Christina Pfirrmann

Berkem Özkaya

Philip Hartmann

Juan-Carlos Umaran

A method for post-treatment of a chromium finish surface to improve corrosion resistance comprising a) providing a substrate having a chromium finish surface, and at least one intermediate layer between the chromium finish surface and the substrate, selected from the group consisting of nickel, nickel alloys, copper and copper alloys, wherein the chromium finish surface is a surface of a trivalent chromium plated layer, obtained by electroplating the substrate, having the at least one intermediate layer, in a plating bath, the plating bath comprising chromium (III) ions; b) contacting the chromium finish surface with an aqueous solution, comprising a permanganate, at least one compound which is selected from a phosphorus-oxygen compound, a hydroxide, a nitrate, a borate, boric acid, a silicate, or a mixture of two or more of these compounds; c) forming a transparent corrosion protection layer onto the chromium finish surface during step b.

Method for treatment of a chromium finish surface

The present invention concerns a method for increasing the adhesion between a chromium surface and a lacquer wherein said chromium surface is contacted with an aqueous solution comprising at least one phosphorous compound according to formulae R&#x2014;P(O)(OR)(OR) 1 and R&#x2014;O&#x2014;P(O)(OR)(OR) 2 wherein Ris a Cto Calkyl group, linear, branched or cyclic comprising at least one polar residue and Rand Rare independently selected from the group consisting of hydrogen, lithium, sodium, potassium, ammonium and Cto Calkyl while passing an external electrical current through said substrate and at least one anode wherein said substrate serves as the cathode.

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Berlin, Germany

Nancy Born