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US 9,752,074 B2Granted
Chromium-free pickle for plastic surfaces
OwnerMark Peter Schildmann, Ulrich Prinz +1inventors
InventorsMark Peter Schildmann, Ulrich Prinz, Christoph Werner
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Abstract
A pickling solution for the surface pre-treatment of plastic surfaces in preparation for metallization, the solution comprising a source of Mn(VII) ions; and an inorganic acid; wherein the pickling solution is substantially free of chromium (VI) ions, alkali ions, and alkaline-earth ions.
Claims20
A process for pickling plastic surfaces comprising:
- a) dispersing a manganese salt in an acid solution in an oxidative cell to produce Mn(VII) ions;
- and
- b) contacting the plastic surface to be pickled with an acidic treatment solution, the acidic treatment solution comprising the Mn(VII) ions and an inorganic acid, wherein the inorganic acid is at least one acid selected from the group consisting of phosphoric acid, peroxomonophosphoric acid, peroxodiphosphoric acid, sulfuric acid, peroxomonosulfuric acid, and peroxodisulfuric acid;
- wherein the acidic treatment solution is substantially free of chromium ions, alkali ions and alkaline earth ions;
- and
- wherein the acid used in the acid solution of the oxidative cell comprises the same acid as the inorganic acid in the acidic treatment solution.
3 more elements
A pickling solution for the surface pre-treatment of plastic surfaces in preparation for metallization, the solution comprising:
- a source of Mn(VII) ions;
- an inorganic acid, the inorganic acid comprising 800 g/l to 1400 g/l sulfuric acid;
- wherein the pickling solution is substantially free of chromium (VI) ions, alkali ions, and alkaline-earth ions;
- and
- wherein the formation of insoluble Mn(III)-compounds is avoided.
2 more elements
A process for pickling plastic surfaces comprising:
- a) providing an oxidation cell comprising an anode space and a cathode space separated from each other by a membrane capable of allowing ions to pass through;
- b) disposing an anolyte in the anode space, the anolyte comprising a concentrated acid and a Mn ion releasing compound;
- c) disposing a catolyte in the cathode space, the catolyte comprising a diluted mineral acid;
- d) applying a current density to galvanically oxidatively form an acidic Mn(VII) containing treatment solution;
- and
- e) contacting the plastic surface to be pickled with the acidic Mn(VII) containing treatment solution inside the anode space or a working container connected to the anode space;
- wherein the acidic treatment solution is substantially free of chromium ions, alkali ions and alkaline earth ions.
4 more elements
Dependencies are inferred from the claim text.