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Title
Vorrichtung und Verfahren zur Regenerierung chromsaeurehaltiger Loesungen in elektrolytischen Verchromungsbaedern
Date Issued
2002
Author(s)
Fryda, M.
Schaefer, L.
Wurm, J.
Patent No
2001-10111727
Abstract
Die vorliegende Erfindung betrifft eine Vorrichtung zur Verchromung, wobei als Arbeitsanoden zur Abscheidung von Chrom und zur Oxidation von gebildetem Chrom III-Ionen zur Chrom VI-Ionen unterschiedliche Elektroden eingesetzt werden, und als Oxidationsanode eine Elektrode eingesetzt wird, die eine leitende Diamantschicht auf einem Grundkoerper aufweist.
WO 200272924 A UPAB: 20030214 NOVELTY - Chroming apparatus comprises: (1) a working anode(s) for deposition; and (2) a separate oxidation anode(s), for oxidation of the Chromium (III) ions to Chromium (IV) ions, that is an electrode with a conductive diamond coating on a substrate. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a chromating process, in which different anodes are used for deposition and oxidation of Chromium (III) ions to Chromium (IV) ions, in which the oxidation anode as above is used. USE - Used for regenerating solutions containing chromic acid by anodic oxidation of Chromium (III) to Chromium (IV) in electrolytic chromating baths, which are used for electroplating, chromation, etching e.g. acrylonitrile-butadiene-styrene (ABS) plastics and anodizing e.g. aluminum. ADVANTAGE - Chromium plating is normally carried out with lead anodes, which combine a double function, as counter-electrode (working electrode) and oxidation anode. In anodic operation, it becomes coated with lead dioxide. However, lead anodes form sludge and have limited dimensional stability. Various coated titanium anodes avoid this problem but have other drawbacks, including the need to add lead. The novel apparatus with the diamond-coated oxidation anode ensures effective oxidation of Chromium (III) to Chromium (IV) without costly maintenance procedures. The process is flexible and simple, even with complex geometries and structures, e.g. internal in plating of pipes and it eliminates the need to add lead and its associated drawbacks.
Language
de
Patenprio
DE 2001-10111727 A: 20010309