METHOD OF PRODUCTION OF PROTECTIVE COATINGS ON THE SURFACE OF ITEMS MADE OUT OF ALLOYS BASED ON COPPER Russian patent published in 2004 - IPC

FIELD: electrochemistry; production of protective coatings on surfaces of items made out of alloys based on copper.

SUBSTANCE: the invention is dealt with electrochemistry, in particular with application of protective coatings on surfaces of items made out of alloys based on copper, mainly out of German silver, and may be used at production of souvenirs, jewelry, cutleries, etc. The method provides for anodic treatment of items made out of German silver in a water solution containing: 100-200 g/l of potassium hydroxide at anodic current density of 2-20 А/dcm² within 6-10 minutes at the temperature of 5-70°С with the cathode made out of German silver. The invention allows to realize the method at a rather high-density of current in a broad temperature range and to apply on items made out of German silver the colorless protective coatings keeping the items original appearance for a long time of storage.

EFFECT: the invention allows to produce the colorless protective coatings on items made out of German silver and keep the items original appearance for a long time of storage.

2 ex