METHOD OF DEPOSITION OF A PROTECTIVE COVER ON A SURFACE OF SILVER ITEMS Russian patent published in 2004 - IPC

FIELD: methods of electro-chemical deposition of protective covers on surfaces of items made out of silver and its alloys.

SUBSTANCE: the invention presents a method of electro-chemical deposition of protective covers on surfaces of items made out of silver and its alloys with copper, that may be used for production of medals, cutleries, wares, jewels, etc. for their protection against tarnish. The method provides for a cathodic treatment of items previously degreased in an electrolyte containing, g/l: potassium chromate - 80-120 and sodium carbonate - 60-80 at the cathodic current density of 0.4-0.8 А/decimeter within 2-10 minutes at the temperature of 5-60°С with the anode made out of graphitized carbon material, the subsequent washing and a drying. The technical result: spreading of the method functionalities at the expense of application of protective covers, that are visually not observable on items made out of silver and its alloys with copper, an intensification and simplification of the method. Besides, the method is effective even in the cases, when treated items already have stains.

EFFECT: the invention allows to apply the protective covers, that are visually not observable even on items with stains.

2 cl, 3 ex