Electroplating solution without cyanogen for plating silver

Abstract

This invention provides a cyanide-free silver-electroplating solution, which comprises: silver-containing organic or inorganic salt 1-200 g/L, purin coordination agent 1-800 g/L, supporting electrolyte 1-200 g/L, pH regulator 0-550 g/L, and additive system. The preparation method comprises: uniformly mixing the above components to prepare the cyanide-free silver-electroplating solution, and adjusting the temperature to 10-60 deg.C. Compared with the traditional formula, the cyanide-free silver-electroplating solution in this invention has such advantages as low or no toxicity, and high stability. Silver ions have a very low displacement rate with copper, nickel, iron, aluminum, chrome, titanium and alloy matrices. The work piece to be plated does not need preliminary silver plating or silver dipping. The silver-electroplating layer has such advantages as high adhesiveness and high shinness, and can be used in decorative and functional electroplating fields.

Description

technical field [0001] The invention belongs to the technical field of electrochemical silver plating, and in particular relates to a cyanide-free silver plating electroplating solution. Background technique [0002] The silver-plated layer has high conductivity, light reflection ability, high chemical stability to organic acids and alkalis, and its price is cheaper than other precious metals. It has been widely used in decorations, tableware and electronic products and other fields. So far, most of the domestic and foreign electroplating silver processes still adopt the cyanide silver plating process to electroplate the silver layer, mainly due to the good stability of the plating solution, good plating ability and depth capability, fine crystallization of the coating, and silvery white appearance. However, cyanide is highly toxic and extremely harmful to the human body and the environment. Good exhaust equipment and wastewater treatment conditions are required during produ...

AI Technical Summary

Problems solved by technology

Compared with cyanide silver plating, there are still many shortcomings in cyanide-free silver plating. The main problems are: (1) The stability of the plating solution

The stability of many cyanide-free silver plating solutions is not good, whether it is an alkaline plating solution, an acidic plating solution or a neutral plating solution, there are problems with the stability of the plating solution to varying degrees, which brings inconvenience to management and operation, and also reduces the cost. increased by

(2) The cost of plating solution is higher

It not only seriously affects the bonding force between the silver plating layer and the substrate, but also the iron and copper ions generated during the replacement process will pollute the plating solution

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