Trivalent chromium plating solution composite, preparation method thereof and chromium plating process

Abstract

The invention aims at providing a trivalent chromium plating solution composite, preparation and chromium plating process thereof. The plating solution composite comprises main salt, conductive salt, a pH stabilizing agent, a complexing agent, a wetting agent and a displacement agent; and five addition agents of a cylinder opening agent, a stabilizing agent, a bending agent, a modifying agent and a regulating agent are adopted and added to the main salt, the conductive salt, the pH stabilizing agent, the complexing agent, the wetting agent and the displacement agent to be prepared into the plating solution composite. The chromium plating process adopting the plating solution composite has characteristics of high current efficiency, good displacement performance, simple management, lower cost and the like; the obtained plating layer is bright and is close to a product obtained through a hexavalent chromium process in color and lustre.

Description

technical field [0001] The invention relates to the field of chromium electroplating, in particular to a trivalent chromium electroplating process. Background technique [0002] The hexavalent chromium plating process is very mature in the application of functional and decorative coatings. However, hexavalent chromium is very toxic, and the wastewater of hexavalent chromium cannot be naturally degraded in nature. It is enriched in organisms and human bodies, forming long-term hazards. It is a carcinogen with strong toxicity and serious environmental pollution, and its use has been banned in various countries at present. At the same time, hexavalent chromium plating has the disadvantages of low current efficiency, poor dispersion and coverage, and the chromium mist in the plating tank is harmful to the human body. In contrast, the toxicity of trivalent chromium electroplating is only one percent of that of hexavalent chromium, and the wastewater is easy to treat. The plating...

AI Technical Summary

Problems solved by technology

[0002] The hexavalent chromium plating process is very mature in the application of functional and decorative coatings. However, hexavalent chromium is very toxic, and the wastewater of hexavalent chromium cannot be naturally degraded in nature. It is enriched in organisms and human bodies, forming long-term hazards. It is a highly toxic carcinogen, and at the same time seriously pollutes the environment. It is currently banned by all countries.

Among them, the plating solution contains ferric chloride which can improve the covering ability of the plating solution, but the color of the plating layer varies with the current, which will cause different colors of the plating layer during use and cannot be applied to production; CN101660182A provides a trivalent chromium plating solution Stabilizer and its electroplating solution, the stabilizer is composed of methanol 0.5-2mol / L, sodium sulfite 0.4-2.0mol / L, iron sulfite 0.5-2.5mol / L

The method of use is to add this stabilizer to the plating solution in an amount of 1-30ml / L. Due to the addition of the stabilizer, the plating solution is relatively stable and no chlorine gas is precipitated, but it is troublesome and expensive to use a coated anode. can not continue to thicken

Provide a kind of sulfate trivalent chromium electroplating solution and preparation method among CN101665960A, its composition comprises main salt, complexing agent, conductive salt, pH stabilizer, plating bath stabilizer, surfactant and accelerator, and its formulation method is cumbersome, The anode adopts stainless steel anode, which will dissolve in the plating solution, so that the iron ion in the plating solution is too high, and the coating will turn black

CN101717975A provides a trivalent chromium plating solution, a preparation method and its application in electroplating stainless steel workpieces. The concentration of each component of the plating solution is: chromium chloride hexahydrate 15-20g / L, ammonium formate 40-60g / L, chloride Potassium 70-80g / L, potassium sulfate 40-50g / L, ammonium chloride 90-100g / L, ammonium bromide 8-12g / L, boric acid 40-70g / L, polyoxyethylene octylphenol ether 2ml / L, glycerol 2ml / L, sulfuric acid to adjust the pH to 4-5, and graphite as the anode, but this method will produce chlorine gas during use, which will cause certain pollution to the environment

[0004] To sum up, the existing trivalent chromium electroplating method, the sulfate type needs to use titanium metal as the anode, which is expensive. If stainless steel or coating is used instead of titanium as the anode, it is easy to dissolve or cause the coating to detach and pollute Plating solution

At the same time, the sulfate-type trivalent chromium plating solution has low current efficiency and poor positioning performance; while the chloride-type trivalent chromium plating solution has low cost, high current efficiency, good electrical conductivity, and good positioning performance, but it is stable. Poor performance, easy to precipitate chlorine gas, have certain pollution to the environment, and have certain difficulties in management

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