Alkaline environmental-friendly zinc-plating additive for changing cyanogen process into cyanogen-free process

Abstract

The invention relates to an alkaline environmental-friendly zinc-plating additive for changing a cyanogen process into a cyanogen-free process. The additive comprises the following substances: at least one organic heterocyclic compound and derivative, at least one organic amine-epoxy halopropane polycondensate, wherein the molar ratio of the organic heterocyclic compound and derivative to an alicyclic amine compound and the polycondensate is 0.5-4.0:0.5-5.0. The additive overcomes the defects of severe environmental pollution caused by the conventional cyanogen zinc plating process. After sodium cyanide is stopped adding, the cyanogen zinc plating process can be gradually changed into a cyanogen-free environmental-friendly alkaline zinc plating process on the premise of not influencing normal production by adopting the zinc-plating additive.

Description

Technical field [0001] The invention belongs to a bright additive for electroplating zinc. More specifically, it is a cyanide-containing to cyanide-free alkaline environmentally friendly galvanizing additive. It is suitable for both the cyanide-containing alkaline zinc plating process and the cyanide-free alkaline zinc plating process, and is especially suitable for the conversion of alkaline cyanide electrolytic zinc plating to alkaline cyanide-free zincate electrolytic zinc plating process. Background technique [0002] The galvanizing process is divided into alkaline galvanizing and acid galvanizing, and alkaline galvanizing is divided into cyanide galvanizing and cyanide-free galvanizing. The plating solution of the cyanide-containing electroplating zinc plating process is composed of sodium hydroxide, zinc oxide and sodium cyanide, which is an environmentally polluting production process. However, national law prohibits the use of highly toxic cyanide, and the cyanide-c...

AI Technical Summary

Problems solved by technology

Therefore, it is the development trend of the electroplating industry to convert cyanide electrogalvanizing to cyanide-free alkali zinc zincate electroplating, but there are still some problems in order to realize such transformation: (1), in the electroplating production, whether to obtain bright , Meticulous and smooth effective coating, additives and additives are very important

But there are still deficiencies, the temperature range is narrow, generally in the range of 5-40 °C; the throwing ability is poor, and the thickness ratio of the high and low areas is large, generally around 4.0

(2) At present, the cyanide-free alkaline zincate galvanizing additives produced in China are difficult to achieve and surpass the unique advantages of cyanide-containing alkaline zincate galvanizing additives

The current range is narrow, easy to burn, generally only 1-2A / dm 2 Within the range; poor deep plating ability, complex workpieces especially with deep holes, it is difficult to obtain a bright coating at deep holes; the temperature range is narrow, generally in the range of 5-40 ° C, the workpiece is easy to black when the temperature is high, It is not bright; the throwing ability is poor, and the thickness ratio of the high and low areas is large, generally above 3.0. The technology in our country is still relatively backward, and the price of cyanide-free alkaline zincate galvanizing additives produced abroad is relatively high.

(3) Alkaline galvanizing process with cyanide is still common in China. There are tens of thousands of cyanide galvanizing manufacturers in the country, and cyanide galvanizing bath solution is calculated in hundreds of millions of tons. Such a large amount of sodium cyanide containing If all the cyanide-alkaline galvanizing baths are discarded or dumped, it will cause a large degree of environmental pollution and waste of resources, and it is not in line with national conditions.

(4) At present, there is no additive suitable for both the cyanide-based alkaline galvanizing process and the cyanide-free alkaline galvanizing process at home and abroad, that is, the cyanide-alkaline galvanizing process can be directly added without affecting normal production. Environmentally friendly galvanizing additives for direct conversion of galvanizing to cyanide-free alkaline galvanizing process

[0003] In view of the above reasons, in order to convert cyanide galvanizing to cyanide-free, the plating solution can only be poured out and a new cyanide-free bath solution can be reconfigured, which cannot achieve the ideal electroplating effect. This will not only bring a lot of waste of resources to the enterprise, Moreover, it has caused very serious environmental pollution, so most of the galvanizing processes in my country are still using toxic cyanide galvanizing.

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