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-free alkaline environment-friendly zinc plating additive. It is suitable for both the cyanide alkaline zinc plating process and the cyanide-free alkaline zinc plating process, and is especially suitable for the conversion of alkaline cyanide zinc electroplating to alkaline non-cyanide zincate zinc electroplating process. Background technique [0002] The zinc plating process is divided into alkaline zinc plating and acid zinc plating, and alkaline zinc plating is divided into cyanide zinc plating and non-cyanide zinc plating. The plating solution of the cyanide electroplating zinc process is composed of sodium hydroxide, zinc oxide and sodium cyanide, which is a production process that pollutes the environment. However, the national law prohibits the use of highly toxic cyanide and eliminates the cyanide electroplating process; cyanide-free alkaline platin...

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 addi...

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