Method for continuously cleaning and passivating copper and copper alloy

Abstract

The invention relates to a method for continuously cleaning and passivating copper and copper alloy, belonging to the technical field of metal surface chemical processing. The method comprises the steps of: scrubbing and degreasing, rinsing with cold water, acid cleaning, scrubbing with cold water, rinsing with hot water, passivating and drying, and is characterized in that in the passivation, passivation solution adopts aqueous solution of benzotriazole or benzotriazole derivatives, and copper ion complexing agent is added in the passivation solution. The method for continuously cleaning and passivating copper and copper alloy adds the copper ion complexing agent in the passivation solution in an adding way, and the copper ion complexing agent preferably complexes with copper ions to lead the passivation solution to be in a solution state for a longer time, thus slowing down the reaction between the effective component benzotriazole and benzotriazole derivatives of the passivation solution and the copper ions. The method has reasonable design, simple operation and less pollution to the environment, saves the cost and improves the service life of the passivation solution, and the obtained copper and copper alloy have good surface quality.

Description

technical field [0001] The invention belongs to the technical field of metal surface chemical treatment, in particular to a method for continuous cleaning and passivation of copper and copper alloys. Background technique [0002] Copper and copper alloys are metals with high corrosion resistance, but electrochemical corrosion and oxidation are prone to occur in high-temperature and high-humidity environments, resulting in discoloration, which affects the quality and appearance of copper and copper alloys. In order to prevent discoloration, benzene is usually used An aqueous solution of triazole and its derivatives or an organic solution is used for anti-discoloration and passivation treatment of copper and copper alloy, and the treatment method is dipping or spraying. [0003] Copper strips include copper alloy strips, which are generally processed by rolling, annealing and other processes in the middle, and finally passivated to maintain the oxidation resistance of the copp...

AI Technical Summary

Problems solved by technology

[0010] Although in the continuous cleaning process, rubber rollers are used to squeeze and reflow between each process to prevent the substances in the previous process from being carried into the next process, but in the actual production process, it is impossible to completely eliminate the impact of the previous process on the next process. The pollution of the process, as time goes by, the accumulation of pollutants to a certain amount will affect the quality of the surface of the copper strip

Especially the sulfuric acid in the pickling tank and the pickling reactants copper sulfate, zinc sulfate, and tin sulfate are attached to the surface of the copper strip and brought into the passivation tank, resulting in the pollution of the passivation solution and affecting the passivation effect.

[0011] Copper strip passivation treatment uses aqueous solution of benzotriazole or its derivatives. The copper ions brought into the passivation tank react with benzotriazole or its derivatives, and accumulate and condense at high temperature (70°C) for a long time This leads to the generation of suspended matter, which is easily bonded to the surface of the copper strip. After being squeezed by the extrusion roller, spots are formed, and the color changes over time, which affects the quality of the copper strip.

[0012] Replacing the passivation solution in a short period of time can solve this problem, but the volume of the passivation tank is generally at least 1 ton, which causes waste and increases the cost of wastewater treatment

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