A pickling agent for nickel-plated layer-free corroded copper alloy and its application

Abstract

The present invention discloses a nickel-plated layer non-corrosive copper alloy pickling agent and its application. It includes a cationic emulsifier and a corrosion inhibitor. The nickel-plated layer non-corrosive copper alloy pickling agent of the present invention can effectively remove the oxide film on the surface of copper metal, restore the bright appearance of copper metal, and will not cause corrosion and discoloration to the copper nickel-plated layer, improve product quality and production efficiency, effectively solve the problem of precipitation of the corrosion inhibitor under acidic conditions, and improve the stability and service life of the pickling agent.

Description

Technical Field

[0001] The present invention relates to the field of light surface treatment of copper and copper alloys, and specifically to an acid pickling agent for copper alloys without corrosion of nickel plating layer. Background Art

[0002] The frame structure inside the battery box of new energy vehicles is composed of plastic and ear tabs, and the material of the ear tabs is composed of copper and copper nickel plating. The ear tabs and the plastic frame are assembled by thermoplastic molding. During this process, the surface of the copper ear tabs reacts with oxygen to form copper oxide, losing the original color and luster of the metal. It reacts with SO2 in the air to form a black copper sulfide film layer. When it comes into contact with humid air containing carbon dioxide, it will also form green basic copper carbonate, while the copper nickel plated ear tabs will not change color. In order to remove the oxide film, sulfide film and basic copper carbonate film layer on the copper surface and restore the gloss of the copper metal, bright acid pickling of copper and copper alloys is required. However, ordinary acid pickling agents will cause corrosion and discoloration of the copper nickel plating layer while removing the oxide film on the copper metal surface, and even dissolve the nickel plating layer. At present, there are few reports in the relevant materials of acid pickling agents for copper and copper alloys that can avoid the corrosion of the copper nickel plating layer. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides an acid pickling agent for copper alloys without corrosion of nickel plating layer, which solves the problem that the existing copper alloy acid pickling agent will cause corrosion and discoloration of the copper nickel plating layer while removing the oxide film on the copper metal surface.

[0004] To achieve the above object, the present invention is realized through the following technical solutions: An acid pickling agent for copper alloys without corrosion of nickel plating layer, comprising a cationic emulsifier and a corrosion inhibitor.

[0005] Further, by mass percentage, the cationic emulsifier is 2 - 5%, and the corrosion inhibitor is 1 - 2%.

[0006] Further, the cationic emulsifier is dodecyl dimethyl benzyl ammonium chloride and / or cetyl trimethyl ammonium bromide.

[0007] Further, the corrosion inhibitor is methyl benzotriazole, hexamine and / or alkyl phosphate ester.

[0008] Further, the acid pickling agent for copper alloys without corrosion of nickel plating layer further comprises concentrated sulfuric acid, organic acid, oxidant, non - ionic surfactant and stabilizer.

[0009] Further, by mass percentage, concentrated sulfuric acid is 0.5 - 1%, organic acid is 2 - 5%, oxidant is 10 - 20%, cationic emulsifier is 2 - 5%, non - ionic surfactant is 1 - 5%, stabilizer is 2 - 5%, and corrosion inhibitor is 1 - 2%.

[0010] Further, the organic acid is citric acid and / or acetic acid.

[0011] Further, the oxidizing agent is hydrogen peroxide.

[0012] Further, the non-ionic surfactant is alkylphenol polyoxyethylene ether (TX-10) and / or sorbitan fatty acid ester (Span 80).

[0013] Further, the stabilizer is ethanol and / or ethylene glycol.

[0014] The present invention provides the application of the nickel-plated layer non-corrosive copper alloy pickling agent in copper and copper-nickel plated workpieces.

[0015] Further, the method is as follows: Dilute the nickel-plated layer non-corrosive copper alloy pickling agent with water to prepare a solution with a mass percentage concentration of 30-50%, and immerse the copper and copper-nickel plated workpieces for 1-2 minutes.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. The nickel-plated layer non-corrosive copper alloy pickling agent of the present invention can effectively remove the oxide film on the surface of copper metal, restore the bright appearance of copper metal, and will not cause corrosion and discoloration to the copper-nickel plating layer, improving product quality and production efficiency.

[0018] 2. The nickel-plated layer non-corrosive copper alloy pickling agent of the present invention can effectively solve the problem of inhibitor precipitation under acidic conditions, improving the stability and service life of the pickling agent. Specific embodiments

[0019] The technical solutions of the present invention will be clearly and completely described below through examples. Obviously, the described examples are only a part of the examples of the present invention, rather than all the examples. All other examples obtained by those of ordinary skill in the art based on the examples of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] A nickel-plated layer non-corrosive copper alloy pickling agent is made from the following raw materials by mass percentage: concentrated sulfuric acid 0.5-1%, organic acid 2-5%, oxidizing agent 10-20%, cationic emulsifier 2-5%, non-ionic surfactant 1-2%, stabilizer 2-5%, corrosion inhibitor 1-2%, and the balance is water.

[0021] In the present invention, the organic acid is citric acid and / or acetic acid, which has the effect of accelerating the removal of the oxide film. Citric acid also has the effect of complexing copper ions and preventing them from accelerating the decomposition of hydrogen peroxide.

[0022] In the present invention, the oxidizing agent is hydrogen peroxide.

[0023] In the present invention, the cationic emulsifier is dodecyldimethylbenzylammonium chloride and / or cetyltrimethylammonium bromide, which has the function of emulsifying phosphate ester and improving its stability under acidic conditions.

[0024] In the present invention, the non-ionic surfactant is TX-10 (alkylphenol polyoxyethylene ether) and / or Span 80 (sorbitan fatty acid ester). The non-ionic surfactant has the function of emulsifying phosphate ester, improving its stability under acidic conditions, and can also improve the brightness of the copper metal surface.

[0025] In the present invention, the stabilizer is ethanol and / or ethylene glycol, which can improve the stability of hydrogen peroxide and also play a role in assisting brightness.

[0026] In the present invention, the corrosion inhibitor is methylbenzotriazole, hexamethylenetetramine and / or alkyl phosphate ester, which has the function of preventing the corrosion and discoloration of copper alloy and nickel-plated copper layer.

[0027] In an example of the present invention, the nickel-plated layer non-corrosive copper alloy pickling agent is composed of the following components in mass percentage:

[0028] Concentrated sulfuric acid 1%, organic acid 2%, oxidant 10%, cationic emulsifier 5%, non-ionic surfactant 1%, stabilizer 5%, corrosion inhibitor 2%, and the balance is pure water.

[0029] Or concentrated sulfuric acid 0.5%, organic acid 5%, oxidant 20%, cationic emulsifier 2%, non-ionic surfactant 5%, stabilizer 2%, corrosion inhibitor 1%, and the balance is pure water.

[0030] To further illustrate the present invention, the following is a detailed description of a nickel-plated layer non-corrosive copper alloy pickling agent provided by the present invention in combination with examples, but it should not be construed as a limitation to the protection scope of the present invention.

[0031] Example 1

[0032] A nickel-plated layer non-corrosive copper alloy pickling agent, in mass percentage, is composed as follows: concentrated sulfuric acid 1%, citric acid 2%, hydrogen peroxide 10%, dodecyldimethylbenzylammonium chloride 5%, TX-10 1%, ethanol 5%, methylbenzotriazole 0.01%, hexamethylenetetramine 1%, alkyl phosphate ester 0.5%, and the balance is pure water.

[0033] Preparation method: Take materials according to the above raw material ratio and stir evenly.

[0034] During use, dilute the above pickling agent with water to form a pickling agent aqueous solution with a mass concentration of 40%. Immerse the degreased copper and nickel-plated copper workpieces in the pickling agent aqueous solution for 1 minute, wash with water and then dry, and conduct appearance inspection.

[0035] If the processed copper and copper-nickel plated workpieces restore the metallic luster of copper and the nickel plating layer does not show corrosion or discoloration, it is regarded as qualified in terms of product appearance quality. The test results are shown in Table 1.

[0036] Example 2

[0037] A copper alloy pickling agent without corrosion of nickel plating layer, by mass percentage, consists of the following components: concentrated sulfuric acid 1%, citric acid 5%, hydrogen peroxide 20%, dodecyldimethylbenzylammonium chloride 5%, TX-10 1%, ethanol 5%, methylbenzotriazole 0.01%, hexamine 1%, alkyl phosphate 0.5%, and the balance is pure water.

[0038] Preparation method: Take materials according to the above raw material ratio and stir evenly.

[0039] When in use, dilute the above pickling agent with water to form a pickling agent aqueous solution with a mass concentration of 40%. Immerse the degreased copper and copper-nickel plated workpieces in the pickling agent aqueous solution for 1 min, wash with water and then dry, and conduct appearance inspection.

[0040] If the processed copper and copper-nickel plated workpieces restore the metallic luster of copper and the nickel plating layer does not show corrosion or discoloration, it is regarded as qualified in terms of product appearance quality. The test results are shown in Table 1.

[0041] Example 3

[0042] A copper alloy pickling agent without corrosion of nickel plating layer, by mass percentage, consists of the following components: concentrated sulfuric acid 0.5%, acetic acid 2%, hydrogen peroxide 10%, cetyltrimethylammonium bromide 2%, span 80 5%, ethylene glycol 2%, methylbenzotriazole 0.01%, hexamine 0.5%, alkyl phosphate 0.5%, and the balance is pure water.

[0043] Preparation method: Take materials according to the above raw material ratio and stir evenly.

[0044] When in use, dilute the above pickling agent with water to form a pickling agent aqueous solution with a mass concentration of 40%. Immerse the degreased copper and copper-nickel plated workpieces in the pickling agent aqueous solution for 1 min, wash with water and then dry, and conduct appearance inspection.

[0045] If the processed copper and copper-nickel plated workpieces restore the metallic luster of copper and the nickel plating layer does not show corrosion or discoloration, it is regarded as qualified in terms of product appearance quality. The test results are shown in Table 1.

[0046] Example 4

[0047] A pickling agent for copper alloy without corrosion of nickel plating layer, by mass percentage, the composition is as follows: concentrated sulfuric acid 0.5%, acetic acid 5%, hydrogen peroxide 20%, cetyltrimethylammonium bromide 2%, span 80 5%, ethylene glycol 2%, methylbenzotriazole 0.01%, hexamine 0.5%, alkyl phosphate 0.5%, and the balance is pure water.

[0048] Preparation method: Take materials according to the above raw material ratio and stir evenly.

[0049] During use, dilute the above pickling agent with water to form an aqueous pickling agent solution with a mass concentration of 40%, immerse the degreased copper and copper-nickel plated workpieces in the aqueous pickling agent solution for 1 minute, wash with water and then dry, and conduct appearance inspection.

[0050] If the copper and copper-nickel plated workpieces obtained after treatment restore the metallic luster of copper and the nickel plating layer does not show corrosion and discoloration, it is regarded as qualified product appearance quality, and the test results are shown in Table 1.

[0051] Table 1 shows the removal of copper metal oxide film and the corrosion and discoloration of copper-nickel plating layer

[0052] Process Removal situation of copper metal oxide film Corrosion and discoloration situation of copper nickel plating layer Example 1 Completely removed Slightly discolored Example 2 Completely removed Discolored Example 3 Slightly residual No discoloration Example 4 Completely removed No discoloration

[0053] The pickling agent composed of the above components in the present invention is used for pickling the smooth surface of copper and copper alloy, which can effectively remove the oxide film on the surface of copper metal, restore the bright appearance of copper metal, and at the same time will not cause corrosion and discoloration to the copper-nickel plating layer, improve the product quality and production efficiency, effectively solve the problem of inhibitor precipitation under acidic conditions, and improve the stability and service life of the pickling agent.

[0054] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made in these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An acid pickling agent for nickel-plated layer-free corroded copper alloy, characterized in that, The nickel-plated layer non-corrosive copper alloy pickling agent comprises concentrated sulfuric acid, organic acid, oxidant, non-ionic surfactant, stabilizer, cationic emulsifier and corrosion inhibitor; The organic acid is citric acid or acetic acid; The oxidant is hydrogen peroxide; The non-ionic surfactant is alkylphenol polyoxyethylene ether and / or sorbitan fatty acid ester; The stabilizer is ethanol and / or ethylene glycol; The cationic emulsifier is dodecyl dimethyl benzyl ammonium chloride and / or cetyl trimethyl ammonium bromide; The corrosion inhibitor is methyl benzotriazole, hexamine and alkyl phosphate ester.

2. The pickling agent for nickel - plated layer - free corroded copper alloy according to claim 1, characterized in that, By mass percentage, the cationic emulsifier is 2-5%, and the corrosion inhibitor is 1-2%.

3. The acid pickling agent for nickel-plated layer-free corrosion copper alloy according to claim 2, wherein By mass percentage, concentrated sulfuric acid is 0.5-1%, organic acid is 2-5%, oxidant is 10-20%, cationic emulsifier is 2-5%, non-ionic surfactant is 1-5%, stabilizer is 2-5%, and corrosion inhibitor is 1-2%.

4. Application of the nickel-plated layer non-corrosive copper alloy pickling agent according to claim 1, 2 or 3 in copper and copper nickel-plated workpieces.

5. The application according to claim 4, characterized in that The method is as follows: Using water as a diluent, the nickel-plated layer non-corrosive copper alloy pickling agent is formulated into a solution with a mass percentage concentration of 30-50%, and the copper and copper nickel-plated workpieces are soaked for 1-2 minutes.