A water-based cleaning agent for copper alloy and a preparation method thereof

Abstract

The application discloses a water-based cleaning agent special for copper alloy and a preparation method thereof, and belongs to the technical field of metal surface cleaning. The application aims at solving the problems that existing cleaning agents are prone to cause over corrosion and surface loss of luster when cleaning copper alloy, cannot efficiently remove copper green / oxide scale / fingerprint, the cleaned copper alloy is prone to rapid oxidation and discoloration, and a single product cannot simultaneously remove oil, oxide and prevent discoloration. The application is composed of the following components in percentage by weight: 8%-20% of a composite oil-removing and oxide-removing agent, 5%-15% of a special anti-discoloring agent for copper alloy, 2%-6% of a mild alkaline adjusting agent, 3%-8% of a complexing and washing aid, 2%-5% of a solubilizing stabilizer, 1%-5% of a water treatment agent, 0.05%-0.2% of a low-foam organic silicon defoaming agent, and the balance of deionized water. The application is suitable for all copper alloy materials such as red copper, brass, bronze and white copper, meets the cleaning requirements of copper alloy parts in the fields of electronic appliances, hardware and bathroom, precision machinery and pipelines and pipe fittings, and does not affect subsequent electroplating, polishing, coating and bonding processes.

Description

Technical Field

[0001] This invention belongs to the field of metal surface cleaning technology, specifically relating to a water-based cleaning agent for copper alloys and its preparation method. This invention is suitable for cleaning contaminants such as oil, oxide scale, verdigris, fingerprints, and cutting fluid residue from the surfaces of copper alloy parts and products. It is applicable to copper alloys such as red copper, brass, bronze, and cupronickel, and simultaneously achieves the dual effects of preventing discoloration and secondary oxidation after cleaning. Background Technology

[0002] Copper alloys possess excellent electrical and thermal conductivity, ductility, and corrosion resistance, making them widely used in electronics, electrical appliances, hardware and sanitary ware, precision machinery, aerospace, and piping fittings. However, copper alloy surfaces are prone to the formation of oxidation products such as verdigris (basic copper carbonate) and cuprous oxide, leading to excessive corrosion during cleaning and rapid discoloration after cleaning. Existing cleaning agents struggle to simultaneously address the material properties of copper alloys and their protective requirements.

[0003] During processing, storage, transportation, and use, copper alloy parts are prone to the adhesion of rolling oil, cutting oil, stamping oil, emulsion residue, dust, and metal shavings. They are also susceptible to the formation of natural oxide scale, verdigris, and fingerprints left by human contact. Therefore, efficient cleaning and protection of surface gloss are necessary to ensure the quality of subsequent electroplating, polishing, assembly, and coating processes.

[0004] Traditional solvent-based cleaning agents are flammable and explosive, with high emissions of volatile organic compounds (VOCs), which can easily cause environmental pollution and harm the health of operators. Their function is mainly limited to degreasing, and they are difficult to remove oxide scale or verdigris. Furthermore, they cannot provide effective protection for copper alloy surfaces after cleaning, which can easily lead to rapid oxidation and discoloration.

[0005] Ordinary water-based cleaning agents often use a strongly alkaline system, which can easily cause excessive corrosion to copper alloys, resulting in surface dullness and pitting. At the same time, they lack anti-discoloration function, and oxidation spots will appear shortly after cleaning.

[0006] General-purpose metal cleaners do not have a dedicated system for removing oxidation and preventing discoloration of copper alloys. They have low efficiency in removing verdigris and oxide scale, and it is difficult to maintain the original luster of copper alloys after cleaning, resulting in poor compatibility. Summary of the Invention

[0007] The purpose of this invention is to provide a specialized water-based cleaning agent with a mild, weakly alkaline system that prevents discoloration and maintains gloss on copper alloy surfaces after cleaning. This agent balances cleaning efficiency with copper alloy surface protection, eliminating the need for an additional discoloration prevention step. It addresses the problems of existing cleaning agents causing over-corrosion and surface dulling when cleaning copper alloys, their inability to effectively remove verdigris / oxide / fingerprints, the rapid oxidation and discoloration of copper alloys after cleaning, and the inability of a single product to simultaneously address degreasing, oxidation removal, and discoloration prevention.

[0008] To address the aforementioned technical problems, the present invention adopts the following technical solution: The purpose of this invention is to provide a water-based cleaning agent specifically for copper alloys, characterized by comprising the following components by weight percentage: 8%-20% compound degreasing and deoxidizing agent, 5%-15% copper alloy special anti-discoloration agent, 2%-6% mild alkaline regulator, 3%-8% complexing detergent aid, 2%-5% solubilizing stabilizer, 1%-5% water treatment agent, 0.05%-0.2% low-foaming silicone defoamer, and the remainder is deionized water.

[0009] Further specifying, the composite degreasing and impurity removal agent is a compound of fatty alcohol polyoxyethylene ether (AEO-9), dispersant (Haomeite FS-1), and organic carboxylic acid in a mass ratio of 1:2:2. This compound achieves the emulsification and dispersion of oil stains on the copper alloy surface and the complexation and removal of light oxide scale / verdigris, taking into account both degreasing and deoxidation effects. The compound of AEO-9 and the dispersant forms a mild nonionic surfactant system with good emulsification and dispersion performance of oil stains and is non-corrosive. The organic hydroxycarboxylic acid can complex copper oxide and verdigris on the copper alloy surface, achieving gentle removal of the light oxide layer without damaging the copper alloy substrate, thereby maintaining the surface gloss.

[0010] Furthermore, the dispersant is specified as Homite FS-1.

[0011] To further specify, the organic carboxylic acid is one or more of dodecanoic acid, octanoic acid, and p-tert-butylbenzoic acid in any proportion.

[0012] Furthermore, the copper alloy-specific anti-tarnishing agent is a compound of benzotriazole (BTA) and methylbenzotriazole (TTA) in a mass ratio of 1:0.6. It forms a dense adsorption protective film on the surface of the copper alloy, preventing oxygen and moisture from contacting the copper alloy and achieving long-term anti-tarnishing. BTA and TTA can form a stable complex film with copper ions. The organic amine carboxylate synergistically enhances the film-forming effect, making the protective film denser and achieving long-term anti-tarnishing function between processes without affecting the adhesion of subsequent electroplating, bonding and other processes.

[0013] Further specifying, the mild alkaline regulator is a compound of triethanolamine and monoethanolamine in a mass ratio of 2:1 to adjust the system to a weak alkaline state, assisting in cleaning and avoiding over-corrosion of copper alloys. This mild alkaline regulator is used to stabilize the pH value of the system in a weak alkaline range of 8.5–10.0, assisting in the saponification and decomposition of oil stains; its alkalinity is mild and will not cause excessive corrosion or surface dulling of copper alloys.

[0014] Furthermore, the complexing cleaning agent is tetrasodium EDTA, which can efficiently complex the copper ions stripped off during the cleaning process, preventing copper ions from redepositing on the copper alloy surface and causing discoloration or mottling. At the same time, it has the function of dispersing and suspending dirt, avoiding secondary adhesion of dirt.

[0015] Furthermore, the solubilizing stabilizer is AEO-9, which improves the compatibility of each functional component, ensures long-term stability of the system, and prevents oil separation and floating.

[0016] Further specifying, the water treatment agent is hydroxyethylidene diphosphonic acid (HEDP).

[0017] Further specifying, the low-foaming silicone defoamer is a polyether-modified silicone, such as B237 from Guangdong Zhongke Hongtai New Materials.

[0018] Another objective of this invention is to provide a method for preparing the aforementioned water-based cleaning agent specifically for copper alloys.

[0019] A method for preparing a water-based cleaning agent specifically for copper alloys includes the following steps: Step 1: While stirring at 180-220 r / min, add a mild alkaline regulator and a complexing detergent to the deionized water in sequence, stirring until completely dissolved, and stabilize the pH value at 8.5-10.0. Step 2: Add the copper alloy-specific anti-discoloration agent and continue stirring until evenly dispersed; Step 3: Then, adjust the stirring speed to 250-300 r / min, add the composite degreasing and impurity removal agent, water treatment agent, and low-foaming silicone defoamer in sequence, stir until uniform, let stand to defoam, and filter through a 200-mesh filter to obtain a water-based cleaning agent for copper alloys.

[0020] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a multi-effect cleaning solution with excellent efficiency: the composite degreasing and deoxidizing agents work synergistically to simultaneously and efficiently remove rolling oil, cutting oil, and other oil stains from the surface of copper alloys, as well as verdigris, light oxide scale, and fingerprints. Immersion / spraying for 4-8 minutes at room temperature can completely remove contaminants without residue or stains, and the cleaning efficiency is more than 50% higher than that of general cleaning agents. This invention provides exclusive protection against discoloration and maintains luster: The special anti-discoloration system forms a dense complex adsorption film on the surface of copper alloys. After cleaning, no additional anti-discoloration process is required. It can prevent discoloration and secondary oxidation on the surface of copper alloys such as red copper, brass, and bronze for 15-30 days, maintaining the original metallic luster of the copper alloys without oxidation spots or discoloration. This invention is mild and non-corrosive, with no surface damage: the system is a mild, weakly alkaline formula of 8.5-10.0, which does not cause over-corrosion, pitting, or loss of gloss on copper alloys. After cleaning, the surface finish meets the standards and satisfies the requirements for use of precision copper alloy parts. This invention is environmentally friendly and safe, and complies with regulations: the water-based system poses no risk of flammability or explosion, has zero VOC emissions, and meets industrial environmental protection requirements; the system has no irritating odor, does not irritate the skin of operators, and is safe and reliable to use; The system of this invention is stable and has a wide range of applications: the solubilizing stabilizer improves the compatibility of each component, and the finished product can be stored at room temperature for more than 12 months without stratification, precipitation or oil floating. It can be used normally in the temperature range of 0℃~55℃ and is suitable for different industrial production scenarios. This invention boasts low operating costs and high versatility: it can be directly diluted (dilution ratio 1:5-50), eliminating the need for rinsing after cleaning, thus saving water resources and cleaning time; it integrates degreasing, deoxidation, and anti-discoloration, reducing the separate anti-discoloration process and raw material costs, resulting in a comprehensive cost reduction of over 35% compared to traditional solvent-based cleaning agents; it is suitable for all copper alloy materials such as copper, brass, bronze, and cupronickel, meeting the cleaning needs of copper alloy parts in fields such as electronics, hardware and sanitary ware, precision machinery, and pipe fittings, without affecting subsequent electroplating, polishing, coating, and bonding processes.

[0021] For a deeper understanding of the features and technical content of this invention, please refer to the accompanying detailed description and drawings. It should be noted that the drawings are provided for illustrative purposes only and are not intended to limit the scope of the invention. Attached Figure Description

[0022] Figure 1 A is a copper alloy sample after being cleaned with the cleaning agent of this invention (and left for 5 days). Figure 1 B is a copper alloy that has been cleaned with a common water-based cleaning agent (and left to stand for 5 days). Figure 2 This refers to the oil removal rate in Example 1; Figure 3 This refers to the oil removal rate in Example 2. Detailed Implementation

[0023] The present invention will be described in detail below with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but should not be considered as limiting the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0024] Example 1: The water-based cleaning agent for copper alloys in this example is composed of the following components by weight percentage: 13% compound degreasing and deoxidizing agent, 5% copper alloy special anti-discoloration agent, 10% mild alkaline regulator, 5% complexing detergent, 1% solubilizing stabilizer, 2% water treatment agent, 0.01% low-foaming silicone defoamer, and the remainder is deionized water.

[0025] The composite degreasing and impurity-removing agent is formulated by combining fatty alcohol polyoxyethylene ether (AEO-9), dispersant (Haomeite FS-1), and organic carboxylic acid (octanoic acid: p-tert-butylbenzoic acid = 1:1) in a mass ratio of 1:2:2. The copper alloy-specific anti-discoloration agent is a compound of benzotriazole (BTA) and methylbenzotriazole (TTA) in a mass ratio of 1:0.6. The mild alkaline regulator is a compound of triethanolamine and monoethanolamine in a mass ratio of 2:1. The complexing builder is tetrasodium ethylenediaminetetraacetate; The solubilizing and stabilizing agent is AEO-9; The water treatment agent is hydroxyethylidene diphosphonic acid (HEDP).

[0026] The low-foaming silicone defoamer is B237 from Guangdong Zhongke Hongtai New Materials Co., Ltd., a polyether-modified silicone. The water-based cleaning agent for copper alloys in this embodiment is prepared according to the following steps: Step 1: While stirring at 200 r / min, add mild alkaline regulator and complexing detergent to deionized water in sequence, stir until completely dissolved, and check the pH of the system to be 9.2; Step 2: Add the copper alloy-specific anti-discoloration agent and continue stirring until evenly dispersed; Step 3: Then adjust the stirring speed to 280 r / min, add the composite degreasing and impurity removal agent, water treatment agent, and low-foaming silicone defoamer in sequence, stir until uniform, let stand to defoam, and filter through a 200-mesh filter to obtain a water-based cleaning agent for copper alloys.

[0027] Cleaning effect: The finished product diluted solution (1:15) was sprayed on the brass parts at room temperature, and the rolling oil and fingerprints on the surface were completely removed in 6 minutes, leaving no residue; Anti-discoloration effect: After cleaning, the brass parts are placed at room temperature and pressure for 22 days, and the surface shows no oxidation or discoloration, maintaining a golden luster; Surface damage test: After cleaning, the surface of the parts showed no loss of gloss or pitting, and the smoothness met the standard; System stability: After the finished product was placed at 45℃ for 72 hours, there was no stratification or oil floating after returning to room temperature, and the performance remained unchanged.

[0028] Test piece A showed no rust spots or oxidation marks on its surface, maintaining its original metallic color; test piece B showed verdigris on its surface, clearly demonstrating the excellent rust-preventing effect of the cleaning agent of this invention.

[0029] Example 2: The copper alloy-specific water-based cleaning agent of this example is composed of the following components by weight percentage: 15% compound degreasing and deoxidizing agent, 2% copper alloy special anti-discoloration agent, 9% mild alkaline regulator, 5% complexing detergent, 3% solubilizing stabilizer, 3% water treatment agent, 0.01% low-foaming silicone defoamer, and the remainder is deionized water.

[0030] The composite degreasing and impurity-removing agent is a compound of fatty alcohol polyoxyethylene ether (AEO-9), dispersant (Haomeite FS-1), and organic carboxylic acid (octanoic acid: p-tert-butylbenzoic acid = 1:1) in a mass ratio of 1:2:1.5. The copper alloy-specific anti-discoloration agent is a compound of benzotriazole (BTA) and methylbenzotriazole (TTA) in a mass ratio of 1:0.6. The mild alkaline regulator is a compound of triethanolamine and monoethanolamine in a mass ratio of 2:1. The complexing builder is tetrasodium ethylenediaminetetraacetate; The solubilizing and stabilizing agent is AEO-9; The water treatment agent is hydroxyethylidene diphosphonic acid (HEDP).

[0031] The low-foaming silicone defoamer is B237 from Guangdong Zhongke Hongtai New Materials Co., Ltd., a polyether-modified silicone. The water-based cleaning agent for copper alloys in this embodiment is prepared according to the following steps: Step 1: While stirring at 200 r / min, add mild alkaline regulator and complexing detergent to deionized water in sequence, stir until completely dissolved, and check the pH of the system to be 9.2; Step 2: Add the copper alloy-specific anti-discoloration agent and continue stirring until evenly dispersed; Step 3: Then adjust the stirring speed to 280 r / min, add the composite degreasing and impurity removal agent, water treatment agent, and low-foaming silicone defoamer in sequence, stir until uniform, let stand to defoam, and filter through a 200-mesh filter to obtain a water-based cleaning agent for copper alloys.

[0032] Cleaning effect: Precision brass parts were soaked in the finished product diluted solution (1:25) at room temperature for 8 minutes. The surface patina and emulsion residue were completely removed, leaving no residue or spots. Color change effect: After cleaning, the brass fittings are placed at room temperature and pressure for 30 days. There are no oxidation spots or color return on the surface, and the original luster of bronze is maintained. Surface damage test: The surface finish of the cleaned parts is the same as that of the uncleaned parts, with no over-corrosion or loss of gloss; System stability: After being refrigerated at -5℃ for 72 hours, the finished product showed no crystallization or stratification upon returning to room temperature, and its performance met the standards.

[0033] Table 1

[0034] The specific embodiments of the present invention have been described in detail above. It should be noted that the present invention is not limited to the specific embodiments described above. Various modifications or alterations can be made by those skilled in the art without departing from the scope of protection defined by the claims, and all such modifications or alterations fall within the scope of the present invention.

Claims

1. A water-based cleaning agent specifically for copper alloys, characterized in that, It consists of the following components by weight percentage: 8%-20% compound degreasing and deoxidizing agent, 5%-15% copper alloy special anti-discoloration agent, 2%-6% mild alkaline regulator, 3%-8% complexing detergent aid, 2%-5% solubilizing stabilizer, 1%-5% water treatment agent, 0.05%-0.2% low-foaming silicone defoamer, and the balance being deionized water.

2. The water-based cleaning agent according to claim 1, characterized in that, The composite degreasing and impurity removal agent is a compound of fatty alcohol polyoxyethylene ether (AEO-9), dispersant and organic carboxylic acid in a mass ratio of 1:2:

2.

3. The water-based cleaning agent according to claim 1, characterized in that, The dispersant is Homite FS-1, and the organic carboxylic acid is one or more of dodecanoic acid, octanoic acid, and p-tert-butylbenzoic acid in any proportion.

4. The water-based cleaning agent according to claim 1, characterized in that, The copper alloy anti-tarnishing agent is a compound of benzotriazole (BTA) and methylbenzotriazole (TTA) in a mass ratio of 1:0.

6.

5. The water-based cleaning agent according to claim 1, characterized in that, The mild alkalinity regulator is a compound of triethanolamine and monoethanolamine in a mass ratio of 2:

1.

6. The water-based cleaning agent according to claim 1, characterized in that, The complexing builder is tetrasodium ethylenediaminetetraacetate.

7. The water-based cleaning agent according to claim 1, characterized in that, The solubilizing stabilizer is AEO-9.

8. The water-based cleaning agent according to claim 1, characterized in that, The water treatment agent is hydroxyethylidene diphosphonic acid (HEDP).

9. The water-based cleaning agent according to claim 1, characterized in that, The low-foaming silicone defoamer is a polyether-modified silicone.

10. The method for preparing the water-based cleaning agent according to any one of claims 1-8, characterized in that, Package the following steps: Step 1: While stirring at 180-220 r / min, add a mild alkaline regulator and a complexing detergent to the deionized water in sequence, stirring until completely dissolved, and stabilize the pH value at 8.5-10.

0. Step 2: Add the copper alloy-specific anti-discoloration agent and continue stirring until evenly dispersed; Step 3: Then, adjust the stirring speed to 250-300 r / min, add the composite degreasing and impurity removal agent, water treatment agent, and low-foaming silicone defoamer in sequence, stir until uniform, let stand to defoam, and filter through a 200-mesh filter to obtain a water-based cleaning agent for copper alloys.

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