Aluminum material cleaning agent and preparation method thereof

Abstract

The invention relates to an aluminum material cleaning agent and a preparation method thereof. The aluminum material cleaning agent comprises the following raw materials: a chelating agent, an alkali buffer agent, a degreaser, a surfactant, a corrosion inhibitor and a solvent, wherein the alkali buffer agent is selected from sodium silicate or sodium carbonate. The alkali buffering agent is additionally added into the aluminum material cleaning agent, so that the aluminum material cleaning agent has the core functions of alkaline buffering, pH stabilization, auxiliary oil removal and slight rust prevention, and meanwhile, the low-corrosion requirement of aluminum material cleaning is met.

Description

Technical Field

[0001] This invention relates to the field of detergent composition technology, and in particular to an aluminum cleaning agent and its preparation method. Background Technology

[0002] Aluminum is widely used in construction, automotive, electronics, aerospace and other fields due to its lightweight, high strength and excellent thermal and electrical conductivity. However, during processing, storage and transportation, aluminum surfaces are easily contaminated with rolling oil, cutting fluid, dust, fingerprints and other pollutants, and a layer of oxide scale or passivation film will naturally form. These substances will directly affect the quality of subsequent coating, welding, bonding and other processes of aluminum materials. Therefore, it is necessary to pre-treat the surface of aluminum materials with aluminum cleaning agents.

[0003] Currently, the mainstream aluminum cleaning agents in the industry are mainly divided into three categories: First, solvent-based cleaning agents, which mainly consist of kerosene, gasoline, alcohols, and dearomatic hydrocarbons. Although they have strong oil-dissolving capabilities, they are highly volatile, flammable and explosive, have poor environmental performance, and pose potential health hazards to operators. Second, water-based cleaning agents, which are based on surfactants and compounded with chelating agents, cleaning aids, and other components. They have the advantages of being environmentally friendly, safe, and low-cost, and are the current mainstream development direction. Third, acidic or alkaline special cleaning agents. Acidic cleaning agents (such as those containing phosphoric acid or nitric acid) are mainly used to remove oxide scale, while alkaline cleaning agents (such as those containing sodium hydroxide or sodium carbonate) are mainly used for degreasing. However, both types of cleaning agents have obvious performance limitations.

[0004] Existing aluminum cleaning agents generally lack excellent acid and alkali resistance and stability. The core problems are reflected in two aspects: First, the core components of water-based cleaning agents, such as surfactants and chelating agents, are prone to hydrolysis or oxidation in acidic (pH < 4) or alkaline (pH > 10) environments, resulting in reduced activity or even failure, and thus failing to exert a sustained cleaning effect. Second, in order to improve cleaning efficiency, some cleaning agents add highly corrosive components, but due to the lack of an acid / alkali resistant buffer system, they are prone to excessive corrosion of the aluminum surface during the cleaning process, resulting in defects such as pitting and loss of gloss, which in turn reduces the processing performance of the aluminum.

[0005] Furthermore, commercially available aluminum cleaners generally only provide short-term cleaning and cannot solve long-term rust prevention problems. This may be because most cleaners do not contain corrosion inhibitors or rust preventers, or the added components (such as inorganic phosphates) are easily washed away with the rinsing solution after cleaning, failing to form a dense protective film on the aluminum surface. This exposes the aluminum surface to air, moisture, or residual contaminants, causing new oxide rust to form within a short period (usually 24-48 hours). Alternatively, some acidic cleaners, after removing oxide scale, leave tiny corrosion pores on the aluminum surface. These pores become accumulation points for moisture and oxygen, accelerating the electrochemical corrosion process. Simultaneously, if residual chloride ions, sulfate ions, or other impurities remain after cleaning, they will further exacerbate the re-rusting rate, severely affecting the adhesion of subsequent coating or welding processes.

[0006] The aforementioned problems have become key factors restricting efficiency improvements in the aluminum processing industry. Therefore, developing an aluminum cleaning agent that combines excellent acid and alkali resistance, high cleaning efficiency, and effective inhibition of rust re-accumulation has become an urgent technical need for the industry. Summary of the Invention

[0007] The purpose of this invention is to disclose an aluminum cleaning agent and its preparation method, so as to solve one or more technical problems existing in the prior art and provide at least one beneficial option or create conditions.

[0008] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this invention is to provide an aluminum cleaning agent. Its raw materials include a chelating agent, an alkaline buffer, a degreasing agent, a surfactant, a corrosion inhibitor, and a solvent, wherein the alkaline buffer is selected from sodium silicate or sodium carbonate. The aluminum cleaning agent contains an additional alkaline buffer, thus possessing the core functions of alkaline buffering, pH stabilization, auxiliary degreasing, and slight rust prevention, while also meeting the low-corrosion requirements of aluminum cleaning.

[0009] In some embodiments of the first aspect of this invention, the sodium silicate is sodium metasilicate pentahydrate. Sodium metasilicate pentahydrate balances stable alkalinity regulation, enhanced cleaning efficiency, and aluminum protection, and is suitable for mainstream applications of water-based cleaning agents, making it a preferred solution balancing performance, cost, and safety. When sodium metasilicate pentahydrate dissolves in water, the silicate ions hydrolyze to equilibrium, stabilizing the pH of the cleaning solution in a strongly alkaline range of 10-12. This range ensures the emulsifying activity of surfactants (such as nonionic surfactants) while rapidly decomposing rolling oil, cutting fluid, and other oil stains on the aluminum surface. The silicate chains in its molecules possess certain surface activity, which can synergistically work with the main surfactant in the cleaning agent to reduce the oil-water interfacial tension, making the oil stains easier to emulsify and peel off, especially improving the cleaning efficiency of stubborn rolling oil by 15-20%. After cleaning aluminum with the aforementioned aluminum cleaning agent, the residual trace amounts of silicate will form an extremely thin silicon film on the aluminum surface, which can provide short-term rust protection for the aluminum in the air for 24 to 48 hours, avoiding re-rusting between cleaning and subsequent processes and reducing secondary processing costs.

[0010] In some embodiments of the first aspect of the present invention, the chelating agent is an EDTA salt; preferably, the chelating agent is EDTA-2Na. As a typical aminocarboxylic acid chelating agent, EDTA-2Na's core function is to form stable six-membered ring chelates with metal ions through the amino and carboxyl groups in its molecule. This chelates hard water ions, preventing calcium and magnesium ions in hard water from reacting with surfactants, ensuring the surfactants continue to perform their emulsifying and penetrating functions, and preventing the cleaning solution from becoming ineffective. Simultaneously, EDTA-2Na can also chelate impurities such as iron filings and copper ions remaining during aluminum processing, preventing localized corrosion or discoloration caused by impurity residues. Furthermore, it can chelate free metal ions, reducing their consumption of corrosion inhibitors and ensuring that corrosion inhibitors are more efficiently adsorbed onto the aluminum surface to form a protective layer.

[0011] In some embodiments of the first aspect of the present invention, the degreasing agent is GX-12 alkali-resistant cationic surfactant. The GX-12 alkali-resistant cationic surfactant maintains molecular structural stability in a highly alkaline environment with a pH of 10-12, ensuring that its degreasing performance does not diminish.

[0012] In some embodiments of the first aspect of the present invention, the surfactant is DT-24 nonionic surfactant. The polyoxyethylene chain in the DT-24 nonionic surfactant molecule provides hydrophilicity, and the hydrophobic alkyl chain can encapsulate nonpolar oil stains to form a stable O / W type emulsion, preventing oil stains from redepositing. It is particularly effective in removing mineral oil-based cutting fluids commonly used in aluminum processing. Furthermore, the DT-24 nonionic surfactant is acid and alkali resistant, has good compatibility with other anionic surfactants, and is a broad-distribution cleaning agent with strong degreasing, dewaxing, and descaling capabilities.

[0013] When the GX-12 alkali-resistant cationic surfactant is compounded with the DT-24 nonionic surfactant, the cationic and nonionic molecules interact through hydrophobic chains to form mixed micelles. This retains the adsorption advantage of cationic surfactants for polar oil stains while leveraging the emulsifying ability of nonionic surfactants for nonpolar oil stains, thus achieving efficient removal of all types of polar / nonpolar oil stains.

[0014] In some embodiments of the first aspect of the present invention, the corrosion inhibitor comprises a film-forming agent and an electrochemical inhibitor. More preferably, the film-forming agent is selected from siloxanes, γ-aminopropyltriethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, or monoalkyl phosphates. The electrochemical inhibitor is selected from benzotriazole, toluenetriazole, mercaptobenzothiazole, benzimidazole, imidazoline oleate, hydroxyethylimidazoline, or sodium tungstate. The two types of corrosion inhibitors work synergistically through film formation isolation and adsorption inhibition, respectively, to address the problem of easy rust re-emergence after aluminum cleaning.

[0015] In some embodiments of the first aspect of the present invention, the mass percentage of the raw materials is: solvent 66-75%, chelating agent 2-3%, alkali buffer 5-8%, degreasing agent 4-6%, surfactant 8-12%, and corrosion inhibitor 3-5%.

[0016] A second aspect of the present invention provides a preparation method for the aluminum cleaning agent described in the first aspect of the present invention. It includes the following steps: 1) Add solvent to the container, add the chelating agent and stir well; 2) Add the alkali buffer to the container and stir well; 3) Add the degreasing agent and stir well; 4) Add the surfactant and stir until well combined; 5) Add corrosion inhibitor and stir well to obtain the final product.

[0017] Compared with existing similar products, the present invention has the following advantages: (1) The aluminum cleaning agent described in this invention is a weak alkaline cleaning agent. It will not cause aluminum oxidation or corrosion after cleaning, nor will it change color. It can maintain the original luster of the workpiece and is suitable for cleaning aluminum materials of various types, especially for precision cleaning needs.

[0018] (2) It can effectively and quickly remove oil stains, carbon deposits and other impurities from the surface of workpieces. It has strong penetrating power, excellent cleaning ability, little residue, and is not easy to form white spots or corrosion after drying. It can quickly remove moderate and heavy oil stains.

[0019] (3) It has high cleaning efficiency, which can significantly shorten the cleaning time or reduce the cleaning steps and save cleaning costs.

[0020] (4) It has low foam and is suitable for traditional soaking, ultrasonic cleaning and high-pressure spray cleaning. Maintaining the cleaning working fluid at 50°C or above can achieve better cleaning effect and lower operating foam.

[0021] (5) It has low cost and good economic benefits. Even when used with a high dilution ratio (up to 20 times), it can still achieve good cleaning results.

[0022] (6) It has short-term rust prevention properties, and the cleaned aluminum material will not rust or oxidize when it comes into contact with steel parts.

[0023] (7) The product does not contain heavy metals, nitrites or other harmful substances. The cleaning wastewater can be naturally decomposed, which meets environmental protection standards. It is harmless to the human body and has no impact on the environment. It is an environmentally friendly product.

[0024] (8) Water-based formulation systems have high safety, are generally non-toxic, not easily flammable or explosive, and are safer to use. Attached Figure Description

[0025] Figure 1 This is a comparison chart showing the effects of using aluminum cleaning agent No. 1 and aluminum cleaning agent No. 5. Detailed Implementation

[0026] Example 1: Preparation of Aluminum Cleaning Agent No. 1 This embodiment provides a preparation process for an aluminum cleaning agent, the specific steps of which include: 1) Prepare materials according to the following mass ratio: 66% deionized water, 3% EDTA-2Na (chelating agent), 8% sodium metasilicate pentahydrate (alkali buffer), 6% GX-12 alkali-resistant cationic surfactant (degreasing agent), 12% DT-24 nonionic surfactant (surfactant), 2.5% siloxane ketone and 2.5% benzotriazole (corrosion inhibitor).

[0027] 2) Mixing and blending: Add deionized water to the mixing tank, and add EDTA-2Na, sodium metasilicate pentahydrate, GX-12 alkali-resistant cationic surfactant, and DT-24 nonionic surfactant one by one in that order and stir evenly. Finally, add siloxane ketone and benzotriazole to form a colorless and transparent liquid, which is the No. 1 aluminum cleaning agent.

[0028] Example 2: Preparation of Aluminum Cleaning Agent No. 2 This embodiment provides an aluminum cleaning agent, the raw material components of which are: 70% deionized water, 2.5% EDTA-2Na (chelating agent), 7% sodium metasilicate pentahydrate (alkali buffer), 5% GX-12 alkali-resistant cationic surfactant (degreasing agent), 11.5% DT-24 nonionic surfactant (surfactant), 2% siloxane ketone, and 2% benzotriazole (corrosion inhibitor). The preparation process is the same as the mixing and formulation steps described in Example 1.

[0029] Obtain aluminum cleaning agent No. 2.

[0030] Example 3: Preparation of Aluminum Cleaning Agent No. 3 This embodiment provides an aluminum cleaning agent, the raw material components of which are: 75% deionized water, 3% EDTA-2Na (chelating agent), 6% sodium metasilicate pentahydrate (alkali buffer), 4% GX-12 alkali-resistant cationic surfactant (degreasing agent), 8% DT-24 nonionic surfactant (surfactant), 2% siloxane ketone, and 2% benzotriazole (corrosion inhibitor). The preparation process is the same as the mixing and formulation steps described in Example 1.

[0031] Obtain aluminum cleaning agent No. 3.

[0032] Example 4: Preparation of Aluminum Cleaning Agent No. 4 This embodiment provides an aluminum cleaning agent, the raw material components of which are: 70% deionized water, 3% EDTA-2Na (chelating agent), 4% sodium metasilicate pentahydrate (alkali buffer), 6% GX-12 alkali-resistant cationic surfactant (degreasing agent), 12% DT-24 nonionic surfactant (surfactant), 2.5% siloxane ketone, and 2.5% benzotriazole (corrosion inhibitor). The preparation process is the same as the mixing and formulation steps described in Example 1.

[0033] Aluminum Cleaning Agent No. 4 was obtained. The difference between it and Aluminum Cleaning Agent No. 1 is that the amount of sodium metasilicate pentahydrate is reduced to below 5%, and it is made up with deionized water.

[0034] Example 5: Preparation of Aluminum Cleaning Agent No. 5 This embodiment provides an aluminum cleaning agent, the raw material components of which are: 70% deionized water, 2.5% EDTA-2Na (chelating agent), 7% sodium metasilicate pentahydrate (alkali buffer), 9% GX-12 alkali-resistant cationic surfactant (degreasing agent), 7.5% DT-24 nonionic surfactant (surfactant), 2% siloxane ketone, and 2% benzotriazole (corrosion inhibitor). The preparation process is the same as the mixing and formulation steps described in Example 1.

[0035] Aluminum Cleaning Agent No. 5 was obtained. The difference between it and Aluminum Cleaning Agent No. 2 is that the total amount of both surfactants remains the same, but the ratio of GX-12 alkali-resistant cationic surfactant to DT-24 nonionic surfactant has changed.

[0036] Experimental Example According to the standard and test methods of "General Water-Based Metal Cleaning Agents QB / T 2117-95", aluminum cleaning agents No. 1 to No. 5 were prepared into 5% concentration solutions, and their cleaning power, corrosion resistance, rust prevention and rinsing performance were tested on hard aluminum.

[0037] The physicochemical performance test results of the product of this invention are shown in Table 1, and it fully complies with the requirements of the light industry standards QB / T 2117-1995 "General Water-based Metal Detergent" and GB / T 13171.2-2009 "Laundry Detergent (Phosphorus-free)".

[0038] Table 1 - Comparison of Aluminum Material Cleaning Effects

[0039] Figure 1 This is a comparison of the effects of using aluminum cleaning agents #1 and #5. The aluminum material on the right was cleaned with cleaning agent #1, while the aluminum material on the left was cleaned with cleaning agent #5. The results show that the aluminum material on the right is cleaner and brighter. While the aluminum material on the left is also clean, its overall color is noticeably darker.

[0040] The experimental data above demonstrates that the aluminum cleaning agent provided by this invention has the advantages of not causing oxidation or corrosion of the aluminum after cleaning, nor causing discoloration. It maintains the original luster of the workpiece and is suitable for cleaning various types of aluminum, especially for precision cleaning needs. It is non-corrosive to aluminum products, removes oil quickly, has excellent cleaning effect, exhibits good physical stability, and is non-toxic, harmless, non-polluting, and safe for the human body. It also exhibits excellent performance with no odor after prolonged use, no deterioration, and a long service life. It has high cleaning efficiency, low foaming, and provides short-term rust prevention. The product does not contain heavy metals, nitrites, or other harmful substances, making it safer to use.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. An aluminum cleaning agent, characterized in that, The raw materials include chelating agents, alkali buffers, degreasing agents, surfactants, corrosion inhibitors, and solvents, wherein the alkali buffer is selected from sodium silicate or sodium carbonate.

2. The aluminum cleaning agent according to claim 1, characterized in that, The sodium silicate is sodium metasilicate pentahydrate.

3. The aluminum cleaning agent according to claim 1, characterized in that, The chelating agent is an EDTA salt; preferably, the chelating agent is EDTA-2Na.

4. The aluminum cleaning agent according to claim 1, characterized in that, The degreasing agent is GX-12 alkali-resistant cationic surfactant.

5. The aluminum cleaning agent according to claim 1, characterized in that, The surfactant is DT-24, a nonionic surfactant.

6. The aluminum cleaning agent according to claim 1, characterized in that, The corrosion inhibitor includes film-forming agents and electrochemical inhibitors.

7. The aluminum cleaning agent according to claim 6, characterized in that, The film-forming agent is selected from siloxane, γ-aminopropyltriethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, or monoalkyl phosphate.

8. The aluminum cleaning agent according to claim 6, characterized in that, The electrochemical inhibitor is selected from benzotriazole, toluenetriazole, mercaptobenzothiazole, benzimidazole, oleic acid imidazoline, hydroxyethyl imidazoline, or sodium tungstate.

9. The aluminum cleaning agent according to claim 1, characterized in that, The raw materials are as follows by mass percentage: solvent 66-75%, chelating agent 2-3%, alkali buffer 5-8%, degreasing agent 4-6%, surfactant 8-12%, and corrosion inhibitor 3-5%.

10. A method for preparing the aluminum cleaning agent according to any one of claims 1 to 9, characterized in that, Including the following steps: 1) Add solvent to the container, add the chelating agent and stir well; 2) Add the alkali buffer to the container and stir well; 3) Add the degreasing agent and stir well; 4) Add the surfactant and stir until well combined; 5) Add corrosion inhibitor and stir well to obtain the final product.

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