Neodymium-iron-boron magnetic material surface cleaning agent and preparation method thereof

Abstract

The invention discloses a neodymium iron boron magnetic material surface cleaning agent and a preparation method thereof, and belongs to the field of cleaning agents. The surface cleaning agent comprises the following raw materials in parts by mass: 8-10 parts of active carrier particles, 16-18 parts of a nonionic surfactant, 3-5 parts of a corrosion inhibitor, 1-3 parts of triethanolamine, 10-12 parts of an anionic surfactant and 100 parts of water, wherein the active carrier particles take cellulose-based microspheres as carriers, and take sodium citrate and tetrasodium glutamate diacetate in a mass ratio of 1: (0.4-0.6) as active components. Tetrasodium glutamate diacetate can make up for high-valence metal binding sites lacking in sodium citrate and improve the chelation effect of active ingredients, after carrier loading, surface tension can be reduced, active carrier particles permeate into pores, the active ingredients are gradually released in the pores, and the needed chelation concentration is continuously provided; therefore, the deep cleaning effect of the magnetic material is achieved.

Description

Technical Field

[0001] This invention relates to the field of cleaning agents, and in particular to a surface cleaning agent for neodymium iron boron magnetic materials and its preparation method. Background Technology

[0002] Neodymium iron boron (NdFeB) magnetic materials, as third-generation rare-earth permanent magnets, possess extremely high magnetic energy product, coercivity, and remanence, and are widely used in various fields such as wind power generation, new energy vehicles, and energy-saving home appliances. However, due to the reactive chemical properties of NdFeB magnetic materials, surface protection is necessary. Thoroughly cleaning the magnet surface before surface protection to remove oil stains or loose magnetic particles and obtain a smooth surface is crucial for improving the adhesion between the protective layer and the NdFeB magnetic material, as well as enhancing corrosion resistance.

[0003] Currently used cleaning agents often contain phosphates. While these can effectively emulsify grease and remove oil from magnetic materials, the use of phosphates as detergent builders in wastewater can easily lead to eutrophication, promoting the rapid growth of algae, causing oxygen depletion in the water, and endangering aquatic animals, thus becoming a major environmental problem. Sodium citrate has a chelating effect on metal ions in water and can be biodegraded, gradually becoming a substitute for phosphates.

[0004] However, sodium citrate is less effective as a detergent additive compared to phosphates, which is the main reason why it is not widely used. Furthermore, neodymium iron boron magnetic materials are not as dense as forged metal materials; they are microporous. Besides removing alkaline substances, acidic substances, grease, and other contaminants from the surface, some oil stains and adhesives are deeply embedded in the porous structure, making conventional soaking and cleaning insufficient for deep cleaning of neodymium iron boron magnetic materials.

[0005] Therefore, there is an urgent need for a cleaning agent that is phosphorus-free, nitrogen-free, environmentally friendly, and capable of deeply cleaning neodymium iron boron magnetic materials and their pores. Summary of the Invention

[0006] This invention provides a surface cleaning agent for neodymium iron boron magnetic materials and its preparation method, which can solve the problems of environmental pollution and poor cleaning efficiency of existing magnetic material cleaning agents.

[0007] In a first aspect, the present invention provides a surface cleaning agent for neodymium iron boron magnetic materials, comprising the following raw materials in parts by weight: 8-10 parts of active carrier particles; 16-18 parts of nonionic surfactant; 3-5 parts corrosion inhibitor; 1-3 parts of triethanolamine; 10-12 parts of anionic surfactant; 100 parts water; The active carrier particles use cellulose-based microspheres as carriers and sodium citrate and tetrasodium diacetate of glutamate in a mass ratio of 1:(0.4-0.6) as active ingredients.

[0008] Preferably, the mass ratio of cellulose-based microspheres to active ingredients is 1:(0.3-0.4).

[0009] Preferably, the nonionic surfactant includes one or more combinations of alkylphenol polyoxyethylene ethers, fatty alcohol polyoxyethylene ethers, alkyl glycosides, and coconut oil fatty acid diethanolamides.

[0010] Preferably, the corrosion inhibitor includes one or a combination of sodium silicate and sodium molybdate.

[0011] Preferably, the anionic surfactant includes one or more combinations of sodium alkyl sulfate, sodium linear alkylbenzene sulfonate, and alkyl diphenyl ether disulfonate.

[0012] Sodium citrate alone has poor chelating effect, and due to its limited molecular diffusion efficiency and sensitivity to pH, sodium citrate has a low chelating rate for transition metal ions such as iron and neodymium ions, making it difficult to directly apply to the surface cleaning of neodymium iron boron magnetic materials.

[0013] By adopting the above technical solution, this invention selects tetrasodium glutamate diacetate and sodium citrate as the active ingredients of the cleaning agent. Tetrasodium glutamate diacetate, as a multidentate ligand, can form a stable structure with metal ions, and has a higher chelating and stabilizing effect on calcium ions, magnesium ions, etc. in water. It also has a good affinity with transition metal ions, which can make up for the lack of high-valence metal binding sites in sodium citrate. In this way, it chelates the loose magnetic particles on the surface of NdFeB magnetic materials and effectively removes rare earth residues on the surface of NdFeB magnetic materials.

[0014] By combining it with tetrasodium glutamate diacetate, the poor chelating effect and low cleaning efficiency of sodium citrate can be improved, thus enhancing the detergency of the cleaning agent, especially its ability to emulsify and remove complex organic-inorganic dirt. Furthermore, tetrasodium glutamate diacetate exhibits good stability, which can improve the overall stability of the active ingredients.

[0015] However, due to the large number of pores on the surface of neodymium iron boron magnetic materials, adding sodium citrate and tetrasodium diglutamate as active ingredients alone will hinder the diffusion of the active ingredients into the pores of the magnetic material due to the high surface tension of the cleaning agent and the tortuous structure of the pores on the surface of the magnetic material. Furthermore, the fluid exchange inside the pores is slow, and the free active ingredients are diluted, making it difficult to maintain an effective chelation concentration. As a result, the cleaning agent cannot deeply clean the neodymium iron boron magnetic material.

[0016] To address the aforementioned issues, the active ingredients of this invention are loaded onto cellulose-based microsphere carriers. The cellulose-based microspheres, as carrier materials, are biodegradable and can be completely degraded in the natural environment, which helps maintain the overall environmental performance of the cleaning agent.

[0017] Furthermore, after loading, the cellulose-based microspheres contain a large number of polar groups, which helps to reduce the surface tension of the active carrier particles, enhance wettability, promote capillary penetration into the pores, gradually release active ingredients in the pores, and continuously provide the required chelation concentration, thereby achieving the deep cleaning effect of magnetic materials.

[0018] Meanwhile, the surface cleaning agent of this invention also contains nonionic and anionic surfactants. These two surfactants work synergistically to weaken the electrostatic repulsion of ionic bonds, reduce the surface tension of the cleaning agent, and further promote its rapid penetration into the pores of the NdFeB surface, improving wetting efficiency. They also enhance the emulsification ability of oil stains and prevent the redeposition of peeled dirt. Triethanolamine mainly acts as a pH buffer, not only promoting the emulsification of oil stains but also preventing the cleaning agent from corroding magnetic materials.

[0019] Preferably, the cellulose-based microspheres are also coated with citric anhydride.

[0020] Preferably, the raw materials for the cellulose-based microspheres include cellulose, citric anhydride, and a crosslinking agent in a mass ratio of 1:(0.05-0.08):(0.08-0.12).

[0021] More preferably, the crosslinking agent includes one or a combination of two of epichlorohydrin and glutaraldehyde.

[0022] Preferably, the cellulose-based microspheres are prepared according to the following method: Cellulose is dispersed in a 10-15% sodium hydroxide aqueous solution, frozen for 1-2 hours, and then thawed by stirring to obtain a cellulose alkaline solution. Citric anhydride was dispersed in an organic solvent, and then a cellulose alkaline solution was added. After stirring and mixing, the mixture was added dropwise to liquid paraffin. A crosslinking agent was then added, and the mixture was stirred for 5–7 hours. Finally, the mixture was filtered, washed, and dried to obtain cellulose-based microspheres.

[0023] More preferably, the organic solvent includes N,N-dimethylformamide.

[0024] More preferably, the volume ratio of liquid paraffin to cellulose alkaline solution is (10-12):1.

[0025] More preferably, the technical problem of the present invention can also be solved by not adding citric anhydride to the cellulose-based microspheres.

[0026] Preferably, the particle size of the cellulose-based microspheres is 5–40 μm.

[0027] By employing the above-mentioned technical solution, citric anhydride can be incorporated into the preparation of cellulose-based microspheres. Citric anhydride achieves this incorporation through ring-opening, forming covalent ester bonds with the hydroxyl groups in the cellulose molecular chain, significantly enhancing the carboxyl group density on the surface of the cellulose-based microspheres. The introduced carboxyl groups enhance the surface polarity of the cellulose-based microspheres, reduce the surface tension of the active carrier particles, and facilitate penetration into the pores of the NdFeB magnetic material surface. Furthermore, the cellulose-based microspheres incorporating citric anhydride can still be completely degraded under natural conditions without affecting the biodegradability of the carrier.

[0028] Furthermore, the introduced carboxyl groups can act as strong anionic sites, forming ionic bonds with the active ingredients through electrostatic interactions. This enhances the adsorption and binding strength between the active ingredients and the carrier, and increases the loading capacity of the active ingredients. Increased loading prolongs the effective contact time of the active ingredients within the pores, maintaining their concentration and achieving efficient dissolution and emulsification of loose magnetic particles and surface oil contaminants.

[0029] Preferably, the active carrier particles are prepared according to the following method: The active ingredient is added to water and stirred to dissolve it, preparing an active solution with a concentration of 4-6%. Cellulose-based microspheres are added to the active solution and shaken at 25-30°C for 20-25 hours. Finally, the solution is washed and dried to obtain the final product.

[0030] By employing the above technical solution, the porous structure and hydroxyl groups on the surface of cellulose-based microspheres can provide physical adsorption sites and diffusion channels for active ingredients, allowing the active ingredients to be loaded onto the surface of the cellulose-based microspheres. The resulting active carrier particles can improve the stability of the active ingredients, enabling sodium citrate and tetrasodium glutamate diacetate to work synergistically and enhance the emulsification and stripping ability of organic-inorganic complex dirt.

[0031] On the other hand, the low surface tension of the active carrier particles enhances the wetting and penetration of the cleaning agent into the pores of the NdFeB magnetic material, helping the active ingredients penetrate deep into the pores and achieve deep cleaning of the NdFeB magnetic material.

[0032] Secondly, the present invention provides a method for preparing a surface cleaning agent for neodymium iron boron magnetic materials, comprising the following process steps: S1. Add nonionic surfactant, anionic surfactant and triethanolamine to water, and stir and disperse at 50-60℃ for 20-30 min to obtain the first solution; S2. Add active carrier particles to water and stir to disperse to obtain a second solution; S3. Add corrosion inhibitor to water and stir to disperse to obtain a third solution; S4. Mix the first solution, the second solution and the third solution, and stir and disperse for 20 to 30 minutes to obtain the final solution.

[0033] The beneficial effects of this invention are: 1. The NdFeB magnetic material surface cleaning agent of the present invention contains active carrier particles, which use cellulose-based microspheres as carriers and sodium citrate and tetrasodium glutamate diacetate as active ingredients. Tetrasodium glutamate diacetate has a good affinity for transition metal ions, which can compensate for the lack of high-valence metal binding sites in sodium citrate, improving the chelating effect of the cleaning agent. It can also effectively remove rare earth residues from the surface of NdFeB magnetic materials and improve the emulsification and stripping ability of organic-inorganic complex dirt.

[0034] 2. The active carrier particles of this invention use cellulose-based microspheres as the carrier material, which can reduce the surface tension of the active carrier particles, promote capillary penetration into the pores, and gradually release the active ingredients in the pores, continuously providing the required chelation concentration, thereby achieving a deep cleaning effect on magnetic materials. Furthermore, the cellulose-based microspheres can be combined with citric anhydride to improve the adsorption and binding strength between the active ingredients and the carrier, and increase the loading capacity of the active ingredients. The increased loading capacity can prolong the effective action time of the active ingredients in the pores, maintain the concentration of active ingredients in the pores, and achieve efficient dissolution and emulsification of loose magnetic particles and surface oil stains. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0036] Preparation Example

[0037] Preparation Example 1: An active carrier particle was prepared according to the following method: Preparation of cellulose-based microspheres: 10g of cellulose was dispersed in 200mL of 10% sodium hydroxide aqueous solution, frozen for 2h, and then stirred to thaw to obtain a cellulose alkaline solution. The cellulose alkaline solution obtained above was added dropwise to liquid paraffin, wherein the volume ratio of liquid paraffin to cellulose alkaline solution was 10:1. Then, 1g of epichlorohydrin was added, and the mixture was stirred for 6 hours. Finally, the mixture was filtered, washed, and dried to obtain cellulose-based microspheres.

[0038] Preparation of active carrier particles: Add 3g of active ingredient to water and stir to dissolve to prepare an active solution with a concentration of 5%. The active ingredient includes sodium citrate and tetrasodium diacetate of glutamic acid in a mass ratio of 1:0.5. Add 10g of the cellulose-based microspheres prepared above to the active solution, shake at 25°C for 24 hours, and finally wash and dry to obtain the final product.

[0039] Preparation Example 2, an active carrier particle, differs from Preparation Example 1 only in that the amount of active ingredient added is 4g.

[0040] Preparation Example 3, an active carrier particle, differs from Preparation Example 1 only in that the active ingredients include sodium citrate and tetrasodium diacetate of glutamate in a mass ratio of 1:0.4.

[0041] Preparation Example 4, an active carrier particle, differs from Preparation Example 1 only in that the active ingredients include sodium citrate and tetrasodium diacetate of glutamate in a mass ratio of 1:0.6.

[0042] Preparation Example 5: An active carrier particle was prepared according to the following method: Preparation of cellulose-based microspheres: 10g of cellulose was dispersed in 200mL of 10% sodium hydroxide aqueous solution, frozen for 2h, and then stirred to thaw to obtain a cellulose alkaline solution. 0.6 g of citric anhydride was dispersed in 10 mL of N,N-dimethylformamide. The resulting cellulose alkaline solution was stirred and mixed, and then added dropwise to liquid paraffin, wherein the volume ratio of liquid paraffin to cellulose alkaline solution was 10:1. Then, 1 g of epichlorohydrin was added, and the mixture was stirred for 6 h. Finally, the mixture was filtered, washed, and dried to obtain cellulose-based microspheres.

[0043] Preparation of active carrier particles: Add 3g of active ingredient to water and stir to dissolve to prepare an active solution with a concentration of 5%. The active ingredient includes sodium citrate and tetrasodium diacetate of glutamic acid in a mass ratio of 1:0.5. Add 10g of the cellulose-based microspheres prepared above to the active solution, shake at 25°C for 24 hours, and finally wash and dry to obtain the final product.

[0044] Preparation Example 6, an active carrier particle, differs from Preparation Example 5 only in that, in the preparation of cellulose-based microspheres, the amount of citric anhydride added is 0.5 g and the amount of epichlorohydrin added is 0.8 g.

[0045] Preparation Example 7, an active carrier particle, differs from Preparation Example 5 only in that, in the preparation of cellulose-based microspheres, the amount of citric anhydride added is 0.8 g and the amount of epichlorohydrin added is 1.2 g.

[0046] Preparation Example 8, an active carrier particle, differs from Preparation Example 1 only in that the active ingredients include sodium citrate and tetrasodium diacetate of glutamate in a mass ratio of 1:0.2.

[0047] Preparation Example 9, an active carrier particle, differs from Preparation Example 1 only in that the active ingredients include sodium citrate and tetrasodium diacetate of glutamate in a mass ratio of 1:0.8.

[0048] Preparation Example 10, an active carrier particle, differs from Preparation Example 1 only in that the active ingredient is sodium citrate.

[0049] Preparation Example 11, an active carrier particle, differs from Preparation Example 5 only in that the amount of citric anhydride added during the preparation of cellulose-based microspheres is 0.2 g.

[0050] Preparation Example 12, an active carrier particle, differs from Preparation Example 5 only in that the amount of citric anhydride added during the preparation of cellulose-based microspheres is 1g.

[0051] Example

[0052] Example 1: A surface cleaning agent for neodymium iron boron magnetic materials was prepared according to the following method: S1. Add 18g of fatty alcohol polyoxyethylene ether (AEO-9), 10g of sodium dodecylbenzenesulfonate and 1g of triethanolamine to 60g of water, and stir and disperse at 60℃ for 20min to obtain the first solution; S2. Add 9g of the active carrier particles prepared in Preparation Example 1 to 30g of water, and stir to disperse to obtain a second solution; S3. Add 3g of sodium silicate to 10g of water and stir to disperse to obtain the third solution; S4. Mix the first solution, the second solution and the third solution, and stir and disperse for 30 minutes to obtain the final product.

[0053] Example 2 is a surface cleaning agent for neodymium iron boron magnetic materials. The only difference from Example 1 is that the active carrier particles prepared in Preparation Example 1 are replaced with an equal amount of the active carrier particles prepared in Preparation Example 5.

[0054] Example 3 is a surface cleaning agent for neodymium iron boron magnetic materials. The only difference from Example 1 is that the active carrier particles prepared in Preparation Example 1 are replaced with an equal amount of the active carrier particles prepared in Preparation Example 2.

[0055] Examples 4 and 5 describe a surface cleaning agent for neodymium iron boron magnetic materials. The only difference between this agent and Example 1 is the adjustment of the raw material ratio, as shown in Table 1. Table 1. Formulations for Examples 1, 4, and 5

[0056] Example 4 uses the active carrier particles prepared in Example 3, and Example 5 uses the active carrier particles prepared in Example 4.

[0057] Example 6, a surface cleaning agent for neodymium iron boron magnetic materials, differs from Example 2 only in that an equal amount of the active carrier particles prepared in Example 6 are used to replace the active carrier particles prepared in Example 1.

[0058] Example 7 is a surface cleaning agent for neodymium iron boron magnetic materials. The only difference from Example 2 is that the active carrier particles prepared in Example 1 are replaced with an equal amount of the active carrier particles prepared in Example 7.

[0059] Example 8, a surface cleaning agent for neodymium iron boron magnetic materials, differs from Example 2 only in that the active carrier particles prepared in Preparation Example 1 are replaced with an equal amount of the active carrier particles prepared in Preparation Example 11.

[0060] Example 9, a surface cleaning agent for neodymium iron boron magnetic materials, differs from Example 2 only in that an equal amount of the active carrier particles prepared in Preparation Example 12 are used to replace the active carrier particles prepared in Preparation Example 1.

[0061] Comparative Example

[0062] Comparative Example 1 is a surface cleaning agent for neodymium iron boron magnetic materials. The only difference from Example 1 is that the active carrier particles prepared in Preparation Example 8 are replaced with an equal amount of the active carrier particles prepared in Preparation Example 1.

[0063] Comparative Example 2 is a surface cleaning agent for neodymium iron boron magnetic materials. The only difference from Example 1 is that the active carrier particles prepared in Preparation Example 9 are replaced with an equal amount of the active carrier particles prepared in Preparation Example 1.

[0064] Comparative Example 3 is a surface cleaning agent for neodymium iron boron magnetic materials. The only difference from Example 1 is that the active carrier particles prepared in Preparation Example 1 are replaced with an equal amount of the active carrier particles prepared in Preparation Example 10.

[0065] Comparative Example 4, a surface cleaning agent for neodymium iron boron magnetic materials, differs from Example 1 only in that the amount of active carrier particles added in Preparation Example 1 is 5g.

[0066] Comparative Example 5, a surface cleaning agent for neodymium iron boron magnetic materials, differs from Example 1 only in that the amount of active carrier particles added in Preparation Example 1 is 12g.

[0067] Comparative Example 6 is a surface cleaning agent for neodymium iron boron magnetic materials. The only difference from Example 1 is that the active carrier particles prepared in Preparation Example 1 are replaced with an equal amount of active ingredients, wherein the active ingredients include sodium citrate and tetrasodium diglutamate in a mass ratio of 1:0.5.

[0068] Performance testing

[0069] The NdFeB magnetic material surface cleaning agent obtained in the examples and comparative examples was used to clean the NdFeB magnetic material. The cleaning steps are as follows: S201. The neodymium iron boron magnetic material is ultrasonically washed with water. The ultrasonic washing power is 1500w and the washing time is 5min. S202. The washed NdFeB magnetic material is immersed in a NdFeB magnetic material surface cleaning agent diluted 20 times with water, the temperature is raised to 40℃, and ultrasonic vibration is performed. The ultrasonic vibration power is 2000w and the vibration time is 5min. Finally, it is washed with water and dried to obtain the final product.

[0070] Let the mass of the NdFeB magnetic material be M0, and the mass of the cleaned and dried NdFeB magnetic material be M. Then the degreasing rate = (M0-M) / M0×100%; the test results are shown in Table 2.

[0071] The cleaned neodymium iron boron magnetic material undergoes surface treatment, specifically: After cleaning and drying, the neodymium iron boron magnetic material is coated with a zinc-aluminum coating by spraying, with a coating thickness of 5μm.

[0072] According to the relevant records in GB / T 9286-2021 "Cross-cut Tests for Paints and Varnishes", the adhesion of NdFeB magnetic material surface coatings obtained by different surface cleaning agents using the same surface treatment method was tested. The test results were divided into 0 to 5 levels, and the test results are shown in Table 3.

[0073] Table 2 Oil removal rate test results

[0074] Table 3 Coating adhesion test results

[0075] Based on Tables 2 and 3, and in conjunction with Examples 1 and 2, it can be seen that the oil removal rate of Example 2 is increased, indicating that the cleaning effect of the cleaning agent in Example 2 is improved. This may be because the cellulose-based microsphere carrier of the active carrier particles in Example 2 is also compounded with citric anhydride. The addition of citric anhydride can further reduce the surface tension of the active carrier particles, promote the entry of the active carrier particles into the pores on the surface of the NdFeB magnetic material, and also increase the loading of active ingredients, thereby enhancing the cleaning effect.

[0076] Combining Examples 2, 8, and 9, it can be seen that the oil removal rate of Examples 8 and 9 is lower than that of Example 2. The reason is that in Example 8, the mass of citric anhydride composited on the cellulose-based microspheres was reduced, which reduced the binding force between the microspheres and the active ingredients, reduced the loading, and consequently reduced the oil removal rate. In Example 9, the amount of citric anhydride added was increased, which caused the citric anhydride to compete with the crosslinking agent for the active sites on the cellulose molecular chain, hindering the formation of the porous channel structure of the cellulose-based microspheres, affecting the release of the active ingredients, and resulting in a decrease in the oil removal rate. The oil stains in the pores of the magnetic material were not completely removed, which directly affected the performance of the coating.

[0077] Based on Examples 1 and Comparative Examples 1-3, it can be seen that the degreasing rate and coating adhesion of Comparative Examples 1-3 are lower than those of Example 1. This may be because Comparative Example 1 reduced the proportion of tetrasodium glutamate diacetate (TGA) in the active carrier particles, thus decreasing the chelating effect and compensating effect on sodium citrate. This reduces the cleaning effect of the resulting cleaning agent on the NdFeB magnetic material surface, leading to a decrease in coating performance. In Comparative Example 3, the active ingredient does not include TGA, resulting in a significant decrease in the chelating effect on metal ions, especially the adsorption and stripping effect of loose magnetic ions, affecting coating performance. In Comparative Example 2, the increased proportion of TGA reduces the emulsifying and stripping ability of the active ingredient, decreasing the detergency effect and leading to a decrease in both degreasing rate and coating performance.

[0078] Combining Example 1 and Comparative Example 6, it can be seen that the degreasing rate and coating adhesion of Comparative Example 6 are significantly lower than those of Example 1. The reason is that the active ingredient in Example 6 is not loaded on cellulose-based microspheres, but is directly mixed with other components. On the one hand, the synergistic effect between sodium citrate and tetrasodium diacetate is not significantly manifested. On the other hand, the high surface tension of the active ingredient will hinder the active ingredient from penetrating into the surface pores of the NdFeB magnetic material, making it impossible to achieve deep cleaning of the magnetic material. Oil stains remain inside the pores of the cleaned NdFeB magnetic material, which will directly affect the adhesion of the coating on the surface of the magnetic material.

[0079] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A surface cleaning agent for neodymium iron boron magnetic materials, characterized in that, The raw materials include the following parts by weight: 8-10 parts of active carrier particles; 16-18 parts of nonionic surfactant; 3-5 parts corrosion inhibitor; 1-3 parts of triethanolamine; 10-12 parts of anionic surfactant; 100 parts water; The active carrier particles use cellulose-based microspheres as carriers and sodium citrate and tetrasodium diacetate of glutamate in a mass ratio of 1:(0.4-0.6) as active ingredients.

2. The NdFeB magnetic material surface cleaning agent according to claim 1, characterized in that, The mass ratio of the cellulose-based microspheres to the active ingredient is 1:(0.3-0.4).

3. The NdFeB magnetic material surface cleaning agent according to claim 1, characterized in that, The cellulose-based microspheres are also coated with citric anhydride.

4. The NdFeB magnetic material surface cleaning agent according to claim 3, characterized in that, The raw materials for the cellulose-based microspheres include cellulose, citric anhydride, and crosslinking agent in a mass ratio of 1:(0.05-0.08):(0.08-0.12).

5. The NdFeB magnetic material surface cleaning agent according to claim 3, characterized in that, The cellulose-based microspheres were prepared according to the following method: Cellulose is dispersed in a 10-15% sodium hydroxide aqueous solution, frozen for 1-2 hours, and then thawed by stirring to obtain a cellulose alkaline solution. Citric anhydride was dispersed in an organic solvent, and then a cellulose alkaline solution was added. After stirring and mixing, the mixture was added dropwise to liquid paraffin. A crosslinking agent was then added, and the mixture was stirred for 5–7 hours. Finally, the mixture was filtered, washed, and dried to obtain cellulose-based microspheres.

6. The NdFeB magnetic material surface cleaning agent according to claim 1, characterized in that, The active carrier particles were prepared according to the following method: The active ingredient is added to water and stirred to dissolve it, preparing an active solution with a concentration of 4-6%. Cellulose-based microspheres are added to the active solution and shaken at 25-30°C for 20-25 hours. Finally, the solution is washed and dried to obtain the final product.

7. The NdFeB magnetic material surface cleaning agent according to claim 1, characterized in that, The nonionic surfactant includes one or more combinations of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkyl glycoside and coconut oil fatty acid diethanolamide.

8. The surface cleaning agent for NdFeB magnetic materials according to claim 1, characterized in that, The corrosion inhibitor includes one or a combination of sodium silicate and sodium molybdate.

9. The NdFeB magnetic material surface cleaning agent according to claim 1, characterized in that, The anionic surfactant includes one or more combinations of sodium alkyl sulfate, sodium linear alkylbenzene sulfonate, and alkyl diphenyl ether disulfonate.

10. A method for preparing a surface cleaning agent for NdFeB magnetic materials according to any one of claims 1 to 9, characterized in that, The process includes the following steps: S1. Add nonionic surfactant, anionic surfactant and triethanolamine to water, and stir and disperse at 50-60℃ for 20-30 min to obtain the first solution; S2. Add active carrier particles to water and stir to disperse to obtain a second solution; S3. Add corrosion inhibitor to water and stir to disperse to obtain a third solution; S4. Mix the first solution, the second solution and the third solution, and stir and disperse for 20 to 30 minutes to obtain the final solution.

Images