Environment-friendly magnesium alloy working fluid and preparation method thereof

Abstract

The invention provides environment-friendly magnesium alloy working fluid and a preparation method thereof, and relates to the technical field of metal working fluid. The magnesium alloy working fluid comprises naphthenic mineral oil, an antirust agent, graphene oxide modified fatty acid amide, a glucose gemini surfactant, an emulsifier, an organic corrosion inhibitor, a phosphate corrosion inhibitor, an anti-wear reagent at extreme pressure, a pH stabilizer, a defoaming agent, a bactericide, a lubricant and water. The preparation method comprises the following steps: heating water, sequentially adding the antirust agent, the organic corrosion inhibitor, the pH stabilizer, the naphthenic mineral oil, the graphene oxide modified fatty acid amide, the glucose type bimolecular surfactant and the emulsifier, and continuously stirring; adding other components except the defoaming agent in sequence; slowly adding a defoaming agent, and stirring at a low speed; and stopping heating, stirring and cooling to obtain the product. On the basis of the naphthenic mineral oil and the water, a microemulsion type system is constructed, and a high-temperature environment required by combustion of the magnesium chips is eliminated from the source, so that the safety of the processing process is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of metalworking fluid technology, and in particular to an environmentally friendly magnesium alloy working fluid and its preparation method. Background Technology

[0002] Magnesium alloys are widely used in aerospace, automotive, and 3C electronics industries due to their low density, high specific strength, good damping properties, and excellent machinability. However, the highly reactive chemical properties of magnesium alloys present three major technical challenges during machining: First, magnesium shavings and powder are highly flammable at high temperatures, posing a serious fire hazard. Currently, the mainstream pure oil-based magnesium alloy machining fluids on the market, being inherently flammable, actually exacerbate this fire risk. Second, magnesium alloys are highly susceptible to electrochemical corrosion in aqueous environments, leading to spots and darkening on the workpiece surface, affecting product appearance and performance. Third, during machining, magnesium alloys react with water to release magnesium ions. These ions react with anionic additives in the water to form insoluble metallic soaps, causing problems such as oil separation, soap formation, stratification, and deterioration in the machining fluid, rapidly diminishing its lubrication, cooling, and rust-preventing properties. This not only severely impacts machining quality but also forces companies to frequently change machining fluids, increasing production costs and the burden of wastewater treatment.

[0003] Therefore, developing a processing fluid that can ensure processing safety, effectively prevent magnesium alloy corrosion, withstand high concentrations of magnesium ions, and maintain long-term system stability has become a pressing technical challenge in this field. Summary of the Invention

[0004] To address the problems of flammable magnesium shavings, high workpiece corrosivity, and low processing stability in existing magnesium alloy processing methods, this invention provides an environmentally friendly magnesium alloy processing fluid and its preparation method.

[0005] In a first aspect, the present invention provides an environmentally friendly magnesium alloy processing fluid, which adopts the following technical solution: An environmentally friendly magnesium alloy processing fluid, by weight percentage, comprises: 15% to 25% naphthenic mineral oil, 3% to 8% rust inhibitor, 8% to 15% graphene oxide modified fatty acid amide, 1% to 2% glucose-type gemini surfactant, 5% to 10% emulsifier, 1% to 3% organic corrosion inhibitor, 1% to 2% phosphate ester corrosion inhibitor, 1% to 3% extreme pressure anti-wear agent, 5% to 15% pH stabilizer, 0.1% to 0.5% defoamer, 1% to 3% bactericide, 3% to 5% lubricant, with the balance being water.

[0006] This invention constructs a microemulsion system based on cycloalkyl mineral oil and water, and the amount of cycloalkyl mineral oil used is significantly reduced compared with the prior art. The high specific heat capacity and latent heat of vaporization of water can rapidly reduce the temperature of the processing zone, eliminating the high-temperature environment required for magnesium scrap combustion from the source. Therefore, it greatly improves the safety of the processing process and fundamentally solves the fire hazard in magnesium alloy processing.

[0007] As the core component of this invention, graphene oxide-modified fatty acid amides possess excellent lubricity due to the fatty acid amide structure in their molecules, thus enabling them to lubricate and reduce the cutting force and frictional heat required for processing. The graphene oxide sheets in the graphene oxide-modified fatty acid amide molecules can form a physical barrier film on the magnesium alloy surface, effectively preventing water and oxygen from contacting the magnesium matrix, thereby inhibiting corrosion. At the same time, its special molecular structure makes it difficult for it to combine with magnesium ions to form precipitates, fundamentally solving the problem of system instability caused by the formation of metal soaps. More importantly, graphene oxide-modified fatty acid amides can synergistically work with emulsifiers to form extremely fine and stable emulsion particles, maintaining stable dispersion even in environments with high magnesium ion concentrations.

[0008] Glucose-type gemini surfactants not only provide essential emulsification but also endow working fluids with superior cleaning capabilities due to their unique molecular structure. This allows for the timely removal and dispersion of magnesium shavings, eliminating the risk of localized overheating and fire caused by shaving accumulation. Furthermore, glucose-type gemini surfactants exhibit excellent resistance to hard water, maintaining the stability of the emulsion system even in harsh environments with continuously increasing magnesium ion concentrations in the processing fluid. This effectively prevents oil separation, stratification, and deterioration caused by surfactant failure. Moreover, the two hydrophilic head groups and two hydrophobic chains of glucose-type gemini surfactants are covalently linked by linking groups, resulting in a more compact molecular structure. During adsorption at the gas-liquid interface, the formed monomolecular film is more densely packed and rigid. This dense and rigid interfacial film has low elasticity and is less prone to encapsulating gas to form stable foam. Even when foam forms, the liquid film drains quickly, has low strength, and is easily ruptured, thus exhibiting low foaming and rapid defoaming characteristics.

[0009] Optionally, the organic corrosion inhibitor is any one of benzotriazole, methylbenzotriazole, and thiadiazole derivatives.

[0010] The present invention uses the above-mentioned nitrogen heterocyclic compound as a corrosion inhibitor. The nitrogen atoms in the molecule contain lone pairs of electrons, which can be strongly chemically adsorbed on the active sites on the metal surface to form a monomolecular hydrophobic shielding film, which isolates moisture and oxygen and effectively inhibits electrochemical corrosion.

[0011] This invention utilizes phosphate ester corrosion inhibitors, which can react with the surface of magnesium alloys to form a dense, strongly adhering phosphate or organic phosphate protective film. This film, together with the adsorption film formed by the organic corrosion inhibitor, constitutes a dual protective barrier, further enhancing the corrosion resistance of magnesium alloys during processing.

[0012] Optionally, the emulsifier is a nonionic alkoxy alcohol ether emulsifier.

[0013] This invention utilizes a nonionic alkoxy alcohol ether emulsifier and graphene oxide-modified fatty acid amide to synergistically construct a stable microemulsion system. By leveraging its nonionic properties, the microemulsion system is less affected by pH and electrolyte levels, and is less prone to binding with magnesium ions and becoming ineffective. This significantly improves the chemical stability of the processing fluid under high hardness conditions and avoids problems such as oil separation, soap formation, stratification, and deterioration that may occur during processing.

[0014] Optionally, the extreme pressure anti-wear agent is an ashless phosphate ester or a thiophosphate ester.

[0015] This invention uses extreme pressure anti-wear agents to protect cutting tools and workpieces under high pressure and high temperature boundary lubrication conditions. While providing excellent extreme pressure anti-wear performance, the above-mentioned extreme pressure anti-wear agents avoid introducing new sources of metal ion contamination, thus maintaining the cleanliness and stability of the machining fluid system from another perspective and preventing blockage and deterioration caused by the formation of metal soaps.

[0016] Optionally, the pH stabilizer is a mixture formed by combining ethanolamine and a special amine.

[0017] Optionally, the ethanolamine is triethanolamine and / or diethanolamine, and the special amine is cyclohexylamine ethoxylate and / or 2-amino-2-methyl-1-propanol.

[0018] The pH stabilizer of this invention can maintain the working fluid of the processing fluid in a weakly alkaline range, which is beneficial for corrosion inhibition and can also inhibit the growth of microorganisms.

[0019] Optionally, the rust inhibitor is a mixture of two or more of the following: tricarboxylic acid, sebacic acid, and dodecanoic acid.

[0020] This invention uses carboxylic acid substances as rust inhibitors, which can undergo strong physicochemical adsorption on metal surfaces. Their hydrophobic long chains form an effective barrier, and multiple carboxylic acids can be combined to form a denser and more complete protective film.

[0021] Optionally, the kinematic viscosity of the naphthenic mineral oil at 40°C is 20-24 mm. 2 / s.

[0022] The present invention uses oils within this viscosity range that have moderate viscosity and good viscosity-temperature characteristics, thus ensuring that the processing fluid has the best lubrication and cooling balance, while also facilitating the stable formation and maintenance of the emulsion system.

[0023] Optionally, the defoamer is a silicone-based defoamer or a polyether-based defoamer.

[0024] Using defoamers can ensure that the processed magnesium alloy workpieces maintain their shine for a long time.

[0025] Secondly, the present invention provides a method for preparing an environmentally friendly magnesium alloy processing fluid, comprising the following steps: Step S1: Add measured water to the reactor, start stirring and heat to 50℃~60℃; Step S2: Add the rust inhibitor, the organic corrosion inhibitor and the pH stabilizer in sequence, and stir until completely dissolved; Step S3: Under uniform stirring, add cycloalkyl mineral oil, graphene oxide modified fatty acid amide, glucose bimolecular surfactant and emulsifier in sequence, and continue stirring for 30 to 40 minutes until the system is homogeneous and transparent. Step S4: Add the other components except the defoamer in sequence. Stir for 10-15 minutes after each component is added to ensure full dispersion and dissolution. Step S5: Slowly add the defoamer while stirring at low speed; Step S6: Stop heating, continue stirring and cooling to room temperature, then discharge the product.

[0026] This invention employs a method of first dissolving water-soluble components to construct a stable aqueous environment, and then gradually adding oil phase and emulsifying and stabilizing components to ensure the formation of a uniform and delicate emulsion. The defoaming agent, which is prone to foaming, is added last at a low speed to avoid excessive foaming that could affect the homogenization process.

[0027] In summary, the present invention has at least one of the following beneficial effects: 1. This invention provides comprehensive protection for magnesium alloy workpieces through the dual effects of physical shielding by graphene oxide-modified fatty acid amides and chemical adsorption by organic corrosion inhibitors, ensuring that the workpiece surface remains bright and new after processing, without corrosion spots.

[0028] 2. The working fluid of the magnesium alloy processing fluid of the present invention can withstand magnesium ion hardness exceeding 20,000 ppm, which is far superior to traditional products. The reason is that its core components do not react with magnesium ions, which fundamentally eliminates the phenomenon of oil and soap separation and ensures the stability of the system in long-term use.

[0029] 3. Because the microemulsion system provided by this invention is stable and not easily deteriorated, it significantly extends the replacement cycle of magnesium alloy processing fluid, reduces users' procurement costs, downtime for fluid replacement, and waste liquid treatment costs, and meets the requirements of green manufacturing and sustainable development.

[0030] 4. The magnesium alloy machining fluid of the present invention has good lubricity and extreme pressure properties, which can effectively protect the cutting tools and improve the surface machining quality of the workpiece.

[0031] 5. The preparation method of the magnesium alloy processing fluid of the present invention is simple and can be obtained by stirring in an industrial reactor at room temperature, making it easy for industrial production. Attached Figure Description

[0032] Figure 1 These are comparative images of magnesium alloy specimens after being immersed and etched in 5% diluted solutions of Examples 1-5 and Comparative Examples 1-2. In the images, a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, d corresponds to Example 4, e corresponds to Example 5, f corresponds to Comparative Example 1, and g corresponds to Comparative Example 2. In each example or comparative example, the left side of the image is a magnesium alloy AZ91D specimen, and the right side is a magnesium alloy AZ31B specimen. Figure 2 These are comparative images of magnesium alloy AZ91D specimens and cast iron sheets after being immersed and etched in 5% diluted solutions of Examples 1-5 and Comparative Examples 1-2. In the images, a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, d corresponds to Example 4, e corresponds to Example 5, f corresponds to Comparative Example 1, and g corresponds to Comparative Example 2. In each example or comparative example, the rectangular magnesium alloy AZ91D specimen is shown, and the circular specimen is shown as a cast iron sheet. Figure 3 These are comparative images of magnesium alloy AZ31B specimens and cast iron sheets after being immersed and etched in 5% diluted solutions of Examples 1-5 and Comparative Examples 1-2. In the images, a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, d corresponds to Example 4, e corresponds to Example 5, f corresponds to Comparative Example 1, and g corresponds to Comparative Example 2. In each example or comparative example, the rectangular magnesium alloy AZ31B specimen is shown, and the circular specimen is shown as a cast iron sheet. Figure 4 This is a comparison chart of the concentrations of 5% diluted solutions of Examples 1-5 and Comparative Examples 1-2 in the hard water stability test, corresponding to the magnesium ion hard water grade concentrations in Table 2. In the table, a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, d corresponds to Example 4, e corresponds to Example 5, f corresponds to Comparative Example 1, and g corresponds to Comparative Example 2. Figure 5The images show a comparison of wear scars in long-term grinding lubrication tests using 5% diluted solutions of Examples 1-5 and Comparative Examples 1-2 as working fluids. In the images, a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, d corresponds to Example 4, e corresponds to Example 5, f corresponds to Comparative Example 1, and g corresponds to Comparative Example 2. Figure 6 The graphs show the comparison of the stability test results of 5% diluted solutions of Examples 1-5 and Comparative Examples 1-2, where a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, d corresponds to Example 4, e corresponds to Example 5, f corresponds to Comparative Example 1, and g corresponds to Comparative Example 2. Detailed Implementation

[0033] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0034] The raw materials used in the following embodiments and comparative examples of this invention are specifically sourced as follows: The naphthenic mineral oil is 22# naphthenic mineral oil produced by Xinjiang Karamay Refinery, with a kinematic viscosity of 20-24 mm² / s at 40°C. The rust inhibitor, tricarboxylic acid, is BASF IRGACOR L190Plus. The rust inhibitor, sebacic acid, is purchased from Shandong Kaisai Biomaterials Co., Ltd. The emulsifier is Genifol 6062 from Nanjing Shangqin New Material Technology Co., Ltd. The organic corrosion inhibitor, benzotriazole, is purchased from Chuzhou Kanghua Electronic Materials Co., Ltd. The extreme pressure anti-wear agent is Geniexeral 1014 from Nanjing Shangqin New Material Technology Co., Ltd. The pH stabilizer, triethanolamine, is purchased from Yangzi BASF. The pH stabilizer, cyclohexylamine ethoxylate, is Geniemine AM620 from Nanjing Shangqin New Material Technology Co., Ltd. The pH stabilizer, 2-amino-2-methyl-1-propanol, is AMP95 from Adalcantica. The defoamer is Dow Corning AFE-1247. The bactericide was BIT-20 from Itofuku Biotechnology (Shanghai) Co., Ltd. The lubricant was purchased from Shandong Ruijie New Materials Co., Ltd. The phosphate ester corrosion inhibitor was Geniphos OMD from Nanjing Shangqin New Materials Technology Co., Ltd. The graphene oxide-modified fatty acid amide was synthesized according to the method disclosed in patent CN111171926B. The glucose-type bimolecular surfactant was synthesized according to the method disclosed in patent CN 104974185 B.

[0035] Example 1:

[0036] Example 1 provides an environmentally friendly magnesium alloy processing fluid, comprising the following components by mass percentage: 25% naphthenic mineral oil, 4% tricarboxylic acid rust inhibitor, 2% sebacic acid rust inhibitor, 15% graphene oxide-modified fatty acid amide, 2% glucose-type gemini surfactant, 7% emulsifier, 1% organic corrosion inhibitor, 2% phosphate ester corrosion inhibitor, 2% extreme pressure anti-wear agent, 15% pH stabilizer, 4% lubricant, 2% bactericide, 0.3% defoamer, and the balance being water. The pH stabilizer is composed of triethanolamine, cyclohexylamine ethoxylate, and 2-amino-2-methyl-1-propanol in a mass ratio of 10:3:2.

[0037] Example 1 also provides a method for preparing the above-mentioned environmentally friendly magnesium alloy processing fluid, which specifically includes the following steps: Step S1: Add measured water to the reactor, start stirring and heat to 50°C; Step S2: Add rust inhibitor, organic corrosion inhibitor and pH stabilizer in sequence, and stir until completely dissolved; Step S3: Under uniform stirring, add cycloalkyl mineral oil, graphene oxide modified fatty acid amide, glucose bimolecular surfactant and emulsifier in sequence, and continue stirring for 30 minutes until the system is homogeneous and transparent. Step S4: Add the other components except the defoamer in sequence, stirring for 10 minutes after each component is added to ensure full dispersion and dissolution; Step S5: Slowly add the defoamer while stirring at low speed; Step S6: Stop heating, continue stirring and cooling to room temperature, then discharge the product.

[0038] Examples 2-5: Examples 2-5 are basically the same as Example 1, except that the types and proportions of some raw materials are different, as shown in Table 1.

[0039] Table 1. Component formulations (mass percentage) for Examples 1-5

[0040] Comparative Example 1: Comparative Example 1 is basically the same as Example 1, except that Comparative Example 1 uses oleic acid amide to replace the graphene oxide modified fatty acid amide in Example 1.

[0041] Comparative Example 2: Comparative Example 2 is basically the same as Example 1, except that Comparative Example 2 uses fatty acid polyoxyethylene ether AEO-3 to replace the glucose-type gemini surfactant in Example 1 by mass.

[0042] Performance testing: The performance of the magnesium alloy processing fluids from Examples 1-5 and Comparative Examples 1-2 was tested. The products obtained from Examples 1-5 and Comparative Examples 1-2 were all concentrated solutions; therefore, they were diluted with deionized water to a working solution with a mass fraction of 5% for testing. The specific test items are as follows, and the test results are shown in Table 2.

[0043] 1. Immersion corrosion test: After cleaning the magnesium alloy (AZ91D and AZ31B) test pieces, immerse them in the respective working solutions and soak them at 55℃ for 24 hours, then observe the surface corrosion. 2. Galvanic corrosion test: After cleaning the magnesium alloy (AZ91D and AZ31B) test pieces and the cast iron sheet, place them on top of each other, drip the working solution in the middle, and let them stand at 55℃ for 4 hours to observe the surface corrosion. 3. Hard water stability test: Magnesium chloride is gradually added to each working solution to simulate the increase of magnesium ion concentration. The state of the emulsion is observed, and the magnesium ion concentration (calculated as CaCO3, ppm) at which oil separation, layering or precipitation begins to occur is recorded. 4. Long-term wear lubrication test: The test machine is a four-ball friction tester. The test conditions are 40Kg, 30min, 1200rpm, and room temperature. The smaller the wear scar diameter, the better the lubrication. 5. Tapping Lubrication Test: The test machine was a TTT-Microtap tapping torque tester. The test conditions were 1500 rpm, hole depth 12 mm, M4F cutting tool, and 7075 aluminum alloy sheet. The smaller the tapping torque value, the better the lubrication.

[0044] 6. Stability test: Seal and let each working solution stand at room temperature for 30 days, and observe whether there is stratification, precipitation or deterioration.

[0045] 7. Defoaming Test: In a circulating foam apparatus, conduct a circulating foam test at a pressure of 2.5 MPa, with the same proportion and dosage. The test conditions are room temperature (25℃). Judgment method: Simultaneously turn off the circulating pump and record the foam height and the time it takes for the foam to emerge from the center liquid surface. The lower the foam height and the shorter the time it takes to emerge from the center liquid surface, the better its defoaming performance.

[0046] Table 2 Test results of Examples 1-5 and Comparative Examples 1-2

[0047] The results of immersion corrosion test and galvanic corrosion test, and Figures 1-3It can be seen that Examples 1-5 exhibited good corrosion resistance, while Comparative Example 1, lacking graphene oxide-modified fatty acid amide, showed slight corrosion in the galvanic corrosion test. This indicates that the present invention achieves effective protection of magnesium alloy workpieces through a dual protective barrier formed by the physical barrier of graphene oxide-modified fatty acid amide and the chemical adsorption of corrosion inhibitor.

[0048] Based on the results of the hard water stability test and Figure 4 It can be seen that the magnesium alloy processing fluids of Examples 1-5 can withstand magnesium ion hardness of up to 20,000 ppm, while Comparative Examples 1 and 2 only have 12,000-15,000 ppm. This indicates that the synergistic effect of graphene oxide modified fatty acid amide and glucose-type gemini surfactant is the key to fundamentally solving the problem of instability and oil separation in the processing fluid due to magnesium ion intrusion.

[0049] The results of long grinding lubrication tests and tapping lubrication tests, and Figure 5 It can be seen that the magnesium alloy processing fluids of Examples 1-5 and Comparative Example 2 exhibit good lubricity.

[0050] From storage stability tests and Figure 6 It can be seen that the emulsion systems of Examples 1-5 and Comparative Examples 1-2 can all remain homogeneous under static conditions, exhibiting good storage stability.

[0051] The results of the defoaming test show that the diluted solutions of Examples 1-5 exhibit excellent low-foaming and fast-dissipating properties, while the foam height of Comparative Examples 1-2 is large and the defoaming time is as long as several minutes. This indicates that the surfactant system used in this invention not only achieves efficient emulsification and cleaning, but also synergistically endows the system with excellent low-foaming properties.

[0052] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An environmentally friendly magnesium alloy processing fluid, characterized in that, By weight percentage, it includes: 15% to 25% naphthenic mineral oil, 3% to 8% rust inhibitor, 8% to 15% graphene oxide modified fatty acid amide, 1% to 2% glucose-type gemini surfactant, 5% to 10% emulsifier, 1% to 3% organic corrosion inhibitor, 1% to 2% phosphate ester corrosion inhibitor, 1% to 3% extreme pressure anti-wear agent, 5% to 15% pH stabilizer, 0.1% to 0.5% defoamer, 1% to 3% bactericide, 3% to 5% lubricant, and the balance being water.

2. The environmentally friendly magnesium alloy processing fluid according to claim 1, characterized in that, The organic corrosion inhibitor is any one of benzotriazole, methylbenzotriazole, and thiadiazole derivatives.

3. The environmentally friendly magnesium alloy processing fluid according to claim 1, characterized in that, Its features are, The emulsifier is a nonionic alkoxy alcohol ether emulsifier.

4. The environmentally friendly magnesium alloy processing fluid according to claim 1, characterized in that, Its features are, The extreme pressure anti-wear agent is an ashless phosphate ester or a thiophosphate ester.

5. The environmentally friendly magnesium alloy processing fluid according to claim 1, characterized in that, Its features are, The pH stabilizer is a mixture formed by combining ethanolamine and a special amine.

6. The environmentally friendly magnesium alloy processing fluid according to claim 5, characterized in that, The ethanolamine is triethanolamine and / or diethanolamine, and the special amine is cyclohexylamine ethoxylate and / or 2-amino-2-methyl-1-propanol.

7. The environmentally friendly magnesium alloy processing fluid according to claim 1, characterized in that, The rust inhibitor is a mixture of two or more of the following: tricarboxylic acid, sebacic acid, and dodecanoic acid.

8. The environmentally friendly magnesium alloy processing fluid according to claim 1, characterized in that, The kinematic viscosity of the naphthenic mineral oil at 40°C is 20-24 mm. 2 / s.

9. The method for preparing the environmentally friendly magnesium alloy working fluid according to any one of claims 1-8, characterized in that, Includes the following steps: Step S1: Add measured water to the reactor, start stirring and heat to 50℃~60℃; Step S2: Add the rust inhibitor, the organic corrosion inhibitor and the pH stabilizer in sequence, and stir until completely dissolved; Step S3: Under uniform stirring, add cycloalkyl mineral oil, graphene oxide modified fatty acid amide, glucose bimolecular surfactant and emulsifier in sequence, and continue stirring for 30 to 40 minutes until the system is homogeneous and transparent. Step S4: Add the other components except the defoamer in sequence. Stir for 10-15 minutes after each component is added to ensure full dispersion and dissolution. Step S5: Slowly add the defoamer while stirring at low speed; Step S6: Stop heating, continue stirring and cooling to room temperature, then discharge the product.

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