High-stability polishing paste, preparation method and application

Abstract

The application belongs to the field of grinding materials, and discloses a high-stability grinding paste, a preparation method and application. The high-stability grinding paste comprises the following raw materials in parts by weight: pumice powder 40-60 parts, composite lubricant 15-25 parts, white mineral oil 12-18 parts, Span 203-5 parts, Tween 20 3-5 parts, modified fatty acid 4-6 parts, and modified nano-silicon dioxide 2-4 parts. The composite lubricant is core-shell particles formed by coating microcrystalline wax on the surface of graphene oxide. The modified fatty acid is an ionic liquid modified fatty acid, which is prepared by reacting an imidazole-based ionic liquid with sodium oleate. The modified nano-silicon dioxide is mesoporous silicon dioxide loaded with nano-silver and then grafted with an antibacterial coupling agent. The antibacterial coupling agent is prepared by reacting chitosan after quaternary ammonium modification with a silane coupling agent. The high-stability grinding paste uses pumice powder as the abrasive, and is compounded with the composite lubricant, the modified fatty acid and the modified nano-silicon dioxide. The prepared grinding paste has high grinding precision, and also has good storage stability, high-temperature stability and antibacterial property.

Description

Technical Field

[0001] This invention belongs to the field of abrasive materials, specifically relating to a highly stable abrasive paste, its preparation method, and its application. Background Technology

[0002] Grinding paste is a soft abrasive tool made of micronized abrasive particles and a paste-like binder. Also known as a loose abrasive, it is used to grind hard and brittle materials to achieve a high surface finish. The grinding process is characterized by the continuous rolling of the abrasive particles, generating both squeezing and cutting actions, gradually smoothing uneven surfaces. Grinding pastes are divided into oil-based and water-based types. Oil-based grinding pastes have good wettability, low grinding force and heat, and are mainly used for machining parts made of high-hardness alloy materials such as cemented carbide, instruments, measuring tools, cutting tools, and grinding wheels. Water-based grinding pastes have low viscosity, easy chip removal, and high processing efficiency, and are mainly used for machining slightly corroded metals, circuit boards, and non-metallic hard and brittle materials such as glass, ceramics, gemstones, and agate. Commonly used grinding pastes include corundum-based, silicon carbide and boron carbide-based, chromium oxide-based, and diamond-based pastes.

[0003] With the continuous development of various modern fields, the demand for polishing pastes is also increasing. Polishing pastes offer economic benefits due to their wear resistance and durability, but current polishing effects have not yet reached an ideal state. Surface roughness does not meet technical requirements, resulting in low yields. Existing polishing pastes suffer from poor micron dispersion characteristics, leading to poor storage stability and easy stratification. The particle size range of the polishing material is too wide, and the lubrication properties of the components are poor, resulting in unsatisfactory surface quality after polishing, making it difficult to meet quality requirements and resulting in a low product qualification rate. Although most polishing pastes can enhance the polishing effect, the high temperature generated during polishing reduces the lubrication effect, leading to poor polishing results. In addition, current polishing pastes are easily corroded by bacteria, losing their original effects. Summary of the Invention

[0004] To address the shortcomings mentioned in the background art, the present invention aims to provide a high-stability grinding paste, its preparation method, and its application. The high-stability grinding paste uses pumice powder as an abrasive, which is combined with a composite lubricant, modified fatty acid, and modified nano-silica. The prepared grinding paste has high grinding precision and also exhibits good storage stability, high-temperature stability, and antibacterial properties.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A highly stable grinding paste comprises the following raw materials in parts by weight: 40-60 parts pumice powder, 15-25 parts composite lubricant, 12-18 parts white mineral oil, 3-5 parts Span 20, 3-5 parts Tween 20, 4-6 parts modified fatty acid, and 2-4 parts modified nano-silica.

[0007] The composite lubricant is a core-shell particle formed by coating microcrystalline wax on the surface of graphene oxide;

[0008] The modified fatty acid is an ionic liquid modified fatty acid, which is prepared by reacting an imidazole ionic liquid with sodium oleate.

[0009] The modified nano-silica is mesoporous silica loaded with nano-silver and grafted with an antibacterial coupling agent. The antibacterial coupling agent is prepared by reacting chitosan, which has been quaternized and modified, with a silane coupling agent.

[0010] Preferably, the pumice powder has a particle size of 10–50 μm and a density of 0.5–1.0 g / cm³. 3 .

[0011] Preferably, the preparation method of the composite lubricant is as follows: graphene oxide is added to deionized water at 60°C and ultrasonically dispersed. Microcrystalline wax is heated to melt and then added to the graphene dispersion. After high-speed homogenization and emulsification, it is rapidly cooled to room temperature to form wax microparticles coated with GO. The composite lubricant is then spray-dried.

[0012] Preferably, the mass ratio of graphene oxide to microcrystalline wax is 1:15 to 20.

[0013] Preferably, the modified fatty acid is prepared by reacting 1-butyl-3-methylimidazolium chloride with sodium oleate in methanol at a molar ratio of 1:1, refluxing at 60°C for 10-12 h, and removing the solvent by rotary evaporation to obtain the ionic liquid modified fatty acid.

[0014] Preferably, the method for preparing modified nano-silica includes the following steps:

[0015] (1) Mesoporous silica was ultrasonically dispersed in anhydrous ethanol, then AgNO3 was added and stirred to dissolve it. After ultrasonication for 5-10 min, the mixture was allowed to stand under a vacuum of -0.1 MPa for 8-12 h. After filtration and washing, Ag was obtained. + Loaded mesoporous silica;

[0016] (2) Ag + The loaded mesoporous silica was ultrasonically dispersed in anhydrous ethanol, and 0.01 mol / L ascorbic acid solution and 0.01 mol / L sodium citrate solution were added dropwise. The mixture was stirred in a sealed container at 40°C in the dark for 20-40 min, filtered, washed and dried to obtain nano-silver loaded mesoporous silica.

[0017] (3) Add chitosan to 5 vol% acetic acid solution and stir until completely dissolved. Add 3-chloro-2-hydroxypropyltrimethylammonium chloride dropwise to the chitosan solution. Adjust the pH to 8-9 with NaOH solution. React at 60-70℃ for 6-12 h. After the reaction is complete, precipitate the product with ethanol. Centrifuge and dissolve the precipitate in deionized water. Place it in a dialysis bag and dialyze for 24-48 h. Finally, freeze dry to obtain quaternized chitosan.

[0018] (4) Add quaternized chitosan to 5 vol% acetic acid solution and sonicate until completely dissolved. Add silane coupling agent to 90 vol% ethanol solution and dissolve. Then slowly add silane coupling agent solution to quaternized chitosan solution and react at 60-80℃ for 4-8h. After the reaction is complete, precipitate with ethanol, collect the product by centrifugation, dialyze for 24-48h, and freeze dry to obtain antibacterial coupling agent.

[0019] (5) Add the nano-silver supported mesoporous silica obtained in step (2) to anhydrous ethanol and disperse it by ultrasonication. Dissolve the antibacterial coupling agent obtained in step (4) in 70 vol% ethanol solution. Then add the antibacterial coupling agent solution to the nano-silver supported mesoporous silica dispersion. Stir magnetically at 60-80°C for 6-12 h. After the reaction is completed, centrifuge, wash and dry to obtain the modified nano-silica.

[0020] Preferably, the molar ratio of chitosan to 3-chloro-2-hydroxypropyltrimethylammonium chloride is 1:1 to 1.2.

[0021] Preferably, the silane coupling agent is 3-aminopropyltriethoxysilane or 3-glycidyl etheroxypropyltrimethoxysilane, and the molar ratio of the quaternized chitosan to the silane coupling agent is 1:1 to 1.2.

[0022] A method for preparing a high-stability polishing paste includes the following steps: mixing white mineral oil, Span 20, Tween 20, and modified fatty acids to obtain a mixture; then adding pumice powder, composite lubricant, and modified nano-silica to the mixture in sequence and dispersing them evenly to obtain the high-stability polishing paste.

[0023] An application of a highly stable polishing paste for polishing and grinding low-hardness polymers or semiconductor materials, resulting in a surface roughness Ra ≤ 0.05 μm.

[0024] The beneficial effects of this invention are:

[0025] This high-stability polishing paste uses pumice powder as the abrasive, providing the hardness and cutting force required for polishing. It is the main abrasive in the paste. The composite lubricant reduces friction during polishing, minimizes damage to the polished surface, and may also help the abrasive disperse evenly. White mineral oil, as the base oil, disperses the components, adjusts the consistency of the polishing paste, and provides lubrication. Span 20 and Tween 20 act as emulsifiers to promote the uniform dispersion of the components, improve the emulsification stability and compatibility of the components. Modified fatty acids assist in lubrication, potentially enhancing the adhesion of the polishing paste, and work synergistically with other lubricants. Modified nano-silica utilizes its antibacterial properties to prevent bacterial growth during storage and use. At the same time, the nanoparticles may fill micro-pits on the polishing surface, improving polishing quality.

[0026] Among them, the composite lubricant is a core-shell particle formed by coating microcrystalline wax on the surface of graphene oxide. The layered structure of GO reduces the coefficient of friction and reduces grinding heat. After the wax phase melts, GO is released to fill the microcracks on the surface. The core-shell structure formed by coating microcrystalline wax not only retains the lubricating adhesion of microcrystalline wax, but also further reduces frictional resistance through the addition of graphene oxide, reducing scratches on the workpiece surface by abrasive, thereby significantly improving the lubrication effect of the polishing paste and the quality of the polished surface.

[0027] The modified fatty acid is an ionic liquid modified fatty acid. 1-Butyl-3-methylimidazolium chloride, as an ionic liquid, has good thermal stability and lubricity. After reacting with sodium oleate, its molecular structure is more likely to form an adsorption film on the friction surface, which enhances the lubrication effect. At the same time, the modified fatty acid can bridge Span / Tween, optimize the emulsion system, and improve the compatibility with other oily components.

[0028] The modified nano-silica is mesoporous silica loaded with nano-silver and grafted with an antibacterial coupling agent. This antibacterial coupling agent is prepared by reacting quaternized chitosan with a silane coupling agent. The nano-silver loaded with mesoporous silica exhibits broad-spectrum antibacterial activity and can disrupt bacterial cell membranes. In the grafted antibacterial coupling agent, quaternized chitosan enhances antibacterial activity and water solubility, while the silane coupling agent improves its binding force with other components, allowing the antibacterial components to function more stably. Simultaneously, the nanoparticles, as a supplement to micron-sized pumice powder, fill the gaps in scratches, improve surface precision, enhance the grinding effect, and the rolling effect reduces substrate damage and wear. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] A composite lubricant, consisting of core-shell particles formed by coating microcrystalline wax on the surface of graphene oxide, is prepared by adding 2.2g of graphene oxide to 200mL of deionized water at 60℃ and dispersing it ultrasonically. Then, 40g of microcrystalline wax is heated to melt and added to the graphene dispersion. After high-speed homogenization and emulsification, the mixture is rapidly cooled to room temperature to form wax microparticles coated with graphene oxide (GO). The composite lubricant is then spray-dried.

[0032] Example 2

[0033] A modified fatty acid is prepared by reacting an imidazole ionic liquid with sodium oleate. The preparation method is as follows: 3.5 g of 1-butyl-3-methylimidazolium chloride and 6.1 g of sodium oleate are reacted in 100 mL of methanol, refluxed at 60 °C for 12 h, and the solvent is removed by rotary evaporation to obtain the ionic liquid modified fatty acid.

[0034] Example 3

[0035] A modified nano-silica is a mesoporous silica loaded with nano-silver and grafted with an antibacterial coupling agent. The antibacterial coupling agent is prepared by reacting chitosan, after quaternization modification, with a silane coupling agent. The preparation method includes the following steps:

[0036] (1) 5.0 g of mesoporous silica was added to 30 mL of anhydrous ethanol and ultrasonically dispersed. Then, 2.8 g of AgNO3 was added and stirred to dissolve. After ultrasonication for 8 min, the mixture was allowed to stand under a vacuum of -0.1 MPa for 10 h. After filtration and washing, Ag was obtained. + Loaded mesoporous silica;

[0037] (2) Take 5.0g Ag + The loaded mesoporous silica was ultrasonically dispersed in 30 mL of anhydrous ethanol. Then, 20 mL of 0.01 mol / L ascorbic acid solution and 10 mL of 0.01 mol / L sodium citrate solution were added dropwise. The mixture was stirred in a sealed container at 40 °C in the dark for 30 min. After filtration, washing and drying, nano-silver loaded mesoporous silica was obtained.

[0038] (3) Add 3.2g of chitosan to 30mL of 5vol% acetic acid solution and stir until completely dissolved. Add 3.5mL of 3-chloro-2-hydroxypropyltrimethylammonium chloride dropwise to the chitosan solution. Adjust the pH to 9 with NaOH solution. React at 65℃ for 10h. After the reaction is complete, precipitate the product with ethanol. Centrifuge and dissolve the precipitate in deionized water. Place it in a dialysis bag and dialyze for 48h. Finally, freeze dry to obtain quaternized chitosan.

[0039] (4) Add 6.0 g of quaternized chitosan to 50 mL of 5 vol% acetic acid solution and sonicate until completely dissolved. Add 5 mL of 3-glycidyl etheroxypropyltrimethoxysilane to 20 mL of 90 vol% ethanol solution and dissolve. Then slowly add the silane coupling agent solution to the quaternized chitosan solution and react at 70 °C for 6 h. After the reaction is complete, precipitate with ethanol, collect the product by centrifugation, dialyze for 48 h, and freeze dry to obtain the antibacterial coupling agent.

[0040] (5) Add 4.0g of nano-silver supported mesoporous silica obtained in step (2) to 20mL of anhydrous ethanol and disperse by ultrasonication. Dissolve 2.5g of antibacterial coupling agent obtained in step (4) in 20mL of 70vol% ethanol solution. Then add the antibacterial coupling agent solution to the nano-silver supported mesoporous silica dispersion. Stir magnetically at 70℃ for 10h. After the reaction is completed, centrifuge, wash and dry to obtain the modified nano-silica.

[0041] Example 4

[0042] A highly stable grinding paste comprises the following raw materials in parts by weight: 40 parts pumice powder, 25 parts composite lubricant, 12 parts white mineral oil, 205 parts Span, 3 parts Tween 20, 6 parts modified fatty acid, and 2 parts modified nano silica.

[0043] The composite lubricant was prepared in Example 1; the modified fatty acid was prepared in Example 2; and the modified nano-silica was prepared in Example 3.

[0044] The preparation method of the above-mentioned high-stability polishing paste includes the following steps: stirring and mixing white mineral oil, Span 20, Tween 20 and modified fatty acid to obtain a mixture; then adding pumice powder, composite lubricant and modified nano silica to the mixture in sequence and dispersing them evenly to obtain the high-stability polishing paste.

[0045] Example 5

[0046] A highly stable grinding paste comprises the following raw materials in parts by weight: 60 parts pumice powder, 15 parts composite lubricant, 18 parts white mineral oil, 3 parts Span 20, 5 parts Tween 20, 4 parts modified fatty acid, and 4 parts modified nano silica.

[0047] The composite lubricant was prepared in Example 1; the modified fatty acid was prepared in Example 2; and the modified nano-silica was prepared in Example 3.

[0048] The preparation method of the above-mentioned high-stability polishing paste includes the following steps: stirring and mixing white mineral oil, Span 20, Tween 20 and modified fatty acid to obtain a mixture; then adding pumice powder, composite lubricant and modified nano silica to the mixture in sequence and dispersing them evenly to obtain the high-stability polishing paste.

[0049] Example 6

[0050] A highly stable grinding paste comprises the following raw materials in parts by weight: 50 parts pumice powder, 20 parts composite lubricant, 15 parts white mineral oil, 4 parts Span 20, 4 parts Tween 20, 5 parts modified fatty acid, and 3 parts modified nano silica.

[0051] The composite lubricant was prepared in Example 1; the modified fatty acid was prepared in Example 2; and the modified nano-silica was prepared in Example 3.

[0052] The preparation method of the above-mentioned high-stability polishing paste includes the following steps: stirring and mixing white mineral oil, Span 20, Tween 20 and modified fatty acid to obtain a mixture; then adding pumice powder, composite lubricant and modified nano silica to the mixture in sequence and dispersing them evenly to obtain the high-stability polishing paste.

[0053] Comparative Example 1

[0054] A highly stable abrasive paste comprises the following raw materials in parts by weight: 50 parts pumice powder, 20 parts microcrystalline wax, 15 parts white mineral oil, 20 parts Span, 4 parts Tween, 5 parts modified fatty acid, and 3 parts modified nano-silica.

[0055] The composite lubricant was prepared in Example 1; the modified fatty acid was prepared in Example 2; and the modified nano-silica was prepared in Example 3.

[0056] The preparation method of the above-mentioned high-stability polishing paste includes the following steps: stirring and mixing white mineral oil, Span 20, Tween 20 and modified fatty acid to obtain a mixture; then adding pumice powder, microcrystalline wax and modified nano silica to the mixture in sequence and dispersing them evenly to obtain the high-stability polishing paste.

[0057] Comparative Example 2

[0058] A highly stable polishing paste comprises the following raw materials in parts by weight: 50 parts pumice powder, 20 parts composite lubricant, 15 parts white mineral oil, 20 parts Span, 4 parts Tween, 5 parts sodium oleate, and 3 parts modified nano silica.

[0059] The composite lubricant was prepared in Example 1; the modified fatty acid was prepared in Example 2; and the modified nano-silica was prepared in Example 3.

[0060] The preparation method of the above-mentioned high-stability polishing paste includes the following steps: stirring and mixing white mineral oil, Span 20, Tween 20 and sodium oleate to obtain a mixture; then adding pumice powder, composite lubricant and modified nano silica to the mixture in sequence and dispersing them evenly to obtain the high-stability polishing paste.

[0061] Comparative Example 3

[0062] A highly stable grinding paste comprises the following raw materials in parts by weight: 50 parts pumice powder, 20 parts composite lubricant, 15 parts white mineral oil, 4 parts Span 20, 4 parts Tween 20, 5 parts modified fatty acid, and 3 parts nano-silica.

[0063] The composite lubricant was prepared in Example 1; the modified fatty acid was prepared in Example 2; and the modified nano-silica was prepared in Example 3.

[0064] The preparation method of the above-mentioned high-stability polishing paste includes the following steps: stirring and mixing white mineral oil, Span 20, Tween 20 and modified fatty acids to obtain a mixture; then adding pumice powder, composite lubricant and nano-silica to the mixture in sequence and dispersing them evenly to obtain the high-stability polishing paste.

[0065] Performance testing

[0066] The high-stability polishing pastes prepared in Examples 4-6 and Comparative Examples 1-3 were subjected to the following performance tests:

[0067] (1) Lubrication performance test: The ball-disc friction and wear tester was used. The grinding paste was evenly applied to the surface of the 45# steel test block. A 5mm diameter GCr15 steel ball was used as the grinding object. The load was 5N, the rotation speed was 300r / min, and the friction time was 30min. The average friction coefficient was recorded. The Ra value of the test block after wear was measured using a surface roughness meter. Five points were measured for each sample and the average value was taken.

[0068] (2) Antibacterial performance test: The inhibition zone method was used to test the antibacterial properties of a concentration of 10... 6 The bacterial suspension of CFU / mL was evenly spread on nutrient agar medium. 0.5g of the grinding paste was placed in a sterile Oxford cup. After incubation at 37℃ for 24h, the diameter of the inhibition zone was measured and the inhibition rate was calculated (inhibition rate = (inhibition zone area - Oxford cup area) / Oxford cup area × 100%).

[0069] (3) Stability test: Place the grinding paste in a sealed container and observe the separation time at room temperature; take another part of the sample and place it in a 50℃ oven for 7 days to observe whether separation, clumping or other phenomena occur.

[0070] The obtained data is shown in Table 1 below:

[0071] Table 1 Performance test results of high-stability polishing paste

[0072]

[0073] As can be seen from the data in Table 1, the friction coefficients of Examples 4-6 are significantly lower than those of Comparative Example 1, and the surface roughness Ra values ​​are also significantly lower. This is because graphene oxide has excellent lubrication and wear resistance; its sheet-like structure can form a good lubricating film at the friction interface. The core-shell structure formed by microcrystalline wax coating retains the lubricating adhesion of microcrystalline wax, and the addition of graphene oxide further reduces frictional resistance, reducing scratches on the workpiece surface by the abrasive, thereby significantly improving the lubrication effect and surface quality of the polishing paste. In terms of stability, the separation time of Examples 4-6 is twice that of Comparative Example 1, and the high-temperature stability is also better, indicating that the core-shell structure of the composite lubricant is more compatible with other components, improving the stability of the system.

[0074] The coefficient of friction and surface roughness of Comparative Example 2 were slightly higher than those of Examples 4-6, indicating that the modified fatty acid had better lubricating properties than the unmodified fatty acid. This is because 1-butyl-3-methylimidazolium chloride, as an ionic liquid, has good thermal stability and lubricity. After reacting with sodium oleate, its molecular structure more easily forms an adsorption film on the friction surface, enhancing the lubrication effect and improving compatibility with other oily components. In terms of stability, the stratification time of Comparative Example 2 was also shorter than that of Examples 4-6, and a small amount of agglomeration occurred at high temperatures, indicating that the modified fatty acid can improve the dispersion stability of the grinding paste and reduce the separation between components.

[0075] Regarding antibacterial properties, the inhibition rates of Escherichia coli and Staphylococcus aureus in Examples 4-6 were significantly higher than those in Comparative Example 3, fully demonstrating the excellent antibacterial effect of modified nano-silica. The silver nanoparticles supported on mesoporous silica exhibit broad-spectrum antibacterial activity and can disrupt bacterial cell membranes. In the grafted antibacterial coupling agent (prepared by reacting quaternized chitosan with a silane coupling agent), the quaternized chitosan enhances antibacterial activity and water solubility, while the silane coupling agent improves its binding force with other components, allowing the antibacterial components to function more stably. In other properties, the coefficient of friction and surface roughness of Comparative Example 3 were not significantly different from those of Examples 4-6, indicating that the modified nano-silica, while imparting antibacterial properties, did not negatively impact the lubrication and grinding effect of the polishing paste. The significantly shorter separation time in Comparative Example 3 compared to Examples 4-6 is due to the reduced dispersibility of the unmodified nano-silica, which makes it prone to agglomeration; however, no significant decrease in high-temperature stability was observed.

[0076] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A highly stable abrasive paste, characterized in that, The raw materials include the following parts by weight: 40-60 parts pumice powder, 15-25 parts composite lubricant, 12-18 parts white mineral oil, 3-5 parts Span 20, 3-5 parts Tween 20, 4-6 parts modified fatty acid, and 2-4 parts modified nano silica. The composite lubricant is a core-shell particle formed by coating microcrystalline wax on the surface of graphene oxide; The modified fatty acid is an ionic liquid modified fatty acid, which is prepared by reacting an imidazole ionic liquid with sodium oleate. The modified nano-silica is mesoporous silica loaded with nano-silver and grafted with an antibacterial coupling agent. The antibacterial coupling agent is prepared by reacting chitosan, which has been quaternized and modified, with a silane coupling agent. The preparation method of the modified nano-silica includes the following steps: (1) Mesoporous silica was ultrasonically dispersed in anhydrous ethanol, AgNO3 was added and stirred to dissolve, followed by ultrasonication for 5-10 min, and then allowed to stand under a vacuum of -0.1 MPa for 8-12 h. After filtration and washing, Ag was obtained. + Loaded mesoporous silica; (2) Ag + The loaded mesoporous silica was ultrasonically dispersed in anhydrous ethanol, and 0.01 mol / L ascorbic acid solution and 0.01 mol / L sodium citrate solution were added dropwise. The mixture was stirred in a sealed container at 40°C in the dark for 20-40 min, filtered, washed and dried to obtain nano-silver loaded mesoporous silica. (3) Add chitosan to 5 vol% acetic acid solution and stir until completely dissolved. Add 3-chloro-2-hydroxypropyltrimethylammonium chloride dropwise to the chitosan solution. Adjust the pH to 8-9 with NaOH solution. React at 60-70℃ for 6-12 h. After the reaction is complete, precipitate the product with ethanol. Centrifuge and dissolve the precipitate in deionized water. Place it in a dialysis bag and dialyze for 24-48 h. Finally, freeze dry to obtain quaternized chitosan. (4) Add quaternized chitosan to 5 vol% acetic acid solution and sonicate until completely dissolved. Add silane coupling agent to 90 vol% ethanol solution and dissolve. Then slowly add silane coupling agent solution to quaternized chitosan solution and react at 60~80℃ for 4~8h. After the reaction is complete, precipitate with ethanol, collect the product by centrifugation, dialyze for 24~48h, and freeze dry to obtain antibacterial coupling agent. (5) Add the nano-silver supported mesoporous silica obtained in step (2) to anhydrous ethanol and disperse it by ultrasonication. Dissolve the antibacterial coupling agent obtained in step (4) in 70 vol% ethanol solution. Then add the antibacterial coupling agent solution to the nano-silver supported mesoporous silica dispersion. Stir the reaction magnetically at 60~80℃ for 6~12 h. After the reaction is completed, centrifuge, wash and dry to obtain the modified nano-silica.

2. The high-stability polishing paste according to claim 1, characterized in that, The pumice powder has a particle size of 10~50μm and a density of 0.5~1.0 g / cm³. 3 .

3. The high-stability polishing paste according to claim 1, characterized in that, The preparation method of the composite lubricant is as follows: graphene oxide is added to deionized water at 60°C and ultrasonically dispersed. Microcrystalline wax is heated to melt and then added to the graphene dispersion. After high-speed homogenization and emulsification, it is rapidly cooled to room temperature to form wax microparticles coated with GO. The composite lubricant is then spray-dried.

4. The high-stability polishing paste according to claim 3, characterized in that, The mass ratio of graphene oxide to microcrystalline wax is 1:15~20.

5. The high-stability polishing paste according to claim 1, characterized in that, The modified fatty acid is prepared by reacting 1-butyl-3-methylimidazolium chloride with sodium oleate in methanol at a molar ratio of 1:1, refluxing at 60°C for 10-12 h, and removing the solvent by rotary evaporation to obtain the ionic liquid modified fatty acid.

6. The high-stability polishing paste according to claim 1, characterized in that, The molar ratio of chitosan to 3-chloro-2-hydroxypropyltrimethylammonium chloride is 1:1 to 1.

2.

7. The high-stability polishing paste according to claim 1, characterized in that, The silane coupling agent is 3-aminopropyltriethoxysilane or 3-glycidyl etheroxypropyltrimethoxysilane, and the molar ratio of the quaternized chitosan to the silane coupling agent is 1:1 to 1.

2.

8. A method for preparing a highly stable polishing paste as described in any one of claims 1 to 7, characterized in that, Includes the following steps: White mineral oil, Span 20, Tween 20, and modified fatty acids are stirred and mixed to obtain a mixture; then pumice powder, composite lubricant, and modified nano-silica are added to the mixture in sequence and dispersed evenly to obtain the high-stability grinding paste.

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