Boron nitride grinding fluid and preparation method thereof

Abstract

The invention relates to the technical field of grinding, in particular to boron nitride grinding fluid and a preparation method thereof. The boron nitride grinding fluid is prepared from, by mass, 18-22 parts of modified boron nitride, 2-3 parts of a suspension synergist, 3-4 parts of a stabilizer, 1-2 parts of a dispersing agent, 3-5 parts of an accelerator, 0.1-0.2 part of nanoparticles and 60-65 parts of a solvent, and the suspension synergist is prepared by mixing isododecanoic acid and ricinoleic acid. According to the boron nitride grinding fluid, under the long-time shearing action, the grinding material still keeps good suspension, and the boron nitride grinding fluid has the advantages of being long in cycle life and high in grinding efficiency; the grinding fluid provided by the invention has an excellent dispersion effect, can effectively disperse nano-particles generated in the grinding process, prevents the nano-particles from being adsorbed to the surface of an abrasive material, avoids the generation of agglomerated large particles, and reduces scratches generated by grinding.

Description

Technical Field

[0001] The present application relates to the field of grinding technology, and in particular to a boron nitride grinding liquid and a preparation method thereof. Background Art

[0002] The grinding of hard materials such as resin lenses is carried out by grinding with a grinding disc. The grinding process requires continuous injection of grinding liquid into the grinding disc. The quality of the grinding liquid is the main factor affecting the grinding effect. At present, the grinding liquid used for grinding resin lenses mainly uses large-particle boron carbide, silicon carbide or diamond powder as abrasives, and then adds a certain proportion of water and dispersant. The dispersant has poor dispersion effect, is very easy to precipitate, has low grinding efficiency, and has a short cycle life. In addition, during the grinding process, the liquid film on the grinding disc is unevenly dispersed, the grinding lubricity is insufficient, the grinding rate is low, and the particles are easy to agglomerate after grinding, resulting in high scratches and high Ra. Summary of the invention

[0003] The purpose of this application is to provide a boron nitride polishing liquid and a preparation method thereof in view of the deficiencies of the current technology. The boron nitride polishing liquid of this application can keep the abrasive in good suspension under long-term shearing, and has the advantages of long cycle life and high grinding efficiency; the polishing liquid of this application has excellent dispersing effect, and can effectively disperse the nanoparticles generated in the grinding process, avoid adsorption to the abrasive surface, avoid the generation of agglomerated large particles, and reduce the scratches caused by grinding. Therefore, the polishing liquid of this application has the advantages of shear resistance, high suspension, high dispersion, high efficiency, as well as good application prospects and large-scale industrial promotion potential.

[0004] In the first aspect, the present application provides a boron nitride polishing liquid, which adopts the following technical solution: A boron nitride polishing liquid comprises the following raw materials by weight: 18-22 parts of modified boron nitride, 2-3 parts of a suspension enhancer, 3-4 parts of a stabilizer, 1-2 parts of a dispersant, 3-5 parts of an accelerator, 0.1-0.2 parts of nanoparticles, and 60-65 parts of a solvent, wherein the suspension enhancer is prepared by mixing isomeric dodecanoic acid and ricinoleic acid.

[0005] By adopting the above technical scheme, modified boron nitride: as one of the main components of the grinding fluid, modified boron nitride provides basic grinding ability. Through the modification of γ-glycidyl ether oxypropyl trimethoxysilane, the dispersion phase and compatibility of modified boron nitride in the grinding fluid are improved, thereby ensuring the dispersion and stability of the grinding fluid. Suspension enhancer: prepared by mixing isomeric dodecanoic acid and ricinoleic acid, used to improve the suspension and dispersibility of the abrasive, while enhancing the fluidity and shear resistance of the grinding fluid. Stabilizer: used to form a stable grinding fluid system, improve the high suspension and dispersibility of the grinding fluid, and at the same time help the stable dispersion of nanoparticles. Dispersant: used to reduce the viscosity of the grinding fluid, improve its spreading fluidity on the grinding disc, ensure that the resin lens is evenly stressed, and reduce the roughness and scratches after grinding. Accelerator: promotes the dispersion and stability of nanoparticles in the grinding fluid, and at the same time brings nanoparticles into the grinding fluid through strong electrostatic action to avoid agglomeration and reduce scratches. Nanoparticles: embedded in the micro cracks of the resin lens, forming a splitting effect, increasing the grinding efficiency, while avoiding agglomeration through strong electrostatic action, reducing scratches, and reducing the surface roughness Ra after grinding. Solvent: provides a medium environment for the grinding fluid, ensuring the effective dissolution and dispersion of other components, while affecting the viscosity and fluidity of the grinding fluid. These components work together to improve the overall performance of the grinding fluid through synergistic effects. Modified boron nitride provides the basis for grinding, suspension enhancers and stabilizers improve the suspension and dispersibility of abrasives, dispersants and accelerators further optimize the fluidity and grinding efficiency of the grinding fluid, and nanoparticles enhance the grinding ability and surface quality of the grinding fluid through their special effects. The interaction of these components ensures that the grinding fluid maintains good suspension and dispersibility under long-term shearing, while improving grinding efficiency and reducing grinding costs.

[0006] Preferably, the mass ratio of the isomeric dodecanoic acid to ricinoleic acid is 3:1.

[0007] Preferably, the preparation method of the modified boron nitride is as follows: after uniformly mixing 6-8 parts of γ-glycidyloxypropyltrimethoxysilane, 200 parts of ethanol and 300 parts of water by mass, 450-500 parts of boron nitride with an average particle size of 10-30 microns is added and stirred for 5-7 hours, heated to 75°C, refluxed for 60 minutes, filtered, and dried to obtain modified boron nitride.

[0008] By adopting the above technical solution, boron nitride is modified by γ-glycidyloxypropyltrimethoxysilane to improve its dispersion phase and compatibility in the polishing liquid, thereby obtaining a boron nitride polishing liquid with good dispersion, stability and extended shelf life.

[0009] Preferably, the stabilizer is prepared by mixing an amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 in a mass ratio of 4:3.

[0010] By adopting the above technical scheme, the role of the stabilizer in this application is mainly to improve the stability of the grinding liquid, avoid agglomeration and precipitation, so as to ensure that the abrasive can maintain a good suspension state during the grinding process. At the same time, the stabilizer also helps to reduce the viscosity of the grinding liquid, improve its spreading fluidity on the grinding disc, so that the resin lens is evenly stressed, and the surface roughness Ra after grinding is reduced and the scratches caused by grinding are reduced. The synergistic effect between the amphoteric surfactant and the fatty alcohol polyoxyethylene ether AEO3 is mainly reflected in the following aspects: 1. Improve the stability of the grinding liquid: the amphoteric surfactant and the fatty alcohol polyoxyethylene ether AEO3 work together to enhance the stability of the grinding liquid, reduce the occurrence of agglomeration and precipitation phenomena, so as to ensure that the abrasive can maintain a good suspension state during the grinding process. 2. Reduce the viscosity of the grinding liquid: the fatty alcohol polyoxyethylene ether AEO3 has a lower surface tension, which can effectively reduce the viscosity of the grinding liquid and improve its spreading fluidity on the grinding disc. And the amphoteric surfactant can further reduce the surface tension of the grinding liquid, enhance its fluidity, make the resin lens more evenly stressed, reduce the surface roughness Ra after grinding and reduce the scratches caused by grinding. 3. Improve the dispersibility of the grinding fluid: The amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 work together to enhance the dispersibility of the grinding fluid, so that the nanoparticles form a stable double electric layer in the solvent to avoid agglomeration. At the same time, these two substances can also modify the nanoparticles, increase their surface charge, and further improve the dispersibility of the nanoparticles in the grinding fluid to ensure that they always remain dispersed during the recycling of the grinding fluid. In summary, there is a synergistic effect between the amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 in the stabilizer, which jointly improves the stability, dispersibility and fluidity of the grinding fluid, reduces the viscosity and surface tension of the grinding fluid, thereby ensuring the high efficiency and stability of the boron nitride grinding fluid in the rough grinding process of the resin lens.

[0011] Preferably, the method for preparing the amphoteric surfactant comprises the following steps: S51, under nitrogen protection, 21.34g of dodecyldimethyl tertiary amine was added to the reactor, followed by 30mL of isopropanol as a solvent, and after stirring at 25°C for 4-5min, 6.46g of 1,3-dichloro-2-propanol was added, and after mixing evenly, the reaction system was heated to 70°C for 8-10h. After the reaction was completed, the solvent was removed by rotary evaporation, and recrystallization was performed 3 times using an ethyl acetate / anhydrous ethanol mixed solvent, wherein the ethyl acetate / anhydrous ethanol mixed solvent was a volume ratio of ethyl acetate to anhydrous ethanol of 15:1, to obtain a white solid; S52. Under nitrogen protection, 22.24 g of white solid was mixed with 30 mL of dichloromethane at 25°C and added to the reactor. Then 5.60 g of chlorosulfonic acid was mixed with 20 mL of dichloromethane and slowly added to the reactor. After reacting for 5 hours, a saturated aqueous solution of NaOH was slowly added to adjust the pH to 9-10. After neutralization, the solvent was removed by rotary evaporation, refluxed in ethanol for 0.5 hours, the inorganic salt was filtered out, and recrystallized three times using acetone to obtain an amphoteric surfactant.

[0012] By adopting the above technical scheme, an amphoteric surfactant with a sulfate ester group on the connecting group is synthesized using dodecyl dimethyl tertiary amine, 1,3-dichloro-2-propanol and chlorosulfonic acid as raw materials. The surfactant has an amphoteric group and can adsorb anions and cations at the same time, so that the boron nitride polishing liquid forms a stable system, and the polishing liquid has high suspension and high dispersion. At the same time, the nanoparticles can be modified to increase their surface charge, improve the dispersibility of the nanoparticles in the polishing liquid, avoid agglomeration, and always keep dispersed during the recycling of the polishing liquid.

[0013] Preferably, the dispersant is prepared by mixing glycerol-3-distearate and dehydrated hexaglycerol dioleate in a mass ratio of 1:2.

[0014] By adopting the above technical solution, glycerol-3-distearate and dehydrated hexaglycerol dioleate as dispersants play a vital role in the boron nitride grinding liquid. The two substances are mixed to form an efficient dispersion system, so that the grinding liquid has excellent dispersion performance. First, the mixed use of glycerol-3-distearate and dehydrated hexaglycerol dioleate enhances the stability of the grinding liquid. These two substances can effectively prevent the abrasive from agglomerating during the grinding process, ensure the uniform distribution of the abrasive in the solvent, and thus improve the grinding efficiency. Secondly, the synergistic effect between the two substances further improves the dispersibility of the grinding liquid. The mixing of glycerol-3-distearate and dehydrated hexaglycerol dioleate allows the nanoparticles to form a more stable double electric layer in the solvent, effectively avoiding the adsorption and agglomeration between the nanoparticles, so that the grinding liquid always maintains a good dispersion state during the recycling process. In addition, these two substances also help to reduce the viscosity of the grinding liquid and improve its spreading fluidity on the grinding disc. This makes the resin lens more evenly stressed during the grinding process, thereby reducing the surface roughness Ra after grinding and reducing the generation of scratches. In summary, glycerol-3-distearate and dehydrated hexaglycerol dioleate play an important role in the boron nitride grinding fluid. Through their synergistic effect, the stability, dispersibility and fluidity of the grinding fluid are improved, thereby ensuring the high efficiency and stability of the boron nitride grinding fluid in the rough grinding process of resin lenses.

[0015] Preferably, the accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate in a mass ratio of 1:1:2.

[0016] By adopting the above technical scheme, the accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate in a mass ratio of 1:1:2, which plays an important role in promoting the boron nitride grinding liquid. The mixed use of these three substances can effectively improve the speed and efficiency of the grinding process. First, the synergistic effect of polyethylene glycol, polyurethane and polyacrylate makes the grinding liquid have stronger reactivity during the grinding process. This accelerator can promote the chemical reaction between the abrasive and the resin lens, increase the grinding speed, and thus shorten the grinding time. Secondly, the mixed use of these three substances can also effectively reduce the energy consumption in the grinding process. By optimizing the grinding conditions, the grinding process is made more energy-efficient and efficient, and the production cost is reduced. Finally, the use of the accelerator can also improve the stability and service life of the grinding liquid. During long-term use, the accelerator can keep the performance of the grinding liquid stable and avoid the problem of poor grinding effect caused by performance degradation. In summary, the accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate in a mass ratio of 1:1:2, which plays an important role in the boron nitride grinding liquid. Through their synergistic effect, the reactivity, energy efficiency and stability of the grinding liquid are improved, thereby ensuring the high efficiency and economy of the boron nitride grinding liquid in the rough grinding process of resin lenses.

[0017] Preferably, the nanoparticles are nano-zirconia with a particle size of 20-40 nanometers.

[0018] Preferably, the solvent is prepared by mixing ethylene glycol and deionized water in a mass ratio of 5:2.

[0019] In a second aspect, the present application provides a method for preparing a boron nitride polishing liquid, using the following technical solution: As a general technical concept, the present application also provides a method for preparing the above-mentioned boron nitride polishing liquid, comprising the following steps: S101, adding a solvent, a stabilizer, a dispersant and a suspension enhancer to a stirred tank in order according to their weight fractions, heating to 4050° C., stirring and mixing to obtain a solution A; S102. Add nanoparticles and accelerator to solution A in order according to their mass fractions, stir at 100 r / min for 0.5-1 h, then add modified boron nitride, and continue stirring for 1-2 h to obtain a boron nitride polishing liquid.

[0020] In summary, the beneficial technical effects of this application are: 1. High suspension and high dispersibility: The synergistic effect of modified boron nitride, suspension enhancer, stabilizer, dispersant and accelerator in the grinding fluid can maintain good suspension of abrasive under long-term shearing action, avoid agglomeration of nanoparticles, and improve grinding efficiency.

[0021] 2. Shear resistance and high efficiency: The structural design of the grinding fluid gives it high static, high viscosity and shear thinning characteristics, which improves the suspension, fluidity and shear resistance of large-sized abrasives in the system, thereby improving grinding efficiency and extending the circulation service life of the grinding fluid.

[0022] 3. Reduce grinding costs: By optimizing the composition and proportion of the grinding fluid, the scratches and roughness during the grinding process are reduced, thereby reducing the subsequent processing costs.

[0023] 4. Improve grinding quality: The use of dispersants and stabilizers, as well as the introduction of nanoparticles, work together to improve the dispersibility and stability of the grinding fluid, making the force on the resin lens more uniform, reducing the surface roughness and scratches after grinding, and improving the grinding quality.

[0024] 5. Extend the shelf life: The modification of modified boron nitride improves its dispersion and compatibility in the polishing liquid, making the polishing liquid have a good shelf life.

[0025] 6. Environmental protection and economy: The composition and preparation method of the grinding liquid take environmental protection and economy into consideration, reducing pollution to the environment while reducing production costs, and has good potential for industrial promotion. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0027] In the following examples and preparation examples, 1 part means 1 kg.

[0028] Preparation Example 1 Preparation of modified boron nitride The preparation method of modified boron nitride is as follows: 7 parts of γ-glycidyloxypropyltrimethoxysilane, 200 parts of ethanol and 300 parts of water are mixed evenly by mass, 480 parts of boron nitride with an average particle size of 15 microns are added, stirred for 6 hours, heated to 75°C, refluxed for 60 minutes, filtered, and dried to obtain modified boron nitride.

[0029] Preparation Example 2 Preparation of amphoteric surfactant The preparation method of the amphoteric surfactant comprises the following steps: S51, under nitrogen protection, 21.34g of dodecyldimethyl tertiary amine was added to the reactor, followed by 30mL of isopropanol as a solvent, and after stirring at 25°C for 5min, 6.46g of 1,3-dichloro-2-propanol was added, and after mixing evenly, the reaction system was heated to 70°C for 10h. After the reaction was completed, the solvent was removed by rotary evaporation, and recrystallization was performed 3 times using an ethyl acetate / anhydrous ethanol mixed solvent, wherein the ethyl acetate / anhydrous ethanol mixed solvent was a volume ratio of ethyl acetate to anhydrous ethanol of 15:1, to obtain a white solid; S52. Under nitrogen protection, 22.24 g of white solid was mixed with 30 mL of dichloromethane at 25°C and added to the reactor. Then 5.60 g of chlorosulfonic acid was mixed with 20 mL of dichloromethane and slowly added to the reactor. After reacting for 5 hours, a saturated aqueous solution of NaOH was slowly added to adjust the pH to 10. After neutralization, the solvent was removed by rotary evaporation, refluxed in ethanol for 0.5 hours, the inorganic salt was filtered out, and recrystallized three times using acetone to obtain an amphoteric surfactant.

[0030] Example 1 A boron nitride polishing liquid comprises the following raw materials, measured by weight: 18 parts of modified boron nitride, 2 parts of a suspension enhancer, 3 parts of a stabilizer, 1 part of a dispersant, 3 parts of an accelerator, 0.1 part of a nano zirconium oxide with a particle size of 30 nanometers, and 60 parts of a solvent, wherein the suspension enhancer is prepared by mixing isomeric dodecanoic acid and ricinoleic acid at a weight ratio of 3:1, the stabilizer is prepared by mixing an amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 at a weight ratio of 4:3, the dispersant is prepared by mixing glycerol-3-distearate and dehydrated hexaglycerol dioleate at a weight ratio of 1:2, the accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate at a weight ratio of 1:1:2, and the solvent is prepared by mixing ethylene glycol and deionized water at a weight ratio of 5:2.

[0031] The preparation method of the above-mentioned boron nitride polishing liquid comprises the following steps: S101, adding a solvent, a stabilizer, a dispersant and a suspension enhancer to a stirred tank in order according to their weight proportions, heating to 40° C., stirring and mixing to obtain a solution A; S102. Add nano zirconium oxide with a particle size of 30 nanometers and an accelerator to solution A in order according to their mass fractions. After stirring at 100 r / min for 0.5 h, add modified boron nitride and continue stirring for 1 h to obtain a boron nitride polishing liquid.

[0032] Example 2 A boron nitride polishing liquid comprises the following raw materials, measured by weight: 22 parts of modified boron nitride, 3 parts of a suspension enhancer, 4 parts of a stabilizer, 2 parts of a dispersant, 5 parts of an accelerator, 0.2 parts of nano zirconium oxide with a particle size of 30 nanometers, and 65 parts of a solvent, wherein the suspension enhancer is prepared by mixing isomeric dodecanoic acid and ricinoleic acid at a weight ratio of 3:1, the stabilizer is prepared by mixing an amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 at a weight ratio of 4:3, the dispersant is prepared by mixing glycerol-3-distearate and dehydrated hexaglycerol dioleate at a weight ratio of 1:2, the accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate at a weight ratio of 1:1:2, and the solvent is prepared by mixing ethylene glycol and deionized water at a weight ratio of 5:2.

[0033] The preparation method of the above-mentioned boron nitride polishing liquid comprises the following steps: S101, adding a solvent, a stabilizer, a dispersant and a suspension enhancer to a stirred tank in order according to their weight proportions, heating to 50° C., stirring and mixing to obtain a solution A; S102. Add nano zirconium oxide with a particle size of 30 nanometers and an accelerator to solution A in order according to their mass fractions. After stirring for 1 hour at 100 r / min, add modified boron nitride and continue stirring for 2 hours to obtain a boron nitride polishing liquid.

[0034] Example 3 A boron nitride polishing liquid comprises the following raw materials, measured by weight: 20 parts of modified boron nitride, 2.5 parts of a suspension enhancer, 3.5 parts of a stabilizer, 1.5 parts of a dispersant, 4 parts of an accelerator, 0.15 parts of nano zirconium oxide with a particle size of 30 nanometers, and 63 parts of a solvent, wherein the suspension enhancer is prepared by mixing isomeric dodecanoic acid and ricinoleic acid in a weight ratio of 3:1, the stabilizer is prepared by mixing an amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 in a weight ratio of 4:3, the dispersant is prepared by mixing glycerol-3-distearate and dehydrated hexaglycerol dioleate in a weight ratio of 1:2, the accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate in a weight ratio of 1:1:2, and the solvent is prepared by mixing ethylene glycol and deionized water in a weight ratio of 5:2.

[0035] The preparation method of the above-mentioned boron nitride polishing liquid comprises the following steps: S101, adding a solvent, a stabilizer, a dispersant and a suspension enhancer to a stirred tank in order according to their weight proportions, heating to 45° C., stirring and mixing to obtain a solution A; S102. Add nano zirconium oxide with a particle size of 30 nanometers and an accelerator to solution A in order according to their mass fractions. After stirring at 100 r / min for 0.8 h, add modified boron nitride and continue stirring for 1.5 h to obtain a boron nitride polishing liquid.

[0036] Comparative Example 1 The same as Example 3, except that an equal amount of boron nitride with an average particle size of 15 microns is used instead of the modified boron nitride.

[0037] Comparative Example 2 The same as Example 3, except that the stabilizer is an amphoteric surfactant.

[0038] Comparative Example 3 The same as Example 3, except that the stabilizer is fatty alcohol polyoxyethylene ether AEO3.

[0039] Comparative Example 4 The same as Example 3, except that the dispersant is glycerol-3-distearate.

[0040] Comparative Example 5 The same as Example 3, except that the dispersant is dehydrated hexaglycerol dioleate.

[0041] Comparative Example 6 Same as Example 3, except that the accelerator is polyethylene glycol.

[0042] Comparative Example 7 The same as Example 3, except that the accelerator is polyurethane.

[0043] Comparative Example 8 The same as Example 3, except that the accelerator is polyacrylate.

[0044] Performance Testing The boron nitride polishing liquids prepared in Example 1, Example 3 and Comparative Examples 1 to Comparative Examples 8 were sampled and subjected to the following evaluation tests. The test results are shown in Table 1.

[0045] The resin lens was used for grinding test, and the removal rate, Ra, maximum scratch width after grinding, surface dirt after grinding, and surface dirt after cleaning were tested as follows: The surface is dirty after grinding: After grinding, take out the resin lens, rinse it with deionized water for 1 minute, blow it dry, and observe whether there is any grinding debris or particles remaining on the surface under a microscope.

[0046] Dirt on the surface after cleaning: First use 5% concentration cleaning solution for two stages of ultrasonic cleaning at 40℃ for 10min, then use deionized water for ultrasonic cleaning at 40℃. After drying, observe the surface under a microscope to see if there are any grinding chips or other residues.

[0047] Maximum scratch width test after grinding: Use a microscope to test the maximum scratch width of the cleaned resin lens at the same magnification and field of view, and measure it 3 times to get the average value.

[0048] Suspension after continuous stirring for 8 hours: Take 200g of deionized water, add 50g of boron nitride grinding liquid, stir at 500r / min for 8 hours, pour into a test tube, let it stand for 1 hour to observe the suspension of modified boron nitride.

[0049] The specific grinding experimental equipment and conditions are as follows: Grinding equipment: Chuangji double-sided grinding machine; Resin lens size: 2 inches; Number of test pieces: 1100 pieces; divided into 11 groups (corresponding to Example 1 to Example 3 and Comparative Example 1 to Comparative Example 8), 100 pieces in each group; Rotation speed: 20 r / min; Pressure: 4.0kpa; Plate temperature: 20-30℃; Grinding time: 10min.

[0050] Table 1 Performance test Analyzing the data in Table 1, we can see that: 1) The boron nitride polishing fluid prepared in Example 1 to Example 3 can keep the abrasive well suspended under long-term shearing action, and has the advantages of long cycle life and high grinding efficiency; the polishing fluid of the present application has excellent dispersing effect, which can effectively disperse the nanoparticles generated during the grinding process, avoid adsorption to the abrasive surface, avoid the generation of large agglomerated particles, and reduce scratches caused by grinding.

[0051] 2) The comparative analysis of the performance of the boron nitride polishing fluids prepared in Example 3 and Comparative Example 1 shows that the boron nitride is modified by γ-glycidyloxypropyltrimethoxysilane to improve its dispersion and compatibility in the polishing fluid, thereby obtaining a boron nitride polishing fluid with good dispersion, stability and extended shelf life.

[0052] 3) The performance comparison analysis of the boron nitride grinding fluid prepared in combination with Example 3 and Comparative Examples 2-3 shows that the stabilizer is prepared by mixing an amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 in a mass ratio of 4:3. The role of the stabilizer in this application is mainly to improve the stability of the grinding fluid, avoid agglomeration and precipitation, thereby ensuring that the abrasive can maintain a good suspension state during the grinding process. At the same time, the stabilizer also helps to reduce the viscosity of the grinding fluid, improve its spreading fluidity on the grinding disc, make the resin lens evenly stressed, reduce the surface roughness Ra after grinding, and reduce the scratches caused by grinding. The synergistic effect between the amphoteric surfactant and the fatty alcohol polyoxyethylene ether AEO3 is used to jointly improve the stability, dispersibility and fluidity of the grinding fluid, reduce the viscosity and surface tension of the grinding fluid, thereby ensuring the efficiency and stability of the boron nitride grinding fluid in the rough grinding process of the resin lens.

[0053] 4) The comparative analysis of the performance of the boron nitride grinding fluids prepared in combination with Example 3 and Comparative Examples 4-5 shows that the dispersant is prepared by mixing glycerol-3-distearate and dehydrated hexaglycerol dioleate in a mass ratio of 1:2. The synergistic effect of glycerol-3-distearate and dehydrated hexaglycerol dioleate in the boron nitride grinding fluid is utilized to improve the stability, dispersibility and fluidity of the grinding fluid, thereby ensuring the high efficiency and stability of the boron nitride grinding fluid in the rough grinding process of the resin lens.

[0054] 5) The performance comparison analysis of the boron nitride grinding fluid prepared in combination with Example 3 and Comparative Examples 6-8 shows that the accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate in a mass ratio of 1:1:2. The mixed use of these three substances can effectively improve the speed and efficiency of the grinding process. First, the synergistic effect of polyethylene glycol, polyurethane and polyacrylate makes the grinding fluid have stronger reactivity during the grinding process. This accelerator can promote the chemical reaction between the abrasive and the resin lens, increase the grinding speed, and thus shorten the grinding time. Secondly, the mixed use of these three substances can also effectively reduce the energy consumption during the grinding process. By optimizing the grinding conditions, the grinding process is made more energy-efficient and efficient, and the production cost is reduced. Finally, the use of the accelerator can also improve the stability and service life of the grinding fluid. During long-term use, the accelerator can maintain the stable performance of the grinding fluid and avoid the problem of poor grinding effect due to performance degradation.

[0055] The above embodiments are only used to explain the technical solutions of the present application rather than to limit them. Although the above embodiments provide a specific description of the present application, relevant technical personnel should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modifications and equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the present application.

Claims

1. A boron nitride polishing liquid, characterized in that: The preparation raw materials include the following by weight: 18-22 parts of modified boron nitride, 2-3 parts of suspension enhancer, 3-4 parts of stabilizer, 1-2 parts of dispersant, 3-5 parts of accelerator, 0.1-0.2 parts of nanoparticles and 60-65 parts of solvent, wherein the suspension enhancer is prepared by mixing isomeric dodecanoic acid and ricinoleic acid.

2. A boron nitride polishing liquid according to claim 1, characterized in that: The mass ratio of the isomeric lauric acid to ricinoleic acid is 3:

1.

3. A boron nitride polishing liquid according to claim 1, characterized in that: The preparation method of the modified boron nitride is as follows: after uniformly mixing 6-8 parts of γ-glycidyloxypropyltrimethoxysilane, 200 parts of ethanol and 300 parts of water by mass, adding 450-500 parts of boron nitride with an average particle size of 10-30 microns and fully stirring for 5-7 hours, heating to 75° C., refluxing for 60 minutes, filtering and drying to obtain the modified boron nitride.

4. A boron nitride polishing liquid according to claim 1, characterized in that: The stabilizer is prepared by mixing an amphoteric surfactant and fatty alcohol polyoxyethylene ether AEO3 in a mass ratio of 4:

3.

5. A boron nitride polishing liquid according to claim 4, characterized in that: The preparation method of the amphoteric surfactant comprises the following steps: S51, under nitrogen protection, 21.34g of dodecyldimethyl tertiary amine was added to the reactor, followed by 30mL of isopropanol as a solvent, and after stirring at 25°C for 4-5min, 6.46g of 1,3-dichloro-2-propanol was added, and after mixing evenly, the reaction system was heated to 70°C for 8-10h. After the reaction was completed, the solvent was removed by rotary evaporation, and recrystallization was performed 3 times using an ethyl acetate / anhydrous ethanol mixed solvent, wherein the ethyl acetate / anhydrous ethanol mixed solvent was a volume ratio of ethyl acetate to anhydrous ethanol of 15:1, to obtain a white solid; S52. Under nitrogen protection, 22.24 g of white solid was mixed with 30 mL of dichloromethane at 25°C and added to the reactor. Then 5.60 g of chlorosulfonic acid was mixed with 20 mL of dichloromethane and slowly added to the reactor. After reacting for 5 hours, a saturated aqueous solution of NaOH was slowly added to adjust the pH to 9-10. After neutralization, the solvent was removed by rotary evaporation, refluxed in ethanol for 0.5 h, the inorganic salt was filtered out, and recrystallized 3 times with acetone to obtain an amphoteric surfactant.

6. A boron nitride polishing liquid according to claim 1, characterized in that: The dispersant is prepared by mixing glycerol-3-distearate and dehydrated hexaglycerol dioleate in a mass ratio of 1:

2.

7. A boron nitride polishing liquid according to claim 1, characterized in that: The accelerator is prepared by mixing polyethylene glycol, polyurethane and polyacrylate in a mass ratio of 1:1:

2.

8. A boron nitride polishing liquid according to claim 1, characterized in that: The nanoparticles are nano zirconium oxide with a particle size of 20-40 nanometers.

9. The boron nitride polishing liquid according to claim 1, characterized in that: The solvent is prepared by mixing ethylene glycol and deionized water in a mass ratio of 5:

2.

10. A method for preparing a boron nitride polishing liquid according to any one of claims 1 to 9, characterized in that: The following steps are involved: S101, adding a solvent, a stabilizer, a dispersant and a suspension enhancer to a stirred tank in order according to their weight fractions, heating to 4050° C., stirring and mixing to obtain a solution A; S102. Add nanoparticles and accelerator to solution A in order according to their mass fractions, stir at 100 r / min for 0.5-1 h, then add modified boron nitride, and continue stirring for 1-2 h to obtain a boron nitride polishing liquid.

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