Polishing solution for processing ultra-smooth surface of optical element and preparation method of polishing solution

Abstract

The invention provides a polishing solution for processing an ultra-smooth surface of an optical element and a preparation method thereof, and relates to the technical field of optical cold processing polishing solutions, the polishing solution comprises 0.5%-3% of an abrasive, 0.1%-0.8% of a dispersant, 0.05%-0.6% of an active agent, 0.1%-0.5% of a pH regulator, and the balance deionized water; wherein the grinding material is processed cerium oxide particles with the particle size range of 200-300 nm, and the particle size range of the high-purity cerium oxide particles is 1-1.5 [mu] m, and the processed cerium oxide particles are obtained through a high-speed polishing machine by a wet crushing method; the dispersing agent is at least one of sodium hexametaphosphate and polyvinyl pyrrolidone, the active agent is at least one of lauryl sodium sulfate and polyethylene glycol, and the PH regulator is at least one of tetramethylammonium hydroxide and triethanolamine. The polishing solution prepared from the grinding material is narrow in particle size distribution, good in dispersity, not prone to generating scratches and capable of meeting the requirement that the surface roughness of the laser gyroscope reflector is better than 0.3 nm.

Description

Technical Field

[0001] The present application relates to the technical field of optical cold processing polishing liquid, and in particular to a polishing liquid for processing ultra-smooth surfaces of optical elements and a preparation method thereof. Background Art

[0002] The improvement of the loss index of high-precision laser gyro reflectors has gradually increased the requirements for substrate surface roughness and surface defects during processing. The laser gyro reflector requires a surface roughness RMS better than 0.3nm, and the properties of the polishing liquid are one of the important factors affecting the quality of the polished surface.

[0003] The particle size, shape, and hardness of the polishing powder play a very important role in the polishing process. The particle size mainly affects the polishing force, and the maximum particle size often plays an important role in the scratches on the glass surface. Usually, the polishing liquid used for optical processing of optical components is composed of polishing powder surfactants, dispersants, deionized water, etc., and is prepared into a polishing liquid by stirring, nitrogen blowing, etc. The particle size distribution of general polishing liquids is relatively wide, and the polishing liquid has poor dispersibility and is prone to scratches. It is suitable for polishing general optical components, but cannot meet the surface roughness requirements of laser gyro reflectors. Summary of the invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present application aims to provide a polishing liquid for ultra-smooth surface processing of optical elements and a preparation method thereof, so as to meet the polishing requirements of surface roughness of optical elements such as laser gyro reflectors.

[0005] In the first aspect, the present application proposes a polishing liquid for ultra-smooth surface processing of optical elements. The polishing liquid for ultra-smooth surface processing of optical elements includes 0.5% to 3% of abrasive, 0.1% to 0.8% of dispersant, 0.05% to 0.6% of active agent, 0.1% to 0.5% of pH regulator, and the remainder is deionized water, based on the total weight of the polishing liquid for ultra-smooth surface processing of optical elements; wherein the abrasive is treated cerium oxide particles with a particle size range of 200 to 300 nm obtained by wet grinding high-purity cerium oxide particles through a high-speed polishing machine, and the particle size range of the high-purity cerium oxide particles is 1 to 1.5 μm; the dispersant is at least one of sodium hexametaphosphate and polyvinyl pyrrolidone, the active agent is at least one of sodium dodecyl sulfate and polyethylene glycol, and the pH regulator is at least one of tetramethylammonium hydroxide and triethanolamine.

[0006] According to the technical solution provided in the embodiment of the present application, the polishing liquid for ultra-smooth surface processing of optical elements includes 0.5% to 2% abrasive, 0.1% to 0.5% dispersant, 0.1% to 0.6% active agent, and 0.1% to 0.5% pH regulator.

[0007] According to the technical solution provided in the embodiment of the present application, the polishing liquid for ultra-smooth surface processing of optical elements includes 1% to 2% abrasive, 0.3% to 0.5% dispersant, 0.1% to 0.4% active agent, and 0.1% to 0.4% pH regulator.

[0008] According to the technical solution provided in the embodiment of the present application, the polishing liquid for ultra-smooth surface processing of optical elements includes 1% to 1.5% of abrasive, 0.3% to 0.5% of dispersant, 0.1% to 0.4% of active agent, and 0.3% to 0.5% of pH regulator.

[0009] In a second aspect, the present application proposes a method for preparing a polishing liquid for ultra-smooth surface processing of an optical element as described above, the preparation method comprising:

[0010] An initial suspension was prepared using high-purity cerium oxide particles with a particle size range of 1 to 1.5 μm;

[0011] Polishing the initial suspension with a laser gyro reflector by a high-speed polishing machine, and wet-crushing the initial suspension to obtain a second suspension;

[0012] Performing a first water selection on the second suspension, firstly ultrasonically dispersing the second suspension, and then taking a middle layer solution after standing to obtain a third suspension;

[0013] Performing a second water selection on the third suspension, firstly dispersing the third suspension by ultrasonic, and then taking a middle layer solution after standing to obtain a fourth suspension;

[0014] Centrifugally drying the fourth suspension to obtain dried abrasive particles; and subjecting the dried abrasive particles to high-temperature heating to obtain treated cerium oxide particles with a particle size ranging from 200 to 300 nm;

[0015] According to the concentration requirements, the treated cerium oxide particles are mixed and stirred evenly with a dispersant, an active agent, a pH regulator and deionized water to obtain a polishing liquid for processing an ultra-smooth surface of an optical element.

[0016] According to the technical solution provided in the embodiment of the present application, the method for preparing the initial suspension includes:

[0017] 1 kg of high-purity cerium oxide particles with a particle size distribution range of 1 to 1.5 um, 30 g of a dispersant and 15 kg of deionized water were mixed and stirred to obtain an initial suspension;

[0018] Preferably, the rotation speed of the stirrer is 300-400 rpm, and the stirring is performed for 3-4 hours.

[0019] According to the technical solution provided in the embodiment of the present application, the preparation method of the second suspension includes:

[0020] Install the polyurethane polishing disc at the corresponding position of the polishing machine, and then place the laser gyro reflector disc on top of the polyurethane polishing disc;

[0021] The initial suspension is continuously delivered to the polishing area between the polyurethane polishing disc and the laser gyro reflector disc, and the main shaft and the swing shaft of the polishing machine are started to drive the polyurethane polishing disc to rotate and drive the laser gyro reflector disc to swing, so as to perform polishing;

[0022] During the polishing process, the polishing liquid circulates, and the abrasive in the polishing liquid is wet-crushed while in contact with the surface of the reflector to obtain a second suspension.

[0023] According to the technical solution provided in the embodiment of the present application, the preparation method of the third suspension includes:

[0024] Firstly, the second suspension is ultrasonically dispersed for 15-20 min at an ultrasonic frequency of 40 kHz, and then the middle layer solution is taken after standing for 1 h to obtain a third suspension;

[0025] Preferably, the ultrasonic dispersion time is 20 min.

[0026] According to the technical solution provided in the embodiment of the present application, the method for preparing the dried abrasive particles comprises:

[0027] The fourth suspension is centrifugally dried at a centrifugal speed of 3000-4000 rpm for 20-30 min;

[0028] Preferably, the centrifugal drying time is 30 min.

[0029] According to the technical solution provided in the embodiment of the present application, the method for preparing the treated cerium oxide particles comprises:

[0030] The dried abrasive particles are placed in a high temperature furnace for heating treatment, the temperature is increased to 350-450° C. at a heating rate of 5-7° C. / min, and the abrasive particles are heat treated at 350-450° C. for 1.5 hours to obtain treated cerium oxide particles;

[0031] Preferably, the heating rate is 6°C / min, and the temperature is raised to 420°C.

[0032] Compared with the prior art, the beneficial effects of the present application are as follows: based on the consideration that the formation of a high-quality ultra-smooth polished surface is a comprehensive effect of mechanical, physical and chemical effects, the present application uses a high-speed polishing machine to obtain a cerium oxide abrasive with a uniform particle size distribution in the range of 200 to 300 nm by a wet grinding method. During the wet grinding process, shear force dominates the force field. The original high-purity cerium oxide particles are more easily polished flat with large edges and irregular parts under shearing, and gradually tend to be spherical. Sodium hexametaphosphate, polyethylene glycol and other high Molecular polymers are used to adjust the viscosity of the polishing liquid and, to a certain extent, control the evolution of the particle shape, which can produce a greater damping effect on the movement of the particles, making the force exerted on the particles during the crushing process more uniform and moderate. Ultimately, not only the particle size range of cerium oxide particles reaches 200-300nm, but also irregular structures such as sharp corners on the surface are smoothed, and the surface morphology of the particles tends to be spherical. The polishing liquid prepared by this abrasive has a narrow particle size distribution, good dispersibility, and is not easy to produce scratches, which can meet the requirement of the laser gyro reflector for a surface roughness better than 0.3nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a test diagram of the ultra-smooth surface roughness provided in Example 1 of the present application;

[0034] Figure 2 This is a test diagram of the ultra-smooth surface roughness provided in Example 2 of the present application;

[0035] Figure 3 This is a test diagram of the ultra-smooth surface roughness provided in Example 3 of the present application;

[0036] Figure 4 This is a test diagram of the ultra-smooth surface roughness provided in Example 4 of the present application;

[0037] Figure 5 This is a test diagram of the ultra-smooth surface roughness provided in Example 5 of the present application. DETAILED DESCRIPTION

[0038] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] As mentioned in the background technology, in response to the problems in the prior art, the present application proposes a polishing liquid for ultra-smooth surface processing of optical elements. Based on the total weight of the polishing liquid for ultra-smooth surface processing of optical elements, the polishing liquid for ultra-smooth surface processing of optical elements includes 0.5% to 3% of abrasive, 0.1% to 0.8% of dispersant, 0.05% to 0.6% of active agent, 0.1% to 0.5% of pH regulator, and the remainder is deionized water; wherein the abrasive is treated cerium oxide particles with a particle size range of 200 to 300 nm obtained by wet grinding high-purity cerium oxide particles through a high-speed polishing machine, and the particle size range of the high-purity cerium oxide particles is 1 to 1.5 μm; the dispersant is at least one of sodium hexametaphosphate and polyvinyl pyrrolidone, the active agent is at least one of sodium lauryl sulfate and polyethylene glycol, and the pH regulator is at least one of tetramethylammonium hydroxide and triethanolamine.

[0041] The preparation method of the polishing liquid for ultra-smooth surface processing of optical elements comprises:

[0042] An initial suspension was prepared using high-purity cerium oxide particles with a particle size range of 1 to 1.5 μm;

[0043] Polishing the initial suspension with a laser gyro reflector by a high-speed polishing machine, and wet-crushing the initial suspension to obtain a second suspension;

[0044] Performing a first water selection on the second suspension, firstly ultrasonically dispersing the second suspension, and then taking a middle layer solution after standing to obtain a third suspension;

[0045] Performing a second water selection on the third suspension, firstly dispersing the third suspension by ultrasonic, and then taking a middle layer solution after standing to obtain a fourth suspension;

[0046] Centrifugally drying the fourth suspension to obtain dried abrasive particles; and subjecting the dried abrasive particles to high-temperature heating to obtain treated cerium oxide particles with a particle size ranging from 200 to 300 nm;

[0047] According to the concentration requirements, the treated cerium oxide particles are mixed and stirred evenly with a dispersant, an active agent, a pH regulator and deionized water to obtain a polishing liquid for processing an ultra-smooth surface of an optical element.

[0048] The preparation method adopts a high-polishing machine to wet-grind the polishing liquid to achieve control of the abrasive particle size and surface morphology. Large-particle abrasives can remove sharp parts of the surface, and the cutting edges of the abrasive particles can be reduced, thereby avoiding deep scratches on the ultra-smooth surface and ensuring the polishing effect.

[0049] The particle size distribution is also controlled through secondary water selection, and the abrasive particle size distribution in the polishing liquid becomes narrower, which stabilizes the properties of the polishing liquid, improves the dispersibility and suspension of the polishing liquid, is conducive to the convergence of surface roughness, and obtains a high-quality ultra-smooth surface.

[0050] In addition, the concentration of the screened polishing liquid can be controlled by centrifugal drying, which is more conducive to controlling the surface roughness. Compared with spray drying and other methods, the centrifugal drying method is simple and easy to operate.

[0051] At the same time, cerium oxide particles have a large specific surface area and high surface energy. They are very easy to agglomerate in aqueous solutions, and the chemical reaction between them and the surface of optical parts is insufficient. The use of activators and dispersants in polishing liquids can improve the dispersion stability of polishing liquids, change the surface properties of abrasive particles, and make the polishing liquid have excellent diffusivity and permeability, which is conducive to the uniform dispersion of the polishing liquid and improves its suspension. During use, it reduces scratches on the ultra-smooth surface and reduces the roughness of the polished surface.

[0052] The above combined effects make the polishing liquid have excellent performance and is suitable for super polishing of high-precision laser gyro reflectors. The surface defect level reaches level 0 and the surface roughness RMS is better than 0.3nm.

[0053] Example 1

[0054] S1-1, 1 kg of high-purity cerium oxide particles with a particle size distribution range of 1 to 1.5 um, 30 g of a dispersant and 15 kg of deionized water were mixed and stirred at a stirrer speed of 300 to 400 rpm for 3 to 4 hours to prepare an initial suspension;

[0055] S1-2, polishing with the initial suspension and the laser gyro reflector by a high-speed polishing machine, the polyurethane polishing disc has a diameter of 210 mm, the mirror disc has a diameter of 190 mm, the mirror disc is on top, the polishing process parameters are: spindle speed 224 r / min, swing frequency 72 times / min, polishing pressure 0.4 MPa, polishing liquid flow rate 4 L / min, wet crushing, the polishing liquid is recycled, the polishing time is 162 h, and the second suspension is obtained;

[0056] S1-3, subjecting the second suspension to the first water selection, firstly ultrasonically disperse the suspension for 20 minutes at an ultrasonic frequency of 40kHz; after standing for 1 hour, taking the middle layer solution (volume of 2 liters) to obtain a third suspension;

[0057] S1-4, performing secondary water separation on the third suspension in the same manner as step S1-3 to obtain a fourth suspension;

[0058] S1-5, the fourth suspension is centrifuged and dried at a centrifugal speed of 3000-4000 rpm for 20 min to obtain dried abrasive particles, which are then placed in a high-temperature furnace for heat treatment, and the temperature is increased to 350° C. at a rate of 7° C. / min, and heat treated at 350° C. for 1.5 h;

[0059] S1-6. When preparing the solution, the mass percentages of the treated cerium oxide particles, dispersant, activator and pH regulator are: 0.5% abrasive, 0.1% dispersant, 0.6% activator and 0.5% pH regulator. S1-7. The polishing liquid is ultrasonically dispersed for 15 minutes before use, and the ultrasonic frequency is 40kHz.

[0060] Implementation effect analysis:

[0061] Application of cerium oxide polishing liquid, φ25mm ultra-smooth reflector, after super polishing, with asphalt polishing pad, polishing time 40h, reference Figure 1 , and the surface roughness was obtained to be 0.229nm.

[0062] Example 2

[0063] S2-1, 1 kg of high-purity cerium oxide particles with a particle size distribution range of 1 to 1.5 um, 30 g of a dispersant and 15 kg of deionized water were mixed and stirred at a stirrer speed of 300 to 400 rpm for 3 to 4 hours to prepare an initial suspension;

[0064] S2-2, polishing with the initial suspension and the laser gyro reflector by a high-speed polishing machine, the polyurethane polishing disc has a diameter of 210 mm, the mirror disc has a diameter of 190 mm, the mirror disc is on top, the polishing process parameters are: spindle speed 230 r / min, swing frequency 80 times / min, polishing pressure 0.2 MPa, polishing liquid flow rate 5 L / min, wet crushing, the polishing liquid is recycled, the polishing time is 168 h, and the second suspension is obtained;

[0065] S2-3, subjecting the second suspension to the first water selection, firstly ultrasonically disperse the suspension for 15 minutes at an ultrasonic frequency of 40kHz; after standing for 1 hour, taking the middle layer solution (volume of 2 liters) to obtain a third suspension;

[0066] S2-4, performing secondary water separation on the third suspension in the same manner as step S1-3 to obtain a fourth suspension;

[0067] S2-5, the fourth suspension is centrifugally dried at a centrifugal speed of 3000-4000 rpm for 20 min to obtain dried abrasive particles, which are then placed in a high temperature furnace for heat treatment, the temperature is increased to 400° C. at a rate of 5° C. / min, and heat treated at 400° C. for 1.5 h;

[0068] S2-6. When preparing the solution, the mass percentages of the treated cerium oxide particles, dispersant, activator and pH regulator are: 1% abrasive, 0.5% dispersant, 0.1% activator and 0.4% pH regulator. S2-7. The polishing liquid is ultrasonically dispersed for 20 minutes before use, and the ultrasonic frequency is 40kHz.

[0069] Implementation effect analysis:

[0070] Application of cerium oxide polishing liquid, φ25mm ultra-smooth reflector, after super polishing, with asphalt polishing pad, polishing time 40h, reference Figure 2 , and the surface roughness was 0.195nm.

[0071] Example 3

[0072] S3-1, 1 kg of high-purity cerium oxide particles with a particle size distribution range of 1 to 1.5 um, 30 g of a dispersant and 15 kg of deionized water were mixed and stirred at a stirrer speed of 300 to 400 rpm for 3 to 4 hours to prepare an initial suspension;

[0073] S3-2, polishing with the initial suspension and the laser gyro reflector by a high-speed polishing machine, the polyurethane polishing disc has a diameter of 210 mm, the mirror disc has a diameter of 185 mm, the mirror disc is on top, the polishing process parameters are: spindle speed 240 r / min, swing frequency 85 times / min, polishing pressure 0.3 MPa, polishing liquid flow rate 6 L / min, wet crushing, the polishing liquid is recycled, the polishing time is 170 h, and the second suspension is obtained;

[0074] S3-3, subjecting the second suspension to the first water selection, firstly ultrasonically disperse the suspension for 15 minutes at an ultrasonic frequency of 40kHz; after standing for 1 hour, take the middle layer solution (volume of 2 liters) to obtain a third suspension;

[0075] S3-4, performing secondary water separation on the third suspension in the same manner as step S1-3 to obtain a fourth suspension;

[0076] S3-5, the fourth suspension is centrifuged and dried at a centrifugal speed of 3000-4000 rpm for 30 min to obtain dried abrasive particles, which are placed in a high-temperature furnace for heat treatment, and the temperature is increased to 420° C. at a rate of 6° C. / min, and heat treated at 420° C. for 1.5 h;

[0077] S3-6. When preparing the solution, the mass percentages of the treated cerium oxide particles, dispersant, activator and pH regulator are: 1.5% abrasive, 0.3% dispersant, 0.4% activator and 0.3% pH regulator respectively. S3-7. The polishing liquid is ultrasonically dispersed for 20 minutes before use, and the ultrasonic frequency is 40kHz.

[0078] Implementation effect analysis:

[0079] Application of cerium oxide polishing liquid, φ25mm ultra-smooth reflector, after super polishing, with asphalt polishing pad, polishing time 40h, reference Figure 3 , and the surface roughness was obtained to be 0.170nm.

[0080] Example 4

[0081] S4-1, 1 kg of high-purity cerium oxide particles with a particle size distribution range of 1 to 1.5 um, 30 g of a dispersant and 15 kg of deionized water were mixed and stirred at a stirrer speed of 300 to 400 rpm for 3 to 4 hours to prepare an initial suspension;

[0082] S4-2, polishing with the initial suspension and the laser gyro reflector by a high-speed polishing machine, the polyurethane polishing disc has a diameter of 210 mm, the mirror disc has a diameter of 185 mm, the mirror disc is on top, the polishing process parameters are: spindle speed 245 r / min, swing frequency 88 times / min, polishing pressure 0.3 MPa, polishing liquid flow rate 7 L / min, wet crushing, the polishing liquid is recycled, the polishing time is 170 h, and the second suspension is obtained;

[0083] S4-3, subjecting the second suspension to a first water selection, firstly ultrasonically dispersing the suspension for 20 minutes at an ultrasonic frequency of 40 kHz; after standing for 1 hour, taking the middle layer solution (volume of 2 liters) to obtain a third suspension;

[0084] S4-4, performing secondary water separation on the third suspension in the same manner as step S1-3 to obtain a fourth suspension;

[0085] S4-5, the fourth suspension is centrifugally dried at a centrifugal speed of 3000-4000 rpm for 25 min to obtain dried abrasive particles, which are then placed in a high temperature furnace for heat treatment, the temperature is increased to 450° C. at a rate of 5° C. / min, and heat treated at 450° C. for 1.5 h;

[0086] S4-6. When preparing the solution, the mass percentages of the treated cerium oxide particles, dispersant, activator and pH regulator are: 2% abrasive, 0.4% dispersant, 0.3% activator and 0.1% pH regulator. S4-7. The polishing liquid is ultrasonically dispersed for 10 minutes before use, and the ultrasonic frequency is 40kHz.

[0087] Implementation effect analysis:

[0088] Application of cerium oxide polishing liquid, φ25mm ultra-smooth reflector, after super polishing, with asphalt polishing pad, polishing time 40h, reference Figure 4 , and the surface roughness was obtained to be 0.219 nm.

[0089] Example 5

[0090] S5-1, 1 kg of high-purity cerium oxide particles with a particle size distribution range of 1 to 1.5 um, 30 g of a dispersant and 15 kg of deionized water were mixed and stirred at a stirrer speed of 300 to 400 rpm for 3 to 4 hours to prepare an initial suspension;

[0091] S5-2, polishing with the initial suspension and the laser gyro reflector by a high-speed polishing machine, the polyurethane polishing disc has a diameter of 210 mm, the mirror disc has a diameter of 190 mm, the mirror disc is on top, the polishing process parameters are: spindle speed 248 r / min, swing frequency 78 times / min, polishing pressure 0.35 MPa, polishing liquid flow rate 7 L / min, wet crushing, the polishing liquid is recycled, the polishing time is 170 h, and the second suspension is obtained;

[0092] S5-3, subjecting the second suspension to a first water selection, firstly ultrasonically disperse the suspension for 18 minutes at an ultrasonic frequency of 40 kHz; after standing for 1 hour, taking the middle layer solution (volume of 2 liters) to obtain a third suspension;

[0093] S5-4, performing secondary water separation on the third suspension in the same manner as step S1-3 to obtain a fourth suspension;

[0094] S5-5, the fourth suspension is centrifuged and dried at a centrifugal speed of 3000-4000 rpm for 28 min to obtain dried abrasive particles, which are placed in a high-temperature furnace for heat treatment, and the temperature is increased to 390° C. at a rate of 6° C. / min, and heat treated at 390° C. for 1.5 h;

[0095] S5-6. When preparing the solution, the mass percentages of the treated cerium oxide particles, dispersant, activator and pH regulator are: 3% abrasive, 0.8% dispersant, 0.05% activator and 0.25% pH regulator. S5-7. The polishing liquid is ultrasonically dispersed for 10 minutes before use, and the ultrasonic frequency is 40kHz.

[0096] Implementation effect analysis:

[0097] Application of cerium oxide polishing liquid, φ25mm ultra-smooth reflector, after super polishing, with asphalt polishing pad, polishing time 40h, reference Figure 5 , and the surface roughness was obtained to be 0.244nm.

[0098] Table 1 Mass composition and implementation effect of Examples 1 to 5

[0099]

[0100] It can be seen from Table 1 that in the five specific embodiments of the method for preparing the polishing liquid for ultra-smooth surface processing of optical elements proposed in the present application, it can be seen that after the polishing liquid prepared by the method is used to polish the ultra-smooth reflector, the surface roughness of the lens of the ultra-smooth reflector is below 0.3nm, indicating that the abrasive of the cerium oxide particles prepared by the method has a uniform particle size distribution and is treated at 200 to 300nm, the structure and appearance are close to spherical, and the surface is smooth. The polishing liquid obtained by the coordinated use of specific dispersants, activators, and pH regulators is used to polish the lens of the ultra-smooth reflector, so that the lens meets the lens use requirements of the ultra-smooth reflector.

[0101] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A polishing liquid for ultra-smooth surface processing of optical elements, characterized in that: include: The polishing liquid for ultra-smooth surface processing of optical elements comprises, based on the total weight of the polishing liquid for ultra-smooth surface processing of optical elements, 0.5% to 3% of abrasive, 0.1% to 0.8% of dispersant, 0.05% to 0.6% of active agent, 0.1% to 0.5% of pH regulator, and the remainder is deionized water; wherein the abrasive is treated cerium oxide particles with a particle size range of 200 to 300 nm obtained by wet grinding high-purity cerium oxide particles through a high-speed polisher, and the particle size range of the high-purity cerium oxide particles is 1 to 1.5 μm; the dispersant is at least one of sodium hexametaphosphate and polyvinyl pyrrolidone, the active agent is at least one of sodium lauryl sulfate and polyethylene glycol, and the pH regulator is at least one of tetramethylammonium hydroxide and triethanolamine.

2. The polishing liquid for ultra-smooth surface processing of optical elements according to claim 1, characterized in that: The polishing liquid for processing the ultra-smooth surface of the optical element comprises 0.5% to 2% of abrasive, 0.1% to 0.5% of a dispersant, 0.1% to 0.6% of an active agent, and 0.1% to 0.5% of a pH regulator.

3. The polishing liquid for processing the ultra-smooth surface of an optical element according to claim 1, characterized in that: The polishing liquid for processing the ultra-smooth surface of the optical element comprises 1% to 2% of abrasive, 0.3% to 0.5% of a dispersant, 0.1% to 0.4% of an activator, and 0.1% to 0.4% of a pH regulator.

4. The polishing liquid for processing an ultra-smooth surface of an optical element according to claim 1, characterized in that: The polishing liquid for processing the ultra-smooth surface of the optical element comprises 1% to 1.5% of abrasive, 0.3% to 0.5% of a dispersant, 0.1% to 0.4% of an active agent, and 0.3% to 0.5% of a pH regulator.

5. The method for preparing a polishing liquid for processing an ultra-smooth surface of an optical element according to any one of claims 1 to 4, characterized in that: The preparation method comprises: An initial suspension was prepared using high-purity cerium oxide particles with a particle size range of 1 to 1.5 μm; Polishing the initial suspension with a laser gyro reflector by a high-speed polishing machine, and wet-crushing the initial suspension to obtain a second suspension; Performing a first water selection on the second suspension, firstly ultrasonically dispersing the second suspension, and then taking a middle layer solution after standing to obtain a third suspension; Performing a second water selection on the third suspension, firstly dispersing the third suspension by ultrasonic, and then taking a middle layer solution after standing to obtain a fourth suspension; Centrifugally drying the fourth suspension to obtain dried abrasive particles; and subjecting the dried abrasive particles to high-temperature heating to obtain treated cerium oxide particles with a particle size ranging from 200 to 300 nm; According to the concentration requirements, the treated cerium oxide particles are mixed and stirred evenly with a dispersant, an active agent, a pH regulator and deionized water to obtain a polishing liquid for processing an ultra-smooth surface of an optical element.

6. The method for preparing a polishing liquid for processing an ultra-smooth surface of an optical element according to claim 5, characterized in that: The preparation method of the initial suspension comprises: 1 kg of high-purity cerium oxide particles with a particle size distribution range of 1 to 1.5 um, 30 g of a dispersant and 15 kg of deionized water were mixed and stirred to obtain an initial suspension; Preferably, the rotation speed of the stirrer is 300-400 rpm, and the stirring is performed for 3-4 hours.

7. The method for preparing a polishing liquid for processing an ultra-smooth surface of an optical element according to claim 5, characterized in that: The preparation method of the second suspension comprises: Install the polyurethane polishing disc at the corresponding position of the polishing machine, and then place the laser gyro reflector disc on top of the polyurethane polishing disc; The initial suspension is continuously delivered to the polishing area between the polyurethane polishing disc and the laser gyro reflector disc, and the main shaft and the swing shaft of the polishing machine are started to drive the polyurethane polishing disc to rotate and drive the laser gyro reflector disc to swing, so as to perform polishing; During the polishing process, the polishing liquid circulates, and the abrasive in the polishing liquid is wet-crushed while in contact with the surface of the reflector to obtain a second suspension.

8. The method for preparing a polishing liquid for processing an ultra-smooth surface of an optical element according to claim 5, characterized in that: The preparation method of the third suspension comprises: Firstly, the second suspension is ultrasonically dispersed for 15-20 min at an ultrasonic frequency of 40 kHz, and then the middle layer solution is taken after standing for 1 h to obtain a third suspension; Preferably, the ultrasonic dispersion time is 20 min.

9. The method for preparing a polishing liquid for processing an ultra-smooth surface of an optical element according to claim 5, characterized in that: The method for preparing the dried abrasive particles comprises: The fourth suspension is centrifugally dried at a centrifugal speed of 3000-4000 rpm for 20-30 min; Preferably, the centrifugal drying time is 30 min.

10. The method for preparing a polishing liquid for processing an ultra-smooth surface of an optical element according to claim 5, characterized in that: The method for preparing the treated cerium oxide particles comprises: The dried abrasive particles are placed in a high temperature furnace for heating treatment, the temperature is increased to 350-450° C. at a heating rate of 5-7° C. / min, and the abrasive particles are heat treated at 350-450° C. for 1.5 hours to obtain treated cerium oxide particles; Preferably, the heating rate is 6°C / min, and the temperature is raised to 420°C.

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