Nano aluminum oxide polishing solution with self-cleaning capability and preparation method of nano aluminum oxide polishing solution

Abstract

The invention discloses a preparation method of a nano-alumina polishing solution with self-cleaning capability, and belongs to the field of polishing solutions, the nano-alumina polishing solution comprises 80-100 parts of nano-alumina particles, 450-500 parts of deionized water, 10-15 parts of a composite self-cleaning functional additive, 4-6 parts of a modified dispersant, 3-5 parts of a dynamic stabilizer, 2-4 parts of a temperature control slow release additive, and 1-2 parts of a pH regulator. The preparation method comprises the following steps: mixing the nano aluminum oxide particles with a modified dispersant in deionized water, and carrying out ultrasonic dispersion for 10-20 minutes; adding a composite self-cleaning functional additive, uniformly stirring, and performing high-shear dispersion for 20-30 minutes; adding a dynamic stabilizer and a temperature-controlled slow-release additive, and stirring at a low speed for 15-20 minutes; and adjusting the pH value to be 6.5-7.5, filtering through a 300-mesh filter screen, and bottling for later use. The polishing solution has the beneficial effects that the environmental adaptability, the self-cleaning efficiency and the storage stability of the polishing solution are improved by improving the components and the process, the application range of the polishing solution is remarkably expanded, and the use cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of polishing liquid, and more specifically, to a nano alumina polishing liquid with self-cleaning ability and a preparation method thereof. Background Art

[0002] Nano-alumina polishing liquid is a high-performance polishing material widely used in the field of precision machining, including optical lenses, semiconductor wafers, metal surfaces and other manufacturing industries with high requirements for surface treatment. Because nano-alumina particles have excellent hardness, good dispersibility and stable chemical properties, they can achieve improved surface flatness and finish while maintaining high polishing efficiency. However, during the use of traditional polishing liquid, the performance will deteriorate due to nano-particle agglomeration, precipitation and particle wear, making it difficult to maintain high-efficiency polishing effects for a long time. In addition, the difficulty of cleaning the polishing liquid and the waste of consumables have also brought great economic and environmental pressures in practical applications. Self-cleaning nano-alumina polishing liquid can automatically remove impurities and sediments attached to the surface during use by adding specific functional additives or modification processes, thereby extending the service life of the polishing liquid. This innovative design not only reduces the need for frequent replacement of polishing liquid, but also significantly improves the stability and efficiency of the polishing process. It has important application value in high-precision machining, energy-saving and environmentally friendly manufacturing, as well as aerospace and electronics industries.

[0003] Although the self-cleaning function improves the performance of the polishing liquid, its preparation process is often complicated and costly, which limits its wide application in general processing fields. At the same time, the complex mechanism of action between additives and nanoparticles affects the long-term stability of the polishing liquid. In addition, the realization of the self-cleaning function will be affected by external working conditions including temperature, pressure, and environmental chemical properties, thereby reducing the actual effect and requiring further optimization and improvement. Summary of the invention

[0004] The purpose of the present invention is to provide a nano-alumina polishing liquid with self-cleaning ability and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology: although the self-cleaning function improves the performance of the polishing liquid, its preparation process is often complicated and costly, which limits its wide application in the field of ordinary processing. At the same time, due to the complex mechanism of action between additives and nanoparticles, the long-term stability of the polishing liquid is affected. In addition, the realization of the self-cleaning function will be affected by external working conditions including temperature, pressure, and environmental chemical properties, thereby reducing the actual effect, and further optimization and improvement are needed.

[0005] Technical solution:

[0006] A nano-alumina polishing liquid with self-cleaning ability comprises the following components in parts by weight: 80-100 parts of nano-alumina particles, 450-500 parts of deionized water, 10-15 parts of a composite self-cleaning functional additive, 4-6 parts of a modified dispersant, 3-5 parts of a dynamic stabilizer, 2-4 parts of a temperature-controlled slow-release additive, and 1-2 parts of a pH regulator.

[0007] Preferably, the composite self-cleaning functional auxiliary agent includes nitrogen-doped titanium dioxide in photocatalytic nanoparticles, modified betaine in biodegradable surfactant, and nano-silicon particles with hydrophobic properties, with a mass ratio of 5:3:2.

[0008] Preferably, the modified dispersant is a multifunctional polycarboxylate containing a high temperature and high pressure resistant structural unit, wherein the high temperature and high pressure resistant structural unit is an aromatic structure benzene ring, a fluorine-containing group perfluoroalkyl, a heterocyclic unit imidazole ring, a siloxane group, a high cross-linking network and a chelating functional group; the high temperature and high pressure resistant structural unit gives the polymer excellent thermal stability, compression resistance and chemical inertness, and maintains stable performance in extreme environments. The dynamic stabilizer is a polyethylene glycol derivative in the polymer protective colloid.

[0009] Preferably, the temperature-controlled sustained-release additive is a temperature-sensitive microcapsule encapsulating sodium tripolyphosphate.

[0010] A nano-alumina polishing liquid with self-cleaning ability, the preparation steps are as follows:

[0011] S1. The nano-alumina particles are mixed with a modified dispersant in deionized water and ultrasonically dispersed for 10-20 minutes;

[0012] S2. Add the composite self-cleaning functional additive, stir evenly and perform high shear dispersion for 20-30 minutes;

[0013] S3. Add dynamic stabilizer and temperature controlled slow-release additive and stir at low speed for 15-20 minutes;

[0014] S4. Adjust the pH to a neutral 6.5-7.5, filter through a 300-mesh filter and bottle for later use.

[0015] Preferably, the surface of the nano-alumina particles is chemically modified.

[0016] Preferably, the chemical modification treatment comprises the following steps:

[0017] S1-1. The dried alumina particles were immersed in a solution of 0.1%-0.5% by mass of dilute hydrochloric acid, and the reaction was stirred for 30 minutes to activate the hydroxyl groups on the surface of the particles; after the reaction, the particles were washed with deionized water until neutral and dried;

[0018] S1-2. Disperse the activated nano-alumina particles in anhydrous ethanol, add silane coupling agent KH-55 solution, and keep the mass ratio of silane to particles at 1:50; stir the reaction at 60-80℃ for 4-6 hours, and the coupling agent will form chemical bonds on the surface of the particles; after the reaction, wash with anhydrous ethanol several times to remove the unreacted coupling agent, and dry at 80℃.

[0019] S1-3. Further modify the functional groups according to application requirements; including hydrophobic treatment and hydrophilic treatment: introducing long-chain alkyl silane OTS and fluorinated silane; adding carboxyl or amino functional molecules citric acid and aminosilane.

[0020] S1-4. The modified particles are heat treated at 120-150°C for 2 hours to further enhance the stability of the chemical bonds and avoid particle agglomeration.

[0021] S1-5. Use infrared spectroscopy and surface potential meter to detect whether the surface functional groups are successfully introduced, and test the dispersion and stability of the particles.

[0022] Preferably, the target pH value of S4 is in the range of 6.8-7.2; if the solution is acidic and the pH value is less than 6.5, 0.1 M sodium hydroxide solution is added dropwise; if the solution is alkaline and the pH value is greater than 7.5, 0.1 M hydrochloric acid solution is added dropwise.

[0023] Preferably, the operating steps are as follows:

[0024] S4-1. Use a glass electrode pH meter to monitor the pH value of the solution in real time; the volume of the regulator added each time should not exceed 0.1 mL, and the solution should be fully stirred before testing; the adjustment process should be slow to avoid exceeding the target range;

[0025] S4-2. Use a 300-mesh filter with a mesh size of 50 μm to remove tiny particles and impurities in the solution; the filtration speed is controlled at 50-100 mL / min to prevent particles from agglomerating or settling and clogging the filter;

[0026] S4-3.Put the filtered polishing liquid into clean high-density polyethylene and glass bottles, seal them and store them to avoid external contamination and volatilization; the recommended storage temperature is 15-25℃, avoid direct sunlight.

[0027] The polishing liquid maintains good dispersibility and photocatalytic performance in the range of -10°C to 70°C, and has no obvious performance degradation under high pressure up to 1.5MPa and strong acid / alkali conditions.

[0028] The photocatalytic performance maintains a self-cleaning efficiency of ≥95% under visible light conditions and increases the decomposition rate of surface dirt by more than 50%.

[0029] The long-term storage stability of the polishing liquid is ≥12 months, and it is suitable for a variety of complex working conditions, including hot and humid, low temperature, and chemical corrosion environments.

[0030] The polishing liquid improves the polishing effect of high-precision surfaces by more than 30%, has a wide working range, and is suitable for high-demand optical, electronic and aviation fields.

[0031] Compared with the prior art, the advantages of the present invention are:

[0032] (1) The present invention significantly enhances the chemical stability of the polishing liquid in extreme temperature and pressure environments by introducing a modified dispersant that is resistant to high temperature and high pressure and adding a temperature-sensitive microcapsule sustained-release agent. The improved polishing liquid can still maintain stable dispersion and catalytic performance at -20°C to 50°C and 5MPa high pressure, and the self-cleaning efficiency is increased by more than 20%, and the adaptability is expanded to more industrial and extreme environment application scenarios.

[0033] (2) The present invention uses a composite self-cleaning functional additive to enhance the photocatalytic and hydrophobic properties of the polishing liquid and optimize its performance under various pH environments. The self-cleaning efficiency is significantly improved, and the pollution degradation capacity is increased by about 30% in acidic, alkaline and neutral environments, and the removal effect on surface oil and particulate pollution is more significant.

[0034] (3) The present invention adopts an improved preparation process and combines chemically modified nano-alumina particles to enhance the dispersibility and stability of the polishing liquid and reduce agglomeration. The storage stability of the polishing liquid is increased by 50%, the filterability is better, and frequent preparation is not required; the service life is extended to 1.5 times the original, greatly reducing the cost of use and reducing resource waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall system of a method for preparing a nano-alumina polishing liquid with self-cleaning ability according to the present invention; DETAILED DESCRIPTION

[0036] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application.

[0037] Example

[0038] Examples 1-3

[0039] Example 1: It includes the following components in parts by weight: 80 parts of nano-alumina particles, 500 parts of deionized water, 15 parts of composite self-cleaning functional additives, 6 parts of modified dispersants, 3 parts of dynamic stabilizers, 4 parts of temperature-controlled slow-release additives, and 1.5 parts of pH regulators.

[0040] The composite self-cleaning functional auxiliary agent includes nitrogen-doped titanium dioxide in photocatalytic nanoparticles, modified betaine in biodegradable surfactant, and nano silicon particles with hydrophobic properties, with a mass ratio of 5:3:2.

[0041] The modified dispersant is a multifunctional polycarboxylate containing high temperature and high pressure resistant structural units, which are aromatic structure benzene rings, fluorine-containing perfluoroalkyl groups, heterocyclic unit imidazole rings, siloxane groups, high cross-linking network and chelating functional groups; the high temperature and high pressure resistant structural units give the polymer excellent thermal stability, pressure resistance and chemical inertness, and maintain stable performance in extreme environments. The dynamic stabilizer is a polyethylene glycol derivative in the polymer protective colloid.

[0042] The temperature-controlled sustained-release additive is a temperature-sensitive microcapsule that encapsulates sodium tripolyphosphate.

[0043] The preparation steps are as follows:

[0044] S1. The nano-alumina particles are mixed with a modified dispersant in deionized water and ultrasonically dispersed for 20 minutes;

[0045] S2. Add the composite self-cleaning functional additive, stir evenly and perform high shear dispersion for 30 minutes;

[0046] S3. Add dynamic stabilizer and temperature controlled slow-release additive and stir at low speed for 20 minutes;

[0047] S4. Adjust the pH to neutral 7, filter through a 300-mesh filter and bottle for later use.

[0048] The surface of the nano-alumina particles is chemically modified.

[0049] Example 2: The difference from Example 1 is that it includes the following components: 90 parts of nano-alumina particles, 500 parts of deionized water, 13 parts of composite self-cleaning functional additive, 5 parts of modified dispersant, 4 parts of dynamic stabilizer, 3 parts of temperature-controlled slow-release additive, and 2 parts of pH regulator

[0050] Example 3: The difference from Example 1 is that it includes the following components: 100 parts of nano-alumina particles, 500 parts of deionized water, 10 parts of composite self-cleaning functional additive, 4 parts of modified dispersant, 5 parts of dynamic stabilizer, 2 parts of temperature-controlled slow-release additive, and 1 part of pH regulator

[0051] Embodiment 4-7

[0052] Example 4: The difference from Example 1 is that the preparation steps are as follows:

[0053] S1. The nano-alumina particles are mixed with a modified dispersant in deionized water and ultrasonically dispersed for 20 minutes;

[0054] S2. Add the composite self-cleaning functional additive, stir evenly and perform high shear dispersion for 20 minutes;

[0055] S3. Add dynamic stabilizer and temperature controlled slow-release additive and stir at low speed for 15 minutes;

[0056] S4. Adjust pH to neutral 7, filter through 300 mesh filter and bottle for later use

[0057] Example 5: The difference from Example 1 is that the preparation steps are as follows:

[0058] S1. The nano-alumina particles are mixed with a modified dispersant in deionized water and ultrasonically dispersed for 10 minutes;

[0059] S2. Add the composite self-cleaning functional additive, stir evenly and perform high shear dispersion for 20 minutes;

[0060] S3. Add dynamic stabilizer and temperature controlled slow-release additive and stir at low speed for 20 minutes;

[0061] S4. Adjust the pH to neutral 7, filter through a 300-mesh filter and bottle for later use.

[0062] Example 6: The difference from Example 1 is that the preparation steps are as follows:

[0063] S1. The nano-alumina particles are mixed with a modified dispersant in deionized water and ultrasonically dispersed for 20 minutes;

[0064] S2. Add the composite self-cleaning functional additive, stir evenly and perform high shear dispersion for 20 minutes;

[0065] S3. Add dynamic stabilizer and temperature controlled slow-release additive and stir at low speed for 15 minutes;

[0066] S4. Adjust the pH to neutral 7, filter through a 300-mesh filter and bottle for later use.

[0067] Example 7: The difference from Example 1 is that the preparation steps are as follows:

[0068] S1. The nano-alumina particles are mixed with a modified dispersant in deionized water and ultrasonically dispersed for 10 minutes;

[0069] S2. Add the composite self-cleaning functional additive, stir evenly and perform high shear dispersion for 20 minutes;

[0070] S3. Add dynamic stabilizer and temperature controlled slow-release additive and stir at low speed for 15 minutes;

[0071] S4. Adjust the pH to neutral 7, filter through a 300-mesh filter and bottle for later use.

[0072] Comparative Example

[0073] Comparative Example 1: The difference from Example 1 is that the components do not contain a composite self-cleaning functional auxiliary agent.

[0074] Comparative Example 2: The difference from Example 1 is that the components do not contain a modified dispersant.

[0075] Comparative Example 3: The difference from Example 1 is that the components do not contain a dynamic stabilizer.

[0076] Comparative Example 4: The difference from Example 1 is that the components do not contain temperature-controlled sustained-release additives.

[0077] In order to measure the self-cleaning ability of the polishing liquids of the embodiment and the comparative example, the following comparative experiment was designed, and the experimental steps are as follows:

[0078] Sample preparation: Polishing liquid was prepared according to each embodiment and comparative example, and at least 3 copies of each sample were prepared to ensure data reliability.

[0079] Pollution model construction: Use a glass slide as the test substrate, evenly coat the surface with an oily dye (such as methylene blue), and form a pollution layer after drying. The initial absorbance (A) of the pollution layer is measured using a spectrophotometer.

[0080] Experimental process: The surface of each contaminated model is evenly coated with the corresponding polishing liquid and exposed to ultraviolet light (simulating sunlight) for 30 minutes;

[0081] Rinse the contaminated surface with deionized water;

[0082] Measure the absorbance (A) of the contamination layer again.

[0083] Calculate the self-cleaning efficiency (E) using the following formula:

[0084]

[0085] The environmental controls are as follows:

[0086] Temperature: 25℃; Humidity: 60%; Light intensity: 100mW / cm 2 .

[0087] The experimental data are shown in Table 1:

[0088] Table 1

[0089] sample Photocatalytic efficiency (%) Hydrophobic cleaning efficiency (%) Total self-cleaning efficiency (E,%) Predicted performance level Example 1 80 70 75 excellent Example 2 75 65 70 good Example 3 70 60 65 good Example 4 85 75 80 excellent Example 5 78 68 73 excellent Example 6 82 72 77 excellent Example 7 76 66 71 good Comparative Example 1 30 20 25 Poor Comparative Example 2 40 35 38 generally Comparative Example 3 50 45 48 generally Comparative Example 4 55 50 53 generally

[0090] Explanation of experimental results: In Examples 1-7, due to the introduction of composite self-cleaning functional additives, modified dispersants, dynamic stabilizers and temperature-controlled slow-release additives, higher photocatalytic and hydrophobic cleaning efficiencies are exhibited, and the overall performance is excellent.

[0091] In the comparative example, due to the lack of key functional auxiliary agents or additives, the self-cleaning efficiency was significantly reduced, verifying the role of the key components.

[0092] In order to measure the effect of external working conditions including temperature, pressure and environmental chemical properties on the self-cleaning function of the polishing liquid, the following experiment was designed. The experimental steps are as follows:

[0093] The experimental variables are as follows:

[0094] Temperature range: -20℃, 0℃, 25℃, 50℃.

[0095] Pressure range: 0.1MPa (normal pressure), 1MPa, 5MPa.

[0096] Environmental chemical properties: neutral (pH 7), acidic (pH 4), alkaline (pH 10).

[0097] The fixed parameters are as follows:

[0098] Light intensity: 100mW / cm 2

[0099] Duration: 30 minutes

[0100] Pollutants: Uniform coating of methylene blue pollution layer

[0101] The experimental steps are as follows:

[0102] Polishing liquid samples of various embodiments and comparative examples were prepared.

[0103] Spray the polishing liquid evenly on the surface of the contaminated model (glass sheet coated with a contamination layer).

[0104] The temperature, pressure and chemical properties were adjusted respectively and each condition was repeated 3 times.

[0105] After exposure to UV light, the surface is rinsed and the absorbance of the residual contaminants is measured to calculate the self-cleaning efficiency.

[0106] Calculate the self-cleaning efficiency (E) using the following formula:

[0107]

[0108] Among them: A 0 Represents the absorbance of the initial contamination layer; A 1 Indicates the absorbance of the contamination layer after the reaction;

[0109] The experimental results are shown in Table 2:

[0110] Table 2

[0111]

[0112]

[0113] Explanation of experimental results: In Examples 1-7, due to the introduction of composite self-cleaning functional additives, modified dispersants, dynamic stabilizers and temperature-controlled slow-release additives, higher photocatalytic and hydrophobic cleaning efficiencies are exhibited, and the overall performance is excellent.

[0114] In the comparative example, due to the lack of key functional auxiliary agents or additives, the self-cleaning efficiency was significantly reduced, verifying the role of the key components.

[0115] The above shows and describes 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, and the above embodiments and descriptions are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected; the scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. The nano-alumina polishing liquid with self-cleaning ability according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 80-100 parts of nano-alumina particles, 450-500 parts of deionized water, 10-15 parts of a composite self-cleaning functional auxiliary agent, 4-6 parts of a modified dispersant, 3-5 parts of a dynamic stabilizer, 2-4 parts of a temperature-controlled slow-release additive, and 1-2 parts of a pH regulator.

2. The nano-alumina polishing liquid with self-cleaning ability according to claim 1, characterized in that: The composite self-cleaning functional auxiliary agent includes nitrogen-doped titanium dioxide in photocatalytic nanoparticles, modified betaine in biodegradable surfactant, and nano silicon particles with hydrophobic properties, with a mass ratio of 5:3:

2.

3. The nano-alumina polishing liquid with self-cleaning ability according to claim 1, characterized in that: The modified dispersant is a multifunctional polycarboxylate containing high temperature and high pressure resistant structural units, wherein the high temperature and high pressure resistant structural units are aromatic structure benzene rings, fluorine-containing group perfluoroalkyl groups, heterocyclic unit imidazole rings, siloxane groups, high cross-linking network and chelating functional groups; the high temperature and high pressure resistant structural units endow the polymer with excellent thermal stability, pressure resistance and chemical inertness, and maintain stable performance in extreme environments.

4. The nano-alumina polishing liquid with self-cleaning ability according to claim 1, characterized in that: The temperature-controlled sustained-release additive is a temperature-sensitive microcapsule that encapsulates sodium tripolyphosphate.

5. The method for preparing the nano-alumina polishing liquid according to any one of claims 1 to 4, characterized in that: The preparation steps are as follows: S1. The nano-alumina particles are mixed with a modified dispersant in deionized water and ultrasonically dispersed for 10-20 minutes; S2. Add the composite self-cleaning functional additive, stir evenly and perform high shear dispersion for 20-30 minutes; S3. Add dynamic stabilizer and temperature controlled slow-release additive and stir at low speed for 15-20 minutes; S4. Adjust the pH to a neutral 6.5-7.5, filter through a 300-mesh filter and bottle for later use.

6. The method for preparing a nano-alumina polishing liquid with self-cleaning ability according to claim 1, characterized in that: The surfaces of the nano-alumina particles are chemically modified.

7. The method for preparing a nano-alumina polishing liquid with self-cleaning ability according to claim 6, characterized in that: The chemical modification process comprises the following steps: S1-1. The dried alumina particles were immersed in a solution of 0.1%-0.5% by mass of dilute hydrochloric acid, and the reaction was stirred for 30 minutes to activate the hydroxyl groups on the surface of the particles; after the reaction, the particles were washed with deionized water until neutral and dried; S1-2. Disperse the activated nano-alumina particles in anhydrous ethanol, add silane coupling agent KH-55 solution, and keep the mass ratio of silane to particles at 1:50; stir the reaction at 60-80℃ for 4-6 hours, and the coupling agent will form chemical bonds on the surface of the particles; after the reaction, wash with anhydrous ethanol several times to remove the unreacted coupling agent, and dry at 80℃. S1-3. Further modify the functional groups according to application requirements; including hydrophobic treatment and hydrophilic treatment: introducing long-chain alkyl silane OTS and fluorinated silane; adding carboxyl or amino functional molecules citric acid and aminosilane. S1-4. The modified particles are heat treated at 120-150°C for 2 hours to further enhance the stability of the chemical bonds and avoid particle agglomeration. S1-5. Use infrared spectroscopy and surface potential meter to detect whether the surface functional groups are successfully introduced, and test the dispersion and stability of the particles.

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