Water-based cleaning agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of water-based cleaning agents, in particular to a water-based cleaning agent and a preparation method and application thereof.According to the water-based cleaning agent, amphiphilic molecules are formed through chemical grafting of beta-cyclodextrin-PEO derivatives and siloxane and serve as core components, and a bio-based solubilizer and a corrosion inhibitor are supplemented; the preparation method comprises the following steps: firstly, preparing a cyclodextrin-PEO derivative through ring opening polymerization of ethylene oxide; then carrying out amidation reaction with amino siloxane to construct a grafted structure; according to the invention, a cyclodextrin cavity provides molecular recognition inclusion ability, a siloxane chain segment enhances interfacial permeability, and the cyclodextrin cavity and the siloxane chain segment cooperate with each other to realize efficient decontamination; the bio-based component ensures environmental friendliness, and practical application verifies that the cleaning agent is particularly suitable for precise cleaning in high-end fields such as semiconductor manufacturing and aerospace.

Description

Technical Field

[0001] This invention relates to the field of water-based cleaning agents, and in particular to a water-based cleaning agent, its preparation method, and its application. Background Technology

[0002] As a core component of the industrial cleaning field, the development level of water-based cleaning agent technology directly affects the cleaning efficiency and product quality of key industries such as manufacturing, electronics, and precision instruments. With increasingly stringent environmental regulations and the continuous improvement of high-end manufacturing demands, water-based cleaning agents have gradually replaced traditional solvent-based cleaning agents, becoming an important way to achieve green cleaning.

[0003] Traditional water-based cleaning agents mainly rely on the physical compounding of surfactants to achieve their cleaning function through emulsification and dispersion. These cleaning agents typically use a simple mixture of anionic and nonionic surfactants. While they have some effect on basic cleaning, they have significant limitations: First, they are less efficient at cleaning complex oil stains, making it difficult to meet the requirements of precision manufacturing; second, they tend to generate a lot of foam during use, affecting the implementation of efficient processes such as spray cleaning; third, some formulations pose a risk of corrosion to metal substrates and have poor biodegradability, resulting in high wastewater treatment costs. The root cause of these problems lies in the lack of precise molecular-level design in traditional technologies. The components are mainly physically mixed, resulting in weak synergistic effects and a tendency for phase separation or performance degradation.

[0004] In high-end fields such as semiconductor manufacturing and electronic component cleaning, more stringent requirements are placed on the performance of water-based cleaning agents. For example, cleaning agents used in wafer processing need to have multiple characteristics such as high efficiency in removing dirt, low foaming, no residue, and corrosion resistance. At the same time, they must meet environmental standards such as low toxicity and biodegradability. Existing technologies cannot achieve these goals simultaneously. In particular, the simple stacking of surfactants in traditional formulations cannot solve deep-seated problems such as antagonistic effects between components and insufficient regulation of interfacial behavior.

[0005] Therefore, developing a novel water-based cleaning agent based on molecular engineering principles, and achieving synergistic effects between components through chemical grafting, structural design, and other means to fundamentally solve the shortcomings of traditional technologies, has become an urgent technical need in this field. Summary of the Invention

[0006] To address the problems mentioned in the background section, this invention provides a water-based cleaning agent, its preparation method, and its application.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a water-based cleaning agent includes the following steps: S1: β-Cyclodextrin and ethylene oxide were reacted at a molar ratio of 1:6.8 at 85±2℃. NaOH at 0.5% of the mass of β-cyclodextrin was added as a catalyst, and the stirring speed was maintained at 300 rpm for 4 h. After the reaction was completed, the system was cooled to 40℃ and neutralized with dilute hydrochloric acid to pH=7.0±0.2. Then, it was purified by dialyzing through a dialysis membrane with a molecular weight cutoff of 1000 Da for 24-36 h, pre-frozen at -50℃ for 4 h, and sublimated and dried at -30℃ for 24 h to obtain β-cyclodextrin-PEO derivative, wherein the degree of polymerization of PEO segments n=3. S2: The β-cyclodextrin-PEO derivative obtained in S1 was mixed with 3-aminopropyltrimethoxysilane at a molar ratio of 1:1.2-1.5. EDC / NHS condensing agent was added in a deionized water environment, wherein the molar ratio of EDC to aminosiloxane was 1:1.2-1.5. The mixture was first reacted in the dark at pH=7.0-7.5 and 25±2℃ for 4 hours, and then the pH was adjusted to 5.5-6.0 and the reaction was continued for 2 hours to obtain a cyclodextrin-siloxane graft with a grafting rate ≥90%. S3: Deionized water was heated to 40°C, and sodium creatine phosphate (1.2% of the total mass of the system) was added as a buffer. The mixture was stirred until completely dissolved. Octyl citrate (2.5% of the total mass of the system) was added as a bio-based solubilizer and sodium lauroyl sarcosinate (1.0% of the total mass of the system) as an auxiliary surfactant. The mixture was stirred for 30 min. The cyclodextrin-siloxane graft from S2 was slowly added and stirred for 1 h until homogeneous. The pH was adjusted to 7.5 ± 0.2 by adding 10% citric acid solution. The mixture was then subjected to ultrasonic dispersion treatment. Finally, impurities were removed through a 0.45 μm microporous membrane to obtain the water-based cleaning agent.

[0008] Furthermore, the cyclodextrin derivative is an etherified derivative of β-cyclodextrin, wherein the hydrophilic segment is a polyoxyethylene segment with a degree of polymerization n=3-5, and the cyclodextrin cavity pore size expands to 1.0-1.2 nm after the etherification reaction, so as to enhance the inclusion ability of oil stains with a molecular weight of 500-1000.

[0009] Furthermore, the siloxane compound is an aminosiloxane oligomer with a degree of polymerization of 3-5 of aminopropyltrimethoxysilane. It forms a synergistic detergency system through an amidation reaction between the amino group and the carboxyl group of the cyclodextrin derivative. The cyclodextrin mainly targets molecular recognition and inclusion, while the siloxane focuses on interfacial penetration and disruption. The siloxane segments account for 35-45% of the total mass of the grafted material.

[0010] Furthermore, the covalent grafting reaction is an amidation reaction, carried out in the presence of condensing agent EDC / NHS, wherein the molar ratio of EDC to aminosiloxane is 1:1.2-1.5, and the pH of the reaction system is controlled at 5.3-5.7 to optimize the amide bond formation efficiency, with a grafting rate ≥90%.

[0011] Furthermore, the bio-based solvent is octyl citrate, which is added at 2.0-3.0% of the total mass of the system, and its octanol / water partition coefficient is 2.5-3.0, which is used to enhance the solubility of hydrophobic oil stains, while the biodegradation rate is ≥80% within 28 days.

[0012] Furthermore, the buffer is sodium creatine phosphate, which is added at 1.0-1.5% of the total mass of the system, and its buffering capacity keeps the final pH of the cleaning agent stable at 7.0-8.0, replacing traditional silicates to avoid white spot residue on the metal surface.

[0013] Furthermore, the surfactant is sodium lauroyl sarcosinate, which is added at 0.5-1.5% of the total mass of the system. When combined with cyclodextrin-siloxane grafting material, the foam height drops to below 10 mm within 5 minutes, making it suitable for spray cleaning processes.

[0014] Furthermore, the homogenization process includes ultrasonic dispersion or mechanical stirring, wherein the ultrasonic dispersion uses a frequency of 40±2kHz and a power density of 0.5±0.1W / cm³. 2 Process for 15±1 min, then mechanically stir at 400-600 rpm for 30±2 min to control the viscosity of the cleaning agent at 10-15 mPa·s at room temperature (25±2℃) and ensure that the micelle size D90 ≤ 100 nm.

[0015] Furthermore, the aqueous solution is deionized water with a conductivity ≤5μS / cm, and its amount accounts for 80-90% of the total mass of the system. The calcium and magnesium ion content in the water is ≤10ppm to prevent hard water from affecting the stability of the cleaning agent.

[0016] Furthermore, the preparation method is carried out at room temperature of 25±5℃ or under heating conditions of ≤60℃. During the reaction, the pH value is controlled by real-time pH monitoring with a deviation within ±0.2. The final product does not separate into layers after being stored in a sealed container at an environment of -5℃ to 40℃ for 12 months.

[0017] The beneficial effects of this invention are: 1. The core of this invention lies in a composite system composed of three layers with different functions: the bottom layer achieves precise decontamination through the molecular inclusion effect of cyclodextrin derivatives; the middle layer enhances penetration and dispersion through an interfacial active network formed by siloxane grafts and ionic liquids; and the top layer obtains wear-resistant repair properties through photo-triggered crosslinking. This hierarchical structure design breaks through the limitations of the single function of traditional cleaning agents and realizes the organic integration of multiple functions such as decontamination, penetration, and protection.

[0018] 2. In this invention, after the cyclodextrin molecule is modified with PEO segments, its hydrophobic cavity size is optimized, which can more effectively encapsulate oil components of specific molecular weights. At the same time, through a precisely controlled grafting reaction, the siloxane segments and cyclodextrin form a stable chemical link, creating a composite molecule with amphiphilic properties. This composite molecule achieves efficient decontamination in the aqueous phase through synergistic effects. The cyclodextrin is responsible for recognizing and encapsulating small molecule oil, while the siloxane segments are responsible for disrupting the interfacial structure of large molecule oil.

[0019] 3. In this invention, the cleaning agent exhibits significant advantages in multiple performance dimensions. Its improved decontamination efficiency is attributed to the precision of molecular recognition and the synergistic enhancement of interfacial activity. Its environmental adaptability stems from the self-regulating ability of the intelligent response structure to different water quality conditions. Its eco-friendly characteristics arise from the rational selection and combination of biodegradable components. Compared with traditional cleaning agents, the product of this invention achieves a super-hydrophilic effect in semiconductor electrostatic chuck cleaning applications, reducing the contact angle from 85° to 5°, with a particulate pollutant removal rate exceeding 95%. In aerospace bearing cleaning, it reaches the highest cleanliness standard of Sa3, without corroding the bearing steel substrate, and extends the service life by more than 50%.

[0020] 4. In this invention, the problem of poor stability in traditional compound systems is solved by multi-component chemical grafting; and the synergistic optimization of performance is achieved through hierarchical structure construction. This rational design method provides a new technical path for the development of high-performance special cleaning agents and has important industry promotion value and application prospects. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Unless otherwise specified, the raw materials used in this invention are all from commercially available conventional products.

[0023] Example 1 S1. Preparation of β-cyclodextrin-PEO derivatives: 100g of β-cyclodextrin and 26.4g of ethylene oxide were weighed and placed in a three-necked flask. 1.2g of NaOH catalyst (accounting for 1.2% of the mass of β-cyclodextrin) was added, and the mixture was reacted at 85±2℃ and 300rpm for 4h. After the reaction was completed, the mixture was dialyzed for 36h using a dialysis membrane with a molecular weight cutoff of 1000Da. Then, it was pre-frozen at -50℃ for 4h and sublimated and dried at -30℃ for 24h to obtain the β-cyclodextrin-PEO derivative, wherein the degree of polymerization of the PEO segment n=3.

[0024] S2. Preparation of cyclodextrin-siloxane grafts: 50g of the β-cyclodextrin-PEO derivative obtained in S1 was mixed with 50g of 3-aminopropyltrimethoxysilane (molar ratio 1:1.5) in deionized water, and EDC / NHS condensing agent (molar ratio of EDC to aminosiloxane was 1:1.5) was added. After the reaction was completed, the grafting rate was detected by HPLC to be ≥90%, and the cyclodextrin-siloxane graft was obtained.

[0025] S3. Compound water-based cleaning agent: Deionized water was heated to 40°C, and sodium creatine phosphate (1.2% by mass of the total system mass) was added as a buffer. The mixture was stirred until completely dissolved. Octyl citrate (a bio-based solubilizer) (2.5% by mass of the total system mass) and sodium lauroyl sarcosinate (1.0% by mass of the total system mass) were added sequentially. The mixture was stirred at 500 rpm for 30 min. Cyclodextrin-siloxane grafted material of S2 (10% by mass of the total system mass) was slowly added, and stirring was continued for 1 h until homogeneous. The pH was adjusted to 7.5 ± 0.2 with 10% citric acid solution. Ultrasonic dispersion was then performed (using a probe-type ultrasonic disperser, frequency 40 ± 2 kHz, power density 0.5 ± 0.1 W / cm³). 2 The power calibration error is controlled within ±5% (time 15min). The final product is stored at 40℃ and RH 75% for 30 days, and the change rate of each indicator is <5%.

[0026] The product in this embodiment has been verified through application and performs excellently in the cleaning of semiconductor electrostatic chucks. For specific application effects, please refer to Application Example 1.

[0027] Example 2 The difference from Example 1 is that in step S1, the degree of polymerization of PEO segments is controlled to be n=5 (achieved by adjusting the amount of ethylene oxide fed), and the remaining steps are the same as in Example 1.

[0028] Example 3 The difference from Example 1 is that in step S2, the molar ratio of EDC to aminosiloxane is adjusted to 1:1.0 (below the preferred range), and the remaining steps are the same as in Example 1.

[0029] Example 4 The difference from Example 1 is that in step S3, the amount of octyl citrate added is adjusted to 2.0% of the total mass of the system (lower than the scope of the claims), and the remaining steps are the same as in Example 1.

[0030] Example 5 The difference from Example 1 is that in step S2, the reaction temperature is adjusted to 40°C (higher than 25±2°C in claim 1), and the remaining steps are the same as in Example 1.

[0031] Comparative Example 1 The traditional water-based cleaning agent formulation and process are adopted: Deionized water is heated to 50±2℃, and sodium silicate (3.0% of the total mass of the system) is added while stirring at 400 rpm. The mixture is stirred for 15 min until completely dissolved. While keeping the temperature constant, sodium fatty alcohol polyoxyethylene ether sulfate (AES) and sodium dodecylbenzene sulfonate (LAS) are added sequentially. The stirring speed is increased to 600 rpm and maintained for 30 min. Triethanolamine (2.0%) is added to adjust the pH to 9.0±0.5. The mixture is stirred for another 15 min and then cooled to room temperature. The traditional cleaning agent is obtained by filtration.

[0032] Comparative Example 2 The difference from Example 1 is that the siloxane grafting step is omitted, and only β-cyclodextrin-PEO derivative (unmodified) is used as the main cleaning agent, with the same amount added as in Example 1.

[0033] Comparative Example 3 The difference from Example 1 is that the cyclodextrin component is omitted, and only 3-aminopropyltrimethoxysilane and sodium lauroyl sarcosinate (mass ratio 60:40) are used. The remaining components are the same as in Example 1.

[0034] Performance testing methods and results To verify the effectiveness of the present invention, the cleaning agents obtained in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests. Three parallel samples were prepared for each group of samples, and the average value was taken after testing. The test method is as follows: Cleaning power: The cleaning power test is conducted according to the standard method of GB / T 35759-2022 "Metal Cleaning Agents". The standard dirt of 150# hydraulic oil was evenly coated onto an HT300 gray cast iron test piece (50mm×25mm×3mm). The amount of oil dirt was controlled at 0.10±0.02g. The test piece was immersed in a 3% cleaning agent solution in a constant temperature water bath at 60±2℃ for 3min, and then swished at a frequency of 30 times / min for 3min. After cleaning, the test piece was dried in an oven at 105±2℃ for 1h. After cooling to room temperature, it was weighed. The formula for calculating the cleaning rate is: η=(m1-m2) / (m1-m0)×100%, where m0 is the original weight of the test piece, m1 is the weight after coating, and m2 is the weight after cleaning. Foam height: Foam performance testing refers to the modified Ross-Miles method of GB / T 13173-2023 "Determination of Foam Performance of Surfactants". Under constant temperature conditions of 40±1℃, the 3% cleaning agent solution is poured from a height of 450mm into a graduated cylinder containing 50mL of test solution at the same temperature. The initial foam height (0s) and the residual foam height after 5min are recorded. The average value is taken for three parallel measurements. Before the test, all glass instruments must be soaked in chromic acid cleaning solution and rinsed with deionized water. Corrosion level: Corrosion testing is conducted in accordance with JB / T 4323.2-2019 "Test Method for Corrosion of Metal Cleaning Agents". A 50mm × 25mm × 3mm 45 steel specimen with a surface roughness Ra = 0.4~0.8μm was selected. The specimen was fully immersed in a 3% cleaning agent solution at 80±2℃ for 2 hours, with a solution volume to specimen area ratio of 20mL / cm². 2 After removal, rinse with running water, dehydrate with anhydrous ethanol, dry with hot air, and cool in a desiccator for 1 hour before weighing the corrosion amount Δm=(m before - m after) / A, where A is the exposed area of ​​the test piece (calculated on both sides). Biodegradation rate: The biodegradation rate test shall be conducted in accordance with the OECD 301B: DOC reduction test standard method. Activated sludge (taken from an urban wastewater treatment plant) was used as inoculum at a concentration of 30 mg / L. It was cultured at 21±1℃ in the dark for 28 days. The concentration of dissolved organic carbon (DOC) was measured periodically. The biodegradation rate was calculated as [1-(Dt-Dblk) / (D0-Dblk)]×100%, where D0 was the initial DOC concentration, Dt was the DOC concentration at time t, and Dblk was the blank value. A reference substance (aniline) was also set up to ensure the effectiveness of the experimental system. The results are shown in the table below: Table 1. Test results of the examples and comparative examples

[0035] Application Example 1: A 300mm wafer electrostatic chuck (Al2O3 ceramic material) was selected as the cleaning target. Surface contaminants included vacuum grease, fingerprints, and particulate matter. The cleaning agent prepared in Example 1 was used, and the cleaning process was as follows: First, the 300mm wafers to be cleaned need to be pre-treated and evaluated using electrostatic chucks. Operators should wear cleanroom-specific anti-static clothing and gloves and operate in an ISO Class 5 clean environment. Carefully remove the used electrostatic chucks from the wafer transfer equipment and place them on an anti-static carrier. Use a pure nitrogen gun to initially blow away large particulate contaminants on the surface. Use a contact angle meter and an optical microscope to inspect and record the surface condition of the chucks. Confirm that the initial contact angle is 85±5° and that there are obvious traces of vacuum grease and fingerprint contaminants on the surface.

[0036] Take the water-based cleaning agent stock solution prepared in Example 1 and dilute it with ultrapure water with a resistivity ≥18.2MΩ·cm. In a clean chemical-grade PP container, first add a predetermined amount of ultrapure water, then slowly add the cleaning agent stock solution. At the same time, use a magnetic stirrer to stir at a speed of 200rpm to ensure uniform mixing and form a cleaning working solution with a mass concentration of 3%. Transfer the prepared cleaning solution to the storage tank of a semi-automatic spray cleaning machine. The liquid temperature is stably controlled at a set temperature of 60±2℃ by the heating system built into the equipment.

[0037] After the spray cleaning is completed, immediately switch to the ultrapure water rinsing program. Use ultrapure water at the same temperature at a flow rate of 2L / min to continuously rinse the suction cup surface for 3 minutes to thoroughly remove residual cleaning agent and contaminants. After rinsing, proceed to the drying process. Use filtered high-purity nitrogen at a pressure of 0.1MPa to blow dry the suction cup surface for 2 minutes to ensure that there are no liquid droplets left on the surface.

[0038] Table 2. Semiconductor Application Performance Test Results (SEMI Standard)

[0039] The dried electrostatic chuck was transferred to the detection area and tested using a contact angle meter. The results showed that the contact angle decreased to 5±2°, reaching a superhydrophilic state. A laser particle counter was used to count the surface particles; the number of particles ≥0.2μm decreased from over 1000 before cleaning to below 50. Surface resistivity testing showed a stable value of (1.2±0.3)×10⁻⁶. 7 Within the Ω·sq range, it meets the requirements of semiconductor process. Finally, the cleaned and qualified chuck is reinstalled back into the production equipment for process verification.

[0040] Application Example 2: Precision bearings made of GCr15 bearing steel for aero-engines (size: Φ50mm×Φ20mm×15mm) are selected. The surface is covered with aviation lubricating oil (MIL-PRF-23699 standard) and metal shavings. After cleaning, they must meet the requirements of high cleanliness, no corrosion and dimensional stability.

[0041] Before cleaning, precision bearings made of GCr15 bearing steel for aero-engines require a comprehensive condition assessment. Operators use magnifying glasses and endoscopes on a clean workbench to carefully inspect all parts of the bearing, recording the grease adhesion and wear condition. Due to the special cleanliness requirements of aerospace, the bearing needs to be partially disassembled using special tools to ensure that the cleaning fluid can reach all critical parts. The original dimensions of the bearing are then precisely measured to establish a data comparison benchmark before and after cleaning.

[0042] A corrosion-resistant stainless steel ultrasonic cleaning tank was selected. First, a predetermined amount of deionized water was added, followed by the slow addition of the cleaning agent stock solution prepared in Example 1, to prepare a 5% (w / v) working solution. The ultrasonic generator was turned on, with the frequency set at 40 kHz and the power density controlled at 0.3 W / cm². 2 The temperature of the cleaning solution is stabilized at 40±1℃ by an immersion heater and monitored in real time using a digital temperature sensor. At the same time, a three-stage countercurrent rinsing tank is prepared, and fresh deionized water is used in each rinsing tank, with the temperature kept consistent with that of the cleaning tank.

[0043] The bearing to be cleaned is placed in a specially made stainless steel mesh basket to ensure that all surfaces of the bearing are fully exposed to the cleaning solution. The basket is slowly immersed in the cleaning tank to avoid air bubbles affecting the propagation of ultrasonic waves. The ultrasonic system is then started, and you can see that the cleaning solution immediately generates uniform microbubbles, and the cavitation effect begins to take effect. During the cleaning process, the aviation lubricating oil on the bearing surface is gradually emulsified and decomposed, and metal shavings fall off from the gaps. The entire ultrasonic cleaning process lasts for 15 minutes, during which the temperature and power are kept stable.

[0044] After ultrasonic cleaning, the bearing basket is transferred sequentially to a three-stage countercurrent rinsing tank for rinsing. The first rinsing tank mainly removes most of the cleaning agent residue, with a rinsing time of 3 minutes. During this time, the basket is gently shaken to ensure thorough rinsing. Then, it is transferred to the second rinsing tank to further remove trace residues, also with a rinsing time of 3 minutes. Finally, a final rinsing is performed in the third rinsing tank to ensure the complete removal of all cleaning agent components. This countercurrent rinsing method not only ensures the cleaning effect but also achieves water conservation.

[0045] After rinsing, the bearing is transferred to a hot air drying oven for drying. The drying temperature is set to 80℃ and the drying time is 10 minutes. Hot air is circulated to ensure that all parts of the bearing are completely dry. After drying, the bearing needs to be cooled to room temperature in a clean working environment before a comprehensive quality inspection is carried out.

[0046] Table 3. Aerospace Standard Test Results

[0047] After cleaning, the bearings fully meet the requirements for aerospace use. In accelerated life testing (equivalent to 1000 hours of operation), no abnormal wear or corrosion was observed, and the service life reached 150% of the design standard.

[0048] The data in the table shows that the cleaning agent prepared in Example 1 has good cleaning power (95.2%), foam height (5.0 mm), and corrosion rate (1.0 mg / cm³). 2It exhibits excellent performance in indicators such as inclusion rate and biodegradability (85.3%), which is attributed to the synergistic effect of cyclodextrin-siloxane grafts: the cyclodextrin cavity (extended to 1.0-1.2nm) encapsulates small molecule oil stains (molecular weight 500-1000), while the siloxane segments adsorb large molecule oil stains, forming a dual "encapsulation-adsorption" mechanism (see the core-shell structure theory in document 3). In addition, the bio-based properties of octyl citrate (Log P=2.5-3.0) and sodium lauroyl sarcosinate ensure its environmental friendliness.

[0049] In Example 2, due to the increased degree of polymerization of PEO segments (n=5), the cavity flexibility decreased slightly, and the cleaning power decreased slightly to 93.5%. In Example 3, due to the low EDC:silane ratio (1:1.0), the grafting rate was only 78%, which weakened the synergistic effect and significantly reduced the cleaning power to 88.7%, confirming the necessity of the molar ratio of 1:1.2-1.5 in claim 4. Comparative Example 1 used a traditional formula, lacked functional modification, and had the lowest cleaning power (79.0%), as well as high foam and poor degradation rate. Comparative Example 2 and Comparative Example 3, which did not have siloxane grafting, and Comparative Example 3, which did not have cyclodextrin inclusion, all verified the synergistic advantage of the indispensable components of the present invention.

[0050] In summary, this invention achieves a balance of high-efficiency cleaning, low foaming, rust prevention, and biodegradability through a cyclodextrin-siloxane grafting structure. Its key performance indicators are significantly better than those of conventional cleaning agents in comparison, making it suitable for high-end scenarios such as precision metal cleaning and the electronics industry.

[0051] In the description of this specification, the terms "preparation example," "example," "various examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that example or preparation example, which are included in at least one example or preparation example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same example or preparation example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more examples or preparation examples.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a water-based cleaning agent, characterized in that, Includes the following steps: S1: β-Cyclodextrin and ethylene oxide were reacted at a molar ratio of 1:6.8 at 85±2℃. NaOH at 0.5% of the mass of β-cyclodextrin was added as a catalyst, and the stirring speed was maintained at 300 rpm for 4 h. After the reaction was completed, the system was cooled to 40℃ and neutralized with dilute hydrochloric acid to pH=7.0±0.

2. Then, it was purified by dialyzing through a dialysis membrane with a molecular weight cutoff of 1000 Da for 24-36 h, pre-frozen at -50℃ for 4 h, and sublimated and dried at -30℃ for 24 h to obtain β-cyclodextrin-PEO derivative, wherein the degree of polymerization of PEO segments n=3. S2: The β-cyclodextrin-PEO derivative obtained in S1 was mixed with 3-aminopropyltrimethoxysilane at a molar ratio of 1:1.2-1.

5. EDC / NHS condensing agent was added in a deionized water environment, wherein the molar ratio of EDC to aminosiloxane was 1:1.2-1.

5. The mixture was first reacted in the dark at pH=7.0-7.5 and 25±2℃ for 4 hours, and then the pH was adjusted to 5.5-6.0 and the reaction was continued for 2 hours to obtain a cyclodextrin-siloxane graft with a grafting rate ≥90%. S3: Deionized water was heated to 40°C, and sodium creatine phosphate (1.2% of the total mass of the system) was added as a buffer. The mixture was stirred until completely dissolved. Octyl citrate (2.5% of the total mass of the system) was added as a bio-based solubilizer and sodium lauroyl sarcosinate (1.0% of the total mass of the system) as an auxiliary surfactant. The mixture was stirred for 30 min. The cyclodextrin-siloxane graft from S2 was slowly added and stirred for 1 h until homogeneous. The pH was adjusted to 7.5 ± 0.2 by adding 10% citric acid solution. The mixture was then subjected to ultrasonic dispersion treatment. Finally, impurities were removed through a 0.45 μm microporous membrane to obtain the water-based cleaning agent.

2. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The cyclodextrin derivative is an etherified derivative of β-cyclodextrin, wherein the hydrophilic segment is a polyoxyethylene segment with a degree of polymerization n=3-5, and the cyclodextrin cavity pore size expands to 1.0-1.2nm after the etherification reaction to enhance the inclusion ability of oil stains with a molecular weight of 500-1000.

3. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The siloxane compound is an aminosiloxane oligomer with a degree of polymerization of 3-5 of aminopropyltrimethoxysilane. It forms a synergistic detergency system through amidation reaction between the amino group and the carboxyl group of the cyclodextrin derivative. The cyclodextrin mainly targets molecular recognition and inclusion, while the siloxane focuses on interfacial penetration and destruction. The siloxane segments account for 35-45% of the total mass of the grafted material.

4. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The covalent grafting reaction is an amidation reaction, carried out in the presence of condensing agent EDC / NHS, wherein the molar ratio of EDC to aminosiloxane is 1:1.2-1.5, and the pH of the reaction system is controlled at 5.3-5.7 to optimize the amide bond formation efficiency, with a grafting rate ≥90%.

5. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The bio-based solvent is octyl citrate, which is added at 2.0-3.0% of the total mass of the system, and its octanol / water partition coefficient is 2.5-3.

0. It is used to enhance the solubility of hydrophobic oil stains, while the biodegradation rate is ≥80% within 28 days.

6. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The buffer is sodium creatine phosphate, which is added at 1.0-1.5% of the total mass of the system. Its buffering capacity keeps the final pH of the cleaning agent stable at 7.0-8.0, replacing traditional silicates to avoid white spot residue on the metal surface.

7. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The surfactant is sodium lauroyl sarcosinate, which is added at 0.5-1.5% of the total mass of the system. When combined with cyclodextrin-siloxane grafting material, the foam height drops to below 10 mm within 5 minutes, making it suitable for spray cleaning processes.

8. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The homogenization process includes ultrasonic dispersion or mechanical stirring, wherein the ultrasonic dispersion uses a frequency of 40±2kHz and a power density of 0.5±0.1W / cm³. 2 Process for 15±1 min, then mechanically stir at 400-600 rpm for 30±2 min to control the viscosity of the cleaning agent at 10-15 mPa·s at room temperature (25±2℃) and ensure that the micelle size D90 ≤ 100 nm.

9. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The aqueous solution is deionized water with a conductivity of ≤5μS / cm, and its amount accounts for 80-90% of the total mass of the system. The calcium and magnesium ion content in the water is ≤10ppm to prevent hard water from affecting the stability of the cleaning agent.

10. The method for preparing a water-based cleaning agent according to claim 1, characterized in that, The preparation method is carried out at room temperature of 25±5℃ or under heating conditions of ≤60℃. During the reaction, the pH value is controlled by real-time pH monitoring with a deviation within ±0.

2. The final product does not separate into layers when stored in a sealed container at an environment of -5℃ to 40℃ for 12 months.

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