Low-temperature quick-drying water-based wood paint for electrostatic spraying and preparation method thereof

Abstract

This invention relates to the field of water-based wood coatings, and more particularly to a low-temperature, fast-drying water-based wood coating for electrostatic spraying and its preparation method. The aforementioned low-temperature, fast-drying water-based wood coating for electrostatic spraying comprises, by weight, the following raw materials: 50-100 parts water-based acrylic resin, 100-200 parts water-based polyurethane acrylic resin, 5-10 parts silica sol, 1-2 parts γ-glycidyl etheroxypropyltrimethoxysilane, 1-2 parts methoxy polyethylene glycol propyltrimethoxysilane, 2-4 parts 6-amino-6-deoxy-β-cyclodextrin, 1-4 parts dopamine hydrochloride, 1-5 parts water-dispersible polycarbodiimide, 1-3 parts dipropylene glycol methyl ether, 1-2 parts defoamer, 1-2 parts wetting agent, 5-10 parts film-forming aid, and 1-2 parts thickener. The coating obtained by this invention is suitable for electrostatic spraying processes, improving coating utilization and coating uniformity, and achieving faster surface and hard drying at lower temperatures.

Description

Technical Field

[0001] This invention relates to the field of water-based wood coatings, and in particular to a low-temperature fast-drying water-based wood coating for electrostatic spraying and its preparation method. Background Technology

[0002] With the development of my country's social economy, traditional solvent-based wood coatings in the furniture market are gradually being replaced by water-based wood coatings due to problems such as high VOC emissions, strong odors during application, and significant environmental pressure. Water-based wood coatings are an important type of industrial coating, referring to coatings that use water as the main dispersion medium and are applied to the surface of wood products for both decorative and protective purposes. Compared with traditional solvent-based wood coatings, water-based wood coatings typically have lower VOCs, milder odors during application, and do not use benzene, toluene, xylene, or other benzene-based solvents as the main solvent, offering advantages in terms of resistance to yellowing and decorative performance.

[0003] However, current water-based wood coatings still suffer from shortcomings in leveling and feel compared to some solvent-based coatings, potentially affecting the decorative effect and tactile feel of the wood surface after application. Electrostatic spraying is a coating method where atomized charged paint particles migrate and deposit onto a conductive and reliably grounded workpiece under the influence of an electrostatic field. Using suitable water-based electrostatic spraying equipment and controlling the paint's viscosity and conductivity can improve paint utilization and coating uniformity.

[0004] However, water-based wood coatings experience reduced moisture evaporation rates under low temperature or high humidity conditions, and are prone to prolonged surface drying and hard drying times, making it difficult to meet the continuous production requirements of furniture factories. Therefore, developing a water-based wood coating suitable for electrostatic spraying and capable of faster drying and good film formation at lower temperatures is of practical significance. Summary of the Invention

[0005] Based on the technical problems existing in the background technology, the present invention proposes a low-temperature fast-drying electrostatic spraying water-based wood coating and its preparation method.

[0006] A low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating comprises, by weight, the following raw materials: 50-100 parts water-based acrylic resin, 100-200 parts water-based polyurethane acrylic resin, 5-10 parts silica sol, 1-2 parts γ-glycidyl etheroxypropyltrimethoxysilane, 1-2 parts methoxy polyethylene glycol propyltrimethoxysilane, 2-4 parts 6-amino-6-deoxy-β-cyclodextrin, 1-4 parts dopamine hydrochloride, 1-5 parts water-dispersible polycarbodiimide, 1-3 parts dipropylene glycol methyl ether, 1-2 parts defoamer, 1-2 parts wetting agent, 5-10 parts film-forming aid, and 1-2 parts thickener.

[0007] Preferably, the silica sol has a solid content of 25-35% and a particle size of 10-25 nm.

[0008] Preferably, the waterborne acrylic resin has a solid content of 40-50%.

[0009] Preferably, the waterborne polyurethane acrylic resin has a solid content of 40-50%.

[0010] Preferably, the defoamer is a water-based silicone defoamer.

[0011] Preferably, the wetting agent is a polyether-modified siloxane.

[0012] Preferably, the film-forming aid is at least one of dipropylene glycol methyl ether and dipropylene glycol butyl ether.

[0013] Preferably, the thickener is an associative polyurethane thickener.

[0014] A method for preparing the low-temperature fast-drying electrostatic spraying water-based wood coating includes the following steps: S1. Add silica sol to water and stir evenly. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add γ-glycidyl etheroxypropyltrimethoxysilane and methoxy polyethylene glycol propyltrimethoxysilane to an ethanol aqueous solution, adjust the pH of the system to 4.5-5.5 with glacial acetic acid, stir at room temperature for 40-50 min, and add dropwise to the pretreated silica sol while stirring. Stir at 400-800 r / min for 2-3 h at a stirring temperature of 55-65℃, adjust the pH of the system to 7-7.5, cool to 30-40℃, add 6-amino-6-deoxy-β-cyclodextrin, continue stirring for 2-4 h, add dipropylene glycol methyl ether and stir for 10-20 min, sonicate for 1-2 h at a sonication frequency of 70-80 kHz, adjust the pH of the system to 7-7.3, and obtain the preform. S3. Add water-based acrylic resin and water-based polyurethane acrylic resin to the pre-mixed material, stir at 200-400 r / min for 2-8 min, and filter through a 100-200 mesh filter; then add defoamer, wetting agent, and film-forming aid, adjust the pH of the system to 7.1-7.3, and stir at 400-600 r / min for 5-15 min; then add thickener, dopamine hydrochloride, and water-dispersible polycarbodiimide, and stir at 400-600 r / min for 5-15 min to obtain a low-temperature fast-drying electrostatic spraying special water-based wood coating.

[0015] Preferably, in S2, the mass fraction of the ethanol aqueous solution is 40-60%.

[0016] Preferably, in S3, N,N-dimethylethanolamine is used to adjust the pH of the system to 7.1-7.3.

[0017] Beneficial effects: In this invention, cyclodextrin combined with dipropylene glycol methyl ether acts gradually during the water evaporation process, which can locally reduce the minimum film-forming temperature at the resin particle interface, improve the particle fusion of waterborne acrylic resin and waterborne polyurethane acrylic resin at low temperatures, and the modified nano-silica forms a uniformly dispersed hydrophilic migration interface in the paint film, avoiding premature sealing of the surface layer at low temperatures, which would lead to internal water retention, thereby shortening the surface drying and complete drying time.

[0018] In this invention, by modifying the silica sol with silane coupling, the compatibility between inorganic nanoparticles and waterborne acrylic resin and waterborne polyurethane acrylic resin is enhanced. This not only improves the density, adhesion, and surface fullness of the paint film, but also improves the wetting, spreading, and leveling effects of waterborne wood coatings on wood surfaces. The waterborne acrylic resin, waterborne polyurethane acrylic resin, and pre-mixed materials are used as the main components. During the wet film stage, as ethanol, water, and some amines evaporate, the pH of the system decreases, and the carboxylates in the main components gradually convert to carboxyl groups. Polycarbodiimide combines with the carboxyl groups, significantly improving early hardness and anti-blocking properties at low temperatures. Furthermore, the addition of dopamine hydrochloride, whose catechol structure facilitates the formation of hydrogen bonds or coordination with hydroxyl groups on the wood surface, enhances the interfacial bonding strength between the coating and the wood substrate.

[0019] The coating obtained by this invention is suitable for electrostatic spraying process, which can improve coating utilization and coating uniformity, and achieve faster surface drying and hard drying at lower temperatures, reducing dependence on forced baking equipment. It is suitable for the decoration and protection of furniture and wood surfaces, and the preparation method is simple, making it suitable for large-scale promotion and application. Attached Figure Description

[0020] Figure 1 This is a comparison chart of the drying time and water permeability of the water-based wood coatings obtained in Example 5 and Comparative Examples 1-2.

[0021] Figure 2 This is a comparison chart of the impact resistance and adhesion grades of the water-based wood coatings obtained in Example 5 and Comparative Examples 1-2. Detailed Implementation

[0022] The following waterborne acrylic resin, with a solid content of 42±2%, was purchased from Jining Tangyi Chemical Co., Ltd., model J-672. The following waterborne polyurethane acrylic resin, with a solid content of 40-50%, was purchased from Jining Tangyi Chemical Co., Ltd., model P-6201D. The following defoamer is a waterborne silicone defoamer, sourced from Dow Corning, model DOWSIL 62Additive. The following wetting agent is a polyether-modified siloxane, sourced from Evonik, model TEGO Wet 270. The following thickener is an associative polyurethane thickener, purchased from UGREEN (Jining) Chemical Technology Co., Ltd., model ThAdd299. The following silica sol, with a solid content of 25-35% and a particle size of 10-25nm, was purchased from Wuhan Jiyesheng Chemical Co., Ltd.

[0023] The technical solution of the present invention will now be described in detail through specific embodiments.

[0024] Example 1: A method for preparing a low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating includes the following steps: S1. Add 5g of silica sol to 20g of deionized water and stir until homogeneous. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add 1g of γ-glycidyl etheroxypropyltrimethoxysilane and 1g of methoxypolyethylene glycol propyltrimethoxysilane to 20g of 40% ethanol aqueous solution. Adjust the pH of the system to 4.5-5.5 with glacial acetic acid. Stir at room temperature for 40min. Add the mixture dropwise to the pretreated silica sol while stirring. Stir at 400r / min for 2h at 55℃. Adjust the pH of the system to 7-7.5. Cool down to 30℃. Add 2g of 6-amino-6-deoxy-β-cyclodextrin. Continue stirring for 2h. Add 1g of dipropylene glycol methyl ether and stir for 10min. Ultrasonic treat for 1h at 70kHz. Adjust the pH of the system to 7-7.3 to obtain the preform. S3. Add 50g of water-based acrylic resin and 100g of water-based polyurethane acrylic resin to the pre-mixed material, stir at 200r / min for 2min, and filter through a 100-mesh filter; then add 1g of defoamer, 1g of wetting agent, and 5g of dipropylene glycol methyl ether, adjust the pH of the system to 7.1-7.3 using a pH adjuster, and stir at 400r / min for 5min; then add 1g of thickener, 1g of dopamine hydrochloride, and 1g of water-dispersible polycarbodiimide, and stir at 400r / min for 5min to obtain a low-temperature fast-drying electrostatic spraying special water-based wood coating.

[0025] Example 2: A method for preparing a low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating includes the following steps: S1. Add 10g of silica sol to 50g of deionized water and stir until homogeneous. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add 2g of γ-glycidyl etheroxypropyltrimethoxysilane and 2g of methoxypolyethylene glycol propyltrimethoxysilane to 40g of 60% ethanol aqueous solution. Adjust the pH of the system to 4.5-5.5 with glacial acetic acid. Stir at room temperature for 50min. Add the mixture dropwise to the pretreated silica sol while stirring. Stir at 800r / min for 3h at 65℃. Adjust the pH of the system to 7-7.5. Cool down to 40℃. Add 4g of 6-amino-6-deoxy-β-cyclodextrin. Continue stirring for 4h. Add 3g of dipropylene glycol methyl ether and stir for 20min. Ultrasonic treat for 2h at 80kHz. Adjust the pH of the system to 7-7.3 to obtain the preform. S3. Add 100g of waterborne acrylic resin and 200g of waterborne polyurethane acrylic resin to the pre-mixed material, stir at 400r / min for 8min, and filter through a 200-mesh filter; then add 2g of defoamer, 2g of wetting agent, and 10g of dipropylene glycol methyl ether, adjust the pH of the system to 7.1-7.3 using a pH adjuster, and stir at 600r / min for 15min; then add 2g of thickener, 4g of dopamine hydrochloride, and 5g of water-dispersible polycarbodiimide, and stir at 600r / min for 15min to obtain a low-temperature fast-drying electrostatic spraying special waterborne wood coating.

[0026] Example 3: A method for preparing a low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating includes the following steps: S1. Add 8g of silica sol to 25g of deionized water and stir until homogeneous. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add 1.2g of γ-glycidyl etheroxypropyltrimethoxysilane and 1.2g of methoxypolyethylene glycol propyltrimethoxysilane to 25g of 45% ethanol aqueous solution. Adjust the pH of the system to 4.5-5.5 with glacial acetic acid. Stir at room temperature for 42min. Add the mixture dropwise to the pretreated silica sol while stirring. Stir at 500r / min for 2.5h at 58℃. Adjust the pH of the system to 7-7.5. Cool down to 32℃. Add 2.5g of 6-amino-6-deoxy-β-cyclodextrin. Continue stirring for 2.5h. Add 1.5g of dipropylene glycol methyl ether and stir for 12min. Ultrasonic treat for 1.2h at 72kHz. Adjust the pH of the system to 7-7.3 to obtain the preform. S3. Add 60g of waterborne acrylic resin and 120g of waterborne polyurethane acrylic resin to the pre-mixed material, stir at 250r / min for 4min, and filter through a 100-mesh filter; then add 1.2g of defoamer, 1.2g of wetting agent, and 6g of dipropylene glycol methyl ether, adjust the pH of the system to 7.1-7.3 using a pH adjuster, and stir at 450r / min for 6min; then add 1.2g of thickener, 2g of dopamine hydrochloride, and 2g of water-dispersible polycarbodiimide, and stir at 450r / min for 6min to obtain a low-temperature fast-drying electrostatic spraying waterborne wood coating.

[0027] Example 4: A method for preparing a low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating includes the following steps: S1. Add 6g of silica sol to 45g of deionized water and stir until homogeneous. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add 1.5g of γ-glycidyl etheroxypropyltrimethoxysilane and 1.5g of methoxypolyethylene glycol propyltrimethoxysilane to 35g of 55% ethanol aqueous solution. Adjust the pH of the system to 4.5-5.5 with glacial acetic acid. Stir at room temperature for 48min. Add the mixture dropwise to the pretreated silica sol while stirring. Stir at 700r / min for 2.5h at 62℃. Adjust the pH of the system to 7-7.5. Cool down to 38℃. Add 3.5g of 6-amino-6-deoxy-β-cyclodextrin. Continue stirring for 3h. Add 2.5g of dipropylene glycol methyl ether and stir for 16min. Ultrasonic treat for 1.5h at 78kHz. Adjust the pH of the system to 7-7.3 to obtain the preform. S3. Add 90g of waterborne acrylic resin and 180g of waterborne polyurethane acrylic resin to the pre-mixed material, stir at 350r / min for 6min, and filter through a 200-mesh filter; then add 1.6g of defoamer, 1.6g of wetting agent, and 8g of dipropylene glycol butyl ether, adjust the pH of the system to 7.1-7.3 using a pH adjuster, and stir at 550r / min for 12min; then add 1.6g of thickener, 3g of dopamine hydrochloride, and 4g of water-dispersible polycarbodiimide, and stir at 550r / min for 12min to obtain a low-temperature fast-drying electrostatic spraying special waterborne wood coating.

[0028] Example 5: A method for preparing a low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating includes the following steps: S1. Add 7g of silica sol to 50g of deionized water and stir until homogeneous. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add 1.5g of γ-glycidyl etheroxypropyltrimethoxysilane and 1.5g of methoxypolyethylene glycol propyltrimethoxysilane to 35g of 50% ethanol aqueous solution. Adjust the pH of the system to 4.5-5.5 with glacial acetic acid. Stir at room temperature for 45min. Add the mixture dropwise to the pretreated silica sol while stirring. Stir at 600r / min for 2.5h at 60℃. Adjust the pH of the system to 7-7.5. Cool down to 35℃. Add 2.5g of 6-amino-6-deoxy-β-cyclodextrin. Continue stirring for 3h. Add 2g of dipropylene glycol methyl ether and stir for 15min. Ultrasonic treat for 1.5h at 75kHz. Adjust the pH of the system to 7-7.3 to obtain the preform. S3. Add 65g of water-based acrylic resin and 150g of water-based polyurethane acrylic resin to the pre-mixed material, stir at 300r / min for 5min, and filter through a 150-mesh filter; then add 2g of defoamer, 2g of wetting agent, and 7g of dipropylene glycol butyl ether, adjust the pH of the system to 7.1-7.3 using a pH adjuster, and stir at 500r / min for 10min; then add 1g of thickener, 2g of dopamine hydrochloride, and 2g of water-dispersible polycarbodiimide, and stir at 500r / min for 10min to obtain a low-temperature fast-drying electrostatic spraying special water-based wood coating.

[0029] Comparative Example 1: A method for preparing a low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating includes the following steps: S1. Add 6g of silica sol to 50g of deionized water and stir until homogeneous. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Weigh 35g of a 50% ethanol aqueous solution, adjust the pH of the system to 4.5-5.5 with glacial acetic acid, and add it dropwise to the pretreated silica sol while stirring. Stir at 600r / min for 2.5h at 60℃, adjust the pH of the system to 7-7.5, cool to 35℃, add 2.5g of 6-amino-6-deoxy-β-cyclodextrin, continue stirring for 3h, add 2g of dipropylene glycol methyl ether and stir for 15min, sonicate for 1.5h at 75kHz, adjust the pH of the system to 7-7.3, and obtain the pre-prepared material. S3. Add 65g of water-based acrylic resin and 150g of water-based polyurethane acrylic resin to the pre-mixed material, stir at 300r / min for 5min, and filter through a 150-mesh filter; then add 2g of defoamer, 2g of wetting agent, and 7g of dipropylene glycol butyl ether, adjust the pH of the system to 7.1-7.3 using a pH adjuster, and stir at 500r / min for 10min; then add 1g of thickener, 2g of dopamine hydrochloride, and 2g of water-dispersible polycarbodiimide, and stir at 500r / min for 10min to obtain a low-temperature fast-drying electrostatic spraying special water-based wood coating.

[0030] Comparative Example 2: A method for preparing a low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating includes the following steps: S1. Add 6g of silica sol to 50g of deionized water and stir until homogeneous. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add 1.5g of γ-glycidyl etheroxypropyltrimethoxysilane and 1.5g of methoxypolyethylene glycol propyltrimethoxysilane to 35g of 50% ethanol aqueous solution. Adjust the pH of the system to 4.5-5.5 with glacial acetic acid. Stir at room temperature for 45min. Add the mixture dropwise to the pretreated silica sol while stirring. Stir at 600r / min for 2.5h at 60℃. Adjust the pH of the system to 7-7.5. Cool to 35℃. Add 2g of dipropylene glycol methyl ether and stir for 15min. Ultrasonic treat for 1.5h at 75kHz. Adjust the pH of the system to 7-7.3 to obtain the preform. S3. Add 65g of water-based acrylic resin and 150g of water-based polyurethane acrylic resin to the pre-mixed material, stir at 300r / min for 5min, and filter through a 150-mesh filter; then add 2g of defoamer, 2g of wetting agent, and 7g of dipropylene glycol butyl ether, adjust the pH of the system to 7.1-7.3 using a pH adjuster, and stir at 500r / min for 10min; then add 1g of thickener, 2g of dopamine hydrochloride, and 2g of water-dispersible polycarbodiimide, and stir at 500r / min for 10min to obtain a low-temperature fast-drying electrostatic spraying special water-based wood coating.

[0031] Performance testing: The water-based wood coatings obtained in Example 5 and Comparative Examples 1-2 were filtered through a 200-mesh filter and allowed to stand for 30 minutes to de-foam. The viscosity of the coating was then adjusted to 20 ± 2 s using deionized water (measured at 25°C using a Forte 4 cup). The conductivity of the coating to be sprayed was controlled to be 800 ± 100 μS / cm.

[0032] A wooden test board with dimensions of 150mm × 70mm × 5mm was selected as the substrate. It was sanded with 240# and 400# sandpaper in sequence, and after dust removal, it underwent a conductive treatment to achieve a surface resistivity of 1–100 × 10⁻⁶. 6 Ω, and reliably grounded through a grounding clamp.

[0033] After equilibrating the above-mentioned coating and test panel in a constant temperature and humidity environment of 10℃ and 50% for 2 hours, the coating was applied using a water-based electrostatic spray gun. The electrostatic spraying parameters were as follows: nozzle diameter 1.0mm, electrostatic voltage -60kV, atomizing air pressure 0.25MPa, coating flow rate 100±10g / min, distance between the spray gun and the test panel 200±20mm, spray gun moving speed 300±50mm / s, overlap rate of adjacent spray patterns 50%, and a cross-spraying method of one horizontal spray and one vertical spray.

[0034] The wet film thickness was controlled to be 80±5μm by adjusting the spraying amount. After spraying, the test panel was immediately placed in an environment with a temperature of 10℃ and a relative humidity of 50% to test its drying performance.

[0035] like Figure 1 As shown, the water-based wood coating obtained in Example 5 had a significantly shorter drying time than the comparative example, and its water permeability was also significantly lower than that of the comparative example. Figure 1 As can be seen, according to the national standard testing methods, the various physicochemical properties of this application fully comply with the standard of GB / T 23999-2009 "Waterborne Wood Coatings for Interior Decoration and Renovation", and it is an excellent waterborne wood coating.

[0036] Further tests were conducted on the sanding properties of the three materials after 6 hours of drying. The water-based wood coating obtained in Example 5 did not stick to sand, the water-based wood coating obtained in Comparative Example 1 had slight sand sticking, and the water-based wood coating obtained in Comparative Example 2 had sand sticking.

[0037] The impact resistance of the water-based wood coatings obtained in Example 5 and Comparative Examples 1-2 was determined in accordance with GB / T1732-2020 "Test Method for Impact Resistance of Coatings".

[0038] The adhesion of the water-based wood coatings obtained in Example 5 and Comparative Examples 1-2 was determined with reference to GB / T9286-2021 "Cross-cut test for paints and varnishes".

[0039] like Figure 2 As shown, the water-based wood coating obtained in Example 5 has the highest impact resistance and the lowest adhesion grade, which is significantly better than the comparative example.

[0040] The storage stability of the water-based wood coatings obtained in Example 5 and Comparative Examples 1-2 was determined in accordance with GB / T23999-2009 "Water-based Wood Coatings for Interior Decoration and Renovation". The results showed that the water-based wood coatings obtained in Example 5 and Comparative Example 2 did not exhibit any stratification or sedimentation, while Comparative Example 1 had a small amount of sedimentation, which could be restored to uniformity after stirring. This indicates that the storage stability of the water-based wood coatings obtained in Example 5 and Comparative Example 2 is better than that of Comparative Example 1.

[0041] 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 low-temperature, fast-drying, electrostatic spraying-specific water-based wood coating, characterized in that, The raw materials, by weight, include: 50-100 parts of waterborne acrylic resin, 100-200 parts of waterborne polyurethane acrylic resin, 5-10 parts of silica sol, 1-2 parts of γ-glycidyl etheroxypropyltrimethoxysilane, 1-2 parts of methoxy polyethylene glycol propyltrimethoxysilane, 2-4 parts of 6-amino-6-deoxy-β-cyclodextrin, 1-4 parts of dopamine hydrochloride, 1-5 parts of water-dispersible polycarbodiimide, 1-3 parts of dipropylene glycol methyl ether, 1-2 parts of defoamer, 1-2 parts of wetting agent, 5-10 parts of film-forming aid, and 1-2 parts of thickener.

2. The low-temperature fast-drying electrostatic spraying water-based wood coating according to claim 1, characterized in that, The silica sol has a solid content of 25-35% and a particle size of 10-25 nm.

3. The low-temperature fast-drying electrostatic spraying water-based wood coating according to claim 1, characterized in that, The water-based acrylic resin has a solid content of 40-50%.

4. The low-temperature fast-drying electrostatic spraying water-based wood coating according to claim 1, characterized in that, The waterborne polyurethane acrylic resin has a solid content of 40-50%.

5. The low-temperature fast-drying electrostatic spraying water-based wood coating according to claim 1, characterized in that, The defoamer is a water-based silicone defoamer.

6. The low-temperature fast-drying electrostatic spraying water-based wood coating according to claim 1, characterized in that, The wetting agent is a polyether-modified siloxane.

7. The low-temperature fast-drying electrostatic spraying water-based wood coating according to claim 1, characterized in that, The film-forming aid is at least one of dipropylene glycol methyl ether and dipropylene glycol butyl ether.

8. The low-temperature fast-drying electrostatic spraying water-based wood coating according to claim 1, characterized in that, The thickener is an associative polyurethane thickener.

9. A method for preparing a low-temperature fast-drying electrostatic spraying water-based wood coating according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Add silica sol to water and stir evenly. Adjust the pH of the system to 7-7.3 using N,N-dimethylethanolamine to obtain pretreated silica sol. S2. Add γ-glycidyl etheroxypropyltrimethoxysilane and methoxy polyethylene glycol propyltrimethoxysilane to an ethanol aqueous solution, adjust the pH of the system to 4.5-5.5, stir at room temperature for 40-50 min, and add dropwise to the pretreated silica sol while stirring. Stir at 55-65℃ for 2-3 h, adjust the pH of the system to 7-7.5, lower the temperature to 30-40℃, add 6-amino-6-deoxy-β-cyclodextrin and continue stirring for 2-4 h, add dipropylene glycol methyl ether and stir for 10-20 min, sonicate for 1-2 h, adjust the pH of the system to 7-7.3, and obtain the preform. S3. Add water-based acrylic resin and water-based polyurethane acrylic resin to the pre-mixed material and stir for 2-8 minutes, then filter. Add defoamer, wetting agent, and film-forming aid to adjust the pH of the system to 7.1-7.3 and stir for 5-15 minutes. Then add thickener, dopamine hydrochloride, and water-dispersible polycarbodiimide and stir for 5-15 minutes to obtain a low-temperature fast-drying electrostatic spraying special water-based wood coating.

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