Organic silicon modified wood lacquer and preparation method thereof

Abstract

The invention discloses organic silicon modified wood lacquer and a preparation method thereof, and relates to the technical field of coatings. The invention discloses organic silicon modified wood lacquer. The water-based silicone sealant is prepared from the following raw materials in parts by weight: 20 to 35 parts of hydroxyl-terminated polydimethylsiloxane, 8 to 15 parts of methyltrimethoxysilane, 12 to 20 parts of bio-based polyol, 6 to 12 parts of isophorone diisocyanate, 3 to 8 parts of modified nano titanium dioxide, 5 to 10 parts of polyvinylidene fluoride, 4 to 9 parts of modified organosilicone elastomer, 0.2 to 0.8 part of dibutyltin dilaurate and 1 to 3 parts of ammonium polyacrylate. 0.5 to 1.5 parts of polyether modified polysiloxane, 2 to 6 parts of alcohol ester-12 and 15 to 30 parts of deionized water. According to the organic silicon modified wood lacquer, hydroxyl-terminated polydimethylsiloxane serves as a matrix, cross-linking is conducted through methyl trimethoxy silane, toughening is conducted through bio-based polyhydric alcohol, an interpenetrating network structure is formed in cooperation with multiple layers of modified nano titanium dioxide and the organic silicon elastomer, the organic silicon modified wood lacquer has high cross-linking density and flexibility, a coating is compact, and weather resistance is high.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, in particular to an organosilicon-modified wood paint and a preparation method thereof. Background Art

[0002] Most wood coatings currently on the market lack the richness of their effects and adaptability to new substrates. Furthermore, traditional wood coatings are complex to apply, require high ambient temperature and humidity, and dry slowly. This not only increases costs but also limits efficiency and application. There is an urgent need to develop new wood coatings that are easy to apply, dry quickly, and offer stable performance, in line with the industry's trend toward environmentally friendly, efficient, multifunctional, and personalized finishes. Summary of the Invention

[0003] In view of the deficiencies of the prior art, the present invention provides an organosilicon-modified wood paint and a preparation method thereof, which solves the problems of poor environmental protection, insufficient weather resistance and poor flexibility of traditional wood paint.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions: A silicone-modified wood paint comprises the following raw materials in parts by weight: 20-35 parts of hydroxyl-terminated polydimethylsiloxane, 8-15 parts of methyltrimethoxysilane, 12-20 parts of bio-based polyol, 6-12 parts of isophorone diisocyanate, 3-8 parts of modified nano-titanium dioxide, 5-10 parts of polyvinylidene fluoride, 4-9 parts of modified silicone elastomer, 0.2-0.8 parts of dibutyltin dilaurate, 1-3 parts of ammonium polyacrylate, 0.5-1.5 parts of polyether-modified polysiloxane, 2-6 parts of alcohol ester-12, and 15-30 parts of deionized water.

[0005] Furthermore, the bio-based polyol is a polyester polyol produced by fermentation of corn starch.

[0006] Furthermore, the polyvinylidene fluoride has a weight average molecular weight of 100,000-300,000, a number average molecular weight of 50,000-150,000, and a degree of polymerization of 500-1500.

[0007] Furthermore, the polyether-modified polysiloxane is a polydimethylsiloxane-polyoxyethylene-polyoxypropylene block copolymer, and the molecular weight of the polyether segment is 1000-3000.

[0008] Furthermore, the modified nano-titanium dioxide is prepared in the following specific steps: A1. Add silane coupling agent KH-550 to an ethanol-water mixed solution and stir evenly; add nano-titanium dioxide to a reaction kettle, pour in the silane coupling agent solution, heat to 55°C, maintain this temperature and stir for 3 hours; after the reaction is completed, stop heating and stirring, filter the reaction product, wash the filter cake with anhydrous ethanol three times, and then dry the filter cake in a vacuum drying oven at 70°C for 7 hours to obtain the first modified nano-titanium dioxide; A2. Dissolve polyvinylidene fluoride in dimethylformamide to prepare a 10% by mass fluorine-containing polymer solution; add the first modified nano-titanium dioxide to a reactor, pour in the fluorine-containing polymer solution, heat to 75°C, and stir at this temperature for 4 hours; after the reaction is completed, cool to room temperature, centrifuge the reaction product, collect the precipitate, wash the precipitate three times with dimethylformamide, and dry the precipitate in a vacuum drying oven at 80°C for 10 hours to obtain the second modified nano-titanium dioxide; A3. Measure the organosilicon oligomer and dissolve it in toluene to prepare a 15% by mass organosilicon oligomer solution; add the second modified nano-titanium dioxide into the reactor, pour in the organosilicon oligomer solution, heat to 65°C, and stir to react for 3 hours; after the reaction is completed, stop heating and stirring, and distill the reaction product under reduced pressure to remove the toluene solvent. Wash the remaining product with acetone three times, and then place it in a vacuum drying oven and dry it at 90°C for 12 hours to obtain the final modified nano-titanium dioxide.

[0009] Furthermore, the mass ratio of the silane coupling agent, the ethanol-water mixed solution, and the nano-titanium dioxide in A1 is 1:7:8, the stirring speed of the silane coupling agent and the ethanol-water mixture is 200 r / min, and the stirring speed of the reactor is 400 r / min.

[0010] Furthermore, the mass ratio of the first modified nano-titanium dioxide and the fluorine-containing polymer solution in A2 is 1:1, and the stirring speed of the reactor is 500 r / min.

[0011] Furthermore, the mass ratio of the second modified nano-titanium dioxide and the organosilicon oligomer solution in A3 is 1.6:1, the stirring speed of the reactor is 600 r / min, and the reduced pressure distillation conditions for removing the toluene solvent from the reaction product are 4 kPa and 70°C.

[0012] First, the nano-titanium dioxide is modified using the silane coupling agent KH-550. The alkoxy groups in the silane coupling agent molecules react with the hydroxyl groups on the surface of the nano-titanium dioxide to form chemical bonds, thereby introducing organic groups on its surface and improving the compatibility of the nano-titanium dioxide with the organic matrix. Next, a second modification is performed using polyvinylidene fluoride. Polyvinylidene fluoride is dissolved in dimethylformamide to form a fluoropolymer solution, which reacts with the first-modified nano-titanium dioxide. The fluoropolymers adhere to its surface, enhancing the nano-titanium dioxide's weather resistance and hydrophobicity. Finally, a third modification is performed using an organosilicon oligomer. The organosilicon oligomer solution reacts with the second-modified nano-titanium dioxide to form an organosilicon coating on its surface, further improving the bonding between the nano-titanium dioxide and the organosilicon matrix while also enhancing the paint film's flexibility and weather resistance.

[0013] Furthermore, the modified silicone elastomer is specifically prepared in the following steps: B1. Add polydimethylsiloxane-polycaprolactone block copolymer and vinyltrimethoxysilane to a reactor, then add toluene, and heat to 80°C. After the temperature stabilizes, add benzoyl peroxide and stir to react for 5 hours. After the reaction is completed, cool to room temperature, and distill the reaction product under reduced pressure to remove the toluene solvent. The remaining product is washed three times with petroleum ether and then dried in a vacuum drying oven at 80°C for 8 hours to obtain a first modified silicone elastomer. B2. The first modified elastomer and bio-based polyol were added to a reactor, followed by butanone. The temperature was raised to 70°C. After the temperature stabilized, dibutyltin dilaurate was added and the reaction was stirred for 3 hours. After the reaction was completed, the reaction product was cooled to room temperature and vacuum distilled to remove the butanone solvent. The remaining product was washed three times with ethyl acetate and then dried in a vacuum drying oven at 80°C for 10 hours to obtain a second modified silicone elastomer. B3. Add the second modified silicone elastomer and modified nano-titanium dioxide into the reactor, add xylene, raise the temperature to 50°C, and stir to react for 2 hours; after the reaction is completed, stop heating and stirring, and distill the reaction product under reduced pressure to remove the xylene solvent. Wash the remaining product with cyclohexane three times, and then place it in a vacuum drying oven at 90°C for 12 hours to obtain the final modified silicone elastomer.

[0014] Furthermore, the mass ratio of polydimethylsiloxane-polycaprolactone block copolymer, vinyltrimethoxysilane, toluene, and benzoyl peroxide in B1 is 1:0.2:5:0.01; the stirring speed of the reactor is 400 r / min, the vacuum distillation conditions for removing the toluene solvent from the reaction product are 4 kPa and 80°C, and the product is washed with petroleum ether three times.

[0015] Furthermore, the mass ratio of the first modified elastomer, bio-based polyol, butanone, and dibutyltin laurate in B2 is 1:1:8:0.02; the stirring speed of the reactor is 500 r / min, and the reduced pressure distillation conditions for removing the butanone solvent from the reaction product are 4 kPa and 60°C.

[0016] Furthermore, the mass ratio of the second modified elastomer, nano-titanium dioxide, and xylene in B3 is 1:0.5:3.5; the stirring speed of the reactor is 600 r / min; and the reduced pressure distillation conditions for removing the xylene solvent from the reaction product are 3 kPa and 80°C.

[0017] In B1, a polydimethylsiloxane-polycaprolactone block copolymer reacts with vinyltrimethoxysilane in toluene, initiated by benzoyl peroxide. Vinyltrimethoxysilane is grafted onto the block copolymer, introducing reactive siloxy groups and improving the crosslinking properties of the elastomer. In B2, the first modified elastomer reacts with a bio-based polyol in butanone, catalyzed by dibutyltin dilaurate. The hydroxyl groups of the bio-based polyol react with the active groups on the elastomer, further extending the chain and improving the elastomer's flexibility and mechanical properties. In B3, the second modified elastomer reacts with modified nano-titanium dioxide in xylene. The modified nano-titanium dioxide and the elastomer bond through physical and chemical reactions, imparting shape memory to the elastomer while enhancing its mechanical properties and weather resistance.

[0018] A method for preparing an organosilicon-modified wood paint comprises the following steps: S1. Add hydroxyl-terminated polydimethylsiloxane, methyltrimethoxysilane, and bio-based polyol into a reactor and stir at 300-400 r / min for 10-15 minutes to form a uniform base material; S2. Add isophorone diisocyanate and dibutyltin dilaurate, raise the temperature to 50-60°C, and continue stirring at the same speed for 20-30 minutes; S3. Add modified nano-titanium dioxide, polyvinylidene fluoride, and polyacrylate ammonium salt in sequence, increase the stirring speed to 500-600 r / min, and disperse for 30-40 minutes; S4. Add modified silicone elastomer, polyether modified polysiloxane and alcohol ester-12, reduce the speed to 300r / min and stir for 15-20min. At the same time, slowly add deionized water to adjust the viscosity to 4 cups of viscosity and adjust it to the construction requirement in 15-25s. S5. Filter through a 100-200 mesh filter to remove impurities, place the coating in a sealed container, and age at 25°C for 24-48 hours to eliminate bubbles and stabilize the system.

[0019] The present invention provides an organosilicon-modified wood paint and a preparation method thereof, which have the following beneficial effects: 1. Through the composite modification of silicone elastomers and modified nano-titanium dioxide, the paint film forms an interpenetrating network structure of "rigid skeleton-flexible buffer." The siloxane bond skeleton formed by cross-linking hydroxyl-terminated polydimethylsiloxane and methyltrimethoxysilane gives the coating high adhesion and deformation resistance, while the flexible segments introduced by bio-based polyols and the toughening effect of polyether-modified polysiloxane make the paint film less prone to cracking when bent. The three-layer modified nano-titanium dioxide is coated with a silane coupling agent, polyvinylidene fluoride, and silicone oligomers, which not only enhances the UV shielding effect but also forms an interfacial synergy with the silicone elastomer, improving overall weather resistance and water resistance, allowing the paint film to maintain long-term protection in complex environments.

[0020] 2. Using deionized water as the primary solvent significantly reduces the use of organic solvents. Combined with the low-volatility alcohol ester-12 additive, the VOC content is controlled to ≤50g / L, significantly lower than similar products on the market. The introduction of bio-based polyols reduces reliance on petroleum-based raw materials. The formulation reduces harmful emissions during production, construction, and use, meeting the stringent environmental standards for interior building materials while balancing environmental friendliness and human health.

[0021] 3. The shape memory properties of modified silicone elastomers enable them to autonomously repair micro-damage in response to temperature fluctuations or external forces. Combined with the surface activity regulation of polyether-modified polysiloxane, the paint film maintains stable performance in humid and sunny environments. Whether exposed to high humidity in kitchens and bathrooms, long-term UV exposure in outdoor furniture, or high-frequency friction in tables, chairs, and floors, the paint film achieves a comprehensive balance of water resistance, weather resistance, and scratch resistance through structural design, broadening the application boundaries of wood coatings.

[0022] 4. Aging during the preparation process promotes full cross-linking of the molecular chains, eliminates air bubbles in the system, and stabilizes viscosity, ensuring the coating exhibits no settling or delamination during storage and excellent leveling during application. A 100-200 mesh filtration process ensures the paint film is free of impurities and particles. The addition of a polyacrylate ammonium salt dispersant prevents brush marks and craters. Compared to traditional wood coatings, this system exhibits excellent adhesion to a variety of wood substrates, significantly improving application efficiency and compatibility. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0024] Example 1: Preparation of organosilicon-modified wood paint. The specific preparation steps are as follows: S1. Add 20 parts of hydroxyl-terminated polydimethylsiloxane, 8 parts of methyltrimethoxysilane, and 12 parts of bio-based polyol into a reactor and stir at 300 r / min for 10 minutes to form a uniform base material; S2. Add 6 parts of isophorone diisocyanate and 0.2 parts of dibutyltin dilaurate, raise the temperature to 50°C, and continue stirring at the same speed for 20 minutes; S3, add 3 parts of modified nano titanium dioxide, 5 parts of polyvinylidene fluoride, and 1 part of polyacrylate ammonium salt in sequence, increase the stirring speed to 500r / min, and disperse for 30min; S4, add 4 parts of modified silicone elastomer, 0.5 parts of polyether-modified polysiloxane, and 2 parts of alcohol ester-12, reduce the speed to 300 r / min and stir for 15 minutes, while slowly adding deionized water to adjust the viscosity to the viscosity of coating-4 cups in 15 seconds; S5. Filter through a 100-mesh filter to remove impurities, place the coating in a sealed container, and age at 25°C for 24 hours to eliminate bubbles and stabilize the system.

[0025] Example 2: Preparation of organosilicon-modified wood paint. The specific preparation steps are as follows: S1. Add 35 parts of hydroxyl-terminated polydimethylsiloxane, 15 parts of methyltrimethoxysilane, and 20 parts of bio-based polyol into a reactor and stir at 400 r / min for 15 minutes to form a uniform base material; S2. Add 12 parts of isophorone diisocyanate and 0.8 parts of dibutyltin dilaurate, raise the temperature to 60°C, and continue stirring at the same speed for 30 minutes; S3, add 8 parts of modified nano titanium dioxide, 10 parts of polyvinylidene fluoride, and 3 parts of polyacrylate ammonium salt in sequence, increase the stirring speed to 600r / min, and disperse for 40min; S4, add 9 parts of modified silicone elastomer, 1.5 parts of polyether-modified polysiloxane, and 6 parts of alcohol ester-12, reduce the speed to 300 r / min and stir for 20 minutes, while slowly adding deionized water to adjust the viscosity to a coating viscosity of 4 cups in 25 seconds; S5. Filter through a 200-mesh filter to remove impurities, place the coating in a sealed container, and age at 25°C for 48 hours to eliminate bubbles and stabilize the system.

[0026] Example 3: Preparation of organosilicon-modified wood coating, specifically the following preparation steps: S1, adding 25 parts of hydroxyl-terminated polydimethylsiloxane, 12 parts of methyltrimethoxysilane, and 16 parts of bio-based polyol into a reactor, stirring at 350 r / min for 13 minutes to form a uniform base material; S2. Add 9 parts of isophorone diisocyanate and 0.5 parts of dibutyltin dilaurate, raise the temperature to 55°C, and continue stirring at the same speed for 25 minutes; S3, add 5 parts of modified nano titanium dioxide, 7 parts of polyvinylidene fluoride, and 2 parts of polyacrylate ammonium salt in sequence, increase the stirring speed to 550r / min, and disperse for 35 minutes; S4, add 6 parts of modified silicone elastomer, 1 part of polyether-modified polysiloxane, and 4 parts of alcohol ester-12, reduce the speed to 300 r / min and stir for 17 minutes, while slowly adding deionized water to adjust the viscosity to a coating viscosity of 4 cups in 20 seconds; S5. Filter through a 200-mesh filter to remove impurities, place the coating in a sealed container, and age at 25°C for 40 hours to eliminate bubbles and stabilize the system.

[0027] Example 4: Preparation of modified nano-titanium dioxide. The specific preparation steps are as follows: A1. Add 10 g of silane coupling agent KH-550 to 70 g of ethanol-water mixed solution and stir evenly at 200 r / min; add 80 g of nano-titanium dioxide to a reactor, pour in the silane coupling agent solution, heat to 55° C., maintain the temperature and stir at 400 r / min for 3 h; after the reaction is completed, stop heating and stirring, filter the reaction product, wash the filter cake with anhydrous ethanol three times, and then place the filter cake in a vacuum drying oven at 70° C. and dry it for 7 h to obtain the first modified nano-titanium dioxide; A2. Dissolve polyvinylidene fluoride in dimethylformamide to prepare a 10% by mass fluoropolymer solution; add 80 g of the first modified nano-titanium dioxide to a reactor, pour in 80 g of the fluoropolymer solution, raise the temperature to 75°C, and stir at 500 rpm for 4 hours at this temperature; after the reaction is completed, cool to room temperature, centrifuge the reaction product, collect the precipitate, wash the precipitate three times with dimethylformamide, and dry the precipitate in a vacuum drying oven at 80°C for 10 hours to obtain the second modified nano-titanium dioxide; A3. Measure the organosilicon oligomer and dissolve it in toluene to prepare an organosilicon oligomer solution with a mass fraction of 15%. Add 80 g of the second modified nano-titanium dioxide into the reactor, pour in 50 g of the organosilicon oligomer solution, heat to 65°C, and stir at 600 r / min for 3 hours. After the reaction is completed, stop heating and stirring, and distill the reaction product under reduced pressure at 4 kPa and 70°C to remove the toluene solvent. Wash the remaining product with acetone three times, and then place it in a vacuum drying oven and dry it at 90°C for 12 hours to obtain the final modified nano-titanium dioxide.

[0028] Example 5, preparing a modified silicone elastomer, the specific preparation steps are as follows: B1. Add 50 g of polydimethylsiloxane-polycaprolactone block copolymer and 10 g of vinyltrimethoxysilane to a reactor, then add 250 g of toluene, and heat to 80° C. After the temperature stabilizes, add 0.5 g of benzoyl peroxide, and stir at 400 r / min for 5 hours. After the reaction is completed, cool to room temperature, and distill the reaction product under reduced pressure at 4 kPa and 80° C. to remove the toluene solvent. The remaining product is washed three times with petroleum ether and then dried in a vacuum drying oven at 80° C. for 8 hours to obtain a first modified silicone elastomer. B2. Add 60 g of the first modified elastomer and 60 g of bio-based polyol to a reactor, then add 480 g of butanone, raise the temperature to 70°C, and after the temperature stabilizes, add 1.2 g of dibutyltin dilaurate, and stir at 500 r / min for 3 hours. After the reaction is completed, cool to room temperature, and distill the reaction product under reduced pressure at 4 kPa and 60°C to remove the butanone solvent. The remaining product is washed with ethyl acetate three times and then dried in a vacuum drying oven at 80°C for 10 hours to obtain a second modified silicone elastomer. B3. Add 100 g of the second modified silicone elastomer and 50 g of modified nano-titanium dioxide into a reactor, add 350 g of xylene, raise the temperature to 50°C, and stir at 600 r / min for 2 h. After the reaction is completed, stop heating and stirring, and distill the reaction product under reduced pressure at 3 kPa and 80°C to remove the xylene solvent. Wash the remaining product with cyclohexane three times, and then place it in a vacuum drying oven and dry it at 90°C for 12 h to obtain the final modified shape memory silicone elastomer.

[0029] Comparative Example 1: Preparation of organosilicon-modified wood paint. The specific preparation steps are as follows: The remaining steps remained unchanged, except that the modified nano-titanium dioxide in Example 3 was replaced by nano-titanium dioxide without any treatment to prepare the organosilicon-modified wood paint.

[0030] Comparative Example 2: Preparation of organosilicon-modified wood paint. The specific preparation steps are as follows: The remaining steps remained unchanged, except that the modified silicone elastomer in Example 3 was replaced by an untreated silicone elastomer to prepare a silicone-modified wood paint.

[0031] Performance Testing The performance test results show that in Examples 1-3, the adhesion of the silicone modified wood paint all reached level 0, the pencil hardness was between 2H-3H, there was no blistering or peeling after 24 hours of water immersion, the color difference ΔE after 1000 hours of xenon lamp aging was less than 1.5, the bending diameter in the flexibility test was as small as 1mm without cracks, and the VOC content was controlled at ≤50g / L, showing excellent performance in all aspects. In Comparative Examples 1 and 2, when unmodified nano-titanium dioxide and silicone elastomer were used respectively, the adhesion dropped to level 1, the pencil hardness was only H, slight blistering or edge peeling occurred in the water resistance test, and the weather resistance color difference was The values ​​were less than 3.0 and 2.5, respectively. Cracks appeared at a flexible bending diameter of 3 mm. The VOC content also increased, and the performance was significantly inferior to that of the embodiment. This shows that modified nano-titanium dioxide and modified silicone elastomer play an important role in improving the overall performance of the wood coating.

[0032] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A silicone-modified wood paint, characterized in that: The invention comprises the following raw materials in parts by weight: 20-35 parts of hydroxyl-terminated polydimethylsiloxane, 8-15 parts of methyltrimethoxysilane, 12-20 parts of bio-based polyol, 6-12 parts of isophorone diisocyanate, 3-8 parts of modified nano-titanium dioxide, 5-10 parts of polyvinylidene fluoride, 4-9 parts of modified silicone elastomer, 0.2-0.8 parts of dibutyltin dilaurate, 1-3 parts of ammonium polyacrylate, 0.5-1.5 parts of polyether-modified polysiloxane, 2-6 parts of alcohol ester-12, and 15-30 parts of deionized water.

2. The organosilicon-modified wood paint according to claim 1, characterized in that: The bio-based polyol is a polyester polyol produced by fermenting corn starch.

3. The organosilicon-modified wood paint according to claim 1, characterized in that: The polyvinylidene fluoride has a weight average molecular weight of 100,000-300,000, a number average molecular weight of 50,000-150,000, and a degree of polymerization of 500-1500.

4. The organosilicon-modified wood paint according to claim 1, characterized in that: The polyether-modified polysiloxane is a polydimethylsiloxane-polyoxyethylene-polyoxypropylene block copolymer, and the molecular weight of the polyether chain segment is 1000-3000.

5. The organosilicon-modified wood paint according to claim 1, characterized in that: The modified nano titanium dioxide is specifically prepared in the following steps: A1. Add silane coupling agent KH-550 to an ethanol-water mixed solution and stir evenly; add nano-titanium dioxide to a reaction kettle, pour in the silane coupling agent solution, heat to 55°C, maintain this temperature and stir for 3 hours; after the reaction is completed, stop heating and stirring, filter the reaction product, wash the filter cake with anhydrous ethanol three times, and then dry the filter cake in a vacuum drying oven at 70°C for 7 hours to obtain the first modified nano-titanium dioxide; A2. Dissolve polyvinylidene fluoride in dimethylformamide to prepare a 10% by mass fluorine-containing polymer solution; add the first modified nano-titanium dioxide to a reactor, pour in the fluorine-containing polymer solution, heat to 75°C, and stir at this temperature for 4 hours; after the reaction is completed, cool to room temperature, centrifuge the reaction product, collect the precipitate, wash the precipitate three times with dimethylformamide, and dry the precipitate in a vacuum drying oven at 80°C for 10 hours to obtain the second modified nano-titanium dioxide; A3. Measure the organosilicon oligomer and dissolve it in toluene to prepare a 15% by mass organosilicon oligomer solution; add the second modified nano-titanium dioxide into the reactor, pour in the organosilicon oligomer solution, heat to 65°C, and stir to react for 3 hours; after the reaction is completed, stop heating and stirring, and distill the reaction product under reduced pressure to remove the toluene solvent. Wash the remaining product with acetone three times, and then place it in a vacuum drying oven and dry it at 90°C for 12 hours to obtain the final modified nano-titanium dioxide.

6. The organosilicon-modified wood paint according to claim 5, characterized in that: The mass ratio of the silane coupling agent, ethanol-water mixed solution, and nano-titanium dioxide in A1 is 1:7:8, the stirring speed of the silane coupling agent and ethanol-water mixture is 200 r / min, and the stirring speed of the reactor is 400 r / min; The mass ratio of the first modified nano-titanium dioxide and the fluorine-containing polymer solution in A2 is 1:1, and the stirring speed of the reactor is 500 r / min; The mass ratio of the second modified nano-titanium dioxide and the organosilicon oligomer solution in A3 is 1.6:1, the stirring speed of the reactor is 600 r / min, and the reduced pressure distillation conditions for removing the toluene solvent from the reaction product are 4 kPa and 70°C.

7. The organosilicon-modified wood paint according to claim 1, characterized in that: The modified silicone elastomer is specifically prepared in the following steps: B1. Add polydimethylsiloxane-polycaprolactone block copolymer and vinyltrimethoxysilane to a reactor, then add toluene, and heat to 80°C. After the temperature stabilizes, add benzoyl peroxide and stir to react for 5 hours. After the reaction is completed, cool to room temperature, and distill the reaction product under reduced pressure to remove the toluene solvent. The remaining product is washed three times with petroleum ether and then dried in a vacuum drying oven at 80°C for 8 hours to obtain a first modified silicone elastomer. B2. The first modified elastomer and bio-based polyol were added to a reactor, followed by butanone. The temperature was raised to 70°C. After the temperature stabilized, dibutyltin dilaurate was added and the reaction was stirred for 3 hours. After the reaction was completed, the reaction product was cooled to room temperature and vacuum distilled to remove the butanone solvent. The remaining product was washed three times with ethyl acetate and then dried in a vacuum drying oven at 80°C for 10 hours to obtain a second modified silicone elastomer. B3. Add the second modified silicone elastomer and modified nano-titanium dioxide into the reactor, add xylene, raise the temperature to 50°C, and stir to react for 2 hours; after the reaction is completed, stop heating and stirring, and distill the reaction product under reduced pressure to remove the xylene solvent. Wash the remaining product with cyclohexane three times, and then place it in a vacuum drying oven at 90°C for 12 hours to obtain the final modified silicone elastomer.

8. The organosilicon-modified wood paint according to claim 7, characterized in that: The mass ratio of polydimethylsiloxane-polycaprolactone block copolymer, vinyltrimethoxysilane, toluene, and benzoyl peroxide in B1 is 1:0.2:5:0.01; the stirring speed of the reactor is 400 r / min, and the reaction product is subjected to reduced pressure distillation to remove the toluene solvent at 4 kPa and 80°C, and washed with petroleum ether three times; The mass ratio of the first modified elastomer, bio-based polyol, butanone, and dibutyltin laurate in B2 is 1:1:8:0.02; the stirring speed of the reactor is 500 r / min, and the vacuum distillation conditions for removing the butanone solvent from the reaction product are 4 kPa and 60° C. The mass ratio of the second modified elastomer, nano-titanium dioxide and xylene in B3 is 1:0.5:3.5; the stirring speed of the reactor is 600 r / min; and the reduced pressure distillation conditions for removing the xylene solvent from the reaction product are 3 kPa and 80°C.

9. A method for preparing a silicone-modified wood paint, characterized in that: The preparation method is used to prepare the organosilicon-modified wood paint according to any one of claims 1 to 8, and the preparation method comprises the following steps: S1. Add hydroxyl-terminated polydimethylsiloxane, methyltrimethoxysilane, and bio-based polyol into a reactor and stir at 300-400 r / min for 10-15 minutes to form a uniform base material; S2. Add isophorone diisocyanate and dibutyltin dilaurate, raise the temperature to 50-60°C, and continue stirring at the same speed for 20-30 minutes; S3. Add modified nano-titanium dioxide, polyvinylidene fluoride, and polyacrylate ammonium salt in sequence, increase the stirring speed to 500-600 r / min, and disperse for 30-40 minutes; S4. Add modified silicone elastomer, polyether modified polysiloxane and alcohol ester-12, reduce the speed to 300r / min and stir for 15-20min. At the same time, slowly add deionized water to adjust the viscosity to 4 cups of viscosity and adjust it to the construction requirement in 15-25s. S5. Filter through a 100-200 mesh filter to remove impurities, place the coating in a sealed container, and age at 25°C for 24-48 hours to eliminate bubbles and stabilize the system.

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