Highly water-resistant polyacrylate emulsion and method for its preparation and use

Abstract

The application provides a high water-resistant polyacrylate emulsion and a preparation and application method thereof. The high water-resistant polyacrylate emulsion comprises a water-based silicone modified polyacrylate dispersion and a curing agent; wherein the water-based silicone modified polyacrylate dispersion is polymerized from raw materials such as mixed monomers, vinyltrimethoxysilane modified silica composite, triethylamine, azobisisobutyronitrile, mixed solvent and deionized water. The high water-resistant polyacrylate emulsion has stable quality and simple preparation process; the adhesive film prepared from the polyacrylate emulsion has excellent mechanical properties, good weather resistance and high water resistance; the coating prepared from the polyacrylate emulsion has high water resistance and stain resistance, and also has good wear resistance and alkali resistance.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a highly water-resistant polyacrylate emulsion and its preparation and application methods. Background Technology

[0002] With the advancement of technology, people have higher expectations for intelligent, simplified, and high-quality living scenarios. Self-cleaning surfaces are more likely to be favored by the public because they are easy to maintain. Furthermore, as public awareness of environmental protection gradually increases, research on water-based stain-resistant coatings is urgently needed.

[0003] In existing technologies, waterborne polyurethane and silicone materials are commonly used as the main components of waterborne stain-resistant coatings. However, the main chain of waterborne polyurethane is composed of highly polar urethane groups, resulting in poor water resistance and making it difficult to remove waterborne stains when used as a stain-resistant coating. Waterborne polyacrylate molecules, on the other hand, have a stronger stain resistance than waterborne polyurethane due to their C / C bonds forming the main chain. They also possess excellent film-forming properties, excellent flexibility, weather resistance, and strong molecular designability, making them more suitable for waterborne stain-resistant coatings. However, they also suffer from poor water resistance, limiting their application range and applications. Silicone materials have extremely low surface tension and hydrophobic and oleophobic properties, which can improve the material's excellent low adhesion and stain resistance, but their mechanical strength and adhesion are poor. Therefore, modifying waterborne polyacrylate with silicone materials can overcome the shortcomings of both materials, thereby obtaining a waterborne stain-resistant coating with excellent overall performance. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of existing technologies, the present invention aims to provide a highly water-resistant polyacrylate emulsion and its preparation and application methods. This method for preparing the highly water-resistant polyacrylate emulsion is simple, easy to control, and suitable for industrial mass production. The resulting highly water-resistant polyacrylate emulsion exhibits stable quality, and the film prepared from it possesses excellent mechanical properties, as well as good weather resistance and high water resistance. The coating prepared from the highly water-resistant polyacrylate emulsion exhibits high water resistance and stain resistance, as well as good abrasion resistance and alkali resistance, demonstrating strong practicality and superior overall performance.

[0005] The objective of this invention is achieved through the following technical solution: a highly water-resistant polyacrylate emulsion, comprising an aqueous organosilicon-modified polyacrylate dispersion and a curing agent; the aqueous organosilicon-modified polyacrylate dispersion comprises the following raw materials in parts by weight: 50-60 parts of mixed monomers, 25-35 parts of vinyltrimethoxysilane-modified silica composite, 8-12 parts of triethylamine, 0.2-0.7 parts of azobisisobutyronitrile, 25-35 parts of mixed solvent, and 180-220 parts of deionized water.

[0006] Furthermore, the mixed monomer comprises the following raw materials in parts by weight: 2-6 parts pentaerythritol tetraacrylate, 2-6 parts styrene, 8-12 parts butyl acrylate, 2-7 parts acrylic acid, 2-3 parts hydroxyethyl methacrylate, 20-30 parts acrylate-terminated organosilicon monomer, and 0.4-0.8 parts n-dodecyl mercaptan.

[0007] This invention reduces the porosity of the paint film by adding a vinyltrimethoxysilane-modified silica composite, thereby lowering the diffusion rate of water molecules through inorganic phase filling. Furthermore, the silane groups can combine with organosilicon monomers and polyacrylate chains, further optimizing water resistance and mechanical properties. The clever arrangement of mixed monomers further enhances water resistance and stain resistance. Specifically, the acrylate-terminated organosilicon monomers form a low surface energy layer on the paint film surface, hindering water molecule penetration. Adjusting the ratio between the hard monomer styrene and the soft monomer butyl acrylate, and adding a small amount of pentaerythritol tetraacrylate, maintains basic crosslinking while ensuring flexibility, avoiding poor abrasion resistance caused by an overly soft paint film. This balances the hardness and brittleness of the paint film, further improving water resistance and stain resistance.

[0008] Furthermore, the mixed solvent is composed of propylene glycol methyl ether acetate, tetrahydrofuran, and butanone in a volume ratio of 8-12:5-8:3-5.

[0009] Furthermore, the preparation method of the vinyltrimethoxysilane-modified silica composite includes the following steps:

[0010] A1. Add nano-silica particles to anhydrous ethanol and ultrasonically disperse for 40-60 minutes to form a stable suspension. Then add silica sol and mix evenly to obtain a silica composite.

[0011] A2. Dissolve vinyltrimethoxysilane in anhydrous ethanol, then slowly add deionized water to obtain vinyltrimethoxysilane hydrolysate;

[0012] A3. Under nitrogen protection, the vinyltrimethoxysilane hydrolysate is added dropwise to the silica complex, and the mixture is magnetically stirred until homogeneous. The reaction is carried out at 50-70℃ for 2-3 hours.

[0013] A4. After the reaction is complete, the solvent is removed by rotary evaporation to obtain a vinyltrimethoxysilane-modified silica composite.

[0014] Furthermore, in step A1, the nano-silica particles are hydrophilic nano-silica particles with a particle size of 5-9 nm, a mass ratio of nano-silica particles to silica sol of 3-5:1, and a mass fraction of nano-silica particles in the suspension of 3-8%.

[0015] Furthermore, in step A2, the amount of vinyltrimethoxysilane added is 3-15% of the total mass of the nano-silica particles and silica sol, the volume ratio of vinyltrimethoxysilane to anhydrous ethanol is 1:3-5, and the amount of deionized water added is 1-2 times the molar amount of vinyltrimethoxysilane.

[0016] Furthermore, in step A4, the rotary evaporation treatment temperature is 40-50℃ and the pressure is 0.06-0.09MPa.

[0017] The present invention also provides a method for preparing the aforementioned high water-resistant polyacrylate emulsion, comprising the following steps:

[0018] B1. Under nitrogen protection, add the mixed solvent to the reaction vessel, heat to 75-85℃ and reflux for 10-20 minutes to remove air from the device, then start adding azobisisobutyronitrile and mixed monomers dropwise. The addition is completed within 2-4 hours, and then the temperature is maintained for 4-6 hours to obtain the mixed solution.

[0019] B2. After cooling the mixed solution to room temperature, add triethylamine and stir for 0.8-1.2 h to neutralize and form salt. Add deionized water and emulsify by high-speed stirring. Then remove the solvent by rotary evaporation to obtain an aqueous organosilicon-modified polyacrylate dispersion.

[0020] B3. After adding the curing agent to the water-based silicone-modified polyacrylate dispersion and stirring at room temperature for 25-35 minutes, a highly water-resistant polyacrylate emulsion is obtained.

[0021] Furthermore, in step B2, the rotary evaporation treatment temperature is 50-60℃ and the pressure is 0.08-0.12MPa.

[0022] Furthermore, in step B3, the curing agent is a blend of aziridine crosslinking agent and isocyanate curing agent, wherein the amount of aziridine crosslinking agent added is 1.8-2.2 wt% of the mixed solution obtained in step B1, and the molar ratio of NCO- in the isocyanate curing agent to -OH in the mixed solution is 0.8-1.4:1.

[0023] The present invention also provides a method for applying the aforementioned high water-resistant polyacrylate emulsion, comprising the following steps:

[0024] S1. Pour the high water-resistant polyacrylate emulsion into a glass mold and dry it at 25-35℃ for 1-3 days to obtain a film.

[0025] S2. After heating the film obtained in step S1 at 75-85℃ for 25-35 minutes, the temperature is further increased to 120-160℃ and heated for 25-35 minutes to obtain an organosilicon-modified polyacrylate film.

[0026] This invention also provides another method for applying the aforementioned high water-resistant polyacrylate emulsion, comprising the following steps:

[0027] F1. Take a carrier, coat the polyurethane dispersion onto the surface of the carrier, and dry it at 25-35℃ for 3-5 hours to form a polyurethane dispersion base coating.

[0028] F2. Apply the high water-resistant polyacrylate emulsion to the surface of the polyurethane dispersion primer and dry it at 25-35℃ for 5-7 hours. Then, raise the temperature to 75-85℃ and hold for 25-35 minutes. Next, raise the temperature to 120-160℃ and heat for 25-35 minutes to obtain the silicone-modified polyacrylate coating.

[0029] The beneficial effects of this invention are as follows:

[0030] In this invention, the high water-resistant polyacrylate emulsion reduces the internal porosity of the paint film by adding a vinyltrimethoxysilane-modified silica composite, thereby lowering the diffusion rate of water molecules through inorganic phase filling. Furthermore, the silane groups can combine with organosilicon monomers and polyacrylate chains, further optimizing water resistance and mechanical properties. The clever arrangement of mixed monomers further enhances water resistance and stain resistance. Specifically, the acrylate-terminated organosilicon monomers form a low surface energy layer on the paint film surface, hindering water molecule penetration. Adjusting the ratio between the hard monomer styrene and the soft monomer butyl acrylate, and adding a small amount of pentaerythritol tetraacrylate, maintains basic crosslinking while ensuring flexibility, avoiding poor abrasion resistance caused by an overly soft paint film. This balances the hardness and brittleness of the paint film while further improving water resistance and stain resistance.

[0031] The preparation method of the high water-resistant polyacrylate emulsion in this invention is simple, easy to operate and control, and conducive to large-scale industrial production. The obtained high water-resistant polyacrylate emulsion has stable quality and can be widely used in the treatment of fabrics, paper and kraft paper to further improve the water resistance and stain resistance of the products.

[0032] The high water-resistant polyacrylate emulsion of this invention has multiple application methods and can be used to make films and coatings, with a wide range of applications. Films made from the high water-resistant polyacrylate emulsion exhibit excellent mechanical properties, as well as good weather resistance and high water resistance. Coatings made from the high water-resistant polyacrylate emulsion exhibit high water resistance and stain resistance, as well as good abrasion resistance and alkali resistance. Detailed Implementation

[0033] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0034] Example 1

[0035] In this embodiment, a highly water-resistant polyacrylate emulsion includes an aqueous organosilicon-modified polyacrylate dispersion and a curing agent; the aqueous organosilicon-modified polyacrylate dispersion includes the following raw materials in parts by weight: 50 parts of mixed monomers, 25 parts of vinyltrimethoxysilane-modified silica composite, 8 parts of triethylamine, 0.2 parts of azobisisobutyronitrile, 25 parts of mixed solvent and 180 parts of deionized water.

[0036] Furthermore, the mixed monomer comprises the following raw materials in parts by weight: 4 parts pentaerythritol tetraacrylate, 5 parts styrene, 10 parts butyl acrylate, 5 parts acrylic acid, 2.5 parts hydroxyethyl methacrylate, 25 parts acrylate-terminated organosilicon monomer, and 0.55 parts n-dodecyl mercaptan.

[0037] In this embodiment, the acrylate-terminated organosilicon monomer has a relative molecular mass of 6000 and is selected from Guangzhou Sloco Polymer Co., Ltd., with model number 3821F42.

[0038] Furthermore, the mixed solvent is composed of propylene glycol methyl ether acetate, tetrahydrofuran, and butanone in a volume ratio of 10:6:4.

[0039] Furthermore, the preparation method of the vinyltrimethoxysilane-modified silica composite includes the following steps:

[0040] A1. Add nano-silica particles to anhydrous ethanol and ultrasonically disperse for 40-60 minutes to form a stable suspension. Then add silica sol and mix evenly to obtain a silica composite.

[0041] A2. Dissolve vinyltrimethoxysilane in anhydrous ethanol, then slowly add deionized water to obtain vinyltrimethoxysilane hydrolysate;

[0042] A3. Under nitrogen protection, the vinyltrimethoxysilane hydrolysate is added dropwise to the silica complex, and the mixture is magnetically stirred until homogeneous. The reaction is carried out at 50-70℃ for 2-3 hours.

[0043] A4. After the reaction is complete, the solvent is removed by rotary evaporation to obtain a vinyltrimethoxysilane-modified silica composite.

[0044] Furthermore, in step A1, the nano-silica particles are hydrophilic nano-silica particles with a particle size of 7 nm, the mass ratio of the nano-silica particles to the silica sol is 4:1, and the mass fraction of the nano-silica particles in the suspension is 6%.

[0045] Furthermore, in step A4, the rotary evaporation treatment temperature is 45°C and the pressure is 0.08 MPa.

[0046] In this embodiment, the silica sol is selected from Shanghai Haiyi Science & Trade Co., Ltd., and the model is LEVASILWV33.

[0047] Furthermore, in step A2, the amount of vinyltrimethoxysilane added is 9% of the total mass of the nano-silica particles and silica sol, the volume ratio of vinyltrimethoxysilane to anhydrous ethanol is 1:4, and the amount of deionized water added is 1.5 times the molar amount of vinyltrimethoxysilane.

[0048] This embodiment also provides a method for preparing the high water-resistant polyacrylate emulsion, comprising the following steps:

[0049] B1. Under nitrogen protection, add the mixed solvent to the reaction vessel, heat to 80°C and reflux for 15 minutes to remove air from the device, then start adding azobisisobutyronitrile and mixed monomers dropwise. The addition is completed within 3 hours, and the mixture is kept at the temperature for another 5 hours to obtain the mixed solution.

[0050] B2. After cooling the mixed solution to room temperature, add triethylamine and stir for 1 h to neutralize and form a salt. Add deionized water and emulsify by high-speed stirring. Then remove the solvent by rotary evaporation to obtain an aqueous organosilicon modified polyacrylate dispersion.

[0051] B3. After adding the curing agent to the water-based silicone-modified polyacrylate dispersion and stirring at room temperature for 30 minutes, a highly water-resistant polyacrylate emulsion is obtained.

[0052] Furthermore, in step B2, the rotary evaporation treatment temperature is 55°C and the pressure is 0.1 MPa.

[0053] Furthermore, in step B3, the curing agent is a blend of aziridine crosslinking agent and isocyanate curing agent, wherein the amount of aziridine crosslinking agent added is 2 wt% of the mixed solution obtained in step B1, and the molar ratio of NCO- in the isocyanate curing agent to -OH in the mixed solution is 1.2:1.

[0054] In this embodiment, the aziridine crosslinking agent is selected from Stahl GmbH, Netherlands, model XL706. The isocyanate curing agent is selected from Asahi Kasei Fine Chemicals Co., Ltd., model WS20-70D, a water-dispersible blocked isocyanate curing agent.

[0055] This embodiment also provides a method for applying the aforementioned high water-resistant polyacrylate emulsion, comprising the following steps:

[0056] S1. Pour the high water-resistant polyacrylate emulsion into a glass mold and dry it at 30°C for 2 days to obtain a film.

[0057] S2. The film obtained in step S1 is heated at 80°C for 30 minutes, and then heated to 140°C for 30 minutes to obtain an organosilicon-modified polyacrylate film.

[0058] This embodiment also provides another method for applying the aforementioned high water-resistant polyacrylate emulsion, including the following steps:

[0059] F1. Take a carrier, coat the polyurethane dispersion onto the surface of the carrier, and dry it at 25-35℃ for 3-5 hours to form a polyurethane dispersion base coating.

[0060] F2. The high water-resistant polyacrylate emulsion was drop-coated onto the surface of the polyurethane dispersion primer and dried at 30°C for 6 hours. Then, the temperature was raised to 80°C and held for 30 minutes. Finally, the temperature was raised to 140°C and heated for 30 minutes to obtain the silicone-modified polyacrylate coating.

[0061] In this embodiment, in step F1, the polyurethane dispersion is selected from Stahl GmbH, Netherlands, and is model PU406.

[0062] Example 2

[0063] In this embodiment, the high water-resistant polyacrylate emulsion includes an aqueous organosilicon-modified polyacrylate dispersion and a curing agent; the aqueous organosilicon-modified polyacrylate dispersion includes the following raw materials in parts by weight: 55 parts of mixed monomers, 30 parts of vinyltrimethoxysilane-modified silica composite, 10 parts of triethylamine, 0.5 parts of azobisisobutyronitrile, 30 parts of mixed solvent and 200 parts of deionized water.

[0064] Furthermore, the mixed monomer comprises the following raw materials in parts by weight: 4 parts pentaerythritol tetraacrylate, 5 parts styrene, 10 parts butyl acrylate, 5 parts acrylic acid, 2.5 parts hydroxyethyl methacrylate, 25 parts acrylate-terminated organosilicon monomer, and 0.55 parts n-dodecyl mercaptan.

[0065] This embodiment also provides a method for preparing the high water-resistant polyacrylate emulsion, comprising the following steps:

[0066] B1. Under nitrogen protection, add the mixed solvent to the reaction vessel, heat to 80°C and reflux for 15 minutes to remove air from the device, then start adding azobisisobutyronitrile and mixed monomers dropwise. The addition is completed within 3 hours, and the mixture is kept at the temperature for another 5 hours to obtain the mixed solution.

[0067] B2. After cooling the mixed solution to room temperature, add triethylamine and stir for 1 h to neutralize and form a salt. Add deionized water and emulsify by high-speed stirring. Then remove the solvent by rotary evaporation to obtain an aqueous organosilicon modified polyacrylate dispersion.

[0068] B3. After adding the curing agent to the water-based silicone-modified polyacrylate dispersion and stirring at room temperature for 30 minutes, a highly water-resistant polyacrylate emulsion is obtained.

[0069] This embodiment also provides a method for applying the aforementioned high water-resistant polyacrylate emulsion, comprising the following steps:

[0070] S1. Pour the high water-resistant polyacrylate emulsion into a glass mold and dry it at 30°C for 2 days to obtain a film.

[0071] S2. The film obtained in step S1 is heated at 80°C for 30 minutes, and then heated to 140°C for 30 minutes to obtain an organosilicon-modified polyacrylate film.

[0072] This embodiment also provides another method for applying the aforementioned high water-resistant polyacrylate emulsion, including the following steps:

[0073] F1. Take a carrier, coat the polyurethane dispersion onto the surface of the carrier, and dry it at 25-35℃ for 3-5 hours to form a polyurethane dispersion base coating.

[0074] F2. The high water-resistant polyacrylate emulsion was drop-coated onto the surface of the polyurethane dispersion primer and dried at 30°C for 6 hours. Then, the temperature was raised to 80°C and held for 30 minutes. Finally, the temperature was raised to 140°C and heated for 30 minutes to obtain the silicone-modified polyacrylate coating.

[0075] The rest of this embodiment is the same as that in Embodiment 1.

[0076] Example 3

[0077] In this embodiment, the high water-resistant polyacrylate emulsion includes an aqueous organosilicon-modified polyacrylate dispersion and a curing agent; the aqueous organosilicon-modified polyacrylate dispersion includes the following raw materials in parts by weight: 60 parts of mixed monomers, 35 parts of vinyltrimethoxysilane-modified silica composite, 12 parts of triethylamine, 0.7 parts of azobisisobutyronitrile, 35 parts of mixed solvent and 220 parts of deionized water.

[0078] Furthermore, the mixed monomer comprises the following raw materials in parts by weight: 4 parts pentaerythritol tetraacrylate, 5 parts styrene, 10 parts butyl acrylate, 5 parts acrylic acid, 2.5 parts hydroxyethyl methacrylate, 25 parts acrylate-terminated organosilicon monomer, and 0.55 parts n-dodecyl mercaptan.

[0079] This embodiment also provides a method for preparing the high water-resistant polyacrylate emulsion, comprising the following steps:

[0080] B1. Under nitrogen protection, add the mixed solvent to the reaction vessel, heat to 80°C and reflux for 15 minutes to remove air from the device, then start adding azobisisobutyronitrile and mixed monomers dropwise. The addition is completed within 3 hours, and the mixture is kept at the temperature for another 5 hours to obtain the mixed solution.

[0081] B2. After cooling the mixed solution to room temperature, add triethylamine and stir for 1 h to neutralize and form a salt. Add deionized water and emulsify by high-speed stirring. Then remove the solvent by rotary evaporation to obtain an aqueous organosilicon modified polyacrylate dispersion.

[0082] B3. After adding the curing agent to the water-based silicone-modified polyacrylate dispersion and stirring at room temperature for 30 minutes, a highly water-resistant polyacrylate emulsion is obtained.

[0083] This embodiment also provides a method for applying the aforementioned high water-resistant polyacrylate emulsion, comprising the following steps:

[0084] S1. Pour the high water-resistant polyacrylate emulsion into a glass mold and dry it at 30°C for 2 days to obtain a film.

[0085] S2. The film obtained in step S1 is heated at 80°C for 30 minutes, and then heated to 140°C for 30 minutes to obtain an organosilicon-modified polyacrylate film.

[0086] This embodiment also provides another method for applying the aforementioned high water-resistant polyacrylate emulsion, including the following steps:

[0087] F1. Take a carrier, coat the polyurethane dispersion onto the surface of the carrier, and dry it at 25-35℃ for 3-5 hours to form a polyurethane dispersion base coating.

[0088] F2. The high water-resistant polyacrylate emulsion was drop-coated onto the surface of the polyurethane dispersion primer and dried at 30°C for 6 hours. Then, the temperature was raised to 80°C and held for 30 minutes. Finally, the temperature was raised to 140°C and heated for 30 minutes to obtain the silicone-modified polyacrylate coating.

[0089] The rest of this embodiment is the same as that in Embodiment 1.

[0090] Comparative Example 1

[0091] The difference between this comparative example and Example 2 is that an equal amount of the hard monomer methyl methacrylate is used instead of pentaerythritol tetraacrylate.

[0092] The rest of this embodiment is the same as that in Embodiment 2.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 2 is that an equal amount of silica composite was used to replace the vinyltrimethoxysilane-modified silica composite, meaning that the silica composite was not modified.

[0095] In this comparative example, the high water-resistant polyacrylate emulsion comprises an aqueous organosilicon-modified polyacrylate dispersion and a curing agent; the aqueous organosilicon-modified polyacrylate dispersion comprises the following raw materials in parts by weight: 55 parts of mixed monomers, 30 parts of silica complex, 10 parts of triethylamine, 0.5 parts of azobisisobutyronitrile, 30 parts of mixed solvent and 200 parts of deionized water.

[0096] Furthermore, the preparation method of the silica composite includes the following steps: adding nano-silica particles to anhydrous ethanol, ultrasonically dispersing for 50 min to form a stable suspension, then adding silica sol and mixing evenly, and removing the solvent by rotary evaporation to obtain the silica composite.

[0097] Furthermore, the nano-silica particles are hydrophilic nano-silica particles with a particle size of 7 nm, the mass ratio of nano-silica particles to silica sol is 4:1, and the mass fraction of nano-silica particles in the suspension is 6%.

[0098] Furthermore, the rotary evaporation treatment temperature is 45°C and the pressure is 0.08 MPa.

[0099] The rest of this embodiment is the same as that in Embodiment 2.

[0100] Comparative Example 3

[0101] The difference between this comparative example and Example 2 is that an equal amount of nano-silica particles are used instead of silica sol.

[0102] The rest of this embodiment is the same as that in Embodiment 2.

[0103] Performance testing

[0104] First, the silicone-modified polyacrylate films prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, including tensile properties, hot air aging resistance, and water absorption. The results are shown in Table 1 below:

[0105] Table 1

[0106] project Tensile strength (MPa) Hot air aging resistance (MPa) Water absorption rate (%) Example 1 3.07 3.03 11.5 Example 2 3.12 3.09 10.4 Example 3 3.15 3.12 9.5 Comparative Example 1 3.01 2.96 11.9 Comparative Example 2 2.87 2.83 13.2 Comparative Example 3 2.92 2.86 12.8

[0107] Tensile strength test: WDT-W type electronic universal testing machine was used, referring to GB / T 1040.1-2025, with a tensile rate of 100 mm / min;

[0108] Hot air aging resistance test: The silicone-modified polyacrylate film was tested according to the national standard GB / T 528-2009. The silicone-modified polyacrylate film was cut into dumbbell strips, aged by hot air at 150℃ for 3 days, and then removed to test its tensile strength.

[0109] Water absorption test: The water resistance of silicone-modified polyacrylate films was determined according to GB / T 1733-1993. The film sample (m0) was immersed in deionized water. After a period of time, the sample was removed, the surface moisture was wiped dry, and the sample (m1) was weighed. The formula for calculating water absorption (W) is:

[0110]

[0111] The silicone-modified polyacrylate coatings prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, including static water contact angle, stain resistance, abrasion resistance, and alkali resistance. The results are shown in Table 2 below.

[0112] Table 2

[0113] project Static water contact angle Stain resistance abrasion resistance Alkali resistance Example 1 107° excellent Okay, the surface is basically free of scratches. Okay, basically no change. Example 2 108.6° excellent Okay, the surface is basically free of scratches. Okay, basically no change. Example 3 110.8° excellent Okay, the surface is basically free of scratches. Okay, basically no change. Comparative Example 1 106.5° good Good, surface scratches are not obvious. Poor quality, sticky surface Comparative Example 2 96.4° middle Poor, with many surface scratches. Poor quality, noticeably sticky, and some coating has peeled off. Comparative Example 3 97.8° good Generally, there are few surface scratches. Poor, sticky surface

[0114] Static water contact angle test: The static water contact angle of the coating was tested using an optical contact angle meter. The water droplet volume was 3 μL, and the average value was obtained from five locations.

[0115] Stain Resistance Test: An oil-based marker was used to leave a stain on the coating surface. After 1 hour, the stain was wiped off with a dry paper towel, and the residue on the coating surface was observed. (Stain resistance evaluation criteria: Excellent - The oil-based marker stain on the coating surface can be completely wiped clean without leaving a stain; Good - A small amount of stain (<5% of the area contaminated by the oil-based marker stain) remains on the coating surface after wiping with a paper towel; Medium - A relatively large amount of stain (<20% of the area contaminated by the oil-based marker stain) remains on the coating surface after wiping with a paper towel.)

[0116] Abrasion resistance test: Place the coating surface on 800CW metallographic sandpaper, apply a pressure of 200g weight from above, drag the coating 10cm and observe the wear of the coating surface;

[0117] Alkali resistance test: The coating surface was wiped 50 times with a 200g weight wrapped in a non-woven fabric soaked in a 40% sodium hydroxide aqueous solution, and the changes on the coating surface were observed.

[0118] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A highly water-resistant polyacrylate emulsion, characterized in that, The product includes an aqueous silicone-modified polyacrylate dispersion and a curing agent; the aqueous silicone-modified polyacrylate dispersion comprises the following raw materials in parts by weight: 50-60 parts of mixed monomers, 25-35 parts of vinyltrimethoxysilane-modified silica composite, 8-12 parts of triethylamine, 0.2-0.7 parts of azobisisobutyronitrile, 25-35 parts of mixed solvent, and 180-220 parts of deionized water; The mixed monomers comprise the following raw materials in parts by weight: 2-6 parts pentaerythritol tetraacrylate, 2-6 parts styrene, 8-12 parts butyl acrylate, 2-7 parts acrylic acid, 2-3 parts hydroxyethyl methacrylate, 20-30 parts acrylate-terminated organosilicon monomers, and 0.4-0.8 parts n-dodecyl mercaptan. The preparation method of the vinyltrimethoxysilane-modified silica composite includes the following steps: A1. Add nano-silica particles to anhydrous ethanol, ultrasonically disperse for 40-60 minutes to form a stable suspension, then add silica sol and mix evenly to obtain a silica composite. A2. Dissolve vinyltrimethoxysilane in anhydrous ethanol, then slowly add deionized water to obtain vinyltrimethoxysilane hydrolysate; A3. Under nitrogen protection, the vinyltrimethoxysilane hydrolysate is added dropwise to the silica complex, and the mixture is magnetically stirred until homogeneous. The reaction is carried out at 50-70℃ for 2-3 hours. A4. After the reaction is complete, the solvent is removed by rotary evaporation to obtain the vinyltrimethoxysilane modified silica composite. In step A1, the mass ratio of the nano-silica particles to the silica sol is 3-5:1; In step A2, the amount of vinyltrimethoxysilane added is 3-15% of the total mass of the nano-silica particles and silica sol.

2. The highly water-resistant polyacrylate emulsion according to claim 1, characterized in that, The mixed solvent is composed of propylene glycol methyl ether acetate, tetrahydrofuran, and butanone in a volume ratio of 8-12:5-8:3-5.

3. A method for preparing a highly water-resistant polyacrylate emulsion according to any one of claims 1-2, characterized in that, Includes the following steps: B1. Under nitrogen protection, add the mixed solvent to the reaction vessel, heat to 75-85℃ and reflux for 10-20 minutes to remove air from the device, then simultaneously start adding azobisisobutyronitrile and the mixed monomers dropwise. The addition is completed within 2-4 hours, and then the temperature is maintained for 4-6 hours to obtain the mixed solution. B2. After cooling the mixed solution to room temperature, add triethylamine and stir for 0.8-1.2 h to neutralize and form salt. Add deionized water and emulsify by high-speed stirring. Then remove the solvent by rotary evaporation to obtain an aqueous organosilicon-modified polyacrylate dispersion. B3. After adding the curing agent to the water-based silicone-modified polyacrylate dispersion and stirring at room temperature for 25-35 minutes, a highly water-resistant polyacrylate emulsion is obtained.

4. The method for preparing a highly water-resistant polyacrylate emulsion according to claim 3, characterized in that, In step B3, the curing agent is a blend of aziridine crosslinking agent and isocyanate curing agent, wherein the amount of aziridine crosslinking agent added is 1.8-2.2 wt% of the mixed solution obtained in step B1, and the molar ratio of NCO- in the isocyanate curing agent to -OH in the mixed solution is 0.8-1.4:

1.

5. The application method of the high water-resistant polyacrylate emulsion according to claim 1, characterized in that, Includes the following steps: S1. Pour the high water-resistant polyacrylate emulsion into a glass mold and dry it at 25-35℃ for 1-3 days to obtain the film. S2. After heating the film obtained in step S1 at 75-85℃ for 25-35 minutes, the temperature is further increased to 120-160℃ and heated for 25-35 minutes to obtain an organosilicon-modified polyacrylate film.

6. The application method of the high water-resistant polyacrylate emulsion according to claim 1, characterized in that, Includes the following steps: F1. Take a carrier, coat the polyurethane dispersion onto the surface of the carrier, and dry it at 25-35℃ for 3-5 hours to form a polyurethane dispersion base coating. F2. Apply the high water-resistant polyacrylate emulsion to the surface of the polyurethane dispersion primer and dry it at 25-35℃ for 5-7 hours. Then, raise the temperature to 75-85℃ and hold for 25-35 minutes. Next, raise the temperature to 120-160℃ and heat for 25-35 minutes to obtain the silicone-modified polyacrylate coating.

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