A super-hydrophobic acrylic resin coating and a method of making the same

Abstract

This invention discloses a superhydrophobic acrylic resin coating and its preparation method in the field of coating technology. The raw materials of the coating include: 40-70 parts of fluorosilicone modified core-shell acrylate copolymer emulsion, 3-10 parts of fluorosilicone modified nanoparticles, and the balance of additives. The raw materials of the fluorosilicone modified nanoparticles include fluorosilane, hydrophilic nanoparticles, and solvent. The method uses fluorosilicone modified core-shell acrylate copolymer emulsion, fluorosilicone modified nanoparticles, and additives to prepare the coating. By modifying the nanoparticles with fluorosilane, the nanoparticles can be uniformly compatible with the fluorosilane acrylate in the shell layer of the fluorosilicone modified core-shell acrylate copolymer emulsion, inhibiting the aggregation of nanoparticles. Through the formation of a multi-level micro-nano structure by the fluorosilane modified nanoparticles and the fluorosilicone modified core-shell acrylate copolymer emulsion, the hydrophobicity of the coating reaches the superhydrophobic level, and the coating also has self-cleaning properties.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a superhydrophobic acrylic resin coating and its preparation method. Background Technology

[0002] Acrylic resins have advantages such as good transparency, bright color, excellent adhesion, and good toughness, and are therefore often used in coating materials. However, acrylic resin coatings also have disadvantages such as poor water resistance and poor weather resistance. Therefore, in order to improve the water resistance and weather resistance of acrylic resins, those skilled in the art have proposed fluorosilicone-modified acrylic resins.

[0003] Fluorosilicone-modified acrylic resins are made by co-modifying acrylates with organofluorine and organosilicon. These resins combine the advantages of both organofluorine and organosilicon, effectively improving coating adhesion, reducing surface energy, and enhancing antistatic, water resistance, weather resistance, temperature resistance, and aging resistance. For example, CN104098735B discloses a fluorosilicone-modified core-shell structured acrylate copolymer finishing agent, its preparation method, and its application. In this technical solution, the fluorosilicone-acrylic resin significantly improves the water resistance and weather resistance of fiber fabrics. This invention uses the fluorosilicone-modified core-shell structured acrylate copolymer provided by this technical solution to prepare coatings. The water contact angle of the coating film after formation can reach 110°, demonstrating excellent hydrophobic properties.

[0004] While the coatings produced by the aforementioned technical solutions exhibit excellent hydrophobicity, moisture can still wet the coating, leading to mold growth and even failure or damage over prolonged use. Therefore, further improvements in the hydrophobicity of these coatings are needed. The existing technology, "Preparation of Self-Cleaning Nano-TiO2-SiO2 / Fluoroacrylate Core-Shell Emulsion," uses n-butyl acrylate, methyl methacrylate, and hydroxypropyl methacrylate as core monomers, and dodecyl fluoroheptyl methacrylate, BA, MMA, and HpA as shell monomers, with rutile-type titanium-silicon nanocomposite oxides as inorganic fillers to prepare a self-cleaning hydrophobic coating. This coating achieves a water contact angle of 135°. This technology indicates that the hydrophobicity of the coating is significantly improved after doping with nanoparticles; however, excessive nanoparticle doping can lead to aggregation, resulting in a decrease in the hydrophobic properties of the coating. This prevents the hydrophobicity of the coating produced by this technology from reaching the superhydrophobic level (contact angle ≥150°). When the hydrophobicity of the coating reaches superhydrophobicity, water droplets will form spheres on the coating surface and easily roll off the coating surface, further improving the waterproof, antifouling and anticorrosive properties. Therefore, the above technical solutions need to be further optimized to achieve superhydrophobic performance. Summary of the Invention

[0005] The purpose of this invention is to improve the hydrophobic properties of acrylic resin coatings.

[0006] The raw materials for this acrylic resin coating include fluorosilicone-modified core-shell structured acrylate copolymers, fluorosilicone-modified nanoparticles, and film-forming aids. This allows the coating to form a micro-nano structure after application, resulting in a coating with superhydrophobicity and self-cleaning properties.

[0007] This method adjusts the content of fluorine and silicon monomers in the fluorosilane-modified core-shell acrylic copolymer emulsion and uses film-forming aids to regulate the phase separation process between the resin and the fluorosilicone-modified nanoparticles. This allows the coating to autonomously construct micro- and nano-structures after curing. The fluorosilane-modified nanoparticles exhibit excellent fluorosilicone compatibility with the shell structure of the fluorosilicone-modified core-shell acrylic copolymer, which can improve the dispersibility of the fluorosilane-modified nanoparticles on the shell structure, enabling the micro- and nano-structures to reach a superhydrophobic level.

[0008] The specific technical solution of this invention is as follows: A superhydrophobic acrylic resin coating comprises, by weight: 40-70 parts of fluorosilicone modified core-shell acrylate copolymer emulsion, 3-10 parts of fluorosilicone modified nanoparticles, and the remainder of additives; the raw materials for the fluorosilicone modified nanoparticles include fluorosilanes, hydrophilic nanoparticles, and solvents, and the fluorine content in the coating is 0.5-2%.

[0009] Preferably, the additives include film-forming agents, film-forming aids, leveling agents, defoamers, and thickeners.

[0010] Preferably, the raw materials for the fluorosilicone modified core-shell acrylate copolymer emulsion include silane coupling agents, acrylic monomers, initiators, and water.

[0011] Preferably, the hydrophilic nanoparticles are one or more of hydrophilic nano-titanium dioxide, hydrophilic nano-zinc oxide, and hydrophilic nano-silica.

[0012] A method for preparing the above-mentioned superhydrophobic acrylic resin coating includes the following steps: (1) Preparation of fluorosilicone modified core-shell acrylate copolymer emulsion; (2) Disperse hydrophilic nanoparticles in a solvent and then add fluorosilane for reflux reaction to prepare fluorosilane nanoparticles; (3) Adding additives and fluorosilane nanoparticles to fluorosilicone modified core-shell acrylate copolymer emulsion to prepare superhydrophobic acrylic resin coating.

[0013] Toluene is preferred as the solvent.

[0014] Preferably, the reflux reaction conditions include: temperature 100~120 ℃ and time 10~14 h.

[0015] As a preferred method, the precipitate is separated by centrifugation after reflux reaction, and the precipitate is washed several times with anhydrous ethanol.

[0016] Preferably, the hydrophilic nanoparticles are dispersed by ultrasonic dispersion for a time of 20-40 min.

[0017] Preferably, the viscosity of the superhydrophobic acrylic resin coating is 90~100 KU.

[0018] This invention provides a superhydrophobic acrylic resin coating. The raw materials of the coating are fluorosilicone modified core-shell acrylic copolymer emulsion, fluorosilicone modified nanoparticles and additives. The coating formed by this coating has superhydrophobicity and self-cleaning properties.

[0019] Existing technologies indicate that coatings made with nanoparticle-doped core-shell acrylate copolymer emulsions exhibit significantly improved hydrophobicity compared to coatings made with core-shell acrylate copolymer emulsions, achieving a water contact angle of 135°. However, these technologies also point out that the nanoparticle doping amount can only reach 0.3 wt%, as excessive amounts lead to agglomeration and a decrease in the coating's hydrophobicity. This limits the hydrophobic properties of nanoparticles in core-shell acrylate copolymer emulsion coatings. This invention further optimizes the aforementioned technical solution by modifying nanoparticles with fluorosilanes, grafting fluorosilanes onto the nanoparticle surface. When the fluorosilane-modified nanoparticles are mixed with the fluorosilane-modified core-shell acrylate copolymer emulsion, the fluorosilane-modified nanoparticles exhibit excellent compatibility with the fluorosilane acrylates in the shell layer of the core-shell acrylate copolymer emulsion. The nanoparticles can be uniformly dispersed on the shell layer of the core-shell acrylate copolymer emulsion, suppressing nanoparticle agglomeration and increasing the nanoparticle doping amount.

[0020] This invention also discovered that after introducing fluorosilanes into the coating, the low surface energy of fluorine causes the fluorine-containing fluorosilane chains to spontaneously aggregate towards the film-air interface during film formation, while the fluorine-free polymer segments aggregate towards the matrix surface, thus forming micro / nano structures on the coating surface. Fluorine-silicone modified nanoparticles are uniformly distributed on the surface of these micro / nano structures, further forming multi-level micro / nano structures, thereby achieving a breakthrough in the hydrophobicity of core-shell acrylate copolymer emulsion coatings to the superhydrophobic level. Furthermore, this invention found that the amount of fluorine introduced has a significant impact on the formed micro / nano structures. Insufficient fluorine leads to insufficient phase separation, hindering the effective formation of micro / nano structures, while excessive fluorine leads to excessive phase separation, damaging the emulsion stability.

[0021] Compared with the prior art, this application has the following technical effects: (1) A coating was prepared by using fluorosilicone modified core-shell acrylate copolymer emulsion, fluorosilicone modified nanoparticles and additives. The coating formed by the coating has superhydrophobicity and self-cleaning properties, and the water contact angle of the coating is ≥150°. (2) By modifying nanoparticles with fluorosilane, the nanoparticles can be uniformly compatible with the fluorosilane acrylate of the fluorosilane-modified core-shell acrylate copolymer emulsion shell, thereby inhibiting the aggregation of nanoparticles, increasing the doping amount of nanoparticles, and improving the hydrophobicity of the coating. (3) After introducing fluorine into the fluorosilane-modified nanoparticles and fluorosilicone-modified core-shell acrylate copolymer emulsion, the fluorine-containing fluorosilicone chains spontaneously aggregate to the film-air interface during the film formation process due to the low surface energy of fluorine. This causes the fluorosilicone acrylate and fluorosilicone-modified nanoparticles to self-assemble during the film formation process, ultimately forming a multi-level micro-nano structure, which makes the hydrophobicity of the coating reach the superhydrophobic level. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments.

[0023] To better understand the content of this invention, further explanation is provided below with reference to specific embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of this invention. Example 1:

[0024] A method for preparing a superhydrophobic acrylic resin coating includes the following steps: (1) Add 20 g of diethylene glycol dimethyl ether solvent to a three-necked flask equipped with a condenser and stir to 120°C. Add acrylate mixed monomer one (7 g acrylic acid, 24 g butyl acrylate, 32 g methyl methacrylate, 2.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) and initiator one (2 g azobisisobutyronitrile, 2 g peroxide (tert-butyl 2-ethylhexanoate)) dropwise, ensuring that the monomers are added within 2.5 h. After keeping warm for 1 h and cooling down, add ammonia water, then add water and stir evenly. Add 0.5 g emulsifier OP-10, then transfer to a 95°C water bath and stir for 5 min. Add one-third of initiator two (2 g ammonium sulfate, 2 g sodium bicarbonate and 70 g water). After the blue phase appears, add the remaining two-thirds of initiator two and acrylate mixed monomer two (1.2 g acrylic acid, 44 g butyl acrylate, 54 g methyl methacrylate, 5.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) dropwise. 2.8 g hydroxyethyl acrylate, 5 g dodecafluoroheptyl methacrylate, and 3 g vinyltrimethoxysilane) are added, ensuring that the addition is completed within 3.5 h. The second initiator must be added within 15 min after the monomer is added. Keep warm for 1 h. After cooling to room temperature, adjust the pH to neutral and filter to prepare a fluorosilicone modified core-shell acrylate copolymer emulsion. (2) Disperse 5 parts of hydrophilic nano zinc oxide in 50 parts of toluene by ultrasonication. After the dispersion is uniform, add 1 part of fluorosilane. Then place the raw material under reflux at 110 °C for 12 h. After the reaction is completed, centrifuge to separate the reaction product and collect the precipitate. Wash the precipitate 5 times with ethanol and dry it in an 80 °C drying oven to prepare fluorosilicone modified nano zinc oxide. (3) Add 8 parts of fluorosilicone modified nano zinc oxide, 5 parts of film-forming agent (styrene-acrylic emulsion), 0.5 parts of film-forming aid (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), 0.3 parts of defoamer (BYK-0163) and 0.2 parts of leveling agent (BYK-331) to 55 parts of fluorosilicone modified core-shell type acrylate copolymer emulsion and mix evenly. Then add 0.4 parts of thickener (hydroxyethyl cellulose) to adjust the viscosity to 90~100 KU and filter to prepare superhydrophobic acrylic resin coating. Example 2:

[0025] A method for preparing a superhydrophobic acrylic resin coating includes the following steps: (1) Add 20 g of diethylene glycol dimethyl ether solvent to a three-necked flask equipped with a condenser and stir to 120°C. Add acrylate mixed monomer one (7 g acrylic acid, 24 g butyl acrylate, 32 g methyl methacrylate, 2.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) and initiator one (2 g azobisisobutyronitrile, 2 g peroxide (tert-butyl 2-ethylhexanoate)) dropwise, ensuring that the monomers are added within 2.5 h. After keeping warm for 1 h and cooling down, add ammonia water, then add water and stir evenly. Add 0.5 g emulsifier OP-10, then transfer to a 95°C water bath and stir for 5 min. Add one-third of initiator two (2 g ammonium sulfate, 2 g sodium bicarbonate and 70 g water). After the blue phase appears, add the remaining two-thirds of initiator two and acrylate mixed monomer two (1.2 g acrylic acid, 44 g butyl acrylate, 54 g methyl methacrylate, 5.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) dropwise. (g hydroxyethyl acrylate, 2.8 g hydroxyethyl methacrylate, 5 g dodecafluoroheptyl methacrylate, 3 g vinyltrimethoxysilane), ensuring the addition is completed within 3.5 h. Initiator 2 must be added within 15 min after the monomer addition is completed. Keep warm for 1 h. After cooling to room temperature, adjust the pPH to neutral. Filter through a screen to prepare a fluorosilicone modified core-shell acrylate copolymer emulsion. (2) Disperse 5 parts of hydrophilic nano zinc oxide in 50 parts of toluene by ultrasonication. After the dispersion is uniform, add 1 part of fluorosilane. Then place the raw material under reflux at 110 °C for 12 h. After the reaction is completed, centrifuge to separate the reaction product and collect the precipitate. Wash the precipitate 5 times with ethanol and dry it in an 80 °C drying oven to prepare fluorosilicone modified nano zinc oxide. (3) Add 3 parts of fluorosilicone modified nano zinc oxide, 5 parts of film-forming agent (styrene-acrylic emulsion), 0.5 parts of film-forming aid (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), 0.3 parts of defoamer (BYK-0163) and 0.2 parts of leveling agent (BYK-331) to 55 parts of fluorosilicone modified core-shell type acrylate copolymer emulsion and mix evenly. Then add 0.4 parts of thickener (hydroxyethyl cellulose) to adjust the viscosity to 90~100 KU and filter to prepare superhydrophobic acrylic resin coating. Example 3:

[0026] A method for preparing a superhydrophobic acrylic resin coating includes the following steps: (1) Add 20 g of diethylene glycol dimethyl ether solvent to a three-necked flask equipped with a condenser and stir to 120°C. Add acrylate mixed monomer one (4 g acrylic acid, 24 g butyl acrylate, 28 g methyl methacrylate, 2.5 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) and initiator one (2 g azobisisobutyronitrile, 2 g peroxide (tert-butyl 2-ethylhexanoate)) dropwise, ensuring that the monomers are added within 2.5 h. After keeping warm for 1 h and cooling down, add ammonia water, then add water and stir evenly. Add 0.5 g emulsifier OP-10, then transfer to a 95°C water bath and stir for 5 min. Add one-third of initiator two (2 g ammonium sulfate, 2 g sodium bicarbonate and 70 g water). After the blue phase appears, add the remaining two-thirds of initiator two and acrylate mixed monomer two (1.2 g acrylic acid, 44 g butyl acrylate, 54 g methyl methacrylate, 5.6 g hydroxyethyl methacrylate, 2 g hydroxyethyl acrylate, 2 g hydroxyethyl meth ... (g hydroxyethyl acrylate, 2.8 g hydroxyethyl methacrylate, 5 g dodecafluoroheptyl methacrylate, 3 g vinyltrimethoxysilane), ensuring the addition is completed within 3.5 h. Initiator 2 must be added within 15 min after the monomer addition is completed. Keep warm for 1 h. After cooling to room temperature, adjust the pPH to neutral. Filter through a screen to prepare a fluorosilicone modified core-shell acrylate copolymer emulsion. (2) Disperse 5 parts of hydrophilic nano zinc oxide in 50 parts of toluene by ultrasonication. After the dispersion is uniform, add 1 part of fluorosilane. Then place the raw material under reflux at 110 °C for 12 h. After the reaction is completed, centrifuge to separate the reaction product and collect the precipitate. Wash the precipitate 5 times with ethanol and dry it in an 80 °C drying oven to prepare fluorosilicone modified nano zinc oxide. (3) Add 10 parts of fluorosilicone modified nano zinc oxide, 5 parts of film-forming agent (styrene-acrylic emulsion), 0.5 parts of film-forming aid (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), 0.3 parts of defoamer (BYK-0163) and 0.2 parts of leveling agent (BYK-331) to 55 parts of fluorosilicone modified core-shell acrylate copolymer emulsion and mix evenly. Then add 0.4 parts of thickener (hydroxyethyl cellulose) to adjust the viscosity to 90~100 KU and filter to prepare superhydrophobic acrylic resin coating. Example 4:

[0027] A method for preparing a superhydrophobic acrylic resin coating includes the following steps: (1) Add 20 g of diethylene glycol dimethyl ether solvent to a three-necked flask equipped with a condenser and stir to 120°C. Add acrylate mixed monomer one (8 g acrylic acid, 24 g butyl acrylate, 27 g methyl methacrylate, 3.2 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) and initiator one (2 g azobisisobutyronitrile, 2 g peroxide (tert-butyl 2-ethylhexanoate)) dropwise, ensuring that the monomers are added within 2.5 h. After keeping warm for 1 h and cooling down, add ammonia water, then add water and stir evenly. Add 0.5 g emulsifier OP-10, then transfer to a 95°C water bath and stir for 5 min. Add one-third of initiator two (2 g ammonium sulfate, 2 g sodium bicarbonate and 70 g water). After the blue phase appears, add the remaining two-thirds of initiator two and acrylate mixed monomer two (1.2 g acrylic acid, 44 g butyl acrylate, 54 g methyl methacrylate, 5.6 g hydroxyethyl methacrylate, 1.2 g hydroxyethyl methacrylate) dropwise. 2.8 g hydroxyethyl acrylate, 5 g dodecafluoroheptyl methacrylate, and 3 g vinyltrimethoxysilane) are added, ensuring that the addition is completed within 3.5 h. The second initiator must be added within 15 min after the monomer is added. Keep warm for 1 h. After cooling to room temperature, adjust the pH to neutral and filter to prepare a fluorosilicone modified core-shell acrylate copolymer emulsion. (2) Disperse 5 parts of hydrophilic nano zinc oxide in 50 parts of toluene by ultrasonication. After the dispersion is uniform, add 1 part of fluorosilane. Then place the raw material under reflux at 110 °C for 12 h. After the reaction is completed, centrifuge to separate the reaction product and collect the precipitate. Wash the precipitate 5 times with ethanol and dry it in an 80 °C drying oven to prepare fluorosilicone modified nano zinc oxide. (3) Add 8 parts of fluorosilicone modified nano zinc oxide, 5 parts of film-forming agent (styrene-acrylic emulsion), 0.5 parts of film-forming aid (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), 0.3 parts of defoamer (BYK-0163) and 0.2 parts of leveling agent (BYK-331) to 40 parts of fluorosilicone modified core-shell type acrylate copolymer emulsion and mix evenly. Then add 0.4 parts of thickener (hydroxyethyl cellulose) to adjust the viscosity to 90~100 KU and filter to prepare superhydrophobic acrylic resin coating. Example 5:

[0028] A method for preparing a superhydrophobic acrylic resin coating includes the following steps: (1) Add 20 g of diethylene glycol dimethyl ether solvent to a three-necked flask equipped with a condenser and stir to 120°C. Add acrylate mixed monomer one (7 g acrylic acid, 24 g butyl acrylate, 32 g methyl methacrylate, 2.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) and initiator one (2 g azobisisobutyronitrile, 2 g peroxide (tert-butyl 2-ethylhexanoate)) dropwise, ensuring that the monomers are added within 2.5 h. After keeping warm for 1 h and cooling down, add ammonia water, then add water and stir evenly. Add 0.5 g emulsifier OP-10, then transfer to a 95°C water bath and stir for 5 min. Add one-third of initiator two (2 g ammonium sulfate, 2 g sodium bicarbonate and 70 g water). After the blue phase appears, add the remaining two-thirds of initiator two and acrylate mixed monomer two (1.2 g acrylic acid, 44 g butyl acrylate, 54 g methyl methacrylate, 5.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) dropwise. (g hydroxyethyl acrylate, 2.8 g hydroxyethyl methacrylate, 5 g dodecafluoroheptyl methacrylate, 3 g vinyltrimethoxysilane), ensuring the addition is completed within 3.5 h. Initiator 2 must be added within 15 min after the monomer addition is completed. Keep warm for 1 h. After cooling to room temperature, adjust the pPH to neutral. Filter through a screen to prepare a fluorosilicone modified core-shell acrylate copolymer emulsion. (2) Disperse 5 parts of hydrophilic nano zinc oxide in 50 parts of toluene by ultrasonication. After the dispersion is uniform, add 1 part of fluorosilane. Then place the raw material under reflux at 110 °C for 12 h. After the reaction is completed, centrifuge to separate the reaction product and collect the precipitate. Wash the precipitate 5 times with ethanol and dry it in an 80 °C drying oven to prepare fluorosilicone modified nano zinc oxide. (3) Add 8 parts of fluorosilicone modified nano zinc oxide, 5 parts of film-forming agent (styrene-acrylic emulsion), 0.5 parts of film-forming aid (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), 0.3 parts of defoamer (BYK-0163) and 0.2 parts of leveling agent (BYK-331) to 70 parts of fluorosilicone modified core-shell acrylate copolymer emulsion and mix evenly. Then add 0.4 parts of thickener (hydroxyethyl cellulose) to adjust the viscosity to 90~100 KU and filter to prepare superhydrophobic acrylic resin coating.

[0029] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that no fluorosilicone modified nanoparticles were added, and the following steps were included: (1) Add 20 g of diethylene glycol dimethyl ether solvent to a three-necked flask equipped with a condenser and stir to 120°C. Add acrylate mixed monomer one (7 g acrylic acid, 24 g butyl acrylate, 32 g methyl methacrylate, 2.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) and initiator one (2 g azobisisobutyronitrile, 2 g peroxide (tert-butyl 2-ethylhexanoate)) dropwise, ensuring that the monomers are added within 2.5 h. After keeping warm for 1 h and cooling down, add ammonia water, then add water and stir evenly. Add 0.5 g emulsifier OP-10, then transfer to a 95°C water bath and stir for 5 min. Add one-third of initiator two (2 g ammonium sulfate, 2 g sodium bicarbonate and 70 g water). After the blue phase appears, add the remaining two-thirds of initiator two and acrylate mixed monomer two (1.2 g acrylic acid, 44 g butyl acrylate, 54 g methyl methacrylate, 5.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) dropwise. (g hydroxyethyl acrylate, 2.8 g hydroxyethyl methacrylate, 5 g dodecafluoroheptyl methacrylate, 3 g vinyltrimethoxysilane), ensuring the addition is completed within 3.5 h. Initiator 2 must be added within 15 min after the monomer addition is completed. Keep warm for 1 h. After cooling to room temperature, adjust the pPH to neutral. Filter through a screen to prepare a fluorosilicone modified core-shell acrylate copolymer emulsion. (2) Add 5 parts of film-forming agent (styrene-acrylic emulsion), 0.5 parts of film-forming aid (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), 0.3 parts of defoamer (BYK-0163) and 0.2 parts of leveling agent (BYK-331) to 55 parts of fluorosilicone modified core-shell acrylate copolymer emulsion and mix evenly. Then add 0.4 parts of thickener (hydroxyethyl cellulose) to adjust the viscosity to 90~100 KU and filter to prepare superhydrophobic acrylic resin coating.

[0030] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that the nanoparticles were not modified with fluorosilane, and the following steps were included: (1) Add 20 g of diethylene glycol dimethyl ether solvent to a three-necked flask equipped with a condenser and stir to 120°C. Add acrylate mixed monomer one (7 g acrylic acid, 24 g butyl acrylate, 32 g methyl methacrylate, 2.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) and initiator one (2 g azobisisobutyronitrile, 2 g peroxide (tert-butyl 2-ethylhexanoate)) dropwise, ensuring that the monomers are added within 2.5 h. After keeping warm for 1 h and cooling down, add ammonia water, then add water and stir evenly. Add 0.5 g emulsifier OP-10, then transfer to a 95°C water bath and stir for 5 min. Add one-third of initiator two (2 g ammonium sulfate, 2 g sodium bicarbonate and 70 g water). After the blue phase appears, add the remaining two-thirds of initiator two and acrylate mixed monomer two (1.2 g acrylic acid, 44 g butyl acrylate, 54 g methyl methacrylate, 5.6 g hydroxyethyl acrylate, 1.2 g hydroxyethyl methacrylate) dropwise. (g hydroxyethyl acrylate, 2.8 g hydroxyethyl methacrylate, 5 g dodecafluoroheptyl methacrylate, 3 g vinyltrimethoxysilane), ensuring the addition is completed within 3.5 h. Initiator 2 must be added within 15 min after the monomer addition is completed. Keep warm for 1 h. After cooling to room temperature, adjust the pPH to neutral. Filter through a screen to prepare a fluorosilicone modified core-shell acrylate copolymer emulsion. (2) Add 8 parts of nano zinc oxide (pre-wetted with ethanol), 5 parts of film-forming agent (styrene-acrylic emulsion), 0.5 parts of film-forming aid (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), 0.3 parts of defoamer (BYK-0163) and 0.2 parts of leveling agent (BYK-331) to 55 parts of fluorosilicone modified core-shell acrylate copolymer emulsion and mix evenly. Then add 0.4 parts of thickener (hydroxyethyl cellulose) to adjust the viscosity to 90~100 KU and filter to prepare superhydrophobic acrylic resin coating.

[0031] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that the amount of fluorosilicone modified nano zinc oxide used was too small, while the amount of fluorosilicone modified nano zinc oxide used was 1 part. All other conditions were the same as in Example 1.

[0032] Comparative Example 4: The difference between Comparative Example 4 and Example 1 is that the amount of fluorosilicone modified nano zinc oxide used was too large, and the amount of fluorosilicone modified nano zinc oxide used was 15 parts. All other conditions were the same as in Example 1.

[0033] Detection Example 1: The superhydrophobic acrylic resin coatings prepared in Examples 1-5 and Comparative Examples 1-4 were coated under the following conditions: room temperature and 70% RH. After film formation, the water contact angle, stain resistance rating, and adhesion of the coatings were tested. The static water contact angle of the coating was measured using a contact angle meter. The water droplet volume was approximately 5 μL. Tests were conducted at three different locations and the average value was taken. The stain resistance was tested according to the content published in GB / T9780-2013 Architectural Coatings and Coatings Stain Resistance Test Method. Level 0 is no stain, Level 1 is very slight stain, Level 2 is slight stain, Level 3 is moderate stain, and Level 4 is severe stain. The adhesion was tested according to the content published in GB / T9286-2021 Paints and Varnishes Cross-cut Test. The evaluation was based on the percentage of coating peeling area in 100 grids. Grade 1 peeling percentage <10%, Grade 2 peeling percentage 10~30%, Grade 3 peeling percentage 30~80%, Grade 4 peeling percentage 80~100%. The test results are shown in Table 1; Table 1 Test Results As shown in Table 1, the water contact angle of the superhydrophobic acrylic resin coating prepared by the present invention is above 150°, the stain resistance reaches level 0, and the adhesion is level 1. The above results indicate that the superhydrophobic acrylic resin coating prepared by the present invention has superhydrophobic and self-cleaning properties.

[0034] Comparative Example 1 is a coating without added fluorosilicone modified nanoparticles. Its water contact angle after film formation is 113°, which does not reach the superhydrophobic level, and its stain resistance is level 1, indicating a lack of self-cleaning properties. The results of Comparative Example 1 and Example 1 show that adding fluorosilicone modified nanoparticles can improve the hydrophobicity of acrylic resin coatings to a superhydrophobic level, while also giving the coating self-cleaning properties and achieving a stain-free level of resistance.

[0035] Comparative Example 2 is a technical solution without fluorosilicone modification of the nanoparticles. The water contact angle of the coating after film formation is only 121°, and the hydrophobicity is significantly reduced. After analyzing the results of Comparative Example 1, Comparative Example 2 and Example 1, it was found that without fluorosilicone modification of the nanoparticles, excessive addition of nanoparticles will cause the nanoparticles to agglomerate. These agglomerated nanoparticles will destroy the formed micro-nano structure, significantly reducing the hydrophobicity of the coating. The agglomerated nanoparticles also significantly reduce the stain resistance of the coating. The present invention modifies nanoparticles with fluorosilicone, resulting in excellent compatibility between the nanoparticles and the fluorosilicone-containing shell of the fluorosilicone-modified core-shell acrylate emulsion. This allows the fluorosilicone-modified nanoparticles to be uniformly dispersed on the shell, thereby inhibiting the aggregation of the nanoparticles themselves. Simultaneously, after the fluorosilicone-modified nanoparticles are dispersed on the shell, the fluorine elements on the surface of the nanoparticles and the fluorine elements in the shell undergo phase separation during the subsequent film formation process. This results in the formation of a multi-level micro-nano structure composed of fluorosilicone acrylate micro-nano structures and fluorosilicone-modified nanoparticles uniformly distributed on the surface of the fluorosilicone acrylate micro-nano structures, enabling the coating to achieve superhydrophobicity and self-cleaning properties.

[0036] Comparative Examples 3 and 4 investigated the dosage of fluorosilicone modified nanoparticles. The results showed that insufficient dosage of fluorosilicone modified nanoparticles prevented the coating from achieving superhydrophobicity, while excessive dosage caused emulsion demulsification. Fluorosilicone modified polyacrylate directly formed a film structure, while fluorosilicone modified nanoparticles, due to their excellent compatibility with fluorosilicone polyacrylate, were uniformly dispersed in the fluorosilicone modified acrylate and could not effectively form micro-nano structures.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A superhydrophobic acrylic resin coating, characterized in that, The raw materials, by mass parts, include: 40-70 parts of fluorosilicone modified core-shell acrylate copolymer emulsion, 3-10 parts of fluorosilicone modified nanoparticles, and the remainder of additives; the raw materials for the fluorosilicone modified nanoparticles include fluorosilanes, hydrophilic nanoparticles, and solvents, and the fluorine content in the coating is 0.5-2%.

2. The superhydrophobic acrylic resin coating according to claim 1, characterized in that, Additives include film-forming agents, film-forming aids, leveling agents, defoamers, and thickeners.

3. The superhydrophobic acrylic resin coating according to claim 1, characterized in that, The raw materials for fluorosilicone modified core-shell acrylate copolymer emulsions include silane coupling agents, acrylic monomers, initiators, and water.

4. The superhydrophobic acrylic resin coating according to claim 1, characterized in that, The hydrophilic nanoparticles are one or more of the following: hydrophilic nano-titanium dioxide, hydrophilic nano-zinc oxide, and hydrophilic nano-silica.

5. A method for preparing a superhydrophobic acrylic resin coating according to any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Preparation of fluorosilicone modified core-shell acrylate copolymer emulsion; (2) Disperse hydrophilic nanoparticles in a solvent and then add fluorosilane for reflux reaction to prepare fluorosilane nanoparticles; (3) Adding additives and fluorosilane nanoparticles to fluorosilicone modified core-shell acrylate copolymer emulsion to prepare superhydrophobic acrylic resin coating.

6. The preparation method according to claim 5, characterized in that, The solvent is toluene.

7. The preparation method according to claim 5, characterized in that, The reflux reaction conditions include: temperature 100~120 ℃, time 10~14 h.

8. The preparation method according to claim 5 or 7, characterized in that, After reflux, the precipitate was separated by centrifugation and washed several times with anhydrous ethanol.

9. The preparation method according to claim 5, characterized in that, The hydrophilic nanoparticles were dispersed using ultrasonic dispersion for 20–40 min.

10. The preparation method according to claim 5, characterized in that, The viscosity of the superhydrophobic acrylic resin coating is 90~100 KU.

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