An aqueous anti-corrosion coating and its preparation method

Abstract

The present invention provides an aqueous anti-corrosion coating and a preparation method thereof, belonging to the technical field of coating preparation, and comprising the following steps: S1. Prepare modified carnauba wax micro needles: Add molten carnauba wax into a glass fiber dispersion liquid, stir evenly to obtain a mixed solution; Pour the above-mentioned mixed solution into a mold, cool and solidify, and obtain modified carnauba wax micro needles after drying; S2. Take an aqueous acrylic resin and an aqueous epoxy resin, add a solvent and stir at a low speed, add a wetting agent and an anti-foaming agent and stir at a high speed; Add modified TiO2 nanoparticles, a siloxanyl acrylate, modified SiO2 nanoparticles and modified carnauba wax micro needles, mix and disperse evenly to obtain an aqueous anti-corrosion coating. The technical solution provided by the present invention realizes the purpose of simultaneously improving the matte performance and waterproof performance of the coating, and achieves the effect of maintaining anti-corrosion.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, and particularly relates to an aqueous anti-corrosion coating and a preparation method thereof. Background Art

[0002] With the dual pursuit of the beauty and practicality of home decoration by people, matte paint has gradually become popular due to its unique texture and visual effects. Compared with glossy paint, matte paint has environmentally friendly raw materials, good wear resistance, good scratch resistance, especially low gloss, which can reduce the irritation of light reflection to the eyes, and its paint surface is softer, giving people an elegant, simple, implicit and soft color experience. Therefore, this kind of paint is widely used not only in interior decoration, such as interior wall coatings and furniture coatings, but also has important applications in fields such as exterior wall painting.

[0003] The patent with the publication number CN113969088A and the name of an anti-smudging exterior wall waterproof coating and its preparation method and use method discloses that the raw material composition of the anti-smudging exterior wall waterproof coating includes: 500 - 900 parts by weight of pure acrylic emulsion, 10 - 40 parts by weight of a matting agent, 10 - 100 parts by weight of a water repellent, and 100 - 500 parts by weight of water; the matting agent is a polyethylene wax emulsion grafted with methyl methacrylate monomer; the water repellent is a fluorinated polysiloxane. In the above technical solution, the matting effect is determined by the polyethylene wax emulsion grafted with methyl methacrylate monomer, which can effectively increase the roughness of the film-forming surface and effectively improve the matting performance.

[0004] However, when matte paint is applied to the exterior wall of a building, it needs to cope with various weather conditions. Especially in the southern regions of China, there are many rainy days, so there are certain requirements for the anti-corrosion property of matte paint. The waterproof effect in the above technical solution depends on the sealing and hydrophobicity of its coating, which means that the surface of the coating needs to have as few pores as possible. However, the principle of producing a matte effect is the diffuse reflection of incident light by the tiny rough structure on the surface, and this rough structure will increase the porosity of the paint, thus reducing the waterproof property and unable to maintain the anti-corrosion effect. Therefore, it is necessary to provide an aqueous anti-corrosion coating and a preparation method thereof to solve the problems existing in the above prior art. Summary of the Invention

[0005] In view of this, the present invention provides an aqueous anti-corrosion coating and a preparation method thereof, achieving the purpose of simultaneously improving the matte performance and waterproof performance of the coating and achieving the effect of maintaining anti-corrosion.

[0006] To achieve the above purpose, the present invention provides a preparation method of an aqueous anti-corrosion coating, including the following steps: S1. Prepare modified carnauba wax micro needles: Add molten carnauba wax to a glass fiber dispersion liquid, stir evenly to obtain a mixed solution; pour the above mixed solution into a mold, cool and solidify, and obtain modified carnauba wax micro needles after drying;

[0007] S2. Take waterborne acrylic resin and waterborne epoxy resin, add solvent and stir at low speed, then add wetting agent and defoaming agent and stir at high speed; add modified TiO2 nanoparticles, siloxanyl acrylate, modified SiO2 nanoparticles and modified carnauba wax microneedles, mix and disperse evenly to obtain waterborne anticorrosive coating.

[0008] In the present invention, the carnauba wax is modified by using glass fiber to achieve complementary performance, and modified carnauba wax is obtained. First, the long-chain fatty acids and alcohol molecules of carnauba wax itself are hydrophobic, making water unable to diffuse on the wax surface, forming water droplets with a high contact angle, having waterproof property and improving the anticorrosive effect; second, a composite structure is formed by glass fiber and carnauba wax, enhancing the toughness of carnauba wax and facilitating the preparation of microneedle structure. Finally, the high tensile strength and elastic modulus of glass fiber can improve the anti-deformation ability of microneedles under bending and compression, and maintain the structural stability of microneedles.

[0009] In the present invention, modified carnauba wax microneedles are introduced into the coating. On the one hand, the microneedle structure reduces the contact area between the liquid droplet and the coating surface by increasing the surface roughness of the coating, increases the contact angle, thereby realizing the superhydrophobicity of the coating surface. The superhydrophobic surface makes the water droplets difficult to spread on the coating surface and only form bead-shaped droplets. These droplets are easy to roll and detach from the coating surface, achieving the effect of preventing water penetration, further improving the anticorrosion property, and because the bead-shaped water droplets roll from top to bottom along the surface under the action of gravity, they can take away tiny particles such as dust and dirt on the coating surface during this process, thus realizing the self-cleaning effect. On the other hand, the microneedle structure increases the scattering path of light, can effectively scatter light, reduces the direct reflection of light, thereby improving the matte effect of the coating. At the same time, modified silica nanoparticles and modified titanium dioxide nanoparticles are filled in the pores brought by the microneedle structure, avoiding the increase in porosity caused by the increase in surface roughness. Therefore, introducing modified carnauba wax microneedles can solve the problem of increased porosity caused by surface roughness, realize the simultaneous improvement of the anticorrosion performance and matte effect of the coating, and have the self-cleaning effect.

[0010] Optionally, the glass fiber dispersion liquid is obtained by dispersing glass fiber cut into anhydrous ethanol, and the content of glass fiber is 0.04 - 0.06 g / ml; the conditions for stirring molten carnauba wax in the glass fiber dispersion liquid are temperature 90 - 100 °C, stirring speed 1000 - 1200 rpm, and stirring time 25 - 35 min.

[0011] The high temperature when stirring carnauba wax in the glass fiber dispersion liquid in the present invention can ensure that carnauba wax remains in a molten state, facilitating uniform stirring.

[0012] Optionally, the parameters of the mold are a height of 10-20 μm and a diameter of 5-15 μm; the conditions for cooling and solidifying are a temperature of 10-15 °C and a time of 1.5-2.5 h; the conditions for drying are a temperature of 45-55 °C and a time of 11-13 h.

[0013] Optionally, it further includes adding modified kaurene in step S2. The weight fraction of the modified kaurene is 2-4 parts. The preparation of the modified kaurene includes the following steps: Mix COF-5 and methyltrimethoxysilane and stir to obtain solution A, heat for reaction, filter and wash, and dry to obtain modified COF-5; dissolve kaurene in dichloromethane to obtain solution B, add modified COF-5, stir, filter and wash, and dry to obtain modified kaurene.

[0014] The porous structure of COF-5 used in the present invention can increase the surface roughness of the coating, enhance the ability of the coating to scatter light, so as to achieve a matte effect. Using it together with the modified carnauba wax microneedles can better improve the matte effect of the coating. However, the dispersibility of COF-5 in the coating is poor and it is prone to agglomeration, which will affect the overall waterproof performance and matte effect of the coating. Therefore, COF-5 is modified with MTMS (methyltrimethoxysilane). After modification, organosilane functional groups are introduced on its surface, effectively improving the dispersibility of COF-5 in the coating. And MTMS has excellent hydrophobic properties, which not only improves the dispersibility of the coating, but also further improves the waterproof and anti-corrosion properties of the coating.

[0015] Kaurene has excellent hydrophobicity. Loading it onto modified COF-5 can further optimize the waterproof performance of the coating. The hydroxyl (-OH) groups in the kaurene molecule have significant antioxidant activity. These hydroxyl groups can donate hydrogen atoms to free radicals, convert them into a relatively stable non-free radical state, thus neutralizing free radicals and enhancing the antioxidant ability of the coating. The conjugated double bonds in the kaurene molecule can stabilize free radicals and disperse the energy of free radicals through the conjugation effect, reduce their activity, inhibit free radical reactions, and strengthen the antioxidant ability of the coating. Moreover, the kaurene molecule chelates with Fe 2+ , Cu 2+ to reduce their ability to catalyze the generation of free radicals, thereby playing an antioxidant role. Through these effects, kaurene strengthens the antioxidant ability of the coating and improves the durability of the coating. The kaurene molecule can insert into the cell membrane of bacteria, change the structure and permeability of the cell membrane, destroy the integrity of the cell membrane, cause the leakage of internal substances of bacteria, resulting in the loss of electrolytes and small molecules in bacteria, and the kaurene molecule can also inhibit the formation of the cell membrane, thereby inhibiting the growth of bacteria, effectively improving the antibacterial performance of the coating and enhancing the anti-corrosion property.

[0016] The present invention uses modified COF-5 to load kaurene. The pore structure and large specific surface area of COF-5 can enable the antioxidant and antibacterial properties of kaurene to be better exerted, and ensure that kaurene can stably play its role. The hydrophobic property of kaurene further enhances the hydrophobicity of COF-5, thereby improving the waterproof performance of the coating. Modified COF-5 can evenly disperse kaurene in the coating, enabling its antibacterial and antioxidant capabilities to effectively play their roles, enhancing the antibacterial and antioxidant capabilities of the coating, and making the coating more durable and weather-resistant. In addition, both COF-5 and kaurene are environmentally friendly materials, without harmful heavy metals and volatile organic compounds, improving the environmental friendliness of the coating.

[0017] Optionally, the mixing and stirring conditions of COF-5 and methyltrimethoxysilane are a stirring speed of 700 - 800 rpm and a stirring time of 1 - 1.5 h, and the content of COF-5 in the solution A is 0.04 - 0.06 g / ml;

[0018] The heating is at a temperature of 55 - 60 °C for 4 - 6 h; the conditions for dissolving kaurene in dichloromethane are a speed of 1000 - 1200 rpm and stirring for 30 - 40 min. The content of kaurene in the solution B is 0.02 - 0.04 g / ml, and the stirring conditions after adding modified COF-5 are a speed of 600 - 800 rpm and a time of 6 - 8 h.

[0019] Optionally, the preparation of the modified TiO2 nanoparticles: TiO2 nanoparticles are taken and mixed with absolute ethanol, and methyltrimethoxysilane is added and mixed evenly. After filtration and drying, the modified TiO2 nanoparticles are obtained;

[0020] The preparation of the modified SiO2 nanoparticles: SiO2 nanoparticles are taken and mixed with absolute ethanol, ammonia water and ethyl stearate are added, and after mixing evenly, the solvent is evaporated to obtain the modified SiO2 nanoparticles.

[0021] In the present invention, MTMS-modified TiO2 nanoparticles and ethyl stearate-modified SiO2 nanoparticles are used to reduce the surface energy of the nanoparticles, improve the dispersibility of the nanoparticles, and the modifiers can be compatible with the matrix material, improving the compatibility of the nanoparticles and avoiding stress concentration caused by agglomeration. When MTMS molecules react, the methoxy groups in their molecules will first undergo hydrolysis reactions to generate silanols. Subsequently, the silanol molecules will undergo hydrogen bond reactions and condensation with the hydroxyl groups on the surface of the inorganic powder particles, thereby forming -SiO-X covalent bonds (X represents the surface of the inorganic powder particles). At the same time, the silanol molecules can also associate and polymerize with each other to form a covering substance with a network structure, which adheres to the outer surface of the powder particles, improving the mechanical strength of the coating. In addition, both modifiers are hydrophobic, further improving the waterproof performance of the coating and correspondingly enhancing the anti-corrosion performance. Moreover, the modified TiO2 nanoparticles and the modified SiO2 nanoparticles can improve the surface roughness of the coating, enabling the coating to have a good matte effect, and can also improve the wear resistance and weather resistance of the coating, extending the service life of the coating.

[0022] Optionally, after mixing TiO2 nanoparticles with absolute ethanol, the content of TiO2 is 0.1 - 0.15 g / ml, and the mass percentage of methyltrimethoxysilane in the mixture of TiO2 nanoparticles and absolute ethanol is 2 - 3 wt%;

[0023] After mixing SiO2 nanoparticles with absolute ethanol, the content of SiO2 is 0.1 - 0.15 g / ml, the mass percentage of ammonia water in the mixture of SiO2 nanoparticles and absolute ethanol is 1 - 2 wt%, and the mass percentage of ethyl stearate in the mixture of SiO2 nanoparticles and absolute ethanol is 4 - 6 wt%.

[0024] Optionally, the conditions for low-speed stirring are a speed of 400 - 600 rpm and a time of 1 - 2 h; the conditions for high-speed stirring are 800 - 1000 rpm and a time of 20 - 30 min.

[0025] Optionally, after adding the modified TiO2 nanoparticles and the modified kaurene, ultrasonic dispersion is carried out respectively, and after adding the siloxanyl acrylate, the modified SiO2 nanoparticles and the modified carnauba wax micro needles, stirring is carried out respectively.

[0026] The present invention uses different dispersion methods for different components to make the components of the coating disperse evenly.

[0027] To achieve the above object, the present invention also provides an aqueous anticorrosive coating prepared by a preparation method of an aqueous anticorrosive coating, which comprises the following raw materials in parts by weight: 90-100 parts of an aqueous acrylic resin, 25-35 parts of an aqueous epoxy resin, 8-12 parts of xylene, 4-6 parts of methyl ethyl ketone, 0.5-1 part of a wetting agent, 0.5-1 part of an antifoaming agent, 4-6 parts of a siloxanyl acrylate, 8-12 parts of modified SiO2 nanoparticles, 3-7 parts of modified TiO2 nanoparticles, and 15-17 parts of modified carnauba wax micro needles.

[0028] The above technical solution of the present invention has at least the following beneficial effects:

[0029] By adopting modified additives in combination with modified TiO2 nanoparticles and modified SiO2 nanoparticles, on the one hand, modified carnauba wax micro needles are prepared by introducing glass fibers. By utilizing the structure of the modified carnauba wax micro needles, the surface roughness of the coating is increased, thereby improving the diffuse scattering of light and enhancing the matte effect of the coating. The modified TiO2 nanoparticles and modified SiO2 nanoparticles are filled in the gaps brought by the micro needle structure, avoiding the increase in pores caused by surface roughness and further improving the matte effect; on the other hand, the micro needle structure also reduces the contact area between the droplet and the coating surface and increases the contact angle by increasing the surface roughness, thereby achieving superhydrophobicity. The superhydrophobic surface makes the water droplets roll easily and detach from the coating surface, preventing water penetration and further enhancing the waterproof property, and overall ensuring the anticorrosion effect. Specific embodiments

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention fall within the scope of protection of the present invention.

[0031] Example 1

[0032] Preparation of modified TiO2 nanoparticles: 10 g of TiO2 nanoparticles are dispersed in 100 ml of absolute ethanol, 2 wt% of a silane coupling agent MTMS based on the weight percentage of the above mixture is added, stirred for 2 h, ultrasonically dispersed for 60 min, filtered and dried for later use.

[0033] Preparation of modified SiO2 nanoparticles: 20 g of SiO2 nanoparticles are taken, dispersed in 200 ml of absolute ethanol, stirred evenly, 1 wt% of ammonia water and 5 wt% of ethyl stearate are added, and the reaction is carried out for 4 hours under stirring conditions. After evaporating the solvent, it is dried for later use.

[0034] Preparation of modified carnauba wax: Take 10 g of glass fiber, shear it with a high-speed shearer, and disperse it in 200 ml of absolute ethanol. Ultrasonically disperse for 30 min to ensure uniform dispersion of the glass fiber, obtaining a glass fiber dispersion. Take 90 g of carnauba wax, heat it to 100 °C until it is completely melted, slowly add the glass fiber dispersion, start stirring at 90 °C, stir at a speed of 1000 rpm for 30 min to ensure uniform dispersion of the glass fiber in the carnauba wax. Slowly pour the molten glass fiber-modified carnauba wax into a mold with a height of 20 microns and a diameter of 15 microns to ensure uniform filling of all mold pores, and cool at 15 °C for 2 h until solidified. Demold, put the obtained microneedle sample into a vacuum drying oven, dry at 50 °C for 12 h to obtain modified carnauba wax microneedles. The modified carnauba wax microneedles are in a powder state after drying.

[0035] Mix 100 parts of waterborne acrylic resin and 30 parts of waterborne epoxy resin, add 10 parts of xylene and 5 parts of methyl ethyl ketone as solvents, stir at a speed of 500 rpm for 1.5 h. After mixing evenly, add 1 part of wetting agent BYK-348 and 1 part of defoaming agent BYK-141, and stir at a speed of 800 rpm for 30 min; add 5 parts of modified TiO2 nanoparticles, use ultrasonic dispersion for 60 min to ensure uniform distribution of the particles; add 5 parts of siloxanyl acrylate, and stir at a speed of 800 rpm for 30 min; add 10 parts of modified SiO2 nanoparticles thereto, and stir at a speed of 1000 rpm for 2 h; add 15 parts of modified carnauba wax microneedles, and stir at a speed of 800 rpm for 30 min to obtain a waterborne anticorrosive coating.

[0036] Example 2

[0037] Preparation of modified TiO2 nanoparticles: Disperse 12 g of TiO2 nanoparticles in 100 ml of absolute ethanol, add 3 wt% of silane coupling agent MTMS based on the weight of the above mixture, stir for 2 h, ultrasonically disperse for 60 min, filter and dry for later use.

[0038] Preparation of modified SiO2 nanoparticles: Take 26 g of SiO2 nanoparticles, disperse them in 200 ml of absolute ethanol, stir evenly, add 2 wt% ammonia water and 4 wt% ethyl stearate, react under stirring conditions for 4 hours, evaporate the solvent and then dry for later use.

[0039] Preparation of Modified Carnauba Wax: Take 8 g of glass fiber, shear it with a high-speed shearer, and disperse it in 200 ml of absolute ethanol. Ultrasonically disperse for 30 min to ensure uniform dispersion of the glass fiber, obtaining a glass fiber dispersion. Take 90 g of carnauba wax, heat it to 90 °C to make it completely molten, slowly add the glass fiber dispersion, start stirring at 100 °C, and stir at a speed of 1100 rpm for 25 min to ensure uniform dispersion of the glass fiber in the carnauba wax. Slowly pour the molten glass fiber-modified carnauba wax into a mold with a height of 10 μm and a diameter of 5 μm to ensure uniform filling of all mold pores, and cool at 12 °C for 2.5 h until solidified. Demold, put the obtained microneedle sample into a vacuum drying oven, and dry at 55 °C for 11 h to obtain modified carnauba wax microneedles. The modified carnauba wax microneedles are in a powder state after drying.

[0040] Preparation of Modified Kaurene: Add 4 g of dry COF-5 to 100 ml of MTMS (methyltrimethoxysilane) solution, and stir at a speed of 800 rpm at room temperature for 60 min to make MTMS uniformly dispersed in the solution. Then heat the solution to 60 °C and react for 4 hours to further condense the methoxy groups of MTMS with the hydroxyl groups on the surface of COF-5 to form stable Si-O-Si bonds. After the reaction, filter and wash the product, and dry it in a vacuum drying oven at 70 °C for 12 h to obtain modified COF-5. Take 2 g of kaurene and add it to 100 ml of dichloromethane, stir at a speed of 1200 rpm for 30 min to ensure its dissolution in the solution. Add the modified COF-5 to the solution, start stirring at room temperature, and stir at a speed of 600 rpm for 8 h to make kaurene completely adsorbed on the modified COF-5. Filter and wash the product, and dry it at room temperature for 12 h to obtain modified COF-5 loaded with kaurene.

[0041] Mix 90 parts of waterborne acrylic resin and 35 parts of waterborne epoxy resin, add 12 parts of xylene and 4 parts of methyl ethyl ketone as solvents, stir at a speed of 400 rpm for 2 h, after mixing evenly, add 0.5 part of wetting agent BYK-348 and 0.8 part of defoaming agent BYK-141, and stir at a speed of 900 rpm for 25 min; add 3 parts of modified TiO2 nanoparticles, use ultrasonic dispersion for 60 min to ensure uniform distribution of the particles; add 6 parts of siloxanyl acrylate, and stir at a speed of 800 rpm for 30 min; add 12 parts of modified SiO2 nanoparticles to it, and stir at a speed of 1000 rpm for 2 h; add 15 parts of modified carnauba wax microneedles, and stir at a speed of 800 rpm for 30 min, and finally add 2 parts of modified COF-5 loaded with kaurene, and ultrasonically disperse for 30 min to ensure uniform dispersion, obtaining a waterborne anticorrosive coating.

[0042] Example 3

[0043] Preparation of modified TiO2 nanoparticles: 15 g of TiO2 nanoparticles were dispersed in 100 ml of absolute ethanol, and 2.5 wt% of silane coupling agent MTMS based on the weight of the above mixture was added. The mixture was stirred for 2 h, ultrasonically dispersed for 60 min, filtered, dried, and reserved for later use.

[0044] Preparation of modified SiO2 nanoparticles: 30 g of SiO2 nanoparticles were taken and dispersed in 200 ml of absolute ethanol. After stirring evenly, 1.5 wt% ammonia water and 6 wt% ethyl stearate were added, and the reaction was carried out under stirring conditions for 4 hours. After evaporating the solvent, it was dried and reserved for later use.

[0045] Preparation of modified carnauba wax: 12 g of glass fibers were sheared by a high-speed shearer and then dispersed in 200 ml of absolute ethanol. After ultrasonic dispersion for 35 min to ensure uniform dispersion of the glass fibers, a glass fiber dispersion was obtained. 90 g of carnauba wax was taken and heated to 95 °C to make it completely molten. The glass fiber dispersion was slowly added, and under the condition of heating at 95 °C, stirring was started and stirred at a speed of 1200 rpm for 35 min to ensure that the glass fibers were uniformly dispersed in the carnauba wax. The molten glass fiber-modified carnauba wax was slowly poured into a mold with a height of 15 μm and a diameter of 10 μm to ensure uniform filling of all mold pores. It was cooled at 10 °C for 1.5 h until solidified. After demolding, the obtained microneedle sample was placed in a vacuum drying oven and dried at 45 °C for 13 h to obtain modified carnauba wax microneedles. The modified carnauba wax microneedles were in a powder state after drying.

[0046] Preparation of modified kaurene: 6 g of dry COF-5 was added to 100 ml of MTMS (methyltrimethoxysilane) solution, and the solution was stirred at a speed of 700 rpm at room temperature for 1.5 h to make MTMS uniformly dispersed in the solution. Then the solution was heated to 55 °C and reacted for 6 hours to further condense the methoxy groups of MTMS with the hydroxyl groups on the surface of COF-5 to form stable Si-O-Si bonds. After the reaction, the product was filtered and washed, and then placed in a vacuum drying oven and dried at 70 °C for 12 h to obtain modified COF-5. 4 g of kaurene was added to 100 ml of dichloromethane and stirred at a speed of 1000 rpm for 40 min to ensure its dissolution in the solution. Modified COF-5 was added to the solution, and stirring was started at room temperature and stirred at a speed of 800 rpm for 6 h to make kaurene completely adsorbed on modified COF-5. The product was filtered and washed, and dried at room temperature for 12 h to obtain modified COF-5 loaded with kaurene.

[0047] Mix 95 parts of waterborne acrylic resin and 25 parts of waterborne epoxy resin, add 8 parts of xylene and 6 parts of methyl ethyl ketone as solvents, stir at a speed of 600 rpm for 1 h. After mixing evenly, add 0.8 part of wetting agent BYK-348 and 0.5 part of defoaming agent BYK-141, and stir at a speed of 1000 rpm for 20 min; add 7 parts of modified TiO2 nanoparticles, disperse ultrasonically for 60 min to ensure uniform distribution of the particles; add 4 parts of siloxanyl acrylate, and stir at a speed of 800 rpm for 30 min; add 8 parts of modified SiO2 nanoparticles into it, and stir at a speed of 1000 rpm for 2 h; add 16 parts of modified carnauba wax micro needles, stir at a speed of 800 rpm for 30 min, and finally add 4 parts of modified COF-5 loaded with ent-kaurene, disperse ultrasonically for 30 min to ensure uniform dispersion, and obtain a waterborne anticorrosive coating.

[0048] Example 4

[0049] Compared with Example 1, the difference is only that the die parameters of the modified carnauba wax micro needles are a height of 12 microns and a diameter of 7 microns, and the rest of the raw materials and steps are the same as those in Example 2.

[0050] Example 5

[0051] Compared with Example 1, the difference is only that the component weight parts of the waterborne anticorrosive coating are 95 parts of waterborne acrylic resin, 35 parts of waterborne epoxy resin, 12 parts of xylene, 4 parts of methyl ethyl ketone, 0.5 part of wetting agent, 0.5 part of defoaming agent, 4 parts of siloxanyl acrylate, 12 parts of modified SiO2 nanoparticles, 7 parts of modified TiO2 nanoparticles and 17 parts of modified carnauba wax micro needles, and the rest of the steps are the same as those in Example 1.

[0052] Example 6

[0053] Compared with Example 2, the difference is only that the component weight parts of the waterborne anticorrosive coating are 100 parts of waterborne acrylic resin, 30 parts of waterborne epoxy resin, 9 parts of xylene, 7 parts of methyl ethyl ketone, 0.9 part of wetting agent, 0.6 part of defoaming agent, 5 parts of siloxanyl acrylate, 10 parts of modified SiO2 nanoparticles, 5 parts of modified TiO2 nanoparticles, 15 parts of modified carnauba wax micro needles and 3 parts of modified ent-kaurene, and the rest of the steps are the same as those in Example 2.

[0054] Comparative Example 1

[0055] Compared with Example 1, the difference is only that the modified carnauba wax micro needles are not used, and the rest of the raw materials and steps are the same as those in Example 1.

[0056] Comparative Example 2

[0057] Compared with Example 1, the difference is only that modified TiO2 nanoparticles and modified SiO2 nanoparticles are not used, and the remaining raw materials and steps are the same as those in Example 1.

[0058] Comparative Example 3

[0059] Compared with Example 2, the difference is only that modified carnauba wax microneedles, modified TiO2 nanoparticles and modified SiO2 nanoparticles are not used, and the remaining raw materials and steps are the same as those in Example 2.

[0060] Comparative Example 4

[0061] Compared with Example 2, the difference is only that modified TiO2 nanoparticles and modified SiO2 nanoparticles are not used, and the remaining raw materials and steps are the same as those in Example 2.

[0062] The basic properties of the coatings prepared in Examples 1-6 and Comparative Examples 1-4 were tested, and the test results are shown in Table 1.

[0063] The hardness test method refers to the national standard GB / T6739-2022 "Paints and varnishes - Determination of film hardness by pencil test". Hardness evaluation: from 9B, 8B, 7B, 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H, the hardness increases in turn.

[0064] The adhesion test method refers to the national standard GB / T9286-2021 "Paints and varnishes - Cross-cut test". Adhesion evaluation: 0-5 levels, the adhesion decreases in turn.

[0065] The aging resistance test method refers to the national standard GB / T1865-2009 "Paints and varnishes - Artificial weathering and exposure to artificial radiation - Filtered xenon-arc radiation". Aging resistance evaluation: whether it is powdered.

[0066] Table 1 Basic property test results of the coatings prepared in Examples 1-6 and Comparative Examples 1-4

[0067]

[0068] As can be seen from Table 1, compared with the coatings prepared in Comparative Examples 1-4, the coatings prepared in Examples 1-6 of the present invention are more excellent in terms of hardness, adhesion and aging resistance.

[0069] As can be seen from Table 1 in combination with the analysis of Example 2 and Comparative Example 4, modified TiO2 nanoparticles and modified SiO2 nanoparticles can improve the adhesion of the coating; as can be seen from Table 1 in combination with the analysis of Comparative Example 2 and Comparative Example 4, modified ent-kaurene is beneficial to improving the aging resistance of the coating.

[0070] The waterproof and glossiness performance of the coatings prepared in Examples 1-6 and Comparative Examples 1-4 was tested, and the test results are shown in Table 2.

[0071] The waterproofness test method refers to the water impermeability test method in the national standard GB / T16777-2008 "Test Methods for Building Waterproof Coatings". The waterproofness test assessment: no water penetration phenomenon within the specified time.

[0072] The glossiness test method refers to the test method under the 85° geometric condition in the national standard GB / T9754-2007 "Determination of 20°, 60° and 85° Specular Gloss of Paints and Varnishes - Paints Without Metallic Pigments". The smaller the glossiness, the better the matte effect.

[0073] Table 2 Test results of the waterproof and glossiness performance of the coatings prepared in Examples 1-6 and Comparative Examples 1-4

[0074]

[0075] As can be seen from Table 2, compared with the coatings prepared in Comparative Examples 1-4, the coatings prepared in Examples 1-6 of the present invention have strong waterproofness and low glossiness, that is, better waterproof effect and matte effect.

[0076] Combined with Table 2, Examples 1 and Comparative Examples 1-2, it can be seen that the combined use of modified carnauba wax, modified TiO2 nanoparticles and modified SiO2 nanoparticles improves the waterproofness and matte effect of the coating.

[0077] The antibacterial and self-cleaning effects of the coatings prepared in Examples 1-6 and Comparative Examples 1-4 were tested, and the test results are shown in Table 3.

[0078] The antibacterial test method refers to the national standard GB / T21866-2008 "Determination Method and Antibacterial Effect of Antibacterial Coatings (Paint Films)". The antibacterial assessment: Grade I, Grade II (Grade I antibacterial property is higher than Grade II).

[0079] The self-cleaning effect test method refers to the outdoor rain stain experiment in the national standard GB / T31815-2015 "Self-Cleaning Coatings for Building Exterior Surfaces". The self-cleaning effect assessment: A, no rain stains; B, slight rain stains; C, obvious rain stains; D, serious rain stains.

[0080] Table 3 Test results of the antibacterial and self-cleaning performance of the coatings prepared in Examples 1-6 and Comparative Examples 1-4

[0081]

[0082] As can be seen from Table 3, compared with the coatings prepared in Comparative Examples 1-4, the coatings prepared in Examples 1-6 of the present invention perform better in terms of antibacterial property and self-cleaning effect.

[0083] Combining Table 2 and Table 3, it can be seen that the coatings prepared in Examples 1-6 of the present invention have more excellent antibacterial property and waterproof property, and overall achieve excellent anti-corrosion effect.

[0084] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a water-based anticorrosive coating, characterized in that: The following steps are involved: S1. Preparation of modified carnauba wax microneedles: adding molten carnauba wax to a glass fiber dispersion, stirring evenly to obtain a mixed solution; pouring the mixed solution into a mold, cooling and solidifying, and drying to obtain modified carnauba wax microneedles; the glass fiber dispersion is obtained by shearing glass fibers and adding them into anhydrous ethanol for dispersion, and the content of glass fibers is 0.04-0.06 g / ml; stirring conditions of the molten carnauba wax in the glass fiber dispersion are a temperature of 90-100° C., a stirring speed of 1000-1200 rpm, and a stirring time of 25-35 min; S2, taking a water-based acrylic resin and a water-based epoxy resin, adding a solvent and stirring at a low speed, adding a wetting agent and a defoaming agent and stirring at a high speed; adding modified TiO2 nanoparticles, siloxane acrylate, modified SiO2 nanoparticles and modified carnauba wax microneedles, mixing and dispersing them evenly to obtain a water-based anticorrosive coating; The method further comprises adding modified kaurene in step S2, wherein the weight proportion of the modified kaurene is 2 to 4 parts, and the preparation of the modified kaurene comprises the following steps: mixing COF-5 and methyltrimethoxysilane to obtain solution A, heating to react, filtering, washing, and drying to obtain modified COF-5; dissolving kaurene in dichloromethane to obtain solution B, adding the modified COF-5, stirring, filtering, washing, and drying to obtain modified kaurene; Preparation of modified TiO2 nanoparticles: Mix TiO2 nanoparticles with anhydrous ethanol, add methyltrimethoxysilane and mix evenly, filter and dry to obtain modified TiO2 nanoparticles; Preparation of modified SiO2 nanoparticles: SiO2 nanoparticles are mixed with anhydrous ethanol, and ammonia water and ethyl stearate are added. After mixing evenly, the solvent is evaporated to obtain modified SiO2 nanoparticles.

2. The method for preparing a water-based anticorrosive coating according to claim 1, characterized in that: The parameters of the mold in step S1 are a height of 10-20 μm and a diameter of 5-15 μm; the cooling and curing conditions are a temperature of 10-15° C. and a time of 1.5-2.5 h; and the drying conditions are a temperature of 45-55° C. and a time of 11-13 h.

3. The method for preparing the water-based anticorrosive coating according to claim 1, characterized in that: The mixing conditions of COF-5 and methyltrimethoxysilane are as follows: a stirring speed of 700-800 rpm, a stirring time of 1-1.5 h, and a content of COF-5 in the solution A of 0.04-0.06 g / ml; The heating is performed at a temperature of 55-60° C. for 4-6 hours; the conditions for dissolving kaurene in dichloromethane are a speed of 1000-1200 rpm and stirring for 30-40 minutes; the content of kaurene in the B solution is 0.02-0.04 g / ml; and the stirring conditions after adding the modified COF-5 are a speed of 600-800 rpm for 6-8 hours.

4. The method for preparing a water-based anticorrosive coating according to claim 1, characterized in that: After the TiO2 nanoparticles are mixed with anhydrous ethanol, the content of TiO2 is 0.1-0.15 g / ml, and the mass percentage of the methyltrimethoxysilane in the mixture of the TiO2 nanoparticles and anhydrous ethanol is 2-3 wt %; After the SiO2 nanoparticles are mixed with anhydrous ethanol, the SiO2 content is 0.1-0.15g / ml, the mass percentage of the ammonia water in the mixture of the SiO2 nanoparticles and anhydrous ethanol is 1-2wt%, and the mass percentage of the ethyl stearate in the mixture of the SiO2 nanoparticles and anhydrous ethanol is 4-6wt%.

5. The method for preparing a water-based anticorrosive coating according to claim 1, characterized in that: The low-speed stirring condition is 400-600 rpm for 1-2 h; the high-speed stirring condition is 800-1000 rpm for 20-30 min.

6. The method for preparing a water-based anticorrosive coating according to claim 1, characterized in that: After adding the modified TiO2 nanoparticles and the modified kaurene, ultrasonic dispersion was performed respectively, and after adding the silicone alkyl acrylate, the modified SiO2 nanoparticles and the modified carnauba wax microneedles, stirring was performed respectively.

7. A water-based anti-corrosion coating prepared by the method for preparing a water-based anti-corrosion coating according to any one of claims 1 to 6, characterized in that: The invention comprises the following raw materials in parts by weight: 90-100 parts of water-based acrylic resin, 25-35 parts of water-based epoxy resin, 8-12 parts of xylene, 4-6 parts of butanone, 0.5-1 part of wetting agent, 0.5-1 part of defoaming agent, 4-6 parts of silicone acrylate, 8-12 parts of modified SiO2 nanoparticles, 3-7 parts of modified TiO2 nanoparticles and 15-17 parts of modified carnauba wax microneedles.

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