A flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material and its preparation method

Abstract

The invention discloses a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material and a preparation method thereof: first, flaky, fibrous and granular solid flame-retardant fillers with large particle size differences are added to a water-based resin diluted with clean water, mixed and stirred evenly, and then sprayed or brushed on the surface of a substrate, thereby forming a coating on the substrate surface with a sponge-like porous and capillary channel interconnected structure both inside and on the surface; second, siloxane is dissolved in a solvent and evenly brushed or sprayed on the surface of the coating, and penetrates into the interior of the coating through the pores and capillary channels; third, a polymer resin and inorganic nanoparticles are dispersed in a solvent and stirred to form a uniform dispersion liquid, and then the polymer resin and inorganic nanoparticles are allowed to penetrate into the pores and capillary channels wrapped and modified by the siloxane by spraying or brushing, and after drying at room temperature, a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material is obtained.

Description

Technical Field

[0001] The invention relates to a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material and a preparation method thereof, belonging to the technical field of coating preparation. Background Art

[0002] Materials such as wood, plastic, and steel structures are increasingly used in electricity, electrical appliances, furniture manufacturing, and mechanical equipment, but they also face many problems, such as fire, high temperature, high humidity, salinity, and chemical corrosion. Using coatings for protection is a common and cost-effective method, but most coatings currently have problems such as single performance, weak adhesion, poor durability, and complex manufacturing processes. Based on this, the present invention discloses a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling multifunctional coating material and its preparation method. This multifunctional coating imitates the interconnected structural characteristics of the porous and capillary channels inside and outside the sponge, disperses different flame-retardant fillers in linear, flaky, and granular shapes in an aqueous emulsion to construct a coating with a sponge-like porous and capillary channel structure, and then uses silicone to wrap and modify this porous and capillary channel structure. Then, on the basis of silicone wrapping and modifying the porous and capillary channel three-dimensional structure, a low-surface-energy polymer resin and nano-inorganic particles are further combined with this porous and capillary channel three-dimensional structure, thereby enhancing the density, flame retardancy, and super-hydrophobicity of the coating. The entire coating preparation process is carried out at room temperature, requiring no special treatment such as heating, making the preparation method simple and convenient. By integrating flame retardancy, corrosion resistance, and super-hydrophobicity, the coating has great application prospects in the fields of anti-seepage, anti-fouling, corrosion resistance, and flame retardancy. Summary of the Invention

[0003] The present invention solves the problems of single coating performance, weak adhesion, poor durability and complex manufacturing process, solves the problem of poor heat resistance efficiency of existing flame retardant materials, and solves the problem of low adhesion of inorganic nanoparticles in porous and capillary channel structures.

[0004] In order to solve the above problems, this application is implemented through the following technical solutions:

[0005] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material comprises the following steps:

[0006] S1. Stirring a flame retardant filler, a water-based resin, a curing agent, and water to obtain a base slurry; applying the base slurry evenly on a substrate and allowing it to stand to obtain a first coating;

[0007] S2, mixing the siloxane and the first solvent after ultrasonication to obtain a primary filler, and evenly coating the primary filler on the surface of the first coating prepared in step S1 to obtain a second coating;

[0008] S3. Mix the second organic solvent, polymer resin and inorganic nanoparticles to obtain a secondary filler, apply it evenly on the second coating prepared in step S2, and dry it to obtain a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material.

[0009] In step S1, the bottom slurry includes flame retardant filler, water-based resin, water and curing agent, and the flame retardant filler is 0.6-1.5 parts, the water-based resin is 3-7 parts, the water is 6-10 parts, and the curing agent is 2-5 parts by mass;

[0010] Wherein, the flame retardant filler is two or more of silicon dioxide, montmorillonite, saponite powder, titanium dioxide, expanded graphite, fly ash, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, barium sulfate, zinc oxide, aluminum oxide, bentonite, sodium aluminum phosphate, zirconium oxide, carbon nanotubes, and magnesium silicate;

[0011] The water-based resin includes one or more of water-based epoxy resin, polyvinyl alcohol, alkyd resin, fluorocarbon resin, water-based acrylic acid, and water-based polyurethane.

[0012] Among them, the curing agent is NX-8502.

[0013] In step S2, the siloxane is one or more of polydimethylsiloxane, methyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldiethoxysilane, aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, triethoxysilane and γ-mercaptopropyltriethoxysilane.

[0014] In step S2, the first solvent is one or more of anhydrous ethanol, ethyl acetate, isopropanol, acetone, ether, acetic acid, and tetrahydrofuran.

[0015] In the step S2, the volume ratio of the primary filler is siloxane:first solvent=5%-10%:1.

[0016] In the step S3, the flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material is calculated in parts by mass, and the ratio of base slurry: primary filler: secondary filler is 1.5-2.5:1:5-7.5.

[0017] In step S3, the secondary filler comprises a polymer resin, a second organic solvent and inorganic nanoparticles, wherein the polymer resin accounts for 0.4-0.7 parts, the second organic solvent accounts for 5-10 parts and the inorganic nanoparticles accounts for 0.4-0.7 parts by mass.

[0018] The polymer resin in step S3 is one or more of polytetrafluoroethylene, polyvinylidene fluoride, fluorosilicone resin, fluorocarbon resin, silicone resin, behenyl acrylate, polystyrene butadiene copolymer, and ethylene-vinyl acetate copolymer.

[0019] In step S3, the second organic solvent is one or more of ethyl acetate, ethanol, n-hexane, isopropanol, diethyl ether, propanol, and dimethyl ether.

[0020] The inorganic nanoparticles in step S3 are one or more of nano-silicon dioxide, nano-aluminum hydroxide, nano-aluminum oxide, nano-magnesium hydroxide, nano-titanium dioxide, nano-sodium aluminum silicate or calcium aluminum phosphate.

[0021] Preferably, the flame retardant filler in step S1 has a shape of two or three of flake, fiber and granule.

[0022] Preferably, the particle size of the fibrous flame retardant filler in step S1 is 0.5-2.4 mm.

[0023] Preferably, the particle size of the flaky flame retardant filler in step S1 is 0.2-0.9 mm.

[0024] Preferably, the particle size of the granular flame retardant filler in step S1 is 0.5-1.0 mm.

[0025] Preferably, the standing time in step S1 is 40 to 60 minutes.

[0026] Preferably, in step S1, the base layer slurry is applied to the surface of the substrate by scraping or spraying.

[0027] Preferably, in step S2, the ultrasonication time is 25 to 40 minutes, and the magnetic stirring time is 30 to 50 minutes.

[0028] Preferably, the particle size of the inorganic nanoparticles in step S3 is 20-200 nm.

[0029] Preferably, the drying time at room temperature in step S3 is 24 to 28 hours.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. This invention utilizes flame-retardant fillers in various shapes, such as flakes, fibers, or particles, with distinctly different shapes and particle sizes, to construct a coating with a sponge-like porous and capillary channel structure. This structure not only enhances the material's flame retardancy but also facilitates the rapid infiltration and low-energy surface modification of subsequent siloxane solutions and inorganic nanoparticles.

[0032] 2. Modify the porous and capillary channel structure in the coating with silicone wrap, on the one hand, promote -CH n The groups and active Si-H bonds are covalently grafted to the surface of the porous and capillary channel structure with the flame retardant filler and the water-based resin, thereby reducing the surface energy of the structure and enhancing the adhesion of subsequent inorganic nanoparticles in the porous and capillary channel structure.

[0033] 3. The porous and capillary channel structure inside the coating formed by wrapping and modifying the water-based resin is formed by silicone penetration, so that the original hydrophilic water-based resin in the coating has hydrophobic properties after wrapping and modification.

[0034] 4. Mixing low-surface-energy polymer resins and inorganic nanoparticles and infiltrating them into the porous and capillary channel structures inside the coating that has been wrapped and modified with silicone, not only enables the inorganic nanoparticles to fully fill the pores and capillary channels in the coating and improve the density of the material, but also enables them to firmly adhere to the surface of the porous and capillary channel structures inside the coating with the help of the silicone wrapping modification in the previous process and the adhesion of the polymer resin itself, thereby optimizing the overall multi-level rough structure inside the coating; the penetration of inorganic nanoparticles into the pores in the filling structure further hinders the penetration of water, further improving the overall self-similar structural characteristics, super-hydrophobic properties, anti-fouling and anti-seepage properties, and flame retardant properties of the material.

[0035] 5. The material of the present invention is prepared entirely at room temperature, requiring no special high-temperature heating treatment, and is therefore widely applicable in practice. It is suitable for a variety of substrates, exhibits strong adhesion, and is simple to prepare. This multifunctional coating material exhibits strong adhesion, simple preparation, a wide range of applications, and excellent flame retardancy, anti-seepage, anti-fouling, and fire resistance. It is particularly well-suited for applications in wood, plastic, and steel structures, providing anti-seepage, anti-fouling, corrosion resistance, and flame retardancy. DETAILED DESCRIPTION

[0036] The present invention uses wood and steel plates as coating substrates for the convenience of description or testing, but does not limit the application of the coating.

[0037] Soapstone powder was purchased from Guzhang County Shanlin Shiyu Mineral Products Co., Ltd., production model SA240118; expanded graphite was purchased from Guangzhou Metal Metallurgy Co., Ltd., production model C-10; fly ash was purchased from Henan Hengyuan New Materials Co., Ltd., the main components of which are silicon dioxide, calcium oxide, and aluminum oxide; bentonite was purchased from Zhejiang Hongyu New Materials Co., Ltd., production model HY-708; montmorillonite was purchased from Lingshou County Dehang Mineral Products Co., Ltd., the main components of which are silicate, aluminum oxide, and magnesium oxide;

[0038] Water-based resin: Water-based epoxy resin was purchased from Shenyang Dongyan Paint Decoration Co., Ltd., model DY-175; polyvinyl alcohol was purchased from Aladdin, model P139535; alkyd resin was purchased from Shandong Aohui Paint Industry Group Co., Ltd., model 389-9A; water-based acrylic acid was purchased from Shenzhen Jitian Chemical Co., Ltd., model E0504; water-based polyurethane was purchased from Shenzhen Jitian Chemical Co., Ltd., model F0401;

[0039] Silicone: Polydimethylsiloxane was purchased from Shanghai Deji Trading Co., Ltd., model H047N6N175; polytetrafluoroethylene was purchased from McLean, model 767293; polyvinylidene fluoride was purchased from Aladdin, model P432380;

[0040] Fluorosilicone resin was purchased from Xinan Chemical New Materials Co., Ltd., production model FS-001; fluorocarbon resin was purchased from Shandong Huaxia Shenzhou New Materials Co., Ltd., production model DS301;

[0041] Epoxy-modified silicone resin was purchased from Shenzhen Weiteli Environmental Protection Materials Co., Ltd., production model VR2404;

[0042] Behenyl acrylate was purchased from Aladdin, model D579667; polystyrene butadiene copolymer was purchased from Aladdin, model P394889; ethylene-vinyl acetate copolymer was purchased from Aladdin, model P101482;

[0043] The curing agent was water-based epoxy curing agent NX-8502, purchased from Cardolite Chemical Co., Ltd. Unless otherwise specified, in the following examples and comparative examples, the heating temperature was set at 437°C. The maximum backside temperature of the uncoated blank steel plate was 437°C. Unless otherwise specified, the contact angle and sliding angle measurements of the coating were performed using water.

[0044] The saturated water absorption rate in the comparative example was 12%. The substrates used in the examples and comparative examples were identical, weighing 6g each. Definition: Coating water absorption rate = (mass of substrate and coating after water absorption - mass of substrate and coating before water absorption) / mass of substrate.

[0045] Example 1

[0046] Step 1. Solid flame retardant filler configuration, in parts by mass: weigh 0.1 parts of granular silica with a particle size of 0.5 mm, 0.1 parts of fibrous alumina with a particle size of 0.5 mm, and 0.4 parts of flaky expanded graphite with a particle size of 0.2 mm; place the solid flame retardant filler and 6 parts of water in a beaker and stir thoroughly at a stirring speed of 300 r / min to obtain a uniform solution; weigh 3 parts of water-based epoxy resin and 2 parts of water-based epoxy curing agent NX-8502 and slowly add them to the solution in the previous step, mix thoroughly and stir for 1 hour to obtain a uniform solution of the base slurry; apply it on the wood by brush and let it stand at room temperature for 1 hour to obtain a coating No. 1 with a film thickness of 1 mm.

[0047] Step 2: Take 1 part of polydimethylsiloxane and 20 parts of the first solvent, anhydrous ethanol, in a beaker, ultrasonicate for 25 minutes, and then magnetically stir for 30 minutes to uniformly disperse them to obtain a primary filler, which is evenly sprayed on the surface of the No. 1 coating prepared in step 1 to obtain the No. 2 coating.

[0048] Step 3: Weigh 0.4 parts of polytetrafluoroethylene and 5 parts of ethyl acetate, a second organic solvent, into a beaker and stir thoroughly for 40 minutes until uniform. Then, weigh 0.2 parts of calcium aluminum phosphate with an average particle size of 20 nanometers and 0.2 parts of silicon dioxide with an average particle size of 40 nanometers and stir for 30 minutes to obtain a uniform solution of the secondary filler. This solution is then sprayed or knife-coated onto the surface of the second coating treated in Step 2 to penetrate the surface, and allowed to dry at room temperature for 24 hours.

[0049] In terms of mass, the base slurry: primary filler: secondary filler = 1.9:1:5.8.

[0050] After complete drying through the above steps, a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling coating material was obtained. The water contact angle on the coating surface was 159±1°, and the rolling angle was 3±0.5°. A temperature tester was used to test a steel plate with this coating, and the maximum back temperature of the plate was 247°C. When a wood block with this coating was immersed in a sodium hydroxide solution with a pH of 13 for 20 days, the contact angle of the coating was 155±1°. After immersion in clean water for 20 days, the water absorption rate of the coating was 1.8%.

[0051] Example 2

[0052] Step 1. Weigh 0.2 parts of granular zirconium oxide with a particle size of 0.4 mm, 0.2 parts of fibrous montmorillonite with a particle size of 0.6 mm, and 0.5 parts of flaky expanded graphite with a particle size of 0.2 mm, and place them in a beaker with 6 parts of water and stir them thoroughly at a stirring speed of 300 r / min to obtain a uniform solution; weigh 3 parts of water-based polyurethane and 2 parts of water-based epoxy curing agent NX-8502 and slowly add them to the solution in the previous step, mix them thoroughly and stir for 1 hour to obtain a uniform solution; apply it on the wood, let it stand at room temperature for 1 hour, and obtain a No. 1 coating with a film thickness of 1 mm.

[0053] Step 2: Take 2 parts of vinylmethyldiethoxysilane and 18 parts of the first solvent ethyl acetate in a beaker, ultrasonicate for 25 minutes, and then magnetically stir for 30 minutes to uniformly disperse them to obtain a primary filler, which is evenly sprayed on the surface of the coating prepared in step 1 to obtain coating No. 2.

[0054] Step 3: Weigh 0.3 parts of polyvinylidene fluoride and 5 parts of isopropyl alcohol, a second organic solvent, into a beaker and stir thoroughly for 40 minutes until uniform. Then, weigh 0.2 parts of aluminum oxide with an average particle size of 20 nanometers and 0.2 parts of magnesium hydroxide with an average particle size of 40 nanometers and stir for 30 minutes to obtain a uniform solution of the secondary filler. Spray or knife-coat the surface of the coating treated in step 2 to penetrate the solution, and dry at room temperature for 24 hours.

[0055] In terms of mass, the base slurry: primary filler: secondary filler = 2:1:5.7.

[0056] After complete drying through the above steps, a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling coating material was obtained. The water contact angle on the coating surface was 155±1°, and the rolling angle was 6±0.5°. A temperature tester was used to test a steel plate with this coating, and the maximum back temperature of the plate was 267°C. When a wood block with this coating was immersed in a sodium hydroxide solution with a pH of 13 for 20 days, the contact angle of the coating was 152±1°. After immersion in clean water for 20 days, the water absorption rate of the coating was 2.3%.

[0057] Example 3

[0058] Step 1. Weigh 0.1 parts of granular aluminum oxide with a particle size of 0.4 mm, 0.1 parts of fibrous zirconium oxide with a particle size of 0.8 mm, and 0.5 parts of flaky magnesium silicate with a particle size of 0.2 mm, and place them in a beaker with 6 parts of water and stir them thoroughly at a stirring speed of 300 r / min to obtain a uniform solution; weigh 3 parts of water-based acrylic acid and 2 parts of water-based epoxy curing agent NX-8502 and slowly add them to the solution in the previous step, mix them thoroughly and stir for 1 hour to obtain a uniform solution; apply it on a wood substrate and let it stand at room temperature for 1 hour to obtain a No. 1 coating with a film thickness of 1 mm.

[0059] Step 2: Take 1 part of methyltrimethoxysilane and 22 parts of the first solvent ether in a beaker, ultrasonicate for 25 minutes, and then magnetically stir for 30 minutes to uniformly disperse them to obtain a primary filler, which is evenly sprayed on the surface of the No. 1 coating prepared in step 1 to obtain the No. 2 coating.

[0060] Step 3: Weigh 0.4 parts of fluorosilicone resin and 5 parts of the second organic solvent, propanol, in a beaker and stir thoroughly for 40 minutes until uniform. Then, weigh 0.1 parts of aluminum hydroxide with an average particle size of 20 nanometers and 0.3 parts of silicon dioxide with an average particle size of 40 nanometers and stir for 30 minutes to obtain a uniform solution of the secondary filler. Spray or knife-coat the surface of the second coating treated in Step 2 to penetrate it, and let it dry at room temperature for 24 hours.

[0061] In terms of mass, the base slurry: primary filler: secondary filler = 1.95:1:5.8.

[0062] Following these steps, a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling coating material was obtained after complete drying. The water contact angle on the coating surface was 153±1°, and the rolling angle was 6±0.5°. A temperature tester was used to test a steel plate with this coating, and the maximum back temperature of the plate was 271°C. When a wood block with this coating was immersed in a sodium hydroxide solution with a pH of 13 for 20 days, the contact angle of the coating was 152±1°. After immersion in clean water for 20 days, the water absorption rate of the coating was 1.9%.

[0063] Example 4

[0064] Step 1: Weigh 0.3 parts of granular alumina with a particle size of 0.4 mm, 0.1 parts of fibrous titanium dioxide with a particle size of 0.5 mm, and 0.3 parts of flaky expanded graphite with a particle size of 0.2 mm, and place them in a beaker with 6 parts of water and stir them thoroughly at a stirring speed of 300 r / min to obtain a uniform solution; weigh 3 parts of water-based polyurethane and 2 parts of water-based epoxy curing agent NX-8502 and slowly add them to the solution in the previous step, mix them thoroughly and stir for 1 hour to obtain a uniform solution; apply it on a wood substrate and let it stand at room temperature for 1 hour to obtain a No. 1 coating with a film thickness of 1 mm.

[0065] Step 2: Take 1 part of aminopropyltriethoxysilane and 19 parts of the first solvent, anhydrous ethanol, in a beaker, ultrasonicate for 25 minutes, and then magnetically stir for 30 minutes to uniformly disperse them to obtain a primary filler, which is evenly sprayed on the surface of the No. 1 coating prepared in step 1 to penetrate and obtain the No. 2 coating.

[0066] Step 3: Weigh 0.4 parts of polytetrafluoroethylene and 5 parts of ethyl acetate, a second organic solvent, into a beaker and stir thoroughly for 40 minutes until uniform. Then, weigh 0.2 parts of aluminum hydroxide with an average particle size of 30 nanometers and 0.2 parts of silicon dioxide with an average particle size of 50 nanometers and stir for 30 minutes to obtain a uniform solution of the secondary filler. This solution is sprayed or knife-coated onto the surface of the second coating treated in Step 2 and dried at room temperature for 24 hours.

[0067] In terms of mass, the base slurry: primary filler: secondary filler = 1.95:1:5.8.

[0068] After complete drying through the above steps, a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling coating material was obtained. The water contact angle on the coating surface was 153±1°, and the rolling angle was 5±0.5°. A temperature tester was used to test a steel plate with this coating, and the maximum back temperature of the plate was 258°C. When a wood block with this coating was immersed in a sodium hydroxide solution with a pH of 13 for 20 days, the coating's contact angle was 153±1°. After immersion in clean water for 20 days, the coating's water absorption rate was 2.5%.

[0069] Comparative Example 1

[0070] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling multifunctional coating material is disclosed. The method and steps are substantially the same as those in Example 1, except that the solid flame-retardant filler comprises 0.1 part of spherical silica with a particle size of 0.5 mm, 0.1 part of spherical alumina with a particle size of 0.5 mm, and 0.4 part of spherical expanded graphite with a particle size of 0.2 mm. The resulting coating No. 1 has a film thickness of 1 mm.

[0071] The coating's surface contact angle was 117±1° and its sliding angle was 21±0.5°, failing to meet superhydrophobicity requirements. A temperature tester tested a steel plate with the coating, revealing a maximum back-temperature of 252°C. When a wood block coated with the coating was immersed in a pH 13 sodium hydroxide solution for 10 days, the coating's contact angle was 96±1°. After immersion in clean water for 10 days, the coating's water absorption reached saturation. This does not meet the flame-retardant, superhydrophobic, and anti-seepage requirements.

[0072] The flame retardant fillers have the same shape, and the arrangement and stacking of the particles are not conducive to the formation of a capillary porous structure, which affects the penetration and modification of the solution in the subsequent steps and reduces the superhydrophobicity of the coating.

[0073] Comparative Example 2

[0074] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling multifunctional coating material, the method and steps being substantially the same as those of Example 1, except that: the solid flame-retardant filler comprises 0.1 parts of spherical silica with a particle size of 20 nm, 0.1 parts of fibrous alumina with a particle size of 20 nm, and 0.4 parts of flaky expanded graphite with a particle size of 20 nm; and finally, a coating No. 1 with a film thickness of 1 mm is obtained.

[0075] The coating's surface contact angle was 117±1° and its sliding angle was 21±0.5°, failing to meet superhydrophobicity requirements. A temperature tester tested a steel plate with this coating, revealing a maximum back-temperature of 252°C. When a wood block coated with this coating was immersed in a pH 13 sodium hydroxide solution for 10 days, the coating's contact angle was 96±1°. After immersion in clean water for 10 days, the coating's water absorption reached saturation. This does not meet the flame retardant, superhydrophobic, and anti-seepage requirements.

[0076] The particle size of the flame retardant filler is at the nanometer level and cannot form a porous capillary structure, which in turn affects the infiltration modification of polydimethylsiloxane in step 2. Polytetrafluoroethylene, nano-silica and calcium aluminum phosphate cannot penetrate and fill into the coating, greatly reducing the hydrophobic self-cleaning performance of the coating.

[0077] Comparative Example 3

[0078] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling multifunctional coating material, the method and steps being substantially the same as those of Example 1, except that: the solid flame-retardant filler comprises 0.1 parts of spherical silica with a particle size of 2 mm, 0.1 parts of fibrous alumina with a particle size of 2 mm, and 0.4 parts of flaky expanded graphite with a particle size of 2 mm; and finally, a coating No. 1 with a film thickness of 1 mm is obtained.

[0079] The coating's surface contact angle was 146±1° and its sliding angle was 9±0.5°, failing to meet superhydrophobicity requirements. A temperature tester tested a steel plate with the coating, revealing a maximum back-temperature of 254°C. When a wood block coated with the coating was immersed in a pH 13 sodium hydroxide solution for 10 days, the coating's contact angle was 131±1°. After immersion in clean water for 10 days, the coating's water absorption reached saturation. This does not meet the flame-retardant, superhydrophobic, and anti-seepage requirements.

[0080] This shows that the porous structure formed by the regular arrangement of particles with consistent size will limit the inflow and infiltration paths of the slurry prepared in steps 2 and 3, resulting in uneven distribution of the slurry and difficulty in adhesion, making the coating unable to achieve a superhydrophobic effect.

[0081] Comparative Example 4

[0082] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material, the method and steps are basically the same as those in Example 1, except that: in step 3, inorganic particles with a particle size of 200 μm are taken; and finally a coating No. 1 with a film thickness of 1 mm is obtained.

[0083] The coating's surface contact angle was 134±1° and its sliding angle was 12±0.5°, failing to meet superhydrophobicity requirements. A temperature tester tested a steel plate with the coating, revealing a maximum back-temperature of 248°C. Immersing a wood block coated with the coating in a pH 13 sodium hydroxide solution for three days resulted in the loss of hydrophobicity. After immersion in clean water for five days, the coating's water absorption reached saturation. This does not meet the flame-retardant, superhydrophobic, and anti-seepage requirements.

[0084] In step 3, the inorganic particles are too large in size to effectively fill and penetrate into the coating, and cannot form a multi-level rough structure, so that the coating fails to meet the super-hydrophobic requirements and reduces the anti-seepage performance.

[0085] Comparative Example 5

[0086] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling multifunctional coating material, the method and steps being basically the same as those in Example 1, except that: the polydimethylsiloxane in step 2 is not added, and on the basis of step 1, the solution prepared in step 3 is infiltrated and modified, and the material is dried at room temperature; finally, a coating No. 1 with a film thickness of 1 mm is obtained.

[0087] The coating's surface contact angle was 141±1°, and its sliding angle was 13±0.5°. A temperature tester tested a steel plate with this coating, revealing a maximum back-temperature of 249°C. When a wood block coated with this coating was immersed in a pH 13 sodium hydroxide solution for 7 days, it lost its superhydrophobicity. After immersion in clean water for 10 days, the coating's water absorption reached saturation. This does not meet the flame retardant, superhydrophobic, and anti-seepage requirements.

[0088] Without polydimethylsiloxane to graft and modify the hydrophilic functional groups in the water-based epoxy resin, flame retardant filler silica, and alumina in the base layer, the surface energy of the coating cannot be effectively reduced, resulting in a decrease in hydrophobic properties.

[0089] Comparative Example 6

[0090] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material, the method and steps are basically the same as those in Example 2, except that: in step 1, the amount of water-based epoxy resin used is 15 parts; and finally, a coating No. 1 with a film thickness of 1 mm is obtained.

[0091] The contact angle of the coating surface is 147±1°, and the rolling angle is 10±0.5°. A temperature tester was used to test a steel plate with the coating, and the maximum back temperature of the steel plate was 267°C. The wood block with the coating lost its hydrophobicity when immersed in a sodium hydroxide solution with a pH of 13 for 30 days. After immersion in clean water for 28 days, the water absorption rate of the coating reached saturation. The requirements for flame retardancy and superhydrophobicity were not met. In Comparative Example 6, the water-based epoxy resin exceeded the specified dosage, but the superhydrophobic performance was not achieved.

[0092] Waterborne epoxy resin itself contains hydrophilic groups. Excessive use of it will increase the proportion of hydrophilic components in the overall system, increase the surface tension of the coating, make it more hydrophilic, and reduce the hydrophobic properties of the coating.

[0093] Comparative Example 7

[0094] A method for preparing a flame-retardant, super-hydrophobic, anti-seepage, and anti-fouling multifunctional coating material, the method and steps are basically the same as in Example 1, except that calcium aluminum phosphate is not added in step 3, the coating surface contact angle is 151±1°, and the rolling angle is 8±0.5°, which does not meet the super-hydrophobic requirements. The steel plate with the coating was tested with a temperature tester, and the maximum back temperature of the steel plate was 372°C. The wood block with the coating was immersed in a sodium hydroxide solution with a pH of 13 for 2 days to lose its hydrophobicity. Soaked in clean water for 7 days, the water absorption rate reached saturation. The flame-retardant, super-hydrophobic, and anti-seepage requirements are not met.

[0095] Calcium aluminum phosphate can promote the carbonization of the coating at high temperatures. The carbon layer formed can isolate oxygen and heat. Without calcium phosphate, the temperature of the steel back increases by about 1.5 times. It has good acid and alkali resistance and is not easily corroded. Without calcium aluminum phosphate, the temperature of the coated steel back will increase.

[0096] The above are preferred embodiments and comparative examples of the present invention, but the present invention is not limited to the contents disclosed in the embodiments. Therefore, any effects or modifications completed without departing from the method disclosed in the present invention fall within the scope of protection of the present invention.

Claims

1. A method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material, characterized in that: The steps include: S1. Stirring a flame retardant filler, a water-based resin, a curing agent, and water to obtain a base slurry; applying the base slurry evenly on a substrate and allowing it to stand to obtain a first coating; S2, mixing the siloxane and the first solvent after ultrasonication to obtain a primary filler, and evenly coating the primary filler on the surface of the first coating prepared in step S1 to obtain a second coating; S3, mixing the second organic solvent, the polymer resin and the inorganic nanoparticles to obtain a secondary filler, uniformly applying the secondary filler on the second coating prepared in step S2, and drying to obtain a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material; In step S1, the flame retardant filler is in a shape of two or three of flake, fiber and granule; The particle size of the fibrous flame retardant filler in step S1 is 0.5-2.4 mm; The particle size of the flaky flame retardant filler in step S1 is 0.2-0.9 mm; In step S1, the particle size of the granular flame retardant filler is 0.5-1.0 mm; In step S1, the bottom slurry includes flame retardant filler, water-based resin, water and curing agent, and the flame retardant filler is 0.6-1.5 parts, the water-based resin is 3-7 parts, the water is 6-10 parts, and the curing agent is 2-5 parts by mass; The inorganic nanoparticles in step S3 are one or more of nano-silicon dioxide, nano-aluminum hydroxide, nano-aluminum oxide, nano-magnesium hydroxide, nano-titanium dioxide, nano-sodium aluminum silicate or calcium aluminum phosphate.

2. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: The flame retardant filler in step S1 is two or more of silicon dioxide, montmorillonite, saponite powder, titanium dioxide, expanded graphite, fly ash, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, barium sulfate, zinc oxide, aluminum oxide, bentonite, sodium aluminum phosphate, zirconium oxide, carbon nanotubes, and magnesium silicate; The water-based resin includes one or more of water-based epoxy resin, polyvinyl alcohol, alkyd resin, fluorocarbon resin, water-based acrylic acid, and water-based polyurethane; The curing agent is NX-8502.

3. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: In step S2, the siloxane is one or more of polydimethylsiloxane, methyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldiethoxysilane, aminopropyltriethoxysilane and γ-mercaptopropyltriethoxysilane.

4. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: In step S2, the first solvent is one or more of anhydrous ethanol, ethyl acetate, isopropanol, acetone, ether, acetic acid, and tetrahydrofuran.

5. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: In the step S2, the volume ratio of the primary filler is siloxane:first solvent=5%-10%:

1.

6. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: In the step S3, the flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material is calculated in parts by mass, and the ratio of base slurry: primary filler: secondary filler is 1.5-2.5:1:5-7.

5.

7. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: In step S3, the secondary filler comprises a polymer resin, a second organic solvent and inorganic nanoparticles, wherein the polymer resin accounts for 0.4-0.7 parts, the second organic solvent accounts for 5-10 parts and the inorganic nanoparticles accounts for 0.4-0.7 parts by mass.

8. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: The polymer resin in step S3 is one or more of polytetrafluoroethylene, polyvinylidene fluoride, fluorosilicone resin, polystyrene butadiene copolymer, and ethylene-vinyl acetate copolymer.

9. The method for preparing a flame-retardant, super-hydrophobic, anti-seepage and anti-fouling multifunctional coating material according to claim 1, characterized in that: In step S3, the second organic solvent is one or more of ethyl acetate, ethanol, n-hexane, diethyl ether, propanol, and dimethyl ether.