A polar self-deicing anticorrosive coating and a method for preparing the same

Abstract

The application discloses a preparation method of a polar self-deicing anticorrosion coating, and comprises the following steps: preparing a flexible end-amino polyurea curing agent, preparing a low-modulus high-toughness epoxy primer and a high-modulus weather-resistant fluorocarbon topcoat, and preparing a gradient modulus structure self-deicing anticorrosion coating; the polar self-deicing anticorrosion coating prepared by the application delays ice formation by means of the hydrophobic surface of the fluorocarbon topcoat; the modulus mismatch between the topcoat and the primer causes the ice-coating interface to wrinkle under external force, so that the interface can be broken in a controllable manner to realize self-deicing; the flaky interface reinforcing filler is used to enhance the compactness and hydrophobicity of the primer coating, and the primer coating and the topcoat are used in cooperation to resist the penetration of corrosive media, so that long-acting anticorrosion is realized; in addition, the primer introduces flexible chain segments and polyurea toughening phases, and is chemically bonded with the topcoat, so that the low-temperature toughness and impact resistance are synergistically enhanced; the application solves the problem that the low-temperature mechanical properties, long-acting anticorrosion and persistent deicing performance of the polar coating material are difficult to be considered simultaneously, and can meet the deicing and anticorrosion requirements of the upper aluminum alloy structure of a polar ship.

Description

Technical Field

[0001] This invention belongs to the field of metal anti-corrosion coating technology, specifically relating to a polar self-de-icing anti-corrosion coating and its preparation method. Background Technology

[0002] With the opening of polar shipping routes and the development and utilization of abundant polar resources, polar vessels have experienced rapid growth. 5xxx series aluminum alloys, due to their lightweight, high specific strength, corrosion resistance, excellent low-temperature performance, and processing properties, are widely used in the superstructures of polar vessels. Compared to steel, using aluminum alloy profiles in ship superstructure construction not only reduces ship weight, improves speed and stability, but also saves fuel, increases payload, and enhances navigation economy. Simultaneously, the passivation film formed on the aluminum alloy surface protects the metal substrate, giving the aluminum alloy good corrosion resistance. However, the complex meteorological and sea conditions in the polar regions, such as low temperatures, snow, and sea fog, easily damage the porous passivation film, inducing corrosion and posing a serious threat to the aluminum alloy structures of ships. Furthermore, in low-temperature environments, the superstructure is prone to snow and ice accumulation, affecting the ship's draft and center of gravity, reducing ship stability and the reliability of the superstructure structure.

[0003] To improve the corrosion resistance and anti-icing performance of aluminum alloy structures in polar marine environments, existing technologies typically apply integrated anti-icing and anti-corrosion coatings to the aluminum alloy surface. These include superhydrophobic coatings, liquid lubricating coatings, "liquid-like" lubricating coatings, and interface-controlled fracture anti-icing coatings. The aim is to extend the service life of aluminum alloy profiles used in ships by preventing ice formation, improving de-icing efficiency, and blocking corrosive media from contacting the aluminum alloy, thus reducing corrosion. However, these coatings suffer from poor moisture resistance and durability, and limited de-icing and anti-corrosion lifespan. Furthermore, traditional organic coatings exhibit decreased elasticity and significant embrittlement under polar low-temperature conditions, making them prone to cracking and peeling during impacts or mechanical de-icing, increasing the corrosion risk of the aluminum alloy substrate. Therefore, developing a composite coating that integrates anti-icing, low-temperature high toughness, low-temperature impact resistance, and anti-corrosion functions is crucial for ensuring the safety and stability of aluminum alloy superstructures during polar navigation.

[0004] Li et al. (Dandan Li, Zaiwen Lin, Qi Liu, et al. A robust and reusable lubricant-infused surface with anticorrosion and anti-icing properties[J]. Progress in Organic Coatings, 2023, 183: 107711) obtained a robust and reusable oil-lubricated anti-icing coating by injecting lubricant into a surface-modified microstructured epoxy resin coating. This coating exhibited excellent passive anti-icing and corrosion resistance, and its anti-icing effect could be restored by re-injecting lubricant. However, due to the low surface energy of the lubricant, it is prone to migration and loss, requiring regular lubricant replenishment to maintain its anti-icing function, which is cumbersome and costly; furthermore, lubricant loss causes environmental pollution. In addition, the epoxy coating has poor low-temperature toughness and is prone to cracking under impact or mechanical de-icing, leading to the failure of its anti-corrosion function.

[0005] Zhang et al. (Pengyuan Zhang, Yamei Zhao, Xiaoqi Gu, et al. Constructing carbon nanotube (CNTs) / silica superhydrophobic coating with multi-stage rough structure for long-term anti-corrosion and low-temperature anti-icing in the marine environment[J]. Composites Science and Technology, 2024, 257: 110798) prepared a multi-stage rough superhydrophobic coating with an interconnected porous framework structure using fluorosilane-modified MWCNTs-SiO2 dot-line composite filler, PVAc binder, and porous PVDF. This coating significantly improved the corrosion resistance and anti-icing performance of aluminum alloys. However, the superhydrophobic surface will fail under long-term high humidity conditions, causing ice accumulation on the surface, and the durability of the surface micro-nano structure is poor. In addition, the toughness of the coating is significantly reduced at low temperatures, making it prone to cracking or breakage, affecting its low-temperature corrosion resistance.

[0006] Nazifi et al. (Sina Nazifi, Zixu Huang, Alireza Hakimian, et al. Fracture-controlled surfaces as extremely durable ice-shedding materials[J]. Materials Horizons, 2022, 9(10): 2524-2532) designed an interface-controlled fracture de-icing coating using polyurethane with a high shear modulus as the matrix phase and polydimethylsiloxane gel with a low shear modulus as the dispersed phase. Due to the chemical and mechanical inhomogeneity of the coating surface structure, under external force, interfacial cracks preferentially form in the dispersed phase of the coating and propagate rapidly, thus causing ice to desorb quickly under low shear force. This coating can significantly reduce the ice adhesion strength of the coating and improve the mechanical stability of the coating surface material. However, the practical application of this coating is limited by the limited crack initiation sites and reduced durability.

[0007] Chinese patent "A Thin-Layer High-Impact Low-Temperature Anti-Corrosion Coating and Its Preparation Method and Application" (Application No.: 202311297301.0, Publication No.: CN 117264520A, Publication Date: 2023.12.22) discloses an anti-corrosion coating prepared from low surface energy modified elastic polyurethane resin, anti-corrosion filler, weather-resistant filler, wetting and dispersing agent, leveling agent, organic solvent, and isocyanate curing agent. This coating maintains excellent mechanical properties, anti-icing and anti-corrosion performance at low temperatures even with a thin coating thickness, meeting the requirements for anti-corrosion and de-icing of ship hulls and superstructures, and reducing the risks of polar navigation. However, the coating only relies on a hydrophobic surface to prevent icing, resulting in poor anti-icing durability; once icing occurs, external force is still required for de-icing, increasing labor costs and potentially damaging the protective coating. Summary of the Invention

[0008] The purpose of this invention is to provide a polar self-de-icing and anti-corrosion coating and its preparation method, so as to solve the problem that it is difficult to simultaneously achieve low-temperature mechanical properties, long-term corrosion resistance and durable anti-icing performance of polar coating materials.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for preparing a polar self-de-icing and anti-corrosion coating is specifically implemented according to the following steps:

[0011] Step 1, Preparation of flexible amino-terminated polyurea curing agent:

[0012] Isophorone diisocyanate and solvent A were added to a three-necked flask and nitrogen gas was introduced for protection. The mixture was heated under stirring, and then dehydrated polyethylene glycol was added dropwise. After stirring in a water bath for a period of time, the mixture was cooled to room temperature. Then it was added dropwise to a solution composed of polyetheramine and solvent B. The mixture was stirred in an ice bath under a nitrogen atmosphere for a period of time. Finally, the solvent was removed by rotary evaporation to obtain a flexible amino-terminated polyurea curing agent.

[0013] Step 2, prepare a low-modulus, high-toughness epoxy primer:

[0014] Step 2.1: Mix two-dimensional sheet-like anti-corrosion filler, aluminum hydroxide, ammonia, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, ethanol, and deionized water. After stirring evenly in a water bath, dry in an oven to obtain a sheet-like superhydrophobic interface strengthening filler.

[0015] Step 2.2: Mix the flexible amino-terminated polyurea curing agent obtained in Step 1 with the superhydrophobic interface strengthening filler, epoxy resin, polyetheramine curing agent, defoamer and solvent obtained in Step 2.1, and stir evenly to obtain a low modulus and high toughness epoxy primer.

[0016] Step 3: Prepare a high-modulus, weather-resistant fluorocarbon topcoat:

[0017] HDI trimer was mixed with γ-aminopropyltriethoxysilane and heated for a period of time to generate silane coupling agent modified HDI trimer. After cooling to room temperature, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate and solvent were added to it. After uniform mixing, a high modulus weather-resistant fluorocarbon topcoat was obtained.

[0018] Step 4: Prepare a self-de-icing and anti-corrosion coating with a gradient modulus structure.

[0019] The low-modulus, high-toughness epoxy primer obtained in step 2 is brushed onto the pretreated aluminum alloy profile. After drying and curing for a period of time, the high-modulus, weather-resistant fluorocarbon topcoat obtained in step 3 is sprayed onto the primer surface of the semi-cured aluminum alloy profile. After heat curing, a polar self-de-icing and anti-corrosion coating with a skin-like gradient modulus structure is obtained.

[0020] Further, in step 1, the mass percentages of isophorone diisocyanate, solvent A, polyethylene glycol, polyetheramine, and solvent B are 19.58%–22.54%, 14.71%–21.47%, 26.32%–30.42%, 11.15%–17.62%, and 14.71%–21.48%, respectively, and the total of the above components is 100%; solvent A and solvent B are one of N,N dimethylformamide, N,N dimethylacetamide, ethyl acetate, and tetrahydrofuran; polyetheramine is one of D230 and D400.

[0021] Further, the specific steps of step 1 are as follows: Isophorone diisocyanate and solvent A are added to a three-necked flask and protected with nitrogen gas. The temperature is raised to 65-80°C under stirring at a speed of 300-500 rpm. Then, dehydrated polyethylene glycol is added dropwise. The polyethylene glycol dehydration process is as follows: the polyethylene glycol is dried at 120°C in a vacuum drying oven at -0.09 MPa for 2-3 hours, with a dropwise addition rate of 5 mL / min. The mixture is stirred in a water bath for 3-4 hours at a temperature of 65-80°C. Then, it is cooled to room temperature and added dropwise to a solution composed of polyetheramine and solvent B. The mixture is stirred in an ice bath under a nitrogen atmosphere for a period of time. The ice bath stirring conditions are: ice bath temperature of 0°C, ice bath stirring speed of 300-500 rpm, and ice bath time of 2-3 hours. Finally, the solvent is removed by rotary evaporation at a temperature of 90-110°C for 2-3 hours to obtain a flexible amino-terminated polyurea curing agent.

[0022] Further, in step 2.1, the mass percentages of the two-dimensional sheet-like anti-corrosion filler, aluminum hydroxide, ammonia, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, deionized water, and ethanol are 5.61%–5.69%, 1.58%–1.68%, 3.98%–4.25%, 9.74%–12.17%, 5.84%–6.56%, and 69.65%–73.25%, respectively, with the total of the above components being 100%. The two-dimensional sheet-like anti-corrosion filler is one of mica and diatomaceous earth. The water bath stirring conditions are: water bath temperature 50–60℃, water bath time 12–15h, and stirring speed 500–700rpm. The drying conditions in the oven are: drying temperature 120–150℃, and drying time 6–10h.

[0023] Further, in step 2.2, the mass percentages of the flexible amino-terminated polyurea curing agent, superhydrophobic interface reinforcing filler, epoxy resin, polyetheramine curing agent, defoamer, and solvent are 10.29%–14.76%, 8.83%–9.71%, 44.14%–48.55%, 9.99%–17.48%, 0.88%–0.97%, and 8.53%–25.87%, respectively, with the total of the above components being 100%. The epoxy resin is any one of E44 and E51, the polyetheramine curing agent is any one of D230 and D400, the defoamer is any one of n-octanol and TEGO 900 silicone defoamer, and the solvent is any one of N,N dimethylformamide, N,N dimethylacetamide, ethyl acetate, and tetrahydrofuran. The stirring speed is 200–500 rpm, and the stirring time is 5–10 min.

[0024] Further, in step 3, the mass percentages of the HDI trimer and γ-aminopropyltriethoxysilane are 90%–98% and 2%–10%, respectively, with the total of the above components being 100%; the mass percentages of the silane coupling agent-modified HDI trimer, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate, and solvent are 7.36%–9.75%, 73.31%–73.64%, 0.95%–0.96%, 0.95%–0.96%, 0.29%–0.37%, and 14.66%–16.79%, respectively, with the total of the above components being 100%; FEVE resin is a polymer copolymerized from fluoroolefin monomers and vinyl ether or ester monomers; the leveling agent is the silicone additive BYK-306; the defoamer is TEGO 900 silicone defoamer; and the solvent is either butyl acetate or xylene.

[0025] Furthermore, in step 3, the HDI trimer and γ-aminopropyltriethoxysilane are mixed and heated to a reaction temperature of 60–80°C for 2–3 hours, with a stirring rate of 300–500 rpm. The conditions for mixing the silane coupling agent-modified HDI trimer, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate, and solvent are: a stirring rate of 200–500 rpm and a stirring time of 5–10 minutes.

[0026] Further, the aluminum alloy profile pretreatment method in step 4 is as follows: after ultrasonic cleaning, the aluminum alloy profile is immersed in sodium hydroxide solution, rinsed with deionized water until neutral, and then immersed in nitric acid solution and rinsed with water until neutral to obtain a surface-pretreated aluminum alloy profile; the mass fraction of sodium hydroxide solution is 4% to 5%, and the immersion time of the aluminum alloy profile in sodium hydroxide solution is 90 to 150 s; the mass fraction of nitric acid solution is 10% to 12%, and the immersion time of the aluminum alloy profile in nitric acid solution is 80 to 120 s.

[0027] Furthermore, in step 4, the brushing amount is 300–600 mL / m 2 The drying and curing temperature is 50–60℃, and the drying and curing time is 0.5–1 hour. The spraying equipment uses an air compressor to provide air pressure of 0.2–0.4 MPa, the spraying distance is 15–20 cm, and the spraying amount is 7.5–15 mL / m. 2 The heat curing temperature is 60-70℃, the heat curing time is 2-3h, the thickness of the low modulus primer coating is 200-400μm, and the thickness of the high modulus topcoat coating is 5-10μm.

[0028] The polar self-de-icing and anti-corrosion coating was prepared according to the above-described method.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] This invention provides a method for preparing a polar self-de-icing and anti-corrosion coating. A composite coating integrating long-lasting anti-icing, low-temperature high toughness, low-temperature impact resistance, and anti-corrosion functions is prepared on the surface of the aluminum alloy superstructure of polar ships. The low surface energy fluorocarbon topcoat of the coating has excellent hydrophobicity, which reduces the adhesion of droplets and prolongs the freezing time of droplets, thus achieving anti-icing function. When ice forms, the skin-like gradient modulus structure of the coating utilizes the instability of the coating surface caused by the modulus mismatch between the thin, hard topcoat and the soft primer. Under external force, numerous wrinkles are generated at the ice-coating interface, inducing interface cracks and stress concentration, thereby reducing the adhesion strength of ice. Large-area ice self-detachment is achieved solely by gravity or wind. The primer coating utilizes flexible terminal amino polyurea as an epoxy resin curing agent, introducing flexible segments into the crosslinking network to lower the glass transition temperature of the material. It enhances toughness, slows crack propagation, and provides energy absorption buffering through molecular chain slippage and phase separation. Simultaneously, it chemically bonds with the topcoat, which possesses excellent low-temperature mechanical properties, synergistically achieving low-temperature toughness and impact resistance. A lamellar superhydrophobic interface-reinforcing filler fills the pores and microcracks in the primer coating, increasing the crosslinking density and enhancing its hydrophobicity. Together with the hydrophobic topcoat, it resists the penetration of corrosive media, achieving long-term anti-corrosion functionality. The skin-like gradient modulus structure polar self-de-icing and anti-corrosion coating prepared in this invention solves the problem of simultaneously achieving low-temperature mechanical properties, long-term anti-corrosion, and durable anti-icing performance in polar coating materials, meeting the de-icing and anti-corrosion needs of the upper aluminum alloy structure of ships navigating in polar regions. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the polar self-de-icing and anti-corrosion coating prepared according to the present invention.

[0032] In the figure, 1-aluminum alloy profile, 2-low modulus primer coating, 3-flaky superhydrophobic interface reinforcing filler, 4-high modulus topcoat coating. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0034] A polar self-de-icing and anti-corrosion coating and its preparation method are specifically implemented according to the following steps:

[0035] Step 1, Preparation of flexible amino-terminated polyurea curing agent:

[0036] Isophorone diisocyanate and solvent A were added to a three-necked flask and protected with nitrogen. The mixture was heated to 65–80°C under stirring at 300–500 rpm. Then, dehydrated polyethylene glycol (PEG dehydration step: drying at 120°C for 2–3 h in a vacuum drying oven at -0.09 MPa) was added dropwise at a rate of 5 mL / min. The mixture was stirred at 300–500 rpm for 3–4 h at 65–80°C and then cooled to room temperature. Next, it was added dropwise to a solution composed of polyetheramine and solvent B. The mixture was stirred in an ice bath at 0°C for 2–3 h under a nitrogen atmosphere at a stirring speed of 300–500 rpm. Finally, the solvent was removed by rotary evaporation at 90–110°C for 2–3 h to obtain a flexible amino-terminated polyurea curing agent.

[0037] The mass percentages of isophorone diisocyanate, solvent A, polyethylene glycol, polyetheramine, and solvent B are 19.58%–22.54%, 14.71%–21.47%, 26.32%–30.42%, 11.15%–17.62%, and 14.71%–21.48%, respectively, with the total of these components being 100%. Solvent A and solvent B are one of N,N dimethylformamide, N,N dimethylacetamide, ethyl acetate, and tetrahydrofuran; the polyetheramine is one of D230 and D400.

[0038] Step 2, prepare a low-modulus, high-toughness epoxy primer:

[0039] Step 2.1: Mix two-dimensional sheet-like anti-corrosion filler, aluminum hydroxide, ammonia, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, ethanol, and deionized water. Stir at 500-700 rpm for 12-15 h at 50-60 °C, and then dry in an oven at 120-150 °C for 6-10 h to obtain a sheet-like superhydrophobic interface strengthening filler.

[0040] The mass percentages of the two-dimensional lamellar anti-corrosion filler, aluminum hydroxide, ammonia, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, deionized water, and ethanol are 5.61%–5.69%, 1.58%–1.68%, 3.98%–4.25%, 9.74%–12.17%, 5.84%–6.56%, and 69.65%–73.25%, respectively, with the total composition being 100%. The two-dimensional lamellar anti-corrosion filler is a type of mica or diatomaceous earth.

[0041] Step 2.2: Mix the flexible amino-terminated polyurea curing agent obtained in Step 1 with superhydrophobic interface strengthening filler, epoxy resin, polyetheramine curing agent, defoamer and solvent, and stir at a stirring speed of 200-500 rpm for 5-10 minutes to obtain a low modulus and high toughness epoxy primer.

[0042] The mass percentages of the flexible amino-terminated polyurea curing agent, superhydrophobic interface reinforcing filler, epoxy resin, polyetheramine curing agent, defoamer, and solvent are 10.29%–14.76%, 8.83%–9.71%, 44.14%–48.55%, 9.99%–17.48%, 0.88%–0.97%, and 8.53%–25.87%, respectively, with the total of these components being 100%. The epoxy resin is either E44 or E51, the polyetheramine curing agent is either D230 or D400, the defoamer is either n-octanol or TEGO 900 silicone defoamer, and the solvent is either N,N dimethylformamide, N,N dimethylacetamide, ethyl acetate, or tetrahydrofuran.

[0043] Step 3: Prepare a high-modulus, weather-resistant fluorocarbon topcoat:

[0044] HDI trimer was mixed with γ-aminopropyltriethoxysilane and stirred at 300-500 rpm for 2-3 hours at 60-80°C to generate silane coupling agent modified HDI trimer. After cooling to room temperature, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate and solvent were added to the mixture and stirred at 200-500 rpm for 5-10 minutes to obtain a high modulus weather-resistant fluorocarbon topcoat.

[0045] The mass percentages of HDI trimer and γ-aminopropyltriethoxysilane are 90%–98% and 2%–10%, respectively, with the total of these components being 100%. The mass percentages of the silane coupling agent-modified HDI trimer, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate, and solvent are 7.36%–9.75%, 73.31%–73.64%, 0.95%–0.96%, 0.95%–0.96%, 0.29%–0.37%, and 14.66%–16.79%, respectively, with the total of these components being 100%. FEVE resin is a polymer copolymerized from fluoroolefin monomers and vinyl ether or ester monomers. The leveling agent is the silicone additive BYK-306, and the defoamer is TEGO 900 silicone defoamer. The solvent is either butyl acetate or xylene.

[0046] Step 4: Prepare a self-de-icing and anti-corrosion coating with a gradient modulus structure.

[0047] The low-modulus, high-toughness epoxy primer obtained in step 2 is applied at a concentration of 300–600 mL / m. 2 For pre-treated aluminum alloy profiles, after brush coating and drying / curing at 50–60℃ for 0.5–1 hour, spray at an air pressure of 0.2–0.4 MPa, maintaining a spraying distance of 15–20 cm and a spray rate of 7.5–15 mL / m. 2The high modulus weather-resistant fluorocarbon topcoat obtained in step 3 is sprayed onto the primer surface of the semi-cured aluminum alloy profile. After heat curing at 60-70℃ for 2-3 hours, a polar self-de-icing and anti-corrosion coating with a skin-like gradient modulus structure is obtained.

[0048] The pretreatment method for aluminum alloy profiles is as follows: After ultrasonic cleaning of the aluminum alloy substrate, it is immersed in a 4%–5% sodium hydroxide solution for 90–150 seconds, rinsed with deionized water until neutral, and then immersed in a 10%–12% nitric acid solution for 80–120 seconds. It is then rinsed with water until neutral to obtain the surface-pretreated aluminum alloy profile. The thickness of the low-modulus primer coating is 200–400 μm, and the thickness of the high-modulus topcoat coating is 5–10 μm.

[0049] The polar self-de-icing and anti-corrosion coating prepared by this invention is as follows: Figure 1 As shown in the figure, the polar self-de-icing and anti-corrosion coating on the surface of the aluminum alloy profile 1 consists of a high-modulus topcoat coating 4 and a low-modulus primer coating 2. The two are covalently bonded together to form a skin-like gradient modulus structure. The low-modulus primer coating 2 contains uniformly distributed lamellar superhydrophobic interface reinforcing filler 3.

[0050] Example 1

[0051] 3.3 g of isophorone diisocyanate and 2.8 g of N,N-dimethylacetamide were added to a three-necked flask and protected with nitrogen. The mixture was heated to 65 °C with stirring at 300 rpm. Then, 4.0 g of dehydrated polyethylene glycol (-0.09 MPa, vacuum dried at 120 °C for 2 h) was added dropwise at a rate of 5 mL / min. The mixture was stirred at 300 rpm at 65 °C for 4 h and then cooled to room temperature. Next, it was added dropwise to a solution composed of 2.2 g of polyetheramine D230 and 2.8 g of N,N-dimethylacetamide. The mixture was stirred in an ice bath at 0 °C with stirring at 300 rpm under a nitrogen atmosphere for 3 h. Finally, the solvent was removed by rotary evaporation at 90 °C for 3 h to obtain a flexible amino-terminated polyurea curing agent.

[0052] 1.2g diatomaceous earth, 0.36g aluminum hydroxide, 0.91g ammonia, 2.09g 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 15.58g ethanol, and 1.25g deionized water were mixed and stirred at 500rpm for 15h at 50℃, followed by drying in an oven at 120℃ for 10h to obtain a sheet-like superhydrophobic interface reinforcing filler. 2.12g flexible amino-terminated polyurea curing agent was mixed with 2.0g superhydrophobic interface reinforcing filler, 10.0g epoxy resin E51, 2.28g polyetheramine D230 curing agent, 0.2g n-octanol, and 4.0g NN dimethylacetamide and stirred at 200rpm for 10min to obtain a low-modulus, high-toughness epoxy primer.

[0053] 1.2g of HDI trimer was mixed with 0.13g of γ-aminopropyltriethoxysilane and stirred at 300rpm for 3h at 60℃ to generate silane coupling agent modified HDI trimer. After cooling to room temperature, 10.0g of FEVE resin, 0.13g of organosilicon additive BYK-306, 0.13g of TEGO 900 organosilicon defoamer, 0.05g of dibutyltin dilaurate and 2g of butyl acetate were added. After stirring at 200rpm for 10min, a high modulus weather-resistant fluorocarbon topcoat was obtained.

[0054] Use a low-modulus, high-toughness epoxy primer at 300 mL / m 2 The coating amount was applied to aluminum alloy profiles that had undergone alkali washing and acid washing pretreatment. After drying and curing at 50℃ for 1 hour, the coating was applied at an air pressure of 0.2MPa, maintaining a spraying distance of 15cm and a spraying rate of 7.5mL / m. 2 A high-modulus weather-resistant fluorocarbon topcoat is sprayed onto the semi-cured primer surface. After heat curing at 60℃ for 3 hours, a skin-like gradient modulus structure polar self-de-icing and anti-corrosion coating with a primer coating thickness of 200μm and a topcoat coating thickness of 5μm is obtained.

[0055] Example 2

[0056] 3.55 g of isophorone diisocyanate and 2.83 g of ethyl acetate were added to a three-necked flask and protected with nitrogen. The mixture was heated to 80 °C with stirring at 500 rpm. Then, 4.8 g of dehydrated polyethylene glycol (-0.09 MPa, vacuum dried at 120 °C for 3 h) was added dropwise at a rate of 5 mL / min. The mixture was stirred at 500 rpm for 3 h at 80 °C and then cooled to room temperature. Next, it was added dropwise to a solution of 1.76 g of polyetheramine D230 and 2.84 g of ethyl acetate. The mixture was stirred at 500 rpm in an ice bath at 0 °C for 3 h under a nitrogen atmosphere. Finally, the solvent was removed by rotary evaporation at 110 °C for 2 h to obtain a flexible amino-terminated polyurea curing agent.

[0057] 1.3g mica, 0.36g aluminum hydroxide, 0.91g ammonia, 2.78g 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 16.0g ethanol, and 1.5g deionized water were mixed and stirred at 700rpm for 12h at 60℃, followed by drying in an oven at 150℃ for 6h to obtain a sheet-like superhydrophobic interface-reinforcing filler. 3.18g flexible amino-terminated polyurea curing agent was mixed with 2.0g superhydrophobic interface-reinforcing filler, 10.0g epoxy resin E44, 2.16g polyetheramine D230 curing agent, 0.2g TEGO 900 silicone defoamer, and 4.0g ethyl acetate, and stirred at 500rpm for 5min to obtain a low-modulus, high-toughness epoxy primer.

[0058] 0.98g of HDI trimer was mixed with 0.02g of γ-aminopropyltriethoxysilane and stirred at 80℃ for 2h at 500rpm to generate silane coupling agent modified HDI trimer. After cooling to room temperature, 10.0g of FEVE resin, 0.13g of organosilicon additive BYK-306, 0.13g of TEGO 900 organosilicon defoamer, 0.04g of dibutyltin dilaurate and 2.28g of xylene were added. After stirring at 500rpm for 5min, a high modulus weather-resistant fluorocarbon topcoat was obtained.

[0059] Use a low-modulus, high-toughness epoxy primer at 600 mL / m 2 The coating amount was applied to aluminum alloy profiles that had undergone alkali washing and acid washing pretreatment. After drying and curing at 60℃ for 0.5 hours, the coating was applied at an air pressure of 0.4MPa, maintaining a spraying distance of 20cm and a spraying rate of 15mL / m. 2 A high-modulus weather-resistant fluorocarbon topcoat is sprayed onto the semi-cured primer surface. After heat curing at 70℃ for 2 hours, a skin-like gradient modulus structure polar self-de-icing and anti-corrosion coating with a primer coating thickness of 400μm and a topcoat coating thickness of 10μm is obtained.

[0060] Example 3

[0061] 3.6 g of isophorone diisocyanate and 2.8 g of N-N dimethylacetamide were added to a three-necked flask and protected with nitrogen. The mixture was heated to 75 °C with stirring at 400 rpm. Then, 4.8 g of dehydrated polyethylene glycol (-0.09 MPa, vacuum dried at 120 °C for 2.5 h) was added dropwise at a rate of 5 mL / min. The mixture was stirred at 400 rpm at 75 °C for 3.5 h and then cooled to room temperature. Next, it was added dropwise to a solution composed of 3.2 g of polyetheramine D400 and 3.8 g of N-N dimethylacetamide. The mixture was stirred at 400 rpm in a nitrogen atmosphere and reacted in an ice bath at 0 °C for 2.5 h. Finally, the solvent was removed by rotary evaporation at 100 °C for 2.5 h to obtain a flexible amino-terminated polyurea curing agent.

[0062] 1.2g diatomaceous earth, 0.36g aluminum hydroxide, 0.91g ammonia, 2.09g 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 15.58g ethanol, and 1.25g deionized water were mixed and stirred at 600rpm for 14h at 55℃, followed by drying in an oven at 140℃ for 8h to obtain a sheet-like superhydrophobic interface reinforcing filler. 2.49g flexible amino-terminated polyurea curing agent was mixed with 2.0g superhydrophobic interface reinforcing filler, 10.0g epoxy resin E51, 3.96g polyetheramine D400 curing agent, 0.2g n-octanol, and 4.0g NN dimethylacetamide and stirred at 400rpm for 8min to obtain a low-modulus, high-toughness epoxy primer.

[0063] 1.2g of HDI trimer was mixed with 0.13g of γ-aminopropyltriethoxysilane and stirred at 70℃ for 2.5h at 400rpm to generate silane coupling agent modified HDI trimer. After cooling to room temperature, 10.0g of FEVE resin, 0.13g of organosilicon additive BYK-306, 0.13g of TEGO 900 organosilicon defoamer, 0.05g of dibutyltin dilaurate and 2g of xylene were added. After stirring at 300rpm for 8min, a high modulus weather-resistant fluorocarbon topcoat was obtained.

[0064] Use a low-modulus, high-toughness epoxy primer at 450 mL / m 2 The coating amount was applied to aluminum alloy profiles that had undergone alkali washing and acid washing pretreatment. After drying and curing at 55℃ for 1 hour, the coating was applied at an air pressure of 0.3MPa, maintaining a spraying distance of 18cm and a spray rate of 9mL / m. 2 A high-modulus weather-resistant fluorocarbon topcoat was sprayed onto the semi-cured primer surface. After heat curing at 65℃ for 2.5 hours, a skin-like gradient modulus structure polar self-de-icing and anti-corrosion coating with a primer coating thickness of 300μm and a topcoat coating thickness of 6μm was obtained.

[0065] Example 4

[0066] 3.33 g of isophorone diisocyanate and 3.65 g of tetrahydrofuran were added to a three-necked flask and protected with nitrogen. The mixture was heated to 65 °C with stirring at 300 rpm. Then, 4.48 g of dehydrated polyethylene glycol (-0.09 MPa, vacuum dried at 120 °C for 2 h) was added dropwise at a rate of 5 mL / min. The mixture was stirred at 300 rpm at 65 °C for 4 h and then cooled to room temperature. Next, it was added dropwise to a solution composed of 1.9 g of polyetheramine D230 and 3.65 g of tetrahydrofuran. The mixture was stirred in an ice bath at 0 °C with stirring at 300 rpm under a nitrogen atmosphere for 2 h. Finally, the solvent was removed by rotary evaporation at 110 °C for 3 h to obtain a flexible amino-terminated polyurea curing agent.

[0067] 1.23g mica, 0.35g aluminum hydroxide, 0.88g ammonia, 2.15g 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 16.0g ethanol, and 1.28g deionized water were mixed and stirred at 700rpm for 12h at 60℃, followed by drying in an oven at 120℃ for 10h to obtain a sheet-like superhydrophobic interface-reinforcing filler. 2.212g flexible amino-terminated polyurea curing agent was mixed with 1.9g superhydrophobic interface-reinforcing filler, 9.49g epoxy resin E44, 2.148g polyetheramine D400 curing agent, 0.19g n-octanol, and 5.56g tetrahydrofuran, and stirred at 500rpm for 10min to obtain a low-modulus, high-toughness epoxy primer.

[0068] 0.95g of HDI trimer was mixed with 0.05g of γ-aminopropyltriethoxysilane and stirred at 80℃ for 2h at 500rpm to generate silane coupling agent modified HDI trimer. After cooling to room temperature, 10.0g of FEVE resin, 0.13g of organosilicon additive BYK-306, 0.13g of TEGO 900 organosilicon defoamer, 0.04g of dibutyltin dilaurate and 2.28g of xylene were added. After stirring at 500rpm for 5min, a high modulus weather-resistant fluorocarbon topcoat was obtained.

[0069] Use a low-modulus, high-toughness epoxy primer at 600 mL / m 2 The coating amount was applied to aluminum alloy profiles that had undergone alkali washing and acid washing pretreatment. After drying and curing at 50℃ for 1 hour, the coating was applied at an air pressure of 0.4MPa, maintaining a spraying distance of 15cm and a spray rate of 15mL / m. 2 A high-modulus weather-resistant fluorocarbon topcoat is sprayed onto the semi-cured primer surface. After heat curing at 70℃ for 3 hours, a skin-like gradient modulus structure polar self-de-icing and anti-corrosion coating with a primer coating thickness of 400μm and a topcoat coating thickness of 10μm is obtained.

[0070] Example 5

[0071] 3.83 g of isophorone diisocyanate and 2.5 g of NN dimethylacetamide were added to a three-necked flask and protected with nitrogen. The mixture was heated to 70 °C with stirring at 300 rpm. Then, 5.17 g of dehydrated polyethylene glycol (-0.09 MPa, vacuum dried at 120 °C for 3 h) was added dropwise at a rate of 5 mL / min. The mixture was stirred at 300 rpm at 70 °C for 4 h and then cooled to room temperature. Next, it was added dropwise to a solution composed of 2.995 g of polyetheramine D400 and 2.5 g of NN dimethylacetamide. The mixture was stirred in an ice bath at 0 °C with stirring at 300 rpm under a nitrogen atmosphere for 2 h. Finally, the solvent was removed by rotary evaporation at 110 °C for 2 h to obtain a flexible amino-terminated polyurea curing agent.

[0072] 1.252g diatomaceous earth, 0.37g aluminum hydroxide, 0.935g ammonia, 2.676g 1H,1H,2H,2H-perfluorodecyltriethoxysilane, 15.32g ethanol, and 1.444g deionized water were mixed and stirred at 700rpm for 15h at 50℃, followed by drying in an oven at 150℃ for 8h to obtain a sheet-like superhydrophobic interface reinforcing filler. 3.174g flexible amino-terminated polyurea curing agent was mixed with 2.087g superhydrophobic interface reinforcing filler, 10.44g epoxy resin E51, 3.758g polyetheramine D400 curing agent, 0.209g TEGO 900 silicone defoamer, and 1.834g NN dimethylacetamide and stirred at 500rpm for 8min to obtain a low-modulus, high-toughness epoxy primer.

[0073] 1.2g of HDI trimer was mixed with 0.13g of γ-aminopropyltriethoxysilane and stirred at 500rpm for 3h at 60℃ to generate silane coupling agent modified HDI trimer. After cooling to room temperature, 10.0g of FEVE resin, 0.13g of organosilicon additive BYK-306, 0.13g of TEGO 900 organosilicon defoamer, 0.05g of dibutyltin dilaurate and 2g of xylene were added. After stirring at 500rpm for 8min, a high modulus weather-resistant fluorocarbon topcoat was obtained.

[0074] Use a low-modulus, high-toughness epoxy primer at 300 mL / m 2 The coating amount was applied to aluminum alloy profiles that had undergone alkali washing and acid washing pretreatment. After drying and curing at 60℃ for 1 hour, the coating was applied at an air pressure of 0.2MPa, maintaining a spraying distance of 15cm and a spraying rate of 7.5mL / m. 2 A high-modulus weather-resistant fluorocarbon topcoat is sprayed onto the semi-cured primer surface. After heat curing at 70℃ for 3 hours, a skin-like gradient modulus structure polar self-de-icing and anti-corrosion coating with a primer coating thickness of 200μm and a topcoat coating thickness of 5μm is obtained.

[0075] Low temperature performance test: Using a constant temperature and humidity test chamber, the temperature is set to -25℃. After the test sample is placed in the low temperature environment for 3 hours, the impact resistance is tested according to the method specified in GB / T 1732-2020; the flexibility is tested according to the method specified in GB / T 1731-1993.

[0076] Corrosion resistance test: Salt spray resistance was tested according to GB / T 1771-2007.

[0077] Table 1 compares the performance of epoxy resin coating, polyurethane / silica / epoxy resin coating, polyvinylidene fluoride / polydimethylsiloxane gradient modulus structure coating, and the skin-like gradient modulus structure polar self-de-icing and anti-corrosion coating prepared in Examples 1 and 2.

[0078] Table 1

[0079]

[0080]

[0081] As shown in Table 1, the epoxy coating exhibits poor low-temperature toughness, impact resistance, and salt spray resistance, but its surface is hydrophilic, resulting in high ice-bonding strength during icing. The polyurethane / silica-modified epoxy resin coating shows significantly improved low-temperature toughness, impact resistance, and salt spray resistance, but its ice-bonding strength remains high during icing. The polyvinylidene fluoride / polydimethylsiloxane gradient modulus structure coating demonstrates good low-temperature mechanical properties and anti-icing effect, but its corrosion resistance is poor. Compared to the above coatings, the skin-like gradient modulus structure polar self-de-icing and anti-corrosion coatings prepared in Examples 1 and 2 possess excellent low-temperature toughness, high impact resistance, and anti-corrosion performance, and can achieve a long-lasting anti-icing effect through surface hydrophobicity and a controllable interfacial fracture mechanism.

[0082] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims. All equivalent changes or modifications made in accordance with the spirit and essence of the invention should be covered within the protection scope of the invention.

Claims

1. A method for preparing a polar self-de-icing and anti-corrosion coating, characterized in that, The specific steps are as follows: Step 1, Preparation of flexible amino-terminated polyurea curing agent: Isophorone diisocyanate and solvent A were added to a three-necked flask and nitrogen gas was introduced for protection. The mixture was heated under stirring, and then dehydrated polyethylene glycol was added dropwise. After stirring in a water bath, the mixture was cooled to room temperature. Then it was added dropwise to a solution composed of polyetheramine and solvent B. The mixture was stirred in an ice bath under a nitrogen atmosphere. Finally, the solvent was removed by rotary evaporation to obtain a flexible amino-terminated polyurea curing agent. Step 2, prepare a low-modulus, high-toughness epoxy primer: Step 2.1: Mix two-dimensional sheet-like anti-corrosion filler, aluminum hydroxide, ammonia, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, ethanol, and deionized water. After stirring evenly in a water bath, dry in an oven to obtain a sheet-like superhydrophobic interface strengthening filler. Step 2.2: Mix the flexible amino-terminated polyurea curing agent obtained in Step 1 with the superhydrophobic interface strengthening filler, epoxy resin, polyetheramine curing agent, defoamer and solvent obtained in Step 2.1, and stir evenly to obtain a low modulus and high toughness epoxy primer. Step 3: Prepare a high-modulus, weather-resistant fluorocarbon topcoat: HDI trimer was mixed with γ-aminopropyltriethoxysilane and heated to react, generating silane coupling agent modified HDI trimer. After cooling to room temperature, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate and solvent were added to it. After uniform mixing, a high modulus weather-resistant fluorocarbon topcoat was obtained. Step 4: Prepare a self-de-icing and anti-corrosion coating with a gradient modulus structure. The low-modulus, high-toughness epoxy primer obtained in step 2 is brushed onto the pretreated aluminum alloy profile. After drying and curing, the high-modulus, weather-resistant fluorocarbon topcoat obtained in step 3 is sprayed onto the primer surface of the semi-cured aluminum alloy profile. After heat curing, a polar self-de-icing and anti-corrosion coating with a skin-like gradient modulus structure is obtained.

2. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 1, characterized in that, In step 1, the mass percentages of isophorone diisocyanate, solvent A, polyethylene glycol, polyetheramine, and solvent B are 19.58%–22.54%, 14.71%–21.47%, 26.32%–30.42%, 11.15%–17.62%, and 14.71%–21.48%, respectively, and the total of the above components is 100%. Solvent A and solvent B are one of N,N dimethylformamide, N,N dimethylacetamide, ethyl acetate, and tetrahydrofuran. Polyetheramine is one of D230 and D400.

3. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 2, characterized in that, Step 1: Isophorone diisocyanate and solvent A are added to a three-necked flask and protected with nitrogen. The temperature is raised to 65-80°C under stirring at 300-500 rpm. Then, dehydrated polyethylene glycol is added dropwise. The polyethylene glycol dehydration process involves drying at 120°C for 2-3 hours in a vacuum drying oven at -0.09 MPa, with a dropwise addition rate of 5 mL / min. The mixture is then stirred in a water bath for 3-4 hours at a temperature of 65-80°C. After cooling to room temperature, it is added dropwise to a solution composed of polyetheramine and solvent B. The reaction is carried out under a nitrogen atmosphere with stirring in an ice bath. The ice bath stirring conditions are: ice bath temperature of 0°C, stirring speed of 300-500 rpm, and ice bath time of 2-3 hours. Finally, the solvent is removed by rotary evaporation at a temperature of 90-110°C for 2-3 hours, yielding a flexible amino-terminated polyurea curing agent.

4. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 1, characterized in that, The mass percentages of the two-dimensional sheet-like anti-corrosion filler, aluminum hydroxide, ammonia, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, deionized water, and ethanol mentioned in step 2.1 are 5.61%–5.69%, 1.58%–1.68%, 3.98%–4.25%, 9.74%–12.17%, 5.84%–6.56%, and 69.65%–73.25%, respectively, with the total of the above components being 100%. The two-dimensional sheet-like anti-corrosion filler is one of mica and diatomaceous earth. The water bath stirring conditions are: water bath temperature 50–60℃, water bath time 12–15h, and stirring speed 500–700rpm. The drying conditions in the oven are: drying temperature 120–150℃, and drying time 6–10h.

5. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 1, characterized in that, The mass percentages of the flexible amino-terminated polyurea curing agent, superhydrophobic interface reinforcing filler, epoxy resin, polyetheramine curing agent, defoamer, and solvent mentioned in step 2.2 are 10.29%–14.76%, 8.83%–9.71%, 44.14%–48.55%, 9.99%–17.48%, 0.88%–0.97%, and 8.53%–25.87%, respectively, with the total of the above components being 100%. The epoxy resin is either E44 or E51, the polyetheramine curing agent is either D230 or D400, the defoamer is either n-octanol or TEGO 900 silicone defoamer, and the solvent is either NN dimethylformamide, NN dimethylacetamide, ethyl acetate, or tetrahydrofuran. The stirring speed is 200–500 rpm, and the stirring time is 5–10 min.

6. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 1, characterized in that, In step 3, the mass percentages of the HDI trimer and γ-aminopropyltriethoxysilane are 90%–98% and 2%–10%, respectively, with the total of these components being 100%. The mass percentages of the silane coupling agent-modified HDI trimer, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate, and solvent are 7.36%–9.75%, 73.31%–73.64%, 0.95%–0.96%, 0.95%–0.96%, 0.29%–0.37%, and 14.66%–16.79%, respectively, with the total of these components being 100%. The leveling agent is the silicone additive BYK-306; the defoamer is TEGO-900; and the solvent is either butyl acetate or xylene.

7. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 6, characterized in that, In step 3, the HDI trimer and γ-aminopropyltriethoxysilane are mixed and heated to a reaction temperature of 60-80℃ for 2-3 hours, with a stirring rate of 300-500 rpm. The conditions for mixing the silane coupling agent-modified HDI trimer, FEVE resin, leveling agent, defoamer, dibutyltin dilaurate, and solvent are: a stirring rate of 200-500 rpm and a stirring time of 5-10 minutes.

8. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 1, characterized in that, The aluminum alloy profile pretreatment method described in step 4 is as follows: After ultrasonic cleaning, the aluminum alloy profile is immersed in sodium hydroxide solution, rinsed with deionized water until neutral, and then immersed in nitric acid solution and rinsed with water until neutral to obtain a surface-pretreated aluminum alloy profile; the mass fraction of sodium hydroxide solution is 4% to 5%, and the immersion time of the aluminum alloy profile in sodium hydroxide solution is 90 to 150 seconds; the mass fraction of nitric acid solution is 10% to 12%, and the immersion time of the aluminum alloy profile in nitric acid solution is 80 to 120 seconds.

9. The method for preparing a polar self-de-icing and anti-corrosion coating according to claim 1, characterized in that, In step 4, the brushing amount is 300-600 mL / m 2 The drying and curing temperature is 50–60℃, and the drying and curing time is 0.5–1 hour. The spraying equipment uses an air compressor to provide air pressure of 0.2–0.4 MPa, the spraying distance is 15–20 cm, and the spraying amount is 7.5–15 mL / m. 2 The heat curing temperature is 60-70℃, the heat curing time is 2-3h, the thickness of the low modulus primer coating is 200-400μm, and the thickness of the high modulus topcoat coating is 5-10μm.

10. The polar self-de-icing and anti-corrosion coating prepared by the method of any one of claims 1-9.

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