A micro-nano composite structure-based anti-condensation corrosion-resistant super-hydrophobic coating material and a preparation method thereof

Abstract

The application relates to the field of super-hydrophobic coating materials, in particular to an anti-condensation corrosion-resistant super-hydrophobic coating material based on a micro-nano composite structure and a preparation method thereof. The anti-condensation corrosion-resistant super-hydrophobic coating material based on the micro-nano composite structure is prepared from raw materials including a film-forming substance, an auxiliary resin, a micro-nano composite agent, a curing agent, an auxiliary reinforcing agent and a solvent. The application aims to provide the anti-condensation corrosion-resistant super-hydrophobic coating material based on the micro-nano composite structure, which not only has the super-hydrophobic property, but also has excellent anti-frosting, anti-condensation and self-cleaning functions and other application performances, can be completely cured at normal temperature, has high adhesion to various substrates, and thus can fully meet the comprehensive application requirements of the super-hydrophobic coating material in the existing application fields.

Description

Technical Field

[0001] This application relates to the field of superhydrophobic coating materials, and in particular to an anti-condensation and corrosion-resistant superhydrophobic coating material based on a micro-nano composite structure and its preparation method. Background Technology

[0002] In industrial production and daily applications, surface protection technology for materials has always been a research hotspot, especially in humid environments or under conditions of drastic temperature changes. Condensation easily occurs on the surfaces of metals and electronic components, which not only leads to decreased insulation performance and short-circuit faults but also significantly shortens the lifespan of equipment. Currently, one widely used surface protection method in industry is the use of "conformal coatings," a special hydrophobic coating typically applied to the surface of printed circuit boards or precision electronic components to form a thin protective film for moisture, salt spray, and mildew prevention. However, traditional conformal coatings mainly rely on their density to block moisture; their surface is inherently insufficiently hydrophilic or hydrophobic. Therefore, in high humidity environments or at dew point temperatures, water molecules can still penetrate or condense to form a film, leading to protective failure.

[0003] In recent years, with the development of bionics, superhydrophobic surface materials have attracted widespread attention from academia and industry. By mimicking the microstructures of natural organisms such as lotus leaves and water strider legs, researchers have discovered that the surface wettability of a material depends not only on its chemical composition but also on its microscopic geometry. When a material surface simultaneously possesses a micrometer-level rough structure and a nanometer-level fine structure, it can trap a large amount of air, causing water droplets to form spherical shapes and roll off easily, thus achieving a "passive defense" against water and water-soluble corrosive media. Based on this principle, numerous reports on superhydrophobic coatings have emerged in existing technologies, such as methods for constructing micro / nano structures on metal substrates by spraying hydrophobically modified silica nanoparticles.

[0004] Although existing superhydrophobic coatings exhibit excellent water contact angles, typically exceeding 150°, under laboratory conditions, several bottlenecks remain in practical applications. Firstly, the fabrication processes for many superhydrophobic coatings are complex, often requiring high-temperature sintering, UV curing, or specialized equipment, limiting their application on heat-sensitive substrates. Secondly, existing superhydrophobic materials generally suffer from poor mechanical durability; their surface micro- and nano-structures are easily damaged by slight scratches or external forces, leading to a sharp decline in hydrophobic properties. Crucially, due to the porosity of the superhydrophobic structure, the actual contact area between the coating and the substrate is small, resulting in generally weak coating adhesion, making them prone to peeling and flaking during thermal cycling or mechanical deformation.

[0005] In summary, there is currently a lack of coating materials that can combine superhydrophobic properties with engineering practicality. Traditional conformal coatings, while having good adhesion and being easy to apply, cannot achieve superhydrophobicity and excellent anti-condensation and corrosion resistance. On the other hand, existing superhydrophobic coatings, although possessing extremely high water contact angles, are often limited by complex curing conditions and low adhesion, making them unable to provide long-term stable service in harsh outdoor or industrial environments. Summary of the Invention

[0006] The purpose of this application is to provide a superhydrophobic coating material based on a micro-nano composite structure that is resistant to condensation and corrosion. This material not only has superhydrophobic properties, but also excellent application performance such as anti-frost, anti-condensation and self-cleaning functions. It can also be fully cured at room temperature and has high adhesion to a variety of substrates, thus fully meeting the comprehensive application needs of superhydrophobic coating materials in existing application fields.

[0007] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this application provides an anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure. By weight, the raw materials include: 50-70 parts of film-forming substance, 20-30 parts of auxiliary resin, 10-20 parts of micro-nano composite agent, 8-16 parts of curing agent, 1-3 parts of adhesion promoter, 2-4 parts of thixotropic agent, 0.3-0.8 parts of antioxidant, 5-10 parts of auxiliary reinforcing agent, and 80-120 parts of solvent.

[0008] In a preferred embodiment, the mass ratio of the film-forming substance, the micro-nano composite agent, and the auxiliary reinforcing agent is (5.5~7):(1~1.8):(0.6~1).

[0009] In a preferred embodiment, the mass ratio of the film-forming substance, the micro-nano composite agent, and the auxiliary reinforcing agent is (6~7):(1.5~1.8):(0.8~1).

[0010] In a preferred embodiment, the film-forming substance is an acrylic resin.

[0011] In a preferred embodiment, the weight-average molecular weight of the acrylic resin is 25,000 to 40,000 Da.

[0012] In a preferred embodiment, the weight-average molecular weight of the acrylic resin is 30,000 to 35,000 Da.

[0013] In a preferred embodiment, the auxiliary resin is a hydroxyl acrylic resin.

[0014] In a preferred embodiment, the hydroxyl value of the hydroxyl acrylic resin is 50~80 mgKOH / g.

[0015] In a preferred embodiment, the hydroxyl value of the hydroxyl acrylic resin is 70~75 mgKOH / g.

[0016] In a preferred embodiment, the micro-nano composite agent is a combination of fumed silica nanoparticles and polytetrafluoroethylene microparticles.

[0017] In a preferred embodiment, the mass ratio of the fumed silica nanoparticles to the polytetrafluoroethylene microparticles is (5~10):(3~8).

[0018] In a preferred embodiment, the mass ratio of the fumed silica nanoparticles to the polytetrafluoroethylene microparticles is (7~9):(5~6).

[0019] In a preferred embodiment, the average particle size of the fumed silica nanoparticles is 10-50 nm.

[0020] In a preferred embodiment, the average particle size of the fumed silica nanoparticles is 10-20 nm.

[0021] In a preferred embodiment, the fumed silica nanoparticles are hydrophobic fumed silica nanoparticles with a surface treated with dimethyldichlorosilane.

[0022] A hybrid system, encompassing both chemical composition and physical morphology, was constructed by combining low surface energy building blocks with micro / nano-structured composite agents. Hydrophobic groups in the molecular chains migrate directionally to the surface during curing, reducing the surface free energy of the coating. Simultaneously, the micro / nano-structured composite agents, uniformly dispersed in nanoparticle form, create fine nanoscale protrusions on the coating surface. Functional fillers, in the form of micron-sized particles, form a supporting framework. Together, they construct a rough surface structure, creating a micro / nano-composite morphology. This allows water droplets to only contact the tips of the micro-protrusions, while air is trapped in the valleys, forming an air cushion layer. This significantly reduces the actual contact area between the solid and liquid, allowing the water droplets to quickly roll off under slight tilting or external force. During this rolling process, surface-adhered dust and contaminants are carried away, achieving a self-cleaning effect. Furthermore, the presence of the air layer effectively prevents water molecules and corrosive media from penetrating the substrate, thus achieving a comprehensive protective effect against condensation and corrosion.

[0023] In a preferred embodiment, the curing agent is an HDI trimer or an IPDI trimer.

[0024] In a preferred embodiment, the curing agent is HDI trimer.

[0025] In a preferred embodiment, the adhesion promoter is at least one selected from phosphate ester resin, titanate coupling agent, zirconium aluminate coupling agent, and phosphate ester modified acrylate.

[0026] In a preferred embodiment, the adhesion promoter is a phosphate ester resin or a titanate coupling agent.

[0027] In a preferred embodiment, the thixotropic agent is at least one of polyamide wax, hydrogenated castor oil, and BYK-410.

[0028] In a preferred embodiment, the thixotropic agent is polyamide wax or BYK-410.

[0029] In a preferred embodiment, the thixotropic agent is BYK-410.

[0030] In a preferred embodiment, the antioxidant is at least one of antioxidant 1010, antioxidant 610, antioxidant 3010, antioxidant 168, and antioxidant DLTP.

[0031] In a preferred embodiment, the antioxidant is antioxidant 1010 or antioxidant 3010.

[0032] In a preferred embodiment, the auxiliary reinforcing agent is a combination of polyethylene wax, polyether-modified polydimethylsiloxane, and carnauba wax emulsion.

[0033] In a preferred embodiment, the mass ratio of the polyethylene wax, polyether-modified polydimethylsiloxane, and carnauba wax emulsion is (1~3):(0.5~1.5):(3~6).

[0034] In a preferred embodiment, the mass ratio of the polyethylene wax, polyether-modified polydimethylsiloxane and carnauba wax emulsion is (2~3):(1~1.3):(4~5).

[0035] In this application, the auxiliary reinforcing agent involves polyethylene wax migrating to the surface during coating drying, filling the pore edges of the micro / nano structure with its micron-sized particles. This enhances the physical density and mechanical wear resistance of the surface layer. Furthermore, the siloxane reduces the surface tension of the system, promoting the uniform spreading and orderly arrangement of the components during curing. This assists the micro / nano structure in achieving consistent self-assembly over a larger area. Finally, the carnauba wax emulsion precipitates out natural microcrystals after solvent evaporation. These microcrystals, with their high hardness and regular crystalline morphology, act as templates, guiding the nano-silica particles to align along the crystal boundaries, thus forming a more regular and dense composite structure. This effectively inhibits the nucleation and growth of water molecule clusters and significantly delays the freezing process of supercooled water. As a result, while maintaining the basic superhydrophobic properties, the coating is endowed with superior anti-condensation and anti-frost properties and durability, achieving a significant improvement in overall performance.

[0036] In a preferred embodiment, the solvent is a combination of butyl acetate, xylene, and ethyl acetate.

[0037] In a preferred embodiment, the mass ratio of butyl acetate, xylene and ethyl acetate is (4~5):(2~3):(1~2).

[0038] In a preferred embodiment, the mass ratio of butyl acetate, xylene, and ethyl acetate is 5:3:2.

[0039] The second aspect of this application provides a method for preparing an anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure, specifically including the following steps: S1: In a clean dispersion vessel, solvent, film-forming substance, and auxiliary resin are added sequentially and stirred to form a uniform mixture. Then, an adhesion promoter and an antioxidant are added, and stirring is continued to obtain a mixed base material; S2: A thixotropic agent is slowly added to the mixed base material, followed by an auxiliary reinforcing agent. After stirring, a micro-nano composite agent is added in three equal portions, ensuring that the material temperature is ≤40℃. After completion, the main material is allowed to stand until the bubbles naturally escape; S3: The main material and curing agent are mixed in proportion and stirred at 400~500 rpm for 3~5 minutes. After standing, the coating material is obtained. When using, it is applied to the surface of the component by spraying or dipping and allowed to dry and cure at room temperature.

[0040] Preferably, the preparation method of the anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure specifically includes the following steps: S1: In a clean dispersion vessel, solvent, film-forming substance, and auxiliary resin are added sequentially, and stirred at 300-500 rpm for 15-20 min to form a uniform mixture. Then, adhesion promoter and antioxidant are added, and stirring is continued for 5-10 min to obtain a mixed base material; S2: Thixotropic agent is slowly added to the mixed base material, the stirring speed is increased to 700-800 rpm, and stirring is continued for 15-20 min, after which the stirring speed is maintained. Add the auxiliary reinforcing agent and continue stirring at a constant speed for 15-20 minutes. Then add the micro-nano composite agent in three equal parts, dispersing at a high speed of 1000-1200 rpm for 30-40 minutes each time, ensuring the material temperature is ≤40℃. After completion, let the main material stand for 15-20 minutes to allow the bubbles to escape naturally. S3: Mix the main material and curing agent in proportion, stir at 400-500 rpm for 3-5 minutes, and let stand for 5-10 minutes to obtain the coating material. When using, apply it to the surface of the component by spraying or dipping and wait for it to dry and cure at room temperature.

[0041] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. The superhydrophobic coating material provided in this application, through the synergistic effect of constructing a micro-nano composite structure and a low surface energy system, achieves excellent hydrophobic properties on the material surface. This effectively inhibits the spread and adhesion of water on the surface, significantly delays condensation formation, and promotes rapid roll-off of condensate, thereby achieving superior anti-condensation and self-cleaning effects. The coating can be fully cured at room temperature, has wide application adaptability, and exhibits excellent bonding strength and flexibility to various substrates, allowing it to withstand slight deformation of the substrate without peeling off. Furthermore, it significantly improves the wear resistance of this type of acrylic coating material, thus maintaining excellent superhydrophobic and anti-condensation properties while avoiding poorer wear resistance. In practical applications, this coating can effectively delay the corrosion process of the substrate, significantly improving the operational reliability and service life of the protected components.

[0042] 2. This application constructs a hybrid system from chemical composition to physical morphology by combining low surface energy constructs with micro-nano structure composite agents. This forms fine nanoscale protrusions on the coating surface, while functional fillers form a supporting framework with micron-sized particles. Together, they build a rough surface structure to form a micro-nano composite morphology, allowing water droplets to only contact the top of the micro-protrusions. Air is trapped in the valleys to form an air cushion layer, which greatly reduces the actual contact area between the solid and liquid. Under slight tilting or external force, the water droplets can quickly roll off. At the same time, during the rolling process, they carry away the dust and pollutants attached to the surface, achieving a self-cleaning effect while effectively blocking the penetration of water molecules and corrosive media into the substrate, thereby achieving a comprehensive protective effect of anti-condensation and corrosion resistance.

[0043] 3. In this application, polyethylene wax migrates to the surface during the coating drying process and fills the pore edges of the micro-nano structure with its micron-sized particles, which enhances the physical density and mechanical wear resistance of the surface layer, forming a more regular and dense composite structure. This effectively inhibits the nucleation and growth of water molecule clusters and significantly slows down the freezing process of supercooled water. Thus, while maintaining the basic superhydrophobic properties, it endows the coating with better anti-condensation and anti-frost properties and durability, achieving a significant improvement in overall performance. Attached Figure Description

[0044] Figure 1 The figure shows a comparison of the waterproof performance of the coating material prepared in Example 1 of this application and the traditional conformal coating; (a) in the figure is Example 1 of this application; (b) is the traditional conformal coating.

[0045] Figure 2 The figure shows a comparison of the anti-condensation and anti-frost performance of the coating material prepared in Example 1 of this application and the conventional conformal coating; (a) conventional conformal coating; (b) Example 1 of this application.

[0046] Figure 3 The figure shows the salt spray resistance test results of the coating material prepared in Example 1 of this application; (a) salt spray resistance for 200h; (b) salt spray resistance for 500h; (c) salt spray resistance for 1000h.

[0047] Figure 4 The figure shows a comparison of the self-cleaning performance of the coating material prepared in Example 1 of this application and a conventional conformal coating; (a) conventional conformal coating; (b) Example 1 of this application. Detailed Implementation

[0048] The technical solutions in the embodiments of this application will be clearly and completely described below. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] In the following specific embodiments, unless otherwise specified, the sources / preparation methods of some raw materials are as follows: Acrylic resin, BR-113, weight average molecular weight 30000 Da, Mitsubishi, Japan.

[0050] Hydroxyacrylate resin, FX-9013, hydroxyl value 73mgKOH / g, Nantong Fangxin Chemical Co., Ltd., China.

[0051] Polytetrafluoroethylene micro powder, TF-9207Z, 3M Chemicals, USA.

[0052] HDI trimer, N3300, Covestro, Germany.

[0053] Titanate coupling agent, HY-311, Hubei Fengcheng Chemical Co., Ltd., China.

[0054] Polyether-modified polydimethylsiloxane, BYK-333, BYK (Germany).

[0055] Brazilian carnauba wax emulsion, 2726, solid content 26%, Green Union (Jining) Chemical Technology.

[0056] Example 1 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 65 parts film-forming substance, 22 parts auxiliary resin, 17.5 parts micro-nano composite agent, 12.5 parts curing agent, 1.9 parts adhesion promoter, 2.8 parts thixotropic agent, 0.5 parts antioxidant, 8.6 parts auxiliary reinforcing agent, and 96 parts solvent.

[0057] The film-forming substance is acrylic resin with a weight-average molecular weight of 30,000 Da.

[0058] The auxiliary resin is a hydroxyl acrylic resin with a hydroxyl value of 73 mg KOH / g.

[0059] The micro-nano composite agent is a combination of fumed nano-silica and polytetrafluoroethylene micro powder in a mass ratio of 8:5.

[0060] The average particle size of the fumed silica nanoparticles is 16 nm.

[0061] The fumed nano silica is a hydrophobic fumed nano silica whose surface has been treated with dimethyl dichlorosilane.

[0062] The curing agent is HDI trimer.

[0063] The adhesion promoter is phosphate resin CP-9500; the thixotropic agent is polyamide wax; and the antioxidant is antioxidant 1010.

[0064] The auxiliary reinforcing agent is a combination of polyethylene wax, polyether-modified polydimethylsiloxane and carnauba wax emulsion in a mass ratio of 2.5:1.5:4.

[0065] The solvent is a composition of butyl acetate, xylene and ethyl acetate in a mass ratio of 5:3:2.

[0066] A method for preparing an anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure includes the following steps: S1: In a clean dispersion vessel, film-forming substances and auxiliary resins are added sequentially, and stirred at 400 rpm for 20 min to form a uniform mixture. Then, adhesion promoters and antioxidants are added, and stirring is continued for 10 min to obtain a mixed base material; S2: Solvents and thixotropic agents are slowly added to the mixed base material, and the stirring speed is increased to 800 rpm. Stirring is continued for 20 min, and then auxiliary reinforcing agents are added while maintaining the stirring speed. Stirring is continued for 20 min while maintaining the speed. Then, micro-nano composite agents are added in equal amounts in three batches, and each addition is dispersed at 1100 rpm for 40 min to ensure that the material temperature is ≤40℃. After completion, the main material is allowed to stand for 20 min to allow bubbles to escape naturally; S3: The main material and curing agent are mixed in proportion, stirred at 500 rpm for 4 min, and allowed to stand for 8 min to obtain the coating material. When using, the coating is applied to the surface of the component by spraying or dipping, and then allowed to dry and cure at room temperature.

[0067] Example 2 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 70 parts film-forming substance, 24.5 parts auxiliary resin, 16.2 parts micro-nano composite agent, 14.5 parts curing agent, 2 parts adhesion promoter, 3 parts thixotropic agent, 0.6 parts antioxidant, 7.5 parts auxiliary reinforcing agent, and 105 parts solvent.

[0068] The remaining implementation methods are the same as in Example 1.

[0069] Example 3 A superhydrophobic coating material based on a micro-nano composite structure for preventing condensation and corrosion, comprising, by weight: 60 parts film-forming substance, 20 parts auxiliary resin, 14.8 parts micro-nano composite agent, 11 parts curing agent, 1.9 parts adhesion promoter, 2.6 parts thixotropic agent, 0.5 parts antioxidant, 9.1 parts auxiliary reinforcing agent, and 90 parts solvent.

[0070] The remaining implementation methods are the same as in Example 1.

[0071] Comparative Example 1 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 80 parts film-forming substance, 30 parts auxiliary resin, 8.5 parts micro-nano composite agent, 16.5 parts curing agent, 2.2 parts adhesion promoter, 3.2 parts thixotropic agent, 0.6 parts antioxidant, 12.8 parts auxiliary reinforcing agent, and 96 parts solvent.

[0072] The remaining implementation methods are the same as in Example 1.

[0073] Comparative Example 2 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 80 parts film-forming substance, 30 parts auxiliary resin, 20 parts micro-nano composite agent, 16.5 parts curing agent, 2.2 parts adhesion promoter, 3.2 parts thixotropic agent, 0.6 parts antioxidant, 3.5 parts auxiliary reinforcing agent, and 96 parts solvent.

[0074] The remaining implementation methods are the same as in Example 1.

[0075] Comparative Example 3 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 65 parts film-forming substance, 22 parts auxiliary resin, 17.5 parts micro-nano composite agent, 12.5 parts curing agent, 1.9 parts adhesion promoter, 2.8 parts thixotropic agent, 0.5 parts antioxidant, 8.6 parts auxiliary reinforcing agent, and 96 parts solvent.

[0076] The micro-nano composite agent is a combination of fumed nano silica and polytetrafluoroethylene micro powder in a mass ratio of 11:2.

[0077] The average particle size of the fumed silica nanoparticles is 50 nm.

[0078] The remaining implementation methods are the same as in Example 1.

[0079] Comparative Example 4 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 65 parts film-forming substance, 22 parts auxiliary resin, 17.5 parts micro-nano composite agent, 12.5 parts curing agent, 1.9 parts adhesion promoter, 2.8 parts thixotropic agent, 0.5 parts antioxidant, 8.6 parts auxiliary reinforcing agent, and 96 parts solvent.

[0080] The micro-nano composite agent is a combination of fumed nano silica and polytetrafluoroethylene micro powder in a mass ratio of 4:9.

[0081] The average particle size of the fumed silica nanoparticles is 12 nm.

[0082] The remaining implementation methods are the same as in Example 1.

[0083] Comparative Example 5 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 65 parts film-forming substance, 22 parts auxiliary resin, 17.5 parts micro-nano composite agent, 12.5 parts curing agent, 1.9 parts adhesion promoter, 2.8 parts thixotropic agent, 0.5 parts antioxidant, 8.6 parts auxiliary reinforcing agent, and 96 parts solvent.

[0084] The auxiliary reinforcing agent is a combination of polyethylene wax, polyether-modified polydimethylsiloxane and carnauba wax emulsion in a mass ratio of 4:2.5:1.5.

[0085] The remaining implementation methods are the same as in Example 1.

[0086] Comparative Example 6 A superhydrophobic coating material based on a micro-nano composite structure, comprising, by weight, 65 parts film-forming substance, 22 parts auxiliary resin, 17.5 parts micro-nano composite agent, 12.5 parts curing agent, 1.9 parts adhesion promoter, 2.8 parts thixotropic agent, 0.5 parts antioxidant, 8.6 parts auxiliary reinforcing agent, and 96 parts solvent.

[0087] The auxiliary reinforcing agent is a combination of polyethylene wax, polyether-modified polydimethylsiloxane and carnauba wax emulsion in a mass ratio of 1:1:6.

[0088] The remaining implementation methods are the same as in Example 1.

[0089] Performance testing 1. Waterproofing Test: The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on the micro-nano composite structure prepared in Example 1 was applied to electronic components and fully cured before a waterproofing test was conducted. A traditional conformal coating (Shin-Etsu KR-251) was used as a control. The test target was 40°C warm water. Samples were immersed in warm water, and samples were collected for 1 hour, 12 hours, 1 day, and 30 days for comparison. The test results are as follows: Figure 1 As shown, the waterproof performance obtained in this application is excellent. No water immersion or waterproof damage occurred during long-term immersion. In contrast, traditional conformal coatings showed obvious water immersion after 12 hours, and the waterproof performance gradually deteriorated until it was completely lost. Immersion waterproof tests were conducted on the coating materials obtained in the examples and comparative examples, with 100 days as the baseline. The requirement was that the waterproof characteristics should be maintained and no waterproof damage should occur.

[0090] 2. Anti-condensation and frosting test: The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on the micro-nano composite structure prepared in Example 1 was coated onto electronic components and fully cured before an anti-condensation and frosting test was conducted. A conventional conformal coating (Shin-Etsu KR-251) was used as a control. The test was conducted on a -10℃ cold plate at an ambient temperature of 25℃ and a relative humidity of 95%. The comparison results are as follows:Figure 2 As shown, conventional conformal coatings begin to condense at 5 seconds, a water film is visible at 25 seconds, dripping occurs at 85 seconds, and a dense frost layer appears at 240 seconds. However, the coating material in this embodiment never exhibits condensation or frost formation.

[0091] 3. Salt spray resistance test: The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on the micro-nano composite structure prepared in Example 1 was coated onto electronic components and completely cured before a salt spray resistance test was conducted. The test target was 5wt% sodium chloride saline solution, and the results were observed after immersion in the water for 200h, 500h, and 1000h. The results are as follows: Figure 3 As shown, the coating material always maintains excellent surface properties and has excellent salt spray resistance. At the same time, all examples and comparative examples were subjected to the same test, with 50 samples in each test group. If there was no surface corrosion, yellowing and damage, it was recorded as qualified. The respective pass rates were recorded in Table 1.

[0092] 4. Cleaning Test: Using fine sand as a self-cleaning medium, the prepared anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure was applied to electronic components and fully cured. The cured surface was then inserted into a pile of fine sand and removed. The sand and gravel on the cured surface were rinsed with a slow-flowing stream of clean water, and the surface cleanliness was observed. A traditional conformal coating (Shin-Etsu KR-251) was used as a control. The comparison results are as follows: Figure 4 As shown, the coating material of Example 1 has more obvious and superior self-cleaning performance compared with traditional conformal coatings. The superhydrophobic coating material of Example 1 completely removes residual sand and gravel contaminants from the surface under the action of water, while traditional conformal coatings cannot be directly removed.

[0093] 5. Adhesion: The coating materials prepared according to the examples and comparative examples were sprayed onto a standard cold-rolled steel plate with a thickness of 1 mm. The wet film thickness was controlled at 50 μm. After complete curing at room temperature, the coating was tested with a cupping tester. A 20 mm spherical punch was used. The coated sample was facing the punch and the punch was pushed towards the sample at a constant speed of 0.2 mm / s. The test was stopped when the coating surface cracked for the first time. The distance the punch moved was recorded. The result was the arithmetic mean of 10 tests and recorded in Table 1.

[0094] 6. Water contact angle: The hydrophobicity of the coating surface was tested by the seat drop method. The coating materials prepared by the examples and comparative examples were sprayed onto the surface of the electronic component sample with a thickness of 50 μm. The wet film thickness was controlled at 50 μm. After complete curing at room temperature, the test was carried out. The test water droplet was 2 μL and the test time was 60 s. The results were taken as the arithmetic mean of 10 tests and recorded in Table 1.

[0095] 7. Abrasion resistance: Sprayed onto a standard test plate, after complete curing at room temperature, a Taber 5135 abrasion tester equipped with a CS-10 grinding wheel was used. The load was 500g, the turntable speed of the tester was set to 60rpm, and the friction cycle was set to 1000 revolutions. The surface water contact angle before and after abrasion was tested. The retention rate of water contact angle (%) was calculated as (value after test / value before test) × 100%. The arithmetic mean of 10 tests was recorded in Table 1.

[0096] Table 1 Performance Test Results

[0097] Analysis of test results: Compared with Comparative Examples 1-6 and traditional conformal coatings, Examples 1-3 of this application achieved superior results in various performance tests. This is due to the fact that this application constructs a mixed system from chemical composition to physical morphology by combining low surface energy constructs and micro-nano structure composite agents. This forms fine nanoscale protrusions on the coating surface, while the functional filler forms a supporting skeleton with micron-sized particles. Together, they build a rough surface structure to form a micro-nano composite morphology, allowing water droplets to only contact the top of the micro-protrusions. Air is trapped in the valleys to form an air cushion layer, greatly reducing the actual contact area between the solid and liquid. In addition, the polyethylene wax in the auxiliary reinforcing agent migrates to the surface during the coating drying process and fills the pore edges of the micro-nano structure with its micron-sized particles, enhancing the physical density and mechanical wear resistance of the surface layer and forming a more regular and dense composite structure, thus providing a foundation for the comprehensive performance of the coating. In contrast, Comparative Examples 1-6 adopted different technical solutions than this application, resulting in a significant decrease in the technical effect of their respective raw materials in the coating system, which ultimately affected the comprehensive performance of the coating material.

[0098] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A superhydrophobic coating material based on a micro / nano composite structure that is resistant to condensation and corrosion, characterized in that: By weight, the raw materials include: 50-70 parts of film-forming substance, 20-30 parts of auxiliary resin, 10-20 parts of micro-nano composite agent, 8-16 parts of curing agent, 1-3 parts of adhesion promoter, 2-4 parts of thixotropic agent, 0.3-0.8 parts of antioxidant, 5-10 parts of auxiliary reinforcing agent, and 80-120 parts of solvent; The micro-nano composite agent is a combination of fumed nano-silica and polytetrafluoroethylene micro powder, with a mass ratio of (7~9):(5~6). The auxiliary reinforcing agent is a combination of polyethylene wax, polyether-modified polydimethylsiloxane and carnauba wax emulsion, with a mass ratio of (1~3):(0.5~1.5):(3~6).

2. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure as described in claim 1, characterized in that: The mass ratio of the film-forming substance, the micro-nano composite agent, and the auxiliary reinforcing agent is (5.5~7):(1~1.8):(0.6~1).

3. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure as described in claim 2, characterized in that: The film-forming substance is an acrylic resin with a weight-average molecular weight of 25,000 to 40,000 Da.

4. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro / nano composite structure as described in claim 3, characterized in that: The auxiliary resin is a hydroxyl acrylic resin; the hydroxyl value of the hydroxyl acrylic resin is 50~80 mgKOH / g.

5. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure as described in claim 4, characterized in that: The curing agent is HDI trimer or IPDI trimer.

6. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure as described in claim 5, characterized in that: The adhesion promoter is at least one of phosphate ester resin, titanate coupling agent, zirconium aluminate coupling agent, and phosphate ester modified acrylate.

7. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure as described in claim 6, characterized in that: The thixotropic agent is at least one of polyamide wax, hydrogenated castor oil, and BYK-410.

8. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure as described in claim 7, characterized in that: The antioxidant is at least one of antioxidant 1010, antioxidant 610, antioxidant 3010, antioxidant 168 and antioxidant DLTP.

9. The anti-condensation, corrosion-resistant, and superhydrophobic coating material based on a micro-nano composite structure as described in claim 8, characterized in that: The average particle size of the fumed silica nanoparticles is 10~50 nm.

10. A method for preparing an anti-condensation, corrosion-resistant, superhydrophobic coating material based on a micro-nano composite structure according to any one of claims 1 to 9, characterized in that: Specifically, the following steps are included: S1: In a clean dispersion vessel, add solvent, film-forming substance and auxiliary resin in sequence and stir to form a uniform mixture. Then add adhesion promoter and antioxidant and continue stirring to obtain a mixed base material. S2: Slowly add thixotropic agent to the mixed base material, then add auxiliary reinforcing agent and stir. Then add micro-nano composite agent in three equal parts to ensure that the material temperature is ≤40℃. After completion, let the main material stand and wait for the bubbles to escape naturally. S3: Mix the main material and curing agent in proportion and stir at 400~500rpm for 3~5min. After standing, the coating material is obtained. When using, apply it to the surface of the component by spraying or dipping and wait for it to dry and cure at room temperature.

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