Super hydrophobic coating for shipborne radar radome and preparation method thereof

Abstract

The present application provides a super-hydrophobic coating for a shipborne radar antenna cover and a preparation method thereof, the method comprising placing glass particles in a piranha solution for activation, in situ growing silica nanoparticles on the surface thereof, and performing low surface energy modification to obtain a super-hydrophobic glass particle suspension; then drying the suspension to remove the volatile organic solvent to obtain a dry super-hydrophobic glass particle powder, and dispersing the powder in a volatile organic solvent with a wave-transmitting resin and an additive in a certain ratio, and after stirring evenly, applying it to the surface of the shipborne radar antenna cover, and then drying and curing at room temperature to obtain a super-hydrophobic coating for the shipborne radar antenna cover. The present application can effectively remove surface dirt on the shipborne radar antenna cover while ensuring the original wave-transmitting performance of the shipborne radar antenna cover, ensuring that the shipborne radar can operate reliably around the clock and maintain a good appearance. The preparation process and equipment of the present application are simple, easy to operate, and low-cost, and are suitable for large-scale preparation and industrialization.

Description

Technical Field

[0001] The present application relates to the technical field of preparation of super-wetting functional coating materials, and in particular to a super-hydrophobic coating for shipborne radar antenna covers and a preparation method thereof. Background Art

[0002] Shipborne extravehicular equipment, such as radomes and antenna pedestals for radar / electronic warfare equipment, is constantly exposed to the wind, rain, and even waves of the marine environment. Dust, rainwater, microorganisms, and salt deposits accumulate on their surfaces, not only degrading the overall aesthetics and protective performance of these devices but also affecting the antenna's ability to radiate or receive electromagnetic signals, increasing transmission loss and degrading electrical performance. Traditionally, manual rinsing and wiping are time-consuming, labor-intensive, and resource-intensive. Cleaning is also challenging for complex radar reflectors, conformal array radomes with difficult-to-clean mounting locations, and large radar / electronic warfare equipment. Furthermore, even after cleaning, water film may remain on the surface of extravehicular equipment, hindering electromagnetic signal transmission. Therefore, it is crucial to develop self-cleaning protective technologies and preparation methods to effectively prevent the accumulation of water droplets and dust on the equipment surface, improve its protective performance, and ensure reliable all-weather operation and a good appearance for extravehicular equipment. At present, some military scientific research institutions at home and abroad have carried out research on self-cleaning technology based on hydrophobic coating to improve extravehicular electronic equipment (mainly for antenna covers), but the results are not good.

[0003] A super-hydrophobic surface refers to a solid surface on which water droplets can roll down under the action of micro-dynamics under the combined action of surface micro-nanostructures and low-surface-energy substances. It has excellent comprehensive properties such as three-proof (waterproof, oil-proof, dustproof), anti-dew, antibacterial, corrosion-resistant, and self-cleaning. It is expected to solve problems such as dust accumulation, water accumulation, and microbial adhesion on the surface of shipborne radar antenna covers. Among them, super-hydrophobic coating technology has the advantages of simple equipment and process, wide application range, and easy large-scale preparation. It is an effective method for constructing super-hydrophobic surfaces. At present, the preparation of super-hydrophobic coatings mainly depends on oxide nanoparticles represented by modified silica, low-surface-energy polymer nanoparticles represented by polytetrafluoroethylene, and binders represented by fluorocarbon resins. However, after being applied to the surface of the radar antenna cover, it is similar to an additional signal barrier layer, which reduces the electromagnetic signal transmission capability of the radar cover, increases transmission loss, causes new problems, and seriously limits its application in the field of radar antenna covers. Summary of the Invention

[0004] The present application provides a super-hydrophobic coating for a shipborne radar radome and a preparation method thereof, which can be used to solve the technical problem that the current hydrophobic coating reduces the electromagnetic signal transmission capability of the radome.

[0005] In a first aspect, an embodiment of the present application provides a method for preparing a super-hydrophobic coating for a shipborne radar radome, the method comprising:

[0006] Step 1: disperse the glass particles in a piranha solution at room temperature to 95° C. and soak for 1 to 4 hours, then rinse with deionized water and dry for later use;

[0007] Step 2: Dispersing 0.5 to 5 parts by mass of glass particles, 2 to 12 parts by mass of an alkaline pH regulating solution, 0.1 to 3 parts by mass of a silica precursor, and 4 to 16 parts by mass of deionized water in 60 to 120 parts by mass of a volatile organic solvent, and continuously stirring for 8 to 72 hours to prepare a modified glass particle suspension;

[0008] Step 3, adding 0.1 to 2 parts by weight of a low surface energy modifier to the modified glass particle suspension, and continuously stirring for 4 to 48 hours to prepare a superhydrophobic glass particle suspension;

[0009] Step 4, spray drying the super-hydrophobic glass particle suspension at room temperature or freeze drying it at -120° C. to -80° C. for 6 to 24 hours to remove the volatile organic solvent to obtain a dry super-hydrophobic glass particle powder;

[0010] Step 5, dissolving 0.2 to 10 parts by mass of a wave-transparent resin and 0.1 to 5 parts by mass of a curing agent in 10 to 100 parts by mass of a volatile organic solvent, mechanically stirring for 5 to 10 minutes, and then adding 0.1 to 5 parts by mass of a super-hydrophobic glass particle powder, 0.1 to 1 part by mass of a dispersant, 0.1 to 0.5 parts by mass of an adhesion promoter, and 0.1 to 0.5 parts by mass of a stabilizer, and mechanically stirring for 0.5 to 4 hours until the powder is evenly dispersed to obtain a super-hydrophobic coating for a shipborne radar radome;

[0011] Step 6: Apply the super-hydrophobic coating to the surface of the shipborne radar antenna cover by spraying, brushing or dipping, and dry and cure at room temperature for 4-24 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

[0012] In combination with the first aspect, in one possible implementation of the first aspect, the glass particles in step 1 are at least one of glass fibers and glass flakes made of E-glass, E-CR glass, C-glass, D glass, or high-strength glass; and the piranha solution is a solution of sulfuric acid and hydrogen peroxide in a volume ratio of 7:3.

[0013] In combination with the first aspect, in one possible implementation of the first aspect, the glass fiber has a diameter ranging from 1 to 10 μm and a length ranging from 20 to 200 μm; and the glass flake has a thickness of 1 to 5 μm.

[0014] In combination with the first aspect, in one possible implementation of the first aspect, the alkaline pH adjusting solution in step 2 is at least one of sodium hydroxide solution, ammonia water and sodium carbonate solution; and the silica precursor is at least one of methylsiloxane, ethylsiloxane and tetraethoxysilane.

[0015] In combination with the first aspect, in an implementation of the first aspect, the volatile organic solvent in steps 2 and 5 is at least one of alcohols, ketones, esters and ethers.

[0016] In combination with the first aspect, in one implementation of the first aspect, the low surface energy modifier in step 3 is at least one of silane, fluorosilane, stearic acid, silicone resin and fluorine-containing acrylic resin.

[0017] In combination with the first aspect, in an implementation method of the first aspect, the wave-transparent resin in step 5 is at least one of a cyanate resin, an acrylic resin, a silicone resin, a polyimide resin and an epoxy resin that does not contain metal ions; and the curing agent is at least one of an isocyanate, an aliphatic polyamine, a vinyl prepolymer and benzoyl peroxide.

[0018] In combination with the first aspect, in an implementation method of the first aspect, the dispersant in step 5 is at least one of modified polyurea, sodium lauryl sulfate, methyl amyl alcohol, polyacrylamide and fatty acid polyethylene glycol ester; the adhesion promoter is at least one of a silane coupling agent, an organosilane, an alkyl phosphate and a chlorinated polyolefin; and the stabilizer is at least one of propylene glycol methyl ether acetate, aminobenzophenone and o-hydroxybenzophenone.

[0019] In a second aspect, an embodiment of the present application provides a super-hydrophobic coating for a shipborne radar radome, the super-hydrophobic coating being prepared using the method provided in the present application, the super-hydrophobic coating comprising:

[0020] 0.1 to 5 parts by mass of super-hydrophobic glass particles with silica nanoparticles grown on the surface, 0.2 to 10 parts by mass of wave-transmitting resin, 0.1 to 5 parts by mass of curing agent, 0.1 to 1 part by mass of dispersant, 0.1 to 0.5 parts by mass of adhesion promoter and 0.1 to 0.5 parts by mass of stabilizer.

[0021] In combination with the second aspect, in one possible implementation of the second aspect, the superhydrophobic coating is used in a shipborne radar antenna cover.

[0022] Compared with the prior art, this application has the following effects:

[0023] (1) The super-hydrophobic coating is prepared by combining glass fiber or glass flakes with a wave-transmitting resin, which synergistically improves the wave-transmitting performance of the coating, making its wave-transmitting rate reach more than 90%, which is 20-30% higher than that of traditional super-hydrophobic coatings, eliminating the adverse effects of the coating on the electromagnetic signal transmission performance of the antenna cover. (2) The glass fiber or glass flakes are dispersed in the wave-transmitting resin as a reinforcing phase, which significantly improves the mechanical properties of the coating, helps it resist mechanical, temperature, chemical and environmental damage, and prolongs the service life of the coating. (3) Based on the sol-gel method, silica nanoparticles are in situ grown on the surface of the glass fiber or glass flake. The large number of silanol groups attached to the surface of the latter can undergo condensation reaction with low surface energy modifiers, giving the coating a low surface energy; at the same time, the composite structure of glass fiber / flakes and silica nanoparticles gives the coating a micro-nano-level rough structure, giving the coating excellent super-hydrophobicity, with a surface water contact angle of >155° and a rolling angle of <5°. (4) The surface of the shipborne radar antenna cover coated with the super-hydrophobic coating of the present invention remains clean and dry during 180 days of outdoor placement. Even if dust is artificially deposited on its surface, it can be self-cleaned by raindrops on rainy days, making the surface clean again. Compared with the shipborne radar antenna cover without coating, the electromagnetic signal transmission efficiency is improved by more than 20%. (5) By regulating the particle size of silica nanoparticles, the content of glass fiber / scales and the type and content of low surface energy modifiers in the super-hydrophobic coating, the coating can obtain different properties, such as super-oleophobicity, mildew resistance and anti-corrosion properties, thereby broadening the application of the coating in the field of shipborne radar antenna covers. (6) The preparation method of the present invention has low requirements on the substrate material and shape, simple equipment, easy operation, low cost, and can be constructed on a large area. It has great application prospects in the fields of glass, metal, polymer and other materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Macroscopic and wettability diagram of superhydrophobic coating for shipborne radar radome;

[0025] Figure 2 Figure 2 is the surface morphology of glass fiber, where a is the structure morphology of glass fiber with silica nanoparticles grown on the surface, and b is the structure morphology of glass fiber without silica nanoparticles grown on the surface;

[0026] Figure 3 This is a diagram showing the wave transmission performance of super-hydrophobic coatings used for shipborne radar radomes;

[0027] Figure 4 Figure 2 is a diagram of the mechanical stability of the superhydrophobic coating used for shipborne radar radomes, where a is a schematic diagram of finger abrasion, b is the stability of the coating after finger abrasion, c is a schematic diagram of falling sand impact, and d is the stability of the coating after falling sand impact;

[0028] Figure 5This is the environmental stability diagram of the super-hydrophobic coating for shipborne radar radome, where a is the stability of the coating after high and low temperature treatment for 48 hours, b is the stability of the coating after outdoor aging test, and c is the stability of the coating after water immersion;

[0029] Figure 6 The chemical stability diagram of the super-hydrophobic coating for shipborne radar radome, where a is the stability of the coating after immersion in acid, alkali and salt solutions for 48 hours, and b is the stability of the coating after long-term immersion in different chemical solutions;

[0030] Figure 7 This is a diagram showing the antifouling performance of superhydrophobic coatings used for shipborne radar radomes;

[0031] Figure 8 A diagram showing the self-cleaning performance of superhydrophobic coatings used for shipborne radar radomes. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application clearer, the implementation methods of this application will be further explained below with reference to the accompanying drawings.

[0033] In a first aspect, an embodiment of the present application provides a method for preparing a super-hydrophobic coating for a shipborne radar radome, the method comprising:

[0034] Step 1: disperse the glass particles in a piranha solution at room temperature to 95° C. and soak for 1 to 4 hours, then rinse with deionized water and dry for later use;

[0035] Step 2: Dispersing 0.5 to 5 parts by mass of glass particles, 2 to 12 parts by mass of an alkaline pH regulating solution, 0.1 to 3 parts by mass of a silica precursor, and 4 to 16 parts by mass of deionized water in 60 to 120 parts by mass of a volatile organic solvent, and continuously stirring for 8 to 72 hours to prepare a modified glass particle suspension;

[0036] Step 3, adding 0.1 to 2 parts by weight of a low surface energy modifier to the modified glass particle suspension, and continuously stirring for 4 to 48 hours to prepare a superhydrophobic glass particle suspension;

[0037] Step 4, spray drying the super-hydrophobic glass particle suspension at room temperature or freeze drying it at -120° C. to -80° C. for 6 to 24 hours to remove the volatile organic solvent to obtain a dry super-hydrophobic glass particle powder;

[0038] Step 5, dissolving 0.2 to 10 parts by mass of a wave-transparent resin and 0.1 to 5 parts by mass of a curing agent in 10 to 100 parts by mass of a volatile organic solvent, mechanically stirring for 5 to 10 minutes, and then adding 0.1 to 5 parts by mass of a super-hydrophobic glass particle powder, 0.1 to 1 part by mass of a dispersant, 0.1 to 0.5 parts by mass of an adhesion promoter, and 0.1 to 0.5 parts by mass of a stabilizer, and mechanically stirring for 0.5 to 4 hours until the powder is evenly dispersed to obtain a super-hydrophobic coating for a shipborne radar radome;

[0039] Step 6: Apply the super-hydrophobic coating to the surface of the shipborne radar antenna cover by spraying, brushing or dipping, and dry and cure at room temperature for 4-24 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

[0040] In combination with the first aspect, in one possible implementation of the first aspect, the glass particles in step 1 are at least one of glass fibers and glass flakes made of E-glass, E-CR glass, C-glass, D glass, or high-strength glass; and the piranha solution is a solution of sulfuric acid and hydrogen peroxide in a volume ratio of 7:3.

[0041] In combination with the first aspect, in one possible implementation of the first aspect, the glass fiber has a diameter ranging from 1 to 10 μm and a length ranging from 20 to 200 μm; and the glass flake has a thickness of 1 to 5 μm.

[0042] In combination with the first aspect, in one possible implementation of the first aspect, the alkaline pH adjusting solution in step 2 is at least one of sodium hydroxide solution, ammonia water and sodium carbonate solution; and the silica precursor is at least one of methylsiloxane, ethylsiloxane and tetraethoxysilane.

[0043] In combination with the first aspect, in an implementation of the first aspect, the volatile organic solvent in steps 2 and 5 is at least one of alcohols, ketones, esters and ethers.

[0044] In combination with the first aspect, in one implementation of the first aspect, the low surface energy modifier in step 3 is at least one of silane, fluorosilane, stearic acid, silicone resin and fluorine-containing acrylic resin.

[0045] In combination with the first aspect, in an implementation method of the first aspect, the wave-transparent resin in step 5 is at least one of a cyanate resin, an acrylic resin, a silicone resin, a polyimide resin and an epoxy resin that does not contain metal ions; and the curing agent is at least one of an isocyanate, an aliphatic polyamine, a vinyl prepolymer and benzoyl peroxide.

[0046] In combination with the first aspect, in an implementation method of the first aspect, the dispersant in step 5 is at least one of modified polyurea, sodium lauryl sulfate, methyl amyl alcohol, polyacrylamide and fatty acid polyethylene glycol ester; the adhesion promoter is at least one of a silane coupling agent, an organosilane, an alkyl phosphate and a chlorinated polyolefin; and the stabilizer is at least one of propylene glycol methyl ether acetate, aminobenzophenone and o-hydroxybenzophenone.

[0047] In a second aspect, an embodiment of the present application provides a super-hydrophobic coating for a shipborne radar radome, the super-hydrophobic coating being prepared using the method provided in the present application, the super-hydrophobic coating comprising:

[0048] 0.1 to 5 parts by mass of super-hydrophobic glass particles with silica nanoparticles grown on the surface, 0.2 to 10 parts by mass of wave-transmitting resin, 0.1 to 5 parts by mass of curing agent, 0.1 to 1 part by mass of dispersant, 0.1 to 0.5 parts by mass of adhesion promoter and 0.1 to 0.5 parts by mass of stabilizer.

[0049] In combination with the second aspect, in one possible implementation of the second aspect, the superhydrophobic coating is used in a shipborne radar antenna cover.

[0050] Example 1

[0051] A method for preparing a super-hydrophobic coating for a shipborne radar radome. In this embodiment, the glass particles are glass fibers made of D glass, the alkaline pH adjusting liquid is a 35 wt.% ammonia solution, the silica precursor is tetraethoxysilane, the volatile organic solvent is acetone, the low surface energy modifier is propyltriethoxysilane, the wave-transmitting resin is an epoxy resin, the curing agent is isocyanate, the dispersant is sodium lauryl sulfate, the adhesion promoter is a silane coupling agent, and the stabilizer is propylene glycol methyl ether acetate. The preparation steps are as follows:

[0052] (1) Disperse the glass particles in piranha solution at room temperature and soak for 1 hour. After treatment, rinse with deionized water and dry for later use.

[0053] (2) dispersing 0.5 parts by mass of glass particles, 2 parts by mass of alkaline pH regulating liquid, 0.1 parts by mass of silica precursor, and 4 parts by mass of deionized water in 60 parts by mass of volatile organic solvent, and continuously stirring for 8 hours to prepare a modified glass particle suspension;

[0054] (3) adding 0.1 parts by mass of a low surface energy modifier to the modified glass particle suspension obtained in step (2), and stirring continuously for 4 hours to obtain a superhydrophobic glass particle suspension;

[0055] (4) spray drying the super-hydrophobic glass particle suspension obtained in step (3) at room temperature to remove volatile organic solvents, thereby obtaining a dry super-hydrophobic glass particle powder;

[0056] (5) 0.2 parts by mass of wave-transparent resin and 0.1 parts by mass of curing agent were dissolved in 10 parts by mass of volatile organic solvent, and after mechanical stirring for 5 minutes, 0.1 parts by mass of super-hydrophobic glass microparticle powder, 0.1 parts by mass of dispersant, 0.1 parts by mass of adhesion promoter, and 0.1 parts by mass of stabilizer were added in sequence, and mechanical stirring was carried out for 0.5 hours until the powder was evenly dispersed to obtain a super-hydrophobic coating for shipborne radar antenna cover;

[0057] (6) The super-hydrophobic coating prepared in step (5) is applied to the surface of the shipborne radar antenna cover by spraying, and dried and cured at room temperature for 4 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

[0058] Figure 1 The macroscopic photograph and wettability of the coating show that the coating is continuous and uniform, and has no defects such as nodules, pinholes, bubbles, pinholes, cracks, peeling, powdering, particles, sagging, exposed bottom, and inclusion of dirt. The thickness is 60-100μm. In addition, the water droplet contact angle on the coating surface is 161.2°, and the rolling angle is 1°. Rainwater drops on the coating surface can easily roll off without any wetting residue, and the coating surface remains dry. After being placed outdoors for 5 years, the water droplet contact angle can still be maintained above 150°, and the rolling angle is 8°.

[0059] Example 2

[0060] A method for preparing a super-hydrophobic coating for a shipborne radar radome. In this embodiment, the glass particles are glass fibers made of E-glass, the alkaline pH adjusting liquid is a sodium hydroxide solution, no silica precursor is added, the volatile organic solvent is a hydrofluoroether, the low surface energy modifier is perfluorooctyltrimethoxysilane, the wave-transmitting resin is an epoxy resin, the curing agent is an aliphatic polyamine, the dispersant is a fatty acid polyethylene glycol ester, the adhesion promoter is an alkyl phosphate ester, and the stabilizer is an amino-acetyl trimethoxysilane. The preparation steps are as follows:

[0061] (1) Disperse the glass particles in piranha solution at 80°C and soak for 1 hour. After treatment, wash with deionized water and dry for later use.

[0062] (2) dispersing 3.5 parts by mass of glass particles, 5 parts by mass of alkaline pH regulating liquid, and 9 parts by mass of deionized water in 90 parts by mass of a volatile organic solvent, and stirring continuously for 8 hours to prepare a glass particle suspension;

[0063] (3) adding 0.8 parts by mass of a low surface energy modifier to the glass particle suspension prepared in step (2), and stirring continuously for 24 hours to prepare a superhydrophobic glass particle suspension;

[0064] (4) freeze-drying the super-hydrophobic glass particle suspension obtained in step (3) at -100° C. for 12 h to remove the volatile organic solvent, thereby obtaining a dry super-hydrophobic glass particle powder;

[0065] (5) 3 parts by mass of wave-transparent resin and 1 part by mass of curing agent were dissolved in 15 parts by mass of volatile organic solvent, and after mechanical stirring for 10 minutes, 1.5 parts by mass of super-hydrophobic glass microparticle powder, 0.4 parts by mass of dispersant, 0.1 parts by mass of adhesion promoter, and 0.1 parts by mass of stabilizer were added in sequence, and mechanical stirring was carried out for 2 hours until the powder was evenly dispersed to obtain a super-hydrophobic coating for shipborne radar antenna cover;

[0066] (6) The super-hydrophobic coating prepared in step (5) is applied to the surface of the shipborne radar antenna cover by brushing, and dried and cured at room temperature for 12 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

[0067] Figure 2 a is the surface morphology of the glass fibers in the coating. It can be found that the diameter of these glass fibers is 4-8 μm, the length is 20-40 μm, and the surface is smooth. Compared with Example 1, in this embodiment, since no silica precursor is added, the in-situ growth of silica nanoparticles does not occur, and thus the phenomenon of a large number of nanoparticles adhering to the surface of the glass fibers as in Example 1 does not occur ( Figure 2 b), on the one hand, it is unable to form a micro-nano hierarchical structure, and on the other hand, the degree of modification by the low surface energy modifier is reduced, so the superhydrophobicity of the coating is reduced, the water droplet contact angle is reduced to about 150°, and the rolling angle is increased to about 30°.

[0068] Example 3

[0069] A method for preparing a super-hydrophobic coating for a shipborne radar radome. In this embodiment, no glass particles are added, the alkaline pH regulating liquid is a sodium carbonate solution, the silica precursor is methyltrimethoxysilane, the volatile organic solvent is anhydrous ethanol, the low surface energy modifier is polydimethylsiloxane, the wave-transparent resin is a polyimide resin, the curing agent is a vinyl prepolymer, the dispersant is a modified polyurea, the adhesion promoter is a chlorinated polyolefin, and the stabilizer is o-hydroxybenzophenone. The preparation steps are as follows:

[0070] (1) dispersing 12 parts by mass of an alkaline pH regulating solution, 3 parts by mass of a silica precursor, and 16 parts by mass of deionized water in 120 parts by mass of a volatile organic solvent, and continuously stirring for 72 hours to prepare a modified glass particle suspension;

[0071] (2) adding 2 parts by mass of a low surface energy modifier to the silica nanoparticle suspension prepared in step (1), and continuously stirring for 48 hours to prepare a superhydrophobic nanoparticle suspension;

[0072] (3) spray drying the super-hydrophobic nanoparticle suspension obtained in step (2) at room temperature to remove volatile organic solvents to obtain dry super-hydrophobic nanoparticle powder;

[0073] (4) Dissolve 10 parts by mass of a wave-transparent resin and 5 parts by mass of a curing agent in 100 parts by mass of a volatile organic solvent, and mechanically stir for 10 minutes. Then, add 5 parts by mass of a super-hydrophobic nanoparticle powder, 1 part by mass of a dispersant, 0.5 parts by mass of an adhesion promoter, and 0.5 parts by mass of a stabilizer in sequence. Mechanically stir for 4 hours until the powder is evenly dispersed to obtain a super-hydrophobic coating for a shipborne radar antenna cover.

[0074] (5) The super-hydrophobic coating prepared in step (4) is applied to the surface of the shipborne radar antenna cover by spraying, and dried and cured at room temperature for 24 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

[0075] Figure 3 The wave transmission performance of the coating is shown in Figure 2. The coating's wave transmission is only 75.5%. Compared to Example 1, since no glass fiber or glass flakes are added as a reinforcement phase, the wave transmission of this coating is much lower than that of the coating in Example 1 (which has a wave transmission of 95%). Furthermore, it can be seen that the wave transmission of the coating in Example 1 is similar to that of the bare radome, indicating that it has no effect on the wave transmission of the radome.

[0076] Example 4

[0077] A method for preparing a super-hydrophobic coating for a shipborne radar radome. In this embodiment, the glass particles are glass flakes made of high-strength glass, the alkaline pH adjusting liquid is a sodium hydroxide solution, the silica precursor is ethyltrimethoxysilane, the volatile organic solvent is ethyl acetate, the low surface energy modifier is a fluorine-containing acrylic resin, the wave-transmitting resin is a cyanate resin, the curing agent is benzoyl peroxide, the dispersant is polyacrylamide, the adhesion promoter is an organosilane, and the stabilizer is o-hydroxybenzophenone. The preparation steps are as follows:

[0078] (1) Disperse the glass particles in piranha solution at 60°C and soak for 2 hours. After treatment, rinse with deionized water and dry for later use.

[0079] (2) dispersing 3 parts by mass of glass particles, 6 parts by mass of alkaline pH regulating liquid, 1 part by mass of silica precursor, and 10 parts by mass of deionized water in 100 parts by mass of volatile organic solvent, and continuously stirring for 24 hours to prepare a modified glass particle suspension;

[0080] (3) adding 1 part by mass of a low surface energy modifier to the modified glass particle suspension obtained in step (2), and stirring continuously for 4 hours to obtain a superhydrophobic glass particle suspension;

[0081] (4) spray drying the super-hydrophobic glass particle suspension obtained in step (3) at room temperature to remove volatile organic solvents, thereby obtaining a dry super-hydrophobic glass particle powder;

[0082] (5) Dissolve 5 parts by mass of a wave-transparent resin and 2 parts by mass of a curing agent in 20 parts by mass of a volatile organic solvent, and mechanically stir for 10 minutes. Then, add 2 parts by mass of super-hydrophobic glass microparticle powder, 0.5 parts by mass of a dispersant, 0.2 parts by mass of an adhesion promoter, and 0.2 parts by mass of a stabilizer in sequence. Mechanically stir for 1 hour until the powder is evenly dispersed to obtain a super-hydrophobic coating for a shipborne radar antenna cover;

[0083] (6) The super-hydrophobic coating prepared in step (5) is applied to the surface of the shipborne radar antenna cover by spraying, and dried and cured at room temperature for 8 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

[0084] Figure 4 For the mechanical stability of the coating, the coating is respectively polished by a finger and impacted by 30cm high falling sand, and its water drop contact angle and rolling angle are measured. It can be found that the coating always keeps the water drop contact angle greater than 150 ° and the rolling angle less than 10 ° during the test, and the super-hydrophobicity is excellent, which can withstand more than 1000 finger polishings and 75min falling sand impacts, and the mechanical stability has met the actual demand of the coating applied on the surface of the shipborne radar antenna cover. In addition, compared with Example 1, due to the glass particle content, alkaline pH regulating liquid content, silica precursor content, and transparent resin content in this embodiment, the strengthening effect of the glass flakes prepared by high-strength glass in the coating is more significant, so the mechanical stability of the coating is much better than that of the coating in Example 1 (the coating in Example 1 can only withstand 300 finger polishings to keep super-hydrophobic).

[0085] Example 5

[0086] Figure 5The environmental stability of the super-hydrophobic coating for the shipborne radar radome in Example 4 is as high as 94%. The coating is subjected to high and low temperature treatment (allowed to return to room temperature naturally after being placed in an environment of -196 to 350 ° C for 48 hours), outdoor aging test (placed outdoors, subjected to sunlight, wind and sand, rain and ice and snow) and immersion treatment (immersing the coating in tap water), and its water drop contact angle and rolling angle are measured. It can be found that the coating always maintains super-hydrophobicity in various tests, proving that it can withstand damage from various harsh environments. At the same time, after the coating is subjected to the above-mentioned various environmental damages, the cross-grid adhesion test is carried out according to the ISO 2409 standard. The adhesion still remains at level 0, and the adhesion does not decrease, proving the excellent environmental stability of the coating. Compared with Example 1, since the coating in this embodiment contains a higher proportion of glass particles, the average wave transmittance is higher, and the average wave transmittance of the coating in Example 1 is 95%. In addition, the coatings in both embodiments have excellent environmental stability, which is because both coatings are strengthened by glass particles.

[0087] Figure 6 The chemical stability of the super-hydrophobic coating for the shipborne radar radome in Example 4 is shown. The coating was placed in an acidic solution prepared with hydrochloric acid, a saline solution prepared with sodium chloride, and an alkaline solution prepared with sodium hydroxide and immersed for 48 hours. It can be found that the surface of the coating remained dry when it was taken out, and the corrosive liquid did not infiltrate any of the water droplet contact angles and rolling angles of the coating remained above 150° and below 10°, maintaining super-hydrophobicity. In addition, the coating was also placed in different chemical solutions for long-term immersion, and it was found that it could withstand chemical erosion for more than 40 days, proving the excellent chemical stability of the coating.

[0088] Example 6

[0089] A method for preparing a super-hydrophobic coating for a shipborne radar radome. In this embodiment, the glass particles are glass fibers made of D glass, the alkaline pH adjusting liquid is an ammonia solution, the silica precursor is tetraethoxysilane, the volatile organic solvent is butyl acetate, the low surface energy modifier is perfluorooctyltriethoxysilane, the wave-transmitting resin is an acrylic resin, the curing agent is isocyanate, the dispersant is modified polyurea, the adhesion promoter is an organosilane, and the stabilizer is propylene glycol methyl ether acetate. The preparation steps are as follows:

[0090] (1) Disperse the glass particles in 95°C piranha solution and soak for 4 hours. After treatment, rinse with deionized water and dry for later use.

[0091] (2) dispersing 5 parts by mass of glass particles, 12 parts by mass of alkaline pH regulating liquid, 3 parts by mass of silica precursor, and 16 parts by mass of deionized water in 120 parts by mass of a volatile organic solvent, and continuously stirring for 72 hours to prepare a modified glass particle suspension;

[0092] (3) adding 2 parts by mass of a low surface energy modifier to the modified glass particle suspension obtained in step (2), and stirring continuously for 48 hours to obtain a superhydrophobic glass particle suspension;

[0093] (4) spray drying the super-hydrophobic glass particle suspension obtained in step (3) at room temperature to remove volatile organic solvents, thereby obtaining a dry super-hydrophobic glass particle powder;

[0094] (5) Dissolve 10 parts by mass of a wave-transparent resin and 5 parts by mass of a curing agent in 100 parts by mass of a volatile organic solvent, and mechanically stir for 10 minutes. Then, add 5 parts by mass of super-hydrophobic glass microparticle powder, 1 part by mass of a dispersant, 0.5 parts by mass of an adhesion promoter, and 0.5 parts by mass of a stabilizer in sequence. Mechanically stir for 4 hours until the powder is evenly dispersed to obtain a super-hydrophobic coating for a shipborne radar antenna cover.

[0095] (6) The super-hydrophobic coating prepared in step (5) is applied to the surface of the shipborne radar antenna cover by spraying, and dried and cured at room temperature for 24 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

[0096] Figure 7 It is an antifouling optical photograph of the coating. It can be found that the coating is immersed in a mixture of water and dust, and the surface remains clean and dry after being taken out, without any dirt staining residue; More importantly, even if the coating is immersed in a mixture of cooking oil and dust, the same phenomenon is shown, indicating that the coating has excellent antifouling performance. Compared with Example 1, the tetraethoxysilane content in this embodiment is higher, the in-situ growth time is longer, the nanoparticle size is larger, and the coating has a rougher micro-nano hierarchical structure, which is conducive to repelling low surface tension liquids. Therefore, the coating in this embodiment not only has the super-hydrophobicity of the coating in Example 1, but also has a unique super-oleophobicity, that is, the oil droplet contact angle is greater than 150° and the rolling angle is less than 10°; Compared with Example 4, since the proportion of glass particles in this embodiment is relatively higher, the bonding force between the particles and the resin is reduced, so the mechanical stability of the coating is far less than that of the coating in Example 4, and it can only withstand finger polishing 200 times.

[0097] Figure 8 The self-cleaning performance of the superhydrophobic coating for a shipborne radar radome in Example 6 was examined. It was found that depositing large amounts of dust on the coating surface not only severely degraded its aesthetics but also reduced its wave transmittance by over 10%, significantly reducing electromagnetic signal transmission efficiency. However, simply by running water, condensation, or frost, the dust on the coating surface could be completely removed, restoring the surface to a clean and dry state, while also restoring wave transmittance to over 95%, a feat unattainable with conventional radomes.

[0098] The above-described embodiments of the present application do not constitute a limitation on the scope of protection of the present application.

Claims

1. A method for preparing a super-hydrophobic coating for a shipborne radar radome, characterized in that: The method comprises: Step 1: disperse the glass fibers or glass flakes in a piranha solution at room temperature to 95° C. and soak for 1 to 4 hours, then rinse with deionized water and dry for later use; Step 2: Dispersing 0.5 to 5 parts by mass of glass fibers or glass flakes, 2 to 12 parts by mass of an alkaline pH regulating solution, 0.1 to 3 parts by mass of a silica precursor, and 4 to 16 parts by mass of deionized water in 60 to 120 parts by mass of a volatile organic solvent, and continuously stirring for 8 to 72 hours to prepare a modified glass fiber or glass flake suspension; Step 3, adding 0.1 to 2 parts by mass of a low surface energy modifier to the modified glass fiber or glass flake suspension, and continuously stirring for 4 to 48 hours to obtain a superhydrophobic glass fiber or glass flake suspension; Step 4, spray drying the super-hydrophobic glass fiber or glass flake suspension at room temperature or freeze drying it at -120°C to -80°C for 6 to 24 hours to remove the volatile organic solvent to obtain a dry super-hydrophobic glass fiber or glass flake powder; Step 5, dissolving 0.2 to 10 parts by mass of a wave-transparent resin and 0.1 to 5 parts by mass of a curing agent in 10 to 100 parts by mass of a volatile organic solvent, mechanically stirring for 5 to 10 minutes, and then adding 0.1 to 5 parts by mass of a super-hydrophobic glass fiber or glass flake powder, 0.1 to 1 part by mass of a dispersant, 0.1 to 0.5 parts by mass of an adhesion promoter, and 0.1 to 0.5 parts by mass of a stabilizer, and mechanically stirring for 0.5 to 4 hours until the powder is evenly dispersed to obtain a super-hydrophobic coating for a shipborne radar radome; Step 6: Apply the super-hydrophobic coating to the surface of the shipborne radar antenna cover by spraying, brushing or dipping, and dry and cure at room temperature for 4-24 hours to obtain the super-hydrophobic coating for the shipborne radar antenna cover.

2. The method for preparing a super-hydrophobic coating for a shipborne radar radome according to claim 1, wherein The glass fiber or glass flake in step 1 is at least one of glass fibers and glass flakes made of E-glass, E-CR glass, C-glass, D glass or high-strength glass; the piranha solution is a solution with a volume ratio of sulfuric acid to hydrogen peroxide of 7:

3.

3. The method for preparing a super-hydrophobic coating for a shipborne radar radome according to claim 2, wherein The glass fiber has a diameter ranging from 1 to 10 μm and a length ranging from 20 to 200 μm; the glass flake has a thickness ranging from 1 to 5 μm.

4. The method for preparing a super-hydrophobic coating for a shipborne radar radome according to claim 1, wherein The alkaline pH regulating solution in step 2 is at least one of sodium hydroxide solution, ammonia water and sodium carbonate solution; and the silicon dioxide precursor is at least one of methylsiloxane, ethylsiloxane and tetraethoxysilane.

5. The method for preparing a super-hydrophobic coating for a shipborne radar radome according to claim 1, wherein The volatile organic solvent in steps 2 and 5 is at least one of alcohols, ketones, esters and ethers.

6. The method for preparing a super-hydrophobic coating for a shipborne radar radome according to claim 1, wherein The low surface energy modifier in step 3 is at least one of silane, stearic acid, silicone resin and fluorine-containing acrylic resin.

7. The method for preparing a super-hydrophobic coating for a shipborne radar radome according to claim 1, wherein The wave-transmitting resin in step 5 is at least one of cyanate resin, acrylic resin, silicone resin, polyimide resin and epoxy resin that do not contain metal ions; the curing agent is at least one of isocyanate, aliphatic polyamine, vinyl prepolymer and benzoyl peroxide.

8. The method for preparing a super-hydrophobic coating for a shipborne radar radome according to claim 1, wherein The dispersant in step 5 is at least one of modified polyurea, sodium lauryl sulfate, methyl amyl alcohol, polyacrylamide and fatty acid polyethylene glycol ester; the adhesion promoter is at least one of silane coupling agent, organosilane, alkyl phosphate and chlorinated polyolefin; the stabilizer is at least one of propylene glycol methyl ether acetate, aminobenzophenone and o-hydroxybenzophenone.

9. A super hydrophobic coating for a shipborne radar radome, characterized in that: The super-hydrophobic coating is prepared by any one of the methods of claims 1 to 8, and the super-hydrophobic coating comprises: 0.1 to 5 parts by mass of super-hydrophobic glass fibers or glass flakes with silica nanoparticles grown on the surface, 0.2 to 10 parts by mass of wave-transmitting resin, 0.1 to 5 parts by mass of curing agent, 0.1 to 1 part by mass of dispersant, 0.1 to 0.5 parts by mass of adhesion promoter and 0.1 to 0.5 parts by mass of stabilizer.

Images