Preparation and use method of anti-static wave-transparent coating for unmanned aerial vehicle radome

Abstract

The invention relates to preparation and use methods of an anti-static wave-transparent coating for an unmanned aerial vehicle radome, the coating is prepared from silicon-containing polymethacrylate resin, a curing agent, a defoaming agent, a leveling agent, a reactive diluent and an antistatic agent, and the preparation method comprises the following steps: (1) preparing the anti-static wave-transparent coating; (2) applying the anti-static wave-transparent coating to the radome, and performing coating construction; and (3) curing the coating. The anti-static effect is good, attenuation of radar signals is reduced through material selection and formula optimization, and efficient work of a radar system is ensured. By adjusting the type and content of the conductive filler, it is ensured that the coating can effectively prevent electrostatic accumulation under various environmental conditions, and interference of electrostatic discharge to a radar system is prevented. According to the invention, by adding the weather-resistant reinforcing agent, the stability of the coating in severe environments such as ultraviolet rays, salt mist, temperature change and the like is improved, and the service life of the coating is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of antistatic coatings, and in particular relates to a preparation and use method of an antistatic wave-transmitting coating for a drone radome. Background Art

[0002] Under complex meteorological conditions, the intense friction between the radome and the air of a high-speed UAV will cause static electricity on the surface. If the static electricity is not released in time, it may cause discharge when it accumulates to a certain extent, thus posing a potential threat to the radome and electronic equipment such as the antenna inside. In addition, the radome is often impacted by raindrops, hail, etc. This long-term scouring may damage the skin of the radome, affecting its structural safety and electrical quality. Therefore, the antistatic coating used for aircraft radomes must not only have the ability to conduct static electricity, but also have excellent mechanical properties. As a key component of an aircraft, the main task of the radome is to protect the aircraft from the harsh environment and ensure the normal propagation of electromagnetic wave signals. Therefore, the performance of the wave-transmitting material directly determines the scope of application of the radome.

[0003] Antistatic coating is a functional coating that has the function of conducting static electricity and eliminating accumulated static charges. It is mainly divided into two types: additive type and intrinsic type. At present, the widely used antistatic coatings are mostly additive type, which achieves the static electricity conduction function by adding a certain amount of conductive filler to the non-conductive base resin. However, the antistatic coatings currently used in radomes mostly rely on conductive powders such as conductive carbon black, conductive mica, and conductive ATO to achieve the antistatic effect. The addition amount of these powders usually exceeds 20%, resulting in unsatisfactory dielectric properties of the coating, which in turn affects the wave transmission ability of the drone radome.

[0004] In summary, traditional antistatic coatings for radomes have the following problems: (1) Some traditional coatings have poor wave transmission performance in specific frequency bands, which will cause attenuation or reflection of radar signals and affect the normal operation of the radar system. (2) Traditional antistatic coatings may not have a good antistatic effect in high humidity, low humidity or high dust environments and are prone to accumulate static electricity. (3) The deterioration of the coating will lead to a decrease in antistatic performance or even peeling, affecting the protective function of the radome and increasing maintenance costs. Some traditional coatings have insufficient adhesion to the radome substrate and are easy to fall off. (4) Traditional coatings have a short service life and require frequent maintenance or replacement. High maintenance costs will increase the overall operating cost of the drone and reduce economic benefits. Summary of the invention

[0005] The present invention discloses a method for preparing and using an anti-static wave-transmitting coating for a drone radome, with the aim of solving the problems described in the background technology section (1) to (4).

[0006] To achieve the above purpose, the technical solution of the present invention is:

[0007] A preparation and use method of an anti-static wave-transmitting coating for a drone radome, wherein the coating is prepared from a silicon-containing polymethacrylate resin, a curing agent, a defoaming agent, a leveling agent, an active diluent and an antistatic agent, and comprises the following steps:

[0008] (1) Preparation of antistatic wave-transmitting coating;

[0009] (2) Using anti-static wave-transmitting coating on radome for coating construction;

[0010] (3) Coating curing.

[0011] Preferably, the silicon-containing polymethacrylate resin is prepared by copolymerization of methyl methacrylate, styrene, n-butyl acrylate and acrylamide.

[0012] Preferably, the step (1) adopts a wet chemical method to synthesize the antistatic wave-transmitting coating, and the specific steps are as follows: in a four-mouth reaction kettle equipped with a stirrer, a reflux condenser and a thermometer, six monomers of methyl methacrylate, 2-ethylhexyl acrylate, ethyl acrylate, styrene, n-butyl acrylate and acrylamide are added in sequence according to a set mass ratio, a mixed solvent is selected, and the feeding order is: first add the mixed solvent, then add each monomer in sequence, and finally add the initiator; the reaction temperature is controlled in the range of 50-84°C; after the reaction is completed, a defoamer, an active diluent and an antistatic agent are added in sequence.

[0013] Preferably, in the step (1), the mass ratio is set as follows: 35-50 parts of methyl methacrylate, 3-8 parts of 2-ethylhexyl acrylate, 14-20 parts of ethyl acrylate, 7-15 parts of styrene, 8-12 parts of n-butyl acrylate and 9-23 parts of acrylamide are added in sequence.

[0014] Preferably, in the step (1), the initiator is an oil-soluble azo compound, the defoamer is one or more of trioctyl phosphate, glyceryl monostearate, and methyl silicone oil, the active diluent is one or more of neodecanoic acid glycidyl ester, alkylene glycidyl ether, and toluene glycidyl ether; and the antistatic agent is one or more of monoalkyl ether phosphate, lauryl amide propyl amine oxide, and dodecyl dimethyl amine oxide.

[0015] Preferably, in the step (1), the mass fraction of each monomer is controlled to be 15% to 40% of the total mass of the antistatic wave-transmitting coating.

[0016] Preferably, the mixed solvent in step (1) is one or more of ethyl acetate, isopropyl alcohol (IPA) and methyl isobutyl ketone (MIBK), and the total mass of the mixed solvent is between 40% and 60% of the total mass of the antistatic wave-transmitting coating.

[0017] Preferably, in step (1), the mass of the defoaming agent is between 0.5% and 1.5% of the total mass of the antistatic wave-transmitting coating.

[0018] Preferably, in step (1), the initiator used to initiate the polymerization is an oil-soluble azo compound such as azobisisobutyronitrile or azobisisovaleronitrile.

[0019] Preferably, in step (1), the mass of the reactive diluent is between 2% and 4% of the total mass of the antistatic wave-transmitting coating.

[0020] Preferably, in step (1), the mass of the antistatic agent is between 7.5% and 15% of the total mass of the antistatic wave-transmitting coating.

[0021] Preferably, the step (2) includes the following specific steps: the surface of the radome needs to be pretreated before construction: first, the surface is cleaned with anhydrous ethanol to remove oil and impurities; then wiped with a lint-free cloth; then the surface is blown dry with a clean air gun; to improve the adhesion of the coating, the surface of the radome is lightly polished with fine sandpaper. According to actual needs, plasma treatment can be selected to activate the surface of the radome, and then the anti-static wave-transmitting coating is sprayed on the surface of the radome.

[0022] Preferably, in the step (3), the sprayed coating is naturally dried at room temperature, and the drying time is controlled between 2-24 hours according to the thickness of the coating; or, to accelerate the curing, it is heated in an oven at 60-100°C, and the curing time is 0.5-4 hours.

[0023] The beneficial effects of the preparation and use method of the anti-static wave-transmitting coating for the drone radome of the present invention are:

[0024] The coating material of the present invention has a low dielectric constant and low dielectric loss, ensuring that electromagnetic waves can efficiently penetrate the coating, reducing signal attenuation and distortion, thereby maintaining the high sensitivity and accuracy of the radar system. The coating can quickly conduct away static charges, avoid potential damage to radar systems and other electronic equipment caused by electrostatic discharge, and improve the stability and reliability of the system. The coating material can resist ultraviolet radiation, salt spray corrosion, and chemical corrosion, maintain long-term performance stability, and adapt to various harsh environmental conditions. The coating material is usually of low density, which helps to reduce the overall weight of the radome, which is particularly important for drones that pursue high performance and long endurance. The coating has excellent adhesion to the radome substrate, and at the same time has certain wear resistance and mechanical strength, and can withstand vibration and friction during flight. By combining these advantages, the anti-static wave-transparent coating for drone radomes not only improves the performance of the radar system, but also enhances the survivability and mission execution efficiency of drones in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 , a graph showing the electrostatic attraction ability of the antistatic wave-transmitting coating provided by the present invention and various plastic (PET, PTFE, Nylon, PI) surfaces to PS microspheres after being rubbed with fingers. DETAILED DESCRIPTION

[0026] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0027] The following embodiments may be understood as individually expressing a part of a local structure or method of the present invention, or may be understood as a combination of the embodiments to explain the connotation of a larger structure or method of the present invention.

[0028] Example 1

[0029] A preparation and use method of an anti-static wave-transmitting coating for a drone radome, wherein the coating is prepared from a silicon-containing polymethacrylate resin, a curing agent, a defoaming agent, a leveling agent, an active diluent and an antistatic agent, and comprises the following steps:

[0030] (1) Preparation of antistatic wave-transmitting coating;

[0031] (2) Using anti-static wave-transmitting coating on radome for coating construction;

[0032] (3) Coating curing.

[0033] Example 2

[0034] Based on Example 1, this example discloses that: the silicon-containing polymethacrylate resin is prepared by copolymerization of methyl methacrylate, styrene, n-butyl acrylate and acrylamide.

[0035] Example 3

[0036] Based on Example 2, this embodiment discloses:

[0037] The step (1) adopts a wet chemical method to synthesize an antistatic wave-transmitting coating, and the specific steps are as follows: in a four-mouth reaction kettle equipped with a stirrer, a reflux condenser and a thermometer, six monomers of methyl methacrylate, 2-ethylhexyl acrylate, ethyl acrylate, styrene, n-butyl acrylate and acrylamide are added in sequence according to a set mass ratio; in order to promote uniform dispersion of the monomers, a mixed solvent is selected, and the order of adding materials is: first adding the mixed solvent, then adding each monomer in sequence, and finally adding the initiator; the reaction temperature is controlled in the range of 50-84°C; this temperature range matches the decomposition temperature of the initiator, which is conducive to the full progress of the polymerization reaction; after the reaction is completed, a defoamer, an active diluent and an antistatic agent are added in sequence.

[0038] Example 4

[0039] Based on Example 3, this embodiment discloses:

[0040] In the step (1), the initiator is an oil-soluble azo compound, the defoamer is one or more of trioctyl phosphate, glyceryl monostearate, and methyl silicone oil, the active diluent is one or more of neodecanoic acid glycidyl ester, alkylene glycidyl ether, and toluene glycidyl ether; and the antistatic agent is one or more of monoalkyl ether phosphate, lauryl amide propyl amine oxide, and dodecyl dimethyl amine oxide.

[0041] Example 5

[0042] Based on Example 4, this embodiment discloses:

[0043] In the step (1), the mass fraction of each monomer is controlled to account for 15% of the total mass of the antistatic wave-transmitting coating.

[0044] The mixed solvent in step (1) is one or more of ethyl acetate, isopropyl alcohol (IPA) and methyl isobutyl ketone (MIBK), and the total mass of the mixed solvent accounts for 60% of the total mass of the antistatic wave-transmitting coating.

[0045] Example 6

[0046] Based on Example 4, this embodiment discloses:

[0047] In the step (1), the mass fraction of each monomer is controlled to account for 40% of the total mass of the antistatic wave-transmitting coating.

[0048] The mixed solvent in step (1) is one or more of ethyl acetate, isopropyl alcohol (IPA) and methyl isobutyl ketone (MIBK), and the total mass of the mixed solvent accounts for 40% of the total mass of the antistatic wave-transmitting coating.

[0049] Example 7

[0050] Based on Example 4, this embodiment discloses:

[0051] In the step (1), the mass of the defoaming agent accounts for 0.5% of the total mass of the antistatic wave-transmitting coating.

[0052] In the step (1), the initiator used to initiate the polymerization is an oil-soluble azo compound, namely azobisisobutyronitrile.

[0053] In the step (1), the mass of the reactive diluent accounts for 2% of the total mass of the antistatic wave-transmitting coating.

[0054] In the step (1), the mass of the antistatic agent accounts for 7.5% of the total mass of the antistatic wave-transmitting coating.

[0055] Example 8

[0056] Based on Example 4, this embodiment discloses:

[0057] In the step (1), the mass of the defoaming agent accounts for 1.5% of the total mass of the antistatic wave-transmitting coating.

[0058] In the step (1), the initiator selected from the oil-soluble azo initiator for initiating polymerization is azobisisovaleronitrile.

[0059] In the step (1), the mass of the reactive diluent accounts for 4% of the total mass of the antistatic wave-transmitting coating.

[0060] In the step (1), the mass of the antistatic agent accounts for 15% of the total mass of the antistatic wave-transmitting coating.

[0061] Example 9

[0062] Based on the above embodiments, the present embodiment discloses: the step (2) comprises the following specific steps: the surface of the radome needs to be pretreated before construction: first, the surface is cleaned with anhydrous ethanol to remove oil and impurities; then, it is wiped with a lint-free cloth; then, the surface is blown dry with a clean air gun; to improve the adhesion of the coating, the surface of the radome is lightly polished with fine sandpaper, and according to actual needs, plasma treatment can be selected to activate the surface of the radome, and then, the anti-static wave-transmitting coating is sprayed on the surface of the radome.

[0063] Example 10

[0064] Based on the above embodiments, this embodiment discloses: in the step (3), the sprayed coating is naturally dried at room temperature, and the drying time is controlled between 2-24 hours according to the coating thickness; or, to accelerate curing, a 60-100°C oven is used for heating, and the curing time is 0.5-4 hours; the performance indicators of the cured coating are as follows: adhesion ≥ 4B level, film thickness 30-40μm, surface resistivity 1-30MΩ / sq (the specific value is affected by thickness and substrate), dielectric constant 1-4, loss tangent value <0.1. In the 2-40GHz frequency band, the electromagnetic wave transmittance is ≥96%.

[0065] Embodiment 11

[0066] In a four-mouth reactor equipped with a stirrer, a reflux condenser and a thermometer, six monomers (30% of the total mass of the coating) including methyl methacrylate (40 parts), 2-ethylhexyl acrylate (3 parts), ethyl acrylate (20 parts), styrene (15 parts), n-butyl acrylate (8 parts) and acrylamide (14 parts) were added in sequence according to the mass ratio. In order to promote the uniform dispersion of the monomers, ethyl acetate, isopropanol and methyl isobutyl ketone were selected as mixed solvents in a ratio of 3:5:2, and their mass accounted for 52% of the total mass. The order of feeding is: first add the mixed solvent, then add each monomer in turn, and finally add the initiator azobisisobutyronitrile. The reaction temperature is controlled in the range of 72°C, which matches the decomposition temperature of the initiator and is conducive to the full polymerization reaction. The initiator system uses oil-soluble azo compounds. After the reaction is completed, add defoamer (2 parts of trioctyl phosphate, 1 part of glycerol monostearate, 2 parts of methyl silicone oil, whose mass is 1% of the total mass), active diluent (1 part of neodecanoic acid glycidyl ester, 3 parts of alkylene glycidyl ether, 1 part of toluene glycidyl ether, whose mass is 3% of the total mass) and antistatic agent (1 part of monoalkyl ether phosphate, 1 part of lauramide propyl amine oxide, 5 parts of dodecyl dimethyl amine oxide, whose mass is 14% of the total mass) in sequence. First, use anhydrous ethanol to clean the surface to remove oil and impurities; then wipe with a lint-free cloth; then blow dry the surface with a clean air gun. In order to improve the adhesion of the coating, plasma treatment is selected for surface activation for 5 minutes. Then spray at a pressure of 7kpa, and dry at room temperature for 6 hours after spraying.

[0067] Example 12

[0068] In a four-mouth reactor equipped with a stirrer, a reflux condenser and a thermometer, six monomers (35% of the total mass) of methyl methacrylate (50 parts), 2-ethylhexyl acrylate (8 parts), ethyl acrylate (18 parts), styrene (7 parts), n-butyl acrylate (8 parts) and acrylamide (9 parts) were added in sequence according to a specific ratio. In order to promote uniform dispersion of the monomers, ethyl acetate, isopropanol and methyl isobutyl ketone were selected as mixed solvents in a ratio of 2:4:1, and their mass was 45% of the total mass. The order of feeding is: first add the mixed solvent, then add each monomer in turn, and finally add the initiator azobisisobutyronitrile. The reaction temperature is controlled in the range of 65°C, which matches the decomposition temperature of the initiator and is conducive to the full polymerization reaction. The initiator system uses oil-soluble azo compounds. After the reaction is completed, add defoamer (2 parts of trioctyl phosphate, 1 part of glycerol monostearate, whose mass is 1.5% of the total mass), active diluent (1 part of neodecanoic acid glycidyl ester, 2 parts of toluene glycidyl ether, whose mass is 4% of the total mass) and antistatic agent (1 part of monoalkyl ether phosphate, 8 parts of lauramide propyl amine oxide, whose mass is 14.5% of the total mass) in sequence. First, use anhydrous ethanol to clean the surface to remove oil and impurities; then wipe with a lint-free cloth; then blow dry the surface with a clean air gun. To improve the adhesion of the coating, use 800 mesh sandpaper to lightly polish the surface. Then spray at a pressure of 7kpa, and dry at room temperature for 6 hours after spraying.

[0069] Embodiment 13

[0070] In a four-mouth reactor equipped with a stirrer, a reflux condenser and a thermometer, six monomers (30% of the total mass) of methyl methacrylate (35 parts), 2-ethylhexyl acrylate (8 parts), ethyl acrylate (14 parts), styrene (8 parts), n-butyl acrylate (12 parts) and acrylamide (23 parts) were added in sequence according to a specific ratio. In order to promote uniform dispersion of the monomers, ethyl acetate, isopropanol and methyl isobutyl ketone were selected as mixed solvents in a ratio of 1:6:3, and their mass was 50% of the total mass. The order of feeding is: first add the mixed solvent, then add each monomer in turn, and finally add the initiator azobisisobutyronitrile. The reaction temperature is controlled in the range of 72°C, which matches the decomposition temperature of the initiator and is conducive to the full polymerization reaction. The initiator system uses oil-soluble azo compounds. After the reaction is completed, add defoamer (2 parts of trioctyl phosphate, its mass is 1.5% of the total mass), active diluent (1 part of neodecanoic acid glycidyl ester, 3 parts of alkylene glycidyl ether, 1 part of toluene glycidyl ether, its mass is 4% of the total mass) and antistatic agent (1 part of monoalkyl ether phosphate, 8 parts of dodecyl dimethyl amine oxide, its mass is 14.5% of the total mass) in sequence. First, use anhydrous ethanol to clean the surface to remove oil and impurities; then wipe it with a lint-free cloth; then blow dry the surface with a clean air gun. In order to improve the adhesion of the coating, use 1200 mesh sandpaper to polish the surface. Then spray at a pressure of 15kpa, and dry at room temperature for 4h after spraying.

Claims

1. A method for preparing and using an anti-static wave-transparent coating for a drone radome, characterized in that the coating is prepared from a silicon-containing polymethacrylate resin, a curing agent, a defoaming agent, a leveling agent, an active diluent and an antistatic agent, and comprises the following steps: (1) Preparation of antistatic wave-transmitting coating; (2) Using anti-static wave-transmitting coating on radome for coating construction; (3) Coating curing.

2. The method for preparing and using the anti-static wave-transmitting coating for the drone radome according to claim 1 is characterized by: The silicon-containing polymethacrylate resin is prepared by copolymerization of methyl methacrylate, styrene, n-butyl acrylate and acrylamide.

3. The method for preparing and using the anti-static wave-transmitting coating for the drone radome according to claim 2 is characterized by: The step (1) adopts a wet chemical method to synthesize an antistatic wave-transmitting coating, and the specific steps are as follows: in a four-mouth reaction kettle equipped with a stirrer, a reflux condenser and a thermometer, six monomers of methyl methacrylate, 2-ethylhexyl acrylate, ethyl acrylate, styrene, n-butyl acrylate and acrylamide are added in sequence according to a set mass ratio, a mixed solvent is selected, and the feeding order is: first add the mixed solvent, then add each monomer in sequence, and finally add the initiator; the reaction temperature is controlled in the range of 50-84°C; after the reaction is completed, a defoamer, an active diluent and an antistatic agent are added in sequence.

4. The method for preparing and using the anti-static wave-transmitting coating for the drone radome according to claim 3 is characterized by: In the step (1), the mass ratio is set as follows: 35-50 parts of methyl methacrylate, 3-8 parts of 2-ethylhexyl acrylate, 14-20 parts of ethyl acrylate, 7-15 parts of styrene, 8-12 parts of n-butyl acrylate and 9-23 parts of acrylamide are added in sequence.

5. The method for preparing and using the anti-static wave-transmitting coating for the drone radome according to claim 4 is characterized by: In the step (1), the initiator is an oil-soluble azo compound, the defoamer is one or more of trioctyl phosphate, glyceryl monostearate, and methyl silicone oil, the active diluent is one or more of neodecanoic acid glycidyl ester, alkylene glycidyl ether, and toluene glycidyl ether; and the antistatic agent is one or more of monoalkyl ether phosphate, lauryl amide propyl amine oxide, and dodecyl dimethyl amine oxide.

6. The method for preparing and using the anti-static wave-transmitting coating for the drone radome according to claim 5 is characterized by: In the step (1), the mass fraction of each monomer is controlled to be 15% to 40% of the total mass of the antistatic wave-transmitting coating; the mixed solvent is one or more of ethyl acetate, isopropyl alcohol (IPA) and methyl isobutyl ketone (MIBK), and the total mass thereof is between 40% and 60% of the total mass of the antistatic wave-transmitting coating; the mass of the defoamer is between 0.5% and 1.5% of the total mass of the antistatic wave-transmitting coating; the initiator is selected from oil-soluble azo to initiate polymerization, such as azobisisobutyronitrile or azobisisovaleronitrile; the mass of the reactive diluent is between 2% and 4% of the total mass of the antistatic wave-transmitting coating; and the mass of the antistatic agent is between 7.5% and 15% of the total mass of the antistatic wave-transmitting coating.

7. The method for preparing and using an antistatic wave-transmitting coating for an unmanned aerial vehicle radome as described in claim 6 is characterized in that: the step (2) comprises the following specific steps: the surface of the radome needs to be pretreated before construction: first, the surface is cleaned with anhydrous ethanol to remove oil and impurities; then, it is wiped with a lint-free cloth; then, the surface is blown dry with a clean air gun; to improve the adhesion of the coating, the surface of the radome is lightly polished with fine sandpaper, and according to actual needs, plasma treatment can be selected to activate the surface of the radome, and then the antistatic wave-transmitting coating is sprayed on the surface of the radome.

8. The method for preparing and using the anti-static wave-transmitting coating for the drone radome according to claim 7 is characterized by: In the step (3), the sprayed coating is naturally dried at room temperature, and the drying time is controlled between 2-24 hours according to the thickness of the coating; or, to accelerate the curing, it is heated in an oven at 60-100°C, and the curing time is 0.5-4 hours.

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