Highly flexible wave-absorbing coating based on ball / sheet composite and preparation method and application thereof

Abstract

This invention discloses a highly flexible absorbing coating based on a spherical / sheet composite, as well as its preparation method and application, relating to the field of electromagnetic shielding technology. The absorbing coating comprises spherical absorbers, sheet absorbers, a rubber toughening agent, a resin matrix, a curing agent, a dispersant, and an anti-settling agent. The invention utilizes a "seesaw" structure design combining spherical and sheet absorbers to maintain the absorbing coating's reflection loss performance while reducing frictional resistance between absorber particles, thereby increasing the coating's Poisson's ratio and enhancing its flexibility.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic shielding, and in particular to a high-flexibility wave-absorbing coating based on a ball / sheet composite, a preparation method and an application thereof. Background Art

[0002] With the rapid development of 5G communication technology and the widespread use of various electronic devices, the electromagnetic environment in modern society has become increasingly complex. Electromagnetic waves across the spectrum can affect the normal operation of various electronic and electrical devices. Absorbent coatings can be applied to various metal substrates, effectively mitigating the harmful effects of electromagnetic waves by converting them into heat through interference or various absorption mechanisms.

[0003] With the widespread application of absorbing coatings, the service environment they face is becoming increasingly complex. For example, when applied to complex substrates, the coating needs to have good flexibility to avoid various defects during coating curing or service. However, there is a contradiction between the absorbing performance of absorbing coatings and high flexibility: on the one hand, according to the Sneok theory, highly anisotropic sheet absorbers can achieve high reflection loss at higher frequencies. However, sheet absorbers have a larger surface area, more interfaces with the substrate, greater deformation resistance, and poorer flexibility. On the other hand, to achieve high reflection loss, absorbing coatings need to be filled with a large amount of absorbers. At this time, the absorbers can contact each other, and the frictional shear force between the absorbers during deformation is large, resulting in poor flexibility.

[0004] In order to solve the problem of poor flexibility of absorbing coatings, many researchers have carried out a series of research and inventions. Wang Hui et al. prepared a flexible absorbing patch with a modified epoxy resin as the matrix and added nanocrystalline absorbers by the casting method. Duan Yuping et al. of Dalian University of Technology used magnetic powder, conductive powder and dielectric powder as absorbers to prepare absorbing coatings by brushing process, and improved the flexibility of the coating by the discontinuous design of the coating. However, existing flexible absorbing coatings such as these all improve the flexibility of the absorbing coating by coating structure design or resin matrix design. There are no related reports on improving the flexibility of absorbing coatings by absorber structure design. Summary of the Invention

[0005] In response to the shortcomings of the aforementioned background technology, the present invention primarily addresses the difficulty in achieving both high flexibility and high reflectivity in existing absorbing coatings. The present invention provides a highly flexible absorbing coating based on a sphere / sheet composite, as well as a preparation method and application. This absorbing coating utilizes a "seesaw" structure design combining spherical absorbers and sheet absorbers. This ensures the absorbing coating's reflection loss performance while reducing frictional resistance between absorber particles, thereby increasing the coating's Poisson's ratio and enhancing its flexibility.

[0006] The first object of the present invention is to provide a highly flexible absorbing coating based on a sphere / sheet composite. The absorbing coating comprises the following components in parts by weight: 3 to 60 parts of a rubber toughening agent, 25 to 55 parts of a resin, 3.2 to 16 parts of a curing agent, 5 to 60 parts of a spherical absorber, 25 to 125 parts of a sheet absorber, 0.5 to 1.5 parts of a dispersant, 0.5 to 1.5 parts of an anti-settling agent, and 15 to 85 parts of a solvent.

[0007] The spherical absorbent is one or more of sendust, iron-silicon-chromium, iron-silicon alloy, carbonyl iron, carbonyl nickel, iron-nickel-molybdenum alloy, iron-cobalt-nickel, and iron-cobalt-nickel-chromium alloy;

[0008] The sheet-like absorbent is one or more of sendust, iron-silicon-chromium, iron-silicon alloy, carbonyl iron, carbonyl nickel, iron-nickel-molybdenum alloy, iron-cobalt-nickel, and iron-cobalt-nickel-chromium alloy.

[0009] Preferably, the mass ratio of the spherical absorbent to the sheet absorbent is 0.5-4.5:10.

[0010] Preferably, the rubber toughening agent is one or more of chloroprene rubber, nitrile rubber, fluororubber, chlorosulfonated polyethylene rubber, acrylate rubber, ethylene acrylate rubber, and chlorinated polyethylene rubber;

[0011] The resin is one or more of silicone resin, epoxy resin, acrylic resin and polyurethane resin.

[0012] Preferably, the curing agent is one or more of polyamide, polyetheramine, and fatty amine;

[0013] The dispersant is DISPERBYK-110 dispersant;

[0014] The anti-settling agent is paraffin and / or organic bentonite.

[0015] Preferably, the solvent is one or more of toluene, xylene, acetone, butanone, isopropyl alcohol, propylene glycol methyl ether acetate, and n-butanol.

[0016] A second object of the present invention is to provide a method for preparing a highly flexible radar-absorbing coating based on a sphere / sheet composite, comprising the following steps:

[0017] Weighing the rubber toughening agent, resin, curing agent, spherical absorbent, flake absorbent, dispersant, anti-settling agent and solvent according to weight, mixing the weighed raw materials, and stirring evenly to obtain an absorbing coating;

[0018] The absorbing coating is evenly sprayed on the surface of the substrate in an S-shaped path, with a spraying thickness of less than 30 μm. After spraying a 0.1 mm coating, the coating is dried at room temperature for 10 to 15 minutes, and then heated and kept warm to solidify the absorbing coating sprayed on the surface of the substrate to obtain an initial absorbing coating;

[0019] Repeat the initial absorbing coating preparation process until an absorbing coating meeting the designed thickness is obtained.

[0020] Preferably, air spraying is adopted during spraying; the process parameters of the air spraying method are: spraying pressure 0.2~0.8MPa, spraying distance 10~60cm, spraying angle 80~100°, and spray gun moving speed 15~45cm / s.

[0021] Preferably, the process parameters of the heating and heat preservation are: curing temperature 60-120° C., and curing time 6-12 hours.

[0022] Preferably, the substrate is a metal plate, which is polished before spraying to ensure that there are no dust particles on the surface of the substrate.

[0023] The third object of the present invention is to provide an application of an absorbing coating in electromagnetic absorption.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention provides a highly flexible absorbing coating based on a sphere / sheet composite, as well as its preparation method and application. This invention utilizes a "seesaw" structure design combining spherical absorbers and sheet absorbers to ensure the absorbing coating's reflection loss performance while reducing friction between absorber particles, thereby increasing the coating's Poisson's ratio and enhancing its flexibility. Furthermore, a rubber toughening agent is used to modify the resin matrix's molecular network. When the coating is deformed, cracks are generated. Rubber particles bridge the cracks, inducing shear deformation of the matrix and forming shear bands. This creates cavities within and on the surface of the rubber particles, which, along with the stretching and shearing of polymer chains between the spaces, leads to plastic deformation of the matrix, thereby enhancing the coating's flexibility.

[0026] In the coating provided by the present invention, spherical absorbers and flaky absorbers serve as main absorbing functional materials. The spherical absorbers reduce the surface-to-surface contact resistance between the flaky absorbers. The flaky absorbers have an extremely high Z-axis demagnetization field, ensuring the reflection loss characteristics of the prepared coating. The resin serves as the matrix of the absorbing coating. On the one hand, it tightly binds the flaky absorbers and spherical absorbers to enhance the electron exchange coupling between the two, and on the other hand, it provides basic mechanical properties for the coating. The curing agent can reduce the curing temperature of the resin and accelerate the curing rate of the resin. The rubber toughening agent can exist in the form of microparticles between the resin macromolecules. The rubber particles are used to induce and branch a large number of silver streaks and bridge the two sides of the silver streaks, triggering shear deformation of the matrix, forming shear bands, and generating cavities inside and on the surface of the rubber particles. The stretching and shearing of the polymer chains between the spaces causes plastic deformation of the matrix, thereby improving the flexibility of the coating. Dispersants and anti-settling agents can evenly distribute spherical absorbers, flake absorbers and rubber toughening agents inside the coating based on electrostatic effects and steric hindrance effects, increase the uniformity of the coating, and ensure that the spherical absorbers are distributed in the gaps between the flake absorbers; solvents can dilute the coating and enhance the workability of the coating. At the same time, through their rheological properties, they can make the flake absorbers inside the coating directional and horizontally arranged, further increasing the conductive loss of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of a highly flexible absorbing coating based on a ball / sheet composite.

[0028] Figure 2 This is the cross section of the spherical sheet composite high-flexibility absorbing coating prepared in Example 5.

[0029] Figure 3 The reflectivity curves of the coatings provided in various embodiments at 2-18 GHz.

[0030] Figure 4 The reflectivity of the coatings provided in Example 1, Comparative Example 1 and Comparative Example 2 at 2-18 GHz. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0032] The purpose of the present invention is to provide a highly flexible absorbing coating based on a sphere / sheet composite, a preparation method, and an application thereof, in view of the fact that the flexibility of the absorbing coating is improved by coating structure design or resin matrix design in the prior art. However, there have been no reports on improving the flexibility of the absorbing coating by absorber structure design.

[0033] The invention provides a high-flexibility absorbing coating. The absorber of the absorbing coating consists of a spherical absorber and a sheet absorber, and the resin molecules are modified by a resin toughening agent.

[0034] To achieve the above objectives, the first aspect of the present invention provides a highly flexible absorbing coating based on a sphere / sheet composite. The absorbing coating comprises the following components in parts by weight: 3 to 60 parts of a rubber toughener, 25 to 55 parts of a resin, 3.2 to 16 parts of a curing agent, 5 to 60 parts of a spherical absorber, 25 to 125 parts of a sheet absorber, 0.5 to 1.5 parts of a dispersant, 0.5 to 1.5 parts of an anti-settling agent, and 15 to 85 parts of a solvent.

[0035] The spherical absorbent is one or more of sendust, ferrosilicon, chromium, an iron-silicon alloy, carbonyl iron, carbonyl nickel, an iron-nickel-molybdenum alloy, iron-cobalt-nickel, or an iron-cobalt-nickel-chromium alloy; all are products of Ganzhou Blue Ocean New Materials Co., Ltd. The particle size of the spherical absorbent is 4 to 16 μm.

[0036] The sheet absorbent is one or more of sendust, iron-silicon-chromium, iron-silicon alloy, carbonyl iron, carbonyl nickel, iron-nickel-molybdenum alloy, iron-cobalt-nickel, and iron-cobalt-nickel-chromium alloy;

[0037] The mass ratio of the spherical absorbent to the sheet absorbent is 0.5-4.5:10.

[0038] The preparation method of the sheet absorbent comprises:

[0039] Zirconia grinding balls, anhydrous ethanol, and spherical absorbent are sequentially added to a stirred ball mill at a ball-to-material ratio of 2-25:1 and a ratio of anhydrous ethanol to spherical absorbent of 0.2-5:1. Ball milling is then performed at a speed of 100-300 rpm for 4-48 hours. After the ball milling operation is completed, the product is filtered and dried to obtain a flake absorbent with a particle size of 6-45 μm.

[0040] The rubber toughening agent is one or more of chloroprene rubber, nitrile rubber, fluororubber, chlorosulfonated polyethylene rubber, acrylate rubber, ethylene acrylate rubber, and chlorinated polyethylene rubber; wherein the rubber toughening agents are all products of Shanghai Advantage Industrial Co., Ltd.

[0041] The resin is one or more of silicone resin, epoxy resin, acrylic resin and polyurethane resin, wherein the resins are all products of Hubei Xinsihai Chemical Industry Co., Ltd.

[0042] The curing agent is one or more of polyamide, polyetheramine, and fatty amine; polyamide is a medium-viscosity brownish-yellow liquid, polyetheramine is a low-viscosity light-yellow liquid, and fatty amine is a medium-viscosity transparent liquid. All are products of Hubei Xinsihai Chemical Co., Ltd.

[0043] The dispersant is DISPERBYK-110 dispersant, which is an oily liquid dispersant and is a product of Shenzhen Pasto Chemical Co., Ltd.

[0044] The anti-settling agent is paraffin and / or organic bentonite. The paraffin anti-settling agent is a milky white paste, and the organic bentonite is a white or light yellow powder. Both are products of Hubei Xinsihai Chemical Co., Ltd.

[0045] The solvent is one or more of toluene, xylene, acetone, butanone, isopropyl alcohol, propylene glycol methyl ether acetate, and n-butanol. Toluene is a colorless, volatile liquid with a distinctive aroma; xylene is a colorless, transparent liquid with a distinctive aromatic odor; acetone is a colorless, flammable liquid with a minty odor; butanone is a colorless, transparent liquid with a minty-like odor; isopropyl alcohol is a colorless, transparent liquid with an odor similar to a mixture of ethanol and acetone; propylene glycol methyl ether acetate is a colorless, hygroscopic liquid with a distinctive odor; and n-butanol is a colorless, transparent liquid with an alcoholic odor. Products of Nanjing Hecheng Chemical Co., Ltd. are used.

[0046] A second aspect of the present invention provides a method for preparing a high-flexibility radar-absorbing coating based on a sphere / sheet composite, comprising the following steps:

[0047] Weighing the rubber toughening agent, resin, curing agent, spherical absorbent, flake absorbent, dispersant, anti-settling agent and solvent according to weight, mixing the weighed raw materials, and stirring evenly to obtain an absorbing coating;

[0048] The absorbing coating is evenly sprayed on the surface of the substrate in an S-shaped path, with a spraying thickness of less than 30 μm. After spraying a 0.1 mm coating, the coating is dried at room temperature for 10 to 15 minutes, and then heated and kept warm to solidify the absorbing coating sprayed on the surface of the substrate to obtain an initial absorbing coating;

[0049] Repeat the initial absorbing coating preparation process until the absorbing coating that meets the designed thickness is obtained; see Figure 1 As shown in the figure, the schematic diagram of the spherical sheet composite high-flexibility absorbing coating structure is used. Through the "seesaw" structure design of the spherical absorber / sheet absorber blend, the reflection loss performance of the absorbing coating is ensured while reducing the friction resistance between the absorber particles, improving the Poisson's ratio of the coating and enhancing the flexibility of the coating.

[0050] Among them, air spraying method is adopted during spraying;

[0051] The process parameters of the air spraying method are: spraying pressure 0.2-0.8 MPa, spraying distance 10-60 cm, spraying angle 80-100°, and spray gun moving speed 15-45 cm / s.

[0052] The heating and heat preservation process parameters are: curing temperature 60-120° C., and curing time 6-12 hours.

[0053] The substrate is a metal plate, which is polished before spraying to remove dust particles from the surface of the substrate.

[0054] A third aspect of the present invention provides an application of an absorbing coating in electromagnetic absorption.

[0055] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0056] Example

[0057] A method for preparing a highly flexible radar-absorbing coating based on a sphere / sheet composite comprises the following steps:

[0058] Step 1. Preparation of substrate

[0059] Aluminum plates, steel plates, tinplate plates and other metal plates are used as the substrate of the coating material. The substrate is polished with 80-grit silicon carbide sandpaper, and then the surface of the substrate is cleaned with alcohol to ensure that there are no dust particles on the surface of the substrate.

[0060] Step 2. Preparation of absorbing coating

[0061] The rubber toughening agent is mixed with a certain amount of an organic solvent and stirred evenly using a stirring disperser. Subsequently, the resin, curing agent, flake absorbent, spherical absorbent, dispersant, anti-settling agent and solvent are weighed according to weight. The weighed raw materials of each component are then mixed and stirred evenly using a homogenizer to obtain an absorbing coating.

[0062] Step 3. Coating preparation

[0063] The microwave-absorbing coating is applied on the surface of the substrate by air spraying, and then heated and cured to prepare the microwave-absorbing coating;

[0064] The specific process is as follows: the absorbing coating is loaded into the spraying device and sprayed evenly on the surface of the substrate in an S-shaped path, with a spraying thickness of less than 30 μm; after each 0.1 mm coating is sprayed, the sample is dried at room temperature for 10 to 15 minutes, and then the sample is placed in an oven and kept warm at 60 to 120°C for 6 to 12 hours to solidify the absorbing coating sprayed on the surface of the substrate to obtain the first layer of absorbing prefabricated layer; the preparation process of the first layer of absorbing prefabricated layer is repeated until the thickness of the obtained absorbing prefabricated layer reaches the designed thickness to obtain the absorbing layer.

[0065] Among them, the process parameters of the air spray method are: spraying pressure 0.2~0.8MPa, spraying distance 10~60cm, spraying angle 80~100°, and spray gun moving speed 15~45cm / s.

[0066] The composition ratios of the highly flexible wave-absorbing coatings in various embodiments are shown in Table 1 below.

[0067] Table 1 Component ratios of the highly flexible absorbing coatings in various embodiments

[0068]

[0069] The process parameters of the sheet absorbent in each embodiment are shown in Table 2 below.

[0070] Table 2 Process parameters of sheet absorbent in each embodiment

[0071]

[0072] The process parameters of each embodiment are shown in Table 3 below.

[0073] Table 3 Process parameters of each embodiment

[0074]

[0075] The spherical absorbent and the sheet absorbent in each embodiment are shown in Table 4 below.

[0076] Table 4 Particle size of absorbent used in each embodiment

[0077]

[0078] In order to illustrate the superior performance of the highly flexible radar-absorbing coating in the embodiment of the present invention, two comparative examples were prepared for comparison and illustration. The specific comparative examples are as follows:

[0079] Comparative Example 1

[0080] A radar absorbing coating, comprising:

[0081] The coating composition ratios were the same as those in Example 1, with all absorbers being spherical absorbers. Specifically, the following components were used: 15 parts chloroprene rubber, 30 parts silicone resin, 8 parts polyamide, 100 parts spherical absorbers, 0.5 parts DISPERBYK-110, 1 part paraffin wax, 50 parts xylene, and 15 parts propylene glycol methyl ether acetate. A sample with a thickness of 1.0 mm was prepared using the process parameters of Example 1 shown in Table 3, yielding the absorbing coating provided in Comparative Example 1.

[0082] Comparative Example 2

[0083] A radar absorbing coating, comprising:

[0084] The coating composition ratios were the same as those in Example 1, with the absorbents being entirely flake-shaped absorbers. Specifically, the following components were used: 15 parts chloroprene rubber, 30 parts silicone resin, 8 parts polyamide, 100 parts flake-shaped absorber, 0.5 parts DISPERBYK-110, 1 part paraffin wax, 50 parts xylene, and 15 parts propylene glycol methyl ether acetate. A sample with a thickness of 1.0 mm was prepared using the process parameters of Example 1 shown in Table 3, yielding the absorbing coating provided in Comparative Example 2.

[0085] To illustrate the structure of the coating prepared by the present invention, a scanning electron microscope was used to observe the cross-sectional structure of the coating prepared in Example 5. The reflectivity and flexibility of the highly flexible coating prepared by the present invention were tested according to the bow method of GJB2038A-2001 "Test Method for Reflectivity of Radar Absorbing Materials", GB / T 1731-2020 "Determination of Impact Resistance of Paint Films", and GB / T 1732-2020 "Determination of Impact Resistance of Paint Films", respectively. The results are as follows.

[0086] Figure 2 This is the cross section of the spherical sheet composite high-flexibility absorbing coating prepared in Example 5, from Figure 2 As can be seen in the figure, the spherical carbonyl nickel is located between multiple flake-like carbonyl nickel absorbers, effectively improving the surface-to-surface contact between the flake-like carbonyl nickel absorbers and thus reducing the frictional resistance between the flake-like carbonyl nickel absorbers. It can also be seen that the absorbers are closely arranged within the coating, and the electromagnetic exchange between the absorbers is good.

[0087] Figure 3 The reflectivity curves of each embodiment 2-18 GHz are as follows: Figure 3 It can be seen that the reflectivity of the prepared examples is less than -4 dB (>80% of the electromagnetic waves are absorbed) at 6-16 GHz, and the peak positions are all within the C2 band or X band.

[0088] The flexibility and impact resistance of each embodiment are shown in Table 4.

[0089] Table 4 Flexibility and impact resistance of each embodiment

[0090]

[0091] As can be seen from Table 4, the high-flexibility absorbing coatings prepared in the embodiments of the present invention can effectively absorb electromagnetic waves in the X-band and Ku-band, have a flexibility of less than 4 mm, and have an impact resistance of greater than 50 cm, meeting the requirements for long-term service on complex substrate surfaces.

[0092] In order to illustrate the flexibility and impact resistance of the high-flexibility absorbing coating of the spherical sheet composite structure, Example 1 was compared with Comparative Examples 1 and 2, and the results are shown in Table 5.

[0093] Table 5 Flexibility and impact resistance of Example 1, Comparative Example 1 and Comparative Example 2

[0094]

[0095] Figure 4 The reflectivity of the absorbing coatings provided in Example 1, Comparative Example 1 and Comparative Example 2 at 2-18 GHz;

[0096] From Table 5 and Figure 4 It can be seen that the absorbers in Comparative Example 1 are all spherical absorbers. The spherical absorbers have small contact points inside the coating, small friction between particles, and high flexibility of the coating, but the absorber anisotropy is poor, the magnetic permeability is low, and the wave absorbing performance is poor. The absorbers in Comparative Example 2 are all flake absorbers, and the flake absorbers are connected in a flake-to-flake overlap manner inside the coating. The friction between the particle layers is large and the flexibility is poor. In Example 1, the spherical absorbers and the flake absorbers are compounded in a certain proportion, and their flexibility and impact resistance are close to those of Comparative Example 1, and the reflectivity is close to that of Comparative Example 2. It can be seen that the wave absorbing coating based on the spherical-flake composite in the present invention can significantly improve the flexibility and impact resistance of the wave absorbing coating while ensuring good reflectivity of the wave absorbing coating. It should be noted that the coatings provided in Comparative Example 1 are all prepared from spherical absorbers; and the coatings provided in Comparative Example 2 are all prepared from flake absorbers.

[0097] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a highly flexible radar-absorbing coating based on a ball / sheet composite, characterized in that: The following steps are involved: Weigh 3-60 parts of rubber toughening agent, 25-55 parts of resin, 3.2-16 parts of curing agent, 5-60 parts of spherical absorber, 25-125 parts of flake absorber, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of anti-settling agent, and 15-85 parts of solvent according to weight, mix the weighed raw materials, and stir evenly to obtain an absorbing coating; The absorbing coating is evenly sprayed on the surface of the substrate in an S-shaped path, with a spraying thickness of less than 30 μm. After spraying a 0.1 mm coating, the coating is dried at room temperature for 10 to 15 minutes, and then heated and kept warm to solidify the absorbing coating sprayed on the surface of the substrate to obtain an initial absorbing coating; Repeating the initial absorbing coating preparation process until an absorbing coating meeting the designed thickness is obtained; Air spraying is used during spraying; the process parameters of the air spraying method are: spraying pressure 0.2~0.8MPa, spraying distance 10~60cm, spraying angle 80~100°, and spray gun moving speed 15~45cm / s; The heating and heat preservation process parameters are: curing temperature 60~120℃, curing time 6~12h; The spherical absorbent is one or more of iron silicon aluminum, iron silicon chromium, iron silicon alloy, carbonyl nickel, iron nickel molybdenum alloy, iron cobalt nickel, and iron cobalt nickel chromium alloy; The particle size of spherical absorbent is 4~16μm; The sheet absorbent is one or more of sendust, iron-silicon-chromium, iron-silicon alloy, carbonyl nickel, iron-nickel-molybdenum alloy, iron-cobalt-nickel, and iron-cobalt-nickel-chromium alloy; Sheet absorbent is 14.7~45μm; The mass ratio of the spherical absorbent to the sheet absorbent is 0.5-4.5:10; The rubber toughening agent is one or more of chloroprene rubber, nitrile rubber, fluororubber, chlorosulfonated polyethylene rubber, acrylate rubber, ethylene acrylate rubber, and chlorinated polyethylene rubber; The resin is one or more of silicone resin, epoxy resin, acrylic resin, and polyurethane resin; The curing agent is one or more of polyamide, polyetheramine and fatty amine; The dispersant is DISPERBYK-110 dispersant; The anti-settling agent is paraffin and / or organic bentonite; The solvent is one or more of toluene, xylene, acetone, butanone, isopropyl alcohol, propylene glycol methyl ether acetate, and n-butanol; Among them, the prepared absorbing coating adopts a "seesaw" structure design of a spherical absorber / sheet absorber blend to ensure the reflection loss performance of the absorbing coating while reducing the friction resistance between the absorber particles, improving the Poisson's ratio of the coating, and enhancing the flexibility of the coating.

2. The method for preparing a high-flexibility radar-absorbing coating based on a ball / sheet composite according to claim 1, characterized in that: The substrate is a metal plate, which is polished before spraying to ensure that there are no dust particles on the surface of the substrate.

3. Use of the absorbing coating prepared by the method according to claim 1 or 2 in electromagnetic absorption.

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