Electromagnetic protection composite material and preparation method and application thereof

Abstract

The present invention relates to an electromagnetic protection composite material and a preparation method and application thereof. The preparation method of the electromagnetic protection composite material comprises the following steps: (1) placing a micro-nano metal mesh layer and a glass fiber reinforced epoxy resin prepreg layer in a vacuum bag according to a preset arrangement rule, wherein the arrangement rule is that two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, and the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer and each prepreg layer are bonded by epoxy resin; (2) subjecting the vacuum bag to a hot pressing treatment to finally obtain a cured electromagnetic protection composite material, which effectively protects against electromagnetic interference of more than 20 dB in the 1 GHz to 18 GHz band and has a light transmittance of more than 50%.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic functional materials, and in particular relates to an electromagnetic protection composite material and a preparation method and application thereof. Background Art

[0002] With the widespread use of electronic products, electromagnetic pollution is becoming increasingly serious, causing significant impacts on human health and precision instruments and equipment. Electromagnetic shielding is a technology for designing materials to block unwanted electromagnetic radiation, which is achieved by designing electromagnetic shielding composite materials to reflect or absorb incident electromagnetic waves.

[0003] Electromagnetic protection composite materials are materials used to protect against electromagnetic interference and electromagnetic radiation. They are designed by combining a variety of materials such as metals, polymers, and ceramics to obtain a material with a specific structure and performance. The electrical conductivity, magnetism, and dielectric properties of the material are used to achieve efficient reflection, absorption, or transmission of electromagnetic waves within a specific frequency range. Such materials are widely used in electromagnetic shielding, radar stealth, microwave devices, and other fields to protect electronic equipment from electromagnetic interference or reduce radar reflection signals.

[0004] At present, silicone rubber-based electromagnetic shielding composite materials have broad application prospects in consumer electronics, 5G communications, new energy vehicles, national defense and military industries due to their advantages such as good flexibility, aging resistance, adjustable hardness, and good adhesion to the substrate. However, the single electromagnetic shielding performance of this type of electromagnetic shielding material can no longer meet the growing demand for electromagnetic protection, and the preparation process is complex and the preparation efficiency is low. Summary of the invention

[0005] The main purpose of the present invention is to provide an electromagnetic protection composite material and its preparation method and application. The technical problem to be solved is how to provide a preparation method of an electromagnetic protection composite material with a simple preparation process and a high degree of design freedom, so that the prepared electromagnetic protection composite material has both transmittance and electromagnetic shielding effect that can meet application requirements, and is corrosion-resistant, aging-resistant, light in weight, and can effectively protect against electromagnetic interference of more than 20dB in the 1GHz to 18GHz band, and has a transmittance of more than 50%.

[0006] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for preparing an electromagnetic protection composite material proposed by the present invention, the method comprises the following steps:

[0007] (1) placing a micro-nano metal mesh layer and a glass fiber reinforced epoxy resin prepreg layer in a vacuum bag according to a preset arrangement rule, wherein the arrangement rule is that two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, and the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer and each prepreg layer are bonded by epoxy resin;

[0008] (2) The vacuum bag is subjected to a heat pressing process to finally obtain a cured electromagnetic protection composite material.

[0009] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0010] Preferably, in the aforementioned method for preparing the electromagnetic shielding composite material, the pressure of the hot pressing treatment is 0.1-20 MPa.

[0011] Preferably, in the aforementioned method for preparing the electromagnetic shielding composite material, the temperature of the hot pressing treatment is 100-220°C.

[0012] Preferably, in the aforementioned method for preparing the electromagnetic shielding composite material, the time of the hot pressing treatment is 40 to 120 minutes.

[0013] Preferably, in the aforementioned method for preparing the electromagnetic protection composite material, the number of the micro-nano metal mesh layers is 1 to 3.

[0014] Preferably, in the aforementioned method for preparing the electromagnetic protection composite material, the number of layers of the glass fiber reinforced epoxy resin prepreg layer is 2 to 10.

[0015] Preferably, in the aforementioned method for preparing the electromagnetic protection composite material, the duty cycle of the micro-nano metal mesh layer is 80% to 95%.

[0016] Preferably, in the aforementioned method for preparing the electromagnetic protection composite material, the micro-nano metal mesh layer has periodically arranged square resonance units.

[0017] Preferably, in the aforementioned method for preparing the electromagnetic shielding composite material, the side length of the square resonance unit is greater than 300 μm and less than 2 mm.

[0018] Preferably, in the aforementioned method for preparing the electromagnetic protection composite material, the metal in the micro-nano metal mesh layer is selected from metals with high electrical conductivity or high magnetic permeability.

[0019] Preferably, in the aforementioned method for preparing the electromagnetic protection composite material, the metal in the micro-nano metal mesh is selected from at least one of Au, Ag, Cu, Fe, Co and Ni.

[0020] The purpose of the present invention and the solution to its technical problems are also achieved by adopting the following technical solutions: According to an electromagnetic protection composite material proposed by the present invention, it comprises: 2 to 10 layers of glass fiber reinforced epoxy resin prepreg layers;

[0021] 1 to 3 layers of micro-nano metal mesh layers, two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, and the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer and each prepreg layer are bonded by epoxy resin.

[0022] The purpose of the present invention and the technical problems solved therein are also achieved by the following technical solutions: A lampshade for aviation and aerospace proposed in the present invention comprises the electromagnetic shielding composite material prepared by the above method or the electromagnetic shielding composite material as described above.

[0023] By means of the above technical solution, the electromagnetic protection composite material and its preparation method and application of the present invention have at least the following advantages:

[0024] The preparation method of the electromagnetic protection composite material provided by the present invention is to place the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer in a vacuum bag according to a preset arrangement rule, and the vacuum bag is subjected to a hot pressing process to finally obtain a cured electromagnetic protection composite material. The method has a high degree of design freedom and strong designability for the electromagnetic protection composite material, and can adjust the material, number of layers, appearance, etc. according to the specific use scenario, and the preparation process is simple and the preparation efficiency is high. The prepared electromagnetic protection composite material has the strength, thickness, surface flatness, transmittance and electromagnetic shielding effect that can meet the application requirements, and is corrosion-resistant, aging-resistant, light-weight, and effectively protects electromagnetic interference in the 1GHz to 18GHz band by more than 20dB, and the transmittance reaches more than 50%.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a diagram of the electromagnetic shielding effectiveness of the electromagnetic protection composite material of Example 1 of the present invention.

[0027] Figure 2 This is a diagram of the electromagnetic shielding effectiveness of the electromagnetic shielding composite material of Example 3 of the present invention. DETAILED DESCRIPTION

[0028] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of an electromagnetic protection composite material and its preparation method and application according to the present invention, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0029] The first aspect of the present invention provides a method for preparing an electromagnetic shielding composite material, which comprises the following steps:

[0030] (1) placing a micro-nano metal mesh layer and a glass fiber reinforced epoxy resin prepreg layer in a vacuum bag according to a preset arrangement rule, wherein the arrangement rule is that two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, and the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer and each prepreg layer are bonded by epoxy resin;

[0031] (2) The vacuum bag is subjected to a heat pressing process to finally obtain a cured electromagnetic protection composite material.

[0032] The preparation method of the electromagnetic protection composite material provided by the present invention, in the first aspect, during the preparation process, it is only necessary to arrange the various layers of materials according to a rule and place them in a vacuum bag, and then use a laminating device to perform a hot pressing treatment on the vacuum bag to obtain the electromagnetic protection composite material, which has a simple process and high efficiency. In the second aspect, during the preparation process, the arrangement rule of the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer is that the two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, thereby, through this structural design, the corrosion-resistant micro-nano metal mesh layer can be protected as an inner layer to avoid corrosion and shedding of the micro-nano metal mesh layer under conditions such as high-altitude flight, sunlight irradiation, ultraviolet aging, etc. Thirdly, during the preparation process, the regularly arranged micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer are placed in a vacuum bag, and the vacuum bag is heated and evacuated. Vacuuming can avoid the formation of bubbles between the layers of materials, which will affect the surface flatness of the electromagnetic protection composite material, making its appearance quality good while ensuring the strength to meet the application requirements. While evacuating, heating is performed. During the heating process, the epoxy resin in the glass fiber reinforced epoxy resin prepreg will melt and adhere to the micro-nano metal mesh, thereby forming an integrated structure for the entire electromagnetic protection composite material.

[0033] The preparation method of the electromagnetic protection composite material provided by the present invention selects appropriate micro-nano metal mesh layers and glass fiber reinforced epoxy resin prepreg layers for arrangement and places them in a vacuum bag for hot pressing treatment. The prepared electromagnetic protection composite material has high design freedom and strong designability, and can be adjusted in terms of materials, number of layers, appearance, etc. according to the needs of specific usage scenarios. The prepared electromagnetic protection composite material has strength, thickness, surface flatness, transmittance and electromagnetic shielding effect that can meet application requirements, is corrosion-resistant and aging-resistant, and is lightweight. It can effectively protect against electromagnetic interference of more than 20 dB in the 1 GHz to 18 GHz band, and has a transmittance of more than 50%.

[0034] In the present invention, a preparation method of the electromagnetic protection composite material is provided, and a micro-nano metal mesh is used. The micro-nano metal mesh is a metal mesh with a micrometer or nanometer scale structure. Due to its special microstructure and metal properties, it can effectively shield electromagnetic interference in a tiny space, protect the normal operation of electronic components, and meet the requirements of the electromagnetic protection composite material for electromagnetic shielding effect.

[0035] In the present invention, the number of layers of the micro-nano metal mesh layer is 1 to 3.

[0036] According to the present invention, the material, number of layers, appearance, etc. can be adjusted according to the specific usage scenario of the electromagnetic protection composite material. For example, the number of layers of the micro-nano metal mesh layer can be 2 layers.

[0037] In the present invention, the duty ratio of the micro-nano metal mesh layer is 80% to 95%. The duty ratio refers to the porosity, that is, the percentage of open space (space not occupied by material) in the metal mesh structure relative to the entire metal mesh surface. The duty ratio has a strong influence on the transmittance of the metal mesh, and the greater the duty ratio, the greater the transmittance.

[0038] In a specific embodiment of the present invention, the micro-nano metal mesh used has periodically arranged square resonant units. Due to the symmetry and uniform distribution of the square grid, it exhibits relatively consistent behavior in electromagnetic wave transmission, reflection or absorption, and because its properties in four directions are almost the same, it has good directional independence, which can effectively improve the electromagnetic shielding effect of the electromagnetic protection composite material.

[0039] In the present invention, the side length of the square resonance unit is greater than 300 μm and less than 2 mm, thereby enabling the electromagnetic protection composite material to have a light transmittance and electromagnetic shielding effect that meet application requirements.

[0040] In the present invention, the diameter of the metal mesh wires of the micro-nano metal mesh is less than 3 μm, thereby the obtained electromagnetic protection composite material has a light transmittance greater than 50%.

[0041] In the present invention, the metal in the micro-nano metal mesh is selected from metals with high electrical conductivity or high magnetic permeability, thereby being able to further effectively reflect the incident electromagnetic waves into free space, preventing the electromagnetic waves from penetrating, and achieving a good electromagnetic shielding effect.

[0042] In the present invention, the metal in the micro-nano metal mesh is selected from at least one of Au, Ag, Cu, Fe, Co and Ni, for example, it can be a micro-nano copper-nickel mesh, a micro-nano copper mesh, etc. Thus, a good electromagnetic shielding effect can be further achieved.

[0043] In the present invention, the preparation method of the electromagnetic protection composite material provided uses glass fiber reinforced epoxy resin prepreg. Since glass fiber is an inert material, it is beneficial for the electromagnetic protection composite material to better maintain chemical stability in the air, and even in extreme environments, it will slow down its corrosion rate and be lighter in weight. In addition, compared with other carbon fibers, glass fiber can meet the requirements of electromagnetic protection composite materials for light transmittance.

[0044] In the present invention, the number of layers of the glass fiber reinforced epoxy resin prepreg layer is 2 to 10.

[0045] According to the present invention, according to the specific usage scenario of the electromagnetic protection composite material, adjustments can be made in terms of materials, number of layers, appearance, etc. For example, the number of layers of the micro-nano metal mesh layer can be 2 layers, and the number of layers of the glass fiber reinforced epoxy resin prepreg layer can be 6 layers.

[0046] According to a specific embodiment of the present invention, the pressure of the hot pressing treatment is 0.1-20 MPa. Preferably, the pressure of the hot pressing treatment is 10-20 MPa, for example, 10 MPa, 13 MPa, 15 MPa, 17 MPa, 20 MPa, etc. By controlling the pressure within the above range, the electromagnetic shielding composite material can have the strength, thickness and surface flatness that meet the application requirements, and it is conducive to the formation of an integrated structure of the entire electromagnetic shielding composite material.

[0047] According to a specific embodiment of the present invention, the temperature of the hot pressing treatment is 100-220°C, preferably, the temperature of the hot pressing treatment is 180-220°C, for example, 180°C, 190°C, 200°C, 210°C, 220°C, etc. If the temperature is less than 100°C, the epoxy resin will not react completely and cannot be completely melted to cover the micro-nano metal mesh; if the temperature is greater than 220°C, the epoxy resin will age and turn yellow, affecting the performance.

[0048] It is noteworthy that the present invention performs hot pressing curing molding at at least one step-wise increasing temperature, wherein the temperature is continuously increased from room temperature to a desired temperature at a heating rate not exceeding 3° C. / 1 min and then maintained at that temperature.

[0049] According to a specific embodiment of the present invention, the time of the hot pressing treatment is 40 to 120 minutes. Preferably, the time of the hot pressing treatment is 40 to 60 minutes, for example, 40 minutes, 43 minutes, 46 minutes, 50 minutes, 53 minutes, 56 minutes, 60 minutes, etc. If the time is less than 40 minutes, the reaction of the epoxy resin is not complete and needs to be continued; if the time is greater than 120 minutes, the reaction of the epoxy resin is complete.

[0050] According to a specific embodiment of the present invention, the temperature of the hot pressing treatment is 200°C±0.5°C, the time is 50 minutes, and the pressure is 15 MPa.

[0051] In a specific embodiment of the present invention, the vacuum bag is placed in a laminating device for heat pressing, and the vacuum bag and the laminating device are separated by a flat mold, so as to finally obtain a cured electromagnetic protection composite material.

[0052] In a specific embodiment of the present invention, the vacuum bag is placed in a laminating device for heat pressing. It should be noted that the present invention has no special requirements for the laminating device, and those skilled in the art can select a device capable of controlling temperature and pressure according to actual needs, such as an automatic flat vulcanizing machine.

[0053] In a specific embodiment of the present invention, the vacuum bag and the laminating device are separated by a flat mold, and the flat mold is conventionally selected in the art. A release agent is provided on the surface of the flat mold, and the release agent is provided in a conventional manner in the art, for example, by spraying, brushing, paving, etc.

[0054] The present invention also provides an electromagnetic protection composite material, which comprises: 2 to 10 layers of glass fiber reinforced epoxy resin prepreg layers;

[0055] 1 to 3 layers of micro-nano metal mesh layers, two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, and the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer and each prepreg layer are bonded by epoxy resin.

[0056] According to the present invention, the thickness of the electromagnetic shielding composite material is 0.6-1.5 mm, for example, it can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc., thereby, the light transmittance of the obtained electromagnetic shielding composite material is more than 50%, and the strength can also meet the requirements of subsequent aerospace lampshades.

[0057] The present invention also provides a lampshade for aerospace, which comprises the electromagnetic shielding composite material prepared by the method described above or the electromagnetic shielding composite material described above.

[0058] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0059] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0060] In the following embodiments, the micro-nano copper mesh, micro-nano copper-nickel mesh and glass fiber reinforced epoxy resin prepreg are all commercially available, wherein the size of the glass fiber reinforced epoxy resin prepreg is 300mm×300mm×0.2mm, the size of the micro-nano copper-nickel mesh is 300mm×300mm, and the size of the micro-nano copper mesh is 300mm×300mm.

[0061] The electromagnetic shielding composite material prepared in the following examples is tested for corrosion resistance using the method of GB / T 9274-1988. First, it is immersed in pure water (with a resistivity of 500 kΩ·cm or more) for 24 hours, and then washed and dried. If the appearance performance is not affected at all, the corrosion resistance is good.

[0062] Example 1

[0063] 1) spraying a release agent on the surface of the flat mold, and then stacking three layers of glass fiber reinforced epoxy resin prepreg layers, one layer of micro-nano copper-nickel mesh layer and two layers of glass fiber reinforced epoxy resin prepreg layers on the flat mold from the bottom layer to the top layer;

[0064] 2) Place the stacked layers of materials in a vacuum bag as a whole, place the vacuum bag inside an automatic flat-plate vulcanizer, and separate the vacuum bag from the automatic flat-plate vulcanizer with a flat mold;

[0065] 3) The vacuum bag is evacuated to about 0.1 MPa, and the automatic flat plate vulcanizer starts to heat the upper and lower flat plate molds at a heating rate not exceeding 3°C / min;

[0066] 4) When heated to 200°C, apply pressure to 15MPa, stop heating and keep the temperature at 200±0.5°C for 50min. During the heating and insulation process, the epoxy resin in the glass fiber reinforced epoxy resin prepreg will melt and adhere to the micro-nano metal mesh. Each time it melts, the pressure will drop, and the pressure must be replenished to 15MPa in time.

[0067] 5) After the reaction is completed, the external pressure is released, and the laminated sample is allowed to cool naturally to room temperature, and the sample is taken out to obtain a cured electromagnetic protection composite material.

[0068] The test shows that the electromagnetic protection composite material obtained in Example 1 has good corrosion resistance, a thickness of 0.5 mm, a transmittance of 53% in the visible light band, and an electromagnetic shielding effectiveness of 25 dB to 60 dB in the 1 GHz to 18 GHz frequency band. Figure 1 As shown, the minimum value of its electromagnetic shielding effectiveness at 7 GHz is above 25 dB.

[0069] Example 2

[0070] 1) spraying a release agent on the surface of the flat mold, and then stacking 3 layers of glass fiber reinforced epoxy resin prepreg layers, 1 layer of micro-nano copper-nickel mesh layer, 2 layers of glass fiber reinforced epoxy resin prepreg layers, 1 layer of micro-nano copper-nickel mesh layer and 3 layers of glass fiber reinforced epoxy resin prepreg layers on the flat mold from the bottom layer to the top layer;

[0071] 2) Place the stacked layers of materials in a vacuum bag as a whole, place the vacuum bag inside an automatic flat-plate vulcanizer, and separate the vacuum bag from the automatic flat-plate vulcanizer with a flat mold;

[0072] 3) The vacuum bag is evacuated to about 0.1 MPa, and the automatic flat plate vulcanizer starts to heat the upper and lower flat plate molds at a heating rate not exceeding 3°C / min;

[0073] 4) When heated to 200°C, apply pressure to 15MPa, stop heating and keep the temperature at 200±0.5°C for 50min. During the heating and insulation process, the epoxy resin in the glass fiber reinforced epoxy resin prepreg will melt and adhere to the micro-nano metal mesh. Each time it melts, the pressure will drop, and the pressure must be replenished to 15MPa in time.

[0074] 5) After the reaction is completed, the external pressure is released, and the laminated sample is allowed to cool naturally to room temperature, and the sample is taken out to obtain a cured electromagnetic protection composite material.

[0075] Tests show that the electromagnetic protection composite material obtained in Example 2 has good corrosion resistance, a thickness of 0.8 mm, a transmittance of 51% in the visible light band, and an electromagnetic shielding effectiveness of more than 20 dB in the 1 GHz to 18 GHz frequency band.

[0076] Example 3

[0077] Example 3 is carried out in the same manner as Example 1, except that the micro-nano copper-nickel mesh layer in Example 1 is replaced by a micro-nano copper mesh layer.

[0078] The test shows that the electromagnetic protection composite material obtained in Example 3 has good corrosion resistance, a thickness of 0.6 mm, a transmittance of 52% in the visible light band, and an electromagnetic shielding effectiveness of more than 20 dB in the 1 GHz to 18 GHz frequency band. Figure 2 As shown, the electromagnetic shielding effectiveness, especially in the 1GHz to 8GHz frequency band, reaches 25dB to 45dB.

[0079] Comparative Example 1

[0080] Comparative Example 1 was carried out in the same manner as Example 1, except that the micro-nano copper-nickel mesh of Example 1 was replaced by a common copper-nickel mesh.

[0081] Tests show that the electromagnetic protection material obtained in Comparative Example 1 has a transmittance of less than 40% in the visible light band, and a portion of the electromagnetic shielding effectiveness in the 1 GHz to 18 GHz frequency band is less than 20 dB.

[0082] Comparative Example 2

[0083] Comparative Example 2 was carried out in the same manner as Example 1, except that the micro-nano copper-nickel mesh was not used, and 5 layers of glass fiber reinforced epoxy resin prepreg were directly used to prepare the electromagnetic protection composite material.

[0084] Tests show that the electromagnetic protection material obtained in Comparative Example 2 has a transmittance of 58% in the visible light band, and a portion of the electromagnetic shielding effectiveness in the 1 GHz to 18 GHz frequency band is below 20 dB.

[0085] Comparative Example 3

[0086] Comparative Example 3 was carried out in the same manner as Example 1, except that the glass fiber reinforced epoxy resin prepreg in Example 1 was replaced by a carbon fiber reinforced epoxy resin prepreg.

[0087] Tests show that the electromagnetic protection material obtained in Comparative Example 3 has a transmittance of less than 40% in the visible light band, and a portion of the electromagnetic shielding effectiveness in the 1 GHz to 18 GHz frequency band is less than 20 dB.

[0088] It can be seen from the above embodiments and comparative examples that the preparation method provided by the present invention has a simple process and high efficiency. The prepared electromagnetic protection composite material has a high degree of design freedom and strong designability, and can be adjusted in terms of materials, number of layers, appearance, etc. according to the needs of specific usage scenarios. The prepared electromagnetic protection composite material has surface flatness, light transmittance and electromagnetic shielding effect that can meet application requirements, is corrosion-resistant, aging-resistant, and lightweight, and can effectively protect against electromagnetic interference of more than 20 dB in the 1GHz to 18GHz band, and has a light transmittance of more than 50%.

[0089] In particular, the electromagnetic protection composite material obtained in Example 1 can effectively protect electromagnetic interference by 25dB to 60dB in the 1GHz to 18GHz band. Figure 1 As shown, its minimum electromagnetic shielding effectiveness at 7 GHz is above 25 dB, and its transmittance is 53%. It can take into account both transmittance and electromagnetic shielding effects to meet the application requirements in the aerospace field.

[0090] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0091] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an electromagnetic protection composite material, characterized in that: It includes the following steps: (1) placing a micro-nano metal mesh layer and a glass fiber reinforced epoxy resin prepreg layer in a vacuum bag according to a preset arrangement rule, wherein the arrangement rule is that two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, and the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer and each prepreg layer are bonded by epoxy resin; (2) The vacuum bag is subjected to a heat pressing process to finally obtain a cured electromagnetic protection composite material.

2. The method according to claim 1, characterized in that In step (2), the pressure of the hot pressing treatment is 0.1 to 20 MPa.

3. The method according to claim 1, characterized in that In step (2), the temperature of the hot pressing treatment is 100 to 220°C; The time of the hot pressing treatment is 40 to 120 minutes.

4. The method according to claim 1, characterized in that: The number of layers of the micro-nano metal mesh layer is 1 to 3; The number of layers of the glass fiber reinforced epoxy resin prepreg layer is 2 to 10.

5. The method according to claim 1, characterized in that: The duty ratio of the micro-nano metal mesh layer is 80% to 95%.

6. The method according to claim 1, characterized in that The micro-nano metal mesh layer has periodically arranged square resonance units; The side length of the square resonance unit is greater than 300 μm and less than 2 mm.

7. The method according to claim 1, characterized in that The metal in the micro-nano metal mesh layer is selected from metals with high electrical conductivity or high magnetic permeability.

8. The method according to claim 1, characterized in that The metal in the micro-nano metal mesh layer is selected from at least one of Au, Ag, Cu, Fe, Co and Ni.

9. An electromagnetic protection composite material, characterized in that: It includes: 2 to 10 layers of glass fiber reinforced epoxy resin prepreg; 1 to 3 layers of micro-nano metal mesh layers, two surfaces of the micro-nano metal mesh layer are adjacent to the glass fiber reinforced epoxy resin prepreg layer, and the micro-nano metal mesh layer and the glass fiber reinforced epoxy resin prepreg layer and each prepreg layer are bonded by epoxy resin.

10. A lampshade for aviation and aerospace, characterized in that: The electromagnetic protection composite material comprises the electromagnetic protection composite material prepared by the method described in any one of claims 1 to 8 or the electromagnetic protection composite material described in claim 9.

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