A radiation-proof shielding type electrical control cabinet

Abstract

The present invention discloses a radiation-proof shielding type electrical control cabinet, comprising a cabinet body and a shielding layer arranged on the cabinet body, wherein the shielding layer comprises a high molecular polymer and a fiber composite layer coated with the high molecular polymer, wherein the fiber composite layer comprises a fiber fabric layer and a carbon nanotube / silver nanowire composite layer, and the composition of the shielding layer is designed in the present invention, wherein a three-dimensional conductive network is formed on the fiber fabric layer by the carbon nanotube / silver nanowire composite, and the electromagnetic shielding performance of the shielding layer is improved, and the shielding layer is flexible and light in weight, and is convenient for molding and installation.

Description

Technical Field

[0001] The invention relates to the technical field of electric control devices, and in particular to an anti-radiation shielding type electric control cabinet. Background Art

[0002] With the advent of the 5G era, high-power electronic devices and portable electronic communication devices have become widely popular, and the electromagnetic radiation that follows is likely to affect the normal operation of other electronic devices. Taking the electrical control cabinet as an example, there are a variety of related electronic equipment installed in the electrical control cabinet. In order to prevent the external electromagnetic radiation from affecting the operation of the equipment, common methods include changing the material of the cabinet and molding the cabinet with metals with electromagnetic shielding properties. However, this type of metal has defects such as large weight, difficulty in moving, and high difficulty in processing and molding. In response to this, some companies have lowered the material requirements for the cabinet and coated the cabinet with flexible materials with electromagnetic shielding properties. This type of flexible material is mostly composed of polymer-coated glass fiber, nanowires or other fillers, which has the advantages of easy processing and low weight. The disadvantage is that the electromagnetic shielding performance is insufficient and needs to be improved. Summary of the invention

[0003] To solve at least one of the above technical defects, the present invention provides the following technical solutions:

[0004] The present application document discloses a radiation-proof shielding type electrical control cabinet, comprising a cabinet body and a shielding layer arranged on the cabinet body, wherein the shielding layer comprises a high molecular polymer and a fiber composite layer coated with the high molecular polymer, and the fiber composite layer comprises a fiber fabric layer and a carbon nanotube / silver nanowire composite layer arranged on the fiber fabric layer.

[0005] In this scheme, the composition of the shielding layer is designed to form a three-dimensional conductive network on the fiber fabric layer through the carbon nanotube / silver nanowire composite, the electromagnetic shielding performance of the shielding layer is improved, and the shielding layer is flexible and light, and is easy to shape and install.

[0006] Furthermore, carbon nanotubes are dispersed in an epoxy resin solution and dripped into a silver nanowire dispersion by a dripping method to form a spherical composite, the composite is laid on a fiber fabric layer and melt-cooled, the cooled product is immersed in a high molecular polymer solution, and after removing the solvent of the high molecular polymer solution, a shielding layer is formed by hot pressing. In the process of forming the spheres with the epoxy resin solution, the silver nanowires are mixed to form a whole. In this way, the distribution of carbon nanotubes and silver nanowires is more uniform, which helps to maintain the required performance while reducing the dosage. The impregnation coating method has the advantages of convenient molding and suitability for large-scale production.

[0007] Furthermore, the carbon nanotubes account for 0.01-0.05% of the mass of the epoxy resin solution, and the concentration of the silver nanowire dispersion is 1-5 mg / ml. With this preferred component ratio, a small amount of application can meet the shielding requirements.

[0008] Furthermore, the high molecular polymer is of epoxy resin type or polyethylene glycol type, such as glycidyl ether, epoxidized olefin, etc.

[0009] Furthermore, the high molecular polymer is synthesized by reacting polyethylene glycol with isocyanatepropyltriethoxysilane. In this scheme, polyethylene glycol is used as the functional soft segment, and a polymer is formed by reacting a hydroxyl group with an isocyanate group, which helps to improve the thermal stability and mechanical properties of the shielding layer.

[0010] Furthermore, the fiber fabric layer is woven from glass fibers, which assist in conducting electricity and improving mechanical properties, thereby helping to further improve shielding performance.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. The present invention redesigns the shielding layer on the cabinet, which helps to improve the electromagnetic shielding performance of the shielding layer.

[0013] 2. The molding process of the shielding layer of the present invention is simple and suitable for large-scale production applications.

[0014] 3. The shielding layer of the present invention has the characteristics of low weight and bendability, and is convenient for molding and installation according to cabinets of different sizes. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with specific embodiments.

[0016] For high molecular polymers, polyethylene glycol type is preferably used, specifically, it is synthesized by the reaction of polyethylene glycol and isocyanatepropyltriethoxysilane. This is a conventional technology and can be prepared by referring to the following synthesis route, or directly purchased from the market.

[0017] For carbon nanotubes, such as single-walled or multi-walled types, the carbon nanotubes contain common carboxyl, amino or hydroxyl groups, and the carbon nanotubes can be of common sizes. Single-walled carboxylated carbon nanotubes are used in the following embodiments.

[0018] For silver nanowires, their dimensions are, for example, in the range of 80-150 nm in diameter and 20-60 μm in length.

[0019] For the fiber fabric layer, glass fiber or other polyester fibers can be selected according to the needs, and the surface density is 80-500g / m 2 .

[0020] For the coating of the fiber composite layer by the high molecular polymer, the infusion process, the dipping coating, etc. are all possible. For the mass ratio of the fiber composite layer to the high molecular polymer, such as 1:3, 1:4, 1:5, 1:6, etc., it is selected according to the needs.

[0021] Example 1

[0022] A radiation-proof shielding type electrical control cabinet comprises a cabinet body and a shielding layer fixed on the peripheral wall of the cabinet body. The shielding layer is prepared as follows:

[0023] Preparation of carbon nanotube / silver nanowire composites:

[0024] Dissolve bisphenol A epoxy resin in acetone solvent, add 0.02% of carboxylated carbon nanotubes (aspect ratio of 100-103) based on the mass of bisphenol A epoxy resin, 0.01% of polyethylene glycol octylphenyl ether based on the mass of bisphenol A epoxy resin, and 12% of modified imidazole latent curing agent based on the mass of bisphenol A epoxy resin, stir for 10 minutes, and ultrasonically disperse for 1 hour for standby use.

[0025] A polyvinyl pyrrolidone dispersant accounting for 3% of the mass of bisphenol A epoxy resin is dissolved in deionized water to form a 0.003g / ml solution, and then silver nanowires are added to the solution to form a 3.5mg / ml mixed solution. The mixed solution is placed in a container and stirred, and the prepared bisphenol A epoxy resin solution is dropped into the stirred mixed solution. The formed spheres are filtered out, repeatedly washed and dried, and the obtained spheres are carbon nanotube / silver nanowire composites with a particle size of 100-200μm.

[0026] The specific synthesis route of the polymer is as follows: polyethylene glycol ( M n 10000), triethoxypropyl isocyanate (Shanghai Aladdin, analytical grade), dibutyltin dilaurate (Shanghai Aladdin, analytical grade) were mixed in a mass g / volume μL ratio of 1:50:25 and added to toluene with a mass g / volume ml ratio of 1:10 of polyethylene glycol, that is, configured in a mass ratio or volume ratio, stirred and reacted at 42°C for 5h, and the resulting product was dissolved in a hydrochloric acid solution (with a volume ratio of 1:1 to toluene), and rotary evaporated at 60°C for 3.5h to obtain a solution of the desired polymer. The subsequent fiber fabric layer was composited with the polymer by an immersion method, and the polymer was directly formed into a solution state. It was verified by infrared detection that the N=C=O stretching peak of triethoxypropyl isocyanate disappeared, and the peak at 1758cm -1 A C=O stretching peak is generated at , indicating that the hydroxyl group of polyethylene glycol reacts with the isocyanate group.

[0027] Fiberglass woven fabric layer, surface density: 100g / m 2 , lay the carbon nanotube / silver nanowire composite on the fiber fabric layer in a mass ratio of 1:2, preheat at 55°C for 15 minutes to melt the spheres to adhere to the fiber fabric layer, cool to room temperature, and set aside.

[0028] The materials were prepared in a mass ratio of 3:1 between the polymer solution and the fiber composite layer, the fiber composite layer was immersed in the polymer solution, the solvent was evaporated to constant weight to obtain a preform, and the preform was hot-pressed at a pressure of 7 MPa and a temperature of 85°C to obtain a shielding layer with a thickness of 2.5 mm. During the hot-pressing process, the spheres were melted for a second time and flattened on the fiber fabric layer to form a carbon nanotube / silver nanowire composite layer.

[0029] Fix the shielding layer to the prefabricated cabinet wall.

[0030] Example 2

[0031] Compared with Example 1, the difference in this example is that the mass ratio of the high molecular polymer solution to the fiber composite layer is 4:1.

[0032] Example 3

[0033] Compared with Example 1, the difference in this example is that the mass ratio of the high molecular polymer solution to the fiber composite layer is 5:1.

[0034] Comparative Example 1

[0035] Compared with Example 1, the difference is that: there is no silver nanowire in the mixed liquid, the silver nanowire is mixed with ethanol, sprayed onto the fiber fabric layer in a spraying manner and dried to form a fiber composite layer.

[0036] Comparative Example 2

[0037] Compared with Example 1, the difference is that: no carbon nanotube / silver nanowire composite is prepared, the carbon nanotubes and silver nanowires are mixed in a resin solution, sprayed onto the fiber fabric layer and dried to form a fiber composite layer.

[0038] The electromagnetic shielding performance of the shielding layer prepared above was tested in a frequency range of 12 to 18 GHz, as shown in Table 1:

[0039] Table 1

[0040]

[0041] It can be seen that the shielding layer formed in the present invention has excellent electromagnetic shielding performance, can effectively protect the electronic equipment in the cabinet, and at the same time reduces the material requirements of the cabinet.

[0042] The reason for the improved electromagnetic shielding performance of the present invention is mainly that: in the carbon nanotube / silver nanowire composite configuration, the carbon nanotubes and silver nanowires inside the sphere are evenly distributed, and after being composited with the fiber fabric layer, the carbon nanotubes and silver nanowires are also evenly distributed, which cooperates to improve the electromagnetic shielding performance of the shielding layer. In comparison, the distribution of carbon nanotubes and silver nanowires in Comparative Examples 1 and 2 will be segregated and agglomerated due to their process reasons, and the uneven distribution will result in a small improvement in electromagnetic shielding performance.

[0043] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A radiation-proof shielding type electrical control cabinet, comprising a cabinet body and a shielding layer arranged on the cabinet body, characterized in that: The shielding layer includes a high molecular polymer and a fiber composite layer coated with the high molecular polymer, and the fiber composite layer includes a fiber fabric layer and a carbon nanotube and silver nanowire composite layer; Carbon nanotubes are dispersed in an epoxy resin solution and dripped into a silver nanowire dispersion to form a spherical composite, the composite is laid on a fiber fabric layer and melted and cooled, the cooled product is immersed in a high molecular polymer solution, and after removing the solvent, the shielding layer is formed by hot pressing; The carbon nanotubes account for 0.01-0.05% of the mass of the epoxy resin solution, and the concentration of the silver nanowire dispersion is 1-5 mg / ml.

2. The radiation shielding type electrical control cabinet according to claim 1, characterized in that: The high molecular polymer is of epoxy resin type or polyethylene glycol type.

3. The radiation shielding type electrical control cabinet according to claim 2, characterized in that: The high molecular polymer is synthesized by reaction of polyethylene glycol and isocyanate propyltriethoxysilane.

4. The radiation shielding type electrical control cabinet according to claim 1, characterized in that: The fiber fabric layer is woven and formed by glass fiber.

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