Preparation method of high-frequency shielding conductive material

Abstract

The invention relates to the technical field of shielding conductive materials, in particular to a preparation method of a high-frequency shielding conductive material, which comprises the following steps: pouring an electromagnetic shielding composite material, a silver nanowire, modified nano silicon dioxide and a dispersing agent into a resin base material, and uniformly stirring to obtain a mixture; and continuously adding the defoaming agent and the acetone solvent into the mixture, and stirring and dispersing to obtain the high-frequency shielding conductive material. According to the invention, by adding the silver nanowires, a disordered silver cross-linked network is constructed in a matrix, and at the same time, the added electromagnetic shielding composite material fills the silver cross-linked network to bring more electron polarization interfaces, so that the reflection of incident waves in the film layer is increased to attenuate the incident waves; and the electromagnetic shielding composite material has excellent dielectric loss and magnetic hysteresis loss capabilities, so that the conductive performance and shielding performance of the high-frequency shielding conductive material are further improved through mutual cooperation of the electromagnetic shielding composite material and the high-frequency shielding conductive material.

Description

Technical Field

[0001] The present invention relates to the technical field of shielding conductive materials, and specifically to a preparation method of a high-frequency shielding conductive material. Background Art

[0002] Electromagnetic shielding windows are usually used to block electromagnetic radiation. They can effectively prevent the penetration of electromagnetic waves to protect equipment or personnel from electromagnetic interference or electromagnetic radiation. These windows can be used in fields such as laboratories, medical facilities, aerospace, and electronic devices. They are usually made of special materials with the ability to shield electromagnetic waves, such as metallized plastics, metal grid glasses, etc.

[0003] During the production and manufacturing process of electromagnetic shielding windows, it is generally necessary to coat conductive materials to improve their shielding efficiency against electromagnetic waves. These conductive coating materials usually have good electrical conductivity and can effectively reflect and absorb electromagnetic waves, thereby reducing the impact of electromagnetic radiation on the indoor environment. Currently, most conductive materials directly add graphite particles or metal particles to the resin matrix. Although the shielding and conductive properties of the resin film layer are improved to a certain extent, it is difficult for the conductive particles to form laps or crosslinks, and the improvement of the shielding and conductive properties is limited. Based on this, a preparation method of a high-frequency shielding conductive material is proposed. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a preparation method of a high-frequency shielding conductive material, which improves the electrical conductivity and shielding performance of the high-frequency shielding conductive material through the cooperation of a cross-linked network constructed by an electromagnetic shielding composite and silver nanowires.

[0005] To achieve the above object, the present invention provides the following technical solution: A preparation method of a high-frequency shielding conductive material, comprising the following steps,

[0006] (1) Pour an electromagnetic shielding composite, silver nanowires, modified nano-silica, and a dispersant into a resin base material, and stir evenly to obtain a mixture.

[0007] (2) Continuously add an antifoaming agent and an acetone solvent to the mixture, and stir and disperse to prepare a high-frequency shielding conductive material.

[0008] Preferably, by weight, the high-frequency shielding conductive material comprises the following raw materials: 150 - 180 parts of a resin base material, 15 - 20 parts of an electromagnetic shielding composite, 10 - 15 parts of silver nanowires, 3 - 5 parts of modified nano-silica, 1 - 2 parts of a dispersant, 0.5 - 1 part of an antifoaming agent, and 30 - 50 parts of an acetone solvent.

[0009] Preferably, the resin base material is selected from acrylic resin and polyurethane resin.

[0010] Preferably, the dispersant is selected from polyoxyethylene ether and methyl cellulose; the defoamer is selected from polysiloxane and polyethylene glycol.

[0011] Preferably, the modified nano-silica is prepared by modifying the surface of nano-silica with silane coupling agent KH-560.

[0012] Preferably, the preparation method of the electromagnetic shielding composite material is as follows: S1. Pour ferrocene monocarboxylic chloride, graphene oxide, dichloromethane and triethylamine into a reactor, stir and react at 55-60 °C for 4-5 h, and obtain a pre-composite material after filtration, washing and drying; S2. Dissolve cobalt dichloride hexahydrate in deionized water, and add 0.1-0.2 wt% of the pre-composite material dispersion liquid to obtain a reaction solution; S3. Heat the reaction solution to 85-90 °C, add 80 wt% hydrazine hydrate solution under a nitrogen atmosphere, continuously react for 3.5-4 h, and obtain the electromagnetic shielding composite material after filtration, washing and drying.

[0013] Preferably, in step S1, the mass ratio of ferrocene monocarboxylic chloride to graphene oxide is (8-10):1; the volume ratio of dichloromethane to triethylamine is 15:1; the material liquid ratio of ferrocene monocarboxylic chloride to dichloromethane is 1:10 g / mL.

[0014] Preferably, in step S2, the material liquid ratio of cobalt dichloride hexahydrate to deionized water is 1:50 g / mL; the volume ratio of deionized water to the pre-composite material dispersion liquid is 1:2.

[0015] The present invention provides a preparation method of a high-frequency shielding conductive material, which has the following beneficial effects compared with the prior art:

[0016] In the present invention, by adding silver nanowires, a disordered silver cross-linked network is constructed in the matrix, and at the same time, the added electromagnetic shielding composite material fills between the silver cross-linked networks to bring more electron polarization interfaces, so as to increase the reflection of the incident wave inside the film layer to attenuate the incident wave, and the electromagnetic shielding composite material itself has excellent dielectric loss and hysteresis loss capabilities, and the mutual cooperation further improves the conductive performance and shielding performance of the high-frequency shielding conductive material.

[0017] In the present invention, by utilizing the fact that the surface of graphene oxide has a large number of active groups, cobalt particles are attached to the surface of graphene oxide, and at the same time, ferrocene groups are introduced onto the surface of graphene oxide to form a large conjugated system, which can accelerate the electron transfer rate to improve the conductive ability of the composite material, and further improve the shielding performance of the composite material. Description of the Drawings

[0018] The accompanying drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0019] Figure 1 It is a cross-sectional microscopic view of the cured film of the high-frequency shielding conductive material of the present invention. Detailed implementation manners

[0020] The following embodiments are used to detail the implementation manners of the present application, so as to fully understand how the present application uses technical means to solve technical problems and achieve the implementation process of technical effects and implement accordingly.

[0021] Embodiment 1

[0022] The preparation method of the electromagnetic shielding composite material is as follows:

[0023] S1. Pour ferrocene monocarboxylic chloride, graphene oxide, dichloromethane and triethylamine into a reactor, stir and react at 55 °C for 5 h, and obtain a pre-composite material through filtration, washing and drying;

[0024] The mass ratio of the above-mentioned ferrocene monocarboxylic chloride to graphene oxide is 8:1; the volume ratio of dichloromethane to triethylamine is 15:1; the material liquid ratio of ferrocene monocarboxylic chloride to dichloromethane is 1:10 g / mL.

[0025] S2. Dissolve cobalt dichloride hexahydrate in deionized water, and add a 0.2 wt% pre-composite material dispersion liquid (prepared by ultrasonic dispersion of the pre-composite material and deionized water) to obtain a reaction solution;

[0026] The material liquid ratio of the above-mentioned cobalt dichloride hexahydrate to deionized water is 1:50 g / mL; the volume ratio of deionized water to the pre-composite material dispersion liquid is 1:2.

[0027] S3. Heat the reaction solution to 85 °C, add an 80 wt% hydrazine hydrate solution under a nitrogen atmosphere, continuously react for 4 h, and obtain the electromagnetic shielding composite material through filtration, washing and drying.

[0028] Embodiment 2

[0029] The preparation method of the electromagnetic shielding composite material is as follows:

[0030] S1. Pour ferrocene monocarboxylic chloride, graphene oxide, dichloromethane and triethylamine into a reactor, stir and react at 60 °C for 4 h, and obtain a pre-composite material through filtration, washing and drying;

[0031] The mass ratio of the above ferrocene monocarbonyl chloride to graphene oxide is 10:1; the volume ratio of dichloromethane to triethylamine is 15:1; the material ratio of ferrocene monocarbonyl chloride to dichloromethane is 1:10 g / mL.

[0032] S2. Dissolve cobalt dichloride hexahydrate in deionized water, and add a 0.1 wt% pre-composite dispersion (prepared by ultrasonic dispersion of the pre-composite and deionized water) to obtain a reaction solution.

[0033] The material ratio of the above cobalt dichloride hexahydrate to deionized water is 1:50 g / mL; the volume ratio of deionized water to the pre-composite dispersion is 1:2.

[0034] S3. Heat the reaction solution to 90 °C, add an 80 wt% hydrazine hydrate solution under a nitrogen atmosphere, and continuously react for 3.5 h. After filtration, washing, and drying, an electromagnetic shielding composite is prepared.

[0035] Example 3

[0036] A preparation method of a high-frequency shielding conductive material, comprising the following steps:

[0037] (1) Weigh the following raw materials in parts by weight: 180 parts of an acrylic resin base material, 15 parts of an electromagnetic shielding composite, 15 parts of silver nanowires, 3 parts of modified nano-silica, 2 parts of a polyoxyethylene ether dispersant, 0.5 part of a polysiloxane defoamer, and 50 parts of an acetone solvent. Among them, the modified nano-silica is prepared by modifying the surface of nano-silica with a silane coupling agent KH-560.

[0038] (1) Pour the electromagnetic shielding composite, silver nanowires, modified nano-silica, and polyoxyethylene ether dispersant into the acrylic resin base material, and stir evenly to obtain a mixed material.

[0039] (2) Continuously add the polysiloxane defoamer and acetone solvent to the mixed material, and stir and disperse to obtain a high-frequency shielding conductive material.

[0040] In this example, the electromagnetic shielding composite prepared in Example 1 is used.

[0041] Example 4

[0042] A preparation method of a high-frequency shielding conductive material, comprising the following steps:

[0043] (1) Weigh the following raw materials in parts by weight: 150 parts of a polyurethane resin base material, 20 parts of an electromagnetic shielding composite, 10 parts of silver nanowires, 5 parts of modified nano-silica, 1 part of a methyl cellulose dispersant, 1 part of a polyethylene glycol defoamer, and 30 parts of an acetone solvent. Among them, the modified nano-silica is prepared by modifying the surface of nano-silica with a silane coupling agent KH-560.

[0044] (1) Pour the electromagnetic shielding composite material, silver nanowires, modified nano-silica, and methyl cellulose dispersant into the polyurethane resin base material, and stir evenly to obtain a mixed material.

[0045] (2) Continuously add polyethylene glycol defoamer and acetone solvent to the mixed material, stir and disperse to obtain a high-frequency shielding conductive material.

[0046] In this embodiment, the electromagnetic shielding composite material prepared in Example 2 is used.

[0047] Example 5

[0048] A preparation method of a high-frequency shielding conductive material includes the following steps:

[0049] (1) Weigh the following raw materials in parts by weight: 160 parts of polyurethane resin base material, 18 parts of electromagnetic shielding composite material, 12 parts of silver nanowires, 4 parts of modified nano-silica, 1 part of polyoxyethylene ether dispersant, 1 part of polysiloxane defoamer, and 40 parts of acetone solvent. Among them, the modified nano-silica is prepared by modifying the surface of nano-silica with silane coupling agent KH-560.

[0050] (1) Pour the electromagnetic shielding composite material, silver nanowires, modified nano-silica, and polyoxyethylene ether dispersant into the polyurethane resin base material, and stir evenly to obtain a mixed material.

[0051] (2) Continuously add polysiloxane defoamer and acetone solvent to the mixed material, stir and disperse to obtain a high-frequency shielding conductive material.

[0052] In this embodiment, the electromagnetic shielding composite material prepared in Example 1 is used.

[0053] Comparative Example 1

[0054] A preparation method of a high-frequency shielding conductive material includes the following steps:

[0055] (1) Weigh the following raw materials in parts by weight: 160 parts of polyurethane resin base material, 18 parts of electromagnetic shielding composite material, 4 parts of modified nano-silica, 1 part of polyoxyethylene ether dispersant, 1 part of polysiloxane defoamer, and 40 parts of acetone solvent. Among them, the modified nano-silica is prepared by modifying the surface of nano-silica with silane coupling agent KH-560.

[0056] (1) Pour the electromagnetic shielding composite material, modified nano-silica, and polyoxyethylene ether dispersant into the polyurethane resin base material, and stir evenly to obtain a mixed material.

[0057] (2) Continuously add polysiloxane defoamer and acetone solvent to the mixed material, stir and disperse to obtain a high-frequency shielding conductive material.

[0058] In this comparative example, the electromagnetic shielding composite material prepared in Example 1 was used.

[0059] Comparative Example 2

[0060] A preparation method of a high-frequency shielding conductive material is basically the same as that of Example 5, the difference being: the preparation method of the electromagnetic shielding composite material is different.

[0061] The preparation method of the electromagnetic shielding composite material in this comparative example is as follows:

[0062] S1. Dissolve cobalt dichloride hexahydrate in deionized water, and add a 0.2 wt% graphene oxide dispersion (prepared by ultrasonic dispersion of graphene oxide and deionized water) to obtain a reaction solution.

[0063] The material ratio of the above cobalt dichloride hexahydrate to deionized water is 1:50 g / mL; the volume ratio of deionized water to the graphene oxide dispersion is 1:2.

[0064] S2. Heat the reaction solution to 85 °C, add an 80 wt% hydrazine hydrate solution under a nitrogen atmosphere, continuously react for 4 h, and obtain the electromagnetic shielding composite material through filtration, washing and drying.

[0065] Comparative Example 3

[0066] A preparation method of a high-frequency shielding conductive material is basically the same as that of Example 5, the difference being: the preparation method of the electromagnetic shielding composite material is different.

[0067] The preparation method of the electromagnetic shielding composite material in this comparative example is as follows:

[0068] S1. Pour ferrocene monocarboxylic chloride, graphene oxide, dichloromethane and triethylamine into a reactor, stir and react at 55 °C for 5 h, and obtain a pre-composite material through filtration, washing and drying, denoted as the electromagnetic shielding composite material.

[0069] The mass ratio of the above ferrocene monocarboxylic chloride to graphene oxide is 8:1; the volume ratio of dichloromethane to triethylamine is 15:1; the material ratio of ferrocene monocarboxylic chloride to dichloromethane is 1:10 g / mL.

[0070] Quality inspection

[0071] Use the high-frequency shielding conductive materials in Examples 3 - 5 and Comparative Examples 1 - 3, coat them on a polyester film, and obtain test specimens after curing.

[0072] 1. Measure the surface resistance using a high resistance meter.

[0073] 2. Perform the test according to the test standard of GB / T 30142 - 2013 and detect under a 10 GHz detection signal.

[0074] The specific test results are shown in the following table.

[0075] Table 1 Performance of High-Frequency Shielding Conductive Materials

[0076] Category Surface Resistance / Ω Shielding Performance Example 3 <![CDATA[3.3×10 6 > 71dB Example 4 <![CDATA[3.8×10 6 > 68dB Example 5 <![CDATA[3.1×10 6 > 73dB Comparative Example 1 <![CDATA[1.2×10 8 > 46dB Comparative Example 2 <![CDATA[6.5×10 7 > 53dB Comparative Example 3 <![CDATA[4.7×10 7 > 58dB

[0077] As can be seen from the above table:

[0078] (1) Compared with Example 5, silver nanowires were not added in Comparative Example 1, resulting in the inability to form a three-dimensional cross-linked network, which seriously affected the conductive and shielding properties of the specimen.

[0079] (2) Compared with Example 5, the conductive and shielding properties of the specimens in Comparative Examples 2 and 3 decreased, indicating that the addition and modification of ferrocene monocarboxylic chloride and cobalt dichloride hexahydrate can indeed improve the overall performance of high-frequency shielding conductive materials.

[0080] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a high-frequency shielding conductive material, characterized in that, It includes the following steps: (1) Pour the electromagnetic shielding composite, silver nanowires, modified nano-silica and dispersant into the resin base material, and stir evenly to obtain a mixed material; (2) Continuously add an antifoaming agent and acetone solvent to the mixed material, stir and disperse to prepare a high-frequency shielding conductive material.

2. The preparation method of the high-frequency shielding conductive material according to claim 1, wherein, By weight, the high-frequency shielding conductive material includes the following raw materials: 150-180 parts of resin base material, 15-20 parts of electromagnetic shielding composite, 10-15 parts of silver nanowires, 3-5 parts of modified nano-silica, 1-2 parts of dispersant, 0.5-1 part of antifoaming agent, and 30-50 parts of acetone solvent.

3. The preparation method of the high-frequency shielding conductive material according to claim 2, characterized in that, The resin base material is selected from acrylic resin and polyurethane resin.

4. The preparation method of the high-frequency shielding conductive material according to claim 2, characterized in that, The dispersant is selected from polyoxyethylene ether and methyl cellulose; the antifoaming agent is selected from polysiloxane and polyethylene glycol.

5. The preparation method of the high-frequency shielding conductive material according to claim 2, characterized in that, The modified nano-silica is prepared by modifying the surface of nano-silica with silane coupling agent KH-560.

6. The preparation method of the shielding conductive material according to claim 2, wherein The preparation method of the electromagnetic shielding composite is as follows: S1. Pour ferrocene monocarboxylic chloride, graphene oxide, dichloromethane and triethylamine into a reactor, stir and react at 55-60 °C for 4-5 h, and obtain a pre-composite material after filtration, washing and drying; S2. Dissolve cobalt dichloride hexahydrate in deionized water, and add 0.1-0.2 wt% of the pre-composite material dispersion to obtain a reaction solution; S3. Heat the reaction solution to 85-90 °C, add 80 wt% hydrazine hydrate solution under a nitrogen atmosphere, continuously react for 3.5-4 h, and obtain the electromagnetic shielding composite after filtration, washing and drying.

7. The preparation method of the high-frequency shielding conductive material according to claim 6, characterized in that, In step S1, the mass ratio of ferrocene monocarboxylic chloride to graphene oxide is (8-10):1; the volume ratio of dichloromethane to triethylamine is 15:1; the material ratio of ferrocene monocarboxylic chloride to dichloromethane is 1:10 g / mL.

8. The preparation method of the high-frequency shielding conductive material according to claim 6, wherein In step S2, the material ratio of cobalt dichloride hexahydrate to deionized water is 1:50 g / mL; the volume ratio of deionized water to the pre-composite material dispersion is 1:2.

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