Modified molybdenum sulfide nanosheet doped matrix resin cable and preparation method thereof

Abstract

The invention relates to the technical field of cables, in particular to a modified molybdenum sulfide nanosheet doped matrix resin cable and a preparation method thereof. The production method comprises the following steps: S1, stranding a plurality of strands of wires to form an inner conductor; s2, coating the inner conductor with a physical foaming dielectric layer; s3, wrapping the dielectric layer with a shielding layer; s4, coating the shielding layer with a protective layer; the dielectric layer is prepared from the following raw materials in parts by mass: 90 to 100 parts of matrix resin, 5 to 15 parts of modified molybdenum sulfide nanosheets and 0.5 to 1.5 parts of nucleating agent; according to the production method, the problems that an existing radio frequency cable is not matched in impedance, large in voltage standing wave ratio, poor in shielding anti-interference performance, poor in flexibility and the like are solved, and the prepared cable has excellent aging resistance and temperature cycle resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of cable preparation, and more specifically, to a cable doped with modified molybdenum disulfide nanosheets in a matrix resin and a preparation method thereof. Background Art

[0002] Generally, a cable usually consists of an outer insulating protective layer and a cable main body such as an inner filling layer and a conductive conductor. Among them, the protective layer directly affects the service life of the cable. To improve the weather resistance of the cable, Chinese Patent with publication number CN117551314A discloses a high-strength and high-weather-resistant cable and a preparation method thereof. This technical solution prepares a modified fluorosilicon crosslinking agent-modified high-density polyethylene material, thereby obtaining a weather-resistant insulating layer with high performance. A large amount of fluorine elements are introduced into the modified fluorosilicon crosslinking agent, and the high electronegativity brought by the fluorine elements is used to improve the friction resistance and water resistance of the weather-resistant insulating layer; on this basis, the modified fluorosilicon crosslinking agent prepared in this technical solution also has an olefin double bond. In a high-temperature environment, the olefin double bond will undergo a further crosslinking reaction with high-density polyethylene, thereby further improving the material stability and enhancing the wear-resistant and ultraviolet-resistant performance of the cable, greatly extending its service life. However, the modified fluorosilicon crosslinking agent-modified high-density polyethylene material may cause a decrease in the flexibility of the cable at low temperatures, and thus lead to poor temperature shock performance of the cable.

[0003] Chinese Patent with publication number CN118325216A discloses a low-temperature-resistant medium-voltage power cable and a preparation method thereof. Weigh the following raw materials in parts by weight: 40-50 parts of EVA resin, 120-150 parts of PE resin, 30-40 parts of reinforcing resin, 6-8 parts of calcium carbonate, 15-30 parts of modified filler, and 5-10 parts of dicumyl peroxide. The raw materials are melt-blended at a temperature of 140-150 °C to obtain a modified resin. The modified resin is coated on the surface of the conductor to form an insulating layer. A wrapping inner liner is provided outside the insulating layer. A filler is filled between the wrapping inner liner and the insulating layer. Finally, a modified resin is coated outside the wrapping inner liner to form a sheath, obtaining a power cable. The reinforcing resin has a silicone chain segment as the main chain, which can improve the low-temperature resistance of the modified resin. At the same time, it contains long-chain alkyl groups as side chains. The long-chain alkyl groups can increase the gap between each molecular chain and reduce the intermolecular force, thereby enhancing the toughness of the modified resin. However, both EVA resin and PE resin are vulnerable to ultraviolet light.

[0004] RF cables are indispensable components in radar and communication equipment, featuring high frequency, impedance matching, low loss, shielding effect, flexibility, and stable frequency response. They are widely used in wireless communication, television broadcasting, radar, aerospace, and other fields. Similar to ordinary cables, RF cables also require a protective layer to extend their service life. Additionally, some common problems may occur during the use of RF cables, which may affect signal transmission quality and system performance, such as signal attenuation, impedance mismatch, increased voltage standing wave ratio, external interference, mechanical damage, uneven frequency response, etc. Summary of the Invention

[0005] The objective of the present invention is to provide a cable doped with modified molybdenum disulfide nanosheets in a matrix resin and its preparation method, which solves the problems of impedance mismatch, large voltage standing wave ratio, poor shielding and anti-interference performance, and poor flexibility in existing RF cables. Moreover, the prepared cable has excellent temperature cycle resistance performance.

[0006] The first aspect of the present invention provides a preparation method for a cable doped with modified molybdenum disulfide nanosheets in a matrix resin, including the following steps: S1. Stranding multiple strands of wires to form an inner conductor; S2. Coating the inner conductor with a physically foamed dielectric layer; S3. Coating a shielding layer on the dielectric layer; S4. Coating a protective layer on the shielding layer; For the dielectric layer, by mass, the raw materials include: 90 - 100 parts of matrix resin, 5 - 15 parts of modified molybdenum disulfide nanosheets, and 0.5 - 1.5 parts of nucleating agent; The matrix resin includes perfluoroethylenepropylene resin, polytetrafluoroethylene resin, and low-density polyethylene resin; the mass ratio of perfluoroethylenepropylene resin, polytetrafluoroethylene resin, and low-density polyethylene resin is (4 - 6):(2 - 4):1; The preparation method of the modified molybdenum disulfide nanosheets includes the following steps: adding molybdenum disulfide nanosheets to an ethanol solution containing stearic acid, stirring evenly, reacting at 40 - 60 °C for 40 - 60 min, and evaporating ethanol to obtain.

[0007] Preferably, the mass ratio of the matrix resin, modified molybdenum disulfide nanosheets, and nucleating agent is (94 - 96):(8 - 12):(0.8 - 1.2).

[0008] Preferably, the melt index of the perfluoroethylenepropylene resin is 8.1 - 12 g / 10 min.

[0009] Preferably, the tensile strength of the polytetrafluoroethylene resin is 28 MPa, and the average particle size is 400 - 900 μm.

[0010] Preferably, the density of the low-density polyethylene resin is 918.5-921.5 g / cm 3 (at 23 °C), and the melt flow rate is 1.84-2.5 g / 10 min.

[0011] Preferably, the ratio of molybdenum disulfide, stearic acid, and ethanol is 1 g: (0.05-0.1) g: (25-30) mL.

[0012] Preferably, the thickness of the molybdenum disulfide nanosheets is 5-10 nm.

[0013] Preferably, the mass ratio of the matrix resin, modified molybdenum disulfide nanosheets, and nucleating agent is 95:10:1.

[0014] The present inventors unexpectedly found during the experiment that when introducing stearic acid-modified molybdenum disulfide nanosheets into the system and controlling the mass ratio of the matrix resin, modified molybdenum disulfide nanosheets, and nucleating agent to be (94-96):(8-12):(0.8-1.2), the obtained cable has excellent corrosion resistance and shielding performance. The present inventors speculate that it is because the matrix resin is inserted into the layered structure of the molybdenum disulfide nanosheets, reducing the possibility of medium intrusion, improving the corrosion resistance, and the formed composite material has more excellent shielding performance. At the same time, the stearic acid-modified molybdenum disulfide nanosheets and the nucleating agent act together to form a dense and uniform cell structure, further improving the corrosion resistance and shielding property of the dielectric layer.

[0015] Preferably, the nucleating agent is selected from at least one of nano silicon nitride, nano boron nitride, nano calcium carbonate, and nano calcium sulfate.

[0016] Preferably, the S2 is specifically: premixing the raw materials of the dielectric layer evenly, then adding them to an extruder for melting at 340-350 °C, introducing carbon dioxide gas into the molten raw materials of the dielectric layer in the extruder, mixing evenly at 340-350 °C, and then evenly extruding it around the inner conductor through the extrusion head, foaming, and cooling to obtain.

[0017] Preferably, the weight ratio of the total weight of the dielectric layer raw materials to the weight of carbon dioxide is 1∶(0.05-0.1).

[0018] Preferably, the raw materials of the shielding layer include: carbon nanotubes, polyvinylidene fluoride, and hollow mesoporous carbon spheres; the mass ratio of the carbon nanotubes, polyvinylidene fluoride, and hollow mesoporous carbon spheres is (0.6-1):(3-5):(0.3-0.5).

[0019] Preferably, the carbon nanotubes include single-walled carbon nanotubes, multi-walled carbon nanotubes, and whisker carbon nanotubes; the mass ratio of the single-walled carbon nanotubes, multi-walled carbon nanotubes, and whisker carbon nanotubes is 1:(4-6):(0.6-0.8).

[0020] Preferably, the diameter of the single-walled carbon nanotubes is 1-2 nm.

[0021] Preferably, the diameter of the multi-walled carbon nanotubes is 8-15 nm.

[0022] Preferably, the inner diameter of the whisker carbon nanotubes is 2-5 nm.

[0023] Preferably, the particle size of the hollow mesoporous carbon spheres is 200-300 nm and the pore diameter is 5 nm.

[0024] The present inventors found that introducing molybdenum disulfide nanosheets into the dielectric layer system and preparing the dielectric layer by using a physical foaming technique can, to a certain extent, improve the shielding performance of the dielectric layer, but the shielding performance is limited. It was unexpectedly found that when the carbon nanotubes include single-walled carbon nanotubes, multi-walled carbon nanotubes and whisker carbon nanotubes, and the diameter of the single-walled carbon nanotubes is controlled to be 1-2 nm, the diameter of the multi-walled carbon nanotubes is 8-15 nm, the inner diameter of the whisker carbon nanotubes is 2-5 nm, and hollow mesoporous carbon spheres with a particle size of 200-300 nm and a pore diameter of 5 nm are introduced, the prepared cable not only has excellent shielding performance, meets the requirements for the safe operation and service life of the cable, but also improves the aging stability of the cable. The present inventors speculate that it is because the shielding layer prepared under these conditions, due to the high specific surface area of the carbon nanotubes and the hollow mesoporous microspheres and the formed composite structure, helps to capture and neutralize harmful substances that may cause aging in the cable while enhancing the strength and durability of the shielding layer, thereby improving the aging stability of the cable.

[0025] Preferably, the raw materials of the protective layer include: methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, inorganic nanomaterials; the mass ratio of the methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nanomaterials is (10-20):(2-4):(5-10):(5-10).

[0026] Preferably, the inorganic nanomaterials include α-phase nano silicon nitride, spherical nano calcium carbonate and alumina nanosheets, and the mass ratio of the α-phase nano silicon nitride, spherical nano calcium carbonate and alumina nanosheets is (2-4):(5-7):1.

[0027] Preferably, the particle size of the α-phase nano silicon nitride is 400-600 nm.

[0028] Preferably, the particle size of the spherical nano calcium carbonate is 50-150 nm.

[0029] Preferably, the particle size of the alumina nanosheets is 2-4 nm.

[0030] In the present invention, inorganic nanomaterials are introduced into the protective layer. When the inorganic nanomaterials include α-phase nano silicon nitride, spherical nano calcium carbonate, and alumina nanosheets with a mass ratio of (2-4):(5-7):1, the obtained cable can have no dimensional change in appearance during the temperature shock process. The inventor of the present invention guesses that this is because under such conditions, the α-phase nano silicon nitride, spherical nano calcium carbonate, and alumina nanosheets interact with methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, and polyvinyl alcohol to form an interpenetrating structure, and the combination between the inorganic nanomaterials and the organic matter is tighter, so that it can resist the temperature shock.

[0031] Preferably, the S4 is specifically as follows: Step 1: Dissolve methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nanomaterials in water respectively; Step 2: Mix the aqueous solution of methyl vinyl phenyl silicone rubber, the aqueous solution of hyperbranched polyurethane, the aqueous solution of polyvinyl alcohol, and the aqueous solution of inorganic nanomaterials evenly to obtain a mixed solution. The mixed solution is assembled by the doctor blade method and then dried to obtain a single-layer composite film; Step 3: Compound the aqueous solution of methyl vinyl phenyl silicone rubber on the surface of the single-layer composite film, then compound a single-layer composite film, then compound the aqueous solution of polyvinyl alcohol on the single-layer composite film, then compound a single-layer composite film, then compound the aqueous solution of hyperbranched polyurethane on the single-layer composite film, and finally compound a single-layer composite film again; the thickness of the single-layer composite film is 20-30 μm; Step 4: After repeating Step 3 for 20-25 times, hot press molding is carried out to obtain a composite material. The composite material is coated on the outside of the shielding layer by an extrusion process to obtain the product.

[0032] In the shielding layer and the protective layer of the present invention, more inorganic substances are introduced. Although the shielding property and protective property of the cable can be improved, the flexibility of the cable is poor. The inventor of the present invention found that when the protective layer raw materials specific to the present invention are used and the protective layer is prepared by the specific process of the present invention, the flexibility of the cable can be significantly improved. The inventor of the present invention guesses that this is because the staggered laminated structure of the prepared composite material increases the fracture interface of the protective layer and improves the ability of the cable to withstand deformation.

[0033] Preferably, the ratio of the methyl vinyl phenyl silicone rubber to water is 0.3-0.5 g / mL, preferably 0.4 g / mL.

[0034] Preferably, the ratio of the hyperbranched polyurethane to water is 0.1-0.3 g / mL, preferably 0.2 g / mL.

[0035] Preferably, the ratio of the polyvinyl alcohol to water is 0.05-0.1 g / mL, preferably 0.08 g / mL.

[0036] Preferably, the ratio of the inorganic nanomaterial to water is 0.1 - 0.15 g / mL, preferably 0.12 g / mL.

[0037] Preferably, the wire is a silver-plated copper wire, and the inner conductor has a diameter of 0.2 - 0.4 mm ± 0.005 mm.

[0038] Preferably, S3 is obtained by extruding the shielding layer raw material through an extruder.

[0039] Preferably, the diameter of the dielectric layer is 0.6 - 0.8 mm ± 0.02 mm.

[0040] Preferably, the diameter of the shielding layer is 0.6 - 0.8 mm.

[0041] Preferably, the diameter of the protective layer is 0.5 - 0.7 mm.

[0042] In the second aspect of the present invention, there is provided a cable obtained by the preparation method of a cable doped with the above-mentioned modified molybdenum disulfide nanosheets in a matrix resin.

[0043] Beneficial effects

[0044] 1. The present invention introduces stearic acid-modified molybdenum disulfide nanosheets into the system, and controls the mass ratio of the matrix resin, modified molybdenum disulfide nanosheets, and nucleating agent to be (94 - 96):(8 - 12):(0.8 - 1.2), and the obtained cable has excellent corrosion resistance and shielding performance.

[0045] 2. When the carbon nanotubes in the present invention include single-walled carbon nanotubes, multi-walled carbon nanotubes, and whisker carbon nanotubes, and control the diameter of the single-walled carbon nanotubes to be 1 - 2 nm, the diameter of the multi-walled carbon nanotubes to be 8 - 15 nm, the inner diameter of the whisker carbon nanotubes to be 2 - 5 nm, and introduce hollow mesoporous carbon spheres with a particle size of 200 - 300 nm and a pore diameter of 5 nm, the prepared cable not only has excellent shielding performance, meets the requirements of cable safe operation and service life, but also improves the aging stability of the cable.

[0046] 3. By introducing inorganic nanomaterials into the protective layer in the present invention, when the inorganic nanomaterials include α-phase nano silicon nitride, spherical nano calcium carbonate, and alumina nanosheets with a mass ratio of (2 - 4):(5 - 7):1, the obtained cable can have no dimensional change in appearance during the temperature shock process.

[0047] 4. When using the specific protective layer raw material of the present invention and preparing the protective layer through the specific process of the present invention, the flexibility of the cable can be significantly improved. Brief description of the drawings

[0048] Figure 1Schematic diagram of the structure of the cable prepared in Example 1 of the present invention; In the figure, 1 - inner conductor, 2 - dielectric layer, 3 - shielding layer, 4 - protective layer. Detailed implementation manners

[0049] In order to better explain the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the examples in the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention. The experimental methods in the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified.

[0050] Example 1

[0051] Example 1 provides a preparation method of a cable doped with modified molybdenum disulfide nanosheets in a matrix resin as shown in Figure 1 the following steps: S1. Stranding multiple strands of wires to form an inner conductor 1; S2. Coating the inner conductor 1 with a physically foamed dielectric layer 2; S3. Coating a shielding layer 3 on the dielectric layer 2; S4. Coating a protective layer 4 on the shielding layer 3; For the dielectric layer 2, by mass, the raw materials include: 95 parts of matrix resin, 10 parts of modified molybdenum disulfide nanosheets, and 1 part of nucleating agent; The matrix resin includes perfluoroethylene propylene resin, polytetrafluoroethylene resin, and low-density polyethylene resin; the mass ratio of the perfluoroethylene propylene resin, polytetrafluoroethylene resin, and low-density polyethylene resin is 5:3:1; The preparation method of the modified molybdenum disulfide nanosheets includes the following steps: adding molybdenum disulfide nanosheets to an ethanol solution containing stearic acid, stirring evenly, reacting at 50 °C for 50 min, and evaporating ethanol to obtain; The melt index of the perfluoroethylene propylene resin is 8.1 - 12 g / 10 min, purchased from Guangzhou Songbai Chemical Co., Ltd., model: SW-4.

[0052] The tensile strength of the polytetrafluoroethylene resin is 28 MPa, and the average particle size is 650 ± 250 μm, purchased from Zhejiang Juhua Co., Ltd., model: JF-4D.

[0053] The density of the low-density polyethylene resin is 918.5 - 921.5 g / cm 3At (23 °C), the melt flow rate is 1.84 - 2.5 g / 10 min, purchased from Maoming Petrochemical, grade: 951 - 050.

[0054] The ratio of molybdenum disulfide, stearic acid, and ethanol is 1 g : 0.1 g : 30 mL.

[0055] The thickness of the molybdenum disulfide nanosheets is 5 - 10 nm, purchased from Hefei Kejing Materials Technology Co., Ltd.

[0056] The nucleating agent is nano boron nitride, purchased from Zhejiang Zhitaina Micro New Materials Co., Ltd., with an average particle size of 100 nm.

[0057] Specifically, S2 is obtained by: pre - mixing the raw materials of the dielectric layer 2 evenly, then adding them to an extruder for melting at 350 °C, introducing carbon dioxide gas into the melted raw materials of the dielectric layer 2 in the extruder, mixing evenly at 350 °C, and then uniformly extruding it around the inner conductor 1 through the extrusion head, foaming, and cooling.

[0058] The weight ratio of the total weight of the raw materials of the dielectric layer 2 to the weight of carbon dioxide is 1∶0.08.

[0059] For the shielding layer 3, the raw materials include: carbon nanotubes, polyvinylidene fluoride, and hollow mesoporous carbon spheres; the mass ratio of carbon nanotubes, polyvinylidene fluoride, and hollow mesoporous carbon spheres is 0.8 : 4 : 0.4.

[0060] The carbon nanotubes include single - wall carbon nanotubes, multi - wall carbon nanotubes, and whisker carbon nanotubes; the mass ratio of single - wall carbon nanotubes, multi - wall carbon nanotubes, and whisker carbon nanotubes is 1 : 5 : 0.7.

[0061] The diameter of the single - wall carbon nanotubes is 1 - 2 nm, the diameter of the multi - wall carbon nanotubes is 8 - 15 nm, the inner diameter of the whisker carbon nanotubes is 2 - 5 nm, the particle size of the hollow mesoporous carbon spheres is 200 - 300 nm, and the pore diameter is 5 nm. They are all purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., with the product numbers being 104699, 100246, 104271, and 104934 respectively.

[0062] The grade of the polyvinylidene fluoride is: Juhua PVDF DE 6 - 4 type resin.

[0063] For the protective layer 4, the raw materials include: methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nano - materials.

[0064] The inorganic nano - materials include α - phase nano - silicon nitride, spherical nano - calcium carbonate, and alumina nanosheets, and the mass ratio of α - phase nano - silicon nitride, spherical nano - calcium carbonate, and alumina nanosheets is 3 : 6 : 1.

[0065] The particle size of the α-phase nano silicon nitride is 500 nm, purchased from Bohuasi Nano-Technology (Ningbo) Co., Ltd., product number: Brofos-Si 3 N 4 -A500.

[0066] The particle size of the spherical nano calcium carbonate is 100 nm, purchased from Bohuasi Nano-Technology (Ningbo) Co., Ltd., product number: Brofos-CaCO 3 -100 The particle size of the aluminum oxide nanosheets is 3 nm, purchased from Bohuasi Nano-Technology (Ningbo) Co., Ltd., model: Brofos-Al 2 O 3 .

[0067] The mass ratio of the methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nano material is 15:3:7:8.

[0068] The specific S4 is as follows: Step 1: Dissolve the methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nano material in water respectively; Step 2: Mix the aqueous solutions of methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nano material evenly to obtain a mixed solution. The mixed solution is assembled by the doctor blade method and then dried to obtain a single-layer composite film; Step 3: Composite the aqueous solution of methyl vinyl phenyl silicone rubber on the surface of the single-layer composite film in sequence, then composite a single-layer composite film, then composite the aqueous solution of polyvinyl alcohol on the single-layer composite film, then composite a single-layer composite film, then composite the aqueous solution of hyperbranched polyurethane on the single-layer composite film, and finally composite a single-layer composite film again; the thickness of the single-layer composite film is 25 μm; Step 4: After repeating Step 3 20 times, hot press and mold to obtain a composite material. The composite material is coated on the outside of the shielding layer 3 through an extrusion process to obtain the product.

[0069] The ratio of the methyl vinyl phenyl silicone rubber to water is 4 g / mL.

[0070] The ratio of the hyperbranched polyurethane to water is 0.2 g / mL.

[0071] The ratio of the polyvinyl alcohol to water is 0.08 g / mL.

[0072] The ratio of the inorganic nano material to water is 0.12 g / mL.

[0073] The S3 is obtained by extruding and molding the raw materials of the shielding layer 3 through an extruder.

[0074] The wire is a silver-plated copper wire, and the inner conductor 1 has a diameter of 0.3 mm ± 0.005 mm.

[0075] The dielectric layer 2 has a diameter of 0.7 mm ± 0.02 mm.

[0076] The shielding layer 3 has a diameter of 0.7 mm.

[0077] The protective layer 4 has a diameter of 0.6 mm.

[0078] A cable obtained by the preparation method of a cable doped with the above-mentioned modified molybdenum disulfide nanosheets in a matrix resin.

[0079] Example 2

[0080] Example 2 provides a preparation method and a cable of a cable doped with modified molybdenum disulfide nanosheets in a matrix resin. The specific implementation manner is the same as that of Example 1, except that for the dielectric layer 2, by mass, the raw materials include: 94 parts of matrix resin, 8 parts of modified molybdenum disulfide nanosheets, and 0.8 part of nucleating agent.

[0081] Example 3

[0082] Example 3 provides a preparation method and a cable of a cable doped with modified molybdenum disulfide nanosheets in a matrix resin. The specific implementation manner is the same as that of Example 1, except that the mass ratio of the perfluoroethylene propylene resin, polytetrafluoroethylene resin, and low-density polyethylene resin is 6:2:1.

[0083] Comparative Example 1 Comparative Example 1 provides a preparation method and a cable of a cable doped with modified molybdenum disulfide nanosheets in a matrix resin. The specific implementation manner is the same as that of Example 1, except that for the dielectric layer 2, by mass, the raw materials include: 90 parts of matrix resin, 15 parts of modified molybdenum disulfide nanosheets, and 0.5 part of nucleating agent.

[0084] Comparative Example 2 Comparative Example 2 provides a preparation method and a cable of a cable doped with modified molybdenum disulfide nanosheets in a matrix resin. The specific implementation manner is the same as that of Example 1, except that the multi-walled carbon nanotubes have a diameter of 20 - 30 nm and are purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., with the product number 100246.

[0085] Comparative Example 3 Comparative Example 3 provides a preparation method and a cable of a cable doped with modified molybdenum disulfide nanosheets in a matrix resin. The specific implementation manner is the same as that of Example 1, except that the hollow mesoporous carbon spheres are replaced with carbon nanocages, which are purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., with the product number 104497.

[0086] Comparative Example 4 Comparative Example 4 provides a method for preparing a cable and a cable in which modified molybdenum disulfide nanosheets are doped into a matrix resin. The specific implementation is the same as that of Example 1, except that the alumina nanosheets are replaced with spherical nano-alumina with a particle size of 2 μm, purchased from Bohuasi Nano-Technology (Ningbo) Co., Ltd., product number: Brofos-Al 2 O 3 -Q02.

[0087] Comparative Example 5 Comparative Example 5 provides a method for preparing a cable and a cable in which modified molybdenum disulfide nanosheets are doped into a matrix resin. The specific implementation is the same as that of Example 1, except that the mass ratio of the α-phase nano-silicon nitride, quasi-spherical nano-calcium carbonate and alumina nanosheets is 1:3:1.

[0088] Comparative Example 6 Comparative Example 6 provides a method for preparing a cable and a cable in which modified molybdenum disulfide nanosheets are doped into a matrix resin. The specific implementation is the same as that of Example 1, except that S4 is: directly extruding and coating the raw materials of the protective layer 4 outside the shielding layer 3.

[0089] Performance test: The cables of Examples 1-3 and Comparative Examples 1-6 were tested as follows: 1. Voltage Standing Wave Ratio: After assembling the connectors on the cable, it was tested with a network analyzer. The scanning frequency points were 801 points. When the voltage standing wave ratio of the cable within the full frequency range ≤ 1.2, it was recorded as qualified.

[0090] 2. Impedance: The impedance of the cable was measured using an impedance analyzer. Within the range of 50 ± 2 Ω, it was recorded as qualified.

[0091] 3. Attenuation performance: After assembling the connectors on the cable, it was tested with a network analyzer. The scanning frequency points were 801 points. When simultaneously satisfying that at a frequency of 0.5 GHz, the attenuation constant ≤ 0.37 dB.m -1 , at a frequency of 1.0 GHz, the attenuation constant ≤ 0.53 dB.m -1 , at a frequency of 3.0 GHz, the attenuation constant ≤ 0.93 dB.m -1 , at a frequency of 6.0 GHz, the attenuation constant ≤ 1.33 dB.m -1 , at a frequency of 8.0 GHz, the attenuation constant ≤ 1.55 dB.m -1 , it was recorded as qualified.

[0092] 4. Aging stability: The cable was placed in an environment of 125 °C for 168 h, then placed at room temperature for 4 h after the test, and then checked whether there were any cracks or bubbles on the cable. Then, the connectors were assembled on the cable, and the network analyzer was used to test whether the voltage standing wave ratio of the cable changed. When there were no cracks or bubbles on the cable and the voltage standing wave ratio ≤ 1.2, it was recorded as qualified.

[0093] 5. Temperature shock: The cable is subjected to temperature treatment at -55°C to +165°C for 20 temperature cycles. Observe whether there is any dimensional change in the cable. Then assemble the connector to the cable and use a network analyzer to test whether there is any change in the voltage standing wave ratio of the cable. When there is no dimensional change in the cable and the voltage standing wave ratio ≤ 1.2, it is recorded as qualified.

[0094] 6. Shielding performance: The test frequency is 50 - 200 MHz.

[0095] 7. Salt spray test: Refer to the salt spray resistance test of IEC 60068-2-52: 5% salt solution, 35°C * 48 h. Observe whether there is any corrosion phenomenon on the cable. When there is no corrosion phenomenon on the cable, it is recorded as qualified.

[0096] 8. Tensile performance: Use a universal testing machine to test the tensile performance of the cable, and the test speed is 20 mm / min.

[0097] Test results: Table 1 Performance test results of Examples 1-3 and Comparative Examples 1-6

[0098] As can be seen from Table 1, in Comparative Example 1, due to changing the raw material ratio of the dielectric layer, the attenuation performance and salt spray performance of the obtained cable are unqualified, and the shielding performance decreases.

[0099] In Comparative Examples 2 and 3, due to changing the diameter of multi-walled carbon nanotubes and hollow mesoporous carbon spheres in the shielding layer, the aging stability of the obtained cable is unqualified, and the shielding performance decreases.

[0100] In Comparative Examples 4 and 5, due to changing the types and ratios of the raw materials of the protective layer, the temperature shock and salt spray test of the obtained cable are unqualified, and the tensile performance decreases.

[0101] In Comparative Example 6, due to the preparation process of the protective layer, the aging of the obtained cable is unqualified, and the tensile performance decreases.

[0102] The above are only specific embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent transformations made using the present invention, directly or indirectly applied in other related technical fields, are similarly included in the patent protection scope of the present invention.

Claims

1. A method for preparing a cable doped with modified molybdenum sulfide nanosheets and matrix resin, characterized in that: The following steps are involved: S1, twist multiple wires to form an inner conductor; S2, the inner conductor is covered with a physically foamed dielectric layer; S3, covering the dielectric layer with a shielding layer; S4. Cover the shielding layer with a protective layer; The dielectric layer comprises, by weight, 90-100 parts of base resin, 5-15 parts of modified molybdenum sulfide nanosheets, and 0.5-1.5 parts of nucleating agent; The matrix resin includes polyperfluoroethylene resin, polytetrafluoroethylene resin and low-density polyethylene resin; the mass ratio of the polyperfluoroethylene resin, polytetrafluoroethylene resin and low-density polyethylene resin is (4-6): (2-4): 1; The preparation method of the modified molybdenum sulfide nanosheet comprises the following steps: adding the molybdenum sulfide nanosheet into an ethanol solution containing stearic acid, stirring evenly, reacting at 40-60° C. for 40-60 minutes, and evaporating the ethanol to obtain the modified molybdenum sulfide nanosheet.

2. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 1, characterized in that: The mass ratio of the base resin, the modified molybdenum sulfide nanosheets and the nucleating agent is (94-96): (8-12): (0.8-1.2).

3. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 1, characterized in that: The shielding layer comprises raw materials including carbon nanotubes, polyvinylidene fluoride and hollow mesoporous carbon balls; the mass ratio of the carbon nanotubes, polyvinylidene fluoride and hollow mesoporous carbon balls is (0.6-1): (3-5): (0.3-0.5).

4. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 3, characterized in that: The carbon nanotubes include single-walled carbon nanotubes, multi-walled carbon nanotubes and whisker carbon nanotubes; the mass ratio of the single-walled carbon nanotubes, multi-walled carbon nanotubes and whisker carbon nanotubes is 1:(4-6):(0.6-0.8).

5. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 4, characterized in that: The diameter of the single-walled carbon nanotube is 1-2 nm; the diameter of the multi-walled carbon nanotube is 8-15 nm; and the inner diameter of the whisker carbon nanotube is 2-5 nm.

6. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 5, characterized in that: The particle size of the hollow mesoporous carbon sphere is 200-300 nm, and the pore size is 5 nm.

7. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 1, characterized in that: The protective layer comprises raw materials including: methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nanomaterials; the mass ratio of the methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol, and inorganic nanomaterials is (10-20): (2-4): (5-10): (5-10).

8. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 7, characterized in that: The inorganic nanomaterial comprises α-phase nano silicon nitride, spherical nano calcium carbonate and aluminum oxide nano sheets, and the mass ratio of the α-phase nano silicon nitride, spherical nano calcium carbonate and aluminum oxide nano sheets is (2-4): (5-7):

1.

9. The method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to claim 8, characterized in that: The S4 is specifically: Step 1: dissolving methyl vinyl phenyl silicone rubber, hyperbranched polyurethane, polyvinyl alcohol and inorganic nanomaterials in water respectively; Step 2: uniformly mixing a methyl vinyl phenyl silicone rubber aqueous solution, a hyperbranched polyurethane aqueous solution, a polyvinyl alcohol aqueous solution, and an inorganic nanomaterial aqueous solution to obtain a mixed solution, assembling the mixed solution by a doctor blade coating method, and then drying to obtain a single-layer composite film; Step 3: Compounding the methyl vinyl phenyl silicone rubber aqueous solution on the surface of the single-layer composite film, then compounding a single-layer composite film, then compounding the polyvinyl alcohol aqueous solution on the single-layer composite film, then compounding a single-layer composite film, then compounding the hyperbranched polyurethane aqueous solution on the single-layer composite film, and finally compounding another single-layer composite film; the thickness of the single-layer composite film is 20-30 μm; Step 4: Repeat step 3 20-25 times and then perform hot pressing to obtain a composite material, and then coat the composite material on the outside of the shielding layer through an extrusion process.

10. A cable obtained by the method for preparing a cable of modified molybdenum sulfide nanosheets doped with a matrix resin according to any one of claims 1 to 9.

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