Land middle-high voltage power cable

Abstract

The invention relates to the technical field of cables, and particularly discloses a land middle-high voltage power cable. The overland middle-high voltage power cable comprises an insulating cable core, a wrapping layer, an inner protective layer, a waterproof layer, a shielding layer, an anti-puncture layer, an armor layer, an outer protective layer and a filler, wherein the outer protective layer is formed by extruding a high-barrier polyethylene material; the high-barrier polyethylene material is mainly prepared from the following raw materials: high-density polyethylene, linear low-density polyethylene, polyamide 6, maleic anhydride grafted polyethylene, 3, 5, 5-trimethyl hexanoic acid tert-butyl peroxide, triallyl isocyanurate, organic modified montmorillonite, a lubricant, a composite anti-aging agent, a silane coupling agent and a flame retardant. The high-barrier polyethylene material has the characteristics of high tensile strength, good hydrophobicity, good barrier property and good moisture resistance, shows good comprehensive performance, improves the mechanical properties, water and moisture resistance, use stability and durability of middle and high voltage power cables, and prolongs the service life.

Description

Technical Field

[0001] The present application relates to the field of cable technology, and more specifically, to a medium- and high-voltage power cable for onshore use. Background Art

[0002] Medium and high voltage power cables are one of the important components of modern power grid construction. They are widely used in urban power transmission and distribution systems, industrial facilities and large infrastructure projects, and are often used on land or at sea. For medium and high voltage power cables for onshore use, they generally include multiple insulating cable cores, the outer circumference of the multiple insulating cable cores is provided with a sheath, and the outer circumference of the sheath is provided with an outer sheath, which can meet the needs of power transmission. However, when the medium and high voltage power cables are buried in the ground, they are in a humid environment and are easily corroded by moisture, resulting in performance degradation, and then causing electrical failures. Therefore, how to improve the moisture resistance of medium and high voltage power cables is particularly important. Summary of the invention

[0003] In order to reduce the water vapor permeability of medium and high voltage power cables and improve the moisture resistance of medium and high voltage power cables, the present application provides a medium and high voltage power cable for onshore use, which adopts the following technical solution: Medium and high voltage power cables for onshore use, the medium and high voltage power cables include a plurality of twisted insulating cable cores, the outer circumference of the plurality of insulating cable cores are sequentially provided with a wrapping layer, an inner protective layer, a water blocking layer, a shielding layer, an anti-puncture layer, an armor layer, and an outer protective layer from the inside to the outside, and a filler is provided between the plurality of insulating cable cores and the wrapping layer, and the outer protective layer is made of a high barrier polyethylene material through extrusion; the high barrier polyethylene material is mainly made of the following raw materials in parts by weight: 50-70 parts of high-density polyethylene, 20-30 parts of linear low-density polyethylene, and polyamide 6 10-20 parts, 8-12 parts of maleic anhydride grafted polyethylene, 2-4 parts of 3,5,5-trimethylhexanoic acid tert-butyl peroxide, 0.5-1.5 parts of triallyl isocyanurate, 4-6 parts of organic modified montmorillonite, 1-3 parts of lubricant, 1-3 parts of composite anti-aging agent, 2-4 parts of silane coupling agent and 20-40 parts of flame retardant; the organic modified montmorillonite is obtained by treating montmorillonite with diethylenetriaminopropyltrimethoxysilane, 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 3-prop-2-enoyloxypropane-1-sulfonate potassium.

[0004] The medium and high voltage power cable for onshore use of the present application is provided with a water-blocking layer, a shielding layer, an anti-puncture layer, and an armor layer on the outer peripheral surface of the inner sheath. The water-blocking layer plays a good role in waterproofing and moisture-proofing. The shielding layer can effectively isolate external interference and improve the ability to resist electromagnetic interference. The anti-puncture layer can reduce the puncture of sharp objects and reduce the short circuit. The armor layer can effectively improve the mechanical strength. And by utilizing the mutual cooperation between the inner sheath, the water-blocking layer, the shielding layer, the anti-puncture layer, the armor layer, and the outer sheath, the mechanical properties, waterproofing and moisture-proofing, anti-electromagnetic interference ability, and the stability and durability of the medium and high voltage power cables are improved, the service life is extended, and the market demand is met.

[0005] The outer protective layer of the present application is made of high barrier polyethylene material through extrusion processing. The raw materials of the high barrier polyethylene material are based on high density polyethylene, linear low density polyethylene and polyamide 6, and maleic anhydride grafted polyethylene is added to increase compatibility. Organic modified montmorillonite is also added, and diethylenetriaminopropyl trimethoxysilane, 1,1,1,3,3,3-hexafluoroisopropyl acrylate, and 3-prop-2-enoyloxypropane-1-sulfonic acid potassium are grafted on the surface of the organic montmorillonite to introduce active groups such as siloxy, ester, fluorine, and sulfonic acid groups. The active groups are used to significantly increase the compatibility, dispersibility, and interfacial bonding strength of the organic modified montmorillonite, improve the integrity and crosslinking density of the high barrier polyethylene material structure, enhance hydrophobicity, increase the water contact angle, fill the gaps in the structure, improve structural defects, block the water vapor penetration path, reduce the continued diffusion of water vapor, reduce the water vapor transmission rate, and improve barrier properties and moisture resistance. The tensile strength of the high barrier polyethylene material is greater than 40MPa, the water contact angle is greater than 155 degrees, and the water vapor transmission rate is less than 1g / (m 2 ·24h), it has the characteristics of high tensile strength, good hydrophobicity, good barrier property and good moisture resistance, showing good comprehensive performance.

[0006] Optionally, the organic modified montmorillonite is mainly prepared by the following method: S1, adding montmorillonite to water, adding diethylenetriaminopropyltrimethoxysilane, stirring for 1-3 hours, filtering, and obtaining grafted montmorillonite; S2. Add grafted montmorillonite to an organic solvent, add 1,1,1,3,3,3-hexafluoroisopropyl acrylate and potassium 3-prop-2-enoyloxypropane-1-sulfonate, stir for 18-22 hours, filter, wash, and dry to obtain organically modified montmorillonite.

[0007] Optionally, the weight ratio of montmorillonite, diethylenetriaminopropyltrimethoxysilane, 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 3-prop-2-enoyloxypropane-1-sulfonate potassium is 20:(2-4):(1-3):(1-3).

[0008] By adopting the above technical scheme, diethylenetriaminopropyltrimethoxysilane is first grafted on the surface of montmorillonite, and secondary amine groups and amino groups are introduced. Then, by utilizing the addition reaction of secondary amine groups, amino groups and carbon-carbon double bonds, 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 3-prop-2-enoyloxypropane-1-sulfonic acid potassium are grafted on the surface of montmorillonite, and active groups such as ester groups, fluorine groups and sulfonic acid groups are introduced to obtain organically modified montmorillonite. The preparation method of the present application grafts montmorillonite in steps, which facilitates the control of the grafting reaction, increases the grafting stability, and improves the grafting density, so that the surface of the organically modified montmorillonite has a better use effect, enhances the tensile strength, hydrophobicity and barrier properties of the high barrier polyethylene material, and improves the durability of medium and high voltage power cables.

[0009] Optionally, the weight ratio of the montmorillonite, water and organic solvent is 2:(7-13):(7-13).

[0010] By adopting the above technical solution, the weight ratio of montmorillonite, water and organic solvent is optimized, the amount of water and organic solvent added is controlled, and the grafted montmorillonite, 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 3-prop-2-enoyloxypropane-1-sulfonic acid potassium are fully contacted and reacted to ensure the stability of the preparation of organic modified montmorillonite. In multiple embodiments, the weight ratio of montmorillonite, water and organic solvent is 2:10:10, and the weight ratio can also be set to 2:7:7, 2:7:10, 2:7:13, 2:10:7, 2:10:13, 2:13:7, 2:13:10, 2:13:13 as needed, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0011] Optionally, the organic solvent is one or more of ethanol, ether, ethyl acetate, acetone, toluene, dimethylformamide, cyclohexanone, and 1,4-dioxane.

[0012] By adopting the above technical solution, the organic solvent is optimized, which facilitates the selection of the organic solvent.

[0013] Optionally, the organic solvents are ethanol, cyclohexanone and 1,4-dioxane, and the weight ratio of ethanol, cyclohexanone and 1,4-dioxane is (1-3):(1-3):(1-3). In multiple embodiments, the weight ratio of ethanol, cyclohexanone and 1,4-dioxane is 2:1:1, and the weight ratio can also be set to 1:1:1, 1:1:2, 1:1:3, 1:3:1, 1:3:2, 1:2:3, 1:3:1, 1:3:2, 1:3:3, 2:1:2, 2:1:3, 2:3:1, 2:3:2, 2:2:3, 2:3:1, 2:3:2, 2:3:3, 3:1:1, 3:1:2, 3:1:3, 3:3:1, 3:3:2, 3:2:3, 3:3:1, 3:3:2, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0014] Optionally, the average particle size of the montmorillonite is 1-50 μm. In multiple embodiments, the average particle size of the montmorillonite is 10 μm, and the average particle size can also be set to 1 μm, 5 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm as required, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Optionally, the lubricant is one or more of oleamide, erucamide, ethylene bisstearamide, stearamide, stearic acid, calcium stearate, and zinc stearate.

[0016] By adopting the above technical solution, the lubricant is optimized and the selection of lubricant is convenient. Moreover, the lubricant can improve the processability of high barrier polyethylene materials, reduce friction during processing, facilitate molding, enhance wear resistance, reduce surface defects such as dents, enhance the overall performance of high barrier polyethylene materials, and extend the stability and durability of medium and high voltage power cables.

[0017] Optionally, the lubricant is erucic acid amide and calcium stearate, and the weight ratio of erucic acid amide and calcium stearate is (1-3): (1-3). In multiple embodiments, the weight ratio of erucic acid amide and calcium stearate is 2:1, and the weight ratio can also be set to 1:1, 1:2, 1:3, 2:3, 3:1, 3:2 as needed, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Optionally, the composite anti-aging agent is an antioxidant and an ultraviolet absorber, and the weight ratio of the antioxidant to the ultraviolet absorber is (2-4):(1-3).

[0019] By adopting the above technical solution, the composite anti-aging agent is optimized, which is convenient for the selection of the composite anti-aging agent, and the antioxidant can inhibit the oxidation reaction at high temperature and improve the oxidation resistance, and the ultraviolet absorber can absorb ultraviolet energy, reduce damage, and improve the ultraviolet resistance. And by using the mutual cooperation between them, the environmental adaptability is increased and the service life is extended. In multiple embodiments, the weight ratio of the antioxidant and the ultraviolet absorber is 3:1, and the weight ratio can also be set to 2:1, 1:1, 2:3, 3:2, 4:1, 4:3 as needed, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] Optionally, the antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant 626, antioxidant 425, antioxidant 264, and antioxidant 168; The ultraviolet absorber is one or more of the ultraviolet absorber UV-P, ultraviolet absorber UV-O, ultraviolet absorber UV-1130, ultraviolet absorber UV-531, ultraviolet absorber UV-329 and ultraviolet absorber UV-327.

[0021] By adopting the above technical solution, antioxidants and ultraviolet absorbers are optimized, which facilitates the selection of antioxidants and ultraviolet absorbers.

[0022] Optionally, the antioxidants are two kinds of antioxidants, namely, antioxidant 1010 and antioxidant 168, and the weight ratio of antioxidant 1010 to antioxidant 168 is (1-3):(1-3). In multiple embodiments, the weight ratio of antioxidant 1010 to antioxidant 168 is 1:2, and the weight ratio can also be set to 1:1, 1:3, 2:1, 2:3, 3:1, 3:2 as needed, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] Optionally, the silane coupling agent is one or more of 3-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, vinyltrimethoxysilane, triacetoxyvinylsilane, and anilinemethyltrimethoxysilane.

[0024] By adopting the above technical solution, the silane coupling agent is optimized, which facilitates the selection of the silane coupling agent. Moreover, the silane coupling agent can improve the compatibility between raw materials, increase the interface bonding ability, improve the overall performance of high barrier polyethylene materials, and enhance the applicability of medium and high voltage power cables.

[0025] Optionally, the flame retardant is one or more of aluminum hydroxide, magnesium hydroxide, ammonium phosphate, diammonium phosphate, diamine hydrogen phosphate, and ammonium tripolyphosphate.

[0026] By adopting the above technical solution, the flame retardant is optimized, which facilitates the selection of the flame retardant. Moreover, the flame retardant decomposes and absorbs heat at high temperature, reduces the combustion temperature, and forms a protective layer to isolate oxygen, thereby effectively inhibiting the spread of flames.

[0027] Optionally, the flame retardant is aluminum hydroxide and magnesium hydroxide, and the weight ratio of aluminum hydroxide to magnesium hydroxide is (1-3): (1-3). In multiple embodiments, the weight ratio of aluminum hydroxide to magnesium hydroxide is 2:1, and the weight ratio can also be set to 1:1, 1:2, 1:3, 2:3, 3:1, 3:2 as needed, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] Optionally, the method for preparing the high barrier polyethylene material mainly comprises the following steps: High-density polyethylene, linear low-density polyethylene, polyamide 6, maleic anhydride grafted polyethylene, 3,5,5-trimethylhexanoic acid tert-butyl peroxide, triallyl isocyanurate, organic modified montmorillonite, lubricant, composite anti-aging agent, silane coupling agent and flame retardant are mixed, melt-extruded and granulated to obtain a high-barrier polyethylene material.

[0029] Optionally, in the method for preparing the high barrier polyethylene material, the temperature of the melt extrusion is 160-180° C. In multiple embodiments, the temperature of the melt extrusion is 170° C., and the temperature can also be set to 160° C., 165° C., 175° C., 180° C. as required, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Optionally, the wrapping layer is made of glass fiber tape through wrapping process.

[0031] Optionally, the inner protective layer is made of high barrier polyethylene material through extrusion processing.

[0032] Optionally, the water-blocking layer is made of a semi-conductive water-blocking tape through wrapping.

[0033] Optionally, the shielding layer is formed by wrapping an aluminum-plastic composite tape.

[0034] Optionally, the puncture-resistant layer is made of polyimide fibers through weaving.

[0035] Optionally, the armor layer is made of stainless steel wires through weaving.

[0036] In summary, this application has at least the following beneficial effects: 1. The medium and high voltage power cable for onshore use of the present application is provided with a water-blocking layer, a shielding layer, a puncture-resistant layer, an armor layer, and an outer protective layer on the outer peripheral surface of the inner protective layer, and the cooperation between them is utilized to improve the mechanical properties, waterproof and moisture-proof properties, anti-electromagnetic interference capability, and use stability and durability of the medium and high voltage power cable, extend the service life, and meet the market demand.

[0037] 2. The outer protective layer of the present application is made of high-barrier polyethylene material. In the high-barrier polyethylene material, high-density polyethylene, linear low-density polyethylene, and polyamide 6 are used as the matrix, and on this basis, organic modified montmorillonite is added. The surface of the organic modified montmorillonite contains active groups such as siloxy, ester, fluorine, and sulfonic acid groups, which not only increase the compatibility, dispersibility, and interface bonding between it and the matrix, improve the structural integrity and cross-linking density, but also enhance the hydrophobicity, improve structural defects, and block the water vapor penetration path, so that the tensile strength of the high-barrier polyethylene material is greater than 40MPa, the water contact angle is greater than 155 degrees, and the water vapor permeability is less than 1g / (m 2 ·24h), it has the characteristics of high tensile strength, good hydrophobicity, good barrier property and good moisture resistance, showing good comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic cross-sectional view of the medium and high voltage power cable of Example 1 of the present application.

[0039] Explanation of the accompanying drawings: 1. Insulated cable core; 11. Filler; 2. Wrapping layer; 3. Inner protective layer; 4. Water-blocking layer; 5. Shielding layer; 6. Anti-puncture layer; 7. Armor layer; 8. Outer protective layer. DETAILED DESCRIPTION

[0040] In order to make the present application easier to understand, the present application will be further described in detail below in conjunction with the examples, which are merely illustrative and are not intended to limit the scope of application of the present application. The raw materials or components used in the present application can be obtained through commercial routes or conventional methods unless otherwise specified.

[0041] Preparation Example Preparation Example I-1 An organic modified montmorillonite is mainly prepared by the following method: S1. Add 20 kg of montmorillonite to 100 kg of water at a stirring rate of 500 r / min and a temperature of 50°C, and stir for 5 minutes. Add 3 kg of diethylenetriaminopropyltrimethoxysilane, and stir for 2 hours. Then filter to obtain grafted montmorillonite.

[0042] The average particle size of montmorillonite is 10 μm, and the montmorillonite is selected from Hebei Hengyue Mineral Products Co., Ltd.

[0043] S2. Add the grafted montmorillonite obtained in step S1 to 100 kg of organic solvent at a stirring rate of 500 r / min and a temperature of 50°C, and stir for 5 minutes. Add 2 kg of 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 2 kg of 3-prop-2-enoyloxypropane-1-sulfonic acid potassium, and stir for 20 hours. Then filter, wash once with 30 kg of organic solvent, wash once with 30 kg of 50% ethanol aqueous solution, wash once with 30 kg of water, and dry to obtain organic modified montmorillonite.

[0044] Among them, the organic solvents are ethanol, cyclohexanone, and 1,4-dioxane, and the weight ratio of ethanol, cyclohexanone, and 1,4-dioxane is 2:1:1.

[0045] Preparation Example I-2 An organically modified montmorillonite, which differs from Preparation Example I-1 in that, in the preparation method of the organically modified montmorillonite, the added amounts of diethylenetriaminopropyltrimethoxysilane, 1,1,1,3,3,3-hexafluoroisopropyl acrylate, and 3-prop-2-enoyloxypropane-1-sulfonate potassium are different, and the added amount of diethylenetriaminopropyltrimethoxysilane is 2kg, the added amount of 1,1,1,3,3,3-hexafluoroisopropyl acrylate is 1kg, and the added amount of 3-prop-2-enoyloxypropane-1-sulfonate potassium is 3kg.

[0046] Preparation Example I-3 An organically modified montmorillonite, which differs from Preparation Example I-1 in that, in the preparation method of the organically modified montmorillonite, the added amounts of diethylenetriaminopropyltrimethoxysilane, 1,1,1,3,3,3-hexafluoroisopropyl acrylate, and 3-prop-2-enoyloxypropane-1-sulfonate potassium are different, and the added amount of diethylenetriaminopropyltrimethoxysilane is 4kg, the added amount of 1,1,1,3,3,3-hexafluoroisopropyl acrylate is 3kg, and the added amount of 3-prop-2-enoyloxypropane-1-sulfonate potassium is 1kg.

[0047] Table 1 Amount of each raw material used for high barrier polyethylene materials (unit: kg) Preparation Example II-1 A high barrier polyethylene material, the raw materials and raw material ratios of which are shown in Table 1.

[0048] Among them, the density of high-density polyethylene is 0.95g / cm 3 ; The density of linear low-density polyethylene is 0.92g / cm 3; Polyamide 6 is BASF polyamide 6 8253HS; maleic anhydride grafted polyethylene is maleic anhydride grafted polyethylene PE-g-MAH, and is selected from Guangdong Chuanheng New Materials Technology Co., Ltd.; organic modified montmorillonite is prepared by the method of Preparation Example I-1; the lubricant is erucamide and calcium stearate, and the weight ratio of erucamide and calcium stearate is 2:1; the composite antioxidant is an antioxidant and an ultraviolet absorber, and the weight ratio of the antioxidant and the ultraviolet absorber is 3:1, the antioxidant is antioxidant 1010 and antioxidant 168, and the weight ratio of antioxidant 1010 and antioxidant 168 is 1:2, and the ultraviolet absorber is ultraviolet absorber UV-531; the silane coupling agent is vinyl trimethoxy silane; the flame retardant is aluminum hydroxide and magnesium hydroxide, and the weight ratio of aluminum hydroxide and magnesium hydroxide is 2:1.

[0049] A method for preparing a high barrier polyethylene material mainly comprises the following steps: Linear low-density polyethylene, polyamide 6, maleic anhydride grafted polyethylene, 3,5,5-trimethylhexanoic acid tert-butyl peroxide, triallyl isocyanurate, organic modified montmorillonite, lubricant, composite anti-aging agent, silane coupling agent, flame retardant were added to high-density polyethylene and stirred for 5 minutes. Then, a twin-screw extruder was used to melt extrude and granulate at a temperature of 170°C and a screw speed of 500r / min to obtain a high-barrier polyethylene material.

[0050] Preparation Example II-2 A high barrier polyethylene material, which is different from Preparation Example II-1 in that the raw material ratio of the high barrier polyethylene material is different, and the raw material ratio of the high barrier polyethylene material is shown in Table 1.

[0051] Preparation Example II-3 A high barrier polyethylene material, which is different from Preparation Example II-1 in that the raw material ratio of the high barrier polyethylene material is different, and the raw material ratio of the high barrier polyethylene material is shown in Table 1.

[0052] Preparation Example II-4 A high barrier polyethylene material, which is different from Preparation Example II-1 in that the raw material ratio of the high barrier polyethylene material is different, and the raw material ratio of the high barrier polyethylene material is shown in Table 1.

[0053] Preparation Example II-5 A high barrier polyethylene material, which is different from Preparation Example II-1 in that the raw material ratio of the high barrier polyethylene material is different, and the raw material ratio of the high barrier polyethylene material is shown in Table 1.

[0054] Preparation Example II-6 A high barrier polyethylene material, which differs from Preparation Example II-1 in that the source of the organically modified montmorillonite in the raw materials of the high barrier polyethylene material is different, and the organically modified montmorillonite is prepared by the method of Preparation Example I-2.

[0055] Preparation Example II-7 A high barrier polyethylene material, which differs from Preparation Example II-1 in that the source of the organically modified montmorillonite in the raw materials of the high barrier polyethylene material is different, and the organically modified montmorillonite is prepared by the method of Preparation Example I-3. Example

[0056] Example 1 A medium and high voltage power cable for onshore use, referring to Figure 1 The cross section of the medium and high voltage power cable is circular, and the medium and high voltage power cable includes three twisted insulating cable cores 1. The outer peripheral surface of the three insulating cable cores 1 is provided with a wrapping layer 2, which is made of glass fiber tape by double wrapping, and the overlap rate of each layer of glass fiber tape is 40%. A filler 11 is provided between the wrapping layer 2 and the insulating cable core 1, and the filler 11 is a glass fiber rope, and the filler 11 is used to make the wrapping layer 2 and the insulating cable core 1 in close contact, reduce the relative displacement, and improve the stability of use.

[0057] Reference Figure 1 The outer peripheral surface of the wrapping layer 2 is provided with an inner protective layer 3, a water-blocking layer 4, a shielding layer 5, an anti-puncture layer 6, an armor layer 7, and an outer protective layer 8 in sequence from the inside to the outside. The inner protective layer 3 is made of high-barrier polyethylene material through extrusion. The water-blocking layer 4 is made of a double-layer wrapping of a semi-conductive water-resistant tape, and the overlap rate of each layer of the semi-conductive water-resistant tape is 40%. The shielding layer 5 is made of a single-layer wrapping of an aluminum-plastic composite tape, which is composed of a plastic film and an aluminum foil. When the aluminum-plastic composite tape is wrapped, the plastic film faces inward and the aluminum foil faces outward, and the overlap rate of the aluminum-plastic composite tape is 50%. The anti-puncture layer 6 is made of polyimide fiber through double-layer weaving, and the weaving density of each layer of polyimide fiber is 80%. The armor layer 7 is made of stainless steel wire through single-layer weaving, and the weaving density of the stainless steel wire is 60%. The outer protective layer 8 is made of high-barrier polyethylene material through extrusion.

[0058] Among them, the high barrier polyethylene material is prepared by the method of Preparation Example II-1.

[0059] Example 2 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that the source of the high-barrier polyethylene material is different, and the high-barrier polyethylene material is prepared by the method of Preparation Example II-2.

[0060] Example 3 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that the source of the high-barrier polyethylene material is different, and the high-barrier polyethylene material is prepared by the method of Preparation Example II-3.

[0061] Example 4 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that the source of the high-barrier polyethylene material is different, and the high-barrier polyethylene material is prepared by the method of Preparation Example II-4.

[0062] Example 5 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that the source of the high-barrier polyethylene material is different, and the high-barrier polyethylene material is prepared by the method of Preparation Example II-5.

[0063] Example 6 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that the source of the high-barrier polyethylene material is different, and the high-barrier polyethylene material is prepared by the method of Preparation Example II-6.

[0064] Example 7 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that the source of the high-barrier polyethylene material is different, and the high-barrier polyethylene material is prepared by the method of Preparation Example II-7.

[0065] Comparative Example Comparative Example 1 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that an equal amount of high-density polyethylene is used to replace organically modified montmorillonite in the raw material of the high-barrier polyethylene material.

[0066] Comparative Example 2 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that an equal amount of montmorillonite is used to replace the organic modified montmorillonite in the raw material of the high barrier polyethylene material.

[0067] Comparative Example 3 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that, in the raw materials of the high-barrier polyethylene material, in the preparation method of the organically modified montmorillonite, diethylenetriaminopropyltrimethoxysilane is used to replace 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 3-prop-2-enoyloxypropane-1-sulfonate potassium in equal amounts.

[0068] Comparative Example 4 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that, in the raw material of the high-barrier polyethylene material, in the preparation method of the organically modified montmorillonite, 1,1,1,3,3,3-hexafluoroisopropyl acrylate is used to replace 3-prop-2-enoyloxypropane-1-sulfonate potassium in an equal amount.

[0069] Comparative Example 5 A medium- and high-voltage power cable for onshore use, which differs from Example 1 in that, in the raw material of the high-barrier polyethylene material, in the preparation method of the organically modified montmorillonite, 1,1,1,3,3,3-hexafluoroisopropyl acrylate is replaced by potassium 3-prop-2-enoyloxypropane-1-sulfonate in an equal amount.

[0070] Performance Testing (1) The high barrier polyethylene materials in Examples 1-7 and Comparative Examples 1-5 were respectively taken, and the tensile strength of the high barrier polyethylene materials was tested according to GB / T1040.1-2008. At the same time, the water contact angle of the high barrier polyethylene materials was tested using a contact angle tester. The higher the water contact angle, the better the hydrophobicity of the high barrier polyethylene material. The test results are shown in Table 2.

[0071] (2) The high barrier polyethylene materials in Examples 1-7 and Comparative Examples 1-5 were respectively taken, and the high barrier polyethylene materials were processed into high barrier polyethylene films with a thickness of 0.05 mm. Then, the water vapor permeability of the high barrier polyethylene films was tested according to GB / T1037-2011. The smaller the water vapor permeability, the better the barrier property of the high barrier polyethylene material. The test results are shown in Table 2.

[0072] (3) The medium and high voltage power cables in Examples 1-5 and Comparative Examples 1-4 were respectively taken, and the vertical flame retardancy level of the medium and high voltage power cables was tested according to GB / T2408-2008. The test results are shown in Table 2.

[0073] Table 2 Test results As can be seen from Table 2, the high barrier polyethylene material of the present application has a higher tensile strength of 40.54-42.66 MPa, showing the characteristics of high tensile strength. It also has a higher water contact angle and a lower water vapor permeability, with a water contact angle of 157-159 degrees and a water vapor permeability of 0.68-0.96 g / (m 2 ·24h), showing the characteristics of high hydrophobicity, good barrier property and good moisture resistance, meeting market demand.

[0074] Comparative Examples 1-3 are compared, and Comparative Example 1 is used as a basis. Compared with Comparative Example 1, Comparative Example 2 adds montmorillonite to the raw material of the high barrier polyethylene material; Comparative Example 3 adds organic modified montmorillonite to the raw material of the high barrier polyethylene material compared with Comparative Example 1. It can be seen that adding montmorillonite to the raw material can improve the tensile strength, water resistance and barrier properties. Furthermore, the montmorillonite is grafted with organic matter to further improve the tensile strength and water contact angle, and further reduce the water vapor permeability, so that the high barrier polyethylene material exhibits better comprehensive performance.

[0075] Comparative Examples 3-5 and Example 1 are compared, and Comparative Example 3 is used as the basis. Compared with Comparative Example 3, in the preparation method of organic modified montmorillonite, 1,1,1,3,3,3-hexafluoroisopropyl acrylate is used to treat the grafted montmorillonite in Comparative Example 4; Compared with Comparative Example 3, in the preparation method of organic modified montmorillonite, 3-prop-2-enoyloxypropane-1-potassium sulfonate is used to treat the grafted montmorillonite in Comparative Example 5; Compared with Comparative Example 3, in the preparation method of organic modified montmorillonite, 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 3-prop-2-enoyloxypropane-1-potassium sulfonate are used to treat the grafted montmorillonite in Example 1. It can be seen from this that on the basis of grafting diethylenetriaminopropyltrimethoxysilane on the surface of montmorillonite, 1,1,1,3,3,3-hexafluoroisopropyl acrylate and potassium 3-prop-2-enoyloxypropane-1-sulfonate are further grafted simultaneously, and active groups such as ester group, fluorine group and sulfonic acid group are introduced. The active groups are utilized to improve not only the dispersibility and compatibility of the organic modified montmorillonite, but also the bonding strength between the organic montmorillonite and the raw materials and the tensile strength, but also the hydrophobicity is improved, the voids are reduced, the water vapor penetration path is blocked, the water contact angle is increased, and the water vapor permeation rate is reduced.

[0076] It should be noted that the embodiments described above are only used to explain the present application and do not constitute any limitation to the present application. The present application is described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present application may be modified as specified within the scope of the claims of the present application, and the present invention may be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein. On the contrary, the present application can be extended to all other methods and applications with the same functions.

Claims

1. Medium and high voltage power cable for onshore use, characterized by: The medium- and high-voltage power cable comprises a plurality of twisted insulating cable cores (1); the outer circumference of the plurality of insulating cable cores (1) is provided with a wrapping layer (2), an inner protective layer (3), a water-blocking layer (4), a shielding layer (5), an anti-puncture layer (6), an armor layer (7), and an outer protective layer (8) in sequence from the inside to the outside; a filler (11) is provided between the plurality of insulating cable cores (1) and the wrapping layer (2); and the outer protective layer (8) is made of a high-barrier polyethylene material through extrusion processing; The high barrier polyethylene material is mainly made of the following raw materials in parts by weight: 50-70 parts of high-density polyethylene, 20-30 parts of linear low-density polyethylene, 10-20 parts of polyamide 6, 8-12 parts of maleic anhydride grafted polyethylene, 2-4 parts of 3,5,5-trimethylhexanoic acid tert-butyl peroxide, 0.5-1.5 parts of triallyl isocyanurate, 4-6 parts of organic modified montmorillonite, 1-3 parts of lubricant, 1-3 parts of composite anti-aging agent, 2-4 parts of silane coupling agent, and 20-40 parts of flame retardant; the organic modified montmorillonite is obtained by treating montmorillonite with diethylenetriaminopropyltrimethoxysilane, 1,1,1,3,3,3-hexafluoroisopropyl acrylate, and 3-prop-2-enoyloxypropane-1-sulfonic acid potassium.

2. The medium and high voltage power cable for onshore use according to claim 1, characterized in that: The organic modified montmorillonite is mainly prepared by the following method: S1, adding montmorillonite to water, adding diethylenetriaminopropyltrimethoxysilane, stirring for 1-3 hours, filtering, and obtaining grafted montmorillonite; S2. Add grafted montmorillonite to an organic solvent, add 1,1,1,3,3,3-hexafluoroisopropyl acrylate and potassium 3-prop-2-enoyloxypropane-1-sulfonate, stir for 18-22 hours, filter, wash, and dry to obtain organically modified montmorillonite.

3. The medium and high voltage power cable for onshore use according to claim 2, characterized in that: The weight ratio of the montmorillonite, diethylenetriaminopropyltrimethoxysilane, 1,1,1,3,3,3-hexafluoroisopropyl acrylate and 3-prop-2-enoyloxypropane-1-sulfonate potassium is 20:(2-4):(1-3):(1-3).

4. The medium and high voltage power cable for onshore use according to claim 2, characterized in that: The weight ratio of the montmorillonite, water and organic solvent is 2:(7-13):(7-13).

5. The medium and high voltage power cable for onshore use according to claim 2, characterized in that: The organic solvent is one or more of ethanol, ether, ethyl acetate, acetone, toluene, dimethylformamide, cyclohexanone and 1,4-dioxane.

6. The medium and high voltage power cable for onshore use according to claim 2, characterized in that: The lubricant is one or more of oleamide, erucamide, ethylene bis stearic acid amide, stearamide, stearic acid, calcium stearate, and zinc stearate.

7. The medium and high voltage power cable for onshore use according to claim 1, characterized in that: The composite anti-aging agent comprises two types: an antioxidant and an ultraviolet absorber, and the weight ratio of the antioxidant to the ultraviolet absorber is (2-4):(1-3).

8. The medium and high voltage power cable for onshore use according to claim 7, characterized in that: The antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant 626, antioxidant 425, antioxidant 264, and antioxidant 168; The ultraviolet absorber is one or more of the ultraviolet absorber UV-P, ultraviolet absorber UV-O, ultraviolet absorber UV-1130, ultraviolet absorber UV-531, ultraviolet absorber UV-329 and ultraviolet absorber UV-327.

9. The medium and high voltage power cable for onshore use according to claim 1, characterized in that: The silane coupling agent is one or more of 3-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, vinyltrimethoxysilane, triacetoxyvinylsilane, and anilinemethyltrimethoxysilane.

10. The medium and high voltage power cable for onshore use according to claim 1, characterized in that: The flame retardant is one or more of aluminum hydroxide, magnesium hydroxide, ammonium phosphate, ammonium dihydrogen phosphate, diamine hydrogen phosphate, and ammonium tripolyphosphate.

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