Cable semiconductive shielding material as well as preparation method and application thereof

Abstract

The invention provides a cable semi-conductive shielding material and a preparation method and application thereof. The cable semi-conductive shielding material comprises the following components in percentage by mass: 60-70% of matrix resin; 25-35% of a black phosphorus quantum dot / reduced graphite oxyalkylene composite material; 1-2% of a lubricant; 0.3%-1.0% of an antioxidant; 0.5-2% of a cross-linking agent; the shielding material disclosed by the invention has relatively excellent electrical performance and mechanical performance, so that the problem that in the existing preparation method, conductive carbon black is easy to agglomerate in an extrusion process of a semi-conductive shielding material, so that the degree of finish of an extruded surface is difficult to meet a super-smooth requirement is solved; the problems of rough surface, poor surface smoothness and the like of the shielding material caused by friction between matrix resin and equipment are solved; in addition, a compact carbon layer generated on the surface of the black phosphorus combustion polymer can play roles in isolating oxygen and slowing down combustion, so that the composite material also has certain self-flame-retardant property.

Description

Technical Field

[0001] The present invention belongs to the field of cable materials, and particularly relates to a semi-conductive shielding material for cables, a preparation method thereof, and an application thereof. Background Art

[0002] In the core structure of high-voltage cables, the semi-conductive shielding layer is a crucial layer of high-voltage power cable structure due to its special shielding effect. The semi-conductive shielding layer can eliminate the interfacial air gap between the conductor core and the insulating layer, equalize the internal electric field distribution of the insulating layer, reduce or even prevent partial discharge, effectively relieve the heating of the cable, reduce power loss, and ultimately improve the operating stability of the cable and further extend its service life.

[0003] At the current technical level, high-voltage semi-conductive shielding materials are usually obtained by melt extrusion of a matrix resin, conductive carbon black, and functional processing aids such as lubricants and cross-linking agents. Therefore, there is a common problem that protrusions will appear on the surface of the high-voltage cable shielding layer. The existence of these protrusions will lead to a reduction in mechanical stability and electrical performance defects during the power transmission process of high-voltage cables. The main reason is that a large number of conductive carbon black particles added in the shielding material components are prone to agglomeration in the matrix resin, forming large-sized microparticles, which will greatly affect the surface smoothness of the shielding material during the cable extrusion process and is not conducive to the construction of the conductive network. Therefore, the modification and optimization or alternative solutions of conductive carbon black are the key issues to be solved in the field of preparation of ultra-smooth high-voltage shielding materials. Currently, the existing ideas for improving conductive carbon black include methods such as increasing the graphitization degree, purity, and conductivity of carbon black, but the corresponding technical difficulties and high raw material costs limit their development.

[0004] On the other hand, in the field of nanotechnology, remarkable progress has been made in the preparation and composite application technology of black phosphorus quantum dots in recent years. As a crystal with a black metallic luster, its structure is similar to the layered structure of graphene, and the layers are combined by van der Waals forces, having advantages such as high carrier mobility, anisotropy, and adjustable bandgap width. There are few reports on its application in high-voltage semi-conductive shielding materials.

[0005] In addition, the flame retardant performance of the shielding material is also a key indicator in the field of high-voltage power transmission. The flame retardant performance of the shielding material can be improved by adding additive flame retardants or reactive flame retardants, but the addition of flame retardants will also cause problems such as precipitation and protrusions, which is also a major problem in the development and application of high-voltage cable materials. Summary of the Invention

[0006] Aiming at the problems existing in the application and technical field of existing shielding materials, the present invention provides a semi-conductive shielding material for cables and a preparation method thereof. The preparation method of the present invention uses black phosphorus quantum dots modified reduced graphene oxide to replace conductive carbon black in the preparation of shielding materials, and improves the problems of easy surface protrusion, unstable extrusion, insufficient conductivity, large impurity content, poor dispersibility, etc. of conventional carbon black shielding materials through the black phosphorus / graphene composite material. The composite material prepared by the present invention not only has the advantages of self-lubrication and good conductive dispersibility, but also has certain flame retardant properties.

[0007] The present invention also provides the application of the semi-conductive shielding material for cables in the field of shielding materials for high, medium and low voltage wires and cables.

[0008] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0009] A semi-conductive shielding material for cables, comprising the following components in mass fractions:

[0010] Matrix resin 60 - 70%;

[0011] Black phosphorus quantum dot / reduced graphene oxide composite material 25 - 35%;

[0012] Lubricant 1 - 2%;

[0013] Antioxidant 0.3 - 1.0%;

[0014] Cross-linking agent 0.5 - 2%;

[0015] Based on the total mass of the above components being 100%.

[0016] Preferably, the matrix resin is an ethylene-acrylate compound; preferably ethylene-ethyl acrylate or ethylene-butyl acrylate.

[0017] The lubricant is a stearate compound or a polyethylene wax; preferably zinc stearate or a polyethylene wax with a molecular weight lower than 2000.

[0018] The antioxidant is one or a compound of two or more of a phosphite antioxidant or a hindered phenol antioxidant;

[0019] The cross-linking agent is an organic peroxide free radical cross-linking agent, preferably one or two of diisopropylbenzene peroxide and 2,5-dimethyl-2,5-di(tert-butylperoxy)ethane.

[0020] Preferably, the preparation method of the black phosphorus quantum dot / reduced graphene oxide composite material is:

[0021] S2: Grind black phosphorus and dissolve it in a first solvent, perform a hydrothermal reaction and then centrifuge to obtain black phosphorus quantum dot liquid separation B;

[0022] S3: Add graphene oxide A into a second solvent for mixing and dispersion, then add black phosphorus quantum dot liquid B and stir for dispersion to obtain a mixed stock solution C;

[0023] S4: Transfer the mixed stock solution C obtained in step (3) into a reaction kettle for hydrothermal reaction, then wash and dry to obtain the black phosphorus quantum dot modified reduced graphene oxide composite material.

[0024] In the present invention, the graphene oxide can be prepared by the following method: S1: Treat graphene with acidic potassium permanganate, and obtain graphene oxide A through separation and washing;

[0025] In the present invention, the treatment step of graphene in S1 is an intercalation oxidation reaction with an acidic potassium permanganate solution; add graphene into a mixed solution containing an acid and potassium permanganate for oxidation. Preferably, the acid is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid.

[0026] The mass ratio of graphene, potassium permanganate, and the acid is 0.1 - 2:0.5 - 1:50 - 150, preferably 0.5 - 1:0.6 - 0.8:80 - 100;

[0027] In the present invention, in S1, the mixed solution of graphene, the acid, and potassium permanganate is dispersed and dissolved under ultrasonic conditions.

[0028] In the present invention, the power of the ultrasonic dispersion is 100 - 400W, preferably 200 - 250W, and the ultrasonic time is 10 - 60min, preferably 20 - 30min;

[0029] In the present invention, in S1, graphene is separated by centrifugation, the centrifugation speed is 5000 - 9000rpm, the time is 10 - 30min, preferably 6000 - 7000rpm, and the time is 15 - 20min.

[0030] In the present invention, in S2, the black phosphorus solution is ultrasonically pulverized at -5 to 10°C.

[0031] In the present invention, the ultrasonic pulverization power of black phosphorus in S2 is 100 - 600W, preferably 200 - 300W, and the ultrasonic time is 10 - 60min, preferably 20 - 30min;

[0032] In the present invention, the hydrothermal reaction conditions in S2 are 120 - 180°C, the time is 2 - 8h, preferably 140 - 160°C, and the time is 4 - 6h.

[0033] In the present invention, the first solvent includes N-methylpyrrolidone, ethylene glycol monobutyl ether, ethylene glycol diethyl ether, dimethylformamide, dimethyl sulfoxide, etc., and preferably N-methylpyrrolidone.

[0034] In the present invention, the concentration of black phosphorus in the first solvent is 0.001 mg / mL - 10 mg / mL.

[0035] In the present invention, the centrifugation speed of S2 is 5000 - 8000 r / min.

[0036] In the present invention, in S3, graphene oxide A is dispersed by ultrasonic treatment. The ultrasonic treatment power is 100 - 400 W, preferably 200 - 300 W, and the ultrasonic treatment time is 10 - 60 min, preferably 20 - 30 min.

[0037] In the present invention, the second solvent includes N-methylpyrrolidone, ethylene glycol monobutyl ether, ethylene glycol diethyl ether, dimethylformamide, dimethyl sulfoxide, etc., and N-methylpyrrolidone is preferred.

[0038] In the present invention, the concentration of graphene oxide A in the second solvent is 0.1 mg / mL - 1 mg / mL.

[0039] In the present invention, in S3, the mass ratio of graphene oxide A to black phosphorus in black phosphorus quantum dot liquid separation B is 1:5 - 50, preferably 1:5 - 15.

[0040] In the present invention, the hydrothermal reaction temperature of S4 is 120 - 180 °C, and the reaction time is 2 - 8 h. Preferably, the temperature is 140 - 160 °C and the reaction is carried out for 4 - 6 h.

[0041] In the present invention, in step S4, the reaction product can be washed with deionized water and anhydrous ethanol respectively.

[0042] Another object of the present invention is to provide a method for preparing a semiconductive shielding material for high-voltage cables: mixing black phosphorus quantum dot / reduced graphene oxide composite powder, matrix resin, lubricant, and antioxidant uniformly, followed by extrusion granulation, and then adding a crosslinking agent by a post-absorption method. The product can be used for cable extrusion of high-voltage cable materials.

[0043] In the present invention, the mixing is carried out using a high-speed mixer. The rotation speed of the high-speed mixer is 100 - 200 rpm, and the stirring time is 5 - 30 min, preferably 150 - 200 rpm.

[0044] In the present invention, the extrusion granulation temperature is 150 - 210 °C, and the main machine rotation speed is 50 - 150 rpm. Preferably, the granulation temperature is 170 - 200 °C and the rotation speed is 75 - 120 rpm.

[0045] In the present invention, after adding the crosslinking agent, the mixture is mixed for 5 - 20 min while shaking continuously. The post-absorption temperature is 60 - 80 °C, and the absorption time is 1 - 4 h. Preferably, the mixture is mixed for 10 - 20 min, the post-absorption temperature is 65 - 75 °C, and the absorption is carried out for 1 - 2 h.

[0046] Another object of the present invention is to provide the application of the semiconductive shielding material for high-voltage cables in the field of semiconductive shielding materials for high, medium and low voltage wires and cables.

[0047] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0048] (1) First, black phosphorus quantum dots modified reduced graphene oxide are used to replace conductive carbon black in the preparation of shielding materials. Based on the surfactant-like effect of hydroxyl and carboxyl groups on the surface and edges of reduced graphene oxide in polar matrix resins, the energy barrier between interfaces can be reduced, and the mechanical properties of the shielding materials can be improved. Moreover, due to the large surface active area of reduced graphene oxide, semiconductive black phosphorus quantum dots can be effectively dispersed and attached to its surface, effectively alleviating the agglomeration problem; this reduced graphene oxide composite material is conducive to the construction of a long-range conductive network, greatly improving the electrical conductivity, mechanical properties and surface smoothness of high-voltage cable shielding materials, and having broad application prospects in the field of ultra-smooth high-voltage shielding cable materials.

[0049] (2) The composite material prepared by the present invention not only has the advantages of self-lubrication and good conductive dispersion, but also has certain flame retardant properties because a dense carbon layer is formed on the surface of the polymer during the combustion of black phosphorus, which can isolate oxygen and slow down combustion. Specific Embodiments

[0050] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0051] The source information of the main raw materials used in the embodiments of the present invention is as follows. Unless otherwise specified, other raw materials are all commercially available:

[0052] Black phosphorus: 99.995%, Shanghai Aladdin Biochemical Technology Co., Ltd. B433863-1EA;

[0053] N-methylpyrrolidone: AR, Shanghai Aladdin Biochemical Technology Co., Ltd. M100588;

[0054] Graphene, high purity grade, >98%, Shanghai Aladdin Biochemical Technology Co., Ltd. G302114

[0055] Sulfuric acid, 98%, Shanghai Aladdin S399850;

[0056] Potassium permanganate, ≥99.0%, Shanghai Aladdin P399460.

[0057] Ethylene-ethyl acrylate, Arkema France 4700.

[0058] Black phosphorus powder, Shanghai Aladdin B196539.

[0059] Example 1

[0060] To prepare a semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots and reduced graphene oxide, the steps are as follows:

[0061] (1) Take 5 g of graphene and add it to 250 ml of sulfuric acid solution containing 4 g of potassium permanganate (mass ratio 1:0.8:90). Ultrasonic at 200 W for 20 min, then wash with HCl and deionized water until neutral; centrifuge at 6000 rpm for 15 min. Vacuum dry to obtain reduced graphene oxide A.

[0062] (2) Grind 5 g of black phosphorus and dissolve it in 200 mL of N-methylpyrrolidone. Ultrasonic crush at 300 W for 30 min in an ice bath at 0-5 °C, carry out hydrothermal reaction at 150 °C for 4 h under N2 atmosphere, and then centrifuge at 6000 r for 10 min to obtain the supernatant to get the black phosphorus quantum dot dispersion B.

[0063] (3) Ultrasonically disperse 1 g of reduced graphene oxide A into 1000 mL of N-methylpyrrolidone, add solution B under stirring, and continue ultrasonic dispersion at 200 W

[0064] for 30 min to obtain the mixed stock solution C.

[0065] (4) Transfer the raw material liquid in step (3) into a reaction kettle, after hydrothermal treatment at 150 °C for 4 h, wash with deionized water and absolute ethanol respectively, and then vacuum dry at 60 °C to obtain the composite nanomaterial of black phosphorus quantum dots modified reduced graphene oxide.

[0066] (5) Blend 70% of ethylene-ethyl acrylate, 26.5% of black phosphorus quantum dot / reduced graphene oxide composite material, 0.5% of zinc stearate + 0.5% of polyethylene wax, 0.8% of antioxidant 1010 + 0.2% of antioxidant 168 by mass ratio, carry out extrusion granulation, then add 1.5% of dicumyl peroxide, shake well for 10 min, and absorb at 65 °C for 2 h to obtain the semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots.

[0067] Example 2

[0068] Referring to Example 1, a semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots and reduced graphene oxide was prepared. The difference lies in that the addition amount of black phosphorus in step (2) is 10 g, and in step (5), the black phosphorus quantum dot / reduced graphene oxide composite powder, matrix resin and additives are blended according to the mass ratio of ethylene-ethyl acrylate 66.5%, black phosphorus quantum dot / reduced graphene oxide composite 30%, zinc stearate 0.5% + polyethylene wax 0.5%, antioxidant 1010 0.8% + antioxidant 168 0.2%, followed by extrusion granulation. Then, 1.5% of diisopropylbenzene peroxide is added, shaken well for 10 min, and absorbed at 65 °C for 2 h to obtain a semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots and reduced graphene oxide.

[0069] Example 3

[0070] Referring to Example 1, a semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots and reduced graphene oxide was prepared. The difference lies in that the addition amount of black phosphorus in step (2) is 25 g, and in step (5), the black phosphorus quantum dot / reduced graphene oxide composite powder, matrix resin and additives are blended according to the mass ratio of ethylene-ethyl acrylate 65%, black phosphorus quantum dot / reduced graphene oxide composite 33.5%, zinc stearate 0.5% + polyethylene wax 0.5%, antioxidant 1010 0.8% + antioxidant 168 0.2%, followed by extrusion granulation. Then, 1.5% of diisopropylbenzene peroxide is added, shaken well for 10 min, and absorbed at 65 °C for 2 h to obtain a semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots and reduced graphene oxide.

[0071] Comparative Example 1

[0072] Referring to Example 1, a semiconductive shielding material for high-voltage cables filled with reduced graphene oxide was prepared. The difference lies in that in step (3), the black phosphorus quantum dot dispersion liquid is not added, and the reduced graphene oxide material powder, matrix resin and additives are blended according to the mass ratio of ethylene-ethyl acrylate 66.5%, reduced graphene oxide material 30%, zinc stearate 0.5% + polyethylene wax 0.5%, antioxidant 1010 0.8% + antioxidant 168 0.2%, followed by extrusion granulation. Then, 1.5% of diisopropylbenzene peroxide is added, shaken well for 10 min, and absorbed at 65 °C for 2 h to obtain a semiconductive shielding material for high-voltage cables filled with reduced graphene oxide.

[0073] Comparative Example 2

[0074] Refer to Example 1 to prepare a semiconductive shielding material for high-voltage cables filled with black phosphorus quantum dots. The difference is that in step (3), graphene oxide powder A is not added. The black phosphorus quantum dot nanomaterial powder, matrix resin, and additives are blended at a mass ratio of ethylene-ethyl acrylate 66.5%, black phosphorus quantum dot nanomaterial 30%, zinc stearate 0.5% + polyethylene wax 0.5%, 1010 0.8% + 168 0.2%, and then extruded and granulated. After that, 1.5% dicumyl peroxide is added, shaken well for 10 min, and absorbed at 65°C for 2 h to obtain a semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots and reduced graphene oxide.

[0075] Comparative Example 3

[0076] Refer to Example 1 to prepare a semiconductive shielding material for high-voltage cables filled with conductive carbon black. The difference is that the preparation steps of the composite nanomaterial in steps (1)-(4) are cancelled. In step (5), they are blended at a mass ratio of ethylene-ethyl acrylate 66.5%, conductive carbon black 30%, zinc stearate 0.5% + polyethylene wax 0.5%, 1010 0.8% + 168 0.2%, and then extruded and granulated. After that, 1.5% dicumyl peroxide is added, shaken well for 10 min, and absorbed at 65°C for 2 h to obtain a semiconductive shielding material for high-voltage cables filled with carbon black.

[0077] Comparative Example 4

[0078] Refer to Example 1 to prepare a semiconductive shielding material for high-voltage cables filled with reduced graphene oxide-dispersed conductive carbon black. The difference is that step (2) is cancelled. In step (3), black phosphorus quantum dot B is replaced with an equal proportion of conductive carbon black. In step (5), they are blended at a mass ratio of ethylene-ethyl acrylate 66.5%, conductive carbon black / reduced graphene oxide composite material 30%, zinc stearate 0.5% + polyethylene wax 0.5%, 1010 0.8% + 168 0.2%, and then extruded and granulated. After that, 1.5% dicumyl peroxide is added, shaken well for 10 min, and absorbed at 65°C for 2 h to obtain a semiconductive shielding material for high-voltage cables modified with black phosphorus quantum dots and reduced graphene oxide.

[0079] After that, the above-prepared semiconductive shielding material for high-voltage cables is put into a flat vulcanizing machine, hot-pressed at 120°C for 15 min and cold-pressed for 5 min to prepare a semiconductive shielding layer for high-voltage cables. Samples are prepared by cutting, and their electrical and mechanical properties are measured. A strip-shaped semiconductive shielding layer is prepared by a single-screw extruder, and its surface finish is tested. The results are shown in Table 1.

[0080] Table 1 Performance test results

[0081]

[0082] As can be seen from Table 1, with the increase in the content of black phosphorus modified reduced graphene oxide, the mechanical properties of the semi-conductive shielding material gradually increase, and its electrical properties are also improved to a certain extent. On the basis of having excellent electrical and mechanical properties, the number of surface protrusions is reduced, and the surface finish of the semi-conductive shielding layer is improved, which is conducive to the construction of a long-range conductive network.

Claims

1. A semi-conductive shielding material for cables, characterized in that, Comprising the following components by mass fraction: Matrix resin 60 - 70%; Black phosphorus quantum dot / reduced graphene oxide composite 25 - 35%; Lubricant 1 - 2%; Antioxidant 0.3 - 1.0%; Crosslinking agent 0.5 - 2%; Based on the total mass of the above components being 100%.

2. The shielding material according to claim 1, wherein The matrix resin is an ethylene - acrylate compound; preferably ethylene - ethyl acrylate, ethylene - butyl acrylate; Preferably, the lubricant is a stearate compound or a polyethylene wax; preferably zinc stearate or a polyethylene wax with a molecular weight below 2000; Preferably, the antioxidant is a phosphite antioxidant or a hindered phenol antioxidant or a compound of one or more of them; Preferably, the crosslinking agent is an organic peroxide free - radical crosslinking agent, preferably one or two of diisopropylbenzene peroxide and 2,5 - dimethyl - 2,5 - bis(tert - butylperoxy)ethane.

3. The shielding material according to claim 1, characterized in that, The preparation method of the black phosphorus quantum dot / reduced graphene oxide composite is as follows: S2: Dissolve black phosphorus in a first solvent, carry out a hydrothermal reaction and then centrifuge to obtain a black phosphorus quantum dot liquid separation B; S3: Add graphene oxide A to a second solvent for mixing and dispersion, then add the black phosphorus quantum dot liquid separation B and stir for dispersion to obtain a mixed stock solution C; S4: Transfer the mixed stock solution C in step S3 into a reaction kettle, carry out a hydrothermal reaction, wash and dry to obtain the black phosphorus quantum dot - modified reduced graphene oxide composite.

4. The shielding material according to claim 3, characterized in that, The graphene oxide is prepared by the following method: S1: Treat graphene with acidic potassium permanganate, and obtain graphene oxide A through separation and washing; Preferably, the graphene treatment step in S1 is an intercalation oxidation reaction with an acidic potassium permanganate solution; add graphene into a mixed solution containing an acid and potassium permanganate for oxidation; Preferably, the acid is selected from one or more of sulfuric acid, hydrochloric acid, and nitric acid; Preferably, the mass ratio of graphene to potassium permanganate and acid is 0.1 - 2:0.5 - 1:50 - 150, preferably 0.5 - 1:0.6 - 0.8:80 - 100; Preferably, in S1, the mixed solution of graphene, acid, and potassium permanganate is dispersed and dissolved under ultrasonic conditions; Preferably, the power of the ultrasonic dispersion is 100 - 400W, preferably 200 - 250W, and the ultrasonic time is 10 - 60min, preferably 20 - 30min; Preferably, in S1, graphene is separated by centrifugation, the centrifugation speed is 5000 - 9000rpm, the time is 10 - 30min, preferably 6000 - 7000rpm, and the time is 15 - 20min.

5. The shielding material according to claim 3 or 4, characterized in that, In S2, the black phosphorus solution is ultrasonically pulverized at - 5 to 10°C; Preferably, the ultrasonic pulverization power of black phosphorus in S2 is 100 - 600W, preferably 200 - 300W, and the ultrasonic time is 10 - 60min, preferably 20 - 30min; Preferably, the hydrothermal reaction conditions in S2 are 120 - 180°C, the time is 2 - 8h, preferably 140 - 160°C, and the time is 4 - 6h; Preferably, the first solvent includes one or more of N - methylpyrrolidone, ethylene glycol monobutyl ether, ethylene glycol diethyl ether, dimethylformamide, dimethyl sulfoxide, preferably N - methylpyrrolidone; Preferably, the concentration of black phosphorus in the first solvent is 0.001 mg / mL - 10 mg / mL; Preferably, the centrifugation speed of S2 is 5000 - 8000 r / min.

6. The shielding material according to any one of claims 3-5, characterized in that In S3, graphene oxide A is dispersed by ultrasonic treatment. The ultrasonic treatment power is 100 - 400 W, preferably 200 - 300 W, and the ultrasonic treatment time is 10 - 60 min, preferably 20 - 30 min; Preferably, the second solvent includes one or more of N-methylpyrrolidone, ethylene glycol monobutyl ether, ethylene glycol diethyl ether, dimethylformamide, dimethyl sulfoxide, preferably N-methylpyrrolidone; Preferably, the concentration of graphene oxide A in the second solvent is 0.1 mg / mL - 1 mg / mL; Preferably, the mass ratio of graphene oxide A to black phosphorus in black phosphorus quantum dots in the liquid separation B of S3 is 1:5 - 50, preferably 1:5 - 15.

7. The shielding material according to any one of claims 3-6, characterized in that, The hydrothermal reaction temperature in S4 is 120 - 180 °C, and the reaction time is 2 - 8 h, preferably 140 - 160 °C, and the reaction is 4 - 6 h; Preferably, in step S4, the reaction product can be washed with deionized water and anhydrous ethanol respectively.

8. A method for preparing the semi-conductive shielding material for cables according to any one of claims 1-7, characterized in that, The black phosphorus quantum dot / reduced graphene oxide composite powder, matrix resin, lubricant, and antioxidant are mixed evenly, and then extrusion granulation is carried out. After that, a cross-linking agent is added by a post-absorption method to obtain a cable semiconductive shielding material.

9. The preparation method according to claim 8, characterized in that, The mixing is carried out using a high-speed mixer. The rotation speed of the high-speed mixer is 100 - 200 rpm, and the stirring time is 5 - 30 min, preferably 150 - 200 rpm; Preferably, the extrusion granulation temperature is 150 - 210 °C, and the main machine rotation speed is 50 - 150 rpm. Preferably, the granulation temperature is 170 - 200 °C, and the rotation speed is 75 - 120 rpm; Preferably, after adding the cross-linking agent, the mixture is mixed for 5 - 20 min, and it is continuously shaken during this period. The post-absorption temperature is 60 - 80 °C, and the absorption time is 1 - 4 h. Preferably, the mixture is mixed for 10 - 20 min, the post-absorption temperature is 65 - 75 °C, and the absorption is 1 - 2 h.

10. Application of the cable semiconductive shielding material according to any one of claims 1 - 7 or the cable semiconductive shielding material prepared by the preparation method according to claim 8 or 9 in the field of high, medium, and low voltage wire and cable shielding materials.

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