High-voltage cable semi-conductive shielding material based on modified conductive carbon black and preparation method thereof

Abstract

The present invention discloses a high-voltage cable semi-conductive shielding material based on modified conductive carbon black and a preparation method thereof, comprising: 60-74 parts of a base resin, 25-35 parts of conductive carbon black, 0.5-2 parts of a cross-linking agent, 0.5-1 part of an antioxidant, 0.5-2 parts of a lubricant, and 0.01-0.5 parts of silk fibroin nanofibers. The preparation method comprises: preparing highly dispersible conductive carbon black; mixing the highly dispersible conductive carbon black with the base resin, lubricant, and antioxidant, and stirring uniformly to obtain a mixture; pelletizing and drying the mixture to form a granular material; mixing the granular material with the cross-linking agent after uniform grinding, and drying the granular material at 65°C for 10 hours to obtain a high-voltage cable semi-conductive shielding material. The conductive carbon black in the semi-conductive shielding material of the present invention is well dispersed, achieving a synergistic improvement in the electromechanical properties and surface finish of the semi-conductive shielding material. The present invention also has the advantages of simple process and reliable preparation.

Description

Technical Field

[0001] The invention relates to the technical field of cross-linked polyethylene cable materials, in particular to a high-voltage cable semi-conductive shielding material based on modified conductive carbon black and a preparation method thereof. Background Art

[0002] High-voltage cables, due to their large capacity, high reliability, and maintenance-free design, have become core electrical equipment for urban, cross-river, and offshore power transmission, and are known as the "blood vessels" of the national economy. The semi-conductive shield is an essential component of high-voltage cables. It uniformly distributes the electric field within the insulation layer and eliminates air gaps at the interface between the conductor and the insulation, thereby reducing damage to the cable insulation caused by electrical stress concentration. Its quality directly impacts the safety and stability of high-voltage cables.

[0003] Semi-conductive shielding materials (raw materials for semi-conductive shielding layers) are mainly obtained by melt blending and compounding of polymer matrix resin, conductive carbon black and processing aids. Among them, conductive carbon black is an important component of high-voltage cable semi-conductive shielding materials. Its own quality and dispersibility in the base resin are key factors affecting the core performance of semi-conductive shielding materials. Among them, conductive carbon black is a nanoparticle with a large specific surface area, high surface energy, and is in a non-thermodynamically stable state, which makes it very easy for them to agglomerate together to form large agglomerates with several weak connection interfaces, which is not conducive to the construction of a conductive network. The conductive and mechanical properties of high-voltage cable shielding materials are poor; in addition, the conductive carbon black agglomeration points will also form obvious protrusions on the surface of high-voltage cable shielding material products, affecting the surface finish. Therefore, improving the dispersibility of conductive carbon black is a key issue that needs to be addressed in the preparation of ultra-smooth high-voltage shielding materials.

[0004] It is well known that surface modification is an effective strategy for improving the dispersibility of conductive carbon black. It can be categorized into two main types: covalent modification and non-covalent modification. Covalent modification primarily involves chemical reactions or chemical adsorption between the surface of the conductive carbon black particles and the treating agent, improving the surface structure and state of the conductive carbon black to enhance its dispersibility and interfacial compatibility. However, the covalent modification process is complex and difficult to control, and it also disrupts the surface structure of the conductive carbon black, resulting in a decrease in intrinsic conductivity. Non-covalent modification, on the other hand, involves the introduction or adsorption of polar groups onto the surface of the conductive carbon black through intermolecular forces such as van der Waals forces and hydrogen bonds. This creates sufficient electrostatic repulsion and / or steric resistance between the conductive carbon black particles to prevent aggregation. Non-covalent modification is currently a common method for producing semi-conductive shielding materials. However, traditional non-covalent modification relies on physical blending, which poses challenges such as low dispersant utilization and difficulty ensuring uniform bonding between the dispersant and the conductive carbon black surface. Furthermore, the insulating coating formed by a large amount of dispersant can reduce the conductivity of the semi-conductive shielding material.

[0005] In the Chinese invention patent "Patent Publication No.: CN110079004A, Name: A Rated Voltage 220kV Ultra-clean and Ultra-smooth Semi-conductive Shielding Material and Its Preparation Method", the invention achieves good dispersion of conductive carbon black by adding 2.4 to 3.5 parts of dispersant and lubricant, and adopts reciprocating extrusion granulation processing equipment to prepare ultra-smooth semi-conductive shielding material and its preparation method.

[0006] However, this technology still has the following disadvantages:

[0007] (1) This method requires the addition of 3 to 4 dispersants and lubricants and the use of reciprocating extrusion granulation processing equipment, which is a complex process.

[0008] (2) These excessive insulating additives will deteriorate the conductive properties of the semi-conductive shielding material and reduce the ability of the semi-conductive shielding layer to homogenize the electric field.

[0009] Therefore, it is urgent to propose a non-covalent bond modification method for conductive carbon black with simple process, reliable preparation and significant effect, and to prepare high-voltage cable semi-conductive shielding materials based on modified conductive carbon black, so as to significantly improve the dispersibility of conductive carbon black at a low addition amount of dispersant, thereby improving the comprehensive performance of the semi-conductive shielding material. Summary of the Invention

[0010] To address the above issues, the present invention aims to provide a high-voltage cable semi-conductive shielding material based on modified conductive carbon black and a method for preparing the same. The method simulates the water washing and granulation process at the source of conductive carbon black production, introduces silk fibroin nanofibers (SF) as a binder and dispersant for the conductive carbon black, and obtains highly dispersible modified conductive carbon black. High-performance high-voltage cable semi-conductive shielding materials are then prepared based on the modified conductive carbon black. The technical solutions adopted by the present invention are as follows:

[0011] A high voltage cable semi-conductive shielding material based on modified conductive carbon black, which is composed of the following components by weight:

[0012] 60-74 parts of base resin;

[0013] 25-35 parts of conductive carbon black;

[0014] 0.5-2 parts of cross-linking agent;

[0015] 0.5-1 part of antioxidant;

[0016] 0.5-2 parts of lubricant;

[0017] 0.01-0.5 parts of silk fibroin nanofiber.

[0018] Furthermore, a high-voltage cable semi-conductive shielding material based on modified conductive carbon black is composed of the following components by weight:

[0019] 67 parts of base resin;

[0020] 30 parts of conductive carbon black;

[0021] 0.05-0.2 parts of silk fibroin nanofiber;

[0022] 1 part lubricant;

[0023] 0.5 parts of antioxidant;

[0024] 1.5 parts of cross-linking agent.

[0025] Preferably, the base resin is ethylene-butyl acrylate; the content of the second copolymerized monomer in the ethylene-butyl acrylate is 18%.

[0026] Preferably, the conductive carbon black has an oil absorption value of 120 to 180 ml / 100 g and an ash content of less than 0.2%.

[0027] Preferably, the lubricant is zinc stearate or pentaerythritol.

[0028] Preferably, the antioxidant is antioxidant 300; and the cross-linking agent is diisopropylbenzene peroxide.

[0029] A method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black comprises the following steps:

[0030] Preparation of highly dispersed conductive carbon black: using silk fibroin nanofibers to prepare a silk fibroin nanofiber dispersion, and slowly adding conductive carbon black to prepare highly dispersed conductive carbon black;

[0031] Mixing highly dispersible conductive carbon black with a base resin, a lubricant, and an antioxidant, and stirring uniformly to obtain a mixture;

[0032] The mixture is pelletized and dried to form granular material;

[0033] The granular material and the evenly ground cross-linking agent are mixed evenly, and the granular material is dried at 65° C. for 10 hours to obtain a high-voltage cable semi-conductive shielding material.

[0034] Furthermore, the preparation steps of the highly dispersible conductive carbon black include:

[0035] Prepare a silk fibroin nanofiber aqueous dispersion; the concentration of the silk fibroin nanofiber aqueous dispersion is 10%;

[0036] Slowly add 2.5 to 10 parts of silk fibroin nanofiber aqueous dispersion and 137.5 to 130 parts of deionized water to 25 to 35 parts of conductive carbon black, ball mill for 10 minutes, and fully disperse the conductive carbon black to obtain a CCB@SF mixed solution;

[0037] The CCB@SF mixture was fully stirred at a speed of 100 rpm to obtain a stable CCB@SF aqueous dispersion; the stirring time was 15 min;

[0038] The CCB@SF aqueous dispersion is dried at 110° C. to 130° C. for 12 h to 24 h to obtain modified conductive carbon black CCB@SF, which is a highly dispersed conductive carbon black.

[0039] Furthermore, the preparation process of the silk fibroin nanofiber dispersion comprises the following steps:

[0040] The silk was boiled in a Na2CO3 solution for 1 hour and rinsed thoroughly with distilled water to remove sericin and impurities to obtain degummed silk fibroin fibers;

[0041] The degummed silk fibroin fibers were dried, dissolved in a CaCl2-formic acid solution for 3 h, and stirred to obtain a silk fibroin nanofiber dispersion;

[0042] Add deionized water and filter and wash 4 to 5 times to remove CaCl2 and formic acid solution;

[0043] The silk fibroin nanofiber aqueous dispersion with a stable dispersion was obtained by high-speed shearing at a rate of 10,000 r / min for 10 minutes, with a concentration of 2%.

[0044] Preferably, the mass concentration of the Na2CO3 is 0.05% w / v; the concentration of the CaCl2 is 5%.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The present invention cleverly utilizes the amphiphilicity of silk fibroin nanofibers (SF) so that they can be adsorbed on conductive carbon black through hydrophobic effects, acting as a binder. Silk fibroin nanofibers contain a large amount of β-folded structures, which are structurally stable and highly hydrophobic. In addition, compared with covalent modification, the non-covalent modification used in the present invention retains the good surface structure of conductive carbon black, so that its excellent electrical properties and thermal properties are better retained. At the same time, the large aspect ratio of SF brings about a steric hindrance effect and the electrostatic repulsion between SFs, which inhibits the agglomeration of conductive carbon black (CCB), improves the dispersibility of CCB, and achieves a synergistic improvement in the electromechanical properties and surface smoothness of the semi-conductive shielding material.

[0047] (2) The modified conductive carbon black of the present invention adopts an aqueous phase dispersion method, which is conducive to the full contact and uniform combination of CCB and SF, improves the utilization rate of SF, and significantly reduces the amount of dispersant used in the semi-conductive shielding material, thereby alleviating the adverse effects of the insulating coating layer formed by the dispersant on properties such as conductivity, and achieves good dispersion of conductive carbon black in the base resin at a low dispersant content, thereby improving the comprehensive performance of the semi-conductive shielding material of the high-voltage cable.

[0048] (3) The conductive carbon black surface modification method provided by the present invention simulates the necessary water washing and granulation steps in the CCB production process (the CCB production process includes high-temperature cracking of crude oil, coagulation, gas-solid separation, air conveying, water washing and granulation, and drying), avoiding the addition of additional steps. The SF preparation process has the advantages of being green, non-toxic, and pollution-free. In addition, this method does not require post-processing or dispersant-assisted dispersion. Due to its simplicity, the process is easy to master and easy to implement.

[0049] In summary, the present invention has the advantages of simple process and reliable preparation, and has high practical value and promotion value in the field of high-voltage cable semi-conductive shielding materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope of protection. For those skilled in the art, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 It is a process flow chart of the preparation of the present invention. DETAILED DESCRIPTION

[0052] To make the purpose, technical solutions, and advantages of this application more clear, the present invention is further described below with reference to the accompanying drawings and examples. Implementation methods of the present invention include, but are not limited to, the following examples. All other embodiments obtained by persons of ordinary skill in the art based on the examples in this application without creative effort are within the scope of protection of this application.

[0053] In this embodiment, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0054] In the description and claims of this embodiment, the terms "first" and "second" are used to distinguish different objects rather than to describe a specific order of objects. For example, a first target object and a second target object are used to distinguish different objects rather than to describe a specific order of objects.

[0055] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0056] Example 1

[0057] like Figure 1 As shown, this embodiment provides a high-voltage cable semiconductive shielding material based on modified conductive carbon black and its preparation method. This technology utilizes the amphiphilicity of silk fibroin nanofibers (SF), enabling them to adsorb to the conductive carbon black through hydrophobic interaction, acting as a binder. The aqueous dispersion method facilitates full contact and uniform bonding between the CCB and SF. Furthermore, the large aspect ratio of SF creates a steric effect and electrostatic repulsion between SF, suppressing the aggregation of the conductive carbon black.

[0058] Specifically, the main raw materials of the high-voltage cable semi-conductive shielding material of this embodiment are as follows: 62 parts by weight of base resin, 30 parts of modified conductive carbon black, 0.05 parts of silk fibroin nanofibers, 1 part of lubricant, 0.5 parts of antioxidant, and 1.5 parts of crosslinking agent. The base resin is ethylene-butyl acrylate, and the content of the second monomer in the copolymer of ethylene-butyl acrylate is 18%. The conductive carbon black has an oil absorption value of 155 ml / 100 g and an ash content of 0.2%. The lubricant is zinc stearate. The antioxidant is Antioxidant 300; and the crosslinking agent is diisopropylbenzene peroxide.

[0059] The preparation process is described in detail below:

[0060] Step 1: Boil the silk in a Na2CO3 solution for 1 hour and rinse thoroughly with distilled water to remove sericin and impurities. The degummed silk fibroin fibers are dried and dissolved in a CaCl2-formic acid (FA) solution (5% CaCl2) for 3 hours. Mechanical stirring is then performed to prepare a silk fibroin nanofiber dispersion.

[0061] Step 2: Add deionized water and filter and wash 4 to 5 times to remove CaCl2 and FA; use a shearing machine to high-speed shear at a rate of 10,000 r / min for 10 minutes to obtain a dispersed and stable SF aqueous dispersion with a concentration of 2%.

[0062] Step 3: Slowly add 2.5 parts of SF dispersion and 137.5 parts of deionized water to 30 parts of conductive carbon black, and ball mill for 10 minutes to fully disperse the conductive carbon black to obtain a CCB@SF mixed solution.

[0063] Step 4: Mechanically stir the CCB@SF mixture to obtain a dispersed and stable CCB@SF aqueous dispersion at a rotation speed of 100 rpm and a stirring time of 15 min.

[0064] Step 5: Dry the CCB@SF aqueous dispersion at 110° C. to 130° C. for 12 h to 24 h to obtain highly dispersed modified conductive carbon black (CCB@SF).

[0065] Step 6: Mix 30 parts of CCB@SF, 1 part of lubricant and 0.5 parts of antioxidant.

[0066] Step 7: The mixed raw material obtained in step 1 was mixed with 67 parts of the base resin in an internal mixer at a temperature of 160° C. and a rotation speed of 100 rpm to mix them evenly.

[0067] Step 8: The mixture obtained in step 8 is pelletized and dried to form granules.

[0068] Step 9: Place the dried pellets in a 65°C oven for 2 hours. Then, thoroughly mix the pellets with 1.5 parts of a uniformly ground crosslinking agent. Next, place the mixed pellets in a 65°C oven for 10 hours to ensure that the pellets fully absorb the crosslinking agent.

[0069] Example 2

[0070] like Figure 1 As shown, this embodiment provides a high-voltage cable semi-conductive shielding material based on modified conductive carbon black and a preparation method thereof. The only difference from Example 1 is that SF is 0.1 parts, that is, 5 parts of SF aqueous dispersion and 135 parts of deionized water are added in step 3.

[0071] Example 3

[0072] like Figure 1 As shown, this embodiment provides a high-voltage cable semi-conductive shielding material based on modified conductive carbon black and a preparation method thereof. The only difference from Example 1 is that SF is 0.2 parts, that is, 10 parts of SF aqueous dispersion and 130 parts of deionized water are added in step 3.

[0073] Comparative Case 1

[0074] like Figure 1As shown, this embodiment provides a high-voltage cable semi-conductive shielding material based on modified conductive carbon black and a preparation method thereof, the only difference from Example 1 being that SF is 0 parts, that is, 0 parts of SF aqueous dispersion and 140 parts of deionized water are added in step 3.

[0075] Comparative Case 2

[0076] like Figure 1 As shown, this embodiment provides a high-voltage cable semi-conductive shielding material based on modified conductive carbon black and its preparation method. The main raw materials are as follows: 67 parts base resin, 30 parts conductive carbon black, 0.2 parts dispersant, 1 part lubricant, 0.5 parts antioxidant, and 1.5 parts cross-linking agent. In this embodiment, the dispersant is ethylene bisstearamide.

[0077] In this embodiment, the preparation process is as follows:

[0078] Step 1: Mix 30 parts of CCB with 2 parts of dispersant, 1 part of lubricant, and 0.5 parts of antioxidant;

[0079] Step 2: Place the mixed raw material obtained in step 1 and 67 parts of base resin in an internal mixer and mix them uniformly at a temperature of 160° C. and a speed of 100 rpm;

[0080] Steps 3 to 4 are consistent with steps 8 to 9 in Example 1.

[0081] Performance testing:

[0082] Semiconductive shielding material pellets were prepared into sheets using a hot press molding process for testing and characterization of their structure and performance. Heat treatment was performed at 180°C and 15 MPa for 15 minutes to fully crosslink and form a complete material. The mechanical properties, electrical conductivity, and surface smoothness of the semiconductive shielding materials for high-voltage cables in Examples 1-3 and Comparative Examples 1-2 are shown in the following table:

[0083] Table 1 Mechanical properties, electrical conductivity and surface finish of the examples and comparative examples

[0084]

[0085] As can be seen from Table 1, the high-voltage cable semi-conductive shielding material prepared by the present invention exhibits excellent mechanical and electrical properties. The mechanical properties, resistivity and surface finish of Examples 1 to 3 are all better than those of Comparative Example 1, with a tensile strength greater than 18 MPa, an elongation at break greater than 200%, resistivities at 23°C and 90°C lower than 30Ω·cm and 60Ω·cm, respectively, and the number of protrusions larger than 50μm is 0. This is because silk fibroin nanofibers (SF) contain a large amount of β-pleated structures, which are structurally stable and highly hydrophobic. The amphiphilicity of SF enables it to be adsorbed on conductive carbon black through hydrophobic effects, acting as a binder. Compared with covalent modification, the non-covalent modification used in the present invention retains the good surface structure of conductive carbon black, so that its excellent electrical and thermal properties are better retained. At the same time, the large aspect ratio of SF brings about a steric hindrance effect and the electrostatic repulsion between SFs, which inhibits the agglomeration of conductive carbon black (CCB), improves the dispersibility of CCB, and achieves a synergistic improvement in the mechanical-electrical properties and surface finish of the semi-conductive shielding material.

[0086] Furthermore, Examples 1-3 all exhibit superior mechanical properties, resistivity, and surface finish to Comparative Example 2. Conventional dispersant physical mixing processes have low dispersant utilization and difficulty ensuring uniform dispersant coating on the CCB surface. Therefore, a higher dispersant content is required to ensure effective dispersion. Excessive dispersant can create an insulating coating that reduces the conductivity of the semiconductive shielding material. However, the present invention utilizes a molecular-level dispersion method, which facilitates full contact and uniform bonding between the CCB and SF. Therefore, at low dispersant content, the conductive carbon black dispersion of Examples 1-3 is significantly superior to that of Comparative Example 2, and the resulting semiconductive shielding materials exhibit superior conductivity, mechanical properties, and surface finish. Example 2 exhibits the best overall performance. This is because the higher SF content in Example 2 significantly improves the dispersibility of the conductive carbon black compared to Example 1. However, the increased amount of insulating rigid fiber SF also degrades the mechanical and electrical properties of the semiconductive shielding material. Furthermore, excessive SF increases the strength of the conductive carbon black particles, which, to a certain extent, affects the processability of the conductive carbon black and can also degrade the performance of the semiconductive shielding material. In summary, 0.1 part SF is the optimal content.

[0087] In summary, the present invention achieves a significant improvement in the dispersibility of conductive carbon black at a low addition amount of dispersant, while alleviating the adverse effect of the insulating coating formed by the dispersant on the conductivity of the semi-conductive shielding material of the high-voltage cable, thereby improving the comprehensive performance of the semi-conductive shielding material of the high-voltage cable.

[0088] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any changes that adopt the design principles of the present invention and any changes made through non-creative work on this basis should fall within the scope of protection of the present invention.

Claims

1. A method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black, characterized in that: The invention is composed of the following components by weight: 60-74 parts of a base resin; 25-35 parts of conductive carbon black; 0.5-2 parts of a crosslinking agent; 0.5-1 parts of an antioxidant; 0.5-2 parts of a lubricant; and 0.01-0.5 parts of silk fibroin nanofibers. The base resin is ethylene-butyl acrylate; and the content of the second copolymer monomer of the ethylene-butyl acrylate is 18%. The preparation method comprises the following steps: Preparation of highly dispersed conductive carbon black: using silk fibroin nanofibers to prepare a silk fibroin nanofiber dispersion, and slowly adding conductive carbon black to prepare highly dispersed conductive carbon black; Mixing highly dispersible conductive carbon black with a base resin, a lubricant, and an antioxidant, and stirring uniformly to obtain a mixture; The mixture is pelletized and dried to form granular material; The granular material and the cross-linking agent that has been ground evenly are mixed evenly, and the granular material is dried at 65° C. for 10 hours to obtain a high-voltage cable semi-conductive shielding material; The preparation process of the silk fibroin nanofiber dispersion comprises the following steps: The silk was boiled in a Na2CO3 solution for 1 h and then rinsed thoroughly with distilled water to remove sericin and impurities to obtain degummed silk fibroin fibers. The degummed silk fibroin fibers were dried and dissolved in a CaCl2-formic acid solution for 3 h, and stirred to obtain a silk fibroin nanofiber dispersion. Add deionized water and filter and wash 4 to 5 times to remove CaCl2 and formic acid solution; The silk fibroin nanofibers were stably dispersed in water and the concentration was 2%.

2. The method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black according to claim 1, characterized in that: Composed of the following components by weight: 67 parts of base resin; 30 parts of conductive carbon black; 0.05-0.2 parts of silk fibroin nanofiber; 1 part lubricant; 0.5 parts of antioxidant; 1.5 parts of cross-linking agent.

3. The method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black according to claim 1 or 2, characterized in that: The conductive carbon black has an oil absorption value of 120-180 ml / 100 g and an ash content of less than 0.2%.

4. The method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black according to claim 1 or 2, characterized in that: The lubricant is zinc stearate or pentaerythritol.

5. The method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black according to claim 1 or 2, characterized in that: The antioxidant is antioxidant 300; the cross-linking agent is diisopropylbenzene peroxide.

6. The method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black according to claim 1, characterized in that: The preparation steps of the highly dispersible conductive carbon black include: Prepare a silk fibroin nanofiber aqueous dispersion; the concentration of the silk fibroin nanofiber aqueous dispersion is 2%; Slowly add 2.5-10 parts of silk fibroin nanofiber aqueous dispersion and 137.5-130 parts of deionized water to 25-35 parts of conductive carbon black, ball mill for 10 minutes, and fully disperse the conductive carbon black to obtain a CCB@SF mixture. The CCB@SF mixture was fully stirred at a speed of 100 rpm to obtain a stable CCB@SF aqueous dispersion; the stirring time was 15 min; The CCB@SF aqueous dispersion is dried at 110°C to 130°C for 12h to 24h to obtain modified conductive carbon black CCB@SF, which is a highly dispersed conductive carbon black.

7. The method for preparing a high-voltage cable semi-conductive shielding material based on modified conductive carbon black according to claim 1, characterized in that: The mass concentration of the Na2CO3 is 0.05% w / v; the concentration of the CaCl2 is 5%.

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