Semi-conductive shielding material, preparation method and application thereof, and high-voltage cable

Abstract

The invention relates to a semiconductive shielding material, a preparation method and application thereof, and a high-voltage cable, and relates to the field of high polymer materials, the semiconductive shielding material comprises the following components by weight: 55-65 parts of matrix resin, 25-35 parts of carbon black, 1-5 parts of a COF material, 1-3 parts of an antioxidant, and 1-2 parts of a dispersant; the COF material is a TpPa type covalent organic framework material, and the TpPa type covalent organic framework material is obtained by taking an aldehyde monomer containing three ketone hydroxyl functional groups and an aromatic diamine monomer as raw materials and carrying out solvothermal reaction. The specific COF material with a proper proportion is introduced, so that the COF material and the carbon black form a stable synergistic composite structure on a micro-scale, ordered adjustment of the microstructure is realized while high conductivity is maintained, and a conductive phase forms more stable and uniform network distribution in a polymer matrix; therefore, a new technical path is provided for development of high-performance and high-reliability semiconductive shielding materials.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and more particularly to a semiconductive shielding material, its preparation method and application, and high-voltage cables. Background Technology

[0002] High-voltage cables, as key equipment for high-voltage power transmission, are core electrical devices for urban power transmission, cross-river and offshore power transmission. They mainly consist of several parts, including conductive cores, a semi-conductive shielding layer, an insulation layer, a metallic shielding layer, and a sheath. As a crucial component of the high-voltage cable structure, the semi-conductive shielding layer's primary function is to eliminate air gaps at the conductor-insulation interface and to uniformly distribute the electric field on the surface of the conductive core. Therefore, this shielding layer not only needs to possess stable volume resistivity and mechanical properties but also must meet the requirements for thermal stability and structural uniformity during long-term processing.

[0003] Semiconducting shielding materials are mainly obtained by melt blending and compounding of polymer matrix resin, conductive carbon black, and processing aids. Currently, the most widely used conductive fillers are acetylene black or furnace black, which achieve the required conductivity by forming interconnected conductive paths in the polymer matrix. Due to the large specific surface area and strong agglomeration of carbon black particles, they are prone to forming large-scale agglomerates during melt processing, leading to local carbon black enrichment or deficiency. This uneven dispersion can cause resistivity fluctuations and reduced mechanical properties of the shielding material, and may even lead to melt fracture, die accumulation, or even scorching under high temperature and high shear conditions, seriously affecting the manufacturing stability and operational reliability of cables.

[0004] Improving the dispersibility of carbon black is crucial for ensuring the uniformity of electrical conductivity and thermal stability of materials. Traditional methods often employ amides, esters, and small-molecule surfactants (such as ethylene bis-stearamide) as dispersants for carbon black. However, due to the limited interaction between these additives and carbon black, and the fact that these interactions are mostly physical adsorption, they are prone to migration, volatilization, or inactivation at high temperatures, making it difficult to achieve long-term stable dispersion of carbon black agglomerates. Furthermore, existing carbon black dispersion methods cannot effectively address the problems of poor interfacial adhesion and poor continuity of conductive pathways at the microscale. Therefore, there is an urgent need to develop a conductive filler that can achieve good dispersion and conductivity, thereby improving the overall electrical-mechanical properties and processing stability of shielding materials. Summary of the Invention

[0005] To address the above problems, this invention provides a semiconductive shielding material, its preparation method and application, and a high-voltage cable.

[0006] In a first aspect, the present invention provides a semiconductive shielding material comprising the following components in parts by weight:

[0007] 55-65 parts of matrix resin, 25-35 parts of carbon black, 1-5 parts of COF material, 1-3 parts of antioxidant, and 1-2 parts of dispersant;

[0008] The COF material is a TpPa-type covalent organic framework material, which is obtained by solvothermal reaction of aldehyde monomers containing three ketone hydroxyl functional groups and aromatic diamine monomers.

[0009] Furthermore, it includes the following components in parts by weight:

[0010] The composition consists of 62 parts matrix resin, 29 parts carbon black, 4 parts COF material, 3 parts antioxidant, and 2 parts dispersant.

[0011] Furthermore, the COF material includes at least one of a first TpPa type covalent organic framework material, a second TpPa type covalent organic framework material, and a third TpPa type covalent organic framework material;

[0012] The chemical structural formulas of the reactant monomers for the first TpPa-type covalent organic framework material are shown below:

[0013] ;

[0014] The chemical structural formulas of the reactant monomers for the second type of TpPa covalent organic framework material are shown below:

[0015] ;

[0016] The chemical structural formulas of the reaction monomer raw materials for the third TpPa type covalent organic framework material are shown below:

[0017] .

[0018] Furthermore, the preparation of the COF material includes the following process:

[0019] The aldehyde monomer containing three ketone hydroxyl functional groups and the aromatic diamine monomer are dissolved in an organic solvent, and then a solvothermal reaction is carried out in a closed container under acidic conditions. After the reaction is completed, the COF material is obtained by centrifugation, washing and drying.

[0020] The molar ratio of the aldehyde monomer containing three ketone hydroxyl functional groups to the aromatic diamine monomer is 1:(1-2).

[0021] The conditions and parameters for the solvothermal reaction include: a reaction temperature of 120-150℃ and a reaction time of 72-120 hours.

[0022] The aldehyde monomer containing three ketone hydroxyl functional groups includes at least one of 1,3,5-trihydroxybenzophenone and trimethoxy-substituted trione.

[0023] The aromatic diamine monomer includes at least one of p-phenylenediamine, phenylenediamine, and 2,5-dimethoxy-p-phenylenediamine;

[0024] The organic solvent includes at least one selected from N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, n-butanol, isobutanol, and ethanol.

[0025] Further, the matrix resin includes at least one selected from ethylene-butyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-vinyl acetate copolymer;

[0026] And / or, the antioxidant includes at least one of phenolic antioxidants, amine antioxidants, and thioether antioxidants;

[0027] And / or, the dispersant includes at least one of nonionic surfactants, polyvinylpyrrolidone, and amide surfactants;

[0028] And / or, the physicochemical properties of the carbon black include: a DBP absorption value of 100-160 mL / 100 g, and an ash content of less than 0.2 wt%.

[0029] Furthermore, the phenolic antioxidant includes at least one of antioxidant 300, antioxidant 1010 and antioxidant 2246, the nonionic surfactant includes fatty acid ester surfactants, and the amide surfactant includes ethylene bis-stearamide.

[0030] In a second aspect, the present invention provides a method for preparing the semiconductive shielding material according to any one of the first aspects, the method comprising the following steps:

[0031] Obtain COF material;

[0032] The COF material, matrix resin, carbon black, antioxidant, and dispersant are stirred and mixed, then added to a twin-screw extruder for melt blending to obtain a mixture.

[0033] The mixture is subjected to hot-press crosslinking, followed by cooling and granulation to obtain the semi-conductive shielding material.

[0034] Furthermore, the working conditions for the melt blending include: temperature of 120-150℃; rotation speed of 30-80 rpm; and time of 5-15 min.

[0035] And / or, the working conditions parameters for the hot-press crosslinking include: temperature of 150-180℃, pressure of 5-15MPa, and time of 5-15min.

[0036] Thirdly, the present invention provides an application of the semiconductive shielding material described in the first aspect or the semiconductive shielding material prepared by the preparation method described in the second aspect in the preparation of high-voltage cables.

[0037] Fourthly, the present invention provides a high-voltage cable, comprising the semi-conductive shielding material described in the first aspect or the semi-conductive shielding material prepared by the preparation method described in the second aspect.

[0038] The technical solutions provided in the embodiments of the present invention have at least the following advantages compared with the prior art:

[0039] This invention provides a semiconductive shielding material, its preparation method, and its application in high-voltage cables. By introducing a suitable proportion of a specific COF material (covalent organic framework material), this invention forms a stable synergistic composite structure with carbon black at the microscale. While maintaining high conductivity, it achieves ordered adjustment of the microstructure, resulting in a more stable and uniform network distribution of the conductive phase within the polymer matrix. This improves the material's conductivity continuity, interfacial adhesion, and processing thermal stability, thus providing a new technical path for the development of high-performance, high-reliability semiconductive shielding materials. Specifically:

[0040] Firstly, this application introduces a certain mass fraction of a specific covalent organic framework (COF) material into the semiconductive shielding material. This type of material possesses a regular two-dimensional layered structure, high thermal stability, and excellent interface control capabilities. By synergistically constructing a composite structure with conductive carbon black, the configuration and distribution of the conductive phase can be optimized at the microscale, effectively improving the dispersion uniformity and network connectivity of carbon black in the matrix, forming a more stable and continuous conductive path, and providing a new technical path for the development of high-performance, high-reliability semiconductive shielding materials.

[0041] Secondly, this application uses the aforementioned specific COF material as a structural aid, which, through its high specific surface area and layered framework, coats carbon black micro-clusters, inhibiting their interfacial migration and aggregation behavior, thereby improving the microstructural stability of the semiconductive material during processing. Simultaneously, its excellent thermal inertia and chemical stability endow the material with stronger thermal aging and interfacial durability, maintaining good electrical performance consistency even under high-temperature extrusion and long-term service conditions. This technology overcomes the limitations of traditional surfactant dispersants (such as stearates) in terms of conductivity regulation and thermal stability, expanding the design possibilities for high-performance semiconductive shielding materials. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the preparation method of the semiconductive shielding material in an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0047] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed according to national standards. If no corresponding national standard exists, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0048] The main raw material information involved in the following examples and comparative examples is as follows:

[0049] EBA: Chinese name is ethylene-butyl acrylate copolymer, purchased from Arkema, item number 17BA07;

[0050] EEA: Chinese name is ethylene-ethyl acrylate copolymer, purchased from Arkema, item number 4700;

[0051] Carbon black: purchased from Cabot, DBP absorbance 100-160 mL / 100g, ash content less than 0.2 wt%;

[0052] Tp: Its Chinese name is 1,3,5-trihydroxyphenyl ketone;

[0053] PVP: Polyvinylpyrrolidone;

[0054] PDA: The Chinese name is paraphenylenediamine.

[0055] Example 1

[0056] This example provides a semiconductive shielding material, comprising the following components in parts by weight:

[0057] The matrix resin (specifically EBA) consists of 65 parts, carbon black of 25 parts, COF material (specifically, first TpPa type covalent organic framework material) of 5 parts, antioxidant (specifically antioxidant 300) of 3 parts, and dispersant (specifically PVP) of 2 parts.

[0058] The chemical structural formulas of the reactant monomers for the first type of TpPa covalent organic framework material are shown below:

[0059] .

[0060] The preparation method of the above-mentioned semiconductive shielding material is as follows: Figure 1 As shown, it includes the following steps:

[0061] (1) Preparation of COF materials: 1,3,5-trihydroxybenzophenone (Tp) and p-phenylenediamine (PDA) were dissolved in a molar ratio of 1:1 in a mixed solvent of N,N-dimethylacetamide (DMAc) and ethanol (volume ratio 3:1). 6 mol / L glacial acetic acid, with a volume of about 10% of the total solvent volume, was added to the reaction system as a catalyst. The reaction was carried out at 120℃ for 72 h as a solvothermal reaction. After washing, the mixture was dried at 60℃ for 12 h to obtain the first TpPa type covalent organic framework material.

[0062] (2) Melt blending: The prepared first TpPa type covalent organic framework material is mixed evenly with carbon black, matrix resin, antioxidant and dispersant and then put into a twin-screw extruder at 150°C for melt blending at 30 rpm for 5 min to obtain the blended mixture;

[0063] (3) Hot-press crosslinking: The blended mixture is hot-pressed at 180℃ and 5MPa for 5min to obtain the hot-pressed material;

[0064] (4) Granulation: After the hot-pressed material is cooled to room temperature, it is cut into small pieces and granulated by a granulator to obtain a semi-conductive shielding material.

[0065] Example 2

[0066] This example provides a semiconductive shielding material, comprising the following components in parts by weight:

[0067] The matrix resin (specifically EEA) consists of 60 parts, carbon black of 35 parts, COF material (specifically, second TpPa type covalent organic framework material) of 2 parts, antioxidant (specifically antioxidant 1010) of 2 parts, and dispersant (specifically EBS) of 1 part.

[0068] The chemical structural formulas of the reactant monomers for the second type of TpPa covalent organic framework material are shown below:

[0069] .

[0070] The preparation method of the above-mentioned semiconductive shielding material includes the following steps:

[0071] (1) Preparation of COF material: 1,3,5-trihydroxybenzophenone (Tp) and phenylenediamine (BD) were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and n-butanol (volume ratio 3:1) at a molar ratio of 1:2. 6 mol / L glacial acetic acid, which accounts for about 15% of the total volume of the solvent, was added to the reaction system as a catalyst. The reaction was carried out at 150 °C for 100 h as a solvothermal reaction. After washing, the mixture was dried at 60 °C for 12 h to obtain the second TpPa type covalent organic framework material.

[0072] (2) Melt blending: The prepared second TpPa type covalent organic framework material is mixed evenly with carbon black, matrix resin, antioxidant and dispersant and then put into a twin-screw extruder at 120°C for melt blending at 80 rpm for 15 min to obtain the blended mixture.

[0073] (3) Hot-press crosslinking: The blended mixture is hot-pressed at 150℃ and 15MPa for 15min to obtain the hot-pressed material;

[0074] (4) Granulation: After the hot-pressed material is cooled to room temperature, it is cut into small pieces and granulated by a granulator to obtain a semi-conductive shielding material.

[0075] Example 3

[0076] This example provides a semiconductive shielding material, comprising the following components in parts by weight:

[0077] The matrix resin (specifically EBA) consists of 62 parts, carbon black of 29 parts, COF material (specifically, third-class TpPa covalent organic framework material) of 4 parts, antioxidant (specifically antioxidant 300) of 3 parts, and dispersant (specifically PVP) of 2 parts.

[0078] The chemical structural formulas of the reactant monomers for the third type of TpPa covalent organic framework material are shown below:

[0079] .

[0080] The preparation method of the above-mentioned semiconductive shielding material includes the following steps:

[0081] (1) Preparation of COF materials: 1,3,5-trihydroxybenzophenone (Tp) and 2,5-dimethoxy-p-phenylenediamine (PDA) were dissolved in a mixed solvent of N-methylpyrrolidone (NMP) and isobutanol (volume ratio 1:1) at a molar ratio of 1:1.5. 6 mol / L glacial acetic acid, which accounts for about 15% of the total volume of the solvent, was added to the reaction system as a catalyst. The reaction was carried out at 140 °C for 120 h as a solvothermal reaction. After washing, the mixture was dried at 60 °C for 12 h to obtain the third TpPa type covalent organic framework material.

[0082] (2) Melt blending: The prepared third TpPa type covalent organic framework material is mixed evenly with carbon black, matrix resin, antioxidant and dispersant and then put into a twin-screw extruder at 130℃ for melt blending at 70 rpm for 9 min to obtain the blended mixture.

[0083] (3) Hot-press crosslinking: The blended mixture is hot-pressed at 155℃ and 12MPa for 12min to obtain the hot-pressed material;

[0084] (4) Granulation: After the hot-pressed material is cooled to room temperature, it is cut into small pieces and granulated by a granulator to obtain a semi-conductive shielding material.

[0085] Example 4

[0086] This example provides a semiconductive shielding material, comprising the following components in parts by weight:

[0087] The matrix resin (specifically EBA) consists of 62 parts, carbon black of 29 parts, COF material (specifically, third-class TpPa covalent organic framework material) of 4 parts, antioxidant (specifically antioxidant 300) of 3 parts, and dispersant (specifically PVP) of 2 parts.

[0088] The chemical structural formulas of the reactant monomers for the third type of TpPa covalent organic framework material are shown below:

[0089] .

[0090] The preparation method of the above-mentioned semiconductive shielding material includes the following steps:

[0091] (1) Preparation of COF materials: 1,3,5-trihydroxybenzophenone (Tp) and 2,5-dimethoxy-p-phenylenediamine (PDA) were dissolved in a mixed solvent of N-methylpyrrolidone (NMP) and isobutanol (volume ratio 1:1) at a molar ratio of 1:1.5. 6 mol / L glacial acetic acid, which accounts for about 15% of the total volume of the solvent, was added to the reaction system as a catalyst. The reaction was carried out at 140 °C for 120 h as a solvothermal reaction. After washing, the mixture was dried at 60 °C for 12 h to obtain the third TpPa type covalent organic framework material.

[0092] (2) Melt blending: The prepared third TpPa type covalent organic framework material is mixed evenly with carbon black, matrix resin, antioxidant and dispersant and then put into a twin-screw extruder at 125℃ for melt blending at 75 rpm for 11 min to obtain the blended mixture;

[0093] (3) Hot-press crosslinking: The blended mixture is hot-pressed at 162℃ and 12MPa for 12min to obtain the hot-pressed material;

[0094] (4) Granulation: After the hot-pressed material is cooled to room temperature, it is cut into small pieces and granulated by a granulator to obtain a semi-conductive shielding material.

[0095] Example 5

[0096] This example provides a semiconductive shielding material, comprising the following components in parts by weight:

[0097] The composition includes 55 parts of matrix resin (specifically EBA), 25 parts of carbon black, 1 part of COF material (specifically, a first-class TpPa covalent organic framework material), 1 part of antioxidant (specifically, antioxidant 300), and 1 part of dispersant (specifically, PVP).

[0098] The preparation method of the above-mentioned semiconductive shielding material is the same as that in Example 1.

[0099] Comparative Example 1

[0100] This example provides a semiconductive shielding material and its preparation method, which differs from Example 2 only in that:

[0101] (1) The weight of COF material is 0.5 parts (i.e. the amount of COF material added is too small).

[0102] Comparative Example 2

[0103] This example provides a semiconductive shielding material and its preparation method, which differs from Example 3 only in that:

[0104] (1) The COF material was adjusted to be a mixture of 1,3,5-trihydroxybenzophenone (Tp) and 2,5-dimethoxy-p-phenylenediamine (PDA) in a molar ratio of 1:1.5 (i.e., no COF material was synthesized).

[0105] Comparative Example 3

[0106] This example provides a semiconductive shielding material and its preparation method, which differs from Example 3 only in that:

[0107] (1) The weight of COF material is 8 parts (i.e., the amount of COF material added is too much).

[0108] Comparative Example 4

[0109] This example provides a semiconductive shielding material and its preparation method, which differs from Example 3 only in that:

[0110] (1) The COF material was adjusted to COF-LZU1, and its CAS number is 1242082-12-7; (i.e., the COF material is a non-TpPa type covalent organic framework material).

[0111] Test case

[0112] This example demonstrates the mechanical and electrical properties of the semiconductive shielding materials obtained in the above embodiments and comparative examples. The testing methods are as follows: The semiconductive shielding materials in the embodiments and comparative examples were prepared into plates by hot pressing molding process, which were used to test and characterize their structure and performance. The mechanical and electrical properties of the plates were tested according to GB / T 31489.2 and GB / T3048.3 standards, respectively. The test results are shown in Table 1 below.

[0113] As shown in Table 1:

[0114] Compared with Comparative Examples 1-4, Examples 1-5 have higher tensile strength, elongation at break, room temperature (23°C) resistivity, and high temperature (90°C) resistivity. Their tensile strength is 14.3-18.5 MPa, elongation at break is 255.7-295.3%, resistivity at 23°C is 11.7-18.4 Ω∙cm, and resistivity at 90°C is 89.4-130.8 Ω∙cm.

[0115] Compared to Comparative Example 1, the amount of the second TpPa type covalent organic framework material added in Example 2 was increased from 0.5 parts to 5 parts, effectively enhancing its structural role in carbon black dispersion control. Although a small amount of COF material was introduced in Comparative Example 2, the insufficient amount prevented the formation of a complete lamellar auxiliary network, resulting in a certain degree of agglomeration and interruption of conductive pathways in the carbon black, leading to limited improvement in mechanical and electrical properties. Test results showed that the tensile strength of Example 2 was 16.6 MPa, an increase of 34.1% compared to Comparative Example 2 (13.1 MPa); the elongation at break was 265.1%, an increase of 31.8% compared to Comparative Example 2 (201.2%); and the resistivity at 23℃ and 90℃ were 13.8 Ω·cm and 97.2 Ω·cm, respectively, a decrease of 51.6% and 61.4% compared to Comparative Example 2.

[0116] Compared to Comparative Example 2, Example 3 first constructed a β-ketoimine covalent organic framework structure (the third type of TpPa covalent organic framework material) between Tp and PDA via a solvothermal reaction, and then synergistically compounded it with carbon black and matrix resin, effectively controlling the spatial distribution and interfacial stability of the conductive phase. Although Comparative Example 3 used the same molar ratio of physically blended Tp and PDA monomers, no bonding polymerization reaction occurred, a stable framework structure was not formed in the system, and it lacked the layered support and confined dispersion capabilities of COF, making it difficult to achieve effective coating and network connection of carbon black. Test results show that the tensile strength of Example 3 is 18.5 MPa, which is 37.6% higher than that of Comparative Example 3 (13.4 MPa), and the elongation at break is 295.3%, which is 18.9% higher. Its resistivity at 90℃ and 23℃ is 89.4 Ω·cm and 11.7 Ω·cm, respectively, which are 65.2% and 38.4% lower than those of Comparative Example 3 (256.8 Ω·cm and 19.0 Ω·cm).

[0117] Compared to Comparative Example 3, in Example 3, when the amount of COF material added exceeded 8 parts, the high filling ratio led to an increased tendency for COF to agglomerate in the matrix, resulting in uneven filler dispersion and interfacial structural defects, thereby weakening the reinforcing effect. The tensile strength and elongation at break decreased to 9.9 MPa and 189.5%, respectively. Simultaneously, the introduction of high COF content diluted the conductive phase of carbon black, blocked the conductive path, and increased the interfacial resistance, causing the resistivity at 90°C and 23°C to increase to 298.7 Ω·cm and 30.1 Ω·cm, respectively.

[0118] Compared with Comparative Example 4, the rigid structure of COF-LZU1 in Example 3 may cause embrittlement of the material under high filling conditions, with tensile strength and elongation at break of 12.0 MPa and 221.6%, respectively. At the same time, COF-LZU1 lacks π-conjugated structure and conductive network bridging ability, and its overall performance in resistivity reduction and conductive network construction is not as good as TpPa-type COFs, with resistivity of 287.6 Ω·cm and 28.9 Ω·cm at 90℃ and 23℃, respectively.

[0119] Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible subranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0120] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A semiconductive shielding material, characterized in that, It includes the following components in parts by weight: 55-65 parts of matrix resin, 25-35 parts of carbon black, 1-5 parts of COF material, 1-3 parts of antioxidant, and 1-2 parts of dispersant; The COF material is a TpPa-type covalent organic framework material, which is obtained by solvothermal reaction of aldehyde monomers containing three ketone hydroxyl functional groups and aromatic diamine monomers.

2. The semiconductive shielding material according to claim 1, characterized in that, It includes the following components in parts by weight: The composition consists of 62 parts matrix resin, 29 parts carbon black, 4 parts COF material, 3 parts antioxidant, and 2 parts dispersant.

3. The semiconductive shielding material according to claim 1, characterized in that, The COF material includes at least one of a first TpPa type covalent organic framework material, a second TpPa type covalent organic framework material, and a third TpPa type covalent organic framework material; The chemical structural formulas of the reactant monomers for the first TpPa-type covalent organic framework material are shown below: ； The chemical structural formulas of the reactant monomers for the second type of TpPa covalent organic framework material are shown below: ； The chemical structural formulas of the reaction monomer raw materials for the third TpPa type covalent organic framework material are shown below: 。 4. The semiconductive shielding material according to any one of claims 1 to 3, characterized in that, The preparation of the COF material includes the following process: The aldehyde monomer containing three ketone hydroxyl functional groups and the aromatic diamine monomer are dissolved in an organic solvent, and then a solvothermal reaction is carried out in a closed container under acidic conditions. After the reaction is completed, the COF material is obtained by centrifugation, washing and drying. The molar ratio of the aldehyde monomer containing three ketone hydroxyl functional groups to the aromatic diamine monomer is 1:(1-2). The conditions and parameters for the solvothermal reaction include: a reaction temperature of 120-150℃ and a reaction time of 72-120 hours. The aldehyde monomer containing three ketone hydroxyl functional groups includes at least one of 1,3,5-trihydroxybenzophenone and trimethoxy-substituted trione. The aromatic diamine monomer includes at least one of p-phenylenediamine, phenylenediamine, and 2,5-dimethoxy-p-phenylenediamine; The organic solvent includes at least one selected from N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, n-butanol, isobutanol, and ethanol.

5. The semiconductive shielding material according to any one of claims 1 to 3, characterized in that, The matrix resin includes at least one of ethylene-butyl acrylate copolymer, ethylene-ethyl acrylate copolymer and ethylene-vinyl acetate copolymer; And / or, the antioxidant includes at least one of phenolic antioxidants, amine antioxidants, and thioether antioxidants; And / or, the dispersant includes at least one of nonionic surfactants, polyvinylpyrrolidone, and amide surfactants; And / or, the physicochemical properties of the carbon black include: a DBP absorption value of 100-160 mL / 100 g, and an ash content of less than 0.2 wt%.

6. The semiconductive shielding material according to claim 5, characterized in that, The phenolic antioxidant includes at least one of antioxidant 300, antioxidant 1010 and antioxidant 2246, the nonionic surfactant includes fatty acid ester surfactants, and the amide surfactant includes ethylene bis-stearamide.

7. A method for preparing a semiconductive shielding material according to any one of claims 1 to 6, characterized in that, The preparation method of the semiconductive shielding material includes the following steps: Obtain COF material; The COF material, matrix resin, carbon black, antioxidant, and dispersant are stirred and mixed, then added to a twin-screw extruder for melt blending to obtain a mixture. The mixture is subjected to hot-press crosslinking, followed by cooling and granulation to obtain the semi-conductive shielding material.

8. The method for preparing the semiconductive shielding material according to claim 7, characterized in that, The working conditions for melt blending include: temperature 120-150℃; rotation speed 30-80 rpm; and time 5-15 min. And / or, the working conditions parameters for the hot-press crosslinking include: temperature of 150-180℃, pressure of 5-15MPa, and time of 5-15min.

9. The application of a semiconductive shielding material according to any one of claims 1 to 6 or a semiconductive shielding material prepared by the preparation method according to any one of claims 7 to 8 in the preparation of high-voltage cables.

10. A high-voltage cable, characterized in that, The material includes any one of the semiconductive shielding materials according to claims 1 to 6 or semiconductive shielding materials prepared by the preparation method according to any one of claims 7 to 8.

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