Shielding material, preparation method and application thereof

Abstract

The invention discloses a shielding material as well as a preparation method and application thereof. The shielding material comprises the following raw materials: 50-76 parts of POE resin; 3 to 10 parts of an ethylene-butyl acrylate copolymer or an ethylene-ethyl acrylate copolymer; 10 to 35 parts of acetylene carbon black; 0.2 to 5 parts of an antioxidant; and 0.5-3 parts of a cross-linking agent. According to the power cable using the shielding material, an insulating layer and a shielding layer have good surface smoothness, generation and transmission of space charges at an interface can be reduced, the number of surface protrusions is reduced, degassing time in the subsequent cable production process is shortened, and cable production energy consumption is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cables, and particularly relates to an ultrahigh-voltage cable direct-current shielding material, a preparation method thereof and application thereof. BACKGROUND

[0002] The direct-current shielding material, as a key component of the ultrahigh-voltage cable, plays an important role in ensuring the safe and stable operation of the cable. However, the traditional cable shielding material has exposed many serious problems in practical application, and it is difficult to meet the increasingly stringent industry requirements. From the perspective of space charge control, the generation and accumulation of space charges of the traditional shielding material are extremely prominent in a high electric field environment. A large amount of charges gather at the interface between the insulating layer and the shielding layer, resulting in serious distortion of the electric field distribution. This electric field distortion not only accelerates the aging process of the insulating material, greatly shortens the service life of the cable, but also may cause partial discharge and even insulation breakdown, bringing great risks to the safe operation of the power system. At the same time, the ultrahigh-voltage direct-current shielding material requires the shielding material to have the characteristics of super-smoothness and low PTC effect, so as to ensure that the direct-current cable can operate stably for a long time.

[0003] At the same time, there is a certain demand for long-time extrusion in the production process of the ultrahigh-voltage cable. The long-time extrusion capability can reduce the generation of joints and reduce the risk of cable breakdown, so there is a requirement for the long-time extrusion anti-burning performance of the direct-current shielding material. Degassing is also an important process in cable production, and reducing the degassing time can effectively reduce the energy consumption of cable production. Therefore, there is a lack of a new shielding material in the prior art to solve the above technical problems. SUMMARY

[0004] The present application provides a new shielding material to solve the problems in the prior art. By using non-polar POE as the main resin matrix and compounding a small amount of ethylene polar copolymer, the surface smoothness is improved and the PTC effect of the shielding material is reduced by using POE resin, thereby reducing the generation of space charges. The dispersion of acetylene black is improved by compounding the polar copolymer, and the conductivity and surface smoothness of the material are further improved. Surprisingly, it is found that the anti-burning performance of the shielding material can be effectively improved after the two resins are compounded, so that the amount of crosslinking agent can be reduced under the premise of ensuring the crosslinking degree, and the generation of crosslinking by-products is reduced, the degassing time is reduced, and the economic efficiency of cable production is greatly improved.

[0005] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0006] In a first aspect, a shielding material comprises the following components:

[0007] POE resin 50-76 parts;

[0008] Ethylene-butyl acrylate copolymer and / or ethylene-ethyl acrylate copolymer 3-10 parts;

[0009] Acetylene carbon black 10-35 parts;

[0010] Antioxidant 0.2-5 parts;

[0011] Crosslinking agent 0.5-3 parts;

[0012] The parts are parts by mass.

[0013] Preferably, the POE resin is an ethylene / alpha-olefin copolymer, the alpha-olefin being a 1-olefin, preferably at least one of propylene, 1-butene, 1-hexene, 1-octene. 10

[0014] Preferably, the POE resin has a melting point of 90-105℃, such as 90, 92, 96, 98, 100, 102, 105℃ or a range formed by any two of them.

[0015] Preferably, the POE resin has a melt index of 1-30 g / 10 min at 190℃, 2.16 kg test conditions, such as 5, 8, 10, 13, 15, 20, 23, 25, 28, 30 g / 10 min or a range formed by any two of them; preferably the melt index is 5-15 g / 10 min.

[0016] Preferably, the POE resin has an alpha-olefin insertion rate of 30-50%, such as 30%, 33%, 35%, 38%, 40%, 42%, 45%, 47%, 50% or a range formed by any two of them, preferably the insertion rate is 32%-40%.

[0017] Preferably, the mass fraction of butyl acrylate monomer units in the ethylene-butyl acrylate copolymer is 15-27%, based on the total mass of the copolymer; the mass fraction of ethyl acrylate monomer units in the ethylene-ethyl acrylate copolymer is 15-35%, based on the total mass of the copolymer. The monomer unit content is tested using nuclear magnetic resonance.

[0018] Preferably, the ethylene-butyl acrylate copolymer and the ethylene-ethyl acrylate copolymer have a melt index of 1-10 g / 10 min at 190℃, 2.16 kg test conditions.

[0019] Preferably, the acetylene carbon black has an oil absorption value of 170-350 cc / 100 g; preferably, the acetylene carbon black has an iodine absorption value of 70-95 g / kg.

[0020] ​Preferably, the antioxidant includes one or more of hindered phenol, thio-bisphenol, hindered amine, the hindered phenol antioxidant includes at least one of antioxidant 1010, antioxidant 1076, antioxidant TMQ; the thio-bisphenol antioxidant includes antioxidant 300; the hindered amine antioxidant includes antioxidant 445.

[0021] Preferably, the crosslinking agent is an organic peroxide, preferably including one or more of 2,5-di(tert-butylperoxy)-2,5-dimethylhexane, di(tert-butylperoxy isopropyl) benzene (BIPB), tert-butyl cumyl peroxide, dicumyl peroxide (DCP).

[0022] In a second aspect, a preparation method of the shielding material is provided, including the following steps:

[0023] The base resin, acetylene carbon black and antioxidant are mixed, extruded, pelletized and dried, and then the crosslinking agent is added for post-absorption crosslinking.

[0024] Specifically, the base resin includes POE resin, ethylene-butyl acrylate copolymer or ethylene-ethyl acrylate copolymer.

[0025] Specifically, the mixing can be performed by using a reciprocating mixer, the melt is filtered through a screen changer, and then enters a melt pump for pressurized extrusion.

[0026] Specifically, the pelletization can be performed by using an underwater pelletization system, and after drying, the particles enter a mixer, the crosslinking agent is atomized and sprayed into the mixer, and then the particles are crosslinked after rotary heating.

[0027] Preferably, the mixing part of the reciprocating mixer is a reciprocating single-screw extruder.

[0028] Preferably, the mixing temperature is 170-220°C, the atomization temperature of the crosslinking agent is 60-75°C, and the post-absorption temperature after rotary heating is 60-85°C.

[0029] In a third aspect, the shielding material can be used for the semiconductive layer of a power cable, especially a high-voltage cable, and more preferably an extra-high-voltage cable.

[0030] Compared with the prior art, the present application has the following positive effects:

[0031] By using POE as the main resin, uniform dispersion of the conductive filler is achieved during the preparation process, carbon black agglomeration is reduced, the smoothness of the shielding layer is improved, and the high-temperature conductivity is improved, the cable electric field concentration and breakdown phenomenon are reduced; the prepared shielding material can almost not have protrusions of more than 50 μm, has the characteristics of super-smoothness, and has excellent conductivity, the resistivity changes little with temperature; the amount of crosslinking agent is reduced, and the degassing time and energy consumption in the subsequent cable production process are reduced. Detailed Implementation

[0032] The present invention will be further described below with reference to the embodiments, but the scope of protection of the present invention is not limited to the embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0033] Reciprocating mixer: Swiss BUSS AG, model: MX-30.

[0034] POE-1: ExxonMobil, EXACT TM POE 0210, with a melt index of 10 g / 10 min and an octene insertion rate of 38% under test conditions of 190℃ and 2.16 kg.

[0035] POE-2: ExxonMobil, EXACT TM POE 3139 has a melt index of 8 g / 10 min and an octene insertion rate of 35% under test conditions of 190℃ and 2.16 kg.

[0036] POE-3: Wanhua Chemical, POE5136, melt index of 13g / 10min under test conditions of 190℃ and 2.16kg, octene insertion rate of 40%.

[0037] EBA-1: Ethylene-butyl acrylate copolymer, Dow Chemical, 3717, with a butyl acrylate monomer unit mass fraction of 17% and a melt index of 7 g / 10 min under test conditions of 190°C and 2.16 kg.

[0038] EBA-2: Ethylene-Butyl Acrylate Copolymer, Dow Chemical ELVALOY TM AC 3427 has a butyl acrylate monomer unit mass fraction of 27% and a melt index of 4 g / 10 min under test conditions of 190℃ and 2.16 kg.

[0039] EEA-1: Ethylene-ethyl acrylate copolymer, Dow Chemical, Elvaloy TM AC 2116 has a mass fraction of ethyl acrylate monomer units of 16% and a melt index of 1 g / 10 min under test conditions of 190℃ and 2.16 kg.

[0040] EEA-2: Ethylene-ethyl acrylate copolymer, Dow Chemical, AMPLIFY TM EA 101 has a mass fraction of 20% ethyl acrylate monomer units and a melt index of 6 g / 10 min under test conditions of 190℃ and 2.16 kg.

[0041] Carbon black: DENKA acetylene black (Japan Electronic Chemical, oil absorption value 189 cc / 100 g, iodine absorption value 93 g / kg); Cabot, VXC500, furnace carbon black (oil absorption value 153 cc / 100 g, iodine absorption value 75 g / kg).

[0042] Crosslinking agent: Bis-tert-butyl peroxyisopropylbenzene BIPB, Akema.

[0043] Other raw materials described in the examples are commercially available products.

[0044] Mechanical property test: the test method is in accordance with ISO 527, ISO 178 and ISO 180 standards, using INSTRON tensile tester INSTRON 5966, and the sample uses 5A standard sample, and the tensile rate is 200 mm / min.

[0045] Density test: the test method is in accordance with GB / T 1033.1 immersion method. Square test pieces are used, with a thickness of 2.0±0.1 mm and a side length of 20-25 mm.

[0046] Thermal extension: it should be executed in accordance with GB / T 2951.5, and the sample preparation should be executed in accordance with GB / T 1040.2.

[0047] Volume resistivity: the volume resistivity at 23℃ is determined, which is executed in accordance with GB / T 3048.3, and the sample is adjusted in an environment with a temperature of 23±3℃ and a relative humidity of 50±5% for not less than 24 h. The volume resistivity at 90℃ is determined, which should be executed in accordance with the provisions in Appendix A of GB / T 3048.3. The volume resistivity at 90℃ after thermal aging at 135℃ for 7 d is determined, which should be executed in accordance with the provisions in Appendix A of GB / T 3048.3, and the thermal aging is executed in accordance with the provisions in GB / T 2951.12.

[0048] Surface protrusion: it is executed in accordance with the provisions in Appendix A of Q / GDW 11883.2—2018 standard, and the detection instrument should have a protrusion height resolution better than 10 μm. Sampling and test standard: thousand-level clean room.

[0049] Space charge: the test is performed using the electro-acoustic pulse method (PEA), and the test equipment is a solid medium space charge test system built by Shanghai Jiaotong University. The semi-conductive electrode uses the shielding material of the examples and the comparative examples, and the insulating layer uses LS4201EHV of Nordic Chemical Industry. The FEF parameter is introduced to represent the space charge, wherein v peak is the peak height (mV) of the ground electrode signal voltage when a high voltage U=40 kv is applied; v peak,cal is the peak height (mV) of the ground electrode signal voltage when a low voltage U cal(kV) when calibration measurements are performed. In the case of a space charge of the same sign as the ground electrode, the electric field will be lower than the calculated field assuming no space charge, i.e. FEF<1. Conversely, when a space charge of the opposite sign is present, the field is higher, i.e. FEF>1. FEF=1 indicates that the space charge has no effect on the ground electrode electric field. The closer the FEF value is to 1, the less space charge is generated.

[0050] Example 1

[0051] The present example provides a shielding material, the cable shielding material includes 60.6 parts by weight of POE-1 resin, 5 parts of EBA-1 resin, 33 parts of DENKA carbon black, 0.6 parts of antioxidant 300, 0.8 parts of crosslinking agent bis-tert-butyl peroxyisopropylbenzene (BIPB).

[0052] The present example provides a preparation method of a cable shielding material, comprising the following steps:

[0053] POE-1, EBA-1 resin, DENKA carbon black, antioxidant 300 are added to the reciprocating mixer for mixing, filtered in the screen changer, pressurized extruded by the melt pump, and the melt is granulated by the underwater pelletizing system and air-dried to obtain a resin composite material; then spray the molten mist BIPB, heat and shake evenly, and then absorb. The mixing and feeding section temperature is 80℃, the melting section temperature is 180℃, the plasticizing section temperature is 190℃, and the extruding section temperature is 200℃, and the screw rotation speed is 300 rpm; in the extruding and granulating, the die head temperature is 200℃, the underwater cutting temperature is 40℃, and the air-drying temperature is 70℃; the BIPB melting temperature is 70℃, and the post-absorption crosslinking temperature is 70℃.

[0054] Example 2

[0055] The present example provides a shielding material, the cable shielding material includes 50 parts by weight of POE-1 resin, 3 parts of EEA-1, 10 parts of DENKA carbon black, 0.2 parts of antioxidant 1010, 0.5 parts of crosslinking agent dicumyl peroxide (DCP).

[0056] The preparation method of the cable shielding material of the present example is as follows:

[0057] POE-1 resin, EEA-1 resin, DENKA carbon black and antioxidant 1010 were put into a reciprocating mixer. During mixing, the temperature of feeding section was set to 75°C, the temperature of melting section was 175°C, the temperature of plasticizing section was 185°C, the temperature of extruding section was 195°C, and the screw rotation speed was 280 rpm. After mixing, the material was filtered by a screen changer, and then was extruded by a melt pump under pressure, and was granulated by an underwater granulating system (the temperature of die head was 200°C, and the temperature of underwater cutting was 40°C), and was dried by blowing air at 65°C. Then, DCP was heated to a molten state, and was sprayed to the dried granules after atomization, and was heated to 70°C and was shaken to be fully absorbed.

[0058] Example 3

[0059] In this example, a shielding material was provided, which included, by weight parts, 76 parts of POE-1, 10 parts of EBA-1, 25 parts of DENKA carbon black, 5 parts of antioxidant 300, and 3 parts of crosslinking agent BIPB.

[0060] The preparation steps of the cable shielding material were as follows:

[0061] POE-1 resin, EBA-1, DENKA carbon black and antioxidant 300 were put into a reciprocating mixer. During mixing, the temperature of feeding section was 85°C, the temperature of melting section was 185°C, the temperature of plasticizing section was 195°C, the temperature of extruding section was 205°C, and the screw rotation speed was 320 rpm. After mixing, the material was filtered by a screen changer, and then was extruded by a melt pump under pressure, and was granulated by an underwater granulating system (the temperature of die head was 200°C, and the temperature of underwater cutting was 40°C), and was dried by blowing air at 75°C. After that, BIPB was heated to 75°C to be molten and atomized, and was sprayed to the granules, and was heated to 85°C and was shaken to be absorbed.

[0062] Example 4

[0063] In this example, a shielding material was provided, which included, by weight parts, 65 parts of POE-2 resin, 8 parts of EEA-2, 30 parts of DENKA acetylene black, 1 part of antioxidant 300, and 1.5 parts of a mixture of crosslinking agents BIPB and DCP (mass ratio 1:1).

[0064] The preparation method was as follows:

[0065] POE-2 resin, EEA-2, DENKA acetylene black and antioxidant 300 were added into a reciprocating mixer. The temperature of the mixing feeding section was set at 82°C, the temperature of the melting section was set at 182°C, the temperature of the plasticizing section was set at 192°C, the temperature of the extruding section was set at 202°C, and the screw rotation speed was set at 310 rpm. After the material was filtered by a screen changer and extruded by a melt pump, the material was granulated by an underwater pelletizing system (the temperature of the die head was 200°C, and the temperature of the underwater pelletizing was 40°C), and then was dried by blowing air at 72°C. BIPB and DCP were mixed in a certain proportion, heated to 72°C to be melted and atomized, sprayed into the granules, heated to 82°C, and then shaken to be absorbed.

[0066] Example 5

[0067] This example provides a shielding material. The cable shielding material includes, by weight, 58 parts of POE-3, 6 parts of EBA-2, 28 parts of DENKA acetylene black, 0.3 parts of antioxidant 300, and 0.8 parts of crosslinking agent BIPB.

[0068] The preparation method is as follows:

[0069] POE-3 resin, EBA-2, DENKA acetylene black and antioxidant 300 were added into a reciprocating mixer. The temperature of the mixing feeding section was set at 80°C, the temperature of the melting section was set at 180°C, the temperature of the plasticizing section was set at 190°C, the temperature of the extruding section was set at 200°C, and the screw rotation speed was set at 300 rpm. After the material was filtered by a screen changer and extruded by a melt pump, the material was granulated by an underwater pelletizing system (the temperature of the die head was 200°C, and the temperature of the underwater pelletizing was 40°C), and then was dried by blowing air at 70°C. BIPB was heated to 70°C to be melted and atomized, sprayed into the granules, heated to 80°C, and then shaken to be absorbed.

[0070] Example 6

[0071] This example provides a shielding material. The cable shielding material includes, by weight, 70 parts of POE-1, 4 parts of EEA-2, 27 parts of DENKA acetylene black, 0.5 parts of antioxidant 1076, and 1.5 parts of crosslinking agent DCP.

[0072] The preparation process is as follows:

[0073] POE-1 resin, EEA-2 resin, DENKA acetylene black and antioxidant 1076 were added into a reciprocating mixer. The temperature of the mixing feeding section was set at 78°C, the temperature of the melting section was set at 178°C, the temperature of the plasticizing section was set at 188°C, the temperature of the extruding section was set at 198°C, and the screw rotation speed was set at 290 rpm. After the material was filtered by a screen changer and extruded by a melt pump, the material was granulated by an underwater pelletizing system (the temperature of the die head was 200°C, and the temperature of the underwater pelletizing was 40°C), and then was dried by blowing air at 68°C. DCP was heated to be melted and atomized, sprayed into the granules, heated to 80°C, and then shaken to be absorbed.

[0074] Example 7

[0075] This example provides a shielding material, the cable shielding material includes 55 parts of POE-1, 7 parts of EBA-2, 32 parts of DENKA acetylene black, 0.4 parts of a mixture of antioxidant 300 and antioxidant 1010 (mass ratio 1:1), 1 part of crosslinking agent BIPB by weight.

[0076] The preparation method is as follows:

[0077] POE-1 resin, EBA-2, DENKA acetylene black and antioxidant mixture are added to a reciprocating mixer. The mixing feeding section temperature is 81°C, the melting section temperature is 181°C, the plasticizing section temperature is 191°C, the extrusion section temperature is 201°C, and the screw speed is 305 rpm. After filtering through a screen changer, pressurizing and extruding by a melt pump, underwater pelletizing (die head temperature is 200°C, underwater cutting temperature is 40°C), and air drying at 71°C. BIPB is heated to 71°C, melted and atomized, sprayed into the particles, and heated to 81°C to shake evenly and absorb.

[0078] Example 8

[0079] This example provides a shielding material, the cable shielding material includes 62 parts of POE-1, 5 parts of EEA-2, 29 parts of DENKA acetylene black, 0.8 parts of antioxidant 300, and a mixture of 1.2 parts of crosslinking agent BIPB and DCP (mass ratio 2:1) by weight.

[0080] The preparation method is as follows:

[0081] POE-1 resin, EEA-2, DENKA acetylene black, and antioxidant 300 are placed in a reciprocating mixer. The mixing feeding section temperature is set to 83°C, the melting section temperature is 183°C, the plasticizing section temperature is 193°C, the extrusion section temperature is 203°C, and the screw speed is 315 rpm. After filtering through a screen changer, pressurizing and extruding by a melt pump, underwater pelletizing (die head temperature is 200°C, underwater cutting temperature is 40°C), and air drying at 73°C. BIPB and DCP are mixed in proportion, heated to 73°C, melted and atomized, sprayed into the particles, and heated to 83°C to shake evenly and absorb.

[0082] Comparative Example 1

[0083] This comparative example provides a shielding material, the cable shielding material includes 65.6 parts of EBA-1 resin, 33 parts of DENKA acetylene black, 0.6 parts of antioxidant 300, and 0.8 parts of crosslinking agent BIPB by weight.

[0084] The preparation method of the cable shielding material of this comparative example is as follows:

[0085] EBA-1 resin, DENKA acetylene black, antioxidant 300 were added into a reciprocating mixer. The temperature of the feeding section was 80℃, the temperature of the melting section was 180℃, the temperature of the plasticizing section was 190℃, and the temperature of the extruding section was 200℃. The screw rotation speed was 300 rpm. After the material was filtered by a screen changer, pressurized by a melt pump, and extruded, underwater pelletization was performed (the temperature of the die head was 200℃, and the temperature of the underwater pelletizer was 40℃), and the pellets were dried by blowing air at 70℃. BIPB was heated to a molten state and then added to the pellets. After being heated to 70℃, the mixture was shaken to absorb the BIPB.

[0086] Comparative Example 2

[0087] The cable shielding material of the present example comprises, by weight, 60.6 parts of POE-1 resin, 5 parts of EBA-1 resin, 33 parts of furnace carbon black VXC500, 0.6 parts of antioxidant 300, and 0.8 parts of crosslinking agent bis-tert-butyl peroxyisopropylbenzene (BIPB).

[0088] The cable shielding material of the present example was prepared by the same method as in Example 1, except that the carbon black was replaced by furnace carbon black VXC500.

[0089] The test samples of each example and comparative example were prepared by a pellet molding method according to the provisions of 6.2.1 in JB / T10738-2007. The test pieces should be smooth, uniform in thickness, and free of bubbles. The thickness of the test pieces should meet the provisions of each test item. The test standards were referred to Q / GDW11883.2-2018, and the standard values are shown in the table. The shielding materials obtained in the examples and comparative examples were tested according to the standard requirements, and the results are shown in Table 1.

[0090] Table 1: Main physical property parameters of each example and comparative example

[0091]

[0092]

[0093] As can be seen from the data in Table 1, the basic properties of the cable shielding materials prepared from the compositions in Examples 1-8 all meet the requirements of Q / GDW11883.2-2018. Compared with the examples, the mechanical properties of the comparative examples are poor, the volume resistivity is out of standard, the surface protrusions are serious and do not meet the standard, and the degassing time and space charge are different from the examples.

[0094] As can be seen from the above comparison, the ultra-high voltage cable shielding material prepared by the present application meets the requirements of ultra-high voltage, greatly reduces the number of surface protrusions of the shielding material, greatly improves the smoothness of the material, shortens the degassing time, reduces the generation of space charge, and can meet the use requirements.

[0095] The above embodiments are only used to describe the preferred embodiments of the present application and not intended to limit the scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can make various modifications and improvements, and the modifications and improvements made by the technical solutions of the present application and the equivalent replacements should fall into the scope of protection defined by the claims of the present application.

Claims

1. A shielding material, characterized in that, Its raw materials contain the following components in parts by weight: 50-76 parts of POE resin; 3-10 parts of ethylene-butyl acrylate copolymer and / or ethylene-ethyl acrylate copolymer; 10-35 parts of acetylene black; Antioxidant 0.2-5 parts; Crosslinking agent 0.5-3 parts.

2. The shielding material according to claim 1, characterized in that, The POE resin satisfies at least one of the following conditions: (1) The POE resin is an ethylene / α-olefin copolymer, wherein the α-olefin is C3-C 10 The 1-olefin; preferably, the α-olefin insertion rate in the POE resin is 30-50%, more preferably 32-40%; (2) The melt index of POE resin under test conditions of 190℃ and 2.16kg is 1-30g / 10min, preferably 5-15g / 10min.

3. The shielding material according to claim 1, characterized in that, The butyl acrylate monomer units in the ethylene-butyl acrylate copolymer have a mass fraction of 15-27% based on the copolymer mass; and / or the ethyl acrylate monomer units in the ethylene-ethyl acrylate copolymer have a mass fraction of 15-35% based on the copolymer mass.

4. The shielding material according to any one of claims 1-3, characterized in that, The antioxidants include one or more of hindered phenols, thiobisphenols, and hindered amines, and preferably include one or more of antioxidants 1010, 1076, TMQ, 300, and 445.

5. The shielding material according to any one of claims 1-3, characterized in that, The crosslinking agent is an organic peroxide, preferably including one or more of 2,5-di(tert-butylperoxide)-2,5-dimethylhexane, di(tert-butylperoxide isopropyl)benzene, tert-butylcumyl peroxide, and dicumyl peroxide.

6. The method for preparing the shielding material according to any one of claims 1-5, characterized in that, Includes the following steps: The POE resin, copolymer, acetylene black, and antioxidant are mixed, extruded, pelletized, and dried, and then a crosslinking agent is added for post-absorption crosslinking.

7. A power cable having a semiconductive layer made of the shielding material according to any one of claims 1 to 5.

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