Anti-scorching cable shielding material as well as preparation method and application thereof

Abstract

The invention provides an anti-scorching cable shielding material as well as a preparation method and application thereof, the anti-scorching cable shielding material is prepared from components including an ethylene polymer and an epoxy modified ethylene polymer, and the total weight of the ethylene polymer and the epoxy modified ethylene polymer is 100 parts by weight, the weight of the ethylene polymer is 60-95 parts by weight; the weight part of the epoxy modified ethylene polymer is 5-40. The anti-scorching cable shielding material provided by the invention is wide in processing condition, good in anti-scorching effect and excellent in crosslinking performance, and can be used as a medium-voltage, high-voltage and ultrahigh-voltage cable shielding material.

Description

Technical Field

[0001] The present invention relates to the field of cable shielding materials, and more particularly to a scorch-resistant cable shielding material and a preparation method and application thereof. Background Art

[0002] Medium / high / extra-high voltage (MV / HV / EHV) cable constructions typically include a primary semiconducting shield, an insulating layer, a secondary semiconducting shield, and a protective sheath for a grounded wire or tape shield. Polymer semiconducting shields have been used in multilayer power cable constructions. These shields provide an intermediate resistivity layer between the high-potential conductor and the primary insulation layer, and between the primary insulation layer and the ground or neutral potential layer. The primary purpose of the semiconducting shield between the conductor and the insulation layer in electrical power cable constructions is to ensure the long-term viability of the solid insulation layer.

[0003] Scorch resistance has always been a significant issue in the processing of cable shielding and insulation materials. Scorch in shielding materials, in particular, not only affects the cable production process, such as curing temperature and processing time, but also leads to a series of quality issues, such as affecting mechanical properties (especially thermal elongation), electrical conductivity, and interface smoothness.

[0004] In order to improve the anti-scorch performance, Chinese patent CN107325389A discloses a scorch-resistant semiconductor shielding material for high-voltage cables and a preparation method thereof. By adding various anti-scorch agents, such as NOBS, PBTT, TAIC, TMPTMA, MOAB, CBS, OTOS, etc., these compounds generally contain sulfur compounds or are good temporary free radical acceptors. They can also partially participate in the cross-linking reaction and can also be good cross-linking aids (such as TAIC, PMPTMA). This invention can reduce the initial cross-linking reaction rate of the system by adding these compounds, without reducing the cross-linking degree of the system or having little effect on the cross-linking degree of the system; however, with the increasing process control and performance requirements for cable production, these common anti-scorch compounds cannot meet the requirements. In particular, in the production of high-voltage or ultra-high-voltage cables, excellent scorch resistance is a very important research direction.

[0005] In the production of high-voltage or ultra-high-voltage cables, special antioxidants are generally compounded with peroxide crosslinkers to achieve better anti-scorch effect. Australian patent AU784703B2 discloses a stable medium- and high-voltage cable insulation composition, which mentions that sulfur-containing compound anti-scorch agents are compounded with special amine anti-scorch agents to achieve better anti-scorch effect. These sulfur-containing compound anti-scorch agents include IRGASTAB Cable KV10, which is widely used in cable production to increase the scorch time without affecting the crosslinking performance of the system. The sulfur-containing compound anti-scorch agent and the special amine anti-scorch agent are compounded according to a certain chemical structure and ratio to enhance the compatibility of peroxide and ethylene copolymer, thereby improving the dispersibility of peroxide in ethylene copolymer, thereby achieving more precise regulation of the speed and degree of the crosslinking reaction and achieving better anti-scorch effect. Summary of the Invention

[0006] In order to further improve the scorch resistance, processing performance and quality of cable shielding materials, the present invention provides a cable shielding material and a preparation method thereof. The special amine anti-scorch agent added to the formula can be grafted onto the ethylene polymer with epoxy groups through a chemical reaction (such as the reaction of amine and epoxy group), thereby improving the material's scorch resistance and curing degree. The obtained cable shielding material has wide processing conditions and excellent performance.

[0007] Firstly, one of the objects of the present invention is to provide a scorch-resistant cable shielding material.

[0008] Specifically, the scorch-resistant cable shielding material is made of components including ethylene polymer and epoxy-modified ethylene polymer, wherein, based on 100 parts by weight of the total weight of ethylene polymer and epoxy-modified ethylene polymer, the weight of ethylene polymer is 60 to 95 parts by weight; preferably 80 to 95 parts by weight; the weight of epoxy-modified ethylene polymer is 5 to 40 parts by weight, preferably 5 to 20 parts by weight.

[0009] Among them, the ethylene polymer can be one or a combination of an elastomer, a flexible body or a plastomer; it can be one or a combination of non-polar and / or polar ethylene polymers, preferably a combination of non-polar and polar ethylene polymers; the epoxy-modified ethylene polymer can be one or a combination of ethylene oxide-modified non-polar and / or polar ethylene polymers; preferably, the epoxy degree of the epoxy-modified ethylene polymer (the molar amount of epoxy groups contained per kilogram of polymer) is 0.01 to 1 mol / kg, preferably 0.1 to 0.7 mol / kg, and more preferably 0.2 to 0.5 mol / kg.

[0010] It is worth mentioning that the epoxy group can be grafted onto the molecular chain of the ethylene copolymer through a grafting reaction or through polymerization.

[0011] Furthermore, the non-polar ethylene polymer is obtained by polymerizing components including ethylene, or at least one α-olefin, or and a diene, wherein the α-olefin is selected from α-olefins containing 3 to 12 carbon atoms, preferably containing 4 to 8 carbon atoms, and is particularly preferably selected from one or a combination of propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene; and the diene is selected from one or a combination of isoprene, 1,3-butadiene, and 1,5-cyclooctadiene.

[0012] Furthermore, in the non-polar ethylene polymer, the weight of α-olefin accounts for 1-20 wt% of the total weight of the polymer, preferably 5-20 wt%; the weight of the diene unit accounts for 1-10 wt% of the total weight of the polymer, preferably 1-3 wt%.

[0013] It is worth mentioning that the non-polar ethylene polymer of the present invention can be high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), very low density polyethylene (VLDPE), homogeneously branched linear ethylene / α-olefin copolymer, homogeneously branched substantially linear ethylene / α-olefin polymer, ethylene block copolymer; preferably, it is a homogeneously branched linear ethylene copolymer.

[0014] Furthermore, the polar ethylene polymer is obtained by polymerizing components including ethylene and at least one unsaturated alkyl ester; wherein the unsaturated alkyl ester is selected from unsaturated alkyl esters containing 4 to 40 carbon atoms, preferably containing 4 to 7 carbon atoms, and particularly preferably selected from one or a combination of alkyl acrylates, alkyl methacrylates, and vinyl carboxylates; wherein the alkyl group in the alkyl acrylates and alkyl methacrylates contains 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, or the alkyl group can be substituted by an oxyalkyltrialkoxysilane, and particularly preferably selected from glycidyl methacrylate, lauryl methacrylate, myristyl methacrylate, palmitoyl methacrylate, octadecyl methacrylate, 3-methacryloylpropyltrimethoxysilane ... The present invention can be selected from the group consisting of acyloxy, cyclohexyl methacrylate, isodecyl methacrylate, 2-methoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, octyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl methacrylate, octyl methacrylate, isooctyl methacrylate, oleyl methacrylate, ethyl acrylate, methyl acrylate, tert-butyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, and tert-butyl acrylate; the carboxylate group contains 2 to 8 carbon atoms, preferably 2 to 5 carbon atoms, and the vinyl carboxylate is particularly preferably selected from the group consisting of vinyl acetate, vinyl butyrate, vinyl pivalate, vinyl neononanoate, vinyl neodecanoate, and ethylene 2-ethylhexanoate.

[0015] Furthermore, in the polar ethylene polymer, the weight of the unsaturated alkyl ester accounts for 5 to 55 wt%, preferably 8 to 40 wt%, of the total weight of the polymer.

[0016] Furthermore, the components for preparing the cable shielding material also include carbon black, peroxide, special amine anti-scorch agent, sulfur-containing anti-scorch agent, and antioxidant. The weight parts of each component are as follows based on 100 parts by weight of the total weight of the ethylene polymer and the epoxy-modified ethylene polymer:

[0017] 50 to 80 parts by weight of carbon black, preferably 60 to 70 parts by weight;

[0018] Peroxide 0 to 5 parts by weight; preferably 1 to 4 parts by weight;

[0019] 0.01 to 1 parts by weight of a special amine anti-scorch agent, preferably 0.2 to 0.7 parts by weight;

[0020] 0.01 to 1 parts by weight, preferably 0.2 to 0.7 parts by weight, of a sulfur-containing anti-scorch agent;

[0021] The antioxidant is 0.01 to 1 part by weight, preferably 0.2 to 0.7 part by weight.

[0022] Preferably, the particle size of the carbon black is 25 to 50 nm, the oil absorption value (DBP) is 130 to 150 mL / 100 g, more preferably 40 to 70 mL / 100 g, and the residue after passing through a 325-mesh sieve is ≤200 ppm.

[0023] Preferably, the peroxide is selected from one or a combination of dicumyl peroxide, tert-butyl peroxide isopropyl, lauroyl peroxide, benzoyl peroxide, tert-butyl perbenzoate, di(tert-butyl) peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl hydroperoxide, isopropyl percarbonate and α,α'-bis(tert-butylperoxy)diisopropylbenzene.

[0024] Preferably, the special amine anti-scorch agent is selected from one or a combination of diphenylamine, 4,4'-di-tert-octyldiphenylamine, 4-tert-butyldiphenylamine, 4-tert-octyldiphenylamine, 4,4'-di-tert-butyldiphenylamine, 2,4,4'-tri-tert-butyl-diphenylamine, 4-tert-butyl-4'-tert-octyldiphenylamine, p,p'-di-tert-octyldiphenylamine, 2,4-di-tert-butyl-4'-tert-octyldiphenylamine, 4,4'-di-tert-octyldiphenylamine, and 2,4-di-tert-octyl-4'-tert-butyldiphenylamine.

[0025] Preferably, the sulfur-containing anti-scorch agent is selected from the sulfur-containing anti-scorch agent disclosed in patent AU784703B2, such as 2,6-di-tert-butyl-4-(octyloxycarbonylmethylthiomethyl)phenol, the specific structure of which is as follows:

[0026]

[0027] Preferably, the antioxidant is selected from conventional antioxidants in the art, such as antioxidant 1010.

[0028] Secondly, the second object of the present invention is to provide a method for preparing the scorch-resistant cable shielding material of one of the objects of the present invention.

[0029] Specifically, the method comprises the following steps:

[0030] Step 1: premixing an ethylene polymer and an epoxy-modified ethylene polymer with an antioxidant, and then adding carbon black to mix, to obtain a shielding material masterbatch containing carbon black;

[0031] Step 2: heating the anti-scorch agent, or the anti-scorch agent and the peroxide, to obtain a transparent liquid mixture;

[0032] Step 3: The shielding masterbatch containing carbon black obtained in step 1 is heated and mixed with the transparent liquid mixture obtained in step 2 to obtain the cable shielding material.

[0033] More specifically, the method comprises the following steps:

[0034] Step 1: premixing the ethylene polymer and the epoxy-modified ethylene polymer with an antioxidant, and then adding carbon black and mixing. The temperature of the internal mixer is 125-135° C., and the internal mixer is mixed for 10-15 minutes to obtain a shielding material masterbatch containing carbon black;

[0035] Step 2: slowly heating the anti-scorch agent, or the anti-scorch agent and the peroxide to obtain a transparent liquid mixture;

[0036] Step 3: Heat the carbon black-containing shielding masterbatch obtained in step 1 to 70-80°C in an oven, then add the transparent liquid mixture obtained in step 2 to the shielding masterbatch in step 1, stir, and place in an oven. Repeat this process several times until all the liquid is absorbed by the shielding masterbatch to obtain the cable shielding material.

[0037] Again, the third object of the present invention is to provide an application of the cable shielding material which is one of the objects of the present invention.

[0038] Specifically, the cable shielding material provided by the present invention is used for medium voltage, high voltage, and ultra-high voltage cable shielding materials.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The present invention adopts an ethylene copolymer with epoxy groups to interact with a special amine anti-scorch agent to form an ethylene copolymer with a special amine group, which not only improves the anti-scorch performance of the material, but also increases the crosslinking degree of the system.

[0041] The reaction process of the special amine anti-scorch agent and the ethylene polymer with epoxy group is as follows:

[0042]

[0043] 2. The special amine anti-scorch agent used in the present invention can be grafted onto ethylene polymers with epoxy groups (such as EBA, EEA, PE) through chemical reactions (such as the reaction of amines with epoxy groups), and then together with special sulfur-containing compound anti-scorch agents, it can play a better anti-scorch effect. Moreover, since amines can catalyze the reaction of epoxy groups, the degree of curing of the system can be improved. The obtained cable shielding material has wide processing conditions, high cross-linking degree, and excellent anti-scorch effect.

[0044] 3. The present invention provides a cable shielding material that is well suited for medium voltage, high voltage or ultra-high voltage cables. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below with reference to specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0046] In the following examples and comparative examples, the raw materials are all derived from commercially available products, among which:

[0047] Polar ethylene copolymer E1770 was purchased from REPSOL (Repsol, Spain), with a butyl acrylate (BA) content of 17% and a melt index (MI) of 7 g / 10 min.

[0048] Non-polar ethylene copolymer LDPE780E was purchased from DOW Chemical, with a melt index (MI) of 2 to 10 g / 10 min.

[0049] Epoxy-modified ethylene polymer Lotader AX8840 was purchased from Ama, France, with a GMA (glycidyl methacrylate) content of 8 wt%, an epoxidation degree of 0.56 mol (epoxy groups) / 1 kg (polymer), and a melt index (MI) of 5 g / 10 min.

[0050] Carbon black VXC500 was purchased from Cabot, with a particle size of 30 nm, an oil absorption value of 140 mL / 100 g, and a residue of ≤10 ppm after passing through a 325-mesh sieve.

[0051] Example 1

[0052] This example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are as follows:

[0053] Step 1: premix the ethylene polymer, epoxy-modified ethylene polymer and antioxidant, add carbon black and mix in a small laboratory internal mixer, set the temperature of the internal mixer to 130°C, and mix for 15 minutes to obtain a shielding material masterbatch containing carbon black.

[0054] Step 2: Mix the peroxide, the special amine anti-scorch agent, and the sulfur-containing anti-scorch agent and slowly heat until a transparent liquid mixture is obtained.

[0055] Step 3: Heat the carbon black-containing shielding masterbatch obtained in step 1 to 70°C in an oven, add the transparent liquid mixture obtained in step 2 to the carbon black-containing shielding masterbatch, stir, and place in an oven. Repeat this process several times until all the liquid is absorbed by the shielding masterbatch to obtain a scorch-resistant cable shielding material.

[0056] The scorch time and maximum torque tests of the scorch-resistant cable shielding material prepared in this embodiment are performed as follows:

[0057] Test method for scorch time:

[0058] 45 g of the above material was added to a small laboratory kneader (model, Brabender Plasticorder814300) and melted at a temperature of 130° C., a speed of 30 rpm, and a pressure of 2 kg. The scorch time was the time when the rotor torque of the kneader increased by 1 Nm.

[0059] Maximum torque test method:

[0060] Maximum torque is measured on a laboratory rheometer (MDR2000). A 6g sample is placed on the rheometer's sample pan and heated to 180°C. The rheometer's dynamic vibration frequency is 1.66Hz, and the vibration angle is ±3°. As the sample solidifies, the torque increases continuously until it stops (generally within 20-30 minutes). The maximum torque is the highest value achieved within these 20-30 minutes.

[0061] The specific evaluation results of the anti-scorch cable shielding material of this embodiment are shown in Table 2.

[0062] Example 2

[0063] This example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are the same as those in Example 1.

[0064] The specific evaluation results of the scorch-resistant cable shielding material of this embodiment are shown in Table 2. The evaluation method is the same as that of Example 1.

[0065] Example 3

[0066] This example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are the same as those in Example 1.

[0067] The specific evaluation results of the scorch-resistant cable shielding material of this embodiment are shown in Table 2. The evaluation method is the same as that of Example 1.

[0068] Example 4

[0069] This example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are the same as those in Example 1.

[0070] The specific evaluation results of the scorch-resistant cable shielding material of this embodiment are shown in Table 2. The evaluation method is the same as that of Example 1.

[0071] Example 5

[0072] This example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are the same as those in Example 1.

[0073] The specific evaluation results of the scorch-resistant cable shielding material of this embodiment are shown in Table 2. The evaluation method is the same as that of Example 1.

[0074] Example 6

[0075] This example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are the same as those in Example 1.

[0076] The specific evaluation results of the scorch-resistant cable shielding material of this embodiment are shown in Table 2. The evaluation method is the same as that of Example 1.

[0077] Comparative Example 1

[0078] This comparative example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are the same as those in Example 1.

[0079] The specific evaluation results of the cable shielding material of this comparative example are shown in Table 2, and the evaluation method is the same as that of Example 1.

[0080] Comparative Example 2

[0081] This comparative example is used to illustrate the preparation of a scorch-resistant cable shielding material. The components and weight parts used are shown in Table 1. The specific steps are the same as those in Example 1.

[0082] The specific evaluation results of the cable shielding material of this comparative example are shown in Table 2, and the evaluation method is the same as that of Example 1.

[0083] Table 1 shows the raw material components and weight proportions of the components required for preparing the scorch-resistant cable shielding materials of Examples 1 to 3 and Comparative Examples 1 to 4.

[0084] Table 1:

[0085]

[0086]

[0087] Table 2 shows the test results of the scorch time and maximum torque performance of the scorch-resistant cable shielding materials provided by Examples 1 to 6 and Comparative Examples 1 to 2.

[0088] Table 2:

[0089]

[0090] As shown in Table 2, the materials provided by Examples 1 to 6 not only have a scorch time greater than 10 minutes, but also have a large torque, and are excellent scorch-resistant cable shielding materials.

[0091] Furthermore, it can be seen from Examples 5 and 6 that when no special amine anti-scorch agent is added, the maximum torque of the material is significantly reduced, but it can still be used as a shielded cable.

[0092] Furthermore, Comparative Examples 1 and 2 show that the scorch time of the materials is significantly reduced when no epoxy-containing ethylene copolymer and / or no special amine anti-scorch agent are added. This is because the epoxy-containing ethylene copolymer can react with the special amine anti-scorch agent to form a grafted ethylene copolymer with the special amine anti-scorch agent. This not only increases the compatibility of the system but also synergizes with the sulfur-containing anti-scorch agent to improve the scorch time. Furthermore, the excess epoxy-containing ethylene copolymer can be catalyzed by the grafted special amine anti-scorch agent, increasing the crosslinking degree of the system, achieving both scorch resistance and improved curing performance.

[0093] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A scorch-resistant cable shielding material, prepared from components including an ethylene polymer and an epoxy-modified ethylene polymer, wherein the weight of the ethylene polymer is 60 to 95 parts by weight based on 100 parts by weight of the total weight of the ethylene polymer and the epoxy-modified ethylene polymer; the weight of the epoxy-modified ethylene polymer is 5 to 40 parts by weight.

2. The scorch-resistant cable shielding material according to claim 1, characterized in that: The weight of the ethylene polymer is 80 to 95 parts by weight; the weight of the epoxy-modified ethylene polymer is 5 to 20 parts by weight.

3. The scorch-resistant cable shielding material according to claim 1, characterized in that: The invention also includes the following components, based on the total weight of the ethylene polymer and the epoxy-modified ethylene polymer as 100 parts by weight, the weight parts of the following components are:

4. The scorch-resistant cable shielding material according to claim 1, characterized in that: The ethylene polymer is selected from non-polar and / or polar ethylene polymers, preferably a combination of non-polar and polar ethylene polymers; and / or, The epoxy-modified ethylene polymer is selected from ethylene oxide-modified non-polar and / or polar ethylene polymers; and / or, The epoxy modified ethylene polymer has an epoxidation degree of 0.01 to 1 mol / kg, preferably 0.1 to 0.7 mol / kg, and more preferably 0.2 to 0.5 mol / kg.

5. The scorch-resistant cable shielding material according to claim 4, characterized in that: The non-polar ethylene polymer is obtained by polymerizing components including ethylene, or at least one α-olefin, or and a diene; and / or, The α-olefin is selected from α-olefins containing 3 to 12 carbon atoms, preferably α-olefins containing 4 to 8 carbon atoms; and / or, In the non-polar ethylene polymer, the weight of the α-olefin accounts for 1-20 wt% of the total weight of the polymer, preferably 5-20 wt%; and / or the weight of the diene accounts for 1-10 wt% of the total weight of the polymer, preferably 1-3 wt%.

6. The scorch-resistant cable shielding material according to claim 4, characterized in that: The polar ethylene polymer is obtained by polymerizing components including ethylene and at least one unsaturated alkyl ester; and / or, The unsaturated alkyl ester is selected from unsaturated alkyl esters containing 4 to 40 carbon atoms, preferably from unsaturated alkyl esters containing 4 to 7 carbon atoms; and / or, Preferably, the unsaturated alkyl ester is selected from one or a combination of alkyl acrylates, alkyl methacrylates, and vinyl carboxylates; and / or, In the polar ethylene polymer, the weight of the unsaturated alkyl ester accounts for 5 to 55 wt%, preferably 8 to 40 wt%, of the total weight of the polymer.

7. The scorch-resistant cable shielding material according to claim 3, characterized in that: The carbon black has a particle size of 25 to 50 nm, an oil absorption value of 130 to 150 mL / 100 g, preferably 40 to 70 mL / 100 g, and a residue amount after passing through a 325-mesh sieve of ≤200 ppm.

8. The scorch-resistant cable shielding material according to claim 3, characterized in that: The special amine anti-scorch agent is selected from one or a combination of diphenylamine, 4,4'-di-tert-octyldiphenylamine, 4-tert-butyldiphenylamine, 4-tert-octyldiphenylamine, 4,4'-di-tert-butyldiphenylamine, 2,4,4'-tri-tert-butyl-diphenylamine, 4-tert-butyl-4'-tert-octyldiphenylamine, p,p'-di-tert-octyldiphenylamine, 2,4-di-tert-butyl-4'-tert-octyldiphenylamine, 4,4'-di-tert-octyldiphenylamine, and 2,4-di-tert-octyl-4'-tert-butyldiphenylamine; and / or, The sulfur-containing anti-scorch agent is selected from 2,6-di-tert-butyl-4-(octyloxycarbonylmethylthiomethyl)phenol.

9. The method for preparing the scorch-resistant cable shielding material according to any one of claims 1 to 8, comprising the following steps: Step 1: premixing an ethylene polymer and an epoxy-modified ethylene polymer with an antioxidant, and then adding carbon black to mix, to obtain a shielding material masterbatch containing carbon black; Step 2: heating the anti-scorch agent, or the anti-scorch agent and the peroxide, to obtain a transparent liquid mixture; Step 3: heating the carbon black-containing shielding masterbatch obtained in step 1 and mixing it with the transparent liquid mixture obtained in step 2 to obtain the cable shielding material.

10. Use of the scorch-resistant cable shielding material according to any one of claims 1 to 8 as medium voltage, high voltage and extra-high voltage cable shielding material.

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