Composition for preparing semiconductive shielding material, semiconductive shielding material as well as preparation method and application of semiconductive shielding material

Abstract

The invention relates to the technical field of power cable materials, and discloses a composition for preparing a semiconductive shielding material, the semiconductive shielding material and a preparation method and application of the semiconductive shielding material. The composition comprises conductive network matrix resin A, non-conductive matrix resin B, conductive carbon black CB, a processing aid and a cross-linking agent, the wetting coefficient omega in a composite system of the conductive network matrix resin, the non-conductive matrix resin and the conductive carbon black is greater than 1, # imgabs0 #, and gamma CB-B is the interfacial tension of the conductive carbon black CB and the non-conductive matrix resin B, mN / m; gamma CB-A is the interfacial tension of the conductive carbon black CB and the conductive network matrix resin A, mN / m; gamma A-B is the interfacial tension of the conductive network matrix resin A and the non-conductive matrix resin B, mN / m; the semi-conductive shielding material can keep good conductivity and lower positive temperature coefficient under the condition of low carbon black addition amount.

Description

Technical Field

[0001] The present invention relates to the technical field of power cable materials, and particularly relates to a composition for preparing a semiconductive shielding material, the semiconductive shielding material, a preparation method thereof, and an application thereof. Background Art

[0002] The semiconductive shielding material is an essential supporting material for high-voltage and extra-high-voltage cables, and is composed of a matrix resin, conductive carbon black, and processing aids. By adding conductive carbon black into the matrix resin, its conductivity is increased, thereby playing a role in uniforming the electric field and preventing local breakdown. In order to ensure a small volume resistivity of the semiconductive shielding material at room temperature, usually a high addition amount of conductive carbon black is required, and the addition of carbon black will reduce the elongation at break of the matrix resin and deteriorate its mechanical properties. At the same time, it increases the friction between the semiconductive shielding material and between the semiconductive shielding material and the processing equipment, reducing its processability. A large amount of heat generated by friction will also cause the semiconductive shielding material to have a scorching phenomenon during processing, which is not conducive to the long-time extrusion for preparing DC cables. The increase in the carbon black content will also increase the number and size of protrusions on the surface of the semiconductive shielding material, making the electric field distribution uneven and more likely to occur insulation layer breakdown. Due to the thermal expansion of the matrix resin, the distance between conductive carbon blacks increases and the contact points decrease when the temperature of the semiconductive shielding material rises, and the volume resistivity also rises accordingly, that is, the volume resistivity has the characteristic of positive temperature coefficient. Therefore, it is necessary to control the volume resistivity of the semiconductive shielding material.

[0003] Therefore, the core problem in the research and development of the semiconductive shielding material is to maintain good conductivity and a low positive temperature coefficient under a low carbon black addition amount. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems of high volume resistivity (23°C or 90°C) of the semiconductive shielding material existing in the prior art, and the defect problem of high positive temperature coefficient (PTC) of the semiconductive shielding material, and to provide a composition for preparing a semiconductive shielding material, the semiconductive shielding material, a preparation method thereof, and an application thereof. The semiconductive shielding material can maintain good conductivity and a low positive temperature coefficient under a low carbon black addition amount.

[0005] In order to achieve the above purpose, in the first aspect of the present invention, a composition for preparing a semiconductive shielding material is provided, wherein the composition includes a conductive network matrix resin, a non-conductive matrix resin, conductive carbon black, processing aids, and a cross-linking agent; wherein, the wetting coefficient ω in the composite system of the conductive network matrix resin, the non-conductive matrix resin, and the conductive carbon black is greater than 1, and the wetting coefficient ω is calculated by formula (1): , formula (1); wherein, A is the conductive network matrix resin; B is the non-conductive matrix resin; CB is the conductive carbon black; γ CB-B is the interfacial tension between the conductive carbon black CB and the non-conductive matrix resin B, mN / m; γ CB-A is the interfacial tension between the conductive carbon black CB and the conductive network matrix resin A, mN / m; γ A-B is the interfacial tension between the conductive network matrix resin A and the non-conductive matrix resin B, mN / m.

[0006] The second aspect of the present invention provides a method for preparing a semi-conductive shielding material using the aforementioned composition, wherein the method includes: Step 1: Contact the conductive carbon black, the conductive network matrix resin, and the processing aid, mix and knead them, and pelletize to obtain a conductive network resin; Step 2: Contact the conductive network resin with the non-conductive matrix resin and the processing aid, mix and knead them, and pelletize to obtain an isolation structure resin; Step 3: Mix the isolation structure resin with a cross-linking agent to obtain a pre-product; Step 4: Heat-treat the pre-product to obtain a semi-conductive shielding material.

[0007] The third aspect of the present invention provides a semi-conductive shielding material prepared by the aforementioned method.

[0008] The fourth aspect of the present invention provides an application of the aforementioned semi-conductive shielding material in a cable.

[0009] Through the above technical solutions, the beneficial effects of the present invention are as follows: (1) The present invention uses two matrix resins with different polarities. Due to the different thermodynamic preferences of the conductive carbon black in the two matrix resins, the carbon black spontaneously distributes in the matrix that is thermodynamically favorable for it or at the interface of the two matrix resins, forming an isolation structure. This isolation structure enables the semi-conductive shielding material to maintain good conductivity and a low positive temperature coefficient at a low carbon black addition amount.

[0010] (2) The present invention uses a two-step method to construct a co-continuous multi-component composite matrix resin, and utilizes the characteristic of the selective distribution of carbon black in the composite matrix resin to form an isolation structure, which can effectively prevent the increase in the resistance of the semi-conductive shielding material caused by temperature rise and reduce the positive temperature coefficient of the semi-conductive shielding material. Description of the Drawings

[0011] Figure 1 is a schematic flow chart of the preparation method of the semi-conductive shielding material of the present invention; Figure 2 is a schematic diagram of the isolation structure of the semi-conductive shielding material of the present invention.

[0012] Description of the Reference Numerals In Figure 2Chinese: 1 - non - conductive matrix resin; 2 - conductive network matrix resin; 3 - conductive carbon black. Detailed implementation manners

[0013] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0014] As described above, the first aspect of the present invention provides a composition for preparing a semi - conductive shielding material. Among them, the composition includes a conductive network matrix resin, a non - conductive matrix resin, conductive carbon black, a processing aid, and a cross - linker; wherein, the wetting coefficient ω in the composite system of the conductive network matrix resin, the non - conductive matrix resin, and the conductive carbon black is greater than 1, and the wetting coefficient ω is calculated by formula (1): , formula (1); Wherein, A is the conductive network matrix resin; B is the non - conductive matrix resin; CB is the conductive carbon black; γ CB-B is the interfacial tension between the conductive carbon black CB and the non - conductive matrix resin B, mN / m; γ CB-A is the interfacial tension between the conductive carbon black CB and the conductive network matrix resin A, mN / m; γ A-B is the interfacial tension between the conductive network matrix resin A and the non - conductive matrix resin B, mN / m.

[0015] In the present invention, the interfacial tension γ 1-2 can be calculated by the geometric mean equation: ; Wherein, γ1 is the surface tension of substance 1 (unit: mN / m), γ1 d is the dispersion component of the surface tension of substance 1 (unit: mN / m), γ1 p is the polar component of the surface tension of substance 1 (unit: mN / m); γ2 is the surface tension of substance 2 (unit: mN / m), γ2 d is the dispersion component of the surface tension of substance 2 (unit: mN / m), γ2 p is the polar component of the surface tension of substance 2 (unit: mN / m).

[0016] In the present invention, the surface tension and its dispersion part and polar part are measured by the Owens two - liquid method.

[0017] The inventors of the present invention have found that: the conductive network matrix resin is thermodynamically favorable for conductive carbon black; the non-conductive matrix resin is thermodynamically unfavorable for conductive carbon black; the present invention uses two matrix resins with different polarities to construct a co-continuous multi-component composite matrix resin, and utilizes the characteristic of the selective distribution of carbon black in the composite matrix resin to form an isolation structure, restricting the carbon black in a single matrix resin phase or at the interface of two phases, forming a continuous three-dimensional conductive network, thereby ensuring a relatively high overall conductivity of the semi-conductive shielding material while reducing the addition amount of carbon black. The high concentration of carbon black locally can effectively prevent the increase in the resistance of the semi-conductive shielding material caused by temperature rise and reduce the positive temperature coefficient of the semi-conductive shielding material.

[0018] Furthermore, due to the reduction in the addition amount of conductive carbon black, the raw material cost of the semi-conductive shielding material of the present invention is lower, it has better extrusion process performance, and at the same time overcomes the problem of easy scorching during long-term extrusion of DC cables.

[0019] According to the present invention, the conductive network matrix resin is selected from one or more of a first ethylene-vinyl acetate copolymer (EVA), a first ethylene-ethyl acrylate copolymer (EEA), and a first ethylene-butyl acrylate copolymer (EBA).

[0020] According to the present invention, the first ethylene-vinyl acetate copolymer (EVA) has a melt index of 25 - 150 g / 10 min at 190 °C and 2.16 kg, and a vinyl acetate content of 27 - 40 wt%; preferably, the ethylene-vinyl acetate copolymer (EVA) has a melt index of 30 - 50 g / 10 min at 190 °C and 2.16 kg, and a vinyl acetate content of 33 - 40 wt%.

[0021] According to the present invention, the first ethylene-ethyl acrylate copolymer (EEA) has a melt index of 30 - 150 g / 10 min at 190 °C and 2.16 kg, and an ethyl acrylate content of 20 - 33 wt%; preferably, the ethylene-ethyl acrylate copolymer (EEA) has a melt index of 30 - 50 g / 10 min at 190 °C and 2.16 kg, and an ethyl acrylate content of 25 - 33 wt%.

[0022] According to the present invention, the first ethylene-butyl acrylate copolymer (EBA) has a melt index of 20 - 150 g / 10 min at 190 °C and 2.16 kg, and a butyl acrylate content of 20 - 33 wt%; preferably, the ethylene-butyl acrylate copolymer (EBA) has a melt index of 20 - 50 g / 10 min at 190 °C and 2.16 kg, and a butyl acrylate content of 25 - 33 wt%.

[0023] According to the present invention, the non-conductive matrix resin is selected from one or more of a second ethylene-vinyl acetate copolymer (EVA), a second ethylene-ethyl acrylate copolymer (EEA), a second ethylene-butyl acrylate copolymer (EBA), polyethylene (PE), and an ethylene-1-octene copolymer (POE).

[0024] According to the present invention, the second ethylene-vinyl acetate copolymer (EVA) has a melt index of 0.7-10 g / 10 min at 190 °C and 2.16 kg, and a vinyl acetate content of 7.5-20 wt%; preferably, the ethylene-vinyl acetate copolymer (EVA) has a melt index of 5-10 g / 10 min at 190 °C and 2.16 kg, and a vinyl acetate content of 1.5-15 wt%.

[0025] According to the present invention, the second ethylene-ethyl acrylate copolymer (EEA) has a melt index of 1-6 g / 10 min at 190 °C and 2.16 kg, and an ethyl acrylate content of 15-18 wt%; preferably, the ethylene-ethyl acrylate copolymer (EEA) has a melt index of 3-6 g / 10 min at 190 °C and 2.16 kg, and an ethyl acrylate content of 16-17 wt%.

[0026] According to the present invention, the second ethylene-butyl acrylate copolymer (EBA) has a melt index of 0.3-7 g / 10 min at 190 °C and 2.16 kg, and a butyl acrylate content of 3-17 wt%; preferably, the ethylene-butyl acrylate copolymer (EBA) has a melt index of 3.5-7 g / 10 min at 190 °C and 2.16 kg, and a butyl acrylate content of 8-17 wt%.

[0027] According to the present invention, the polyethylene (PE) has a melt index of 0.6-10 g / 10 min at 190 °C and 2.16 kg, and a density of 0.91-0.96 g / cm 3 ; preferably, the polyethylene (PE) has a melt index of 5-10 g / 10 min at 190 °C and 2.16 kg, and a density of 0.92-0.93 g / cm 3 .

[0028] According to the present invention, the ethylene-1-octene copolymer (POE) has a melt index of 0.5-30 g / 10 min at 190 °C and 2.16 kg; preferably, the ethylene-1-octene copolymer (POE) has a melt index of 5-15 g / 10 min at 190 °C and 2.16 kg.

[0029] According to the present invention, the conductive carbon black is furnace black and / or acetylene black. In the present invention, it should be noted that: furnace black refers to carbon black formed by incomplete combustion of hydrocarbons in a high-temperature furnace, and acetylene black refers to carbon black formed by thermal decomposition or combustion of acetylene gas.

[0030] Further, the oil absorption value is 100 - 250 mL / 100 g, the iodine absorption value is 50 - 250 mg / g, the particle size is less than 100 nm, the BET specific surface area is 50 - 150 m 2 / g, the residue on a 325-mesh sieve is less than 10 ppm, the ash content is less than 0.1%, and the total sulfur content is less than 0.1%.

[0031] According to the present invention, the processing aid is an antioxidant and / or a lubricant and / or a crosslinking agent.

[0032] According to the present invention, the antioxidant is at least one of antioxidant MB, antioxidant DNP, antioxidant AP, antioxidant 168, and antioxidant 1010.

[0033] According to the present invention, the lubricant is at least one of polyethylene wax, polypropylene wax, ethylene bisstearamide, and stearate.

[0034] According to the present invention, the crosslinking agent is selected from bis(tert-butylperoxyisopropyl)benzene (BIPB) and / or dicumyl peroxide (DCP).

[0035] According to the present invention, the composition comprises: the content of the conductive network matrix resin is 1 - 65 parts, the content of the non-conductive matrix resin is 5 - 80 parts, the content of the conductive carbon black is 5 - 40 parts, the content of the antioxidant is 0.1 - 1.5 parts, the content of the lubricant is 0.1 - 1.5 parts, and the content of the crosslinking agent is 0.1 - 1.5 parts; preferably, the content of the conductive network matrix resin is 5 - 61 parts, the content of the non-conductive matrix resin is 5 - 70 parts, the content of the conductive carbon black is 5 - 35 parts, the content of the antioxidant is 0.3 - 1 part, the content of the lubricant is 0.4 - 2 parts, and the content of the crosslinking agent is 0.5 - 1.5 parts; more preferably, the content of the conductive network matrix resin is 10 - 25 parts, the content of the non-conductive matrix resin is 45 - 70 parts, the content of the conductive carbon black is 15 - 32 parts, the content of the antioxidant is 0.6 - 1 part, the content of the lubricant is 0.5 - 2 parts, and the content of the crosslinking agent is 0.5 - 1.5 parts; the total number of parts of each component is 100 parts.

[0036] In the present invention, it should be noted that "parts" is equivalent to "parts by weight"; and, the sum of the components of the composition for preparing the semi-conductive shielding material is 100 parts, that is, the sum of the various components included in the composition is 100 parts.

[0037] The second aspect of the present invention provides a method for preparing a semi-conductive shielding material using the aforementioned composition, wherein the method comprises: Step 1: Mix and pelletize conductive carbon black, a conductive network matrix resin, and a processing aid in contact to obtain a conductive network resin; Step 2: Mix and pelletize the conductive network resin with a non-conductive matrix resin and a processing aid in contact to obtain an isolation structure resin; Step 3: Mix the isolation structure resin with a crosslinking agent to obtain a pre-product; Step 4: Heat-treat the pre-product to obtain a semi-conductive shielding material.

[0038] According to the present invention, the mixing is performed using at least one of a twin-screw extruder, a reciprocating single-screw extruder, a kneader, and an open mill.

[0039] According to the present invention, the mixing speed of the twin-screw extruder is 200 - 500 rpm, and the mixing temperature is 150 - 180 °C.

[0040] According to the present invention, the mixing speed of the reciprocating single-screw extruder is 200 - 500 rpm, and the mixing temperature is 140 - 190 °C.

[0041] According to the present invention, the mixing speed of the kneader is 20 - 100 rpm, and the mixing temperature is 150 - 180 °C.

[0042] According to the present invention, the mixing speed of the open mill is 5 - 25 rpm, and the mixing temperature is 150 - 180 °C.

[0043] According to the present invention, in Step 3, preferably, the isolation structure resin is mixed with the ground crosslinking agent to obtain a pre-product; wherein the grinding is performed in an agate mortar. In the present invention, the grinding conditions include: a grinding temperature of 22 - 24 °C, a grinding time of 8 - 12 min, and preferably, a grinding temperature of 23 °C and a grinding time of 10 min.

[0044] According to the present invention, in Step 4, the heat-treatment conditions include: a temperature of 40 - 60 °C and a time of 30 - 120 min.

[0045] According to a particularly preferred embodiment of the present invention, as Figure 1 shown, Figure 1 is a schematic flow diagram of the method for preparing a semi-conductive shielding material provided by the present invention. A method for preparing a semi-conductive shielding material includes: (1) Mix and pelletize the formula amounts of conductive carbon black, a conductive network matrix resin, an antioxidant, and a lubricant through a mixing system to obtain a conductive network resin; (2) Mix the conductive network resin, non-conductive matrix resin, antioxidant, and lubricant through a kneading system and pelletize to obtain the isolation structure resin; (3) Mix the isolation structure resin with the ground crosslinking agent to obtain a pre-product; (4) Heat-treat the pre-product to obtain a semi-conductive shielding material with an isolation structure.

[0046] The third aspect of the present invention provides a semi-conductive shielding material prepared by the aforementioned method.

[0047] According to the present invention, based on the total weight of the semi-conductive shielding material, the content of the conductive network matrix resin is 1-65 wt%, the content of the non-conductive matrix resin is 5-80 wt%, the content of the conductive carbon black is 5-40 wt%, the content of the antioxidant is 0.1-1.5 wt%, the content of the lubricant is 0.1-1.5 wt%, and the content of the crosslinking agent is 0.1-1.5 wt%; preferably, based on the total weight of the semi-conductive shielding material, the content of the conductive network matrix resin is 5-61 wt%, the content of the non-conductive matrix resin is 5-70 wt%, the content of the conductive carbon black is 5-35 wt%, the content of the antioxidant is 0.3-1 wt%, the content of the lubricant is 0.4-2 wt%, and the content of the crosslinking agent is 0.5-1.5 wt%; more preferably, based on the total weight of the semi-conductive shielding material, the content of the conductive network matrix resin is 10-25 wt%, the content of the non-conductive matrix resin is 45-70 wt%, the content of the conductive carbon black is 15-32 wt%, the content of the antioxidant is 0.6-1 wt%, the content of the lubricant is 0.5-2 wt%, and the content of the crosslinking agent is 0.5-1.5 wt%.

[0048] According to the present invention, the semi-conductive shielding material has an isolation structure; as Figure 2 shown, the conductive network matrix resin and the non-conductive matrix resin of the semi-conductive shielding material form a co-continuous structure, that is, both resins have a continuous network structure, and the conductive carbon black is distributed in the conductive network resin or at the interface between the conductive network matrix resin and the non-conductive matrix resin.

[0049] According to the present invention, the volume resistivity of the semi-conductive shielding material at 23 °C is 10-80 Ω·cm, preferably 10-25 Ω·cm.

[0050] According to the present invention, the volume resistivity of the semi-conductive shielding material at 90 °C is 50-200 Ω·cm, preferably 50-100 Ω·cm.

[0051] And / or, the PTC coefficient of the semi-conductive shielding material is 2.5-8, preferably 3-5.

[0052] In the fourth aspect of the present invention, there is provided an application of the aforementioned semiconductive shielding material in a cable.

[0053] According to the present invention, the conditions for the application include: the application environment is a submarine cable or a land cable, the voltage level is 110 - 500 kV, and in the present invention, the semiconductive shielding material is preferably used for direct current.

[0054] The semiconductive shielding material is heat-treated at a pressure of 0.1 - 3 MPa and a temperature of 170 - 190 °C for 0.5 - 3 hours.

[0055] The present invention will be described in detail below through examples.

[0056] In the following examples and comparative examples: The tensile strength parameter and the elongation at break parameter are measured by the method specified in GB / T 1040.3 - 2022; the test instrument is a commercially available product of Instron with the model number 68SC - 05.

[0057] The volume resistivity parameter is measured by the method specified in Part 3 of GB / T 3048 - 2007 for the volume resistivity test of semiconductive rubber and plastic materials; the test instrument is a commercially available product of Beijing Huace Testing Instruments Co., Ltd. with the model number Huace - 191.

[0058] The PTC coefficient is calculated from the volume resistivity, and the specific calculation method is shown in the following formula:

[0059] where ρ 90 is the volume resistivity at 90 °C, and ρ 23 is the volume resistivity at 23 °C.

[0060] Example 1 This example is to illustrate the semiconductive shielding material prepared by the present invention.

[0061] (1) By mass, a conductive network resin is prepared, and the raw materials are: 38 parts of a first ethylene - butyl acrylate copolymer EBA (the first ethylene - butyl acrylate copolymer EBA has a melt index of 20 g / 10 min at 190 °C and 2.16 kg, and the butyl acrylate content is 27 wt%) as the conductive network matrix resin, 60 parts of furnace black (average particle size is 40 nm, BET specific surface area is 80 m 2 / g, iodine absorption value of 75 mg / g, oil absorption value of 150 mL / 100 g) as conductive carbon black, 0.5 part of antioxidant MB as antioxidant, and 1.5 parts of stearic acid ester as lubricant. The above raw materials are kneaded using a reciprocating single-screw extruder at a kneading temperature of 150 °C and a rotation speed of 300 rpm. After kneading, extrusion granulation is carried out to obtain conductive network resin.

[0062] (2) By mass fraction, prepare the isolation structure resin. The raw materials are: 69 parts of polyethylene PE (the polyethylene PE has a melt index of 10 g / 10 min at 190 °C and 2.16 kg, and a density of 0.93 g / cm 3 ) as non-conductive matrix resin, 30 parts of the conductive network resin prepared in step (1), 0.5 part of antioxidant DNP as antioxidant, 0.5 part of polyethylene wax as lubricant. The above raw materials are kneaded using a reciprocating single-screw extruder at a kneading temperature of 170 °C and a rotation speed of 500 rpm. After kneading, extrusion granulation is carried out to obtain isolation structure resin.

[0063] (3) By mass fraction, mix 99 parts of the isolation structure resin prepared in step (2) with 1 part of the ground crosslinking agent bis(tert-butylperoxyisopropyl)benzene BIPB to obtain a pre-product. The pre-product is heated at 60 °C for 120 min to obtain a semi-conductive shielding material for standby.

[0064] The wetting coefficient ω of the EBA-PE-furnace black system used in this example is 7, and the furnace black is distributed in the conductive network matrix resin EBA.

[0065] By mass fraction, the final composition of the semi-conductive shielding material prepared in this example is obtained by calculation, specifically: conductive network matrix resin 11.286 wt%, non-conductive matrix resin 68.31 wt%, conductive carbon black 17.82 wt%, antioxidant 0.6435 wt%, lubricant 0.9405 wt%, crosslinking agent 1 wt%.

[0066] Example 2 This example is to illustrate the semi-conductive shielding material prepared by the present invention.

[0067] (1) By mass fraction, prepare the conductive network resin. The raw materials are: 48 parts of the first ethylene-butyl acrylate copolymer EBA (the first ethylene-butyl acrylate copolymer has a melt index of 20 g / 10 min at 190 °C and 2.16 kg, and the butyl acrylate content is 27 wt%) as the conductive network matrix resin, 50 parts of furnace black (average particle size of 40 nm, BET specific surface area of 80 m 2 / g, iodine absorption value of 75 mg / g, oil absorption value of 150 mL / 100 g) as conductive carbon black, 1 part of antioxidant AP as antioxidant, and 1 part of ethylene bisstearamide as lubricant. The above raw materials are kneaded using a twin-screw extruder, the kneading temperature is 160 °C, the rotation speed is 300 rpm, and after kneading is completed, extrusion and pelletizing are carried out to obtain conductive network resin.

[0068] (2) By mass fraction, prepare the isolation structure resin. The raw materials are: 49 parts of ethylene-1-octene copolymer POE (the melt index of the ethylene-1-octene copolymer POE at 190 °C and 2.16 kg is 15 g / 10 min) as non-conductive matrix resin, 50 parts of the conductive network resin prepared in step (1), 0.5 part of antioxidant AP as antioxidant, 0.5 part of ethylene bisstearamide as lubricant. The above raw materials are kneaded using a reciprocating single-screw extruder, the kneading temperature is 170 °C, the rotation speed is 500 rpm, and after kneading is completed, extrusion and pelletizing are carried out to obtain the isolation structure resin.

[0069] (3) By mass fraction, mix 99.5 parts of the isolation structure resin prepared in step (2) with 0.5 part of the ground crosslinking agent bis(tert-butylperoxyisopropyl)benzene BIPB to obtain a pre-product. The pre-product is heated at 60 °C for 120 min to obtain a semi-conductive shielding material.

[0070] The wetting coefficient ω of the EBA-POE-furnace black system used in this example is 5, and the furnace black is distributed in the conductive network matrix resin EBA.

[0071] By mass fraction, the final composition of the semi-conductive shielding material prepared in this example is: conductive network matrix resin 23.88 wt%, non-conductive matrix resin 48.755 wt%, conductive carbon black 24.875 wt%, antioxidant 0.995 wt%, lubricant 0.995 wt%, crosslinking agent 0.5 wt%.

[0072] Example 3 This example is to illustrate the semi-conductive shielding material prepared by the present invention.

[0073] (1) By mass fraction, prepare the conductive network resin. The raw materials are: 27 parts of the first ethylene-ethyl acrylate copolymer EEA (the melt index of the first ethylene-ethyl acrylate copolymer EEA at 190 °C and 2.16 kg is 40 g / 10 min, and the ethyl acrylate content is 25 wt%) as the conductive network matrix resin, 70 parts of acetylene black (average particle size is 50 nm, BET specific surface area is 60 m 2 / g, iodine absorption value of 45 mg / g, oil absorption value of 200 mL / 100 g) as conductive carbon black, 0.5 part of antioxidant MB as antioxidant, and 2.5 parts of stearic acid ester as lubricant. The above raw materials are kneaded in a mixer, the kneading temperature is 180 °C, the rotation speed is 50 rpm, and the conductive network resin is obtained after kneading.

[0074] (2) By mass fraction, prepare the isolation structure resin. The raw materials are: 54 parts of the second ethylene-vinyl acetate copolymer EVA (the second ethylene-vinyl acetate copolymer EVA has a melt index of 10 g / 10 min at 190 °C and 2.16 kg, and the vinyl acetate content is 15 wt%) as the non-conductive matrix resin, 45 parts of the conductive network resin prepared in step (1), 0.5 part of antioxidant DNP as antioxidant, 0.5 part of ethylene bisstearamide as lubricant. The above raw materials are kneaded using a reciprocating single-screw extruder, the kneading temperature is 180 °C, the rotation speed is 500 rpm, and after kneading, extrusion granulation is carried out to obtain the isolation structure resin.

[0075] (3) By mass fraction, mix 99.5 parts of the isolation structure resin prepared in step (2) with 0.5 part of the ground crosslinking agent bis(tert-butylperoxyisopropyl)benzene BIPB to obtain a pre-product. The pre-product is heated at 60 °C for 120 min to obtain a semi-conductive shielding material.

[0076] The wetting coefficient ω of the EEA-EVA-acetylene black system used in this example is 2, and the acetylene black is distributed in the conductive network matrix resin EEA.

[0077] By mass fraction, the final composition of the semi-conductive shielding material prepared in this example is: conductive network matrix resin 12.08925 wt%, non-conductive matrix resin 53.73 wt%, conductive carbon black 31.3425 wt%, antioxidant 0.721375 wt%, lubricant 1.616875 wt%, crosslinking agent 0.5 wt%.

[0078] Example 4 This example is to illustrate the semi-conductive shielding material prepared by the present invention.

[0079] (1) By mass fraction, prepare the conductive network resin. The raw materials are: 49 parts of the first ethylene-vinyl acetate copolymer EVA (the first ethylene-vinyl acetate copolymer EVA has a melt index of 30 g / 10 min at 190 °C and 2.16 kg, and the vinyl acetate content is 35 wt%) as the conductive network matrix resin, 50 parts of furnace black (average particle size is 40 nm, BET specific surface area is 80 m 2 / g, iodine absorption value of 75 mg / g, oil absorption value of 150 mL / 100 g) as conductive carbon black, 0.5 parts of antioxidant 168 as antioxidant, and 0.5 parts of stearic acid ester as lubricant. The above raw materials were kneaded using a reciprocating single-screw extruder at a kneading temperature of 160 °C and a rotational speed of 500 rpm. After kneading, extrusion granulation was carried out to obtain conductive network resin.

[0080] (2) By mass fraction, prepare the isolation structure resin. The raw materials are: 29.8 parts of ethylene-1-octene copolymer POE (the ethylene-1-octene copolymer POE has a melt index of 10 g / 10 min at 190 °C and 2.16 kg) as non-conductive matrix resin, 70 parts of the conductive network resin prepared in step (1), 0.1 part of antioxidant MB as antioxidant, and 0.1 part of polypropylene wax as lubricant. The above raw materials were kneaded using an open mill at a kneading temperature of 180 °C and a rotational speed of 25 rpm. After kneading, extrusion granulation was carried out to obtain isolation structure resin.

[0081] (3) By mass fraction, mix 98.5 parts of the isolation structure resin prepared in step (2) with 1.5 parts of the ground crosslinking agent bis(tert-butylperoxyisopropyl)benzene BIPB to obtain a pre-product. The pre-product was heated at 60 °C for 60 min to obtain a semi-conductive shielding material.

[0082] The wetting coefficient ω of the EVA-POE-furnace black system used in this example is 12, and the furnace black is distributed in the conductive network matrix resin EVA.

[0083] By mass fraction, the final composition of the semi-conductive shielding material prepared in this example is: conductive network matrix resin 33.7855 wt%, non-conductive matrix resin 29.353 wt%, conductive carbon black 34.475 wt%, antioxidant 0.44325 wt%, lubricant 0.44325 wt%, crosslinking agent 1.5 wt%.

[0084] Example 5 This example is to illustrate the semi-conductive shielding material prepared by the present invention.

[0085] (1) By mass fraction, prepare the conductive network resin. The raw materials are: 68 parts of the first ethylene-butyl acrylate copolymer EBA (the first ethylene-butyl acrylate copolymer EBA has a melt index of 150 g / 10 min at 190 °C and 2.16 kg, and the butyl acrylate content is 25 wt%) as the conductive network matrix resin, 30 parts of acetylene black (average particle size is 50 nm, BET specific surface area is 60 m 2 / g, iodine absorption value of 45 mg / g, oil absorption value of 200 mL / 100 g) is conductive carbon black, 1 part of antioxidant 168 as an antioxidant, and 1 part of stearate as a lubricant. A reciprocating single-screw extruder is used to knead the above raw materials at a kneading temperature of 150 °C and a rotation speed of 500 rpm. After kneading, extrusion granulation is carried out to obtain conductive network resin.

[0086] (2) By mass fraction, prepare the isolation structure resin. The raw materials are: 9.8 parts of ethylene-vinyl acetate copolymer EVA (the ethylene-vinyl acetate copolymer EVA has a melt index of 5 g / 10 min at 190 °C and 2.16 kg, and the butyl acrylate content is 15 wt%) as the non-conductive matrix resin, 90 parts of the conductive network resin prepared in step (1), 0.1 part of antioxidant MB as an antioxidant, and 0.1 part of ethylene bis-stearamide as a lubricant. A reciprocating single-screw extruder is used to knead the above raw materials at a kneading temperature of 170 °C and a rotation speed of 500 rpm. After kneading, extrusion granulation is carried out to obtain the isolation structure resin.

[0087] (3) By mass fraction, mix 98.5 parts of the isolation structure resin prepared in step (2) with 1.5 parts of the ground cross-linking agent bis(tert-butylperoxyisopropyl)benzene BIPB to obtain a pre-product. The pre-product is heated at 60 °C for 60 min to obtain a semi-conductive shielding material.

[0088] The wetting coefficient ω of the EBA-EVA-acetylene black system used in this example is 3, and the furnace black is distributed in the conductive network matrix resin EBA.

[0089] By mass fraction, the final composition of the semi-conductive shielding material prepared in this example is: conductive network matrix resin 60.282 wt%, non-conductive matrix resin 9.653 wt%, conductive carbon black 26.595 wt%, antioxidant 0.985 wt%, lubricant 0.985 wt%, cross-linking agent 1.5 wt%.

[0090] Example 6 This example is to illustrate the semi-conductive shielding material prepared by the present invention.

[0091] (1) By mass fraction, prepare the conductive network resin. The raw materials are: 26 parts of the first ethylene-vinyl acetate copolymer EVA (the first ethylene-vinyl acetate copolymer EVA has a melt index of 50 g / 10 min at 190 °C and 2.16 kg, and the vinyl acetate content is 40 wt%) as the conductive network matrix resin, 70 parts of furnace black (average particle size is 40 nm, BET specific surface area is 80 m 2 / g, iodine absorption value 75 mg / g, oil absorption value 150 mL / 100 g) as conductive carbon black, 1 part of antioxidant AP as antioxidant, and 3 parts of stearic acid ester as lubricant. The above raw materials are kneaded in a mixer, the kneading temperature is 180 °C, the rotation speed is 50 rpm, and the conductive network resin is obtained after kneading.

[0092] (2) By mass fraction, prepare the isolation structure resin. The raw materials are: 69 parts of ethylene-1-octene copolymer POE (the melt index of the ethylene-1-octene copolymer POE at 190 °C and 2.16 kg is 5 g / 10 min) as non-conductive matrix resin, 30 parts of the conductive network resin prepared in step (1), 0.5 part of antioxidant MB as antioxidant, 0.5 part of polypropylene wax as lubricant. The above raw materials are kneaded by a reciprocating single-screw extruder, the kneading temperature is 170 °C, the rotation speed is 500 rpm, and after kneading, extrusion granulation is carried out to obtain the isolation structure resin.

[0093] (3) By mass fraction, mix 99.5 parts of the isolation structure resin prepared in step (2) with 0.5 part of the ground crosslinking agent bis(tert-butylperoxyisopropyl)benzene BIPB to obtain a pre-product. The pre-product is heated at 60 °C for 120 min to obtain a semi-conductive shielding material.

[0094] The wetting coefficient ω of the EVA-POE-furnace black system used in this example is 15, and the furnace black is distributed in the conductive network matrix resin EVA.

[0095] By mass fraction, the final composition of the semi-conductive shielding material prepared in this example is: conductive network matrix resin 7.761 wt%, non-conductive matrix resin 68.655 wt%, conductive carbon black 20.895 wt%, antioxidant 0.796 wt%, lubricant 1.393 wt%, crosslinking agent 0.5 wt%.

[0096] Example 7 This example is to illustrate the semi-conductive shielding material prepared by the present invention.

[0097] (1) By mass fraction, prepare the conductive network resin. The raw materials are: 79 parts of the first ethylene-vinyl acetate copolymer EVA (the melt index of the first ethylene-vinyl acetate copolymer EVA at 190 °C and 2.16 kg is 40 g / 10 min, and the vinyl acetate content is 35 wt%) as the conductive network matrix resin, 20 parts of furnace black (average particle size is 40 nm, BET specific surface area is 80 m 2 / g, iodine absorption value 75 mg / g, oil absorption value 150 mL / 100 g) as conductive carbon black, 0.5 parts of antioxidant 1010 as antioxidant, and 0.5 parts of stearate as lubricant. The above raw materials were kneaded using a reciprocating single-screw extruder at a kneading temperature of 160 °C and a rotational speed of 500 rpm. After kneading, extrusion granulation was carried out to obtain conductive network resin.

[0098] (2) By mass fraction, prepare the isolation structure resin. The raw materials are: 54.8 parts of polyethylene PE (the polyethylene PE has a melt index of 5 g / 10 min at 190 °C and 2.16 kg, and a density of 0.92 g / cm 3 ) as non-conductive matrix resin, 45 parts of the conductive network resin prepared in step (1), 0.1 part of antioxidant MB as antioxidant, 0.1 part of polypropylene wax as lubricant. The above raw materials were kneaded using a reciprocating single-screw extruder at a kneading temperature of 170 °C and a rotational speed of 500 rpm. After kneading, extrusion granulation was carried out to obtain isolation structure resin.

[0099] (3) By mass fraction, mix 99.5 parts of the isolation structure resin prepared in step (2) with 0.5 part of the ground crosslinking agent bis(tert-butylperoxyisopropyl)benzene BIPB to obtain a pre-product. The pre-product was heated at 50 °C for 120 min to obtain a semi-conductive shielding material.

[0100] The wetting coefficient ω of the EVA-PE-furnace black system used in this example is 11, and the furnace black is distributed in the conductive network matrix resin ethylene-vinyl acetate copolymer EVA.

[0101] By mass fraction, the final composition of the semi-conductive shielding material prepared in this example is: conductive network matrix resin 35.37225 wt%, non-conductive matrix resin 54.526 wt%, conductive carbon black 8.955 wt%, antioxidant 0.32338 wt%, lubricant 0.32338 wt%, crosslinking agent 0.5 wt%.

[0102] Example 8 This example is to illustrate the semi-conductive shielding material prepared by the present invention.

[0103] The semi-conductive shielding material was prepared in the same manner as in Example 1, except that: In step (2), "polyethylene PE (the polyethylene PE has a melt index of 10 g / 10 min at 190 °C and 2.16 kg, and a density of 0.93 g / cm 3Replace ") with "Second ethylene-butyl acrylate copolymer EBA (the second ethylene-butyl acrylate copolymer EBA has a melt index of 3.5 g / 10 min at 190 °C and 2.16 kg, and the butyl acrylate content is 8 wt%)".

[0104] As a result, a semiconductive shielding material was prepared.

[0105] The wetting coefficient ω of the EBA-EBA-furnace black system used in this example is 2, and the furnace black is distributed in the conductive network matrix resin EBA.

[0106] By mass fraction, the final composition of the semiconductive shielding material prepared in this example was calculated as follows: conductive network matrix resin 23.88 wt%, non-conductive matrix resin 48.755 wt%, conductive carbon black 24.875 wt%, antioxidant 0.995 wt%, lubricant 0.995 wt%, crosslinking agent 0.5 wt%.

[0107] Example 9 This example is to illustrate the semiconductive shielding material prepared by the present invention.

[0108] The semiconductive shielding material was prepared in the same manner as in Example 1, except that: In step (1), replace "First ethylene-butyl acrylate copolymer EBA (the first ethylene-butyl acrylate copolymer has a melt index of 20 g / 10 min at 190 °C and 2.16 kg, and the butyl acrylate content is 27 wt%)" with "First ethylene-ethyl acrylate copolymer EEA (the first ethylene-ethyl acrylate copolymer EEA has a melt index of 30 g / 10 min at 190 °C and 2.16 kg, and the ethyl acrylate content is 33 wt%)".

[0109] As a result, a semiconductive shielding material was prepared.

[0110] The wetting coefficient ω of the EEA-PE-furnace black system used in this example is 10, and the furnace black is distributed in the conductive network matrix resin EEA.

[0111] By mass fraction, the final composition of the semiconductive shielding material prepared in this example was calculated as follows: conductive network matrix resin 11.286 wt%, non-conductive matrix resin 68.31 wt%, conductive carbon black 17.82 wt%, antioxidant 0.6435 wt%, lubricant 0.9405 wt%, crosslinking agent 1 wt%.

[0112] Comparative Example 1 In the comparative example, a traditional one-step method was used to prepare the semiconductive shielding material.

[0113] (1) By mass fraction, the raw materials for preparing the pre - product are as follows: 78 parts of the first ethylene - butyl acrylate copolymer EBA (the melt index of the first ethylene - butyl acrylate copolymer EBA at 190 °C and 2.16 kg is 20 g / 10 min, and the butyl acrylate content is 27 wt%) as the conductive network matrix resin, 20 parts of furnace black as the conductive carbon black (the average particle size is 40 nm, the BET specific surface area is 80 m 2 / g, the iodine absorption value is 75 mg / g, and the oil absorption value is 150 mL / 100 g), 1 part of antioxidant MB as the antioxidant, and 1 part of stearate as the lubricant.

[0114] (2) Use a reciprocating single - screw extruder to mix the above raw materials. The mixing temperature is 150 °C, the rotation speed is 300 rpm. After mixing, perform extrusion granulation to obtain granulated materials. Mix 99 parts of the granulated materials with 1 part of the ground cross - linker bis - tert - butyl peroxyisopropyl benzene BIPB to obtain the pre - product. Heat the pre - product at 60 °C for 120 min to obtain the semi - conductive shielding material.

[0115] By mass fraction, the final composition of the semi - conductive shielding material prepared in this comparative example is obtained by calculation, specifically: matrix resin 77.22 wt%, conductive carbon black 19.8 wt%, antioxidant 0.99 wt%, lubricant 0.99 wt%, cross - linker 1 wt%.

[0116] Comparative Example 2 The comparative example uses the traditional one - step method to prepare the semi - conductive shielding material.

[0117] (1) By mass fraction, the raw materials for preparing the pre - product are as follows: 40 parts of the first ethylene - butyl acrylate copolymer EBA (the melt index of the first ethylene - butyl acrylate copolymer at 190 °C and 2.16 kg is 20 g / 10 min, and the butyl acrylate content is 27 wt%) and 28 parts of polyethylene PE (the melt index of the polyethylene at 190 °C and 2.16 kg is 10 g / 10 min, and the density is 0.93 g / cm 3 ) as the conductive network matrix resin, 30 parts of acetylene black as the conductive carbon black, 1 part of antioxidant MB as the antioxidant, and 1 part of stearate as the lubricant.

[0118] (2) Use a reciprocating single - screw extruder to mix the above raw materials. The mixing temperature is 150 °C, the rotation speed is 300 rpm. After mixing, perform extrusion granulation to obtain granulated materials. Mix 99 parts of the granulated materials with 1 part of the ground cross - linker bis - tert - butyl peroxyisopropyl benzene to obtain the pre - product. Heat the pre - product at 60 °C for 120 min to obtain the semi - conductive shielding material.

[0119] By mass fraction, the final composition of the semi-conductive shielding material prepared in this comparative example is obtained through calculation, specifically: matrix resin 67.32 wt%, conductive carbon black 29.7 wt%, antioxidant 0.99 wt%, lubricant 0.99 wt%, cross-linking agent 1 wt%.

[0120] Comparative Example 3 The semi-conductive shielding material was prepared in the same manner as in Example 1, except that: In step (2), "polyethylene PE (the melt index of the polyethylene PE at 190 °C and 2.16 kg is 10 g / 10 min, and the density is 0.93 g / cm 3 )" was replaced with "ethylene-vinyl acetate copolymer EVA (the melt index of the ethylene-vinyl acetate copolymer EVA at 190 °C and 2.16 kg is 10 g / 10 min, and the butyl acrylate content is 15 wt%)".

[0121] The wetting coefficient ω of the EBA-EVA-furnace black system used in this example is -3, and the furnace black is distributed in the non-conductive matrix resin EVA.

[0122] As a result, a semi-conductive shielding material was prepared.

[0123] By mass fraction, the final composition of the semi-conductive shielding material prepared in this comparative example is obtained through calculation, specifically: conductive network matrix resin 11.286 wt%, non-conductive matrix resin 68.31 wt%, conductive carbon black 17.82 wt%, antioxidant 0.6435 wt%, lubricant 0.9405 wt%, cross-linking agent 1 wt%.

[0124] Comparative Example 4 The semi-conductive shielding material was prepared in the same manner as in Example 1, except that: In step (1), "furnace black (average particle size is 40 nm, BET specific surface area is 80 m 2 / g, iodine absorption value is 75 mg / g, oil absorption value is 150 mL / 100 g)" was replaced with "acetylene black (average particle size is 50 nm, BET specific surface area is 60 m 2 / g, iodine absorption value is 45 mg / g, oil absorption value is 200 mL / 100 g)".

[0125] The wetting coefficient ω of the EBA-PE-acetylene black system used in this example is -9, and the acetylene black is distributed in the non-conductive matrix resin PE.

[0126] As a result, a semi-conductive shielding material was prepared.

[0127] By mass fraction, the final composition of the semi-conductive shielding material prepared in this comparative example is obtained through calculation, specifically: conductive network matrix resin 11.286 wt%, non-conductive matrix resin 68.31 wt%, conductive carbon black 17.82 wt%, antioxidant 0.6435 wt%, lubricant 0.9405 wt%, cross-linking agent 1 wt%.

[0128] Application Example The semi-conductive shielding materials prepared in the examples and comparative examples were pre-dried at 60 °C for 4 h, and the mechanical properties and electrical properties were tested according to the standards of GB / T1040.3-2022 and GB / T 3048-2007 respectively. The test results are shown in Table 1.

[0129] Table 1

[0130] Note: The PTC coefficient, that is, the Positive Temperature Coefficient.

[0131] As can be seen from Table 1, the mechanical properties and electrical properties of the semi-conductive shielding material prepared in the examples are better than those of Comparative Example 1 and Comparative Example 2, indicating that compared with the traditional one-step blending method for preparing semi-conductive shielding materials, the isolation structure constructed by the two-step method of the present invention can effectively reduce the resistivity and PTC coefficient of the semi-conductive shielding material.

[0132] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A composition for preparing a semiconductive shielding material, characterized in that, The composition comprises a conductive network matrix resin, a non-conductive matrix resin, conductive carbon black, a processing aid and a crosslinking agent; wherein, the wetting coefficient ω in the composite system of the conductive network matrix resin, the non-conductive matrix resin and the conductive carbon black is greater than 1, and the wetting coefficient ω is calculated by formula (1): , formula (1); Wherein, A is the conductive network matrix resin; B is the non-conductive matrix resin; CB is the conductive carbon black; γ CB-B is the interfacial tension between the conductive carbon black CB and the non-conductive matrix resin B, mN / m; γ CB-A is the interfacial tension between the conductive carbon black CB and the conductive network matrix resin A, mN / m; γ A-B is the interfacial tension between the conductive network matrix resin A and the non-conductive matrix resin B, mN / m.

2. The composition according to claim 1, wherein, The conductive network matrix resin is selected from one or more of a first ethylene-vinyl acetate copolymer, a first ethylene-ethyl acrylate copolymer and a first ethylene-butyl acrylate copolymer.

3. The composition according to claim 2, wherein The melt index of the first ethylene-vinyl acetate copolymer at 190 °C and 2.16 kg is 25-150 g / 10 min, and the vinyl acetate content is 27-40 wt%. And / or, the melt index of the first ethylene-ethyl acrylate copolymer at 190 °C and 2.16 kg is 30-150 g / 10 min, and the ethyl acrylate content is 20-33 wt%. And / or, the melt index of the first ethylene-butyl acrylate copolymer at 190 °C and 2.16 kg is 20-150 g / 10 min, and the butyl acrylate content is 20-33 wt%.

4. The composition according to claim 1, wherein The non-conductive matrix resin is selected from one or more of a second ethylene-vinyl acetate copolymer, a second ethylene-ethyl acrylate copolymer, a second ethylene-butyl acrylate copolymer, polyethylene and an ethylene-1-octene copolymer.

5. The composition according to claim 4, wherein, The melt index of the second ethylene-vinyl acetate copolymer at 190 °C and 2.16 kg is 0.7-10 g / 10 min, and the vinyl acetate content is 7.5-20 wt%. And / or, the melt index of the second ethylene-ethyl acrylate copolymer at 190 °C and 2.16 kg is 1-6 g / 10 min, and the ethyl acrylate content is 15-18 wt%. And / or, the melt index of the second ethylene-butyl acrylate copolymer at 190 °C and 2.16 kg is 0.3-7 g / 10 min, and the butyl acrylate content is 3-17 wt%. and / or, the polyethylene has a melt index of 0.6 - 10 g / 10 min at 190 °C and 2.16 kg, and a density of 0.91 - 0.96 g / cm 3 ; And / or, the melt index of the ethylene-1-octene copolymer at 190 °C and 2.16 kg is 0.5-30 g / 10 min.

6. The composition according to claim 1, wherein, The processing aid is an antioxidant and / or a lubricant; And / or, the crosslinking agent is selected from ditert-butyl peroxyisopropylbenzene and / or dicumyl peroxide.

7. The composition according to claim 6, wherein The composition comprises: the content of the conductive network matrix resin is 1-65 parts, the content of the non-conductive matrix resin is 5-80 parts, the content of the conductive carbon black is 5-40 parts, the content of the antioxidant is 0.1-1.5 parts, the content of the lubricant is 0.1-1.5 parts, and the content of the crosslinking agent is 0.1-1.5 parts.

8. A method for preparing a semi-conductive shielding material using the composition according to any one of claims 1-7, characterized in that, The method described above includes: Step 1, contacting the conductive carbon black, the conductive network matrix resin and the processing aid for mixing and pelletizing to obtain a conductive network resin; Step 2, contacting the conductive network resin with the non-conductive matrix resin and the processing aid for mixing and pelletizing to obtain an isolation structure resin; Step 3: Mix the isolation structure resin with a crosslinking agent to obtain a pre-product; Step 4: Heat-treat the pre-product to obtain a semi-conductive shielding material.

9. The method according to claim 8, wherein, The mixing is performed using at least one of a twin-screw extruder, a reciprocating single-screw extruder, an internal mixer, and an open mill.

10. The method according to claim 9, wherein, The mixing speed of the twin-screw extruder is 200 - 500 rpm, and the mixing temperature is 150 - 180 °C; and / or, the mixing speed of the reciprocating single-screw extruder is 200 - 500 rpm, and the mixing temperature is 140 - 190 °C; and / or, the mixing speed of the internal mixer is 20 - 100 rpm, and the mixing temperature is 150 - 180 °C; and / or, the mixing speed of the open mill is 5 - 25 rpm, and the mixing temperature is 150 - 180 °C.

11. A semi-conductive shielding material prepared by the method according to any one of claims 8 - 10.

12. The semiconductive shielding material according to claim 11, wherein, The semi-conductive shielding material has an isolation structure; and / or, the conductive network matrix resin and the non-conductive matrix resin form a co-continuous network structure, and the conductive carbon black is distributed at the interface between the conductive network matrix resin and the non-conductive matrix resin.

13. The semiconductive shielding material according to claim 11 or 12, wherein, The volume resistivity of the semi-conductive shielding material at 23 °C is 10 - 80 Ω·cm; and / or, the volume resistivity of the semi-conductive shielding material at 90 °C is 50 - 200 Ω·cm; and / or, the PTC coefficient of the semi-conductive shielding material is 2.5 - 8.

14. An application of the semi-conductive shielding material according to any one of claims 11 - 13 in a cable.

15. The application according to claim 14, wherein The conditions of the application include: the semi-conductive shielding material is heat-treated at a pressure of 0.1 - 3 MPa and a temperature of 170 - 190 °C for 0.5 - 3 hours.

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