High-performance composite electric stress control belt and preparation method thereof

Abstract

The composite electric stress control tape is mainly composed of a backing layer and an adhesive layer, wherein the backing layer is a plasticized PVC film layer; the raw material components of the adhesive layer mainly include base rubber, dielectric filler, conductive filler, plasticizer, tackifier, reinforcing filler and antioxidant. The composite electric stress control tape has excellent mechanical and electrical properties, thereby ensuring the integrity, stability and reliability of the product during long-term use.

Description

Technical Field

[0001] This invention relates to the field of materials and manufacturing technology for wire and cable accessories, and more specifically, to a composite electrical stress control strip and its preparation method. Background Technology

[0002] In high-voltage power cable systems, the construction of cable terminations and equipment connections, as well as cable joints, is crucial. During the construction of high-voltage power cable connections, the cable's semiconductor layer needs to be cut, causing distortion and uneven distribution of the electric field. This uneven electric field can lead to high stress concentration, resulting in strong discharges that can directly damage cable accessories and potentially trigger large-scale power system failures. Therefore, it is necessary to control the electric stress at the cut points of the high-voltage cable's semiconductor layer, homogenize the electric field at the cable joint, and prevent electrical breakdown and losses.

[0003] Currently, commonly used stress control materials mainly include two types: stress control tubes and stress control strips. Traditional electrical stress control strips are mostly single-layer structures made by adding functional fillers to a rubber substrate. Their performance uniformity is poor, and inconsistencies often occur in different areas of the product. Simultaneously, their electrical performance is poor, specifically exhibiting low volume resistivity, poor insulation, low breakdown field strength (making them prone to breakdown during use), and high dielectric loss, leading to overheating and potential cable burnout. These shortcomings prevent them from effectively homogenizing the electric field, which is detrimental to the stable operation of power systems. Furthermore, the single-layer structure results in poor tensile strength, making them prone to breakage when wrapped around the cut point of the cable's semiconductor layer, affecting normal use. Summary of the Invention

[0004] The present invention aims to develop a composite electrical stress control tape with superior overall performance, while simultaneously addressing the performance deficiencies of the aforementioned products. The technical solution of the present invention is as follows:

[0005] A composite electrical stress control strip mainly consists of a liner and an adhesive layer. The liner is a plasticized polyvinyl chloride (PVC) film layer. The raw material components of the adhesive layer mainly include: base rubber, dielectric filler, conductive filler, plasticizer, tackifier, reinforcing filler, and antioxidant.

[0006] According to the composite electrical stress control strip of the present invention, the liner is a plasticized polyvinyl chloride (PVC) film with a density of 1.2 g / cm³. 3 -1.5g / cm 3 For example, 1.25-1.35 g / cm³ 3Hardness is A50-A65 (measured by a Type A Shore hardness tester), for example A50-55; light transmittance is 35%-50%, for example 45-50%; softening temperature is 85℃-100℃, for example 90-93℃.

[0007] According to the composite electrical stress control strip of the present invention, those skilled in the art can adjust its thickness according to actual needs. For example, the thickness of the lining can be 0.1-0.8 mm, preferably 0.3-0.5 mm; the thickness of the adhesive layer can be 0.35-0.45 mm.

[0008] According to the composite electrical stress control strip of the present invention, the preparation of the plasticized polyvinyl chloride (PVC) film is known in the prior art. It plasticizes the PVC using a plasticizer, which may be: phthalates, such as dioctyl phthalate (DOP), dibutyl phthalate, diisononyl phthalate, etc.; terephthalates, such as dioctyl terephthalate (DOTP); epoxy plasticizers, such as epoxidized soybean oil; cyclohexane dicarboxylic acid ester plasticizers, such as diisononyl cyclohexane 1,2-dicarboxylic acid (DINCH); polyester plasticizers, such as polyethylene terephthalate (PET); citrate plasticizers, such as acetyl tributyl citrate (ATBC), etc.

[0009] According to the composite electrical stress control strip of the present invention, the adhesive layer is mainly composed of the following raw material components in parts by weight:

[0010]

[0011] Preferably, the mass ratio of the raw material components of the adhesive layer is as follows:

[0012]

[0013] According to the composite electrical stress control strip of the present invention, the raw material components of the adhesive layer include:

[0014] The base rubber is one or a combination of nitrile rubber, chlorinated butyl rubber, and so on. The nitrile rubber's molecular backbone is composed of butadiene and acrylonitrile monomer units. Preferably, the acrylonitrile content is 35%-45%, more preferably 40-45%, and the Mooney viscosity [ML(1+4)100℃] of the nitrile rubber is 50-80, for example 60-70. The chlorinated butyl rubber preferably has a chlorine group content of 0.5%-4.0%, for example 1-2%. When the base rubber is a combination of nitrile rubber and chlorinated butyl rubber, the mass ratio of the two is 3-6:1.

[0015] The dielectric filler is one or more of barium titanate, barium strontium titanate, calcium titanate, β-silicon carbide, zinc oxide, silicon dioxide, and silicon carbide, with a preferred particle size of 3μm to 5μm.

[0016] The conductive filler is one or more of carbonyl iron powder, carbon black, and conductive carbon nanotubes, preferably carbonyl iron powder.

[0017] Plasticizers include: phthalates, such as dioctyl phthalate (DOP), dibutyl phthalate, diisononyl phthalate, etc.; terephthalates, such as dioctyl terephthalate (DOTP); epoxy plasticizers, such as epoxidized soybean oil; cyclohexane dicarboxylic acid ester plasticizers, such as diisononyl cyclohexane 1,2-dicarboxylic acid (DINCH); polyester plasticizers, such as polyethylene terephthalate (PET); citrate plasticizers, such as acetyl tributyl citrate (ATBC), naphthenic oil, and one or more chlorinated paraffins.

[0018] The tackifier is one or more of polyisobutylene, liquid rosin resin, coumarone resin, and terpene resin.

[0019] The reinforcing filler is one or more of fumed silica and precipitated silica, with a preferred specific surface area of ​​200–400 m². 2 / g.

[0020] The antioxidant is a hindered phenolic antioxidant, an amine antioxidant, a phenolic antioxidant, or a phosphite antioxidant. Specifically, it includes one or more of antioxidants such as antioxidant 168, antioxidant 1010, antioxidant 1035, antioxidant 1076, antioxidant 300, and antioxidant DSTDP.

[0021] The present invention also provides a method for preparing the above-mentioned composite electrical stress control strip, which mainly includes the following steps:

[0022] (1) Lining step: Cut the plasticized polyvinyl chloride (PVC) film into the required size;

[0023] (2) Adhesive layer step: Add the above adhesive layer raw materials to the kneader, set the temperature to 80℃~140℃, and knead for 50min~70min to knead the rubber into a ball.

[0024] (3) The mixed rubber mass obtained in step (2) is rolled into triangular bundles 3-5 times in a two-roll mill at 40℃-80℃, and then stored after thinning.

[0025] (4) Add the adhesive layer material obtained in step (3) into an extruder heated to 80℃-120℃ and extrude a sheet of a certain thickness.

[0026] (5) The liner obtained in step (1) is bonded to the sheet obtained in step (4) by a calender to prepare a composite structure electrical stress control strip product.

[0027] Beneficial effects

[0028] The substrate rubber selected in this invention possesses excellent dielectric properties, reaching 5-8. Compared to traditional product formulations, this invention's substrate selection improves the dielectric constant while reducing dielectric loss, achieving superior electrical performance. Furthermore, this invention requires only a small amount of functional filler to achieve the target electrical performance, reducing material costs to some extent. The low-particle-size dielectric filler selected in this invention achieves high dispersibility in the polymer matrix, significantly improving the uniformity of product performance. Simultaneously, the use of surface-modified conductive fillers in this invention also improves the dispersibility of conductive fillers in the polymer matrix, greatly reducing agglomeration, thereby enhancing the uniformity and mechanical properties of the product, as well as its dielectric properties, breakdown field strength, and other electrical properties. The double-layer structure of the liner and adhesive layer selected in this invention exhibits superior mechanical properties (tensile strength) and electrical properties (dielectric constant, dielectric loss, volume resistivity, breakdown field strength parameters) compared to a single-layer structure, thus ensuring the integrity, stability, and reliability of the product during long-term use. Attached Figure Description

[0029] Figure 1 : Actual photos of (a) the adhesive layer and (b) the lining layer of Embodiments 1-3 of the present invention;

[0030] Figure 2 : Actual photos of (a) the adhesive layer and (b) the lining layer of Comparative Examples 8-9 of the present invention. Detailed Implementation

[0031] The stress control strip and its preparation according to the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0032] Example 1:

[0033] A high-performance composite electrical stress control strip, specifically:

[0034] Liner: PVC film plasticized with dioctyl phthalate (DOP), 0.42 mm thick, density: 1.25 g / cm³ 3 Hardness: A50, light transmittance: 45%, softening temperature: 90℃, roll up for later use.

[0035] Adhesive layer: The raw material components are as described in Table 1 below:

[0036] Table 1

[0037]

[0038] The acrylonitrile content of the above-mentioned nitrile rubber is 41%, and the Mooney viscosity [ML(1+4)100℃] is 60;

[0039] The mass content of chlorinated groups in the above-mentioned chlorinated butyl rubber is 1.18% to 1.34%.

[0040] The particle size of the above barium titanate powder is 3 μm;

[0041] The above-mentioned carbonyl iron powder has the following properties: Fe ≥ 98.0, C ≤ 0.80, D50 ≤ 3.5 μm.

[0042] The specific surface area of ​​the above-mentioned fumed silica is 200±25m². 2 / g;

[0043] The molecular weight of the polyisobutylene mentioned above is 2000-5000.

[0044] In this embodiment, the method for preparing the composite electrical stress control strip is as follows:

[0045] (1) Liner selection: Select plasticized PVC film with a thickness of 0.42mm;

[0046] (2) Adhesive layer preparation method: 100 parts of nitrile rubber, 25 parts of chlorinated butyl rubber, 100 parts of barium titanate, 16 parts of carbonyl iron powder, 20 parts of fumed silica, 40 parts of polyisobutylene, 6 parts of dioctyl phthalate, and 4 parts of antioxidant 168 are weighed and added to a kneader. The machine speed is set to 50 rpm and the processing temperature is 90℃~120℃ to make the rubber compound form a ball. Then, a two-roll mill is used to roll the rubber into triangular pieces 3-5 times at 50-60℃ and thin sheets are produced to obtain the compound for later use.

[0047] (3) The compounded rubber is placed in an extruder heated to about 100°C and extruded to form a smooth, flat sheet. The liner and adhesive layer are then bonded together using a calender. A composite structure product is thus prepared.

[0048] (4) After the composite structure product is left to stand for 24 hours, it is cut to a specific size for testing.

[0049] Example 2:

[0050] A high-performance composite electrical stress control strip, specifically:

[0051] Liner: PVC film plasticized with dioctyl phthalate (DOP), 0.42 mm thick, density: 1.25 g / cm³3 Hardness: A50, light transmittance: 45%, softening temperature: 90℃.

[0052] Adhesive layer: The raw material composition is shown in Table 2 below:

[0053] Table 2

[0054]

[0055] The acrylonitrile content of the above-mentioned nitrile rubber is 41%, and the Mooney viscosity [ML(1+4)100℃] is 60;

[0056] The mass content of chlorinated groups in the above-mentioned chlorinated butyl rubber is 1.18% to 1.34%.

[0057] The dielectric filler selected above is barium strontium titanate powder with a particle size of 3 μm;

[0058] The conductive filler selected above is conductive carbon black with a specific surface area of ​​200-350 m². 2 / g, resistivity 0.3~0.5(Ω·cm);

[0059] The specific surface area of ​​the above-mentioned fumed silica is 200±25m². 2 / g;

[0060] The above-mentioned tackifier is selected from water-based terpene resins;

[0061] In this embodiment, the method for preparing the high-performance composite electrical stress control strip is as follows:

[0062] (1) Liner selection: Select plasticized PVC film with a thickness of 0.42mm;

[0063] (2) Adhesive layer preparation method: 100 parts of nitrile rubber, 25 parts of chlorinated butyl rubber, 100 parts of barium strontium titanate, 16 parts of conductive carbon black, 20 parts of fumed silica, 35 parts of terpene resin, 6 parts of dioctyl phthalate, and 4 parts of antioxidant 168 are weighed and added to a kneader. The machine speed is set to 50 rpm and the processing temperature is 90℃~120℃ to make the rubber compound form a ball. Then, a two-roll mill is used to roll the rubber into triangular pieces 3-5 times at 50-60℃ and thin sheets are produced to obtain the compound for later use.

[0064] (3) The compound rubber is put into an extruder heated to about 100°C and extruded to form a smooth and flat sheet. Then, the liner and adhesive layer are bonded together by a calender to prepare a composite structure product.

[0065] (4) After the composite structure product is left to stand for 24 hours, it is cut to a specific size for testing.

[0066] Example 3:

[0067] A high-performance composite electrical stress control strip, specifically:

[0068] Liner: PVC film plasticized with dioctyl phthalate (DOP), 0.42 mm thick, density: 1.25 g / cm³ 3 Hardness: A50, light transmittance: 45%, softening temperature: 90℃.

[0069] Adhesive layer: The raw material composition is shown in Table 3 below:

[0070] Table 3

[0071]

[0072] The acrylonitrile content of the above-mentioned nitrile rubber is 41%, and the Mooney viscosity [ML(1+4)100℃] is 60;

[0073] The mass content of chlorinated groups in the above-mentioned chlorinated butyl rubber is 1.18% to 1.34%.

[0074] The dielectric filler selected above is β-phase silicon carbide powder with a particle size of 3μm. Under this crystal phase, silicon carbide powder has good dielectric properties.

[0075] The conductive filler selected above is conductive carbon nanotubes with an aspect ratio of 10. 4 Specific surface area: 200-230 m² 2 / g, volume resistivity 0.04~0.05(Ω·cm);

[0076] The specific surface area of ​​the above-mentioned fumed silica is 200±25m². 2 / g;

[0077] The molecular weight of the polyisobutylene mentioned above is 2000-5000.

[0078] In this embodiment, the method for preparing the high-performance composite electrical stress control strip is as follows:

[0079] (1) Liner selection: Select plasticized PVC film with a thickness of 0.42mm;

[0080] (2) Adhesive layer preparation method: 100 parts of nitrile rubber, 25 parts of chlorinated butyl rubber, 100 parts of β-silicon carbide, 16 parts of conductive carbon nanotubes, 20 parts of fumed silica, 40 parts of polyisobutylene, 6 parts of dioctyl phthalate, and 4 parts of antioxidant 168 were weighed and added to a kneader. The machine speed was set to 50 rpm and the processing temperature was 90℃~120℃ to make the rubber compound form a ball. Then, a two-roll mill was used to roll the rubber into triangular pieces 3-5 times at 50-60℃ and thin sheets were produced to obtain the compound for later use.

[0081] (3) The compound rubber is put into an extruder heated to about 100°C and extruded to form a smooth and flat sheet. Then, the liner and adhesive layer are bonded together by a calender to prepare a composite structure product.

[0082] (4) After the composite structure product is left to stand for 24 hours, it is cut to a specific size for testing.

[0083] Comparative Example 1:

[0084] The difference between this comparative example and Example 1 is that a nitrile rubber with a low acrylonitrile content was selected. In this comparative example, a nitrile rubber with an acrylonitrile content of 19.5% and a Mooney viscosity [ML(1+4)100℃] of 43 was selected to replace the nitrile rubber in Example 1, in order to explore the effect of acrylonitrile content on product performance.

[0085] Comparative Example 2:

[0086] The difference between this comparative example and Example 1 is that a nitrile rubber with a medium to high acrylonitrile content was selected. In this comparative example, a nitrile rubber with an acrylonitrile content of 33% and a Mooney viscosity [ML(1+4)100℃] of 66 was selected to replace the nitrile rubber in Example 1, in order to explore the effect of acrylonitrile content on product performance.

[0087] Comparative Example 3:

[0088] The difference between this comparative example and Example 1 is that a nitrile rubber with an extremely high acrylonitrile content was selected. In this comparative example, a nitrile rubber with an acrylonitrile content of 48% and a Mooney viscosity [ML(1+4)100℃] of 65 was selected to replace the nitrile rubber in Example 1, in order to explore the effect of acrylonitrile content on product performance.

[0089] Comparative Example 4:

[0090] Compared to Example 1, this comparative example differs in that untreated metallic iron powder was used instead of carbonyl iron powder, aiming to explore the impact of surface modification of metal powder on product performance.

[0091] Comparative Example 5:

[0092] The difference between this comparative example and Example 1 is that the surface-mount silane coupling agent KH-550 (density approximately 1.04 g / cm³) was selected. 3 The study aimed to explore the impact of surface modification of metal powders on product performance by replacing carbonyl iron powder with metal iron powder treated with a pH value between 4 and 6.

[0093] Comparative Example 6

[0094] The difference between this comparative example and Example 1 is that an aminovinyltriethoxysilane (AEAPS) (density 1.05-1.10 g / cm³) was selected for the surface treatment.3 The study aimed to explore the impact of surface modification of metal powders on product performance by replacing carbonyl iron powder with metal iron powder treated with pH 4-6.

[0095] Comparative Example 7

[0096] This comparative example involves purchasing commercially available single-layer electrical stress control strip products and testing their various performance characteristics. The aim is to explore the impact of structural design on product performance by comparing these products with the embodiments described in this invention.

[0097] Comparative Example 8

[0098] The difference between this comparative example and Example 1 is the use of a stiffer plasticized PVC film. In this comparative example, the liner is a PVC film plasticized with dioctyl phthalate (DOP), with a thickness of 0.42 mm and a density of 1.25 g / cm³. 3 The film has a hardness of A70, a light transmittance of 45%, and a softening temperature of 90°C. Compared to Example 1, this comparative example uses a PVC film with higher hardness to explore the impact of different hardness of backing materials on the processing performance of the overall composite product.

[0099] Comparative Example 9

[0100] The difference between this comparative example and Example 1 is the use of a softer plasticized PVC film. In this comparative example, the liner is a PVC film plasticized with dioctyl phthalate (DOP), with a thickness of 0.42 mm and a density of 1.25 g / cm³. 3 The film has a hardness of A40, a light transmittance of 45%, and a softening temperature of 90°C. Compared to Example 1, this comparative example uses a PVC film with lower hardness to explore the impact of different hardness of backing materials on the processing performance of the overall composite product.

[0101] Table 4 below shows the performance comparison results between Examples 1-3 and Comparative Examples 1-3:

[0102] Table 4

[0103]

[0104]

[0105] Examples 1, 2, and 3 all used nitrile rubber with an acrylonitrile content of 41% as the substrate, while Comparative Examples 1, 2, and 3 used nitrile rubber with low, medium-high, and ultra-high acrylonitrile contents, respectively, as the substrate. The results showed that while the nitrile rubber with low acrylonitrile content (Comparative Example 1) had lower dielectric loss, it also had a low dielectric constant and poor mechanical properties, indicating weak overall performance. The nitrile rubber with medium-high acrylonitrile content (Comparative Example 2) did not perform well in terms of dielectric constant and dielectric loss. Although the nitrile rubber with ultra-high acrylonitrile content (Comparative Example 3) had a higher dielectric constant, its dielectric loss increased significantly, failing to meet the product application requirements. Therefore, a higher acrylonitrile content in the substrate rubber is not necessarily better. Research indicates that nitrile rubber with an acrylonitrile content in the range of 35%-45% performs best as the substrate and is most suitable for the application requirements of this invention.

[0106] Table 5 below shows the performance comparison results of Example 1 with Comparative Examples 4, 5, and 6, exploring the impact of different inorganic powder surface modification methods on product performance and identifying the optimal surface modification method. Furthermore, Comparative Example 7 investigates the performance differences between single-layer and double-layer structure products.

[0107] Table 5

[0108]

[0109] Example 1 used carbonyl iron powder as the conductive filler, while Comparative Examples 4, 5, and 6 used unmodified metallic iron powder, metallic iron powder modified with silane coupling agent (KH-550), and metallic iron powder modified with aminovinyltriethoxysilane (AEAPS), respectively, as conductive fillers. Data shows that the unmodified conductive filler in Comparative Example 4 resulted in a lower dielectric constant and higher dielectric loss in the final product compared to Example 1, indicating poorer performance. Comparative Example 5, using KH-550 surface-modified metallic iron powder, showed improved dielectric constant and dielectric loss performance, but still fell short of Example 1. Similarly, the use of aminovinyltriethoxysilane (AEAPS) modified metallic iron powder (Comparative Example 6) also failed to reach the performance level of Example 1. Therefore, we can conclude that: 1. Surface modification of inorganic powders can improve the dielectric properties of products, but the degree of improvement varies significantly among powders with different surface modifications; 2. Through research and analysis, the carbonyl iron powder of this invention forms a better synergistic effect with the nitrile rubber matrix and other functional fillers in the formulation (such as barium titanate, barium strontium titanate, etc.), resulting in a product with a higher dielectric constant, lower dielectric loss, and optimal mechanical properties, making it most suitable for the application requirements of this invention.

[0110] Embodiment 1 of this invention employs a double-layer composite structure, which, compared to commercially available single-layer structure products (Comparative Example 7), exhibits superior mechanical properties (such as tensile strength) and electrical properties (including dielectric constant, dielectric loss, volume resistivity, and breakdown field strength). The integrity, stability, and reliability of the composite structure product of this invention are fully guaranteed during long-term use.

[0111] Table 6 shows the appearance comparison results of Examples 1-3 and Comparative Examples 8-9 after 24 hours of placement. See also the appendix. Figure 1 and 2 Comparison:

[0112] Table 6

[0113]

[0114] In this invention, the hardness of the liner film in Examples 1, 2, and 3 was A50, and the resulting products had a good appearance without wrinkles. However, in Comparative Example 8, the liner hardness was A70, and in Comparative Example 9, the liner hardness was A40, resulting in poor product appearance and wrinkles. The results indicate that the choice of liner material affects the product appearance, and the choice of liner material hardness is crucial. In this invention, the hardness of the PVC liner is maintained within a moderate range (A50-A65), which allows the PVC layer to achieve a good balance between softness and rigidity, thus matching the elasticity of the adhesive layer, reducing stress differences caused by thermal expansion or contraction, avoiding inconsistent interlayer shrinkage, and ensuring that the composite structure does not wrinkle.

[0115] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite electrical stress control strip, mainly composed of a liner and an adhesive layer, wherein the liner is a plasticized polyvinyl chloride (PVC) film layer; the adhesive layer mainly comprises the following raw material components: Base rubber, dielectric filler, conductive filler, plasticizer, tackifier, reinforcing filler, antioxidant.

2. The composite electrical stress control strip according to claim 1, wherein the lining is a plasticized polyvinyl chloride (PVC) film with a hardness of A50-A65 (measured by a type A Shore hardness tester).

3. The composite electrical stress control strip according to any one of claims 1-2, wherein the adhesive layer is mainly composed of the following raw material components in parts by weight: Base rubber: 100-150 parts Dielectric filler: 80-150 parts Conductive filler: 15-35 parts Plasticizer: 2-10 parts Tackifier: 20-50 parts Reinforcing filler: 10-30 parts Antioxidant: 2-8 parts.

4. The composite electrical stress control strip according to claim 3, wherein the mass ratio of the raw material components of the adhesive layer is as follows: Base rubber: 110-130 parts Dielectric filler: 80-100 parts Conductive filler: 15-20 parts Plasticizer: 4-7 parts Tackifier: 35-45 parts Reinforcing filler: 15-25 parts Antioxidant: 2-5 parts.

5. The composite electrical stress control strip according to any one of claims 1-2, wherein the raw material components of the adhesive layer are: The base rubber is one or a combination of nitrile rubber, chlorinated butyl rubber, etc. The main molecular chain of the nitrile rubber is composed of two monomer units, butadiene and acrylonitrile, preferably nitrile rubber with an acrylonitrile content of 35% to 45%; the chlorine group content of the chlorinated butyl rubber is 0.5% to 4.0%. And / or, the dielectric filler is one or more of barium titanate, barium strontium titanate, calcium titanate, β-silicon carbide, zinc oxide, silicon dioxide, and silicon carbide; And / or, the conductive filler is one or more of carbonyl iron powder, carbon black, and conductive carbon nanotubes; And / or, the plasticizer is one or more of the following: phthalates, terephthalates, epoxy plasticizers, cyclohexane dicarboxylate plasticizers, polyester plasticizers, citrate plasticizers, naphthenic oils, and chlorinated paraffins; And / or, the tackifier is one or more of polyisobutylene, liquid rosin resin, coumarone resin, and terpene resin; And / or, the reinforcing filler is one or more of fumed silica and precipitated silica; The antioxidant is one or more of the following: hindered phenolic antioxidants, amine antioxidants, phenolic antioxidants, and phosphite antioxidants.

6. The composite electrical stress control strip according to claim 5, wherein, The base rubber is a combination of nitrile rubber and chlorinated butyl rubber, with a mass ratio of 3 to 6:

1. And / or, the acrylonitrile content in the nitrile rubber is 40-45%, and the Mooney viscosity (ML1+4 100℃) of the nitrile rubber is 50-80, for example 60-70; And / or, the chlorinated butyl rubber contains 1-2% chlorine groups; And / or, the particle size of the dielectric filler is 3μm to 5μm; And / or, the conductive filler is carbonyl iron powder; And / or, the plasticizer is one or more of the following: dioctyl phthalate (DOP), dibutyl phthalate, diisononyl phthalate, dioctyl terephthalate (DOTP), epoxidized soybean oil, diisononyl cyclohexane 1,2-dicarboxylate (DINCH), polyethylene terephthalate (PET), acetyl tributyl citrate (ATBC), naphthenic oil, and chlorinated paraffin. And / or, the antioxidant is one or more of antioxidant 168, antioxidant 1010, antioxidant 1035, antioxidant 1076, antioxidant 300, and antioxidant DSTDP.

7. A method for preparing the composite electrical stress control strip according to claim 1, mainly comprising the following steps: (1) Lining step: Cut the plasticized polyvinyl chloride (PVC) film into the required size; (2) Adhesive layer step: Add the above adhesive layer raw materials to the kneader, set the temperature to 80℃~140℃, and knead for 50min~70min to knead the rubber into a ball. (3) The mixed rubber mass obtained in step (2) is rolled into triangular bundles 3-5 times in a two-roll mill at 40℃-80℃, and then stored after thinning. (4) Add the adhesive layer material obtained in step (3) into an extruder heated to 80℃-120℃ and extrude a sheet of a certain thickness. (5) The liner obtained in step (1) is bonded to the sheet obtained in step (4) by a calender to prepare a composite structure electrical stress control strip product.

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