An insulating shroud for live-line work

Abstract

The application provides a live working insulation shielding blanket, which comprises a surface layer and an inner layer, the surface layer has two layers and is attached to the outer surface of the inner layer, the inner layer is a multi-layer structure arranged in a laminated mode, the raw material of the surface layer comprises EVA, montmorillonite loaded with imidazole polybasic borate complex, natural rubber, PA6 short fibers, EVA-g-MAH, a flame retardant, an antioxidant and a colorant, and the raw material of the inner layer comprises EVA, montmorillonite loaded with imidazole polybasic borate complex, natural rubber, EVA-g-MAH and a colorant. The montmorillonite loaded with imidazole polybasic borate complex is added to the surface layer and the inner layer in cooperation, multiple protections of outer molten prevention and inner collapse prevention are realized, the service life of the material in an extreme environment is effectively prolonged, and the problems of easy softening and insulation failure of a traditional EVA insulation shielding blanket under high temperature are solved.

Description

Technical Field

[0001] This invention relates to the field of insulating shielding blankets, and more particularly to an insulating shielding blanket for live-line work. Background Technology

[0002] Insulating blankets for live-line work are specialized safety protection devices used in live-line work in power systems. Their main function is to provide effective insulation protection for operators in energized environments to prevent electric shock accidents caused by contact with or proximity to live conductors. These products are typically made of multiple layers of insulating materials through processes such as composite calendering, molding, and vulcanization, and are widely used in the maintenance and repair of power lines and equipment in transmission, distribution, and other power systems.

[0003] Ethylene-vinyl acetate copolymer (EVA) is a polymer formed by the co-reaction of vinyl acetate monomers into ethylene. It possesses characteristics such as reducing material crystallinity and improving flexibility and impact resistance, and is widely used in foam materials, functional films, wires and cables, and solar cell encapsulation films. EVA insulating blankets are commonly used in live-line work, but under high temperature and high load conditions, they often experience heat melting and mechanical damage, leading to insulation failure. Therefore, improving the high-temperature resistance of EVA-containing insulating blankets has become a critical technical problem that urgently needs to be solved. Summary of the Invention

[0004] In view of this, the present invention proposes an insulating shielding blanket for live-line work with good high-temperature resistance.

[0005] The technical solution of the present invention is implemented as follows: On the one hand, the present invention provides an insulating shielding blanket for live-line work, the shielding blanket comprising a surface layer and an inner layer, the surface layer having two layers and being attached to the outer surface of the inner layer; the inner layer having a multi-layer structure with layers stacked on top of each other;

[0006] The surface layer materials include EVA, montmorillonite loaded with imidazole polyboronic acid complex, natural rubber, PA6 short fiber, EVA-g-MAH, flame retardant, antioxidant and colorant.

[0007] The inner layer consists of EVA, montmorillonite loaded with imidazole polyboronic acid complex, natural rubber, EVA-g-MAH, and colorant.

[0008] MAH-g-EVA is used to enhance the interfacial bonding between EVA / rubber and polar fillers, improving dispersion and overall composite material performance. PA6 short fibers are used to increase tear and puncture resistance.

[0009] Montmorillonite sheets have a good two-dimensional arrangement structure, forming a "labyrinth structure" in composite materials. This effectively blocks the diffusion paths of heat, oxygen, and small molecules, thereby delaying thermal decomposition, melting, and gas penetration, making the matrix more resistant to sudden high temperatures.

[0010] The imidazole ring has a lone pair of electrons and a basic nitrogen atom, while the borate ion is negatively charged. When these two elements are complexed or grafted, the molecule exhibits strong ionic characteristics, forming an ionic cross-linked network of positive and negative charges between resin / rubber matrix segments. At room temperature, this ionic cross-linking provides "physical anchors" for the molecular chains, improving mechanical strength and heat distortion temperature, inhibiting disordered molecular chain movement, and significantly enhancing the overall heat resistance and mechanical load-bearing capacity of the material. At high temperatures, the ionic bonds are non-covalent and can dynamically and reversibly dissociate, allowing the polymer chains to acquire "controllable movement." When the material suffers microscopic damage (such as microcracks), the molecular chains can migrate and recombine after the ionic bonds break, achieving self-repair of microcracks and maintaining the material's structural integrity and thermal stability.

[0011] Montmorillonite has a porous, layered structure. After being loaded with imidazole polyboronic acid complexes, polar complexes are intercalated between the layers. These complexes can interact with the acetate groups in EVA, the unsaturated bonds in natural rubber, the ether / epoxy groups provided by PEGDE, and even the anhydride groups in EVA-g-MAH, "through condensation, nucleophilic addition, or polar coordination," to construct an organic-inorganic interpenetrating network between the polymer chains and the montmorillonite layers. This interpenetrating network makes montmorillonite more uniformly dispersed, less prone to agglomeration and sedimentation, and less susceptible to structural damage or migration under long-term high temperature / high load conditions. In addition, the interpenetrating network can also reinforce the interface, improve the interfacial bonding strength, and make the layered material less prone to peeling or decomposition under heat and mechanical pressure.

[0012] Based on the above technical solutions, preferably, the raw materials of the surface layer, calculated by weight, include: 60-78 parts of EVA, 8-12 parts of montmorillonite loaded with imidazole polyboronic acid complex, 8-12 parts of natural rubber, 3-7 parts of PA6 short fiber, 3-6 parts of MAH-g-EVA, 10-15 parts of flame retardant, 1-2 parts of antioxidant, and 1-4 parts of colorant.

[0013] Based on the above technical solutions, preferably, the inner layer further includes polyethylene glycol diglycidyl ether (PEGDE).

[0014] To enhance the material's flexibility, this invention incorporates PEGDE into the inner layer. PEGDE is a flexible polyether structure containing end-cap epoxy groups. Its long-chain flexible portion (polyethylene glycol) can act as a "separator" or "plasticizer" in the polymer network, increasing the degree of freedom of the molecular chains and thus significantly improving the material's flexibility, resilience, and low-temperature toughness. Furthermore, its epoxy groups can react with active hydrogen structures in the formulation (such as alcohols, carboxyl groups, acetate groups in the EVA portion, and double bonds in the rubber portion) or anhydride groups in EVA-g-MAH, forming mild cross-linking or grafting, further optimizing the mechanical structure.

[0015] The epoxy in PEGDE reacts chemically with EVA, and can also react with the unsaturated groups in natural rubber and the anhydride of EVA-g-MAH, improving interfacial compatibility and overall material uniformity. The surface of montmorillonite-supported modifiers contains organic functional groups and residual hydroxyl groups, which PEGDE can also interact with in small amounts, beneficial for dispersion and the flexibility of the lamellar micro-interface.

[0016] In summary, the addition of PEGDE not only improves flexibility but also disperses and modifies montmorillonite, increases interfacial compatibility, and thus enhances the overall performance of the insulating blanket.

[0017] Based on the above technical solutions, preferably, the raw materials of the inner layer, calculated by weight, include: 75-85 parts of EVA, 3-5 parts of montmorillonite loaded with imidazole polyboronic acid complex, 10-20 parts of natural rubber, 1.5-3 parts of MAH-g-EVA, 6-12 parts of polyethylene glycol diglycidyl ether, and 1-4 parts of colorant.

[0018] Based on the above technical solutions, preferably, the thickness of each surface layer is 100-220μm, the thickness of each inner layer is 156-164μm, and there are 10 inner layers.

[0019] Based on the above technical solutions, preferably, the preparation method of the montmorillonite loaded with imidazole polyboronic acid complex includes the following steps:

[0020] S11, add montmorillonite to dilute hydrochloric acid solution, ultrasonically disperse at 60-80℃ for 0.5-1h, filter after the process, wash with deionized water until the wash solution is neutral, and then filter and dry to obtain acid-modified montmorillonite;

[0021] S12, dissolve phenyl-1,3,5-trimethyltriboronic acid in an ethanol solution, add 2-imidazol-1-ylethylamine while stirring, adjust the pH to 7-9 after the addition is complete, and continue stirring for 50-60 min to obtain an imidazolium polyboronic acid complex solution.

[0022] S13, acid-modified montmorillonite was added to deionized water and dispersed evenly to obtain a montmorillonite suspension; then an imidazole polyboronic acid complex solution was added, and the mixture was reacted at 40-60℃ for 2-4 hours. After the reaction was completed, the mixture was filtered and dried to obtain montmorillonite loaded with imidazole polyboronic acid complex.

[0023] Based on the above technical solutions, preferably, the mass ratio of 2-imidazol-1-ylethylamine, phenyl-1,3,5-trimethyltriboronic acid and acid-modified montmorillonite is 1.3-1.5:1:10.

[0024] Based on the above technical solutions, preferably, the flame retardant is one or two of aluminum hydroxide and magnesium hydroxide, the antioxidant is one or two of antioxidant 1010 and antioxidant 1076, and the colorant is one of permanent orange, titanium dioxide, chrome yellow, titanium green or rubber red.

[0025] On the other hand, the present invention also provides a method for preparing an insulating shielding blanket for live-line work, comprising the following steps:

[0026] S21, Surface preparation: EVA, montmorillonite loaded with imidazole polyboronic acid complex, natural rubber, PA6 short fiber, EVA-g-MAH, flame retardant, antioxidant and colorant are put into an internal mixer and mixed. After the mixing is completed, the mixed material is put into a rubber mixing mill, accelerator DM and sulfur are added and mixed. After the mixing is completed, the material is pressed into sheet 1 for later use.

[0027] S22, Inner layer preparation: EVA, montmorillonite loaded with imidazole polyboronic acid complex, natural rubber, polyethylene glycol diglycidyl ether, EVA-g-MAH and colorant are added to a mixer and mixed; after the end, the mixed material is put into a rubber mixing mill, accelerator DM and sulfur are added and mixed, and after the end, the mixture is pressed into sheet 2 for later use.

[0028] S23, Lamination and Composite: Ten layers of film 2 are calendered and laminated to obtain composite film 2. Then, two layers of film 1 are placed on the outside of composite film 2 and calendered and laminated again to obtain composite film. Then, the composite film is flattened and vulcanized. After completion, the edges are trimmed and finished to obtain insulating shielding blanket.

[0029] Based on the above technical solutions, preferably, in steps S21 and S22, the mixing temperature is 90-100℃ and the time is 10-13 min; the blending temperature is 60-90℃ and the time is 5-9 min; the dosage of accelerator DM and sulfur is 0.8%-1.5% and 1.2%-2.2% of the weight of the mixed material, respectively.

[0030] In step S23, the roller temperature is 60-85℃, the roller pressure is 4-12MPa, and the roller linear speed is 0.1-0.25m / s during calendering and bonding; the pressure is 10-18MPa, the temperature is 155-170℃, and the time is 15-30min during vulcanization.

[0031] The live-line working insulating blanket of the present invention has the following advantages over the prior art:

[0032] This invention introduces montmorillonite loaded with imidazole polyboronic acid complexes into the material system, enabling the construction of a multi-point ionic cross-linked network between polymer segments. This network significantly enhances mechanical and thermal stability at room temperature and exhibits dynamic and reversible dissociation at high temperatures, achieving self-repair of the molecular chains. Therefore, it helps suppress thermal melting, reduce mechanical damage, and maintain insulation performance under high-temperature and high-load conditions. Simultaneously, the loaded complexes impart stronger chemical and physical bonding between the montmorillonite sheets and the matrix, forming an organic-inorganic interpenetrating network. This not only improves the nanodispersion of montmorillonite but also further enhances interfacial strength and structural stability. This synergistic mechanism as a whole endows the composite material with superior high-temperature resistance, fatigue resistance, and long-term insulation performance, significantly solving the failure problem of traditional materials under harsh environments.

[0033] This invention synergistically adds montmorillonite loaded with imidazole polyboronic acid complex to both the surface and inner layers, achieving multiple protections against melting on the outside and collapse on the inside, effectively extending the service life of the material in extreme environments, and solving the problems of traditional EVA insulation blankets such as easy softening and insulation failure at high temperatures.

[0034] To further enhance the flexibility of the material, this invention incorporates PEGDE into the inner layer. PEGDE is a flexible polyether structure containing end-group epoxy. Its long-chain flexible portion (polyethylene glycol) can act as a "separator" or "plasticizer" in the polymer network, increasing the degree of freedom of the molecular chain, thereby significantly improving the flexibility, resilience and low-temperature toughness of the material. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of the insulating shielding blanket for live-line work of the present invention, where 1 is the outer layer and 2 is the inner layer;

[0037] Figure 2 This is a physical image of the insulating shielding blanket for live-line work according to the present invention. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] The EVA used in this invention was purchased from Lianhong New Material Technology Co., Ltd., model UL01833. MAH-g-EVA was purchased from Shanghai Jiuju Polymer Materials Co., Ltd., model 265B. The PA6 (polyamide 6 fiber) staple fiber was nylon PA6 staple fiber, purchased from Jiangsu Heshili New Material Co., Ltd. Polyethylene glycol diglycidyl ether (PEG-DGE) was purchased from Xiamen Sainuobang Biotechnology Co., Ltd. Benzene-1,3,5-trimethyltriboronic acid (CAS No.: 89641-21-4) was purchased from (Alpha) Zhengzhou Alpha Chemical Co., Ltd.

[0040] Example 1

[0041] The live-line working insulating blanket of this embodiment includes a surface layer and an inner layer. The surface layer has two layers, each with a thickness of 210 μm, and is attached to the outer surface of the inner layer. The inner layer has ten layers, each with a thickness of 158 μm, and is stacked together.

[0042] The raw materials for the surface layer are: 1320g EVA, 180g montmorillonite loaded with imidazole polyboronic acid complex, 220g natural rubber, 80g PA6 short fiber, 120g of MAH-g-EVA, 220g aluminum hydroxide, 40g antioxidant 1010, and 20g chrome yellow.

[0043] The inner layer is made of the following raw materials: 1600g of EVA, 80g of montmorillonite loaded with imidazole polyboronic acid complex, 280g of natural rubber, 60g of MAH-g-EVA, and 70g of chrome yellow.

[0044] A method for preparing an insulating shielding blanket for live-line working includes the following steps:

[0045] S1, Preparation of montmorillonite loaded with imidazole polyboronic acid complex

[0046] S11. Montmorillonite was added to a 10-fold volume of dilute hydrochloric acid (0.5wt%) solution and ultrasonically dispersed at 65°C for 0.5 hours. After dispersion, the mixture was filtered and washed with deionized water until the wash solution was neutral. The resulting solution was then filtered and dried to obtain acid-modified montmorillonite.

[0047] S12, dissolve 30g of benzene-1,3,5-trimethyltriboronic acid in 1L of ethanol solution (50% by volume), add 40g of 2-imidazol-1-ylethylamine while stirring, adjust the pH to 8 with ammonia water after the addition is complete, and continue stirring for 60min to obtain an imidazolium polyboronic acid complex solution.

[0048] S13, 300g of acid-modified montmorillonite was added to 3L of deionized water and dispersed evenly to obtain a montmorillonite suspension; then the imidazole polyboronic acid complex solution prepared in step S12 was added, and the mixture was reacted at 50℃ for 3h. After the reaction was completed, the mixture was filtered and washed repeatedly with deionized water 3-4 times until the washing solution was neutral. Then, it was washed once with a small amount of ethanol to remove unintercalated organic matter. Finally, it was dried to obtain montmorillonite loaded with imidazole polyboronic acid complex.

[0049] S2, Surface preparation: First, EVA, natural rubber, PA6 short fiber and EVA-g-MAH are put into a mixer and mixed at 95°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex, flame retardant, antioxidant and colorant are added and mixed for another 3 minutes. After the end, the mixed material is put into a rubber mixing mill, and 1% of the weight of the mixed material of accelerator DM and 1.8% of sulfur are added. The mixture is mixed at 74°C for 6 minutes. After the end, it is pressed into sheet to make sheet I for later use.

[0050] S3, Inner Layer Preparation: First, EVA, natural rubber and EVA-g-MAH are put into a mixer and mixed at 95°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex and colorant are added, and the mixing continues for 2 minutes. After the mixing is completed, the mixed material is put into a rubber mixing mill, and 1% of the weight of the mixed material of accelerator DM and 1.8% of sulfur are added. The mixture is mixed at 75°C for 6 minutes. After the mixing is completed, the mixture is pressed into sheet II for later use.

[0051] S4, Lamination and Composite: Ten layers of film II are calendered and laminated to obtain composite film II. Then, two layers of film I are placed on the outside of composite film II and calendered and laminated again to obtain a composite film. During calendering and lamination, the roller temperature is 70℃, the roller pressure is 10MPa, and the roller linear speed is 0.2m / s. The composite film is then turned into a flat vulcanizing machine and vulcanized at 15MPa and 160℃ for 20 minutes. After the vulcanization is completed, the edges are trimmed to obtain an insulating shielding blanket.

[0052] Example 2

[0053] Compared with Example 1, Example 2 increased the raw material of the inner layer by 140g of polyethylene glycol diglycidyl ether.

[0054] The inner layer is made of the following raw materials: 1600g EVA, 80g montmorillonite loaded with imidazole polyboronic acid complex, 280g natural rubber, 60g MAH-g-EVA, 140g polyethylene glycol diglycidyl ether, and 70g chrome yellow.

[0055] Step S3, Inner Layer Preparation: First, EVA, natural rubber, EVA-g-MAH and polyethylene glycol diglycidyl ether are put into a mixer and mixed at 95°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex and colorant are added, and the mixing continues for 2 minutes. After the mixing is completed, the mixed material is put into a rubber mixing mill, and 1% by weight of accelerator DM and 1.8% sulfur are added. The mixture is mixed at 75°C for 6 minutes. After the mixing is completed, the mixture is pressed into sheet II for later use.

[0056] The rest of the content is the same.

[0057] Example 3

[0058] The live-line working insulating blanket of this embodiment includes a surface layer and an inner layer. The surface layer has two layers, each with a thickness of 180μm, and is attached to the outer surface of the inner layer. The inner layer has ten layers, each with a thickness of 164μm, and is stacked on top of each other.

[0059] The surface layer consists of: 1560g EVA, 240g montmorillonite loaded with imidazole polyboronic acid complex, 160g natural rubber, 140g PA6 short fiber, 60g MAH-g-EVA, 300g aluminum hydroxide, 20g antioxidant 1076, and 40g rubber red.

[0060] The inner layer is made of the following raw materials: 1700g EVA, 100g montmorillonite loaded with imidazole polyboronic acid complex, 200g natural rubber, 30g MAH-g-EVA, 240g polyethylene glycol diglycidyl ether, and 20g rubber red.

[0061] A method for preparing an insulating shielding blanket for live-line working includes the following steps:

[0062] S1, Preparation of montmorillonite loaded with imidazole polyboronic acid complex

[0063] S11. Montmorillonite was added to a 10-fold volume of dilute hydrochloric acid (0.5wt%) solution and ultrasonically dispersed at 75°C for 1 hour. After dispersion, the mixture was filtered and washed with deionized water until the wash solution was neutral. The resulting solution was then filtered and dried to obtain acid-modified montmorillonite.

[0064] S12, dissolve 30g of benzene-1,3,5-trimethyltriboronic acid in 1L of ethanol solution (50% by volume), add 43g of 2-imidazol-1-ylethylamine while stirring, adjust the pH to 7.5 with ammonia water after the addition is complete, and continue stirring for 55min to obtain an imidazolium polyboronic acid complex solution.

[0065] S13, 300g of acid-modified montmorillonite was added to 3L of deionized water and dispersed evenly to obtain a montmorillonite suspension; then the imidazole polyboronic acid complex solution prepared in step S12 was added, and the mixture was reacted at 55℃ for 3h. After the reaction was completed, the mixture was filtered and washed repeatedly with deionized water 3-4 times until the washing solution was neutral. Then, it was washed once with a small amount of ethanol to remove unintercalated organic matter. Finally, it was dried to obtain montmorillonite loaded with imidazole polyboronic acid complex.

[0066] S2, Surface preparation: First, EVA, natural rubber, PA6 short fiber and EVA-g-MAH are put into a mixer and mixed at 95°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex, flame retardant, antioxidant and colorant are added and mixed for another 3 minutes. After the end, the mixed material is put into a rubber mixing mill and 1.3% of accelerator DM and 1.8% of sulfur by weight of the mixed material are added. The mixture is mixed at 85°C for 7 minutes. After the end, it is pressed into sheet I for later use.

[0067] S3, Inner Layer Preparation: First, EVA, natural rubber, EVA-g-MAH and polyethylene glycol diglycidyl ether are put into a mixer and mixed at 95°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex and colorant are added, and the mixing continues for 3 minutes. After the mixing is completed, the mixed material is put into a rubber mixing mill, and 1.3% of accelerator DM and 1.8% of sulfur by weight of the mixed material are added. The mixture is mixed at 85°C for 7 minutes. After the mixing is completed, the mixture is pressed into sheet II for later use.

[0068] S4, Lamination and Composite: Ten layers of film II are calendered and laminated to obtain composite film II. Then, two layers of film I are placed on the outside of composite film II and calendered and laminated again to obtain a composite film. During calendering and lamination, the roller temperature is 80℃, the roller pressure is 6MPa, and the roller linear speed is 0.22m / s. The composite film is then turned into a flat vulcanizing machine and vulcanized at 16MPa and 165℃ for 20 minutes. After the vulcanization is completed, the edges are trimmed and finished to obtain an insulating shielding blanket.

[0069] Example 4

[0070] The live-line working insulating blanket of this embodiment includes a surface layer and an inner layer. The surface layer has two layers, each with a thickness of 200μm, and is attached to the outer surface of the inner layer. The inner layer has ten layers, each with a thickness of 160μm, and is stacked on top of each other.

[0071] The raw materials for the surface layer are: 1400g EVA, 200g montmorillonite loaded with imidazole polyboronic acid complex, 200g natural rubber, 100g PA6 short fiber, 90g MAH-g-EVA, 260g aluminum hydroxide, 30g antioxidant 1010, and 80g solid orange peel.

[0072] The inner layer is made of the following raw materials: 1500g EVA, 70g montmorillonite loaded with imidazole polyboronic acid complex, 320g natural rubber, 40g MAH-g-EVA, 160g polyethylene glycol diglycidyl ether, and 50g solid orange peel.

[0073] A method for preparing an insulating shielding blanket for live-line working includes the following steps:

[0074] S1, Preparation of montmorillonite loaded with imidazole polyboronic acid complex

[0075] S11. Montmorillonite was added to a 10-fold volume of dilute hydrochloric acid (0.5wt%) solution and ultrasonically dispersed at 65°C for 1 hour. After dispersion, the mixture was filtered and washed with deionized water until the wash solution was neutral. The resulting solution was then filtered and dried to obtain acid-modified montmorillonite.

[0076] S12, dissolve 30g of benzene-1,3,5-trimethyltriboronic acid in 1L of ethanol solution (50% by volume), add 40g of 2-imidazol-1-ylethylamine while stirring, adjust the pH to 8.5 with ammonia water after the addition is complete, and continue stirring for 55min to obtain an imidazolium polyboronic acid complex solution.

[0077] S13, 300g of acid-modified montmorillonite was added to 3L of deionized water and dispersed evenly to obtain a montmorillonite suspension; then the imidazole polyboronic acid complex solution prepared in step S12 was added, and the mixture was reacted at 45℃ for 3.5h. After the reaction was completed, the mixture was filtered and washed repeatedly with deionized water 3-4 times until the washing solution was neutral. Then, it was washed once with a small amount of ethanol to remove unintercalated organic matter. Finally, it was dried to obtain montmorillonite loaded with imidazole polyboronic acid complex.

[0078] S2, Surface preparation: First, EVA, natural rubber, PA6 short fiber and EVA-g-MAH are put into a mixer and mixed at 95°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex, flame retardant, antioxidant and colorant are added and mixed for another 4 minutes. After the end, the mixed material is put into a rubber mixing mill, and 1.1% of the weight of the mixed material of accelerator DM and 2% of sulfur are added. The mixture is mixed at 65°C for 7 minutes. After the end, it is pressed into sheet to make sheet I for later use.

[0079] S3, Inner Layer Preparation: First, EVA, natural rubber, EVA-g-MAH and polyethylene glycol diglycidyl ether are put into a mixer and mixed at 95°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex and colorant are added, and the mixing continues for 4 minutes. After the mixing is completed, the mixed material is put into a rubber mixing mill, and 1.1% of the weight of the mixed material, 1% of the accelerator DM and 2% of the sulfur are added. The mixture is mixed at 65°C for 7 minutes. After the mixing is completed, the mixture is pressed into sheet II for later use.

[0080] S4, Lamination and Composite: Ten layers of film II are calendered and laminated to obtain composite film II. Then, two layers of film I are placed on the outside of composite film II and calendered and laminated again to obtain a composite film. During calendering and lamination, the roller temperature is 65℃, the roller pressure is 10MPa, and the roller linear speed is 0.15m / s. The composite film is then turned into a flat vulcanizing machine and vulcanized at 12MPa and 165℃ for 18 minutes. After the vulcanization is completed, the edges are trimmed and finished to obtain an insulating shielding blanket.

[0081] Example 5

[0082] The live-line working insulating blanket of this embodiment includes a surface layer and an inner layer. The surface layer has two layers, each with a thickness of 190μm, and is attached to the outer surface of the inner layer. The inner layer has ten layers, each with a thickness of 162μm, and is stacked on top of each other.

[0083] The surface layer consists of: 1200g EVA, 160g montmorillonite loaded with imidazole polyboronic acid complex, 180g natural rubber, 120g PA6 short fiber, 100g MAH-g-EVA, 280g aluminum hydroxide, 20g antioxidant 1010, and 60g titanium green.

[0084] The inner layer is made of the following raw materials: 1660g of EVA, 90g of montmorillonite loaded with imidazole polyboronic acid complex, 400g of natural rubber, 36g of MAH-g-EVA, 200g of polyethylene glycol diglycidyl ether, and 30g of titanium green.

[0085] A method for preparing an insulating shielding blanket for live-line working includes the following steps:

[0086] S1, Preparation of montmorillonite loaded with imidazole polyboronic acid complex

[0087] S11. Montmorillonite was added to a 10-fold volume of dilute hydrochloric acid (0.5wt%) solution and ultrasonically dispersed at 80°C for 0.5 hours. After dispersion, the mixture was filtered and washed with deionized water until the wash solution was neutral. The resulting solution was then filtered and dried to obtain acid-modified montmorillonite.

[0088] S12, dissolve 30g of benzene-1,3,5-trimethyltriboronic acid in 1L of ethanol solution (50% by volume), add 45g of 2-imidazol-1-ylethylamine while stirring, adjust the pH to 7 with ammonia water after the addition is complete, and continue stirring for 60min to obtain an imidazolium polyboronic acid complex solution.

[0089] S13, 300g of acid-modified montmorillonite was added to 3L of deionized water and dispersed evenly to obtain a montmorillonite suspension; then the imidazole polyboronic acid complex solution prepared in step S12 was added, and the mixture was reacted at 40℃ for 4h. After the reaction was completed, the mixture was filtered and washed repeatedly with deionized water 3-4 times until the washing solution was neutral. Then, it was washed once with a small amount of ethanol to remove unintercalated organic matter. Finally, it was dried to obtain montmorillonite loaded with imidazole polyboronic acid complex.

[0090] S2, Surface preparation: First, EVA, natural rubber, PA6 short fiber and EVA-g-MAH are put into a mixer and mixed at 90°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex, flame retardant, antioxidant and colorant are added and mixed for another 5 minutes. After the end, the mixed material is put into a rubber mixing mill, and 0.8% of accelerator DM and 2.2% sulfur by weight of the mixed material are added. The mixture is mixed at 60°C for 9 minutes. After the end, it is pressed into sheet to make sheet I for later use.

[0091] S3, Inner Layer Preparation: First, EVA, natural rubber, EVA-g-MAH and polyethylene glycol diglycidyl ether are put into a mixer and mixed at 90°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex and colorant are added, and the mixing continues for 5 minutes. After the mixing is completed, the mixed material is put into a rubber mixing mill, and 0.8% of accelerator DM and 2.2% sulfur by weight of the mixed material are added. The mixture is mixed at 60°C for 9 minutes. After the mixing is completed, the mixture is pressed into sheet II for later use.

[0092] S4, Lamination and Composite: Ten layers of film II are calendered and laminated to obtain composite film II. Then, two layers of film I are placed on the outside of composite film II and calendered and laminated again to obtain a composite film. During calendering and lamination, the roller temperature is 60℃, the roller pressure is 12MPa, and the roller linear speed is 0.1m / s. The composite film is then turned into a flat vulcanizing machine and vulcanized at 18MPa and 155℃ for 30 minutes. After the vulcanization is completed, the edges are trimmed and finished to obtain an insulating shielding blanket.

[0093] Example 6

[0094] The live-line working insulating blanket of this embodiment includes a surface layer and an inner layer. The surface layer has two layers, each with a thickness of 210 μm, and is attached to the outer surface of the inner layer. The inner layer has ten layers, each with a thickness of 158 μm, and is stacked together.

[0095] The raw materials for the surface layer are: 1480g EVA, 220g montmorillonite loaded with imidazole polyboronic acid complex, 240g natural rubber, 60g PA6 short fiber, 80g MAH-g-EVA, 200g magnesium hydroxide, 39g antioxidant 1076, and 70g titanium dioxide.

[0096] The inner layer is made of the following raw materials: 1560g of EVA, 60g of montmorillonite loaded with imidazole polyboronic acid complex, 300g of natural rubber, 50g of MAH-g-EVA, 120g of polyethylene glycol diglycidyl ether, and 80g of titanium dioxide.

[0097] A method for preparing an insulating shielding blanket for live-line working includes the following steps:

[0098] S1, Preparation of montmorillonite loaded with imidazole polyboronic acid complex

[0099] S11. Montmorillonite was added to a 10-fold volume of dilute hydrochloric acid (0.5wt%) solution and ultrasonically dispersed at 60°C for 1 hour. After dispersion, the mixture was filtered and washed with deionized water until the wash solution was neutral. The resulting solution was then filtered and dried to obtain acid-modified montmorillonite.

[0100] S12, dissolve 30g of benzene-1,3,5-trimethyltriboronic acid in 1L of ethanol solution (50% by volume), add 39g of 2-imidazol-1-ylethylamine while stirring, adjust the pH to 9 with ammonia water after the addition is complete, and continue stirring for 50min to obtain an imidazolium polyboronic acid complex solution.

[0101] S13, 300g of acid-modified montmorillonite was added to 3L of deionized water and dispersed evenly to obtain a montmorillonite suspension; then the imidazole polyboronic acid complex solution prepared in step S12 was added, and the mixture was reacted at 60℃ for 2h. After the reaction was completed, the mixture was filtered and washed repeatedly with deionized water 3-4 times until the washing solution was neutral. Then, it was washed once with a small amount of ethanol to remove unintercalated organic matter. Finally, it was dried to obtain montmorillonite loaded with imidazole polyboronic acid complex.

[0102] S2, Surface preparation: First, EVA, natural rubber, PA6 short fiber and EVA-g-MAH are put into a mixer and mixed at 100°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex, flame retardant, antioxidant and colorant are added and mixed for another 2 minutes. After the end, the mixed material is put into a rubber mixing mill and 1.5% of accelerator DM and 1.2% sulfur by weight of the mixed material are added. The mixture is mixed at 90°C for 5 minutes. After the end, it is pressed into sheet to make sheet I for later use.

[0103] S3, Inner Layer Preparation: First, EVA, natural rubber, EVA-g-MAH and polyethylene glycol diglycidyl ether are put into a mixer and mixed at 100°C for 8 minutes. Then, montmorillonite loaded with imidazole polyboronic acid complex and colorant are added, and the mixing continues for 2 minutes. After the mixing is completed, the mixed material is put into a rubber mixing mill, and 1.5% of accelerator DM and 1.2% sulfur by weight of the mixed material are added. The mixture is mixed at 90°C for 5 minutes. After the mixing is completed, the mixture is pressed into sheet II for later use.

[0104] S4, Lamination and Composite: Ten layers of film II are calendered and laminated to obtain composite film II. Then, two layers of film I are placed on the outside of composite film II and calendered and laminated again to obtain a composite film. During calendering and lamination, the roller temperature is 85℃, the roller pressure is 4MPa, and the roller linear speed is 0.25m / s. The composite film is then turned into a flat vulcanizing machine and vulcanized at 10MPa and 170℃ for 15 minutes. After the vulcanization is completed, the edges are trimmed to obtain an insulating shielding blanket.

[0105] Comparative Example 1

[0106] Compared with Example 1, Comparative Example 1 used acid-modified montmorillonite directly without loading, while the rest of the contents were the same.

[0107] Comparative Example 2

[0108] Compared with Example 1, Comparative Example 2 was identical except that the montmorillonite was only loaded with 2-imidazol-1-ylethylamine.

[0109] The loading method is as follows: 300g of acid-modified montmorillonite is added to 3L of deionized water and dispersed evenly to obtain a montmorillonite suspension; 40g of 2-imidazol-1-ylethylamine is dissolved in 1L of ethanol solution (volume concentration 50%), and then poured into the montmorillonite suspension. The mixture is stirred at 60℃ for 8 hours. After the reaction is completed, the precipitate is collected by centrifugation and washed repeatedly with deionized water 3-4 times until the washing solution is neutral. Then, it is washed once with a small amount of ethanol to remove unintercalated organic matter. Finally, it is dried to obtain montmorillonite loaded with 2-imidazol-1-ylethylamine.

[0110] Comparative Example 3

[0111] Compared with Example 1, Comparative Example 3 only had benzene-1,3,5-trimethyltriboronic acid loaded on montmorillonite, while the rest were the same.

[0112] The loading method is as follows: 300g of acid-modified montmorillonite is added to 3L of deionized water and dispersed evenly to obtain a montmorillonite suspension; 30g of benzene-1,3,5-trimethyltriboronic acid is dissolved in 1L of ethanol solution (volume concentration 50%), and then added to the montmorillonite suspension. The mixture is stirred at 60℃ for 8 hours. After the reaction is completed, the precipitate is collected by centrifugation and washed repeatedly with deionized water 3-4 times until the washing solution is neutral. Then, it is washed once with a small amount of ethanol to remove unintercalated organic matter. Finally, it is dried to obtain montmorillonite loaded with benzene-1,3,5-trimethyltriboronic acid.

[0113] Comparative Example 4

[0114] Compared with Example 1, the amount of montmorillonite loaded with imidazole polyboronic acid complex in Comparative Example 4 exceeded the specified range, specifically 350g, while the rest were the same.

[0115] Comparative Example 5

[0116] Compared with Example 2, Comparative Example 5 used 300g of polyethylene glycol diglycidyl ether, which exceeded the specified range. All other contents were the same.

[0117] The insulating blanket prepared above was cut into 900mm*1000mm sizes. The elongation at break (%) and tensile strength (MPa) at room temperature (25℃) and high temperature (80℃) were tested according to the standard DL / T 803-2015 "Insulating Blankets for Live Working". The results are shown in Table 1.

[0118] Table 1 High Temperature Resistance of Insulating Shielding Blankets

[0119]

[0120] As shown in Table 1, the performance of Example 2 is superior to that of Example 1. This indicates that PEGDE significantly enhances the composite system's strength and flexibility. Furthermore, the addition of PEGDE greatly improves the material's high-temperature mechanical stability and inhibits thermally induced elongation deformation. The initial tensile strength and elongation at break of Comparative Examples 1-5 are lower than those of Examples 1 and 2, indicating that the overall mechanical properties are weaker without synergistic crosslinking modification and interface optimization.

[0121] Comparative Example 1 shows that the EVA-based insulation blanket system without montmorillonite loading exhibits accelerated thermal deformation and degradation, resulting in significant losses in flexibility and overall strength. Comparative Examples 2 and 3, being single-component loadings, show limited performance improvement and are less effective than the examples with synergistic complex loading. Comparative Examples 4 and 5, with an excess of one component (surface loading and PEGDE), show slightly lower reduction rates than Comparative Examples 1-3, but are still inferior to Examples 1 and 2. Comparative Example 5 shows slightly better performance in terms of elongation at break retention, but its overall performance remains poor, indicating that the balance between ligand and structural adjustments is more crucial than extreme increases in the dosage of a single component.

[0122] The reference standard is DL / T 803-2015 "Insulating Blankets for Live Working". The test results of the insulating blankets at room temperature (25℃) are shown in Table 2.

[0123] Table 2. Puncture resistance, tear resistance and insulation properties of insulating blankets (25℃)

[0124]

[0125] As shown in Table 2, the performance of Example 2 is superior to that of Example 1 in all aspects. This is mainly attributed to the introduction of PEGDE (polyethylene glycol diglycidyl ether) crosslinking agent, which forms a denser and more strongly interfacially bonded three-dimensional network structure within the composite material, further optimizing the synergistic effect between the nano-montmorillonite sheets and the polymer matrix. This dense structure not only improves mechanical properties (especially puncture and tear resistance) but also reduces the migration channels for electrons and ions, thereby significantly improving insulation performance.

[0126] The puncture resistance, tear strength, and insulation properties of the comparative examples were all lower than those of Example 1. Comparative Example 1 demonstrates that the bonding between the acid-modified montmorillonite and the matrix interface is poor, making it difficult to effectively strengthen the material. Comparative Examples 2 and 3 showed slightly better performance than Comparative Example 1, but the difference was still significant, indicating that while there was a positive effect, the synergistic effect was insufficient. Comparative Example 4 showed that excessive load led to poor dispersion or agglomeration, stress concentration, and was detrimental to mechanical and insulation properties. Comparative Example 5 demonstrated that excessive PEGDE dosage caused over-crosslinking of the system, making the material brittle and also negatively impacting overall mechanical and insulation performance.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An insulating shielding blanket for live-line work, characterized in that: The covering blanket includes a surface layer and an inner layer. The surface layer has two layers and is attached to the outer surface of the inner layer. The inner layer has a multi-layer structure with layers stacked on top of each other. The raw materials of the surface layer, calculated by weight, include: 60-78 parts of EVA, 8-12 parts of montmorillonite loaded with imidazole polyboronic acid complex, 8-12 parts of natural rubber, 3-7 parts of PA6 short fiber, 3-6 parts of MAH-g-EVA, 10-15 parts of flame retardant, 1-2 parts of antioxidant, and 1-4 parts of colorant. The raw materials of the inner layer, calculated by weight, include: 75-85 parts of EVA, 3-5 parts of montmorillonite loaded with imidazole polyboronic acid complex, 10-20 parts of natural rubber, 1.5-3 parts of MAH-g-EVA, 6-12 parts of polyethylene glycol diglycidyl ether, and 1-4 parts of colorant. The method for preparing the montmorillonite loaded with imidazole polyboronic acid complex includes the following steps: S11, add montmorillonite to dilute hydrochloric acid solution, ultrasonically disperse at 60-80℃ for 0.5-1h, filter after the process, wash with deionized water until the wash solution is neutral, and then filter and dry to obtain acid-modified montmorillonite; S12, dissolve phenyl-1,3,5-trimethyltriboronic acid in an ethanol solution, add 2-imidazol-1-ylethylamine while stirring, adjust the pH to 7-9 after the addition is complete, and continue stirring for 50-60 min to obtain an imidazolium polyboronic acid complex solution. S13, acid-modified montmorillonite was added to deionized water and dispersed evenly to obtain a montmorillonite suspension; then an imidazole polyboronic acid complex solution was added, and the mixture was reacted at 40-60℃ for 2-4 hours. After the reaction was completed, the mixture was filtered and dried to obtain montmorillonite loaded with imidazole polyboronic acid complex.

2. The insulating and shielding blanket for live-line work as described in claim 1, characterized in that: The thickness of each surface layer is 100-220μm, and the thickness of each inner layer is 156-164μm. There are 10 inner layers.

3. The insulating shielding blanket for live-line work as described in claim 1, characterized in that: The mass ratio of 2-imidazol-1-ylethylamine, phenyl-1,3,5-trimethyltriboronic acid, and acid-modified montmorillonite is 1.3-1.5:1:

10.

4. The insulating and shielding blanket for live-line work as described in claim 1, characterized in that: The flame retardant is one or both of aluminum hydroxide and magnesium hydroxide, the antioxidant is one or both of antioxidant 1010 and antioxidant 1076, and the colorant is one of permanent orange, titanium dioxide, chrome yellow, titanium green or rubber red.

5. The method for preparing an insulating shielding blanket for live-line work as described in claim 1, characterized in that: Includes the following steps: S21, Surface preparation: EVA, montmorillonite loaded with imidazole polyboronic acid complex, natural rubber, PA6 short fiber, EVA-g-MAH, flame retardant, antioxidant and colorant are put into an internal mixer and mixed. After the mixing is completed, the mixed material is put into a rubber mixing mill, accelerator DM and sulfur are added and mixed. After the mixing is completed, the material is pressed into sheet 1 for later use. S22, Inner layer preparation: EVA, montmorillonite loaded with imidazole polyboronic acid complex, natural rubber, polyethylene glycol diglycidyl ether, EVA-g-MAH and colorant are added to a mixer and mixed; after the end, the mixed material is put into a rubber mixing mill, accelerator DM and sulfur are added and mixed, and after the end, the mixture is pressed into sheet 2 for later use. S23, Lamination and Composite: Ten layers of film 2 are calendered and laminated to obtain composite film 2. Then, two layers of film 1 are placed on the outside of composite film 2 and calendered and laminated again to obtain composite film. Then, the composite film is flattened and vulcanized. After completion, the edges are trimmed and finished to obtain insulating shielding blanket.

6. The method for preparing an insulating shielding blanket for live-line work as described in claim 5, characterized in that: In steps S21 and S22, the internal mixing temperature is 90-100℃ and the time is 10-13 min; the mixing temperature is 60-90℃ and the time is 5-9 min; the dosage of accelerator DM and sulfur is 0.8%-1.5% and 1.2%-2.2% of the weight of the internally mixed material, respectively. In step S23, the roller temperature is 60-85℃, the roller pressure is 4-12MPa, and the roller linear speed is 0.1-0.25m / s during calendering and bonding; the pressure is 10-18MPa, the temperature is 155-170℃, and the time is 15-30min during vulcanization.

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