A high performance insulation blanket

Abstract

The application provides a high-performance insulation blanket, which comprises a surface layer, an EVA adhesive layer and a surface layer arranged in sequence, and the surface layer and the EVA adhesive layer are calendered and bonded; the preparation raw materials of the surface layer comprise, in parts by weight, 45-55 parts of ethylene-vinyl acetate copolymer, 10-20 parts of natural rubber, 8-18 parts of PA6 short fiber, 7-10 parts of dopamine modified mica powder, 6-10 parts of MAH-g-EVA, 10-15 parts of flame retardant, 0.2-0.4 parts of antioxidant, 0.8-1.2 parts of lubricant and 2-4 parts of colorant. In the surface layer formula system, the natural rubber, the PA6 short fiber and the dopamine modified mica powder synergistically act, so that the tear resistance and the puncture resistance of the material are greatly improved, and meanwhile, the material has excellent comprehensive performances such as high-temperature resistance, insulation, flame retardation and aging resistance, and is suitable for high-demand insulation protection fields.

Description

Technical Field

[0001] This invention relates to the field of insulating blanket technology, and more particularly to a high-performance insulating blanket. Background Technology

[0002] With the continuous development of urban economy, people have higher requirements for the quality of power supply. Even a short power outage can cause great losses to production and life. Therefore, the emergency repair or operation of power lines now adopts the method of live working.

[0003] Insulating blankets are equipment used by electrical workers to prevent accidental electric shock accidents when inspecting and maintaining cables and live conductors. They are widely used in the field of power maintenance. However, existing insulating blankets have poor tear and puncture resistance, and cannot effectively prevent damage and tearing in complex or harsh working environments, resulting in a short service life. Summary of the Invention

[0004] In view of this, the present invention proposes a high-performance insulating blanket with good tear and puncture resistance.

[0005] The technical solution of the present invention is implemented as follows: On the one hand, the present invention provides a high-performance insulating blanket, comprising a surface layer, an EVA adhesive layer and a surface layer arranged sequentially, wherein the surface layer and the EVA adhesive layer are calendered and bonded together;

[0006] The raw materials for preparing the surface layer, calculated by weight, include: 45-55 parts of ethylene-vinyl acetate copolymer, 10-20 parts of natural rubber, 8-18 parts of PA6 short fiber, 7-10 parts of dopamine-modified mica powder, 6-10 parts of MAH-g-EVA, 10-15 parts of flame retardant, 0.2-0.4 parts of antioxidant, 0.8-1.2 parts of lubricant, and 2-4 parts of colorant.

[0007] Natural rubber (NR) molecules are flexible and elastic, possessing high ductility and energy absorption capacity. When punctured or torn by external forces, the NR matrix can significantly dissipate external energy, effectively slowing down or blunting crack tip growth around stress concentration areas, preventing crack propagation, and giving the composite system high elongation at break and good dynamic fatigue performance.

[0008] PA6 short fibers are similar to the reinforcing bars in reinforced concrete. The short fibers are distributed in any orientation within the matrix, which helps to block and disperse crack propagation. When a crack encounters a fiber, more energy is required to bend / pull out / break the fiber, thus "absorbing" the puncture or tearing energy. This results in a significant improvement in the overall tear and puncture resistance of the material.

[0009] Mica powder, a layered and sheet-like inorganic reinforcing agent, can prevent cracks from penetrating along the thickness direction, enhancing surface "barrier properties." The dopamine structure, similar to a "strong universal adhesive," achieves good interfacial bonding between mica powder and organic polymers (EVA, natural rubber), preventing detachment or agglomeration. Furthermore, the synergistic effect of the mica sheet filler and the matrix locally "passivates" crack propagation paths, disperses energy, and improves puncture / tear resistance. The modified mica powder is more uniformly dispersed, resulting in a superior overall reinforcing effect.

[0010] Natural rubber, PA6 short fibers, and dopamine-modified mica powder combine to create a balance of rigidity and flexibility: NR provides the overall toughness and deformation recovery of the material, acting as a "buffer layer" against cracking and puncture damage. PA6 short fibers, as a high-strength skeleton, are distributed within the elastic network, forming a "composite barrier" and "skeleton reinforcement" against tearing and puncture. Dopamine-modified mica powder forms sheet-like microbarriers that bond strongly with the matrix interface, further weakening crack-guided penetration.

[0011] In addition, dopamine enhances the adhesion between inorganic mica and organic matrix; PA6 short fibers also have an interfacial assisting effect with dopamine / mica to a certain extent, further improving the interfacial strength of the composite material and inhibiting interlaminar delamination and stress concentration.

[0012] Based on the above technical solutions, preferably, the thickness of each surface layer is 150-250μm, the thickness of each EVA adhesive layer is 150-170μm, and there are 10 EVA adhesive layers.

[0013] Based on the above technical solutions, preferably, the surface of the dopamine-modified mica powder is coated with polycaprolactone.

[0014] The dopamine coating has given mica powder good "anchoring" and bonding ability. After PCL coating, the physical entanglement and inter-crystallization between PCL and matrix molecular chains are stronger, resulting in greater bonding force between inorganic filler and polymer matrix, thus greatly preventing peeling and delamination.

[0015] After coating, the polycaprolactone (PCL) layer acts as an "organic buffer layer," significantly mitigating the interfacial stress gradient between the rigid mica sheets and the flexible organic phase (EVA / NR). This prevents the agglomeration and detachment of the sheet-like filler, improving the high dispersion of the filler in the composite material. The PCL-coated mica particles exhibit a triple structure of "rigid sheet layer - flexible shell - strong interfacial adhesion." When subjected to tearing or puncture impact, the external stress is first partially absorbed by the PCL "soft buffer," and then the mica "rigidly blocks" the crack tip from propagating. The overall material exhibits improved tear and puncture resistance, and is not brittle but more flexible.

[0016] PCL is an electrically stable polymer. Its coating does not weaken the insulation properties of mica itself; on the contrary, it helps the composite material to have good resistance to electrical tracking and long-term electrical safety. In addition, PCL can maintain good flexibility at low temperatures, and the coating, as a soft phase, makes the entire material less prone to brittleness even at low temperatures.

[0017] Based on the above technical solutions, the preferred method for preparing the polycaprolactone-coated dopamine-modified mica powder is as follows:

[0018] S11, dopamine hydrochloride was dissolved in Tris-HCl buffer solution at pH 8.5, mica powder was added and dispersed evenly, and then the mixture was stirred and reacted for 20-24 hours. After the reaction was completed, the precipitate was separated by centrifugation. The precipitate was washed and dried to obtain dopamine-modified mica powder.

[0019] S12, dopamine-modified mica powder is dispersed in toluene, ε-caprolactone monomer and benzyl alcohol are added, DBU is added under a nitrogen atmosphere, the temperature is raised to 60-80℃, and the reaction is carried out for 4-8 hours. After the reaction is completed, the temperature is lowered to 20-30℃, dilute acetic acid is added to terminate the reaction, the precipitate is collected by centrifugation, and then polycaprolactone-coated dopamine-modified mica powder is obtained after washing and drying.

[0020] Based on the above technical solutions, preferably, in step S11, the mass ratio of dopamine hydrochloride to mica powder is 0.2-0.4:1, and in step S12, the mass-volume ratio of dopamine-modified mica powder, ε-caprolactone monomer, benzyl alcohol and DBU is 10:12-15:0.3-0.5:0.1-0.35.

[0021] Based on the above technical solutions, preferably, the flame retardant is aluminum hydroxide or magnesium hydroxide, the lubricant is one or more of paraffin wax, stearic acid and polyethylene glycol, 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 blue green or rubber red.

[0022] Based on the above technical solutions, preferably, the raw materials for preparing the EVA adhesive layer, calculated by weight, include: 60-70 parts of ethylene-vinyl acetate copolymer (EVA), 10-20 parts of natural rubber (NR), 5-10 parts of MAH-g-EVA, 3-8 parts of rosin glycerol ester, and 2-4 parts of colorant.

[0023] EVA is a polar polymer, while NR is non-polar, resulting in limited compatibility between polymer chains. The polar groups and soft chain structure of rosin glycerol ester can act as a "bridge" between EVA and NR, improving the compatibility, interpenetration, and mixing effect of the two-phase interface. It also works synergistically with MAH-g-EVA compatibilizer to improve the structural uniformity and overall performance of the material, and enhances the adhesion between layers, preventing delamination or peeling after use.

[0024] Rosin glycerol ester is an insulating material that does not damage the electrical insulation properties of the EVA adhesive layer. It also has certain antioxidant and anti-aging effects on the NR / EVA system, improving the reliability and lifespan of the material in complex environments. In addition, rosin glycerol ester can adjust the flexibility and feel of the material, allowing the EVA adhesive layer to remain flexible and less prone to cracking at both room temperature and low temperature.

[0025] On the other hand, the present invention also provides a method for preparing a high-performance insulating blanket, comprising the following steps:

[0026] S21, Surface preparation: Ethylene-vinyl acetate copolymer, natural rubber, PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, MAH-g-EVA, antioxidant, lubricant and colorant are added to an internal mixer for internal mixing; the mixed material is then fed into a rubber mixing mill, accelerator DM and sulfur are added and mixed evenly, and then pressed into sheets for later use.

[0027] S22, EVA rubber layer preparation: Ethylene-vinyl acetate copolymer, natural rubber, MAH-g-EVA, rosin glycerol ester and colorant are added to an internal mixer for internal mixing; the mixed material is fed into a rubber mixing mill, accelerator DM and sulfur are added and mixed evenly, and then pressed into sheets for later use.

[0028] S23, laminated composite: 10 layers of EVA adhesive are calendered and laminated together, and then 2 outer layers are placed on the outside of the EVA adhesive layers and calendered and laminated again to obtain a composite layered material.

[0029] S24, Vulcanization treatment: The composite layered material is placed in a flat vulcanizing machine for vulcanization. After the vulcanization is completed, the insulation blanket is trimmed and finished.

[0030] Based on the above technical solutions, preferably, in steps S21 and S22, the mixing temperature is 95-110℃ and the time is 10-15min; the blending temperature is 55-65℃ and the time is 20-30min; the dosage of accelerator DM and sulfur is 0.6%-1.2% and 1.5%-2.2% of the material weight, respectively.

[0031] Based on the above technical solutions, preferably, in step S23, the roller temperature is 100-130℃, the roller pressure is 40-80MPa, and the roller linear speed is 0.5-1.0m / s during calendering and bonding; in step S24, the pressure is 10-20MPa, the temperature is 160-170℃, and the time is 20-30min during vulcanization.

[0032] The high-performance insulating blanket of the present invention has the following advantages over the prior art:

[0033] (1) In the surface formulation system of this invention, natural rubber gives the material excellent elasticity and energy absorption capacity, effectively slowing down crack propagation under external force; PA6 short fibers block and restrain crack propagation in the form of skeleton, significantly improving tear resistance and puncture resistance; dopamine modified mica powder is dispersed in the matrix, providing physical barrier of sheet-like micro-barriers, enhancing interfacial adhesion, and comprehensively improving the mechanical and insulating functions of the material; under the synergistic effect of the three, the material's tear resistance and puncture resistance are greatly improved, while also possessing excellent comprehensive properties such as high temperature resistance, insulation, flame retardancy and anti-aging, making it suitable for high-requirement insulation protection fields.

[0034] (2) Further coating the surface of dopamine-modified mica powder with polycaprolactone (PCL) significantly improves the interfacial compatibility and dispersibility between the filler and the polymer matrix, enhances the mechanical toughness, tear resistance, and puncture resistance of the composite material, and further improves low-temperature flexibility, aging resistance, and long-term interfacial stability. Simultaneously, PCL coating provides an engineering basis for the realization of multifunctional surface applications of the material. This multi-level coating strategy is particularly suitable for high-value-added fields such as high-performance insulation and abrasion protection.

[0035] (3) In the EVA / natural rubber composite system, rosin glycerol ester mainly plays a role in increasing adhesion, plasticizing, improving interlayer bonding, and promoting compatibility. It has a good synergistic adhesion-increasing effect with natural rubber and works synergistically with the polar compatibilizer MAH-g-EVA to enhance the compatibility between EVA and rubber, and improve the uniformity and overall performance of the material. At the same time, rosin glycerol ester also helps to improve the processing technology and the flexibility of the material, without affecting the electrical insulation and aging resistance, making it an indispensable functional additive for the EVA adhesive layer structure. Attached Figure Description

[0036] 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.

[0037] Figure 1These are actual images of the high-performance insulating blanket of the present invention. Image A shows the front side, and image B shows the back side.

[0038] Figure 2 This is a schematic diagram of the structure of the high-performance insulating blanket of the present invention. In the figure, 1 is the surface layer and 2 is the EVA adhesive layer. Detailed Implementation

[0039] 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.

[0040] EVA 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; PA6 (polyamide 6 fiber) staple fiber was nylon PA6 staple fiber, purchased from Jiangsu Heshili New Material Co., Ltd.; dopamine hydrochloride (CAS No. 62-31-7) was purchased from Zhongshan Dixing Chemical Co., Ltd.; ε-caprolactone was purchased from Hunan Juren Chemical New Material Technology Co., Ltd.

[0041] Example 1

[0042] The high-performance insulating blanket of this embodiment includes a surface layer, an EVA adhesive layer and another surface layer arranged sequentially, with the surface layer and the EVA adhesive layer being calendered and bonded together; the thickness of each surface layer is 200μm, the thickness of each EVA adhesive layer is 160μm, and there are 10 layers of EVA adhesive layer.

[0043] The raw materials for preparing the surface layer include: 1000g of ethylene-vinyl acetate copolymer, 350g of natural rubber, 280g of PA6 short fiber, 160g of dopamine-modified mica powder, 180g of MAH-g-EVA, 250g of aluminum hydroxide, 10106g of antioxidant, 20g of paraffin wax, and 60g of chrome yellow.

[0044] The preparation method of dopamine-modified mica powder is as follows: 80g of dopamine hydrochloride is dissolved in 5L of pH 8.5 Tris-HCl buffer solution, 250g of mica powder is added and dispersed evenly, and then the mixture is stirred and reacted for 20h. After the reaction is completed, the precipitate is separated by centrifugation. The precipitate is washed and dried to obtain dopamine-modified mica powder.

[0045] The raw materials for preparing the EVA adhesive layer include: 850g of ethylene-vinyl acetate copolymer, 180g of natural rubber, 80g of MAH-g-EVA, 60g of rosin glycerol ester, and 30g of chrome yellow.

[0046] A method for preparing a high-performance insulating blanket includes the following steps:

[0047] S21, Surface preparation: Ethylene-vinyl acetate copolymer (EVA), natural rubber (NR), PA6 short fiber, dopamine-modified mica powder, MAH-g-EVA, antioxidant, lubricant and colorant are added to a mixer for internal mixing. The order of feeding is as follows: EVA and NR matrix are added first for plasticization; then PA6 short fiber, dopamine-modified mica powder and flame retardant are added to prevent excessive instantaneous torque; lubricant, MAH-g-EVA, antioxidant, etc. are added after dispersion, and colorant is added last; the mixing temperature is 105℃ and the time is 15min; the mixed material is fed into a rubber mixing mill, and then 1wt% accelerator DM and 2wt% sulfur are added (1 part accelerator DM and 2 parts sulfur are added to 100 parts by weight of material) and mixed evenly. The mixing temperature is 60℃ and the time is 25min. After mixing, the material is pressed into sheets with a thickness of 150-250μm for later use.

[0048] S22, EVA rubber layer preparation: Ethylene-vinyl acetate copolymer (EVA), natural rubber (NR), MAH-g-EVA, rosin glycerol ester and colorant are added to a mixing mill for mixing. The order of feeding is: the main materials EVA, NR and MAH-g-EVA are plasticized first, and the rosin glycerol ester and colorant are added later. The mixing temperature is 100℃ and the time is 15min. The mixed material is then fed into a rubber mixing mill, and 1wt% accelerator DM and 2wt% sulfur are added (1 part accelerator DM and 2 parts sulfur are added to 100 parts by weight of material). The mixture is mixed evenly at 60℃ for 25min. After mixing, the mixture is pressed into sheets with a thickness of 150-180μm for later use.

[0049] S23, Lamination: Ten layers of EVA adhesive are calendered and laminated, and then two outer layers are placed on the outside of the EVA adhesive layers and calendered and laminated again to obtain a composite layered material; the roller temperature is 110℃, the roller pressure is 60MPa, and the roller linear speed is 0.8m / s during calendering and lamination.

[0050] S24, Vulcanization treatment: The composite layered material is placed in a flat vulcanizing machine and vulcanized at 18MPa and 165℃ for 25 minutes. After the vulcanization is completed, the insulation blanket is trimmed and finished.

[0051] Example 2

[0052] The difference between Example 2 and Example 1 is that dopamine-modified mica powder is coated with polycaprolactone. The preparation method is as follows: 200g of dopamine-modified mica powder prepared in Example 1 is dispersed in 1500mL of toluene, 280g of ε-caprolactone monomer and 8g of benzyl alcohol are added, 5g of DBU is added under a nitrogen atmosphere, the temperature is raised to 72℃, and the reaction is carried out for 6h. After the reaction is completed, the temperature is lowered to 25℃, dilute acetic acid is added to terminate the reaction, the precipitate is collected by centrifugation, and then polycaprolactone-coated dopamine-modified mica powder is obtained after washing and drying.

[0053] The remaining steps are the same as in Example 1.

[0054] Example 3

[0055] The high-performance insulating blanket of this embodiment includes a surface layer, an EVA adhesive layer and another surface layer arranged sequentially, with the surface layer and the EVA adhesive layer being calendered and bonded together; the thickness of each surface layer is 250μm, the thickness of each EVA adhesive layer is 150μm, and there are 10 layers of EVA adhesive layer.

[0056] The raw materials for preparing the surface layer include: 1100g of ethylene-vinyl acetate copolymer, 400g of natural rubber, 360g of PA6 short fiber, 200g of polycaprolactone-dopamine modified mica powder, 200g of MAH-g-EVA, 300g of magnesium hydroxide, 10768g of antioxidant, 24g of stearic acid, and 80g of chrome yellow.

[0057] The raw materials for preparing the EVA adhesive layer include: 800g of ethylene-vinyl acetate copolymer, 100g of natural rubber, 50g of MAH-g-EVA, 30g of rosin glycerol ester, and 20g of chrome yellow.

[0058] The preparation method of polycaprolactone-coated dopamine-modified mica powder is as follows:

[0059] S11, 60g of dopamine hydrochloride was dissolved in 5L of Tris-HCl buffer solution with pH 8.5, 250g of mica powder was added and dispersed evenly, and then the mixture was stirred and reacted for 20h. After the reaction was completed, the precipitate was separated by centrifugation. The precipitate was washed and dried to obtain dopamine-modified mica powder.

[0060] S12, 200g of dopamine-modified mica powder was dispersed in 1500mL of toluene, 240g of ε-caprolactone monomer and 10g of benzyl alcohol were added, 7g of DBU was added under a nitrogen atmosphere, the temperature was raised to 60℃ and the reaction was carried out for 8h. After the reaction was completed, the temperature was lowered to 30℃, dilute acetic acid was added to terminate the reaction, the precipitate was collected by centrifugation, and then polycaprolactone-coated dopamine-modified mica powder was obtained after washing and drying.

[0061] A method for preparing a high-performance insulating blanket includes the following steps:

[0062] S21, Surface preparation: Ethylene-vinyl acetate copolymer, natural rubber, PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, MAH-g-EVA, antioxidant, lubricant, and colorant are added to an internal mixer for internal mixing. The order of feeding is as follows: EVA and NR matrix are added first for plasticization; then PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, and flame retardant are added to prevent excessive instantaneous torque; lubricant, MAH-g-EVA, antioxidant, etc. are added after dispersion; colorant is added last; the mixing temperature is 100℃ and the time is 15min; the mixed material is fed into a rubber mixing mill, and 0.6wt% accelerator DM and 1.5wt% sulfur are added (0.6 parts accelerator DM and 1.5 parts sulfur are added to 100 parts by weight of material) and mixed evenly. The mixing temperature is 55℃ and the time is 30min. After mixing, the mixture is pressed into a sheet with a thickness of 250μm for later use.

[0063] S22, EVA rubber layer preparation: Ethylene-vinyl acetate copolymer, natural rubber, MAH-g-EVA, rosin glycerol ester and colorant are added to a mixing mill for mixing. The order of feeding is: main materials EVA, NR, and MAH-g-EVA are plasticized first, and rosin glycerol ester and colorant are added later. The mixing temperature is 100℃ and the time is 15min. The mixed material is then fed into a rubber mixing mill, and 0.6wt% accelerator DM and 1.5wt% sulfur are added (0.6 parts accelerator DM and 1.5 parts sulfur are added to 100 parts by weight of material). The mixture is mixed evenly at 55℃ for 30min. After mixing, the mixture is pressed into a sheet with a thickness of 150μm for later use.

[0064] S23, Lamination: Ten layers of EVA adhesive are calendered and laminated, and then two outer layers are placed on the outside of the EVA adhesive layers and calendered and laminated again to obtain a composite layered material; the roller temperature is 100℃, the roller pressure is 80MPa, and the roller linear speed is 0.5m / s during calendering and lamination.

[0065] S24, Vulcanization treatment: The composite layered material is placed in a flat vulcanizing machine and vulcanized at 10MPa and 170℃ for 20 minutes. After the vulcanization is completed, the insulation blanket is trimmed and finished.

[0066] Example 4

[0067] The high-performance insulating blanket of this embodiment includes a surface layer, an EVA adhesive layer and another surface layer arranged sequentially, with the surface layer and the EVA adhesive layer being calendered and bonded together; the thickness of each surface layer is 150μm, the thickness of each EVA adhesive layer is 170μm, and there are 10 layers of EVA adhesive layer.

[0068] The raw materials for preparing the surface layer include: 900g of ethylene-vinyl acetate copolymer, 200g of natural rubber, 160g of PA6 short fiber, 140g of polycaprolactone-coated dopamine-modified mica powder, 120g of MAH-g-EVA, 200g of aluminum hydroxide, 10104g of antioxidant, 16g of polyethylene glycol, and 40g of chrome yellow.

[0069] The raw materials for preparing the EVA adhesive layer include: 900g of ethylene-vinyl acetate copolymer, 200g of natural rubber, 100g of MAH-g-EVA, 80g of rosin glycerol ester, and 40g of chrome yellow.

[0070] The preparation method of polycaprolactone-coated dopamine-modified mica powder is as follows:

[0071] S11, 50g of dopamine hydrochloride was dissolved in 5L of Tris-HCl buffer solution with pH 8.5, 250g of mica powder was added and dispersed evenly, and then the mixture was stirred and reacted for 23h. After the reaction was completed, the precipitate was separated by centrifugation. The precipitate was washed and dried to obtain dopamine-modified mica powder.

[0072] S12, 200g of dopamine-modified mica powder was dispersed in 1500mL of toluene, 300g of ε-caprolactone monomer and 6g of benzyl alcohol were added, 2g of DBU was added under a nitrogen atmosphere, the temperature was raised to 80℃ and the reaction was carried out for 4h. After the reaction was completed, the temperature was lowered to 20℃, dilute acetic acid was added to terminate the reaction, the precipitate was collected by centrifugation, and then polycaprolactone-coated dopamine-modified mica powder was obtained after washing and drying.

[0073] A method for preparing a high-performance insulating blanket includes the following steps:

[0074] S21, Surface preparation: Ethylene-vinyl acetate copolymer, natural rubber, PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, MAH-g-EVA, antioxidant, lubricant, and colorant are added to an internal mixer for internal mixing. The order of feeding is as follows: EVA and NR matrix are added first for plasticization; then PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, and flame retardant are added to prevent excessive instantaneous torque; lubricant, MAH-g-EVA, antioxidant, etc. are added after dispersion; colorant is added last; the mixing temperature is 110℃ and the time is 12min; the mixed material is fed into a rubber mixing mill, and 1.2wt% accelerator DM and 2.2wt% sulfur are added (1.2 parts accelerator DM and 2.2 parts sulfur are added to 100 parts by weight of material) and mixed evenly. The mixing temperature is 65℃ and the time is 20min. After mixing, the mixture is pressed into a sheet with a thickness of 150μm for later use.

[0075] S22, EVA rubber layer preparation: Ethylene-vinyl acetate copolymer, natural rubber, MAH-g-EVA, rosin glycerol ester and colorant are added to a mixing mill for mixing. The order of feeding is: main materials EVA, NR, and MAH-g-EVA are plasticized first, and rosin glycerol ester and colorant are added later. The mixing temperature is 95℃ and the time is 15min. The mixed material is then fed into a rubber mixing mill, and 1.2wt% accelerator DM and 2.2wt% sulfur are added (1.2 parts accelerator DM and 2.2 parts sulfur are added to 100 parts by weight of material). The mixture is mixed evenly at 65℃ for 20min. After mixing, the mixture is pressed into a sheet with a thickness of 170μm for later use.

[0076] S23, Lamination: Ten layers of EVA adhesive are calendered and laminated, and then two outer layers are placed on the outside of the EVA adhesive layers and calendered and laminated again to obtain a composite layered material; the roller temperature is 130℃, the roller pressure is 40MPa, and the roller linear speed is 1.0m / s during calendering and lamination.

[0077] S24, Vulcanization treatment: The composite layered material is placed in a flat vulcanizing machine and vulcanized at 20MPa and 160℃ for 20 minutes. After the vulcanization is completed, the insulation blanket is trimmed and finished.

[0078] Example 5

[0079] The high-performance insulating blanket of this embodiment includes a surface layer, an EVA adhesive layer and another surface layer arranged sequentially, with the surface layer and the EVA adhesive layer being calendered and bonded together; the thickness of each surface layer is 165μm, the thickness of each EVA adhesive layer is 167μm, and there are 10 layers of EVA adhesive layer.

[0080] The raw materials for preparing the surface layer include: 1000g of ethylene-vinyl acetate copolymer, 300g of natural rubber, 250g of PA6 short fiber, 180g of polycaprolactone-coated dopamine-modified mica powder, 150g of MAH-g-EVA, 270g of magnesium hydroxide, 10106g of antioxidant, 20g of paraffin wax, and 50g of chrome yellow.

[0081] The raw materials for preparing the EVA adhesive layer include: 850g of ethylene-vinyl acetate copolymer, 150g of natural rubber, 70g of MAH-g-EVA, 50g of rosin glycerol ester, and 25g of chrome yellow.

[0082] The preparation method of polycaprolactone-coated dopamine-modified mica powder is as follows:

[0083] S11, 90g of dopamine hydrochloride was dissolved in 5L of Tris-HCl buffer solution with pH 8.5, 250g of mica powder was added and dispersed evenly, and then the mixture was stirred and reacted for 20h. After the reaction was completed, the precipitate was separated by centrifugation. The precipitate was washed and dried to obtain dopamine-modified mica powder.

[0084] S12, 200g of dopamine-modified mica powder was dispersed in 1500mL of toluene, 260g of ε-caprolactone monomer and 9g of benzyl alcohol were added, 6g of DBU was added under a nitrogen atmosphere, the temperature was raised to 70℃ and reacted for 5h. After the reaction was completed, the temperature was lowered to 20℃, dilute acetic acid was added to terminate the reaction, the precipitate was collected by centrifugation, and then polycaprolactone-coated dopamine-modified mica powder was obtained after washing and drying.

[0085] A method for preparing a high-performance insulating blanket includes the following steps:

[0086] S21, Surface preparation: Ethylene-vinyl acetate copolymer, natural rubber, PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, MAH-g-EVA, antioxidant, lubricant, and colorant are added to a mixing mill for mixing. The order of feeding is as follows: EVA and NR matrix are added first for plasticization; then PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, and flame retardant are added to prevent excessive instantaneous torque; lubricant, MAH-g-EVA, antioxidant, etc. are added after dispersion; colorant is added last; the mixing temperature is 105℃ and the time is 15min; the mixed material is fed into a rubber mixing mill, and 0.8wt% accelerator DM and 1.8wt% sulfur are added (0.8 parts accelerator DM and 1.8 parts sulfur are added to 100 parts by weight of material) and mixed evenly. The mixing temperature is 58℃ and the time is 25min. After mixing, the mixture is pressed into a sheet with a thickness of 165μm for later use.

[0087] S22, EVA rubber layer preparation: Ethylene-vinyl acetate copolymer, natural rubber, MAH-g-EVA, rosin glycerol ester and colorant are added to a mixing mill for mixing. The order of feeding is: main materials EVA, NR, and MAH-g-EVA are plasticized first, and rosin glycerol ester and colorant are added later. The mixing temperature is 100℃ and the time is 15min. The mixed material is then fed into a rubber mixing mill, and 0.8wt% accelerator DM and 1.8wt% sulfur are added (0.8 parts accelerator DM and 1.8 parts sulfur are added to 100 parts by weight of material). The mixture is mixed evenly at 63℃ for 22min. After mixing, the mixture is pressed into a sheet with a thickness of 167μm for later use.

[0088] S23, Lamination: Ten layers of EVA adhesive are calendered and laminated, and then two outer layers are placed on the outside of the EVA adhesive layers and calendered and laminated again to obtain a composite layered material; the roller temperature is 110℃, the roller pressure is 70MPa, and the roller linear speed is 0.9m / s during calendering and lamination.

[0089] S24, Vulcanization treatment: The composite layered material is placed in a flat vulcanizing machine and vulcanized at 18MPa and 165℃ for 30 minutes. After the vulcanization is completed, the insulation blanket is trimmed and finished.

[0090] Comparative Example 1

[0091] Compared with Example 1, Comparative Example 1 lacked dopamine-modified mica powder in the surface raw material, but the rest was the same as in Example 1.

[0092] Comparative Example 2

[0093] Compared with Example 1, Comparative Example 2 had a dopamine-modified mica powder content that exceeded the limit, specifically 220g, while the rest was the same as in Example 1.

[0094] Comparative Example 3

[0095] Compared with Example 1, Comparative Example 3 lacked rosin glycerol ester in its EVA adhesive layer material, but the rest was the same as in Example 1.

[0096] Comparative Example 4

[0097] Compared with Example 1, Comparative Example 4 had a rosin glycerol ester content that exceeded the specified range, specifically 100g, while the rest of the contents were the same as in Example 1.

[0098] Comparative Example 5

[0099] Compared with Example 1, Comparative Example 5 lacked PA6 short fibers in the surface material, but the rest was the same as in Example 1.

[0100] The insulating blankets prepared in the examples and comparative examples were cut to a size of 900mm*1000mm. The tensile strength, tear resistance and other properties of the insulating blankets were tested, with reference to the standards DL / T 803-2015 "Insulating Blankets for Live Working" and DL / T 976-2005 "Preventive Test Procedures for Live Working Tools, Devices and Equipment". The results are shown in Table 1.

[0101] Table 1 Performance of Insulation Blankets

[0102]

[0103] As shown in Table 1, the insulation blanket prepared in Example 2 has better strength and insulation properties than that in Example 1, indicating that polycaprolactone coating can improve the interfacial bonding between mica powder and polymer matrix, enhance filler dispersibility, and thus improve mechanical and insulation properties.

[0104] Comparative Example 1 lacked dopamine-modified mica powder, resulting in a lack of inorganic framework support on the surface, poor interfacial bonding, and a significant decrease in both mechanical and insulation properties. Comparative Example 2 had dopamine-modified mica powder exceeding the limit; although inorganic filler (dopamine-modified mica powder) is beneficial for reinforcement, excessive amounts often lead to difficulty in system dispersion, agglomeration, and interface deterioration, resulting in a slight decrease in mechanical properties. Comparative Example 3's EVA adhesive layer lacked rosin-free glycerol ester, significantly reducing elastomer processability, EVA / NR compatibility, flexibility, and strength, especially impacting puncture and tear resistance. Comparative Example 4 had excessive rosin glycerol ester, softening the elastomer system, decreasing mechanical strength, and slightly lower insulation properties. PA6 short fibers are typical fiber-reinforced materials, significantly improving tensile strength, tear resistance, and puncture resistance. Comparative Example 5, lacking PA6 short fiber reinforcement, showed a significant decrease in overall mechanical properties; electrical insulation properties mainly depend on the matrix and mica powder, and the removal of PA6 short fibers had a relatively small impact on this aspect.

[0105] 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. A high-performance insulating blanket, characterized in that: It includes a surface layer, an EVA adhesive layer and a surface layer arranged in sequence, with the surface layer and the EVA adhesive layer being calendered and bonded together. The raw materials for preparing the surface layer, calculated by weight, include: 45-55 parts of ethylene-vinyl acetate copolymer, 10-20 parts of natural rubber, 8-18 parts of PA6 short fiber, 7-10 parts of dopamine-modified mica powder, 6-10 parts of MAH-g-EVA, 10-15 parts of flame retardant, 0.2-0.4 parts of antioxidant, 0.8-1.2 parts of lubricant, and 2-4 parts of colorant; The raw materials for preparing the EVA adhesive layer, calculated by weight, include: 80-90 parts of ethylene-vinyl acetate copolymer, 10-20 parts of natural rubber, 5-10 parts of MAH-g-EVA, 3-8 parts of rosin glycerol ester, and 2-4 parts of colorant.

2. The high-performance insulating blanket as described in claim 1, characterized in that: Each surface layer is 150-250μm thick, each EVA adhesive layer is 150-170μm thick, and there are 10 EVA adhesive layers.

3. The high-performance insulating blanket as described in claim 2, characterized in that: The dopamine-modified mica powder is coated with polycaprolactone.

4. The high-performance insulating blanket as described in claim 3, characterized in that: The preparation method of the polycaprolactone-coated dopamine-modified mica powder is as follows: S11, dopamine hydrochloride was dissolved in Tris-HCl buffer solution at pH 8.5, mica powder was added and dispersed evenly, and then the mixture was stirred and reacted for 20-24 hours. After the reaction was completed, the precipitate was separated by centrifugation. The precipitate was washed and dried to obtain dopamine-modified mica powder. S12, dopamine-modified mica powder is dispersed in toluene, ε-caprolactone monomer and benzyl alcohol are added, DBU is added under a nitrogen atmosphere, the temperature is raised to 60-80℃, and the reaction is carried out for 4-8 hours. After the reaction is completed, the temperature is lowered to 20-30℃, dilute acetic acid is added to terminate the reaction, the precipitate is collected by centrifugation, and then polycaprolactone-coated dopamine-modified mica powder is obtained after washing and drying.

5. A high-performance insulating blanket as described in claim 4, characterized in that: In step S11, the mass ratio of dopamine hydrochloride to mica powder is 0.2-0.4:

1.

6. The high-performance insulating blanket as described in claim 4, characterized in that: The flame retardant is aluminum hydroxide or magnesium hydroxide, the lubricant is one or more of paraffin wax, stearic acid and polyethylene glycol, 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 blue green or rubber red.

7. A method for preparing a high-performance insulating blanket as described in any one of claims 3-6, characterized in that: Includes the following steps: S21, Surface preparation: Ethylene-vinyl acetate copolymer, natural rubber, PA6 short fiber, polycaprolactone-coated dopamine-modified mica powder, MAH-g-EVA, antioxidant, lubricant and colorant are added to an internal mixer for internal mixing; the mixed material is then fed into a rubber mixing mill, accelerator DM and sulfur are added and mixed evenly, and then pressed into sheets for later use. S22, EVA rubber layer preparation: Ethylene-vinyl acetate copolymer, natural rubber, MAH-g-EVA, rosin glycerol ester and colorant are added to an internal mixer for internal mixing; the mixed material is fed into a rubber mixing mill, accelerator DM and sulfur are added and mixed evenly, and then pressed into sheets for later use. S23, laminated composite: 10 layers of EVA adhesive are calendered and laminated together, and then 2 surface layers are placed on the outside of the EVA adhesive layers and calendered and laminated again to obtain a composite layered material. S24, Vulcanization treatment: The composite layered material is placed in a flat vulcanizing machine for vulcanization. After the vulcanization is completed, the insulation blanket is trimmed and finished.

8. The method for preparing a high-performance insulating blanket as described in claim 7, characterized in that: In steps S21 and S22, the mixing temperature is 95-110℃ and the time is 10-15 min; the mixing temperature is 55-65℃ and the time is 20-30 min; the dosage of accelerator DM and sulfur is 0.6%-1.2% and 1.5%-2.2% of the material weight, respectively.

9. The method for preparing a high-performance insulating blanket as described in claim 7, characterized in that: In step S23, the roller temperature is 100-130℃, the roller pressure is 40-80MPa, and the roller linear speed is 0.5-1.0m / s during calendering and bonding; in step S24, the pressure is 10-20MPa, the temperature is 160-170℃, and the time is 25-30min during vulcanization.

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