Epoxy insulating material with high toughness and high insulating strength and preparation method thereof

Abstract

The invention belongs to the technical field of polymer insulating materials, and particularly discloses a high-toughness and high-insulating-strength epoxy insulating material and a preparation method thereof. Single-end amine-terminated straight-chain alkyl groups with different chain lengths in a specific molar ratio are grafted to fluorine-containing epoxy resin to construct a side chain structure, and then a step curing process is adopted to form a three-dimensional cross-linked network with a curing agent under the action of an accelerant. The fracture toughness is remarkably improved by utilizing an epoxy body chain extension effect in a side chain grafting process and a uniform microphase separation structure formed by self-assembly of a long alkyl side chain in a curing process; meanwhile, through the synergistic effect of steric hindrance of a short alkyl side chain and a fluorine atom charge trap, delocalized electron transmission of a benzene ring conjugated structure is inhibited, and the insulating property is synchronously enhanced. Compared with a traditional toughening technology, insulation deterioration caused by toughening modification is effectively avoided, and an epoxy resin material with mechanical reliability and insulation stability is provided for high-voltage electrical equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer insulating materials, and particularly relates to an epoxy insulating material with high toughness and high insulation strength and a preparation method thereof. Background Art

[0002] Due to its excellent electrical insulation and thermal stability, epoxy resin has long been widely used in insulating components of high-voltage power transmission and transformation equipment, such as high-voltage bushings, cable terminals, and epoxy castings in GIS (Gas Insulated Switchgear). However, its inherent brittleness problem is prone to induce microcracks or even cracking under the combined action of high electric fields and complex mechanical stresses (such as power grid short-circuit impacts and uneven thermal expansion), becoming a key cause of insulation failure in high-voltage equipment. Traditional modification methods for toughening epoxy resin, due to the introduction of heterogeneous interfaces or structural defects, severely weaken the insulation strength, becoming a key bottleneck restricting the improvement of equipment reliability.

[0003] The elastomer toughening technology absorbs impact energy by introducing soft-phase components (such as rubber particles), but the modulus / dielectric constant mismatch at the interface between the elastomer and the epoxy matrix leads to an exacerbation of local electric field distortion under high electric fields, ultimately resulting in a significant reduction in the insulation strength of the material. The introduction of nano-aluminum oxide / silicon dioxide can synergistically regulate mechanical and dielectric properties, but the interface defects formed by particle agglomeration are prone to become preferential paths for the development of electrical trees during long-term operation at high voltages. Especially under complex electric field conditions with DC superimposed harmonics, the accelerated injection and accumulation of charges lead to a much faster deterioration of insulation performance than in traditional AC operating conditions. Although reactive toughening agents improve the toughness of the material, they reduce the crosslinking network density, resulting in a significant deterioration of insulation performance.

[0004] The common contradiction of the above technical solutions lies in that the realization of the toughening mechanism depends on the introduction of heterogeneous structures (elastomer phase / nano-particles / reactive toughening agents), and exogenous heterogeneous bodies inevitably become dielectric weak areas during high-voltage operation - electric field distortion, charge injection, and the resulting insulation deterioration are all amplified by such defects. Therefore, there is an urgent need to develop an epoxy resin modification strategy that can synergistically optimize the toughness and electrical insulation performance of the material. Summary of the Invention

[0005] One of the objectives of the present invention is to provide an epoxy insulating material with high toughness and high insulation strength. By using the extension of the epoxy resin main chain brought by side-chain grafting and combining with the uniform microphase separation structure formed by the self-assembly of long alkyl side chains, the fracture toughness is significantly improved; through the steric hindrance effect of short alkyl side chains and the charge trapping of fluorine atoms, the delocalized electron transport caused by the conjugated structure of benzene rings in the epoxy resin chain is inhibited, simultaneously increasing the breakdown strength and volume resistivity.

[0006] To achieve the above object, the present invention adopts the following technical solution: a method for preparing an epoxy insulating material with high toughness and high insulation strength, comprising the following steps: S1, take a single-terminal amine-terminated alkyl H2N-(CH2) n -CH3, when n is an integer of 2-5, it is a short-chain alkyl group, when n is an integer of 6-11, it is a long-chain alkyl group, and the short-chain alkyl group and the long-chain alkyl group are grafted onto the epoxy side chain of the fluorine-containing epoxy resin monomer through reaction to obtain a modified epoxy monomer; The general structural formula of the fluorine-containing epoxy resin monomer is: ; The R group in the fluorinated epoxy resin monomer is selected from any one of the following structures: , , , , ; The general structural formula of the modified epoxy monomer is: ; S2, fully mixing the modified epoxy monomer, curing agent and accelerator at a constant temperature and then degassing under vacuum to obtain a mixture; S3, pouring the mixture into a mold, performing low-temperature pre-curing and high-temperature curing in sequence, and demoulding after cooling to room temperature to obtain an epoxy insulation material with high toughness and high insulation strength.

[0007] Further improvement of the preparation method of epoxy insulating material with high toughness and high insulation strength: Preferably, in step S1, the molar ratio of the fluorine-containing epoxy resin monomer to the long-chain alkyl and the short-chain alkyl is 20:(1-2):(1-2).

[0008] Preferably, in step S1, the fluorine-containing epoxy resin monomer, the short-chain alkyl and the long-chain alkyl are mixed and placed in a reaction kettle, and stirred at 60-100° C. at a speed of 200-400 rad / s for 0.5-3 h to obtain a modified epoxy monomer.

[0009] Preferably, the curing agent in step S2 is one or a combination of two or more of an anhydride curing agent and an amine curing agent.

[0010] Preferably, the accelerator in step S2 is , 2,4,6-tris(dimethylaminomethyl)phenol, 2-methylimidazole and 2-ethyl-4-methylimidazole, or a combination of two or more thereof.

[0011] Preferably, in step S2, the mixing mass ratio of the modified epoxy monomer to the curing agent and the accelerator is 100:(70 - 100):(0.1 - 0.5).

[0012] Preferably, in step S2, the modified epoxy monomer is mixed with the curing agent and the accelerator at a temperature of 60 - 100°C, then stirred at a speed of 200 - 400 rad / s for 0.5 - 2 hours, and degassed under vacuum conditions for more than 30 minutes to obtain a mixture.

[0013] Preferably, in step S3, the temperature of the low-temperature pre-curing is controlled at 60 - 100°C, and the curing time is 2 - 6 hours.

[0014] Preferably, in step S3, the temperature of the high-temperature curing is controlled at 110 - 160°C, and the curing time is 5 - 20 hours.

[0015] The second object of the present invention is to provide a highly tough and high-insulation-strength epoxy insulating material prepared by the preparation method of the highly tough and high-insulation-strength epoxy insulating material described in any one of the above.

[0016] The beneficial effects of the present invention compared with the prior art are as follows: (1) Aiming at the problem of insulation performance deterioration caused by the toughening method of existing epoxy resin insulating materials, the present invention provides a technical method for synergistically improving toughness and insulation performance based on molecular structure design. The design of this technical process is based on the following technical principles: Fluorinated epoxy backbone + long side-chain grafting: A flexible alkyl chain with a carbon chain length of C7 - C12 is introduced at the side-chain site of the fluorinated epoxy resin monomer, and a uniform nano-scale microphase separation structure is formed through its self-assembly, significantly improving toughness.

[0017] Fluorine atom functionalization + short side-chain grafting: A flexible alkyl chain with a carbon chain length of C3 - C6 is introduced at the side-chain site of the fluorinated epoxy resin monomer. Through its steric hindrance effect, the benzene ring conjugated structure in the epoxy resin chain is inhibited, thereby reducing the transmission of delocalized electrons. Further, in synchronization with the high electronegativity of fluorine atoms inducing the intramolecular electron cloud shift effect, charge traps are constructed inside the resin matrix to achieve the localized capture of carriers, thereby increasing the volume resistivity and strengthening the insulation strength.

[0018] Two-stage stepped curing strategy: Perform pre-curing treatment at a low temperature of 60 - 100°C to delay the formation rate of the crosslinked network and provide a dynamic migration window for the self-assembly of alkyl chains. Construct a highly crosslinked fluorinated insulating backbone through curing at a high temperature of 110 - 160°C to ensure the mechanical strength and insulation stability of the material.

[0019] (2) Traditional technologies (such as core-shell rubber toughening and nanoparticle compounding) lead to deterioration of insulation performance; the microphase separation structure formed by the self-assembly of alkyl chains in the present invention avoids heterogeneous interface defects, and there is no local discharge deterioration caused by interface electric field distortion during long-term operation. It can withstand strong electric field aging, taking into account toughness and insulation performance. Traditional technologies require additional dispersion or surface modification processes, while this solution is directly compatible with existing molding processes, reducing production costs. Traditional materials are prone to local discharge and corona aging due to heterogeneous interface defects, while this solution has no interface defects, significantly extending the service life. The preparation process of the present invention has compatibility and is adapted to the vacuum casting / molding process of existing high-voltage insulation components without the need to add complex new processes. Compared with traditional modification technologies such as elastomer blending and nanoparticle filling, the present invention shows two-way advantages in ultra-high voltage application scenarios: there is no local discharge deterioration caused by interface electric field distortion during long-term operation, and it has both the stability of anti-mechanical fatigue cracking and the aging durability of withstanding strong electric fields, providing a material solution for the reliability and compact design of high-voltage equipment.

[0020] (3) The present invention provides an epoxy insulating material with high toughness and high insulation strength, and the performance of this material has the following advantages: Toughness enhancement: The microphase separation structure formed by the self-assembly of alkyl chains effectively buffers mechanical stress, inhibits crack propagation, and significantly improves toughness. Insulation performance enhancement: The volume resistivity and breakdown strength are improved: The suppression of delocalized electrons combined with the construction of charge traps significantly increases the resistivity. It is suitable for ultra-high voltage equipment, meeting the dual requirements of anti-mechanical fatigue (such as anti-cracking) and resistance to corona erosion. It supports the compact design of high-voltage equipment (such as reducing the wall thickness of insulation components), improving reliability and long-term operation stability. Detailed implementation methods

[0021] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further details the present invention in conjunction with embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0022] Example 1 This example provides a preparation method for an epoxy insulating material with high toughness and high insulation strength. The specific steps are as follows: S1. Weigh fluorinated epoxy resin monomers, n-propylamine (H2N-(CH2)2-CH3), and n-heptylamine (H2N-(CH2)6-CH3) in a molar ratio of 10:1:1, put them into a reaction kettle, and stir at 80°C at a speed of 300 rad / s for 2 h to obtain modified epoxy monomers; The structural formula of the fluorinated epoxy resin monomer is: Formula (1); The structural general formula of the modified epoxy monomer is as follows. Specifically, it is a composition of modified epoxy monomers with two structures when the values of n are 2 and 6 in sequence: Formula (2); S2. Add a curing agent (methyltetrahydrophthalic anhydride) and an accelerator ( ) to the above-mentioned modified epoxy monomer and mix them. The mass ratio of the modified epoxy monomer, the curing agent, and the accelerator is 100:88.9:0.5. Stir at a speed of 300 rad / s for 2 h at 80 °C until fully mixed, and degas for more than 30 min under vacuum conditions to obtain a mixture; S3. Pour the mixture into a mold, and carry out low-temperature pre-curing and high-temperature curing in sequence. The temperature of low-temperature pre-curing is 80 °C and the time is 4 h; the temperature of high-temperature curing is 140 °C and the time is 14 h. After curing is completed, naturally cool to room temperature and then demold to obtain an epoxy insulating material 1 with high toughness and high insulation strength.

[0023] Example 2 This example provides a preparation method of an epoxy insulating material with high toughness and high insulation strength. The specific steps refer to Example 1, and the difference is only that: in step S1, a fluorinated epoxy resin monomer, n-hexylamine (H2N-(CH2)5-CH3), and n-dodecylamine (H2N-(CH2) 11 -CH3) with a molar ratio of 10:1:1 are weighed; among them, the structural formula of the fluorinated epoxy resin monomer is the same as formula (1) in Example 1; The structural general formula of the modified epoxy monomer is the same as formula (2) in Example 1. Specifically, it is a composition of modified epoxy monomers with two structures when the values of n are 5 and 11 in sequence; Finally, an epoxy insulating material 2 with high toughness and high insulation strength is obtained.

[0024] Example 3 This example provides a preparation method of an epoxy insulating material with high toughness and high insulation strength. The specific steps refer to Example 1, and the difference is only that: in step S1, a fluorinated epoxy resin monomer, n-propylamine (H2N-(CH2)2-CH3), and n-heptylamine (H2N-(CH2)6-CH3) with a molar ratio of 20:1:1 are weighed; among them, the structural formula of the fluorinated epoxy resin monomer is the same as formula (1) in Example 1; The structural general formula of the modified epoxy monomer is the same as formula (2) in Example 1. Specifically, it is a composition of modified epoxy monomers with two structures when the values of n are 2 and 6 in sequence; Finally, an epoxy insulating material 3 with high toughness and high insulation strength is obtained.

[0025] Example 4 This embodiment provides a preparation method of an epoxy insulating material with high toughness and high insulation strength. The specific steps refer to Embodiment 1, and the difference is only that: the structural formula of the fluorinated epoxy resin monomer in Step S1 is: ; The general structural formula of the modified epoxy monomer is as follows, specifically a composition of two structural modified epoxy monomers when n takes values of 2 and 6 in sequence: ; Finally, an epoxy insulating material 4 with high toughness and high insulation strength is prepared.

[0026] Embodiment 5 This embodiment provides a preparation method of an epoxy insulating material with high toughness and high insulation strength. The specific steps are as follows: S1. Weigh a fluorinated epoxy resin monomer, n-butylamine (H2N-(CH2)3-CH3), and n-nonylamine (H2N-(CH2)8-CH3) in a molar ratio of 20:2:1, put them into a reaction kettle, and stir at a speed of 300 rad / s at 80 °C for 2 h to obtain a modified epoxy monomer; The structural formula of the fluorinated epoxy resin monomer is: ; The general structural formula of the modified epoxy monomer is as follows, specifically a composition of two structural modified epoxy monomers when n takes values of 3 and 8 in sequence: ; S2. Add a curing agent (diaminodiphenylmethane) and an accelerator (2,4,6-tris(dimethylaminomethyl)phenol) to the above-mentioned modified epoxy monomer and mix them. The mass ratio of the modified epoxy monomer, the curing agent, and the accelerator is 100:70:0.1. Stir at a speed of 400 rad / s at 60 °C for 0.5 h until fully mixed, and degas for more than 30 min under a vacuum state to obtain a mixture; S3. Pour the mixture into a mold, and perform low-temperature pre-curing and high-temperature curing in sequence. The temperature of low-temperature pre-curing is 80 °C and the time is 2 h; the temperature of high-temperature curing is 130 °C and the time is 10 h; after curing is completed, cool naturally to room temperature and then demold to obtain an epoxy insulating material 5 with high toughness and high insulation strength.

[0027] Embodiment 6 This embodiment provides a preparation method of an epoxy insulating material with high toughness and high insulation strength. The specific steps are as follows: S1. Weigh a fluorinated epoxy resin monomer, n-propylamine (H2N-(CH2)2-CH3), and n-dodecylamine (H2N-(CH2) 11-CH3), and put it into a reaction kettle, stir at a speed of 300 rad / s at 80 °C for 2 h to obtain a modified epoxy monomer; The structural formula of the fluorinated epoxy resin monomer is: ; The general structural formula of the modified epoxy monomer is as follows. Specifically, it is a composition of two kinds of modified epoxy monomers when n takes values of 2 and 11 in sequence: ; S2. Add a curing agent (methyl nadic anhydride) and an accelerator (2-methylimidazole) to the above-mentioned modified epoxy monomer and mix them. The mass ratio of the modified epoxy monomer, the curing agent, and the accelerator is 100:100:0.5. Stir at a speed of 300 rad / s at 100 °C for 1.5 h until fully mixed, and degas for more than 30 min under a vacuum state to obtain a mixture; S3. Pour the mixture into a mold, and carry out low-temperature pre-curing and high-temperature curing in sequence. The temperature of low-temperature pre-curing is 100 °C and the time is 3 h; the temperature of high-temperature curing is 160 °C and the time is 10 h; after curing is completed, naturally cool to room temperature and then demold to obtain an epoxy insulating material 6 with high toughness and high insulation strength.

[0028] Example 7 This example provides a preparation method of an epoxy insulating material with high toughness and high insulation strength. The specific steps are as follows: S1. Weigh fluorinated epoxy resin monomer, n-hexylamine (H2N-(CH2)5-CH3), and n-heptylamine (H2N-(CH2)6-CH3) with a molar ratio of 20:1.5:1.5, put them into a reaction kettle, stir at a speed of 300 rad / s at 80 °C for 2 h to obtain a modified epoxy monomer; The structural formula of the fluorinated epoxy resin monomer is: ; The general structural formula of the modified epoxy monomer is as follows. Specifically, it is a composition of two kinds of modified epoxy monomers when n takes values of 5 and 6 in sequence: ; S2. Add a curing agent (diaminodiphenyl sulfone) and an accelerator (2-ethyl-4-methylimidazole) to the above-mentioned modified epoxy monomer and mix them. The mass ratio of the modified epoxy monomer, the curing agent, and the accelerator is 100:90:0.3. Stir at a speed of 300 rad / s at 70 °C for 1.5 h until fully mixed, and degas for more than 30 min under a vacuum state to obtain a mixture; S3. Pour the mixture into a mold, and carry out low-temperature pre-curing and high-temperature curing in sequence. The temperature of low-temperature pre-curing is 60 °C and the time is 2 h; the temperature of high-temperature curing is 110 °C and the time is 5 h. After curing is completed, naturally cool to room temperature and then demold to obtain the epoxy insulating material 7 with high toughness and high insulation strength.

[0029] Comparative Example 1 This comparative example provides a preparation method of a common epoxy resin material. The specific steps refer to Example 1, and the difference is only that: in step S1, a fluorinated epoxy resin monomer and n-propylamine (H2N-(CH2)2-CH3) with a molar ratio of 5:1 are weighed and put into a reaction kettle, and stirred at 80 °C at a speed of 300 rad / s for 2 h to obtain a modified epoxy monomer; Among them, the structural formula of the epoxy resin monomer is the same as formula (1) in Example 1; The general structural formula of the modified epoxy monomer is the same as formula (2) in Example 1, and n takes the value of 2; Finally, a common epoxy resin material 1 is obtained.

[0030] Comparative Example 2 This comparative example provides a preparation method of a common epoxy resin material. The specific steps refer to Example 1, and the difference is only that: in step S1, a fluorinated epoxy resin monomer and n-heptylamine (H2N-(CH2)6-CH3) with a molar ratio of 5:1 are weighed and put into a reaction kettle, and stirred at 80 °C at a speed of 300 rad / s for 2 h to obtain a modified epoxy monomer; Among them, the structural formula of the epoxy resin monomer is the same as formula (1) in Example 1; The general structural formula of the modified epoxy monomer is the same as formula (2) in Example 1, and n takes the value of 6; Finally, a common epoxy resin material 2 is obtained.

[0031] Comparative Example 3 This comparative example provides a preparation method of a common epoxy resin material. The specific steps refer to Example 1, and the difference is only that: S3. Pour the mixture into a mold and cure it at a constant temperature of 120 °C for 16 h. After curing is completed, naturally cool to room temperature and then demold.

[0032] Finally, a common epoxy resin material 3 is obtained.

[0033] Comparative Example 4 This comparative example provides a preparation method of a common epoxy resin material. The specific steps refer to Example 1, and the difference is only that: the operation of step S1 is not carried out, and the fluorinated epoxy resin monomer is directly mixed with a curing agent (methyltetrahydrophthalic anhydride) and an accelerator ( Mixing: The mixing mass ratio of the fluorinated epoxy resin monomer, curing agent, and accelerator is 100:88.9:0.5. Stir at a speed of 300 rad / s for 2 h at 80 °C until fully mixed, and degas for 30 min under vacuum to obtain a mixed material. The structural general formula of the fluorinated epoxy resin monomer is the same as formula (1) in Example 1. Finally, a common epoxy resin material 4 is prepared.

[0034] The epoxy resin samples prepared in the above examples and comparative examples were subjected to impact strength testing, volume resistivity testing, and AC breakdown strength testing. Among them, the impact strength testing refers to the national standard GB / T 1043.1-2008, and the test conditions are at room temperature; the volume resistivity testing refers to the national standard GB / T 1410-2006, and the test voltage is 100 V; the AC breakdown strength testing refers to the national standard GB / T 1408.1-2016, and the voltage rise rate is 1 kV / s, with uniform voltage rise. The test results are as follows: Table 1 Performance testing of epoxy resin samples prepared in Examples 1-7 and Comparative Examples 1-4 ; It can be seen from the test data in Table 1 that the epoxy material preparation method provided by this application can effectively improve the toughness and insulation performance of the modified epoxy resin material synergistically. From Examples 1 and Comparative Examples 1-2, it can be seen that grafting long-chain alkyl groups and short-chain alkyl groups on the fluorinated epoxy resin monomer in a specific molar ratio can simultaneously achieve the effects of toughening and enhancing insulation performance, while grafting with side chains of a single chain length cannot meet the performance requirements. From Examples 1 and Comparative Examples 3-4, it can be seen that for epoxy insulating materials without using a stepped curing system or without grafting side chains, their toughness and insulation performance both decrease significantly. Examples 2-4 adjusted a single variable, including the raw material ratio, side chain length, and fluorine-containing structure of the modified epoxy resin monomer. Examples 5-7, on the other hand, achieved a significant improvement in the insulation performance and toughness of the material by simultaneously changing multiple variables, including the variables adjusted in Examples 2-4 above, as well as the types of curing agents, accelerators, and curing systems in the preparation process of the epoxy insulating material. The toughening mechanism lies in: the extension effect of the epoxy main chain generated by side chain grafting, combined with the uniform microphase separation structure formed by the self-assembly of long alkyl side chains in the low-temperature pre-curing stage. The simultaneous improvement of insulation performance stems from: the short alkyl side chains inhibit the delocalized electron transport of the benzene ring conjugate structure through steric hindrance effects and produce a synergistic effect with the trapping effect of fluorine atom charge traps. In addition, the stepped curing system ensures the integrity and uniformity of the crosslinked network structure, thereby effectively maintaining the intrinsic insulation strength of the material.

[0035] Those skilled in the art should understand that the above are only several specific embodiments of the present invention, rather than all embodiments. It should be noted that many variations and improvements can be made by those of ordinary skill in the art, and all variations or improvements that do not exceed the scope described in the claims shall be regarded as the protection scope of the present invention.

Claims

1. A preparation method of an epoxy insulating material with high toughness and high insulation strength, characterized in that, The following steps are involved: S1. Take a monoamine-terminated alkyl H2N-(CH2) n -CH3, which is a short-chain alkyl when n is an integer from 2 to 5 and a long-chain alkyl when n takes an integer from 6 to 11. Graft the short-chain alkyl and the long-chain alkyl onto the epoxy side chain of the fluorinated epoxy resin monomer through a reaction to obtain a modified epoxy monomer; The general structural formula of the fluorine-containing epoxy resin monomer is: ； The R group in the fluorinated epoxy resin monomer is selected from any one of the following structures: 、 、 、 、 ； The general structural formula of the modified epoxy monomer is: ； S2, fully mixing the modified epoxy monomer, curing agent and accelerator at a constant temperature and then degassing under vacuum to obtain a mixture; S3, pouring the mixture into a mold, performing low-temperature pre-curing and high-temperature curing in sequence, and demoulding after cooling to room temperature to obtain an epoxy insulation material with high toughness and high insulation strength.

2. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 1, characterized in that, In step S1, the molar ratio of the fluorine-containing epoxy resin monomer to the long-chain alkyl and the short-chain alkyl is 20:(1-2):(1-2).

3. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 1 or 2, characterized in that, In step S1, the fluorine-containing epoxy resin monomer, the short-chain alkyl and the long-chain alkyl are mixed and placed in a reaction kettle, and stirred at 60-100° C. at a speed of 200-400 rad / s for 0.5-3 h to obtain a modified epoxy monomer.

4. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 1, characterized in that, The curing agent in step S2 is one or a combination of two or more of an anhydride curing agent and an amine curing agent.

5. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 1, characterized in that, The accelerator described in step S2 is one or a combination of two or more of 2,4,6-tris(dimethylaminomethyl)phenol, 2-methylimidazole, and 2-ethyl-4-methylimidazole.

6. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 1 or 4 or 5, characterized in that, In step S2, the mixing mass ratio of the modified epoxy monomer to the curing agent and the accelerator is 100:(70-100):(0.1-0.5).

7. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 6, characterized in that, In step S2, the modified epoxy monomer is mixed with the curing agent and the accelerator at a temperature of 60-100° C., and then stirred at a speed of 200-400 rad / s for 0.5-2 hours, and degassed under vacuum conditions for more than 30 minutes to obtain a mixture.

8. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 1, characterized in that, In step S3, the temperature of the low-temperature pre-curing is controlled at 60-100° C., and the curing time is 2-6 hours.

9. The preparation method of the epoxy insulating material with high toughness and high insulation strength according to claim 1 or 8, characterized in that, The temperature of high temperature curing in step S3 is controlled at 110-160° C., and the curing time is 5-20 hours.

10. An epoxy insulating material with high toughness and high insulating strength obtained by the method for preparing an epoxy insulating material with high toughness and high insulating strength as claimed in any one of claims 1 to 9.

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