A high-toughness, high-insulation-strength epoxy insulation material and its preparation method

Abstract

The present invention belongs to the technical field of polymer insulation materials, and specifically discloses an epoxy insulation material with high toughness and high insulation strength and a preparation method thereof. The present invention constructs a side chain structure by grafting single-ended amine-terminated linear alkyl groups of different chain lengths at a specific molar ratio onto a fluorine-containing epoxy resin, and then adopts a step-curing process to form a three-dimensional cross-linked network with a curing agent under the action of a accelerator. The fracture toughness is significantly improved by utilizing the chain extension effect of the epoxy body during the side chain grafting process and the uniform microphase separation structure formed by the self-assembly of the long alkyl side chains during the curing process; at the same time, the steric hindrance of the short alkyl side chains and the synergistic effect of the fluorine atom charge trap inhibit the delocalized electron transmission of the conjugated structure of the benzene ring, and the insulation performance is simultaneously enhanced. Compared with traditional toughening technology, it effectively avoids the insulation degradation caused by toughening modification, and provides high-voltage electrical equipment with an epoxy resin material that has both mechanical reliability and insulation stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer insulating materials, and in particular relates to an epoxy insulating material with high toughness and high insulating 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 distribution equipment, such as high-voltage bushings, cable terminals, and epoxy castings in GIS (gas-insulated switchgear). However, its inherent brittleness, under the combined effects of high electric fields and complex mechanical stresses (such as grid short-circuit shocks and uneven thermal expansion), can easily induce microcracks or even cracks, becoming a key cause of insulation failure in high-voltage equipment. Traditional modification methods for epoxy resin to improve toughness introduce heterogeneous interfaces or structural defects, severely weakening insulation strength and becoming a key bottleneck restricting improved equipment reliability.

[0003] Elastomer toughening technology absorbs impact energy by introducing soft phase components (such as rubber particles). However, the modulus / dielectric constant mismatch at the interface between the elastomer and the epoxy matrix leads to increased local electric field distortion under high electric fields, ultimately causing a significant reduction in the material's dielectric strength. While the introduction of nano-alumina / silica can synergistically regulate mechanical and dielectric properties, the interfacial defects formed by particle agglomeration can easily become a preferred path for the development of electrical dendrites during long-term high-voltage operation. This is especially true under complex electric field conditions with DC superimposed harmonics, where the accelerated injection and accumulation of charges causes insulation performance to degrade much faster than under traditional AC operating conditions. While active toughening agents improve material toughness, they reduce the cross-linking network density, leading to a significant degradation of insulation performance.

[0004] A common contradiction among these technical solutions is that the toughening mechanism relies on the introduction of heterogeneous structures (elastomer phase / nanoparticles / active toughening agents). However, these heterogeneous structures inevitably become dielectric weak zones during high-voltage operation. These defects amplify electric field distortion, charge injection, and the resulting insulation degradation. Therefore, there is an urgent need to develop an epoxy resin modification strategy that can synergistically optimize the material's toughness and electrical insulation properties. 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 dielectric strength. The fracture toughness is significantly improved by utilizing the epoxy resin chain extension brought about by side chain grafting and combining it with the uniform microphase separation structure formed by self-assembly of long alkyl side chains. The delocalized electron transport caused by the conjugated structure of the benzene ring in the epoxy resin chain is inhibited through the steric hindrance effect of the short alkyl side chains and the fluorine atom charge trap, thereby simultaneously improving 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:

[0007] 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, 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;

[0008] The general structural formula of the fluorine-containing epoxy resin monomer is:

[0009] ;

[0010] The R group in the fluorinated epoxy resin monomer is selected from any one of the following structures:

[0011] 、 、 、 、 ;

[0012] The general structural formula of the modified epoxy monomer is:

[0013] ;

[0014] S2, fully mixing the modified epoxy monomer, curing agent and accelerator at a constant temperature and then degassing under vacuum to obtain a mixture;

[0015] S3. The mixture is poured into a mold, and low-temperature pre-curing and high-temperature curing are performed in sequence. After cooling to room temperature, the mixture is demoulded to obtain an epoxy insulation material with high toughness and high insulation strength.

[0016] Further improvements in the preparation method of epoxy insulation materials with high toughness and high dielectric strength:

[0017] Preferably, in step S1, the molar ratio of the fluorine-containing epoxy resin monomer to the long-chain alkyl group and the short-chain alkyl group is 20:(1-2):(1-2).

[0018] Preferably, in step S1, the fluorine-containing epoxy resin monomer, the short-chain alkyl group and the long-chain alkyl group 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.

[0019] 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.

[0020] 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.

[0021] 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).

[0022] 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.

[0023] Preferably, the temperature of the low-temperature pre-curing in step S3 is controlled at 60-100° C., and the curing time is 2-6 hours.

[0024] Preferably, the temperature of high-temperature curing in step S3 is controlled at 110-160° C., and the curing time is 5-20 hours.

[0025] A second object of the present invention is to provide an epoxy insulating material with high toughness and high insulating strength obtained by the preparation method of the epoxy insulating material with high toughness and high insulating strength described in any one of the above items.

[0026] The beneficial effects of the present invention compared to the prior art are:

[0027] (1) This invention addresses the problem of insulation performance degradation caused by existing toughening methods for epoxy resin insulation materials and 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:

[0028] Fluorinated epoxy backbone + long side chain grafting: Flexible alkyl chains with a carbon chain length of C7-C12 are introduced into the side chain sites of the fluorinated epoxy resin monomer, and a uniform nanoscale microphase separation structure is formed through its self-assembly, which significantly improves the toughness.

[0029] Fluorine atom functionalization + short side chain grafting: Flexible C3-C6 alkyl chains are introduced into the side chains of the fluorinated epoxy resin monomer. Their steric hindrance inhibits the conjugated structure of the benzene ring within the epoxy resin chain, thereby reducing the transmission of delocalized electrons. Furthermore, the high electronegativity of the fluorine atom simultaneously induces an intramolecular electron cloud shift effect, creating charge traps within the resin matrix and achieving localized carrier capture, thereby increasing volume resistivity and enhancing insulation strength.

[0030] A two-stage cascade curing strategy: Pre-curing at a low temperature of 60-100°C slows down the formation of the cross-linked network and provides a dynamic migration window for alkyl chain self-assembly. Curing at a high temperature of 110-160°C builds a highly cross-linked fluorinated insulating skeleton, ensuring the material's mechanical strength and insulation stability.

[0031] (2) Conventional technologies (such as core-shell rubber toughening and nanoparticle composites) 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 degradation caused by interface electric field distortion under long-term operation, and it can withstand strong electric field aging, taking into account both toughness and insulation performance. Conventional 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 and significantly extends the service life. The preparation process of the present invention is compatible and adaptable to the existing vacuum casting / molding process of high-voltage insulation components without adding complex processes. Compared with traditional modification technologies such as elastomer blending and nanoparticle filling, the present invention exhibits two-way advantages in ultra-high voltage application scenarios: there is no local discharge degradation caused by interface electric field distortion under long-term operation, and it has both stability against mechanical fatigue cracking and durability against aging in strong electric fields, providing a material solution for the reliability and compact design of high-voltage equipment.

[0032] (3) The present invention provides an epoxy insulation material with high toughness and high insulation strength. The performance of this material has the following advantages: Enhanced toughness: The microphase separation structure formed by the self-assembly of alkyl chains effectively buffers mechanical stress, inhibits crack propagation, and significantly improves toughness. Enhanced insulation performance: Improved volume resistivity and breakdown strength: The suppression of delocalized electrons and the construction of charge traps significantly improve the resistivity. It is suitable for ultra-high voltage equipment and meets the dual requirements of mechanical fatigue resistance (such as crack resistance) and corona erosion resistance. It supports the compact design of high-voltage equipment (such as reducing the wall thickness of insulating components), improving reliability and long-term operational stability. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] This embodiment provides a method for preparing an epoxy insulation material with high toughness and high insulation strength, and the specific steps are as follows:

[0036] S1. Weigh a fluorine-containing epoxy resin monomer, n-propylamine (H2N-(CH2)2-CH3), and n-heptylamine (H2N-(CH2)6-CH3) in a molar ratio of 10:1:1, place them in a reaction kettle, and stir at 80°C at a speed of 300 rad / s for 2 hours to obtain a modified epoxy monomer;

[0037] The structural formula of the fluorine-containing epoxy resin monomer is:

[0038] Formula (1);

[0039] The general structural formula of the modified epoxy monomer is as follows, specifically a composition of modified epoxy monomers with two structures when n is 2 and 6 respectively:

[0040] Formula (2)

[0041] S2, add curing agent (methyltetrahydrophthalic anhydride), accelerator ( ) were mixed, with the mass ratio of modified epoxy monomer, curing agent and accelerator being 100:88.9:0.5, stirred at 80° C. at a speed of 300 rad / s for 2 h until fully mixed, and degassed under vacuum for more than 30 min to obtain a mixture;

[0042] S3. Pour the mixture into a mold and perform low-temperature pre-curing and high-temperature curing in sequence. The low-temperature pre-curing temperature is 80°C and the time is 4 hours; the high-temperature curing temperature is 140°C and the time is 14 hours. After the curing is completed, the mixture is naturally cooled to room temperature and then demoulded to obtain an epoxy insulation material 1 with high toughness and high insulation strength.

[0043] Example 2

[0044] This embodiment provides a method for preparing an epoxy insulating material with high toughness and high insulation strength. The specific steps are similar to those in Example 1, except that: in step S1, a fluorine-containing epoxy resin monomer, n-hexylamine (H2N-(CH2)5-CH3) and n-dodecylamine (H2N-(CH2)5-CH3) in a molar ratio of 10:1:1 are weighed. 11 -CH3); wherein the structural formula of the fluorine-containing epoxy resin monomer is the same as formula (1) in Example 1;

[0045] The general structural formula of the modified epoxy monomer is the same as that of formula (2) in Example 1, specifically a composition of modified epoxy monomers with two structures when n is 5 and 11 respectively;

[0046] Finally, an epoxy insulation material 2 with high toughness and high insulation strength is obtained.

[0047] Example 3

[0048] This embodiment provides a method for preparing an epoxy insulating material with high toughness and high insulation strength. The specific steps are similar to those in Example 1, except that: Step S1 comprises weighing a fluorine-containing epoxy resin monomer, n-propylamine (H2N-(CH2)2-CH3) and n-heptylamine (H2N-(CH2)6-CH3) in a molar ratio of 20:1:1; wherein the structural formula of the fluorine-containing epoxy resin monomer is the same as that of Formula (1) in Example 1;

[0049] The general structural formula of the modified epoxy monomer is the same as that of formula (2) in Example 1, specifically a composition of modified epoxy monomers with two structures when n is 2 and 6 respectively;

[0050] Finally, an epoxy insulation material 3 with high toughness and high insulation strength is obtained.

[0051] Example 4

[0052] This embodiment provides a method for preparing an epoxy insulation material with high toughness and high insulation strength. The specific steps are similar to those in Example 1, except that the structural formula of the fluorine-containing epoxy resin monomer in step S1 is:

[0053] ;

[0054] The general structural formula of the modified epoxy monomer is as follows, specifically a composition of modified epoxy monomers with two structures when n is 2 and 6 respectively:

[0055] ;

[0056] Finally, an epoxy insulation material 4 with high toughness and high insulation strength is obtained.

[0057] Example 5

[0058] This embodiment provides a method for preparing an epoxy insulation material with high toughness and high insulation strength, and the specific steps are as follows:

[0059] 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, place them in a reaction kettle, and stir at 80°C at a speed of 300 rad / s for 2 hours to obtain a modified epoxy monomer;

[0060] The structural formula of the fluorine-containing epoxy resin monomer is:

[0061] ;

[0062] The general structural formula of the modified epoxy monomer is as follows, specifically a composition of modified epoxy monomers with two structures when n is 3 and 8 respectively:

[0063] ;

[0064] S2. Add a curing agent (diaminodiphenylmethane) and an accelerator (2,4,6-tris(dimethylaminomethyl)phenol) to the modified epoxy monomer, wherein the mass ratio of the modified epoxy monomer, the curing agent, and the accelerator is 100:70:0.1. Stir the mixture at a speed of 400 rad / s at 60° C. for 0.5 h until fully mixed. Degas the mixture under vacuum for more than 30 min to obtain a mixture.

[0065] S3. Pour the mixture into a mold and perform low-temperature pre-curing and high-temperature curing in sequence. The low-temperature pre-curing temperature is 80°C for 2 hours; the high-temperature curing temperature is 130°C for 10 hours. After the curing is completed, the mixture is naturally cooled to room temperature and then demoulded to obtain an epoxy insulation material 5 with high toughness and high insulation strength.

[0066] Example 6

[0067] This embodiment provides a method for preparing an epoxy insulation material with high toughness and high insulation strength, and the specific steps are as follows:

[0068] S1, weigh fluorinated epoxy resin monomer, n-propylamine (H2N-(CH2)2-CH3) and n-dodecylamine (H2N-(CH2)2-CH3) in a molar ratio of 20:1:2. 11 -CH3), put into a reactor, and stir at 80 ° C at a speed of 300 rad / s for 2 h to obtain a modified epoxy monomer;

[0069] The structural formula of the fluorine-containing epoxy resin monomer is:

[0070] ;

[0071] The general structural formula of the modified epoxy monomer is as follows, specifically a composition of modified epoxy monomers with two structures when n is 2 and 11 respectively:

[0072] ;

[0073] S2. Add a curing agent (methyl nadic anhydride) and an accelerator (2-methylimidazole) to the modified epoxy monomer, wherein 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 under vacuum for more than 30 min to obtain a mixture.

[0074] S3. Pour the mixture into a mold and perform low-temperature pre-curing and high-temperature curing in sequence. The low-temperature pre-curing temperature is 100°C and the time is 3 hours; the high-temperature curing temperature is 160°C and the time is 10 hours. After the curing is completed, the mixture is naturally cooled to room temperature and then demoulded to obtain an epoxy insulation material 6 with high toughness and high insulation strength.

[0075] Example 7

[0076] This embodiment provides a method for preparing an epoxy insulation material with high toughness and high insulation strength, and the specific steps are as follows:

[0077] S1. Weigh a fluorinated epoxy resin monomer, n-hexylamine (H2N-(CH2)5-CH3) and n-heptylamine (H2N-(CH2)6-CH3) in a molar ratio of 20:1.5:1.5, place the mixture into a reactor, and stir the mixture at 80°C and 300 rad / s for 2 h to obtain a modified epoxy monomer.

[0078] The structural formula of the fluorine-containing epoxy resin monomer is:

[0079] ;

[0080] The general structural formula of the modified epoxy monomer is as follows, specifically a composition of modified epoxy monomers with two structures when n is 5 and 6 respectively:

[0081] ;

[0082] S2. Add a curing agent (diaminodiphenyl sulfone) and an accelerator (2-ethyl-4-methylimidazole) to the modified epoxy monomer, wherein 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 under vacuum for more than 30 min to obtain a mixture.

[0083] S3. Pour the mixture into a mold and perform low-temperature pre-curing and high-temperature curing in sequence. The low-temperature pre-curing temperature is 60°C and the time is 2 hours; the high-temperature curing temperature is 110°C and the time is 5 hours. After the curing is completed, the mixture is naturally cooled to room temperature and then demoulded to obtain an epoxy insulation material 7 with high toughness and high insulation strength.

[0084] Comparative Example 1

[0085] This comparative example provides a method for preparing a common epoxy resin material. The specific steps are similar to those in Example 1, except that: in step S1, a fluorine-containing epoxy resin monomer and n-propylamine (H2N-(CH2)2-CH3) in a molar ratio of 5:1 are weighed and placed in a reaction kettle, and stirred at 80°C at a speed of 300 rad / s for 2 hours to obtain a modified epoxy monomer;

[0086] Wherein, the structural formula of the epoxy resin monomer is the same as formula (1) in Example 1;

[0087] The general structural formula of the modified epoxy monomer is the same as formula (2) in Example 1, and the value of n is 2;

[0088] Finally, ordinary epoxy resin material 1 was obtained.

[0089] Comparative Example 2

[0090] This comparative example provides a method for preparing a common epoxy resin material. The specific steps are similar to those in Example 1, except that: in step S1, a fluorine-containing epoxy resin monomer and n-heptylamine (H2N-(CH2)6-CH3) in a molar ratio of 5:1 are weighed and placed in a reaction kettle, and stirred at 80°C at a speed of 300 rad / s for 2 hours to obtain a modified epoxy monomer;

[0091] Wherein, the structural formula of the epoxy resin monomer is the same as formula (1) in Example 1;

[0092] The general structural formula of the modified epoxy monomer is the same as formula (2) in Example 1, and the value of n is 6;

[0093] Finally, ordinary epoxy resin material 2 was obtained.

[0094] Comparative Example 3

[0095] This comparative example provides a method for preparing a common epoxy resin material. The specific steps are similar to those in Example 1, with the following differences: S3, pouring the mixture into a mold and curing it at a constant temperature of 120°C for 16 hours. After curing, the mixture is naturally cooled to room temperature and then demolded.

[0096] Finally, ordinary epoxy resin material 3 was obtained.

[0097] Comparative Example 4

[0098] This comparative example provides a method for preparing a common epoxy resin material. The specific steps are similar to those in Example 1, except that: the operation of step S1 is not performed, and the fluorine-containing epoxy resin monomer is directly mixed with a curing agent (methyltetrahydrophthalic anhydride), an accelerator ( ) were mixed, with the mass ratio of the fluorinated epoxy resin monomer to the curing agent and the accelerator being 100:88.9:0.5, stirred at 80° C. at a speed of 300 rad / s for 2 h until fully mixed, and degassed under vacuum for 30 min to obtain a mixture;

[0099] The general structural formula of the fluorine-containing epoxy resin monomer is the same as formula (1) in Example 1;

[0100] Finally, ordinary epoxy resin material 4 was obtained.

[0101] The epoxy resin samples prepared in the above examples and comparative examples were subjected to impact strength tests, volume resistivity tests, and AC breakdown strength tests. The impact strength test was conducted in accordance with national standard GB / T 1043.1-2008 at room temperature; the volume resistivity test was conducted in accordance with national standard GB / T 1410-2006 at a test voltage of 100V; and the AC breakdown strength test was conducted in accordance with national standard GB / T 1408.1-2016 at a constant voltage increase rate of 1kV / s. The test results are as follows:

[0102] Table 1 Performance test of epoxy resin samples prepared in Examples 1-7 and Comparative Examples 1-4

[0103] ;

[0104] It can be seen from the test data in Table 1 that the epoxy material preparation method provided in the present application can effectively achieve the synergistic improvement of the toughness and insulation performance of the modified epoxy resin material. It can be seen from Example 1 and Comparative Examples 1-2 that the grafting of long-chain alkyl and short-chain alkyl groups on the fluorine-containing epoxy resin monomer in a specific molar ratio can simultaneously achieve the effect of toughening and enhancing the insulation performance, while the side chain grafting of a single chain length cannot meet the performance requirements. It can be seen from Example 1 and Comparative Examples 3-4 that the toughness and insulation performance of epoxy insulation materials that do not adopt a step-by-step curing system or are not grafted with side chains are significantly reduced. Examples 2-4 adjust a single variable, including the raw material ratio, side chain length and fluorine-containing structure of the modified epoxy resin monomer, while Examples 5-7 achieve a significant improvement in the insulation performance and toughness of the material by simultaneously changing multiple variables, including the variables adjusted in the above Examples 2-4 and the types of curing agents, promoters and curing systems in the preparation process of the epoxy insulation material. The mechanism for improving toughness lies in the epoxy chain extension effect generated by side-chain grafting, combined with the uniform microphase separation structure formed by the self-assembly of long alkyl side chains during the low-temperature pre-curing stage. The simultaneous improvement in insulation performance stems from the steric hindrance of short alkyl side chains, which inhibits the delocalized electron transport of the conjugated benzene ring structure and creates a synergistic effect with the charge trapping effect of fluorine atoms. Furthermore, the step-by-step curing system ensures the integrity and uniformity of the cross-linked network structure, effectively maintaining the material's intrinsic insulating strength.

[0105] Those skilled in the art will appreciate that the foregoing descriptions are merely specific embodiments of the present invention, and not exhaustive. It should be noted that numerous variations and modifications are possible for those skilled in the art, and all such variations and modifications that do not exceed the scope of the claims should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an epoxy insulation material with high toughness and high insulation strength, characterized in that: The following steps are involved: 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 terminated by a single-terminal amine; when n is an integer of 6-11, it is a long-chain alkyl group terminated by a single-terminal amine; the short-chain alkyl group terminated by a single-terminal amine and the long-chain alkyl group terminated by a single-terminal amine 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, and sequentially performing low-temperature pre-curing and high-temperature curing, wherein the temperature of the low-temperature pre-curing is controlled at 60-100° C., and the curing time is 2-6 hours; The high temperature curing temperature is controlled at 110-160°C, and the curing time is 5-20 hours; after cooling to room temperature, demoulding is carried out to obtain an epoxy insulation material with high toughness and high insulation strength.

2. The method for preparing the epoxy insulation material with high toughness and high dielectric 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 group terminated with a single-end amine and the short-chain alkyl group terminated with a single-end amine is 20:(1-2):(1-2).

3. The method for preparing the epoxy insulation material with high toughness and high dielectric strength according to claim 1 or 2, characterized in that: In step S1, a fluorine-containing epoxy resin monomer, a short-chain alkyl group terminated with a single-end amine, and a long-chain alkyl group terminated with a single-end amine 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 hours to obtain a modified epoxy monomer.

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

6. The method for preparing the epoxy insulation material with high toughness and high dielectric strength according to claim 1, 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 method for preparing the epoxy insulation material with high toughness and high dielectric 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., 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. An epoxy insulating material with high toughness and high dielectric strength obtained by the method for preparing an epoxy insulating material with high toughness and high dielectric strength according to any one of claims 1 to 7.

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