A flame-retardant high modulus, high toughness, filament winding epoxy resin composition and a method for preparing the same

Abstract

The application relates to the field of epoxy resins, in particular to a flame-retardant high-modulus and high-toughness winding epoxy resin composition and a preparation method thereof, wherein the epoxy resin composition comprises an epoxy resin A component and a curing agent B component; raw materials of the epoxy resin A component include the following components in parts by weight: an epoxy resin mixture 40-50 parts, a flame retardant 35-45 parts, a diluent 8-9 parts, a toughening agent 6-15 parts, and a surfactant 0.5-1 part; wherein the toughening agent is a mixture of core-shell rubber and CNTs in a weight ratio of (5-15):(0.2-1). The application solves the problems of the traditional epoxy resin matrix material in the aspects of high strength and toughness and flame retardancy.

Description

Technical Field

[0001] This application relates to the field of epoxy resins, and more specifically, to a flame-retardant, high-modulus, high-toughness wound epoxy resin composition and a method for preparing the same. Background Technology

[0002] With the upgrading of modern military requirements, traditional metal airborne equipment cannot meet the requirements for lightweighting due to its large weight, susceptibility to corrosion, and manufacturing defects. Composite materials, with their advantages of high specific strength, high specific modulus, and designability, have shown significant potential in improving storage reliability, launch accuracy, and battlefield adaptability, making them ideal materials for next-generation launch tubes. Resin-based composite materials with carbon fiber as reinforcement and epoxy resin as matrix have been widely used in the field of launch tube manufacturing due to their lightweight, high strength, corrosion resistance, and fatigue resistance.

[0003] In actual use, the launch tube must maintain launch accuracy and stability under extreme temperatures and launch impacts. This requires the molding material to balance good mechanical stability with certain fire resistance requirements to ensure the launch tube's battlefield adaptability and reliability throughout its life cycle. Traditional epoxy resin products suffer from low strength and poor toughness, and lack flame retardant properties, failing to meet usage requirements. Furthermore, the toughening and flame retardant modification of the matrix often comes at the cost of sacrificing mechanical strength, or maintaining mechanical strength while failing to achieve a high level of toughness, thus not meeting the molding performance requirements of the launch tube. Summary of the Invention

[0004] This application proposes a flame-retardant, high-strength, and high-toughness wound epoxy resin composition and its preparation method. It aims to solve the shortcomings of traditional epoxy resin matrix materials in terms of high strength, toughness, and flame retardancy through innovative material design and preparation process, and provide a new solution for the molding of high-performance composite material components such as launch tubes.

[0005] In a first aspect, this application provides a flame-retardant, high-strength, high-toughness wound epoxy resin composition, characterized by the following technical solution:

[0006] A flame-retardant, high-strength, high-toughness wound epoxy resin composition, comprising epoxy resin component A and curing agent component B;

[0007] The epoxy resin component A raw material comprises the following components by weight: 40-50 parts epoxy resin mixture, 35-45 parts flame retardant, 8-9 parts diluent, 6-15 parts toughening agent, and 0.5-1 part surfactant.

[0008] The toughening agent is a mixture of core-shell rubber and CNTs in a weight ratio of (5-15):(0.2-1), wherein the CNTs are single-walled carbon nanotubes, the dispersion medium is ethoxylated alcohol, the effective content is >80wt%, the carbon nanotube length is 5-10μm, and the diameter is 1.5-2.0nm; the core-shell rubber is at least one of MX-150, MX-154, and MX-160, and the particle size is 100-200nm.

[0009] The raw materials of component B of the curing agent include the following components by weight: 97-100 parts of acid anhydride curing agent and 1-2 parts of accelerator.

[0010] Furthermore, the epoxy resin mixture includes one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and multifunctional epoxy resin.

[0011] Furthermore, the bisphenol A type epoxy resin includes at least one of E-51, E-54, E-44, E-20, and E-12, the bisphenol F type epoxy resin includes NPEF-170, and the multifunctional epoxy resin includes at least one of AG-80, AFG-90, and TDE-85.

[0012] Furthermore, the flame retardant is a brominated epoxy resin with a bromine content of 46-50%.

[0013] Further, the diluent is one or a mixture of several of the following: monofunctional epoxy reactive diluents, difunctional epoxy reactive diluents, and multifunctional epoxy reactive diluents. Even further, the diluent is one or a mixture of several of the following: 12-14 alkyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether.

[0014] Furthermore, the surfactant is one or a mixture of several of BYK-A530, BYK-9920, and KH550.

[0015] Furthermore, the anhydride curing agent is one or a mixture of several of methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, and methylnadic anhydride.

[0016] Further, the accelerator is one or a mixture of several imidazoles or tertiary amines. Even further, the accelerator is one or a mixture of several benzylammonium chloride, benzyldimethylamine, N,N-dimethylbenzylamine, 1-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, and derivatives of such imidazoles.

[0017] Secondly, this application provides a method for preparing a flame-retardant, high-strength, high-toughness wound epoxy resin composition, using the following technical solution:

[0018] A method for preparing a flame-retardant, high-strength, high-toughness wound epoxy resin composition includes the following steps:

[0019] Preparation of component A of the epoxy resin system: A portion of epoxy resin, surfactant, and CNTs are dispersed at high speed in a reactor at 80±10℃ for 2-3 hours at a dispersion speed of 1500-2000 rad / min; then the temperature is raised to 120±5℃, a portion of epoxy resin and flame retardant are added, the dispersion speed is adjusted to 100-200 rad / min, and the temperature is maintained for 1.5-2.5 hours; the temperature is lowered to 70±10℃, the remaining epoxy resin, diluent, and core-shell rubber are added, and the mixture is stirred at a speed of 200-300 rad / min for 1-2 hours, and then cooled to room temperature to obtain component A;

[0020] Preparation of component B of epoxy resin system: The anhydride curing agent and accelerator are stirred thoroughly at 35-55℃ for 30-40 min according to the weight ratio; the temperature is then lowered to 25-35℃ to obtain component B;

[0021] Mixing component A and component B in a specific mass ratio yields an epoxy resin composition suitable for preparing launch tubes using a winding process.

[0022] In summary, this application has the following beneficial effects:

[0023] (1) The epoxy resin system material prepared in this application is suitable for the launch tube winding molding process and can be wound quickly at 25-45℃. The cured product of this system material has a Tg ≥ 130℃, tensile strength ≥ 80MPa, tensile modulus ≥ 3.4GPa, elongation at break ≥ 4%, flame retardant rating up to UL-94V0, and a pot life of 6-12h, which meets the performance requirements of launch tube molding.

[0024] (2) This application adopts a synergistic reinforcement and toughening method of core-shell rubber and CNTs. During the resin curing process, the rubber particles exhibit an "island"-like microphase separation structure. When the material is subjected to external force, the rubber particles can induce local plastic deformation and absorb a large amount of energy, thereby hindering the propagation of cracks. Due to their large specific surface area and surface roughness, CNTs can enhance the interlaminar crack resistance between resin and fiber or between fibers in the composite material through mechanical interlocking effect, thereby improving the strength and toughness of the product. The synergy of the two can achieve the simultaneous improvement of the toughness and strength of the resin system. Furthermore, this application uses a specified type of core-shell rubber and a specified type of carbon nanotube as a toughening agent, so that the "island"-like microphase separation structure of the core-shell rubber and the mechanical interlocking effect of carbon nanotubes achieve dynamic balance and full coordination in the epoxy resin system of this application, effectively improving the toughness and strength of the resin system.

[0025] (3) The raw materials of this application are readily available, the process is simple, the cost is low, the safety is high, and it is suitable for process promotion. Detailed Implementation

[0026] The present application will be further described in detail below with reference to the embodiments.

[0027] Example

[0028] This application first provides a flame-retardant, high-strength, high-toughness wound epoxy resin composition, comprising epoxy resin component A and curing agent component B in a weight ratio of 100:(80-85);

[0029] The epoxy resin component A raw material includes the following components by weight: 40-50 parts epoxy resin mixture, 35-45 parts flame retardant, 8-9 parts diluent, 6-15 parts toughening agent, and 0.5-1 part surfactant.

[0030] The epoxy resin mixture includes one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and multifunctional epoxy resin. Preferably, the bisphenol A type epoxy resin includes at least one of E-51, E-54, E-44, E-20, and E-12, the bisphenol F type epoxy resin includes NPEF-170, and the multifunctional epoxy resin includes at least one of AG-80, AFG-90, and TDE-85.

[0031] The toughening agent is a mixture of core-shell rubber and CNTs in a weight ratio of (5-15):(0.2-1). The CNTs are single-walled carbon nanotubes, the dispersion medium is ethoxylated alcohol, the effective content is >80wt%, the carbon nanotubes are 5-10μm in length and 1.5-2.0nm in diameter; the core-shell rubber is at least one of MX-150, MX-154, and MX-160, with a particle size of 100-200nm.

[0032] The flame retardant is a brominated epoxy resin with a bromine content of 46-50%.

[0033] The diluent is one or a mixture of several of the following: monofunctional epoxy reactive diluents, difunctional epoxy reactive diluents, and multifunctional epoxy reactive diluents. Preferably, the diluent used in the embodiments of this application is one or a mixture of several of the following: 12-14 alkyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether.

[0034] The surfactant is one or a mixture of several of BYK-A530, BYK-9920, and KH550.

[0035] The curing agent component B raw material includes the following components by weight: 97-100 parts of acid anhydride curing agent and 1-2 parts of accelerator.

[0036] The anhydride curing agent is one or a mixture of several of methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, and methylnadic anhydride.

[0037] The accelerator is one or a mixture of several imidazoles or tertiary amines. Preferably, the accelerator used in this embodiment is one or a mixture of several benzylammonium chloride, benzyldimethylamine, N,N-dimethylbenzylamine, 1-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, and derivatives of such imidazoles.

[0038] This application also provides a method for preparing a flame-retardant, high-strength, high-toughness wound epoxy resin composition, comprising the following steps:

[0039] Preparation of component A of the epoxy resin system: A portion of epoxy resin, surfactant, and CNTs are dispersed at high speed in a reactor at 80±10℃ for 2-3 hours at a dispersion speed of 1500-2000 rad / min; then the temperature is raised to 120±5℃, a portion of epoxy resin and flame retardant are added, the dispersion speed is adjusted to 100-200 rad / min, and the temperature is maintained for 1.5-2.5 hours; the temperature is lowered to 70±10℃, the remaining epoxy resin, diluent, and core-shell rubber are added, and the mixture is stirred at a speed of 200-300 rad / min for 1-2 hours, and then cooled to room temperature to obtain component A;

[0040] Preparation of component B of epoxy resin system: The anhydride curing agent and accelerator are stirred thoroughly at 35-55℃ for 30-40 min according to the weight ratio; the temperature is then lowered to 25-35℃ to obtain component B;

[0041] Mixing component A and component B in a specific mass ratio yields an epoxy resin composition suitable for preparing launch tubes using a winding process.

[0042] Specifically, the preparation method of the flame-retardant high-strength, high-toughness wound epoxy resin composition in Examples 1-5 of this application includes the following steps:

[0043] Preparation of component A of the epoxy resin system: A portion of epoxy resin, surfactant, and CNTs were dispersed at high speed in a reactor at 80±10℃ for 2.5h at a dispersion speed of 1800rad / min; then the temperature was raised to 120±5℃, a portion of epoxy resin and flame retardant were added, the dispersion speed was adjusted to 180rad / min, and the temperature was maintained for 2h; the temperature was lowered to 70±10℃, the remaining epoxy resin, diluent, and core-shell rubber were added, and the mixture was stirred at a speed of 280rad / min for 2h, and then cooled to room temperature to obtain component A;

[0044] Preparation of component B of epoxy resin system: The anhydride curing agent and accelerator are stirred thoroughly at 35-55℃ for 40 min according to the weight ratio; the temperature is then lowered to 25-35℃ to obtain component B.

[0045] The following explanation is provided through specific examples.

[0046] Example 1

[0047] This embodiment provides a flame-retardant, high-strength, and high-toughness wound epoxy resin composition, which is divided into epoxy resin component A and curing agent component B, with a weight ratio of epoxy resin component A to curing agent component B of 100:85.

[0048] The epoxy resin component A raw material includes the following components by weight: 40 parts epoxy resin mixture, 40 parts flame retardant, 8 parts diluent, 15 parts toughening agent, and 0.5 parts surfactant.

[0049] The raw materials of curing agent component B include the following components by weight: 40 parts of methyltetrahydrophthalic anhydride, 57 parts of methylhexahydrophthalic anhydride, and 2 parts of N,N-dimethylbenzylamine.

[0050] The epoxy resin mixture consists of 32 parts of epoxy resin E54 and 8 parts of AFG90.

[0051] The toughening agent is a mixture of core-shell rubber and CNTs in a mass ratio of (14.8):(0.2); the polybutadiene-polymethyl methacrylate core-shell toughening agent is specifically MX-160;

[0052] The diluent is 1,4-butanediol diglycidyl ether, and the surfactant is BYK-A530.

[0053] Example 2

[0054] This embodiment provides a flame-retardant, high-strength, and high-toughness wound epoxy resin composition, which is divided into epoxy resin component A and curing agent component B, with a weight ratio of epoxy resin component A to curing agent component B of 100:85.

[0055] The epoxy resin component A raw material includes the following components by weight: 50 parts epoxy resin mixture, 35 parts flame retardant, 9 parts diluent, 6 parts toughening agent, and 1 part surfactant.

[0056] The raw materials of component B of the curing agent include the following components by weight: 60 parts of methyltetrahydrophthalic anhydride, 39 parts of methylnadic anhydride, and 1 part of 2-ethyl-4-methylimidazole.

[0057] The epoxy resin mixture consists of 34 parts of E54, 9 parts of TDE-85, and 7 parts of E20.

[0058] The toughening agent is a mixture of core-shell rubber and CNTs in a mass ratio of (5):(1); the core-shell toughening agent is specifically MX150;

[0059] The diluent is 1,4-butanediol diglycidyl ether, and the surfactants are 0.5 parts of BYK-9920 and 0.5 parts of KH550.

[0060] Example 3

[0061] This embodiment provides a flame-retardant, high-strength, and high-toughness wound epoxy resin composition, which is divided into epoxy resin component A and curing agent component B, with a weight ratio of epoxy resin component A to curing agent component B of 100:80.

[0062] The epoxy resin component A raw material includes the following components by weight: 45 parts epoxy resin mixture, 36 parts flame retardant, 9 parts diluent, 10.5 parts toughening agent, and 1 part surfactant.

[0063] The raw materials of component B of the curing agent include the following components by weight: 80 parts of methylhexahydrophthalic anhydride, 19 parts of methylnadic anhydride, and 1 part of 2-methylimidazole.

[0064] The epoxy resin mixture consists of 36 parts of epoxy resin E54, 5 parts of AG-80, and 4 parts of E12.

[0065] The toughening agent is a mixture of core-shell rubber and CNTs in a mass ratio of (10):(0.5); the core-shell toughening agent is specifically MX154;

[0066] The diluent is C12-14 alkyl glycidyl ether, and the surfactants are 0.5 parts of BYK-9920 and 0.5 parts of KH550.

[0067] Example 4

[0068] This embodiment provides a flame-retardant, high-strength, and high-toughness wound epoxy resin composition, which is divided into epoxy resin component A and curing agent component B, with a weight ratio of epoxy resin component A to curing agent component B of 100:80.

[0069] The epoxy resin component A raw material includes the following components by weight: 40 parts epoxy resin mixture, 45 parts flame retardant, 9 parts diluent, 10.5 parts toughening agent, and 1 part surfactant.

[0070] The raw materials of component B of the curing agent include the following components by weight: 38 parts of methylhexahydrophthalic anhydride, 60 parts of methylnadic anhydride, and 1 part of 2-ethyl-4-methylimidazole.

[0071] The epoxy resin mixture consists of 40 parts of epoxy resin E54.

[0072] The toughening agent is a mixture of core-shell rubber and CNTs in a mass ratio of (10):(0.5); the core-shell toughening agent is specifically MX160;

[0073] The diluent is C12-14 alkyl glycidyl ether, and the surfactants are 0.5 parts of BYK-9920 and 0.5 parts of KH550.

[0074] Example 5

[0075] This embodiment provides a flame-retardant, high-strength, and high-toughness wound epoxy resin composition, which is divided into epoxy resin component A and curing agent component B, with a weight ratio of epoxy resin component A to curing agent component B of 100:80.

[0076] The epoxy resin component A raw material includes the following components by weight: 40-50 parts epoxy resin mixture, 40 parts flame retardant, 8 parts diluent, 11 parts toughening agent, and 1 part surfactant.

[0077] The raw materials of component B of the curing agent include the following components by weight: 80 parts of methylhexahydrophthalic anhydride, 20 parts of methylnadic anhydride, and 1 part of 1-methylimidazole.

[0078] The epoxy resin mixture consists of 50 parts of epoxy resin E54.

[0079] The toughening agent is a mixture of core-shell rubber and CNTs in a mass ratio of (10):(1); the core-shell toughening agent is specifically MX154;

[0080] The diluent is 1,4-butanediol diglycidyl ether, and the surfactants are 0.5 parts of BYK-9920 and 0.5 parts of KH550.

[0081] Comparative Example

[0082] The difference between Comparative Example 1 and Example 1 is that carbon nanotubes are replaced with an equal amount of core-shell rubber in the toughening agent.

[0083] The difference between Comparative Example 2 and Example 1 is that no core-shell rubber is added to the toughening agent.

[0084] The difference between Comparative Example 3 and Example 1 is that the core-shell rubber in the toughening agent is replaced with an equal amount of carboxyl-terminated butadiene-acrylonitrile rubber (CTBN).

[0085] The difference between Comparative Example 4 and Example 1 is that the core rubber in the toughening agent is replaced with polyether polyol HM6300.

[0086] The difference between Comparative Example 5 and Example 1 is that the carbon nanotubes in the toughening agent are multi-walled carbon nanotubes (MWNTs), with a length of 30-50 μm and a diameter of 1-8 nm.

[0087] The difference between Comparative Example 6 and Example 1 is that the toughening agent is 5 parts shell-core rubber and 2 parts CNTs.

[0088] Performance testing

[0089] The epoxy resin compositions obtained in the examples and comparative examples were subjected to performance testing, and the test results are shown in Table 1. Additionally, the epoxy resin composition obtained in Example 4 was used to prepare a composite material according to standard JC / T 773, with T700 carbon fiber, and its interlaminar shear strength was tested to be 84 MPa.

[0090] Table 1 Performance test results of the examples and comparative examples

[0091]

[0092] Firstly, based on the performance test data of Examples 1 to 5, it can be seen that the epoxy resin composition of this application has good mechanical properties, toughness and flame retardant properties, with a Tg ≥ 130℃, tensile strength ≥ 80MPa, tensile modulus ≥ 3.4GPa, elongation at break ≥ 4%, flame retardant rating up to UL-94V0, and pot life of 6-12h, meeting the performance requirements for launching tube molding.

[0093] The following analysis is made in conjunction with comparative examples regarding the superior performance obtained in this application:

[0094] Combining the performance tests of Comparative Examples 1 and 2, it can be seen that, although the Tg, flame retardancy, and pot life of Comparative Example 1 were not significantly affected due to the absence of carbon nanotubes, its mechanical properties and toughness decreased to varying degrees. Comparative Example 2, on the other hand, suffered a significant decrease in toughness and mechanical properties due to the lack of core-shell rubber. Generally, rubber-like substances primarily improve toughness but have a negative impact on mechanical properties. The decrease in mechanical properties observed in Comparative Example 2 indicates that simply using carbon nanotubes cannot improve the mechanical properties of the resin system in this application. This demonstrates that in the toughening agent system, the synergistic effect of carbon nanotubes and core-shell rubber is necessary for the resin to possess both good mechanical properties and toughness.

[0095] To further analyze the synergistic effect of carbon nanotubes and core-shell rubber, the performance of Comparative Examples 3-5 was analyzed. Comparative Example 3 used other types of rubber, Comparative Example 4 used other types of toughening agents, and Comparative Example 5 used carbon nanotubes of different sizes and morphologies. It is evident that neither other types of rubber nor toughening agents can achieve the same effect as in this application. Furthermore, the use of carbon nanotubes of different morphologies and sizes cannot improve the performance of the resin system in this application. This is because the core-shell rubber and carbon nanotubes used in this application achieve a synergistic effect between the "island"-like microphase separation structure of the core-shell rubber and the mechanical locking effect of the carbon nanotubes. They achieve dynamic equilibrium and full coordination in the epoxy resin system of this application, effectively improving the toughness and strength of the resin system. Additionally, based on the performance of Comparative Example 6, the ratio of the amounts of carbon nanotubes and core-shell rubber used in this application is also crucial in the synergistic effect process.

[0096] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A flame-retardant, high-strength, high-toughness wound epoxy resin composition, characterized in that, Includes epoxy resin component A and curing agent component B; The epoxy resin component A raw material comprises the following components by weight: 40-50 parts epoxy resin mixture, 35-45 parts flame retardant, 8-9 parts diluent, 6-15 parts toughening agent, and 0.5-1 part surfactant. The toughening agent is a mixture of core-shell rubber and CNTs in a weight ratio of (5~15):(0.2~1), wherein the CNTs are single-walled carbon nanotubes, the dispersion medium is ethoxylated alcohol, the effective content is >80wt%, the carbon nanotube length is 5-10μm, and the diameter is 1.5~2.0 nm; the core-shell rubber is at least one of MX-150, MX-154, and MX-160, and the particle size is 100-200nm; The raw material of component B of the curing agent includes the following components by weight: 97-100 parts of acid anhydride curing agent and 1-2 parts of accelerator; The prepared wound epoxy resin system material is suitable for the launch tube winding molding process.

2. The flame-retardant, high-strength, high-toughness wound epoxy resin composition according to claim 1, characterized in that, The epoxy resin mixture includes one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and multifunctional epoxy resin.

3. The flame-retardant, high-strength, high-toughness wound epoxy resin composition according to claim 2, characterized in that, The bisphenol A type epoxy resin includes at least one of E-51, E-54, E-44, E-20, and E-12; the bisphenol F type epoxy resin includes NPEF-170; and the multifunctional epoxy resin includes at least one of AG-80, AFG-90, and TDE-85.

4. The flame-retardant, high-strength, high-toughness wound epoxy resin composition according to claim 1, characterized in that, The flame retardant is a brominated epoxy resin with a bromine content of 46-50%.

5. The flame-retardant, high-strength, high-toughness wound epoxy resin composition according to claim 1, characterized in that, The diluent is one or a mixture of several of the following: monofunctional epoxy reactive diluents, difunctional epoxy reactive diluents, and multifunctional epoxy reactive diluents.

6. The flame-retardant, high-strength, high-toughness wound epoxy resin composition according to claim 1, characterized in that, The surfactant is one or a mixture of several of BYK-A530, BYK-9920, and KH550.

7. The flame-retardant, high-strength, high-toughness wound epoxy resin composition according to claim 1, characterized in that, The anhydride curing agent is one or a mixture of several of methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, and methylnadic anhydride.

8. The flame-retardant, high-strength, high-toughness wound epoxy resin composition according to claim 1, characterized in that, The promoter is one or a mixture of several imidazoles or tertiary amines.

9. A method for preparing a flame-retardant, high-strength, high-toughness wound epoxy resin composition as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Preparation of component A of the epoxy resin system: A portion of epoxy resin, surfactant, and CNTs were dispersed at high speed in a reactor at 80±10℃ for 2-3 hours at a dispersion speed of 1500-2000 rad / min; then the temperature was raised to 120±5℃, a portion of epoxy resin and flame retardant were added, the dispersion speed was adjusted to 100-200 rad / min, and the temperature was maintained for 1.5-2.5 hours; the temperature was lowered to 70±10℃, the remaining epoxy resin, diluent, and core-shell rubber were added, and the mixture was stirred at a speed of 200-300 rad / min for 1-2 hours, and then cooled to room temperature to obtain component A; Preparation of component B of epoxy resin system: The anhydride curing agent and accelerator are stirred thoroughly at 35~55℃ for 30~40min according to the weight parts; then cooled to 25~35℃ to obtain component B; Mixing component A and component B in a specific mass ratio yields an epoxy resin composition suitable for preparing launch tubes using a winding process.

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