Epoxy resin composition, epoxy resin material, and preparation method and application thereof

Abstract

This invention relates to the field of epoxy resins, and discloses an epoxy resin composition, epoxy resin material, its preparation method, and its application. The composition comprises 40-60 parts by weight of glycidyl amine epoxy resin, 10-20 parts by weight of polyenol acetal, 15-45 parts by weight of phenolic epoxy resin, 10-40 parts by weight of phosphorus-containing flame retardant, 1-5 parts by weight of carbon nanotubes, 1-10 parts by weight of curing agent, and 1-10 parts by weight of curing accelerator; the curing agent is a latent curing agent. The epoxy resin composition and epoxy resin material provided by this invention have excellent flame retardant properties, as well as good mechanical and thermal properties.

Description

Technical Field

[0001] This invention relates to the field of epoxy resins, specifically to an epoxy resin composition, epoxy resin materials, their preparation methods, and applications. Background Technology

[0002] Epoxy resin possesses excellent mechanical properties, good adhesion, and strong process adaptability, making it the most widely used and applied resin matrix in high-performance composite materials. However, epoxy resin is flammable and can continue to burn even after the ignition source has been removed, increasing the risk of fire.

[0003] The main way to improve fire resistance in the prior art is to add flame retardants to the epoxy resin system. For example, CN202311836551.7 provides an epoxy resin composition for prepreg, which uses a phosphorus-containing flame retardant, benzoxazine resin and inorganic filler to obtain a flame retardant resin system. However, due to the poor compatibility of inorganic fillers and the high curing temperature of benzoxazine resin, the fluidity of the resin system is reduced, which seriously affects the processability of the substrate and downstream applications. To address the issues of poor dispersion and easy agglomeration of flame retardants in epoxy resins, existing technologies have conducted extensive modification studies. CN202210801138.6 discloses a flame retardant and its preparation method, which involves coating the surface of zinc metaborate doped with anionic surfactants to reduce the polarity of the doped zinc metaborate and improve its compatibility with the polymer resin. CN202011350705.8 uses piperazine phosphate, melamine and its derivatives as halogen-free flame retardants, and adds metal salt flame retardant synergists, superdispersants, and low-melting-point lubricating flame retardant additives to improve compatibility and dispersibility in the resin. However, due to the poor compatibility of the modified system with carbon fiber, and the unavoidable excessive addition of solid powder to ensure flame retardant performance, the mechanical properties of the composite material, especially its toughness, are significantly reduced.

[0004] In summary, existing technologies cannot resolve the contradiction between the flame retardancy, processability, and mechanical properties of epoxy resins through a single approach. Summary of the Invention

[0005] To overcome the problem of poor overall performance of existing epoxy resin systems, particularly the contradiction between processability, mechanical properties, and flame retardant properties, this invention provides an epoxy resin composition, epoxy resin material, its preparation method, and its applications. The epoxy resin composition and epoxy resin material provided by this invention exhibit excellent flame retardant properties, along with good mechanical and thermal properties.

[0006] The first aspect of the present invention provides an epoxy resin composition comprising 40-60 parts by weight of glycidyl amine epoxy resin, 10-20 parts by weight of polyenol acetal, 15-45 parts by weight of phenolic epoxy resin, 10-40 parts by weight of phosphorus-containing flame retardant, 1-5 parts by weight of carbon nanotubes, 1-10 parts by weight of curing agent and 1-10 parts by weight of curing accelerator.

[0007] The curing agent is a latent curing agent.

[0008] A second aspect of the present invention provides a method for preparing epoxy resin materials using the composition provided in the first aspect of the present invention, comprising the following steps:

[0009] S1. Mix glycidyl amine epoxy resin, polyenol acetal, phenolic epoxy resin, phosphorus-containing flame retardant and carbon nanotubes.

[0010] S2. Mix the mixture obtained in S1 with a curing agent and a curing accelerator to obtain an epoxy resin system;

[0011] S3. Curing the epoxy resin system to obtain epoxy resin material.

[0012] A third aspect of the present invention provides an epoxy resin material prepared according to the method provided in the second aspect of the present invention.

[0013] The fourth aspect of the present invention provides an application of the epoxy resin material provided in the third aspect of the present invention in rail transit.

[0014] The epoxy resin composition provided by this invention has good compatibility among its components, and the cured epoxy resin material has good mechanical and thermal properties. Furthermore, through the phosphorus-nitrogen synergistic flame retardant effect, it achieves excellent flame retardant performance with the addition of a small amount of flame retardant, and can pass the UL-94 V-0 rating test.

[0015] Furthermore, the present invention, through the synergistic effect of dicyandiamide with urea-based accelerators and imidazole-based accelerators, enables the epoxy resin system to have good latency, long shelf life, short curing time, and high processing efficiency, making it suitable for use in prepregs. Detailed Implementation

[0016] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0017] The first aspect of the present invention provides an epoxy resin composition comprising 40-60 parts by weight of glycidyl amine epoxy resin, 10-20 parts by weight of polyenol acetal, 15-45 parts by weight of phenolic epoxy resin, 10-40 parts by weight of phosphorus-containing flame retardant, 1-5 parts by weight of carbon nanotubes, 1-10 parts by weight of curing agent and 1-10 parts by weight of curing accelerator.

[0018] The curing agent is a latent curing agent.

[0019] In this invention, when the specific types and proportions of each component in the epoxy resin composition are within the above-mentioned range, the glycidyl amine epoxy resin contains multiple epoxy groups and aromatic rings, which can increase the crosslinking density and aromatic density of the epoxy resin material, thereby improving the mechanical strength and heat resistance of the epoxy resin material; the phenolic epoxy resin also contains multiple epoxy groups and aromatic rings, and crosslinks with the glycidyl amine epoxy resin, which can further improve the mechanical and thermal properties of the epoxy resin material; the latent curing agent can extend the storage period and operating time of the composition at room temperature.

[0020] Through the synergistic flame retardant effect of phosphorus and nitrogen, excellent flame retardant performance can be achieved with the addition of a small amount of flame retardant, and it can pass the UL-94 V-0 rating test.

[0021] According to a preferred embodiment of the present invention, the composition comprises 45-55 parts by weight of glycidyl amine epoxy resin, 10-15 parts by weight of polyenol acetal, 25-35 parts by weight of phenolic epoxy resin, 20-30 parts by weight of phosphorus-containing flame retardant, 1-2 parts by weight of carbon nanotubes, 5-10 parts by weight of curing agent and 1-4 parts by weight of curing accelerator.

[0022] In this invention, when the specific types and proportions of each component in the epoxy resin composition are within the above-mentioned range, the mechanical properties, thermal properties, and flame retardant properties of the epoxy resin material can be further improved.

[0023] According to the present invention, preferably, the mass ratio of the glycidylamine epoxy resin and the phenolic epoxy resin is 1:0.3-1.

[0024] In this invention, when the mass ratio of glycidylamine epoxy resin and phenolic epoxy resin in the epoxy resin composition is within the above-mentioned range, the epoxy resin material has better mechanical and thermal properties.

[0025] According to the present invention, preferably, the mass ratio of the curing agent to the curing accelerator is 1:0.2-1.

[0026] In this invention, when the mass ratio of curing agent to curing accelerator is within the above-mentioned range, the mechanical and thermal properties of epoxy resin materials can be further improved.

[0027] This invention does not particularly limit the specific type of glycidyl amine epoxy resin, and those skilled in the art can choose conventionally. According to a preferred embodiment of the invention, the glycidyl amine epoxy resin has a dynamic viscosity of 6000-10000 cP at 25°C.

[0028] According to the present invention, preferably, the glycidyl amine epoxy resin has a structure as shown in Formula I.

[0029]

[0030] R1-R4 are each independently selected from C2-C6 epoxy groups.

[0031] In this invention, when the glycidylamine epoxy resin has the above-mentioned structure, the epoxy resin material has better mechanical and thermal properties.

[0032] This invention does not particularly limit the specific type of phenolic epoxy resin, and those skilled in the art can choose it conventionally. According to a preferred embodiment of the invention, the softening point of the phenolic epoxy resin is 25-40°C.

[0033] In this invention, the softening point is the Vicat softening temperature, referring to B in GB / T 1633-2000. 50 The initial temperature was 20℃, as determined by the method.

[0034] According to the present invention, preferably, the phenolic epoxy resin has a structure as shown in Formula II.

[0035]

[0036] Wherein, R' is independently selected from C1-C4 alkyl groups, and n is an integer from 0 to 6.

[0037] In this invention, when the phenolic epoxy resin has the above-mentioned structure, the epoxy resin material has better mechanical and thermal properties.

[0038] The present invention does not particularly limit the specific type of polyenol acetal, and those skilled in the art can choose conventionally. According to a preferred embodiment of the present invention, the polyenol acetal is selected from at least one of polyvinyl alcohol formaldehyde, polyvinyl alcohol acetal, polyvinyl alcohol propionate, and polyvinyl alcohol butyral, preferably polyvinyl alcohol butyral.

[0039] In this invention, when the polyenol acetal is polyvinyl butyral, the epoxy resin material has better mechanical and thermal properties.

[0040] According to the present invention, preferably, the weight-average molecular weight of polyenol acetal is 3000-4000 g / mol.

[0041] According to a preferred embodiment of the present invention, the phosphorus-containing flame retardant comprises a first phosphorus-containing flame retardant and a second phosphorus-containing flame retardant;

[0042] The first phosphorus-containing flame retardant contains organic phosphorus;

[0043] The second phosphorus-containing flame retardant includes phosphazene flame retardants;

[0044] In this invention, when the phosphorus-containing flame retardant includes the two specific types mentioned above, the epoxy resin material exhibits better flame retardancy.

[0045] According to the present invention, preferably, the composition comprises 10-20 parts by weight of a first phosphorus-containing flame retardant and 10-20 parts by weight of a second phosphorus-containing flame retardant.

[0046] In this invention, when the ratio of the two phosphorus-containing flame retardants is within the above-mentioned range, the flame retardancy of the epoxy resin material can be further improved.

[0047] According to the present invention, preferably, the mass ratio of the first phosphorus-containing flame retardant and the second phosphorus-containing flame retardant is 1:0.5-2, more preferably 1:0.6-1.5.

[0048] In this invention, when the mass ratio of the first phosphorus-containing flame retardant and the second phosphorus-containing flame retardant meets the above-mentioned range, the flame retardancy of the epoxy resin material can be further improved.

[0049] According to the present invention, preferably, the first phosphorus-containing flame retardant comprises a phosphate ester, more preferably a bisphenol A-modified phosphate ester.

[0050] According to the present invention, preferably, the second phosphorus-containing flame retardant comprises at least one of polydiphenoxyphosphazene, hexaphenoxycyclotriphosphazene, and ethoxy(pentafluoro)cyclotriphosphazene.

[0051] In this invention, when the phosphorus-containing flame retardant belongs to the specific type described above, the epoxy resin material provided by this invention has better flame retardancy.

[0052] According to a preferred embodiment of the present invention, the curing agent is dicyandiamide (DICY).

[0053] According to the present invention, preferably, the average particle size of dicyandiamide is 3-10 nm;

[0054] According to a preferred embodiment of the present invention, the curing accelerator comprises urea accelerators and imidazole accelerators.

[0055] The inventors of this invention have discovered that the synergistic use of dicyandiamide with urea-based accelerators and imidazole-based accelerators can further improve the latency of epoxy resin systems, extend their shelf life at room temperature, and further increase the curing speed of epoxy resin systems at high temperatures.

[0056] According to the present invention, preferably, the mass ratio of urea accelerator to imidazole accelerator is 1:0.3-1.0.

[0057] In this invention, when the mass ratio of urea-based accelerators to imidazole-based accelerators is within the above-mentioned range, the latency of the epoxy resin system and the curing speed of the epoxy resin system at high temperatures can be further improved. This invention does not particularly limit the specific type of carbon nanotubes; those skilled in the art can choose conventionally. According to a preferred embodiment of this invention, the carbon nanotubes are hydroxylated multi-walled carbon nanotubes.

[0058] According to the present invention, preferably, the carbon nanotubes are hydroxylated multi-walled carbon nanotubes modified with epoxy groups.

[0059] According to the present invention, preferably, the carbon nanotubes have a diameter of 20-30 nm and a length of 10-30 μm.

[0060] The second invention of the inventors provides a method for preparing epoxy resin materials using the composition provided in the first aspect of the invention, comprising the following steps:

[0061] S1. Mix glycidyl amine epoxy resin, polyenol acetal, phenolic epoxy resin, phosphorus-containing flame retardant and carbon nanotubes.

[0062] S2. Mix the mixture obtained in S1 with a curing agent and a curing accelerator to obtain an epoxy resin system;

[0063] S3. Curing the epoxy resin system to obtain epoxy resin material.

[0064] According to a preferred embodiment of the present invention, the curing conditions include: a temperature of 100-150°C, preferably 120-140°C; and a curing time of 60-240 min, preferably 120-180 min.

[0065] The present invention does not impose any particular limitation on the mixing conditions in S1 and S2, and those skilled in the art can make conventional choices.

[0066] According to the present invention, preferably, the mixing temperature in S1 is 110-150°C and the time is 120-240 min.

[0067] According to the present invention, preferably, the mixing temperature in S2 is 70-90°C and the mixing time is 60-120 min.

[0068] A third aspect of the present invention provides an epoxy resin material prepared according to the method provided in the second aspect of the present invention.

[0069] The fourth aspect of the present invention provides an application of the epoxy resin material provided in the third aspect of the present invention in rail transit.

[0070] According to a particularly preferred embodiment of the present invention, the composition comprises, by weight, 45-55 parts of glycidyl amine epoxy resin, 10-15 parts of polyenol acetal, 25-35 parts of phenolic epoxy resin, 20-30 parts of phosphorus-containing flame retardant, 1-2 parts of carbon nanotubes, 5-10 parts of curing agent and 1-4 parts of accelerator.

[0071] The mass ratio of the glycidylamine epoxy resin and the phenolic epoxy resin is 1:0.3-1.

[0072] The mass ratio of the curing agent to the curing accelerator is 1:0.2-1.

[0073] The glycidyl amine epoxy resin has a dynamic viscosity of 6000-10000 cP at 25°C.

[0074] The phenolic epoxy resin is a semi-solid product with a softening point of 25-40℃.

[0075] The polyenol acetal has a weight-average molecular weight of 3000-4000 g / mol.

[0076] The phosphorus-containing flame retardant comprises 10-20 parts of a first phosphorus-containing flame retardant and 10-20 parts of a second phosphorus-containing flame retardant, with a mass ratio of 1:0.6-1.5.

[0077] The first phosphorus-containing flame retardant comprises a phosphate ester, more preferably a bisphenol A-modified phosphate ester.

[0078] The second phosphorus-containing flame retardant comprises at least one of polydiphenoxyphosphazene, hexaphenoxycyclotriphosphazene, and ethoxy(pentafluoro)cyclotriphosphazene.

[0079] The curing agent is dicyandiamide, and the average particle size of dicyandiamide is 3-10 nm.

[0080] The curing accelerator includes urea-based accelerators and imidazole-based accelerators.

[0081] The mass ratio of urea accelerators to imidazole accelerators is 1:0.3-1.0.

[0082] The above composition was used to prepare an epoxy resin material according to the following method:

[0083] S1. Mix glycidyl amine epoxy resin, polyenol acetal, phenolic epoxy resin, phosphorus-containing flame retardant and carbon nanotubes.

[0084] S2. Mix the mixture obtained in S1 with a curing agent and a curing accelerator to obtain an epoxy resin system;

[0085] S3. Curing the epoxy resin system to obtain epoxy resin material.

[0086] The mixing temperature in S1 is 110-150℃, and the mixing time is 120-240 min.

[0087] The mixing temperature in S2 is 70-90℃, and the mixing time is 60-120 min.

[0088] The curing temperature of S3 is 120-140℃; the curing time is 120-180min.

[0089] The present invention will be described in detail below through embodiments:

[0090] In the following embodiments, unless otherwise specified, all parts refer to parts by weight.

[0091] Glass transition temperature T g The temperature was measured using a differential scanning calorimeter (DSC) at a rate of 10℃ / min, with a test temperature range of 50-300℃.

[0092] The mechanical properties were measured using an electronic universal testing machine. The tensile test was performed according to GB / T 1447-2005 at a test rate of 2 mm / min; the bending test was performed according to GB / T 1449-2005 at a test rate of 2 mm / min.

[0093] Flame retardant properties were measured using a horizontal and vertical combustion tester, in accordance with GB / T 2406.2-2009.

[0094] All reagents were commercially available, specifically:

[0095] The glycidylamine epoxy resins were purchased from Hubei Zhenzhengfeng New Material Co., Ltd., with the grades MF4101H and MF4115. The main component of both is 4,4-diaminodiphenylmethane tetraglycidylamine. The dynamic viscosity of MF4101H at 50℃ is 4000-5000 cP, and the dynamic viscosity of MF4115 at 25℃ is 8000-10000 cP.

[0096] Phenolic epoxy resins were purchased from Hubei Zhenzhengfeng New Materials Co., Ltd., with grades MF3038 (softening point 25-30℃) and MF3051 (softening point 30-40℃).

[0097] PVB was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with a weight-average molecular weight of 3500 g / mol.

[0098] DICY was purchased from Lepcu HS5850 by Lepcu Advanced Materials (Shanghai) Co., Ltd., with an average particle size of 10 μm.

[0099] Urea accelerators were purchased from Complex High-Tech Materials (Shanghai) Co., Ltd., brand name LepcuHUA5050, with an average particle size of 10μm;

[0100] The modified imidazole was purchased from Complex High-Tech Materials (Shanghai) Co., Ltd., brand name LepcuHD2004;

[0101] Bisphenol A bis(diphenyl) phosphate (BDP) was purchased from Zhangjiagang Yarui Chemical Co., Ltd., and its dynamic viscosity at 40°C was 1800-2600 cP.

[0102] Hexaphenoxycyclotriphosphazene was purchased from Aladdin, with a phosphorus content of 13 wt% and a nitrogen content of 13 wt%.

[0103] The polydiphenoxyphosphazene was purchased from Hubei Yongkuo Technology Co., Ltd., with a phosphorus content of 13 wt% and a nitrogen content of 7 wt%.

[0104] Flame retardant XP701 was purchased from Zibo Kesiwei Flame Retardant Technology Co., Ltd. It is a phosphorus / nitrogen-based organic flame retardant with a phosphorus content of 20wt% and a nitrogen content of 45wt%.

[0105] Hydroxylated multi-walled carbon nanotubes were purchased from Complex High-Tech Materials (Shanghai) Co., Ltd., with the grade XFM20, a diameter of 20-30 nm and a length of 10-30 nm.

[0106] Examples 1-13

[0107] (1) Glycidyl amine epoxy resin, polyenol acetal, phenolic epoxy resin, phosphorus-containing flame retardant and carbon nanotubes are first mixed.

[0108] (2) Add the curing agent and curing accelerator to the above mixture for a second mixing to obtain an epoxy resin system;

[0109] (3) Curing the epoxy resin system to obtain epoxy resin material.

[0110] The raw material composition of the above embodiments is shown in Tables 1-3, and the process conditions are shown in Table 4.

[0111] Table 1

[0112]

[0113] Table 2

[0114]

[0115] Table 3

[0116]

[0117]

[0118] Table 4

[0119]

[0120] Example 14

[0121] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that 8 parts of diaminodiphenyl sulfone (DDS) were added, and DICY was not added.

[0122] Comparative Example 1

[0123] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that 80 parts of general-purpose epoxy resin E51 were added, and glycidyl amine epoxy resin and phenolic epoxy resin were not added.

[0124] Comparative Example 2

[0125] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that PVB was not added.

[0126] Comparative Example 3

[0127] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that 35 parts of MF4101H were added.

[0128] Comparative Example 4

[0129] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that 65 parts of MF4101H were added.

[0130] Comparative Example 5

[0131] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that 30 parts of PVB were added.

[0132] Comparative Example 6

[0133] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that 50 parts of MF3051 were added.

[0134] Comparative Example 7

[0135] Epoxy resin materials were prepared using the same raw material composition and process conditions as in Example 1, except that 20 parts of DICY were added.

[0136] Test case

[0137] The performance of the epoxy resin systems and epoxy resin materials of the above embodiments and comparative examples was tested according to the test methods described in the Detailed Description of the Invention, and the results are shown in Table 5.

[0138] Table 5

[0139]

[0140] The results of the above embodiments and comparative examples show that the epoxy resin material obtained by using the technical solution of the present invention has good flame retardant properties, strength, and heat resistance. The epoxy resin material obtained by the preferred embodiment has high comprehensive performance, and can achieve good flame retardant properties while also taking into account tensile strength, flexural strength, elongation at break, and glass transition temperature.

[0141] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An epoxy resin composition, characterized by comprising: The composition comprises 40-60 parts by weight of glycidyl amine epoxy resin, 10-20 parts by weight of polyenol acetal, 15-45 parts by weight of phenolic epoxy resin, 10-40 parts by weight of phosphorus-containing flame retardant, 1-5 parts by weight of carbon nanotubes, 1-10 parts by weight of curing agent and 1-10 parts by weight of curing accelerator. The curing agent is a latent curing agent.

2. The composition of claim 1, wherein, The composition comprises 45-55 parts by weight of glycidyl amine epoxy resin, 10-15 parts by weight of polyenol acetal, 25-35 parts by weight of phenolic epoxy resin, 20-30 parts by weight of phosphorus-containing flame retardant, 1-2 parts by weight of carbon nanotubes, 5-10 parts by weight of curing agent and 1-4 parts by weight of curing accelerator. Preferably, the mass ratio of the glycidylamine epoxy resin to the phenolic epoxy resin is 1:0.3-1; Preferably, the mass ratio of the curing agent to the curing accelerator is 1:0.2-1.

3. The composition according to claim 1 or 2, characterized in that, The glycidyl amine epoxy resin has a dynamic viscosity of 6000-10000 CP at 25°C. Preferably, the glycidyl amine epoxy resin has the structure shown in Formula I. R1-R4 are each independently selected from C2-C6 epoxy groups.

4. The composition according to any one of claims 1 to 3, characterized in that, The softening point of the phenolic epoxy resin is 25-40℃; Preferably, the phenolic epoxy resin has the structure shown in Formula II. Wherein, R' is independently selected from C1-C4 alkyl groups, and n is an integer from 0 to 6.

5. The composition according to any one of claims 1 to 4, wherein The polyenol acetal is selected from at least one of polyvinyl alcohol formaldehyde, polyvinyl alcohol acetal, polyvinyl alcohol propionate, and polyvinyl alcohol butyral, preferably polyvinyl alcohol butyral; Preferably, the weight-average molecular weight of the polyenol acetal is 3000-4000 g / mol.

6. The composition according to any one of claims 1 to 5, wherein, The phosphorus-containing flame retardant comprises a first phosphorus-containing flame retardant and a second phosphorus-containing flame retardant. The first phosphorus-containing flame retardant contains organic phosphorus; The second phosphorus-containing flame retardant includes phosphazene flame retardants; Preferably, the mass ratio of the first phosphorus-containing flame retardant to the second phosphorus-containing flame retardant is 1:0.5-2, more preferably 1:0.6-1.5; Preferably, the first phosphorus-containing flame retardant comprises a phosphate ester; Preferably, the second phosphorus-containing flame retardant comprises at least one of polydiphenoxyphosphazene, hexaphenoxycyclotriphosphazene, and ethoxy(pentafluoro)cyclotriphosphazene.

7. The composition according to any one of claims 1 to 6, wherein The curing agent is dicyandiamide; Preferably, the average particle size of dicyandiamide is 3-10 nm; And / or, the curing accelerator comprises urea accelerators and imidazole accelerators; Preferably, the mass ratio of urea accelerator to imidazole accelerator is 1:0.3-1.

0.

8. The composition according to any one of claims 1 to 7, wherein The carbon nanotubes are hydroxylated multi-walled carbon nanotubes; Preferably, the carbon nanotubes are hydroxylated multi-walled carbon nanotubes modified with epoxy groups; Preferably, the carbon nanotubes have an average diameter of 20-30 nm and an average length of 10-30 μm.

9. A method of preparing an epoxy material using the composition according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Mix glycidyl amine epoxy resin, polyenol acetal, phenolic epoxy resin, phosphorus-containing flame retardant and carbon nanotubes. S2. Mix the mixture obtained in S1 with a curing agent and a curing accelerator to obtain an epoxy resin system; S3. Curing the epoxy resin system to obtain epoxy resin material.

10. The method of claim 9, wherein, The curing conditions include: a curing temperature of 100-150℃, preferably 120-140℃; and a curing time of 60-240 min, preferably 120-180 min. And / or, the mixing temperature in S1 is 110-150℃, and the time is 120-240min; And / or, the mixing temperature in S2 is 70-90℃, and the time is 60-120min.

11. An epoxy resin material prepared according to the method of claim 9 or 10.

12. The application of the epoxy resin material of claim 11 in rail transit.

Images