Epoxy resin composition with low curing sensitivity, preparation method thereof and prepreg

Abstract

The invention relates to the technical field of composite materials, in particular to a low-curing-sensitivity epoxy resin composition, a preparation method thereof and a prepreg. The low-curing-sensitivity epoxy resin composition is prepared from the following raw materials: an epoxy amino resin component, a toughening component and a curing agent component, an amino structure in the epoxy amino resin component is a para-position isosymmetric structure, the molar ratio of epoxy groups in the epoxy amino resin component to reactive hydrogen in the curing agent component is 1: (0.8-1.2), the molar ratio of the epoxy groups in the epoxy amino resin component to reactive hydrogen in the curing agent component is 1: (0.8-1.2), and the molar ratio of the toughening component to reactive hydrogen in the curing agent component is 1: (0.8-1.2). The mass of the toughening component accounts for 15-35% of the total mass of the raw materials. The low-curing-sensitivity epoxy resin composition improves the influence of a heat preservation platform and / or a low heating rate on the resin composition in the curing process, and the toughness of the formed composite material is maintained.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, in particular to a low-curing-sensitivity epoxy resin composition and a preparation method and a prepreg thereof. Background Art

[0002] Advanced composite materials have the advantages of high specific strength, high specific modulus, strong performance designability, good fatigue fracture resistance, and corrosion resistance. They are one of the main structural materials for aviation and aerospace vehicles. Large-scale structures such as fuselage compartments, wing boxes, integral mailboxes, beams, and fuselage skins are currently important areas of development in the field of composite materials. In recent years, with the advancement of composite material design and manufacturing technology, the application of composite materials in large civil aircraft structures has also made great progress, among which A380 and B787 are the most representative. Among them, the fuselage wall panels of A380 adopt Glare laminate structure and use a large amount of composite materials, which reduces weight by 25% compared with traditional metal structures.

[0003] Composite materials are very sensitive to impact damage. Impacts, scratches and other damages caused during manufacturing, service and maintenance are fatal to composite structural parts. Therefore, under the dual background of current aviation safety requirements and efficient weight reduction, the load-bearing capacity of composite structures under damage must be fully considered. How to improve the toughness of composite materials and improve the damage tolerance performance is the key to solving the long-term development of composite materials in this field. The design and development of high-toughness resin-based composite materials has always been a research hotspot. Existing research has many ways to improve the toughness of resin materials. For example, patent CN105733193B uses thermoplastic surface felt to perform hot pressing on prepreg to solve the problem of controllable toughening and conventional toughening material exhaust difficulties; such as WO9009410 A, etc., dispersed particles are added between layers for toughening; patent 201110376947.9 proposes a three-dimensional continuous structure that uses polyimide foam precursors to foam between layers and construct toughening materials; patent CN112677602A obtains a toughening layer by pressing carbon material aerogel and thermoplastic composite materials to solve the processability problem of composite materials. Patent CN111086283A achieves improved toughness by forming a toughening layer through a combination of resin and toughening agent without affecting process performance and heat resistance.

[0004] Theoretically, the above method should be able to significantly improve the toughness of the resin, but the actual result is that the toughness of the resin is not significantly improved. The inventors further conducted in-depth research and found that in the actual production process of parts, it is usually necessary to add an insulation platform to solve the uneven heating of the parts and the resin fluidity problems caused by the heat transfer lag of the steel mold. The temperature and time of such an insulation platform depend on the condition of the part, the curing temperature and rheological properties of the material itself. For example, the medium-temperature curing system often selects a temperature range of 70°C to 90°C and a insulation time of 0.5h to 4h; the high-temperature curing system often selects a temperature range of 100°C to 140°C and a insulation time of 1h to 8h. The inventors have found that in the actual production process, the above-mentioned insulation platform and low heating rate may cause irreversible negative effects on the toughened structure, resulting in the performance of the composite material not showing the level achieved in the initial design in the final engineering application, which is very fatal for aircraft design.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a low curing sensitivity epoxy resin composition and a preparation method and prepreg thereof. The embodiment of the present invention provides a low curing sensitivity epoxy resin composition, which improves the influence of the heat preservation platform and / or the low heating rate on the resin composition during the curing process, and maintains the toughness of the formed composite material.

[0007] The present invention is achieved in that:

[0008] In a first aspect, the present invention provides a low curing sensitivity epoxy resin composition, the raw materials of which include an epoxy amino resin component, a toughening component and a curing agent component, wherein the amino structure in the epoxy amino resin component is a para-symmetrical structure, the molar ratio of the epoxy group in the epoxy amino resin component to the active hydrogen in the curing agent component is 1:(0.8-1.2), and the mass of the toughening component accounts for 15-35% of the total mass of the raw materials.

[0009] In an optional embodiment, the molar ratio of the epoxy groups in the epoxy amino resin component to the active hydrogen in the curing agent component is 1:(0.9-1).

[0010] In an optional embodiment, the amino structure in the epoxy amino resin component is derived from at least one of p-diaminodiphenylmethane, p-diaminodiphenyl ether, p-xylylenediamine and p-diaminodiphenyl sulfone;

[0011] Preferably, the para-isosymmetrical structure of the epoxy-amino resin component is formed by glycidylation;

[0012] Preferably, the epoxy functionality of the epoxy amino resin component is greater than or equal to 3;

[0013] More preferably, the epoxy amino resin component is selected from at least one of tetraglycidyl diaminodiphenylmethane, diisopropylphenylene tetraglycidylamine and N,N,N',N'-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]propane.

[0014] In an optional embodiment, the mass of the toughening component accounts for 20-27% of the total mass of the raw material.

[0015] In an optional embodiment, the toughening component includes toughening particles and thermoplastic material, and the mass ratio of the toughening particles to the thermoplastic material is 1:(1.5-2.5).

[0016] In an optional embodiment, the toughening particles include toughening particles having a melting point less than 180° C.; preferably, polyamide toughening particles;

[0017] The thermoplastic material is selected from materials that can be dissolved in the epoxy amino resin component at 110-150°C and undergo phase change during the curing process;

[0018] Preferably, the thermoplastic material is selected from at least one of PES, PEI, PPO, PEK-C and PEEK.

[0019] In an optional embodiment, the mass content of the resin in the epoxy amino resin component whose reaction temperature of the resin and the toughening particles is higher than or equal to the curing temperature of the system is not less than 60%, preferably not less than 70%;

[0020] Preferably, the reaction temperature of the resin and toughening particles is obtained by the Kissinger-Akahira-Sunose method.

[0021] In an optional embodiment, the curing agent component is selected from an amine curing agent;

[0022] Preferably, the curing agent is selected from the compounds represented by the following structural formula:

[0023] Wherein, R1 and R6 are primary amino groups, R3, R4, R8, and R9 represent hydrogen atoms and halogen atoms, respectively, and R2, R5, R7, and R 10 are any aliphatic hydrocarbon groups having 2 to 5 carbon atoms;

[0024] Preferably, the curing agent is selected from at least one of meta-diaminodiphenyl sulfone, para-diaminodiphenyl sulfone and diaminodiphenylmethane.

[0025] In a second aspect, the present invention provides a method for preparing the low curing sensitivity epoxy resin composition described in the aforementioned embodiment, comprising: mixing an epoxy amino resin component, a toughening component and a curing agent component.

[0026] In a third aspect, the present invention provides a prepreg comprising fibers and the low curing sensitivity epoxy resin composition described in the aforementioned embodiment, which are fully mixed;

[0027] Preferably, the fibers include carbon fibers;

[0028] Preferably, the fibers are selected from unidirectional fabrics, warp knitted fabrics or three-dimensional woven fabrics;

[0029] Preferably, the surface density of the fiber is 50 to 1000 g / m 2 ;

[0030] Preferably, the mass content of the low curing sensitivity epoxy resin composition is 25%-60%.

[0031] The present invention has the following beneficial effects: the embodiments of the present invention select an epoxy-amino resin component with a specific symmetrical structure, and limit the dosage of the epoxy-amino resin component, the toughening component and the curing agent component, thereby improving the thermal insulation platform and / or the low heating rate during the curing process, which will cause irreversible negative impact on the toughened structure, and ensure the toughness of the formed composite material. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0033] Many methods have been used in the prior art to improve the performance of composite materials, such as toughening. In theory, the existing methods should be able to significantly improve the performance of composite materials. However, the performance improvement of the composite materials obtained in actual production is not obvious. The inventors further discovered that there are insulation platforms and low heating rate processes in the composite material molding process, and these processes have a significant impact on the resin composition, which in turn affects the performance of the formed composite material and does not reach the initial design level.

[0034] Specifically, according to relevant research findings at home and abroad, the mechanisms that affect the sensitivity of the curing process of high-toughness prepreg systems mainly include: thermal deformation of toughening particles, molten state of toughening particles, debonding of toughening particles / resin matrix, thermal aging of toughening particles, etc. Combined with the toughening means commonly used in the current industry, debonding of toughening particles / resin matrix is ​​the most important mechanism of the curing sensitivity of toughened prepregs. Polyamide toughening particles are currently commonly used insoluble toughening agents (hereinafter referred to as "toughening particles"), and their amide groups can react with epoxy resins to form a chemical cross-linking structure, thereby improving the interface strength between toughening particles / resins, and thus achieving efficient toughening. However, it is precisely because of this reaction mechanism that the toughened prepreg forms a certain degree of cross-linking network in the early curing reaction of the resin under the condition of increasing the long-term curing platform or low heating rate, affecting the collision between the toughening particles and the resin functional groups, delaying or inhibiting the reaction between the two, so that a weak bonding interface phase is formed between the resin and the particles. After the composite material is impacted, cracks can easily pass through this weak interface, resulting in a significant decrease in the toughness of the final composite material.

[0035] Furthermore, the inventors have found that when the reaction temperature of the resin and the toughening particles is close to or lower than the curing temperature of the resin system, and higher than the selected platform curing temperature, the toughening efficiency caused by the platform curing may decrease. Therefore, the embodiments of the present invention select a specific resin matrix to keep the curing temperature of the resin and the toughening particles away from the platform curing temperature and the system curing temperature range. Specifically, the curing temperature of the resin and the toughening particles is lower than the platform curing temperature and higher than the system curing temperature, thereby reducing the curing sensitivity of the composite material.

[0036] Among them, the curing temperature of the above-mentioned resin and toughening particles refers to the temperature at which the epoxy resin and toughening particles can undergo an interfacial reaction. The platform curing temperature refers to the insulation platform temperature during the heating process. The system curing temperature refers to the theoretical or designed curing temperature of the resin or the temperature used in actual engineering to achieve a certain degree of curing crosslinking density and heat resistance. Curing sensitivity or low curing sensitivity means that the performance or structure of the epoxy resin will not be destroyed at the insulation platform temperature or at a low heating rate.

[0037] Specifically, the resin matrix used in the embodiment of the present invention is an epoxy amino resin, which is a multifunctional epoxy resin, for example, a multifunctional epoxy resin with an epoxy functionality greater than or equal to 3. Multifunctional epoxy generally has two or more amino structures. The position of the amino structure and the steric hindrance effect of the structure connected to the amino group directly affect the reactivity of the resin. The activity of epoxy resins with relatively symmetrical structures such as para-amino groups is relatively low, and the reaction temperature of the corresponding resin and toughening particles will increase. Therefore, the amino structure in the epoxy amino resin component in the embodiment of the present invention is a para-symmetrical structure.

[0038] Specifically, the para-isosymmetrical structure of the epoxy amino resin component is formed by glycidylation; the amino structure in the epoxy amino resin component is derived from at least one of p-diaminodiphenylmethane, p-diaminodiphenyl ether, p-phenylenediamine and p-diaminodiphenyl sulfone. For example, the epoxy amino resin component includes but is not limited to at least one of tetraglycidyldiaminodiphenylmethane (TGDDM), diisopropylphenylene tetraglycidylamine (TGBAP) and N,N,N',N'-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]propane (TGBAPOPP).

[0039] Furthermore, the reaction temperature between the epoxy amino resin component and the toughening particles is determined by the following method:

[0040] Differential scanning calorimetry (DSC) is the most commonly used method for curing kinetics analysis in thermal analysis, with the characteristics of easy operation and small sampling volume. The trend of reaction enthalpy changes with time and temperature is determined by isothermal and non-isothermal methods, and analyzed by kinetic models.

[0041] The reaction equation according to the Kissinger-Akahira-Sunose (KAS) method is:

[0042]

[0043] Where β is the heating rate, T P is the peak temperature of the DSC curve, E is the apparent activation energy, A is the pre-exponential factor, and R is the gas constant.

[0044] By making the peak temperatures at different heating rates, the reaction peak temperature when the heating rate is zero can be obtained by extrapolating the above formula. This method can be used to obtain the true reaction temperature between the epoxy amino resin component and the toughening particles, which helps determine the reliability of the selected resin matrix.

[0045] Furthermore, the mass content of the low-sensitivity resin in the epoxy-amino resin component is not less than 60%, preferably not less than 70%. The low-sensitivity resin refers to a resin in the epoxy-amino resin component whose reaction temperature with the toughening particles is higher than or equal to the curing temperature of the system.

[0046] The low curing sensitivity epoxy resin composition provided by an embodiment of the present invention also includes a toughening component, the mass of the toughening component accounts for 15-35% of the total mass of the raw materials, for example, 15%, 20%, 25%, 30% and 35%, any value between 15-35% or a range value between any two values, for example, preferably 20% to 27%.

[0047] The toughening component includes toughening particles and thermoplastic material, and the mass ratio of the toughening particles to the thermoplastic material is 1:(1.5-2.5), such as 1:1.5, 1:2, 1:2.5, and any other value between 1:(1.5-2.5).

[0048] Furthermore, the above-mentioned thermoplastic material is selected from epoxy amino resin components that can be dissolved at 110-150°C, such as 140°C.

[0049] Specifically, the thermoplastic material may include, but is not limited to, powder particles of PES, PEI, PPO, PEK-C, PEEK, etc., more preferably, PES, PE KC, PEEK, etc.

[0050] Toughening particles can be selected from various types of polyamide particles, such as Orgasal 1002D NAT1, Orgasal 3202DNat1, GRILAMID TR60, GRILAMID TR90, 2159, etc., more preferably, should contain at least toughening particles with a melting point less than 180°C.

[0051] The low curing sensitivity epoxy resin composition provided by the embodiment of the present invention also includes a curing agent component. In the resin curing process, the thermoplastic material will reduce the compatibility with the resin, and then phase change (such as sea island structure, bicontinuous structure and phase inversion structure, etc.) will occur. A large number of studies have shown that when the thermoplastic material presents a bicontinuous structure and a phase inversion structure, it can effectively organize crack diffusion and significantly improve toughening efficiency. The embodiment of the present invention uses a curing agent of a specific structure to further reduce the compatibility of the resin and the thermoplastic material, achieve a larger scale of phase inversion, make the resin ball diameter larger, reduce the contact area with the polyamide particles, and then affect the reaction of the resin / toughening particles, and can also play an unexpected role in improving the toughening effect.

[0052] Specifically, the curing agent component is selected from amine curing agents; for example, the curing agent is selected from the compound represented by the following structural formula:

[0053] Wherein, R1 and R6 are primary amino groups, R3, R4, R8, and R9 represent hydrogen atoms and halogen atoms, respectively, and R2, R5, R7, and R 10 are any aliphatic hydrocarbon groups having 2 to 5 carbon atoms;

[0054] Specifically, the curing agent includes but is not limited to at least one of meta-diaminodiphenyl sulfone, para-diaminodiphenyl sulfone and diaminodiphenylmethane.

[0055] Furthermore, the molar ratio of the epoxy group in the epoxy amino resin component to the active hydrogen in the curing agent component is 1:(0.8-1.2), for example, any value between 1:0.8, 1:0.9, 1:1, 1:1.1 and 1:1.2, or a range value between any two values, preferably 1:0.9-1.

[0056] In a second aspect, the present invention provides a method for preparing the low curing sensitivity epoxy resin composition described in the aforementioned embodiment, comprising: mixing an epoxy amino resin component, a toughening component and a curing agent component. The low curing sensitivity epoxy resin composition of the embodiment of the present invention is obtained by physical mixing. To ensure sufficient dissolution and dispersion of the resin, a planetary agitator is preferably used for heating and dispersion until the viscosity measured by a vertebral plate viscometer at 75°C is 10000 cP to 1000000 cP.

[0057] In a third aspect, the present invention provides a prepreg, which comprises fibers and the low curing sensitivity epoxy resin composition described in the above embodiment, which are fully mixed; wherein the fibers can be selected from carbon fibers; can be unidirectional fabrics, warp knitted fabrics or three-dimensional woven fabrics; and its surface density is 50 to 1000 g / m 2 The mass content of the low curing sensitivity epoxy resin composition is 25%-60%, and the mass content of the fiber is 75%-40%.

[0058] The above-mentioned prepreg is prepared by existing methods and steps, such as a one-film process, a two-film or more-film process, etc. Therefore, the embodiments of the present invention will not be described in detail.

[0059] The raw material information used in the embodiment of the present invention is as follows:

[0060] Tailuk-AG-80H, the epoxy value is 0.9 mol / 100 g, and the reaction temperature of the resin and the polyamide toughened particles is determined to be 185° C. by the KAS method provided in the embodiment of the present invention.

[0061] AG-602, the epoxy value is 0.96 mol / 100 g, and the reaction temperature of the resin and the polyamide toughened particles is determined to be 135° C. by the KAS method provided in the embodiment of the present invention.

[0062] AFG-90MH, the epoxy value is 1 mol / 100 g, and the reaction temperature of the resin and the polyamide toughened particles is determined to be 157° C. by the KAS method provided in the embodiment of the present invention.

[0063] EBA-65, the epoxy value is 0.71 mol / 100 g, and the reaction temperature of the resin and the polyamide toughened particles is determined to be 199° C. by the KAS method provided in the embodiment of the present invention.

[0064] The toughening agent component uses the following commercial products:

[0065] Toughening particles: Orgasal 1002D NAT1 (melting point > 180°C), 2159 (melting point < 180°C); thermoplastic materials: Ultem 1000, PEK-C from Xuzhou Engineering Plastics Factory.

[0066] The following commercial products were used as curing components:

[0067] MMEA, conforming to the general structural formula 1, has an active hydrogen equivalent of 70.5.

[0068] MDEA, conforming to the general structural formula 1, has an active hydrogen equivalent of 77.5.

[0069] 3,3'-DDS, Zhangjiagang Yarui Chemical Co., Ltd., active hydrogen equivalent is 62.

[0070] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0071] Examples 1-6 and Comparative Examples 1-6

[0072] The above-mentioned Examples 1-6 and Comparative Examples 1-6 all provide an epoxy resin composition, and the components thereof are shown in Table 1 below.

[0073] The above-mentioned Examples 1-6 and Comparative Examples 1-6 also provide a corresponding method for preparing an epoxy resin composition, comprising: in a planetary agitator, dispersing and dissolving the epoxy component, thermoplastic material and curing agent component at 100°C until they are transparent, cooling to 75°C, adding toughening particles for dispersion, and obtaining the desired resin state by controlling the dispersion time.

[0074] The above-mentioned Examples 1-6 and Comparative Examples 1-6 also provide a method for preparing a prepreg, comprising:

[0075] Jiangsu Hengshen HF40S carbon fiber (T800 grade) was used as the reinforcing material. The resin compositions of Examples 1-6 and Comparative Examples 1-6 were respectively heated and pressurized on an impregnation device by melt impregnation, and composited with the reinforcing material to form a unidirectional prepreg. The prepared fiber surface density was 145 g / m 2 , the resin content is 35%.

[0076] The prepregs were cured at 180°C*2h and 135°C*8h+180°C*2h, respectively. Samples were prepared according to the dimensions required by the test standards ASTM D7136 & ASTM D7137. The post-impact compressive strength of the cured prepregs was tested. The results are shown in Table 1.

[0077] 180℃*2h curing is the system curing temperature, and 135℃*8h+180℃*2h curing process is 135℃*8h as the platform curing temperature and time.

[0078] Table 1 Epoxy resin composition composition and test results

[0079]

[0080]

[0081] The compressive strength after impact (CAI) is often used to characterize the toughness of composite materials. It is greatly affected by the curing process and is used as a key evaluation item for evaluating the curing sensitivity of composite materials in the present invention.

[0082] According to the above table, the low curing sensitivity epoxy resin composition provided by Examples 1-6 of the present invention can not only maintain a relatively high post-impact compressive strength, but is also less affected by the thermal insulation platform, with the retention rate being above 90%.

[0083] By comparing Examples 1-6 and Comparative Examples 1-2 and 4, it can be seen that when the mass proportion of the resin with a reaction temperature of less than 180°C with the polyamide toughened particles is higher, the curing sensitivity of the prepreg is stronger. When the proportion reaches 100%, it is kept down to about 72%, and the performance loss is serious.

[0084] By comparing Example 3 and Comparative Example 3, it can be seen that when the curing agent does not contain the curing agent of structural formula 1, the curing sensitivity of the prepreg is enhanced. This is mainly because the curing agent of structural formula 1 can reduce the compatibility between the resin curing cross-linking network and the thermoplastic material, achieve a larger scale of phase inversion, make the resin ball diameter larger, reduce the contact area with the polyamide particles, and thus affect the reaction of the resin / toughened particles.

[0085] By comparing Example 2, Comparative Examples 5 and 6, it can be seen that when the amount of curing agent used is too much, the cured structure of the prepreg turns to brittle, resulting in a decrease in the post-impact compressive strength; and when the amount of curing agent used is too little, the reaction of the prepreg is shifted back and the curing sensitivity is enhanced. Therefore, it is necessary to strictly control the range of the curing agent dosage.

[0086] By comparing Examples 1 and 6 and Comparative Examples 4 and 7, it can be seen that when toughening particles with a melting point of less than 180° C. are present in the formula, the interlayer structure of the composite material has a stronger crack resistance and can further improve the post-impact compression strength.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low curing sensitivity epoxy resin composition, characterized in that: The raw materials include an epoxy amino resin component, a toughening component and a curing agent component, wherein the amino structure in the epoxy amino resin component is a para-symmetrical structure, the molar ratio of the epoxy group in the epoxy amino resin component to the active hydrogen in the curing agent component is 1:(0.8-1.2), and the mass of the toughening component accounts for 15-35% of the total mass of the raw materials.

2. The low curing sensitivity epoxy resin composition according to claim 1, characterized in that: The molar ratio of the epoxy groups in the epoxy amino resin component to the active hydrogen in the curing agent component is 1:(0.9-1).

3. The low curing sensitivity epoxy resin composition according to claim 1 or 2, characterized in that: The amino structure in the epoxy amino resin component is derived from at least one of p-diaminodiphenylmethane, p-diaminodiphenyl ether, p-xylylenediamine and p-diaminodiphenyl sulfone; Preferably, the para-isosymmetrical structure of the epoxy-amino resin component is formed by glycidylation; Preferably, the epoxy functionality of the epoxy amino resin component is greater than or equal to 3; More preferably, the epoxy amino resin component is selected from at least one of tetraglycidyl diaminodiphenylmethane, diisopropylphenylene tetraglycidylamine and N,N,N',N'-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]propane.

4. The low curing sensitivity epoxy resin composition according to claim 3, characterized in that: The mass of the toughening component accounts for 20-27% of the total mass of the raw materials.

5. The low curing sensitivity epoxy resin composition according to claim 3, characterized in that: The toughening component comprises toughening particles and thermoplastic material, and the mass ratio of the toughening particles to the thermoplastic material is 1:(1.5-2.5).

6. The low curing sensitivity epoxy resin composition according to claim 5, characterized in that: The toughening particles include toughening particles with a melting point less than 180°C; preferably, polyamide toughening particles; The thermoplastic material is selected from materials that can be dissolved in the epoxy amino resin component at 110-150°C and undergo phase change during the curing process; Preferably, the thermoplastic material is selected from at least one of PES, PEI, PPO, PEK-C and PEEK.

7. The low curing sensitivity epoxy resin composition according to claim 5, characterized in that: The mass content of the resin in the epoxy amino resin component whose reaction temperature of the resin and the toughening particles is higher than or equal to the curing temperature of the system is not less than 60%, preferably not less than 70%; Preferably, the reaction temperature of the resin and toughening particles is obtained by the Kissinger-Akahira-Sunose method.

8. The low curing sensitivity epoxy resin composition according to claim 1, characterized in that: The curing agent component is selected from amine curing agents; Preferably, the curing agent is selected from the compounds represented by the following structural formula: Wherein, R1 and R6 are primary amino groups, R3, R4, R8, and R9 represent hydrogen atoms and halogen atoms, respectively, and R2, R5, R7, and R 10 are any aliphatic hydrocarbon groups having 2 to 5 carbon atoms; Preferably, the curing agent is selected from at least one of meta-diaminodiphenyl sulfone, para-diaminodiphenyl sulfone and diaminodiphenylmethane.

9. A method for preparing the low curing sensitivity epoxy resin composition according to claim 1, characterized in that: include: The epoxy amino resin component, the toughening component and the curing agent component are prepared.

10. A prepreg, characterized in that: It comprises fibers and the low curing sensitivity epoxy resin composition of claim 1 which are fully mixed; Preferably, the fibers include carbon fibers; Preferably, the fibers are selected from unidirectional fabrics, warp knitted fabrics or three-dimensional woven fabrics; Preferably, the surface density of the fiber is 50 to 1000 g / m 2 ; Preferably, the mass content of the low curing sensitivity epoxy resin composition is 25%-60%.

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