Amino-containing modified silica, inorganic nanofiber curing agent composition and application, epoxy resin composition and epoxy resin product

Abstract

The application relates to the field of organic polymers and discloses an amino-containing modified silica, an inorganic nanofiber curing agent composition and application, an epoxy resin composition and an epoxy resin product. The curing agent composition comprises a curing agent, inorganic nanofibers and water; the curing agent is modified nanosilica shown in formula I; the curing agent composition contains modified nanosilica with a specific structure and inorganic nanofibers; the polyamino groups in the modified nanosilica present a dendritic morphology on the surface of the nanosilica; when the modified nanosilica is added to the epoxy resin, bonding reaction can occur between the modified nanosilica and the epoxy groups in the epoxy resin, the advantages of the two are fully exerted, and the inorganic nanofibers are used in cooperation, so that the cured epoxy resin has relatively large compressive strength and is not prone to softening.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic polymers, in particular to a kind of amino-containing modified silica, inorganic nanofiber curing agent composition and application, epoxy resin composition and epoxy resin product. BACKGROUND

[0002] The commonly used types of petroleum fracturing proppants mainly include natural quartz sand, artificial ceramic and resin-coated sand, and the ideal proppant needs to have high mechanical strength, high conductivity, low compatibility, low cost, low density, not easy to flow back and not easy to embed characteristics.But these advantages are often difficult to achieve.In order to effectively support the induced fracture under high temperature and closed pressure conditions, the proppant should not be easily softened under high temperature and high pressure, and have higher compressive strength.

[0003] Epoxy resin as a kind of traditional polymer material is applied in many fields, such as electronic, energy, machinery, chemical industry and other fields, but when used as a proppant, it must be matched with a curing agent to play a role.The epoxy curing agent on the market is not suitable for phase change fracturing fluid, mainly showing that it is cured in the body of epoxy resin, and cannot fill various size cracks and microcracks, resulting in low conductivity and difficulty in supporting the far end of the crack.In addition, small molecule curing agents have high toxicity and fast curing speed, which is not conducive to the control of curing speed. SUMMARY

[0004] The present application aims to overcome the problems of poor curing performance, high toxicity, and difficult to control the curing speed of the existing curing agent, and the product prepared by applying the curing agent to epoxy resin has poor compressive strength and is easy to soften, and provides a kind of amino-containing modified silica, inorganic nanofiber curing agent composition and application, epoxy resin composition and epoxy resin product.The curing agent composition contains modified nanosilica with a specific structure and inorganic nanofiber, the multiple amino groups in the modified nanosilica present a dendritic morphology on the surface of nanosilica, when the modified nanosilica is added to the epoxy resin, it can react with the epoxy groups in the epoxy resin, fully exerting the advantages between the two, and cooperating with inorganic nanofiber, the cured epoxy resin has high compressive strength and is not easy to soften.

[0005] To achieve the above-mentioned purpose, the first aspect of the present application provides a kind of curing agent composition, wherein the curing agent composition includes curing agent, inorganic nanofiber and water;

[0006] The curing agent is modified nanosilica shown in formula I;

[0007]

[0008] In formula I, M is a nano-silica particle, x is an integer of 1-4, and R is an alkyl group with a carbon atom number of 1-4;

[0009] n is an integer of 0-3, m is an integer of 1-3, and n+m=3;

[0010] A is a structural unit from an acid anhydride compound, and B is a structural unit from a polyamino compound.

[0011] The second aspect of the present application provides application of the curing agent composition of the first aspect of the present application as a curing agent in an epoxy resin.

[0012] The third aspect of the present application provides an epoxy resin composition, wherein the epoxy resin composition comprises an epoxy resin and a curing agent;

[0013] The curing agent is the curing agent composition of the first aspect of the present application;

[0014] The epoxy resin and the curing agent are each independently present.

[0015] The fourth aspect of the present application provides an epoxy resin product prepared by mixing and curing the epoxy resin composition of the third aspect of the present application.

[0016] Through the above technical solution, the amino-containing modified silica, inorganic nanofiber curing agent composition and application, epoxy resin composition and epoxy resin product provided by the present application have the following beneficial effects: the multiple amino groups in the modified nano-silica present a dendritic morphology on the surface of the nano-silica. When the modified nano-silica is added to the epoxy resin, it can react with the epoxy groups in the epoxy resin, fully exerting the advantages between the two, and cooperating with the inorganic nanofiber, so that the cured epoxy resin can have a larger compressive strength and is not easy to soften, and is not easy to deform at high temperature. DETAILED DESCRIPTION

[0017] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The ranges or values should be construed to be approximations that allow for significant variation. Various ranges of values that are explicitly delineated are not to be construed as having only the precise values given. The endpoints of the ranges and any values are provided as a separate point for each endpoint, and each separate point can be independently combined with any other point or point range to define a new range or a new value. These new ranges or values are to be considered disclosed in this document.

[0018] The first aspect of the present application provides a curing agent composition, wherein the curing agent composition comprises a curing agent, inorganic nanofiber and water;

[0019] The curing agent is a modified nano-silica shown in formula I;

[0020]

[0021] In formula I, M is a nano-silica particle, x is an integer of 1-4, and R is an alkyl group with 1-4 carbon atoms;

[0022] n is an integer of 0-3, m is an integer of 1-3, and n+m=3;

[0023] A is a structural unit from an acid anhydride compound, and B is a structural unit from a polyamino compound.

[0024] In the present application, the polyamino group is modified on the surface of the nano-silica particle M, and the amino group on the surface of the nano-silica particle M assumes a dendritic morphology. When the modified nano-silica is added to the epoxy resin, it can bond with the epoxy groups in the epoxy resin, fully exerting the advantages of both. In combination with inorganic nanofibers, the cured epoxy resin can serve as a proppant, which has a large compressive strength and is not prone to softening and deformation at high temperatures.

[0025] According to the present application, the acid anhydride compound in formula I is selected from at least one of maleic anhydride, phthalic anhydride and succinic anhydride.

[0026] According to the present application, the polyamino compound is a linear polyethylene polyamino compound having the structure shown in formula II or a non-linear polyethylene imine with a number average molecular weight of 300-3000:

[0027]

[0028] wherein p is an integer of 1-6.

[0029] In the present application, the polyamino compound is selected from the above-mentioned compounds, so that the amino content in the modified nano-silica is high, further improving the curing performance of the epoxy resin.

[0030] According to the present application, the particle size of the nano-silica particle M is 10-500 nm, and the specific surface area is 10-300 m 2 / g.

[0031] According to the present application, the particle size of the modified nano-silica is 10-500 nm, and the specific surface area is 50-500 m 2 / g.

[0032] According to the present application, the particle size dispersion coefficient of the modified nano-silica is 0.09-0.15.

[0033] According to the present application, the amino content of the modified nano-silica is 0.1-5 mmol / g.

[0034] In the present application, the modified nano-silica can be prepared according to the following steps:

[0035] S1, dispersing nano-silica particles M in a first solvent in the presence of a protective gas, adding amino silane to perform a first reaction, to obtain amino-functionalized nano-silica shown in formula III;

[0036]

[0037] S2, performing a second reaction between the amino-functionalized nano-silica and an acid anhydride compound in the presence of a second solvent, to obtain carboxyl-functionalized nano-silica shown in formula IV;

[0038]

[0039] S3, mixing and activating the carboxyl-functionalized nano-silica with a condensing agent in the presence of a basic catalyst, and then adding a polyamino compound to perform a third reaction, to obtain modified nano-silica.

[0040] In the present application, the protective gas is nitrogen and / or inert gas.

[0041] In the present application, each of the steps S1, S2 and S3 independently comprises a separation, washing and drying step.

[0042] Further, the separation method is not particularly limited, for example, it can be at least one of filtration, rotary evaporation or centrifugal separation.

[0043] Further, the washing conditions are not particularly limited, for example, it can be washed 3-4 times with a solvent commonly used in the art, wherein the solvent can be at least one of methanol, ethanol and acetone, preferably, in the step S1, acetone and dichloromethane are used for washing.

[0044] According to the present application, in the step S1, the mass ratio of the nano-silica particles M to the amino silane is 5-100:1.

[0045] Further, the mass ratio of the nano-silica particles M to the amino silane is 10-50:1.

[0046] According to the present application, the amino silane is at least one selected from aminopropyl triethoxysilane, aminopropyl trimethoxysilane, aminopropyl methyl dimethoxysilane and aminopropyl methyl diethoxysilane.

[0047] According to the present application, the conditions of the first reaction include a reaction temperature of 120-160℃ and a reaction time of 2-24h.

[0048] According to the present application, in step S2, the mass ratio of the amino-functionalized nanosilica to the acid anhydride compound is 5-100:1.

[0049] According to the present application, the acid anhydride compound is selected from at least one of maleic anhydride, phthalic anhydride and succinic anhydride.

[0050] According to the present application, the conditions of the second reaction include: the reaction temperature is 90-160℃, and the reaction time is 2-12h.

[0051] According to the present application, the first solvent and the second solvent are each independently selected from at least one of toluene, xylene, benzene and N,N-dimethylformamide.

[0052] According to the present application, in step S3, the mass ratio of the carboxyl-functionalized nanosilica, the condensing agent, the basic catalyst and the polyamino compound is 1:0.05-0.5:0.01-0.1:0.1-5.

[0053] In the present application, when the mass ratio of the carboxyl-functionalized nanosilica, the condensing agent, the basic catalyst and the polyamino compound meets the above-mentioned preferred range, the obtained modified nanosilica has the best comprehensive performance, and further improves the curing performance on the epoxy resin.

[0054] According to the present application, the condensing agent is selected from one of dicyclohexyl carbodiimide, diisopropyl carbodiimide and 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide.

[0055] According to the present application, the basic catalyst is selected from at least one of 4-dimethylaminopyridine, 1,8-diazabicycloundec-7-ene and triethylamine.

[0056] According to the present application, the conditions of the third reaction include: the reaction temperature is 0-40℃, and the reaction time is 2-48h.

[0057] According to the present application, in step S3, the activation conditions include: the activation temperature is 10-25℃, and the activation time is 8-24h.

[0058] According to the present application, the diameter of the inorganic nanofiber is 500-900nm, and the aspect ratio is 10-20:1.

[0059] In the present application, the diameter and the aspect ratio of the inorganic nanofiber meet the above-mentioned range, which can have the characteristics of significantly enhancing and not blocking the pores when used as an epoxy resin curing agent enhancer.

[0060] Further, the inorganic fiber has a diameter of 500-600 nm and an aspect ratio of 16-20:1.

[0061] According to the present application, the inorganic nanofiber is selected from at least one of carbon fiber, SiC fiber, ceramic fiber and nanoglass fiber.

[0062] Further, the inorganic nanofiber is nanoglass fiber.

[0063] According to the present application, the content of the curing agent is 40-70 parts by weight, the content of the inorganic nanofiber is 0.2-1 parts by weight and the content of the water is 29-50 parts by weight, based on the total weight of the curing agent composition.

[0064] In the present application, the components in the curing agent composition satisfy the above-mentioned ranges, and the components synergize with each other, so that the compressive strength of the cured epoxy resin is further improved when the composition is applied to the epoxy resin, and the cured epoxy resin is not easy to deform at high temperature.

[0065] Further, the content of the curing agent is 45-60 parts by weight, the content of the inorganic nanofiber is 0.3-0.8 parts by weight and the content of the water is 35-50 parts by weight, based on the total weight of the curing agent composition.

[0066] According to the present application, the curing agent composition further comprises 2-5 parts by weight, preferably 2.5-4 parts by weight, of an accelerator.

[0067] According to the present application, the accelerator is selected from polycarboxylic acid and / or small molecule polyamine.

[0068] According to the present application, the polycarboxylic acid is selected from at least one of terephthalic acid (PTA), citric acid (CA), tartaric acid, oxalic acid, malic acid, citric acid and ascorbic acid.

[0069] According to the present application, the small molecule polyamine is selected from at least one of polyethylene polyamine, ethylenediamine, 1,6-hexanediamine, isophorone diamine, 2-methyl-1,5 pentanediamine, 3-methyl-1,5 pentanediamine, hydrazine and bis-hydrazide.

[0070] According to the present application, the accelerator is a mixture of polycarboxylic acid and small molecule polyamine, and the mass ratio of the polycarboxylic acid to the small molecule polyamine is 1:0.1-0.8.

[0071] In the present application, the accelerator is a mixture of polycarboxylic acid and small molecule polyamine, which can ensure the fluidity of the curing agent composition while improving its high temperature resistance. Further, when the mass ratio of the polycarboxylic acid to the small molecule polyamine satisfies the above-mentioned range, the high temperature resistance of the curing composition can be significantly improved.

[0072] Further, the mass ratio of the polycarboxylic acid and the small molecule polyamine is 1:0.4-0.7.

[0073] According to the present application, the apparent viscosity of the curing agent composition is 100-400 mPa·s, preferably 150-250 mPa·s at 25℃.

[0074] The second aspect of the present application provides an application of the curing agent composition of the first aspect of the present application as a curing agent in an epoxy resin.

[0075] The third aspect of the present application provides an epoxy resin composition, wherein the epoxy resin composition comprises an epoxy resin and a curing agent.

[0076] The curing agent is the curing agent composition of the first aspect of the present application.

[0077] The epoxy resin and the curing agent are each independently present.

[0078] In the present application, the epoxy resin and the curing agent in the epoxy resin composition are each independently stored separately, which can avoid the premature curing of the epoxy resin affecting the subsequent normal use. In subsequent process use, the epoxy resin and the curing agent are respectively injected into the formation at the same time, so that they perform a curing reaction in the formation, thereby preparing a honeycomb product for use as a proppant.

[0079] According to the present application, the amount of the curing agent is 40-80 parts by weight relative to 100 parts by weight of the epoxy resin.

[0080] In the present application, the amount of the curing agent meets the above range, which can make the cured epoxy resin product have a higher compressive strength, and is not easy to deform at high temperature.

[0081] Further, the amount of the curing agent is 60-70 parts by weight relative to 100 parts by weight of the epoxy resin.

[0082] The fourth aspect of the present application provides an epoxy resin product, which is prepared by mixing and curing the epoxy resin composition of the third aspect of the present application.

[0083] According to the present application, the deformation rate of the epoxy resin product is less than or equal to 4%, preferably less than or equal to 1% at 120℃ and 50MPa.

[0084] According to the present application, the softening point of the epoxy resin product is 110-140℃, preferably 130-140℃.

[0085] In the present application, the epoxy resin product can realize long-term pressure-bearing operation at 120℃-130℃.

[0086] The present application will be described in detail below by way of examples. In the following examples,

[0087] The particle size of the modified nanosilica was measured by transmission electron microscopy (TEM) and scanning electron microscopy (SEM);

[0088] The specific surface area of the modified nanosilica was measured by the BET adsorption method;

[0089] The particle size dispersion index (PDI) of the modified nanosilica was measured by a laser particle size analyzer (DLS);

[0090] The amino content in the modified nanosilica was measured by the acid-base neutralization titration method;

[0091] The diameter of the inorganic nanofiber was measured by the scanning electron microscopy (SEM) method;

[0092] The aspect ratio of the inorganic nanofiber was measured by the scanning electron microscopy (SEM) method;

[0093] The apparent viscosity of the curing agent composition was measured by the six-speed rotary viscometer method;

[0094] The glass transition temperature of the epoxy resin product was measured by the DSC method;

[0095] The deformation rate of the epoxy resin product was measured according to the following method:

[0096] At normal pressure and 25°C, the diameter of the epoxy resin product was tested as D0, after the epoxy resin product was extruded by a high-low temperature universal material testing machine at 50 MPa and 120°C, the diameter of the extruded epoxy resin product was tested as D1, and the deformation rate = (D0-D1) / D0 x 100%.

[0097] The permeability change rate of the epoxy resin product was measured according to the following method:

[0098] At room temperature and 40 MPa, the initial permeability of the epoxy resin product was tested as M0, after the initial epoxy resin product was operated at 120°C and 40 MPa for 30 days, the permeability was tested again as M1, and the permeability change rate = (M0-M1) / M0 x 100%. The permeability of the epoxy resin product was tested by using a high-pressure displacement device, and was tested according to the Enterprise Standard Q / SH1020 of Shengli Oilfield Administration Bureau, "High Permeability Consolidated Core Permeability Determination Method".

[0099] The raw materials used in the following examples and comparative examples were all from commercially available products, and the parameters of the inorganic nanofiber were as follows:

[0100] S1: diameter 500 nm, aspect ratio 20:1;

[0101] S2: 550 nm in diameter, 10:1 in aspect ratio;

[0102] S3: 400 nm in diameter, 8:1 in aspect ratio.

[0103] The modified nano-silica M1-M2 is prepared according to the following method:

[0104] Preparation of nano-silica M1

[0105] S1, preparation of amino-propyl functionalized nano-silica:

[0106] 2 g of nano-silica particles with an average particle size of 30 nm and a specific surface area of 200 m 2 / g were weighed into 100 mL of anhydrous toluene, then 0.2 g of amino-propyl triethoxysilane was added, and the mixture was stirred under reflux at 150°C for 24 hours under nitrogen protection. After the reaction was completed, the solid product was obtained by centrifugation, and the obtained solid product was repeatedly washed with acetone and dichloromethane for 3 times, and then vacuum dried at 40°C for 12 h to obtain the amino-propyl functionalized nano-silica.

[0107] S2, preparation of carboxyl functionalized nano-silica:

[0108] 2 g of the above-prepared amino-propyl functionalized nano-silica was weighed into 50 mL of dimethylbenzene, then 0.2 g of maleic anhydride was added, and the mixture was stirred under reflux at 160°C for 6 hours under nitrogen protection. After the reaction was completed, the mixture was repeatedly washed with methanol for 3 times, and then vacuum dried at 40°C for 12 h to obtain the carboxyl functionalized nano-silica.

[0109] S3, preparation of modified nano-silica:

[0110] 1 g of the above-prepared carboxyl functionalized nano-silica was weighed into 50 mL of toluene, then 0.25 g of diisopropyl carbodiimide (DIC) and 0.06 g of 1,8-diazabicycloundec-7-ene (DBU) were added, and the mixture was stirred at room temperature (25°C) for 1 hour for activation, then 4 g of polyethyleneimine (number average molecular weight of 1500) was added, and the mixture was continuously stirred at room temperature for 12 hours. After the reaction was completed, the mixture was repeatedly washed with methanol for 3 times, and then vacuum dried at 40°C for 12 h to obtain the modified nano-silica M1 of formula I, wherein n is 0, m is 3, and x is 3.

[0111] The particle size of the modified nano-silica M1 is 30 nm, the specific surface area is 300 m 2 / g, the amino content is 2 mmol / g, and the dispersion coefficient PDI is 0.11.

[0112] Preparation of nano-silica M2

[0113] According to the preparation method of M1, except that the specific surface area of the nanosilica particles is 100 m 2 / g, and in step S3, the amount of polyethyleneimine used is 0.4 g; the particle size of the modified nanosilica M2 prepared is 30 nm, the specific surface area is 230 m 2 / g, the amino content is 0.1 mmol / g, and the dispersion coefficient PDI is 0.13.

[0114] The following preparation examples and comparative preparation examples are used to illustrate the preparation of the cured resin composition

[0115] Preparation Example 1

[0116] The modified nanosilica 48 g, 0.72 g of polyethylene polyamine, 1.8 g of terephthalic acid, 0.3 g of inorganic nanofiber, and 49.68 g of water are mixed and stirred uniformly to obtain a curing agent composition A1, and the apparent viscosity of the curing agent composition A1 is tested to be 225 mPa·s.

[0117] Preparation Examples A2-A10

[0118] The curing agent composition A is prepared according to the method of Preparation Example 1, except that the types and amounts of the curing agent, accelerator, and nanofiber are different from those of Preparation Example 1, and the specific details are shown in Table 1. The apparent viscosities of the curing agent compositions A2-A10 are shown in Table 3.

[0119] Table 1

[0120]

[0121] Comparative Preparation Examples 1-3

[0122] The curing agent compositions D1-D3 are prepared according to the method of Preparation Example 1, except that the types and amounts of the curing agent, accelerator, and nanofiber are different from those of Preparation Example 1, and the specific details are shown in Table 2. The apparent viscosities of the curing agent compositions D1-D3 are shown in Table 3.

[0123] Table 2

[0124]

[0125] * water-dispersed SiO2

[0126] Table 3

[0127] Curing agent composition Apparent viscosity / mPa·s A1 225 A2 192 A3 189 A4 267 A5 243 A6 156 A7 174 A8 186 A9 309 A10 396 D1 627 D2 750 D3 96

[0128] The following examples are used to illustrate the preparation of the epoxy resin product

[0129] Examples 1-10

[0130] The curing agent composition prepared in Preparation Example 1-10 was mixed with epoxy resin E51, and cured at a curing temperature of 120°C and a curing time of 4h to obtain epoxy resin products P1-P10. The specific types and amounts of the raw materials are shown in Table 4. The deformation rate, softening point, and permeability change rate of the products were tested at 120°C and 50MPa, and the results are shown in Table 4.

[0131] Examples 11 and 12

[0132] The method of Example 1 was followed, except that the amounts of the curing agent composition and epoxy resin E51 were different, as shown in Table 4. The deformation rate, softening point, and permeability change rate of the products were tested at 120°C and 50MPa, and the results are shown in Table 4.

[0133] Comparative Examples 1-3

[0134] The curing agent composition prepared in Comparative Preparation Example 1-3 was mixed with epoxy resin E51, and cured at a curing temperature of 120°C and a curing time of 4h to obtain epoxy resin products DP1-DP3. The specific types and amounts of the raw materials are shown in Table 4. The deformation rate, softening point, and permeability change rate of the products were tested at 120°C and 50MPa, and the results are shown in Table 4.

[0135] Comparative Example 4

[0136] The method of Example 1 was followed to prepare epoxy resin product DP4, except that the amounts of the curing agent composition and epoxy resin E51 were different, as shown in Table 4. The deformation rate, softening point, and permeability change rate of the products were tested at 120°C and 50MPa, and the results are shown in Table 4.

[0137] Table 4

[0138]

[0139]

[0140] According to the above results, it can be seen that Examples 1-12 of the present application achieve good technical effects, in that the deformation rate of the cured epoxy resin at 120°C and 50MPa is not greater than 2%, while the softening point is not lower than 110°C. Furthermore, the permeability change rate after 30 days is not greater than 3%.

[0141] Further, preferred Examples 1-2, 5 achieve significantly better technical effects, in that the deformation rate of the cured epoxy resin at 120°C and 50MPa is not greater than 0.7%, while the softening point is not lower than 125°C. Furthermore, the permeability change rate after 30 days is not greater than 1.5%.

[0142] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A curing agent composition, characterized in that, The curing agent composition includes a curing agent, inorganic nanofibers, and water; The curing agent is the modified nano-silica shown in Formula I; , Formula I; In Formula I, M represents nano-silica particles, x is an integer from 1 to 4, and R is an alkyl group with 1 to 4 carbon atoms; n is an integer from 0 to 3, m is an integer from 1 to 3, and n + m = 3; A is a structural unit derived from acid anhydride compounds, and B is a structural unit derived from polyamine compounds; The polyamine compound is a linear polyethyleneimine compound having the structure shown in Formula II or a nonlinear polyethyleneimine with a number-average molecular weight of 300-3000. Formula II; Where p is an integer from 1 to 6.

2. The curing agent composition according to claim 1, wherein, In Formula I, the acid anhydride compound is selected from at least one of maleic anhydride, phthalic anhydride, and succinic anhydride.

3. The curing agent composition according to claim 1 or 2, wherein, The nano-silica particles M have a particle size of 10-500 nm and a specific surface area of ​​10-300 m². 2 / g; And / or, the particle size distribution coefficient of the modified nano-silica is 0.09-0.15; And / or, the modified nano-silica contains 0.1-5 mmol / g of amino groups.

4. The curing agent composition according to claim 3, wherein, The modified nano-silica has a particle size of 10-500 nm and a specific surface area of ​​50-300 m². 2 / g.

5. The curing agent composition according to claim 1, wherein, The inorganic nanofibers have a diameter of 500-900 nm and an aspect ratio of 10-20:

1.

6. The curing agent composition according to claim 5, wherein, The inorganic nanofibers have a diameter of 500-600 nm and an aspect ratio of 16-20:

1.

7. The curing agent composition according to claim 1 or 2, wherein, The inorganic nanofibers are selected from at least one of carbon fiber, SiC fiber, ceramic fiber and nanoglass fiber.

8. The curing agent composition according to claim 7, wherein, The inorganic nanofibers are nanoglass fibers.

9. The curing agent composition according to claim 1 or 2, wherein, Based on the total weight of the curing agent composition, the content of the curing agent is 40-70 parts by weight, the content of the inorganic nanofiber is 0.2-1 parts by weight, and the content of water is 29-50 parts by weight.

10. The curing agent composition according to claim 9, wherein, Based on the total weight of the curing agent composition, the content of the curing agent is 45-60 parts by weight, the content of the inorganic nanofiber is 0.3-0.8 parts by weight, and the content of water is 35-50 parts by weight.

11. The curing agent composition according to claim 1, wherein, The curing agent composition also includes 2-5 parts by weight of an accelerator.

12. The curing agent composition according to claim 11, wherein, The curing agent composition further includes 2.5-4 parts by weight of an accelerator.

13. The curing agent composition according to claim 11, wherein, The accelerator is selected from polycarboxylic acids and / or small molecule polyamines.

14. The curing agent composition according to claim 13, wherein, The polycarboxylic acid is selected from at least one of terephthalic acid, citric acid, tartaric acid, oxalic acid, and malic acid; And / or, the small molecule polyamine is selected from at least one of polyethylene polyamine, ethylenediamine, 1,6-hexanediamine, isophoronediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, hydrazine, and dihydrazide.

15. The curing agent composition according to claim 13, wherein, The accelerator is a mixture of polycarboxylic acids and small molecule polyamines, wherein the mass ratio of the polycarboxylic acid to the small molecule polyamine is 1:0.1-0.

8.

16. The curing agent composition according to claim 15, wherein, The accelerator is a mixture of polycarboxylic acids and small molecule polyamines, wherein the mass ratio of the polycarboxylic acid to the small molecule polyamine is 1:0.4-0.

7.

17. The curing agent composition according to claim 1 or 2, wherein, At 25°C, the apparent viscosity of the curing agent composition is 100-400 mPa·s.

18. The curing agent composition according to claim 17, wherein, At 25°C, the apparent viscosity of the curing agent composition is 150-250 mPa·s.

19. The use of the curing agent composition according to any one of claims 1-18 as a curing agent in epoxy resins.

20. An epoxy resin composition, characterized in that, The epoxy resin composition includes an epoxy resin and a curing agent; The curing agent is the curing agent composition according to any one of claims 1-18; The epoxy resin and the curing agent exist independently of each other.

21. The epoxy resin composition according to claim 20, wherein, The amount of curing agent used is 40-80 parts by weight relative to 100 parts by weight of epoxy resin.

22. The epoxy resin composition according to claim 21, wherein, The amount of curing agent used is 60-70 parts by weight relative to 100 parts by weight of epoxy resin.

23. An epoxy resin product, characterized in that, The epoxy resin product is obtained by mixing and curing the epoxy resin composition according to any one of claims 20-22.

24. The epoxy resin product according to claim 23, wherein, At 120°C and 50 MPa, the deformation rate of the epoxy resin product is less than or equal to 4%. And / or, the softening point of the epoxy resin product is 110-140℃.

25. The epoxy resin product according to claim 24, wherein, At 120°C and 50 MPa, the deformation rate of the epoxy resin product is less than or equal to 1%. And / or, the softening point of the epoxy resin product is 130-140°C.

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