Semi-latent polyamine composition, preparation method and epoxy prepreg containing the same

Abstract

The present invention discloses a semi-latent polyamine composition, a preparation method and an epoxy prepreg containing the semi-latent polyamine composition, wherein the semi-latent polyamine composition comprises the following components: the secondary amine group in the semi-latent polyamine mixture obtained by the present invention does not react with epoxy resin at medium and low temperatures due to the influence of steric hindrance, has latency, and can react quickly with epoxy resin under high temperature conditions to form a cross-linked structure; at the same time, the presence of the primary amine group in the mixture can react with epoxy resin during the production process of prepreg cloth, and play the role of a thickener, thereby realizing the rapid shaping of prepreg cloth and long-term storage at medium and low temperatures. It has good applications in the fields of composite battery shells, composite leaf springs, composite automobile top covers, automobile engine covers, etc. produced based on epoxy SMC process.

Description

Technical Field

[0001] The invention relates to an epoxy resin curing agent for composite material prepreg, in particular to a semi-latent polyamine composition and a preparation method thereof and an epoxy prepreg containing the semi-latent polyamine composition. Background Art

[0002] Fiber-reinforced resin-based composite materials have the advantages of light weight, high specific strength, high specific modulus, high temperature resistance, corrosion resistance, etc., and have become the best choice to replace metal substrates. They have begun to be widely used in civil, aerospace, military and other fields, such as: automobile roof, automobile leaf spring, new energy vehicle battery shell, etc., and are showing a rapid growth trend. More than 80% of composite products are initially supplied in the form of prepreg cloth, and their prepreg system is epoxy resin + latent curing agent. Since traditional liquid aromatic amines and liquid alicyclic amine curing agents do not have latency, it is difficult to directly apply them in this prepreg system. The commonly used latent curing agents are mainly dicyandiamide and its derivatives, organic acid hydrazides, imidazole compounds, etc., which are high-melting point powdered solids at room temperature. It is difficult to evenly disperse into the resin matrix, which can easily cause uneven resin curing, incomplete curing or over-curing, resulting in defects in the product. And the structure of this type of latent curing agent determines that it is difficult for this prepreg system to achieve an effective combination of heat resistance and toughness.

[0003] Patent CN102532806 A discloses a method for preparing epoxy resin composite materials by SMC process. The patent uses epoxy resin + micronized dicyandiamide as the curing system. Although it can improve the dispersion effect of dicyandiamide, it has high requirements for the dispersion equipment. And it is difficult to avoid the problem of uneven dispersion in the end, resulting in micro-phase defects in the product, which is difficult to meet the performance requirements of high-end applications.

[0004] Patent CN112048154 A discloses an epoxy glass fiber SMC sheet and a preparation method thereof. The system adopts a system of epoxy resin + dicyandiamide + active alicyclic amine to obtain a glass fiber SMC sheet with rapid prototyping function. In the system, dicyandiamide is also difficult to disperse uniformly, and the alicyclic amine reacts quickly with the epoxy resin. The viscosity of the mixed system is difficult to control during the sheet production process, which will cause uneven wetting of the final SMC sheet.

[0005] In order to better exert the performance of composite products, achieve uniform dispersion of curing agent in resin, control the degree of curing, improve the production efficiency of prepreg, reduce the storage conditions and storage cost of prepreg, and solve the problems of incomplete curing of products in the production process, there is an urgent need for a liquid semi-latent polyamine curing agent in the market to meet the performance requirements of SMC products. Summary of the invention

[0006] The invention provides a semi-latent polyamine composition. The semi-latent polyamine composition is used in an epoxy prepreg system and has excellent mixing uniformity, preforming property, medium and high temperature latency, mechanical properties and heat resistance. The semi-latent polyamine composition can solve the problems of uneven curing of products and many product defects caused by uneven dispersion of solid powdered latent curing agents in epoxy prepreg systems. At the same time, the toughness of the products can be improved while maintaining the heat resistance of the products.

[0007] Another object of the present invention is to provide a method for preparing the semi-latent polyamine composition.

[0008] Another object of the present invention is to provide an epoxy prepreg using the semi-latent polyamine composition.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] A semi-latent polyamine composition comprising the following components:

[0011]

[0012]

[0013] Among them, R 1 is selected from aliphatic hydrocarbon groups; preferably, the aliphatic hydrocarbon group is selected from one or more of methyl, ethyl, propyl, isopropyl, butyl, butyl, diisopropyl, and vinyl, and more preferably one or more of ethyl, propyl, and isobutyl. 2 is selected from one or more of methyl, ethyl, propyl, butyl and isobutyl, more preferably methyl and isobutyl, R 3 Selected from One or two types of H, n=1, 2, 3.

[0014] In a specific embodiment, the semi-latent polyamine composition, based on the total mass of the composition, has a specific composition ratio of:

[0015] Formula I 30% to 90%, preferably 45% to 85%;

[0016] Formula II 10% to 70%, preferably 15% to 55%.

[0017] On the other hand, a method for preparing a semi-latent polyamine composition comprises the steps of dissolving a mixture of diaminodiphenylmethane and polyaminopolyphenylmethane and a ketone in a certain proportion, adding an appropriate amount of an auxiliary agent, and carrying out a hydrogenation reaction by a supported catalyst under a hydrogen atmosphere to obtain a semi-latent polyamine composition. The auxiliary agent is an α-hydroxycarboxylic acid, and a commonly used one is lactic acid (30 wt %), and the amount of the auxiliary agent added is generally 0.1 wt %, based on the mass of the primary amine.

[0018] In a specific embodiment, the structural formula of the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane is as shown in formula III and IV:

[0019]

[0020]

[0021] Wherein, based on the total mass of the mixture, formula III accounts for 30% to 90%, preferably 45% to 85%; formula IV accounts for 10% to 70%, preferably 15% to 55%; n=1, 2 or 3. .

[0022] In a specific embodiment, the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane is selected from one or two of WanamineMDA45 (Formula III: 45%, Formula IV: 55%), WanamineMDA60 (Formula III: 60%, Formula IV: 40%), WanamineMDA75 (Formula III: 75%, Formula IV: 25%), and WanamineMDA85 (Formula III: 85%, Formula IV: 15%) of Wanhua Chemical.

[0023] In a specific embodiment, the ketone is one or more of methyl ethyl ketone, methyl propyl ketone, methyl diisopropyl ketone, methyl vinyl ketone, and diisobutyl ketone, preferably one or more of methyl ethyl ketone, methyl propyl ketone, methyl diisopropyl ketone, and diisobutyl ketone.

[0024] In a specific embodiment, the ratio of the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane to ketone is: n 伯胺 :n 酮基 =1: 0.9~0.6, preferably n 伯胺 :n 酮基 =1: 0.85 to 0.65, more preferably n 伯胺 :n 酮基 =1:0.8~0.7.

[0025] In a preferred embodiment, the preparation method of the semi-latent polyamine composition of the present invention comprises the following steps: adding 1wt% catalyst pt / C and a certain amount of lactic acid to a high-pressure reactor with a built-in filter, then mixing the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane with ketone, adding the mixture to the reactor, and heating the mixture with N 2 After the replacement, the reaction is carried out on a hydrogenation device at a hydrogen pressure of 2-5 MPa, preferably a hydrogen pressure of 3.0-4.0 MPa, and a temperature of 80°C-120°C, preferably 90°C-100°C. After the reaction time is 200min-300min, preferably 220min-280min, the reaction product is separated by a built-in filter to remove the catalyst, thereby obtaining the final semi-latent polyamine composition.

[0026] In the preparation method of the present invention, any part not particularly described may refer to patent CN114315607A, and the method and process conditions for preparing dibasic secondary amines thereof may be introduced into the present invention.

[0027] On the other hand, an epoxy prepreg comprises the following composition:

[0028]

[0029] Wherein, the semi-latent polyamine composition is the semi-latent polyamine composition described above or prepared by the aforementioned preparation method;

[0030] The liquid epoxy resin is selected from one or more of E51, E54 and E44, preferably E51;

[0031] The flame retardant is aluminum hydroxide.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1) The polyamine composition obtained by the method of the present invention is a flowable liquid at room temperature. In the prepreg production process, the polyamine composition can be mixed with the epoxy resin at the molecular level, thereby solving the problems of uneven mixing of solid powder latent amines and epoxy resins used in traditional prepregs, high performance requirements for mixing equipment, and high mixing energy consumption.

[0034] 2) The method of the present invention prepares a polyamine composition containing both primary amino groups and secondary amine groups. The primary amine can quickly react with the epoxy resin to form a cross-linked structure during the prepreg molding period, thereby improving the prepreg molding efficiency. At the same time, the secondary amine in the composition does not react with the epoxy group when the temperature is lower than 100°C, and has latency, which can realize the medium-temperature storage of the prepreg, effectively reducing the storage cost.

[0035] 3) In the epoxy SMC prepreg system, the semi-latent polyamine composition obtained by the present invention is mixed with a common epoxy resin to obtain an epoxy prepreg system. The products obtained by using the raw material system have better toughness and mechanical properties.

[0036] 4) The secondary amine group in the semi-latent polyamine composition of the present invention does not react with the epoxy resin at medium and low temperatures due to the influence of steric hindrance, and has latency. Under high temperature conditions, it can react quickly with the epoxy resin to form a cross-linked structure; at the same time, the presence of the primary amine group in the composition can react with the epoxy resin during the production process of the prepreg, and play the role of a thickener, thereby achieving rapid shaping of the prepreg and long-term storage at medium and low temperatures. The semi-latent polyamine composition can effectively solve the problem that the current dicyandiamide / imidazole curing agent needs to be mixed with a thickener. And the semi-latent polyamine composition of the present invention is liquid at room temperature, which is easier to mix with resin than the powdered latent curing agent currently on the market, thereby effectively reducing the difficulty of prepreg dispersion. The semi-latent polyamine composition can effectively improve the toughness of composite products while maintaining the heat resistance of the composite material. It has a good application in the fields of composite battery shells, composite leaf springs, composite automobile top covers, and automobile engine covers produced based on epoxy SMC processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the infrared spectrum of the semi-latent polyamine mixture prepared in Preparation Example 1 of the present invention. DETAILED DESCRIPTION

[0038] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0039] The semi-latent polyamine mixture prepared in Preparation Example 1 of the present invention was qualitatively characterized by infrared spectroscopy. The infrared testing instrument was Thermo Fisher Nicolet iS5, and the characterization was performed in FIRT mode. The characterization results are shown in FIG. Figure 1 .

[0040] The mixture of diaminodiphenylmethane and polyaminopolyphenylmethane comes from Wanhua WanamineMDA45 (Formula III: 45%, Formula IV: 55%), WanamineMDA60 (Formula III: 60%, Formula IV: 40%), WanamineMDA75 (Formula III: 75%, Formula IV: 25%), and WanamineMDA85 (Formula III: 85%, Formula IV: 15%).

[0041] The remaining raw materials and their sources are shown in Table 1:

[0042] Table 1 Raw materials and sources

[0043] Chemical name factory WANAMINE MDA-45 Wanhua Chemical WANAMINE MDA-60 Wanhua Chemical WANAMINE MDA-75 Wanhua Chemical WANAMINE MDA-85 Wanhua Chemical Methyl Ethyl Ketone Aladdin Methyl Propyl Ketone Aladdin Methyl isobutyl ketone Aladdin Diisobutyl Ketone Aladdin E51 Epoxy Resin South Asia Aluminum hydroxide Aladdin Dicyandiamide Aladdin Organic urea Aladdin Glass Fiber Tarzan Release agent G40 Corning BYK-A530 BYK Isophorone diamine Wanhua Chemical

[0044] Preparation of semi-latent polyamine compositions

[0045] Table 2 Raw material composition and dosage in each example

[0046]

[0047] Preparation Example 1

[0048] In a 1L high-pressure reactor with a built-in filter, 1wt% catalyst pt / C and 0.2g lactic acid were added, and then 200g WanamineMDA45 and 115.2g methyl ethyl ketone were added to the reactor and mixed evenly. 2 After replacement, the reaction was carried out on a hydrogenation device at a hydrogen pressure of 4 MPa and a temperature of 100°C. After the reaction lasted for 280 minutes, the reaction product was separated by a built-in filter to remove the catalyst, and the final semi-latent polyamine mixture HD-1 was obtained. Its infrared spectrum is shown in FIG. Figure 1 As shown, 1700cm -1 The disappearance of the ketone carbonyl C=O absorption peak indicates that all ketones in the mixture participated in the reaction.

[0049] Preparation Example 2

[0050] In a 1L autoclave with a built-in filter, 1wt% catalyst pt / C and 0.2g lactic acid were added, and then 200g Wanamine MDA60 and 120.6g methyl propyl ketone were added to the autoclave and mixed evenly. 2 After the replacement, the reaction was carried out on a hydrogenation device at a hydrogen pressure of 3 MPa and a temperature of 90° C. After the reaction for 220 minutes, the reaction product was separated by a built-in filter to remove the catalyst, thereby obtaining the final semi-latent polyamine mixture HD-2.

[0051] Preparation Example 3

[0052] In a 1L autoclave with a built-in filter, 1wt% catalyst pt / C and 0.2g lactic acid were added, and then 100g WanamineMDA45, 100g WanamineMDA60 and 150.24g methyl isobutyl ketone were added to the autoclave and mixed evenly. 2 After the replacement, the reaction was carried out on a hydrogenation device at a hydrogen pressure of 3.5 MPa and a temperature of 95° C. After the reaction for 270 minutes, the reaction product was separated by a built-in filter to remove the catalyst, thereby obtaining the final semi-latent polyamine mixture HD-3.

[0053] Preparation Example 4

[0054] In a 1L autoclave with a built-in filter, 1wt% catalyst pt / C and 0.2g lactic acid were added, and then 200g Wanamine MDA75, 57.6g methyl ethyl ketone and 80.13g methyl isobutyl ketone were added to the autoclave and mixed evenly. 2 After the replacement, the reaction was carried out on a hydrogenation device at a hydrogen pressure of 3.7 MPa and a temperature of 98° C. After the reaction lasted for 250 minutes, the reaction product was separated by a built-in filter to remove the catalyst, thereby obtaining the final semi-latent polyamine mixture HD-4.

[0055] Preparation Example 5

[0056] In a 1L autoclave with a built-in filter, 1wt% catalyst pt / C and 0.2g lactic acid were added, and then 200g Wanamine MDA85, 64.6g methyl propyl ketone and 75.12g methyl isobutyl ketone were added to the autoclave and mixed evenly. 2 After the replacement, the reaction was carried out on a hydrogenation device at a hydrogen pressure of 3.8 MPa and a temperature of 94° C. After the reaction for 230 minutes, the reaction product was separated by a built-in filter to remove the catalyst, thereby obtaining the final semi-latent polyamine mixture HD-5.

[0057] Preparation Example 6

[0058] In a 1L autoclave with a built-in filter, 1wt% catalyst pt / C and 0.2g lactic acid were added, and then 200g WanamineMDA45 and 207.32g diisobutyl ketone were added to the autoclave and mixed evenly. 2 After the replacement, the reaction was carried out on a hydrogenation device at a hydrogen pressure of 3.2 MPa and a temperature of 97°C. After the reaction lasted for 250 minutes, the reaction product was separated by a built-in filter to remove the catalyst, thereby obtaining the final semi-latent polyamine mixture HD-6.

[0059] Comparative Example 1

[0060] 14 g of dicyandiamide and 3 g of organic urea were physically mixed uniformly to obtain comparative example DY.

[0061] Preparation of SMC Sheet Molding Compound

[0062] 100g of epoxy resin E51, 6g of internal mold release agent, 0.75g of defoamer and 0.75g of wetting agent were stirred in a reactor. After the resin was melted and mixed evenly, 100g of aluminum hydroxide was added to the reactor and stirred at high speed to mix evenly. Then, the semi-latent curing agent synthesized in the preparation example was added in equimolar amounts (the number of moles of epoxy groups in the epoxy resin = the number of moles of hydrogen on the amine groups (primary amines and secondary amines) in the curing agent). After stirring and mixing evenly in the reactor, vacuum degassing was performed to obtain HD-SMC resin paste; the prepared epoxy SMC resin paste was impregnated with 25mm disordered short-cut glass fibers, rolled by an SMC sheet feeder, and sent to a 35°C drying room for aging for 20 hours to obtain the epoxy sheet molding compound P-HD.

[0063] The epoxy SMC sheet molding compound preparation method was adopted, and the semi-latent polyamine mixtures of HD-1 to HD-6 in the preparation examples 1 to 6 were respectively prepared according to the above steps to obtain epoxy sheet molding compounds P-HD-1 to P-HD-6.

[0064] Comparative Example SMC Sheet Molding Compound Preparation

[0065] 83g E51 epoxy resin, 6g internal release agent, 0.75g defoamer and 0.75g sizing agent were stirred in a reactor. After the resin was melted and mixed evenly, 100g aluminum hydroxide was added to the reactor and stirred at high speed to mix evenly to obtain material 1; 17g E51 epoxy resin and comparative example DY curing agent were mixed and stirred in a reactor. After mixing evenly, three-roll grinding was performed. After grinding, the particle size of the mixture was less than 10μm to obtain material 2; material 2 was added to material 1, stirred and vacuum degassed, 4.4g IPDA was added, and stirred evenly to obtain epoxy DY-SMC resin paste; the prepared epoxy DY-SMC resin paste was impregnated with 25mm disordered short-cut glass fiber, and after rolling by an SMC sheet material machine, it was sent to a 35°C drying room for aging for 20 hours to obtain epoxy sheet molding compound P-DY.

[0066] The epoxy SMC resin paste and epoxy sheet molding compound obtained in the examples and comparative examples were cured and tested respectively, and the curing conditions and test standards and methods used were as follows:

[0067] The mechanical properties of the epoxy SMC resin paste mixture were vacuum degassing and casting resin tensile and bending test strips according to the requirements of GB / T2567-2008. The curing conditions were 150°C × 5min to obtain the epoxy resin cured casting body.

[0068] Mechanical properties test of epoxy SMC sheet molding compound cured product: Rapid curing and molding in a mold with a size of 500mm*500mm*4mm under the curing conditions of 150*5min, and the obtained cured material sheet is cut into tensile, bending and impact specimens for testing according to GB / T15568-2008 standard.

[0069] Flexural modulus test standard: DIN ISO 527;

[0070] Impact strength test standard: GB / T 1043-2008;

[0071] The tensile strength test standard is: DIN ISO 527;

[0072] The elongation at break test standard is: DIN ISO 527;

[0073] Flame retardant grade test standard: UL-94 (vertical burning);

[0074] Glass transition temperature test: GBT19466.2-2004.

[0075] The test results are listed in Table 2 and Table 3 below.

[0076] Table 3 Comparison of basic parameters of epoxy SMC resin paste and mechanical properties of its cured product

[0077]

[0078] Table 3 Comparison of mechanical properties of epoxy SMC sheet molding compound cured products

[0079] P-HD-1 P-HD-2 P-HD-3 P-HD-4 P-HD-5 P-HD-6 P-DY Flexural modulus / GPa 15.32 14.58 15.12 14.35 14.11 14.91 13.75 Bending strength / MPa 356.2 331.2 342.1 329.1 328.1 334.2 321.4 <![CDATA[Impact strength (KJ / m 2 )]]> 153 140 149 147 149 147 131 Tensile strength / MPa 264.3 247.8 257.2 247 245.2 250.4 234.4 Elongation at break / % 3％ 2.5％ 2.8％ 3.1％ 3.4％ 2.2％ 1.5％

[0080] As can be seen from the above comparison table, compared with traditional latent curing agents, the semi-latent polyamine composition obtained by the present invention is used in the field of epoxy SMC, has a lower viscosity at room temperature, can be mixed with epoxy resin at molecular level, and effectively improves the production efficiency and curing performance of SMC resin paste. At the same time, primary amine groups and secondary amine groups are simultaneously present in the molecular chain of the semi-latent polyamine composition, which can achieve rapid prototyping in the early stage of epoxy SMC sheet production and long-term storage at room temperature. Thereby reducing production and storage costs. At the same time, the introduction of multifunctional structure can improve the heat resistance and mechanical properties of composite materials.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A semi-latent polyamine composition, characterized in that Contains the following ingredients: Wherein, R1 is selected from aliphatic hydrocarbon groups; R2 is selected from one or more of methyl, ethyl, propyl and butyl; R3 is selected from One or two of H; n is selected from 1, 2 or 3; The composition is as follows: formula I accounts for 30% to 90%, and formula II accounts for 10% to 70%, based on the total mass of the composition.

2. The semi-latent polyamine composition according to claim 1, characterized in that The aliphatic hydrocarbon group is selected from one or more of methyl, ethyl, propyl, butyl, diisopropyl and vinyl; R2 is selected from one or both of methyl and isobutyl.

3. The semi-latent polyamine composition according to claim 2, characterized in that The aliphatic hydrocarbon group is selected from one or more of ethyl, propyl and isobutyl.

4. The semi-latent polyamine composition according to any one of claims 1 to 3, characterized in that The composition is as follows: formula I accounts for 45% to 85%; formula II accounts for 15% to 55%, based on the total weight of the composition.

5. The method for preparing the semi-latent polyamine composition according to any one of claims 1 to 4, characterized in that: The method comprises the steps of dissolving a mixture of diaminodiphenylmethane and polyaminopolyphenylmethane and ketone in proportion, adding a proper amount of alpha-hydroxycarboxylic acid auxiliary agent, and carrying out hydrogenation reaction by supporting a catalyst in a hydrogen atmosphere to obtain a semi-latent polyamine composition.

6. The preparation method according to claim 5, characterized in that: The structure of the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane is: Wherein, based on the total mass of the mixture, formula III accounts for 30% to 90%; formula IV accounts for 10% to 70%; and n=1, 2 or 3.

7. The preparation method according to claim 6, characterized in that: Based on the total mass of the mixture, formula III accounts for 45% to 85%; formula IV accounts for 15% to 55%.

8. The preparation method according to claim 6, characterized in that: The mixture of diaminodiphenylmethane and polyaminopolyphenylmethane is selected from one or two of WanamineMDA45, WanamineMDA60, WanamineMDA75 and WanamineMDA85 of Wanhua Chemical.

9. The preparation method according to claim 5, characterized in that: The ketone is selected from one or more of methyl ethyl ketone, methyl propyl ketone, methyl diisopropyl ketone, methyl vinyl ketone, methyl isobutyl ketone and diisobutyl ketone.

10. The preparation method according to claim 9, characterized in that: The ketone is selected from one or more of methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone and diisobutyl ketone.

11. The preparation method according to claim 5, characterized in that: The ratio of the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane to ketone is: n 伯胺 :n 酮基 =1:0.9~0.

6.

12. The preparation method according to claim 11, characterized in that: The ratio of the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane to ketone is: 伯胺 :n 酮基 =1:0.85~0.

65.

13. The preparation method according to claim 12, characterized in that: The ratio of the mixture of diaminodiphenylmethane and polyaminopolyphenylmethane to ketone is: n 伯胺 :n 酮基 =1:0.8~0.

7.

14. The preparation method according to claim 5, characterized in that: The method comprises the following steps: adding a loaded catalyst and an alpha-hydroxycarboxylic acid auxiliary agent into a high-pressure reactor with a built-in filter, then uniformly mixing a mixture of diaminodiphenylmethane and polyaminopolyphenylmethane with ketone, adding the mixture into the reactor, replacing the mixture with N2 three times, and then replacing the mixture with H2 three times, then heating the reactor, introducing H2 into the reactor through a hydrogen flow controller to ensure stable pressure, releasing the pressure after a certain reaction time, filtering and separating the liquid with a built-in filter, and obtaining a final semi-latent polyamine composition.

15. An epoxy prepreg, characterized in that: Contains the following components: Wherein, the semi-latent polyamine composition is a semi-latent polyamine composition as described in any one of claims 1 to 4 or prepared by the preparation method of any one of claims 5 to 14; The liquid epoxy resin is selected from one or more of E51, E54 or E44.

16. The epoxy prepreg according to claim 15, characterized in that: Contains the following components: The liquid epoxy resin is E51.

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