A fast-curing epoxy resin curing agent and preparation method thereof

Abstract

The present application relates to the technical field of curing agents, and more specifically, it relates to a fast-curing epoxy resin curing agent and a preparation method thereof. A fast-curing epoxy resin curing agent comprises isocyanate silane, polyol phosphate, imidazole and solvent; the preparation method thereof is as follows: after mixing the isocyanate silane and the solvent, adding the polyol phosphate, stirring and mixing at 70-80°C for 1-2h, then adding the imidazole, stirring and mixing for 1-2h, and obtaining the epoxy resin curing agent. The present application adopts polyol phosphate, imidazole and isocyanate silane for grafting reaction, and the obtained curing agent has high reaction activity and good stability, and can quickly cure epoxy resin at room temperature.

Description

Technical Field

[0001] The present application relates to the technical field of curing agents, and more specifically, to a fast-curing epoxy resin curing agent and a preparation method thereof. Background Art

[0002] Epoxy resin, also known as artificial resin, is a type of organic high molecular polymer containing two or more epoxy groups in its molecular structure. It has been widely used in actual production because of its excellent corrosion resistance and medium resistance.

[0003] However, epoxy resin is an amorphous viscous liquid that becomes plastic when heated and has no obvious melting point. It softens and gradually melts and becomes sticky when heated, and it does not harden by itself. Therefore, epoxy resin needs to be used with a curing agent to form a three-dimensional network structure polymer material before it can be cured to form a hard coating.

[0004] At present, small molecule polyamide has become a commonly used epoxy resin room temperature curing agent at home and abroad because it can cure epoxy resin at room temperature and the curing process is simple. However, due to the low amine value and low activity of small molecule polyamide, the curing reaction speed of small molecule polyamide and epoxy resin is slow, which is not suitable for rapid bonding in the building decoration industry, rapid plugging in the chemical industry, and rapid repair of damaged highway routes and other scenarios that require rapid operation. Summary of the invention

[0005] In order to increase the curing speed of room temperature curing epoxy resin, the present application provides a fast curing epoxy resin curing agent and a preparation method thereof.

[0006] In a first aspect, the present application provides a fast-curing epoxy resin curing agent, which adopts the following technical solution: a fast-curing epoxy resin curing agent, which is made of raw materials containing the following parts by weight:

[0007] 20-30 parts of isocyanate silane;

[0008] Polyol phosphate 10-24 parts;

[0009] Imidazole 4-15 parts;

[0010] 10-20 parts of solvent.

[0011] By adopting the above technical scheme, after mixing isocyanate silane, polyol phosphate and imidazole, isocyanate reacts with the hydroxyl group on the phosphate and the secondary amine on the imidazole to obtain a curing agent mixture containing flexible segments terminated with phosphate or imidazole, which has good stability. When the curing agent of the present application is used to cure epoxy resin, since the phosphate group in the curing agent can react with the epoxy group in the epoxy resin, the tertiary nitrogen atom in the imidazole ring in the curing agent can also catalyze the ring-opening polymerization reaction of the epoxy group in the epoxy resin, so the curing agent has good reactivity with the epoxy resin and can quickly cure the epoxy resin at room temperature.

[0012] At the same time, polyol phosphate containing flexible segments and imidazole containing five-membered aromatic heterocycles are grafted to isocyanate silane, and the resulting curing agent has not only good flexibility but also strong strength. Therefore, grafting the curing agent to the epoxy network is also beneficial to improving the flexibility and strength of the epoxy resin system after curing.

[0013] Preferably, the isocyanate silane, polyol phosphate and imidazole are mixed in a weight ratio of 1:(0.5-0.8):(0.2-0.5).

[0014] By adopting the above technical scheme, the mixing ratio of isocyanate silane, polyol phosphate and imidazole is optimized, and the grafting rate of phosphate and imidazole with isocyanate silane in the curing agent mixture is increased, which is beneficial to increasing the curing rate of the curing agent for the epoxy resin system and improving the flexibility and strength of the epoxy resin after curing.

[0015] Preferably, the isocyanate silane includes one or more of isocyanate propyl methyl diethoxy silane, isocyanate propyl methyl dimethoxy silane and isocyanate propyl triethoxy silane.

[0016] By adopting the above technical solution, after the above-mentioned types of isocyanate silanes are mixed with polyol phosphate and imidazole for reaction, the resulting curing agent has high reactivity, which is beneficial to improving the curing rate of the curing agent for epoxy resin. At the same time, the introduction of ethoxy and / or methoxy groups into the curing agent is beneficial to improving the stability of the resulting curing agent.

[0017] Preferably, the isocyanate silane is a mixture of isocyanate propylmethyldimethoxysilane and isocyanate propylmethyldiethoxysilane in a weight ratio of 1:(0.8-1.2).

[0018] By adopting the above technical solution, the above-mentioned types of isocyanate silanes are mixed with polyol phosphates and imidazoles for reaction, thereby increasing the types of active groups in the curing agent, which is beneficial to improving the stability and reactivity of the obtained curing agent.

[0019] Preferably, the preparation method of the polyol phosphate is: adding polypropylene glycol to polyphosphoric acid, stirring and reacting at 30-50° C. for 3-5 hours, then adding water, stirring and mixing for 1-2 hours to obtain the polyol phosphate.

[0020] By adopting the above technical scheme, on the one hand, polypropylene glycol and polyphosphoric acid are reacted to generate polyol phosphate ester, and the obtained polyol phosphate ester has high reactivity and low viscosity, which is beneficial to improve the dispersibility of polyol phosphate ester in isocyanate silane and imidazole, promote the reaction of polyol phosphate ester and isocyanate silane, and obtain a curing agent with high reactivity and high stability, thereby improving the reaction and curing rate of the obtained curing agent on epoxy resin.

[0021] On the other hand, when polypropylene glycol is added to polyphosphoric acid under the above reaction conditions, polypropylene glycol and polyphosphoric acid react fully, thereby increasing the flexible segment of the polyol phosphate and reducing the content of residual phosphoric acid in the polyol phosphate, which is beneficial to improving the flexibility and stability of the resulting curing agent.

[0022] Preferably, the polypropylene glycol and polyphosphoric acid are mixed in a weight ratio of 100:(3.5-4.3).

[0023] By adopting the above technical scheme, the weight ratio of the polypropylene glycol and polyphosphoric acid reaction is optimized, which is conducive to obtaining a polyol phosphate with high reaction activity, low residual phosphoric acid content and high fluidity, and is conducive to improving the reaction activity and stability of the obtained curing agent.

[0024] Preferably, the molecular weight of the polypropylene glycol is 360-1000.

[0025] By adopting the above technical scheme, polypropylene glycol with the above molecular weight is reacted with polyphosphoric acid, and the obtained polyol phosphate has low viscosity and high fluidity, which is conducive to the mixed reaction of polyol phosphate, isocyanate silane and imidazole, and improves the stability of the obtained curing agent.

[0026] In a second aspect, the present application provides a method for preparing a fast-curing epoxy resin curing agent, using the following technical solution:

[0027] A method for preparing a fast-curing epoxy resin curing agent comprises the following preparation steps:

[0028] After mixing the isocyanate silane and the solvent, add the polyol phosphate, stir and mix at 70-80° C. for 1-2 hours, then add imidazole, stir and mix for 1-2 hours to obtain the epoxy resin curing agent.

[0029] By adopting the above technical scheme, the mixing order and reaction conditions of isocyanate silane, polyol phosphate and imidazole are controlled, and the grafting rate of phosphate and imidazole with isocyanate silane in the curing agent mixture is increased, which is beneficial to improving the reactivity, stability, flexibility and strength of the obtained curing agent.

[0030] In summary, this application has the following beneficial effects:

[0031] The present application adopts polyol phosphate, imidazole and isocyanate silane for grafting reaction, and the obtained curing agent mixture not only has high structural stability, but also contains phosphate groups for addition to epoxy groups, and tertiary nitrogen atoms for promoting ring-opening polymerization of epoxy groups. Therefore, the epoxy resin can be quickly cured and the curing temperature of the epoxy resin system can be effectively reduced. DETAILED DESCRIPTION

[0032] The present application is further described in detail below with reference to the embodiments.

[0033] Preparation Example of Polyol Phosphate

[0034] Preparation Example 1

[0035] A polyol phosphate, the raw materials and their weights are shown in the following table:

[0036]

[0037] The preparation method of the polyol phosphate ester is as follows: adding polyphosphoric acid to polypropylene glycol at 0-5°C and nitrogen environment, stirring and reacting at 40°C for 4 hours, and then adding water and stirring and mixing for 1.5 hours to obtain the polyol phosphate ester.

[0038] In the examples of the present application, the grade of polypropylene glycol is PPG-600, the molecular weight is 540-660, the acid value is ≤0.5 mgKOH / g, and the pH value (1% aqueous solution) is 5.0-7.0.

[0039] Polyphosphoric acid, CAS No. 8017-16-1, was purchased from Shandong Guohua Chemical.

[0040] Preparation Example 2-3

[0041] A polyol phosphate, which is different from Preparation Example 1 in that the raw materials and their weights are shown in the following table:

[0042]

[0043] Preparation Example 4

[0044] A polyol phosphate ester, which is different from Preparation Example 1 in that the brand of polypropylene glycol is PPG-400, the molecular weight is 360-440, the acid value is ≤0.5 mgKOH / g, and the pH value (1% aqueous solution) is 5.0-7.0.

[0045] Preparation Example 5

[0046] A polyol phosphate ester, which is different from Preparation Example 1 in that the brand of polypropylene glycol is PPG-1000, the molecular weight is 900-1000, the acid value is ≤0.5 mgKOH / g, and the pH value (1% aqueous solution) is 5.0-7.0.

[0047] Preparation Example 6

[0048] A polyol phosphate ester, which is different from Preparation Example 1 in that the preparation method of the polyol phosphate ester is: adding polyphosphoric acid to polypropylene glycol at 0-5°C and a nitrogen environment, stirring the reaction at 30°C for 3 hours, then adding water, stirring and mixing for 1 hour to obtain the polyol phosphate ester.

[0049] Preparation Example 7

[0050] A polyol phosphate ester, which is different from Preparation Example 1 in that the preparation method of the polyol phosphate ester is: adding polyphosphoric acid to polypropylene glycol at 0-5°C and a nitrogen environment, stirring the reaction at 50°C for 5 hours, and then adding water and stirring and mixing for 2 hours to obtain the polyol phosphate ester.

[0051] Preparation Example 8

[0052] A polyol phosphate ester, which is different from Preparation Example 1 in that an equal weight of polyether polyol is used to replace polypropylene glycol, wherein the polyether polyol model is CP1005, the functionality is 3, the molecular weight is 1000, and it is purchased from Dow's official brand station.

[0053] Example

[0054] Example 1

[0055] A fast-curing epoxy resin curing agent, the raw materials and their weights are shown in the following table:

[0056]

[0057]

[0058] The method for preparing the above-mentioned fast-curing epoxy resin curing agent comprises the following preparation steps:

[0059] After mixing the isocyanate silane and the solvent, polyol phosphate was added, and the mixture was stirred and mixed at 75° C. for 1.5 hours. Then, imidazole was added, and the mixture was stirred and mixed for 1.5 hours to obtain an epoxy resin curing agent.

[0060] In the embodiment of the present application, the isocyanate silane is a mixture of isocyanate propylmethyldimethoxysilane and isocyanate propylmethyldiethoxysilane in a weight ratio of 1:1.

[0061] The polyol phosphate was prepared according to Preparation Example 1.

[0062] The solvent is diethyl ether.

[0063] Embodiment 2-5

[0064] A fast-curing epoxy resin curing agent, which is different from Example 1 in that the raw materials and their weights are shown in the following table:

[0065]

[0066] Embodiment 6-9

[0067] A fast-curing epoxy resin curing agent, which is different from Example 1 in that the type and weight of the isocyanate silane are shown in the following table:

[0068]

[0069] Embodiment 10-11

[0070] A fast-curing epoxy resin curing agent is different from Example 1 in that the weights of the raw materials in the polyol phosphate are different.

[0071] The preparation of polyol phosphate is shown in the following table:

[0072] Example 1 Example 10 Embodiment 11 Preparation Example 1 Preparation Example 2 Preparation Example 3

[0073] Examples 12-13

[0074] A fast-curing epoxy resin curing agent is different from Example 1 in that the molecular weight of the polypropylene glycol in the polyol phosphate is different.

[0075] The preparation of polyol phosphate is shown in the following table:

[0076] Example 1 Example 12 Embodiment 13 Preparation Example 1 Preparation Example 4 Preparation Example 5

[0077] Examples 14-15

[0078] A fast-curing epoxy resin curing agent is different from Example 1 in that the preparation method of the polyol phosphate is different in the polyol phosphate.

[0079] The preparation of polyol phosphate is shown in the following table:

[0080] Example 1 Embodiment 14 Embodiment 15 Preparation Example 1 Preparation Example 6 Preparation Example 7

[0081] Example 16

[0082] A fast-curing epoxy resin curing agent, which is different from Example 1 in that an equal weight of polyether polyol is used to replace polypropylene glycol, wherein the polyether polyol model is CP1005, the functionality is 3, the molecular weight is 1000, and it is purchased from Dow's official brand website.

[0083] Polyol phosphate was prepared according to Preparation Example 8.

[0084] Embodiment 17

[0085] A fast-curing epoxy resin curing agent, which is different from Example 1 in that an equal weight of pentaerythritol phosphate is used to replace the polyol phosphate.

[0086] Embodiment 18

[0087] A fast-curing epoxy resin curing agent, which is different from Example 1 in that a method for preparing the fast-curing epoxy resin curing agent comprises the following preparation steps:

[0088] After mixing the isocyanate silane and the solvent, polyol phosphate was added, and the mixture was stirred and mixed at 70° C. for 2 hours. Then, imidazole was added, and the mixture was stirred and mixed for 2 hours to obtain an epoxy resin curing agent.

[0089] Embodiment 19

[0090] A fast-curing epoxy resin curing agent, which is different from Example 1 in that a method for preparing the fast-curing epoxy resin curing agent comprises the following preparation steps:

[0091] After mixing the isocyanate silane and the solvent, the polyol phosphate was added, and the mixture was stirred and mixed at 80° C. for 1 hour. Then, imidazole was added, and the mixture was stirred and mixed for 1 hour to obtain an epoxy resin curing agent.

[0092] Comparative Example

[0093] Comparative Example 1

[0094] An epoxy resin curing agent, which is different from Example 1 in that an equal weight of isocyanate is used to replace the isocyanate silane, wherein the model of the isocyanate is PAPI 27, which is purchased from the Dow official brand website.

[0095] Comparative Example 2

[0096] An epoxy resin curing agent, which is different from Example 1 in that an equal weight of polyol phosphate is used to replace imidazole, wherein the polyol phosphate is prepared by Preparation Example 1.

[0097] Comparative Example 3

[0098] An epoxy resin curing agent, which is different from Example 1 in that an equal weight of imidazole is used to replace the polyol phosphate.

[0099] Comparative Example 4

[0100] An epoxy resin curing agent, which is different from Example 1 in that an equal weight of 2-ethylimidazole is used instead of imidazole.

[0101] Comparative Example 5

[0102] An epoxy resin curing agent, which is different from Example 1 in that a preparation method of the epoxy resin curing agent comprises the following preparation steps:

[0103] After mixing the isocyanate silane and the solvent, adding the polyol phosphate and the imidazole, stirring and mixing at 70° C. for 4 hours, an epoxy resin curing agent is obtained.

[0104] Performance Testing

[0105] The fast-curing epoxy resin curing agents obtained in Examples 1-19 of the present application and the epoxy resin curing agents obtained in Comparative Examples 1-5 were tested for viscosity and storage stability. The testing method is as follows:

[0106] Viscosity test: Refer to GB / T 22314-2008 to test the viscosity of the curing agent at 25°C.

[0107] Storage stability test: Place the curing agent at room temperature (20-25°C) for 6 months to observe whether the viscosity of the curing agent changes and whether it has good fluidity.

[0108] The performance test results are shown in the following table:

[0109]

[0110]

[0111]

[0112] By analyzing the data in the above table, it can be seen that the fast-curing epoxy resin curing agent obtained in Examples 1-19 has a viscosity in the range of 2650-4200 mPa·s at 25° C., and the curing agent has no viscosity change and good fluidity after being stored at room temperature for 4-6 months.

[0113] The epoxy resin curing agent obtained in Comparative Examples 1-3 has a viscosity in the range of 4520-5850 mPa·s at 25° C. The curing agent has no viscosity change and good fluidity when stored at room temperature for 1-3 weeks.

[0114] The epoxy resin curing agent obtained in Comparative Example 4-5 has a viscosity in the range of 4520-4690 mPa·s at 25°C. After being stored at room temperature for 3-4 days, the curing agent has no viscosity change and has good fluidity.

[0115] According to the fast-curing epoxy resin curing agent obtained in Examples 1-19 and the epoxy resin curing agent obtained in Comparative Examples 1-5, it can be seen that the fast-curing epoxy resin curing agent obtained in Examples 1-19 has lower viscosity and better storage stability at room temperature.

[0116] Application Examples

[0117] Application Example 1

[0118] An epoxy resin adhesive is obtained by stirring and mixing 10 kg of an epoxy resin curing agent and 12.5 kg of epoxy resin E51.

[0119] In the application example of the present application, the epoxy resin curing agent is prepared by Example 1.

[0120] Application Example 2-24

[0121] An epoxy resin adhesive, which is different from Application Example 1 in that an embodiment of preparing an epoxy resin curing agent is shown in the following table:

[0122] Application Example 1 Example 1 Application Example 2 Example 2 Application Example 3 Example 3 Application Example 4 Example 4 Application Example 5 Example 5 Application Example 6 Example 6 Application Example 7 Example 7 Application Example 8 Example 8 Application Example 9 Example 9 Application Example 10 Example 10 Application Example 11 Embodiment 11 Application Example 12 Example 12 Application Example 13 Embodiment 13 Application Example 14 Embodiment 14 Application Example 15 Embodiment 15 Application Example 16 Example 16 Application Example 17 Embodiment 17 Application Example 18 Embodiment 18 Application Example 19 Embodiment 19 Application Example 20 Comparative Example 1 Application Example 21 Comparative Example 2 Application Example 22 Comparative Example 3 Application Example 23 Comparative Example 4 Application Example 24 Comparative Example 5

[0123] The epoxy resin adhesives obtained in Application Examples 1-24 of this application were tested for gel time, surface drying time, Vicat temperature, pencil hardness and impact resistance. The test standards are as follows:

[0124] Gel time test: refer to GB12007.7-89;

[0125] The test method of surface drying time is as follows: the epoxy resin adhesive of the embodiment or comparative example is coated on a glass slide with a coating thickness of 0.5 mm, and after the gel is solidified, a PET plastic sheet is used to touch the coating surface, and a stopwatch is used to count from the beginning of the stirring of the mixture until the PET has no adhesion and residue on the coating, indicating that the coating has been surface dried, at 25°C and a humidity of 65%;

[0126] Vicat temperature: refer to GBT1633-2000.

[0127] Pencil hardness and impact resistance test: refer to GB / T 22374-2008.

[0128] The performance test results are shown in the following table:

[0129]

[0130]

[0131] By analyzing the data in the above table, it can be seen that the epoxy resin adhesive prepared by using the curing agent obtained in Example 1-3 in Application Example 1-3 has a shorter gel time and surface dry time than the epoxy resin adhesive prepared by using the curing agent obtained in Example 1-3 in Application Example 4-5. This shows that in the total raw materials for preparing the curing agent of the present application, isocyanate silane, polyol phosphate and imidazole are mixed in a weight ratio of 1: (0.5-0.8): (0.2-0.5), which is conducive to improving the curing rate of the curing agent for epoxy resin.

[0132] The epoxy resin adhesive prepared by using the curing agent obtained in Examples 1, 6 and 7 in Application Examples 1, 6 and 7 has a shorter gel time and surface dry time than the epoxy resin adhesive prepared by using the curing agent obtained in Examples 8 and 9 in Application Examples 8 and 9. This shows that in the total raw materials for preparing the curing agent of the present application, the isocyanate silane is mixed with isocyanate propylmethyldimethoxysilane and isocyanate propylmethyldiethoxysilane in a weight ratio of 1: (0.8-1.2), which is beneficial to improve the curing rate of the curing agent for the epoxy resin.

[0133] Application Examples 1, 10, and 11 The epoxy resin adhesive prepared by using the curing agent obtained in Examples 1, 10, and 11 has a gel time as low as 6-6.41 minutes and a surface dry time as low as 11-13.01 minutes. This shows that in the total raw materials for preparing the curing agent of the present application, polypropylene glycol and polyphosphoric acid are mixed in a weight ratio of 100:(3.5-4.3), and the obtained curing agent can quickly cure epoxy resin.

[0134] Application Examples 1, 12, and 13 The epoxy resin adhesive prepared by using the curing agent obtained in Examples 1, 12, and 13 has a gel time as low as 6-6.23 minutes and a surface dry time as low as 11-12.73 minutes. This shows that in the total raw materials for preparing the curing agent of the present application, the molecular weight of polypropylene glycol is 360-1000, and the obtained curing agent can quickly cure the epoxy resin.

[0135] Application Examples 1, 14, and 15 The epoxy resin adhesive prepared by using the curing agent obtained in Examples 1, 14, and 15 has a gel time as low as 6-6.18 minutes and a surface dry time as low as 11-12.54 minutes. This shows that the curing agent of the present application uses homemade polyol phosphate in the total raw materials for preparing the curing agent, and the obtained curing agent can quickly cure the epoxy resin.

[0136] Compared with the curing agent obtained in Example 16 and the curing agent obtained in Example 17, the epoxy resin adhesive finally prepared in Example 1 has a shorter gel time and surface dry time. This shows that the polyol phosphate prepared by polypropylene glycol and polyphosphoric acid in the total raw materials for preparing the curing agent of the present application can improve the curing rate of the curing agent for epoxy resin.

[0137] The epoxy resin adhesive prepared by using the curing agent obtained in Examples 1, 18 and 19 has a gel time as low as 6-6.37 min and a surface dry time as low as 11-12.97 min. This shows that the curing agent prepared by the preparation method of the curing agent in the present application can quickly cure the epoxy resin.

[0138] The curing agent prepared by using isocyanate silane, polyol phosphate and imidazole in Application Example 1 has a shorter gel time and surface dry time than the curing agent prepared by using isocyanate, polyol phosphate and imidazole in Application Example 20, the curing agent prepared by using isocyanate and polyol phosphate in Application Example 21, and the curing agent prepared by using isocyanate and imidazole in Application Example 23. This shows that in the total raw materials for preparing the curing agent of the present application, the compounding of isocyanate silane, polyol phosphate and imidazole is beneficial to improve the curing rate of the curing agent for epoxy resin.

[0139] The curing agent prepared by the preparation method of Example 1 in Application Example 1 has a shorter gel time and surface dry time than the curing agent prepared by the preparation method of Example 24 in Application Example 24. This shows that in the preparation method of the curing agent of the present application, by controlling the mixing order of isocyanate silane, polyol phosphate and imidazole, it is beneficial to improve the curing rate of the curing agent for the epoxy resin.

[0140] The epoxy resin adhesives obtained in Application Examples 1-24 of the present application were tested for Vicat temperature, pencil hardness and impact resistance. The test results showed that the epoxy resin adhesives obtained in Application Examples 1-19 of the present application had a Vicat temperature of up to 100-135°C, a pencil hardness of up to 2H-3H, and an impact resistance of up to Grade II. The epoxy resin adhesives obtained in Application Examples 20-24 of the present application had a Vicat temperature in the range of 75-90°C, a pencil hardness in the range of 1H-2H, and an impact resistance of Grade II. Based on the epoxy resin adhesives obtained in Application Examples 1-19 and the epoxy resin adhesives obtained in Application Examples 20-24, it can be seen that the epoxy resin adhesives obtained in Application Examples 1-19 of the present application have higher heat resistance stability and strength.

[0141] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A fast-curing epoxy resin curing agent, characterized in that: Made from the following raw materials in parts by weight: 20-30 parts of isocyanate silane; Polyol phosphate 10-24 parts; Imidazole 4-15 parts; 10-20 parts of solvent; The method for preparing the fast-curing epoxy resin curing agent comprises the following steps: After mixing the isocyanate silane and the solvent, add the polyol phosphate, stir and mix at 70-80° C. for 1-2 hours, then add imidazole, stir and mix for 1-2 hours to obtain the epoxy resin curing agent.

2. The fast-curing epoxy resin curing agent according to claim 1, characterized in that: The isocyanate silane, polyol phosphate and imidazole are mixed in a weight ratio of 1:(0.5-0.8):(0.2-0.5).

3. The fast-curing epoxy resin curing agent according to claim 1, characterized in that: The isocyanate silane includes one or more of isocyanate propyl methyl diethoxy silane, isocyanate propyl methyl dimethoxy silane and isocyanate propyl triethoxy silane.

4. The fast-curing epoxy resin curing agent according to claim 3, characterized in that: The isocyanate silane is a mixture of isocyanate propylmethyldimethoxysilane and isocyanate propylmethyldiethoxysilane in a weight ratio of 1:(0.8-1.2).

5. The fast-curing epoxy resin curing agent according to claim 1, characterized in that: The preparation method of the polyol phosphate ester is as follows: adding polypropylene glycol to polyphosphoric acid, stirring and reacting at 30-50° C. for 3-5 hours, and then adding water, stirring and mixing for 1-2 hours to obtain the polyol phosphate ester.

6. The fast-curing epoxy resin curing agent according to claim 5, characterized in that: The polypropylene glycol and polyphosphoric acid are mixed in a weight ratio of 100:(3.5-4.3).

7. The fast-curing epoxy resin curing agent according to claim 5, characterized in that: The molecular weight of the polypropylene glycol is 360-1000.

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