Latent curing agent based on dynamic crosslinking-controllable solubility mechanism

Abstract

The application provides a latent curing agent based on a dynamic cross-linking-controllable dissolving mechanism. The latent curing agent at least comprises a reaction product of a component with a maleimide structure, a component with a furan ring structure and an amine component with at least two amino groups or imino groups, and the reaction product has a dynamic cross-linking network structure comprising a Diels-Alder addition structure. Compared with the prior art, the latent curing agent can realize long-term storage and medium-low temperature curing of a single-component thermosetting material, especially when the latent curing agent is applied to an epoxy-anhydride system, an epoxy-phenolic system and an epoxy-dicyandiamide system, the curing temperature is reduced, the storage period is longer, the preparation process of the latent curing agent is simple, the operation is simple and convenient, the controllability is good, the latent curing agent is easy to implement, and the latent curing agent is suitable for large-scale industrial production.

Description

Technical Field

[0001] This application specifically relates to a class of latent curing agents based on a dynamic cross-linking-controllable dissolution mechanism and their preparation method, belonging to the field of polymer materials technology. Background Technology

[0002] Thermosetting plastics are widely used in electronic packaging materials, coatings, adhesives, and composite materials due to their excellent thermal, mechanical, chemical, and dimensional stability. To achieve high performance, thermosetting materials (including epoxy resins, unsaturated polyesters, phenolic resins, polyurethanes, and rubbers) are typically used with crosslinking agents (also known as hardeners and curing agents) to obtain a permanently crosslinked network. To avoid pre-use crosslinking reactions, thermosetting materials and crosslinking agents need to be freshly mixed (called two-component thermosetting materials), which leads to wasted time, inconsistent quality, inflexible processing times, and waste of leftover product. Conversely, one-component thermosetting materials, containing thermosetting resin monomers and crosslinking agents in a single batch, solve these problems. For one-component thermosetting materials, latent crosslinking agents (or accelerators) play a crucial role. To date, three methods exist for obtaining latent crosslinking agents (or accelerators): high melting point, chemical modification, and microencapsulation to reduce or reversibly block the reactivity of highly reactive crosslinking agents (or accelerators). However, single-component thermosetting materials often require very low storage temperatures (e.g., -18°C) to achieve long-term storage; and due to the decrease in activity, high temperatures are required to complete cross-linking. Therefore, single-component thermosetting materials that combine long storage life with rapid cross-linking at medium and low temperatures remain a significant challenge. Summary of the Invention

[0003] The main objective of this application is to provide a class of latent curing agents based on a dynamic crosslinking-controllable dissolution mechanism and their preparation method, so as to overcome the shortcomings of the prior art.

[0004] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows.

[0005] The first aspect of this application provides a latent curing agent based on a dynamic crosslinking-controllable dissolution mechanism, the chemical structure of which is a dynamic crosslinking network, the dynamic chemical structure in which the crosslinking network includes a Diels-Alder addition structure.

[0006] A second aspect of this application provides a latent curing agent based on a dynamic crosslinking-controlled dissolution mechanism, which comprises at least the reaction product of the following components:

[0007] Component A includes components having a maleimide structure.

[0008] Component B includes components having a furan ring structure.

[0009] Component C includes amine components having at least two amino or imino groups;

[0010] The reaction product has a dynamic cross-linked network structure including a Diels-Alder addition structure.

[0011] In one embodiment, the mass ratio of the component having the maleimide structure to the component having the furan ring structure is 5:1 to 20, preferably 5:1 to 10, and more preferably 5:2 to 6, to facilitate the obtaining of cross-linked polymer compounds and to make the product easier to break down.

[0012] In one embodiment, the mass ratio of the amine component having at least two amino or imine groups to the component having a maleimide structure is 25:3 to 5. If the mass ratio is too large or too small, some structures in both components may not be cross-linked or the product may not be easily broken down.

[0013] In one embodiment, the component having a maleimide structure includes 1,5-bis(maleimide-cisbutenediimide)-2-methyl-pentane, 1,5-di(maleamide)pentane, 1,5-di(maleamide)hexane, N',N-1,3-phenylenebismaleimide, N',N-1,4-phenylenebismaleimide, N,N-(4-methyl-1,3-phenylene)bismaleimide, 4,4'-bismaleimide-diphenylmethane, 1,2-di(maleimide)ethane, and N',N- The following are any one or more combinations of isophorone bismaleimide, 1,1′-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bismaleimide, 1,1′-methylenebis(cyclohexanediyl)bismaleimide, 1,1′-[1,4-cyclohexanediylbis(methylene)]bismaleimide, tris(2-maleiminoethyl)amine, 6-maleimidehexanoic acid, 11-maleimidedecanoic acid, 3-maleimidepropionic acid, and 4-(maleimino)phenyl isocyanate, and are not limited thereto.

[0014] In one embodiment, the component having a furan ring structure includes any one or a combination of two or more of furfuryl alcohol glycidyl ether, furanyl dimethyl diglycidyl ether, furfurylamine diglycidylamine, furfural, furanyl acrylate, 2-furanacetic acid, tris(2-furanyl)phosphine, and 5-piperidin-1-yl-2-furanaldehyde, and is not limited thereto.

[0015] In one embodiment, the amine component having at least two amino or imino groups includes diethylenetriamine, pentamethyldiethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, 4,4′-diaminodiphenylmethane, ethylenediamine, hexamethylenediamine, adipamide, 1,5-diamino-2-methylpentane, 1,7-diaminoheptane, pentanediamine, diethylaminopropylamine, montananediamine, isophoronediamine, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, bis(4′-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, etc. The following are some of the following: (-amino-3-methylcyclohexyl)methane, 4,4′-diaminodicyclohexylmethane, polyamide, tris(2-aminoethyl)amine, polyetheramine, histamine, propylenediamine, N,N-dimethyldipropylenetriamine, diethylenetriaminepropyltrimethoxysilane, bis(hexamethylene)triamine, N-(6-aminohexyl)-1,6-hexanediamine, trientinium impurity, m-phenylenediamine, polyethylenepolyamine, N-(3-aminopropyl)cyclohexylamine, and N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, or combinations thereof, and are not limited thereto.

[0016] In one embodiment, to obtain the reaction product, a first reaction and a second reaction can be carried out sequentially. The first reaction mainly occurs between a component having a maleimide structure and a component having a furan ring structure, including a Diels-Alder addition reaction. The second reaction mainly occurs between the product of the first reaction and an amine component having at least two amino or imine groups, including one or more of the following: an addition reaction of an epoxide with an amine, an ionization reaction of an organic acid with an amine, a Schiff base reaction, and an addition reaction of an isocyanate with an amine. The temperature of the first reaction can be 40–90°C. The temperature of the second reaction can be 0–90°C, preferably 20–80°C, to promote reaction efficiency.

[0017] A third aspect of this application provides a method for preparing the latent curing agent based on the dynamic crosslinking-controllable dissolution mechanism, comprising:

[0018] A first reaction is carried out in a first homogeneous mixture containing component A, component B, and solvent to obtain a first reaction mixture;

[0019] A second reaction is carried out on a second homogeneous mixture containing the first reaction mixture and component C to obtain the latent curing agent;

[0020] Wherein, component A includes a component having a maleimide structure, component B includes a component having a furan ring structure, component C includes an amine component having at least two amino or imine groups, the first reaction includes a Diels-Alder addition reaction, and the second reaction includes one or more of the following: an addition reaction of an epoxy with an amine, an ionization reaction of an organic acid with an amine, a Schiff base reaction, and an addition reaction of an isocyanate with an amine.

[0021] In one embodiment, the mass ratio of the component having the maleimide structure to the component having the furan ring structure is 5:1 to 20, preferably 5:1 to 10, and more preferably 5:2 to 6.

[0022] In one embodiment, the mass ratio of the amine component having at least two amino or imine groups to the component having a maleimide structure is 25:3 to 5.

[0023] In one embodiment, the mass ratio of the solvent to the component having a maleimide structure is 0–50:10, preferably 0–30:10, more preferably 0–20:10, to make the target product more readily available.

[0024] In one embodiment, the component having a maleimide structure includes 1,5-bis(maleimide-cisbutenediimide)-2-methyl-pentane, 1,5-di(maleamide)pentane, 1,5-di(maleamide)hexane, N',N-1,3-phenylenebismaleimide, N',N-1,4-phenylenebismaleimide, N,N-(4-methyl-1,3-phenylene)bismaleimide, 4,4'-bismaleimide-diphenylmethane, 1,2-di(maleimide)ethane, and N',N- The following are any one or more combinations of isophorone bismaleimide, 1,1′-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bismaleimide, 1,1′-methylenebis(cyclohexanediyl)bismaleimide, 1,1′-[1,4-cyclohexanediylbis(methylene)]bismaleimide, tris(2-maleiminoethyl)amine, 6-maleimidehexanoic acid, 11-maleimidedecanoic acid, 3-maleimidepropionic acid, and 4-(maleimino)phenyl isocyanate, and are not limited thereto.

[0025] In one embodiment, the component having a furan ring structure includes any one or a combination of two or more of furfuryl alcohol glycidyl ether, furanyl dimethyl diglycidyl ether, furfurylamine diglycidylamine, furfural, furanyl acrylate, 2-furanacetic acid, tris(2-furanyl)phosphine, and 5-piperidin-1-yl-2-furanaldehyde, and is not limited thereto.

[0026] In one embodiment, the amine component having at least two amino or imino groups includes diethylenetriamine, pentamethyldiethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, 4,4′-diaminodiphenylmethane, ethylenediamine, hexamethylenediamine, adipamide, 1,5-diamino-2-methylpentane, 1,7-diaminoheptane, pentanediamine, diethylaminopropylamine, montananediamine, isophoronediamine, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, bis(4′-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, etc. The following are some of the following: (-amino-3-methylcyclohexyl)methane, 4,4′-diaminodicyclohexylmethane, polyamide, tris(2-aminoethyl)amine, polyetheramine, histamine, propylenediamine, N,N-dimethyldipropylenetriamine, diethylenetriaminepropyltrimethoxysilane, bis(hexamethylene)triamine, N-(6-aminohexyl)-1,6-hexanediamine, trientinium impurity, m-phenylenediamine, polyethylenepolyamine, N-(3-aminopropyl)cyclohexylamine, and N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine, or combinations thereof, and are not limited thereto.

[0027] In one embodiment, the solvent includes any one or a combination of two or more of toluene, xylene, N',N-dimethylformamide, 1,4-dioxane, dimethyl sulfoxide, chloroform, water, tetrahydrofuran, ethanol, propanol, isopropanol, n-butanol, isobutanol, and N-methylpyrrolidone, and is not limited thereto.

[0028] In one embodiment, the temperature of the first reaction is 40–90°C, preferably 60–80°C, to obtain higher reaction efficiency and make the reaction more complete. If the temperature of the first reaction is too high or too low, the Diels-Alder addition structure will be more reversibly larger than the forward reaction or will not form at all.

[0029] In one embodiment, the reaction time of the first reaction is 2 to 72 hours, preferably 6 to 24 hours.

[0030] In one embodiment, the temperature of the second reaction is 0–90°C, preferably 20–80°C, to obtain higher reaction efficiency and make the reaction more complete. However, if the temperature of the second reaction is too high or too low, it will cause the Diels-Alder bonds to dissociate or fail to crosslink.

[0031] In one embodiment, the second reaction time is 0.5 to 36 hours, preferably 0.5 to 10 hours.

[0032] In one embodiment, after the second reaction is completed, the target product, namely the latent curing agent, can be obtained by post-processing from the formed second reaction mixture. The post-processing may include operations such as solvent removal, washing, and drying.

[0033] The fourth aspect of this application provides the use of the aforementioned latent curing agent based on a dynamic crosslinking-controlled dissolution mechanism in the preparation of latent epoxy resin curing agents, latent epoxy resin curing accelerators, one-component coatings, adhesives, electronic packaging materials, or composite prepregs. Furthermore, the latent curing agent can also be used in the aerospace field.

[0034] A fifth aspect of this application provides a resin composition comprising an epoxy resin and the latent curing agent based on a dynamic crosslinking-controlled dissolution mechanism.

[0035] In one embodiment, the mass ratio of the latent curing agent to the epoxy resin is 0.5 to 150:100, preferably 3 to 80:100.

[0036] In one embodiment, the resin composition comprises an epoxy system. Further, the epoxy system comprises any one or a combination of two or more of an epoxy-anhydride system, an epoxy-phenolic system, and an epoxy-dicyandiamide system, and is not limited thereto.

[0037] The sixth aspect of this application provides a single-component thermosetting material that can be formed from an epoxy resin and the latent curing agent based on a dynamic crosslinking-controlled dissolution mechanism.

[0038] In one embodiment, the mass ratio of the latent curing agent to the epoxy resin is 0.5 to 150:100, preferably 3 to 80:100.

[0039] Compared with the prior art, this application has at least the following beneficial effects:

[0040] Firstly, a latent curing agent based on a dynamic cross-linked network structure was constructed. This agent introduces a dynamic cross-linking-controllable dissolution mechanism: at low temperatures (e.g., room temperature), the curing agent, as a cross-linked network structure, is insoluble in epoxy resin and exhibits no curing activity; under heating conditions, the dynamic cross-linked structure in the curing agent de-crosslinks, dissolves in epoxy resin, and exhibits high curing activity. This provides a new, simple, and efficient strategy for developing single-component thermosetting resins. Using this latent curing agent as a latent curing agent or curing accelerator for thermosetting resins can effectively conceal and control the reactivity of the highly active cross-linking agent, achieving long-term storage and rapid cross-linking of single-component thermosetting materials. In particular, it balances long-term storage at room temperature and rapid curing at medium and low temperatures, showing broad application prospects in single-component coatings, adhesives, electronic packaging materials, and composite prepregs.

[0041] Secondly, the process for preparing the latent curing agent based on the dynamic cross-linked network structure is simple, easy to operate, well controllable, easy to implement, and suitable for large-scale industrial production. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a photograph of a latent curing agent from Embodiment 1 of this application;

[0044] Figure 2 This is a temperature-varying infrared spectrum of a latent curing agent in Example 1 of this application;

[0045] Figure 3 This is a latent curing agent after heating in Embodiment 1 of this application. 1 H NMR spectrum. Detailed Implementation

[0046] To further understand this application, several embodiments are described below. It should be understood that these embodiments are for illustrative purposes only and not for limiting the scope of this application. Non-essential improvements and adjustments made by those skilled in the art under the core guiding principles of this application are still within the protection scope of this application. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise specified, the experimental materials used in the embodiments below can be purchased from conventional biochemical reagent stores.

[0047] The specific test methods used in the following embodiments are as follows:

[0048] Rheological experiments: The viscosity of the samples was measured by isothermal rheological experiments using a rheometer (MCR) 302e (Anton Paar, Austria) on a 25 mm sample tray with a parallel plate geometry. The shear strain ranged from 0.01% to 10% (the specific shear strain value was determined based on the test value in the linear elastic region), the frequency was 1 Hz, the temperature was 25 °C, and the time was 10 min.

[0049] Differential scanning calorimetry (DSC): A Mettler-Toledo Star3 DSC (Mettler-Toledo, USA) was used in a nitrogen atmosphere at a rate of 50 mL / min. -1 The flow rate, and the heating rate from 25 to 180°C, is 10°C / min. -1 Record the DSC curve to measure the glass transition temperature.

[0050] Tensile test: A general-purpose testing machine UTM4000 (Shenzhen Sansi Zongheng Technology Co., Ltd., China) was used. The gauge length of the specimen was 40 mm, and the specimen dimensions were 80 mm (length) × 6 mm (width) × 0.3 mm (thickness). The test was conducted at 5 mm min. -1 Tests were conducted at various speeds.

[0051] Example 1

[0052] 100 parts (unless otherwise specified, all parts are by weight) of 1,5-bis(maleimide maleate diimide)-2-methyl-pentane, 110 parts of furfuryl alcohol glycidyl ether, and 200 parts of toluene were placed in a round-bottom flask and stirred with a stirrer for a first reaction at 70°C for 8 hours. After cooling to room temperature, 80 parts of tetraethylenepentamine were added. After a second reaction at 70°C for 36 hours, the solvent was removed, the mixture was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the target product, i.e., the latent curing agent, which is in powder form, such as... Figure 1 As shown. The temperature-varying infrared spectrum of this latent curing agent is as follows. Figure 2 As shown, at 1650cm- 1 The characteristic infrared absorption peaks are those of the Diels-Alder addition structure. Figure 3 The image shows the latent curing agent after being heated and dissolved in DMSO-d6 at 130°C. 1 The H NMR spectrum shows peaks for the furan ring after the reverse Diels-Alder reaction and for hydrogen atoms on the maleimide structure, which are part of the Diels-Alder addition structure.

[0053] Comparative Example 1

[0054] 100 parts of 1,5-bis(maleimide maleide diimide)-2-methyl-pentane, 110 parts of furfuryl alcohol glycidyl ether and 200 parts of toluene were placed in a round-bottom flask, stirred with a stirrer and reacted at 70°C for 8 hours. Then the mixture was cooled to room temperature, the solvent was removed, the mixture was pulverized into a fine powder, washed with petroleum ether and dried to obtain the final product.

[0055] Comparative Example 2

[0056] 100 parts of 1,5-bis(maleimide maleide diimide)-2-methyl-pentane, 110 parts of furfuryl alcohol glycidyl ether, 80 parts of tetraethylenepentamine and 200 parts of toluene were placed in a round-bottom flask, stirred with a stirrer and reacted at 70°C for 44 hours. The solvent was removed, the mixture was pulverized into a fine powder, washed with petroleum ether and dried to obtain the final product.

[0057] Comparative Example 3 provides a method for preparing a latent curing agent that is basically the same as that in Example 1, except that 500 parts of tetraethylenepentamine were used.

[0058] The preparation method of the latent curing agent provided in Comparative Example 4 is basically the same as that in Example 1, except that 60 parts of tetraethylenepentamine were used.

[0059] The preparation method of the latent curing agent provided in Comparative Example 5 is basically the same as that in Example 1, except that the temperature of the first reaction is set to 35°C.

[0060] The preparation method of the latent curing agent provided in Comparative Example 6 is basically the same as that in Example 1, except that the temperature of the first reaction is set to 95°C.

[0061] The preparation method of the latent curing agent provided in Comparative Example 7 is basically the same as that in Example 1, except that the temperature of the first reaction is set to -1℃.

[0062] Example 2

[0063] 100 parts of N',N-isophorone bismaleimide and 120 parts of furfuryl alcohol glycidyl ether were placed in a round-bottom flask, stirred, and reacted at 90°C for 2 hours. After cooling to room temperature, 80 parts of tetraethylenepentamine were added. After reacting at 0°C for 36 hours, the mixture was pulverized into a fine powder, washed with ethanol, and dried to obtain the target product in powder form.

[0064] Example 3

[0065] 358 parts of 4,4'-bismaleimide diphenylmethane, 240 parts of furanyl dimethyl diglycidyl ether, and 1790 parts of ethanol were placed in a round-bottom flask, stirred, and reacted at 70°C for 5 hours. After cooling to room temperature, 750 parts of 4,4'-diaminodiphenylmethane were added. After reacting at 90°C for 1 hour, the solvent was removed, the mixture was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0066] Example 4

[0067] 358 parts of N',N-1,3-phenylenebismaleimide, 240 parts of furanyl dimethyl diglycidyl ether, and 380 parts of 1,4-dioxane were placed in a round-bottom flask, stirred, and reacted at 70°C for 5 hours. After cooling to room temperature, 750 parts of N-aminoethylpiperazine were added. After reacting at 70°C for 0.5 hours, the solvent was removed, the product was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0068] Example 5

[0069] 100 parts of 4,4'-bismaleimide diphenylmethane, 150 parts of furfuryl alcohol glycidyl ether, and 280 parts of 1,4-dioxane were placed in a round-bottom flask, stirred, and reacted at 70°C for 3 hours. After cooling to room temperature, 100 parts of trientin impurity were added. After reacting at 70°C for 36 hours, the solvent was removed, the mixture was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0070] Example 6

[0071] 100 parts of 1,5-bis(maleimide maleate diimide)-2-methyl-pentane and 120 parts of furfurylamine diglycidyl ether were placed in a round-bottom flask, stirred, and reacted at 70°C for 72 hours. After cooling to room temperature, 60 parts of polyetheramine D230 were added. After reacting at 70°C for 6 hours, a gel-like product was obtained. The gel was crushed and vacuum dried at 70°C for 24 hours to remove the solvent. The product was then pulverized into a fine powder, dried, and the powdered target product was obtained.

[0072] Example 7

[0073] 80 parts of tris(2-maleimide ethyl)amine, 64 parts of furfuryl alcohol glycidyl ether, and 400 parts of 1,4-dioxane were placed in a round-bottom flask, stirred, and reacted at 70°C for 10 hours. After cooling to room temperature, 400 parts of tris(2-aminoethyl)amine were added. After reacting at 0°C for 36 hours, the solvent was removed, the mixture was pulverized into a fine powder, washed with water, and dried to obtain the powdered target product.

[0074] Example 8

[0075] 20 parts of 4-(maleimide)phenyl isocyanate, 15 parts of furfuryl alcohol glycidyl ether, and 100 parts of N-methylpyrrolidone were placed in a round-bottom flask, stirred, and reacted at 70°C for 5 hours. After cooling to room temperature, 100 parts of 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane were added, and the mixture was reacted at 70°C for 0.5 hours. The solvent was removed, the mixture was pulverized into a fine powder, washed with water, and dried to obtain the powdered target product.

[0076] Example 9

[0077] 100 parts of 1,5-bis(maleimide maleate diimide)-2-methyl-pentane, 110 parts of furfuryl alcohol glycidyl ether, and 80 parts of N',N-dimethylformamide were placed in a round-bottom flask, stirred, and reacted at 50°C for 12 hours. After cooling to room temperature, 80 parts of 4,4′-diaminodiphenylmethane were added. The mixture was reacted at 90°C for 0.5 hours, the solvent was removed, the product was pulverized into a fine powder, washed with propanol, and dried to obtain the powdered target product.

[0078] Example 10

[0079] 20 parts of 1,1′-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bismaleimide, 60 parts of furfuryl alcohol glycidyl ether, and 100 parts of xylene were placed in a round-bottom flask, stirred, and reacted at 90°C for 5 hours. After cooling to room temperature, 80 parts of triethylenetetramine were added. After reacting at 90°C for 0.5 hours, the solvent was removed, the product was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0080] Example 11

[0081] 100 parts of 1,1′-[1,4-cyclohexanediylbis(methylene)]bismaleimide, 150 parts of furfurylamine diglycidylamine, and 500 parts of toluene were placed in a round-bottom flask and stirred at 70°C for 22 hours. After cooling to room temperature, 160 parts of triethylenetetramine were added. After reacting at 0°C for 20 hours, the solvent was removed, the mixture was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0082] Example 12

[0083] 100 parts of 1,1′-[1,4-cyclohexanediyl-bis(methylene)]bismaleimide, 100 parts of 5-phenyl-2-furancarboxylic acid, and 280 parts of anisole were placed in a round-bottom flask, stirred, and reacted at 70°C for 22 hours. After cooling to room temperature, 160 parts of triethylenetetramine were added. After reacting at 80°C for 5 hours, the solvent was removed, the mixture was pulverized into a fine powder, washed with ethanol, and dried to obtain the powdered target product.

[0084] Example 13

[0085] 50 parts of N',N-1,3-phenylenebismaleimide, 50 parts of 5-piperidin-1-yl-2-furanaldehyde, and 180 parts of tetrahydrofuran were placed in a round-bottom flask, stirred, and reacted at 65°C for 8 hours. After cooling to room temperature, 60 parts of propylenediamine were added. After reacting at 60°C for 5 hours, the solvent was removed, the mixture was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0086] Example 14

[0087] 70 parts of 3-maleimide propionic acid, 60 parts of furanylpropionic acid, and 80 parts of chloroform were placed in a round-bottom flask, stirred, and reacted at 70°C for 72 hours. After cooling to room temperature, 80 parts of m-phenylenediamine were added. The mixture was reacted at 90°C for 15 hours, the solvent was removed, the product was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0088] Example 15

[0089] 70 parts of 4,4'-bismaleimide diphenylmethane, 130 parts of furfural, and 140 parts of 1,4-dioxane were placed in a round-bottom flask, stirred, and reacted at 70°C for 12 hours. After cooling to room temperature, 80 parts of tetraethylenepentamine were added. The mixture was reacted at 70°C for 3 hours, the solvent was removed, the product was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0090] Example 16

[0091] 100 parts of 6-maleimide hexanoic acid, 220 parts of furfural, and 300 parts of ethylene glycol monomethyl ether were placed in a round-bottom flask, stirred, and reacted at 70°C for 5 hours. After cooling to room temperature, 80 parts of tetraethylenepentamine were added. The mixture was reacted at 70°C for 36 hours, the solvent was removed, the product was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the target product in powder form.

[0092] Example 17

[0093] 100 parts of 11-maleimide decanoic acid, 300 parts of furfural, and 300 parts of dimethyl sulfoxide were placed in a round-bottom flask, stirred, and reacted at 60°C for 5 hours. After cooling to room temperature, 500 parts of diethylenetriamine-propyltrimethoxysilane were added. The reaction was carried out at 0°C for 20 hours, the solvent was removed, the product was pulverized into a fine powder, washed with water, and dried to obtain the target product in powder form.

[0094] Example 18

[0095] 200 parts of tris(2-maleimide ethyl)amine, 40 parts of furfural, and 400 parts of chloroform were placed in a round-bottom flask, stirred, and reacted at 60°C for 22 hours. After cooling to room temperature, 120 parts of pentanediamine were added. The mixture was reacted at 70°C for 36 hours, the solvent was removed, the product was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the target product in powder form.

[0096] Example 19

[0097] 100 parts of tris(2-maleimide ethyl)amine, 400 parts of furfural, and 200 parts of 1,4-dioxane were placed in a round-bottom flask, stirred, and reacted at 70°C for 12 hours. After cooling to room temperature, 100 parts of pentanediamine were added. The mixture was reacted at 50°C for 18 hours, the solvent was removed, the product was pulverized into a fine powder, washed with petroleum ether, and dried to obtain the powdered target product.

[0098] Example 20

[0099] 500 parts of tris(2-maleimide ethyl)amine, 100 parts of tris(2-furanyl)phosphine, 300 parts of 1,4-dioxane, and 200 parts of acetonitrile were placed in a round-bottom flask, stirred, and reacted at 70°C for 10 hours. After cooling to room temperature, 300 parts of polyetheramine D230 were added. The mixture was reacted at 60°C for 3 hours, the solvent was removed, the product was pulverized into a fine powder, washed with water, and dried to obtain the powdered target product.

[0100] Application Example 1

[0101] 60 parts of the final product of Example 1 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 6 months, the viscosity was 1.05 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2.5 hours, and the glass transition temperature was 75°C and the tensile strength was 85 MPa.

[0102] Comparative Application Example 1-1

[0103] 60 parts of the final product of Comparative Example 1 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 6 months, the viscosity was 1.01 times that of the initial viscosity. The mixture was heated at 130°C for 2.5 hours and remained liquid without curing.

[0104] Comparative Application Examples 1-2

[0105] 60 parts of the final product of Comparative Example 2 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 6 months, the viscosity was 3.2 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2.5 hours, and the glass transition temperature was 60°C and the tensile strength was 40 MPa.

[0106] Comparative Application Examples 1-3

[0107] 60 parts of the final product of Comparative Example 3 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After one day, the viscosity was 6 times that of the initial viscosity, and after half a month, it had become solid. The single-component mixture was heated at 130°C for 2.5 hours, and the glass transition temperature was 45°C and the tensile strength was 35 MPa.

[0108] Compare and contrast examples 1-4

[0109] 60 parts of the final product of Comparative Example 4 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 6 months, the viscosity was 1.01 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2.5 hours, and the glass transition temperature was 67°C and the tensile strength was 50 MPa.

[0110] Compare and contrast examples 1-5

[0111] 60 parts of the final product of Comparative Example 5 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 1 day, it turned into a solid. The single-component mixture was heated at 130°C for 2.5 hours, and the glass transition temperature was 68°C and the tensile strength was 74 MPa.

[0112] Comparative Application Examples 1-6

[0113] 60 parts of the final product of Comparative Example 6 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 2 months, the viscosity was 2.1 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2.5 hours, and the glass transition temperature was 65°C and the tensile strength was 70 MPa.

[0114] Compare and contrast examples 1-7

[0115] 60 parts of the final product of Comparative Example 6 were added to 100 parts of bisphenol A epoxy resin (E-51) and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 0.5 months, the viscosity was 2.3 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2.5 hours, and the glass transition temperature was 63°C and the tensile strength was 65 MPa.

[0116] Application Example 2

[0117] Three parts of the final product of Example 1 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 4 months, the viscosity remained basically unchanged. The single-component mixture was heated at 130°C for 2 hours, and the glass transition temperature was 125°C and the tensile strength was 110 MPa.

[0118] Comparative application example 2-1

[0119] Three parts of the final product of Comparative Example 1 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 4 months, the viscosity was 1.01 times the initial viscosity. The single-component mixture was heated at 130°C for 2 hours and remained liquid, unable to solidify.

[0120] Comparative application example 2-2

[0121] Three parts of the final product of Comparative Example 2 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After half a month, the viscosity was 2.6 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2 hours, and the glass transition temperature was 104°C and the tensile strength was 95 MPa.

[0122] Compare and contrast with example 2-3

[0123] Three parts of the final product of Comparative Example 3 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After one day, the viscosity was 2.4 times that of the initial viscosity, and after half a month, it had become a solid. The single-component mixture was heated at 130°C for 2 hours, and the glass transition temperature was 106°C and the tensile strength was 98 MPa.

[0124] Compare and apply examples 2-4

[0125] Three parts of the final product of Comparative Example 4 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 4 months, the viscosity was 1.01 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2 hours, and the glass transition temperature was 92°C and the tensile strength was 89 MPa.

[0126] Compare and contrast with example 2-5

[0127] Three parts of the final product of Comparative Example 5 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After 2 days, the viscosity was 2.3 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2 hours, and the glass transition temperature was 95°C and the tensile strength was 92 MPa.

[0128] Compare and apply examples 2-6

[0129] Three parts of the final product of Comparative Example 6 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After one month, the viscosity was 2.2 times that of the initial viscosity. The single-component mixture was heated at 130°C for 2 hours, and the glass transition temperature was 100°C and the tensile strength was 91 MPa.

[0130] Compare and apply example 2-7

[0131] Three parts of the final product of Comparative Example 7 were added to 100 parts of bisphenol A epoxy resin (AG-80) and 140 parts of polyazelic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. After one month, the viscosity was 2.1 times the initial viscosity. The single-component mixture was heated at 130°C for 2 hours, and the glass transition temperature was 98°C and the tensile strength was 92 MPa.

[0132] Application Example 3

[0133] Three parts of the final product of Example 1 were added to 100 parts of bisphenol A epoxy resin (E-51) and 7 parts of dicyandiamide and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. The viscosity was 1.2 times that of the initial viscosity after 6 months. The single-component mixture was cured at 130°C for 1 hour and at 150°C for 3 hours. The glass transition temperature was 110°C and the tensile strength was 60 MPa.

[0134] Application Example 4

[0135] 0.5 parts of the final product of Example 2 were added to 100 parts of bisphenol A epoxy resin (DER-331) and 70 parts of tetrahydrophthalic anhydride and mixed evenly. The viscosity was then monitored by a rheometer at room temperature. The viscosity was 1.01 times that of the initial viscosity after 6 months. The single component was cured at 120°C for 0.5 hours and then cured at 150°C for 2.5 hours. The glass transition temperature was 100°C and the tensile strength was 75 MPa.

[0136] Application Example 5

[0137] 40 parts of the final product of Example 3 were added to 100 parts of bisphenol A epoxy resin (DER-331) and mixed evenly. The mixture was then stored at room temperature for 5 months. After 6 months, the viscosity was 1.01 times that of the initial viscosity. The single-component mixture was cured at 110°C for 1 hour and then at 160°C for 3 hours. The glass transition temperature was 165°C and the tensile strength was 80 MPa.

[0138] Application Example 6

[0139] Fifty parts of the final product from Examples 4-10 were added to 100 parts of bisphenol A epoxy resin (DER-331) and mixed uniformly. The viscosity was then monitored using a rheometer at room temperature. After 6 months, the viscosity was 1.02 times, 1.03 times, 1.01 times, 1.12 times, 1.01 times, and 1.02 times that of the initial viscosity, respectively. The single component was cured at 140°C for 2 hours, and the glass transition temperatures were 121°C, 90°C, 78°C, 95°C, 110°C, 157°C, and 135°C, respectively. The tensile strengths were 105 MPa, 80 MPa, 70 MPa, 83 MPa, 120 MPa, 95 MPa, and 125 MPa, respectively.

[0140] Application Example 7

[0141] Fifty parts of the final products from Examples 19 and 20 were added to 100 parts of bisphenol A epoxy resin (E-54) and mixed evenly. The viscosity was then monitored using a rheometer at room temperature. After 6 months, the viscosity was 1.01 times, 1.19 times, and 1.03 times that of the initial viscosity, respectively. The three single-component mixtures were cured at 150°C for 5 hours to successfully prepare cured products with glass transition temperatures of 123°C, 130°C, and 125°C, and tensile strengths of 126 MPa, 115 MPa, and 130 MPa, respectively.

[0142] Application Example 8

[0143] Forty parts of the final products from Examples 12, 14, and 18 were added to 100 parts of bisphenol A epoxy resin (E-54) and mixed uniformly. The viscosity was then monitored using a rheometer at room temperature. After 6 months, the viscosities were 1.3 times, 1.4 times, and 1.03 times the initial values, respectively. The three-component mixtures were cured at 130°C for 5 hours, followed by curing at 150°C for 2.5 hours to successfully prepare cured products. The glass transition temperatures were 81°C, 175°C, and 95°C, respectively, and the tensile strengths were 100 MPa, 85 MPa, and 65 MPa, respectively.

[0144] Application Example 9

[0145] Fifty parts of the final products from Examples 12, 14, and 18 were added to 100 parts of bisphenol A epoxy resin (E-54) and mixed uniformly. The viscosity was then monitored using a rheometer at room temperature. After 6 months, the viscosity was 1.3 times, 1.4 times, and 1.05 times that of the initial viscosity, respectively. The three single-component mixtures were cured at 120°C for 5 hours and then at 160°C for 2.5 hours to successfully prepare cured products. The glass transition temperatures were 90°C, 180°C, and 100°C, respectively, and the tensile strengths were 105 MPa, 90 MPa, and 70 MPa, respectively.

[0146] Application Example 10

[0147] Three portions of the final products from Examples 13, 15, and 16 were added to 100 portions of bisphenol F epoxy resin (S-170) and 60 portions of phenolic resin, respectively, and mixed uniformly. The viscosity was then monitored using a rheometer at room temperature. After 6 months, the viscosity was 1.4 times, 1.5 times, and 1.05 times that of the initial viscosity, respectively. The three single-component mixtures were then cured at 130°C for 5 hours, followed by curing at 140°C for 2.5 hours to successfully prepare cured products. The glass transition temperatures were 115°C, 120°C, and 98°C, respectively, and the tensile strengths were 75 MPa, 80 MPa, and 93 MPa, respectively.

[0148] In addition, the applicant also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0149] As can be seen from the above embodiments, the epoxy resin latent curing agent (or accelerator) developed in this application based on the dynamic crosslinking-controllable dissolution mechanism has a simple preparation process, is easy to operate, is well controllable, easy to implement, and is suitable for large-scale industrial production. Moreover, based on this type of epoxy resin latent curing agent (or accelerator), long-term storage and medium-low temperature curing of single-component thermosetting materials can be achieved. In particular, when applied to epoxy-anhydride systems, epoxy-phenolic systems, and epoxy-dicyandiamide systems, it not only reduces the curing temperature but also significantly extends the storage period, and provides a new, simple, and efficient strategy for developing single-component thermosetting resins.

[0150] Although this application has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of this application, and that elements of the described embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of this application to adapt particular situations or materials to the teachings of this application. Therefore, this application is not intended to be limited to the specific embodiments disclosed for carrying out this application, but rather is intended to include all embodiments falling within the scope of the appended claims.

Claims

1. A latent curing agent based on a dynamic cross-linking-controllable dissolution mechanism, characterized in that, The reaction products must include at least the following components: Component A includes components having a maleimide structure. Component B includes components having a furan ring structure. Component C includes amine components having at least two amino or imino groups; The reaction product has a dynamic cross-linked network structure including a Diels-Alder addition structure, and the reaction product is obtained by means of: A first reaction is carried out in a first homogeneous mixed reaction system containing component A, component B and solvent to obtain a first reaction mixture, wherein the temperature of the first reaction is 40~90℃. A second reaction is carried out in a second homogeneous mixture containing the first reaction mixture and component C. The temperature of the second reaction is 0~90°C. The second reaction includes one or more of the following: addition reaction of epoxy with amine, ionization reaction of organic acid with amine, Schiff base reaction, and addition reaction of isocyanate with amine. The mass ratio of the component having a maleimide structure to the component having a furan ring structure is 5:1 to 20, and the mass ratio of the amine component having at least two amino or imine groups to the component having a maleimide structure is 25 to 3:

5.

2. The latent curing agent based on a dynamic crosslinking-controllable dissolution mechanism according to claim 1, characterized in that: The components having a maleimide structure include 1,5-bis(maleimide-cisbutenediimide)-2-methyl-pentane, 1,5-di(maleamide)pentane, 1,5-di(maleamide)hexane, N',N-1,3-phenylenebismaleimide, N',N-1,4-phenylenebismaleimide, N,N-(4-methyl-1,3-phenylene)bismaleimide, 4,4'-bismaleimide diphenylmethane, 1,2-di(maleimide)ethane, and N',N-isophorone bismaleimide, 1,1′-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bismaleimide. The first one or a combination of two or more of the following: maleimide, 1,1′-methylenebis(cyclohexyl)bismaleimide, 1,1′-[1,4-cyclohexanediylbis(methylene)]bismaleimide, tris(2-maleimide ethyl)amine, 6-maleimide hexanoic acid, 11-maleimide decanoic acid, 3-maleimide propionic acid, and 4-(maleimide) phenyl isocyanate.

3. The latent curing agent based on a dynamic crosslinking-controllable dissolution mechanism according to claim 1, characterized in that: The components having a furan ring structure include any one or a combination of two or more of furfuryl alcohol glycidyl ether, furanyl dimethyl diglycidyl ether, furfurylamine diglycidylamine, furfural, furanyl acrylate, 2-furanacetic acid, tris(2-furanyl)phosphine, and 5-piperidin-1-yl-2-furanaldehyde.

4. The latent curing agent based on a dynamic crosslinking-controllable dissolution mechanism according to claim 1, characterized in that: The amine components having at least two amino or imino groups include diethylenetriamine, pentamethyldiethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, 4,4'-diaminodiphenylmethane, ethylenediamine, hexamethylenediamine, adipamide, 1,5-diamino-2-methylpentane, 1,7-diaminoheptane, pentanediamine, diethylaminopropylamine, montananediamine, isophoronediamine, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, bis(4- One or more combinations of amino-3-methylcyclohexyl)methane, 4,4'-diaminodicyclohexylmethane, polyamide, tris(2-aminoethyl)amine, polyetheramine, histamine, propylenediamine, N,N-dimethyldipropylenetriamine, diethylenetriaminopropyltrimethoxysilane, bis(hexamethylene)triamine, N-(6-aminohexyl)-1,6-hexanediamine, trientine impurities, m-phenylenediamine, polyethylenepolyamine, N-(3-aminopropyl)cyclohexylamine, and N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine.

5. A method for preparing a latent curing agent based on a dynamic cross-linking-controllable dissolution mechanism, characterized in that, include: A first reaction is carried out in a first homogeneous mixed reaction system containing component A, component B and solvent to obtain a first reaction mixture, wherein the temperature of the first reaction is 40~90℃. The second uniformly mixed reaction system containing the first reaction mixture and component C is subjected to a second reaction to obtain the latent curing agent. The temperature of the second reaction is 0~90℃. Wherein, component A includes a component having a maleimide structure, component B includes a component having a furan ring structure, component C includes an amine component having at least two amino or imine groups, the first reaction includes a Diels-Alder addition reaction, and the second reaction includes one or more of the following: an addition reaction of an epoxy with an amine, an ionization reaction of an organic acid with an amine, a Schiff base reaction, and an addition reaction of an isocyanate with an amine. Furthermore, the mass ratio of the component having a maleimide structure to the component having a furan ring structure is 5:1 to 20, the mass ratio of the amine component having two or more amino or imine groups to the component having a maleimide structure is 25 to 3:5, and the mass ratio of the solvent to the component having a maleimide structure is 0 to 50:

10.

6. The preparation method according to claim 5, characterized in that: The components having a maleimide structure include 1,5-bis(maleimide-cisbutenediimide)-2-methyl-pentane, 1,5-di(maleamide)pentane, 1,5-di(maleamide)hexane, N',N-1,3-phenylenebismaleimide, N',N-1,4-phenylenebismaleimide, N,N-(4-methyl-1,3-phenylene)bismaleimide, 4,4'-bismaleimide diphenylmethane, 1,2-di(maleimide)ethane, and N',N-iso The following are any one or a combination of two or more of the following: phorone bismaleimide, 1,1′-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bismaleimide, 1,1′-methylenebis(cyclohexanediyl)bismaleimide, 1,1′-[1,4-cyclohexanediylbis(methylene)]bismaleimide, tris(2-maleiminoethyl)amine, 6-maleimide hexanoic acid, 11-maleimide decanoic acid, 3-maleimide propionic acid, and 4-(maleimino)phenyl isocyanate.

7. The preparation method according to claim 5, characterized in that: The components having a furan ring structure include any one or a combination of two or more of furfuryl alcohol glycidyl ether, furanyl dimethyl diglycidyl ether, furfurylamine diglycidylamine, furfural, furanyl acrylate, 2-furanacetic acid, tris(2-furanyl)phosphine, and 5-piperidin-1-yl-2-furanaldehyde.

8. The preparation method according to claim 5, characterized in that: The amine components having at least two amino or imino groups include diethylenetriamine, pentamethyldiethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, 4,4'-diaminodiphenylmethane, ethylenediamine, hexamethylenediamine, adipamide, 1,5-diamino-2-methylpentane, 1,7-diaminoheptane, pentanediamine, diethylaminopropylamine, montananediamine, isophoronediamine, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, bis(4... One or more of the following: (-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, polyamide, tris(2-aminoethyl)amine, polyetheramine, histamine, propylenediamine, N,N-dimethyldipropylenetriamine, diethylenetriaminepropyltrimethoxysilane, bis(hexamethylene)triamine, N-(6-aminohexyl)-1,6-hexanediamine, trientinium impurity, m-phenylenediamine, polyethylenepolyamine, N-(3-aminopropyl)cyclohexylamine, and N'-(3-aminopropyl)-N,N-dimethyl-1,3-propanediamine.

9. The preparation method according to claim 5, characterized in that: The solvent includes any one or a combination of two or more of toluene, xylene, N',N-dimethylformamide, 1,4-dioxane, dimethyl sulfoxide, chloroform, water, tetrahydrofuran, ethanol, propanol, isopropanol, n-butanol, isobutanol, N-methylpyrrolidone, acetonitrile, anisole, or ethylene glycol monomethyl ether.

10. The preparation method according to claim 5, characterized in that: The reaction time for the first reaction is 2 to 72 hours.

11. The preparation method according to claim 5, characterized in that: The second reaction takes 0.5 to 36 hours.

12. A latent curing agent based on a dynamic cross-linking-controllable dissolution mechanism, characterized in that, It is prepared by the method described in any one of claims 6-11.

13. The use of the latent curing agent based on the dynamic crosslinking-controllable dissolution mechanism according to any one of claims 1-5 and 12 in the preparation of epoxy resin latent curing agents, epoxy resin latent curing accelerators, single-component coatings, adhesives, electronic packaging materials or composite prepregs.

14. A resin composition comprising an epoxy resin, characterized in that: The resin composition further includes any one of claims 1-5 and 12, a latent curing agent based on a dynamic crosslinking-controlled dissolution mechanism.

15. The resin composition according to claim 14, characterized in that: The mass ratio of the latent curing agent to the epoxy resin is 0.5~150:

100.

16. The resin composition according to claim 14, characterized in that: The resin composition includes an epoxy system, which includes any one or a combination of two or more of the following: epoxy-anhydride system, epoxy-phenolic system, and epoxy-dicyandiamide system.

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