Resin composition

Abstract

The application discloses a resin composition, which comprises, in mass parts, 10-60 mass parts of a rigid curing agent comprising a ring structure and an active group; 62-240 mass parts of a flexible cross-linking curing agent comprising a long-chain structure and an active group; and 50-200 mass parts of an epoxy resin prepolymer; and at least one of the rigid curing agent and the flexible cross-linking curing agent comprises a dynamic bond. The resin composition can obtain an epoxy resin polymer with good rigidity, good toughness and good self-repairing performance.

Description

Technical Field

[0001] This application relates to a resin composition. Background Technology

[0002] Traditional thermosetting resins, such as epoxy resins, are made from epoxy resin prepolymers and curing agents. Under room temperature or heating conditions, the active groups in the curing agent undergo ring-opening addition reactions with the epoxy groups to generate a highly cross-linked network structure.

[0003] However, traditional thermosetting resins generally suffer from problems such as high rigidity, poor fracture toughness, and insufficient interfacial bond strength. During use, the brittle fracture behavior of thermosetting resins is irreversible, and interfacial layer failure is easily triggered during the microcrack initiation and propagation stages, leading to overall structural failure and limiting their reliability and durability under complex stress environments. Summary of the Invention

[0004] This application provides a resin composition that can yield an epoxy resin polymer with good stiffness, good toughness, and good self-healing properties.

[0005] This application provides a resin composition comprising, by weight parts: 10 to 60 parts by weight of a rigid curing agent, the rigid curing agent comprising a cyclic structure and active groups; 62 to 240 parts by weight of a flexible crosslinking curing agent, the flexible crosslinking curing agent comprising a long-chain structure and active groups; and 50 to 200 parts by weight of an epoxy resin prepolymer; at least one of the rigid curing agent and the flexible crosslinking curing agent comprising dynamic bonds.

[0006] In some embodiments, the curing agent comprises, by weight parts: 20 to 30 parts of a rigid curing agent, the rigid curing agent comprising a cyclic structure and active groups; 80 to 160 parts of a flexible crosslinking curing agent, the flexible crosslinking curing agent comprising a long-chain structure and active groups; and 100 to 140 parts of an epoxy resin prepolymer; at least one of the rigid curing agent and the flexible crosslinking curing agent comprising dynamic bonds.

[0007] In some embodiments, the dynamic bond includes one or more of the following: borate ester bond, hydrogen bond, metal coordination bond, and Diels-Alder bond.

[0008] In some embodiments, the cyclic structure includes one or more of the following: aroma ring, ester ring, and heterocycle.

[0009] In some embodiments, the long-chain structure includes one or more of carbon chains of C2 to C500 and heterochains of C2 to C500.

[0010] In some embodiments, the dynamic bond includes a borate ester bond.

[0011] In some embodiments, the cyclic structure comprises a benzene ring.

[0012] In some embodiments, the long-chain structure comprises polyethers of C2 to C500.

[0013] In some embodiments, the active group includes one or more of amino, imino, hydroxyl, thiol, and carboxyl groups.

[0014] In some embodiments, the rigid curing agent includes one or more of 3-[4-(aminomethyl)-1,3,2-dioxane-2-yl]aniline, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfone, 2,6-diaminopyridine, 1,3-phenylenediamine / 1,4-phenylenediamine, bisphenol A, and hydroquinone.

[0015] In some embodiments, the flexible crosslinking curing agent includes one or more of polyetheramine, polyenol, and polyenamine.

[0016] In some embodiments, the epoxy resin prepolymer includes one or more of alicyclic and aliphatic epoxy resin prepolymers, bisphenol A and its modified epoxy resin prepolymers, and hydrogenated bisphenol epoxy resin prepolymers.

[0017] In some embodiments, the polyetheramine includes one or more of polypropylene glycol diamine, polyethylene glycol diamine, polyethertriamine, and aliphatic polyetheramine.

[0018] In some embodiments, polyenols include one or more of polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polyvinyl alcohol, and polycaprolactone glycol.

[0019] In some embodiments, polyenamine includes one or more of amino-terminated polybutadiene and amino-terminated hydrogenated polybutadiene.

[0020] In some embodiments, the aliphatic epoxy resin prepolymer includes one or more of 4-cyclohexene-1,2-dicarboxylic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate, dicyclopentadiene diepoxide, and alicyclic diglycidyl ether.

[0021] In some embodiments, bisphenol A and its modified epoxy resin prepolymers include one or more of bisphenol A type epoxy resin, bisphenol A modified epoxy resin, and high molecular weight bisphenol A epoxy resin.

[0022] In some embodiments, the hydrogenated bisphenol epoxy resin prepolymer includes hydrogenated bisphenol A diglycidyl ether.

[0023] In some embodiments, the functionality of the rigid curing agent and the flexible crosslinking curing agent are f, respectively. 刚 and f 柔The amounts of rigid curing agent and flexible cross-linking curing agent are n respectively. 刚 and n 柔 n 刚* f 刚 :n 柔* f 柔 =1:1 to 1:20.

[0024] In some embodiments, n 刚* f 刚 :n 柔* f 柔 =1:1 to 1:5.

[0025] In some embodiments, the active hydrogen equivalent ratio of the rigid curing agent and the flexible crosslinking curing agent is 1:1 to 1:20.

[0026] In some embodiments, the active hydrogen equivalent ratio of the rigid curing agent and the flexible crosslinking curing agent is 1:1 to 1:5.

[0027] In some embodiments, the resin composition further includes one or more of an accelerator, a filler, and a diluent. The accelerator includes one or more of imidazole accelerators, tertiary amine accelerators, and organophosphorus accelerators. The filler includes one or more of silicates, oxides, and carbonates. The diluent includes one or more of reactive diluents, inactive diluents, and internally plasticizing reactive diluents.

[0028] In some embodiments, imidazole accelerators include one or more of 2-methylimidazole and 2-ethyl-4-methylimidazole, tertiary amine accelerators include one or more of triethylamine, benzyldimethylamine and 2,4,6-tris(dimethylaminomethyl)phenol, and organophosphorus accelerators include triphenylphosphine.

[0029] In some embodiments, silicates include one or more of glass fiber and talc, oxides include one or more of fumed silica, precipitated silica, alumina and zinc oxide, and carbonates include calcium carbonate.

[0030] In some embodiments, the reactive diluent includes one or more of butyl glycidyl ether, phenyl glycidyl ether, C12–C14 aliphatic glycidyl ether, neopentyl glycol diglycidyl ether, and bisphenol A type low viscosity epoxy diluent; the inactive diluent includes phthalates; and the internally plasticized reactive diluent includes one or more of epoxidized soybean oil and epoxidized fatty acid methyl esters. Detailed Implementation

[0031] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of this application, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments.

[0033] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0034] Unless otherwise specified, all embodiments and optional embodiments of this application may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of this application.

[0035] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions, and such technical solutions shall be deemed to be included in the disclosure of this application.

[0036] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0037] Unless otherwise specified, in this application, the terms "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0038] In this application, the terms "multiple" or "various" refer to two or more kinds.

[0039] In the description of the embodiments of this application, unless otherwise specified, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] Unless otherwise stated, the test temperature for all parameters mentioned in this application is 25°C.

[0041] In view of the problems in the background technology, this application provides a resin composition based on a "rigid dynamic-flexible permanent" network synergistic design strategy. By designing a specific ratio of rigid curing agent and flexible crosslinking curing agent, the epoxy resin polymer has a rigid cyclic structure, a flexible long-chain structure and a network composed of dynamic bonds, thereby achieving a combination of rigid strength, flexible toughness and dynamic self-healing. As a result, the epoxy resin polymer has good self-healing function, good stiffness and good toughness.

[0042] This application provides a resin composition comprising, by weight parts: 10 to 60 parts by weight of a rigid curing agent, the rigid curing agent comprising a cyclic structure and active groups; 62 to 240 parts by weight of a flexible crosslinking curing agent, the flexible crosslinking curing agent comprising a long-chain structure and active groups; and 50 to 200 parts by weight of an epoxy resin prepolymer; at least one of the rigid curing agent and the flexible crosslinking curing agent comprising dynamic bonds.

[0043] The mass fraction of the rigid curing agent in the resin composition of this application embodiment is 10 to 60. For example, it can be 10, 20, 30, 40, 50, 60, or any range of the above values.

[0044] The mass fraction of the flexible crosslinking curing agent in the resin composition of this application embodiment is 62 to 240. For example, it can be 62, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, or any range of the above values.

[0045] The epoxy resin prepolymer in the resin composition of this application embodiment is 50 to 200 parts by mass. For example, it can be 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, or any range of the above values.

[0046] Dynamic bonds, also known as dynamic covalent bonds or reversible bonds, are a type of chemical bond that can be reversibly broken and reformed under specific external stimuli (such as heat, light, pH, mechanical force, etc.).

[0047] The ratio of rigid ring structures to flexible long-chain structures directly affects the crosslinking density and chain segment entanglement of the epoxy resin polymer network, thereby influencing the material's mechanical properties such as strength, modulus, and toughness, and its ability to suppress network deconstruction and performance degradation. Higher crosslinking density results in higher modulus and strength for the epoxy resin polymer, but restricts chain segment mobility, leading to insufficient toughness. Higher chain segment entanglement enhances intersegment slippage, which is beneficial for energy dissipation and deformation absorption, thus improving toughness. However, excessive chain segment slippage can reduce material strength and stiffness.

[0048] Both the rigid and flexible curing agents in the resin compositions of this application contain active groups. These active groups can undergo ring-opening addition reactions with the epoxy groups in the epoxy resin prepolymer, introducing the rigid and flexible components, as well as dynamic bonds, from the curing agent into the polymer segments. Finally, segmental curing treatment can form an epoxy resin polymer with a network cross-linked structure. A suitable mass ratio of the rigid curing agent, flexible curing agent, and epoxy resin prepolymer enables the epoxy resin polymer to possess excellent self-healing properties, as well as good rigidity and toughness.

[0049] Optionally, the rigid curing agent is present in parts by weight of 20 to 30.

[0050] Optionally, the flexible crosslinking curing agent is present in parts by weight of 80 to 160.

[0051] Optionally, the epoxy resin prepolymer is in the form of 100 to 140 parts by weight.

[0052] In some embodiments, the dynamic bond includes one or more of the following: borate ester bond, hydrogen bond, metal coordination bond, and Diels-Alder bond.

[0053] The Diels-Alder bond is a six-membered ring consisting of two new C-C single bonds formed by the [4+2] cycloaddition reaction of a diene and a dienophile. It can be reversibly broken and reformed under heating conditions.

[0054] The embodiments of this application have the aforementioned dynamic bonds, which can improve the self-healing and reprocessing capabilities of epoxy resin polymers.

[0055] In borate ester bonds, a reversible esterification condensation reaction occurs between a boric acid group (B(OH)2 or its derivative) and a cis-diol. Under suitable conditions, the boron atom coordinates with the oxygen atoms of the two alcohol hydroxyl groups, forming a negatively charged tetrahedral borate ester structure and releasing a water molecule. When water is present in the environment or the system is acidic, the water molecule attacks the boron atom, causing the ester bond to hydrolyze and regenerate boric acid and a diol. In the presence of multiple diols or multiple boric acids, borate ester bonds can undergo transesterification. A borate ester can decompose and combine with other diols to form new borate ester bonds. Hydrogen bonds, at room temperature, have low bond energies, and the thermal motion of molecules is sufficient to cause frequent dissociation and recombination. This process does not require special chemical stimulation and occurs continuously. Metal coordination bonds dissociate under mechanical forces (bond breaking), heat (equilibrium shift), or the addition of competing ligands (such as EDTA, stronger acids / bases). When conditions return to normal or other coordination sites are present, the metal ion can recoordinate with the same or different ligands. Diels-Alder bonds can undergo a reverse Diels-Alder reaction at higher temperatures (typically >110°C), reversibly cleaving back to the original dienes and diephiles.

[0056] Optionally, the dynamic bond includes a borate ester bond.

[0057] In some embodiments, the cyclic structure includes one or more of the following: aroma ring, ester ring, and heterocycle.

[0058] Aromatic rings contain large π bonds, and electrons are delocalized throughout the ring, forming a highly stable conjugated system. This resonance effect gives aromatic rings a planar rigid structure, making them difficult to twist or deform, thus giving the ring structure rigidity.

[0059] Ester rings form saturated rings through sp³ hybridization of carbon atoms, and the geometry of the ring restricts bond rotation. Small rings (such as cyclopropane and cyclobutane) exhibit significant ring strain, while large rings can maintain stability through conformational adjustments. This allows cyclic structures to possess rigidity.

[0060] Heteroatoms (O, N, etc.) in heterocycles can enhance intermolecular forces (such as hydrogen bonds and dipole-dipole interactions) and restrict chain segment movement, thus making the ring structure rigid.

[0061] Alternatively, the cyclic structure may include a benzene ring.

[0062] In some embodiments, the long-chain structure includes one or more of carbon chains of C2 to C500 and heterochains of C2 to C500.

[0063] Long-chain structures have a lower rotation barrier, and the conformation of the molecular chain can be continuously changed by rotating single bonds, thus making long-chain structures flexible.

[0064] Optionally, the long-chain structure includes C2 to C50 polyethers.

[0065] Ring structures and long-chain structures can be tested using a Fourier transform infrared spectrometer (FTIR).

[0066] In some embodiments, the active group includes one or more of amino, imino, hydroxyl, thiol, and carboxyl groups.

[0067] In some embodiments, the rigid curing agent includes one or more of 3-[4-(aminomethyl)-1,3,2-dioxane-2-yl]aniline, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfone, 2,6-diaminopyridine, 1,3-phenylenediamine / 1,4-phenylenediamine, bisphenol A, and hydroquinone.

[0068] In some embodiments, the flexible crosslinking curing agent includes one or more of polyetheramine, polyenol, and polyenamine.

[0069] Optionally, the polyetheramine includes one or more of polypropylene glycol diamine, polyethylene glycol diamine, polyether triamine, and aliphatic polyetheramine.

[0070] Optionally, the polyenol includes one or more of polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polyvinyl alcohol, and polycaprolactone glycol.

[0071] Optionally, the polyenamine includes one or more of terminal amino polybutadiene and terminal amino hydrogenated polybutadiene.

[0072] Further optionally, the polyetheramine may include one or more of the grades D-230, D-400, D2000, ED600, ED900, T-403 and T-5000.

[0073] Different types of flexible crosslinking curing agents and rigid curing agents have different molecular weights and degrees of branching. Their dosage can be adjusted to allow rigid and flexible crosslinking curing agents to better crosslink with epoxy resin prepolymers, thereby giving the epoxy resin polymer good self-healing function, good rigidity and good toughness.

[0074] In some embodiments, the epoxy resin prepolymer includes one or more of alicyclic and aliphatic epoxy resin prepolymers, bisphenol A and its modified epoxy resin prepolymers, and hydrogenated bisphenol epoxy resin prepolymers.

[0075] Optionally, the aliphatic epoxy resin prepolymer includes one or more of 4-cyclohexene-1,2-dicarboxylic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexanecarboxylic acid ester, dicyclopentadiene diepoxide, and alicyclic diglycidyl ether.

[0076] Optionally, bisphenol A and its modified epoxy resin prepolymers include one or more of bisphenol A type epoxy resin, bisphenol A modified epoxy resin, and high molecular weight bisphenol A epoxy resin.

[0077] Optionally, the hydrogenated bisphenol epoxy resin prepolymer includes hydrogenated bisphenol A diglycidyl ether.

[0078] Different types of epoxy resin prepolymers can give epoxy resin polymers good self-healing properties, good stiffness, and good toughness.

[0079] In some embodiments, the functionality of the rigid curing agent and the flexible crosslinking curing agent are f, respectively. 刚 and f 柔 The amounts of rigid curing agent and flexible cross-linking curing agent are n respectively. 刚 and n 柔 n 刚* f 刚 :n 柔* f 柔 =1:1 to 1:20.

[0080] Functionality refers to the average number of active atoms / groups on a curing agent molecule that can react with the prepolymer. For example, in amine-cured epoxy, functionality is the number of active hydrogen atoms on each amine molecule; the functionality of primary amines is 2, and that of secondary amines is 1. In the embodiments of this application, 3-[4-(aminomethyl)-1,3,2-dioxanepent-2-yl]aniline (NBN) is a diprimary amine with a functionality of 2*2=4. Similarly, in hydroxy-isocyanate systems, functionality is the number of hydroxyl groups on each polyol molecule.

[0081] n 刚* f 刚 This reflects the number of network connection points of the rigid curing agent in the epoxy resin polymer, and thus reflects the proportion of cyclic structures in the rigid curing agent in the epoxy resin polymer; similarly, n 柔* f 柔 This reflects the proportion of chain structures in the flexible crosslinking curing agent within the epoxy resin polymer. Therefore, the proportions of both can better reflect the ratio of cyclic and chain structures in the epoxy resin polymer. The rigid curing agent and flexible crosslinking curing agent in the embodiments of this application satisfy the above conditions, enabling the cured epoxy resin polymer to possess both good rigidity and good toughness.

[0082] Optionally, n 刚* f 刚 :n 柔* f 柔 =1:1 to 1:5.

[0083] As can be seen from the above formula, the rigid curing agent and / or flexible crosslinking curing agent can have a suitable active atom / group equivalent ratio by adjusting the mass fraction and functionality of the rigid curing agent and / or flexible crosslinking curing agent.

[0084] In some embodiments, the equivalent ratio of active hydrogen in the rigid curing agent to the flexible crosslinking curing agent is 1:1 to 1:20. Under these conditions, the rigid curing agent and the flexible crosslinking curing agent synergistically participate in the crosslinking and network formation of the epoxy resin during the curing reaction, resulting in an epoxy resin polymer with appropriate amounts of rigid and flexible structural units. This allows the material to maintain good stiffness and strength while possessing good toughness and deformability.

[0085] Optionally, the equivalent ratio of active hydrogen in the rigid curing agent to the flexible crosslinking curing agent is 1:1 to 1:5.

[0086] In some embodiments, the resin composition further includes one or more of an accelerator, a filler, and a diluent.

[0087] In some embodiments, the accelerator includes one or more of imidazole accelerators, tertiary amine accelerators, and organophosphorus accelerators.

[0088] Alternatively, the imidazole accelerator includes one or more of 2-methylimidazole and 2-ethyl-4-methylimidazole.

[0089] Alternatively, tertiary amine accelerators include one or more of triethylamine, benzyldimethylamine, and 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30).

[0090] Alternatively, organophosphorus accelerators include triphenylphosphine.

[0091] In some embodiments, the filler includes one or more of silicates, oxides, and carbonates.

[0092] Alternatively, silicates include one or more of glass fibers and talc.

[0093] Alternatively, the oxides include one or more of fumed silica, precipitated silica, aluminum oxide, and zinc oxide.

[0094] Optionally, carbonates include calcium carbonate.

[0095] In some embodiments, the diluent includes one or more of reactive diluents, inactive diluents, and internally plasticized reactive diluents.

[0096] Optionally, the reactive diluent includes one or more of butyl glycidyl ether, phenyl glycidyl ether, C12–C14 aliphatic glycidyl ether, neopentyl glycol diglycidyl ether, and bisphenol A type low viscosity epoxy diluent.

[0097] Optionally, non-reactive diluents include phthalates.

[0098] Optionally, the internally plasticizing reactive diluent includes one or more of epoxidized soybean oil and epoxidized fatty acid methyl esters.

[0099] The resin composition of this application embodiment also includes one or more of the above-mentioned accelerators, fillers and diluents, which can enable the resin composition to be cured better, so as to obtain an epoxy resin polymer with stronger rigidity, better toughness and stronger self-healing properties.

[0100] The rigid curing agent and the flexible crosslinking curing agent in the resin composition of this application embodiment are dissolved in a solvent to obtain a mixed curing agent; then the mixed curing agent is mixed with the epoxy resin prepolymer and subjected to segmented curing treatment to obtain an epoxy resin polymer.

[0101] Therefore, the epoxy resin polymer obtained by curing the resin composition of this application embodiment has good rigidity and good toughness. At the same time, since at least one of the rigid curing agent and the flexible crosslinking curing agent includes dynamic bonds, the dynamic bond structure can be introduced into the epoxy resin polymer network. The reversible breaking and recombination characteristics of the dynamic bonds can be utilized to enable the epoxy resin polymer to achieve stress relaxation and energy dissipation under stress or external stimuli, and endow the epoxy resin polymer with self-healing and reprocessing capabilities.

[0102] In some embodiments, the tensile strength of the epoxy resin polymer is from 5 MPa to 35 MPa. For example, it can be 5 MPa, 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, or any range of the above values.

[0103] In some embodiments, the elongation at break of the epoxy resin polymer is 110% to 280%. For example, it can be 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200%, 210%, 220%, 230%, 240%, 250%, 260%, 270%, 280%, or any range of the above values.

[0104] In some embodiments, the segmented curing process includes a first curing process and a second curing process.

[0105] The initial curing treatment involves maintaining a temperature of 50°C to 70°C for 4 to 6 hours. The temperature can be 50°C, 55°C, 60°C, 65°C, 70°C, or any combination thereof. The duration of the curing treatment can be 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, or any combination thereof.

[0106] The second curing treatment involves maintaining a temperature of 75℃ to 95℃ for 2 hours to 4 hours. The temperature can be 75℃, 80℃, 85℃, 90℃, 95℃, or any combination thereof. The time can be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, or any combination thereof.

[0107] Example The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0108] Example 1 Preparation of rigid curing agents 13.7 g of 3-aminophenylboronic acid was dissolved in 100 mL of methanol, and 9.1 g of (S)-3-amino-1,2-propanediol was dissolved in 50 mL of methanol. The two solutions were mixed, and 15 g of anhydrous magnesium sulfate was added as a dehydrating agent. The reaction system was mechanically stirred at room temperature for 24 h. After the reaction was complete, the magnesium sulfate residue was removed by filtration. The filtrate was concentrated by rotary evaporation, and excess acetonitrile was added to precipitate a white solid product, 3-[4-(aminomethyl)-1,3,2-dioxanepent-2-yl]aniline (NBN). The precipitate was filtered and vacuum dried for 12 h to obtain a white powdery product, the rigid curing agent component NBN.

[0109] By nuclear magnetic resonance hydrogen spectrum ( 1 The structure of the above product was characterized by H NMR. The positions of the characteristic peaks in the spectrum were consistent with the hydrogen element environment in the theoretical structure, which verified the successful synthesis of the target compound.

[0110] Preparation of mixed curing agents Weigh 10 parts by weight of dried NBN curing agent and add it to 20 parts by weight of flexible crosslinking curing agent polyetheramine; then add 1 mL of methanol for dissolution, and dissolve under magnetic stirring to obtain a mixed curing agent. The polyetheramine is grade D-400 and weighs 3.45 g, and the active hydrogen equivalent ratio of NBN curing agent to polyetheramine is 1:3.

[0111] Preparation of epoxy resin polymers Weigh 50 parts by weight of the prepolymer 4-cyclohexene-1,2-dicarboxylic acid diglycidyl ester, add it to the above-mentioned mixed curing agent, and mix thoroughly at room temperature under mechanical stirring. Then, transfer the mixture to a programmable temperature-controlled autoclave for staged curing: first, pre-curing at 60°C for 5 hours to complete initial cross-linking and structural stabilization; then, raising the temperature to 80°C and holding for 3 hours to promote complete reaction and further enhance thermomechanical properties. After curing, allow it to cool naturally to room temperature to obtain the epoxy resin polymer.

[0112] Examples 2-5, Comparative Examples 1-6 Except for the different mass proportions of the rigid curing agent NBN, the flexible crosslinking curing agent D-400, and the prepolymer 4-cyclohexene-1,2-dicarboxylic acid diglycidyl ester, the preparation of the epoxy resin polymer was the same as in Example 1. See the table below for specific formulations.

[0113] Table 1 As can be seen from the table above, the resin composition of the embodiments of this application has a specific mass fraction of curing agent and prepolymer, which can make the cured epoxy resin polymer have good self-healing properties, good toughness and good rigidity.

[0114] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A resin composition, characterized in that, By weight, it includes: A rigid curing agent comprising 10 to 60 parts by weight, wherein the rigid curing agent includes a cyclic structure and active groups; A flexible crosslinking curing agent comprising 62 to 240 parts by weight, wherein the flexible crosslinking curing agent includes a long-chain structure and active groups; 50 to 200 parts by weight of epoxy resin prepolymer; At least one of the rigid curing agent and the flexible crosslinking curing agent includes dynamic bonds.

2. The resin composition according to claim 1, characterized in that, By weight, it includes: 20 to 30 parts by weight of a rigid curing agent, said rigid curing agent comprising a cyclic structure and active groups; 80 to 160 parts by weight of a flexible crosslinking curing agent, wherein the flexible crosslinking curing agent comprises a long-chain structure and active groups; 100 to 140 parts by weight of epoxy resin prepolymer; At least one of the rigid curing agent and the flexible crosslinking curing agent includes dynamic bonds.

3. The resin composition according to claim 1 or 2, characterized in that, The dynamic bond includes one or more of the following: borate ester bond, hydrogen bond, metal coordination bond, and Diels-Alder bond; and / or, The cyclic structure includes one or more of aroma rings, ester rings, and heterocycles; and / or, The long-chain structure includes one or more of carbon chains from C2 to C500 and heterochains from C2 to C500.

4. The resin composition according to claim 1 or 2, characterized in that, The dynamic bond includes a borate ester bond; and / or, The cyclic structure includes a benzene ring; and / or, The long-chain structure includes polyethers with C2 to C500; and / or, The active group includes one or more of amino, imino, hydroxyl, thiol, and carboxyl groups.

5. The resin composition according to claim 1 or 2, characterized in that, The rigid curing agent comprises one or more of 3-[4-(aminomethyl)-1,3,2-dioxane-2-yl]aniline, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfone, 2,6-diaminopyridine, 1,3-phenylenediamine / 1,4-phenylenediamine, bisphenol A, and hydroquinone; and / or The flexible crosslinking curing agent includes one or more of polyetheramine, polyenol, and polyenamine; and / or, The epoxy resin prepolymer includes one or more of alicyclic and aliphatic epoxy resin prepolymers, bisphenol A and its modified epoxy resin prepolymers, and hydrogenated bisphenol epoxy resin prepolymers.

6. The resin composition according to claim 5, characterized in that, The polyetheramine includes one or more of polypropylene glycol diamine, polyethylene glycol diamine, polyethertriamine, and aliphatic polyetheramines; and / or, The polyenol includes one or more of polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and polyvinyl alcohol; and / or, The polyenamine includes one or more of terminal amino-terminated polybutadiene and terminal amino-terminated hydrogenated polybutadiene; and / or The aliphatic epoxy resin prepolymer comprises one or more of the following: 4-cyclohexene-1,2-dicarboxylic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate, dicyclopentadiene diepoxide, and alicyclic diglycidyl ether; and / or The bisphenol A and its modified epoxy resin prepolymers include one or more of bisphenol A type epoxy resin, bisphenol A modified epoxy resin, and high molecular weight bisphenol A epoxy resin; and / or, The hydrogenated bisphenol epoxy resin prepolymer includes hydrogenated bisphenol A diglycidyl ether.

7. The resin composition according to claim 1, characterized in that, The functionalities of the rigid curing agent and the flexible crosslinking curing agent are f, respectively. 刚 and f 柔 The amounts of the rigid curing agent and the flexible crosslinking curing agent are n respectively. 刚 and n 柔 n 刚* f 刚 :n 柔* f 柔 =1:1 to 1:

20.

8. The resin composition according to claim 7, characterized in that, n 刚* f 刚 :n 柔* f 柔 =1:1 to 1:

5.

9. The resin composition according to claim 1, characterized in that, The active hydrogen equivalent ratio of the rigid curing agent and the flexible crosslinking curing agent is 1:1 to 1:

20.

10. The resin composition according to claim 9, characterized in that, The active hydrogen equivalent ratio of the rigid curing agent and the flexible crosslinking curing agent is 1:1 to 1:

5.

11. The resin composition according to claim 1, characterized in that, The resin composition further includes one or more of an accelerator, a filler, and a diluent. The accelerator includes one or more of imidazole accelerators, tertiary amine accelerators, and organophosphorus accelerators. The filler includes one or more of silicates, oxides, and carbonates. The diluent includes one or more of reactive diluents, inactive diluents, and internally plasticized reactive diluents.

12. The resin composition according to claim 11, characterized in that, The imidazole accelerator includes one or more of 2-methylimidazole and 2-ethyl-4-methylimidazole; the tertiary amine accelerator includes one or more of triethylamine, benzyldimethylamine, and 2,4,6-tris(dimethylaminomethyl)phenol; the organophosphorus accelerator includes triphenylphosphine; and / or... The silicates include one or more of glass fiber and talc; the oxides include one or more of fumed silica, precipitated silica, alumina, and zinc oxide; and the carbonates include calcium carbonate; and / or, The active diluent includes one or more of butyl glycidyl ether, phenyl glycidyl ether, C12–C14 aliphatic glycidyl ether, neopentyl glycol diglycidyl ether, and bisphenol A type low viscosity epoxy diluent; the inactive diluent includes phthalates; and the internally plasticized active diluent includes one or more of epoxidized soybean oil and epoxidized fatty acid methyl esters.

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