Diamine monomer, polyimide resin and preparation methods thereof

Abstract

The invention relates to the technical field of polyimide, in particular to a diamine monomer, polyimide resin and preparation methods of the diamine monomer and the polyimide resin. When the diamine monomer provided by the invention is used for preparing polyimide resin, an adamantyl group and an aromatic heterocyclic structure can be introduced into a polyimide molecular chain, the aromatic heterocyclic structure is introduced into a main chain to improve the chain rigidity, and a large-volume adamantane structure is introduced to weaken the tight stacking of the molecular chain, so that the balance design of the solubility, thermal performance and processability of the resin is realized. Polyimide resin prepared from the diamine monomer provided by the invention is novel soluble TPI resin, has the outstanding advantages of high heat-resistant grade, good manufacturability, high solubility and the like, can be used for preparing pure resin profiles and filler reinforced resin profiles, can also be used for preparing continuous fiber reinforced composite materials in a solution preimpregnation manner, and is suitable for industrial production. The problems of low use temperature, high melt viscosity, poor solubility, complex preparation process and the like of the current thermoplastic polyimide resin are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of polyimide, specifically diamine monomers, polyimide resins and their preparation methods. Background Art

[0002] With the development needs of the aviation, electronics, and industrial fields, the demand for lightweight and heat-resistant materials is extremely urgent. Thermoplastic polyimide (TPI) resin materials have the advantages of high temperature resistance, high toughness, anti-damage, and low cost. Moreover, they have a short molding time, the materials can be reused, and it is easy to achieve low-cost manufacturing, becoming an important development trend of new materials in related fields.

[0003] The performance of TPI is mainly determined by its chemical structure. Introducing flexible structural units such as ether bonds and alkyl groups into the main chain of the polyimide molecule can reduce the intermolecular force, improve the movement ability of the molecular chain, and improve its melt processing performance. The polyimide prepared from isomeric dianhydride has higher T g and better melt fluidity. Introducing large-volume side groups into the polyimide molecular chain can maintain the rigidity of the molecular chain while reducing the intermolecular force between the molecular chains and increasing the free volume of the molecules, thereby improving the melt fluidity and solubility of the polyimide. Preparing polyimide by copolymerizing multiple monomers, due to the differences in the monomer structures, the regularity and symmetry of the polyimide molecular chain are destroyed, making the molecular chain arrangement loose and easy to move.

[0004] Currently, representative TPI resins abroad include the Ultem @ series resins of Saudi SABIC, the Aurum @ resins of Mitsui Chemicals, Inc. of Japan, the LaRC @ resins of NASA of the United States, the Avimid @ series resins of DuPont, and the Matrimid @ series resins of Huntsman Corporation, etc. The resin product types of domestic TPI manufacturers are relatively single, and a series of products covering multiple temperature resistance grades and various molding processes have not been formed. The products are mainly pure resins, self-lubricating materials, and short fiber-reinforced materials, and there is less research on continuous fiber-reinforced thermoplastic composites. Summary of the Invention

[0005] In view of this, the technical problems to be solved by the present invention are diamine monomers, polyimide resins and their preparation methods. The polyimide resin prepared by using the diamine monomer provided by the present invention has high heat resistance, mechanical properties and excellent processing performance.

[0006] The present invention provides a diamine monomer having a structure of Formula III-a or Formula III-b:

[0007]

[0008] X is -NH- or O.

[0009] Specifically, the structure of Formula III-a is preferably any one of Formula III-a1 to Formula III-a6;

[0010]

[0011] The structure of Formula III-b is specifically preferably Formula III-b1 structure or Formula III-b2 structure;

[0012]

[0013] In the present invention, the adamantyl group and the heteroaromatic ring structure are constructed into a diamine monomer through molecular structure regulation, and then the adamantyl group and the heteroaromatic ring structure are introduced into the polyimide molecular chain, which can realize the balanced design of the resin solubility, thermal properties and processing properties. The prepared TPI also has the advantages of simple synthesis process, easy molding and processing, and excellent mechanical properties.

[0014] The present invention provides a preparation method of the diamine monomer described in any one of the above technical solutions. In the first aspect of the present invention, the preparation method of the diamine monomer having the structure of Formula III-a includes the following steps:

[0015] Under the action of a reducing agent and a water absorbent, a compound having the structure of Formula I-1 and a compound having the structure of Formula II-1 are subjected to a reduction reaction to obtain a diamine monomer having the structure of Formula III-a;

[0016]

[0017] Wherein, R1 and R2 are independently a carboxyl group or an acyl chloride group; R3 is a hydroxyl group or an amino group.

[0018] Specifically, in an inert gas atmosphere, a reducing agent, a water absorbent, a compound having the structure of Formula I-1 and a compound having the structure of Formula II-1 are subjected to a reduction reaction in a solvent to obtain a diamine monomer having the structure of Formula III-a. More specifically, in an inert gas atmosphere, a reducing agent, a water absorbent, a compound having the structure of Formula I-1 and a compound having the structure of Formula II-1 are added to a solvent, and heated to carry out a reduction reaction to obtain a diamine monomer having the structure of Formula III-a.

[0019] The protective gas described in the first aspect of the present invention is one or more of nitrogen, argon or helium. The solvent described in the present invention is one or more of boric acid, polyphosphoric acid and concentrated sulfuric acid. The reducing agent described in the first aspect of the present invention is tin powder and stannous chloride. The water absorbent described in the first aspect of the present invention is phosphorus pentoxide or magnesium sulfate. The molar ratio of the compound having the structure of formula I-1 to the compound having the structure of formula II-1 in the first aspect of the present invention is (1 to 2.1):(1 to 2.1), the amount of the reducing agent is 5% to 30% of the molar amount of the compound having the structure of formula I-1, the amount of the water absorbent is 0.5 to 2 times the molar amount of the compound having the structure of formula I-1; the amount of the solvent is 5 to 15 times the mass of the compound having the structure of formula II-1. The temperature of the reduction reaction in the first aspect of the present invention is 170°C to 220°C, and the time of the reduction reaction is 5h to 16h.

[0020] In one embodiment of the present invention, according to the preparation method provided in the first aspect of the present invention, under the action of a reducing agent and a water absorbent, and are subjected to a reduction reaction to obtain the aforementioned diamine monomer having the structure of formula III-a1.

[0021] In another embodiment of the present invention, according to the preparation method provided in the first aspect of the present invention, under the action of a reducing agent and a water absorbent, and are subjected to a reduction reaction to obtain the aforementioned diamine monomer having the structure of formula III-a4.

[0022] In the second aspect of the present invention, the preparation method of the diamine monomer having the structure of formula III-b includes the following steps:

[0023]

[0024] Wherein, the R4 is a carboxyl group or an acyl chloride group; the R5 is a hydroxyl group or an amino group.

[0025] Under the action of a reducing agent and a water absorbent, the compound having the structure of formula I-2 and the compound having the structure of formula II-2 are subjected to a reduction reaction to obtain the diamine monomer having the structure of formula III-b.

[0026] Specifically, in an atmosphere of a protective gas, the reducing agent, the water absorbent, the compound having the structure of formula I-2 and the compound having the structure of formula II-2 are subjected to a reduction reaction in a solvent to obtain the diamine monomer having the structure of formula III-a. More specifically, in an atmosphere of a protective gas, the reducing agent, the water absorbent, the compound having the structure of formula I-2 and the compound having the structure of formula II-2 are added to a solvent, and heated to carry out a reduction reaction to obtain the diamine monomer having the structure of formula III-a.

[0027] In the second aspect of the present invention, the protective gas, solvent, reducing agent, water absorbent, temperature of the reduction reaction, and time of the reduction reaction are the same as those described in the first aspect of the present invention, and will not be elaborated here. In the second aspect of the present invention, the molar ratio of the compound having the structure of formula I-2 to the compound having the structure of formula II-2 is (1-2.1):(1-2.1), the amount of the reducing agent used is 5%-30% of the molar amount of the compound having the structure of formula I-2, and the amount of the water absorbent used is 0.5-2 times the molar amount of the compound having the structure of formula I-2.

[0028] In one embodiment of the present invention, according to the preparation method provided in the second aspect of the present invention, under the action of a reducing agent and a water absorbent, and are subjected to a reduction reaction to obtain the diamine monomer having the structure of formula III-b1 described above.

[0029] In another embodiment of the present invention, according to the preparation method provided in the second aspect of the present invention, under the action of a reducing agent and a water absorbent, and are subjected to a reduction reaction to obtain the diamine monomer having the structure of formula III-b2 described above.

[0030] The present invention also provides a polyimide resin, which is prepared from an aromatic dianhydride and an aromatic diamine, and the aromatic diamine includes the diamine monomer described in any of the above technical solutions or the diamine monomer obtained by the preparation method described in any of the above technical solutions.

[0031] Preferably, the polyimide resin provided by the present invention is prepared from an aromatic dianhydride and an aromatic diamine with a molar ratio of (0.9-1):1. Preferably, the aromatic dianhydride described in the present invention is selected from one or more of the compounds having the structures shown in formula 1 to formula 10; among them, the abbreviations of the compounds having the structures shown in formula 1 to formula 10 are: PMDA, 4,4-BPDA, 4,4-HQDPA, 3,3-HQDPA, 3,4-BPDA, 3,4-ODPA, BPADA, 4,4-ODPA, 6FDA, BTDA;

[0032]

[0033] Preferably, the aromatic diamine described in the present invention further includes one or more of the compounds having the structures shown in formula 11 to formula 16;

[0034]

[0035] Among them, L1 is a group selected from O, S, sulfonyl group (-SO2-), methylene group (-CH2-), carbonyl group (-CO-), a group of the structure shown in formula a or a group of the structure shown in formula b;

[0036]

[0037] L2 is O, S or -NH-.

[0038] The present invention also provides a method for preparing the polyimide resin according to any one of the above technical solutions, comprising the following steps:

[0039] S1) Polymerize a material comprising an aromatic dianhydride and an aromatic diamine to obtain a polyamic acid;

[0040] S2) Perform a cyclization dehydration reaction on the polyamic acid obtained in step S1) to obtain a polyimide resin.

[0041] The present invention first polymerizes a material comprising an aromatic dianhydride and an aromatic diamine in step S1) to obtain a polyamic acid. Specifically, in an atmosphere of a protective gas, the material comprising an aromatic dianhydride and an aromatic diamine is polymerized in an organic solvent to obtain a polyamic acid. In certain embodiments of the present invention, in an atmosphere of a protective gas, the material comprising an aromatic dianhydride and an aromatic diamine is dissolved in an organic solvent, stirred, and polymerized to obtain a polyamic acid.

[0042] Among them, the selection and dosage ratio of the aromatic dianhydride and the aromatic diamine in the present invention are the same as those described above, and will not be elaborated here. The organic solvent in the present invention is selected from aprotic solvents, more specifically, one or more of aprotic solvents such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), etc. The protective gas in the present invention is one or more of nitrogen, argon or helium.

[0043] The material in the present invention may or may not include a capping agent. If a capping agent is included, based on 10 moles of the aromatic diamine, the dosage of the capping agent is 2 moles or less. The capping agent in the present invention is phthalic anhydride. The temperature of the polymerization reaction in the present invention is 10°C to 50°C, and the time of the polymerization reaction is 3 h to 24 h. When performing the polymerization reaction in the present invention, the solid content of the material is 5 wt% to 20 wt%.

[0044] After obtaining the polyamic acid in step S1), in step S2), the obtained polyamic acid is subjected to a cyclodehydration reaction to obtain a polyimide resin. Specifically, in an inert gas atmosphere, under the action of a dehydrating agent and a catalyst, the obtained polyamic acid is subjected to a cyclodehydration reaction to obtain a polyimide resin. In some embodiments of the present invention, in an inert gas atmosphere, a dehydrating agent and a catalyst are added to the obtained polyamic acid, and a rapid stirring is carried out for the cyclodehydration reaction. The precipitate is immersed in water to precipitate a powder, which is washed and dried to obtain a polyimide resin.

[0045] The dehydrating agent in the present invention is acetic anhydride. The catalyst in the present invention is one or both of triethylamine and pyridine. The inert gas in the present invention is the same as described above and will not be elaborated here. The temperature of the cyclodehydration reaction in the present invention is 0°C to 50°C, and the reaction time is 2 h to 10 h. The dosages of the dehydrating agent and the catalyst are based on the dosage of the aromatic diamine in step S1). The molar ratio of the aromatic diamine, the dehydrating agent, and the catalyst is 1:(2 - 5):(0.1 - 2).

[0046] The present invention also provides another preparation method of the polyimide resin according to any one of the above technical solutions, comprising the following steps: subjecting a material comprising an aromatic dianhydride and an aromatic diamine to an imidization reaction to obtain a polyimide resin. Specifically, in an inert gas atmosphere, the material comprising an aromatic dianhydride and an aromatic diamine is subjected to an imidization reaction in an organic solvent to obtain a polyimide resin.

[0047] The inert gas, the aromatic dianhydride, the aromatic diamine, and the organic solvent in the present invention are the same as described above and will not be elaborated here. The material may or may not include a capping agent, and the capping agent is the same as described above and will not be elaborated here. The dosages of the respective raw materials and the solid content of the material during the imidization reaction are the same as described above and will not be elaborated here. The temperature of the imidization reaction in the present invention is 0°C to 50°C, and the reaction time of the imidization reaction is 2 h to 12 h.

[0048] The present invention provides diamine monomers, polyimide resins and their preparation methods. The diamine monomers provided by the present invention are constructed by regulating the molecular structure with adamantyl groups and heteroaromatic ring structures. Using the diamine monomers provided by the present invention to prepare polyimide resins can introduce adamantyl groups and heteroaromatic ring structures into the polyimide molecular chain. Introducing a heteroaromatic ring structure into the main chain increases the chain rigidity, and introducing a large-volume adamantane structure weakens the close packing of the molecular chain, achieving a balanced design of the solubility, thermal properties and processing properties of the resin. The polyimide resin prepared by using the diamine monomers provided by the present invention is a new type of soluble and fusible TPI resin, which has outstanding advantages such as high heat resistance grade, good processability and high solubility. It can be used to prepare pure resin profiles and filler-reinforced resin profiles, and can also prepare continuous fiber-reinforced composites by solution pre-impregnation, expanding the application space of domestic TPI, and solving the problems of low use temperature, high melt viscosity, poor solubility and complex preparation process of current thermoplastic polyimide resins, and has broad application prospects in the fields of aviation, vehicles and industry. Brief Description of the Drawings

[0049] Figure 1 1H NMR spectrum of the diamine monomer prepared in Example 1 of the present invention; 1

[0050] Figure 2 Differential scanning calorimetry (DSC) curve of TPI prepared in Example 5 of the present invention;

[0051] Figure 3 Thermogravimetric analysis (TGA) curve of TPI prepared in Example 5 of the present invention;

[0052] Figure 4 Heating rheology curve of TPI prepared in Example 5 of the present invention;

[0053] Figure 5 Viscosity curve of 20% solid content DMAc solution of TPI prepared in Example 5 of the present invention;

[0054] Figure 6 Photo of the composite material of TPI and glass fiber prepared in Example 5 of the present invention. Detailed Description of the Invention

[0055] The present invention discloses diamine monomers, polyimide resins and their preparation methods. Those skilled in the art can draw on the content of this article and appropriately modify the process parameters to achieve. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make changes or appropriate changes and combinations to the methods and applications in this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.​

[0056] The present invention will be further described in conjunction with the following embodiments:

[0057] Example 1

[0058] Heat polyphosphoric acid to 60 °C. Under nitrogen protection, add polyphosphoric acid (1000 g), 1,3-adamantanediacetic acid (44.85 g, 0.2 mol), stannous chloride dihydrate (0.02 mol, 4.513 g) into a 2 L three-necked flask, and add 2,4-diaminophenol dihydrochloride (78.824 g, 0.4 mol) in batches. After the addition is complete, stir for 3 h until no more HCl gas volatilizes. Then add phosphorus pentoxide (P2O5) (28.388 g, 0.2 mol) and stir for 0.5 h. Slowly raise the temperature to 150 °C and stir for 3 h, then raise the temperature to 200 °C and react for 10 h. After the reaction is complete, cool the solution to room temperature. Then adjust the pH value of the solution to about 8 - 9 using saturated sodium carbonate solution, wash three times with water and ethanol respectively, filter, and dry to obtain the crude diamine product. After purification, a white solid is obtained with a yield of 77%.

[0059] The purified product was characterized by 1H NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO-d6) δ = 7.30 (d, J = 8.6, 1H), 6.80 (d, J = 2.2, 1H), 6.59 (dd, J = 8.6, 2.3, 1H), 5.00 (s, 2H), 2.38 (s, 1H), 2.26 (p, J = 3.0, 1H), 2.11 (dd, J = 12.9, 3.0, 2H), 2.04 (d, J = 13.4, 2H), 1.81 (d, J = 3.2, 1H). As Figure 1 shown, Figure 1 is the 1 1H NMR spectrum of the diamine monomer prepared in Example 1 of the present invention.

[0060] The molecular structure of the product in this example is:

[0061]

[0062] Example 2

[0063] Under nitrogen protection, bisphenol A dianhydride BPADA (52.1 g, 0.096 mol), diamine with the structure shown in formula (III-1a) in Example 1 (40.1 g, 0.1 mol), phthalic anhydride (1.2 g, 0.008 mol), and 500 g of DMAc were added to a three-necked flask and reacted at room temperature for 24 h. Then, 10 g of triethylamine and 30 g of acetic anhydride were added, and stirring was continued for 5 h. The solution was transferred to water for precipitation, filtered, broken wall, and dried to obtain polyimide powder.

[0064] Example 3

[0065] Under nitrogen protection, 3,4-oxydiphthalic anhydride 3,4-ODPA (30.1 g, 0.097 mol), diamine with the structure shown in formula (III-1a) in Example 1 (40.1 g, 0.1 mol), phthalic anhydride (0.9 g, 0.006 mol), and 550 g of DMAc were added to a three-necked flask and reacted at room temperature for 12 h. Then, 10 g of triethylamine and 30 g of acetic anhydride were added, and stirring was continued for 5 h. The solution was transferred to water for precipitation, filtered, broken wall, and dried to obtain polyimide powder.

[0066] Example 4

[0067] Under nitrogen protection, 3,4-biphenyldianhydride 3,4-BPDA (28.5 g, 0.097 mol), diamine with the structure shown in formula (III-1a) in Example 1 (40.1 g, 0.1 mol), phthalic anhydride (0.9 g, 0.006 mol), and 550 g of DMAc were added to a three-necked flask and reacted at room temperature for 12 h. Then, 10 g of triethylamine and 30 g of acetic anhydride were added, and stirring was continued for 5 h. The solution was transferred to water for precipitation, filtered, broken wall, and dried to obtain polyimide powder.

[0068] Example 5

[0069] Under nitrogen protection, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride 6FDA (43.5 g, 0.098 mol), diamine with the structure shown in formula (III-1a) in Example 1 (40.1 g, 0.1 mol), phthalic anhydride (0.6 g, 0.004 mol), and 550 g of DMAc were added to a three-necked flask and reacted at room temperature for 12 h. Then, 10 g of triethylamine and 30 g of acetic anhydride were added, and stirring was continued for 5 h. The solution was transferred to water for precipitation, filtered, broken wall, and dried to obtain polyimide powder.

[0070] Example 6

[0071] Under nitrogen protection, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride 6FDA (43.5 g, 0.098 mol), diamine with the structure shown in formula (III-1a) in Example 1 (20.1 g, 0.05 mol), 4,4'-diaminodiphenyl ether (10.0 g, 0.05 mol), phthalic anhydride (0.6 g, 0.004 mol) and 650 g of DMAc were added to a three-necked flask and reacted at room temperature for 12 h. Then 10 g of triethylamine and 30 g of acetic anhydride were added, and stirring was continued for 5 h. The solution was transferred to water for precipitation, filtered, broken and dried to obtain polyimide powder.

[0072] The polyimide prepared in Example 5 above was analyzed by differential scanning calorimetry, and the results are as Figure 2 shown. Figure 2 This is the differential scanning calorimetry (DSC) curve of TPI prepared in Example 5 of the present invention.

[0073] The polyimide prepared in Example 5 above was subjected to thermogravimetric analysis, and the results are as Figure 3 shown. Figure 3 This is the thermogravimetric analysis (TGA) curve of TPI prepared in Example 5 of the present invention.

[0074] The polyimide prepared in Example 5 above was subjected to heating rheological analysis, and the results are as Figure 4 shown. Figure 4 This is the heating rheological curve of TPI prepared in Example 5 of the present invention.

[0075] The polyimide prepared in Example 5 above was subjected to viscosity analysis of a 20% solids content DMAc solution, and the results are as Figure 5 shown. Figure 5 This is the viscosity curve of a 20% solids content DMAc solution of TPI prepared in Example 5 of the present invention.

[0076] The polyimide prepared in Example 5 above was compounded with glass fiber, as Figure 6 shown. Figure 6 This is a photo of the composite material of TPI and glass fiber prepared in Example 5 of the present invention.

[0077] The polyimide prepared in Example 5 above was subjected to mechanical property testing, and the results are shown in Table 1:

[0078] Table 1

[0079] Item Unit Example 5 Tensile strength (23°C) MPa 91 Tensile modulus (23°C) GPa 3.5 Flexural strength (23°C) MPa 137 Flexural modulus (23°C) GPa 3.6 Compressive strength (23°C) MPa 155 Impact strength (23°C) <![CDATA[KJ / m 2 > 81 Tensile strength (250°C) MPa 49 Flexural strength (250°C) MPa 77

[0080] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A diamine monomer, characterized in that, It has a structure of Formula III-a or a structure of Formula III-b: X is -NH- or O.

2. The diamine monomer according to claim 1, characterized in that, The specific structure of Formula III-a is any one of Formula III-a1 to Formula III-a6; The specific structure of Formula III-b is Formula III-b1 or Formula III-b2; 3. The preparation method of the diamine monomer according to claim 1 or 2, characterized in that, It includes the following steps: Under the action of a reducing agent and a water absorbent, a compound having a structure of Formula I-1 and a compound having a structure of Formula II-1 are subjected to a reduction reaction to obtain a diamine monomer having a structure of Formula III-a; Wherein, R1 and R2 are independently a carboxyl group or an acyl chloride group; R3 is a hydroxyl group or an amino group; Or, Under the action of a reducing agent and a water absorbent, a compound having a structure of Formula I-2 and a compound having a structure of Formula II-2 are subjected to a reduction reaction to obtain a diamine monomer having a structure of Formula III-b; Wherein, R4 is a carboxyl group or an acyl chloride group; R5 is a hydroxyl group or an amino group.

4. The preparation method according to claim 3, characterized in that, Under the action of a reducing agent and a water absorbent, a compound having a structure of Formula I-1 and a compound having a structure of Formula II-1 are subjected to a reduction reaction, wherein the molar ratio of the compound having a structure of Formula I-1 to the compound having a structure of Formula II-1 is (1 to 2.1):(1 to 2.1), the amount of the reducing agent is 5% to 30% of the molar amount of the compound having a structure of Formula I-1, and the amount of the water absorbent is 0.5 to 2 times the molar amount of the compound having a structure of Formula I-1; Or, it includes the following steps: Under the action of a reducing agent and a water absorbent, a compound having a structure of Formula I-2 and a compound having a structure of Formula II-2 are subjected to a reduction reaction, wherein the molar ratio of the compound having a structure of Formula I-2 to the compound having a structure of Formula II-2 is (1 to 2.1):(1 to 2.1), the amount of the reducing agent is 5% to 30% of the molar amount of the compound having a structure of Formula I-2, and the amount of the water absorbent is 0.5 to 2 times the molar amount of the compound having a structure of Formula I-2.

5. The preparation method according to claim 3, characterized in that The temperature of the reduction reaction is 170°C to 220°C, and the time of the reduction reaction is 5h to 16h.

6. A polyimide resin, characterized in that, It is prepared from an aromatic dianhydride and an aromatic diamine, and the aromatic diamine includes the diamine monomer described in Claim 1 or 2 or the diamine monomer obtained by the preparation method described in any one of Claims 3 to 6.

7. The polyimide resin according to claim 6, wherein The aromatic dianhydride is selected from one or more of the compounds having the structures shown in Formula 1 to Formula 10; 8. The polyimide resin according to claim 6, characterized in that, The aromatic diamine further includes one or more of the compounds having the structures shown in Formula 11 to Formula 16; Wherein, L1 is a group selected from O, S, sulfonyl group, methylene group, carbonyl group, a group having the structure shown in Formula a or a group having the structure shown in Formula b; L2 is O, S or -NH-.

9. The polyimide resin according to claim 6, characterized in that, The molar ratio of the aromatic dianhydride to the aromatic diamine is (0.9 to 1):

1.

10. The method for preparing the polyimide resin according to any one of claims 6 to 9, characterized in that, It includes the following steps: S1) Polymerize a material including an aromatic dianhydride and an aromatic diamine to obtain a polyamic acid; S2) Subject the polyamic acid obtained in step S1) to a cyclization dehydration reaction to obtain a polyimide resin; Or, it includes the following steps: Subject the material comprising an aromatic dianhydride and an aromatic diamine to an imidization reaction to obtain a polyimide resin.

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