Fluorine-containing polyimide resin and epoxy resin adhesive based on fluorine-containing polyimide resin

Abstract

According to the fluorine-containing polyimide resin and the epoxy resin adhesive based on the fluorine-containing polyimide resin, 2-trifluoromethyl-4, 4 '-diaminodiphenyl ether containing-CF3 is used as a raw material, and dianhydride containing a flexible group and dianhydride containing a rigid group are subjected to proportion optimization and compounding to synthesize the fluorine-containing polyimide resin. And mixing the epoxy resin with tetrafunctional epoxy resin, bifunctional epoxy resin and a curing agent to obtain the epoxy resin adhesive. According to the fluorine-containing polyimide resin, the glass transition temperature of the adhesive can be increased, the heat resistance of the adhesive is enhanced, meanwhile, due to the fact that the fluorine-containing polyimide resin contains-CF3, the solubility of the fluorine-containing polyimide resin in an epoxy system can be increased, and the water absorption rate and the dielectric constant of the adhesive are reduced.

Description

Technical Field

[0001] The invention relates to a fluorine-containing polyimide resin and an epoxy resin adhesive based thereon, belonging to the technical field of polymer materials. Background Art

[0002] With the rapid development of electronic technology, in the field of electronic product manufacturing, the chip packaging density continues to rise, and components such as inductors generate a lot of heat during operation. The operating temperature often exceeds the limit that traditional epoxy resin adhesives can withstand. Once ordinary epoxy resin adhesives encounter high temperatures, they will quickly soften and lose viscosity, leading to serious problems such as inductor parameter drift and chip debonding, which greatly affects the stability and service life of electronic products and is difficult to meet the use requirements under the development trend of miniaturized, high-performance, and high-reliability electronic products. Therefore, it is urgent to improve the temperature resistance of adhesives.

[0003] Polyimide resin with aromatic structure as the main chain has become one of the most widely used polymer resins in the electronics field due to its excellent heat resistance, electrical insulation, chemical resistance and weather resistance. It is often physically blended with traditional epoxy adhesives. However, due to the rigid structure of polyimide, it has strong intramolecular / intermolecular forces, which makes it difficult to dissolve in solvents and difficult to process. The current common strategy to increase solubility is to use spirofluorene structure to introduce a twisted non-coplanar structure, destroy the symmetry of the molecular chain, and increase the rotation resistance of the molecular chain. However, due to the introduction of rigid fluorene, the toughness will be reduced. In the Chinese patent applications with publication numbers CN116574259A and CN114369243A and the article "High performance imide oligomers and thermosets derived from 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride" (Polymer 2023, 281, 126086), it is reported that a non-coplanar torsional rigid fluorene structure is used to synthesize polyimide, so that the polyimide resin has high solubility after imidization and the resin cured product has high heat resistance. However, the monomer used is a rigid fluorene structure, which is affected by the structural rigidity of the monomer itself, resulting in a high viscosity of the resin melt, poor processability, and insufficient toughness of the cured material. Therefore, the development of a soluble polyimide resin that is resistant to high temperatures, has high toughness, and is easy to process is a technical problem that needs to be solved urgently. Summary of the invention

[0004] Based on the above problems existing in the prior art, the present invention provides a fluorinated polyimide resin and an epoxy resin adhesive based thereon. In the synthesis of the fluorinated polyimide resin, the present invention uses 2-trifluoromethyl-4,4'-diaminodiphenyl ether containing -CF3 as a raw material, and optimizes the proportion of a dianhydride containing a flexible group and a dianhydride containing a rigid group, which can not only overcome the contradiction between the heat resistance, solubility and toughness of the existing polyimide resin, but also reduce the water absorption rate and dielectric constant to meet the needs of precision electronic applications.

[0005] In order to achieve the purpose, the present invention adopts the following technical scheme:

[0006] The invention firstly discloses a preparation method of a fluorine-containing polyimide resin, comprising the following steps: firstly adding 2-trifluoromethyl-4,4'-diaminodiphenyl ether into a three-necked flask equipped with a rotor, adding a solvent to completely dissolve the 2-trifluoromethyl-4,4'-diaminodiphenyl ether under a nitrogen atmosphere, then adding dianhydride, and carrying out a polycondensation reaction at room temperature; after reacting for 5 to 7 hours, adding a catalyst triethylamine and a dehydrating agent acetic anhydride, reacting at room temperature for 0.5 to 1 hour, and then placing the mixture at 120 to 130 DEG C to react for 6 to 8 hours; then terminating the reaction, and after cooling, pouring the obtained reaction solution into a beaker filled with ethanol and stirring, and drying the obtained precipitate to obtain the target product fluorine-containing polyimide resin; wherein the usage ratio of 2-trifluoromethyl-4,4'-diaminodiphenyl ether, dianhydride, triethylamine and acetic anhydride is 1 mol: 1 mol: 1.6 to 1.8 mL: 4.3 to 4.5 mL.

[0007] As a preferred embodiment, the solvent is at least one of anisole, m-cresol, N-methylpyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide.

[0008] As a preferred embodiment, the dianhydride is a mixture of a first dianhydride and a second dianhydride, wherein the first dianhydride is 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, and the second dianhydride is at least one of 2,3,3',4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride, and the first dianhydride accounts for 50% to 100% of the total molar amount of the dianhydrides.

[0009] As a preferred embodiment, the 2-trifluoromethyl-4,4'-diaminodiphenyl ether is prepared according to the following steps:

[0010] Step 1: Add 22.56 g of 2-chloro-5-nitro-trifluorotoluene, 13.91 g of p-nitrophenol, 13.82 g of potassium carbonate and 100 mL of N,N'-dimethylformamide to a three-necked flask equipped with a rotor and a spherical condenser, and stir the mixture at 135-150° C. for 6-8 hours under a nitrogen atmosphere; pour the resulting reaction solution into distilled water for precipitation, add an appropriate amount of hydrochloric acid to promote product precipitation, stir for 20-30 minutes, filter and dry the precipitated solid matter, and then recrystallize it with a mixed solution of ethanol and water to obtain 2-trifluoromethyl-4,4'-dinitrodiphenyl ether;

[0011] Step 2: Add 10 mmol of 2-trifluoromethyl-4,4'-dinitrodiphenyl ether, 0.25 g of wet palladium carbon and 100 mL of anhydrous ethanol into a three-necked flask, stir and heat to 60-75° C., then dropwise add 15 mL of 80% hydrazine monohydrate solution within 2 hours, and then reflux for reaction for 7-8 hours; filter the resulting mixture to remove the wet palladium carbon, then evaporate to remove the ethanol, and then recrystallize with a mixed solution of ethanol and water to obtain 2-trifluoromethyl-4,4'-diaminodiphenyl ether.

[0012] The structural formula of the fluorinated polyimide resin prepared according to the above preparation method is as follows:

[0013]

[0014] Wherein, x is the percentage of the molar amount of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride to the total molar amount of dianhydride, y1 and y2 are the molar percentages of 2,3,3',4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride, respectively, and x+y1+y2=1.

[0015] The present invention also provides an epoxy resin adhesive, whose raw materials include epoxy resin, curing agent and the fluorinated polyimide resin, wherein the epoxy resin is composed of a tetrafunctional epoxy resin and a bifunctional epoxy resin in a mass ratio of 20% to 80%:80% to 20%, the mass ratio of the curing agent to the epoxy resin is 6:5 to 6, and the fluorinated polyimide resin accounts for 5% to 20% of the mass of the epoxy resin.

[0016] As a preferred embodiment: the tetrafunctional epoxy resin is one of N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl sulfone, and N,N,N',N'-tetraglycidyl-3,3'-dimethyl-4,4'-diaminodiphenylmethane; the bifunctional epoxy resin is at least one of E-20 epoxy resin, E-44 epoxy resin, and E-51 epoxy resin. The curing agent is one of 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, and m-phenylenediamine.

[0017] The preparation method of the epoxy resin adhesive of the present invention is: adding fluorine-containing polyimide resin to a solvent and mechanically stirring it until it is clear and transparent, then adding epoxy resin and curing agent and mixing them mechanically stirring them until they are clear and transparent, then pouring them into a mold, vacuum degassing, removing the solvent by reduced pressure distillation, and curing to obtain the epoxy resin adhesive.

[0018] As a preferred embodiment, the temperature of the vacuum degassing is 60-85°C and the time is 2-3 hours; the temperature of the reduced pressure distillation is 80-90°C and the time is 1-2 hours; the temperature of the curing is 120-180°C and the curing time is 2-4 hours.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. In the synthesis of the fluorinated polyimide resin, the present invention optimizes the ratio of rigid dianhydride to flexible dianhydride, so that not only can the synthesized fluorinated polyimide resin have excellent solubility in the epoxy resin adhesive system, but also can improve its heat resistance without reducing the toughness of the adhesive, prevent the adhesive from softening at high temperature and losing viscosity, protect the stability of electronic products and extend their life.

[0021] 2. In the synthesis of fluorinated polyimide resin, the present invention uses 2-trifluoromethyl-4,4'-diaminodiphenyl ether containing -CF3 as a raw material, so that its application in epoxy adhesive can not only increase the solubility, but also reduce the water absorption rate of the adhesive to prevent electronic products from failing due to moisture, and can also reduce the dielectric constant to protect the stable transmission of electrical signals.

[0022] 3. The epoxy resin adhesive of the present invention uses a synergistic combination of tetrafunctional and difunctional epoxy resins. Compared with a single epoxy resin system, it can improve heat resistance while avoiding damage to mechanical properties.

[0023] 4. The adhesive of the present invention has a simple preparation process and stable performance, and meets the high standard requirements of electronic products such as inductors and electronic packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The 2-trifluoromethyl-4,4'-diaminodiphenyl ether synthesized in the embodiment of the present invention is 1 H NMR spectrum.

[0025] Figure 2 The DSC graphs of the adhesives obtained in various embodiments of the present invention are shown in FIG.

[0026] Figure 3 Graph showing dielectric constants of adhesives obtained in various embodiments of the present invention;

[0027] Figure 4 Graph showing the mechanical properties of the adhesives obtained in various embodiments of the present invention. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments improved or modified by ordinary technicians in this field belong to the scope of protection of the present invention. It should be understood that the embodiments of the present invention are only used to illustrate the technical achievements of the present invention, rather than to limit the scope of protection of the present invention. In the embodiments, the methods used are conventional methods unless otherwise specified.

[0029] Example 1

[0030] In this embodiment, the fluorinated polyimide resin and the epoxy resin adhesive based thereon are prepared according to the following steps:

[0031] Step 1: Synthesis of 2-trifluoromethyl-4,4'-diaminodiphenyl ether

[0032] In a three-necked flask equipped with a rotor and a spherical condenser, 22.56 g of 2-chloro-5-nitro-trifluorotoluene, 13.91 g of p-nitrophenol, 13.82 g of potassium carbonate and 100 mL of N,N'-dimethylformamide were added, and the mixture was stirred at 150°C for 6 h under a nitrogen atmosphere; the obtained reaction solution was poured into distilled water for precipitation, and then an appropriate amount of hydrochloric acid was added to promote the precipitation of the product, and the mixture was stirred for 30 min. The precipitated solid matter was filtered and dried, and then recrystallized with a mixed solution of ethanol and water (the volume ratio of the two was 6:4) to obtain 2-trifluoromethyl-4,4'-dinitrodiphenyl ether.

[0033] 10 mmol (3.28 g) of 2-trifluoromethyl-4,4'-dinitrodiphenyl ether, 0.25 g of wet palladium carbon (10% Pd / C) and 100 mL of anhydrous ethanol were added to a three-necked flask, stirred and heated to 75°C, and then 15 mL of 80% hydrazine monohydrate solution was added dropwise within 2 hours, and then refluxed for 8 hours; the obtained mixture was filtered to remove the wet palladium carbon, and then the ethanol was removed by rotary evaporation, and then recrystallized with a mixed solution of ethanol and water (the volume ratio of the two was 6:4) to obtain 2-trifluoromethyl-4,4'-diaminodiphenyl ether, which 1 HNMR spectrum Figure 1 shown.

[0034] Step 2: Synthesis of fluorinated polyimide resin

[0035] First, add 1 mol of 2-trifluoromethyl-4,4'-diaminodiphenyl ether to a three-necked flask equipped with a rotor. Under a nitrogen atmosphere, add 18 mL of DMAc to completely dissolve 2-trifluoromethyl-4,4'-diaminodiphenyl ether, and then add 1 mol of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride to carry out polycondensation at room temperature. After reacting for 6 hours, add 1.6 mL of triethylamine and 4.3 mL of acetic anhydride, react at room temperature for 30 minutes, and then place at 120°C for 6 hours. Then terminate the reaction, and after cooling, pour the resulting reaction solution into a beaker filled with ethanol and stir. The resulting precipitate is then vacuum dried at 60°C to obtain the target product, a fluorinated polyimide resin, which is recorded as PIs-1.

[0036] Step 3: Synthesize epoxy resin adhesive

[0037] Add 0.15 g of fluorinated polyimide resin to DMA C The solution was mechanically stirred until clear and transparent, and then 1.5g N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 1.5g E-51 epoxy resin and 2.55g curing agent 4,4'-diaminodiphenylmethane were added, mixed and mechanically stirred until the solution was clear and transparent. The resulting mixture was poured into a mold, degassed at 85°C for 2h in a vacuum oven, and distilled at 85°C under reduced pressure for 1h, then cured at 140°C for 2h and 180°C for 2h to obtain an epoxy resin adhesive, which was recorded as PIs / EP-1.

[0038] Example 2

[0039] In this example, a fluorinated polyimide resin and epoxy resin adhesive was synthesized in the same manner as in Example 1, except that the amount of PIs-1 added in step 3 was 0.3 g. The resulting adhesive was designated as PIs / EP-2.

[0040] Example 3

[0041] In this example, a fluorinated polyimide resin and an epoxy resin adhesive were synthesized by the same method as in Example 2, except that 1 mol of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride in step 2 was replaced by 0.5 mol of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride and 0.5 mol of pyromellitic dianhydride. The resulting polyimide resin was designated as PIs-2, and the resulting adhesive was designated as PIs / EP-3.

[0042] Comparative Example 1

[0043] In this comparative example, a fluorinated polyimide resin was synthesized in the same manner as in Example 1, except that 1 mol of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride in step 2 was replaced by 1 mol of 2,3,3',4'-biphenyltetracarboxylic dianhydride. The obtained fluorinated polyimide resin was designated as PIs-3.

[0044] Comparative Example 2

[0045] In this comparative example, a fluorinated polyimide resin was synthesized by the same method as in Example 1, except that 1 mol of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride in step 2 was replaced by 0.75 mol of 2,3,3',4'-biphenyltetracarboxylic dianhydride and 0.25 mol of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride. The obtained fluorinated polyimide resin was recorded as PIs-4.

[0046] Comparative Example 3

[0047] 3g of E-51 epoxy resin and 2.55g of curing agent 4,4'-diaminodiphenylmethane were mixed and mechanically stirred until the solution was clear and transparent. The resulting mixture was poured into a mold, degassed at 85°C for 2h in a vacuum oven, and distilled at 85°C under reduced pressure for 1h, and then cured at 140°C for 2h and 180°C for 2h to obtain an epoxy resin adhesive, which was recorded as E1.

[0048] Comparative Example 4

[0049] 1.5 g of N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 1.5 g of E-51 epoxy resin and 2.55 g of curing agent 4,4'-diaminodiphenylmethane were mixed and mechanically stirred until the solution was clear and transparent. The resulting mixture was poured into a mold, degassed at 85°C for 2 h in a vacuum oven, and distilled at 85°C under reduced pressure for 1 h, and then cured at 140°C for 2 h and 180°C for 2 h to obtain an epoxy resin adhesive, which was recorded as EP1.

[0050] The solubility properties of the fluorinated polyimide resins obtained in the above examples and comparative examples in different solvent systems are shown in Table 1, where √ represents complete solubility, ○ represents partial solubility, and × represents insolubility.

[0051] Table 1

[0052]

[0053] It can be seen from Table 1 that when the molar ratio of the flexible dianhydride is not less than 50%, the obtained fluorine-containing polyimide resin has excellent solubility in various solvents.

[0054] Figure 2 The DSC graphs of the adhesives obtained in each embodiment are shown in Figure 2. Comparison between adhesives PIs / EP-1 and PIs / EP-2 shows that as the content of fluorinated polyimide resin increases, Tg will gradually increase from 175°C to 185°C; comparison between adhesives PIs / EP-2 and PIs / EP-3 shows that as the rigidity content of fluorinated polyimide resin increases, its heat resistance continues to increase, and Tg increases from 185°C to 193°C. Comparison between E1 and EP1 shows that the addition of tetrafunctional epoxy resin increases the crosslinking density of the adhesive, increasing Tg from 148°C to 166°C.

[0055] Figure 3 The dielectric constant diagram of the adhesive obtained in each embodiment is shown in FIG. By comparison, it can be seen that the dielectric constant of the adhesive added with fluorinated polyimide resin can be reduced due to the presence of -CF3 in the structure. When the PIs-2 content reaches 10%, the dielectric constant at high frequency is reduced by 31.4%.

[0056] Figure 4 The following are the mechanical properties of the adhesives obtained in various embodiments. It can be seen from the comparison between adhesive E1 and PIs / EP-1 and PIs / EP-2 that with the increase of flexible groups, its mechanical properties continue to increase, from 60Mpa to 82Mpa. It can be seen from the comparison between adhesive E1 and PIs / EP-1, PIs / EP-2 and PIs / EP-3 that when the fluorinated polyimide resin system is introduced into the rigid structure, its mechanical properties will decrease, but will be improved compared to the mechanical properties of the adhesive without the addition of fluorinated polyimide resin.

[0057] Table 2 is a table of water absorption of the adhesive obtained in each embodiment. The test method is as follows: the cured resin sample is made into a disc with a diameter of 2.0 cm and a thickness of 2 mm, placed in a 60°C oven for drying for 8 hours, weighed with an analytical balance, and the mass is recorded as m0. Then, the sample is placed in deionized water at room temperature for 24 hours, taken out and the surface moisture is wiped off, and the mass is recorded as m1. The water absorption calculation formula is:

[0058] Table 2

[0059] sample Water absorption (%) E1 1.21 PIs / EP-1 0.89 PIs / EP-2 0.71 PIs / EP-3 0.64

[0060] It can be seen from Table 2 that adding fluorinated polyimide resin can significantly reduce the water absorption rate.

[0061] The above are merely exemplary embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a fluorinated polyimide resin, characterized in that: The steps include: First, add 2-trifluoromethyl-4,4'-diaminodiphenyl ether to a three-necked flask equipped with a rotor, add a solvent to completely dissolve the 2-trifluoromethyl-4,4'-diaminodiphenyl ether under a nitrogen atmosphere, then add dianhydride to carry out a polycondensation reaction at room temperature; after reacting for 5 to 7 hours, add a catalyst triethylamine and a dehydrating agent acetic anhydride, react at room temperature for 0.5 to 1 hour, and then place at 120 to 130° C. to react for 6 to 8 hours; then terminate the reaction, and after cooling, pour the obtained reaction solution into ethanol and stir, and dry the obtained precipitate to obtain the target product fluorinated polyimide resin; wherein the amount ratio of 2-trifluoromethyl-4,4'-diaminodiphenyl ether, dianhydride, triethylamine and acetic anhydride is 1 mol: 1 mol: 1.6 to 1.8 mL: 4.3 to 4.5 mL.

2. The method for preparing a fluorinated polyimide resin according to claim 1, wherein: The solvent is at least one of anisole, m-cresol, N-methylpyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide.

3. The method for preparing a fluorinated polyimide resin according to claim 1, characterized in that: The dianhydride is a mixture of a first dianhydride and a second dianhydride, wherein the first dianhydride is 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, and the second dianhydride is at least one of 2,3,3',4'-biphenyl tetracarboxylic dianhydride and pyromellitic dianhydride, and the first dianhydride accounts for 50% to 100% of the total molar amount of the dianhydrides.

4. The method for preparing a fluorinated polyimide resin according to claim 1, characterized in that: The 2-trifluoromethyl-4,4'-diaminodiphenyl ether is prepared according to the following steps: Step 1: Add 22.56 g of 2-chloro-5-nitro-trifluorotoluene, 13.91 g of p-nitrophenol, 13.82 g of potassium carbonate and 100 mL of N,N'-dimethylformamide to a three-necked flask equipped with a rotor and a spherical condenser, and stir the mixture at 135-150° C. for 6-8 hours under a nitrogen atmosphere; pour the resulting reaction solution into distilled water for precipitation, add an appropriate amount of hydrochloric acid to promote product precipitation, stir for 20-30 minutes, filter and dry the precipitated solid matter, and then recrystallize it with a mixed solution of ethanol and water to obtain 2-trifluoromethyl-4,4'-dinitrodiphenyl ether; Step 2: Add 10 mmol of 2-trifluoromethyl-4,4'-dinitrodiphenyl ether, 0.25 g of wet palladium carbon and 100 mL of anhydrous ethanol into a three-necked flask, stir and heat to 60-75° C., then dropwise add 15 mL of 80% hydrazine monohydrate solution within 2 hours, and then reflux for reaction for 7-8 hours; filter the resulting mixture to remove the wet palladium carbon, then evaporate to remove the ethanol, and then recrystallize with a mixed solution of ethanol and water to obtain 2-trifluoromethyl-4,4'-diaminodiphenyl ether.

5. A fluorine-containing polyimide resin obtained by the preparation method according to any one of claims 1 to 4.

6. An epoxy resin adhesive, characterized in that: The raw materials include epoxy resin, curing agent and the fluorinated polyimide resin as described in claim 5, wherein the epoxy resin is composed of a tetrafunctional epoxy resin and a bifunctional epoxy resin in a mass ratio of 20% to 80%:80% to 20%, the mass ratio of the curing agent to the epoxy resin is 6:5 to 6, and the fluorinated polyimide resin accounts for 5% to 20% of the mass of the epoxy resin.

7. The epoxy resin adhesive according to claim 6, characterized in that: The tetrafunctional epoxy resin is one of N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl sulfone and N,N,N',N'-tetraglycidyl-3,3'-dimethyl-4,4'-diaminodiphenylmethane; the bifunctional epoxy resin is at least one of E-20 epoxy resin, E-44 epoxy resin and E-51 epoxy resin.

8. The epoxy resin adhesive according to claim 6, characterized in that: The curing agent is one of 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane and m-phenylenediamine.

9. A method for preparing the epoxy resin adhesive according to any one of claims 6 to 8, characterized in that: The fluorine-containing polyimide resin is added to the solvent and mechanically stirred until it is clear and transparent, and then the epoxy resin and the curing agent are added and mixed and mechanically stirred until it is clear and transparent, and then poured into a mold, vacuum degassing, reduced pressure distillation to remove the solvent, and curing to obtain an epoxy resin adhesive.

10. The preparation method according to claim 9, characterized in that: The temperature of the vacuum degassing is 60-85°C and the time is 2-3h; the temperature of the reduced pressure distillation is 80-90°C and the time is 1-2h; the temperature of the curing is 120-180°C and the curing time is 2-4h.

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