Preparation method of high-temperature-resistant heat-conducting polyimide gasket

Abstract

The invention discloses a preparation method of a high-temperature-resistant heat-conducting polyimide gasket, which comprises the following raw materials: 4, 4 '-diaminodiphenylmethane (MDA), 3, 3', 4, 4 '-benzophenonetetracarboxylic dianhydride (BTDA), hexagonal boron nitride (BN) and hydrogen-containing polyether silicone oil, and comprises the following steps: S1, in an aprotic polar solvent and under the protection of a nitrogen environment, adding diamine and dianhydride, and carrying out a primary reaction; s2, dispersing heat-conducting powder and a stabilizer in the dispersion liquid, and then sequentially mixing with the resin prepared by the primary reaction in the step S1; s3, carrying out filtration and vacuum defoaming on the resin obtained in the step S2, uniformly coating the resin into a special mold, and carrying out heat treatment by using a hot-pressing instrument to form a thin film; s4, after the thin film in the step S3 is subjected to heating imidization, the heat-conducting polyimide gasket is obtained; the gasket has the effects of excellent high-temperature resistance and insulation characteristics, and the heat-conducting property of the gasket is improved; the product strength is improved; and the BN powder is not easy to fall off.

Description

Technical Field

[0001] The invention relates to a method for preparing a thermally conductive polyimide gasket, and in particular to a method for preparing a high-temperature resistant thermally conductive polyimide gasket. The high thermally conductive polyimide heat dissipation gasket is filled with hexagonal boron nitride (BN), has a thermal conductivity of up to 20W / mK, is resistant to high temperatures and has good comprehensive performance. Background Art

[0002] Nowadays, in order to keep up with the development of the times, the size of highly integrated and high-power electronic equipment products has gradually decreased, resulting in an increasingly prominent problem of exponentially increasing heat generated in dense spaces, which seriously affects the operability and service life of the products. Therefore, thermal conductive materials are needed to transfer excess energy from the inside of electronic devices to the outside to maintain the stable operation of electronic devices. Compared with traditional metal, carbon and ceramic materials, polymer-based thermal conductive composites have received extensive research and attention due to their excellent electrical insulation properties, strong impact resistance, chemical resistance and good thermal stability.

[0003] Among them, polyimide (PI) has excellent stability and mechanical properties and has broad development prospects in the field of electronic and electrical engineering. However, its amorphous state makes its thermal conductivity low, which limits the wide application of PI. At present, adding thermal conductive fillers to the polymer matrix is ​​a common strategy to improve the thermal conductivity of PI. Commonly used thermal conductive fillers include inorganic materials such as reduced graphene oxide, carbon nanotubes, boron nitride and aluminum oxide. Among them, hexagonal boron nitride (BN) is widely used as a filler due to its high in-plane and out-of-plane thermal conductivity values, which are as high as 400 W / mK and 5 W / mK respectively.

[0004] However, fillers are chemically inert and have poor compatibility with the polymer matrix. At low filler levels, the thermal conductivity of the film is low due to the high interfacial thermal resistance between the dispersed fillers and the lack of effective heat transfer paths in the entire composite material; at high filler levels, the mechanical and electrical insulation properties of the composite material are inevitably sacrificed, which hinders the preparation of high thermal conductivity polyimide gaskets. Summary of the invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies in the prior art and to provide a method for preparing a high-temperature resistant thermally conductive polyimide gasket, a method for preparing a high-temperature resistant thermally conductive polyimide gasket with a high BN filling and a thermal conductivity coefficient of up to 20 W / mK. The obtained thermally conductive polyimide gasket has a thermal conductivity of up to 20 W / mK, a thermal decomposition temperature of higher than 400°C, and a film breaking elongation of greater than 10%. In addition, under normal use, the BN powder will not fall off.

[0006] In order to achieve the above object, the measures taken by the present invention are: A preparation method of a high-temperature resistant thermally conductive polyimide gasket, comprising raw materials of 4,4'-diaminodiphenylmethane (MDA), 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA), hexagonal boron nitride (BN) and hydrogen-containing polyether silicone oil, firstly using MDA and BTDA to synthesize a polyamic acid precursor in N-methylpyrrolidone (NMP), adding boron nitride and hydrogen-containing polyether silicone oil in an intermediate step, and finally using a thermal imidization method to obtain a polyimide gasket; the specific preparation method comprises the following steps: S1. In a non-protonic polar solvent and under nitrogen environment protection, diamine and dianhydride are added and a preliminary reaction is carried out, wherein the molar ratio of dianhydride to diamine is 0.9-0.94:1; S2, dispersing the thermal conductive powder and the stabilizer in the dispersion and then mixing them with the resin prepared by the preliminary reaction in step S1 in sequence, and adjusting the anhydride with dianhydride, so that the molar ratio of dianhydride to diamine is 0.94-0.99:1; S3, filtering and vacuum defoaming the resin obtained in step S2, and evenly coating it in a special mold, and heat-treating it in a hot pressing apparatus at a certain temperature and a certain vacuum degree to form a film; S4, after the film in step S3 is subjected to programmed temperature increase and complete imidization, a final thermally conductive polyimide gasket is obtained; In order to meet the requirements of mechanical properties of the material, a special flexible monomer is used. In step S1, the diamine is 4,4'-diaminodiphenylmethane (MDA), and the dianhydride in step S1 is 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA). Considering universality and operational feasibility, the aprotic polar solvent in step S1 is N-methylpyrrolidone (NMP); Before synthesizing the precursor resin, the thermally conductive powder and stabilizer are shear-dispersed in NMP, and the dispersed thermally conductive powder is ensured to be evenly mixed with the polyimide precursor resin. The thermally conductive powder is hexagonal boron nitride, the average particle size of the thermally conductive powder should be less than 5μm, and the added mass percentage should be between 75-85%, which will help balance the thermal conductivity and mechanical properties of the polyimide gasket. The elongation at break of the thermally conductive polyimide gasket is higher than 10%, and the thermal conductivity reaches 20 W / mK.

[0007] The stabilizer is hydrogen-containing polyether silicone oil, and its main purpose is to allow the resin to accommodate more thermally conductive powder and improve the mechanical properties of the product; the stabilizer is added in an amount of 5wt% to ensure the stabilizing effect.

[0008] In order to achieve higher thermal conductivity, adding too high a proportion of thermal conductive powder to polyamic acid will easily lead to lower mechanical properties of the film and affect the difficulty of mass production. Therefore, it is very important to find a suitable ratio to coordinate the thermal conductivity and mechanical properties of polyimide gaskets.

[0009] In step S1, the diamine is 4,4'-methylenediaminodiphenylmethane (MDA), and the dianhydride is 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA); In step S2, the thermally conductive powder is hexagonal boron nitride, the particle size of the thermally conductive powder is less than 5 μm, and the addition amount is 75-85wt%; the stabilizer is hydrogenated polyether silicone oil, and the addition amount is 5wt%; The certain temperature in step S3 is 100°C-330°C, and the certain vacuum degree is -0.04~-0.06MPa; the temperature of the programmed temperature rise in step S4 is specifically: 70°C-150°C / 1h, 150°C-250°C / 1h, 250°C-330°C / 1h; The thickness of the thermally conductive polyimide gasket is 100-150 μm.

[0010] In order to obtain a high-quality high-temperature-resistant and thermally conductive polyimide gasket with high BN filling, the present invention first needs to select suitable dianhydride and diamine monomers so that the resin can maintain certain mechanical and electrical properties even after adding a high proportion of powder to the resin. Secondly, by adding a stabilizer such as hydrogen-containing polyether silicone oil to the resin, the resin can accommodate a higher proportion of BN powder.

[0011] The beneficial effects of the present invention are as follows: (1) The present invention has certain operability in production by carrying out condensation polymerization reaction through special flexible diamine monomers and dianhydride monomers. At the same time, both monomers do not contain fluorine atoms or other halogen elements, are environmentally friendly, and conform to the environmental protection policy of today's Chinese society.

[0012] (2) The present invention adds a high proportion of BN powder, which not only has the high temperature resistance and insulation properties of polyimide, but also greatly improves the thermal conductivity of the gasket. By adjusting the ratio and the type of raw materials, the gasket also has certain mechanical properties.

[0013] (3) In the present invention, by adding hydrogen-containing polyether silicone oil, the strength of the product can be improved to a certain extent. Its extremely strong amphiphilicity can also increase the powder holding capacity of the material, so that it can accommodate a higher proportion of BN powder, which is of positive significance for expanding production.

[0014] (4) The shape and size of the gasket can be customized, and the BN powder is not easy to fall off during the use of the gasket.

[0015] (5) The high temperature resistant thermally conductive polyimide gasket prepared by the method of the present invention has different material ratios, which mainly leads to differences in thermal conductivity. The higher the ratio, the better the thermal conductivity of the material. The high temperature resistant thermally conductive polyimide gasket prepared by the patent application of the present invention has a material insulation strength of >6kv / mm. The difference in insulation is determined by the characteristics of the added thermally conductive powder itself. PI itself is an insulating material.

[0016] (6) A high proportion of thermal conductive powder will lead to poor mechanical properties of the material and difficulty in molding. Hydrogenated polyether silicone oil can mainly play the role of "molecular bridge" between polymer and inorganic matter, improve the bonding strength between thermal conductive powder and resin, and then increase the filling amount of thermal conductive powder in the resin. Without adding hydrogenated polyether silicone oil, 75% BN was added, and the elongation at break of the material was less than 10%. Under the same conditions, the elongation at break of the material with the addition of hydrogenated polyether silicone oil was 17%. DETAILED DESCRIPTION

[0017] A preparation method of a high-temperature resistant thermally conductive polyimide gasket, comprising raw materials of 4,4'-diaminodiphenylmethane (MDA), 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA), hexagonal boron nitride (BN) and hydrogen-containing polyether silicone oil, firstly using MDA and BTDA to synthesize a polyamic acid precursor in N-methylpyrrolidone (NMP), adding boron nitride and hydrogen-containing polyether silicone oil in an intermediate step, and finally using a thermal imidization method to obtain a polyimide gasket; the specific preparation method comprises the following steps: S1. In a non-protonic polar solvent and under nitrogen environment protection, diamine and dianhydride are added and a preliminary reaction is carried out, wherein the molar ratio of dianhydride to diamine is 0.9-0.94:1; S2, dispersing the thermal conductive powder and the stabilizer in the dispersion and then mixing them with the resin prepared by the preliminary reaction in step S1 in sequence, and adjusting the anhydride with dianhydride, so that the molar ratio of dianhydride to diamine is 0.94-0.99:1; S3, filtering and vacuum defoaming the resin obtained in step S2, and evenly coating it in a special mold, and heat-treating it in a hot pressing apparatus at a certain temperature and a certain vacuum degree to form a film; S4. After the film in step S3 is subjected to programmed temperature increase and complete imidization, a final thermally conductive polyimide gasket is obtained.

[0018] The aprotic polar solvent in step S1 is N-methylpyrrolidone (NMP).

[0019] In step S1, the diamine is 4,4'-methylenediaminodiphenylmethane (MDA), and the dianhydride is 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA).

[0020] In step S2, the thermally conductive powder is hexagonal boron nitride, the particle size of the thermally conductive powder is less than 5 μm, and the addition amount is 75-85wt%; the stabilizer is hydrogenated polyether silicone oil, and the addition amount is 5wt%.

[0021] The certain temperature in step S3 is 100°C-330°C, and the certain vacuum degree is -0.04~-0.06MPa; the temperature of the programmed temperature rise in step S4 is specifically: 70°C-150°C / 1h, 150°C-250°C / 1h, 250°C-330°C / 1h.

[0022] The thickness of the thermally conductive polyimide gasket is 100-150 μm.

[0023] According to the above method steps, the preferred embodiments of the present invention are further described below. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention application, and are not used to limit the present invention application.

[0024] In order to fully illustrate the purpose of the present invention, the present invention is further described in detail through specific implementation cases, but this specific embodiment is only used as an explanation of the present invention and does not limit the scope of protection involved in the present invention. Those skilled in the art should not violate the spirit of the present invention on the basis of understanding the technical solution of the present invention, and modifications or replacements based on a certain scope should all be covered within the scope of protection of the present invention. Embodiment 1:

[0025] The present embodiment provides a method for preparing a high-temperature-resistant and thermally conductive polyimide gasket with high BN filling, which comprises raw materials of 4,4'-diaminodiphenylmethane (MDA), 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA), hexagonal boron nitride (BN) and hydrogen-containing polyether silicone oil. MDA and BTDA are first used to synthesize a polyamic acid precursor in N-methylpyrrolidone (NMP), boron nitride and hydrogen-containing polyether silicone oil are added in the middle step, and finally a polyimide gasket is obtained by a thermal imidization method. The specific preparation method comprises the following steps: S1: Add 500 mL of N-methylpyrrolidone (NMP) into a reactor, and under nitrogen protection, add 4,4'-diaminodiphenylmethane (MDA) into the reactor. After the diamine is completely dissolved, add 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA) into the reactor to make the molar ratio of diamine to dianhydride 0.9-0.94:1; then stir and react at 30℃-40℃ for 2 h to obtain a polyamic acid (PAA) homogeneous solution with a viscosity of 1000-10000cp; S2: adding hexagonal boron nitride dispersion and hydrogenated polyether silicone oil dispersion to the PAA solution prepared in step S1, wherein the mass proportion of hexagonal boron nitride in the film is 75%, and the mass proportion of hydrogenated polyether silicone oil in the film is 5%, and after stirring evenly, using BTDA to adjust the anhydride so that the final molar ratio of dianhydride to diamine is 0.94-0.99:1, and stirring the reaction at a temperature of 40°C for 4 hours to obtain a uniform precursor resin; S3: After filtering, remove the larger particle impurities, and then vacuum defoam, the precursor resin is scraped onto a clean hot pressing mold; S4: Finally, the mold is fixed on the hot press, and the vacuum degree is controlled at -0.04~-0.06MPa and then the temperature is raised in a programmed manner, specifically: 70-150℃ / 1h, 150-250℃ / 1h, 250-330℃ / 1h.

[0026] The thickness of the thermally conductive polyimide gasket prepared above is 100 μm. After testing, the thermal conductivity coefficient of the thermally conductive polyimide gasket obtained is 20.3 W / mK, the elongation at break is 17%, and the tensile strength reaches 102 MPa. Embodiment 2:

[0027] The present embodiment provides a method for preparing a high-temperature-resistant and thermally conductive polyimide gasket with high BN filling, which comprises raw materials of 4,4'-diaminodiphenylmethane (MDA), 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA), hexagonal boron nitride (BN) and hydrogen-containing polyether silicone oil. MDA and BTDA are first used to synthesize a polyamic acid precursor in N-methylpyrrolidone (NMP), boron nitride and hydrogen-containing polyether silicone oil are added in the middle step, and finally a polyimide gasket is obtained by a thermal imidization method. The specific preparation method comprises the following steps: S1: Add 500 mL of N-methylpyrrolidone (NMP) into a reactor, add 4,4'-diaminodiphenylmethane (MDA) into the reactor under nitrogen protection, and after the diamine is completely dissolved, add 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA) into the reactor to make the molar ratio of diamine to dianhydride be 0.9-0.94:1; then stir and react at 30℃-40℃ for 2h to obtain a polyamic acid (PAA) homogeneous solution with a viscosity of 1000-10000cp; S2: adding hexagonal boron nitride dispersion and hydrogenated polyether silicone oil dispersion to the PAA solution prepared in step S1, wherein the mass proportion of hexagonal boron nitride in the film is 80%, and the mass proportion of hydrogenated polyether silicone oil in the film is 5%. After stirring evenly, BTDA is used to adjust the anhydride so that the final molar ratio of dianhydride to diamine is 0.94-0.99:1. The mixture is stirred at 40°C for 4 hours to obtain a uniform precursor resin. S3: After filtering, remove the larger particle impurities, and then vacuum defoam, the precursor resin is scraped onto a clean hot pressing mold; S4: Finally, the mold is fixed on the hot press, and the vacuum degree is controlled at -0.04~-0.06MPa and then the temperature is raised in a programmed manner, specifically: 70-150℃ / 1h, 150-250℃ / 1h, 250-330℃ / 1h.

[0028] The thickness of the thermally conductive polyimide gasket prepared above is 100 μm. After testing, the thermal conductivity coefficient of the thermally conductive polyimide gasket obtained is 23.8 W / mK, the elongation at break is 15%, and the tensile strength reaches 95 MPa. Embodiment three:

[0029] The present embodiment provides a method for preparing a high-temperature-resistant and thermally conductive polyimide gasket with high BN filling, which comprises raw materials of 4,4'-diaminodiphenylmethane (MDA), 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA), hexagonal boron nitride (BN) and hydrogen-containing polyether silicone oil. MDA and BTDA are first used to synthesize a polyamic acid precursor in N-methylpyrrolidone (NMP), boron nitride and hydrogen-containing polyether silicone oil are added in the middle step, and finally a polyimide gasket is obtained by a thermal imidization method. The specific preparation method comprises the following steps: S1: Add 500 mL of N-methylpyrrolidone (NMP) into a reactor, and under nitrogen protection, add 4,4'-diaminodiphenylmethane (MDA) into the reactor. After the diamine is completely dissolved, add 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA) into the reactor to make the molar ratio of diamine to dianhydride 0.9-0.94:1; then stir and react at 30℃-40℃ for 2 h to obtain a polyamic acid (PAA) homogeneous solution with a viscosity of 1000-10000cp; S2: adding hexagonal boron nitride dispersion and hydrogenated polyether silicone oil dispersion to the PAA solution prepared in step S1, wherein the mass proportion of hexagonal boron nitride in the film is 85%, and the mass proportion of hydrogenated polyether silicone oil in the film is 5%, and after stirring evenly, using BTDA to adjust the anhydride so that the final molar ratio of dianhydride to diamine is 0.94-0.99:1, and stirring the reaction at 40°C for 4h to obtain a uniform precursor resin; S3: After filtering, remove the larger particle impurities, and then vacuum defoam, the precursor resin is scraped onto a clean hot pressing mold; S4: Finally, the mold is fixed on the hot press, and the vacuum degree is controlled at -0.04~-0.06MPa and then the temperature is raised in a programmed manner, specifically: 70-150℃ / 1h, 150-250℃ / 1h, 250-330℃ / 1h.

[0030] The thickness of the thermally conductive polyimide gasket prepared above is 100 μm. After testing, the thermal conductivity coefficient of the thermally conductive polyimide gasket obtained is 25.6 W / mK, the elongation at break is 11%, and the tensile strength reaches 79 MPa.

[0031] Comparison case: The present comparative example provides a method for preparing a thermally conductive polyimide gasket, comprising using 4,4'-diaminodiphenyl ether (ODA), pyromellitic acid dianhydride (PMDA) and hexagonal boron nitride thermally conductive powder, synthesizing a polyamic acid precursor from 4,4'-diaminodiphenyl ether (ODA) and pyromellitic acid dianhydride (PMDA) by a two-step thermal imidization method, and adding the thermally conductive powder in the middle step. The specific preparation method comprises the following steps: S1: Add 500 mL of N-methylpyrrolidone (NMP) into a reactor, add 4,4'-diaminodiphenyl ether (ODA) into the reactor under nitrogen protection, and after the diamine is completely dissolved, add pyromellitic dianhydride (PMDA) into the reactor to make the molar ratio of dianhydride to diamine be 0.9-0.94:1; then stir and react at 30℃-40℃ for 2 h to obtain a polyamic acid (PAA) homogeneous solution with a viscosity of 1000-10000cp; S2: adding hexagonal boron nitride dispersion to the PAA solution prepared in step S1, wherein the mass proportion of hexagonal boron nitride in the film is 55%, stirring evenly, using PMDA to adjust the anhydride, so that the final molar ratio of dianhydride to diamine is 0.94-0.99:1, stirring and reacting at a temperature of 40°C for 4 hours to obtain a uniform precursor resin; S3: After vacuum filtration to remove larger particle impurities, and then vacuum defoaming, the precursor resin is scraped onto a clean glass substrate, and the film is baked in an oven at 100-200°C to obtain a wet film; S4: Finally, the wet film is fixed on a nail plate of a certain size and placed in an oven for programmed heating, specifically: 70-150℃ / 1h, 150-250℃ / 1h, 250-350℃ / 1h. The thickness of the thermally conductive polyimide film prepared above is 100μm, the thermal conductivity is 1.6W / mK, the elongation at break is 5%, and the tensile strength reaches 60MPa.

[0032] Results The various properties of the white polyimide film obtained in the examples were measured using the following methods.

[0033] (1) Tensile strength and elongation at break: measured using a tensile testing machine (QT-6203, Suzhou Qiantong Instrument Co., Ltd.).

[0034] (2) Lab test: measured using a Spectro-guide integrating sphere (Spectro-guide CD-6834, BYK Chemical (Tongling) Co., Ltd.).

[0035] (3) Thermal conductivity test: Use a thermal conductivity tester (ai-Phase mobile M3 type1, Japan).

[0036] The performance comparison table of the embodiments of the present invention and the comparative examples is shown below: project formula <![CDATA[Thermal conductivity W·mK -1 > Tensile strength MPa Elongation at break % Example 1 MDA / BPDA with 75% BN / 5% Hydrogenated Polyether Silicone Oil 20.3 102 17 Example 2 MDA / BPDA with 80% BN / 5% Hydrogenated Polyether Silicone Oil 23.8 95 15 Example 3 MDA / BPDA with 85% BN / 5% Hydrogenated Polyether Silicone Oil 25.6 79 11 Comparative Cases ODA / PMDA with 55% BN 1.6 60 5 The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any equivalent modifications and substitutions made by any technician familiar with the technical field within the technical scope disclosed by the present invention and based on the technical solution and inventive concept of the present invention are all covered by the protection scope and disclosure scope defined by the claims of the present invention.

Claims

1. A method for preparing a high temperature resistant thermally conductive polyimide gasket, comprising raw materials of 4,4'-diaminodiphenylmethane (MDA), 3,3',4,4'-benzophenone tetraacid dianhydride (BTDA), hexagonal boron nitride (BN) and hydrogen-containing polyether silicone oil, characterized in that: First, MDA and BTDA are used to synthesize a polyamic acid precursor in N-methylpyrrolidone (NMP), boron nitride and hydrogen-containing polyether silicone oil are added in the intermediate step, and finally a polyimide gasket is obtained by a thermal imidization method; the specific preparation method includes the following steps: S1. In a non-protonic polar solvent and under nitrogen environment protection, diamine and dianhydride are added and a preliminary reaction is carried out, wherein the molar ratio of dianhydride to diamine is 0.9-0.94:1; S2, dispersing the thermal conductive powder and the stabilizer in the dispersion and then mixing them with the resin prepared by the preliminary reaction in step S1 in sequence, and adjusting the anhydride with dianhydride, so that the molar ratio of dianhydride to diamine is 0.94-0.99:1; S3, filtering and vacuum defoaming the resin obtained in step S2, and evenly coating it in a special mold, and heat-treating it in a hot pressing apparatus at a certain temperature and a certain vacuum degree to form a film; S4. After the film in step S3 is subjected to programmed temperature increase and complete imidization, a final thermally conductive polyimide gasket is obtained.

2. The method for preparing a high temperature resistant thermally conductive polyimide gasket according to claim 1, characterized in that: The aprotic polar solvent in step S1 is N-methylpyrrolidone (NMP).

3. The method for preparing a high temperature resistant thermally conductive polyimide gasket according to claim 1 or 2, characterized in that: In step S1, the diamine is 4,4'-methylenediaminodiphenylmethane (MDA), and the dianhydride is 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA).

4. The method for preparing a high temperature resistant thermally conductive polyimide gasket according to claim 3, characterized in that: In step S2, the thermally conductive powder is hexagonal boron nitride, the particle size of the thermally conductive powder is less than 5 μm, and the addition amount is 75-85wt%; the stabilizer is hydrogenated polyether silicone oil, and the addition amount is 5wt%.

5. The method for preparing a high temperature resistant thermally conductive polyimide gasket according to claim 4, characterized in that: The certain temperature in step S3 is 100°C-330°C, and the certain vacuum degree is -0.04~-0.06MPa; the temperature of the programmed temperature rise in step S4 is specifically: 70°C-150°C / 1h, 150°C-250°C / 1h, 250°C-330°C / 1h.

6. The method for preparing a high temperature resistant thermally conductive polyimide gasket according to claim 5, characterized in that: The thickness of the thermally conductive polyimide gasket is 100-150 μm.