Polyimide film with high thermal conductivity

Abstract

The invention discloses a high-thermal-conductivity polyimide film, and belongs to the technical field of polyimide film preparation. The high-thermal-conductivity polyimide film is prepared from the following components in parts by weight: 30 to 50 parts of diamine monomer, 19.12 to 32.08 parts of dicarboxylic anhydride monomer, 69 to 78 parts of N, N-dimethylacetamide, 30 to 43.5 parts of bisphenol A diglycidyl ether, 8.3 to 9.6 parts of modified heat conduction agent and 7.8 to 9.2 parts of composite wear-resistant agent, the composite wear-resistant agent is prepared by taking 2, 2-bis (4-hydroxy-3-benzyl) propane and carboxylated carbon nanotubes as main raw materials, and the composite wear-resistant agent is prepared by taking 2-aminoethanethiol, 5-amino-1, 3, 4-thiadiazole-2-thiol and 4-(trifluoromethyl) phenol as main raw materials. The polyimide film prepared by the method has excellent heat-conducting property, thermal stability and wear resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of polyimide film preparation, and particularly relates to a high thermal conductivity polyimide film. Background Art

[0002] As an engineering plastic with excellent comprehensive performance, polyimide film has a wide temperature range of -269℃ to +400℃, a 16 High insulation resistivity above Ω·cm and excellent mechanical strength have long dominated core fields such as flexible circuit board substrates, aerospace thermal control systems, and new energy battery packaging. However, its intrinsic thermal conductivity of less than 0.2W / m·K has exposed a fatal shortcoming in high-power density applications such as 5G communications, new energy vehicles, and artificial intelligence chips. When the integration of electronic devices exceeds 200W / cm 2 When the temperature of a battery pack exceeds 60°C, the thermal resistance of traditional polyimide film can cause the chip surface temperature to rise by more than 30°C, resulting in a 40% increase in signal delay and a 60% reduction in device life. This heat accumulation effect is particularly significant in the field of power batteries. When the operating temperature of the battery pack exceeds 60°C, the heat dissipation lag of traditional polyimide encapsulation film will directly induce the growth of lithium dendrites, causing the battery cycle life to drop by 50%, and even causing the risk of thermal runaway.

[0003] Patent CN113896921A discloses a method for preparing a high-thermal-conductivity polyimide film. The specific composition ratio of the high-thermal-conductivity polyimide film includes 10-20 parts of tetracarboxylic dianhydride, 8-10 parts of dimethyl diphenyl ether, 15-17 parts of aromatic diamine, 8-10 parts of biphenyl dianhydride, 12-14 parts of graphene, and 9-11 parts of nanofilm. The specific steps of the high-thermal-conductivity polyimide film preparation method are as follows. The high-thermal-conductivity polyimide film preparation method adds graphene and nanofilm to the prepared polyimide film, so that the high-thermal-conductivity polyimide film not only has the excellent properties of ordinary polyimide films, but also has excellent uniform thermal conductivity. However, the thermal conductivity and wear resistance of the polyimide film prepared by this method still have room for improvement. Summary of the Invention

[0004] The object of the present invention is to provide a high thermal conductivity polyimide film, which is used to solve the technical problem of poor thermal conductivity and wear resistance of polyimide films in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention provides a high-thermal-conductivity polyimide film, which is composed of the following components in parts by weight: 30-50 parts of a diamine monomer, 19.12-32.08 parts of a dibasic acid anhydride monomer, 69-78 parts of N,N-dimethylacetamide, 30-43.5 parts of bisphenol A diglycidyl ether, 8.3-9.6 parts of a modified thermal conductor, and 7.8-9.2 parts of a composite wear-resistant agent. The modified thermal conductor is prepared by using 5-chloro-2-nitrotrifluorotoluene, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, hydrazine hydrate, and carboxylated carbon nanotubes as main raw materials, and the composite wear-resistant agent is prepared by using 2-aminoethanethiol, thiourea, 5-amino-1,3,4-thiadiazole-2-thiol, and 4-(trifluoromethyl)phenol as main raw materials.

[0007] Preferably, the preparation method of the modified thermal conductive agent comprises the following steps:

[0008] Q1: Add 5-chloro-2-nitrotrifluorotoluene, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, potassium carbonate, and N,N-dimethylformamide to a container equipped with a thermometer and a nitrogen channel, heat the reaction, and condense and reflux. After the reaction, precipitate, filter, wash, vacuum dry, and recrystallize to obtain compound 1;

[0009] Q2: Compound 1, anhydrous ethanol and palladium-carbon were heated to reflux reaction, and hydrazine hydrate was added dropwise during the reaction, and the addition time was controlled. After the addition was completed, the reflux reaction was maintained. After the reaction was completed, the mixture was filtered while hot, concentrated, filtered, and vacuum dried to obtain compound 2;

[0010] Q3: Add carboxylated carbon nanotubes to a container containing a mixed solution of ethanol and chloroform, disperse by ultrasonication, then add EDC hydrochloride and NHS, dissolve by ultrasonication, then add compound 2, heat and stir to react, centrifuge, wash, and dry after the reaction is completed to obtain a modified thermal conductor.

[0011] In the above process, the synthetic reaction formula of compound 2 is as follows:

[0012]

[0013] The results of mass spectrometry analysis of compound 1 were: m / z: 634.15 (100.0%), 635.16 (34.0%), 636.16 (6.8%), 637.16 (1.1%); the results of mass spectrometry analysis of compound 2 were: m / z: 574.21 (100.0%), 575.21 (33.9%), 576.21 (6.1%).

[0014] Preferably, in Q1, the amount ratio of 5-chloro-2-nitrotrifluorotoluene, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, potassium carbonate and N,N-dimethylformamide is (19.1-20.6) g: (10.02-10.47) g: (6.12-7.69) g: (120-180) mL, the temperature of the reaction is 120-150°C, the reaction time is 10-14 h, the reaction is added to a 1 mol / L hydrochloric acid solution at 0°C and precipitated for 10-12 h, and the vacuum drying temperature is 80-90°C and the time is 10-12 h.

[0015] Preferably, in Q2, the amount ratio of compound 1, anhydrous ethanol, palladium-carbon and hydrazine hydrate is (24.12-26.53) g: (220-280) mL: (0.22-0.35) g: (32-47) mL, the dropwise addition time is controlled to be 1-2 h, the reflux reaction time is maintained to be 10-12 h, and the vacuum drying temperature is 80-85 ° C.; in Q3, the amount ratio of carboxylated carbon nanotubes, ethanol, chloroform, EDC hydrochloride, NHS and compound 2 is (0.1-0.13) g: (50-75) mL: (50-80) mL: (0.2-0.25) g: (0.2-0.28) g: (0.94-1.42) g, the ultrasonic dispersion time is 30-45 min, and the ultrasonic dissolution time is 20-35 min.

[0016] Preferably, the preparation method of the composite anti-wear agent comprises the following steps:

[0017] S1: Add water and ethanol to a container, stir and mix, then add 2-aminoethanethiol and thiourea, stir in an ice bath, then add hydrochloric acid solution, then dropwise add hydrogen peroxide solution, control the addition time, stir and react, after the reaction is completed, rotary evaporate, filter with suction, and recrystallize to obtain intermediate A;

[0018] S2: Add intermediate A and 5-amino-1,3,4-thiadiazole-2-thiol to a container, then add ethanol, stir, then add sodium bicarbonate solution dropwise, continue stirring to react, and after the reaction is completed, rotary evaporation, suction filtration, washing the filter cake, drying, and recrystallization to obtain intermediate B;

[0019] S3: Add the intermediate B, 4-(trifluoromethyl)phenol and paraformaldehyde to a container filled with xylene, heat and reflux to react, and after the reaction is completed, cool, filter and vacuum dry to obtain a composite wear-resistant agent.

[0020] In the above process, the synthetic reaction formula of the composite wear-resistant agent is as follows:

[0021]

[0022] The results of mass spectrometry analysis of intermediate A were: m / z: 187.00 (100.0%), 189.00 (41.1%), 188.00 (6.0%), 190.99 (3.1%), 190.00 (2.0%); the results of mass spectrometry analysis of intermediate B were: m / z: 207.99 (100.0%), 209.99 (13.8%), 208.99 (8.2%); the results of mass spectrometry analysis of the composite wear-resistant agent were: m / z: 580.05 (100.0%), 581.05 (27.7%), 582.05 (15.0%), 583.05 (3.3%), 582.06 (2.8%).

[0023] Preferably, in S1, the amount ratio of water, ethanol, 2-aminoethanethiol, thiourea, hydrochloric acid solution and hydrogen peroxide solution is (3-7) mL: (12.5-17.2) mL: (0.91-1.13) g: (0.62-0.92) g: (0.9-1.4) mL: (1.01-1.19) mL, the ice bath stirring temperature is 0-5°C, the volume fraction of the hydrochloric acid solution is 38vt%, the volume fraction of the hydrogen peroxide solution is 30vt%, the dropwise addition time is controlled to 30-45 min, and the stirring reaction time is 3-5 h.

[0024] Preferably, in S2, the amount ratio of intermediate A, 5-amino-1,3,4-thiadiazole-2-thiol, ethanol and sodium bicarbonate solution is (1.78-2.32) g: (1.11-1.56) g: (18-23) mL: (18-22) mL, the concentration of sodium bicarbonate solution is 0.063 g / mL, and the stirring reaction time is continued for 2-3 h.

[0025] Preferably, in S3, the amount ratio of intermediate B, 4-(trifluoromethyl)phenol, paraformaldehyde and xylene is (4.2-5.5) g: (6.12-6.93) g: (2.12-2.75) g: (140-180) mL, the heating reflux reaction time is 5-8 h, and the vacuum drying temperature is 60-70 ° C, and the time is 10-12 h.

[0026] Preferably, the method for preparing a high thermal conductive polyimide film comprises the following steps:

[0027] Step 1: Add diamine monomer and dibasic acid anhydride monomer to N,N-dimethylacetamide, heat under reflux and continue stirring, then add bisphenol A diglycidyl ether, continue stirring and reacting to obtain a viscous substance;

[0028] Step 2: Add the modified thermal conductor and the composite wear-resistant agent to the viscous substance, stir and mix evenly, then add it to the mold, solidify, and cool to obtain a high thermal conductive polyimide film.

[0029] Preferably, in the step 1, the heating reflux temperature is 70-73°C, the stirring time is 8-10h, and the stirring reaction time is continued for 1-2h; in the step 2, the curing process is maintained at 80-90°C for 1-2h, 120-130°C for 1-2h, and 170-190°C for 1-2h, and then the temperature is increased to 230-250°C and maintained for 2-4h.

[0030] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0031] 1. The present invention first prepares a modified thermal conductive agent using 5-chloro-2-nitrotrifluorotoluene, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, hydrazine hydrate and carboxylated carbon nanotubes as main raw materials, and then prepares a composite wear-resistant agent using 2-aminoethanethiol, thiourea, 5-amino-1,3,4-thiadiazole-2-thiol and 4-(trifluoromethyl)phenol as main raw materials. During the preparation process of the polyimide film, the modified thermal conductive agent and the composite wear-resistant agent are added to effectively improve its thermal conductivity, thermal stability and wear resistance.

[0032] 2. The present invention adds the prepared modified thermal conductive agent to the preparation process of the polyimide film, which can effectively improve its thermal conductivity and thermal stability. The carbon nanotubes contained in the modified thermal conductive agent have high thermal conductivity, and the amino groups contained therein can form amide bonds with carboxyl groups to achieve covalent bond connection and reduce interfacial thermal resistance. At the same time, the trifluoromethyl groups contained therein have strong electronegativity and can capture free radicals, delaying the thermal oxidative degradation of the polyimide main chain. The presence of carbon nanotubes can also form a physical barrier to improve the thermal stability of the polyimide film.

[0033] 3. The present invention adds the prepared composite wear-resistant agent to the preparation process of the polyimide film, which can effectively improve its wear resistance and thermal stability. The supporting effect of the rigid heterocyclic skeleton contained in the composite wear-resistant agent and the presence of the sulfur-based self-lubricating network can effectively improve its wear resistance. The aromatic heterocycle contained in the composite wear-resistant agent can form an extended conjugation with the polyimide aromatic ring, thereby improving the thermal decomposition activation performance and improving its thermal stability. DETAILED DESCRIPTION

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] Example 1: This example discloses a method for preparing a modified thermal conductive agent, comprising the following steps:

[0036] Q1: 18.3 g of 5-chloro-2-nitrotrifluorotoluene, 10.25 g of 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 6.9 g of potassium carbonate, and 150 mL of N,N-dimethylformamide were added to a container equipped with a thermometer and a nitrogen channel. The reaction was heated to 130°C for 14 h and condensed under reflux. After the reaction was completed, the mixture was added to a 1 mol / L hydrochloric acid solution at 0°C and precipitated for 12 h. The mixture was filtered, washed, and dried in vacuo at 85°C for 12 h. The mixture was recrystallized to obtain compound 1.

[0037] Q2: 25.33 g of compound 1, 250 mL of anhydrous ethanol and 0.29 g of palladium-carbon were heated to reflux reaction. During the reaction, 39.5 mL of hydrazine hydrate was added dropwise for 1 h. After the addition was completed, the reflux reaction was maintained for 12 h. After the reaction was completed, the mixture was filtered while hot, concentrated, filtered, and dried in vacuo at 85 °C to obtain compound 2;

[0038] Q3: Add 0.115 g of carboxylated carbon nanotubes to a container containing a mixed solution of 62.5 mL of ethanol and 65 mL of chloroform, and ultrasonically disperse for 45 minutes. Then add 0.22 g of EDC hydrochloride and 0.24 g of NHS, and ultrasonically dissolve for another 30 minutes. Then add 1.23 g of compound 2, heat and stir to react. After the reaction is completed, centrifuge, wash, and dry to obtain a modified thermal conductor.

[0039] This embodiment discloses a method for preparing a composite anti-wear agent, comprising the following steps:

[0040] S1: 5 mL of water and 14.8 mL of ethanol were added to a container, stirred and mixed, and then 1.07 g of 2-aminoethanethiol and 0.77 g of thiourea were added. The mixture was stirred in an ice bath at 0°C, and then 1.15 mL of a 38% by volume hydrochloric acid solution was added. Then, 1.1 mL of a 30% by volume hydrogen peroxide solution was added dropwise. The addition time was controlled to be 30 minutes. The mixture was stirred and reacted for 3 hours. After the reaction was completed, the mixture was rotary evaporated, filtered, and recrystallized to obtain intermediate A.

[0041] S2: 2.01 g of intermediate A and 1.33 g of 5-amino-1,3,4-thiadiazole-2-thiol were added to a container, and then 20.5 mL of ethanol was added and stirred. Subsequently, 20 mL of 0.063 g / mL sodium bicarbonate solution was added dropwise and the reaction was continued with stirring for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered with suction, and the filter cake was washed, dried, and recrystallized to obtain intermediate B;

[0042] S3: 4.7 g of intermediate B, 6.51 g of 4-(trifluoromethyl)phenol and 2.43 g of paraformaldehyde were added to a container containing 160 mL of xylene, and the mixture was heated under reflux for 6 h. After the reaction was completed, the mixture was cooled, filtered, and vacuum dried at 65° C. for 12 h to obtain a composite wear-resistant agent.

[0043] This embodiment discloses a high thermal conductivity polyimide film, which is composed of the following components by weight: 40 parts of 4,4'-diaminodiphenyl ether, 26.01 parts of 4,4'-bismaleimide diphenylmethane, 73.5 parts of N,N-dimethylacetamide, 36.5 parts of bisphenol A diglycidyl ether, 8.8 parts of a modified thermal conductor, and 8.5 parts of a composite wear-resistant agent.

[0044] This embodiment discloses a method for preparing a high thermal conductivity polyimide film, comprising the following steps:

[0045] Step 1: Add 4,4'-diaminodiphenyl ether and 4,4'-bismaleimide diphenylmethane to N,N-dimethylacetamide, heat under reflux at 72°C and continue stirring for 10 hours, then add bisphenol A diglycidyl ether, continue stirring and reacting for 2 hours to obtain a viscous substance;

[0046] Step 2: Add the modified thermal conductor and composite wear-resistant agent to the viscous substance, stir and mix evenly, then add it to the mold, solidify, keep it at 85°C for 1 hour, keep it at 120°C for 1 hour, keep it at 180°C for 1 hour, then heat it to 240°C and keep it for 2 hours, post-process, and cool to obtain a high thermal conductive polyimide film.

[0047] Example 2: This example discloses a method for preparing a modified thermal conductive agent, comprising the following steps:

[0048] Q1: 19.1 g of 5-chloro-2-nitrotrifluorotoluene, 10.02 g of 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 6.12 g of potassium carbonate, and 120 mL of N,N-dimethylformamide were added to a container equipped with a thermometer and a nitrogen channel. The reaction was heated to 130°C for 14 h and condensed under reflux. After the reaction was completed, the mixture was added to a 1 mol / L hydrochloric acid solution at 0°C and precipitated for 12 h. The mixture was filtered, washed, and dried in vacuo at 85°C for 12 h. The mixture was recrystallized to obtain compound 1.

[0049] Q2: 24.12 g of compound 1, 220 mL of anhydrous ethanol and 0.22 g of palladium-carbon were heated to reflux reaction. During the reaction, 32 mL of hydrazine hydrate was added dropwise for 1 hour. After the addition was completed, the reflux reaction was maintained for 12 hours. After the reaction was completed, the mixture was filtered while hot, concentrated, filtered, and dried in vacuo at 85°C to obtain compound 2;

[0050] Q3: 0.1 g of carboxylated carbon nanotubes was added to a container containing a mixed solution of 50 mL of ethanol and 50 mL of chloroform, and ultrasonically dispersed for 45 minutes. Subsequently, 0.2 g of EDC hydrochloride and 0.28 g of NHS were added, and ultrasonically dissolved for another 30 minutes. Then, 0.94 g of compound 2 was added, and the mixture was heated and stirred for reaction. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain a modified thermal conductor.

[0051] This embodiment discloses a method for preparing a composite anti-wear agent, comprising the following steps:

[0052] S1: 3 mL of water and 12.5 mL of ethanol were added to a container, stirred and mixed, and then 0.91 g of 2-aminoethanethiol and 0.62 g of thiourea were added. The mixture was stirred in an ice bath at 0°C, and then 0.9 mL of a 38% by volume hydrochloric acid solution was added. Then, 1.01 mL of a 30% by volume hydrogen peroxide solution was added dropwise. The addition time was controlled to be 30 minutes. The mixture was stirred and reacted for 3 hours. After the reaction was completed, the mixture was rotary evaporated, filtered, and recrystallized to obtain intermediate A.

[0053] S2: 1.78 g of intermediate A and 1.11 g of 5-amino-1,3,4-thiadiazole-2-thiol were added to a container, and then 18 mL of ethanol was added and stirred. Subsequently, 18 mL of 0.063 g / mL sodium bicarbonate solution was added dropwise and the reaction was continued with stirring for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered with suction, and the filter cake was washed, dried, and recrystallized to obtain intermediate B;

[0054] S3: 4.2 g of intermediate B, 6.12 g of 4-(trifluoromethyl)phenol and 2.12 g of paraformaldehyde were added to a container containing 140 mL of xylene, and the mixture was heated under reflux for 6 h. After the reaction was completed, the mixture was cooled, filtered, and vacuum dried at 65° C. for 12 h to obtain a composite wear-resistant agent.

[0055] This embodiment discloses a high thermal conductivity polyimide film, which is composed of the following components by weight: 30 parts of 4,4'-diaminodiphenyl ether, 19.12 parts of 4,4'-bismaleimide diphenylmethane, 69 parts of N,N-dimethylacetamide, 30 parts of bisphenol A diglycidyl ether, 8.3 parts of a modified thermal conductor, and 7.8 parts of a composite wear-resistant agent.

[0056] This embodiment discloses a method for preparing a high thermal conductivity polyimide film, comprising the following steps:

[0057] Step 1: Add 4,4'-diaminodiphenyl ether and 4,4'-bismaleimide diphenylmethane to N,N-dimethylacetamide, heat under reflux at 72°C and continue stirring for 10 hours, then add bisphenol A diglycidyl ether, continue stirring and reacting for 2 hours to obtain a viscous substance;

[0058] Step 2: Add the modified thermal conductor and composite wear-resistant agent to the viscous substance, stir and mix evenly, then add it to the mold, solidify, keep it at 85°C for 1 hour, keep it at 120°C for 1 hour, keep it at 180°C for 1 hour, then heat it to 240°C and keep it for 2 hours, post-process, and cool to obtain a high thermal conductive polyimide film.

[0059] Example 3: This example discloses a method for preparing a modified thermal conductive agent, comprising the following steps:

[0060] Q1: 20.6 g of 5-chloro-2-nitrotrifluorotoluene, 10.47 g of 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 7.69 g of potassium carbonate and 180 mL of N,N-dimethylformamide were added to a container equipped with a thermometer and a nitrogen channel, heated to 130°C for 14 h and condensed under reflux. After the reaction, the mixture was added to a 1 mol / L hydrochloric acid solution at 0°C for 12 h, filtered, washed, dried in vacuo at 85°C for 12 h, and recrystallized to obtain compound 1;

[0061] Q2: 26.53 g of compound 1, 280 mL of anhydrous ethanol, and 0.35 g of palladium-carbon were heated to reflux reaction. During the reaction, 47 mL of hydrazine hydrate was added dropwise for 1 h. After the addition was completed, the reflux reaction was maintained for 12 h. After the reaction was completed, the mixture was filtered while hot, concentrated, filtered, and dried in vacuo at 85°C to obtain compound 2;

[0062] Q3: 0.13 g of carboxylated carbon nanotubes was added to a container containing a mixed solution of 75 mL of ethanol and 80 mL of chloroform, and ultrasonically dispersed for 45 minutes. Subsequently, 0.25 g of EDC hydrochloride and 0.2 g of NHS were added, and ultrasonically dissolved for another 30 minutes. Then, 1.42 g of compound 2 was added, and the mixture was heated and stirred for reaction. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain a modified thermal conductor.

[0063] This embodiment discloses a method for preparing a composite anti-wear agent, comprising the following steps:

[0064] S1: 7 mL of water and 17.2 mL of ethanol were added to a container, stirred and mixed, and then 1.13 g of 2-aminoethanethiol and 0.92 g of thiourea were added. The mixture was stirred in an ice bath at 0°C, and then 1.4 mL of a 38% by volume hydrochloric acid solution was added. Then, 1.19 mL of a 30% by volume hydrogen peroxide solution was added dropwise. The addition time was controlled to be 30 min. The mixture was stirred and reacted for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered, and recrystallized to obtain intermediate A.

[0065] S2: 2.32 g of intermediate A and 1.56 g of 5-amino-1,3,4-thiadiazole-2-thiol were added to a container, and then 23 mL of ethanol was added and stirred. Subsequently, 22 mL of 0.063 g / mL sodium bicarbonate solution was added dropwise and the reaction was continued with stirring for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered with suction, and the filter cake was washed, dried, and recrystallized to obtain intermediate B;

[0066] S3: 5.5 g of intermediate B, 6.93 g of 4-(trifluoromethyl)phenol and 2.75 g of paraformaldehyde were added to a container containing 180 mL of xylene, and the mixture was heated under reflux for 6 h. After the reaction was completed, the mixture was cooled, filtered, and vacuum dried at 65° C. for 12 h to obtain a composite anti-wear agent.

[0067] This embodiment discloses a high thermal conductivity polyimide film, which is composed of the following components in parts by weight: 50 parts of 4,4'-diaminodiphenyl ether, 32.08 parts of 4,4'-bismaleimide diphenylmethane, 78 parts of N,N-dimethylacetamide, 43.5 parts of bisphenol A diglycidyl ether, 9.6 parts of a modified thermal conductor, and 9.2 parts of a composite wear-resistant agent.

[0068] This embodiment discloses a method for preparing a high thermal conductivity polyimide film, comprising the following steps:

[0069] Step 1: Add 4,4'-diaminodiphenyl ether and 4,4'-bismaleimide diphenylmethane to N,N-dimethylacetamide, heat under reflux at 72°C and continue stirring for 10 hours, then add bisphenol A diglycidyl ether, continue stirring and reacting for 2 hours to obtain a viscous substance;

[0070] Step 2: Add the modified thermal conductor and composite wear-resistant agent to the viscous substance, stir and mix evenly, then add it to the mold, solidify, keep it at 85°C for 1 hour, keep it at 120°C for 1 hour, keep it at 180°C for 1 hour, then heat it to 240°C and keep it for 2 hours, post-process, and cool to obtain a high thermal conductive polyimide film.

[0071] Example 4: This example discloses a method for preparing a modified thermal conductive agent, comprising the following steps:

[0072] Q1: 18.7 g of 5-chloro-2-nitrotrifluorotoluene, 10.13 g of 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 6.51 g of potassium carbonate, and 130 mL of N,N-dimethylformamide were added to a container equipped with a thermometer and a nitrogen channel. The reaction was heated to 130°C for 14 h and condensed under reflux. After the reaction was completed, the mixture was added to a 1 mol / L hydrochloric acid solution at 0°C and precipitated for 12 h. The mixture was filtered, washed, and dried in vacuo at 85°C for 12 h. The mixture was recrystallized to obtain compound 1.

[0073] Q2: 24.87 g of compound 1, 235 mL of anhydrous ethanol and 0.25 g of palladium-carbon were heated to reflux reaction. During the reaction, 35 mL of hydrazine hydrate was added dropwise for 1 hour. After the addition was completed, the reflux reaction was maintained for 12 hours. After the reaction was completed, the mixture was filtered while hot, concentrated, filtered, and dried in vacuo at 85°C to obtain compound 2;

[0074] Q3: Add 0.11 g of carboxylated carbon nanotubes to a container containing a mixed solution of 55 mL of ethanol and 55 mL of chloroform, and ultrasonically disperse for 45 minutes. Then add 0.21 g of EDC hydrochloride and 0.22 g of NHS, and ultrasonically dissolve for another 30 minutes. Then add 1.08 g of compound 2, heat and stir to react. After the reaction is completed, centrifuge, wash, and dry to obtain a modified thermal conductor.

[0075] This embodiment discloses a method for preparing a composite anti-wear agent, comprising the following steps:

[0076] S1: 4 mL of water and 13.2 mL of ethanol were added to a container, stirred and mixed, and then 0.98 g of 2-aminoethanethiol and 0.69 g of thiourea were added. The mixture was stirred in an ice bath at 0°C, and then 1.1 mL of a 38% by volume hydrochloric acid solution was added. Then, 1.06 mL of a 30% by volume hydrogen peroxide solution was added dropwise. The addition time was controlled to 30 min. The mixture was stirred and reacted for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered, and recrystallized to obtain intermediate A.

[0077] S2: 1.87 g of intermediate A and 1.21 g of 5-amino-1,3,4-thiadiazole-2-thiol were added to a container, and then 19 mL of ethanol was added and stirred. Subsequently, 19 mL of 0.063 g / mL sodium bicarbonate solution was added dropwise and the reaction was continued with stirring for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered with suction, and the filter cake was washed, dried, and recrystallized to obtain intermediate B;

[0078] S3: 4.4 g of intermediate B, 6.32 g of 4-(trifluoromethyl)phenol and 2.29 g of paraformaldehyde were added to a container containing 150 mL of xylene, and the mixture was heated under reflux for 6 h. After the reaction was completed, the mixture was cooled, filtered, and vacuum dried at 65° C. for 12 h to obtain a composite wear-resistant agent.

[0079] This embodiment discloses a high thermal conductivity polyimide film, which is composed of the following components in parts by weight: 35 parts of 4,4'-diaminodiphenyl ether, 22.11 parts of 4,4'-bismaleimide diphenylmethane, 71 parts of N,N-dimethylacetamide, 33.1 parts of bisphenol A diglycidyl ether, 8.5 parts of a modified thermal conductor, and 8.1 parts of a composite wear-resistant agent.

[0080] This embodiment discloses a method for preparing a high thermal conductivity polyimide film, comprising the following steps:

[0081] Step 1: Add 4,4'-diaminodiphenyl ether and 4,4'-bismaleimide diphenylmethane to N,N-dimethylacetamide, heat under reflux at 72°C and continue stirring for 10 hours, then add bisphenol A diglycidyl ether, continue stirring and reacting for 2 hours to obtain a viscous substance;

[0082] Step 2: Add the modified thermal conductor and composite wear-resistant agent to the viscous substance, stir and mix evenly, then add it to the mold, solidify, keep it at 85°C for 1 hour, keep it at 120°C for 1 hour, keep it at 180°C for 1 hour, then heat it to 240°C and keep it for 2 hours, post-process, and cool to obtain a high thermal conductive polyimide film.

[0083] Example 5: This example discloses a method for preparing a modified thermal conductive agent, comprising the following steps:

[0084] Q1: 20.1 g of 5-chloro-2-nitrotrifluorotoluene, 10.38 g of 2,2-bis(4-hydroxy-3-phenylmethyl)propane, 7.32 g of potassium carbonate, and 165 mL of N,N-dimethylformamide were added to a container equipped with a thermometer and a nitrogen channel. The reaction was heated to 130°C for 14 h and condensed under reflux. After the reaction was completed, the mixture was added to a 1 mol / L hydrochloric acid solution at 0°C and precipitated for 12 h. The mixture was filtered, washed, dried in vacuo at 85°C for 12 h, and recrystallized to obtain compound 1;

[0085] Q2: 25.91 g of compound 1, 275 mL of anhydrous ethanol, and 0.31 g of palladium-carbon were heated to reflux reaction. During the reaction, 42 mL of hydrazine hydrate was added dropwise for 1 hour. After the addition was completed, the reflux reaction was maintained for 12 hours. After the reaction was completed, the mixture was filtered while hot, concentrated, filtered, and dried in vacuo at 85°C to obtain compound 2;

[0086] Q3: 0.12 g of carboxylated carbon nanotubes was added to a container containing a mixed solution of 68 mL of ethanol and 75 mL of chloroform, and ultrasonically dispersed for 45 minutes. Subsequently, 0.24 g of EDC hydrochloride and 0.26 g of NHS were added, and ultrasonically dissolved for another 30 minutes. Then, 1.36 g of compound 2 was added, and the mixture was heated and stirred for reaction. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain a modified thermal conductor.

[0087] This embodiment discloses a method for preparing a composite anti-wear agent, comprising the following steps:

[0088] S1: 6 mL of water and 16.1 mL of ethanol were added to a container, stirred and mixed, and then 1.11 g of 2-aminoethanethiol and 0.83 g of thiourea were added. The mixture was stirred in an ice bath at 0°C, and then 1.3 mL of a 38% by volume hydrochloric acid solution was added. Then, 1.12 mL of a 30% by volume hydrogen peroxide solution was added dropwise. The addition time was controlled to be 30 min. The mixture was stirred and reacted for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered, and recrystallized to obtain intermediate A.

[0089] S2: 2.16 g of intermediate A and 1.43 g of 5-amino-1,3,4-thiadiazole-2-thiol were added to a container, and then 21 mL of ethanol was added and stirred. Subsequently, 21 mL of 0.063 g / mL sodium bicarbonate solution was added dropwise and the reaction was continued with stirring for 3 h. After the reaction was completed, the mixture was rotary evaporated, filtered with suction, and the filter cake was washed, dried, and recrystallized to obtain intermediate B;

[0090] S3: 5.1 g of intermediate B, 6.79 g of 4-(trifluoromethyl)phenol and 2.68 g of paraformaldehyde were added to a container containing 170 mL of xylene, and the mixture was heated under reflux for 6 h. After the reaction was completed, the mixture was cooled, filtered, and vacuum dried at 65° C. for 12 h to obtain a composite wear-resistant agent.

[0091] This embodiment discloses a high thermal conductivity polyimide film, which is composed of the following components by weight: 45 parts of 4,4'-diaminodiphenyl ether, 30.17 parts of 4,4'-bismaleimide diphenylmethane, 74 parts of N,N-dimethylacetamide, 40.2 parts of bisphenol A diglycidyl ether, 9.2 parts of a modified thermal conductor, and 8.8 parts of a composite wear-resistant agent.

[0092] This embodiment discloses a method for preparing a high thermal conductivity polyimide film, comprising the following steps:

[0093] Step 1: Add 4,4'-diaminodiphenyl ether and 4,4'-bismaleimide diphenylmethane to N,N-dimethylacetamide, heat under reflux at 72°C and continue stirring for 10 hours, then add bisphenol A diglycidyl ether, continue stirring and reacting for 2 hours to obtain a viscous substance;

[0094] Step 2: Add the modified thermal conductor and composite wear-resistant agent to the viscous substance, stir and mix evenly, then add it to the mold, solidify, keep it at 85°C for 1 hour, keep it at 120°C for 1 hour, keep it at 180°C for 1 hour, then heat it to 240°C and keep it for 2 hours, post-process, and cool to obtain a high thermal conductive polyimide film.

[0095] Comparative Example 1: Compared with Example 1, in the process of preparing the high thermal conductive polyimide film in Comparative Example 1, no modified thermal conductive agent is added, and other conditions remain unchanged.

[0096] Comparative Example 2: Compared with Example 1, in Comparative Example 2, during the preparation of the high thermal conductive polyimide film, no composite wear-resistant agent was added, and other conditions remained unchanged.

[0097] Experimental Example: The properties of the high thermal conductivity polyimide films prepared in Examples 1-5 and Comparative Examples 1-2 were tested. The thermal conductivity of the samples was tested according to GB / T 22588-2008, the thermal stability of the samples was tested according to GB / T 13542.6-2006, and the wear resistance of the samples was tested according to GB / T 3960-2016. The test results are shown in Table 1:

[0098] Table 1

[0099]

[0100]

[0101] The test results in Table 1 show that the polyimide films prepared in Examples 1-5 of the present invention have excellent thermal conductivity, thermal stability, and wear resistance. A comparison between Comparative Example 1 and Examples 1-5 shows that the addition of a modified thermal conductive agent can effectively improve the thermal conductivity and thermal stability of the polyimide films; a comparison between Comparative Example 2 and Examples 1-5 shows that the addition of a composite wear-resistant agent can effectively improve the thermal stability and wear resistance of the polyimide films.

[0102] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

[0103] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high thermal conductivity polyimide film, characterized in that: The invention is composed of the following components in parts by weight: 30-50 parts of diamine monomer, 19.12-32.08 parts of dibasic acid anhydride monomer, 69-78 parts of N,N-dimethylacetamide, 30-43.5 parts of bisphenol A diglycidyl ether, 8.3-9.6 parts of modified thermal conductive agent, and 7.8-9.2 parts of composite wear-resistant agent, wherein the modified thermal conductive agent is prepared from 5-chloro-2-nitrotrifluorotoluene, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, hydrazine hydrate and carboxylated carbon nanotubes as main raw materials, and the composite wear-resistant agent is prepared from 2-aminoethanethiol, thiourea, 5-amino-1,3,4-thiadiazole-2-thiol and 4-(trifluoromethyl)phenol as main raw materials.

2. The high thermal conductivity polyimide film according to claim 1, characterized in that: The preparation method of the modified thermal conductive agent comprises the following steps: Q1: Add 5-chloro-2-nitrotrifluorotoluene, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, potassium carbonate, and N,N-dimethylformamide to a container equipped with a thermometer and a nitrogen channel, heat the reaction, and condense and reflux. After the reaction, precipitate, filter, wash, vacuum dry, and recrystallize to obtain compound 1; Q2: Compound 1, anhydrous ethanol and palladium-carbon were heated to reflux reaction, and hydrazine hydrate was added dropwise during the reaction, and the addition time was controlled. After the addition was completed, the reflux reaction was maintained. After the reaction was completed, the mixture was filtered while hot, concentrated, filtered, and vacuum dried to obtain compound 2; Q3: Add carboxylated carbon nanotubes to a container containing a mixed solution of ethanol and chloroform, disperse by ultrasonication, then add EDC hydrochloride and NHS, dissolve by ultrasonication, then add compound 2, heat and stir to react, centrifuge, wash, and dry after the reaction is completed to obtain a modified thermal conductor.

3. The high thermal conductivity polyimide film according to claim 2, characterized in that: In Q1, the usage ratio of 5-chloro-2-nitrotrifluorotoluene, 2,2-bis(4-hydroxy-3-phenylmethyl)propane, potassium carbonate and N,N-dimethylformamide is (19.1-20.6) g: (10.02-10.47) g: (6.12-7.69) g: (120-180) mL.

4. The high thermal conductivity polyimide film according to claim 2, characterized in that: In Q2, the usage ratio of compound 1, anhydrous ethanol, palladium-carbon and hydrazine hydrate is (24.12-26.53) g: (220-280) mL: (0.22-0.35) g: (32-47) mL; in Q3, the usage ratio of carboxylated carbon nanotubes, ethanol, chloroform, EDC hydrochloride, NHS and compound 2 is (0.1-0.13) g: (50-75) mL: (50-80) mL: (0.2-0.25) g: (0.2-0.28) g: (0.94-1.42) g.

5. The high thermal conductivity polyimide film according to claim 1, characterized in that: The preparation method of the composite anti-wear agent comprises the following steps: S1: Add water and ethanol to a container, stir and mix, then add 2-aminoethanethiol and thiourea, stir in an ice bath, then add hydrochloric acid solution, then dropwise add hydrogen peroxide solution, control the addition time, stir and react, after the reaction is completed, rotary evaporate, filter with suction, and recrystallize to obtain intermediate A; S2: Add intermediate A and 5-amino-1,3,4-thiadiazole-2-thiol to a container, then add ethanol, stir, then add sodium bicarbonate solution dropwise, continue stirring to react, and after the reaction is completed, rotary evaporation, suction filtration, washing the filter cake, drying, and recrystallization to obtain intermediate B; S3: Add the intermediate B, 4-(trifluoromethyl)phenol and paraformaldehyde to a container filled with xylene, heat and reflux to react, and after the reaction is completed, cool, filter and vacuum dry to obtain a composite wear-resistant agent.

6. The high thermal conductivity polyimide film according to claim 5, characterized in that: In S1, the usage ratio of water, ethanol, 2-aminoethanethiol, thiourea, hydrochloric acid solution and hydrogen peroxide solution is (3-7) mL: (12.5-17.2) mL: (0.91-1.13) g: (0.62-0.92) g: (0.9-1.4) mL: (1.01-1.19) mL.

7. The high thermal conductivity polyimide film according to claim 5, characterized in that: In S2, the usage ratio of intermediate A, 5-amino-1,3,4-thiadiazole-2-thiol, ethanol and sodium bicarbonate solution is (1.78-2.32) g: (1.11-1.56) g: (18-23) mL: (18-22) mL.

8. The high thermal conductivity polyimide film according to claim 5, characterized in that: In the above-mentioned S3, the usage ratio of the intermediate B, 4-(trifluoromethyl)phenol, paraformaldehyde and xylene is (4.2-5.5) g: (6.12-6.93) g: (2.12-2.75) g: (140-180) mL.

9. The high thermal conductivity polyimide film according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: Step 1: Add diamine monomer and dibasic acid anhydride monomer to N,N-dimethylacetamide, heat under reflux and continue stirring, then add bisphenol A diglycidyl ether, continue stirring and reacting to obtain a viscous substance; Step 2: Add the modified thermal conductor and the composite wear-resistant agent to the viscous substance, stir and mix evenly, then add it to the mold, solidify, post-process, and cool to obtain a high thermal conductive polyimide film.

10. The high thermal conductivity polyimide film according to claim 9, characterized in that: In the step 1, the heating reflux temperature is 70-73°C, the stirring time is 8-10 hours, and the stirring reaction time is continued for 1-2 hours; in the step 2, the curing process is maintained at 80-90°C for 1-2 hours, 120-130°C for 1-2 hours, and 170-190°C for 1-2 hours, and then the temperature is raised to 230-250°C and maintained for 2-4 hours.

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