Preparation method of heat-resistant, high-dispersibility, self-repairing and high-adhesion conductive adhesive

Abstract

The application relates to a preparation method of heat-resistant, high-dispersibility, self-repairing and high-adhesion conductive glue and relates to the technical field of conductive glue. Fire-retardant, low-smoke, low-shrinkage, self-repairing polyurethane, carbon nanotube dispersion liquid, epoxy resin dispersion, diethylene triamine, 2-ethyl-4-methyl imidazole and acetone are stirred and mixed to obtain a mixture A; antioxidant, conductive silver powder and a coupling agent are added into the mixture A to obtain a mixture B; the mixture B is vacuum defoamed for 10 minutes to obtain the heat-resistant, high-dispersibility, self-repairing and high-adhesion conductive glue, the self-repairing rate of the obtained conductive glue is more than 90%, the mass loss rate is lower than 5.72%, the volume resistivity is lower than 4.35*10 ‑5 Omega.cm, and the conductive glue has good heat resistance, high dispersibility, self-repairing and high adhesion.

Description

Technical Field

[0001] This invention relates to the field of conductive adhesive technology, specifically to a method for preparing a heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive. Background Technology

[0002] With the continuous development of electronic technology, especially in high-frequency, high-density, and miniaturized electronic devices, traditional solder materials face numerous challenges. Although solder is widely used in electronic assembly, it is difficult to meet the requirements for long-term stability and reliability in certain specific application scenarios. Particularly in applications with high performance, vibration resistance, and high-frequency stability requirements, solder is prone to fatigue failure, thermal stress problems, and degradation of conductivity.

[0003] Conductive adhesive is a type of adhesive that becomes conductive after curing or drying, enabling the bonding of various conductive materials and creating an electrical path between them. In the electronics industry, conductive adhesive has become an indispensable key material. As a substitute for solder, conductive adhesive, due to its excellent conductivity, good temperature resistance, and operational flexibility, is gradually becoming a core technology in high-performance electronic assembly. Conductive adhesive can not only replace solder in traditional soldering processes but also effectively solve problems such as heat damage and soldering defects during the soldering process.

[0004] Conductive adhesives typically consist of conductive fillers, an adhesive matrix, solvents, and additives. Fillers are primarily silver, copper, gold, nickel, and carbon-based materials, with silver powder being the most commonly used. Adhesive matrices commonly include epoxy resin, silicone rubber, polyurethane, and acrylates, with epoxy resin being the most prevalent. Solvents often include water, alcohols, ketones, and esters. Epoxy resin matrices offer high adhesion and heat resistance, making them suitable for precision chip bonding, printed circuit board component bonding, rigid connections of metal electrodes, and conductive connections in high-temperature environments. However, epoxy resin adhesives are insufficient for applications requiring flexibility (such as flexible circuit reinforcement), high shock resistance (such as automotive sensors in vibration environments), and elastic compression and rebound (such as electromagnetic shielding gasket bonding). Polyurethane adhesives offer good flexural strength, but suffer from insufficient heat resistance and lower adhesion compared to epoxy resin adhesives. Therefore, when used in flexible circuit applications where flexibility is crucial, polyurethane adhesives require further improvements in heat resistance and adhesion.

[0005] Invention patent CN119799117B describes a process where carbon nanotubes are initially unwound using a specific solvent to prepare a uniformly dispersed carbon nanotube dispersion. Polyaniline is then added to the carbon nanotube dispersion, and after solvent evaporation or purification, a carbon nanotube / polyaniline composite is obtained. Finally, this composite is compounded with epoxy resin to obtain a carbon nanotube / polyaniline-modified epoxy resin conductive coating. This conductive coating exhibits superior mechanical and electrical properties compared to traditional conductive coatings, making it suitable for applications in aerospace, batteries, communications, and new energy fields. While this patent addresses the dispersion stability issue of carbon nanotubes, it does not address the cracking of the epoxy resin composite under repeated stretching and bending conditions, nor does it address the heat resistance and combustion smoke performance of the composite material.

[0006] Chinese invention patent CN120173542B discloses a conductive adhesive, its preparation method, and its application. This conductive adhesive is formed by the stirring and reaction of synthetic acrylic resin, epoxy resin, conductive filler, latent curing agent, diluent, and other additives. By adding a latent curing agent, this invention reduces the possibility of reaction between acrylic resin and epoxy resin at room temperature, thereby improving the storage stability of the conductive adhesive. It also enhances the overall performance of electronic products and meets the needs of different application scenarios. The preparation method involves directly and uniformly mixing the raw materials, eliminating the need for separate storage. This simplifies the usage process, reduces production costs, and improves production efficiency and product quality. However, this conductive adhesive has a high resistance and does not address the core performance indicators that this invention focuses on, such as flexural strength, heat resistance, and self-healing.

[0007] Invention patent application CN121182208A relates to a polyurethane-modified silicone rubber, a sprayable conductive adhesive, and a method for preparing the same. The polyurethane-modified silicone rubber proposed in this invention has higher mechanical strength and is less prone to tearing compared to traditional silicone rubber. When used to prepare a sprayable conductive adhesive, the resulting conductive layer exhibits excellent conductivity and significantly improved mechanical properties, with a minimum volume resistivity of 3 × 10⁻⁶. -4 Ω·cm. This modification mainly enhances the conductivity and electromagnetic shielding properties of silicone, has a high volume resistivity, and does not address core performance indicators for flexible circuits such as flexural strength, heat resistance, and smoke resistance.

[0008] Invention patent application CN121086700A relates to a salt spray resistant water-based conductive adhesive. This salt spray resistant water-based conductive adhesive uses polyurethane resin with polytetrahydrofuran alcohol and polycaprolactone polyol as the main resin, which endows the system with excellent water resistance and salt spray resistance. After curing, it exhibits outstanding hydrolytic stability and works synergistically with conductive silver powder to improve anti-settling performance. It mainly solves the problem of salt spray resistance of conductive adhesives, but does not address the core indicators of polyurethane conductive adhesives such as heat resistance, high dispersibility and high adhesion.

[0009] Our research group previously disclosed a method for preparing flame-retardant, high-refractive-index, and drip-resistant polyurethane coatings using patent CN119842310B. The method involves adding diol, isocyanate, and dibutyltin dilaurate to a flask to obtain a polyurethane prepolymer. A charring agent is then added to the prepolymer, followed by the addition of 2,2-dimethylolbutyric acid and amino carbon nanotubes for reaction. A high-refractive-index material is then added, followed by triethylamine for reaction. Deionized water is added, and ammonium polyphosphate solution is added at high speed, followed by high-speed shear emulsification to obtain the flame-retardant, high-refractive-index, and drip-resistant polyurethane coating. This polyurethane coating exhibits high flame retardancy, high refractive index, and drip-resistant properties, but its smoke generation rate and film shrinkage rate still have room for improvement. Furthermore, heat resistance is also an important consideration for conductive adhesives. In addition, this patent only relates to the adhesive matrix and does not cover the entire composition of the conductive adhesive.

[0010] Currently, there is no existing technology that can simultaneously address the shortcomings of polyurethane conductive adhesives in terms of heat resistance, adhesion, and self-healing, let alone a solution to the self-healing problem of flexible electronics during folding. This problem is a significant challenge affecting the lifespan of flexible electronics during use. Summary of the Invention

[0011] This invention primarily addresses the shortcomings of conductive adhesives used in flexible electronics, such as insufficient heat resistance, adhesion, self-healing properties, and conductivity of polyurethane adhesives, which lead to defects such as localized overheating, adhesive layer detachment, excessive smoke during combustion, and shortened service life.

[0012] A method for preparing a heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive is as follows:

[0013] (1) Mix 20-25 parts of flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane, 3-7 parts of carbon nanotube dispersion, 3-8 parts of epoxy resin dispersion, 3.0-3.2 parts of diethylenetriamine, 0.8-1 parts of 2-ethyl-4-methylimidazole, and 16-22 parts of acetone evenly to obtain mixture A; (2) Add 0.2-0.6 parts of antioxidant, 55-65 parts of conductive silver powder, and 0.3-1.8 parts of coupling agent to mixture A and stir evenly to obtain mixture B; (3) Degas mixture B under vacuum degree <-0.095MPa for 10 minutes to obtain heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive;

[0014] The preparation method of the flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane is as follows:

[0015] (1) Take 28g of polypropylene glycol with a number average molecular weight of 2000g / mol, 16.36g of isophorone diisocyanate and 0.2~0.3g of dibutyltin dilaurate and add them into a 500 mL three-necked flask. Under nitrogen protection, heat to 70~80 ℃ and stir at 300r / min for 1~2 h to obtain polyurethane prepolymer;

[0016] (2) Add 1.2 g of 2,2-dimethylolbutyric acid, 1.1-1.5 g of 2,2-dithiodiethanol and 4.12-5.38 g of nitrogen-phosphorus intumescent flame retardant to the polyurethane prepolymer and react at 60-75 °C for 1-1.5 h. Then add 2.1-2.7 g of triethylamine and react for 0.5-1 h. Cool to room temperature, add 70 mL of deionized water and emulsify at 2000 r / min for 0.5 h. Then add 7-8 g of epoxy resin E51 and 3-5 g of softener and stir at 500 r / min for 0.25-0.5 h to disperse evenly. Distill under reduced pressure to a solid content of 70% to obtain flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane.

[0017] The fabric softener is prepared as follows: 0.3-0.5 g of chloroplatinic acid and 7-9 g of isopropanol are added to a four-necked flask, the temperature is raised to 70-80 °C, and 2.1 g of terminal hydrogen silicone oil and 25-31 g of allyl epoxy polyether are slowly added dropwise over a period of 1 h. Glacial acetic acid is added to maintain the pH of the system at 5-6, and the reaction is carried out at 90-100 °C for 3-5 h to obtain intermediate A. 10-12 g of polyetheramine D400 and 1.1-2.2 g of ethylboric acid are then added to intermediate A, the pH of the system is maintained at 5-6, and the reaction is carried out at 70-90 °C for 2-5 h. After cooling, the fabric softener is obtained.

[0018] The preparation method of the epoxy resin dispersion is as follows: 3-5 g of hexagonal boron nitride is added to 20 g of furfuryl alcohol glycidyl ether, and ultrasonicated in an ice-water bath for 1-2 h to obtain a uniformly dispersed hexagonal boron nitride dispersion. Then, 100-120 g of epoxy resin E51 is added, and the mixture is stirred at 500-1000 r / min for 0.5-1.0 h to obtain the epoxy resin dispersion.

[0019] The hexagonal boron nitride particles have a particle size of approximately 100 nm.

[0020] The preparation method of the nitrogen-phosphorus intumescent flame retardant is as follows:

[0021] (1) Using 100 mL of tetrahydrofuran as solvent, 21.6 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 9.8 g of maleic anhydride were added to a four-necked flask and stirred in an oil bath at 50 °C for 3-6 h. The mixture was then dried in a vacuum oven to obtain intermediate B.

[0022] (2) Add 13.3 g of diisopropanolamine and 0.43 g of p-toluenesulfonic acid to intermediate B, add toluene that has been submerged in the amount of the drug, heat in an oil bath at 100 °C for 3-6 h, and dry under vacuum at 70-85 °C to constant weight to obtain intermediate C;

[0023] (3) Add 60.9 g of tetrahydroxymethylphosphoric acid to the product obtained in step (2), react for 1-2 h, and dry under vacuum at 70-85 °C to constant weight to obtain tetrahydroxymethylphosphoric acid modified flame retardant;

[0024] (4) Add 4.6~5.2g of diethylthiophosphoric acid to the tetrahydroxymethylphosphoric acid modified flame retardant obtained in step (3), stir and react at 70~80 ℃ for 1~2 h, then add 5.2~5.8g of zirconium sulfate, 0.21~0.35g of aspartic acid, 0.13~0.32g of 1H-indole-2-carboxamide and 5~8g of water, react at 45~65 ℃ for 0.25~0.5 h, and vacuum dry to constant weight to obtain nitrogen-phosphorus intumescent flame retardant.

[0025] Its conductive silver powder is composed of flake silver powder and spherical silver powder in a weight ratio of 3:1 to 4:1.

[0026] The preparation method of carbon nanotube dispersion is as follows: 1 g of carbon nanotubes, 0.2~0.3 g of ultra-long carbon nanotubes and 1.1~1.5 g of dispersant are added to 65 g of deionized water and stirred at 500~1000 r / min to completely wet the carbon nanotubes with water; then 1.5~2.7 g of p-hydroxybenzaldehyde is added, and the dispersion is further dispersed using an ultrasonic cell disruptor with an output power of 600~700W and an ultrasonic dispersion time of 10~50 min. The dispersion is then centrifuged at a speed of 1000~1200 r / min for 10~30 min to obtain carbon nanotube dispersion.

[0027] The dispersant is obtained by mixing sodium glycocholate, glycerol, dodecyl dimethyl betaine, and aminoacetic acid in a weight ratio of 4:1:0.2~0.5:0.3~0.35. The coupling agent is any one of KH550 and KH560, or a mixture of both in any ratio. The antioxidant is any one of benzotriazole and antioxidant 1010, or a mixture of both in any ratio.

[0028] The advantages of this invention are:

[0029] (1) In this invention, flake silver powder is used as a “conductive skeleton” or “conductive pathway”, and spherical silver powder is used as a “conductive filler” to fill the gaps, grooves and uncontacted areas between the flake silver powders, connecting the tiny gaps between the flake structures like “balls” and repairing the breaks in the conductive network. When the total silver content is the same, a three-dimensional network with tighter connections, fewer defects and less anisotropy can be formed, thereby obtaining higher and more stable conductivity; the “ball effect” of spherical particles can significantly reduce the viscosity of the mixed system, improve fluidity, and make the conductive adhesive easier to stir and degas; furthermore, spherical particles can separate the flake powders, reduce their surface-to-surface contact probability, thereby alleviating agglomeration, improving storage stability, and making the filler distribution more uniform; the addition of spherical particles can also play a role in stress buffering and dispersion, thereby improving the toughness, impact resistance and fatigue resistance of the adhesive layer.

[0030] (2) Due to the high aspect ratio of carbon nanotubes, they can overlap with each other to form a three-dimensional conductive network that runs through the entire colloid with extremely low addition amounts. Since the contact between carbon nanotubes is a line contact or a surface contact, electrons can tunnel through more easily. On the one hand, a very small amount of addition is required to achieve conductivity, and the uniformly dispersed carbon nanotube network can provide isotropic conductivity, thereby reducing the amount of silver used and controlling costs; on the other hand, the carbon nanotube network itself is flexible and can deform with the matrix without easily breaking, so that the resistance of the conductive adhesive changes very little after bending and stretching cycles, which meets the requirements of flexible electronics and wearable devices; in addition, carbon nanotubes have extremely high axial thermal conductivity. Introducing carbon nanotubes into the conductive adhesive can not only conduct electricity, but also significantly improve the thermal conductivity of the colloid, which helps the heat dissipation of components and improves reliability and lifespan.

[0031] (3) The electrical and thermal conductivity of carbon nanotubes is improved through the synergistic effect of carbon nanotubes and ultra-long carbon nanotubes (the ultra-long carbon nanotubes of this invention are prepared according to Example 1 in Chinese Invention Patent CN2022113612725). To address the potential aggregation problem of ultra-long carbon nanotubes, this invention effectively dissociates aggregated carbon nanotubes from the aggregates through the synergistic effect of electrostatic repulsion and steric hindrance of dispersant molecules, forming a uniformly dispersed carbon nanotube dispersion. Specifically, glycerol and sodium glycocholate interact through hydrogen bonds and non-covalent bonds to form a stable adsorption layer on the surface of carbon nanotubes, achieving functional group modification and micronization; dodecyl dimethyl betaine reduces the surface tension of carbon nanotubes, promoting their wetting and dispersion in the solvent; glycine regulates the ionic environment of the system, maintaining the stability of the dispersion system. Glycerol and sodium glycocholate, as dispersing stabilizers for ultra-long carbon nanotubes, exert a synergistic effect of small molecule desorption and large molecule steric hindrance, constructing a multi-scale molecular film structure dispersion system. This composite structure allows small dispersant molecules to penetrate the interior of ultralong carbon nanotube aggregates, bind to the tube walls, and disrupt the original aggregation driving force. Simultaneously, a steric hindrance layer is formed on the surface of the monodispersed ultralong carbon nanotubes, effectively inhibiting secondary aggregation. Furthermore, ultrasonic treatment and the addition of p-hydroxybenzaldehyde further disperse potentially agglomerated carbon nanotubes, reducing the likelihood of aggregation and improving the dispersion stability. The resulting carbon nanotubes and ultralong carbon nanotubes are uniformly distributed within the voids of the conductive silver powder, synergistically enhancing the conductivity of the conductive silver powder.

[0032] (4) In this invention, the phosphorus-hydrogen bond in DOPO undergoes an addition reaction with the carbon-carbon double bond on maleic anhydride to generate an intermediate. DOPO provides the carbon source and acid source, while maleic anhydride provides the carbon source. The anhydride group in the intermediate undergoes a ring-opening reaction with the NH bond and hydroxyl group in diisopropanolamine to generate a compound that further reacts with the hydroxyl group in tetrahydroxyphosphoric acid, thereby improving the flexibility of the flame retardant through branching. At the same time, the remaining hydroxyl groups in the system undergo complexation with zirconium in zirconium sulfate, introducing the heat-resistant zirconium sulfate into the system. Aspartic acid and 1H-indole-2-carboxamide can improve the combination of zirconium sulfate with the flame retardant system, enhancing and improving the heat resistance of the flame retardant. Isopropanolamine provides the gas source, forming an expansion system of carbon source, acid source, and gas source. When the flame retardant is heated and decomposed, it produces non-flammable gases such as ammonia and nitrogen oxides. These gases are encapsulated in the system, thereby isolating the air and reducing the contact area with the combustion-supporting gases, thus achieving flame retardancy. On the other hand, the thermal decomposition of flame retardants continuously produces acidic substances such as polyphosphoric acid and metaphosphoric acid, which promotes the carbonization of the material surface and forms a dense porous carbon layer and zirconium layer, delaying the combustion process and inhibiting the release of smoke. At the same time, the phosphorus element in DOPO will capture oxygen free radicals released by combustibles, reducing the possibility of combustion.

[0033] (5) Since conductive adhesives face the risk of being damaged by continuous folding in flexible electronic components, this invention utilizes the fact that the SS bonds in polyurethane adhesive can reconnect with the broken SS bonds under certain heat (heating) to generate new SS bonds and undergo a translocation exchange reaction. The damage is repaired by the chemical bond repair method under heat, thus extending the service life of heated electronic materials. In addition, epoxy compounds are added to polyurethane conductive adhesives. The interwoven network polymer formed by the interpenetration of polyurethane and epoxy resin polymers, with epoxy resin dispersed between polyurethane macromolecules, cross-penetrates and entangles with each other, plays a role in mutual penetration and synergy, making the molecular chains of different structures finer. This entanglement between networks can significantly improve the dispersibility of polyurethane and synergistically promote the self-repair of polyurethane under heat. In addition, epoxy resin can also make up for the poor adhesion of polyurethane.

[0034] (6) During combustion, hexagonal boron nitride migrates to the surface of the material, forming a dense and stable ceramic-like protective layer. This layer acts as a physical shield, free radical capture, and thermal / oxygen barrier, effectively delaying or preventing combustion and significantly reducing the release of toxic fumes and gases. Dispersing furfuryl alcohol glycidyl ether in epoxy resin adhesive, and then dispersing it in conductive adhesive based on the adhesive properties of the epoxy resin, improves the thermal conductivity of the conductive adhesive material and extends its service life.

[0035] (7) By utilizing the double bonds of allyl epoxy polyether and the hydrogen in the terminal hydrogen silicone oil, under the action of the catalyst chloroplatinic acid, a compound with epoxy bonds at both ends is formed, introducing the flexible silicone oil into the molecular chain. At the same time, the reaction of polyetheramine with epoxy bonds is utilized to form a silicon-hydrogen bond conversion product. Under the action of ethylboric acid, the reaction between this epoxy bond and polyetheramine is enhanced, thereby increasing its hydrophilicity. This flexibility allows the epoxy resin to be dispersed between polyurethane macromolecules, cross-penetrating and entangled, playing a role of mutual penetration and synergy. This entanglement resistance is reduced, which is conducive to its good dispersion and enhances its self-healing ability. Detailed Implementation

[0036] In this invention, parts are by weight, corresponding to grams (g), kilograms (Kg), etc. The flake silver powder used is from Ningbo Jinlei Nanomaterials Technology Co., Ltd. (item number: JL-Ag-N20); the spherical silver powder is from Zhejiang Manli Nanotechnology Co., Ltd. (item number: ML-Ag-N20); 1H-indole-2-carboxamide is from Zhengzhou Alpha Chemical Co., Ltd.; the terminal hydrogen silicone oil is a product of Huawi Ruike Chemical Co., Ltd., with a molecular weight of 208.4 g / mol; and the allyl epoxy polyether is APE600 from Guangdong Yunxing Biotechnology Co., Ltd. Other materials can be used as long as their main components are the same, without manufacturer restrictions.

[0037] The invention will be further illustrated below with examples.

[0038] Example 1

[0039] A method for preparing a heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive is as follows:

[0040] (1) Mix 20 parts of flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane, 3 parts of carbon nanotube dispersion, 3 parts of epoxy resin dispersion, 3.0 parts of diethylenetriamine, 0.8 parts of 2-ethyl-4-methylimidazole, and 16 parts of acetone, and stir until homogeneous to obtain mixture A; (2) Add 0.2 parts of benzotriazole, 55 parts of conductive silver powder, and 0.3 parts of coupling agent KH550 to mixture A, and stir until homogeneous to obtain mixture B; (3) Degas mixture B under vacuum degree <-0.095MPa for 10 min to obtain heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive;

[0041] The preparation method of flame-retardant, low-smoke, low-shrinkage, and self-healing polyurethane is as follows:

[0042] (1) Take 28 g of polypropylene glycol with a number average molecular weight of 2000 g / mol, 16.36 g of isophorone diisocyanate and 0.2 g of dibutyltin dilaurate and add them to a 500 mL three-necked flask. Under nitrogen protection, heat to 70 °C and stir at 300 r / min for 1 h to obtain polyurethane prepolymer;

[0043] (2) Add 1.2 g of 2,2-dimethylolbutyric acid, 1.1 g of 2,2-dithiodiethanol and 4.12 g of nitrogen-phosphorus intumescent flame retardant to the polyurethane prepolymer and react at 60 °C for 1 h. Then add 2.1 g of triethylamine and react for 0.5 h. Cool to room temperature, add 70 mL of deionized water and emulsify at 2000 r / min for 0.5 h. Then add 7 g of epoxy resin E51 and 3 g of softener and stir at 500 r / min for 0.25 h to disperse evenly. Distill under reduced pressure to a solid content of 70% to obtain flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane.

[0044] Preparation method of fabric softener: Add 0.3 g of chloroplatinic acid and 7 g of isopropanol to a four-necked flask, heat to 70 ℃, slowly add 2.1 g of terminal hydrogen silicone oil and 25 g of allyl epoxy polyether dropwise, control the dropwise addition time to 1 h, add glacial acetic acid to maintain the pH of the system at 5~6, react at 90 ℃ for 3 h to obtain intermediate A; continue to add 10 g of polyetheramine D400 and 1.1 g of ethylboric acid to intermediate A, maintain the pH of the system at 5~6, react at 70 ℃ for 2 h, and obtain fabric softener after cooling.

[0045] Preparation method of epoxy resin dispersion: 3 g of hexagonal boron nitride was added to 20 g of furfuryl alcohol glycidyl ether and sonicated in an ice-water bath for 1 h to obtain a uniformly dispersed hexagonal boron nitride dispersion. Then, 100 g of epoxy resin E51 was added and stirred at 500 r / min for 0.5 h to obtain epoxy resin dispersion.

[0046] The hexagonal boron nitride has a particle size of approximately 100 nm.

[0047] The preparation method of nitrogen-phosphorus intumescent flame retardant is as follows:

[0048] (1) Using 100 mL of tetrahydrofuran as solvent, 21.6 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 9.8 g of maleic anhydride were added to a four-necked flask and stirred in an oil bath at 50 °C for 3 h. The mixture was then dried in a vacuum oven to obtain intermediate B.

[0049] (2) Take 13.3 g of diisopropanolamine and 0.43 g of p-toluenesulfonic acid and add them to the flask containing intermediate B. Add toluene that has been submerged in the amount of the drug. Heat the mixture in an oil bath at 100 °C for 3 h and dry it under vacuum at 70 °C to constant weight to obtain intermediate C.

[0050] (3) Add 60.9 g of tetrahydroxymethylphosphoric acid to the product obtained in step (2), react at 40 °C for 1 h, and dry under vacuum at 70 °C to constant weight to obtain tetrahydroxymethylphosphoric acid modified flame retardant.

[0051] (4) Add 4.6 g of diethylthiophosphoric acid to the tetrahydroxymethylphosphoric acid modified flame retardant obtained in step (3), stir and react at 70 °C for 1 h, then add 5.2 g of zirconium sulfate, 0.21 g of aspartic acid, 0.13 g of 1H-indole-2-carboxamide and 5 g of water, react at 45 °C for 0.25 h, and vacuum dry to constant weight to obtain a nitrogen-phosphorus intumescent flame retardant with a branched structure.

[0052] The conductive silver powder is composed of flake silver powder and spherical silver powder in a weight ratio of 3:1.

[0053] The preparation method of carbon nanotube dispersion is as follows: 1 g of carbon nanotubes, 0.2 g of ultralong carbon nanotubes, and 1.1 g of dispersant are added to 65 g of deionized water, and stirred at 500 r / min to completely wet the carbon nanotubes; then 1.5 g of p-hydroxybenzaldehyde is added, and the dispersion is further performed using an ultrasonic cell disruptor with an output power of 600 W for 10 min; finally, the dispersion is centrifuged at 1000 r / min for 10 min to obtain the carbon nanotube dispersion. The dispersant is composed of sodium glycocholate, glycerol, dodecyl dimethyl betaine, and aminoacetic acid in a weight ratio of 4:1:0.2:0.3.

[0054] Example 2

[0055] A method for preparing a heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive is as follows:

[0056] (1) Mix 25 parts of flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane, 7 parts of carbon nanotube dispersion, 8 parts of epoxy resin dispersion, 3.2 parts of diethylenetriamine, 1.0 part of 2-ethyl-4-methylimidazole, and 22 parts of acetone to obtain mixture A; (2) Add 0.6 parts of antioxidant 1010, 65 parts of conductive silver powder, and 1.8 parts of KH-560 to mixture A and stir to obtain mixture B; (3) Degas mixture B under a vacuum of <-0.095MPa for 10 minutes to obtain a heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive;

[0057] The preparation method of flame-retardant, low-smoke, low-shrinkage, and self-healing polyurethane is as follows: (1) Take 28 g of polypropylene glycol with a number average molecular weight of 2000 g / mol, 16.36 g of isophorone diisocyanate and 0.3 g of dibutyltin dilaurate and add them to a 500 mL three-necked flask. Under nitrogen protection, heat the mixture to 80 °C and stir it at 300 r / min for 2 h to obtain polyurethane prepolymer;

[0058] (2) Add 1.2 g of 2,2-dimethylolbutyric acid, 1.5 g of 2,2-dithiodiethanol and 5.38 g of nitrogen-phosphorus intumescent flame retardant to the polyurethane prepolymer and react at 75 °C for 1.5 h. Then add 2.7 g of triethylamine and react for 1 h. Cool to room temperature, add 70 mL of deionized water, and emulsify at 2000 r / min for 0.5 h. Then add 8 g of epoxy resin E51 and 5 g of softener and stir at 500 r / min for 0.5 h to disperse evenly. Distill under reduced pressure to a solid content of 70% to obtain flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane.

[0059] Preparation method of fabric softener: Add 0.5 g of chloroplatinic acid and 9 g of isopropanol to a four-necked flask, heat to 80 ℃, slowly add 2.1 g of terminal hydrogen silicone oil and 31 g of allyl epoxy polyether dropwise, control the dropwise addition time to 1 h, add glacial acetic acid to maintain the pH of the system at 5~6, react at 100 ℃ for 5 h to obtain intermediate A; continue to add 12 g of polyetheramine D400 and 2.2 g of ethylboric acid to intermediate A, maintain the pH of the system at 5~6, react at 90 ℃ for 5 h, and obtain fabric softener after cooling.

[0060] Preparation method of epoxy resin dispersion: 5 g of hexagonal boron nitride (particle size of about 100 nm) was added to 20 g of furfuryl alcohol glycidyl ether, and ultrasonicated in an ice-water bath for 2 h to obtain a uniformly dispersed hexagonal boron nitride dispersion. Then, 120 g of epoxy resin E51 was added and stirred at 1000 r / min for 1.0 h to obtain epoxy resin dispersion.

[0061] The preparation method of nitrogen-phosphorus intumescent flame retardant is as follows:

[0062] (1) Using 100 mL of tetrahydrofuran as solvent, 21.6 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 9.8 g of maleic anhydride were added to a four-necked flask and stirred in an oil bath at 50 °C for 6 h. The mixture was then dried in a vacuum oven to obtain intermediate B.

[0063] (2) Add 13.3 g of diisopropanolamine and 0.43 g of p-toluenesulfonic acid to the flask containing intermediate B, add toluene that has been submerged in the amount of the drug, heat in an oil bath at 100 °C for 6 h, and dry under vacuum at 85 °C to constant weight to obtain intermediate C;

[0064] (3) Add 60.9 g of tetrahydroxymethylphosphoric acid to the product obtained in step (2), react at 50 °C for 2 h, and dry under vacuum at 85 °C to constant weight to obtain tetrahydroxymethylphosphoric acid modified flame retardant.

[0065] (4) Add 5.2 g of diethylthiophosphoric acid to the tetrahydroxymethylphosphoric acid modified flame retardant obtained in step (3), stir and react at 80 °C for 2 h, then add 5.8 g of zirconium sulfate, 0.35 g of aspartic acid, 0.32 g of 1H-indole-2-carboxamide and 8 g of water, react at 65 °C for 0.5 h, and vacuum dry to constant weight to obtain a nitrogen-phosphorus intumescent flame retardant with a branched structure.

[0066] The conductive silver powder is composed of flake silver powder and spherical silver powder in a weight ratio of 4:1.

[0067] The preparation method of carbon nanotube dispersion is as follows: 1g of carbon nanotubes, 0.3g of ultralong carbon nanotubes and 1.5g of dispersant are added to 65g of deionized water and stirred at 1000 r / min to completely wet the carbon nanotubes with water; then 2.7g of p-hydroxybenzaldehyde is added and further dispersed using an ultrasonic cell disruptor with an output power of 700 W and an ultrasonic dispersion time of 50 min; finally, the dispersion is centrifuged at 1200 r / min for 30 min to obtain carbon nanotube dispersion.

[0068] The dispersant is a mixture of sodium glycocholate, glycerol, dodecyl dimethyl betaine and aminoacetic acid in a weight ratio of 4:1:0.5:0.35.

[0069] Example 3

[0070] A method for preparing a heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive is as follows:

[0071] (1) Mix 22.5 parts of flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane, 5 parts of carbon nanotube dispersion, 5.5 parts of epoxy resin dispersion, 3.1 parts of diethylenetriamine, 0.9 parts of 2-ethyl-4-methylimidazole, and 19 parts of acetone to obtain mixture A; (2) Add 0.4 parts of antioxidant 1010 (mixed at a weight ratio of 1:1), 60 parts of conductive silver powder, and 1.05 parts of coupling agent (KH550 is KH-560 mixed at a weight ratio of 2:1) to mixture A and stir evenly to obtain mixture B; (3) Degas mixture B under a vacuum degree <-0.095MPa for 10 minutes to obtain heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive;

[0072] The preparation method of the flame-retardant, low-smoke, low-shrinkage, and self-healing polyurethane is as follows: (1) Take 28 g of polypropylene glycol with a number average molecular weight of 2000 g / mol, 16.36 g of isophorone diisocyanate and 0.25 g of dibutyltin dilaurate and add them to a 500 mL three-necked flask. Under nitrogen protection, heat the mixture to 75 °C and stir it at 300 r / min for 1.5 h to obtain the polyurethane prepolymer.

[0073] (2) Add 1.2 g of 2,2-dimethylolbutyric acid, 1.3 g of 2,2-dithiodiethanol and 4.75 g of nitrogen-phosphorus intumescent flame retardant to the polyurethane prepolymer and react at 70 °C for 1.25 h. Then add 2.4 g of triethylamine and react for 0.75 h. Cool to room temperature, add 70 mL of deionized water and emulsify at 2000 r / min for 0.5 h. Then add 17.5 g of epoxy resin E5 and 4 g of softener and stir at 500 r / min for 0.3 h to disperse evenly. Distill under reduced pressure to a solid content of 70% to obtain flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane.

[0074] Preparation method of fabric softener: Add 0.4 g of chloroplatinic acid and 8 g of isopropanol to a four-necked flask, heat to 75 ℃, slowly add 2.1 g of terminal hydrogen silicone oil and 28 g of allyl epoxy polyether dropwise over 1 h, add glacial acetic acid to maintain the pH of the system at 5-6, react at 95 ℃ for 4 h to obtain intermediate A; continue to add 11 g of polyetheramine D400 and 1.65 g of ethylboric acid to intermediate A, maintain the pH of the system at 5-6, react at 80 ℃ for 3.5 h, and obtain fabric softener after cooling.

[0075] Preparation method of epoxy resin dispersion: 4 g of hexagonal boron nitride (particle size of about 100 nm) was added to 20 g of furfuryl alcohol glycidyl ether and sonicated in an ice-water bath for 1.5 h to obtain a uniformly dispersed hexagonal boron nitride dispersion. Then, 110 g of epoxy resin E51 was added and stirred at 750 r / min for 0.75 h to obtain the epoxy resin dispersion.

[0076] The preparation method of nitrogen-phosphorus intumescent flame retardant is as follows:

[0077] (1) Using 100 mL of tetrahydrofuran as solvent, 21.6 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 9.8 g of maleic anhydride were added to a four-necked flask and stirred in an oil bath at 50 °C for 4.5 h. The mixture was then dried in a vacuum oven to obtain intermediate B.

[0078] (2) Add 13.3 g of diisopropanolamine and 0.43 g of p-toluenesulfonic acid to the flask containing intermediate B, add toluene that has been submerged in the amount of the drug, heat in an oil bath at 100 °C for 4.5 h, and dry under vacuum at 78 °C to constant weight to obtain intermediate C;

[0079] (3) Add 60.9 g of tetrahydroxymethylphosphoric acid to the product obtained in step (2), react at 60 °C for 1.5 h, and dry under vacuum at 78 °C to constant weight to obtain tetrahydroxymethylphosphoric acid modified flame retardant;

[0080] (4) Add 4.9 g of diethylthiophosphoric acid to the tetrahydroxymethylphosphoric acid modified flame retardant obtained in step (3), stir and react at 75 °C for 1.5 h, then add 5.5 g of zirconium sulfate, 0.28 g of aspartic acid, 0.22 g of 1H-indole-2-carboxamide and 6.5 g of water, react at 55 °C for 0.35 h, and vacuum dry to constant weight to obtain a nitrogen-phosphorus intumescent flame retardant with a branched structure.

[0081] The conductive silver powder is composed of flake silver powder and spherical silver powder in a weight ratio of 3.5:1.

[0082] The preparation method of the carbon nanotube dispersion is as follows: 1 g of carbon nanotubes, 0.25 g of ultralong carbon nanotubes, and 1.3 g of dispersant are added to 65 g of deionized water, and stirred at 750 r / min to ensure the carbon nanotubes are completely wetted by water; then 2.1 g of p-hydroxybenzaldehyde is added, and the dispersion is further performed using an ultrasonic cell disruptor with an output power of 650 W for 30 min; finally, the dispersion is centrifuged at 1100 r / min for 20 min to obtain the carbon nanotube dispersion. The dispersant is composed of sodium glycocholate, glycerol, dodecyl dimethyl betaine, and aminoacetic acid in a weight ratio of 4:1:0.35:0.32.

[0083] Film preparation: Mix the conductive adhesive according to the weight formula, pour it into a polytetrafluoroethylene mold to form a film, and then perform performance testing.

[0084] Example 2 of CN117946583B and Example 4 of CN121086700A were selected for comparison with the present invention (if the comparison patent has corresponding index tests, the test data in the literature will be used; otherwise, the present invention will be used for testing). The heat resistance of the film was measured by placing the formed film in a muffle furnace under nitrogen protection at 700 °C for 10 s and then removing it, and measuring its mass loss rate and area shrinkage rate.

[0085] Self-healing rate: The self-healing rate was tested for membranes with a thickness of 0.8~1 mm and a width of 5 mm, with other parameters according to GB / T 1040.3-2006. The membrane was cut in the middle with a blade and irradiated at 30 ℃ with a wavelength of 365~400 nm for 6 h. Tensile tests were then performed on the uncut original sample and the sample after the self-healing test using an electronic universal testing machine (UTM2502HB) at room temperature. The tensile rate was 50 mm / min. The ratio of the maximum strain before and after repair was taken as the self-healing rate.

[0086] Cone calorimetry was performed according to ISO 5660-1 standard: the sample was cut into 100 mm × 100 mm × 3 mm pieces with a heat flux density of 35 kW / m², and the peak smoke generation rate (pSPR) of combustion was measured in m³ / s. 2 / s.

[0087] Volume resistivity: The volume resistivity was measured using a four-probe resistance tester according to the method in GJB 548C—2021 standard.

[0088] Bending resistance stability: The ratio of the resistance of the conductive film to the original resistance was measured after 200 bending cycles at 60 ℃ and a bending radius of 15 mm.

[0089] Tensile resistance stability: The ratio of resistance to original resistance was measured after 100 cycles at 60 ℃ and 2.5% tensile strain.

[0090] Stability of resistance under torsion: The conductive adhesive was torn at an angle of 150 degrees and subjected to 150 torsion cycles. The ratio of the resistance to the original resistance was then measured.

[0091] Thermal conductivity: The sample was measured using the laser pulse method. The sample size was 10 mm × 10 mm and the thickness was 3 mm.

[0092] Bond strength: The conductive adhesive is coated on polyimide to a thickness of 3 mm and tested according to GB / T 2792-2014.

[0093] Aging test: High temperature and high humidity aging is adopted. The resistance change rate is less than 20% after aging for 500 hours at 85 ℃ and 85% RH. The stability is considered to be up to standard.

[0094] Carbon residue and expansion height: The carbon residue and expansion height of the samples were determined in a muffle furnace at 500 ℃. 1 g of nitrogen-phosphorus intumescent flame retardant sample was placed in each crucible. The muffle furnace was heated from 100 ℃ to 500 ℃ and held for 10 min. After cooling to room temperature in a drying oven, the samples were weighed, and the expansion height and carbon residue were measured.

[0095] Table 1. Properties of heat-resistant, highly dispersible, self-healing, and highly adhesive conductive films

[0096] Self-repair rate (%) 90.12 90.56 91.23 - 20.3 Heat resistance (mass loss rate, %) 5.61 5.72 4.83 - 11.25 Heat resistance (area shrinkage rate, %) 1.86 2.36 3.42 - 6.52 Thermal conductivity (W / m·K) 2.21 2.31 2.15 0.11 0.68 Volume resistivity (Ω·cm) <![CDATA[3.12×10 -5 ]]> <![CDATA[2.62×10 -5 ]]> <![CDATA[4.35×10 -5 ]]> <![CDATA[1.2×10 9 ]]> <![CDATA[1×10 -4 ]]> Bending resistance stability 1.33 1.35 1.29 - 2.99 Stretching resistance stability 1.61 1.56 1.53 - 3.02 Torsional resistance stability 1.58 1.62 1.48 - 3.29 High temperature and high humidity aging Meets standards Meets standards Meets standards Substandard Substandard <![CDATA[pSPR Peak smoke generation rate (m 2 / s)]]> 0.172 0.168 0.176 0.287 0.962 Bond strength (N / cm) 2.22 2.31 2.26 - 1.06

[0097] Note that "-" indicates that testing is unnecessary.

[0098] As can be seen from Table 1, the present invention is superior to the prior art in terms of self-healing rate, heat resistance, thermal conductivity, volume resistivity, resistance stability and high temperature and high humidity aging.

[0099] Taking Example 1 as an example, the following properties were measured: the carbon residue rate and expansion height of the nitrogen-phosphorus intumescent flame retardant were 73.6% and 5.96 cm, respectively; the self-healing rate of the flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane film was 90.01%, it did not produce molten droplets during combustion, had a low film shrinkage rate, and produced almost no smoke during combustion.

[0100] Control experiments: Multiple comparative samples were set up, with samples without zirconium sulfate, aspartic acid, 1H-indole-2-carboxamide, hexagonal boron nitride, furfuryl alcohol glycidyl ether, and fabric softener added. All other conditions in the conductive adhesive preparation method were the same as in Example 1. The performance data of the conductive adhesive are shown in Table 2.

[0101] Table 2. Conductive adhesive performance data in the control experiment

[0102] Heat resistance (mass loss rate, %) 7.91 Conductive film without zirconium sulfate Heat resistance (mass loss rate, %) 6.63 Conductive film without aspartic acid Heat resistance (mass loss rate, %) 6.54 Without 1H-indole-2-carboxamide Thermal conductivity (W / m·K) 0.56 Conductive adhesive film without hexagonal boron nitride Thermal conductivity (W / m·K) 1.88 Without furfuryl alcohol glycidyl ether Self-repair rate (%) 85.21 No fabric softener Self-repair rate (%) 88.32 Ethylboronic acid is not added during the preparation of fabric softener. Volume resistivity (Ω·cm) <![CDATA[9.76×10 -4 ]]> Without adding ultra-long carbon nanotubes Volume resistivity (Ω·cm) <![CDATA[4.72×10 -4 ]]> No p-hydroxybenzaldehyde added

[0103] As shown in Table 2, the above-mentioned zirconium sulfate, aspartic acid, 1H-indole-2-carboxamide, hexagonal boron nitride, furfuryl alcohol glycidyl ether, etc., all have significant effects.

[0104] When using only flake-shaped silver powder or only spherical silver powder, the volume resistivity of the resulting conductive adhesive is 1.12 × 10⁻⁶. -4 Ω·cm and 9.56×10 -4 Ω·cm.

[0105] The carbon nanotube dispersion exhibited a static stability exceeding 72 h. Without the addition of a dispersant or p-hydroxybenzaldehyde, the resulting carbon nanotube dispersion showed precipitation after 10 min of standing, and precipitation after more than 24 h but less than 48 h. Other substances also showed similar effects, which will not be elaborated upon here.

Claims

1. A method for preparing a heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive, characterized in that, Its preparation method is as follows: (1) Mix 20-25 parts of flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane, 3-7 parts of carbon nanotube dispersion, 3-8 parts of epoxy resin dispersion, 3.0-3.2 parts of diethylenetriamine, 0.8-1 parts of 2-ethyl-4-methylimidazole, and 16-22 parts of acetone evenly to obtain mixture A; (2) Add 0.2-0.6 parts of antioxidant, 55-65 parts of conductive silver powder, and 0.3-1.8 parts of coupling agent to mixture A and stir evenly to obtain mixture B; (3) Degas mixture B under vacuum degree <-0.095MPa for 10 minutes to obtain heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive; The preparation method of the flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane is as follows: (1) Take 28 g of polypropylene glycol with a number average molecular weight of 2000 g / mol, 16.36 g of isophorone diisocyanate and 0.2~0.3 g of dibutyltin dilaurate, add them to a 500 mL three-necked flask, heat to 70~80 ℃ under nitrogen protection, stir at 300 r / min for 1~2 h to obtain polyurethane prepolymer; (2) Add 1.2 g of 2,2-dimethylolbutyric acid, 1.1-1.5 g of 2,2-dithiodiethanol and 4.12-5.38 g of nitrogen-phosphorus intumescent flame retardant to the polyurethane prepolymer, react at 60-75 °C for 1-1.5 h, then add 2.1-2.7 g of triethylamine and continue the reaction for 0.5-1 h; after cooling to room temperature, add 70 mL of deionized water, emulsify at 2000 r / min for 0.5 h, then add 7-8 g of epoxy resin E51 and 3-5 g of softener, stir at 500 r / min for 0.25-0.5 h, disperse evenly, and distill under reduced pressure to a solid content of 70% to obtain flame-retardant, low-smoke, low-shrinkage, self-healing polyurethane; The fabric softener is prepared as follows: 0.3-0.5 g of chloroplatinic acid and 7-9 g of isopropanol are added to a four-necked flask, the temperature is raised to 70-80 °C, 2.1 g of terminal hydrogen silicone oil and 25-31 g of allyl epoxy polyether are slowly added dropwise over 1 hour, glacial acetic acid is added to adjust the pH of the system to 5-6, and the reaction is carried out at 90-100 °C for 3-5 hours to obtain intermediate A; 10-12 g of polyetheramine D400 and 1.1-2.2 g of ethylboric acid are added to intermediate A, the pH of the system is maintained at 5-6, and the reaction is carried out at 70-90 °C for 2-5 hours. After cooling, the fabric softener is obtained. The preparation method of the epoxy resin dispersion is as follows: 3-5 g of hexagonal boron nitride is added to 20 g of furfuryl alcohol glycidyl ether, and ultrasonicated in an ice-water bath for 1-2 h to obtain a uniformly dispersed hexagonal boron nitride dispersion. Then, 100-120 g of epoxy resin E51 is added, and the mixture is stirred at 500-1000 r / min for 0.5-1.0 h to obtain the epoxy resin dispersion. The preparation method of the nitrogen-phosphorus intumescent flame retardant is as follows: (1) Using 100 mL of tetrahydrofuran as solvent, 21.6 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 9.8 g of maleic anhydride were added to a four-necked flask and stirred in an oil bath at 50 °C for 3-6 h. After drying in a vacuum oven, intermediate B was obtained. (2) Add 13.3 g of diisopropanolamine and 0.43 g of p-toluenesulfonic acid to intermediate B, add toluene until the reactants are submerged, heat in an oil bath at 100 °C for 3-6 h, and dry under vacuum at 70-85 °C to constant weight to obtain intermediate C; (3) Add 60.9 g of tetrahydroxymethylphosphoric acid to the product obtained in step (2), react for 1-2 h, and dry under vacuum at 70-85 °C to constant weight to obtain tetrahydroxymethylphosphoric acid modified flame retardant; (4) Add 4.6~5.2 g of diethylthiophosphoric acid to the tetrahydroxymethylphosphoric acid modified flame retardant obtained in step (3), stir and react at 70~80 °C for 1~2 h, then add 5.2~5.8 g of zirconium sulfate, 0.21~0.35 g of aspartic acid, 0.13~0.32 g of 1H-indole-2-carboxamide and 5~8 g of water, react at 45~65 °C for 0.25~0.5 h, and vacuum dry to constant weight to obtain a nitrogen-phosphorus intumescent flame retardant with a branched structure; The carbon nanotube dispersion is prepared as follows: 1 g of carbon nanotubes, 0.2-0.3 g of ultralong carbon nanotubes and 1.1-1.5 g of dispersant are added to 65 g of deionized water and stirred at 500-1000 r / min to completely wet the carbon nanotubes; then 1.5-2.7 g of p-hydroxybenzaldehyde is added, and the dispersion is further carried out using an ultrasonic cell disruptor with an output power of 600-700 W and an ultrasonic dispersion time of 10-50 min; the dispersion is then centrifuged at 1000-1200 r / min for 10-30 min to obtain the carbon nanotube dispersion.

2. The preparation method of the heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive according to claim 1, characterized in that, The particle size of the hexagonal boron nitride is 100 nm.

3. The preparation method of the heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive according to claim 1, characterized in that, The conductive silver powder is composed of flake silver powder and spherical silver powder in a weight ratio of 3:1 to 4:

1.

4. The preparation method of the heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive according to claim 1, characterized in that, The dispersant is composed of sodium glycocholate, glycerol, dodecyl dimethyl betaine and aminoacetic acid in a weight ratio of 4:1:0.2~0.5:0.3~0.

35.

5. The preparation method of the heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive according to claim 1, characterized in that, The coupling agent is any one of KH550 and KH560 or a mixture of the two in any proportion.

6. The preparation method of the heat-resistant, highly dispersible, self-healing, and highly adhesive conductive adhesive according to claim 1, characterized in that, The antioxidant is any one of benzotriazole and antioxidant 1010, or a mixture of the two in any proportion.