Polyurethane adhesive with high heat resistance and preparation method thereof

Abstract

The invention discloses a polyurethane adhesive with high heat resistance and a preparation method thereof, and relates to the technical field of adhesives, the polyurethane adhesive with high heat resistance comprises the following components: 40%-50% of a polyol component, 20%-30% of an isocyanate component, 5%-10% of a cross-linking agent, 5%-15% of a nano filler, 1%-5% of an auxiliary agent, and 3%-8% of a curing system. According to the polyurethane adhesive disclosed by the invention, the resorcinol diglycidyl ether is added to improve the heat resistance of the polyurethane adhesive, and the polytetrahydrofuran ether glycol is matched for use, so that good flexibility and low-temperature performance are provided, and the polytetrahydrofuran ether glycol and the resorcinol diglycidyl ether are complementary, so that the adhesive has relatively good elasticity while keeping the heat resistance. Similarly, the diphenylmethane diisocyanate provides high-strength heat resistance, the alicyclic isocyanate improves the flexibility and yellowing resistance of the adhesive, and the combination of the diphenylmethane diisocyanate and the alicyclic isocyanate optimizes the performance of the polyurethane adhesive. And by adding the nano filler, the thermal stability of the adhesive is improved, and the dispersity of the adhesive is improved at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and specifically to a polyurethane adhesive with high heat resistance and a preparation method thereof. Background Art

[0002] Polyurethane adhesive is a kind of polymer material, which is composed of polyurethane resin, curing agent, additives, etc., and has excellent adhesive properties, temperature resistance, chemical corrosion resistance and physical and mechanical properties.

[0003] Polyurethane adhesives are widely used in many fields due to their excellent adhesive properties, flexibility and chemical corrosion resistance. However, relatively speaking, their heat resistance is poor, which limits their application in high-temperature environments. The long-term use temperature of polyurethane adhesives is usually around 80 °C. When the temperature exceeds 120 °C, their performance will decline rapidly and they can only be used for a short time.

[0004] Specifically, the urethane bond in the polyurethane molecule is easily broken at high temperatures, resulting in the degradation of the molecular chain, thereby reducing the performance of the adhesive. The soft segments and hard segments in the polyurethane molecule have different thermal stabilities and are prone to phase separation at high temperatures, affecting the uniformity and adhesive strength of the adhesive. The crosslinking density of polyurethane adhesives is relatively low, and the molecular chains are prone to sliding at high temperatures, resulting in the deformation of the adhesive layer and the decrease of the adhesive strength.

[0005] Therefore, due to the limitation of heat resistance, polyurethane adhesives are restricted in some high-temperature application scenarios such as automotive engine compartments and electronic devices. In high-temperature environments, the adhesive strength, chemical corrosion resistance and other properties of polyurethane adhesives will decrease significantly, affecting their long-term stability and reliability.

[0006] Therefore, we propose a polyurethane adhesive with high heat resistance and a preparation method thereof to solve the problems mentioned above.

[0007] The above information disclosed in this background art is only used to increase the understanding of the background art of the present invention. Therefore, it may include prior art that is not known to those of ordinary skill in the art. Summary of the Invention

[0008] The purpose of the present invention is to provide a polyurethane adhesive with high heat resistance and a preparation method thereof to solve the problems such as poor heat resistance mentioned in the above background art.

[0009] To achieve the above purpose, the present invention provides the following technical solutions:

[0010] A polyurethane adhesive with high heat resistance performance, comprising the following components: polyol component: 40%-50%, isocyanate component: 20%-30%, crosslinking agent: 5%-10%, nano filler: 5%-15%, additive: 1%-5%, curing system: 3%-8%.

[0011] As a further optimized solution of the present invention, the polyol component is resorcinol diglycidyl ether: 20%-30%, polytetrahydrofuran ether diol: 10%-20%, hydroquinone diglycidyl ether: 5%-10%, polyethylene adipate: 5%-10%, polycarbonate diol: 5%-10%, silicon-containing polyol: 1%-5%.

[0012] As a further optimized solution of the present invention, the isocyanate component is diphenylmethane diisocyanate: 60%-70%, naphthalene diisocyanate: 20%-30%, toluene diisocyanate: 5%-10%, isophorone diisocyanate: 5%-10%, silicon-containing isocyanate: 1%-5%.

[0013] As a further optimized solution of the present invention, the crosslinking agent is trimethylolpropane: 40%-50%, pentaerythritol: 20%-30%, diethanolamine: 10%-20%, triethanolamine: 5%-10%, silicon-containing crosslinking agent: 1%-5%.

[0014] As a further optimized solution of the present invention, the nano filler is nano silica: 40%-50%, nano alumina: 20%-30%, nano calcium carbonate: 10%-20%, nano zinc oxide: 5%-10%, nano graphene: 1%-5%, nano titanium dioxide: 1%-5%.

[0015] As a further optimized solution of the present invention, the additive is a catalyst, a dispersant, a wetting agent, an antifoaming agent, an antioxidant, a thickening agent, a flame retardant, a conductive agent.

[0016] As a further optimized solution of the present invention, the catalyst is an organotin catalyst: 0.1%-0.3%, triethylenediamine: 0.1%-0.2%; the dispersant is a high molecular weight polyether dispersant: 1%-2%; the wetting agent is a non-ionic surfactant: 0.5%-1%; the antifoaming agent is a silicone antifoaming agent: 0.1%-0.3%; the antioxidant is a hindered phenol antioxidant: 0.5%-1%; the thickening agent is fumed silica: 0.5%-1%; the flame retardant is a phosphate flame retardant: 1%-3%; the conductive agent is carbon black: 1%-2%.

[0017] As a further optimized solution of the present invention, the curing system includes: aromatic polyisocyanate curing agent: 40%-50%, alicyclic polyisocyanate curing agent: 20%-30%, polyether polyol: 10%-20%, curing accelerator: 1%-5%, heat-resistant additive: 1%-3%, antioxidant: 0.5%-1%.

[0018] A preparation method of a polyurethane adhesive with high heat resistance includes the following steps:

[0019] Step 1: Mix the polyol components in proportion, heat to 80-100°C and stir. The stirring time is 10-15 minutes. Slowly add the isocyanate components in proportion, keep the temperature at 80-100°C, and continuously stir for 2-3 hours until the reaction is complete to form a prepolymer;

[0020] Step 2: Mix the crosslinking agent and the nano-filler in proportion, add a dispersant and a wetting agent, and use a high-speed disperser for dispersion. The stirring and dispersion time is 30-60 minutes, and the rotation speed is 1000-1500 rpm until a uniform dispersion liquid is formed;

[0021] Step 3: Add the catalyst, dispersant, wetting agent, defoaming agent, anti-aging agent, thickening agent, flame retardant, and conductive agent to the prepolymer in proportion and stir. The stirring time is 15-30 minutes, and the rotation speed is 200-300 rpm;

[0022] Step 4: Mix and stir the aromatic polyisocyanate curing agent, alicyclic polyisocyanate curing agent, polyether polyol, curing accelerator, heat-resistant additive, and antioxidant in proportion. The stirring time is 10-20 minutes, and the rotation speed is 200-300 rpm to form a curing system;

[0023] Step 5: Add the dispersion liquid of the crosslinking agent and the nano-filler to the prepolymer and stir evenly. The stirring time is 10-15 minutes, and the rotation speed is 200-300 rpm. Finally, add the curing system and stir. The stirring time is 15-30 minutes, and the rotation speed is 300-400 rpm;

[0024] Step 6: Remove the bubbles from the mixed adhesive by degassing. The degassing time is 10-30 minutes. After degassing, fill the adhesive into a packaging container and seal it for storage.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] The polyurethane adhesive in the present invention can remain stable in a high-temperature environment and is not easily decomposed, making it suitable for applications under high-temperature working conditions, such as in automotive engine compartments, electronic devices, etc. It can provide excellent bonding strength at both room temperature and high temperature, enabling the bonded materials to be firmly combined in various environments. Moreover, the curing system design enables the adhesive to react rapidly and cure completely during the curing process, shortening the construction period and improving production efficiency.

[0027] In the present invention, by adding resorcinol diglycidyl ether, the heat resistance of the polyurethane adhesive is improved. At the same time, the combined use of polytetrahydrofuran ether glycol provides good flexibility and low-temperature performance, forming a complement with resorcinol diglycidyl ether, so that the adhesive has good elasticity while maintaining heat resistance. Similarly, diphenylmethane diisocyanate provides high-strength heat resistance, while alicyclic isocyanate improves the flexibility and yellowing resistance of the adhesive. The combination of the two optimizes the performance of the polyurethane adhesive. By adding nano-fillers, the thermal stability of the adhesive is improved, and at the same time, its dispersibility is improved. Finally, by selecting environmentally friendly raw materials and additives, the emission of harmful substances is reduced, meeting the development trend of green environmental protection.

[0028] The above summary is only for the purpose of the specification and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will be readily apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow block diagram of the preparation method of the polyurethane adhesive in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Example 1

[0032] A polyurethane adhesive with high heat resistance, comprising the following components: polyol component: 40%, isocyanate component: 20%, crosslinking agent: 5%, nano-filler: 5%, additive: 1%, curing system: 3%.

[0033] The polyol components are resorcinol diglycidyl ether: 20%, polytetrahydrofuran ether diol: 10%, hydroquinone diglycidyl ether: 5%, polyethylene adipate: 5%, polycarbonate diol: 5%, and silicon-containing polyol: 1%.

[0034] The isocyanate components are diphenylmethane diisocyanate: 60%, naphthalene diisocyanate: 20%, toluene diisocyanate: 5%, isophorone diisocyanate: 5%, and silicon-containing isocyanate: 1%.

[0035] The crosslinking agents are trimethylolpropane: 40%, pentaerythritol: 20%, diethanolamine: 10%, triethanolamine: 5%, and silicon-containing crosslinking agent: 1%.

[0036] The nano-fillers are nano-silica: 40%, nano-alumina: 20%, nano-calcium carbonate: 10%, nano-zinc oxide: 5%, nano-graphene: 1%, and nano-titanium dioxide: 1%.

[0037] The additives are catalyst, dispersant, wetting agent, defoaming agent, anti-aging agent, thickening agent, flame retardant, and conductive agent.

[0038] The catalyst is organotin catalyst: 0.1%, triethylenediamine: 0.1%; the dispersant is high molecular weight polyether dispersant: 1%; the wetting agent is non-ionic surfactant: 0.5%; the defoaming agent is silicone defoaming agent: 0.1%; the anti-aging agent is hindered phenol anti-aging agent: 0.5%; the thickening agent is fumed silica: 0.5%; the flame retardant is phosphate flame retardant: 1%; the conductive agent is carbon black: 1%.

[0039] The curing system includes aromatic polyisocyanate curing agent: 40%, alicyclic polyisocyanate curing agent: 20%, polyether polyol: 10%, curing accelerator: 1%, heat-resistant additive: 1%, and antioxidant: 0.5%.

[0040] A method for preparing a polyurethane adhesive with high heat resistance, comprising the following steps:

[0041] Step 1: Mix the polyol components in proportion, heat to 80 - 100 °C and stir for 10 - 15 minutes. Slowly add the isocyanate components in proportion while maintaining the temperature at 80 - 100 °C and continue stirring for 2 - 3 hours until the reaction is complete to form a prepolymer;

[0042] Step 2: Mix the crosslinking agent and nano-fillers in proportion, add the dispersant and wetting agent, and disperse using a high-speed disperser for 30 - 60 minutes at a rotation speed of 1000 - 1500 rpm until a uniform dispersion is formed;

[0043] Step 3: Add the catalyst, dispersant, wetting agent, defoamer, antioxidant, thickener, flame retardant, and conductive agent into the prepolymer in proportion and stir. The stirring time is 15 - 30 min, and the rotation speed is 200 - 300 rpm;

[0044] Step 4: Mix and stir the aromatic polyisocyanate curing agent, alicyclic polyisocyanate curing agent, polyether polyol, curing accelerator, heat - resistant additive, and antioxidant in proportion. The stirring time is 10 - 20 min, and the rotation speed is 200 - 300 rpm to form a curing system;

[0045] Step 5: Add the dispersion of the cross - linker and nano - filler into the prepolymer and stir evenly. The stirring time is 10 - 15 min, and the rotation speed is 200 - 300 rpm. Finally, add the curing system and stir. The stirring time is 15 - 30 min, and the rotation speed is 300 - 400 rpm;

[0046] Step 6: Remove the bubbles from the mixed adhesive through degassing. The degassing time is 10 - 30 min. After degassing, fill the adhesive into the packaging container and seal it for storage.

[0047] Example 2

[0048] A polyurethane adhesive with high heat - resistant performance, comprising the following components: polyol component: 45%, isocyanate component: 25%, cross - linker: 7%, nano - filler: 10%, additive: 3%, curing system: 5%.

[0049] The polyol component is resorcinol diglycidyl ether: 25%, polytetrahydrofuran ether diol: 15%, hydroquinone diglycidyl ether: 7%, polyethylene adipate: 7%, polycarbonate diol: 8%, silicon - containing polyol: 4%.

[0050] The isocyanate component is diphenylmethane diisocyanate: 65%, naphthalene diisocyanate: 25%, toluene diisocyanate: 7%, isophorone diisocyanate: 7%, silicon - containing isocyanate: 4%.

[0051] The cross - linker is trimethylolpropane: 45%, pentaerythritol: 25%, diethanolamine: 15%, triethanolamine: 7%, silicon - containing cross - linker: 4%.

[0052] The nano - filler is nano - silica: 45%, nano - alumina: 25%, nano - calcium carbonate: 15%, nano - zinc oxide: 7%, nano - graphene: 4%, nano - titanium dioxide: 4%.

[0053] The auxiliary agents are catalyst, dispersant, wetting agent, defoamer, antioxidant, thickener, flame retardant, and conductive agent. The catalyst is organotin catalyst: 0.2%, triethylenediamine: 0.15%; the dispersant is high molecular weight polyether dispersant: 1.5%; the wetting agent is nonionic surfactant: 0.7%; the defoamer is silicone defoamer: 0.2%; the antioxidant is hindered phenol antioxidant: 0.7%; the thickener is fumed silica: 0.8%; the flame retardant is phosphate flame retardant: 2%; the conductive agent is carbon black: 1.5%.

[0054] The curing system includes aromatic polyisocyanate curing agent: 45%, alicyclic polyisocyanate curing agent: 25%, polyether polyol: 15%, curing accelerator: 4%, heat-resistant additive: 2%, antioxidant: 0.7%.

[0055] Example 3

[0056] A polyurethane adhesive with high heat resistance performance comprises the following components: polyol component: 50%, isocyanate component: 30%, crosslinking agent: 10%, nano filler: 15%, auxiliary agent: 5%, curing system: 8%.

[0057] The polyol component is resorcinol diglycidyl ether: 30%, polytetrahydrofuran ether diol: 20%, hydroquinone diglycidyl ether: 10%, polyethylene adipate: 10%, polycarbonate diol: 10%, silicon-containing polyol: 5%.

[0058] The isocyanate component is diphenylmethane diisocyanate: 70%, naphthalene diisocyanate: 30%, toluene diisocyanate: 10%, isophorone diisocyanate: 10%, silicon-containing isocyanate: 5%.

[0059] The crosslinking agent is trimethylolpropane: 50%, pentaerythritol: 30%, diethanolamine: 20%, triethanolamine: 10%, silicon-containing crosslinking agent: 5%.

[0060] The nano filler is nano silica: 50%, nano alumina: 30%, nano calcium carbonate: 20%, nano zinc oxide: 10%, nano graphene: 5%, nano titanium dioxide: 5%.

[0061] The auxiliary agents are catalyst, dispersant, wetting agent, defoamer, antioxidant, thickener, flame retardant, and conductive agent. The catalyst is organotin catalyst: 0.3%, triethylenediamine: 0.2%; the dispersant is high molecular weight polyether dispersant: 2%; the wetting agent is nonionic surfactant: 1%; the defoamer is silicone defoamer: 0.3%; the antioxidant is hindered phenol antioxidant: 1%; the thickener is fumed silica: 1%; the flame retardant is phosphate flame retardant: 3%; the conductive agent is carbon black: 2%.

[0062] The curing system includes aromatic polyisocyanate curing agent: 50%, alicyclic polyisocyanate curing agent: 30%, polyether polyol: 20%, curing accelerator: 5%, heat-resistant additive: 3%, antioxidant: 1%.

[0063] Experimental Examples

[0064] Experimental purpose: To verify the heat resistance, bonding strength, and chemical stability of the polyurethane adhesive prepared by the present invention.

[0065] Experimental materials: Prepare the polyurethane adhesive according to the present invention.

[0066] Experimental equipment: Thermogravimetric analyzer (TGA), tensile testing machine, constant temperature oven, chemical reagents.

[0067] Experimental methods:

[0068] Heat resistance test: Use a thermogravimetric analyzer to conduct a thermal stability test on the adhesive. Set the heating rate to 10°C / min, and the temperature range from room temperature to 600°C. Record the thermogravimetric curve of the adhesive and analyze its thermal decomposition temperature and residual mass.

[0069] Bonding strength test: Evenly apply the adhesive on a standard test piece. After curing, conduct a tensile test. Use a tensile testing machine to measure the tensile strength and shear strength of the adhesive, and compare the changes in bonding strength at room temperature, 100°C, 150°C, and 200°C.

[0070] Chemical stability test: Immerse the cured adhesive sample in acids, alkalis, and organic solvents. After soaking for a certain period of time, observe the appearance and weight changes of the sample to evaluate the chemical stability of the adhesive.

[0071] Experimental results:

[0072] Temperature (°C) Thermogravimetric loss (%) Thermal decomposition temperature (°C) 200 1.2 >400 300 3.5 >400 400 8.0 425 500 15.0 425

[0073] Table 1 Heat resistance at different temperatures

[0074] As can be seen from Table 1, the adhesive prepared by this solution has no obvious thermal weight loss below 400°C, and its thermal decomposition temperature is significantly higher than that of ordinary polyurethane adhesives. This indicates that the adhesive has excellent heat resistance and is suitable for applications in high-temperature environments.

[0075] Temperature (°C) Tensile strength (MPa) Shear strength (MPa) Room temperature 12.5 8.0 100 11.0 7.5 150 9.5 6.8 200 8.0 6.0

[0076] Table 2 Bonding strength at different temperatures

[0077] As can be seen from Table 2, within the range of room temperature to 200 °C, both the tensile strength and shear strength of the adhesive remain at a relatively high level. Compared with ordinary polyurethane adhesives, the adhesive prepared by the present invention can still maintain good bonding performance at high temperatures.

[0078] Chemical reagent Appearance change Weight change (%) Sulfuric acid (10%) None 0.5 Sodium hydroxide (10%) None 0.3 Ethanol None 0.2 Benzene None 0.4

[0079] Table 3 Stability under Different Chemical Reagents

[0080] As can be seen from Table 3, there are no obvious appearance changes and weight losses of the specimens in acids, alkalis, and organic solvents. This indicates that the adhesive has good chemical stability and can resist the erosion of various chemical media.

[0081] Experimental conclusion: Through this experiment, it can be proved that the polyurethane adhesive prepared by the present invention has excellent heat resistance, is suitable for applications in high-temperature environments, and can still maintain good bonding strength and chemical stability at high temperatures, and can resist the erosion of various chemical media.

[0082] In summary, the polyurethane adhesive in the present invention can remain stable in high-temperature environments, is not easily decomposed, is suitable for applications under high-temperature working conditions, such as automotive engine compartments, electronic devices, etc., and can provide excellent bonding strength at both room temperature and high temperatures, enabling the bonded materials to be firmly combined in various environments. Moreover, the design of the curing system enables the adhesive to react rapidly and cure completely during the curing process, shortening the construction period, improving production efficiency, and ultimately reducing the emission of harmful substances, meeting the development trend of green environmental protection.

[0083] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0084] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A polyurethane adhesive with high heat resistance performance, characterized in that, It includes the following components: polyol component: 40%-50%, isocyanate component: 20%-30%, crosslinking agent: 5%-10%, nano filler: 5%-15%, additive: 1%-5%, curing system: 3%-8%.

2. The polyurethane adhesive with high heat resistance according to claim 1, characterized in that: The polyol component is resorcinol diglycidyl ether: 20%-30%, polytetrahydrofuran glycol: 10%-20%, hydroquinone diglycidyl ether: 5%-10%, polyethylene adipate: 5%-10%, polycarbonate diol: 5%-10%, silicon-containing polyol: 1%-5%.

3. The polyurethane adhesive with high heat resistance according to claim 1, characterized in that: The isocyanate component is diphenylmethane diisocyanate: 60%-70%, naphthalene diisocyanate: 20%-30%, toluene diisocyanate: 5%-10%, isophorone diisocyanate: 5%-10%, silicon-containing isocyanate: 1%-5%.

4. A polyurethane adhesive with high heat resistance according to claim 1, characterized in that: The crosslinking agent is trimethylolpropane: 40%-50%, pentaerythritol: 20%-30%, diethanolamine: 10%-20%, triethanolamine: 5%-10%, silicon-containing crosslinking agent: 1%-5%.

5. A polyurethane adhesive with high heat resistance according to claim 1, characterized in that: The nano filler is nano silica: 40%-50%, nano alumina: 20%-30%, nano calcium carbonate: 10%-20%, nano zinc oxide: 5%-10%, nano graphene: 1%-5%, nano titanium dioxide: 1%-5%.

6. The polyurethane adhesive with high heat resistance according to claim 1, characterized in that: The additive is catalyst, dispersant, wetting agent, defoamer, antioxidant, thickener, flame retardant, conductive agent.

7. The polyurethane adhesive with high heat resistance according to claim 6, characterized in that: The catalyst is organotin catalyst: 0.1%-0.3%, triethylenediamine: 0.1%-0.2%; the dispersant is high molecular weight polyether dispersant: 1%-2%; The wetting agent is non-ionic surfactant: 0.5%-1%; the defoamer is silicone defoamer: 0.1%-0.3%; the antioxidant is hindered phenol antioxidant: 0.5%-1%; the thickener is fumed silica: 0.5%-1%; the flame retardant is phosphate flame retardant: 1%-3%; the conductive agent is carbon black: 1%-2%.

8. The polyurethane adhesive with high heat resistance according to claim 1, wherein: The curing system includes aromatic polyisocyanate curing agent: 40%-50%, alicyclic polyisocyanate curing agent: 20%-30%, polyether polyol: 10%-20%, curing accelerator: 1%-5%, heat-resistant additive: 1%-3%, antioxidant: 0.5%-1%.

9. A preparation method of a polyurethane adhesive with high heat resistance, characterized in that, It includes the following steps: Step 1: Mix the polyol component in proportion, heat it to 80-100°C and stir. The stirring time is 10-15 minutes. Slowly add the isocyanate component in proportion, keep the temperature at 80-100°C, and continuously stir for 2-3 hours until the reaction is complete to form a prepolymer; Step 2: Mix the crosslinking agent and the nano filler in proportion, add the dispersant and the wetting agent, and disperse them using a high-speed disperser. The stirring and dispersing time is 30-60 minutes, and the rotation speed is 1000-1500 rpm until a uniform dispersion liquid is formed; Step 3: Add the catalyst, dispersant, wetting agent, defoamer, antioxidant, thickener, flame retardant, and conductive agent in proportion to the prepolymer and stir. The stirring time is 15-30 minutes, and the rotation speed is 200-300 rpm; Step 4: Mix and stir the aromatic polyisocyanate curing agent, alicyclic polyisocyanate curing agent, polyether polyol, curing accelerator, heat-resistant additive, and antioxidant in proportion. The stirring time is 10 - 20 min, and the rotation speed is 200 - 300 rpm to form a curing system; Step 5: Add the dispersion of the crosslinking agent and nano filler to the prepolymer and stir evenly. The stirring time is 10 - 15 min, and the rotation speed is 200 - 300 rpm. Finally, add the curing system and stir. The stirring time is 15 - 30 min, and the rotation speed is 300 - 400 rpm; Step 6: Remove the bubbles from the mixed adhesive through degassing. The degassing time is 10 - 30 min. After degassing, fill the adhesive into the packaging container and store it sealed.

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