A rapid-curing polyurethane structural adhesive and a preparation method thereof

Abstract

The application relates to the field of polyurethane sealants, and discloses a fast-curing polyurethane structural adhesive and a preparation method thereof. The fast-curing polyurethane structural adhesive is composed of an A component and a B component, the A component is composed of the following raw materials in parts by weight: isocyanate-terminated polyurethane prepolymer 40-50 parts, heat-conducting filler 0-400 parts, stabilizer 6-10 parts, water-removing agent 0.5-1.5 parts and antioxidant 1-3 parts; and the B component is composed of the following raw materials in parts by weight: polycaprolactone polyol 10-15 parts, polyether polyol 8-12 parts, heat-conducting filler 0-400 parts, dispersant 1-2 parts and catalyst 0.1-2 parts. The preparation method is that the raw materials of the A component and the raw materials of the B component are respectively subjected to temperature rising and vacuum mixing. The polyurethane structural adhesive has good curing efficiency, adhesion and heat conductivity, can provide sufficient assembly time and adhesion for a power battery pack, can be quickly cured after assembly, and has high assembly efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polyurethane sealant, more particularly, it relates to a kind of fast curing polyurethane structural glue and preparation method thereof. BACKGROUND

[0002] The performance stability of power battery pack as the power source of new energy vehicle directly affects the driving state of new energy vehicle, and the power battery pack is assembled by a plurality of batteries in parallel, and the polyurethane structural glue plays a crucial role in the process of packaging power battery pack, it not only has good thermal conductivity to ensure that the heat generated by the battery in the working process can be effectively transmitted and dissipated, but also requires fast curing and excellent bonding performance to improve assembly quality and production efficiency.

[0003] The polyurethane structural glue is a kind of block copolymer prepared from isocyanate, polyester polyol, polyether polyol and catalyst, and the hardness can be adjusted, which has excellent wear resistance, elasticity, chemical corrosion resistance, adhesion and shock absorption, etc., however, the thermal conductivity of pure polyurethane resin is low, only 0.18-0.20 W / (m.k), which cannot meet the demand of power battery pack packaging on thermal conductivity.

[0004] In order to improve the thermal conductivity of polyurethane structural glue, it is usually necessary to add thermal conductive filler to polyurethane structural glue, the addition of thermal conductive filler improves the thermal conductivity of polyurethane structural glue, but it is difficult to meet the requirements of battery pack assembly process on operation time and curing speed. If the curing speed is fast, the operation time of polyurethane structural glue in assembly is short; if the operation time is met, the curing speed is slow, the power battery pack cannot be cured in time to achieve a certain initial adhesion to meet the requirements of the next process, thereby reducing the assembly efficiency of power battery pack. SUMMARY

[0005] In order to solve the problem that polyurethane structural glue cannot better consider the thermal conductivity and meet the requirements of power battery pack assembly process on operation time and curing speed, and reduce the assembly efficiency of power battery pack, the present application provides a kind of fast curing polyurethane structural glue and preparation method thereof.

[0006] In the first aspect, the present application provides a kind of fast curing polyurethane structural glue, which adopts the following technical scheme:

[0007] A fast-curing polyurethane structural adhesive comprises component A and component B. Component A consists of the following raw materials in parts by weight: 40-50 parts isocyanate-terminated polyurethane prepolymer, 0-400 parts thermally conductive filler, 6-10 parts stabilizer, 0.5-1.5 parts dehydrating agent, and 1-3 parts antioxidant. Component B consists of the following raw materials in parts by weight: 10-15 parts polycaprolactone polyol, 8-12 parts polyether polyol, 0-400 parts thermally conductive filler, 1-2 parts dispersant, and 0.1-2 parts catalyst.

[0008] By adopting the above technical solution, the polyurethane structural adhesive of this application is a two-component adhesive. Component A consists of isocyanate-terminated polyurethane prepolymer, stabilizer, dehydrating agent, and antioxidant. Under the action of the stabilizer and isocyanate-terminated polyurethane prepolymer, the addition of thermally conductive filler can effectively disperse the thermally conductive filler. Component B consists of polycaprolactone polyol, polyether polyol, dispersant, and catalyst. Under the action of the dispersant, polycaprolactone polyol, and polyether polyol, the addition of thermally conductive filler can ensure uniform dispersion of the thermally conductive filler and catalyst. Components A and B... After the components are mixed, under the action of catalysts and antioxidants, each component can slowly and stably cross-link over a relatively long period of time, providing sufficient operating time for the assembly of the power battery pack. After a certain amount of heat accumulates during the reaction, the catalytic ability of the catalyst rapidly increases, further synergizing with the isocyanate-terminated polyurethane prepolymer to accelerate the cross-linking reaction of each component, thereby achieving a certain bonding strength. The assembled power battery pack can then be rapidly cured, resulting in a fast-curing polyurethane structural adhesive with a slow-to-fast curing efficiency. The polyurethane structural adhesive obtained in this way has a stable curing rate and bonding stability. Further preferably, the amount of thermally conductive filler in component A is 25-35 parts, and the amount of thermally conductive filler in component B is 15-25 parts. Adding a more optimal amount of thermally conductive filler can improve the thermal conductivity of the polyurethane structural adhesive while also providing good tensile shear strength, effectively improving the heat dissipation effect and assembly efficiency of the power battery pack.

[0009] Preferably, the isocyanate-terminated polyurethane prepolymer is prepared from the following raw materials in parts by weight:

[0010] 50-60 parts of diisocyanate

[0011] 10-20 parts of polyether polyol

[0012] 5-8 parts of hydroxyl-terminated polybutadiene

[0013] 4-6 parts of diethylene glycol

[0014] 1-3 parts of 3-aminopropyltrihydroxysilane

[0015] Catalyst 0.2-0.4 parts.

[0016] By adopting the above technical solution, diisocyanate provides isocyanate groups, and polyether polyol provides alcohol hydroxyl groups. Under the action of a catalyst, a polymerization reaction is carried out. Hydroxyl-terminated polybutadiene, diethylene glycol, and 3-aminopropyltrihydroxysilane in a better ratio are added to the reaction system to introduce vinyl, long-chain ether, and siloxane segments into the reaction system. The resulting isocyanate-terminated polyurethane can significantly improve the dispersion performance of thermally conductive fillers in polyurethane structural adhesives, and improve the problem of reduced curing efficiency of polyurethane structural adhesives caused by the addition of thermally conductive fillers. At the same time, it can stably undergo further cross-linking reactions with other components, thereby improving the heat dissipation performance, rapid curing performance, and adhesion performance of the resulting polyurethane structural adhesive, thus improving the assembly stability and production efficiency of power battery packs.

[0017] Preferably, the isocyanate-terminated polyurethane prepolymer is prepared by the following steps: adding diisocyanate, polyether polyol and catalyst into a reaction device, reacting under vacuum, and then adding hydroxyl-terminated polybutadiene, diethylene glycol and 3-aminopropyltrihydroxysilane to react and obtain the isocyanate-terminated polyurethane prepolymer.

[0018] By adopting the above technical solution, diisocyanate and polyether polyol react first under the action of a catalyst to introduce polyether segments onto the isocyanate chain. Then, hydroxyl-terminated polybutadiene, diethylene glycol and 3-aminopropyltrihydroxysilane are added to extend the isocyanate chain and introduce vinyl, long-chain ether and siloxane segments. This process prepares isocyanate-terminated polyurethane prepolymers, which improves the reaction efficiency and quality of isocyanate polyurethane prepolymers, thereby enhancing the adhesion performance and curing efficiency of polyurethane structural adhesives.

[0019] Preferably, the thermally conductive fillers of both component A and component B are composed of aluminum oxide, boron nitride and magnesium oxide in a weight ratio of 1:(2-3):(0.2-0.4).

[0020] By adopting the above technical solution, using alumina, boron nitride and magnesium oxide in a better ratio as thermally conductive fillers, the three thermally conductive fillers can produce a good synergistic effect and be uniformly dispersed in the polyurethane structural adhesive system. This improves the thermal conductivity while enhancing the rapid curing performance and excellent adhesion of the polyurethane structural adhesive.

[0021] Preferably, the stabilizer is composed of trimethylolpropane trimethacrylate and 3-isocyanate-propyltriethoxysilane in a weight ratio of 1:(0.5-1.5).

[0022] By adopting the above technical solution, using trimethylolpropane trimethacrylate and 3-isocyanate-propyltriethoxysilane in a better ratio as stabilizers, the crosslinking stability of components A and B can be improved, forming a uniform macromolecular network system. This allows the thermally conductive filler to be uniformly interwoven and dispersed, thereby improving the thermal conductivity and curing stability of the polyurethane structural adhesive and ensuring the stability and reliability of the polyurethane structural adhesive during use.

[0023] Preferably, the dispersant is composed of dibutyl itaconic acid and glyceryl cocoate in a weight ratio of (3-4):1.

[0024] By adopting the above technical solution, using dibutyl itaconic acid and glyceryl cocoate in a better ratio as dispersants, the dispersion uniformity of each component can be improved, the flowability of the polyurethane structural adhesive system can be improved, and the curing efficiency of the polyurethane structural adhesive can be improved, so that the polyurethane structural adhesive has good thermal conductivity and good adhesion performance.

[0025] Preferably, the catalyst is one or a combination of organotin catalysts.

[0026] By adopting the above technical solution, the catalyst can effectively control the curing rate of polyurethane structural adhesive, so that the polyurethane structural adhesive has uniform curing performance, providing suitable operating time and bonding performance for the assembly of power battery packs. After assembly, it can further achieve rapid curing, shorten the assembly time of power battery packs on the production line, and improve the assembly stability and production efficiency of power battery packs.

[0027] Preferably, the dehydrating agent is any one of molecular sieve and anhydrous calcium chloride, and the antioxidant is one or a combination of antioxidant 1010, antioxidant 168, antioxidant 1076 and antioxidant 1098.

[0028] By adopting the above technical solution and selecting the above-mentioned dehydrating agent, not only can the moisture in the polyurethane structural adhesive be effectively removed, but the system stability of the polyurethane structural adhesive can also be maintained; and by selecting the above-mentioned antioxidant, the antioxidant performance of the polyurethane structural adhesive can be improved, thereby extending the service life of the polyurethane structural adhesive.

[0029] Preferably, the ratio of component A to component B in terms of dosage is (0.9-1.1):1.

[0030] By adopting the above technical solution, the ratio of component A to component B is controlled within the range of (0.9-1.1):1, which ensures that the polyurethane structural adhesive has good thermal conductivity while allowing component A and component B to crosslink stably. This provides operation time and assembly adhesion for the assembly of the power battery pack, and enables rapid curing after assembly, thereby improving the assembly stability and production efficiency of the power battery pack.

[0031] Secondly, this application provides a method for preparing a rapid-curing polyurethane structural adhesive, employing the following technical solution:

[0032] A method for preparing a fast-curing polyurethane structural adhesive includes the following steps: heating and vacuum mixing isocyanate-terminated polyurethane prepolymer, thermally conductive filler, stabilizer, dehydrating agent and antioxidant to obtain component A;

[0033] Component B is prepared by heating and vacuum mixing polycaprolactone polyol, polyether polyol, thermally conductive filler, dispersant and catalyst to obtain component B.

[0034] By adopting the above technical solution, the preparation method of this rapid-curing polyurethane structural adhesive can ensure that components A and B are fully and uniformly mixed, thereby improving the overall performance of the polyurethane structural adhesive. Preparing components A and B by heating and vacuum mixing not only effectively removes moisture from the raw materials, avoiding any impact on the curing effect, but also ensures the uniform dispersion of the thermally conductive filler, thus improving the thermal conductivity and curing efficiency of the polyurethane structural adhesive and exhibiting good storage stability.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. The rapid-curing polyurethane structural adhesive of this application uses isocyanate-terminated polyurethane prepolymer, thermally conductive filler, stabilizer, dehydrating agent and antioxidant as component A, and polycaprolactone polyol, polyether polyol, thermally conductive filler, dispersant and catalyst as component B. The resulting polyurethane structural adhesive is used in the encapsulation of power battery packs, providing sufficient operating time and good initial tack performance for the assembly of power battery packs. It can be rapidly cured after assembly. While having good thermal conductivity, it also has good curing rate and bonding stability, which can effectively improve the heat dissipation effect and assembly efficiency of power battery packs.

[0037] 2. Using isocyanate-terminated polyurethane prepolymers prepared from diisocyanate, polyether polyol, hydroxyl-terminated polybutadiene, diethylene glycol, 3-aminopropyltrihydroxysilane and catalyst can significantly improve the dispersion performance of thermally conductive fillers in polyurethane structural adhesives. At the same time, it can stably undergo further crosslinking reactions with other components, thereby improving the rapid curing performance and adhesion performance of the prepared polyurethane structural adhesives.

[0038] 3. Using trimethylolpropane trimethacrylate and 3-isocyanate-propyltriethoxysilane in a better ratio as stabilizers can improve the crosslinking stability of components A and B, forming a uniform macromolecular network system. This allows the thermally conductive filler to be uniformly interwoven and dispersed, thereby improving the thermal conductivity and curing stability of the polyurethane structural adhesive and ensuring the stability and reliability of the polyurethane structural adhesive during use. Detailed Implementation

[0039] The present application will be further described in detail below with reference to the embodiments.

[0040] The following are some of the sources and specifications of the raw materials used in this application. The raw materials used in the preparation examples and embodiments of this application can all be obtained commercially, including but not limited to the following models and manufacturers of raw materials. Raw materials with equivalent performance can also be used:

[0041] 1. Hydroxyl-terminated polybutadiene: Kmick, CAS No. 69102-90-5, hydroxyl value 0.47-0.53mgKOH / g, content 99%;

[0042] 2. Alumina: 99.99% purity, spherical alumina, particle size 30-70nm;

[0043] 3. Boron nitride: purity 99.9%, particle size 100-150nm;

[0044] 4. Magnesium oxide: 99.9% purity, particle size 30-50nm;

[0045] 5. Trimethylolpropane trimethacrylate: Lanable, 99% purity, CAS No. 3290-92-4;

[0046] 6. 3-Isocyanate-propyltriethoxysilane: Shin-Etsu KBE-9007;

[0047] 7. Dibutyl itaconic acid: CAS No. 2155-60-4, content 98%;

[0048] 8. Molecular sieve: particle size 2-6 micrometers, model JZ-AZ3, Jiuzhou Chemical.

[0049] Preparation example of isocyanate-terminated polyurethane prepolymer

[0050] Preparation Example 1

[0051] Preparation Example 1 discloses an isocyanate-terminated polyurethane prepolymer, which is prepared by the following steps: 5 kg of isoflurane diisocyanate, 1 kg of polytetramethylene ether glycol as a polyether polyol, and 0.02 kg of catalyst (stannous octoate) are added to a reactor. The vacuum degree is controlled at -0.08 MPa, the temperature is raised to 75°C, and the reaction is carried out for 1 h. Then, 0.5 kg of hydroxyl-terminated polybutadiene, 0.4 kg of diethylene glycol, and 0.1 kg of 3-aminopropyltrihydroxysilane are added. The vacuum degree is controlled at -0.08 MPa, and the reaction is carried out at 75°C for another 30 min to obtain the isocyanate-terminated polyurethane prepolymer. The polytetramethylene ether glycol has a molecular weight of 2000 and a hydroxyl value of 54.7-57.5 mg KOH / g.

[0052] Preparation Examples 2-3

[0053] The difference between Preparation Example 2-3 and Preparation Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 1 below.

[0054] Table 1. Raw material amounts and preparation conditions for preparation examples 1-3

[0055]

[0056]

[0057] Preparation Example 4

[0058] The difference between Preparation Example 4 and Preparation Example 1 is that diethylene glycol is replaced with an equal amount of 1,4-butanediol, otherwise the same as Preparation Example 1.

[0059] Preparation Example 5

[0060] The difference between Preparation Example 5 and Preparation Example 1 is that 3-aminopropyltrihydroxysilane is replaced with vinyltrimethoxysilane in equal amounts, while the rest is the same as Preparation Example 1.

[0061] Preparation Example 6

[0062] The difference between Preparation Example 6 and Preparation Example 1 is that the hydroxyl-terminated polybutadiene is replaced with an equal amount of diethylene glycol, while the rest is the same as Preparation Example 1.

[0063] Preparation Example 7

[0064] The difference between Preparation Example 7 and Preparation Example 1 is that 3-aminopropyltrihydroxysilane is replaced with an equal amount of diethylene glycol, otherwise the same as Preparation Example 1.

[0065] Example

[0066] Example 1

[0067] Example 1 discloses a fast-curing polyurethane structural adhesive, which is prepared by the following steps:

[0068] 4 kg of commercially available isocyanate-terminated polyurethane prepolymer, 2.5 kg of thermally conductive filler (composed of alumina, boron nitride, and magnesium oxide in a weight ratio of 1:3:0.2), 0.6 kg of 3-isocyanate-propyltriethoxysilane as a stabilizer, 0.1 kg of molecular sieve as a dehydrating agent, and 0.1 kg of antioxidant (composed of antioxidant 1010 and antioxidant 168 in a weight ratio of 2:1) were heated to 55°C and the vacuum degree was controlled at -0.08 MPa. Component A was obtained after 60 minutes. Component B was obtained by mixing 1 kg of polycaprolactone diol as polycaprolactone polyol, 0.8 kg of polytetramethylene ether diol as polyether polyol, 1.5 kg of thermally conductive filler (composed of alumina, boron nitride, and magnesium oxide in a weight ratio of 1:3:0.2), 0.1 kg of dioctyl phthalate as dispersant, and 0.1 kg of catalyst (stannous octoate). The mixture was heated to 55°C, and the vacuum degree was controlled at -0.08 MPa. After 50 minutes, the mixture was prepared.

[0069] Among them, the isocyanate-terminated polyurethane prepolymer is a commercially available MDI-type polyurethane prepolymer with an isocyanate group content of 7-9%; the polycaprolactone diol has a molecular weight of 2000 and a hydroxyl value of 54-58 mg KOH / g; and the polytetramethylene ether diol has a molecular weight of 2000 and a hydroxyl value of 54.7-57.5 mg KOH / g.

[0070] Example 2-3

[0071] The difference between Examples 2-3 and Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 2 below.

[0072] Table 2. Raw material usage and preparation conditions for Examples 1-3

[0073]

[0074]

[0075] Examples 4-10

[0076] The difference between Examples 4-10 and Example 1 is that the sources of the isocyanate-terminated polyurethane prepolymers are different, as detailed in Table 3 below.

[0077] Table 3. Sources of isocyanate-terminated polyurethane prepolymers in Examples 4-10

[0078]

[0079]

[0080] Example 11

[0081] The difference between Example 11 and Example 4 is that the stabilizer is different. The stabilizer in Example 11 consists of trimethylolpropane trimethacrylate and 3-isocyanate-propyltriethoxysilane. The amount of trimethylolpropane trimethacrylate is 0.4 kg and the amount of 3-isocyanate-propyltriethoxysilane is 0.2 kg. Everything else is the same as in Example 4.

[0082] Example 12

[0083] The difference between Example 12 and Example 4 is that the stabilizer in Example 12 is composed of trimethylolpropane trimethacrylate and 3-isocyanate-propyltriethoxysilane. The amount of trimethylolpropane trimethacrylate is 0.2 kg and the amount of 3-isocyanate-propyltriethoxysilane is 0.4 kg. The rest is the same as in Example 4.

[0084] Comparative Example

[0085] Comparative Example 1

[0086] The difference between Comparative Example 1 and Example 1 is that the isocyanate-terminated polyurethane prepolymer was replaced with an equal amount of isoflurane diisocyanate, while the rest was the same as in Example 1.

[0087] Performance testing was conducted on the rapid-curing polyurethane structural adhesives prepared in Examples 1-12 and Comparative Example 1.

[0088] 1. Thermal conductivity test:

[0089] The thermal conductivity (unit: W / (m·K)) of the rapid curing polyurethane structural adhesive was tested according to the test method in ASTM D 5470, and the test results were recorded.

[0090] 2. Operation time detection:

[0091] Place the fast-curing polyurethane structural adhesive in a constant temperature room at 25℃ / 50%RH and mix for 10 minutes. After mixing evenly, use an extrusion gun to extrude a strip of adhesive with a width of 2cm and a thickness of 10mm. Start timing and lightly touch the adhesive strip with your finger. Stop timing when the adhesive strip no longer shows stringing. Record this as the workable time (unit: min), keeping one decimal place. Test and record the test results.

[0092] 3. Initial cured tensile shear strength test:

[0093] Referring to the test method in GB / T7124-2008 "Test Method for Tensile Shear Strength of Adhesives", the tensile shear strength (unit: MPa) of a fast-curing polyurethane structural adhesive at a curing temperature of 25℃ and a curing time of 40min was tested and the test results were recorded.

[0094] 4. Fully cured tensile shear strength test:

[0095] Referring to the test method in GB / T7124-2008 "Test Method for Tensile Shear Strength of Adhesives", the full tensile shear strength (unit: MPa) of the fast-curing polyurethane structural adhesive at a curing temperature of 25℃ and a curing time of 7 days was tested and the test results were recorded.

[0096] The following are the performance test data of the rapid-curing polyurethane structural adhesives of Examples 1-12 and Comparative Example 1 of this application, as detailed in Table 4 below.

[0097] Table 4 Performance test data of Examples 1-12 and Comparative Example 1

[0098]

[0099] Based on Examples 1-3 and Examples 4-10, Comparative Example 1, and Table 4, it can be concluded that the polyurethane structural adhesive prepared using the isocyanate-terminated polyurethane prepolymer obtained in this application has a high thermal conductivity, a moderate workability time, and a moderate initial tensile shear strength. It can quickly position the power battery pack and cure rapidly after heating. Compared with Examples 7-10, Example 4 shows an increase in thermal conductivity of 0.24 W / (m·K), an extension of workability time of 2.7 min, and an increase in initial cured tensile shear strength of 0.2 MPa. a) The fully cured tensile shear strength increased by 2.1 MPa, which indicates that the synergistic effect of the hydroxyl-terminated butadiene, diethylene glycol, and 3-aminopropyltrihydroxysilane in this application can significantly improve the thermal conductivity and curing rate of the prepared polyurethane structural adhesive, enabling rapid assembly and curing, thus improving the assembly efficiency of the product. In Comparative Example 1, replacing the isocyanate-terminated polyurethane prepolymer with an equal amount of isoflurane diisocyanate resulted in a polyurethane structural adhesive with a longer workability time and a significantly reduced initial cured tensile shear strength.

[0100] Based on Examples 1 and 4, Examples 11-12, and Table 4, it can be concluded that using the preferred ratio of trimethylolpropane trimethacrylate and 3-isocyanate-propyltriethoxysilane as stabilizers in this application can further enhance the synergistic effect with the isocyanate-terminated polyurethane prepolymer prepared in this application, thereby further improving the thermal conductivity and curing efficiency of the prepared polyurethane structural adhesive.

[0101] The polyurethane structural adhesive of this application can achieve a thermal conductivity of 0.1-3 W / (m·K) by adjusting the addition ratio of thermally conductive filler, with the amount of thermally conductive filler adjustable between 0-400 parts by weight. It has an operable time of 22-32 min at room temperature and can maintain stable bonding performance, with an initial bonding strength of over 0.7 MPa, which can stabilize and position the product. After complete curing, it can impart a tensile shear strength of 13.2 MPa to the product, providing good assembly stability and improving assembly efficiency.

[0102] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A fast-curing polyurethane structural adhesive, characterized in that, The product is composed of component A and component B. Component A consists of the following raw materials in parts by weight: 40-50 parts isocyanate-terminated polyurethane prepolymer, 0-400 parts thermally conductive filler, 6-10 parts stabilizer, 0.5-1.5 parts dehydrating agent, and 1-3 parts antioxidant. Component B consists of the following raw materials in parts by weight: 10-15 parts polycaprolactone polyol, 8-12 parts polyether polyol, 0-400 parts thermally conductive filler, 1-2 parts dispersant, and 0.1-2 parts catalyst. The isocyanate-terminated polyurethane prepolymer is obtained from the following raw materials in parts by weight: 50-60 parts of diisocyanate 10-20 parts of polyether polyol 5-8 parts of hydroxyl-terminated polybutadiene 4-6 parts of diethylene glycol 1-3 parts of 3-aminopropyltrihydroxysilane Catalyst 0.2-0.4 parts; The stabilizer is composed of trimethylolpropane trimethacrylate and 3-isocyanate-propyltriethoxysilane in a weight ratio of 1:(0.5-1.5).

2. The rapid-curing polyurethane structural adhesive according to claim 1, characterized in that, The isocyanate-terminated polyurethane prepolymer is prepared by the following steps: adding diisocyanate, polyether polyol and catalyst into a reaction device, reacting under vacuum, and then adding hydroxyl-terminated polybutadiene, diethylene glycol and 3-aminopropyltrihydroxysilane to react and obtain the isocyanate-terminated polyurethane prepolymer.

3. The rapid-curing polyurethane structural adhesive according to claim 1, characterized in that, Both component A and component B are thermally conductive fillers composed of aluminum oxide, boron nitride and magnesium oxide in a weight ratio of 1:(2-3):(0.2-0.4).

4. The rapid-curing polyurethane structural adhesive according to claim 1, characterized in that, The dispersant is composed of dibutyl itaconic acid and glyceryl cocoate in a weight ratio of (3-4):

1.

5. The rapid-curing polyurethane structural adhesive according to claim 1, characterized in that, The catalyst is one or a combination of organotin catalysts and organobismuth catalysts.

6. The rapid-curing polyurethane structural adhesive according to claim 1, characterized in that, The dehydrating agent is any one of molecular sieve and anhydrous calcium chloride, and the antioxidant is one or a combination of antioxidant 1010, antioxidant 168, antioxidant 1076 and antioxidant 1098.

7. The rapid-curing polyurethane structural adhesive according to claim 1, characterized in that, The ratio of component A to component B is (0.9-1.1):

1.

8. A method for preparing a rapid-curing polyurethane structural adhesive as described in any one of claims 1-7, characterized in that, Includes the following steps: Isocyanate-terminated polyurethane prepolymer, thermally conductive filler, stabilizer, dehydrating agent and antioxidant are heated and vacuum-mixed to obtain component A. Component B is prepared by heating and vacuum mixing polycaprolactone polyol, polyether polyol, thermally conductive filler, dispersant and catalyst to obtain component B.

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