Low-temperature fast-curing type two-component polyurethane structural adhesive and preparation method thereof

Abstract

The invention discloses a low-temperature fast-curing type two-component polyurethane structural adhesive and a preparation method thereof, and belongs to the field of adhesives. The structural adhesive comprises a component A and a component B which are cooperatively used according to the volume ratio of 1: 1, wherein the component A comprises the following raw materials in parts by weight: 65-75 parts of polyester glycol, 10-15 parts of polyether triol, 3-5 parts of polyether amine, 3-7 parts of bisphenol A polyoxyethylene ether, 4-5 parts of a molecular sieve and 0.1-0.5 part of a catalyst; and the component B comprises the following raw materials in parts by weight: 85-94 parts of a polyurethane prepolymer, 3-5 parts of an anti-aging agent and 3-5 parts of a dewatering agent. The low-temperature fast-curing type two-component polyurethane structural adhesive has the characteristics of fast curing at 0 DEG C, high bonding strength, vibration resistance and the like, is suitable for structural bonding of automotive trim, indoor decoration and the like in a low-temperature environment, and has excellent bonding performance on metal aluminum, composite materials, wood and the like.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, specifically relating to a low-temperature fast-curing two-component polyurethane structural adhesive and its preparation method. Background Technology

[0002] Polyurethane adhesives possess advantages such as high elasticity, high strength, and low VOC emissions, making them widely used in automotive and home interior bonding. The curing process of conventional polyurethane adhesives is affected by ambient temperature and humidity, especially during cold winter weather. Temperature significantly impacts the adhesive's performance. On one hand, low temperatures slow down the curing speed, significantly extending the construction period and reducing production efficiency. On the other hand, low temperatures reduce the substrate surface temperature, hindering adhesive wetting and affecting bond strength.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a low-temperature fast-curing two-component polyurethane structural adhesive and its preparation method, which can achieve rapid curing at low temperatures, with short surface drying and initial curing times, high bonding strength to various substrates, elastic interfacial bonding, high toughness at low temperatures, and resistance to vibration and impact. During the curing process, it can rapidly release heat, heating the substrate, improving the interfacial wetting ability of the adhesive, and enhancing the bonding strength, thus effectively solving the technical problem of slow curing of conventional polyurethane adhesives in low-temperature environments.

[0005] The objective of this invention is achieved through the following technical solution: A low-temperature, fast-curing two-component polyurethane structural adhesive includes component A and component B, which are mixed in a 1:1 volume ratio; wherein, Component A comprises the following components in parts by weight: Component A: 65-75 parts polyester diol, 10-15 parts polyether triol, 3-5 parts polyether amine, 3-7 parts bisphenol A polyoxyethylene ether, 4-5 parts molecular sieve, and 0.1-0.5 parts catalyst. Component B comprises the following components in parts by weight: Component B: 85-94 parts of polyurethane prepolymer, 3-5 parts of anti-aging agent, and 3-5 parts of dehydrating agent.

[0006] Preferably, in the above structural adhesive, the hydroxyl value of the polyester diol in component A is 160±20 mgKOH / g.

[0007] Preferably, in the above structural adhesive, the polyether triol in component A has a molecular weight of one or more of 400 and 700.

[0008] Preferably, in the above structural adhesive, the polyetheramine in component A is one of D230, D400, and T400.

[0009] Preferably, in the above structural adhesive, the hydroxyl value of bisphenol A polyoxyethylene ether in component A is 280±20 mgKOH / g; The molecular sieve has a particle size D50 of 10 μm.

[0010] Preferably, in the above-mentioned structural adhesive, the catalyst in component A is one or more of amine catalysts, organotin catalysts, and organobismuth catalysts.

[0011] Preferably, in the above structural adhesive, the polyurethane prepolymer in component B is an NCO-terminated polymer obtained by reacting modified castor oil polyol, polyether triol, and diisocyanate, and the isocyanate group content of the polyurethane prepolymer is 16% to 16.5%.

[0012] Preferably, in the above structural adhesive, the anti-aging agent in component B is TH-1135; The dehydrating agent is p-methylbenzenesulfonyl isocyanate.

[0013] A method for preparing the low-temperature fast-curing two-component polyurethane structural adhesive of the present invention, comprising the following steps, using the raw materials according to the formulation of the present invention: Prepare component A and component B separately. Preparation of Component A: Polyester diol, polyether triol, polyether amine, bisphenol A polyoxyethylene ether, molecular sieve and catalyst from the raw materials of Component A are put into a stirred tank and stirred under vacuum for 30 min. The mixing temperature is ≤50℃ and the vacuum degree is 0.08~0.09MPa to obtain Component A. To prepare component B, the polyurethane prepolymer, anti-aging agent, and dehydrating agent from the raw materials of component B are added to another mixing vessel and stirred under vacuum for 30 minutes. The mixing temperature is ≤50℃ and the vacuum degree is 0.08~0.09MPa to obtain component B. Preparation of structural adhesive: Mix the above-prepared component A and component B in a volume ratio of 1:1 to obtain a low-temperature fast-curing two-component polyurethane structural adhesive.

[0014] Preferably, the polyurethane prepolymer used in the preparation step of component B of the above method is prepared in the following manner, including: By weight percentage, 23.6 parts of modified castor oil polyol and 9.1 parts of polyether triol were added to a container, and the mixture was stirred under vacuum to remove water. The temperature was 120-130℃, the vacuum degree was 0.08-0.09MPa, and the reaction time was 1.5-2h. The temperature was then lowered to 40-50℃, and the water content was measured to be ≤500ppm. 67.3 parts of diisocyanate were added, and the mixture was stirred at room temperature for 15min. The temperature was then raised to 80℃ and reacted for 2h. The NCO value was measured to be 16%-16.5%. The mixture was then cooled to room temperature to obtain the isocyanate prepolymer.

[0015] Compared with the prior art, the low-temperature fast-curing two-component polyurethane structural adhesive and its preparation method provided by the present invention have the following advantages: 1) This low-temperature fast-curing two-component polyurethane structural adhesive has the advantage of rapid curing at low temperatures compared with traditional polyurethane structural adhesives. At 0℃, the surface drying time is 1-3 minutes and the initial curing time is maintained at 5-10 minutes.

[0016] 2) This low-temperature, fast-curing two-component polyurethane structural adhesive incorporates polyetheramine into the system. On one hand, the rapid reaction between isocyanate and amino groups enhances the initial tack of the adhesive. On the other hand, the polyurea reaction releases heat, and by controlling the type and content of polyetheramine, the substrate temperature can be heated to 40–60°C at an ambient temperature of 0°C. This accelerates the reaction of other polyols and isocyanates while promoting the wetting of the adhesive into the substrate, thereby improving adhesion.

[0017] 3) In component B of this low-temperature fast-curing two-component polyurethane structural adhesive, the polyurethane prepolymer used employs two blocks: bio-based modified castor oil polyol and polyether polyol. Compared with traditional polyurethane prepolymers prepared using polyether polyol, modified castor oil polyol has stronger rigidity and hydrophobicity, which can prevent moisture penetration, resulting in adhesives with superior bonding strength and resistance to humid heat aging.

[0018] 4) This low-temperature fast-curing two-component polyurethane structural adhesive has high bonding strength to metal aluminum, composite substrates, wood and other materials, elastic bonding at the interface, high toughness at low temperatures, and resistance to vibration and impact.

[0019] 5) This low-temperature fast-curing two-component polyurethane structural adhesive rapidly releases heat during the curing process, heating the substrate, improving the adhesive's interfacial wetting ability, and enhancing the bonding strength. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the specific content of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, which do not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0021] First, the following explanations are provided for the terms that may be used in this article: The term "and / or" means that either or both can be achieved simultaneously. For example, X and / or Y means that it includes both "X" or "Y" as well as the three cases of "X and Y".

[0022] The terms "comprising," "including," "containing," "having," or other similar semantic descriptions should be interpreted as non-exclusive inclusion. For example, including a technical feature element (such as raw material, component, ingredient, carrier, dosage form, material, size, part, component, mechanism, device, step, process, method, reaction conditions, processing conditions, parameter, algorithm, signal, data, product or article of manufacture, etc.) should be interpreted as including not only the expressly listed technical feature element, but also other technical feature elements that are not expressly listed and are well-known in the art.

[0023] The term "composed of" excludes any technical features not expressly listed. When used in a claim, it closes the claim to exclude all technical features other than those expressly listed, except for associated conventional impurities. If the term appears only in a clause of a claim, it limits the claim to the elements expressly listed in that clause; elements recited in other clauses are not excluded from the overall claim.

[0024] The term "parts by mass" indicates the mass ratio between multiple components. For example, if component X is described as x parts by mass and component Y as y parts by mass, then the mass ratio of component X to component Y is x:y. One part by mass can represent any mass; for example, one part by mass can be expressed as 1 kg or 3.1415926 kg, etc. The sum of the parts by mass of all components is not necessarily 100 parts; it can be greater than 100 parts, less than 100 parts, or equal to 100 parts. Unless otherwise stated, parts, proportions, and percentages mentioned herein are all measured by mass.

[0025] When concentration, temperature, pressure, size, or other parameters are expressed as numerical ranges, such ranges should be understood to specifically disclose all ranges formed by any pairing of upper limits, lower limits, or preferred values ​​within that range, regardless of whether the range is explicitly stated; for example, if the numerical range "2 to 8" is stated, then that range should be interpreted to include ranges such as "2 to 7", "2 to 6", "5 to 7", "3 to 4 and 6 to 7", "3 to 5 and 7", "2 and 5 to 7", etc. Unless otherwise stated, the numerical ranges described herein include both their endpoints and all integers and fractions within that range.

[0026] The solution provided by this invention will be described in detail below. Contents not described in detail in the embodiments of this invention are prior art known to those skilled in the art. Where specific conditions are not specified in the embodiments of this invention, they shall be performed according to conventional conditions in the art or conditions recommended by the manufacturer. Reagents or instruments used in the embodiments of this invention whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0027] This invention provides a low-temperature, fast-curing two-component polyurethane structural adhesive, comprising the following components in parts by weight: (1) Component A: 65-75 parts polyester diol, 10-15 parts polyether triol, 3-5 parts polyether amine, 3-7 parts bisphenol A polyoxyethylene ether, 4-5 parts molecular sieve, 0.1-0.5 parts catalyst. (2) Component B: 85-94 parts of polyurethane prepolymer, 3-5 parts of anti-aging agent, and 3-5 parts of dehydrating agent; When using, component A and component B are mixed and reacted in a 1:1 volume ratio.

[0028] In some specific embodiments, the hydroxyl value of the polyester diol in component A of the above-mentioned structural adhesive is in the range of 160±20mgKOH / g.

[0029] In some specific embodiments, the polyether triol in component A of the above-mentioned structural adhesive has a molecular weight of one or more of 400 and 700.

[0030] In some specific embodiments, the polyetheramine in component A of the above-mentioned structural adhesive is one of D230, D400, and T400.

[0031] In some specific embodiments, the hydroxyl value of the bisphenol A polyoxyethylene ether in component A of the above-mentioned structural adhesive is 280±20 mgKOH / g;

[0032] In some specific embodiments, the molecular sieve particle size D50 in component A of the above-mentioned structural adhesive is 10 μm.

[0033] In some specific embodiments, the catalyst in component A of the above-mentioned structural adhesive is one or more of amine catalysts, organotin catalysts, and organobismuth catalysts.

[0034] In some specific embodiments, the polyurethane prepolymer in component B of the above-mentioned structural adhesive is an NCO-terminated polymer obtained by reacting modified castor oil polyol, polyether triol, and diisocyanate. The isocyanate group content of this polyurethane prepolymer is 16% to 16.5%.

[0035] In some specific embodiments, the anti-aging agent in component B of the above-mentioned structural adhesive is TH-1135.

[0036] In some specific embodiments, the dehydrating agent in component B of the above-mentioned structural adhesive is p-toluenesulfonyl isocyanate.

[0037] This invention also provides a method for preparing a low-temperature fast-curing two-component polyurethane structure, comprising the following steps: D1. Preparation of Component A: Add 65-75 parts of polyester diol, 10-15 parts of polyether triol, 3-5 parts of polyether amine, 3-7 parts of bisphenol A polyoxyethylene ether, 4-5 parts of molecular sieve, and 0.1-0.5 parts of catalyst into a stirred tank and stir under vacuum for 30 minutes. The mixing temperature is ≤50℃ and the vacuum degree is 0.08-0.09MPa to obtain Component A. D2. Preparation of polyurethane prepolymer: According to weight percentage, the modified castor oil polyol and polyether triol are added to a flask, and the mixture is stirred under vacuum to remove water. The temperature is 120-130℃, the vacuum degree is 0.08-0.09MPa, and the time is 1.5-2h. The temperature is then lowered to 40-50℃, and the water content is measured to be ≤500ppm. Diisocyanate is added, and the mixture is stirred at room temperature for 15min. Then the temperature is raised to 80℃ and reacted for 2h. The NCO value is measured to be 16%-16.5%. The mixture is then cooled to room temperature to obtain the isocyanate prepolymer. D3. Preparation of component B: Add 85-94 parts of polyurethane prepolymer, 3-5 parts of anti-aging agent, and 3-5 parts of dehydrating agent to a mixing tank and stir under vacuum for 30 minutes. The mixing temperature is ≤50℃ and the vacuum degree is 0.08-0.09MPa to obtain component B.

[0038] To more clearly demonstrate the technical solution and its effects provided by the present invention, the following detailed description of the low-temperature fast-curing two-component polyurethane structural adhesive provided by the present invention is based on specific embodiments.

[0039] Example 1 This embodiment provides a low-temperature, fast-curing, two-component polyurethane structural adhesive, the preparation method of which is as follows: (1) First, prepare the polyurethane prepolymer: Weigh 236g of modified castor oil polyol with a hydroxyl value of 170±10mgKOH / g and 91g of polyether diol with a molecular weight of 2000 into an open reactor by weight percentage. Heat to 120-130℃ and remove water under vacuum for 1.5-2h. Then cool to 40-50℃, add 673g of diisocyanate, heat to 80℃ under nitrogen atmosphere, and react for 2-2.5h. The NCO value is measured to be 16%-16.5%. Add 3g of dehydrating agent, stir for 3min, and then cool to room temperature to obtain the polyurethane prepolymer.

[0040] (2) Preparation of two-component polyurethane adhesive: Preparation of Component A: Take 70g of polyester diol with a molecular weight of 153±20mgKOH / g, 13g of polyether triol with a molecular weight of 400, 5g of bisphenol A polyoxyethylene ether with a molecular weight of 280±20mgKOH / g, 4g of polyether diamine with a molecular weight of 230, 4g of molecular sieve, and 0.25g of organic bismuth catalyst. Use a homogenizer or fast mixer with a speed of 1200rpm, a vacuum of 0.08~0.09MPa, and a mixing time of 2min to obtain Component A. Step B component: Take 92g of the polyurethane prepolymer, 4g of anti-aging agent and 4g of dehydrating agent prepared above, and use a homogenizer fast mixer with a speed set at 1200rpm, a vacuum degree of 0.08~0.09MPa and a mixing time of 2min to obtain component B.

[0041] In use, components A and B are mixed in a 1:1 volume ratio to obtain the low-temperature fast-curing two-component polyurethane structural adhesive of this embodiment.

[0042] Example 2 This embodiment provides a low-temperature, fast-curing, two-component polyurethane structural adhesive, the preparation method of which is as follows: (1) Prepare polyurethane prepolymer, as in Example 1.

[0043] (2) Preparation of two-component polyurethane adhesive: Preparation of Component A: Take 70g of polyester diol with a molecular weight of 153±20mgKOH / g, 13g of polyether triol with a molecular weight of 400, 5g of bisphenol A polyoxyethylene ether with a molecular weight of 280±20mgKOH / g, 4g of polyether diamine with a molecular weight of 230, 4g of molecular sieve, and 0.2g of organic bismuth catalyst. Use a homogenizer or fast mixer with a speed of 1200rpm, a vacuum of 0.08~0.09MPa, and a mixing time of 2min to obtain Component A.

[0044] Preparation of component B: Take 94g of the polyurethane prepolymer, 3g of anti-aging agent and 3g of dehydrating agent obtained above, and use a homogenizer to mix them at a speed of 1200rpm, a vacuum of 0.08~0.09MPa and a mixing time of 2min to obtain component B.

[0045] When using, components A and B are mixed in a 1:1 volume ratio to obtain the low-temperature fast-curing two-component polyurethane structural adhesive of this embodiment.

[0046] Example 3 This embodiment provides a low-temperature, fast-curing, two-component polyurethane structural adhesive, the preparation method of which is as follows: (1) Prepare polyurethane prepolymer, as in Example 1.

[0047] (2) Preparation of two-component polyurethane adhesive: Preparation of Component A: Take 70g of polyester diol with a molecular weight of 153±20mgKOH / g, 13g of polyether triol with a molecular weight of 400, 5g of bisphenol A polyoxyethylene ether with a molecular weight of 280±20mgKOH / g, 4g of polyether diamine with a molecular weight of 230, 4g of molecular sieve, and 0.3g of organic bismuth catalyst. Use a homogenizer or fast mixer with a speed of 1200rpm, a vacuum of 0.08~0.09MPa, and a mixing time of 2min to obtain Component A.

[0048] Preparation of component B: Take 90g of the polyurethane prepolymer, 5g of anti-aging agent, and 5g of dehydrating agent obtained above, and use a homogenizer or fast mixer with a speed setting of 1200rpm, a vacuum degree of 0.08~0.09MPa, and a mixing time of 2min to obtain component B.

[0049] In use, components A and B are mixed in a 1:1 volume ratio to obtain the low-temperature fast-curing two-component polyurethane structural adhesive of this embodiment.

[0050] Comparative Example 1 This comparative example provides a two-component polyurethane structural adhesive, the preparation method of which is as follows: (1) Prepare polyurethane prepolymer, as in Example 1.

[0051] (2) Preparation of two-component polyurethane adhesive: Preparation of Component A: Take 70g of polyester diol with a molecular weight of 153±20mgKOH / g, 13g of polyether triol with a molecular weight of 400, 5g of bisphenol A polyoxyethylene ether with a molecular weight of 280±20mgKOH / g, 4g of polyether diamine with a molecular weight of 230, 4g of molecular sieve, and 0.5g of organotin catalyst. Use a homogenizer or fast mixer with a speed of 1200rpm, a vacuum of 0.08-0.09MPa, and a mixing time of 2min to obtain Component A.

[0052] Preparation of component B: Take 92 parts of the polyurethane prepolymer, 4 parts of the anti-aging agent, and 4 parts of the dehydrating agent obtained above, and use a homogenizer to mix them at a speed of 1200 rpm, a vacuum of 0.08-0.09 MPa, and a mixing time of 2 min to obtain component B.

[0053] When using, components A and B are mixed in a 1:1 volume ratio to obtain the two-component polyurethane structural adhesive of this comparative example.

[0054] Comparative Example 2 This comparative example provides a two-component polyurethane structural adhesive, the preparation method of which is as follows: (1) Prepare polyurethane prepolymer, as in Example 1.

[0055] (2) Preparation of two-component polyurethane adhesive D1, Component A: Take 70g of polyester diol with a molecular weight of 153±20mgKOH / g, 13g of polyether triol with a molecular weight of 400, 5g of bisphenol A polyoxyethylene ether with a molecular weight of 280±20mgKOH / g, 4g of polyether triamine with a molecular weight of 400, 4g of molecular sieve, and 0.25g of organic bismuth catalyst. Use a homogenizer or fast mixer with a speed set at 1200rpm, a vacuum degree of 0.08-0.09MPa, and a mixing time of 2min to obtain component A.

[0056] D2, Component B: Take 92 parts of polyurethane prepolymer, 4 parts of anti-aging agent, and 4 parts of dehydrating agent, and use a homogenizer / fast mixer with a speed setting of 1200 rpm, a vacuum degree of 0.08-0.09 MPa, and a mixing time of 2 min to obtain component B.

[0057] When using, components A and B are mixed in a 1:1 volume ratio to obtain the two-component polyurethane structural adhesive of this comparative example.

[0058] Comparative Example 3 This comparative example provides a two-component polyurethane structural adhesive, the preparation method of which is as follows: (1) Preparation of polyurethane prepolymer: Preparation of polyurethane prepolymer B: Weigh 380g of polyether diol with a molecular weight of 2000 (hydroxyl value) into an open reactor, heat to 120-130℃ and remove water under vacuum for 1.5-2h. Then cool to 40-50℃, add 620g of diisocyanate, heat to 80℃ under nitrogen atmosphere, react for 2-2.5h, and measure the NCO value to be 16.3%-16.7%. Add 3g of dehydrating agent, stir for 3min and then cool to room temperature to obtain polyurethane prepolymer B.

[0059] (2) Preparation of two-component polyurethane adhesive: Preparation of Component A: Take 70g of polyester diol with a molecular weight of 153±20mgKOH / g, 13g of polyether triol with a molecular weight of 400, 5g of bisphenol A polyoxyethylene ether with a molecular weight of 280±20mgKOH / g, 4g of polyether diamine with a molecular weight of 230, 4g of molecular sieve, and 0.25g of organic bismuth catalyst. Use a homogenizer or fast mixer with a speed of 1200rpm, a vacuum of 0.08-0.09MPa, and a mixing time of 2min to obtain Component A.

[0060] Preparation of component B: Take 92 parts of polyurethane prepolymer B, 4 parts of anti-aging agent, and 4 parts of dehydrating agent, and use a homogenizer or fast mixer with a speed setting of 1200 rpm, a vacuum degree of 0.08-0.09 MPa, and a mixing time of 2 min to obtain component B.

[0061] When using, components A and B are mixed in a 1:1 volume ratio to obtain the two-component polyurethane structural adhesive of this comparative example.

[0062] It is understood that Comparative Examples 1-3 were designed to demonstrate the influence of certain raw materials on the performance of the final structural adhesive and do not belong to existing technology.

[0063] test: The polyurethane structural adhesives obtained from the above embodiments and comparative examples were subjected to the following performance tests, and the results are shown in Table 1.

[0064] (1) Surface drying time test The surface drying time test should be performed according to GB / T 13477.5-2002. The test environment temperature is 0℃, and the adhesive must be stored at 0℃ for more than 12 hours before the test.

[0065] (2) Shear strength test Shear strength is referenced to GB / T 7124-2008; the substrate is 6061 aluminum, and the curing conditions are 25℃ for 7 days.

[0066] (3) Curing speed test Test method: Test the shear strength after curing at 0℃ for 40 min.

[0067] (4) Exothermic temperature test Test method: Use a temperature gun to test the temperature change of the adhesive at 0℃ and record the highest value.

[0068] Table 1 compares the test data of each embodiment with those of each comparative example. ; As shown in Table 1, Comparative Example 1 did not use a suitable organic bismuth catalyst, resulting in slow curing speed and difficulty in bonding at low temperatures; Comparative Example 2 did not use a polyetheramine with a suitable molecular weight, resulting in slow curing speed and slow strength development at low temperatures; Comparative Example 3 did not use a polyurethane prepolymer prepared with modified castor oil polyol, resulting in low final cured strength. In summary, the low-temperature fast-curing two-component polyurethane structural adhesive and its preparation method of the present invention have advantages such as rapid curing and fast strength development at low temperatures compared with existing two-component polyurethane structural adhesives.

[0069] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A low-temperature, fast-curing, two-component polyurethane structural adhesive, characterized in that, It includes component A and component B, which are used in a 1:1 volume ratio; among which, Component A comprises the following components in parts by weight: Component A: 65-75 parts polyester diol, 10-15 parts polyether triol, 3-5 parts polyether amine, 3-7 parts bisphenol A polyoxyethylene ether, 4-5 parts molecular sieve, and 0.1-0.5 parts catalyst. Component B comprises the following components in parts by weight: Component B: 85-94 parts of polyurethane prepolymer, 3-5 parts of anti-aging agent, and 3-5 parts of dehydrating agent.

2. The low-temperature fast-curing two-component polyurethane structural adhesive according to claim 1, characterized in that, The hydroxyl value of the polyester diol in component A is 160±20 mgKOH / g.

3. The low-temperature fast-curing two-component polyurethane structural adhesive according to claim 1, characterized in that, The polyether triol in component A has a molecular weight of one or more of 400 and 700.

4. The low-temperature fast-curing two-component polyurethane structural adhesive according to claim 1, characterized in that, The polyetheramine in component A is one of D230, D400, and T400.

5. The low-temperature fast-curing two-component polyurethane structural adhesive according to claim 1, characterized in that, The hydroxyl value of bisphenol A polyoxyethylene ether in component A is 280±20 mgKOH / g; The molecular sieve has a particle size D50 of 10 μm.

6. The low-temperature fast-curing two-component polyurethane structural adhesive according to claim 1, characterized in that, The catalyst in component A is one or more of amine catalysts, organotin catalysts, and organobismuth catalysts.

7. The low-temperature fast-curing two-component polyurethane structural adhesive according to claim 1, characterized in that, The polyurethane prepolymer in component B is an NCO-terminated polymer obtained by reacting modified castor oil polyol, polyether triol, and diisocyanate. The isocyanate group content of the polyurethane prepolymer is 16% to 16.5%.

8. The low-temperature fast-curing two-component polyurethane structural adhesive according to claim 1, characterized in that, The anti-aging agent in component B is TH-1135; The dehydrating agent is p-methylbenzenesulfonyl isocyanate.

9. A method for preparing the low-temperature fast-curing two-component polyurethane structural adhesive according to any one of claims 1-8, characterized in that, The raw materials are prepared according to the formulation of any one of claims 1-8, comprising the following steps: Prepare component A and component B separately. Preparation of Component A: Polyester diol, polyether triol, polyether amine, bisphenol A polyoxyethylene ether, molecular sieve and catalyst from the raw materials of Component A are put into a stirred tank and stirred under vacuum for 30 min. The mixing temperature is ≤50℃ and the vacuum degree is 0.08~0.09MPa to obtain Component A. To prepare component B, the polyurethane prepolymer, anti-aging agent, and dehydrating agent from the raw materials of component B are added to another mixing vessel and stirred under vacuum for 30 minutes. The mixing temperature is ≤50℃ and the vacuum degree is 0.08~0.09MPa to obtain component B. Preparation of structural adhesive: Mix the above-prepared component A and component B in a volume ratio of 1:1 to obtain a low-temperature fast-curing two-component polyurethane structural adhesive.

10. The preparation method of the low-temperature fast-curing two-component polyurethane structural adhesive according to claim 9, characterized in that, The polyurethane prepolymer used in the preparation of component B of the method is prepared in the following manner, including: By weight, 23.6 parts of modified castor oil polyol and 9.1 parts of polyether triol were added to a container, and the mixture was stirred under vacuum to remove water. The temperature was 120-130℃, the vacuum degree was 0.08-0.09MPa, and the reaction time was 1.5-2h. The temperature was then lowered to 40-50℃, and the water content was measured to be ≤500ppm. 67.3 parts of diisocyanate were added, and the mixture was stirred at room temperature for 15min. The temperature was then raised to 80℃ and reacted for 2h. The NCO value was measured to be 16%-16.5%. The mixture was then cooled to room temperature to obtain the isocyanate prepolymer.