Wide-temperature-range epoxy structural adhesive for automobile manufacturing and preparation method of wide-temperature-range epoxy structural adhesive

Abstract

The invention relates to the technical field of adhesives, in particular to a wide-temperature-range epoxy structural adhesive for automobile manufacturing and a preparation method of the wide-temperature-range epoxy structural adhesive. The invention discloses an epoxy structural adhesive with a wide temperature range for automobile manufacturing. Comprising the following components in parts by weight: 4 to 10 parts of solid bisphenol A epoxy resin, 30 to 50 parts of liquid bisphenol A epoxy resin, 0.1 to 3 parts of bifunctional epoxy reactive diluent, 10 to 20 parts of elastomer modified epoxy resin, 1 to 5 parts of CTBN modified epoxy resin, 1 to 5 parts of block polyurethane, 5 to 25 parts of imidazole latent curing agent, 0.1 to 10 parts of deformable filler and 5 to 22.8 parts of thixotropic filler. The epoxy structural adhesive with the wide temperature range for automobile manufacturing has the characteristics of high strength and 100% cohesive failure at the same time within the temperature range of-40 DEG C to 80 DEG C, and is good in impact resistance, high in toughness, good in storage stability, adjustable in curing temperature, good in thermal stability and good in thermal stability. The technical problems that an existing epoxy structural adhesive is insufficient in toughness, poor in impact resistance, poor in storage stability and limited in use temperature range are solved.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to an epoxy structural adhesive with a wide temperature range for automobile manufacturing and a preparation method thereof. Background Art

[0002] Structural adhesives for automobile manufacturing are suitable for parts that require high-strength bonding and sealing, such as automobile bodies, engines, chassis, etc. They can reduce body welds, improve appearance, increase body strength, reduce vibration, and effectively reduce the weight of the vehicle and improve the overall performance of the vehicle. Cars are driven under different climatic conditions, and structural adhesives are required to be able to adapt to temperature changes and maintain good performance in both high-temperature engine compartments and low-temperature outdoor environments. Existing structural adhesives for automobiles are mainly epoxy resin structural adhesives. Existing epoxy resin structural adhesives still have the disadvantages of insufficient toughness, poor impact resistance, poor storage stability, and a limited temperature range of use, which limits the use of epoxy resin structural adhesives. Summary of the invention

[0003] In response to the problems raised by the background technology, the purpose of the present invention is to propose an epoxy structural adhesive with a wide temperature range for automobile manufacturing, which can have the characteristics of high strength and 100% cohesive failure in the temperature range of -40°C to 80°C, good impact resistance, high toughness, good storage stability, and adjustable curing temperature, thereby solving the technical problems of existing epoxy structural adhesives such as insufficient toughness, poor impact resistance, poor storage stability and limited temperature range of use.

[0004] Another object of the present invention is to provide a method for preparing the above-mentioned epoxy structural adhesive with a wide temperature range for automobile manufacturing.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] The invention discloses an epoxy structural adhesive with a wide temperature range for automobile manufacturing, which comprises the following components, calculated by weight: 4 to 10 parts of solid bisphenol A epoxy resin, 30 to 50 parts of liquid bisphenol A epoxy resin, 0.1 to 3 parts of bifunctional epoxy reactive diluent, 10 to 20 parts of elastomer modified epoxy resin, 1 to 5 parts of CTBN modified epoxy resin, 1 to 5 parts of segmented polyurethane, 5 to 25 parts of imidazole latent curing agent, 0.1 to 10 parts of deformable filler and 5 to 22.8 parts of thixotropic filler.

[0007] Preferably, the solid bisphenol A epoxy resin is a combination of any one or more of solid bisphenol A epoxy resin E-20 and solid bisphenol A epoxy resin E-12;

[0008] The liquid bisphenol A epoxy resin is any one or more combinations of liquid bisphenol A epoxy resin E-51 and liquid bisphenol A epoxy resin E-44.

[0009] Preferably, the elastomer-modified epoxy resin is a combination of any one or more of polyurethane-modified epoxy resin, silicone-modified epoxy resin and dimer acid-modified epoxy resin;

[0010] The segmented polyurethane is a QR-9466 segmented polyurethane.

[0011] Preferably, the deformable filler is any one or more combinations of hollow glass microspheres, floating beads and expandable graphite.

[0012] Preferably, the thixotropic filler is any one or more combinations of fumed silica, organic bentonite and active nano-calcium carbonate.

[0013] Preferably, the imidazole latent curing agent is a microcapsule-encapsulated imidazole curing agent.

[0014] Preferably, the bifunctional epoxy reactive diluent is any one or more combinations of ethylene glycol diglycidyl ether, hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

[0015] A method for preparing an epoxy structural adhesive with a wide temperature range for automobile manufacturing, which is used to prepare the epoxy structural adhesive with a wide temperature range for automobile manufacturing, comprises the following steps:

[0016] Step S1, heating and melting solid bisphenol A epoxy resin, adding liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent in sequence, and stirring to obtain an epoxy mixture;

[0017] Step S2, after the reaction temperature is lowered, add the elastomer-modified epoxy resin, the CTBN-modified epoxy resin, the segmented polyurethane, the deformable filler and the thixotropic filler in sequence, and continue stirring;

[0018] Step S3: adding an imidazole latent curing agent and stirring to obtain an epoxy structural adhesive with a wide temperature range for automobile manufacturing.

[0019] Preferably, in step S1, the solid bisphenol A epoxy resin is heated and melted at 70 to 90° C.;

[0020] In the step S2, the heating is stopped, and after the reaction temperature drops by 40 to 60° C., the elastomer-modified epoxy resin, the CTBN-modified epoxy resin, the segmented polyurethane, the deformable filler and the thixotropic filler are added in sequence;

[0021] In the step S3, an imidazole latent curing agent is added at a temperature below 40°C.

[0022] Preferably, the step S2 sequentially adds the elastomer-modified epoxy resin, the CTBN-modified epoxy resin, the segmented polyurethane, the deformable filler and the thixotropic filler, and after continuing to stir, further comprises the step of high-speed dispersion: increasing the rotation speed and performing high-speed dispersion;

[0023] After the step S3 of adding the imidazole latent curing agent, the method further comprises the step S4 of starting the vacuum pump to stir and remove bubbles.

[0024] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0025] 1. By using solid bisphenol A epoxy resin and liquid bisphenol A epoxy resin as the main resin, solid bisphenol A epoxy resin has a higher molecular weight, good adhesion, high heat deformation temperature, and good high and low temperature resistance; liquid bisphenol A epoxy resin has a moderate molecular weight, good toughness, and convenient construction. The combination of solid bisphenol A epoxy resin and liquid bisphenol A epoxy resin combines the advantages of good high and low temperature performance of solid bisphenol A epoxy resin and good toughness and good construction of liquid bisphenol A epoxy resin, broadens the application field of single epoxy resin, realizes performance complementarity, and makes the epoxy structural adhesive with a wide temperature range for automobile manufacturing obtain more excellent performance;

[0026] 2. By adding elastomer-modified epoxy resin as a toughening agent and using it together with segmented polyurethane, the two are used synergistically so that the cured product forms an epoxy resin-elastomer-polyurethane interpenetrating polymer network or island structure, which can greatly improve the toughness of the material and enhance the adhesion of the adhesive layer;

[0027] 3. The adhesion of structural adhesive to different substrates is further improved by using CTBN modified epoxy resin. The active groups such as carboxyl in the molecular structure of CTBN can react chemically with epoxy resin to form a strong chemical bond, thus enhancing the bonding strength of epoxy structural adhesive to various substrates.

[0028] 4. Use imidazole latent curing agent. Imidazole-cured epoxy structural adhesive has good adhesion. The disadvantage is that imidazole easily reacts with oxygen and moisture in the air, causing the curing agent to fail. Imidazole latent curing agent can form a physical barrier between the imidazole curing agent and the outside world, effectively isolating the air, moisture and active ingredients of epoxy resin to prevent reactions, which can effectively improve the storage stability of epoxy structural adhesive. Due to the good storage stability, a large amount of imidazole latent curing agent can be added to the system. The curing speed can be accurately adjusted by using different amounts of imidazole latent curing agent to meet the needs of different baking temperatures. Imidazole latent curing agent can achieve different curing conditions according to the different addition amounts. The curing temperature can be reduced from the lowest 160°C of existing structural adhesives to 120°C to 160°C and can be freely adjusted;

[0029] 5. The cohesive force of the structural adhesive is controlled by using a deformable filler. When the structural adhesive is impacted or stretched by an external force, the deformable filler can absorb energy by its own deformation to prevent the rapid expansion of cracks. By adding the above-mentioned deformable filler in parts by weight, the cohesive strength and adhesive force of the structural adhesive can be balanced, so that the structural adhesive can have the characteristics of high strength and 100% cohesive failure (100% CF) in the temperature range of -40°C to 80°C. DETAILED DESCRIPTION

[0030] The invention discloses an epoxy structural adhesive with a wide temperature range for automobile manufacturing, which comprises the following components, calculated by weight: 4 to 10 parts of solid bisphenol A epoxy resin, 30 to 50 parts of liquid bisphenol A epoxy resin, 0.1 to 3 parts of bifunctional epoxy reactive diluent, 10 to 20 parts of elastomer modified epoxy resin, 1 to 5 parts of CTBN modified epoxy resin, 1 to 5 parts of segmented polyurethane, 5 to 25 parts of imidazole latent curing agent, 0.1 to 10 parts of deformable filler and 5 to 22.8 parts of thixotropic filler.

[0031] The epoxy structural adhesive with a wide temperature range for automobile manufacturing of the present invention has the following characteristics:

[0032] 1. By using solid bisphenol A epoxy resin and liquid bisphenol A epoxy resin as the main resin, solid bisphenol A epoxy resin has a higher molecular weight, good adhesion, high heat deformation temperature, and good high and low temperature resistance; liquid bisphenol A epoxy resin has a moderate molecular weight, good toughness, and convenient construction. The combination of solid bisphenol A epoxy resin and liquid bisphenol A epoxy resin combines the advantages of good high and low temperature performance of solid bisphenol A epoxy resin and good toughness and good construction of liquid bisphenol A epoxy resin, broadens the application field of single epoxy resin, realizes performance complementarity, and makes the epoxy structural adhesive with a wide temperature range for automobile manufacturing obtain more excellent performance;

[0033] 2. By adding elastomer-modified epoxy resin as a toughening agent and using it together with segmented polyurethane, the two are used synergistically so that the cured product forms an epoxy resin-elastomer-polyurethane interpenetrating polymer network or island structure, which can greatly improve the toughness of the material and enhance the adhesion of the adhesive layer;

[0034] 3. The adhesion of structural adhesive to different substrates is further improved by using CTBN modified epoxy resin. The active groups such as carboxyl in the molecular structure of CTBN can react chemically with epoxy resin to form a strong chemical bond, thus enhancing the bonding strength of epoxy structural adhesive to various substrates.

[0035] 4. Use imidazole latent curing agent. Imidazole-cured epoxy structural adhesive has good adhesion. The disadvantage is that imidazole easily reacts with oxygen and moisture in the air, causing the curing agent to fail. Imidazole latent curing agent can form a physical barrier between the imidazole curing agent and the outside world, effectively isolating the air, moisture and active ingredients of epoxy resin to prevent reactions, which can effectively improve the storage stability of epoxy structural adhesive. Due to the good storage stability, a large amount of imidazole latent curing agent can be added to the system. The curing speed can be accurately adjusted by using different amounts of imidazole latent curing agent to meet the needs of different baking temperatures. Imidazole latent curing agent can achieve different curing conditions according to the different addition amounts. The curing temperature can be reduced from the lowest 160°C of existing structural adhesives to 120°C to 160°C and can be freely adjusted;

[0036] 5. The cohesive force of the structural adhesive is controlled by using a deformable filler. When the structural adhesive is impacted or stretched by an external force, the deformable filler can absorb energy by its own deformation to prevent the rapid expansion of cracks. By adding the above-mentioned deformable filler in parts by weight, the cohesive strength and adhesive force of the structural adhesive can be balanced, so that the structural adhesive can have the characteristics of high strength and 100% cohesive failure (100% CF) in the temperature range of -40°C to 80°C. If the amount of deformable filler added is too high, it is easy to reduce the mechanical properties of the structural adhesive and reduce the strength.

[0037] The epoxy structural adhesive with a wide temperature range for automobile manufacturing is prepared by using solid bisphenol A epoxy resin and liquid bisphenol A epoxy resin as the main resin, adding a bifunctional epoxy reactive diluent, an elastomer-modified epoxy resin, a CTBN-modified epoxy resin and a segmented polyurethane for dilution and toughening, an imidazole-type latent curing agent can improve the storage stability of the epoxy structural adhesive, and the curing temperature of the epoxy structural adhesive can be adjusted by changing the amount of the imidazole-type latent curing agent added, and the deformable filler can balance the cohesive strength and adhesion of the structural adhesive, and cooperate with the above raw materials to make the structural adhesive have the characteristics of high strength and 100% cohesive failure (100% CF) in the temperature range of -40°C to 80°C. The epoxy structural adhesive can maintain stable performance in a wide temperature range, can maintain excellent impact resistance at a temperature of -40°C or even lower, and can have high shear strength and T-peel strength at a temperature of 80°C or even higher. The invention solves the technical problems of the existing epoxy structural adhesive, such as insufficient toughness, poor impact resistance, poor storage stability and limited operating temperature range.

[0038] Due to the advantages of adjustable curing temperature and wide applicable temperature range, the epoxy structural adhesive with a wide temperature range for automobile manufacturing of the present invention can be widely used for bonding of welding parts of vehicle bodies, engines, gearboxes and the like.

[0039] Further, the solid bisphenol A epoxy resin is a combination of any one or more of solid bisphenol A epoxy resin E-20 and solid bisphenol A epoxy resin E-12;

[0040] The liquid bisphenol A epoxy resin is any one or more combinations of liquid bisphenol A epoxy resin E-51 and liquid bisphenol A epoxy resin E-44.

[0041] Further, the elastomer-modified epoxy resin is a combination of any one or more of polyurethane-modified epoxy resin, silicone-modified epoxy resin and dimer acid-modified epoxy resin;

[0042] The segmented polyurethane is a QR-9466 segmented polyurethane.

[0043] To further illustrate, the deformable filler is any one or more combinations of hollow glass microspheres, floating beads and expandable graphite.

[0044] Preferably, the thixotropic filler is any one or more combinations of fumed silica, organic bentonite and active nano-calcium carbonate.

[0045] By adding the thixotropic filler, the fluidity of the epoxy structural adhesive can be reduced, the sagging phenomenon of the epoxy structural adhesive during the construction process can be reduced, the overall construction quality and qualitative effect can be improved, and the effect after construction can be more stable and reliable.

[0046] Further, the imidazole latent curing agent is a microcapsule-encapsulated imidazole curing agent. The microcapsule-encapsulated imidazole curing agent can form a physical barrier between the imidazole curing agent and the outside world, effectively isolating air, moisture and epoxy resin active ingredients, and effectively improving the storage stability of the epoxy structural adhesive. Specifically, the imidazole latent curing agent can be a curing agent model MC120D produced by Guangdong Guyan Electronic Materials Co., Ltd.

[0047] To further illustrate, the bifunctional epoxy reactive diluent is any one or more combinations of ethylene glycol diglycidyl ether, hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

[0048] A method for preparing an epoxy structural adhesive with a wide temperature range for automobile manufacturing, which is used to prepare the epoxy structural adhesive with a wide temperature range for automobile manufacturing, comprises the following steps:

[0049] Step S1, heating and melting solid bisphenol A epoxy resin, adding liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent in sequence, and stirring to obtain an epoxy mixture;

[0050] Step S2, after the reaction temperature is lowered, add the elastomer-modified epoxy resin, the CTBN-modified epoxy resin, the segmented polyurethane, the deformable filler and the thixotropic filler in sequence, and continue stirring;

[0051] Step S3: adding an imidazole latent curing agent and stirring to obtain an epoxy structural adhesive with a wide temperature range for automobile manufacturing.

[0052] The epoxy structural adhesive with a wide temperature range for automobile manufacturing prepared by the above preparation method can have the characteristics of high strength and 100% cohesive failure (100% CF) in the temperature range of -40°C to 80°C. It can maintain excellent impact resistance at temperatures of -40°C or even lower, and has high shear strength and T-peel strength at temperatures of 80°C or even higher. It maintains stable performance in a wide temperature range, has good storage stability, and has an adjustable curing temperature.

[0053] Preferably, in step S1, the solid bisphenol A epoxy resin is heated and melted at 70 to 90° C.;

[0054] In the step S2, the heating is stopped, and after the reaction temperature drops by 40 to 60° C., the elastomer-modified epoxy resin, the CTBN-modified epoxy resin, the segmented polyurethane, the deformable filler and the thixotropic filler are added in sequence;

[0055] In the step S3, an imidazole latent curing agent is added at a temperature below 40°C.

[0056] Specifically, in step S1, solid bisphenol A epoxy resin is put into a planetary mixer, and heating is turned on, the heating temperature is 70-90°C, and after the solid bisphenol A epoxy resin is melted, liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent are added in sequence, and stirring is turned on for 30-60 minutes, and the stirring speed is 30r / min to obtain an epoxy mixture. By using a planetary mixer, the temperature can be accurately controlled, and different components can be added at different temperatures, which can not only achieve uniform mixing of each component, but also effectively avoid premature curing of the epoxy resin caused by overheating, thereby ensuring the smooth progress of the preparation process.

[0057] Specifically, in step S2, heating is stopped, and when the reaction temperature drops to 40-60° C., elastomer-modified epoxy resin, CTBN-modified epoxy resin, segmented polyurethane, deformable filler and thixotropic filler are added in sequence, and stirring is continued for 30-60 min at a stirring speed of 30 r / min.

[0058] Specifically, in step S3, an imidazole latent curing agent is added at a temperature of 30 to 40°C.

[0059] Preferably, the step S2 sequentially adds elastomer-modified epoxy resin, CTBN-modified epoxy resin, segmented polyurethane, deformable filler and thixotropic filler, and after continued stirring, further comprises a high-speed dispersion step: increasing the rotation speed and performing high-speed dispersion; by increasing the rotation speed and performing high-speed dispersion, specifically, the rotation speed of the high-speed dispersion is 1500r / min, and the dispersion time is 10 to 20min, to ensure that all components are mixed evenly.

[0060] After the step S3 of adding the imidazole latent curing agent, the method further comprises the step S4 of starting the vacuum pump to stir and remove bubbles.

[0061] Specifically, after adding the imidazole latent curing agent in step S3, the imidazole latent curing agent is added at a temperature below 40°C, and stirring is started for 15 to 30 minutes, with a stirring speed of 30 r / min; in step S4, the stirring speed is reduced to 15 r / min, and the vacuum pump is turned on. The timing is started when the negative pressure reaches 0.08 MPa, and the bubbles are stirred for 30 to 60 minutes. After the bubbles are removed, the epoxy structural adhesive with a wide temperature range for automobile manufacturing is extruded and packaged.

[0062] In order to facilitate the understanding of the present invention, the present invention is described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0063] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0064] Example 1

[0065] An epoxy structural adhesive with a wide temperature range for automobile manufacturing, calculated by weight, is composed of the following components: 6 parts of solid bisphenol A epoxy resin (6 parts of solid bisphenol A epoxy resin E-20), 44 parts of liquid bisphenol A epoxy resin (44 parts of liquid bisphenol A epoxy resin E-51), 1 part of bifunctional epoxy reactive diluent (polypropylene glycol diglycidyl ether), 15 parts of elastomer modified epoxy resin (102C-5 polyurethane modified epoxy resin produced by Taizhou Hengchuang Insulation Materials Co., Ltd.), CTBN 4 parts of modified epoxy resin (using CTBN modified epoxy resin 861340 from Shenzhen Jiadida New Material Technology Co., Ltd.), 4 parts of segmented polyurethane (using segmented polyurethane model QR-9466 from Japan Aidico), 5.5 parts of imidazole latent curing agent (using microcapsule coated imidazole curing agent model MC120D from Guangdong Guyan Electronic Materials Co., Ltd.), 0.5 parts of deformable filler (using hollow glass microspheres) and 20 parts of thixotropic filler (using 4 parts of fumed silica and 16 parts of active nano-calcium carbonate).

[0066] Example 2

[0067] An epoxy structural adhesive with a wide temperature range for automobile manufacturing, calculated by weight, is composed of the following components: 4 parts of solid bisphenol A epoxy resin (using 4 parts of solid bisphenol A epoxy resin E-12), 38 parts of liquid bisphenol A epoxy resin (using 38 parts of liquid bisphenol A epoxy resin E-51), 2 parts of bifunctional epoxy reactive diluent (using polyethylene glycol diglycidyl ether), 18 parts of elastomer modified epoxy resin (using organic silicon modified epoxy resin ES3202 of Complex High-tech Materials (Shanghai) Co., Ltd.), CT 3 parts of BN modified epoxy resin (using CTBN modified epoxy resin 861340 from Shenzhen Jiadida New Materials Technology Co., Ltd.), 5 parts of segmented polyurethane (using Japan Aidico QR-9466 segmented polyurethane), 9.5 parts of imidazole latent curing agent (using microcapsule coated imidazole curing agent model MC120D from Guangdong Guyan Electronic Materials Co., Ltd.), 2 parts of deformable filler (using floating beads) and 18.5 parts of thixotropic filler (using 5 parts of organic bentonite and 13.5 parts of active nano calcium carbonate).

[0068] Example 3

[0069] A wide temperature range epoxy structural adhesive for automobile manufacturing, calculated by weight, consists of the following components: 5 parts of solid bisphenol A epoxy resin (using 5 parts of solid bisphenol A epoxy resin E-20), 46 parts of liquid bisphenol A epoxy resin (using 46 parts of liquid bisphenol A epoxy resin E-44), 1.5 parts of bifunctional epoxy reactive diluent (using hexanediol diglycidyl ether), 14 parts of elastomer modified epoxy resin (using dimer acid modified epoxy resin ED1702 of Complex High-tech Materials (Shanghai) Co., Ltd.), CTBN modified epoxy resin, 14 parts of epoxy resin modified by epoxy resin, 10 ... 3.5 parts of epoxy resin (CTBN modified epoxy resin 861340 produced by Shenzhen Jiadida New Material Technology Co., Ltd.), 4.5 parts of segmented polyurethane (QR-9466 segmented polyurethane produced by Japan Aidico), 13.5 parts of imidazole latent curing agent (MC120D microcapsule coated imidazole curing agent produced by Guangdong Guyan Electronic Materials Co., Ltd.), 3 parts of deformable filler (expandable graphite) and 9 parts of thixotropic filler (2 parts of fumed silica, 2 parts of organic bentonite and 5 parts of active nano calcium carbonate).

[0070] Example 4

[0071] A wide-temperature epoxy structural adhesive for automobile manufacturing, which is composed of the following components by weight: 7 parts of solid bisphenol A epoxy resin (using 7 parts of solid bisphenol A epoxy resin E-20), 34 parts of liquid bisphenol A epoxy resin (using 20 parts of liquid bisphenol A epoxy resin E-51 and 14 parts of liquid bisphenol A epoxy resin E-44), 2.5 parts of bifunctional epoxy reactive diluent (using ethylene glycol diglycidyl ether), 15 parts of elastomer modified epoxy resin (using 10 parts of 102C-5 polyurethane modified epoxy resin of Taizhou Hengchuang Insulation Material Co., Ltd. and 5 parts of complex high-tech materials (Shanghai) Co., Ltd. The epoxy resin is prepared by mixing with the following ingredients: 1) dimer acid modified epoxy resin ED1702 produced by Shenzhen Jiadida New Material Technology Co., Ltd., 4 parts CTBN modified epoxy resin (CTBN modified epoxy resin 861340 produced by Shenzhen Jiadida New Material Technology Co., Ltd.), 4.5 parts of segmented polyurethane (QR-9466 segmented polyurethane produced by Japan Aidico), 18.5 parts of imidazole latent curing agent (microcapsule coated imidazole curing agent model MC120D produced by Guangdong Guyan Electronic Materials Co., Ltd.), 5 parts of deformable filler (2 parts of floating beads and 3 parts of expandable graphite) and 9.5 parts of thixotropic filler (2 parts of organic bentonite and 7.5 parts of active nano calcium carbonate).

[0072] Example 5

[0073] A wide-temperature epoxy structural adhesive for automobile manufacturing, which is composed of the following components by weight: 6 parts of solid bisphenol A epoxy resin (using 3 parts of solid bisphenol A epoxy resin E-20 and 3 parts of solid bisphenol A epoxy resin E-12), 33 parts of liquid bisphenol A epoxy resin (using 33 parts of liquid bisphenol A epoxy resin E-51), 2 parts of bifunctional epoxy reactive diluent (using 1 part of polyethylene glycol diglycidyl ether and 1 part of polypropylene glycol diglycidyl ether), 15 parts of elastomer modified epoxy resin (using 10 parts of Taizhou Hengchuang Insulation Material Co., Ltd. 102C-5 polyurethane modified epoxy resin and 5 parts of complex high-tech materials (Shanghai) Co., Ltd. ES3202 silicone modified epoxy resin), 5 parts of CTBN modified epoxy resin (using 861340 CTBN modified epoxy resin of Shenzhen Jiadida New Material Technology Co., Ltd.), 3 parts of segmented polyurethane (using Japan Aidico QR-9466 segmented polyurethane), 22.5 parts of imidazole latent curing agent (using Guangdong Guyan Electronic Materials Co., Ltd. model MC120D microcapsule coated imidazole curing agent), 2 parts of deformable filler (using floating beads) and 11.5 parts of thixotropic filler (using 3 parts of fumed silica, 3 parts of organic bentonite and 5.5 parts of active nano calcium carbonate).

[0074] Example 6

[0075] A wide-temperature epoxy structural adhesive for automobile manufacturing, which is composed of the following components by weight: 10 parts of solid bisphenol A epoxy resin (using 4 parts of solid bisphenol A epoxy resin E-20 and 6 parts of solid bisphenol A epoxy resin E-12), 50 parts of liquid bisphenol A epoxy resin (using 50 parts of liquid bisphenol A epoxy resin E-51), 0.1 parts of bifunctional epoxy reactive diluent (using 0.1 parts of polyethylene glycol diglycidyl ether), 10 parts of elastomer modified epoxy resin (using 5 parts of polyurethane 102C-5 produced by Taizhou Hengchuang Insulation Materials Co., Ltd.), 10 parts of epoxy resin modified by elastomer (using ... Ester-modified epoxy resin and 5 parts of silicone-modified epoxy resin ES3202 from Complex High-tech Materials (Shanghai) Co., Ltd.), 1 part of CTBN-modified epoxy resin, 1 part of segmented polyurethane (QR-9466 segmented polyurethane), 5 parts of imidazole latent curing agent (microcapsule-coated imidazole curing agent model MC120D from Guangdong Guyan Electronic Materials Co., Ltd.), 0.1 parts of deformable filler (using floating beads) and 22.8 parts of thixotropic filler (5 parts of fumed silica, 5 parts of organic bentonite and 12.8 parts of active nano-calcium carbonate).

[0076] Example 7

[0077] A wide-temperature epoxy structural adhesive for automobile manufacturing, calculated by weight, is composed of the following components: 5 parts of solid bisphenol A epoxy resin (using 5 parts of solid bisphenol A epoxy resin E-20), 30 parts of liquid bisphenol A epoxy resin (using 30 parts of liquid bisphenol A epoxy resin E-51), 3 parts of bifunctional epoxy reactive diluent (using 3 parts of polyethylene glycol diglycidyl ether), 20 parts of elastomer modified epoxy resin (using 10 parts of Taizhou Hengchuang Insulation Material Co., Ltd. 102C-5 polyurethane modified epoxy resin and 10 parts of Complex High-tech Materials (Shanghai) Co., Ltd. ES3 202 silicone modified epoxy resin), 1 part of CTBN modified epoxy resin (using CTBN modified epoxy resin 861340 from Shenzhen Jiadida New Material Technology Co., Ltd.), 1 part of segmented polyurethane (using Japan Aidico QR-9466 segmented polyurethane), 25 parts of imidazole latent curing agent (using Guangdong Guyan Electronic Materials Co., Ltd. model MC120D microcapsule coated imidazole curing agent), 10 parts of deformable filler (using floating beads) and 5 parts of thixotropic filler (using 1 part of fumed silica, 1 part of organic bentonite and 3 parts of active nano calcium carbonate).

[0078] The preparation method of the epoxy structural adhesive with a wide temperature range for automobile manufacturing of the above Examples 1 to 7 (according to the above formula) is as follows:

[0079] Step S1, putting solid bisphenol A epoxy resin into a planetary mixer, turning on the heating, the heating temperature is 80° C., after the solid bisphenol A epoxy resin is heated and melted, liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent are added in sequence, stirring is started for 60 minutes, the stirring speed is 30 r / min, and the epoxy mixture is obtained by stirring;

[0080] Step S2, stop heating, wait until the reaction temperature drops to 50°C, add elastomer-modified epoxy resin, CTBN-modified epoxy resin, segmented polyurethane, deformable filler and thixotropic filler in sequence, continue stirring for 60 minutes, the stirring speed is 30 r / min, increase the speed and perform high-speed dispersion, the speed of high-speed dispersion is 1500 r / min, and the dispersion time is 20 minutes;

[0081] Step S3, adding imidazole latent curing agent at a temperature of 35° C., stirring for 30 minutes at a stirring speed of 30 r / min;

[0082] Step S4, reducing the stirring speed to 15 r / min, turning on the vacuum pump, starting the timing when the negative pressure reaches 0.08 MPa, stirring to remove bubbles for 60 minutes, extruding and packaging to obtain the epoxy structural adhesive with a wide temperature range for automobile manufacturing.

[0083] Comparative Example 1

[0084] Compared with Example 1, 6 parts of solid bisphenol A epoxy resin E-20 are not added in Comparative Example 1, and the remaining raw material compositions are consistent with those in Example 1. The preparation method is as follows:

[0085] Step S1, putting liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent into a planetary mixer, turning on heating, the heating temperature is 60° C., turning on stirring for 60 minutes, the stirring speed is 30 r / min, and stirring to obtain an epoxy mixture;

[0086] Step S2, stop heating, wait until the reaction temperature drops to 50°C, add elastomer-modified epoxy resin, CTBN-modified epoxy resin, segmented polyurethane, deformable filler and thixotropic filler in sequence, continue stirring for 60 minutes, the stirring speed is 30 r / min, increase the speed and perform high-speed dispersion, the speed of high-speed dispersion is 1500 r / min, and the dispersion time is 20 minutes;

[0087] Step S3, adding imidazole latent curing agent at a temperature of 35° C., stirring for 30 minutes at a stirring speed of 30 r / min;

[0088] Step S4, reducing the stirring speed to 15 r / min, turning on the vacuum pump, starting the timing when the negative pressure reaches 0.08 MPa, stirring to degas for 60 minutes, extruding and packaging to obtain an epoxy structural adhesive.

[0089] Comparative Example 2

[0090] Compared with Example 2, in Comparative Example 2, 3 parts of CTBN modified epoxy resin and 5 parts of segmented polyurethane are not added, and the remaining raw material compositions are consistent with those in Example 2. The preparation method is as follows:

[0091] Step S1, putting solid bisphenol A epoxy resin into a planetary mixer, turning on the heating, the heating temperature is 80° C., after the solid bisphenol A epoxy resin is heated and melted, liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent are added in sequence, stirring is started for 60 minutes, the stirring speed is 30 r / min, and the epoxy mixture is obtained by stirring;

[0092] Step S2, stop heating, wait until the reaction temperature drops to 50°C, add the elastomer-modified epoxy resin, the deformable filler and the thixotropic filler in sequence, continue stirring for 60 minutes, the stirring speed is 30 r / min, increase the speed and perform high-speed dispersion, the speed of high-speed dispersion is 1500 r / min, and the dispersion time is 20 minutes;

[0093] Step S3, adding imidazole latent curing agent at a temperature of 35° C., stirring for 30 minutes at a stirring speed of 30 r / min;

[0094] Step S4, reducing the stirring speed to 15 r / min, turning on the vacuum pump, starting the timing when the negative pressure reaches 0.08 MPa, stirring to degas for 60 minutes, extruding and packaging to obtain an epoxy structural adhesive.

[0095] Comparative Example 3

[0096] Compared with Example 3, 3 parts of expandable graphite are not added in Comparative Example 3, and the remaining raw material compositions are consistent with those in Example 3. The preparation method is as follows:

[0097] Step S1, putting solid bisphenol A epoxy resin into a planetary mixer, turning on the heating, the heating temperature is 80° C., after the solid bisphenol A epoxy resin is heated and melted, liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent are added in sequence, stirring is started for 60 minutes, the stirring speed is 30 r / min, and the epoxy mixture is obtained by stirring;

[0098] Step S2, stop heating, wait until the reaction temperature drops to 50°C, add elastomer-modified epoxy resin, CTBN-modified epoxy resin, block polyurethane and thixotropic filler in sequence, continue stirring for 60 minutes, the stirring speed is 30 r / min, increase the speed and perform high-speed dispersion, the speed of high-speed dispersion is 1500 r / min, and the dispersion time is 20 minutes;

[0099] Step S3, adding imidazole latent curing agent at a temperature of 35° C., stirring for 30 minutes at a stirring speed of 30 r / min;

[0100] Step S4, reducing the stirring speed to 15 r / min, turning on the vacuum pump, starting the timing when the negative pressure reaches 0.08 MPa, stirring to degas for 60 minutes, extruding and packaging to obtain an epoxy structural adhesive.

[0101] Comparative Example 4

[0102] Compared with Example 4, the imidazole latent curing agent in Comparative Example 4 is replaced by an imidazole curing agent (using the imidazole curing agent of Japanese Ajinomoto PN-23), and the remaining raw material composition is consistent with that of Example 4. The preparation method is as follows:

[0103] Step S1, putting solid bisphenol A epoxy resin into a planetary mixer, turning on the heating, the heating temperature is 80° C., after the solid bisphenol A epoxy resin is heated and melted, liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent are added in sequence, stirring is started for 60 minutes, the stirring speed is 30 r / min, and the epoxy mixture is obtained by stirring;

[0104] Step S2, stop heating, wait until the reaction temperature drops to 50°C, add elastomer-modified epoxy resin, CTBN-modified epoxy resin, segmented polyurethane, deformable filler and thixotropic filler in sequence, continue stirring for 60 minutes, the stirring speed is 30 r / min, increase the speed and perform high-speed dispersion, the speed of high-speed dispersion is 1500 r / min, and the dispersion time is 20 minutes;

[0105] Step S3, adding imidazole curing agent at a temperature of 35° C., stirring for 30 min at a stirring speed of 30 r / min;

[0106] Step S4, reducing the stirring speed to 15 r / min, turning on the vacuum pump, starting the timing when the negative pressure reaches 0.08 MPa, stirring to degas for 60 minutes, extruding and packaging to obtain an epoxy structural adhesive.

[0107] Comparative Example 5

[0108] An epoxy structural adhesive, calculated by weight, consists of the following components: 5 parts of solid bisphenol A epoxy resin (using 5 parts of solid bisphenol A epoxy resin E-20), 30 parts of liquid bisphenol A epoxy resin (using 30 parts of liquid bisphenol A epoxy resin E-51), 3 parts of bifunctional epoxy reactive diluent (using 3 parts of polyethylene glycol diglycidyl ether), 20 parts of elastomer modified epoxy resin (using 10 parts of 102C-5 polyurethane modified epoxy resin of Taizhou Hengchuang Insulation Material Co., Ltd. and 10 parts of ES3202 of Complex High-tech Materials (Shanghai) Co., Ltd. Silicone modified epoxy resin), 1 part of CTBN modified epoxy resin (using CTBN modified epoxy resin 861340 from Shenzhen Jiadida New Material Technology Co., Ltd.), 1 part of segmented polyurethane (using segmented polyurethane of QR-9466 type from Japan Aidico), 25 parts of imidazole latent curing agent (using microcapsule coated imidazole curing agent model MC120D from Guangdong Guyan Electronic Materials Co., Ltd.), 11 parts of deformable filler (using floating beads) and 5 parts of thixotropic filler (using 1 part of fumed silica, 1 part of organic bentonite and 3 parts of active nano calcium carbonate). The preparation method of comparative example 5 is consistent with that of example 5, and an epoxy structural adhesive is prepared.

[0109] The following mechanical property tests were performed on the epoxy structural adhesives prepared in Examples 1-7, Comparative Examples 1-3 and Comparative Example 5. The test results are shown in Table 1 below:

[0110] 1. Shear strength: Take three groups of 100×25×2mm cold-rolled steel test pieces with anti-rust oil, without surface treatment, and apply 25×12.5mm glue samples on the test pieces. Put two 0.2mm thin copper wires on each of the two test pieces (two in a group) coated with glue samples, then overlap the two test pieces together, scrape off the excess glue on the edges, and clamp them with clips. Place the three groups of adhesive parts in an electric constant temperature drying oven at 170±2℃ and bake for 20min. After taking them out, place them at 23±2℃ for more than 2h, and measure the shear strength with a tensile machine. The tensile speed is 10mm / min. The average value of the three groups of data is the shear strength of the glue sample at 23℃. The preparation of shear strength specimens at -40℃ and 80℃ is the same as that of the above specimens. The prepared specimens are placed in a tensile testing machine environment box with high and low temperature functions at -40℃ or 80℃ for 1 hour, and their shear strength is measured. The tensile speed is 10mm / min. The average value of the three groups of data is the shear strength of the rubber sample at -40℃ or 80℃.

[0111] 2. T-peel strength: Take three groups of 200×25×0.8mm cold-rolled steel test pieces with anti-rust oil, without surface treatment, and apply a layer of 150×25mm glue sample on the test pieces. Place 3-4 0.2mm thin copper wires on each of the two test pieces (two in a group) coated with glue samples, then overlap the two test pieces together, scrape off the excess glue on the edges, and clamp them with clips. Place the three groups of adhesive parts in an electric constant temperature drying oven at 170±2℃ and bake for 20min. After taking them out, place them at 23±2℃ for more than 2h, and measure the T-peel strength with a tensile machine at a tensile speed of 200m / min. The average value of the three groups of data is the T-peel strength of the glue sample at 23℃. The preparation of T-peel strength specimens at -40℃ and 80℃ is the same as that of the above specimens. The prepared specimens are placed in a tensile testing machine environment box with high and low temperature functions at -40℃ or 80℃ for 1 hour, and their T-peel strength is measured at a tensile speed of 20mm / min. The average value of the three groups of data is the T-peel strength of the rubber sample at -40℃ or 80℃.

[0112] 3. Impact peel strength: Prepare the impact peel strength test specimen according to the provisions of GB / T 36877-2018, take three groups of 90×20×1mm cold-rolled steel test pieces with anti-rust oil, without surface treatment, apply 30×20mm glue sample on the test pieces, put two 0.2mm thin copper wires on each of the two test pieces (two in a group) coated with glue sample, then overlap the two test pieces together, scrape off the excess glue on the edge, and clamp them with clips, bake the three groups of adhesive parts in an electric constant temperature drying oven at 170±2℃ for 20min, take them out and place them at 23±2℃ for more than 2h, and measure their impact peel strength with an impact tester. The impact speed is 2m / s, and the average value of the three groups of data is the impact peel strength of the glue sample at 23℃. The preparation of the impact peel strength specimens at -40℃ and 80℃ is the same as the preparation of the above specimens. The prepared specimens are placed in an environmental box of an impact testing machine with high and low temperature functions at -40℃ or 80℃ for 1 hour, and the impact peel strength is measured. The impact speed is 2m / s. The average value of the three groups of data is the impact peel strength of the rubber sample at -40℃ or 80℃.

[0113] Table 1 Mechanical properties test results of Examples 1-7, Comparative Examples 1-3 and Comparative Example 5

[0114]

[0115]

[0116] From the above test results, it can be seen that Examples 1 to 7 can simultaneously have the advantages of high shear strength, high T-glass strength and high impact glass strength at -40°C, 23°C and 80°C, and the interface failure form is 100% cohesive failure (100% CF), maintaining stable performance in a wide temperature range. Compared with Comparative Example 1, Example 1 uses a mixture of solid bisphenol A epoxy resin and liquid bisphenol A epoxy resin, and the T-peel strength and impact peel strength at -40°C are significantly improved, and the failure interface also reaches 100% cohesive failure (100% CF), indicating that the combination of solid bisphenol A epoxy resin and liquid bisphenol A epoxy resin produces a good synergistic effect and achieves performance complementarity.

[0117] Compared with Comparative Example 2, Example 2 adds end-capped polyurethane and CTBN modified epoxy resin. Polyurethane and rubber particles form an interpenetrating polymer network or island structure in the epoxy resin, which greatly improves the toughness of the material. At the same time, the carboxyl group of CTBN can significantly improve the adhesion of the adhesive layer. The test results show that the T-peel strength of Example 2 at 23°C and -40°C is significantly improved, and the failure interface is 100% CF. The most obvious is the impact peel strength at -40°C, which is increased from 16N / mm to 27N / mm.

[0118] Example 3 Compared with Comparative Example 3, the formula of Example 3 introduces a deformable filler. The deformable filler itself has good plasticity and ductility. When the structural adhesive is subjected to temperature changes, external impacts, and vibrations, it can absorb energy through its own deformation, thereby maintaining a tight structure between the structural adhesive and the adherend, achieving a balance between cohesive force and adhesive force, and keeping the adherend from being damaged to the greatest extent. From the T-peel strength test results at 80°C, it can be seen that the addition of deformable fillers increases the strength from 98N / 25mm to 162N / 25mm, and the damage interface also changes from 100% interface damage (100% AF) to 100% cohesive damage (100% CF). The addition of deformable fillers solves the problem of low T-peel strength of structural adhesives under high temperature environments.

[0119] In Comparative Example 5, the amount of deformable filler added is too much, the mechanical properties of the structural adhesive are reduced, and the strength is reduced, which is reflected in the performance test results that the shear strength, T-peel strength, and impact peel strength are all reduced, especially the impact peel strength at 23°C, which decreases from 41N / mm to 32N / mm.

[0120] The following storage stability test was performed on the epoxy structural adhesives prepared in Examples 1-7 and Comparative Example 4. The test results are shown in Table 2 below:

[0121] Storage stability test method: First, test the initial pressure flow viscosity of the sample at room temperature. Put about 250 ml of the sample into a wide-mouth bottle, cover it and place it in a constant temperature incubator at (40±2)℃ for 168 hours, then take it out and cool it to room temperature. Test the pressure flow viscosity after aging.

[0122] The viscosity change rate Y (%) was calculated by the following formula, and the average value of three measurements was taken as the measurement result.

[0123]

[0124] Where:

[0125] Y——rate of change, %;

[0126] η1——initial viscosity of the sample, g / min;

[0127] η2——Viscosity of the sample after storage at (40±2)℃ for 168h, g / min.

[0128] Table 2 Storage stability test results of Examples 1-7 and Comparative Example 4

[0129]

[0130] From the test results in Table 2, it can be seen that the epoxy structural adhesive with a wide temperature range for automobile manufacturing prepared by the present invention has good storage stability, and the viscosity change is less than 30% after storage at 40°C for 168 hours. In Comparative Example 4, after the imidazole latent curing agent of Example 4 is replaced with an imidazole curing agent, the storage stability is significantly reduced, and the viscosity change rate reaches 82%. Since the microcapsules encapsulate and protect the active ingredients of imidazole, it prevents imidazole from oxidation, hydrolysis, and reaction with the active ingredients in the epoxy adhesive. After heating to a certain temperature, the microcapsules rupture and initiate a curing reaction.

[0131] The curing speeds of Examples 1-7 were compared, and the comparison results are shown in Table 3 below:

[0132] Table 3 Comparison of curing speed of Examples 1-7

[0133]

[0134] From the test results in Table 3, it can be seen that the epoxy structural adhesive with a wide temperature range for automobile manufacturing prepared by the present invention significantly reduces the curing temperature with the increase of the amount of imidazole latent curing agent added, and realizes the free adjustment of the curing temperature from 120°C to 160°C. In this way, it can ensure that the epoxy structural adhesive has a long storage validity period in a room temperature storage room and can be quickly cured when used.

[0135] In summary, the present invention prepares a wide temperature range epoxy structural adhesive for automobile manufacturing by using solid bisphenol A epoxy resin, liquid bisphenol A epoxy resin, bifunctional epoxy reactive diluent, elastomer modified epoxy resin, CTBN modified epoxy resin, segmented polyurethane, imidazole latent curing agent, deformable filler, thixotropic filler, etc. The structural adhesive has the advantages of high shear strength, high T-peel strength, and high impact peel strength at -40°C, 23°C, and 80°C, and the interface failure form is 100% cohesive failure (100% CF). The deformable filler has a positive effect on the failure form of the structural adhesive and the substrate to relieve stress concentration, increase ductility, and increase interface bonding force. The use of imidazole latent curing agent can significantly improve the storage stability and rapid curing of the structural adhesive. The structural adhesive prepared by the present invention can be widely used for structural bonding of automobile sunroofs, side panels, floors, engine compartment assemblies, etc.

[0136] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An epoxy structural adhesive with a wide temperature range for automobile manufacturing, characterized in that: Calculated in parts by weight, the invention comprises the following components: 4 to 10 parts of solid bisphenol A epoxy resin, 30 to 50 parts of liquid bisphenol A epoxy resin, 0.1 to 3 parts of bifunctional epoxy reactive diluent, 10 to 20 parts of elastomer modified epoxy resin, 1 to 5 parts of CTBN modified epoxy resin, 1 to 5 parts of segmented polyurethane, 5 to 25 parts of imidazole latent curing agent, 0.1 to 10 parts of deformable filler and 5 to 22.8 parts of thixotropic filler.

2. The epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 1, characterized in that: The solid bisphenol A epoxy resin is any one or more of solid bisphenol A epoxy resin E-20 and solid bisphenol A epoxy resin E-12; The liquid bisphenol A epoxy resin is any one or more combinations of liquid bisphenol A epoxy resin E-51 and liquid bisphenol A epoxy resin E-44.

3. The epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 1, characterized in that: The elastomer-modified epoxy resin is any one or more of a polyurethane-modified epoxy resin, a silicone-modified epoxy resin and a dimer acid-modified epoxy resin; The segmented polyurethane is a QR-9466 segmented polyurethane.

4. The epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 1, characterized in that: The deformable filler is any one or more combinations of hollow glass microspheres, floating beads and expandable graphite.

5. The epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 1, characterized in that: The thixotropic filler is any one or more combinations of fumed silica, organic bentonite and active nano calcium carbonate.

6. The epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 1, characterized in that: The imidazole latent curing agent is a microcapsule-encapsulated imidazole curing agent.

7. The epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 1, characterized in that: The bifunctional epoxy reactive diluent is any one or more combinations of ethylene glycol diglycidyl ether, hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

8. A method for preparing a wide temperature range epoxy structural adhesive for automobile manufacturing, characterized in that: The method for preparing the epoxy structural adhesive with a wide temperature range for automobile manufacturing as claimed in any one of claims 1 to 7 comprises the following steps: Step S1, heating and melting solid bisphenol A epoxy resin, adding liquid bisphenol A epoxy resin and bifunctional epoxy reactive diluent in sequence, and stirring to obtain an epoxy mixture; Step S2, after the reaction temperature is lowered, add the elastomer-modified epoxy resin, the CTBN-modified epoxy resin, the segmented polyurethane, the deformable filler and the thixotropic filler in sequence, and continue stirring; Step S3: adding an imidazole latent curing agent and stirring to obtain an epoxy structural adhesive with a wide temperature range for automobile manufacturing.

9. The method for preparing the epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 8, characterized in that: In the step S1, the solid bisphenol A epoxy resin is heated and melted at 70-90° C.; In the step S2, the heating is stopped, and after the reaction temperature drops by 40 to 60° C., the elastomer-modified epoxy resin, the CTBN-modified epoxy resin, the segmented polyurethane, the deformable filler and the thixotropic filler are added in sequence; In the step S3, an imidazole latent curing agent is added at a temperature below 40°C.

10. The method for preparing the epoxy structural adhesive with a wide temperature range for automobile manufacturing according to claim 8, characterized in that: The step S2 includes sequentially adding an elastomer-modified epoxy resin, a CTBN-modified epoxy resin, a segmented polyurethane, a deformable filler and a thixotropic filler, and continuing to stir, and further includes a high-speed dispersion step: increasing the rotation speed and performing high-speed dispersion; After the step S3 of adding the imidazole latent curing agent, the method further comprises the step S4 of starting the vacuum pump to stir and remove bubbles.

Images