Epoxy resin adhesive used at low temperature as well as preparation method and use method thereof

Abstract

The invention discloses an epoxy resin adhesive used at low temperature and a preparation method and a use method thereof, and belongs to the field of adhesives, the adhesive comprises a component A and a component B according to a ratio of 1.5-1.7: 1 by mass, the component A comprises 10-30% of SW-70, 10-20% of E51, 0.1-1% of an antifoaming agent and the balance of a first filler, and the component B comprises 20-40% of a curing agent, 0.1-1 wt% of an accelerator and the balance of a second filler; the filler contains reinforced fibers and silicon dioxide. After being cured, the epoxy resin has relatively high hardness and strength, can bear relatively high weight, still has relatively high modulus and strength at low temperature, and also has relatively high impact resistance; the adhesive can be cured at room temperature or even lower temperature, has good adhesive property at low temperature, is moderate in curing rate and moderate in construction time, and solves the problem of short construction time; the adhesive has thixotropic property and can be used in places where flowable adhesives cannot be used.

Description

Technical Field

[0001] The present invention relates to an epoxy resin adhesive for low temperature, its preparation method and usage method, belonging to the field of adhesives. Background Art

[0002] Liquefied petroleum gas (LPG) is a high-calorific value and clean secondary energy source that needs to be stored at low temperature. Currently, the use of LPG is increasing day by day, and currently LPG is mainly transported by tankers. The adhesives used on LPG ships need to have good low-temperature resistance and mechanical properties. Epoxy resin adhesives are often used for bonding LPG ships due to their low curing shrinkage rate and good creep properties.

[0003] However, the current compressive strength and impact resistance of LPG epoxy resins are still at a relatively low level. At the same time, in an ultra-low temperature environment, the mechanical properties of epoxy resin adhesives will decline, making it easy for materials to break. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides an epoxy resin adhesive for low temperature, which still has a high compressive strength in a low-temperature environment, and provides a preparation method and a usage method for the epoxy resin adhesive.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows: In the first aspect, the present application provides an epoxy resin adhesive for low temperature, including component A and component B. By mass, the working ratio of component A to component B is 1.5 - 1.7:1; Component A includes 10wt% - 30wt% of SW-70, 10wt% - 20wt% of E51, 0.1wt% - 1wt% of defoamer, and the balance is the first filler; Component B includes 20wt% - 40wt% of diamine curing agent, 0.1wt% - 1wt% of curing accelerator, and the balance is the second filler; The first filler contains reinforcing fibers, and both the first filler and the second filler contain silica.

[0006] The epoxy resin adhesive for low temperature provided by the present application is green and environmentally friendly and has a high compressive strength. As a solvent-free adhesive that can adapt to the LPG environment, this product introduces IPN (interpenetrating polymer network) technology to maintain a high strength of the epoxy resin; the raw material formula makes the epoxy resin have a high thixotropy.

[0007] Furthermore, the reinforcing fiber is bacterial cellulose; in the first filler, the mass ratio of the silica to the bacterial cellulose is 4 to 5.5:2. Bacterial cellulose assists in constructing a three-dimensional network structure in the epoxy matrix, significantly improving the shear resistance and compressive modulus. The optimized ratio helps ensure the uniformity of the interpenetrating network, taking into account both toughness and strength.

[0008] Bacterial cellulose constructs a three-dimensional network structure in the epoxy matrix, disperses the load through physical cross-linking, effectively inhibits the yield of the matrix and the generation of microcracks, and thus improves the shear performance and compressive modulus of the material.

[0009] Furthermore, the second filler also contains heavy calcium carbonate, and the particle size of the heavy calcium carbonate is smaller than that of the silica; in the second filler, the mass ratio of the silica to the heavy calcium carbonate is 4 to 5:1.

[0010] The combination of heavy calcium carbonate and silica is beneficial to making the cured resin denser, improving the compressive strength and compressive modulus.

[0011] Furthermore, the silica in the first filler is 1250-mesh silica; the silica in the second filler is 1250-mesh silica. This is beneficial to improving the hardness, compressive strength and thixotropy.

[0012] 1250-mesh silica belongs to micron-sized filler. Its particle size is moderate, which can not only provide sufficient physical support, effectively improve the hardness and compressive strength of the adhesive, but also endow the adhesive with a certain thixotropy to meet the use requirements in specific construction scenarios.

[0013] Furthermore, in the component A, the mass ratio of the SW-70 to the E51 is 1 to 4:2; the diamine curing agent is 4,4'-diaminodiphenylmethane.

[0014] Controlling the ratio of SW-70 to E51 is beneficial to optimizing the IPN effect and comprehensive performance. The DDM (4,4'-diaminodiphenylmethane) curing agent contains a benzene ring rigid structure, which synergistically improves the strength after curing with SW-70. DDM has high reactivity and can form a high cross-linking density network with SW-70. When SW-70 and E51 are mixed in a ratio of 1 to 4:2, it can not only give play to the high strength advantage brought by the high cross-linking degree of SW-70, but also utilize the good adhesion performance of E51. The IPN effect formed by the two further enhances the comprehensive mechanical properties of the adhesive. As a diamine curing agent, DDM acts together with the benzene ring rigid structure in SW-70, which can increase the cross-linking density and rigidity of the epoxy resin, enabling the adhesive to maintain a high modulus and strength even at low temperatures, and generating a synergistic effect between the resins.

[0015] Furthermore, the curing accelerator is DMP-30, which can accelerate the curing reaction, improve the crosslinking degree, enhance the mechanical properties, and improve the adhesive ability of epoxy resin.

[0016] DMP-30 can effectively increase the curing speed and degree of curing, enabling the adhesive to meet the mechanical property requirements faster. At the same time, the hydroxyl groups it contains can interact with epoxy resin, improving the adhesive ability of the adhesive and ensuring the firmness of the bonding interface.

[0017] Furthermore, the defoaming agent is XY-692, which can eliminate the bubbles generated during the stirring and mixing of SW-70 and E51, improve the mixing uniformity, reduce curing defects, and ensure the integrity of mechanical properties.

[0018] During the preparation of the adhesive, XY-692 can effectively remove the bubbles generated during the stirring process, improve the uniformity after mixing and coating, reduce the internal defects of the material caused by the existence of bubbles, thereby enhancing the mechanical properties and durability of the cured adhesive.

[0019] In the second aspect, the present application provides a method for preparing an epoxy resin adhesive for low temperature as described in the first aspect, and the steps include: Mix the raw materials including the silica and the reinforcing fiber to obtain the first filler in powder form; Stir and mix the SW-70 and the E51 to obtain a mixed resin; Mix the first filler and the mixed resin, add the defoaming agent, and heat and stir to obtain the component A; Mix the raw materials including the silica to obtain the second filler; Stir and mix the diamine curing agent and the second filler, add the curing accelerator, and heat and stir to obtain the component B.

[0020] This preparation step is beneficial to reducing the risk of filler agglomeration, ensuring uniform dispersion. Adding silica in two parts to component A and component B is beneficial to reducing the viscosity of any single component and ensuring that the silica reaches the expected content, promoting the uniform mixing of the high filling amount system.

[0021] Furthermore, the requirements for the heat and stir are: heat up to 70 °C and stir at a speed of 50 rpm for 2 h.

[0022] Controlling the temperature and time is beneficial to uniform mixing, avoiding local overheating or insufficient reaction, and at the same time controlling the speed to prevent shear damage to the high filler system, such as avoiding the fracture of the reinforcing fiber.

[0023] Thirdly, the present application provides a method for using the epoxy resin adhesive for low temperature as described in the first aspect. The component A and the component B are stirred and mixed at a mass ratio of 1.5 - 1.7:1, and the temperature is raised to 40°C - 50°C while stirring. After construction, it is cured at room temperature for 7 to 8 days.

[0024] Construction at 40°C - 50°C can reduce the mixing viscosity, improve the fluidity, and extend the pot life. After curing at room temperature for 7 - 8 days, sufficient cross-linking ensures the final strength.

[0025] The beneficial effects of the present invention are as follows: The epoxy resin adhesive for low temperature of the present invention has high hardness and strength after curing, can bear a high weight, and still has high modulus and strength at low temperature. At the same time, it also has strong impact resistance; this adhesive can be stably cured at room temperature or even lower temperature, and has good bonding performance at low temperature. The curing rate is moderate, and the pot life is moderate, solving the problem of short pot life; this adhesive has thixotropic properties and can be used in places where flowable adhesives cannot be used. Description of the Drawings

[0026] Figure 1 It is a graph of the compression test results of the adhesives prepared in each example after curing at room temperature.

[0027] Figure 2 It is a graph of the compression test results of the adhesives prepared in each example after curing at -50°C.

[0028] Figure 3 It is a graph of the compression test results of the adhesives prepared in each example after curing at -110°C.

[0029] Figure 4 It is a graph of the shear test results of the adhesives prepared in each example after curing at room temperature. Detailed Embodiments

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below. Apparently, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts fall within the scope of protection of the present invention.

[0031] It should be understood that, on the premise of no conflict, any and all implementation schemes of the present invention can be combined with the technical features in any other implementation scheme or multiple other implementation schemes to obtain additional implementation schemes. The present invention includes such additional implementation schemes obtained by combination.

[0032] In this specification, groups and their substituents can be selected by those skilled in the art to provide stable structural moieties and compounds. When a substituent is described by a conventional chemical formula written from left to right, the substituent also includes chemically equivalent substituents obtained when the structural formula is written from right to left.

[0033] Unless otherwise specified, all technical and scientific terms used herein have the standard meanings in the field to which the claimed subject matter pertains. If there are multiple definitions for a term, the definition herein shall prevail.

[0034] An embodiment of the present application provides an epoxy resin adhesive for low temperature, comprising component A and component B. By mass, the working ratio of component A to component B is 1.7 - 1.5:1; Component A includes 10wt% - 30wt% of SW - 70, 10wt% - 20wt% of E51, 0.1wt% - 1wt% of an antifoaming agent, and the balance is the first filler; Component B includes 20wt% - 40wt% of a diamine curing agent, 0.1wt% - 1wt% of a curing accelerator, and the balance is the second filler; The first filler contains reinforcing fibers, and both the first filler and the second filler contain silica.

[0035] SW - 70 (one of the tetraglycidylamine type epoxy resins) has a high epoxy value and can form a highly cross - linked structure when cured with a diamine curing agent. Coupled with the IPN effect generated by its combination with E51 (one of the bisphenol A type epoxy resins), the degree of cross - linking is further increased, significantly enhancing the hardness and strength of the adhesive, and the components synergistically enhance the strength of the adhesive. When the ratio of component A to component B is within the range of 1.5 - 1.7:1, it can ensure that the epoxy resin and the curing agent react fully, making the cross - linked network more perfect, thereby optimizing the mechanical properties of the adhesive.

[0036] In the embodiment of the present application, the epoxy resin is a composition of SW - 70 and E51, and the corresponding mass ratio is (1 - 4):2. The curing agent is selected as the diamine curing agent DDM.

[0037] The inventors found that SW - 70 in the present application has a high epoxy value and can obtain a highly cross - linked epoxy resin when cured with the diamine curing agent DDM, achieving higher hardness and strength. At the same time, SW - 70 and DDM contain a rigid benzene ring structure, which can effectively improve the strength of the epoxy resin. The E51 type epoxy resin has good adhesion performance and can form an IPN effect with SW - 70, further promoting the degree of cross - linking of the epoxy resin, and enhancing the strength and hardness of the finally obtained epoxy resin adhesive.

[0038] Specifically, the complete components of the adhesive are, for example: Component A: SW-70 10-30%, E51 10-20%, bacterial cellulose 1-20%, defoamer 0.1-1%, silica with a mesh size of 1250, the balance.

[0039] Component B: DDM 20-40%, silica with a mesh size of 1250 40-60%, heavy calcium carbonate 10-30%, accelerator 0.1-1%.

[0040] The adhesive of the present invention also has good bonding performance at low temperatures, can be stably cured at room temperature or even lower temperatures, has a moderate curing rate and a moderate pot life, solves the problem of a short pot life, has thixotropic properties, can be used in places where a flowable adhesive cannot be used, has a high hardness and strength after curing, can withstand a high weight, the epoxy resin at low temperatures still has a high modulus and strength, and at the same time has a strong impact resistance; has strong corrosion resistance and its properties will not change after long-term storage.

[0041] The adhesive of the present invention does not contain heavy metal salts, is safe, environmentally friendly, non-toxic and odorless. The treatment solution does not contain toxic substances such as nickel, cobalt or other heavy metals, and the wastewater is non-toxic and harmless. It can be widely used in the fields of construction, furniture, household appliances, etc.

[0042] The silica in the first filler and the second filler, as a micron-level filler, can effectively improve the hardness, compressive strength and impact resistance of the adhesive after curing. At the same time, the addition of a large amount of silica endows the adhesive with good thixotropy, enabling it to be applied in scenarios where a flowable adhesive cannot be used.

[0043] In this application, bacterial cellulose, silica and heavy calcium carbonate are selected as fillers. Preferably, in Component A, the mass ratio of silica to bacterial cellulose is (4-5.5):2, and in Component B, the mass ratio of silica to heavy calcium carbonate is (4-5):1.

[0044] When the mass ratio of silica to bacterial cellulose is in the range of 4-5.5:2, it can not only ensure the strengthening effect of silica on the strength, but also give full play to the toughening effect of bacterial cellulose, avoiding performance degradation caused by too much or too little of a certain component.

[0045] The inventors found that adding a large amount of micron-sized silica in this application can effectively improve the hardness, compressive strength, and impact resistance of the cured epoxy resin. At the same time, adding a large amount of silica can effectively improve the thixotropic property of the epoxy resin, enabling it to be used in places where flowable epoxy resin cannot be used. Adding a certain amount of bacterial cellulose can construct a three-dimensional network in the epoxy matrix, disperse the load through physical cross-linking, inhibit matrix yielding and microcrack generation, and thus endow the material with better shear properties and compressive modulus. Adding a certain amount of finer ground calcium carbonate can effectively fill the voids between the micron-sized silica, making the cured epoxy resin denser, with higher compressive strength and compressive modulus. At the same time, the interfacial property between the ground calcium carbonate and the epoxy resin is good, which can ensure good dispersion of the ground calcium carbonate in the epoxy resin.

[0046] In this application, a curing accelerator and an antifoaming agent are selected as additives. Preferably, DMP-30 is selected as the accelerator, and XY-692 is selected as the preferred antifoaming agent.

[0047] The inventors found that adding DMP-30 can effectively increase the curing speed and degree of curing, thereby achieving the purpose of improving its mechanical properties. At the same time, DMP-30 contains hydroxyl groups, which can effectively improve the adhesion ability of the epoxy resin. Adding XY-692 can remove the bubbles generated during the stirring process, improve the uniformity after mixing and coating, reduce bubbles, and thus improve the mechanical properties after curing.

[0048] The embodiment of this application also provides a preparation method of the above epoxy resin adhesive for low temperature, including the following steps: Component A: (1) First, premix the silica and bacterial cellulose with a stirrer for 1 h to obtain powder A (the first filler).

[0049] (2) Then, premix SW-70 and E51 with a mixing paddle for 1 h to obtain resin A (the mixed resin).

[0050] (3) Mix powder A and resin A in a certain proportion (meeting the dosage relationship of component A), add the antifoaming agent, heat up to 70 °C, and stir at a stirring speed of 50 rpm for 2 h.

[0051] (4) After mixing evenly, take out the sample for use.

[0052] Component B: (1) First, premix the silica and ground calcium carbonate with a stirrer for 1 h to obtain powder B (the second filler).

[0053] (2) Then, mix DDM and powder B in a certain proportion, add the accelerator, heat up to 70 °C, and stir at a stirring speed of 50 rpm for 2 h.

[0054] (3) After mixing evenly, take out the sample for use.

[0055] By premixing the filler and the resin, this method enables fillers such as silica and bacterial cellulose to come into full contact with the resin. Then, under the conditions of heating at 70 °C and stirring at 50 rpm for 2 h, the viscosity of the resin is reduced, the uniform mixing of each component is promoted, ensuring that the filler is evenly dispersed in the resin and avoiding the occurrence of agglomeration phenomena. The heating and stirring process helps the defoaming agent to fully exert its function, remove bubbles, and at the same time makes the performance of the adhesive more stable.

[0056] The embodiment of the present application also provides a method for using the above-mentioned epoxy resin adhesive for low temperature, including the following steps: (1) Take samples of components A and B in a mass ratio of 1.5 - 1.7:1, stir with a stirring paddle, and raise the temperature to 40 °C - 50 °C while stirring, and stir evenly.

[0057] Curing time (25 °C): (1) Curing starts at 30 h - 36 h; (2) The hardness reaches 30 at 72 h; (3) Completely cured in 7 - 8 days.

[0058] Example 1 Example 1 provides a two-component epoxy adhesive. Calculated by mass percentage, the two-component epoxy adhesive includes the following components: Component A: SW-70 (Hunan Selway New Materials Technology Co., Ltd.) 15%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 15%, 1250-mesh silica 60%, bacterial cellulose 9%, defoaming agent (XY-692, Wuhan Lanabai Medical and Chemical Co., Ltd.) 1%; Component B: DDM 40%, 1250-mesh silica 49.9%, heavy calcium 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0059] The mass mixing ratio of the two-component epoxy adhesive is A:B = 1.7:1.

[0060] On the other hand, this embodiment also provides a preparation method for the two-component epoxy adhesive (epoxy resin adhesive for low temperature), including the following steps: Component A: (1) First, premix silica and bacterial cellulose with a mixer and stir for 1 h to obtain powder A.

[0061] (2) Premix SW-70 and E51 with a stirring paddle and stir for 1 h to obtain resin A.

[0062] (3) Mix powder A and resin A in a certain proportion, add defoaming agent, raise the temperature to 70°C, and stir at 50 rpm for 2 hours.

[0063] (4) After mixing evenly, take out the sample for later use.

[0064] Component B: (1) Premix silica and heavy calcium using a blender and stir for 1 hour to obtain powder B.

[0065] (2) Then, DDM and powder B were mixed in a certain proportion, and accelerator was added. The temperature was raised to 70°C and the stirring speed was 50 rpm for 2 h.

[0066] This embodiment also provides a method for using a two-component epoxy resin, comprising the following steps: Take samples of components A and B in a certain proportion, stir with a stirring paddle, raise the temperature to 40-50℃ while stirring, and stir evenly.

[0067] Example 2

[0068] Example 2 provides a two-component epoxy adhesive, which includes the following components, calculated by mass percentage: A: SW-70 (Hunan Saierwei New Materials Technology Co., Ltd.) 20%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 10%, 1250 mesh silica 60%, bacterial cellulose 9%, defoamer (XY-692, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.) 1%; B: DDM 40%, 1250 mesh silica 49.9%, heavy calcium 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0069] The mass mixing ratio of the two-component epoxy adhesive is A:B=1.6:1.

[0070] The preparation method is the same as that of Example 1.

[0071] The method of use is the same as that of Example 1.

[0072] Example 3

[0073] Example 3 provides a two-component epoxy adhesive, which includes the following components, calculated by mass percentage: A: SW-70 (Hunan Saierwei New Materials Technology Co., Ltd.) 20%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 10%, 1250 mesh silica 60%, bacterial cellulose 9%, defoamer (XY-692, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.) 1%; B: DDM 40%, 1250 mesh silica 39.9%, heavy calcium 20%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0074] The mass mixing ratio of the two-component epoxy adhesive is A:B = 1.6:1.

[0075] The preparation method is the same as that of Example 1.

[0076] The usage method is the same as that of Example 1.

[0077] Example 4

[0078] Example 4 provides a two-component epoxy adhesive. Calculated by mass percentage, the two-component epoxy adhesive includes the following components: A: SW-70 (Hunan Selway New Materials Technology Co., Ltd.) 20%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 10%, 1250-mesh silica 60%, bacterial cellulose 9%, defoaming agent (XY-692, Wuhan Lana White Pharmaceutical and Chemical Co., Ltd.) 1%; B: DDM 40%, 1250-mesh silica 49%, heavy calcium 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 1%.

[0079] The mass mixing ratio of the two-component epoxy adhesive is A:B = 1.6:1.

[0080] The preparation method is the same as that of Example 1.

[0081] The usage method is the same as that of Example 1.

[0082] Example 5

[0083] Example 5 provides a two-component epoxy adhesive. Calculated by mass percentage, the two-component epoxy adhesive includes the following components: A: SW-70 (Hunan Selway New Materials Technology Co., Ltd.) 20%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 10%, 1250-mesh silica 50%, bacterial cellulose 19%, defoaming agent (XY-692, Wuhan Lana White Pharmaceutical and Chemical Co., Ltd.) 1%; B: DDM 40%, 1250-mesh silica 49.9%, heavy calcium 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0084] The mass mixing ratio of the two-component epoxy adhesive is A:B = 1.6:1.

[0085] The preparation method is the same as that of Example 1.

[0086] The usage method is the same as that of Example 1.

[0087] Example 6

[0088] Example 6 provides a two-component epoxy adhesive, which includes the following components, calculated by mass percentage: A: SW-70 (Hunan Sailvi New Materials Technology Co., Ltd.) 15%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 15%, 1250 mesh silica 50%, bacterial cellulose 19%, defoamer (XY-692, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.) 1%; B: DDM 40%, 1250 mesh silica 49.9%, heavy calcium 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0089] The mass mixing ratio of the two-component epoxy adhesive is A:B=1.7:1.

[0090] The preparation method is the same as that of Example 1.

[0091] The method of use is the same as that of Example 1.

[0092] Example 7

[0093] Example 7 provides a two-component epoxy adhesive, which includes the following components, calculated by mass percentage: A: SW-70 (Hunan Saierwei New Materials Technology Co., Ltd.) 10%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 20%, 1250 mesh silica 50%, bacterial cellulose 19%, defoamer (XY-692, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.) 1%; B: DDM 40%, 1250 mesh silica 49.9%, heavy calcium 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0094] The mass mixing ratio of the two-component epoxy adhesive is A:B=1.5:1.

[0095] The preparation method is the same as that of Example 1.

[0096] The method of use is the same as that of Example 1.

[0097] Comparative Example 1 Comparative Example 1 provides a two-component epoxy adhesive, which includes the following components, calculated by mass percentage: A: AG-80 (Guangzhou Yihuisheng Chemical Co., Ltd.) 10%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 20%, 1250 mesh silica 50%, bacterial cellulose 19%, defoamer (XY-692, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.) 1%; B: DDM 40%, 1250 mesh silica 49.9%, heavy calcium 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0098] The mass mixing ratio of the two-component epoxy adhesive is A:B=1.5:1.

[0099] Except that SW-70 in step (2) of preparing component A is replaced with AG-80 (another tetraglycidylamine type epoxy resin), the remaining steps are the same as those in Example 1.

[0100] The usage method is the same as that in Example 1.

[0101] Comparative Example 2 Comparative Example 2 provides a two-component epoxy adhesive. Calculated by mass percentage, the two-component epoxy adhesive includes the following components: Component A: SW-70 (Hunan Selway New Materials Technology Co., Ltd.) 10%, E44 (Zhengzhou Penghui Chemical Products Co., Ltd.) 20%, 1250-mesh silica 50%, bacterial cellulose 19%, defoaming agent (XY-692, Wuhan Lanabai Medical and Chemical Co., Ltd.) 1%; Component B: DDM 40%, 1250-mesh silica 49.9%, heavy calcium carbonate 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0102] The mass mixing ratio of the two-component epoxy adhesive is A:B = 1.5:1.

[0103] Except that E51 in step (2) of preparing component A is replaced with E44 (another bisphenol A type epoxy resin), the remaining steps are the same as those in Example 1.

[0104] The usage method is the same as that in Example 1.

[0105] Comparative Example 3 Comparative Example 3 provides a two-component epoxy adhesive. Calculated by mass percentage, the two-component epoxy adhesive includes the following components: Component A: E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 30%, 1250-mesh silica 50%, bacterial cellulose 19%, defoaming agent (XY-692, Wuhan Lanabai Medical and Chemical Co., Ltd.) 1%; Component B: DDM 40%, 1250-mesh silica 59.9%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0106] The mass mixing ratio of the two-component epoxy adhesive is A:B = 1.5:1.

[0107] Except that SW-70 is not added in step (2) of preparing component A and heavy calcium carbonate is not added in step (1) of preparing component B, the remaining steps are the same as those in Example 1.

[0108] The usage method is the same as that in Example 1.

[0109] Comparative Example 4 Comparative Example 4 provides a two-component epoxy adhesive. Calculated by mass percentage, the two-component epoxy adhesive comprises the following components: A: SW-70 (Hunan Selway New Materials Technology Co., Ltd.) 10%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 20%, 1250-mesh silica 69%, defoaming agent (XY-692, Wuhan Lana White Pharmaceutical and Chemical Co., Ltd.) 1%; B: DDM 40%, 1250-mesh silica 49.9%, heavy calcium carbonate 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0110] The mass mixing ratio of the two-component epoxy adhesive is A:B = 1.5:1.

[0111] Except that bacterial cellulose is not added in step (1) of preparing component A, the remaining steps are the same as those in Example 1.

[0112] The usage method is the same as that in Example 1.

[0113] Comparative Example 5 Comparative Example 5 provides a two-component epoxy adhesive. Calculated by mass percentage, the two-component epoxy adhesive comprises the following components: A: SW-70 (Hunan Selway New Materials Technology Co., Ltd.) 10%, E51 (Zhengzhou Penghui Chemical Products Co., Ltd.) 20%, 1250-mesh silica 50%, bacterial cellulose 19%, defoaming agent (XY-692, Wuhan Lana White Pharmaceutical and Chemical Co., Ltd.) 1%; B: DDM 40%, 1250-mesh silica 49.9%, heavy calcium carbonate 10%, accelerator (DMP-30, Shandong Jinruida New Materials Co., Ltd.) 0.1%.

[0114] The mass mixing ratio of the two-component epoxy adhesive is A:B = 3:1.

[0115] The preparation method is the same as that in Example 1.

[0116] The usage method is the same as that in Example 1 (of course, the mixing ratio is different).

[0117] The mechanical properties of the cured epoxy resin adhesives of each example and comparative example are measured.

[0118] 1. Compression test The two-component epoxy resins prepared in each example and comparative example are weighed and cured according to the specified mixing ratio, and tested after curing at room temperature for 7 days or at 60 °C for 8 h. The compression test method conforms to the standard ASTM D695. The mixed epoxy resin is cured in a rectangular mold of 50 mm × 12.7 mm × 12.7 mm for testing the elastic modulus and compression strength. The prepared epoxy resin is placed in a universal testing machine for compression performance testing at different temperatures (20 °C, -50 °C, -110 °C).

[0119] 2. Tensile Shear Performance Test The two-component epoxy resins prepared in each example and comparative example were weighed and cured according to the specified mixing ratio, and tested after curing at room temperature for 7 days or at 60 °C for 8 h. The tensile shear test method conforms to the standard ASTM D1002. The mixed epoxy resin was coated on the top of a stainless steel sheet in an area approximately 25.4 mm × 12.5 mm in size, covered with another stainless steel sheet, and then cured. The prepared epoxy resin was placed in a universal testing machine, and the tensile shear performance was tested at different temperatures (20 °C, -50 °C, -110 °C).

[0120] The test results are shown in Table 1, Figures 1 to 4 .

[0121] Table 1

[0122] Among them, Figure 1 are the results of compression tests at room temperature, Figure 2 are the compression test results at -50 °C, Figure 3 are the test results at -110 °C.

[0123] It can be seen that the shear strength of Example 7 is the strongest among all examples and comparative examples. Although the elastic modulus and compressive strength are not the strongest, they are the most balanced. Comparing Example 7 with Example 6 and Example 5, it can be found that adding more SW-70 will increase the crosslinking density of the material, making the material itself more brittle, and the shear strength, compressive strength and elastic modulus will decrease instead. Comparing Comparative Example 5 with the examples, it can be seen that if the dosages of Component B and Component A do not match, the performance will decline, because the reaction is incomplete and the crosslinking density is low. Comparing Comparative Example 4 with Example 1, it can be seen that adding a certain amount of bacterial cellulose can effectively improve the compressive strength and compressive modulus of the material, because bacterial cellulose can assist in forming a three-dimensional network structure, effectively avoid crack propagation, and improve the mechanical properties of epoxy resin.

[0124] In the description of this specification, the descriptions referring to terms such as "one embodiment", "certain embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the said embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0125] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. An epoxy resin adhesive for low temperature, characterized in that, It includes Component A and Component B. By mass, the working ratio of Component A to Component B is 1.5 - 1.7:1; Component A includes 10wt% - 30wt% of SW - 70, 10wt% - 20wt% of E51, 0.1wt% - 1wt% of defoamer, and the balance is the first filler; Component B includes 20wt% - 40wt% of diamine curing agent, 0.1wt% - 1wt% of curing accelerator, and the balance is the second filler; The first filler contains reinforcing fibers, and both the first filler and the second filler contain silica.

2. The epoxy resin adhesive for low temperature according to claim 1, wherein, The reinforcing fiber is bacterial cellulose; in the first filler, the mass ratio of silica to bacterial cellulose is 4 - 5.5:

2.

3. The epoxy resin adhesive for low temperature according to claim 1, characterized in that, The second filler also contains heavy calcium, and the particle size of the heavy calcium is smaller than that of the silica; in the second filler, the mass ratio of silica to heavy calcium is 4 - 5:

1.

4. The epoxy resin adhesive for low temperature according to claim 1, characterized in that, The silica in the first filler is 1250 - mesh silica; the silica in the second filler is 1250 - mesh silica.

5. The epoxy resin adhesive for low temperature according to claim 1, characterized in that, In Component A, the mass ratio of SW - 70 to E51 is 1 - 4:2; the diamine curing agent is 4,4 - diaminodiphenylmethane.

6. The epoxy resin adhesive for low temperature according to claim 1, characterized in that The curing accelerator is DMP - 30.

7. The epoxy resin adhesive for low temperature according to claim 1, characterized in that, The defoamer is XY - 692.

8. The preparation method of the epoxy resin adhesive for low temperature according to any one of claims 1 to 7, characterized in that the steps It includes: Mix the raw materials including the silica and the reinforcing fibers to obtain the powdery first filler; Stir and mix SW - 70 and E51 to obtain a mixed resin; Mix the first filler and the mixed resin, add the defoamer, and heat and stir to obtain Component A; Mix the raw materials including the silica to obtain the second filler; Stir and mix the diamine curing agent and the second filler, add the curing accelerator, and heat and stir to obtain Component B.

9. The preparation method according to claim 8, characterized in that, The requirements for the heat - stirring are: heat up to 70°C and stir at a speed of 50 rpm for 2 h.

10. The method of using the epoxy resin adhesive for low temperature according to any one of claims 1 to 7, characterized in that, Stir and mix Component A and Component B according to a mass ratio of 1.5 - 1.7:1, raise the temperature to 40°C - 50°C during stirring, and cure at room temperature for 7 to 8 days after construction.

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