Epoxy resin dual-curing adhesive as well as preparation method and application thereof

Abstract

The invention provides an epoxy resin dual-curing adhesive as well as a preparation method and application thereof. The epoxy resin dual-curing adhesive comprises the following components: long-chain flexible acrylic acid modified epoxy resin, second epoxy resin, a cationic photoinitiator and a photosensitizer, the preparation raw materials of the long-chain flexible acrylic acid modified epoxy resin comprise long-chain flexible acrylic acid and first epoxy resin; the long-chain flexible acrylic acid comprises an acrylic acid derivative of which the main chain has more than 8 carbon atoms. Long-chain flexible acrylic acid modified epoxy resin is adopted for chain extension and toughening, unsaturated double bonds are introduced, then epoxy resin is added, the initial bonding force of the adhesive is improved, cationic ring-opening epoxy groups and UV free radicals are adopted for dual curing, and after UV irradiation, the shear strength and stripping force of the adhesive are improved; therefore, the toughness of the epoxy resin is obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and relates to an epoxy resin dual-curing adhesive, a preparation method and an application thereof, and specifically relates to an epoxy resin dual-curing adhesive based on long-chain flexible acrylic acid modification, a preparation method and an application thereof. Background Art

[0002] An adhesive is an inorganic or organic material that can firmly connect two or more materials together. It mainly achieves the bonding effect by generating chemical bonds and van der Waals forces at the interface. Epoxy resin is a common adhesive that is widely used in various fields due to its excellent bonding strength, chemical corrosion resistance and good mechanical properties. However, the curing process of epoxy resin usually requires high temperature and long time, which limits its use in certain applications. In addition, epoxy resin is brittle and prone to fracture under high stress environments.

[0003] In order to improve the brittleness of epoxy resin and increase its curing efficiency, researchers have proposed a variety of solutions. For example, toughening agents such as polyurethane and acrylate are added to increase the toughness of epoxy resin. In addition, some researchers have tried to blend epoxy resin with other polymer materials such as polyester resin and polyimide to improve the comprehensive performance of epoxy resin.

[0004] Although existing solutions can improve the performance of epoxy resins to a certain extent, there are still some problems. First, although adding toughening agents can improve the toughness of epoxy resins, it often reduces their bonding strength and chemical corrosion resistance. Second, although blending modification can give epoxy resins new functions, it may affect their original properties, and the compatibility and stability of the blends are also difficult to control.

[0005] Therefore, how to develop an epoxy resin adhesive that can maintain the original properties of epoxy resin while improving its toughness and curing efficiency is a problem that needs to be solved urgently in this field. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide an epoxy resin dual-curing adhesive and a preparation method and application thereof, and specifically to provide an epoxy resin dual-curing adhesive based on long-chain flexible acrylic acid modification and a preparation method and application thereof.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an epoxy resin dual-curing adhesive, the epoxy resin dual-curing adhesive comprising the following components: a long-chain flexible acrylic modified epoxy resin, a second epoxy resin, a cationic photoinitiator, and a photosensitizer;

[0009] The raw materials for preparing the long-chain flexible acrylic acid-modified epoxy resin include long-chain flexible acrylic acid and a first epoxy resin;

[0010] The long-chain flexible acrylic acid includes acrylic acid derivatives having 8 or more carbon atoms in the main chain (eg, 8, 9, 10, 12, 14, 16, etc.).

[0011] The present invention adopts long-chain flexible acrylic acid to modify epoxy resin for chain extension and toughening, introduces unsaturated double bonds, and then adds epoxy resin, thereby improving the initial bonding force of the adhesive, adopts cationic ring-opening epoxy groups and UV free radicals for dual curing, and improves the shear strength and peeling force of the adhesive after UV irradiation, thereby significantly improving the toughness of the epoxy resin; the present invention adopts UV curing technology, utilizes the effects of cationic photoinitiators and photosensitizers, and allows the epoxy resin to be quickly cured under UV irradiation, thereby greatly improving the curing efficiency of the epoxy resin; the present invention first adopts long-chain flexible acrylic acid to modify the epoxy resin, and then additionally adds epoxy resin, thereby improving the compatibility and stability of the system.

[0012] That is, the present invention achieves the effects of increasing initial bonding strength and improving shear strength and peel strength after UV irradiation by adding long-chain flexible acrylic acid and epoxy resin while adopting UV curing technology, thereby improving the performance of epoxy resin and reducing the curing cost of epoxy resin.

[0013] Preferably, the long-chain flexible acrylic acid includes any one of 2-((3-(acryloyloxy)propoxy)carbonyl)-1-methylcyclohexane-1-carboxylic acid, (E)-4-(2-(acryloyloxy)ethoxy)-4-oxobut-2-enoic acid, and 2-(((6-(acryloyloxy)-6-oxohexyl)oxy)carbonyl)benzoic acid, or a combination of at least two thereof.

[0014] The structural formula of 2-((3-(acryloyloxy)propoxy)carbonyl)-1-methylcyclohexane-1-carboxylic acid is as follows:

[0015]

[0016] The structural formula of (E)-4-(2-(acryloyloxy)ethoxy)-4-oxobut-2-enoic acid is as follows:

[0017]

[0018] The structural formula of 2-(((6-(acryloyloxy)-6-oxohexyl)oxy)carbonyl)benzoic acid is as follows:

[0019]

[0020] Preferably, the first epoxy resin comprises bisphenol A epoxy resin and / or bisphenol F epoxy resin.

[0021] Preferably, the long-chain flexible acrylic acid-modified epoxy resin is prepared by the following method:

[0022] The long-chain flexible acrylic acid and the first epoxy resin are mixed and reacted to obtain the long-chain flexible acrylic acid-modified epoxy resin.

[0023] Preferably, the mass ratio of the long-chain flexible acrylic acid to the first epoxy resin is 1:(1.5-2.5), for example, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, etc.

[0024] Preferably, the reaction is carried out in the presence of a catalyst.

[0025] Preferably, the catalyst comprises triphenylphosphine.

[0026] Preferably, the amount of the catalyst is 0.3%-0.8% of the total weight of the long-chain flexible acrylic acid and the first epoxy resin, for example, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, etc.

[0027] Preferably, the reaction temperature is 60-150°C, for example 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc., and the reaction time is 1-3 hours, for example 1 hour, 2 hours, 3 hours, etc.

[0028] Preferably, the second epoxy resin comprises an aliphatic epoxy resin.

[0029] Preferably, the second epoxy resin includes 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate.

[0030] Preferably, the cationic photoinitiator includes any one of Omnicat 250, Omnicat 432 or QITAI 1176, or a combination of at least two thereof.

[0031] Preferably, the photosensitizer includes photoinitiator 184 (Irgacure 184).

[0032] Preferably, the epoxy resin dual-curing adhesive comprises the following components in parts by weight:

[0033]

[0034] Preferably, the epoxy resin dual-curing adhesive may include 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, etc., in amounts by weight.

[0035] Preferably, the epoxy resin dual-curing adhesive may include 80 parts, 82 parts, 84 parts, 86 parts, 88 parts, 90 parts, 92 parts, 94 parts, 96 parts, 98 parts, 100 parts, 102 parts, 104 parts, 106 parts, 108 parts, 110 parts, 112 parts, 114 parts, 116 parts, 118 parts, 120 parts, etc. in amounts by weight.

[0036] Preferably, the amount of the cationic photoinitiator in the epoxy resin dual-curing adhesive can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc., calculated by weight.

[0037] Preferably, the amount of the photosensitizer in the epoxy resin dual-curing adhesive can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc., based on parts by weight.

[0038] In a second aspect, the present invention provides a method for preparing the epoxy resin dual-curing adhesive as described in the first aspect, the preparation method comprising the following steps:

[0039] The long-chain flexible acrylic modified epoxy resin is mixed with the second epoxy resin, and then a cationic photoinitiator and a photosensitizer are added and mixed again to obtain the epoxy resin dual-curing adhesive.

[0040] In a third aspect, the present invention provides a bonding method of the epoxy resin dual-curing adhesive as described in the first aspect, the bonding method comprising the following steps:

[0041] The epoxy resin dual-curing adhesive is coated on the substrate, and the epoxy resin dual-curing adhesive is irradiated and cured by a UV light source to complete the bonding.

[0042] Preferably, the power of the UV light source is 450-550W, for example 450W, 460W, 470W, 480W, 490W, 500W, 510W, 520W, 530W, 540W, 550W, etc.

[0043] Preferably, the irradiation time is 1-2 minutes, such as 1 minute, 1.5 minutes, 2 minutes, etc.

[0044] Preferably, the curing temperature is 55-65°C, for example, 55°C, 58°C, 60°C, 62°C, 63°C, 65°C, etc.

[0045] In summary, in order to solve the problems in the prior art, the main technical means adopted by the present invention are as follows: 1. Use long-chain flexible acrylic acid to modify epoxy resin for chain extension and toughening: First, mix long-chain flexible acrylic acid with epoxy resin, introduce unsaturated double bonds through chemical reaction, thereby increasing the flexibility of epoxy resin and improving its fracture resistance. 2. Add epoxy resin: Add an appropriate amount of epoxy resin to the modified epoxy resin to enhance the initial adhesion. 3. Use cationic ring-opening epoxy group and UV free radical dual curing: Add cationic photoinitiator and photosensitizer to the mixture, use UV light source for irradiation, so that the epoxy group undergoes cationic ring-opening reaction, and at the same time initiates free radical polymerization reaction, thereby improving shear strength and peeling force after UV irradiation. 4. Control curing temperature and time: By adjusting the power and irradiation time of the UV light source, the curing temperature and time of the epoxy resin are controlled to improve the curing efficiency and shorten the curing cycle. 5. Select the appropriate photosensitizer and photoinitiator: Selecting the appropriate photosensitizer and photoinitiator can not only ensure the effect of UV curing, but also reduce the generation of harmful ultraviolet radiation and reduce the curing cost. 6. Optimize the blending ratio: By optimizing the blending ratio of long-chain flexible acrylic modified epoxy resin, epoxy resin, photosensitizer and photoinitiator, the compatibility and stability of epoxy resin can be improved.

[0046] In a fourth aspect, the present invention provides a use of the epoxy resin dual-curing adhesive as described in the first aspect in an adhesive or a sealant.

[0047] The epoxy resin dual-curing adhesive provided by the present invention is widely used in the fields of adhesives and sealants, composite materials, and polymer chemistry. In the field of adhesives and sealants, the present invention provides a new type of epoxy resin adhesive, which not only maintains the original excellent bonding strength, chemical corrosion resistance, and good mechanical properties of epoxy resin, but also introduces long-chain flexible acrylic modified epoxy resin for chain extension and toughening, so that the toughness of the adhesive is significantly improved, and it can better adapt to high stress environments and meet various industrial application requirements. At the same time, by adopting cationic ring-opening epoxy groups and UV free radical dual curing, not only the curing time is greatly shortened and the production efficiency is improved, but also the problem of high temperature and long time required in the traditional epoxy resin curing process is avoided, energy consumption is reduced, and there is significant economic benefit. In the field of composite materials, the epoxy resin adhesive provided by the present invention can be used as a matrix material and compounded with other reinforcing materials such as carbon fiber, glass fiber, etc. to prepare a high-performance composite material. Since the epoxy resin adhesive in the present invention has excellent bonding properties and mechanical properties, it can effectively transfer loads, improve the strength and toughness of composite materials, and meet the needs of aerospace, automobile manufacturing, wind power generation and other fields for high-performance composite materials. In the field of polymer chemistry, the present invention provides a novel epoxy resin synthesis method, by introducing a long-chain flexible acrylic modified epoxy resin for chain extension and toughening, then adding epoxy resin, using cationic ring-opening epoxy groups and UV free radicals for dual curing, the modification of epoxy resin is achieved. This synthesis method is not only simple to operate, but also has mild reaction conditions, and can accurately control the reaction process and improve the quality of the product. Therefore, the adhesive provided by the present invention has important application value in the field of polymer chemistry, and is expected to promote the research and development and application of epoxy resin and related materials thereof. In general, the adhesive provided by the present invention has broad application prospects in the fields of adhesives and sealants, composite materials and polymer chemistry, and has huge market demand, and is expected to promote technological progress and industrial development in related fields.

[0048] Compared with the prior art, the present invention has at least the following beneficial effects:

[0049] (1) The present invention uses long-chain flexible acrylic acid to modify epoxy resin for chain extension and toughening, introduces unsaturated double bonds, and then adds epoxy resin, and adopts cationic ring-opening epoxy groups and UV free radical dual curing. This design not only maintains the original bonding strength and chemical corrosion resistance of the epoxy resin, but also improves the toughness and curing efficiency of the epoxy resin by introducing long-chain flexible acrylic acid and double bonds.

[0050] (2) The curing process of the present invention does not require high temperature and long time, only UV irradiation is required, which greatly shortens the curing time and improves production efficiency. At the same time, due to the use of dual curing of UV curing and free radical curing, the use of expensive UV light source equipment is avoided, and harmful ultraviolet radiation is also reduced, which is more environmentally friendly and safe.

[0051] (3) The blending modification method of the present invention first uses long-chain flexible acrylic acid to modify the epoxy resin, and then adds additional epoxy resin, which not only gives the epoxy resin new functions but also maintains its original properties; moreover, by optimizing the compatibility and stability of the blend, the overall performance of the blend is improved.

[0052] (4) The initial bonding strength, shear strength and peel strength of the adhesive of the present invention after UV irradiation are significantly improved, indicating that the epoxy resin adhesive of the present invention has better bonding performance and durability.

[0053] (5) The epoxy resin dual-curing adhesive of the present invention has a simple preparation process, readily available raw materials, low cost, and is suitable for large-scale production.

[0054] In summary, compared with the prior art, the present invention not only improves the toughness and curing efficiency of epoxy resin, but also maintains its original performance, is more environmentally friendly and safe, has higher bonding performance and durability, and has a simple preparation process, low cost, and is suitable for large-scale production, with significant advantages. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] Preparation Example 1

[0057] In this preparation example, a long-chain flexible acrylic acid-modified epoxy resin is provided, and the preparation method comprises the following steps:

[0058] The long-chain flexible acrylic acid, epoxy resin and catalyst (triphenylphosphine) are mixed and reacted at 90° C. for 3 hours to obtain the long-chain flexible acrylic acid-modified epoxy resin;

[0059] Among them, the long-chain flexible acrylic acid is 2-((3-(acryloyloxy)propoxy)carbonyl)-1-methylcyclohexane-1-carboxylic acid, the epoxy resin is bisphenol A epoxy resin (128 epoxy resin), the mass ratio of the long-chain flexible acrylic acid and the epoxy resin is 1:2, and the amount of the catalyst used is 0.5% of the total weight of the long-chain flexible acrylic acid and the epoxy resin.

[0060] Preparation Example 2

[0061] In this preparation example, a long-chain flexible acrylic acid-modified epoxy resin is provided, and the preparation method comprises the following steps:

[0062] The long-chain flexible acrylic acid, epoxy resin and catalyst (triphenylphosphine) are mixed and reacted at 100° C. for 2 hours to obtain the long-chain flexible acrylic acid-modified epoxy resin;

[0063] Among them, the long-chain flexible acrylic acid is (E)-4-(2-(acryloyloxy)ethoxy)-4-oxobut-2-enoic acid, the epoxy resin is bisphenol A epoxy resin (128 epoxy resin), the mass ratio of the long-chain flexible acrylic acid and the epoxy resin is 1:1.5, and the amount of the catalyst used is 0.5% of the total weight of the long-chain flexible acrylic acid and the epoxy resin.

[0064] Preparation Example 3

[0065] In this preparation example, a long-chain flexible acrylic acid-modified epoxy resin is provided, and the preparation method comprises the following steps:

[0066] The long-chain flexible acrylic acid, epoxy resin and catalyst (triphenylphosphine) are mixed and reacted at 100° C. for 2 hours to obtain the long-chain flexible acrylic acid-modified epoxy resin;

[0067] Among them, the long-chain flexible acrylic acid is 2-(3-(acryloyloxy)propoxy)carbonyl)-1-methylcyclohexane-1-carboxylic acid, the epoxy resin is bisphenol F epoxy resin (NPEF-170), the mass ratio of the long-chain flexible acrylic acid and the epoxy resin is 1:2.5, and the amount of the catalyst used is 0.5% of the total weight of the long-chain flexible acrylic acid and the epoxy resin.

[0068] Comparative Preparation Example 1

[0069] This comparative preparation example provides an acrylic acid-modified epoxy resin, which is different from Preparation Example 1 only in that the long-chain flexible acrylic acid is replaced by an acrylic acid of equal weight.

[0070] Example 1

[0071] In this embodiment, an epoxy resin dual-curing adhesive is provided, and the epoxy resin dual-curing adhesive comprises the following components in parts by weight:

[0072]

[0073] The long-chain flexible acrylic modified epoxy resin is provided by Preparation Example 1, the epoxy resin is 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, the cationic photoinitiator is Omnicat 250, and the photosensitizer is Irgacure184.

[0074] The preparation method comprises the following steps:

[0075] The epoxy resin dual-curing adhesive is obtained by mixing a formulated amount of long-chain flexible acrylic acid-modified epoxy resin with epoxy resin, then adding a cationic photoinitiator and a photosensitizer, and mixing again.

[0076] Example 2

[0077] In this embodiment, an epoxy resin dual-curing adhesive is provided, and the epoxy resin dual-curing adhesive comprises the following components in parts by weight:

[0078]

[0079] The long-chain flexible acrylic modified epoxy resin is provided by Preparation Example 2, the epoxy resin is 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, the cationic photoinitiator is Omnicat 432, and the photosensitizer is Irgacure184.

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

[0081] Example 3

[0082] In this embodiment, an epoxy resin dual-curing adhesive is provided, and the epoxy resin dual-curing adhesive comprises the following components in parts by weight:

[0083]

[0084] The long-chain flexible acrylic modified epoxy resin is provided by Preparation Example 3, the epoxy resin is 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, the cationic photoinitiator is QIT 1176, and the photosensitizer is Irgacure 184.

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

[0086] Example 4

[0087] In this embodiment, an epoxy resin dual-curing adhesive is provided, and the epoxy resin dual-curing adhesive comprises the following components in parts by weight:

[0088]

[0089] The long-chain flexible acrylic modified epoxy resin is provided by Preparation Example 1, the epoxy resin is 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester, the cationic photoinitiator is Omnicat 432, and the photosensitizer is Irgacure184.

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

[0091] Comparative Example 1

[0092] The only difference between this comparative example and Example 1 is that the long-chain flexible acrylic modified epoxy resin is replaced by the acrylic modified epoxy resin provided in Comparative Preparation Example 1.

[0093] Comparative Example 2

[0094] The only difference between this comparative example and Example 1 is that the amount of the long-chain flexible acrylic modified epoxy resin used is 30 parts.

[0095] Comparative Example 3

[0096] The only difference between this comparative example and Example 1 is that the amount of the long-chain flexible acrylic modified epoxy resin used is 70 parts.

[0097] The epoxy resin dual-curing adhesive provided in the embodiment and the comparative example was tested, and the test method was as follows:

[0098] (1) Initial Adhesion Strength: According to GBT 2792-1998, the epoxy resin dual-curing adhesive provided in the Examples and Comparative Examples was coated onto a 50 μm thick PET film using a laboratory coater to make the film thickness 30 μm. A 25.4 mm wide and 250 mm long adhesive tape was bonded to a cleaned aluminum test plate. A pressure roller was moved back and forth on the test plate three times at a speed of 300 mm / min under its own weight. After standing for 20 minutes, a 180° peel strength test was performed at a test speed of 300 mm / min.

[0099] (2) Open time: sensory evaluation. It takes a lot of force to tear the tape by hand. It is the time from when the tape is attached to the aluminum plate to when it becomes difficult to tear.

[0100] (3) Final shear strength: After UVB irradiation, the aluminum plate was bonded within 2 minutes. According to GB / T33332-2016, the tape sample was placed at the center of one end of the test aluminum plate. Without applying pressure, the tape sample was evenly rolled and pasted within an area of ​​(12±0.5) mm×(12±0.5) mm using the mass of the roller itself. The coating thickness was 30 μm, and the substrate was 50 μm transparent PET. The back of the tape was fixed with Debon 2020 structural adhesive (fixed in the middle with copper wire (2 μm in diameter) to form a certain thickness). The test speed was 5 mm / min.

[0101] (4) Final peeling force: According to GBT 2792-1998, the epoxy resin dual-curing adhesive provided in the embodiment and the comparative example was coated on a 50 μm thick PET film using a laboratory coater to make the film thickness 30 μm. Then, a 365 nm LED UV curing machine was used at 2000 mJ / cm 2The energy of the adhesive surface (25.4mm×200mm) was irradiated, and the irradiated tape was attached to an aluminum plate (size: 30mm×120mm) within 1 minute. Subsequently, the obtained laminate was placed at 23°C and its reaction rate was tested by infrared; after the reaction was complete, the 180° peel strength was tested.

[0102] The performance test results are shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106] It can be seen from Table 1 that the epoxy resin dual-curing adhesives provided in the embodiments of the present invention all have high initial adhesion (5.6-8.2 N / 25 mm), and have high shear strength (9.8-12.4 MPa) and peel strength (18.6-22.7 N / 25 mm) after UV irradiation curing.

[0107] Compared with Example 1, the epoxy resin dual-curing adhesive provided in Comparative Example 1 adopts conventional acrylic modified epoxy resin, and the adhesive has insufficient bonding force to the surface of the adhered object, resulting in low peeling force and shear strength. The epoxy resin dual-curing adhesive provided in Comparative Example 2 has a small amount of long-chain flexible acrylic modified epoxy resin, and insufficient wetting of the surface of the back-adhesive aluminum plate, resulting in insufficient peeling force and shear strength. The epoxy resin dual-curing adhesive provided in Comparative Example 3 has a large amount of long-chain flexible acrylic modified epoxy resin, insufficient cohesion of the adhesive layer, and reduced shear strength.

[0108] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the epoxy resin dual-curing adhesive of the present invention and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An epoxy resin dual-curing adhesive, characterized in that: The epoxy resin dual-curing adhesive comprises the following components: a long-chain flexible acrylic modified epoxy resin, a second epoxy resin, a cationic photoinitiator, and a photosensitizer; The raw materials for preparing the long-chain flexible acrylic acid-modified epoxy resin include long-chain flexible acrylic acid and a first epoxy resin; The long-chain flexible acrylic acid includes acrylic acid derivatives with a main chain carbon number of 8 or more.

2. The epoxy resin dual-curing adhesive according to claim 1, characterized in that: The long-chain flexible acrylic acid includes any one of 2-((3-(acryloyloxy)propoxy)carbonyl)-1-methylcyclohexane-1-carboxylic acid, (E)-4-(2-(acryloyloxy)ethoxy)-4-oxobut-2-enoic acid, and 2-(((6-(acryloyloxy)-6-oxohexyl)oxy)carbonyl)benzoic acid, or a combination of at least two thereof.

3. The epoxy resin dual-curing adhesive according to claim 1 or 2, characterized in that: The first epoxy resin includes bisphenol A epoxy resin and / or bisphenol F epoxy resin.

4. The epoxy resin dual-curing adhesive according to any one of claims 1 to 3, characterized in that: The long-chain flexible acrylic acid-modified epoxy resin is prepared by the following method: The long-chain flexible acrylic acid and the first epoxy resin are mixed and reacted to obtain the long-chain flexible acrylic acid-modified epoxy resin.

5. The epoxy resin dual-curing adhesive according to claim 4, characterized in that: The mass ratio of the long-chain flexible acrylic acid to the first epoxy resin is 1:(1.5-2.5); Preferably, the reaction is carried out in the presence of a catalyst; Preferably, the catalyst comprises triphenylphosphine; Preferably, the catalyst is used in an amount of 0.3% to 0.8% of the total weight of the long-chain flexible acrylic acid and the first epoxy resin; Preferably, the reaction temperature is 60-150° C., and the reaction time is 1-3 hours.

6. The epoxy resin dual-curing adhesive according to any one of claims 1 to 5, characterized in that: The second epoxy resin comprises an aliphatic epoxy resin; Preferably, the second epoxy resin comprises 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate; Preferably, the cationic photoinitiator comprises any one of Omnicat 250, Omnicat 432 or QiTi 1176 or a combination of at least two thereof; Preferably, the photosensitizer includes a photoinitiator 184 .

7. The epoxy resin dual-curing adhesive according to any one of claims 1 to 6, characterized in that: The epoxy resin dual-curing adhesive comprises the following components in parts by weight:

8. A method for preparing the epoxy resin dual-curing adhesive according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The long-chain flexible acrylic modified epoxy resin is mixed with the second epoxy resin, and then a cationic photoinitiator and a photosensitizer are added and mixed again to obtain the epoxy resin dual-curing adhesive.

9. A bonding method using the epoxy resin dual-curing adhesive as claimed in any one of claims 1 to 7, characterized in that: The bonding method comprises the following steps: Applying an epoxy resin dual-curing adhesive on a substrate, and curing the epoxy resin dual-curing adhesive by irradiation with a UV light source to complete bonding; Preferably, the power of the UV light source is 450-550W; Preferably, the irradiation time is 1-2 minutes; Preferably, the curing temperature is 55-65°C.

10. Use of the epoxy resin dual-curing adhesive according to any one of claims 1 to 7 in an adhesive or a sealant.

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