An epoxy adhesive, its preparation method and application

Abstract

The application provides an epoxy adhesive as well as a preparation method and application thereof, raw materials of the epoxy adhesive include, by mass fraction, 62-80 parts of polybutadiene with terminal epoxy groups, 24-37 parts of epoxy resin, 1-20 parts of fumed silica, 16-26 parts of a curing agent, 1-10 parts of a diluent, 0.5-3 parts of a coupling agent and 0.5-5 parts of a curing accelerator. The epoxy adhesive has excellent elastic performance and strength in a low-temperature environment.

Description

Technical Field

[0001] This invention relates to an epoxy adhesive, its preparation method, and its application, belonging to the field of rubber materials. Background Technology

[0002] Epoxy adhesives are often called universal adhesives because they have many excellent properties, such as good adhesion, high adhesive strength, dimensional stability, excellent electrical properties, resistance to chemical media, and simple processing. They are widely used in aerospace, construction, machinery, electrical appliances and other fields.

[0003] The bonding process of epoxy adhesives is a complex physical and chemical process, including steps such as wetting, adhesion, and curing, ultimately forming a cured product with a three-dimensional cross-linked structure to achieve bonding. However, the cured product formed during the bonding process of existing epoxy adhesives becomes brittle at low temperatures, easily cracking and severely affecting the performance of the epoxy adhesive. Therefore, developing a novel epoxy adhesive whose cured product possesses excellent elastic properties and strength in low-temperature environments has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] This invention provides an epoxy adhesive whose cured product exhibits excellent elasticity and strength in low-temperature environments.

[0005] The present invention also provides a method for preparing an epoxy adhesive. The cured epoxy adhesive prepared by this method has good elastic properties and strength in a low-temperature environment. Moreover, the preparation method has the advantages of simple preparation process and easy operation.

[0006] The present invention also provides a battery that uses the above-mentioned epoxy adhesive, which can perform well in low-temperature environments, and especially when used as a sealant, it can facilitate battery disassembly and repair.

[0007] The first aspect of the present invention provides an epoxy adhesive, wherein the raw materials of the epoxy adhesive include, by weight, 62-80 parts of epoxy-terminated polybutadiene, 24-37 parts of epoxy resin, 1-20 parts of fumed silica, 16-26 parts of curing agent, 1-10 parts of diluent, 0.5-3 parts of coupling agent, and 0.5-5 parts of curing accelerator.

[0008] According to one embodiment of the present invention, the epoxy value of the terminal epoxy polybutadiene is 0.03-0.07 mol / 100g.

[0009] According to one embodiment of the present invention, the epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, and phenolic epoxy resin;

[0010] And / or, the curing agent includes at least one of aliphatic amine curing agents, alicyclic amine curing agents, aromatic amine curing agents, polyether amine curing agents, and polyamide curing agents;

[0011] And / or, the diluent includes at least one of benzyl glycidyl ether and neopentyl glycol diglycidyl ether;

[0012] And / or, the coupling agent is at least one of KH550, KH560, and KH570.

[0013] According to one embodiment of the present invention, the curing agent comprises the polyetheramine curing agent and the polyamide curing agent, wherein the mass ratio of the polyetheramine curing agent to the polyamide curing agent is not less than 2:1.

[0014] According to one embodiment of the present invention, the epoxy adhesive is prepared by a method comprising the following steps:

[0015] After mixing components A and B, the mixture is subjected to vacuum degassing and curing treatment in sequence to obtain the epoxy adhesive.

[0016] Component A includes the epoxy-terminated polybutadiene, the epoxy resin, the fumed silica, the diluent, and the coupling agent; component B includes the curing agent, the curing accelerator, and the fumed silica.

[0017] In another aspect, the present invention provides a method for preparing an epoxy adhesive, comprising the following steps: the preparation method includes the following steps:

[0018] After mixing components A and B, the mixture is subjected to vacuum degassing and curing treatment in sequence to obtain the epoxy adhesive.

[0019] Component A includes epoxy-terminated polybutadiene, epoxy resin, fumed silica, diluent, and coupling agent; component B includes curing agent, curing accelerator, and fumed silica.

[0020] According to one embodiment of the present invention, the portion of fumed silica is 0.5-10 parts, and the remaining fumed silica is 0.5-10 parts by mass.

[0021] According to one embodiment of the present invention, a mixture comprising epoxy-terminated polybutadiene, epoxy resin, a portion of fumed silica, a diluent, and a coupling agent is subjected to a first vacuum degassing treatment to obtain component A, wherein the vacuum degree of the first vacuum degassing treatment is not higher than -0.09 MPa; and / or,

[0022] The mixture system comprising curing agent, curing accelerator and residual fumed silica is subjected to a second vacuum degassing treatment to obtain component B. The vacuum degree of the second vacuum degassing treatment is not higher than -0.09 MPa.

[0023] According to one embodiment of the present invention, the curing treatment is performed at a temperature of 50-70°C for 3-8 days.

[0024] Another aspect of the present invention provides a battery comprising the above-described epoxy adhesive.

[0025] The epoxy adhesive of this invention is prepared by reacting raw materials according to a certain mass ratio. The epoxy-terminated polybutadiene contains a large number of double bonds, exhibiting a certain degree of toughness at low temperatures, while the epoxy resin possesses a certain degree of strength. The epoxy-terminated polybutadiene and epoxy resin are compounded in a certain mass ratio and then cured with a curing agent. The resulting cured product not only maintains considerable elasticity at low temperatures but also possesses a certain degree of strength. Furthermore, the addition of fumed silica, diluent, curing accelerator, and coupling agent enables the epoxy adhesive to maintain sufficient elasticity and strength while also exhibiting excellent performance characteristics.

[0026] The preparation method of the epoxy adhesive of the present invention prepares the above-mentioned epoxy adhesive, which has good elastic properties and strength even in low temperature environment, and the preparation process is simple, easy to operate, does not require harsh conditions, and is environmentally friendly.

[0027] The battery provided by this invention includes the above-mentioned epoxy adhesive, and therefore has good performance in low-temperature environments. In particular, when used as a sealant, it facilitates battery disassembly and repair. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] The first aspect of this invention provides an epoxy adhesive, wherein the raw materials of the epoxy adhesive include, by weight, 62-80 parts of epoxy-terminated polybutadiene, 24-37 parts of epoxy resin, 1-20 parts of fumed silica, 16-26 parts of curing agent, 1-10 parts of diluent, 0.5-3 parts of coupling agent, and 0.5-5 parts of curing accelerator.

[0030] This invention does not limit the specific selection of epoxy resin, fumed silica, curing agent, diluent, coupling agent, and curing accelerator; commonly used compounds in the art can be selected according to the actual situation.

[0031] The epoxy-terminated polybutadiene referred to in this invention is a homopolymer or copolymer having epoxy groups at both ends. This invention does not limit the number-average molecular weight of the epoxy-terminated polybutadiene; the number-average molecular weight can be selected according to actual conditions, for example, a number-average molecular weight of 400 to 10000.

[0032] Specifically, the amount of epoxy-terminated polybutadiene is 62-80 parts by weight. For example, the amount of epoxy-terminated polybutadiene by weight includes, but is not limited to, a range of 62, 64, 66, 68, 70, 72, 74, 76, 78, 80 or any two of these.

[0033] The epoxy resin is 24-37 parts by weight. For example, the epoxy resin is composed of, but is not limited to, 24, 26, 28, 30, 32, 34, 36, 37 or any two of these.

[0034] The mass fraction of fumed silica is 1-20 parts, for example, the mass fraction of fumed silica includes, but is not limited to, a range of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 or any two of these.

[0035] The curing agent is 16-26 parts by weight. For example, the curing agent may be in the range of 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 or any two of these.

[0036] The diluent is supplied in parts by weight of 1 to 10. For example, the parts by weight of the diluent include, but are not limited to, a range consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or any two of these.

[0037] The coupling agent is used in portions of 0.5 to 3 parts by weight. For example, the mass of the coupling agent includes, but is not limited to, a range of 0.5, 1, 1.5, 2, 2.5, 3, or any two of these.

[0038] The curing accelerator is used in portions of 0.5-5 parts by weight. For example, the curing accelerator may be in portions of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 or any combination thereof.

[0039] According to the solution provided by the present invention, the epoxy adhesive formed after curing the mixture of the above-mentioned raw materials in the above-mentioned mass parts exhibits excellent elastic properties and strength at low temperatures, specifically including elongation at break, tensile strength, Shore hardness, etc. Based on this phenomenon, the inventors analyzed that the reason may be: when the raw materials of the epoxy adhesive include the above-mentioned components, the epoxy-terminated polybutadiene contains a large number of double bonds, exhibiting a certain degree of flexibility at low temperatures, while the epoxy resin possesses a certain degree of strength. Curing the epoxy-terminated polybutadiene and epoxy resin with a curing agent in a certain mass part results in a cured product that not only maintains considerable elasticity at low temperatures but also possesses a certain degree of strength. Furthermore, the addition of a certain mass part of fumed silica, diluent, curing accelerator, and coupling agent further strengthens and thickens the epoxy adhesive while maintaining sufficient elasticity and strength, thereby improving the performance of the epoxy adhesive.

[0040] Therefore, the excellent elastic properties of the epoxy adhesive of the present invention in low-temperature environments can meet the requirements for use of adhesives in low-temperature environments.

[0041] Based on the above-mentioned characteristics of the epoxy adhesive of the present invention, the epoxy adhesive of the present invention can be applied to fields including civil engineering, electronics, special coatings, automotive machinery and aerospace materials.

[0042] Furthermore, according to a specific embodiment of the present invention, the epoxy value of the epoxy-terminated polybutadiene is 0.03-0.07 mol / 100g.

[0043] Specifically, the epoxy value of the epoxy-terminated polybutadiene includes, but is not limited to, a range consisting of 0.030 mol / 100g, 0.035 mol / 100g, 0.040 mol / 100g, 0.045 mol / 100g, 0.050 mol / 100g, 0.055 mol / 100g, 0.060 mol / 100g, 0.065 mol / 100g, 0.07 mol / 100g, or any two of these ranges.

[0044] When the epoxy value of the epoxy-terminated polybutadiene is within the above range, on the one hand, it can further improve the elastic properties of epoxy adhesives in low-temperature environments; on the other hand, the epoxy-terminated polybutadiene with the above epoxy value is simple and readily available, reducing raw material costs.

[0045] Furthermore, according to a specific embodiment of the present invention, the epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, and phenolic epoxy resin.

[0046] And / or, the curing agent includes at least one of aliphatic amine curing agents, cycloaliphatic amine curing agents, aromatic amine curing agents, polyether amine curing agents, and polyamide curing agents;

[0047] And / or, the diluent includes at least one of benzyl glycidyl ether and neopentyl glycol diglycidyl ether;

[0048] And / or, the coupling agent is at least one of KH550, KH560, and KH570.

[0049] This invention does not limit the specific molecular weight and viscosity of bisphenol A type epoxy resin, bisphenol F type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, or phenolic epoxy resin. The required epoxy resin can be selected according to actual needs, such as bisphenol A type epoxy resin with an epoxy equivalent (eew(g / eq)) of 180-190 and a viscosity (cps@25℃) of 8000-15000. One type of epoxy resin can be selected, or multiple epoxy resins can be mixed and used.

[0050] This invention does not limit the specific product parameters of aliphatic amine curing agents, cycloaliphatic amine curing agents, aromatic amine curing agents, polyether amine curing agents, and polyamide curing agents. One of them can be used as a curing agent, or multiple types can be selected and mixed to form a curing agent.

[0051] When the above-mentioned raw materials are selected, not only can the elasticity of epoxy adhesives be guaranteed in low-temperature environments, but the raw materials are also simple and readily available, saving the preparation cost of epoxy adhesives.

[0052] Furthermore, according to a specific embodiment of the present invention, the curing agent includes a polyetheramine curing agent and a polyamide curing agent, wherein the mass ratio of the polyetheramine curing agent to the polyamide curing agent is not less than 2:1.

[0053] Specifically, the mass ratio of polyetheramine curing agent to polyamide curing agent is not less than 2:1. For example, the mass ratio of polyetheramine curing agent to polyamide curing agent includes, but is not limited to, 2:1, 2.5:1, 3:1, 3.5:1, 4:1 or any two of these ranges.

[0054] When the curing agent includes polyetheramine curing agent and polyamide curing agent and is formulated according to the above mass ratio, the crosslinking density of the epoxy adhesive obtained after curing treatment can be effectively reduced, the flexibility of the crosslinking network can be increased, and the elasticity of the cured product in low temperature environment can be further improved.

[0055] This invention does not limit the specific preparation method of the epoxy adhesive, as long as the mixing and curing reaction of the various raw materials can be achieved, thus enabling the epoxy adhesive product to function. For example, the raw materials can be weighed according to the above-mentioned mass proportions, directly mixed, and allowed to undergo a curing reaction to obtain the epoxy adhesive.

[0056] To further improve the storage stability of epoxy adhesives before curing, components A (terminated epoxy polybutadiene, epoxy resin, a portion of fumed silica, diluent, and coupling agent) and components B (curing agent, curing accelerator, and remaining fumed silica) can be prepared separately. Components A and B are then mixed before use to allow a curing reaction, resulting in the epoxy adhesive. This avoids premature curing of the epoxy adhesive at certain temperatures and improves its performance.

[0057] Furthermore, according to a specific embodiment of the present invention, the epoxy adhesive is prepared by a method comprising the following processes:

[0058] After mixing components A and B, the mixture is subjected to vacuum degassing and curing treatment in sequence to obtain epoxy adhesive.

[0059] Component A includes epoxy-terminated polybutadiene, epoxy resin, some fumed silica, diluent, and coupling agent; Component B includes curing agent, curing accelerator, and remaining fumed silica.

[0060] Specifically, component A refers to the raw material system obtained by mixing epoxy-terminated polybutadiene, epoxy resin, a portion of fumed silica, diluent, and coupling agent; component B refers to the raw material system obtained by mixing curing agent, curing accelerator, and remaining fumed silica.

[0061] After mixing components A and B, the air bubbles in the mixture are removed by vacuum degassing. Then, at a certain temperature, the epoxy-terminated polybutadiene and epoxy resin in component A and the curing agent in component B undergo a curing reaction in an atmosphere of fumed silica, diluent, coupling agent and curing accelerator to obtain epoxy adhesive.

[0062] The above preparation method can not only produce epoxy adhesives with high elasticity and high strength under low temperature conditions, but also is simple and easy to operate, without the need for harsh preparation conditions, which further improves the performance of epoxy adhesives and facilitates the preparation and promotion of epoxy adhesives in this invention.

[0063] As described above, the present invention does not limit the specific preparation method of epoxy adhesive, and commonly used epoxy adhesive preparation methods in the art can be selected according to the actual situation.

[0064] To improve the storage stability of epoxy adhesives before curing and ensure their performance, this invention also provides a method for preparing epoxy adhesives, comprising the following steps:

[0065] After mixing components A and B, the mixture is subjected to vacuum degassing and curing treatment in sequence to obtain the epoxy adhesive.

[0066] Component A includes epoxy-terminated polybutadiene, epoxy resin, fumed silica, diluent, and coupling agent; component B includes curing agent, curing accelerator, and fumed silica.

[0067] Specifically, component A refers to the raw material system obtained by mixing epoxy-terminated polybutadiene, epoxy resin, a portion of fumed silica, diluent, and coupling agent; component B refers to the raw material system obtained by mixing curing agent, curing accelerator, and remaining fumed silica.

[0068] This invention does not limit the specific preparation process of component A and component B, and can choose common preparation methods in the art.

[0069] This invention does not limit the order in which raw materials are added during the preparation of components A and B, and can be adjusted according to actual needs.

[0070] After mixing components A and B, the mixture is subjected to vacuum degassing and curing treatments in sequence to obtain epoxy adhesive.

[0071] In detail, the purpose of vacuum degassing is to ensure that the raw materials are mixed evenly and without interference from the external environment, thus guaranteeing the uniformity of the raw material system. This is beneficial for maximizing the elasticity and strength of the cured epoxy adhesive at low temperatures by improving the utilization rate of the raw materials and ensuring sufficient curing reaction between the raw materials.

[0072] This invention does not limit the specific method of vacuum degassing treatment. For example, the mixed system can be treated in a vacuum environment at a certain temperature. The specific temperature, pressure and time can be adjusted according to the specific type and mass fraction of each raw material in component A and component B.

[0073] After degassing, the mixture needs to be cured to allow the epoxy-terminated polybutadiene, epoxy resin, and curing agent to undergo a curing reaction, resulting in an epoxy adhesive.

[0074] The specific curing temperature and time can be determined based on the selection of raw materials and the proportions between them.

[0075] The above preparation method can not only produce epoxy adhesives with high elasticity and high strength under low temperature conditions, but also is simple and easy to operate, without the need for harsh preparation conditions, which facilitates the preparation and promotion of the epoxy adhesives in this invention.

[0076] Furthermore, in one specific embodiment of the present invention, the fumed silica comprises 0.5-10 parts and the remaining fumed silica comprises 0.5-10 parts.

[0077] The epoxy adhesive provided by this invention may require components A and B to be stored before mixing and use. During storage, crystallization and precipitation may occur, affecting the use of the epoxy adhesive. Therefore, fumed silica is added to components A and B of this invention to play a rheological control role and prevent precipitation and crystallization.

[0078] The fumed silica comprises 0.5-10 parts, and the remaining fumed silica comprises 0.5-10 parts. For example, the mass fraction of the fumed silica includes, but is not limited to, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, or any two of these ranges.

[0079] The remaining fumed silica mass fractions include, but are not limited to, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10 or any two of these ranges.

[0080] When the mass fractions of partial fumed silica and remaining fumed silicon disilicide meet the above range, they can better play a role in rheological control, further reduce the difficulty of mixing component A and component B, and improve the preparation efficiency of epoxy adhesives.

[0081] Furthermore, in a specific embodiment of the present invention, a first vacuum degassing treatment is performed on a mixed system comprising epoxy-terminated polybutadiene, epoxy resin, a portion of fumed silica, a diluent, and a coupling agent to obtain component A, wherein the vacuum degree of the first vacuum degassing treatment is not higher than -0.09 MPa; and / or, a second vacuum degassing treatment is performed on a mixed system comprising a curing agent, a curing accelerator, and the remaining fumed silica to obtain component B, wherein the vacuum degree of the second vacuum degassing treatment is not higher than -0.09 MPa.

[0082] Specifically, epoxy-terminated polybutadiene, epoxy resin, a portion of fumed silica, diluent, and coupling agent are thoroughly stirred and mixed, followed by a first vacuum degassing treatment to obtain component A.

[0083] The curing agent, curing accelerator, and residual fumed silica were thoroughly mixed and then subjected to a second vacuum degassing treatment to obtain component B.

[0084] This invention does not limit the above-mentioned parameters such as time and temperature for vacuum degassing, and appropriate parameter ranges can be selected according to actual needs.

[0085] The vacuum level during the first vacuum degassing process shall not exceed -0.09 MPa. For example, the vacuum level may include, but is not limited to, -0.09 MPa, -0.10 MPa, -0.11 MPa, -0.12 MPa, -0.13 MPa, -0.14 MPa, -0.15 MPa, or any two of these ranges.

[0086] The vacuum degree during the second vacuum degassing process shall not exceed -0.09 MPa. For example, the vacuum degree includes, but is not limited to, -0.09 MPa, -0.10 MPa, -0.11 MPa, -0.12 MPa, -0.13 MPa, -0.14 MPa, -0.15 MPa, or any two of these ranges.

[0087] It is understandable that in practical applications, after the preparation of components A and B, a certain time and spatial span may be required for them to be mixed and cured to obtain the epoxy adhesive. Therefore, after vacuum degassing, components A and B can be further packaged separately.

[0088] When the vacuum level is controlled within the above range, the preparation time of epoxy adhesive components A and B can be shortened while ensuring the performance of the epoxy adhesive, thereby improving production efficiency.

[0089] Furthermore, according to a specific embodiment of the present invention, the curing temperature is 50-70°C and the time is 3-8 days.

[0090] Specifically, the curing temperature is 50-70℃. For example, the curing temperature includes, but is not limited to, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃, and 70℃.

[0091] The curing time is 3-8 days. For example, the curing time includes but is not limited to 3, 3.5 days, 4 days, 4.5 days, 5 days, 5.5 days, 6 days, 6.5 days, 7 days, 7.5 days, and 8 days.

[0092] When different raw material systems are selected, the curing temperature and time can be adjusted within the above range.

[0093] When the curing temperature and time are selected from the above range, the curing reaction process can be made more complete, and the epoxy adhesive has better low-temperature resistance, high elasticity and high strength properties.

[0094] Another aspect of the present invention provides a battery comprising the above-described epoxy adhesive.

[0095] Understandably, the manufacture of this battery also includes other common components, such as the positive electrode, negative electrode, electrolyte, separator, and casing.

[0096] This invention does not limit the specific function and usage steps of the epoxy adhesive in the battery. The application of epoxy adhesive in the battery can be selected according to conventional methods, such as battery sealing. When used for battery sealing, the epoxy adhesive provided by this invention has excellent elasticity and strength, which facilitates battery disassembly and repair.

[0097] Thanks to the use of the aforementioned epoxy adhesive, the battery exhibits excellent performance in low-temperature environments.

[0098] The epoxy adhesive of the present invention will be described in detail below through specific embodiments.

[0099] Example 1

[0100] The epoxy adhesive preparation steps in this embodiment are as follows:

[0101] 1) Take 62 parts of terminal epoxy polybutadiene (epoxy value 0.05mol / 100g), 37 parts of glycidyl ether type epoxy resin E-44, 0.5 parts of fumed silica, 1 part of C12-14 alkyl glycidyl ether (AGE reactive diluent), and 0.5 parts of KH560 coupling agent and stir them in a stirred tank. Then, perform vacuum degassing at a vacuum degree of -0.09MPa. Then, discharge and package to obtain component A.

[0102] 2) Mix 10 parts of polyetheramine D400, 3 parts of polyamide 651, and 3 parts of modified polyetheramine 3400 as a curing agent. Take 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazolium (2E4MZ-CN) and 0.5 parts of fumed silica and stir them in a mixing tank. Then, perform vacuum degassing at a vacuum degree of -0.09MPa. Then, discharge and package to obtain component B.

[0103] 3) Mix component A and component B to obtain a mixed system. Degas the mixed system under vacuum and cure it at room temperature for 7 days to obtain epoxy adhesive.

[0104] Example 2

[0105] The preparation method of the epoxy adhesive in this embodiment is basically the same as that in Example 1, except that:

[0106] Step 1) 80 parts of mid-terminal epoxy polybutadiene and 37 parts of glycidyl ether epoxy resin E-44 are replaced with 24 parts of bisphenol A epoxy resin E-51.

[0107] Example 3

[0108] The preparation method of the epoxy adhesive in this embodiment is basically the same as that in Example 2, except that:

[0109] In step 1), the amount of bisphenol A epoxy resin E-51 is 37 parts; the amount of fumed silica is 10 parts; and the amount of AGE reactive diluent is 10 parts.

[0110] In step 2), the curing agent consists of 16 parts of polyetheramine D400, 5 parts of polyamide 651, 5 parts of modified polyetheramine 3400, 10 parts of fumed silica, and 5 parts of 2E4MZ-CN.

[0111] Example 4

[0112] The preparation method of the epoxy adhesive in this embodiment is basically the same as that in Example 2, except that:

[0113] Step 1) 62 parts of mid-terminal epoxy polybutadiene, 10 parts of fumed silica, 10 parts of AGE reactive diluent, and 3 parts of coupling agent KH560.

[0114] In step 2), the curing agent consists of 10 parts of polyetheramine D400, 4 parts of polyamide 651, 5 parts of modified polyetheramine 3400, and 10 parts of fumed silica.

[0115] Example 5

[0116] The preparation method of the epoxy adhesive in this embodiment is basically the same as that in Example 2, except that:

[0117] Step 1) 70 parts of intermediate epoxy polybutadiene, 35 parts of bisphenol A epoxy resin E-51, 5 parts of fumed silica, 2 parts of coupling agent KH560, and 5 parts of AGE reactive diluent.

[0118] In step 2), the curing agent consists of 13 parts of polyetheramine D400, 5 parts of polyamide 651, 5 parts of modified polyetheramine 3400, 5 parts of fumed silica, and 3 parts of 2E4MZ-CN.

[0119] Example 6

[0120] The preparation method of the epoxy adhesive in this embodiment is basically the same as that in Example 5, except that:

[0121] In step 2), the curing agent consists of 5 parts polyetheramine D400, 13 parts polyamide 651, and 5 parts modified polyetheramine 3400.

[0122] Comparative Example 1

[0123] The preparation steps of the epoxy adhesive in this comparative example are basically the same as those in Example 1, except that:

[0124] Step 1) 150 parts of mid-terminal epoxy polybutadiene and 37 parts of glycidyl ether type epoxy resin E-44 are replaced with 25 parts of bisphenol A epoxy resin E-51.

[0125] In step 2), the curing agent consists of 10 parts of polyetheramine D400, 5 parts of polyamide 651, and 5 parts of modified polyetheramine 3400.

[0126] Comparative Example 2

[0127] The preparation steps of the epoxy adhesive in this comparative example are basically the same as those in Example 1, except that:

[0128] Step 1) 62 parts of mid-terminal epoxy polybutadiene, 37 parts of glycidyl ether epoxy resin E-44 replaced with 50 parts of bisphenol A epoxy resin E-51, and 10 parts of AGE reactive diluent.

[0129] Comparative Example 3

[0130] The preparation steps of the epoxy adhesive in this comparative example are basically the same as those in Comparative Example 1, except that:

[0131] Step 1) 70 parts of mid-terminal epoxy polybutadiene, 30 parts of bisphenol A epoxy resin E-51, 5 parts of AGE reactive diluent, and 15 parts of fumed silica.

[0132] In step 2), the amount of fumed silica is 15 parts.

[0133] Comparative Example 4

[0134] The preparation steps of the epoxy adhesive in this comparative example are basically the same as those in Comparative Example 3, except that:

[0135] In step 1), the amount of fumed silica is 10 parts, the amount of AGE reactive diluent is 20 parts, and the amount of coupling agent KH560 is 1 part.

[0136] In step 2), the curing agent is composed of 10 parts of polyetheramine D400, 6 parts of polyamide 651, 6 parts of modified polyetheramine 3400, and 10 parts of fumed silica.

[0137] Comparative Example 5

[0138] The preparation steps of the epoxy adhesive in this comparative example are basically the same as those in Example 3, except that:

[0139] In step 1), 10 parts of fumed silica and 1 part of coupling agent KH560 are used;

[0140] In step 2), the curing agent consists of 10 parts of polyetheramine D400, 20 parts of polyamide 651, 10 parts of fumed silica, and 1 part of 2E4MZ-CN.

[0141] Comparative Example 6

[0142] The preparation steps of the epoxy adhesive in this comparative example are basically the same as those in Example 5, except that:

[0143] In step 2), there are 10 copies of 2E4MZ-CN.

[0144] Comparative Example 7

[0145] The preparation steps of the epoxy adhesive in this comparative example are basically the same as those in Example 5, except that:

[0146] Step 1) Use 10 parts of coupling agent KH560.

[0147] Test case

[0148] The relevant properties of the epoxy adhesives prepared in the above embodiments and comparative examples were tested.

[0149] Shore hardness (HD) test method: Prepare the cured sample into a cylinder with a thickness of 6 mm and a diameter of 30 mm. At room temperature, place the sample to be tested in an appropriate position on the hardness tester platform, press it for 3 seconds, and immediately read the hardness data.

[0150] Glass transition temperature test method: Using a Mettler DSC instrument, the temperature is increased from 40℃ to 150℃ at a rate of 5K / min, then decreased to -150℃ at a rate of 5K / min, and finally increased to 150℃ at a rate of 5K / min; the second heating curve is taken as the glass transition temperature point.

[0151] Test methods for tensile strength and elongation at break: Prepare the cured sample into a dumbbell specimen with a thickness of 2 mm, and test it at a certain temperature using a universal tensile testing machine at a tensile speed of 10 mm / min to obtain the tensile strength and elongation at break.

[0152] The test results are shown in Table 1.

[0153] Table 1

[0154]

[0155] According to the test results, compared with the comparative example, the epoxy adhesive prepared by the method of the present invention has better elastic properties and strength in low temperature environment. As can be seen from Table 1, at -45℃, the epoxy adhesive prepared according to Examples 1-6 has a tensile strength of not less than 30MPa and an elongation at break of not less than 80%, while the epoxy adhesive prepared according to Examples 1-6 has a Shore hardness of not more than 60HD and a glass transition temperature of not more than -50℃ at room temperature.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An epoxy adhesive, characterized in that, The raw materials of the epoxy adhesive, by weight, include: 62-80 parts of epoxy-terminated polybutadiene, 24-37 parts of epoxy resin, 1-20 parts of fumed silica, 16-26 parts of curing agent, 1-10 parts of diluent, 0.5-3 parts of coupling agent, and 0.5-5 parts of curing accelerator.

2. The epoxy adhesive according to claim 1, characterized in that, The epoxy value of the terminally epoxy-terminated polybutadiene is 0.03-0.07 mol / 100g.

3. The epoxy adhesive according to any one of claims 1-2, characterized in that, The epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, and phenolic epoxy resin. And / or, the curing agent includes at least one of aliphatic amine curing agents, alicyclic amine curing agents, aromatic amine curing agents, polyether amine curing agents, and polyamide curing agents; And / or, the diluent includes at least one of benzyl glycidyl ether and neopentyl glycol diglycidyl ether; And / or, the coupling agent is at least one of KH550, KH560, and KH570.

4. The epoxy adhesive according to claim 3, characterized in that, The curing agent includes the polyetheramine curing agent and the polyamide curing agent, and the mass ratio of the polyetheramine curing agent to the polyamide curing agent is not less than 2:

1.

5. The epoxy adhesive according to any one of claims 1, 2, and 4, characterized in that, The epoxy adhesive is prepared by a method comprising the following steps: After mixing components A and B, the mixture is subjected to vacuum degassing and curing treatment in sequence to obtain the epoxy adhesive. Component A includes the epoxy-terminated polybutadiene, the epoxy resin, a portion of the fumed silica, the diluent, and the coupling agent; component B includes the curing agent, the curing accelerator, and the remainder of the fumed silica.

6. A method for preparing the epoxy adhesive according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: After mixing components A and B, the mixture is subjected to vacuum degassing and curing treatment in sequence to obtain the epoxy adhesive. Component A includes epoxy-terminated polybutadiene, epoxy resin, a portion of fumed silica, diluent, and coupling agent; component B includes curing agent, curing accelerator, and remaining fumed silica.

7. The preparation method according to claim 6, characterized in that, The portion of fumed silica is 0.5-10 parts, and the remaining fumed silica is 0.5-10 parts.

8. The preparation method according to claim 6 or 7, characterized in that, A first vacuum degassing treatment is performed on a mixture comprising epoxy-terminated polybutadiene, epoxy resin, a portion of fumed silica, a diluent, and a coupling agent to obtain component A. The vacuum degree of the first vacuum degassing treatment is not higher than -0.09 MPa; and / or, The mixture system comprising curing agent, curing accelerator and residual fumed silica is subjected to a second vacuum degassing treatment to obtain component B. The vacuum degree of the second vacuum degassing treatment is not higher than -0.09 MPa.

9. The preparation method according to claim 6 or 7, characterized in that, The curing process is carried out at a temperature of 50-70℃ for 3-8 days.

10. A battery, characterized in that, The battery comprises the epoxy adhesive as described in any one of claims 1-5 or the epoxy adhesive prepared by the preparation method described in any one of claims 6-9.

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