Oil-resistant and high-temperature-resistant structural adhesive and structural member

Abstract

The invention provides an oil-resistant and high-temperature-resistant structural adhesive and a structural member. The structural adhesive comprises a component A and a component B, the component A is prepared from the following components in parts by weight: 50 to 60 parts of polyurethane prepolymer, 25 to 45 parts of fluorine-containing acrylate monomer and acrylate monomer, and 0.2 to 2.0 parts of reducing agent; the mass ratio of the fluorine-containing acrylate monomer to the acrylate monomer is at least 3: 7; the component B comprises the following components in parts by weight: 15-30 parts of an oxidizing agent and 60-80 parts of a reactive diluent; the reactive diluent comprises an epoxy group; wherein the polyurethane prepolymer is a hydroxyl acrylic ester end capped polyurethane prepolymer. Through the design of the components in the structural adhesive, the structural adhesive has better oil resistance and high temperature resistance.

Description

Technical Field

[0001] The present application relates to the technical field of structural adhesives, and in particular to an oil-resistant and high-temperature-resistant structural adhesive and a structural component. Background Art

[0002] Structural adhesives are generally used for bonding components and sealing pipes or containers. When structural adhesives are used in energy storage systems, the energy storage system generally includes an energy storage unit and a heat exchange system. The heat exchange system can provide rapid heat exchange for the energy storage unit to prevent the energy storage unit from overheating and causing danger. The heat exchange system may include: a container for storing heat exchange liquid (such as thermal oil) and a pipe for transmitting the heat exchange liquid. These containers and pipes can be sealed with structural adhesive to prevent leakage. Taking pipes as an example, since there is thermal oil in the pipes, when using structural adhesive to seal the pipes, if the structural adhesive has poor oil resistance, the structural adhesive may be corroded by the thermal oil, resulting in holes or gaps in the seal, which in turn reduces the sealing performance of the pipe or makes it impossible to achieve the sealing effect, and ultimately causes the thermal oil to overflow from the pipe and leak.

[0003] When structural adhesives are used in new energy vehicles, the advanced oil-cooled drive motors in new energy vehicles include stators and rotors. The steel sheets in the stator are bonded together with structural adhesives, and the steel sheets in the rotor are bonded together with structural adhesives. After the structural adhesives at the bonding points are exposed to high-temperature oil for a long time, their performance deteriorates, which may cause the stator and rotor to fail, and further lead to failure of the entire drive motor.

[0004] Based on this, improving the oil and high temperature resistance of structural adhesives has become an urgent problem to be solved. Summary of the Invention

[0005] The present application provides an oil-resistant and high-temperature-resistant structural adhesive and a structural component, which are used to improve the oil-resistant and high-temperature-resistant performance of the structural adhesive.

[0006] In a first aspect, an embodiment of the present application provides a structural adhesive, which may include component A and component B; in parts by weight, component A includes: 50 to 60 parts of a polyurethane prepolymer, 25 to 45 parts of a fluorinated acrylate monomer and an acrylate monomer, and 0.2 to 2.0 parts of a reducing agent; the mass ratio of the fluorinated acrylate monomer to the acrylate monomer is at least 3:7, such as but not limited to: 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, 10:0; in parts by weight, component B includes: 15 to 30 parts of an oxidant, and 60 to 80 parts of a reactive diluent; the reactive diluent includes an epoxy group; wherein the polyurethane prepolymer is a hydroxy acrylate-terminated polyurethane prepolymer.

[0007] In the above structural adhesive, the hydroxy acrylate groups, fluorinated acrylate monomers, and acrylate monomers in the polyurethane prepolymer all contain C=C. These C=C groups undergo free radical polymerization in the reducing agent and oxidizing agent system, resulting in crosslinking of the polyurethane prepolymer, fluorinated acrylate monomer, and acrylate monomer. Furthermore, the carbamate in the polyurethane prepolymer undergoes polymerization with the epoxy groups in the reactive diluent, resulting in crosslinking of the polyurethane prepolymer and the reactive diluent. Thus, in this system, not only free radical polymerization occurs, but also another polymerization reaction. These two types of reactions increase the crosslink density of the system. As the crosslink density increases, the high-temperature resistance of the cured structural adhesive increases, thereby improving the high-temperature resistance of the structural adhesive. Furthermore, fluorine can be introduced into the above system through free radical polymerization. Over time, due to its poor compatibility with other substances in the system, the fluorine migrates. When the fluorine migrates to the surface of the cured structural adhesive, due to its good oleophobicity, the cured structural adhesive has good oil resistance. Therefore, by designing the components in the structural adhesive, the structural adhesive can have better oil and high temperature resistance.

[0008] In addition, the price of fluorinated acrylate monomers is relatively high, generally higher than that of acrylate monomers. Therefore, by designing the ratio of fluorinated acrylate monomers to acrylate monomers, it is possible to ensure that the structural adhesive has good oil and high temperature resistance, and it is also beneficial to reduce the production cost of the structural adhesive.

[0009] For example, by weight, the acrylate monomer can be 20 to 30 parts, such as but not limited to 20 parts, 25 parts, 30 parts, and other parts, and the fluorine-containing acrylate monomer can be 5 to 15 parts, such as but not limited to 5 parts, 10 parts, 15 parts, and other parts. The specific ratio of the acrylate monomer and the fluorine-containing acrylate monomer can be designed according to actual needs and is not specifically limited here. For example, since the price of the fluorine-containing acrylate monomer is relatively high, if it is necessary to reduce the production cost of the structural adhesive, the amount of the fluorine-containing acrylate monomer can be reduced and the amount of the acrylate monomer can be increased; if it is necessary to improve the oil resistance of the structural adhesive without considering the cost, the amount of the fluorine-containing acrylate monomer can be increased and the amount of the acrylate monomer can be reduced. In this way, by controlling the amount of the acrylate monomer and the fluorine-containing acrylate monomer within an appropriate range, the oil resistance of the structural adhesive can be improved and the high production cost can be avoided.

[0010] Exemplarily, by weight, component A may also include: 10 to 20 parts of modified ceramic particles, such as but not limited to: 10 parts, 15 parts, 20 parts and other parts, which can be set according to actual needs and are not limited here. The modified ceramic particles are ceramic particles with a silane coupling agent on the surface. In this way, the silane coupling agent can increase the dispersion effect of the ceramic particles in component A, so that it has a nano effect, and can also make the ceramic particles better combined with other organic matter in component A, thereby improving the cohesive strength of the structural adhesive, thereby improving the bonding effect of the structural adhesive, and also improving the high temperature resistance of the structural adhesive. In addition, the organosilicon in the silane coupling agent has good oil resistance, and other groups in the silane coupling agent (such as epoxy groups, carbon-carbon double bonds) can also undergo cross-linking reactions with amino groups and carbon-carbon double bonds respectively, so that when component A and component B are mixed, a three-dimensional network structure can be formed, thereby further improving the oil resistance and high temperature resistance.

[0011] The particle size of the ceramic particles can be set to no greater than 100 nm, furthermore, no greater than 50 nm, and even further, no greater than 10 nm. Since smaller ceramic particles have a larger specific surface area and better reinforcement, setting the particle size within an appropriate range can further enhance the cohesive strength and bonding performance of the structural adhesive. The ceramic particles can include, but are not limited to, at least one of silicon oxide nanoparticles, aluminum oxide nanoparticles, titanium oxide nanoparticles, and zirconium oxide nanoparticles. The specific type of ceramic particles can be selected as needed and is not limited herein.

[0012] Furthermore, component A may also include, by weight, 0.1 to 1.0 parts of a silane coupling agent. That is, when component A includes modified ceramic particles, a silane coupling agent may be added to component A to further enhance the dispersion of the ceramic particles in component A, further enhance the cohesive strength and bonding of the structural adhesive, and further enhance oil and high-temperature resistance. The silane coupling agent may be selected from at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and other silane coupling agents. The specific silane coupling agent may be selected based on actual needs and is not limited herein.

[0013] Of course, when component A does not include modified ceramic particles, component A may also include a silane coupling agent. The silane coupling agent can increase the dispersibility between the substances in component A, thereby improving the performance of the structural adhesive and further improving the oil and high temperature resistance.

[0014] Exemplarily, by weight, component A may further include: 0.1 to 1.0 parts of a stabilizer, such as but not limited to: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, and other parts, which may be set according to actual needs and are not limited thereto. The stabilizer may be selected from at least one of other compounds having stabilizer effects, such as phenolic compounds, quinone compounds, phenothiazine, and metal ion complexes, wherein the phenolic compounds may include but are not limited to: p-hydroxyanisole, hydroquinone, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, and the like; the quinone compounds may include but are not limited to: methylhydroquinone, and the like; the metal ion complexes may include but are not limited to: Na2EDTA, Na4EDTA, and the like; and may be set according to actual needs and are not limited thereto. Before the components A and B of the structural adhesive are mixed, the stability of the structural adhesive during storage and transportation affects the shelf life of the structural adhesive. Therefore, by adding stabilizers, early cross-linking between the substances in component A during storage and transportation can be avoided, and the stability of the structural adhesive during storage and transportation can be improved, thereby extending the life and shelf life of the structural adhesive.

[0015] Exemplarily, by weight, component B may also include: 5 to 15 parts of a toughening agent, such as but not limited to: 5 parts, 10 parts, 15 parts, and other parts. The specific amount can be set according to actual needs and is not limited here. Among them, the toughening agent can be selected from: liquid rubber and other compounds with toughening functions. The liquid rubber can include but is not limited to: at least one of liquid nitrile rubber and liquid chloroprene rubber with a molecular weight of 5000-10000. The specific amount can be set according to actual needs and is not limited here. By adding a toughening agent, the impact resistance of the structural adhesive under dynamic conditions can be increased, thereby improving the tensile strength of the structural adhesive and further improving the performance of the structural adhesive. Moreover, in the redox system formed when components A and B are mixed, the liquid rubber can react with epoxy groups and carbon-carbon double bonds to crosslink, so that the crosslinking density can be increased after components A and B are mixed, thereby increasing the bonding effect of the structural adhesive.

[0016] Of course, in addition to being set in component B, the toughening agent can also be set in component A. In other words, component A includes the toughening agent, and component B does not include the toughening agent; or, component A does not include the toughening agent, and component B includes the toughening agent; or, component A includes the toughening agent, and component B also includes the toughening agent; the specific design can be based on actual needs and is not limited here.

[0017] In short, when designing structural adhesives, the several setting methods mentioned above can be used in combination or separately. The specific settings can be made according to actual needs and are not limited here.

[0018] Exemplarily, the hydroxyacrylate monomer can be selected from at least one of other hydroxyacrylate monomers such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, etc. The specific selection can be based on actual needs and is not limited here.

[0019] The fluorine-containing acrylate monomer can be selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate and other fluorine-containing acrylate monomers. The specific monomer can be selected according to actual needs and is not limited here.

[0020] The acrylate monomer can be selected from at least one of the following acrylate monomers: isooctyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, etc. The specific acrylate monomer can be selected according to actual needs and is not limited here.

[0021] The oxidant can be selected from other types of oxidants such as peroxides, and can further be selected from dicumyl peroxide. The selection of the oxidant can be specifically made according to actual needs and is not limited here.

[0022] The reducing agent may be selected from at least one of variable-valence metal organic salts, aniline compounds, and other types of reducing agents. Variable-valence metal organic salt compounds include, but are not limited to, copper octoate, iron hexanoate, iron propionate, and other variable-valence metal organic salt compounds. Aniline compounds include, but are not limited to, N,N-dihydroxyethyl-p-toluidine, N,N-dimethyl-p-toluidine, N,N-dimethylaniline, N,N-diisopropyl-p-toluidine, N,N-diethylaniline, and other amine compounds. The choice of reducing agent can be determined based on practical needs and is not limited here.

[0023] The reactive diluent can be selected from: glycerol ether compounds and other compounds containing epoxy groups, wherein the glycerol ether compounds can include but are not limited to: butyl glycidyl ether, carbon 12-14 alkyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether and other glycerol ether compounds. The choice of reactive diluent can be made according to actual needs and is not limited here. It is worth noting that the reactive diluent can not only undergo polymerization reaction with the urethane in the polyurethane prepolymer, but also play a diluting role, reducing the viscosity of component A, thereby improving the ease of operation of the structural adhesive.

[0024] For example, when using the structural adhesive, component A and component B can be mixed, applied within a preset time, and cured, thereby achieving the adhesive's bonding and sealing properties. The weight ratio of component A to component B can be set to 10:0.1-5, such as, but not limited to, 10:0.1, 10:1, 10:2, 10:3, 10:4, 10:5, and other ratios. The specific ratio can be set based on actual needs and is not limited here.

[0025] In a second aspect, embodiments of the present application further provide a structural adhesive, which may include component A and component B. Component A comprises, by weight, 50-60 parts of a polyurethane prepolymer, 25-45 parts of a fluorinated acrylate monomer and an acrylate monomer, and 15-30 parts of an oxidant. The mass ratio of the fluorinated acrylate monomer to the acrylate monomer is at least 3:7, such as, but not limited to, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, or 10:0. Component B comprises, by weight, 0.2-2.0 parts of a reducing agent and 60-80 parts of a reactive diluent. The reactive diluent includes an epoxy group. The polyurethane prepolymer is a hydroxyacrylate-terminated polyurethane prepolymer. Thus, by designing the components of the structural adhesive, the structural adhesive can exhibit excellent oil and high-temperature resistance.

[0026] It should be understood that since the principle of solving the problem by this structural adhesive is similar to that of the aforementioned structural adhesive, the implementation and technical effects of this structural adhesive can refer to the implementation and technical effects of the aforementioned structural adhesive, and the repeated parts will not be repeated.

[0027] In a third aspect, embodiments of the present application further provide a structural member, which may include multiple components, each of which is bonded together using the structural adhesive described in the first aspect and any embodiment thereof, or each of which is bonded together using the structural adhesive described in the second aspect and any embodiment thereof. In this manner, when the structural adhesive exhibits excellent oil and high temperature resistance, the stability of the structural member can be improved.

[0028] For example, the structural component may be, but is not limited to, a stator or rotor in a driving electrode, a container or pipe in a heat exchange system, etc., which is not limited here.

[0029] It should be understood that since the principle of solving the problem by this structural part is similar to the principle of solving the problem by the aforementioned structural adhesive, the implementation and technical effects of this structural part can refer to the implementation and technical effects of the aforementioned structural adhesive, and the repeated parts will not be repeated. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the test results of the test samples provided in the embodiments of the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0032] It should be noted that the same reference numerals in the drawings of this application represent the same or similar structures, and thus their repeated description will be omitted. The words expressing positions and directions described in this application are all explained using the drawings as examples, but they can be modified as needed, and such modifications are included in the scope of protection of this application. The drawings of this application are only for illustrating relative positional relationships and do not represent true proportions.

[0033] In order to facilitate understanding of the technical solution provided by the embodiments of the present application, its application scenario is first explained below.

[0034] The technical solutions provided by the embodiments of the present application can be widely used in the fields of new energy vehicles, energy storage, and power generation. In the field of new energy vehicles, new energy vehicles may include a powertrain for driving the wheels to move, the powertrain includes a drive motor, and the drive motor may include a stator and a rotor. Taking the stator as an example, the multiple steel sheets in the stator can be bonded by structural adhesive. At this time, the stator can be regarded as a structural member, and the steel sheets can be regarded as components in the structural member. In the field of energy storage, the energy storage system generally includes an energy storage unit and a heat exchange system. The heat exchange system can provide rapid heat exchange for the energy storage unit to avoid the danger of excessive temperature of the energy storage unit. The heat exchange system may include: a container for storing heat exchange liquid (such as thermal oil), and a pipeline for transmitting the heat exchange liquid. These containers and these pipelines can be sealed with structural adhesive to prevent leakage. In the field of power generation, the power generation system will also include a heat exchange system. The containers and pipelines in the heat exchange system can also be sealed with structural adhesive to prevent leakage.

[0035] For example, in heat exchange systems, pipes contain thermal oil. If structural adhesive is used to seal the pipes, poor oil resistance can corrode the adhesive, leading to holes or cracks in the seals. This can reduce or even eliminate the seal, ultimately causing the thermal oil to overflow and leak. Another example is in advanced oil-cooled drive motors, where the stator and rotor steel sheets are bonded together using structural adhesive. Long-term exposure to high-temperature oil can lead to deterioration in the adhesive's performance, potentially causing both the stator and rotor to fail, ultimately leading to malfunction of the entire drive motor. Therefore, improving the oil and high-temperature resistance of structural adhesives is crucial.

[0036] Based on this, an embodiment of the present application provides an oil-resistant and high-temperature resistant structural adhesive, which may include component A and component B. The configuration of component A and component B may include the following two methods:

[0037] The first type: Component A comprises, by weight, 50 to 60 parts of a polyurethane prepolymer, 25 to 45 parts of a fluorinated acrylate monomer and an acrylate monomer, and 0.2 to 2.0 parts of a reducing agent; the mass ratio of the fluorinated acrylate monomer to the acrylate monomer is at least 3:7, such as but not limited to: 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, 10:0; Component B comprises, by weight, 15 to 30 parts of an oxidant and 60 to 80 parts of a reactive diluent; the reactive diluent comprises an epoxy group; wherein the polyurethane prepolymer is a hydroxy acrylate-terminated polyurethane prepolymer.

[0038] The second type: Component A includes, by weight, 50 to 60 parts of a polyurethane prepolymer, 25 to 45 parts of a fluorinated acrylate monomer and an acrylate monomer, and 15 to 30 parts of an oxidant; the mass ratio of the fluorinated acrylate monomer to the acrylate monomer is at least 3:7, such as but not limited to: 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, 10:0; Component B includes, by weight, 0.2 to 2.0 parts of a reducing agent and 60 to 80 parts of a reactive diluent; the reactive diluent includes an epoxy group; wherein the polyurethane prepolymer is a hydroxy acrylate-terminated polyurethane prepolymer.

[0039] In other words, the two configurations are essentially similar, differing only in the component in which the oxidizing agent and reducing agent are located. This allows for the design and adjustment of components A and B based on actual needs to meet the design requirements of different application scenarios, increasing the flexibility of structural adhesive design. It should be understood that the 25-45 parts by weight ratio of the fluorinated acrylate monomer to the acrylate monomer refers to the sum of the weight ratios of the fluorinated acrylate monomer and the acrylate monomer being 25-45 parts by weight.

[0040] In the above structural adhesive, regardless of the configuration, the hydroxyl acrylate groups, fluorinated acrylate monomers, and acrylate monomers in the polyurethane prepolymer all contain C=C. These C=C groups undergo free radical polymerization in the reducing agent and oxidizing agent system, causing the polyurethane prepolymer, fluorinated acrylate monomer, and acrylate monomer to crosslink. Furthermore, the carbamate in the polyurethane prepolymer undergoes polymerization with the epoxy groups in the reactive diluent, causing the polyurethane prepolymer and the reactive diluent to crosslink. Thus, in the above system, not only free radical polymerization occurs, but also another polymerization reaction. These two types of reactions can increase the crosslinking density of the above system. As the crosslinking density increases, the high-temperature resistance of the cured structural adhesive increases, thereby improving the high-temperature resistance of the structural adhesive. Furthermore, fluorine can be introduced into the above system through free radical polymerization. Over time, due to the poor compatibility of fluorine with other substances in the system, the fluorine element will migrate. When the fluorine element migrates to the surface of the cured structural adhesive, due to its good oleophobicity, the cured structural adhesive has good oil resistance. Therefore, by designing the components in the structural adhesive, the structural adhesive can have better oil and high temperature resistance.

[0041] In addition, the price of fluorinated acrylate monomers is relatively high, generally higher than that of acrylate monomers. Therefore, by designing the ratio of fluorinated acrylate monomers to acrylate monomers, it is possible to ensure that the structural adhesive has good oil and high temperature resistance, and it is also beneficial to reduce the production cost of the structural adhesive.

[0042] It should be understood that free radical polymerization is a polymerization reaction initiated by free radicals, which causes chain growth (or chain growth) free radicals to continue to grow, also known as free radical polymerization or addition polymerization. In free radical polymerization, the vast majority of them are made from olefin monomers containing unsaturated double bonds as raw materials. By opening the double bonds in the monomer molecules, repeated addition reactions are carried out between the molecules to connect many monomers to form macromolecules. Free radical polymerization usually requires the action of light, heat, radiation, and initiators to activate the monomer molecules into active free radicals, which are then chain-polymerized with the monomers. Among them, the initiator can include an oxidant and a reducing agent. In this case, the oxidant can provide positive charges to oxidize the organic matter into free radicals, and the reducing agent can provide electrons to reduce the organic matter into free radicals. Therefore, in the reducing agent and oxidant system, the hydroxy acrylate group, the fluorinated acrylate monomer and the acrylate monomer can generate free radicals and achieve free radical polymerization.

[0043] Exemplarily, the hydroxyacrylate monomer can be selected from at least one of other hydroxyacrylate monomers such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate, etc. The specific selection can be based on actual needs and is not limited here.

[0044] The fluorine-containing acrylate monomer can be selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate and other fluorine-containing acrylate monomers. The specific monomer can be selected according to actual needs and is not limited here.

[0045] The acrylate monomer can be selected from at least one of the following acrylate monomers: isooctyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, etc. The specific acrylate monomer can be selected according to actual needs and is not limited here.

[0046] The oxidant can be selected from other types of oxidants such as peroxides, and can further be selected from dicumyl peroxide. The selection of the oxidant can be specifically made according to actual needs and is not limited here.

[0047] The reducing agent may be selected from at least one of variable-valence metal organic salts, aniline compounds, and other types of reducing agents. Variable-valence metal organic salt compounds include, but are not limited to, copper octoate, iron hexanoate, iron propionate, and other variable-valence metal organic salt compounds. Aniline compounds include, but are not limited to, N,N-dihydroxyethyl-p-toluidine, N,N-dimethyl-p-toluidine, N,N-dimethylaniline, N,N-diisopropyl-p-toluidine, N,N-diethylaniline, and other amine compounds. The choice of reducing agent can be determined based on practical needs and is not limited here.

[0048] The reactive diluent can be selected from: glycerol ether compounds and other compounds containing epoxy groups, wherein the glycerol ether compounds can include but are not limited to: butyl glycidyl ether, carbon 12-14 alkyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether and other glycerol ether compounds. The choice of reactive diluent can be made according to actual needs and is not limited here. It is worth noting that the reactive diluent can not only undergo polymerization reaction with the urethane in the polyurethane prepolymer, but also play a diluting role, reducing the viscosity of component A, thereby improving the ease of operation of the structural adhesive.

[0049] For example, for component A, the following configuration may also be included:

[0050] 1. By weight, the acrylate monomer can be 20-30 parts, such as, but not limited to, 20 parts, 25 parts, 30 parts, or other parts. The fluorinated acrylate monomer can be 5-15 parts, such as, but not limited to, 5 parts, 10 parts, 15 parts, or other parts. The specific ratio of the acrylate monomer to the fluorinated acrylate monomer can be designed according to actual needs and is not specifically limited here. For example, due to the high price of fluorinated acrylate monomers, if the production cost of the structural adhesive needs to be reduced, the amount of fluorinated acrylate monomer can be reduced and the amount of acrylate monomer can be increased. If the oil resistance of the structural adhesive needs to be improved without considering cost, the amount of fluorinated acrylate monomer can be increased and the amount of acrylate monomer can be reduced. In this way, by controlling the amounts of acrylate monomer and fluorinated acrylate monomer within an appropriate range, the oil resistance of the structural adhesive can be improved while avoiding high production costs.

[0051] 2. By weight, component A may also include: 10 to 20 parts of modified ceramic particles, such as but not limited to: 10 parts, 15 parts, 20 parts and other parts. The specific amount can be set according to actual needs and is not limited here. The modified ceramic particles are ceramic particles with a silane coupling agent on the surface. In this way, the silane coupling agent can increase the dispersion effect of the ceramic particles in component A, giving it a nano effect, and can also make the ceramic particles better combined with other organic matter in component A, thereby improving the cohesive strength of the structural adhesive, thereby improving the bonding effect of the structural adhesive, and also improving the high temperature resistance of the structural adhesive. In addition, the organosilicon in the silane coupling agent has good oil resistance, and other groups in the silane coupling agent (such as epoxy groups, carbon-carbon double bonds) can also undergo cross-linking reactions with amino groups and carbon-carbon double bonds respectively, so that when components A and B are mixed, a three-dimensional network structure can be formed, thereby further improving the oil resistance and high temperature resistance. The particle size of the ceramic particles can be set to no greater than 100 nm, furthermore, no greater than 50 nm, and even further, no greater than 10 nm. Since smaller ceramic particles have a larger specific surface area and better reinforcement, setting the particle size within an appropriate range can further enhance the cohesive strength and bonding performance of the structural adhesive. The ceramic particles can include, but are not limited to, at least one of silicon oxide nanoparticles, aluminum oxide nanoparticles, titanium oxide nanoparticles, and zirconium oxide nanoparticles. The specific type of ceramic particles can be selected as needed and is not limited herein.

[0052] Furthermore, component A may also include, by weight, 0.1 to 1.0 parts of a silane coupling agent. That is, when component A includes modified ceramic particles, a silane coupling agent may be added to component A to further enhance the dispersion of the ceramic particles in component A, further enhance the cohesive strength and bonding of the structural adhesive, and further enhance oil and high-temperature resistance. The silane coupling agent may be selected from at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and other silane coupling agents. The specific silane coupling agent may be selected based on actual needs and is not limited herein.

[0053] Of course, when component A does not include modified ceramic particles, component A may also include a silane coupling agent. The silane coupling agent can increase the dispersibility between the substances in component A, thereby improving the performance of the structural adhesive and further improving the oil and high temperature resistance.

[0054] 3. By weight, component A may further include: 0.1 to 1.0 parts of a stabilizer, such as but not limited to: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, and other parts, which may be set according to actual needs and are not limited to herein. Wherein, the stabilizer may be selected from at least one of other compounds having a stabilizer effect, such as a phenolic compound, a quinone compound, a phenothiazine, a metal ion complex, and the like. The phenolic compound may include but is not limited to: p-hydroxyanisole, hydroquinone, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, and the like. The quinone compound may include but is not limited to: methylhydroquinone, and the like. The metal ion complex may include but is not limited to: Na2EDTA, Na4EDTA, and the like. The specific amount may be set according to actual needs and are not limited to herein. Before the components A and B of the structural adhesive are mixed, the stability of the structural adhesive during storage and transportation affects the shelf life of the structural adhesive. Therefore, by adding stabilizers, early cross-linking between the substances in component A during storage and transportation can be avoided, and the stability of the structural adhesive during storage and transportation can be improved, thereby extending the life and shelf life of the structural adhesive.

[0055] For component B, the following configuration may also be included: by weight, component B may also include: 5 to 15 parts of a toughening agent, such as but not limited to: 5 parts, 10 parts, 15 parts, and other parts. The specific configuration can be based on actual needs and is not limited here. The toughening agent can be selected from: liquid rubber and other compounds with toughening functions. The liquid rubber can include but is not limited to: at least one of liquid nitrile rubber and liquid chloroprene rubber with a molecular weight of 5000-10000. The specific configuration can be based on actual needs and is not limited here. By adding a toughening agent, the impact resistance of the structural adhesive under dynamic conditions can be increased, thereby increasing the tensile strength of the structural adhesive and further improving the performance of the structural adhesive. In addition, in the redox system formed when components A and B are mixed, the liquid rubber can react with epoxy groups and carbon-carbon double bonds to crosslink. This can increase the crosslinking density after components A and B are mixed, thereby increasing the bonding effect of the structural adhesive.

[0056] Of course, in addition to being set in component B, the toughening agent can also be set in component A. In other words, component A includes the toughening agent, and component B does not include the toughening agent; or, component A does not include the toughening agent, and component B includes the toughening agent; or, component A includes the toughening agent, and component B also includes the toughening agent; the specific design can be based on actual needs and is not limited here.

[0057] In summary, when designing structural adhesives, the several configuration methods mentioned above can be used in combination or individually. The specific configuration can be based on actual needs and is not limited here. In this way, the structural adhesive can have the following advantages:

[0058] 1) Component A is prepared using raw materials such as a hydroxyl acrylate-terminated polyurethane prepolymer, an acrylate monomer, a fluorinated acrylate monomer, and a reducing agent, and component B is prepared using raw materials such as an oxidant and a reactive diluent. After the two are mixed, the carbon-carbon double bonds in the acrylate undergo free radical polymerization, and the epoxy groups in the reactive diluent undergo polymerization with the carbamate in the polyurethane prepolymer. Through multiple polymerization reactions, the crosslinking density is increased, thereby improving the oil and high temperature resistance of the structural adhesive.

[0059] 2) The fluorine element in the fluorine-containing acrylate monomer is introduced into the structural adhesive through a free radical polymerization reaction. After components A and B in the structural adhesive are mixed and cured, the fluorine element can migrate to the surface over time, further improving the oil resistance and high temperature resistance of the structural adhesive. Among them, the shear strength test specimen of the structural adhesive can reach a shear strength of more than 5MPa when tested at 200°C, showing high bonding strength. After the shear strength test specimen of the structural adhesive is placed in thermal oil at a temperature of 160±2°C and containing 2000ppm of water for 1200 hours, the shear strength decay is no more than 50%, indicating that the structural adhesive has high oil and high temperature resistance.

[0060] 3) When using modified ceramic particles, the silane coupling agent on the surface of the modified ceramic particles can improve the dispersion of the ceramic particles, giving them a nano-effect. Furthermore, the silane coupling agent can form chemical bonds with other components in the structural adhesive through in-situ chemical reactions. In other words, the organic groups on the surface of the modified ceramic particles can form chemical bonds with groups in the organic system, further improving the adhesive's adhesion and cohesive strength. For example, at around 400°C, the ceramic particles can ceramicize, forming a dense protective network structure, allowing the structural adhesive to withstand higher temperatures.

[0061] 4) The use of polyurethane prepolymer and reactive liquid rubber to achieve double toughening can improve the mechanical strength of structural adhesives, thereby meeting the dynamic use requirements of structural adhesives in the fields of automobiles, machinery, etc.

[0062] 5) The structural adhesive has excellent performance, good compatibility between the components, low raw material cost, high production efficiency, and is easy to industrialize. No toxic solvents are released during the entire process. It is a non-toxic, pollution-free, environmentally friendly, oil-resistant and high-temperature resistant structural adhesive with broad application prospects.

[0063] For example, when using the structural adhesive, component A and component B can be mixed, applied within a preset time, and cured, thereby achieving the adhesive's bonding and sealing properties. The weight ratio of component A to component B can be set to 10:0.1-5, such as, but not limited to, 10:0.1, 10:1, 10:2, 10:3, 10:4, 10:5, and other ratios. The specific ratio can be set based on actual needs and is not limited here.

[0064] Based on the above content, an embodiment of the present application also provides a method for preparing a structural adhesive, which can produce the structural adhesive introduced in the above content. The preparation method may include: weighing 50 to 60 parts of a polyurethane prepolymer, 25 to 45 parts of a fluorine-containing acrylate monomer and an acrylate monomer, and 0.2 to 2.0 parts of a reducing agent, and mixing them, and the mass ratio of the fluorine-containing acrylate monomer to the acrylate monomer is at least 3:7, and the polyurethane prepolymer is a hydroxy acrylate-terminated polyurethane prepolymer to obtain component A; weighing 15 to 30 parts of an oxidant and 60 to 80 parts of an active diluent, and mixing them, and the active diluent includes an epoxy group, to obtain component B. Component A and component B constitute the structural adhesive.

[0065] Alternatively, the preparation method may include: weighing 50 to 60 parts of a polyurethane prepolymer, 25 to 45 parts of a fluorine-containing acrylate monomer and an acrylate monomer, and 15 to 30 parts of an oxidant, respectively, and mixing them, and the mass ratio of the fluorine-containing acrylate monomer to the acrylate monomer is at least 3:7, and the polyurethane prepolymer is a hydroxy acrylate-terminated polyurethane prepolymer, to obtain component A; weighing 0.2 to 2.0 parts of a reducing agent and 60 to 80 parts of an active diluent, respectively, and mixing them, and the active diluent includes an epoxy group, to obtain component B, and components A and B constitute a structural adhesive.

[0066] For example, for a hydroxy acrylate-terminated polyurethane prepolymer, the specific production process may include: reacting a certain mass of polyether polyol and a certain mass of polyisocyanate at a preset temperature for a period of time, adding a certain amount of hydroxy acrylate-terminated polyisocyanate and continuing the reaction for a period of time to prepare a hydroxy acrylate-terminated polyurethane prepolymer.

[0067] The molecular weight of the polyether polyol is about 1000-5000, and the polyether polyol may include, but is not limited to, at least one of polyethylene oxide polyol, polypropylene oxide polyol, polytetramethylene oxide polyol, ethylene oxide-propylene oxide copolymer polyol, tetramethylene oxide-propylene oxide copolymer polyol, and other polyether polyols, and the specific configuration can be made according to actual needs and is not limited here. The polyisocyanate may be selected from at least one of isophorone diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and other polyisocyanates, and the specific configuration can be made according to actual needs and is not limited here.

[0068] Furthermore, when weighing the polyether polyol and polyisocyanate, the molar ratio of -NCO to -OH can be set to 1.3-1.8, such as, but not limited to, 1.3, 1.4, 1.5, 1.6, 1., 1.8, and other values. The specific ratio can be set according to actual needs and is not limited here. In this way, the polyether polyol and polyisocyanate can fully react to form a polyurethane prepolymer.

[0069] For example, when component A also includes modified ceramic particles, the modified ceramic particles can be prepared by dissolving a certain amount of ceramic particles in a solvent, heating the solvent to a predetermined temperature, adding a certain amount of a silane coupling agent, reacting the solvent for a period of time, cooling the solvent, filtering the solvent, and drying the solvent to obtain the modified ceramic particles. The solvent can be, but is not limited to, ethanol.

[0070] It should be understood that when preparing component A, the corresponding raw materials can be weighed according to the components described in any of the embodiments described above, and then mixed; similarly, when preparing component B, the corresponding raw materials can also be weighed according to the components described in any of the embodiments described above, and then mixed.

[0071] The performance of the structural adhesive is tested below.

[0072] Preparation of structural adhesive.

[0073] Example 1:

[0074] S1.1. The preparation process of the polyurethane prepolymer may include: adding 100 parts by mass of polyoxypropylene polyol and 20 parts by mass of isophorone diisocyanate respectively, heating to a certain temperature and reacting for a period of time, adding 11 parts by mass of hydroxypropyl acrylate, continuing the reaction and then cooling to room temperature to obtain the polyurethane prepolymer.

[0075] S1.2. The production process of modified ceramic particles may include: putting 10 parts by mass of silica nanoparticles with a particle size of about 9 nm and 100 parts by mass of ethanol into a reactor, heating to a certain temperature, adding 0.1 parts by mass of γ-aminopropyltriethoxysilane, reacting for a period of time, cooling to room temperature, filtering, and drying to obtain modified ceramic particles.

[0076] S1.3, the preparation process of component A can include: stirring and evenly mixing 50 parts by mass of the polyurethane prepolymer prepared in the above S1.1, 20 parts by mass of ethylene glycol dimethacrylate, 10 parts by mass of 2,2,2-trifluoroethyl methacrylate, 20 parts by mass of the modified ceramic particles prepared in the above S1.2, 0.2 parts by mass of N,N-dihydroxyethyl-p-toluidine, 0.1 parts by mass of γ-aminopropyltriethoxysilane, 0.1 parts by mass of p-hydroxyanisole, and 0.1 parts by mass of Na2EDTA, and then vacuum degassing to obtain component A.

[0077] S1.4. The preparation process of component B may include: stirring and uniformly mixing 15 parts by mass of dicumyl peroxide, 80 parts by mass of butyl glycidyl ether, and 5 parts by mass of liquid nitrile rubber with a molecular weight of 5000, and vacuum degassing to obtain component B.

[0078] Example 2:

[0079] S2.1. The preparation process of the polyurethane prepolymer may include: adding 100 parts by mass of polytetramethylene diisocyanate and 12.6 parts by mass of hexamethylene diisocyanate respectively, heating to a certain temperature and reacting for a period of time, adding 8 parts by mass of hydroxypropyl methacrylate, continuing the reaction and then cooling to room temperature to obtain the polyurethane prepolymer.

[0080] S2.2. The production process of modified ceramic particles may include: putting 10 parts by mass of titanium dioxide nanoparticles with a particle size of about 7 nm and 100 parts by mass of ethanol into a reactor, heating to a certain temperature, adding 0.5 parts by mass of γ-methacryloxypropyltrimethoxysilane, reacting for a period of time, cooling to room temperature, filtering, and drying to obtain modified ceramic particles.

[0081] S2.3, the preparation process of component A can include: stirring and evenly mixing 55 parts by mass of the polyurethane prepolymer prepared in the above S2.1, 10 parts by mass of isodecyl acrylate, 10 parts by mass of diethylene glycol dimethacrylate, 5 parts by mass of glycol diacrylate, 5 parts by mass of dodecafluoroheptyl methacrylate, 15 parts by mass of the modified ceramic particles prepared in the above S2.2, 1.2 parts by mass of N,N-diisopropyl-p-toluidine, 0.6 parts by mass of γ-methacryloyloxypropyltrimethoxysilane, 0.3 parts by mass of 2,5-di-tert-butylhydroquinone, and 0.2 parts by mass of Na2EDTA, and then vacuum degassing to obtain component A.

[0082] S2.4. The preparation process of component B may include: stirring and uniformly mixing 20 parts by mass of dicumyl peroxide, 40 parts by mass of benzyl glycidyl ether, 30 parts by mass of ethylene glycol diglycidyl ether, and 10 parts by mass of liquid nitrile rubber with a molecular weight of 10,000, and vacuum degassing to obtain component B.

[0083] Example 3:

[0084] S3.1. The preparation process of the polyurethane prepolymer may include: adding 100 parts by mass of ethylene oxide-propylene oxide copolymer polyol and 16.3 parts by mass of diphenylmethane diisocyanate respectively, heating to a certain temperature and reacting for a period of time, adding 9 parts by mass of pentaerythritol triacrylate, continuing the reaction and then cooling to room temperature to obtain the polyurethane prepolymer.

[0085] S3.2. The production process of modified ceramic particles may include: putting 10 parts by mass of aluminum oxide nanoparticles with a particle size of about 5 nm and 100 parts by mass of ethanol into a reactor, heating to a certain temperature, adding 1 part by mass of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, reacting for a period of time, cooling to room temperature, filtering, and drying to obtain modified ceramic particles.

[0086] S3.3, the preparation process of component A can include: stirring and evenly mixing 60 parts by mass of the polyurethane prepolymer prepared in the above S3.1, 20 parts by mass of cyclohexyl acrylate, 5 parts by mass of trimethylolpropane tri(meth)acrylate, 5 parts by mass of hexafluorobutyl methacrylate, 10 parts by mass of the modified ceramic particles prepared in the above S3.2, 2.0 parts by mass of copper octoate, 1.0 parts by mass of N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, 0.6 parts by mass of phenothiazine, and 0.4 parts by mass of Na2EDTA, and then vacuum degassing to obtain component A.

[0087] S3.4. The preparation process of component B may include: stirring and uniformly mixing 30 parts by mass of dicumyl peroxide, 40 parts by mass of C12-C14 alkyl glycidyl ether, 20 parts by mass of polypropylene glycol diglycidyl ether, and 10 parts by mass of liquid chloroprene rubber with a molecular weight of 8000, and vacuum degassing to obtain component B.

[0088] Comparative Example 1:

[0089] S4.1. The preparation process of component A may include: stirring and uniformly mixing 75 parts by mass of ethylene glycol dimethacrylate, 25 parts by mass of ABS resin, 15 parts by mass of zinc sulfate, 40 parts by mass of calcium carbonate, 0.2 parts by mass of N,N-dihydroxyethyl-p-toluidine, 0.1 parts by mass of γ-aminopropyltriethoxysilane, 0.1 parts by mass of p-hydroxyanisole, and 0.1 parts by mass of Na2EDTA, and then vacuum degassing to obtain component A.

[0090] S4.2. The preparation process of component B may include: stirring and uniformly mixing 15 parts by mass of dicumyl peroxide, 80 parts by mass of trioctyl citrate, and 5 parts by mass of nano-titanium oxide, and vacuum degassing to obtain component B.

[0091] Test method.

[0092] 1. Shear Strength Test: Remove the protective film from the aluminum shear test pieces to be bonded, and wipe the surface with acetone to remove dust and oil. Mix component A and component B in a mass ratio of 10:1. Apply the mixture evenly to two aluminum shear test pieces within 5 minutes, with a coating length of at least 12.5 mm. Overlap the two aluminum shear test pieces and secure them with binder clips. Cure at 23°C for 24 hours. Test according to GB / T 7124-2008.

[0093] 2. Peel Strength Test: Remove the protective film from the aluminum shear test piece to be bonded, and wipe the surface with acetone to remove dust and oil. Mix components A and B in a mass ratio of 10:1. Apply the mixture evenly to the aluminum shear test piece within 5 minutes, with a coating length of at least 150 mm. Cover with PET (Polyethylene Terephthalate) film, secure with binder clips, and cure at 23°C for 24 hours. Test according to GB / T 7122-2008.

[0094] 3. Oil resistance test: After the shear strength test sample is placed in thermal oil containing 2000ppm water at a temperature of 160±2℃ for 1200 hours, the test is carried out in accordance with GB / T 7124-2008.

[0095] 4. Hygrothermal aging shear strength test: Place the shear strength test sample in a hygrothermal aging chamber at a temperature of 80±2°C and a humidity of 90±2% for 96 hours, and then test it in accordance with GB / T 7124-2008.

[0096] 5. Heat-resistant shear strength test: Place the shear strength test sample at 200±2℃ for 120h, cool to room temperature and test the shear strength according to GB / T 7124-2008.

[0097] 6. Solvent resistance shear strength test: Mix components A and B evenly at a mass ratio of 10:1 and apply the glue within 5 minutes to allow the mixed structural adhesive to crosslink and cure. Soak the cured structural adhesive in ethanol for 48 hours and test the shear strength in accordance with GB / T7124-2008.

[0098] 7. Medium shear strength test: Mix components A and B in a mass ratio of 10:1. Complete the adhesive application within 5 minutes to allow the mixed structural adhesive to crosslink and cure. Soak the cured structural adhesive in a 10% NaOH aqueous solution for 48 hours and test the shear strength in accordance with GB / T 7124-2008.

[0099] 8. High temperature resistance test: After the shear strength test sample is kept at 200±2℃ for 30 minutes, the shear strength is tested at 200±2℃ in accordance with GB / T7124-2008.

[0100] Test results.

[0101] The performance test results are shown in Table 1:

[0102] Table 1

[0103] Example 1 Example 2 Example 3 Comparative Example 1 Shear strength / MPa 30.6 29.5 30.2 19.8 Peel strength / MPa 17.2 16.3 16.7 7.2 Oil resistance test / MPa 21.8 20.6 21.3 3.6 Hygrothermal aging shear strength / MPa 26.8 25.1 26.4 10.6 Heat-resistant shear strength / MPa 27.5 26.2 27.8 11.3 Solvent resistance shear strength / MPa 27.5 28.4 27.9 11.5 Medium shear strength / MPa 28.7 29.2 28.4 10.7 High temperature resistance 5.6 4.5 4.9 0.2

[0104] From the test data shown in Table 1 it can be determined that:

[0105] Compared to Comparative Example 1, the shear strength, peel strength, oil resistance, and high temperature resistance of the structural adhesives in Examples 1 to 3 were significantly improved. Furthermore, in Examples 1 to 3, compared to shear strength, the decreases in wet heat aging shear strength, heat-resistant shear strength, solvent-resistant shear strength, and dielectric shear strength were minimal. In Comparative Example 1, however, the decreases in wet heat aging shear strength, heat-resistant shear strength, solvent-resistant shear strength, and dielectric shear strength were significant compared to shear strength. This is due to:

[0106] On the one hand, the main raw materials such as polyurethane prepolymer, acrylate monomer, fluorinated acrylate monomer in the structural adhesive provided by the embodiment of the present application are all reactive. After curing, they are chemically bonded to the main chain or side chain of the structural adhesive, making the structural adhesive more stable and non-toxic. Moreover, after curing, the polarity of the structural adhesive is further improved, and the cohesive strength of the structural adhesive is also improved, so that the shear failure is cohesive failure, such as Figure 1 As shown in the figure, the structural adhesive on the surface of the sample (such as Figure 1 The sample (shown in the dotted circle) is intact, and the interface between the sample and the structural adhesive is not damaged, indicating that the structural adhesive itself has been damaged, and thus indicating that the structural adhesive provided in the embodiment of the present application has good bonding properties. It should be understood that, taking two aluminum sheets bonded with structural adhesive as an example, the types of shear failure may include: interface failure, cohesive failure, and substrate failure. Interface failure can be regarded as failure that occurs from the bonding surface between the structural adhesive and the aluminum sheet. At this time, there may be some structural adhesive on the surface of the aluminum sheet, or there may be no structural adhesive; cohesive failure can be regarded as failure that occurs from the inside of the structural adhesive. At this time, there will be complete structural adhesive on the surface of the aluminum sheet, and the bonding surface between the structural adhesive and the aluminum sheet is intact; substrate failure can be regarded as failure that occurs from the aluminum sheet. At this time, the aluminum sheet itself will be damaged.

[0107] On the other hand, the structural adhesive provided in the embodiments of the present application is added with modified ceramic particles, which have good compatibility with the organic system, so that the modified ceramic particles have a better dispersion effect in the organic system; and the organic groups on the surface of the modified ceramic particles can form chemical bonds with the groups in the organic system, thereby further improving the adhesion and cohesive strength of the structural adhesive.

[0108] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include such modifications and variations.

Claims

1. A structural adhesive, characterized in that: It includes component A and component B; The component A comprises, by weight, 50 to 60 parts of a polyurethane prepolymer, 25 to 45 parts of a fluorinated acrylate monomer and an acrylate monomer, and 0.2 to 2.0 parts of a reducing agent; the mass ratio of the fluorinated acrylate monomer to the acrylate monomer is at least 3:7; In parts by weight, the B component comprises: 15 to 30 parts of an oxidant and 60 to 80 parts of a reactive diluent; the reactive diluent comprises an epoxy group; Wherein, the polyurethane prepolymer is a hydroxy acrylate terminated polyurethane prepolymer.

2. A structural adhesive, characterized in that: It includes component A and component B; The component A comprises, by weight, 50 to 60 parts of a polyurethane prepolymer, 25 to 45 parts of a fluorinated acrylate monomer and an acrylate monomer, and 15 to 30 parts of an oxidant; the mass ratio of the fluorinated acrylate monomer to the acrylate monomer is at least 3:7; The B component comprises, by weight, 0.2 to 2.0 parts of a reducing agent and 60 to 80 parts of a reactive diluent; the reactive diluent comprises an epoxy group; Wherein, the polyurethane prepolymer is a hydroxy acrylate terminated polyurethane prepolymer.

3. The structural adhesive according to claim 1 or 2, characterized in that: In parts by weight, the acrylate monomer is 20 to 30 parts, and the fluorine-containing acrylate monomer is 5 to 15 parts.

4. The structural adhesive according to any one of claims 1 to 3, characterized in that: In parts by weight, the component A further comprises: 10 to 20 parts of modified ceramic particles, wherein the modified ceramic particles are ceramic particles having a silane coupling agent on the surface.

5. The structural adhesive according to claim 4, wherein: The particle size of the ceramic particles is no greater than 100 nm.

6. The structural adhesive according to claim 4 or 5, characterized in that: The ceramic particles include at least one of silicon oxide nanoparticles, aluminum oxide nanoparticles, titanium oxide nanoparticles, and zirconium oxide nanoparticles.

7. The structural adhesive according to any one of claims 4 to 6, characterized in that: In parts by weight, the component A further comprises: 0.1 to 1.0 parts of the silane coupling agent.

8. The structural adhesive according to any one of claims 1 to 7, characterized in that: In parts by weight, the component A further comprises: 0.1 to 1.0 parts of a stabilizer.

9. The structural adhesive according to any one of claims 1 to 8, characterized in that: In parts by weight, the component B further comprises 5 to 15 parts of a toughening agent.

10. The structural adhesive according to any one of claims 1 to 9, characterized in that: The hydroxy acrylate monomer is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, trimethylolpropane diacrylate, and pentaerythritol triacrylate.

11. The structural adhesive according to any one of claims 1 to 10, characterized in that: The fluorine-containing acrylate monomer is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, trimethylolpropane diacrylate, and pentaerythritol triacrylate.

12. The structural adhesive according to any one of claims 1 to 11, characterized in that: The acrylate monomer is selected from at least one of isooctyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tri(meth)acrylate.

13. The structural adhesive according to any one of claims 1 to 12, characterized in that: The oxidizing agent is selected from peroxides.

14. The structural adhesive according to any one of claims 1 to 13, characterized in that: The reducing agent is selected from at least one of variable valence metal organic salt compounds and aniline compounds.

15. The structural adhesive according to any one of claims 1 to 14, characterized in that: The weight ratio of the component A to the component B is 10:0.1-5.

16. A structural member, characterized in that: include: A plurality of components, each of the components being bonded together by the structural adhesive according to any one of claims 1 to 15.

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