Structural adhesive, preparation method thereof and wind power blade

Abstract

The invention discloses a structural adhesive and a preparation method thereof and a wind turbine blade, the structural adhesive comprises a component A and a component B, the mass ratio of the component A to the component B in the structural adhesive is 100: (35-45), and based on the total mass of the component A, the component A comprises 1 wt%-2 wt% of an assistant thixotropic agent, 0.8 wt%-1.2 wt% of a silane coupling agent, 2.5 wt%-3 wt% of hydrophilic fumed silica and the balance of components. The hydrophilic fumed silica is adopted in the structural adhesive, a good synergistic effect is generated after the proportion of the hydrophilic fumed silica, the silane coupling agent and the auxiliary thixotropic agent is adjusted according to the proportion of the structural adhesive, the tensile shear performance of the structural adhesive can be improved, meanwhile, compared with at least 8 wt% of silicon dioxide in an existing structural adhesive, the tensile shear performance of the structural adhesive is improved, and the tensile shear performance of the structural adhesive is improved. The silicon dioxide content is low, and the overall cost of the structural adhesive can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of wind power generation technology, and particularly relates to a structural adhesive and its preparation method, as well as wind turbine blades. Background Technology

[0002] Currently, in the wind power industry, structural adhesives are generally used as bonding agents in the mold-fitting process during wind turbine blade manufacturing. These structural adhesives are also commonly referred to as "mold-fitting adhesives." Most structural adhesives used for blades are epoxy structural adhesives with an epoxy resin matrix. Epoxy structural adhesives typically consist of components A and B, with component A currently using hydrophobic fumed silica as a thixotropic agent.

[0003] Existing structural adhesives use hydrophobic fumed silica as a thixotropic agent in their A component, resulting in poor bonding interface performance and high cost when used in wind turbine blades. Summary of the Invention

[0004] This invention provides a structural adhesive and its preparation method, as well as a wind turbine blade. The structural adhesive of this application uses a low content of hydrophilic fumed silica thixotropic agent and co-thixotropic agent in component A, which improves the tensile and shear properties of the structural adhesive while reducing its cost.

[0005] In a first aspect, a structural adhesive is provided, comprising a component A and a component B, wherein the mass ratio of component A to component B in the structural adhesive is 100:(35-45), wherein, based on the total mass of component A, component A comprises a thixotropic agent: 1 wt% to 2 wt%; a silane coupling agent: 0.8 wt% to 1.2 wt%; hydrophilic fumed silica: 2.5 wt% to 3 wt%; and other components.

[0006] In the first possible implementation, the tensile and compressive fatigue m value of the structural adhesive is ≥12.5, and / or, when the number of cycles is tens of millions, the tensile stress amplitude of the structural adhesive is ≥56MPa.

[0007] In a second possible implementation, combining the above-mentioned possible methods, the hydrophilic fumed silica includes amino-functionalized fumed silica and / or epoxy-functionalized fumed silica. In a third possible implementation, combining the above-mentioned possible methods, the silane coupling agent is KH560; and / or, the co-thixotropic agent is a polyhydroxy compound, preferably, one or more of trimethylolpropane propylene glycol ether, ethylene glycol, diethylene glycol, glycerol, triethylene glycol, tetraethylene glycol, and dipropylene glycol.

[0008] In combination with the above possible implementations, in the fourth possible implementation, based on the total mass of component A, component A may further include bisphenol A epoxy resin: 55wt% to 60wt%; bisphenol F epoxy resin: 28wt% to 33wt%; and diluent: 7wt% to 13wt%.

[0009] In combination with the above possible implementations, in the fifth possible implementation, the bisphenol A epoxy resin is a low molecular weight bisphenol A epoxy resin, preferably, the low molecular weight bisphenol A epoxy resin is bisphenol A diglycidyl ether; and / or, the bisphenol F epoxy resin is a low molecular weight bisphenol F epoxy resin, preferably, the low molecular weight bisphenol F epoxy resin is bisphenol F diglycidyl ether; and / or, the diluent is a glycol diglycidyl ether, preferably, the diluent is butanediol diglycidyl ether and / or cyclohexanediol diglycidyl ether.

[0010] In combination with the above possible implementations, in the sixth possible implementation, based on the total mass of component B, component B includes polyetheramine: 30wt%–32wt%; amino polyamide: 20wt%–22wt%; heat-resistant amine-IPDA: 11wt%–13wt%; toughening agent: 29wt%–31wt%; and fumed silica: 4wt%–6wt%.

[0011] In combination with the above possible implementations, in the seventh possible implementation, the polyetheramine is a polyetheramine with a functionality ≥4, preferably D230 and / or T403; and / or, the toughening agent is one or more of the following: core-shell polymer toughening agent, carboxyl-terminated butadiene-acrylonitrile rubber, amino-terminated butadiene-acrylonitrile rubber, amino-terminated polyether (high molecular weight polyetheramine), amino-terminated butyl rubber, or polyurethane toughening agent, preferably polyetheramine T-5000; and / or, the fumed silica is hydrophilic fumed silica.

[0012] Secondly, a method for preparing a structural adhesive is provided, wherein component A is prepared by the following method:

[0013] Mix the thixotropic agent, silane coupling agent and other components in component A evenly to obtain the mixture;

[0014] Hydrophilic fumed silica was added to the mixture in multiple batches and dispersed to obtain component A.

[0015] In the first possible implementation, in the step of adding hydrophilic fumed silica to the mixture in multiple batches for dispersion treatment to obtain component A, the mass of each addition of hydrophilic fumed silica does not exceed 0.3% of the total mass of component A; and / or, after each addition of hydrophilic fumed silica, dispersion treatment is performed, and the next addition of hydrophilic fumed silica is performed only after sufficient dispersion.

[0016] Thirdly, a wind turbine blade is provided, wherein the structural adhesive of the first aspect is used in the manufacturing process of the wind turbine blade and / or the structural adhesive prepared by the preparation method of the second aspect is used in the manufacturing process.

[0017] Compared with existing technologies, the structural adhesive provided in this application uses hydrophilic fumed silica. Furthermore, by adjusting the ratio of hydrophilic fumed silica, silane coupling agent, and thixotropic agent to 1 wt%–2 wt%, 0.8 wt%–1.2 wt% silane coupling agent, and 2.5 wt%–3 wt% hydrophilic fumed silica, a good synergistic effect is achieved, improving the tensile and shear properties of the structural adhesive. Simultaneously, compared to the at least 8 wt% silica content in existing structural adhesives, the silica content in this application is lower, reducing the overall cost of the structural adhesive. The thixotropic agent helps or promotes thixotropy of the hydrophilic fumed silica and bridges the thixotropic agents, thereby increasing their performance. The numerous hydrophilic functional groups on the surface of the hydrophilic fumed silica can form numerous hydrogen bonds with the epoxy resin, further enhancing the performance of the structural adhesive. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a hydrophobic fumed silica.

[0020] Figure 2 This is a schematic diagram of the structure of hydrophilic fumed silica according to an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of a surface-amino-functionalized hydrophilic fumed silica according to an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of hydrophilic fumed silica with surface epoxy functionalization according to an embodiment of the present invention. Detailed Implementation

[0023] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present invention and not to limit the present invention. For those skilled in the art, the present invention can be practiced without some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present invention by illustrating examples of the invention.

[0024] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, although not explicitly stated, every point or individual value between the endpoints of the range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit and combined with any other point or individual value or with other lower or upper limits to form a range not explicitly stated.

[0025] The foregoing description of this application is not intended to describe every disclosed embodiment or implementation. The following description illustrates exemplary embodiments in more detail. Throughout the application, guidance is provided through a series of embodiments that can be used in various combinations. In each example, the enumeration is merely representative and should not be construed as exhaustive. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] Currently, in the wind power industry, structural adhesives are generally used as bonding agents in the mold bonding process during wind turbine blade manufacturing. These structural adhesives are also commonly referred to as "mold bonding adhesives." Most of the structural adhesives used for blades are epoxy structural adhesives with an epoxy resin matrix.

[0027] In wind turbine blades, epoxy structural adhesive is mainly distributed at the interface between the two skins and at the interface between the skin and the web. Epoxy structural adhesive plays two main roles in the fabrication of wind turbine blades:

[0028] 1) The I-beam connects the main beam and web of the wind turbine blade into a whole, becoming the main load-bearing structure.

[0029] 2) Connect the two skins into a whole to form the blade shape structure that performs the power generation function.

[0030] Epoxy structural adhesives typically consist of component A and component B, with component A commonly using hydrophobic fumed silica as a thixotropic agent. The structural adhesive itself contains numerous weak interfaces, making it susceptible to failure under cyclic stress. The surface of hydrophobic fumed silica lacks active groups, resulting in poor adhesion between the resin and the silica surface. Excessive silica addition prevents sufficient dispersion within the structural adhesive, leading to numerous interfacial defects. This can easily cause cracking during tensile fatigue. Existing structural adhesives, due to the use of hydrophobic fumed silica as a thixotropic agent in component A, suffer from poor bonding interface performance and high costs in wind turbine blade applications. Hydrophobic fumed silica refers to surface modification of fumed silica using hydrophobic groups, for example... Figure 1 As shown, organosilicon hydrophobic groups can be grafted onto the surface of fumed silica.

[0031] To address the aforementioned issues, this invention provides a structural adhesive in which component A contains a low content of hydrophilic fumed silica thixotropic agent and co-thixotropic agent, thereby improving the tensile and shear properties of the structural adhesive while reducing its cost.

[0032] The structural adhesive provided by this invention will be introduced below.

[0033] According to this application, the structural adhesive comprises component A and component B, wherein the mass ratio of component A to component B in the structural adhesive is 100:(35-45). Based on the total mass of component A, component A comprises: 1 wt% to 2 wt% of a thixotropic agent; 0.8 wt% to 1.2 wt% of a silane coupling agent; 2.5 wt% to 3 wt% of hydrophilic fumed silica; and the remaining components. For example, the mass ratio of component A to component B can be 100:35, 100:36, 100:37, 100:38, 100:39, 100:40, 100:41, 100:42, 100:43, 100:44, 100:45, or any combination of the above values; the mass percentage of the thixotropic agent in component A can be 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2 wt%, or any combination thereof. The mass percentage of the silane coupling agent in component A can be 0.80wt%, 0.85wt%, 0.90wt%, 0.95wt%, 1.00wt%, 1.05wt%, 1.10wt%, 1.15wt%, 1.20wt%, or any combination of the above values; the mass percentage of hydrophilic fumed silica in component A can be 2.5wt%, 2.55wt%, 2.60wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3wt%, or any combination of the above values.

[0034] The inventors discovered that the use of hydrophilic fumed silica in this application, and the adjustment of the ratio of hydrophilic fumed silica, silane coupling agent, and thixotropic agent to thixotropic agent: 1wt% to 2wt%, silane coupling agent: 0.8wt% to 1.2wt%, and hydrophilic fumed silica: 2.5wt% to 3wt%, produces a good synergistic effect, improving the tensile and shear properties of the structural adhesive. At the same time, compared with the existing structural adhesives containing at least 8wt% silica, the silica content of this application is lower, which can reduce the overall cost of the structural adhesive.

[0035] Thixotropic agents can help or promote thixotropy in hydrophilic fumed silica and bridge between thixotropic agents, thereby increasing their performance. The numerous hydrophilic functional groups on the surface of hydrophilic fumed silica can form a large number of hydrogen bonds with epoxy resin, thereby improving the performance of structural adhesives.

[0036] In some embodiments, the structural schematic diagram of hydrophilic fumed silica can be as follows: Figure 2 As shown, where, Figure 2 This is merely an illustrative example and is not intended to limit the hydroxyl content and morphology of the fumed silica surface. Specifically, hydrophilic fumed silica can be selected from Evonik Degussa. 380F; the tensile and compressive fatigue m value of the structural adhesive is ≥12.5, and / or, when the number of cycles is tens of millions, the tensile stress amplitude of the structural adhesive is ≥56MPa.

[0037] In some of the specific embodiments described above, the compressive fatigue resistance and tensile stress amplitude of the structural adhesive of this application are significantly better than those of existing structural adhesives.

[0038] It should be noted that the hydrophilic silica in this application can be prepared by adding a small amount of hydroxyl-containing compound (such as methanol or ethanol) to a silicon tetrachloride (SiCl4) hydrolysis system or by lowering the reaction temperature. Alternatively, it can be prepared by immersing fumed silica in deionized water or dilute acid solution and generating hydroxyl groups (Si-O-Si+H2O→2Si-OH) through the hydrolytic cleavage of silicon-oxygen bonds (Si-O-Si). It can also be obtained by treating the surface of fumed silica with a hydrophilic modifier, such as grafting with polyols or polyethylene glycol.

[0039] In some embodiments, the hydrophilic fumed silica can be surface-amino-functionalized hydrophilic fumed silica, such as... Figure 3 As shown, amino groups are grafted onto the surface of fumed silica. Figure 3 This is for illustrative purposes only and is not intended to limit the amino content and morphology of amino-functionalized fumed silica surfaces.

[0040] In some embodiments, the hydrophilic fumed silica can be a surface-epoxy-functionalized hydrophilic fumed silica, such as... Figure 4 As shown, epoxy groups are grafted onto the surface of fumed silica. Figure 4 This is for illustrative purposes only and is not intended to limit the content and morphology of epoxy groups on the surface of epoxy-functionalized fumed silica.

[0041] In some embodiments, the silane coupling agent is KH560; and / or, the co-thixotropic agent is a polyhydroxy compound, preferably, the co-thixotropic agent is one or more of trimethylolpropane propylene glycol ether, ethylene glycol, diethylene glycol, glycerol, triethylene glycol, tetraethylene glycol, and dipropylene glycol. For example, the co-thixotropic agent can be any proportion of trimethylolpropane propylene glycol ether, ethylene glycol, diethylene glycol, glycerol, triethylene glycol, tetraethylene glycol, dipropylene glycol, trimethylolpropane propylene glycol ether and diethylene glycol, any proportion of trimethylolpropane propylene glycol, ethylene glycol, and diethylene glycol, or any proportion of ethylene glycol, glycerol, triethylene glycol, and dipropylene glycol.

[0042] In some specific embodiments, based on the total mass of component A, component A may further include bisphenol A epoxy resin: 55wt% to 60wt%; bisphenol F epoxy resin: 28wt% to 33wt%; and diluent: 7wt% to 13wt%. For example, the mass percentage of bisphenol A epoxy resin in component A can be any combination of 55wt%, 55.5wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, or more; the mass percentage of bisphenol F epoxy resin in component A can be any combination of 28wt%, 28.5wt%, 29wt%, 30wt%, 31wt%, 32wt%, or more; and the mass percentage of diluent in component A can be any combination of 7wt%, 7.5wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, or more.

[0043] In some specific embodiments, the bisphenol A epoxy resin is a low molecular weight bisphenol A epoxy resin, preferably bisphenol A diglycidyl ether; and / or, the bisphenol F epoxy resin is a low molecular weight bisphenol F epoxy resin, preferably bisphenol F diglycidyl ether; and / or, the diluent is a glycol diglycidyl ether, preferably butylene glycol diglycidyl ether and / or cyclohexanediol diglycidyl ether. For example, the diluent can be butylene glycol diglycidyl ether, cyclohexanediol diglycidyl ether, or a mixture of butylene glycol diglycidyl ether and cyclohexanediol diglycidyl ether in any proportion.

[0044] In some specific embodiments, based on the total mass of component B, component B comprises polyetheramine: 30wt%–32wt%; amino polyamide: 20wt%–22wt%; heat-resistant amine-IPDA: 11wt%–13wt%; toughening agent: 29wt%–31wt%; and fumed silica: 4wt%–6wt%. For example, the mass percentage of polyetheramine in component B can be 30wt%, 30.2wt%, 30.5wt%, 30.8wt%, 31wt%, 31.5wt%, 32wt%, or any combination thereof; the mass percentage of amino polyamide in component B can be 20wt%, 20.2wt%, 20.5wt%, 20.8wt%, 21wt%, 21.5wt%, 22wt%, or any combination thereof; and the mass percentage of heat-resistant amine-IPDA in component B can be 11wt%, 11.2wt%, 1 ... The mass percentage of toughening agent in component B can be any combination of 0.5 wt%, 11.8 wt%, 12 wt%, 12.5 wt%, 13 wt%, or higher. The mass percentage of fumed silica in component B can be any combination of 29 wt%, 29.2 wt%, 29.5 wt%, 29.8 wt%, 30 wt%, 30.5 wt%, 31 wt%, or higher.

[0045] In some specific embodiments, the polyetheramine is a polyetheramine with a functionality ≥4, preferably D230 and / or T403. For example, the polyetheramine can be D230, T403, or a mixture of D230 and T403 in any proportion; and / or, the toughening agent is one or more of the following: core-shell polymer toughening agent, carboxyl-terminated nitrile butadiene rubber, amino-terminated nitrile butadiene rubber, amino-terminated polyether (high molecular weight polyetheramine), amino-terminated butyl rubber, or polyurethane toughening agent, preferably polyetheramine T-5000; and / or, the fumed silica is hydrophilic fumed silica.

[0046] Secondly, this application provides a method for preparing a structural adhesive, wherein component A is prepared by the following method:

[0047] The thixotropic agent, silane coupling agent and other components in component A are mixed to obtain a mixture;

[0048] Component A is obtained by adding hydrophilic fumed silica to the mixture in multiple batches for dispersion treatment.

[0049] In some specific embodiments, in the step of adding hydrophilic fumed silica to the mixture in multiple batches for dispersion treatment to obtain component A, the mass of each addition of hydrophilic fumed silica does not exceed 0.3% of the total mass of component A. For example, it can be any combination of 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, or the above values; and / or, after each addition of hydrophilic fumed silica, dispersion treatment is performed, and the next addition of hydrophilic fumed silica is performed only after sufficient dispersion.

[0050] Thirdly, this application provides a wind turbine blade, wherein the wind turbine blade is manufactured using the structural adhesive of the first aspect and / or the structural adhesive prepared by the manufacturing method of the second aspect.

[0051] The following embodiments describe the contents disclosed in this application in more detail. These embodiments are for illustrative purposes only.

[0052] In this specific embodiment, the tensile and compressive fatigue (R=-1) test was conducted at 23±2℃ and 50±10% humidity in accordance with ISO13003-2003 standard.

[0053] The hydrophilic silica used in this embodiment is of the type Evonik Degussa. 380F.

[0054] The hydrophobic fumed silica used is from Evonik Degussa. R208.

[0055] Example 1

[0056] A structural adhesive comprises component A and component B in a mass ratio of 100:43. Component A comprises 58 wt% bisphenol A diglycidyl ether, 29 wt% bisphenol F diglycidyl ether, 8 wt% butylene glycol diglycidyl ether, 1.5 wt% trimethylolpropane propylene glycol ether, 1 wt% KH560, and 2.5 wt% hydrophilic fumed silica.

[0057] Component A is prepared by the following method: Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, butylene glycol diglycidyl ether, KH560, and trimethylolpropane propylene glycol ether are mixed evenly, and hydrophilic fumed silica is added in small amounts multiple times. The hydrophilic fumed silica is added to the mixture in multiple batches for dispersion treatment to obtain component A. In this step, the mass of each addition of hydrophilic fumed silica does not exceed 0.3% of the total mass of component A. After each addition of hydrophilic fumed silica, dispersion treatment is performed, and the next addition of hydrophilic fumed silica is carried out only after sufficient dispersion.

[0058] Component B comprises 31.5 wt% polyetheramine, 21 wt% amino polyamide, 11.9 wt% heat-resistant amine-IPDA, 30 wt% polyetheramine T-5000, and 5.6 wt% hydrophilic fumed silica.

[0059] The structural adhesive of this embodiment was subjected to tensile and compressive fatigue tests. The tensile and compressive fatigue (R=-1) performance was tested according to ISO 13003-2003 standard. At the 95% confidence interval, the tensile and compressive fatigue m value of the structural adhesive was 12.7, and the number of cycles N=10. 7 At (tens of millions of cycles), the tensile stress amplitude of the structural adhesive is 56.17 MPa.

[0060] Example 2

[0061] A structural adhesive comprises component A and component B in a mass ratio of 100:43. Component A comprises 57.6 wt% bisphenol A diglycidyl ether, 29 wt% bisphenol F diglycidyl ether, 8 wt% butylene glycol diglycidyl ether, 1.6 wt% trimethylolpropane propylene glycol ether, 1 wt% KH560 and 2.8 wt% hydrophilic fumed silica.

[0062] Component A is prepared by the following method: Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, butylene glycol diglycidyl ether, KH560, and trimethylolpropane propylene glycol ether are mixed evenly, and hydrophilic fumed silica is added in small amounts multiple times. The hydrophilic fumed silica is added to the mixture in multiple batches for dispersion treatment to obtain component A. In this step, the mass of each addition of hydrophilic fumed silica does not exceed 0.3% of the total mass of component A. After each addition of hydrophilic fumed silica, dispersion treatment is performed, and the next addition of hydrophilic fumed silica is carried out only after sufficient dispersion.

[0063] Component B comprises 31.5 wt% polyetheramine, 21 wt% amino polyamide, 11.9 wt% heat-resistant amine-IPDA, 30 wt% polyetheramine T-5000, and 5.6 wt% hydrophilic fumed silica.

[0064] The structural adhesive of this embodiment was subjected to tensile and compressive fatigue tests. The tensile and compressive fatigue (R=-1) performance was tested according to ISO 13003-2003 standard. At the 95% confidence interval, the tensile and compressive fatigue m value of the structural adhesive was 13.3, and the number of cycles N=10. 7 At tensile stress amplitude of 57.06 MPa (millions of cycles).

[0065] Example 3

[0066] A structural adhesive comprises component A and component B in a mass ratio of 100:43. Component A comprises 57 wt% bisphenol A diglycidyl ether, 29 wt% bisphenol F diglycidyl ether, 8 wt% butylene glycol diglycidyl ether, 2 wt% trimethylolpropane propylene glycol ether, 1 wt% KH560 and 3 wt% hydrophilic fumed silica.

[0067] Component A is prepared by the following method: Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, butylene glycol diglycidyl ether, KH560, and trimethylolpropane propylene glycol ether are mixed evenly, and hydrophilic fumed silica is added in small amounts multiple times. The hydrophilic fumed silica is added to the mixture in multiple batches for dispersion treatment to obtain component A. In this step, the mass of each addition of hydrophilic fumed silica does not exceed 0.3% of the total mass of component A. After each addition of hydrophilic fumed silica, dispersion treatment is performed, and the next addition of hydrophilic fumed silica is carried out only after sufficient dispersion.

[0068] Component B comprises 31.5 wt% polyetheramine, 21 wt% amino polyamide, 11.9 wt% heat-resistant amine-IPDA, 30 wt% polyetheramine T-5000, and 5.6 wt% hydrophilic fumed silica.

[0069] The structural adhesive of this embodiment was subjected to tensile and compressive fatigue tests. The tensile and compressive fatigue (R=-1) performance was tested according to ISO 13003-2003 standard. At the 95% confidence interval, the tensile and compressive fatigue m value of the structural adhesive was 14, and the number of cycles N=10. 7 At tensile stress amplitude of 56.84 MPa (millions of cycles).

[0070] Comparative Example 1

[0071] A structural adhesive comprises component A and component B in a mass ratio of 100:43. Component A comprises 59.9 wt% bisphenol A diglycidyl ether, 29 wt% bisphenol F diglycidyl ether, 8 wt% butylene glycol diglycidyl ether, 0.6 wt% trimethylolpropane propylene glycol ether, 1 wt% KH560, and 1.5 wt% hydrophilic fumed silica.

[0072] Component B comprises 31.5 wt% polyetheramine, 21 wt% amino polyamide, 11.9 wt% heat-resistant amine-IPDA, 30 wt% polyetheramine T-5000, and 5.6 wt% hydrophilic fumed silica.

[0073] Tensile and compressive fatigue tests were conducted on the structural adhesive of this comparative example. The tensile and compressive fatigue (R=-1) performance was tested according to the ISO 13003-2003 standard. At the 95% confidence interval, the tensile and compressive fatigue m value of the structural adhesive was 9.8. When the number of cycles N=107 (ten million cycles), the tensile stress amplitude of the structural adhesive was 54.20 MPa.

[0074] Comparative Example 2

[0075] A structural adhesive comprises component A and component B in a mass ratio of 100:43. Component A comprises 59.6 wt% bisphenol A diglycidyl ether, 30 wt% bisphenol F diglycidyl ether, 8 wt% butylene glycol diglycidyl ether, 0.4 wt% trimethylolpropane propylene glycol ether, 1 wt% KH560 and 1 wt% hydrophilic fumed silica.

[0076] Component B comprises 31.5 wt% polyetheramine, 21 wt% amino polyamide, 11.9 wt% heat-resistant amine-IPDA, 30 wt% polyetheramine T-5000, and 5.6 wt% hydrophilic fumed silica.

[0077] Tensile and compressive fatigue tests were conducted on the structural adhesive of this comparative example. The tensile and compressive fatigue (R=-1) performance was tested according to the ISO 13003-2003 standard. At the 95% confidence interval, the tensile and compressive fatigue m value of the structural adhesive was 9.1. When the number of cycles N=107 (ten million cycles), the tensile stress amplitude of the structural adhesive was 54.88 MPa.

[0078] Comparative Example 3

[0079] A structural adhesive comprises component A and component B in a mass ratio of 100:43. Component A comprises 54.3 wt% bisphenol A diglycidyl ether, 30 wt% bisphenol F diglycidyl ether, 8 wt% butylene glycol diglycidyl ether, 2.7 wt% trimethylolpropane propylene glycol ether, 1 wt% KH560 and 4 wt% hydrophilic fumed silica.

[0080] Component B comprises 31.5 wt% polyetheramine, 21 wt% amino polyamide, 11.9 wt% heat-resistant amine-IPDA, 30 wt% polyetheramine T-5000, and 5.6 wt% hydrophilic fumed silica.

[0081] Tensile and compressive fatigue tests were conducted on the structural adhesive of this comparative example. The tensile and compressive fatigue (R=-1) performance was tested according to the ISO 13003-2003 standard. At the 95% confidence interval, the tensile and compressive fatigue m value of the structural adhesive was 10.4. When the number of cycles N=107 (ten million cycles), the tensile stress amplitude of the structural adhesive was 55.01 MPa.

[0082] Comparative Example 4

[0083] A structural adhesive comprises component A and component B, wherein the mass ratio of component A to component B is 100:43, wherein,

[0084] Component A comprises 55 wt% bisphenol A diglycidyl ether, 28 wt% bisphenol F diglycidyl ether, 9 wt% butylene glycol diglycidyl ether and 8 wt% hydrophobic fumed silica.

[0085] Component B comprises 31.5 wt% polyetheramine, 21 wt% amino polyamide, 11.9 wt% heat-resistant amine-IPDA, 30 wt% polyetheramine T-5000, and 5.6 wt% hydrophobic fumed silica.

[0086] Tensile and compressive fatigue tests were conducted on the structural adhesive of this comparative example. The tensile and compressive fatigue (R=-1) performance was tested according to the ISO 13003-2003 standard. At the 95% confidence interval, the tensile and compressive fatigue m value of the structural adhesive was 8.9. When the number of cycles N=107 (ten million cycles), the tensile stress amplitude of the structural adhesive was 53.97 MPa.

[0087] Because various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages and ratios reported in the following examples are based on mass, and all raw materials used in the examples are commercially available or prepared by conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0088] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A structural adhesive, characterized in that, The structural adhesive comprises component A and component B, wherein the mass ratio of component A to component B is 100:(35-45), and component A comprises, based on the total mass of component A, component A: Thixotropic agent: 1wt%–2wt%, silane coupling agent: 0.8wt%–1.2wt%, hydrophilic fumed silica: 2.5wt%–3wt%, and other components.

2. The structural adhesive according to claim 1, characterized in that, The structural adhesive has a tensile and compressive fatigue m value ≥ 12.5, and / or, when the number of cycles is tens of millions, the tensile stress amplitude of the structural adhesive is ≥ 56 MPa.

3. The structural adhesive according to claim 2, characterized in that, The hydrophilic fumed silica includes amino-functionalized fumed silica and / or epoxy-functionalized fumed silica.

4. The structural adhesive according to claim 1, characterized in that, The silane coupling agent is KH560; And / or, the co-thixotropic agent is a polyhydroxy compound, preferably, one or more of trimethylolpropane propylene glycol ether, ethylene glycol, diethylene glycol, glycerol, triethylene glycol, tetraethylene glycol, and dipropylene glycol.

5. The structural adhesive according to claim 1, characterized in that, Based on the total mass of component A, component A further includes: Bisphenol A epoxy resin: 55wt%–60wt%, Bisphenol F epoxy resin: 28wt%–33wt%, Diluent: 7wt%–13wt%.

6. The structural adhesive according to claim 5, characterized in that, The bisphenol A epoxy resin is a low molecular weight bisphenol A epoxy resin, preferably, the low molecular weight bisphenol A epoxy resin is bisphenol A diglycidyl ether. And / or, the bisphenol F epoxy resin is a low molecular weight bisphenol F epoxy resin, preferably, the low molecular weight bisphenol F epoxy resin is bisphenol F diglycidyl ether; And / or, the diluent is a diglycidyl glycol ether, preferably, the diluent is butylene glycol diglycidyl ether and / or cyclohexanediol diglycidyl ether.

7. The structural adhesive according to claim 1, characterized in that, Based on the total mass of component B, component B comprises: Polyetheramine: 30wt%–32wt%, amino polyamide: 20wt%–22wt%, heat-resistant amine-IPDA: 11wt%–13wt%, toughening agent: 29wt%–31wt%, fumed silica: 4wt%–6wt%.

8. The structural adhesive according to claim 7, characterized in that, The polyetheramine is a polyetheramine with a functionality of ≥4, preferably D230 and / or T403; And / or, the toughening agent is one or more of the following: core-shell polymer toughening agent, carboxyl-terminated butadiene-acrylonitrile rubber, amino-terminated butadiene-acrylonitrile rubber, amino-terminated polyether, amino-terminated butyl rubber or polyurethane toughening agent, preferably polyetheramine T-5000. And / or, the fumed silica is hydrophilic fumed silica.

9. A method for preparing a structural adhesive as described in any one of claims 1 to 8, characterized in that, Component A is prepared by the following method: The thixotropic agent, silane coupling agent and other components in component A are mixed to obtain a mixture; Hydrophilic fumed silica was added to the mixture in multiple batches for dispersion treatment to obtain component A.

10. The preparation method according to claim 9, characterized in that, In the step of adding hydrophilic fumed silica to the mixture in multiple batches for dispersion treatment to obtain component A, the mass of each addition of hydrophilic fumed silica does not exceed 0.3% of the total mass of component A. And / or, after each addition of hydrophilic fumed silica, a dispersion treatment is performed, and the next addition of hydrophilic fumed silica is performed only after sufficient dispersion.

11. A wind turbine blade, characterized in that, The structural adhesive used in the preparation process is the structural adhesive as described in any one of claims 1 to 8 and / or the structural adhesive prepared by the preparation method as described in any one of claims 9 to 10.

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