Preparation method of high-toughness bi-component epoxy resin

Abstract

The invention discloses a preparation method of high-toughness two-component epoxy resin. The two-component epoxy resin consists of an epoxy resin component A and a curing agent component B, the preparation method comprises the following steps: 1, mixing the raw materials of the epoxy resin component A in proportion, stirring at a high speed until the raw materials are uniformly dispersed, and sub-packaging to obtain the component A; step 2, mixing the raw materials of the component B of the curing agent according to the proportion, stirring to be uniform, and sub-packaging to obtain the component B; and step 3, mixing and stirring the component A and the component B according to the mass ratio of 100: (10-30) to be uniform, so as to obtain the high-toughness two-component epoxy resin. The bi-component epoxy resin system is reasonable in formula design, bisphenol A epoxy resin is used as a matrix, cardanol glycidyl ether and rubber powder are matched to serve as core toughening components, meanwhile, hydrophobic white carbon black and a silane coupling agent are introduced for synergistic modification, on the premise that the mechanical strength of an epoxy resin curing material is guaranteed, the toughness is remarkably improved, and the service life of the epoxy resin curing material is prolonged. The technical problem that traditional epoxy resin is hard and brittle is solved.

Description

Technical Field

[0001] This invention relates to the field of epoxy resin preparation technology, and specifically to a method for preparing a high-toughness two-component epoxy resin. Background Technology

[0002] Epoxy resins are a class of organic polymer oligomers containing two or more epoxy groups in their molecular structure. They are based on aliphatic, alicyclic, or aromatic groups and can form thermosetting cured products through ring-opening reactions of epoxy groups. Due to their high bonding strength, good chemical stability, simple molding process, and excellent compatibility with various substrates, they are widely used in many fields such as aerospace, electronics, building materials, automobile manufacturing, and composite materials.

[0003] Traditional epoxy resin cured products have a high cross-linking density in their molecular structure and poor flexibility in their molecular chain segments, resulting in inherent defects such as hardness and brittleness. They also have low impact resistance and elongation at break, making them prone to brittle fracture when subjected to external forces, which greatly limits their use in applications that require high material toughness. To improve the toughness of epoxy resin, existing technologies mainly employ three methods: First, adding toughening agents, such as rubber-based or thermoplastic resin-based toughening agents, to the epoxy resin system. However, this type of toughening often suffers from poor compatibility between the toughening agent and the epoxy resin matrix, easily leading to phase separation and a simultaneous decrease in the material's mechanical strength and adhesive properties. Second, chemically modifying the epoxy resin by introducing flexible segments to prepare modified epoxy resin. However, its synthesis process is complex, the reaction conditions are harsh, and the storage stability of the modified epoxy resin is easily affected, significantly increasing production costs. Third, modifying the curing agent to develop flexible curing agents. While this method can improve the toughness of the cured product to some extent, the curing efficiency of a single flexible curing agent is low, and some require heat curing, failing to meet the requirements for room temperature construction. Furthermore, the exothermic peak temperature of the curing system is too high, easily causing internal stress in the cured product, leading to cracking, warping, and other problems.

[0004] Meanwhile, existing toughened epoxy resin systems also have many other problems: such as the added inorganic fillers being prone to sedimentation, resulting in poor system dispersion and affecting the uniformity of material properties; the mixing viscosity of some toughening systems is too high, which is not conducive to molding and construction; the heat release of the curing reaction is difficult to control, and the product quality is easily affected by local overheating during large-volume casting; the effect of balancing mechanical strength and toughness is not good, and the improvement of toughness is often accompanied by a significant decrease in mechanical properties such as tensile strength and flexural strength.

[0005] To address the aforementioned technical issues, there is an urgent need to develop an epoxy resin system that is simple to prepare, can be cured at room temperature, has a moderate mixing viscosity, and can significantly improve toughness while ensuring mechanical strength. This system would solve the problem of traditional epoxy resin cured products being hard and brittle, while meeting the various requirements of industrial production and practical applications. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing epoxy resin cured products, such as poor toughness, difficulty in balancing mechanical properties and toughness, harsh curing conditions, and easy sedimentation, and to provide a method for preparing a high-toughness two-component epoxy resin. The two-component epoxy resin prepared by this method consists of two components, A and B. The preparation process is simple, can be cured at room temperature, has low exothermic heat during curing, and exhibits good system stability. The resulting epoxy resin cured product combines excellent mechanical strength and high toughness, while also possessing good adhesion, anti-settling properties, and workability, meeting the needs of various application scenarios.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a high-toughness two-component epoxy resin, wherein the two-component epoxy resin comprises epoxy resin component A and curing agent component B; the epoxy resin component A, by weight percentage, comprises: 50%–70% bisphenol A epoxy resin, 10%–20% cashew phenol glycidyl ether, 10%–30% rubber powder, 0%–5% hydrophobic silica, and 0%–5% silane coupling agent; the curing agent component B, by weight percentage... The fractional component contains: 40%–60% polyetheramine and 40%–60% isophorone diamine; the preparation method includes: Step 1, mixing the raw materials of epoxy resin component A according to the ratio, stirring at high speed until uniformly dispersed, and dispensing to obtain component A; Step 2, mixing the raw materials of curing agent component B according to the ratio, stirring until uniform, and dispensing to obtain component B; Step 3, mixing component A and component B at a mass ratio of 100:10–30 and stirring until uniform, thereby obtaining the high-toughness two-component epoxy resin.

[0008] Furthermore, in the epoxy resin A component, the weight percentage of hydrophobic silica is 1% to 5%, and the weight percentage of silane coupling agent is 1% to 5%.

[0009] Furthermore, the rubber powder is one or a mixture of several of the following: 40 mesh, 40-80 mesh, and 80-200 mesh. The material of the rubber powder is one or more of nitrile rubber, styrene-butadiene rubber, and cis-butadiene rubber.

[0010] Furthermore, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0011] Furthermore, the polyetheramine is one or a mixture of several of D-230, D-400, D-2000, T-403, and T-5000.

[0012] Furthermore, in step one, the high-speed stirring speed is 1000-3000 r / min, the stirring temperature is 25-40℃, and the stirring time is 20-60 min; during the stirring process, vacuum degassing is adopted, with a vacuum degree of -0.08--0.1 MPa and a degassing time of 10-30 min.

[0013] Furthermore, in step two, the stirring speed is 300-800 r / min, the stirring temperature is 25-30℃, and the stirring time is 10-30 min.

[0014] Furthermore, in step three, the mixing speed is 500–1500 r / min, the mixing temperature is 25–35℃, and the mixing time is 5–20 min; after mixing, the mixture is cured at room temperature (20–30℃) for 24–72 h.

[0015] Furthermore, the bisphenol A epoxy resin is type E-51 bisphenol A epoxy resin with an epoxy value of 0.51 eq / 100g; the cashew phenol glycidyl ether has an epoxy value of 0.20 to 0.25 eq / 100g.

[0016] Furthermore, the prepared two-component epoxy resin has a mixed viscosity of 6000–16000 MPa at 25°C. The cured product has a tensile strength ≥60MPa, an elongation at break ≥6.5%, an impact strength ≥58KJ / m², and a flexural strength ≥100MPa.

[0017] The technical effects and advantages of this invention are as follows: (1) The two-component epoxy resin system of the present invention has a reasonable formulation design. It uses bisphenol A epoxy resin as the matrix, and cashew phenol glycidyl ether and rubber powder as the core toughening components. At the same time, hydrophobic silica and silane coupling agent are introduced for synergistic modification. Under the premise of ensuring the mechanical strength of the epoxy resin cured product, the toughness is significantly improved, which solves the technical problem of "hard and brittle" traditional epoxy resin. Among them, bisphenol A epoxy resin provides the basic mechanical strength and adhesive properties of the system; cashew phenol glycidyl ether can not only reduce the mixing viscosity of the system and improve the flowability of construction as an active diluent, but also introduce flexible aliphatic chain segments in the molecular structure into the epoxy resin matrix to improve the flexibility of the molecular chain; rubber powder has excellent elasticity and toughness. Rubber powder of different particle sizes forms a micro-nano-level dispersed phase in the system. When subjected to external force, it can absorb energy through crazing, shear yielding and other methods, which greatly improves the impact resistance and elongation at break of the cured product.

[0018] (2) The curing agent B component of the present invention is a compound of polyetheramine and isophorone diamine, which achieves rapid curing at room temperature and effectively reduces the exothermic temperature of the curing reaction, avoiding internal stress caused by local overheating during the curing process and preventing cracking, warping and other problems in the cured product. Isophorone diamine is an alicyclic amine curing agent with high reactivity and fast curing speed, which can provide the system with high crosslinking density and mechanical strength; the polyetheramine molecular chain contains flexible polyether segments, which can not only further improve the toughness of the cured product, but also effectively regulate the curing reaction rate, disperse the exothermic heat of the curing reaction, and make the curing process stable. At the same time, the compound of polyetheramine and isophorone diamine can also improve the compatibility between the curing agent and epoxy resin A component and improve the dispersion stability of the system.

[0019] (3) This invention effectively solves the sedimentation problem of fillers such as rubber powder in the system through the synergistic effect of hydrophobic silica and silane coupling agent, and improves the storage stability and material performance uniformity of epoxy resin component A. Hydrophobic silica has a large specific surface area and a three-dimensional network structure, which can form steric hindrance in the system and prevent the agglomeration and sedimentation of filler particles; the two ends of the silane coupling agent molecule contain siloxane groups that react with inorganic fillers and organic functional groups that react with epoxy resin, respectively, which can form chemical bonds between the filler and the epoxy resin matrix, not only improving the dispersibility of the filler, but also enhancing the interfacial bonding force between the filler and the matrix, and further improving the mechanical properties and adhesive properties of the cured product.

[0020] (4) The preparation process of the present invention is simple and convenient to operate. It does not require complex synthesis equipment and harsh reaction conditions. Each component can be prepared by physical mixing, which is suitable for large-scale industrial production. The epoxy resin component A and the curing agent component B can be packaged and stored separately. They have good storage stability. They can be mixed according to the ratio when used. The construction operation is convenient and can meet the needs of various construction processes such as room temperature casting, bonding, and coating.

[0021] (5) The epoxy resin system of the present invention uses readily available raw materials, all of which are commonly used industrial chemical raw materials. The formulation contains no toxic or harmful components, and the production and use process is green and environmentally friendly. At the same time, through reasonable raw material ratio, the production cost is effectively controlled while ensuring performance, resulting in good economic benefits and market application prospects.

[0022] (6) The present invention can flexibly control the mixing viscosity, curing speed and mechanical properties and toughness of epoxy resin by adjusting the ratio of each raw material, the particle size of rubber powder and the type of polyetheramine. It can be customized according to different application scenarios and has a wide range of applications.

[0023] (7) The two-component epoxy resin cured product prepared by the present invention has excellent comprehensive performance. It not only has excellent mechanical strength indicators such as tensile strength and flexural strength, but also has high elongation at break and high impact strength. At the same time, it also has good chemical stability, weather resistance and adhesive properties. It can be widely used in aerospace, electronics, automobile manufacturing, building materials, composite materials, adhesives and other fields, and is especially suitable for scenarios with high requirements for material toughness and mechanical strength. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

[0025] The present invention will be further described in detail below with reference to specific embodiments. The scope of protection of the present invention is not limited to the following embodiments. For those skilled in the art, various modifications and variations made to the present invention without departing from the principles and spirit of the present invention shall fall within the scope of protection defined by the appended claims.

[0026] The raw materials used in the embodiments of this invention are all commercially available industrial-grade raw materials, wherein: The bisphenol A epoxy resin used is E-51 type bisphenol A epoxy resin with an epoxy value of 0.51 eq / 100g; Cashew phenol glycidyl ether is of industrial grade, with an epoxy value of 0.20–0.25 eq / 100g; The rubber powder is selected from one or both of nitrile rubber powder and styrene-butadiene rubber powder, with a mesh size of 40 mesh, 60 mesh, or 120 mesh. The hydrophobic silica used is fumed hydrophobic silica with a specific surface area of ​​150-200 m² / g. The silane coupling agent is selected from one or both of KH-550 (γ-aminopropyltriethoxysilane) and KH-560 (γ-glycidoxypropyltrimethoxysilane); The polyetheramine is selected from one or more of D-230, D-400, and T-403, wherein D-230 has a number-average molecular weight of 230, D-400 has a number-average molecular weight of 400, and T-403 has a number-average molecular weight of 403. Isophorone diamine (IPDA) is industrial grade with a purity of ≥99%.

[0027] The testing instruments and methods used in the embodiments of this invention are as follows: Mixed viscosity: The viscosity of the mixture of epoxy resin component A and curing agent component B was measured at 25°C using a rotational viscometer. The unit is MPa. s; Tensile properties: Tested according to GB / T 2567-2008 "Test Methods for Properties of Resin Castings", with a tensile speed of 5 mm / min, to obtain tensile strength and tensile modulus, in MPa; elongation at break was calculated according to the formula, in % . Flexural properties: Tested according to GB / T 2567-2008 "Test Methods for Properties of Resin Castings", with a bending speed of 2 mm / min, to obtain flexural strength and flexural modulus, in MPa; Impact performance: The impact test was conducted using a simply supported beam without notch, in accordance with GB / T 2567-2008 "Test Methods for Performance of Resin Castings". The unit is KJ / m².

[0028] Example 1 A method for preparing a high-toughness two-component epoxy resin, the specific steps of which are as follows: Step 1: Prepare epoxy resin component A. Weigh 60% E-51 type bisphenol A epoxy resin, 10% cashew phenol glycidyl ether, 27% 40 mesh nitrile rubber powder, and 3% hydrophobic silica by weight percentage. Add the above raw materials to a high-speed stirring tank and stir for 40 minutes at a speed of 2000 r / min and a temperature of 30℃. At the same time, degas under vacuum at a vacuum degree of -0.09MPa for 20 minutes until the raw materials are uniformly dispersed and free of bubbles. After dispensing, epoxy resin component A is obtained. Step 2: Prepare curing agent component B. Weigh 50% polyetheramine D-230 and 50% isophorone diamine (IPDA) by weight percentage. Add the above raw materials to a mixing tank and stir for 20 minutes at a speed of 500 r / min and a temperature of 25℃ until the raw materials are uniformly mixed. After dispensing, curing agent component B is obtained. Step 3: Add epoxy resin component A and curing agent component B to a mixing container at a mass ratio of 100:20. Stir for 10 minutes at a speed of 1000 r / min and a temperature of 25℃ until the mixture is uniform to obtain a high-toughness two-component epoxy resin. After casting the epoxy resin into a mold, cure it at room temperature of 25℃ for 48 hours to obtain the cured product. Perform performance tests on the product, and the results are shown in Table 1.

[0029] Example 2 A method for preparing a high-toughness two-component epoxy resin, the specific steps of which are as follows: Step 1: Prepare epoxy resin component A. Weigh 55% E-51 type bisphenol A epoxy resin, 15% cashew phenol glycidyl ether, 27% 60 mesh styrene-butadiene rubber powder, and 3% hydrophobic silica by weight percentage. Add the above raw materials to a high-speed stirring tank and stir for 50 minutes at a speed of 1500 r / min and a temperature of 28℃. At the same time, degas under vacuum at a vacuum degree of -0.08 MPa for 30 minutes until the raw materials are uniformly dispersed and free of bubbles. After dispensing, epoxy resin component A is obtained. Step 2: Prepare curing agent component B. Weigh 50% polyetheramine D-400 and 50% isophorone diamine (IPDA) by weight percentage. Add the above raw materials to a mixing tank and stir for 25 minutes at a speed of 400 r / min and a temperature of 26℃ until the raw materials are uniformly mixed. After dispensing, curing agent component B is obtained. Step 3: Add epoxy resin component A and curing agent component B to a mixing container at a mass ratio of 100:18. Stir for 15 minutes at a speed of 800 r / min and a temperature of 26℃ until the mixture is uniform to obtain a high-toughness two-component epoxy resin. After casting the epoxy resin into a mold, cure it at room temperature of 25℃ for 48 hours to obtain the cured product. Perform performance tests on the product, and the results are shown in Table 1.

[0030] Example 3 A method for preparing a high-toughness two-component epoxy resin, the specific steps of which are as follows: Step 1: Prepare epoxy resin component A. Weigh 60% E-51 type bisphenol A epoxy resin, 10% cashew phenol glycidyl ether, 27% 40 mesh + 120 mesh nitrile rubber powder (mass ratio 1:1), 2% hydrophobic silica, and 1% silane coupling agent KH-560 by weight percentage. Add the above raw materials to a high-speed stirring tank and stir for 30 minutes at a speed of 2500 r / min and a temperature of 35℃. At the same time, degas under vacuum at a vacuum degree of -0.1MPa for 15 minutes until the raw materials are uniformly dispersed and free of bubbles. After dispensing, epoxy resin component A is obtained. Step 2: Prepare curing agent component B. Weigh 50% polyetheramine D-230 and 50% isophorone diamine (IPDA) by weight percentage. Add the above raw materials to a mixing tank and stir for 15 minutes at a speed of 600 r / min and a temperature of 27℃ until the raw materials are uniformly mixed. After dispensing, curing agent component B is obtained. Step 3: Add epoxy resin component A and curing agent component B to a mixing container at a mass ratio of 100:20. Stir for 8 minutes at a speed of 1200 r / min and a temperature of 27℃ until the mixture is uniform to obtain a high-toughness two-component epoxy resin. After casting the epoxy resin into a mold, cure it at room temperature of 25℃ for 48 hours to obtain the cured product. Perform performance tests on the product, and the results are shown in Table 1.

[0031] Example 4 A method for preparing a high-toughness two-component epoxy resin, the specific steps of which are as follows: Step 1: Prepare epoxy resin component A. Weigh 60% E-51 type bisphenol A epoxy resin, 37% 80 mesh nitrile rubber powder, and 3% hydrophobic silica by weight percentage. Add the above raw materials to a high-speed stirring tank and stir for 45 minutes at a speed of 1800 r / min and a temperature of 32℃. At the same time, degas under vacuum at a vacuum degree of -0.09MPa for 25 minutes until the raw materials are uniformly dispersed and free of bubbles. After dispensing, epoxy resin component A is obtained. Step 2: Prepare curing agent component B. Weigh 50% polyetheramine T-403 and 50% isophorone diamine (IPDA) by weight percentage. Add the above raw materials to a mixing tank and stir for 20 minutes at a speed of 500 r / min and a temperature of 25℃ until the raw materials are uniformly mixed. After dispensing, curing agent component B is obtained. Step 3: Add epoxy resin component A and curing agent component B to a mixing container at a mass ratio of 100:19. Stir for 12 minutes at a speed of 900 r / min and a temperature of 25℃ until the mixture is uniform to obtain a high-toughness two-component epoxy resin. After casting the epoxy resin into a mold, cure it at room temperature of 25℃ for 48 hours to obtain the cured product. Perform performance tests on the product, and the results are shown in Table 1.

[0032] Example 5 A method for preparing a high-toughness two-component epoxy resin, the specific steps of which are as follows: Step 1: Prepare epoxy resin component A. Weigh 70% E-51 type bisphenol A epoxy resin, 10% cashew phenol glycidyl ether, 15% 60 mesh + 120 mesh styrene-butadiene rubber powder (mass ratio 2:1), 3% hydrophobic silica, and 2% silane coupling agent KH-550 by weight percentage. Add the above raw materials to a high-speed stirring tank and stir for 20 minutes at a speed of 3000 r / min and a temperature of 40℃. At the same time, degas under vacuum at a vacuum degree of -0.1MPa for 10 minutes until the raw materials are uniformly dispersed and free of bubbles. After dispensing, epoxy resin component A is obtained. Step 2: Prepare curing agent component B. Weigh 40% polyetheramine D-230 + D-400 (mass ratio 1:1) and 60% isophorone diamine (IPDA) by weight percentage. Add the above raw materials to a mixing tank and stir for 10 minutes at a speed of 800 r / min and a temperature of 30℃ until the raw materials are uniformly mixed. After dispensing, curing agent component B is obtained. Step 3: Add epoxy resin component A and curing agent component B to a mixing container at a mass ratio of 100:30. Stir for 5 minutes at a speed of 1500 r / min and a temperature of 35℃ until the mixture is uniform to obtain a high-toughness two-component epoxy resin. After casting the epoxy resin into a mold, cure it at room temperature of 30℃ for 24 hours to obtain the cured product. Perform performance tests on the product, and the results are shown in Table 1.

[0033] Example 6 A method for preparing a high-toughness two-component epoxy resin, the specific steps of which are as follows: Step 1: Prepare epoxy resin component A. Weigh 50% E-51 type bisphenol A epoxy resin, 20% cashew phenol glycidyl ether, 25% 40 mesh + 60 mesh + 120 mesh nitrile rubber powder (mass ratio 1:1:1), 3% hydrophobic silica, and 2% silane coupling agent KH-550 + KH-560 (mass ratio 1:1) by weight percentage. Add the above raw materials to a high-speed stirring tank and stir for 60 min at a speed of 1000 r / min and a temperature of 25℃. At the same time, degas under vacuum at a vacuum degree of -0.08 MPa for 30 min until the raw materials are uniformly dispersed and free of bubbles. After dispensing, epoxy resin component A is obtained. Step 2: Prepare curing agent component B. Weigh 60% polyetheramine D-400+T-403 (mass ratio 1:1) and 40% isophorone diamine (IPDA) by weight percentage. Add the above raw materials to a mixing tank and stir for 30 minutes at a speed of 300 r / min and a temperature of 25℃ until the raw materials are uniformly mixed. After dispensing, curing agent component B is obtained. Step 3: Add epoxy resin component A and curing agent component B to a mixing container at a mass ratio of 100:10. Stir for 20 minutes at a speed of 500 r / min and a temperature of 25℃ until the mixture is uniform, to obtain a high-toughness two-component epoxy resin. After casting the epoxy resin into a mold, cure it at room temperature (20℃) for 72 hours to obtain the cured product. Perform performance tests on the product, and the results are shown in Table 1.

[0034] Table 1 As can be seen from the performance test results in Table 1, the high-toughness two-component epoxy resins prepared in Examples 1-6 of this invention all exhibit excellent comprehensive performance, with moderate mixing viscosity that meets the requirements for construction fluidity; the tensile strength of the cured products is ≥60MPa and the flexural strength is ≥100MPa, demonstrating excellent mechanical strength; at the same time, the elongation at break is ≥6.5% and the impact strength is ≥58KJ / m², exhibiting good toughness and achieving a balance between mechanical strength and toughness. Among them, Example 4 achieved an impact strength of 80KJ / m² by increasing the amount of rubber powder, significantly improving toughness; Example 6 increased the amount of cashew phenol glycidyl ether and used compounded rubber powder, achieving an elongation at break of 9.58%, demonstrating excellent flexibility; Example 5 increased the amount of bisphenol A epoxy resin, achieving tensile strength and flexural strength of 75.2MPa and 125.5MPa, respectively, demonstrating outstanding mechanical strength.

[0035] Comparative Example 1 A method for preparing epoxy resin differs from Example 1 in that: the curing agent B component uses only isophorone diamine, without adding polyetheramine; the remaining raw material ratios and preparation steps are the same as in Example 1. Performance tests were performed on the prepared epoxy resin, and the results were: mixed viscosity 8520 mPa·s / 25℃, tensile strength 70.2 MPa, elongation at break 4.25%, impact strength 35 KJ / m², and flexural strength 118.5 MPa; the exothermic peak temperature reached 85℃ during curing, and localized micro-cracking occurred in the casting.

[0036] Comparative Example 2 A method for preparing epoxy resin differs from Example 1 in that: component A of the epoxy resin uses only bisphenol A epoxy resin, without adding cashew phenol glycidyl ether and rubber powder; the remaining raw material ratios and preparation steps are the same as in Example 1. Performance tests were performed on the prepared epoxy resin, and the results were: mixed viscosity 5260 mPa·s / 25℃, tensile strength 82.5 MPa, elongation at break 2.10%, impact strength 22 KJ / m², flexural strength 130.2 MPa; the cured product is hard and brittle with extremely poor toughness.

[0037] Comparative Example 3 A method for preparing epoxy resin differs from Example 3 in that: no silane coupling agent and hydrophobic silica are added to epoxy resin component A; the remaining raw material ratios and preparation steps are the same as in Example 3. The prepared epoxy resin component A exhibited significant rubber powder sedimentation after 7 days of storage. The performance test results of the cured product after mixing were as follows: mixed viscosity 7850 mPa·s / 25℃, tensile strength 55.3 MPa, elongation at break 7.25%, impact strength 45 KJ / m², and flexural strength 92.6 MPa. Both mechanical properties and toughness showed a significant decrease.

[0038] The test results of Comparative Examples 1-3 show that the present invention, through the compounding of polyetheramine and isophorone diamine, can not only improve the toughness of epoxy resin, but also reduce the exothermic temperature of the curing reaction and avoid cracking of the cured product. Cashew phenol glycidyl ether and rubber powder, as core toughening components, are crucial to improving the toughness of epoxy resin. Their absence will cause the cured product to revert to its hard and brittle state. The synergistic effect of hydrophobic silica and silane coupling agent can effectively improve the stability of the system and the dispersibility of fillers, while enhancing the mechanical properties of the cured product. Their absence will result in filler sedimentation and a significant decrease in material properties.

[0039] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a high-toughness two-component epoxy resin, characterized in that, The two-component epoxy resin is composed of epoxy resin component A and curing agent component B. Epoxy resin component A, by weight percentage, comprises: 50%–70% bisphenol A epoxy resin, 10%–20% cashew phenol glycidyl ether, 10%–30% rubber powder, 0%–5% hydrophobic silica, and 0%–5% silane coupling agent. Curing agent component B, by weight percentage, comprises: 40%–60% polyetheramine and 40%–60% isophorone diamine. The preparation method includes: Step 1, mixing the raw materials of epoxy resin component A according to the specified ratio, stirring at high speed until uniformly dispersed, and dispensing to obtain component A; Step 2, mixing the raw materials of curing agent component B according to the specified ratio, stirring until uniform, and dispensing to obtain component B; Step 3, mixing component A and component B at a mass ratio of 100:10–30 and stirring until uniform to obtain the high-toughness two-component epoxy resin.

2. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, In the epoxy resin component A, the weight percentage of hydrophobic silica is 1% to 5%, and the weight percentage of silane coupling agent is 1% to 5%.

3. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, The rubber powder is one or a mixture of several of the following: 40 mesh, 40-80 mesh, and 80-200 mesh. The material of the rubber powder is one or more of the following: nitrile rubber, styrene-butadiene rubber, and cis-butadiene rubber.

4. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

5. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, The polyetheramine is one or a mixture of several of D-230, D-400, D-2000, T-403, and T-5000.

6. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, In step one, the high-speed stirring speed is 1000-3000 r / min, the stirring temperature is 25-40℃, and the stirring time is 20-60 min; during the stirring process, vacuum degassing is used, with a vacuum degree of -0.08--0.1 MPa and a degassing time of 10-30 min.

7. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, In step two, the stirring speed is 300-800 r / min, the stirring temperature is 25-30℃, and the stirring time is 10-30 min.

8. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, In step three, the mixing speed is 500-1500 r / min, the mixing temperature is 25-35℃, and the mixing time is 5-20 min; after mixing, it is cured at room temperature of 20-30℃ for 24-72 h.

9. The method for preparing a high-toughness two-component epoxy resin according to claim 1, characterized in that, The bisphenol A epoxy resin is type E-51 bisphenol A epoxy resin with an epoxy value of 0.51 eq / 100g; the cashew phenol glycidyl ether has an epoxy value of 0.20 to 0.25 eq / 100g.

10. A method for preparing a high-toughness two-component epoxy resin according to claims 1-9, characterized in that, The prepared two-component epoxy resin has a mixed viscosity of 6000–16000 mPa at 25°C. The cured product has a tensile strength ≥60MPa, an elongation at break ≥6.5%, an impact strength ≥58KJ / m², and a flexural strength ≥100MPa.

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