A modified epoxy resin with thermal stability, and a preparation method and application thereof

Abstract

The application belongs to the technical field of insulation packaging, and particularly relates to a modified epoxy resin with thermal stability, a preparation method and application. The modified epoxy resin with thermal stability provided in the application is loaded with aluminum oxide-supported tin-bismuth alloy nanoparticles (Al2O3-Sn 57 Bi 43 ), which interacts with epoxy resin molecules to form hydrogen bonds, chemical bonds or van der Waals forces and other interaction forces, greatly improving the energy required for the breaking of epoxy resin molecular chains during heating. Meanwhile, the aluminum oxide-supported tin-bismuth alloy nanoparticles (Al2O3-Sn 57 Bi 43 ) have good heat conduction performance and can dissipate heat as a heat conduction path, which increases the thermal decomposition temperature of the material and enhances the thermal stability of the epoxy resin, thereby solving the defect of poor thermal stability of the epoxy resin.

Description

Technical Field

[0001] This application belongs to the field of insulating encapsulation technology, and particularly relates to a thermally stable modified epoxy resin, its preparation method, and its application. Background Technology

[0002] In recent years, in the field of electronic components, the development of microelectronic integration and assembly technology has led to the miniaturization and lightweighting of electronic appliances, with microelectronic integrated circuits moving towards high speed, high integration, high frequency, multi-functionality, and miniaturization. In the field of electrical equipment, with the rapid growth of power transmission engineering, electrical equipment is developing towards large capacity, high voltage, and high power density, resulting in a continuous increase in the voltage and power levels of power electrical devices. Consequently, the electrical energy consumed and the heat generated by electronic components and power electrical equipment are increasing, and the operating temperature is rapidly tilting towards higher temperatures. The continuous accumulation of this heat will accelerate the aging and failure of insulating dielectrics, greatly reducing the reliability and lifespan of electronic components and electrical equipment. Epoxy resin is one of the most widely used insulating encapsulation materials for electronic components and electrical equipment; however, the current epoxy resin has relatively low thermal stability and other properties. Summary of the Invention

[0003] In view of this, this application provides a modified epoxy resin with improved thermal stability, its preparation method, and its application, in order to solve the technical problem of low thermal stability of epoxy resins in the prior art.

[0004] The first aspect of this application provides a thermally stable modified epoxy resin, the raw materials of which include an epoxy resin curing component and modified nanocomposite particles.

[0005] The epoxy resin curing component includes an epoxy resin matrix, a curing agent, and an accelerator;

[0006] The modified nanocomposite particles are selected from alumina-supported tin-bismuth alloy nanoparticles.

[0007] Preferably, in the thermally stable modified epoxy resin, the doping amount of modified nanocomposite particles is no more than 20 wt%.

[0008] Preferably, in the thermally stable modified epoxy resin, the doping amount of modified nanocomposite particles is no more than 7 wt%.

[0009] Preferably, the particle size of the modified nanocomposite particles is 1–500 nm.

[0010] Preferably, in the modified nanocomposite particles, the molar ratio of alumina to tin-bismuth alloy is 8-12:1-2;

[0011] In the tin-bismuth alloy, the molar ratio of tin atoms to bismuth atoms is 7–11:5–9.

[0012] Preferably, in the epoxy resin curing component, the mass ratio of epoxy resin matrix, curing agent, and accelerator is 5-20:0.5-2:0.1-1.

[0013] Preferably, the epoxy resin matrix is ​​selected from at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester type epoxy resin, and glycidyl amine type epoxy resin.

[0014] The curing agent is selected from at least one of polyamide curing agents, acid anhydride curing agents, and aliphatic polyamine curing agents;

[0015] The accelerator is selected from at least one of tertiary amine accelerators, substituted urea accelerators, and imidazole accelerators.

[0016] Preferably, the epoxy resin matrix is ​​selected from bisphenol A type epoxy resin EPIKOTE828L;

[0017] The curing agent is selected from polyamide curing agent 650;

[0018] The accelerator is selected from tertiary amine accelerators 2,4,6-tris(dimethylaminomethyl)phenol.

[0019] The second aspect of this application provides a method for preparing a thermally stable modified epoxy resin, the method comprising the steps of:

[0020] Step S1: Mix the epoxy resin matrix, curing agent, and accelerator and stir until homogeneous to obtain the epoxy resin curing component;

[0021] Step S2: Add the modified nanocomposite particles to the epoxy resin curing component and stir evenly. Let it stand at room temperature to obtain a thermally stable modified epoxy resin.

[0022] Preferably, in step S1, the mass ratio of epoxy resin matrix, curing agent, and accelerator in the epoxy resin curing component is 5-20:0.5-2:0.1-1;

[0023] In step S2, the amount of modified nanocomposite particles in the thermally stable modified epoxy resin is no more than 20 wt%.

[0024] Preferably, in step S2, the method for preparing the modified nanocomposite particles includes the following steps:

[0025] S21. Under an inert atmosphere, a mixed solution of tin salt and bismuth salt is added dropwise to an alumina suspension containing a reducing agent to obtain modified nanocomposite particles.

[0026] Preferably, in the mixed solution of tin salt and bismuth salt, the molar ratio of solute tin ions to bismuth ions is 7-11:5-9.

[0027] The molar ratio of tin ions to bismuth ions in the alumina suspension and the mixed solution of the tin and bismuth salts is 8-12:1-2.

[0028] Preferably, the reducing agent is selected from at least one of sodium borohydride, ascorbic acid, sodium thiosulfate, and ferrous ammonium sulfate.

[0029] The third aspect of this application provides the application of thermally stable modified epoxy resins in the field of electronic component or electrical equipment packaging.

[0030] In summary, this application provides a thermally stable modified epoxy resin, its preparation method, and its application. The thermally stable modified epoxy resin includes epoxy resin, curing agent, accelerator, and other epoxy resin curing components, as well as modified nanocomposite particles. The curing agent and accelerator accelerate the curing speed of the epoxy resin, while the alumina-supported tin-bismuth alloy nanoparticles, as modified nanocomposite particles, have good compatibility with the epoxy resin matrix, facilitating the formation of hydrogen bonds, chemical bonds, or van der Waals forces with the epoxy resin molecules. This increases the energy required for the epoxy resin molecular chains to break during heating. Furthermore, compared to epoxy resin, the alumina-supported tin-bismuth alloy nanoparticles have better thermal conductivity, serving as a heat conduction pathway to dissipate heat, thereby improving the thermal stability of the epoxy resin. The thermally stable modified epoxy resin provided in this application improves the thermal stability of the epoxy resin by having the alumina-supported tin-bismuth alloy nanoparticles interact with the epoxy resin on one hand and act as a heat conduction pathway on the other, thus solving the technical problem of low thermal stability of epoxy resins in the prior art. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 TGA curves of epoxy resin modified with tin-bismuth alloy nanoparticles supported on alumina with different doping amounts provided in Examples 2-7 of this application;

[0033] Figure 2 Differential scanning calorimetry analysis diagrams of the alumina-supported tin-bismuth alloy nanoparticle modified epoxy resin provided in Example 2 of this application and the alumina-modified epoxy resin provided in Example 8;

[0034] Figure 3 The images shown are scanning electron microscope (SEM) images of tin-bismuth alloy nanoparticles modified with alumina supported by different doping amounts provided in Examples 2-7 of this application; 3a is an SEM image of tin-bismuth alloy nanoparticles modified with alumina supported by 0 wt% doping amount, 3b is an SEM image of tin-bismuth alloy nanoparticles modified with alumina supported by 1 wt% doping amount, 3c is an SEM image of tin-bismuth alloy nanoparticles modified with alumina supported by 3 wt% doping amount, 3d is an SEM image of tin-bismuth alloy nanoparticles modified with alumina supported by 5 wt% doping amount, 3e is an SEM image of tin-bismuth alloy nanoparticles modified with alumina supported by 7 wt% doping amount, and 3f is an SEM image of tin-bismuth alloy nanoparticles modified with alumina supported by 10 wt% doping amount. Detailed Implementation

[0035] This application provides a modified epoxy resin with improved thermal stability, its preparation method, and its application, to solve the technical problem of low thermal stability of epoxy resins in the prior art.

[0036] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] Example 1

[0038] Given the poor thermal stability of current epoxy resins, Example 1 of this application provides a modified epoxy resin with improved thermal stability. The modified epoxy resin comprises an epoxy resin matrix, curing agents, accelerators, and other epoxy resin curing components, as well as alumina-supported tin-bismuth alloy nanoparticles as modified nanocomposite particles. Specifically, after the alumina-supported tin-bismuth alloy nanoparticles are incorporated into the epoxy resin matrix, they form alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn...). 57 Bi 43 The good compatibility between alumina and epoxy resin leads to strong interaction between the two, forming a good interfacial effect. The tin-bismuth alloy nanoparticles (Al2O3-Sn) supported on alumina exhibit good interfacial properties. 57 Bi 43 The tin-bismuth alloy nanoparticles (Al2O3-Sn) can interact with epoxy resin molecules to form hydrogen bonds, chemical bonds, or van der Waals forces. This significantly increases the energy required for the epoxy resin molecular chains to break during heating. On the other hand, alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) 57 Bi 43The thermal conductivity of tin-bismuth alloy nanoparticles (Al2O3-Sn) is greater than that of epoxy resin. When used as a thermal conduction pathway, it can effectively dissipate heat, thereby increasing the thermal decomposition temperature of the material and enhancing the thermal stability of the epoxy resin. Therefore, the thermal stability-modified epoxy resin provided in this application improves the thermal stability of the epoxy resin by having alumina-supported tin-bismuth alloy nanoparticles interact with the epoxy resin on one hand and act as a thermal conduction pathway on the other. Furthermore, scanning electron microscopy images show that the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) exhibit... 57 Bi 43 As nanoparticles, they can also be dispersed in the epoxy resin matrix, reducing the concentration of energy and consuming some energy when subjected to external impact. The modified epoxy resin is not easy to break, and the mechanical properties such as toughness of the epoxy resin are improved, thereby solving the defect of poor thermal stability of the epoxy resin provided in this application.

[0039] Preferably, for the thermally stable modified epoxy resin, the doping amount of alumina-supported tin-bismuth alloy nanoparticles can be selected to be no more than 20 wt%; more preferably, the doping amount is no more than 7 wt%. When the doping amount of alumina-supported tin-bismuth alloy nanoparticles is greater than 7 wt%, due to the high content of alumina-supported tin-bismuth alloy nanoparticles, the alumina-supported tin-bismuth alloy nanoparticles will agglomerate, which will destroy the relatively ordered structure of the epoxy resin, increase the proportion of amorphous structure in the material, reduce the orderliness of the original material structure, and lead to a decrease in the thermal decomposition temperature of the material. However, after doping with alumina-supported tin-bismuth alloy nanoparticles, the thermal decomposition temperature of the thermally stable modified epoxy resin will be higher than that of pure epoxy resin.

[0040] Preferably, in the modified epoxy resin with improved thermal stability, the content of each component in the alumina-supported tin-bismuth alloy nanoparticles depends on the amount of raw materials added during the preparation process. In this application, 8 to 12 moles of alumina nanoparticles are selected and supported with 1 to 2 moles of tin-bismuth alloy. In the tin-bismuth alloy, the molar ratio of tin atoms to bismuth atoms is 7 to 11: 5 to 9.

[0041] Example 2

[0042] Example 2 of this application provides a method for preparing a thermally stable modified epoxy resin, which is used to prepare the thermally stable modified epoxy resin described in Example 1. The preparation method includes the steps of preparing alumina-supported tin-bismuth alloy nanoparticles by co-precipitation and modifying the epoxy resin using alumina-supported tin-bismuth alloy nanoparticles.

[0043] The steps for preparing alumina-supported tin-bismuth alloy nanoparticles by coprecipitation include: dissolving 20.67 g (0.09 mol) SnCl2·2H2O and 21.54 g (0.07 mol) BiCl3 in 500 ml of HCl aqueous solution; then, under N2 protection and ice bath conditions, dissolving 78.2 g (1.45 mol) KBH4 in 1000 ml of water, and adding 100 g of Al2O3; subsequently, under the same conditions, adding the initially prepared mixture dropwise to the freshly prepared solution over 3-4 hours, and allowing it to react for 1 hour; then centrifuging, discarding the supernatant, adding an appropriate amount of water for dilution, and centrifuging again according to the above method, repeating this process 3-4 times to thoroughly remove unreacted BiCl3, HCl, and other impurities from the first two steps; finally, drying the precipitate in a vacuum drying oven at 80℃ for 24 hours to obtain gray alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn). 57 Bi 43 ).

[0044] The steps for modifying epoxy resin using alumina-supported tin-bismuth alloy nanoparticles include: uniformly mixing 100g of bisphenol A type epoxy resin EPIKOTE828L (epoxy equivalent EEW = 184g / eg, viscosity 1500-3000mPa·s (25℃), Guangzhou Taoyuan Trading Co., Ltd.), 10g of curing agent polyamide 650 (active hydrogen equivalent 156g / eg, Hubei Wuhan Hanhai Synthetic Resin Development Co., Ltd.), and 5g of accelerator 2,4,6-tris(dimethylaminomethyl)phenol DMP-30 (Hangzhou Molott Chemical Technology Co., Ltd.) in a beaker at room temperature (25℃), and then adding 1.2g (doping amount approximately 1wt%) of alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn). 57 Bi 43 After stirring evenly, the mixture is allowed to stand and cure to obtain a modified epoxy resin with good thermal stability.

[0045] Example 3

[0046] Example 3 of this application provides a method for preparing a thermally stable modified epoxy resin, used to prepare the thermally stable modified epoxy resin described in Example 1. The difference between the preparation method and Example 2 is that the step of modifying the epoxy resin with alumina-supported tin-bismuth alloy nanoparticles is as follows: 100g of epoxy resin bisphenol A type EPIKOTE828L (epoxy equivalent EEW = 184g / eg, viscosity 1500-3000mPa·s (25℃), Guangzhou Taoyuan Trading Co., Ltd.), 10g of curing agent polyamide 650 (active hydrogen equivalent 156g / eg, Hubei Wuhan Hanhai Synthetic Resin Development Co., Ltd.), and 5g of accelerator 2,4,6-tris(dimethylaminomethyl)phenol DMP-30 (Hangzhou Molott Chemical Technology Co., Ltd.) are uniformly mixed in a beaker at room temperature (25℃), and then 3.6g (doping amount approximately 3wt%) of alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) are added. 57 Bi 43 After stirring evenly, the mixture is allowed to stand and cure to obtain a modified epoxy resin with good thermal stability.

[0047] Example 4

[0048] Example 4 of this application provides a method for preparing a thermally stable modified epoxy resin, used to prepare the thermally stable modified epoxy resin described in Example 1. The difference between the preparation method and Example 2 is that the step of modifying the epoxy resin with alumina-supported tin-bismuth alloy nanoparticles is as follows: 100g of bisphenol A type epoxy resin EPIKOTE828L (epoxy equivalent EEW = 184g / eg, viscosity 1500-3000mPa·s (25℃), Guangzhou Taoyuan Trading Co., Ltd.), 10g of curing agent polyamide 650 (active hydrogen equivalent 156g / eg, Hubei Wuhan Hanhai Synthetic Resin Development Co., Ltd.), and 5g of accelerator 2,4,6-tris(dimethylaminomethyl)phenol DMP-30 (Hangzhou Molott Chemical Technology Co., Ltd.) are uniformly mixed in a beaker at room temperature (25℃), and then 6g (doping amount approximately 5wt%) of alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) are added. 57 Bi 43 After stirring evenly, the mixture is allowed to stand and cure to obtain a modified epoxy resin with good thermal stability.

[0049] Example 5

[0050] Example 5 of this application provides a method for preparing a thermally stable modified epoxy resin, used to prepare the thermally stable modified epoxy resin described in Example 1. The difference between the preparation method and Example 2 is that the step of modifying the epoxy resin with alumina-supported tin-bismuth alloy nanoparticles is as follows: 100g of epoxy resin bisphenol A type EPIKOTE828L (epoxy equivalent EEW = 184g / eg, viscosity 1500-3000mPa·s (25℃), Guangzhou Taoyuan Trading Co., Ltd.), 10g of curing agent polyamide 650 (active hydrogen equivalent 156g / eg, Hubei Wuhan Hanhai Synthetic Resin Development Co., Ltd.), and 5g of accelerator 2,4,6-tris(dimethylaminomethyl)phenol DMP-30 (Hangzhou Molott Chemical Technology Co., Ltd.) are uniformly mixed in a beaker at room temperature (25℃), and then 8.5g (doping amount approximately 7wt%) of alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) are added. 57 Bi 43 After stirring evenly, the mixture is allowed to stand and cure to obtain a modified epoxy resin with good thermal stability.

[0051] Example 6

[0052] Example 6 of this application provides a method for preparing a thermally stable modified epoxy resin, used to prepare the thermally stable modified epoxy resin described in Example 1. The difference between the preparation method and Example 2 is that the step of modifying the epoxy resin with alumina-supported tin-bismuth alloy nanoparticles is as follows: 100g of epoxy resin bisphenol A type EPIKOTE828L (epoxy equivalent EEW = 184g / eg, viscosity 1500-3000mPa·s (25℃), Guangzhou Taoyuan Trading Co., Ltd.), 10g of curing agent polyamide 650 (active hydrogen equivalent 156g / eg, Hubei Wuhan Hanhai Synthetic Resin Development Co., Ltd.), and 5g of accelerator 2,4,6-tris(dimethylaminomethyl)phenol DMP-30 (Hangzhou Molott Chemical Technology Co., Ltd.) are uniformly mixed in a beaker at room temperature (25℃), and then 13g (doping amount approximately 10wt%) of alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) are added. 57 Bi 43 After stirring evenly, the mixture is allowed to stand and cure to obtain a modified epoxy resin with good thermal stability.

[0053] Example 7

[0054] Example 7 of this application provides a method for preparing a cured epoxy resin. As a comparative example of the thermally stable modified epoxy resin described in Example 1, the difference in the preparation method of Example 2 is that the epoxy resin is prepared directly in the following steps: 100g of bisphenol A type epoxy resin EPIKOTE828L (epoxy equivalent EEW = 184g / eg, viscosity 1500-3000mPa·s (25℃), Guangzhou Taoyuan Trading Co., Ltd.), 10g of curing agent polyamide 650 (active hydrogen equivalent 156g / eg, Hubei Wuhan Hanhai Synthetic Resin Development Co., Ltd.), and 5g of accelerator 2,4,6-tris(dimethylaminomethyl)phenol DMP-30 (Hangzhou Molott Chemical Technology Co., Ltd.) are uniformly mixed in a beaker at room temperature (25℃). Then, tin-bismuth alloy nanoparticles (Al2O3-Sn57Bi) supported on alumina are not added. 43 After stirring evenly, allow it to stand and cure to obtain cured epoxy resin.

[0055] Example 8

[0056] Example 8 of this application provides a method for preparing cured epoxy resin. As a comparative example of the thermally stable modified epoxy resin described in Example 1, the difference in the preparation method of Example 2 is that the epoxy resin is directly prepared by modifying it with alumina: 100g of bisphenol A type epoxy resin EPIKOTE828L (epoxy equivalent EEW = 184g / eg, viscosity 1500~3000mPa·s (25℃), Guangzhou Taoyuan Trading Co., Ltd.), 10g of curing agent polyamide 650 (active hydrogen equivalent 156g / eg, Hubei Wuhan Hanhai Synthetic Resin Development Co., Ltd.), and 5g of accelerator 2,4,6-tris(dimethylaminomethyl)phenol DMP-30 (Hangzhou Molott Chemical Technology Co., Ltd.) are uniformly mixed in a beaker at room temperature (25℃), and then 1.2g (doped amount about 1wt%) of alumina (Al2O3) is added, stirred evenly, and then allowed to stand for curing to obtain cured epoxy resin.

[0057] Experimental Example 1

[0058] Experimental Example 1 of this application tests the performance of the epoxy resins provided in Examples 2-8. Specifically, differential scanning calorimetry (DSC) was used to analyze the epoxy resins provided in Examples 2-7, and DSC was used to analyze the epoxy resins provided in Examples 2 and 8 at different temperatures. The thermogravimetric analysis (TGA) used for the DSC sample consisted of approximately 10g of cured epoxy resin. The samples were tested using a Perkin Elmer N5350030 Diamond TGA thermal analyzer. The samples were placed in an alumina crucible of the analyzer under nitrogen protection. The temperature range for the sample testing was 150℃-600℃, the flow rate was 40mL / min, and the heating rate was 10℃ / min.

[0059] The results of differential scanning calorimetry (DSC) analysis of the epoxy resins provided in Examples 2-7 are as follows: Figure 1 As shown in Table 1.

[0060] Content (wt%) Initial thermal decomposition temperature (°C) 0 307.63 1 407.13 3 406.75 5 405.59 7 408.07 10 406.17

[0061] Table 1

[0062] from Figure 1 It can be seen that, compared with the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) provided in Example 7, 57 Bi 43 Compared to epoxy resin with a doping content of 0 wt% having a thermal decomposition temperature of 300 °C, the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) provided in Examples 2-6 of this application have a thermal decomposition temperature of 300 °C. 57 Bi 43 The thermal decomposition temperature of epoxy resin with a doping amount of 1-10 wt% is around 400℃, which indicates that the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) provided in this application have a thermal decomposition temperature of around 400℃. 57 Bi 43 This can improve the thermal stability of epoxy resins; further refer to Table 1, as shown in Table 1, the tin-bismuth alloy nanoparticles (Al2O3-Sn supported on alumina) can improve the thermal stability of epoxy resins; 57 Bi 43 When the doping concentration is in the range of 1–7 wt%, the thermal stability of epoxy resin shows a wave-like upward trend, while when the doping concentration is in the range of 1–7 wt%, the thermal stability of epoxy resin increases. 57 Bi 43 The thermal stability decreased after the doping amount reached 10 wt%, which may be due to the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn). 57 Bi 43 When the content is high, the tin-bismuth alloy nanoparticles supported by alumina agglomerate, which destroys the relatively ordered structure of the epoxy resin, increases the proportion of amorphous structure in the material, reduces the orderliness of the original material structure, and leads to a decrease in the thermal decomposition temperature of the material. In summary, the epoxy resin modified by alumina-supported tin-bismuth alloy nanoparticles provided in this application can be used in the packaging of electronic components and electrical equipment in the temperature range not exceeding 400°C.

[0063] Furthermore, the scanning electron microscope (SEM) images of the epoxy resin provided in Examples 2-7 are as follows: Figure 3 As shown, from Figure 3 As can be seen from Example 7, the epoxy resin and alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) provided in Example 7 57 Bi 43 The doping concentration is 0 wt%, and its fracture surface is relatively smooth and flat, without other impurities. The fracture lines are relatively neat, which is a typical characteristic of brittle fracture. Figure 3 As can be seen from bc, the tin-bismuth alloy nanoparticles (Al2O3-Sn) supported on alumina 57 Bi 43 When the doping amount is 1 wt%, the tin-bismuth alloy nanoparticles (Al2O3-Sn) supported on alumina 57 Bi 43 The alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) are uniformly dispersed. 57 Bi 43 When the doping concentration is 3 wt%, a small amount of aggregates appear, but they are uniformly dispersed, and the two-phase interface is well bonded, which corresponds to the thermal stability test data; at the same time, from Figure 3 c also shows that Al2O3-Sn is found at the tip of the material fracture. 57 Bi 43 The particles, shaped like ripples created when water encounters pebbles on a shallow beach, aptly illustrate the mechanism by which nanoparticles reinforce and toughen epoxy. Therefore, the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) provided in this application... 57 Bi 43 Doping can also improve the toughness and other mechanical properties of epoxy resin to a certain extent.

[0064] from Figure 3 d shows that, with Figure 3 Compared to c, alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) 57 Bi 43 When the doping amount is 5wt%, Al2O3-Sn 57 Bi 43 The particles are more densely distributed in the resin matrix, but overall the dispersion is relatively uniform, with a small number of agglomerated particles and no large irregular agglomerates. Its cross-sectional morphology is similar to... Figure 3 c; from Figure 3 As can be seen from e, the tin-bismuth alloy nanoparticles (Al2O3-Sn) supported on alumina 57 Bi 43 When the doping amount is 7wt%, with Figure 3 Compared to d, a large amount of Al2O3-Sn was found in the epoxy matrix. 57 Bi 43 Particle aggregates, occasionally with voids, disrupt the integrity of the epoxy resin matrix, reduce the continuity of the material, and lead to a decrease in the toughness of the composite material. Figure 3 f shows that the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) 57 Bi 43 When the doping amount is 10wt%, compared with the scan Figure 3 Compared to ae, Figure 3 Numerous bumps and depressions appeared in f, resembling small hills and basins. Large aggregated particles appeared in the epoxy matrix, and the uniformly dispersed Al2O3-Sn was no longer visible. 57 Bi 43 The continuity and integrity of the resin matrix are severely damaged, the interfacial bonding between the two phases decreases, the performance of the material is reduced, and the epoxy resin exhibits a decline in mechanical properties such as thermal stability and toughness.

[0065] Differential scanning calorimetry (DSC) analysis was performed on the epoxy resins provided in Examples 2 and 8 at different temperatures. Apparent activation energy, pre-exponential factor, and reaction order are important guiding parameters for determining curing process parameters and selecting curing schemes. There are multiple ways to solve for the apparent activation energy and pre-exponential factor of the curing reaction; among them, the Kissinger method is a commonly used method for solving the apparent activation energy. It has a good linear relationship with 1 / Tp.

[0066]

[0067] Where β is the heating rate; T p It is the peak temperature of the exothermic peak of the curing reaction read from the DSC spectrum; E α η is the apparent activation energy; R is the universal gas constant; and n is the reaction order.

[0068] DSC tests were conducted at different temperatures, and linear fitting was performed on the peak temperature of the curing reaction and the peak temperature of the melting reaction. The apparent activation energy, pre-exponential factor, and reaction order can be obtained from the slope and intercept of the fitted line. Based on this, non-isothermal DSC tests were performed on the epoxy resins provided in Examples 2 and 8, respectively. The test parameters were set at heating temperatures of 50℃, 100℃, 150℃, 200℃, 250℃, and 300℃. The test results are as follows: Figure 2 As shown, from Figure 2 As can be seen, the alumina-doped modified epoxy resin provided in Example 3 did not show an absorption peak, while the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn) provided in Example 2... 57 Bi 43 The modified epoxy resin exhibited an absorption peak at around 138℃, which corresponds to the absorption peak of the alumina-supported tin-bismuth alloy nanoparticles (Al2O3-Sn). 57 Bi 43 Sn 57 Bi 43 The melting absorption peak of the alloy particles, the Sn 57 Bi 43 After the alloy particles melt, they can act as a heat conduction path to dissipate heat, thereby improving the thermal stability of epoxy resin.

[0069] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A thermally stable modified epoxy resin, characterized in that, The raw materials include epoxy resin curing components and modified nanocomposite particles; The epoxy resin curing component includes an epoxy resin matrix, a curing agent, and an accelerator; The modified nanocomposite particles are selected from alumina-supported tin-bismuth alloy nanoparticles; The doping amount of the modified nanocomposite particles is no more than 20 wt%; The molar ratio of the alumina to the tin-bismuth alloy is 8~12:1~2; In the tin-bismuth alloy, the molar ratio of tin atoms to bismuth atoms is 7~11:5~9.

2. The modified epoxy resin with improved thermal stability according to claim 1, characterized in that, The modified nanocomposite particles have a particle size of 1~500 nm.

3. The modified epoxy resin with improved thermal stability according to claim 1, characterized in that, In the epoxy resin curing component, the mass ratio of epoxy resin matrix, curing agent, and accelerator is 5~20:0.5~2:0.1~1.

4. The modified epoxy resin with improved thermal stability according to claim 1, characterized in that, The epoxy resin matrix is ​​selected from at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester type epoxy resin, and glycidyl amine type epoxy resin. The curing agent is selected from at least one of polyamide curing agents, acid anhydride curing agents, and aliphatic polyamine curing agents; The accelerator is selected from at least one of tertiary amine accelerators, substituted urea accelerators, and imidazole accelerators.

5. A method for preparing a thermally stable modified epoxy resin according to any one of claims 1-4, characterized in that, Including the following steps: Step S1: Mix the epoxy resin matrix, curing agent, and accelerator and stir until homogeneous to obtain the epoxy resin curing component; Step S2: Add the modified nanocomposite particles to the epoxy resin curing component and stir evenly. Let it stand at room temperature to obtain a thermally stable modified epoxy resin.

6. The method for preparing a thermally stable modified epoxy resin according to claim 5, characterized in that, In step S2, the preparation method of the modified nanocomposite particles includes the following steps: S21. Under an inert atmosphere, a mixed solution of tin salt and bismuth salt is added dropwise to an alumina suspension containing a reducing agent to obtain modified nanocomposite particles.

7. The method for preparing a thermally stable modified epoxy resin according to claim 6, characterized in that, The reducing agent is selected from at least one of sodium borohydride, ascorbic acid, sodium thiosulfate, and ferrous ammonium sulfate.

8. The application of the thermally stable modified epoxy resin according to any one of claims 1-4 in the field of electronic component or electrical equipment packaging.

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