High-temperature-resistant high-purity low-chlorine epoxy resin and preparation method thereof

Abstract

The invention discloses high-temperature-resistant high-purity low-chlorine epoxy resin and a preparation method thereof. On one hand, the high-purity low-chlorine epoxy resin resistant to high temperature is provided, the high-purity low-chlorine epoxy resin is prepared by curing an epoxy resin base material through a composite curing agent, and the epoxy resin base material is prepared from, by mass, 100 parts of low-chlorophenyl multifunctional epoxy resin and 12-20 parts of epoxy silicon resin; the composite curing agent comprises the following raw material components in parts by mass: 100 parts of a DDS curing agent, 30-40 parts of a bio-based phenolic aldehyde amine curing agent and 6-12 parts of boron modified phenolic resin. On the other hand, the invention provides a preparation method of the high-temperature-resistant high-purity low-chlorine epoxy resin. The epoxy resin material disclosed by the invention has relatively high glass transition temperature, relatively excellent high-temperature resistance and high-temperature aging resistance, low moisture absorption rate and excellent electrical insulation performance.

Description

Technical Field

[0001] This application relates to the field of electronic packaging materials technology, and in particular to a high-temperature resistant, high-purity, low-chlorine epoxy resin and its preparation method. Background Technology

[0002] Electronic packaging materials, acting as the "armor" of power electronic modules, are primarily used to carry and protect electronic devices and their interconnections. They also protect chips and bonded components from moisture, corrosive substances, and other factors, making them a crucial component for ensuring the stable operation of power electronic modules. Epoxy resin, as an important thermosetting plastic material, is widely used in the field of electronic packaging materials due to its excellent physical and mechanical properties, electrical insulation properties, and chemical stability.

[0003] However, with the widespread adoption of third-generation power electronic modules, the inherent limitations of traditional epoxy resins in terms of high-temperature resistance are increasingly failing to meet the stringent electrical and thermal requirements of the electronic packaging field. Third-generation semiconductor power electronic modules, based on silicon carbide and gallium nitride, have gradually replaced silicon-based power electronic modules and are now widely used. These modules feature high switching frequencies, high operating temperatures, high operating voltages, and high power densities, representing a significant performance improvement over silicon-based power electronic modules. Furthermore, with the increasing frequency, integration, and miniaturization of power electronic modules, operating temperatures have risen from around 120°C in traditional silicon-based modules to over 180°C currently. Most integrated and miniaturized power electronic modules operate at full load temperatures exceeding 220°C, and some high-power chips can even reach extreme operating temperatures above 260°C, posing a significant challenge to electronic packaging technology.

[0004] Traditional epoxy resins typically have a glass transition temperature of around 120°C, while existing high-temperature resistant multifunctional epoxy resins can reach glass transition temperatures above 220°C, representing a significant improvement over traditional epoxy resins. However, when used for packaging in electronic applications, primarily third-generation power electronic modules, these high-temperature resistant epoxy resins still exhibit cracking and delamination under full-load operation, and their resistance to high-temperature aging is also insufficient. Summary of the Invention

[0005] To address at least one of the aforementioned technical problems, and to develop an epoxy resin encapsulation material with a high glass transition temperature, excellent high-temperature resistance and high-temperature aging resistance, low moisture absorption, and excellent electrical insulation properties, this application provides a high-purity, low-chlorine epoxy resin with high-temperature resistance and its preparation method.

[0006] On one hand, this application provides a high-purity, low-chlorine epoxy resin resistant to high temperatures. The high-purity, low-chlorine epoxy resin is made by curing an epoxy resin substrate with a composite curing agent. The epoxy resin substrate comprises the following components in the following mass ratio: 100 parts of low-chlorine phenyl polyfunctional epoxy resin and 12-20 parts of epoxy silicone resin. The composite curing agent comprises the following components in the following mass ratio: 100 parts of DDS curing agent, 30-40 parts of bio-based phenolic amine curing agent, and 6-12 parts of boron-modified phenolic resin. The low-chlorine phenyl polyfunctional epoxy resin is an epoxy resin prepared by reacting bisphenol A or 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane with epichlorohydrin. The bio-based phenolic amine curing agent is a bio-based phenolic amine curing agent obtained by reacting polyethyleneimine, methyl eugenol, and furfural.

[0007] Optionally, the mass ratio of the epoxy resin substrate to the composite curing agent is 100:54~58.

[0008] Optionally, the mass ratio of each raw material component in the epoxy resin substrate includes: 100 parts of low-chlorinated phenyl polyfunctional epoxy resin and 16-18 parts of epoxy silicone resin; the mass ratio of each raw material component in the composite curing agent includes: 100 parts of DDS curing agent, 32-34 parts of bio-based phenolic amine curing agent, and 8-10 parts of boron-modified phenolic resin.

[0009] Optionally, the preparation of the low-chlorinated phenyl polyfunctional epoxy resin includes the following steps: S1-a. Bisphenol A or 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane and epichlorohydrin are mixed at a molar ratio of 1:0.55~0.65, and then quaternary ammonium salt accounting for 120~140% of the total mass of the mixture is added. The mixture is stirred at 75~80℃ for more than 1 hour to obtain the etherification reaction solution. S1-b: Add sodium hydroxide (30-40% by mass of the mixture) and 15-crown ether-5 catalyst (6-10% by mass of the mixture) to the etherification reaction solution obtained in step S1-a, and react at 60-65°C for more than 2 hours to obtain a prepolymerization reaction solution. S1-c: The prepolymer reaction solution obtained in step S1-b is subjected to vacuum distillation at 180~185℃ to remove unreacted epichlorohydrin and 15-crown ether-5 catalyst. Then, a strong basic anion exchange resin is added, and dechlorination is carried out by applying 220V AC power for more than 5 minutes. The bimetallic oxide and solid sodium hydroxide are filtered out, and the quaternary ammonium salt is filtered out by nanofiltration. The solution is then naturally cooled to room temperature to obtain a low-chlorinated phenyl polyfunctional epoxy resin.

[0010] Further optionally, in step S1-a, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane is selected as the raw material.

[0011] Optionally, in step S1-c, the strongly basic anion exchange resin is selected from type 717 anion exchange resin.

[0012] Optionally, the preparation of the bio-based phenolic amine curing agent includes the following steps: S2-a. According to the molar ratio of low molecular weight polyethyleneimine, methyl eugenol and furfural of 1:3~4:3~4, accurately weigh low molecular weight polyethyleneimine, methyl eugenol and furfural, add 40~60% glacial acetic acid solution to prepare a reaction solution. S2-b: The reaction solution from step S2-a is reacted at 80~85℃ for more than 12 hours under nitrogen protection, naturally cooled to room temperature, filtered to obtain the solid product, washed with deionized water, and dried to constant weight to obtain the bio-based phenolic amine curing agent.

[0013] Optionally, in step S2-a, the molecular weight of the low molecular weight polyethyleneimine is 600-1200.

[0014] Optionally, in step S2-a, the amount of glacial acetic acid solution added is 1 to 1.2 times the total volume of low molecular weight polyethyleneimine, methyl eugenol, and furfural.

[0015] On the other hand, this application provides a method for preparing the above-mentioned high-temperature resistant, high-purity, low-chlorine epoxy resin, comprising the following steps: S1. Prepare low-chlorinated phenyl polyfunctional epoxy resin. Weigh the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin according to the ratio, mix them thoroughly, and obtain epoxy resin substrate. S2. Prepare a bio-based phenolic amine curing agent. Accurately weigh DDS curing agent, bio-based phenolic amine curing agent and boron-modified phenolic resin according to the formula, mix them thoroughly to obtain a composite curing agent. S3. The epoxy resin substrate obtained in step S1 and the composite curing agent obtained in step S2 are thoroughly mixed and cured at a temperature of 140~160℃ for more than 2 hours, and then cured at a temperature of 180~200℃ for more than 2 hours to obtain a high-purity low-chlorine epoxy resin with high temperature resistance.

[0016] In summary, the present invention has at least one of the following beneficial technical effects: 1. This application uses low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin as epoxy resin base materials, and a composite curing agent obtained by mixing three specific curing agents as curing agent. After curing, an epoxy resin material is obtained, which introduces polyphenyl and silicon functional groups, as well as bio-based phenolic and boron-modified phenolic functional groups. This gives the epoxy resin material a high crosslinking density and a better molecular structure, significantly increases the glass transition temperature of the epoxy resin material, and gives it excellent high-temperature resistance.

[0017] 2. The epoxy resin material of this application uses a suitable ratio of low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin as the base material, and is combined with a composite curing agent. After curing, it can form a dense interpenetrating network structure with high and low molecular weight crosslinking, and has excellent mechanical and electrical insulation properties. At the same time, the introduction of various functional groups can greatly improve the high-temperature stability of the epoxy resin material, giving it superior high-temperature aging resistance.

[0018] 3. The epoxy resin material of this application is relatively simple to prepare, and it introduces silicon-based functional groups and bio-based phenolic functional groups, which greatly improves hydrophobicity and reduces moisture absorption. Detailed Implementation

[0019] The present application will be further described in detail below with reference to the embodiments.

[0020] This application provides a high-purity, low-chlorine epoxy resin resistant to high temperatures. The high-purity, low-chlorine epoxy resin is made by curing an epoxy resin substrate with a composite curing agent. The epoxy resin substrate comprises the following components in the following mass ratio: 100 parts of low-chlorine phenyl polyfunctional epoxy resin and 12-20 parts of epoxy silicone resin. The composite curing agent comprises the following components in the following mass ratio: 100 parts of DDS curing agent, 30-40 parts of bio-based phenolic amine curing agent, and 6-12 parts of boron-modified phenolic resin. The low-chlorine phenyl polyfunctional epoxy resin is an epoxy resin prepared by reacting bisphenol A or 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane with epichlorohydrin. The bio-based phenolic amine curing agent is a bio-based phenolic amine curing agent obtained by reacting polyethyleneimine, methyleugenol, and furfural.

[0021] The preparation method of the above-mentioned high-purity, low-chlorine epoxy resin with high temperature resistance includes the following steps: S1. Prepare low-chlorinated phenyl polyfunctional epoxy resin. Weigh the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin according to the ratio, mix them thoroughly, and obtain epoxy resin substrate. S2. Prepare a bio-based phenolic amine curing agent. Accurately weigh DDS curing agent, bio-based phenolic amine curing agent and boron-modified phenolic resin according to the formula, mix them thoroughly to obtain a composite curing agent. S3. The epoxy resin substrate obtained in step S1 and the composite curing agent obtained in step S2 are thoroughly mixed and cured at a temperature of 140~160℃ for more than 2 hours, and then cured at a temperature of 180~200℃ for more than 2 hours to obtain a high-purity low-chlorine epoxy resin with high temperature resistance.

[0022] Prior to this application, most high-temperature resistant epoxy resin materials prepared in the prior art used bisphenol A epoxy resin as the base material and were cured using various composite curing agents to introduce groups such as polyphenyl, heterocyclic, and phenolic groups, thereby increasing the crosslinking density and improving the molecular structure of the epoxy resin material to achieve the purpose of increasing its glass transition temperature. However, due to the curing characteristics of epoxy resin materials, these multifunctional epoxy resin materials, after hyperbranching curing, all require the addition of fillers to improve density, reduce material purity, and increase internal stress. Consequently, under long-term high-temperature conditions, they are prone to aging and cracking, and their high-temperature aging resistance is insufficient. Furthermore, due to material characteristics, the aforementioned existing multifunctional epoxy resin materials all exhibit a certain degree of hygroscopicity, resulting in problems with their electrical insulation performance in humid environments.

[0023] This application uses a composite substrate formed by combining a high-polymerization-degree low-chlorinated phenyl polyfunctional epoxy resin with a low-molecular-weight liquid epoxy silicone resin, and then uses a composite curing agent prepared with a specific multifunctional curing agent as the curing agent. After curing, the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin can form a dense interpenetrating cross-linked network structure, and the low-molecular-weight liquid epoxy silicone resin can form a good filling effect on the material after curing. A highly dense interpenetrating cross-linked network structure can be formed without fillers, greatly improving the purity and stability of the material under high-temperature conditions. The introduction of silicon-based and biophenolic functional groups allows for widespread distribution in the cross-linked network structure of the material, giving the material strong hydrophobicity, greatly reducing moisture absorption, and ensuring excellent moisture resistance and electrical insulation properties. The design of this application achieves a balance of high-temperature resistance, moisture resistance, electrical insulation, and high-temperature aging resistance, effectively solving the problems existing in the prior art. The high-purity, low-chlorine epoxy resin of this application, through a specific process design, significantly reduces the chlorine content in the epoxy resin material, bringing the total chlorine content down to below 400 ppm. At the same time, through the design of the resin system, without adding any functional fillers while ensuring the various properties of the material, the purity of the resin material is greatly improved, effectively avoiding the problem of high-temperature cracking of the resin material.

[0024] The following are preparation examples and embodiments of this application.

[0025] The main raw materials used in the embodiments of this application are all commercially available.

[0026] Among them, bisphenol A, with a purity of over 99.5%, was purchased from Jinan Liyang Chemical Co., Ltd.; 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, with a purity of over 99%, was purchased from Hubei Shishun Biotechnology Co., Ltd.; epoxy silicone resin, specifically epoxy-modified organosilicon resin 9614, was purchased from Hubei Longsheng Sihai New Material Co., Ltd.; epichlorohydrin was purchased from Jinan Chuangshi Chemical Co., Ltd.; 15-crown ether-5 catalyst was purchased from Wuhan Jixin Yibang Biotechnology Co., Ltd.; and 717 type anion exchange resin was purchased from [unclear - possibly a company name]. Haiyuanye Biotechnology Co., Ltd.; Phenolic amine curing agent, model DMP-30, purchased from Tianjin Zhongheshengtai Chemical Co., Ltd.; Methyl eugenol, purity 99%, purchased from Shanghai Chunyou Biotechnology Co., Ltd.; Furfural, purity 99%, purchased from Wuhan Jiyesheng Chemical Co., Ltd.; Low molecular weight polyethyleneimine, liquid, molecular weight 600~1200, purchased from Shanghai Aladdin; Boron-modified phenolic resin, purchased from Jining Benok Biotechnology Co., Ltd.; DDS curing agent, purchased from Shenzhen Huiya New Material Technology Co., Ltd.

[0027] The following is a preparation example of this application.

[0028] Preparation Example 1 The preparation of the low-chlorinated phenyl polyfunctional epoxy resin in this example includes the following steps: S1-a. Bisphenol A and epichlorohydrin are mixed in a molar ratio of 1:0.55, and then tetramethylammonium chloride, accounting for 120% of the total mass of the mixture, is added. The mixture is stirred at 75~80℃ for 1 hour to obtain the etherification reaction solution. S1-b: Add sodium hydroxide (30% of the total mass of the mixture) and 15-crown ether-5 catalyst (6% of the total mass of the mixture) to the etherification reaction solution obtained in step S1-a, and react at 60~65℃ for more than 2 hours to obtain a prepolymerization reaction solution. S1-c: The prepolymer reaction solution obtained in step S1-b is subjected to vacuum distillation at 180~185℃ to remove unreacted epichlorohydrin and 15-crown ether-5 catalyst. Then, 100% of the total mass of 717 type anion exchange resin is added, and dechlorination is carried out by applying 220V AC power for 5 minutes. The bimetallic oxide and solid sodium hydroxide are filtered out, and the quaternary ammonium salt is filtered out by nanofiltration. The solution is then naturally cooled to room temperature to obtain low-chlorinated phenyl polyfunctional epoxy resin.

[0029] Preparation Example 2 The preparation of the low-chlorinated phenyl polyfunctional epoxy resin in this example includes the following steps: S1-a. Bisphenol A and epichlorohydrin are mixed at a molar ratio of 1:0.65, and then tetramethylammonium chloride, accounting for 140% of the total mass of the mixture, is added. The mixture is stirred at 75~80℃ for 1 hour to obtain the etherification reaction solution. S1-b: Add sodium hydroxide (40% of the total mass of the mixture) and 15-crown ether-5 catalyst (10% of the total mass of the mixture) to the etherification reaction solution obtained in step S1-a, and react at 60~65℃ for 2 hours to obtain the prepolymerization reaction solution. S1-c: The prepolymer reaction solution obtained in step S1-b is subjected to vacuum distillation at 180~185℃ to remove unreacted epichlorohydrin and 15-crown ether-5 catalyst. Then, 717 type anion exchange resin accounting for 120% of the total mass of the mixture is added, and dechlorination is carried out by applying 220V AC power for 5 minutes. The bimetallic oxide and solid sodium hydroxide are filtered out, and the quaternary ammonium salt is filtered out by nanofiltration. The mixture is then naturally cooled to room temperature to obtain low-chlorinated phenyl polyfunctional epoxy resin.

[0030] Preparation Example 3 The preparation of the low-chlorinated phenyl polyfunctional epoxy resin in this example includes the following steps: S1-a. Bisphenol A and epichlorohydrin are mixed in a molar ratio of 1:0.6, and then tetramethylammonium chloride, accounting for 130% of the total mass of the mixture, is added. The mixture is stirred at 75~80℃ for 1 hour to obtain the etherification reaction solution. S1-b: Add sodium hydroxide (35% by mass of the mixture) and 15-crown ether-5 catalyst (8% by mass of the mixture) to the etherification reaction solution obtained in step S1-a, and react at 60~65℃ for 2 hours to obtain the prepolymerization reaction solution. S1-c: The prepolymer reaction solution obtained in step S1-b is subjected to vacuum distillation at 180~185℃ to remove unreacted epichlorohydrin and 15-crown ether-5 catalyst. Then, 150% of the total mass of the mixture of 717 type anion exchange resin is added, and dechlorination is carried out by 220V AC power for 5 minutes. The bimetallic oxide and solid sodium hydroxide are filtered out, and the quaternary ammonium salt is filtered out by nanofiltration. The mixture is then naturally cooled to room temperature to obtain low-chlorinated phenyl polyfunctional epoxy resin.

[0031] Preparation Example 4 The difference between this preparation example and preparation example 3 is that bisphenol A is replaced with an equal amount of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane.

[0032] Preparation Example 5 The preparation of the bio-based phenolic amine curing agent in this example includes the following steps: S2-a. According to the molar ratio of low molecular weight polyethyleneimine, methyl eugenol and furfural of 1:3:3, accurately weigh low molecular weight polyethyleneimine, methyl eugenol and furfural, add an equal volume of 40% glacial acetic acid solution to prepare a reaction solution. S2-b: The reaction solution from step S2-a is reacted at 80-85°C for 12 hours under nitrogen protection, then naturally cooled to room temperature. The solid product is filtered out, washed with deionized water, and vacuum dried at 80°C to constant weight to obtain the bio-based phenolic amine curing agent.

[0033] Preparation Example 6 The preparation of the bio-based phenolic amine curing agent in this example includes the following steps: S2-a. According to the molar ratio of low molecular weight polyethyleneimine, methyl eugenol and furfural of 1:4:4, accurately weigh low molecular weight polyethyleneimine, methyl eugenol and furfural, add 60% glacial acetic acid solution accounting for 1.2 times the volume of the raw material mixture, and prepare a reaction solution. S2-b: The reaction solution from step S2-a is reacted at 80-85°C for 12 hours under nitrogen protection, then naturally cooled to room temperature. The solid product is filtered out, washed with deionized water, and vacuum dried at 80°C to constant weight to obtain the bio-based phenolic amine curing agent.

[0034] Preparation Example 7 The preparation of the bio-based phenolic amine curing agent in this example includes the following steps: S2-a. According to the molar ratio of low molecular weight polyethyleneimine, methyl eugenol and furfural of 1:3.5:3.5, accurately weigh low molecular weight polyethyleneimine, methyl eugenol and furfural, add 50% glacial acetic acid solution accounting for 1.2 times the volume of the raw material mixture, and prepare a reaction solution. S2-b: The reaction solution from step S2-a is reacted at 80-85°C for 12 hours under nitrogen protection, then naturally cooled to room temperature. The solid product is filtered out, washed with deionized water, and vacuum dried at 80°C to constant weight to obtain the bio-based phenolic amine curing agent.

[0035] The following are embodiments of this application. Example 1

[0036] The method for preparing high-purity, low-chlorine epoxy resin resistant to high temperatures in this embodiment includes the following steps: S1. Select the low-chlorinated phenyl polyfunctional epoxy resin of Preparation Example 1, accurately weigh the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin at a mass ratio of 100:12, mix them thoroughly to obtain epoxy resin substrate. S2. Select the bio-based phenolic amine curing agent from Preparation Example 5, accurately weigh DDS curing agent, bio-based phenolic amine curing agent and boron-modified phenolic resin according to the mass ratio of 100:30:6, mix them thoroughly to obtain a composite curing agent. S3. The epoxy resin substrate obtained in step S1 and the composite curing agent obtained in step S2 are thoroughly mixed at a mass ratio of 100:50, cured at 150°C for 2 hours, and then cured at 200°C for another 2 hours to obtain a high-purity, low-chlorine epoxy resin resistant to high temperatures. Example 2

[0037] The method for preparing high-purity, low-chlorine epoxy resin resistant to high temperatures in this embodiment includes the following steps: S1. Select the low-chlorinated phenyl polyfunctional epoxy resin of Preparation Example 1, accurately weigh the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin at a mass ratio of 100:20, mix them thoroughly to obtain epoxy resin substrate. S2. Select the bio-based phenolic amine curing agent from Preparation Example 5, accurately weigh DDS curing agent, bio-based phenolic amine curing agent and boron-modified phenolic resin according to the mass ratio of 100:40:12, mix them thoroughly to obtain a composite curing agent. S3. The epoxy resin substrate obtained in step S1 and the composite curing agent obtained in step S2 are thoroughly mixed at a mass ratio of 100:50, cured at 150°C for 2 hours, and then cured at 200°C for another 2 hours to obtain a high-purity, low-chlorine epoxy resin resistant to high temperatures. Example 3

[0038] The method for preparing high-purity, low-chlorine epoxy resin resistant to high temperatures in this embodiment includes the following steps: S1. Select the low-chlorinated phenyl polyfunctional epoxy resin of Preparation Example 1, accurately weigh the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin at a mass ratio of 100:16, mix them thoroughly, and obtain epoxy resin substrate. S2. Select the bio-based phenolic amine curing agent from Preparation Example 5, accurately weigh DDS curing agent, bio-based phenolic amine curing agent and boron-modified phenolic resin according to the mass ratio of 100:32:8, mix them thoroughly to obtain a composite curing agent. S3. The epoxy resin substrate obtained in step S1 and the composite curing agent obtained in step S2 are thoroughly mixed at a mass ratio of 100:50, cured at 150°C for 2 hours, and then cured at 200°C for another 2 hours to obtain a high-purity, low-chlorine epoxy resin resistant to high temperatures. Example 4

[0039] The method for preparing high-purity, low-chlorine epoxy resin resistant to high temperatures in this embodiment includes the following steps: S1. Select the low-chlorinated phenyl polyfunctional epoxy resin of Preparation Example 1, accurately weigh the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin at a mass ratio of 100:18, mix them thoroughly to obtain epoxy resin substrate. S2. Select the bio-based phenolic amine curing agent from Preparation Example 5, accurately weigh DDS curing agent, bio-based phenolic amine curing agent and boron-modified phenolic resin according to the mass ratio of 100:34:10, mix them thoroughly to obtain a composite curing agent; S3. The epoxy resin substrate obtained in step S1 and the composite curing agent obtained in step S2 are thoroughly mixed at a mass ratio of 100:50, cured at 150°C for 2 hours, and then cured at 200°C for another 2 hours to obtain a high-purity, low-chlorine epoxy resin resistant to high temperatures. Example 5

[0040] The difference between this embodiment and embodiment 4 is that in step S3, the epoxy resin substrate and the composite curing agent are thoroughly mixed at a mass ratio of 100:54. Example 6

[0041] The difference between this embodiment and embodiment 4 is that in step S3, the epoxy resin substrate and the composite curing agent are thoroughly mixed at a mass ratio of 100:56. Example 7

[0042] The difference between this embodiment and embodiment 4 is that in step S3, the epoxy resin substrate and the composite curing agent are thoroughly mixed at a mass ratio of 100:58. Example 8

[0043] The difference between this embodiment and Example 6 is that the low-chlorinated phenyl polyfunctional epoxy resin of Preparation Example 2 and the bio-based phenolic amine curing agent of Preparation Example 6 are used. Example 9

[0044] The difference between this embodiment and Example 6 is that the low-chlorinated phenyl polyfunctional epoxy resin of Preparation Example 3 and the bio-based phenolic amine curing agent of Preparation Example 7 are used. Example 10

[0045] The difference between this embodiment and Example 6 is that the low-chlorinated phenyl polyfunctional epoxy resin of Preparation Example 4 and the bio-based phenolic amine curing agent of Preparation Example 7 are used.

[0046] Comparative Example 1 AGF-90 multifunctional epoxy resin and DDS curing agent produced by Shanghai Huayi Resin Co., Ltd. were thoroughly mixed at a mass ratio of 100:57 and cured at 130℃ / 2h+150℃ / 2h+180℃ / 2h+200℃ / 2h. The resulting epoxy resin material was used as Comparative Example 1.

[0047] Comparative Example 2 The difference between this comparative example and Example 10 is that an equal amount of low-chlorinated phenyl polyfunctional epoxy resin is used to replace the epoxy silicone resin.

[0048] Comparative Example 3 The difference between this comparative example and Example 10 is that an equal amount of DMP-30 phenolic amine curing agent produced by Tianjin Zhonghe Shengtai Chemical Co., Ltd. was used to replace the bio-based phenolic amine curing agent.

[0049] Comparative Example 4 The difference between this comparative example and Example 10 is that boron-modified phenolic resin was not added.

[0050] Product performance testing: The performance of the products from Examples 1-10 and Comparative Examples 1-4 was tested, including total chlorine content, high temperature resistance, moisture absorption, impact resistance, and electrical insulation properties.

[0051] The total chlorine content was tested according to the method described in GB / T 12007.3-1989; The high-temperature resistance was tested according to the method described in GB / T 194667.2-2004, with the glass transition temperature being determined accordingly. The moisture absorption rate was tested according to the method described in GB / T 1034-1998; Impact resistance mechanical properties were tested according to the method described in GB / T 2567-2008; The volume resistivity of the material was tested using a four-probe tester to assess its electrical insulation properties.

[0052] The results are shown in Table 1 below.

[0053] Table 1 Performance test results of Examples 1-10 and Comparative Examples 1-4 Chlorine content (ppm) Glass transition temperature (°C) Moisture absorption rate (%) <![CDATA[Impact strength (kJ / m 2 )]]> Volume resistivity (Ω·cm) Example 1 334 261 0.26 34.9 <![CDATA[1×10 16 The End]]> Example 2 297 262 0.25 35.2 <![CDATA[1×10 16 The End]]> Example 3 314 264 0.23 35.4 <![CDATA[1×10 16 The End]]> Example 4 319 265 0.22 35.5 <![CDATA[1×10 16 End<!-- 7 --> ]]> Example 5 308 269 0.20 35.9 <![CDATA[1×10 16 The End]]> Example 6 306 274 0.19 36.6 <![CDATA[1×10 16 The End]]> Example 7 303 272 0.19 36.5 <![CDATA[1×10 16 The End]]> Example 8 302 274 0.18 36.7 <![CDATA[1×10 16 The End]]> Example 9 303 275 0.17 36.9 <![CDATA[1×10 16 The End]]> Example 10 301 278 0.15 37.4 <![CDATA[1×10 16 The End]]> Comparative Example 1 1042 234 2.74 9.4 <![CDATA[1×10 15 The End]]> Comparative Example 2 321 249 0.92 14.2 <![CDATA[1×10 15 The End]]> Comparative Example 3 303 241 1.07 33.8 <![CDATA[1×10 16 The End]]> Comparative Example 4 302 246 0.19 37.1 <![CDATA[1×10 16 The End]]> The products of Examples 1-10 and Comparative Examples 1-4 were subjected to aging treatment, and their various properties were then tested. The results are shown in Table 2 below. Aging: 200℃ temperature, 85% humidity, UV intensity 0.45W / m 2 Under these conditions, the treatment lasted for 30 days.

[0054] Table 2. Aging performance test results of Examples 1-10 and Comparative Examples 1-4 Glass transition temperature (°C) Moisture absorption rate (%) <![CDATA[Impact strength (kJ / m 2 )]]> Volume resistivity (Ω·cm) Example 1 260 0.28 34.4 <![CDATA[1×10 16 The End]]> Example 2 260 0.26 34.6 <![CDATA[1×10 16 The End]]> Example 3 262 0.25 35.0 <![CDATA[1×10 16 The End]]> Example 4 263 0.24 35.2 <![CDATA[1×10 16 The End]]> Example 5 268 0.22 35.6 <![CDATA[1×10 16 The End]]> Example 6 272 0.21 36.2 <![CDATA[1×10 16 The End]]> Example 7 271 0.20 36.0 <![CDATA[1×10 16 The End]]> Example 8 273 0.19 36.4 <![CDATA[1×10 16 The End]]> Example 9 275 0.18 36.6 <![CDATA[1×10 16 The End]]> Example 10 278 0.16 37.2 <![CDATA[1×10 16 The End]]> Comparative Example 1 226 2.74 7.7 <![CDATA[1×10 14 The End]]> Comparative Example 2 242 1.87 12.1 <![CDATA[1×10 15 The End]]> Comparative Example 3 237 1.33 32.5 <![CDATA[1×10 16 The End]]> Comparative Example 4 242 0.21 36.7 <![CDATA[1×10 16 The End]]> As can be seen from the data in Table 1, the epoxy resin materials prepared in Examples 1-10 of this application have slightly improved electrical insulation, significantly reduced total chlorine content, and significantly improved high temperature and moisture resistance compared to the epoxy resin material of Comparative Example 1 used in the prior art. Furthermore, as can be seen from the data in Table 2, the epoxy resin materials prepared in Examples 1-10 of this application have excellent high temperature aging resistance, significantly better than the epoxy resin material of Comparative Example 1 in the prior art. After high temperature aging treatment, their performance did not change significantly.

[0055] A comparison of the data from Examples 1-10 in Tables 1 and 2 shows that, after adjusting the raw material ratio and the ratio of epoxy resin substrate to curing agent, the various properties and high-temperature aging resistance of the epoxy resin can be further improved. Furthermore, in the epoxy resin material system of this application, the use of 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane as a raw material to prepare low-chlorinated phenyl multifunctional epoxy resin further enhances the material's performance.

[0056] Comparing the data in Tables 1 and 2 between Example 10 and Comparative Examples 2-4, it can be seen that the mechanical and electrical insulation properties of Comparative Example 2 are significantly lower than those of Example 10, and its high-temperature aging resistance is also significantly insufficient. This shows that the addition of epoxy silicone resin in this application can significantly construct a denser cross-linked network structure, thereby effectively improving the various properties of the material. In addition, the high-temperature resistance of Comparative Examples 3 and 4 is significantly lower than that of Example 10. This shows that the use of specific bio-based phenolic curing agents and boron-modified phenolic resin curing agents in this application can significantly improve the high-temperature resistance of the material. Comparing the data in Tables 1 and 2 between Example 10 and Comparative Examples 2-4, it can also be seen that the epoxy resin material obtained by using epoxy silicone resin as an auxiliary substrate and a specific composite curing agent has the best performance. The material performance benefits from the systematic structural improvement; the improvement of material performance by a single method is relatively limited, and the combination of various methods has a significant synergistic effect.

[0057] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-purity, low-chlorine epoxy resin resistant to high temperatures, characterized in that, The high-purity, low-chlorine epoxy resin is made by curing an epoxy resin substrate with a composite curing agent. The mass ratio of each raw material component in the epoxy resin substrate includes: 100 parts of low-chlorine phenyl polyfunctional epoxy resin and 12-20 parts of epoxy silicone resin. The mass ratio of each raw material component in the composite curing agent includes: 100 parts of DDS curing agent, 30-40 parts of bio-based phenolic amine curing agent, and 6-12 parts of boron-modified phenolic resin. The low-chlorine phenyl polyfunctional epoxy resin is an epoxy resin prepared by reacting bisphenol A or 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane with epichlorohydrin. The bio-based phenolic amine curing agent is a bio-based phenolic amine curing agent prepared by reacting polyethyleneimine, methyleugenol, and furfural.

2. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 1, characterized in that, The mass ratio of the epoxy resin substrate to the composite curing agent is 100:54~58.

3. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 1, characterized in that, The epoxy resin substrate comprises the following components in the following mass ratios: 100 parts of low-chlorinated phenyl polyfunctional epoxy resin and 16-18 parts of epoxy silicone resin; the composite curing agent comprises the following components in the following mass ratios: 100 parts of DDS curing agent, 32-34 parts of bio-based phenolic amine curing agent, and 8-10 parts of boron-modified phenolic resin.

4. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 1, characterized in that, The preparation of the low-chlorinated phenyl polyfunctional epoxy resin includes the following steps: S1-a. Bisphenol A or 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane and epichlorohydrin are mixed at a molar ratio of 1:0.55~0.65, and then quaternary ammonium salt accounting for 120~140% of the total mass of the mixture is added. The mixture is stirred at 75~80℃ for more than 1 hour to obtain the etherification reaction solution. S1-b: Add sodium hydroxide (30-40% by mass of the mixture) and 15-crown ether-5 catalyst (6-10% by mass of the mixture) to the etherification reaction solution obtained in step S1-a, and react at 60-65°C for more than 2 hours to obtain a prepolymerization reaction solution. S1-c: The prepolymer reaction solution obtained in step S1-b is subjected to vacuum distillation at 180~185℃ to remove unreacted epichlorohydrin and 15-crown ether-5 catalyst. Then, a strong basic anion exchange resin is added, and dechlorination is carried out by applying 220V AC power for more than 5 minutes. The bimetallic oxide and solid sodium hydroxide are filtered out, and the quaternary ammonium salt is filtered out by nanofiltration. The solution is then naturally cooled to room temperature to obtain a low-chlorinated phenyl polyfunctional epoxy resin.

5. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 4, characterized in that, In step S1-a, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane is selected as the raw material.

6. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 4, characterized in that, In step S1-c, the strongly basic anion exchange resin is selected as type 717 anion exchange resin.

7. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 1, characterized in that, The preparation of the bio-based phenolic amine curing agent includes the following steps: S2-a. According to the molar ratio of low molecular weight polyethyleneimine, methyl eugenol and furfural of 1:3~4:3~4, accurately weigh low molecular weight polyethyleneimine, methyl eugenol and furfural, add 40~60% glacial acetic acid solution to prepare a reaction solution. S2-b: The reaction solution from step S2-a is reacted at 80~85℃ for more than 12 hours under nitrogen protection, naturally cooled to room temperature, filtered to obtain the solid product, washed with deionized water, and dried to constant weight to obtain the bio-based phenolic amine curing agent.

8. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 7, characterized in that, In step S2-a, the molecular weight of the low molecular weight polyethyleneimine is 600~1200.

9. The high-purity, low-chlorine epoxy resin resistant to high temperatures according to claim 7, characterized in that, In step S2-a, the amount of glacial acetic acid solution added is 1 to 1.2 times the total volume of low molecular weight polyethyleneimine, methyl eugenol, and furfural.

10. A method for preparing the high-purity, low-chlorine epoxy resin according to claim 1, characterized in that, Includes the following steps: S1. Prepare low-chlorinated phenyl polyfunctional epoxy resin. Weigh the low-chlorinated phenyl polyfunctional epoxy resin and epoxy silicone resin according to the ratio, mix them thoroughly, and obtain epoxy resin substrate. S2. Prepare a bio-based phenolic amine curing agent. Accurately weigh DDS curing agent, bio-based phenolic amine curing agent and boron-modified phenolic resin according to the formula, mix them thoroughly to obtain a composite curing agent. S3. The epoxy resin substrate obtained in step S1 and the composite curing agent obtained in step S2 are thoroughly mixed and cured at a temperature of 140~160℃ for more than 2 hours, and then cured at a temperature of 180~200℃ for more than 2 hours to obtain a high-purity low-chlorine epoxy resin with high temperature resistance.