WO-2026091643-A1 - AROMATIC AMINE EPOXY RESIN CURING AGENT, INSULATING EPOXY RESIN AND PREPARATION METHOD THEREFOR

Abstract

The present invention belongs to the technical field of insulation, and discloses an aromatic amine epoxy resin curing agent, an insulating epoxy resin and a preparation method therefor. The curing agent is designed to include at least two benzene ring structures connected via a functional bridging linkage, with an amino functional group arranged at each end of the designed structure, and no strong electron withdrawing substituent provided at the ortho positions of the designed amino functional groups, thereby yielding the aromatic amine epoxy resin curing agent, wherein the functional bridging linkage is located at the 1,4 or 1,3 positions of the benzene ring structures. A polyaromatic diamine is used as a curing agent component for an epoxy resin, and a rigid aromatic structure is introduced into an epoxy backbone to enhance the thermal stability thereof and increase the glass transition temperature thereof; and a functional bridging linkage is also introduced between benzene rings to break the conjugation structure of the benzene ring and improve the electrical performance. An insulating epoxy resin for a high-voltage direct current with a high thermal stability and a high resistivity can be prepared. The present invention helps to solve the electrical performance problems of a key insulating member in a direct current GIS/GIL under a high temperature gradient and a high electric field.

Inventors

• ZHANG, Boya
• LI, JIE
• Li, Xingwen
• ZHANG, Xuanjie
• LI, YiXuan

Assignees

• 西安交通大学

Dates

Publication Date

20260507

Application Date

20250630

Priority Date

20241029

Claims (9)

1. An aromatic amine epoxy resin curing agent, characterized in that it comprises: The design structure consists of at least two benzene rings connected by functional bridge bonds; an amino functional group is set at each end of the design structure; no strong electron-withdrawing substituents are set at the adjacent positions of the amino functional groups. The functional bridging bond is located at the 1,4 substitution site or the 1,3 substitution site of the benzene ring structure.
2. According to claim 1, the aromatic amine epoxy resin curing agent is characterized in that the functional bridging bond is a strong electron-withdrawing group or a large steric hindrance group.
3. According to claim 2, the aromatic amine epoxy resin curing agent is characterized in that the strong electron-withdrawing group is -C=O or -SO2 .
4. According to claim 2, the aromatic amine epoxy resin curing agent is characterized in that the large steric hindrance group is -C2H6 , -C2F6 or -C6H12 .
5. A method for preparing an insulating epoxy resin, characterized by comprising the following steps: 1) Dissolve the aromatic amine epoxy resin curing agent according to any one of claims 1-4 in a mixed solvent of acetone and dimethylacetamide, and heat and stir for the first time until completely dissolved to obtain an aromatic amine epoxy resin curing agent solution; 2) Add the aromatic amine epoxy resin curing agent solution obtained in step 1) to the preheated epoxy resin monomer, and perform a second heating and stirring under continuous vacuum conditions; then add filler, perform a third heating and stirring, and perform a first degassing treatment to obtain the casting material. 3) Pour the casting material obtained in step 2) into a preheated mold, perform a second degassing treatment, and after curing, allow it to cool naturally to room temperature before demolding to obtain insulating epoxy resin.
6. According to the method for preparing insulating epoxy resin according to claim 5, the ratio of aromatic amine epoxy resin curing agent: acetone: dimethylacetamide in step 1) is (10-15)g: (2-8)mL: (10-15)mL. The heating temperature for the first heating and stirring is 50~80℃, and the stirring time is 20~40min.
7. The method for preparing insulating epoxy resin according to claim 5 is characterized in that the weight ratio of aromatic amine epoxy resin curing agent: epoxy resin monomer: filler is (5-30):(10-40):(30-60). The preheating temperature of the epoxy resin monomer is 50~80℃, and the preheating time is 4~8h; The heating temperature for the second heating and stirring is 60~120℃, and the stirring time is 10~60min; The heating temperature for the third heating and stirring is 60~120℃, and the stirring time is 10-30min; The conditions for the first degassing treatment are: under a vacuum of 1~10 mbar, at a temperature and pressure of 60~120℃ for 30~120 min.
8. The method for preparing insulating epoxy resin according to claim 5 is characterized in that, in step 3), the method for obtaining the preheated mold includes: spraying a release agent in advance and heating to 100°C; The conditions for the second degassing treatment are: under a vacuum of 1-10 mbar, at a temperature and pressure of 60-120°C for 30-60 minutes. The curing conditions are as follows: heat to 120~140℃ and hold for 60~180 min; then heat to 150~180℃ for 60~120 min and hold for 120~300 min; then heat to 190~210℃ for 60~120 min and hold for 60~180 min.
9. An insulating epoxy resin, characterized in that it is prepared by the preparation method described in any one of claims 5-8.

Description

An aromatic amine epoxy resin curing agent, an insulating epoxy resin, and a method for preparing the same. Technical Field This invention belongs to the field of insulation technology, specifically relating to an aromatic amine epoxy resin curing agent, an insulating epoxy resin, and a method for preparing the same. Background Technology With the large-scale development of offshore wind power and high-altitude hydropower, DC GIS (Gas Insulated Switchgear)/GIL (Gas Insulated Transmission Lines) have become the main equipment for large-scale clean energy transmission due to their advantages such as small footprint, high reliability, and minimal environmental impact. Under DC voltage, the internal electric field of the material exhibits a resistive distribution, unlike the resistive distribution of the internal electric field under traditional DC voltage. This easily leads to the accumulation of surface charges on the surface of the insulating material, inducing surface flashover faults. Since the conductor temperature is close to the glass transition temperature of the epoxy material, and the resistivity of epoxy material decreases significantly with increasing temperature, a radial temperature gradient forms inside the insulator. The location of the maximum electric field shifts towards the grounded outer shell, resulting in a decrease in the effective insulation distance, further distortion of the surface electric field, and a significant drop in the surface flashover voltage. Currently, researchers mainly propose using micron- and nanoparticle doping to modify materials and enhance the electrical properties of epoxy composites. However, due to the large specific surface area of nanoparticles, they are prone to agglomeration and cannot be uniformly dispersed within the material, thus failing to meet the requirements of large-scale industrial applications. Furthermore, the glass transition temperature of commercial epoxy resin matrix materials used for electrical insulation is only around 120°C, further limiting the electrical performance of epoxy materials under high temperature gradients and high electric fields. Effective solutions to these technical problems have not yet been proposed, making it difficult to meet the design requirements of critical insulation components in DC GIS/GIL. In response to the problems of nanoparticle agglomeration, uneven dispersion, and low glass transition temperature of epoxy resin matrix materials during the modification process of epoxy composites, there is an urgent need to find a new epoxy resin with high thermal stability and high resistivity for high voltage DC insulation and its preparation method, so as to meet the design requirements of key insulation components in DC GIS/GIL under high temperature gradient and high electric field conditions. Attached Figure Description Figure 1 shows the Fourier transform infrared spectra of the insulating epoxy resins obtained in Examples 1-5 and Comparative Example 1 of the present invention. Figure 2 shows the differential scanning calorimetry results of the insulating epoxy resins obtained in Examples 1-5 and Comparative Example 1 of the present invention. Figure 3 is a comparison of the high-temperature DC breakdown strength and high-temperature volume resistivity of the insulating epoxy resins obtained in Examples 1-5 and Comparative Example 1 of the present invention. Embodiments of the present invention To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention. It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The present invention will now be described in further detail with reference to the a