An epoxy resin modified by in-situ generated Cu2S nanoparticles for high voltage direct current and a preparation method thereof

Abstract

The application discloses in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current and a preparation method thereof, and belongs to the technical field of high-voltage direct current insulation epoxy resin, and comprises an epoxy resin, a filler, a curing agent and an accelerator, wherein the filler comprises Al2O3 microparticle basic filler and in-situ generated Cu2S nanoparticle reinforced filler; the Cu2S nanoparticles are prepared by in-situ reduction of copper N,N-dibutyl dithiocarbamate in the epoxy resin. The Cu2S nanoparticles have good dispersibility in the matrix and good compatibility with the epoxy resin; due to the formation of an epoxy interface trap and the increase of a surface defect state, the Cu2S nanoparticles can form carrier traps at the interface, enhance the direct current resistivity, and on the other hand, as a semiconductor, can disperse an electric field in the epoxy resin, reduce the local electric field strength, thereby reducing the risk of corona discharge and improving insulation reliability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-voltage direct-current insulating epoxy resin, and particularly relates to an epoxy resin for high-voltage direct current based on in-situ generated Cu2S nanoparticles and a preparation method thereof. BACKGROUND

[0002] Under the background of global energy structure transformation and continuous growth of power demand, high-voltage direct-current transmission (HVDC) technology, as a key means to realize long-distance and large-capacity power transmission and power grid interconnection, is increasingly highlighting its importance. With the rapid development of renewable energy, such as a large number of distributed energy sources like wind energy and solar energy, and the increasing demand for cross-regional energy allocation, HVDC technology not only can effectively reduce energy loss in the process of power transmission and improve transmission efficiency, but also can promote the efficient development and extensive use of clean energy, which has important significance for building a green, low-carbon and efficient energy system. In this process, as a key component to ensure the safe and stable operation of power equipment, the performance improvement of insulating materials is directly related to the reliability and economy of the entire power transmission system.

[0003] Epoxy resin, with its excellent mechanical strength, good corrosion resistance and outstanding insulation performance, has become an indispensable insulating support material in high-voltage direct-current transmission equipment. In particular, in key components such as direct-current gas-insulated switchgear (GIS / GIL), insulating rods and wall bushings, the application of epoxy resin is particularly widespread. In order to further improve the insulation performance of epoxy resin in high-voltage direct-current environment, researchers have carried out extensive research. On the one hand, by modifying the epoxy resin itself, such as introducing special functional groups, adjusting the crosslinking density or using new curing agents, etc., in order to obtain higher insulation resistivity and lower dielectric loss. On the other hand, by physical blending or chemical grafting, etc., micro-nano particles (such as silicon dioxide, aluminum oxide, graphene, etc.) are uniformly dispersed in the epoxy resin matrix, and the special properties of these particles are used to enhance the insulation performance and thermal stability of the composite material, providing a new material basis for the development of high-voltage direct-current transmission technology.

[0004] Although the introduction of micro-nanoparticles provides an effective way to improve the insulation performance of epoxy resin, there are still many challenges in practical application. The primary problem is the dispersibility of nanoparticles. Due to the extremely high specific surface area of nanoparticles, the surface energy is large, so agglomeration phenomenon is easy to occur during the preparation of the composite, which not only affects the uniform distribution of the particles in the epoxy resin, but also may cause defects in the material, thereby reducing the insulation performance and mechanical strength of the composite. In addition, the interface interaction between nanoparticles and epoxy resin matrix is also a key factor affecting the performance of the composite. If the interface is not tightly bonded, it may cause charge accumulation at the interface, increase dielectric loss, and even cause partial discharge, which threatens the long-term safe operation of the equipment. Therefore, how to effectively solve the problem of dispersion of nanoparticles and optimize the interface bonding between particles and matrix has become a technical problem to be solved in the current research on improving the insulation performance of epoxy resin. SUMMARY

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a kind of epoxy resin based on in-situ generated Cu2S nanoparticles modified for high voltage direct current and its preparation method, to solve the technical problem that nanoparticles are easy to agglomerate in epoxy resin, realize the uniform dispersion of nanoparticles, and improve the insulation performance of epoxy resin under high voltage direct current.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The application discloses a kind of epoxy resin based on in-situ generated Cu2S nanoparticles modified for high voltage direct current, including epoxy resin, filler, curing agent and accelerator;Filler includes basic filler and reinforcing filler;Basic filler is Al2O3 microparticle;Reinforcing filler is Cu2S nanoparticle;Cu2S nanoparticle is prepared by N, N-dibutyl dithiocarbamic acid copper in-situ reduction in epoxy resin.

[0008] Preferably, the mass fraction ratio of epoxy resin, Al2O3 microparticle, N, N-dibutyl dithiocarbamic acid copper, curing agent and accelerator is (90-110) : (100-200) : (3-15) : (60-80) : 1.

[0009] Preferably, the epoxy resin is any one of bisphenol A type epoxy resin E51 and bisphenol A type epoxy resin E42.

[0010] Preferably, the curing agent is any one of acid anhydride curing agent, tetrahydrophthalic acid, hydrogenated phthalic acid and maleic anhydride.

[0011] Preferably, the accelerator is 2, 4, 6-tris (dimethylaminomethyl) phenol.

[0012] The application further discloses a preparation method of the epoxy resin modified by in-situ generated Cu2S nanoparticles for high-voltage direct current, and comprises the following steps: dissolving the epoxy resin in a mixed solvent of DMF and NMP, and stirring sufficiently until the epoxy resin is dissolved; adding copper N,N-dibutyl dithiocarbamate, uniformly stirring at a high speed, and performing secondary dispersion through ultrasonic; after temperature rising and reaction, heating and stirring until the solvent is completely volatilized, so that the epoxy resin containing in-situ generated Cu2S nanoparticle reinforced fillers is obtained; adding a curing agent, an accelerator and Al2O3 microparticles, uniformly stirring, placing in a mold, performing vacuum degassing and high-temperature curing, then demolding, and obtaining the epoxy resin modified by in-situ generated Cu2S nanoparticles for high-voltage direct current.

[0013] Preferably, the mass ratio of the epoxy resin, the Al2O3 microparticles, the copper N,N-dibutyl dithiocarbamate, the curing agent and the accelerator is (90-110):(100-200):(3-15): (60-80):1; the volume ratio of the DMF and the NMP is (80-120):(80-120); and the stirring temperature is 70-100 DEG C.

[0014] Preferably, the temperature rising and reaction are performed at a temperature rising rate of 1-2 DEG C / min to 160-200 DEG C, and the temperature is kept for 3-6 h.

[0015] Preferably, the heating and stirring are performed at a temperature of 70-90 DEG C; the vacuum degassing is performed at 100-120 DEG C for 25-45 min; and the high-temperature curing is performed at 110-130 DEG C for 70-110 min, then at 155-175 DEG C for 90-130 min, and finally at 185-205 DEG C for 80-120 min.

[0016] Preferably, 1 mol of the copper N,N-dibutyl dithiocarbamate generates 1 mol of Cu2S nanoparticles.

[0017] Compared with the prior art, the application has the following beneficial effects:

[0018] The application discloses a kind of epoxy resin for high voltage direct current based on in-situ generated Cu2S nanoparticles modification, by in-situ generation of evenly dispersed Cu2S nanoparticles in epoxy resin matrix, and can act as carrier trap, facilitate the pouring of large-scale insulation, to improve the insulation performance of material.Using the technology of in-situ generation of nanoparticles in epoxy resin, the nanoparticles can be uniformly dispersed in the epoxy resin matrix, and the dispersibility is greatly improved compared with direct addition;Cu2S nanoparticles contain the decomposition products of copper N,N-dibutyl dithiocarbamate around it, which can enhance the interface wettability of nanoparticles and epoxy matrix;Using Cu2S nanoparticles as reinforcing filler, on the one hand, carrier traps can be formed at the interface to enhance the direct current resistivity, on the other hand, as a semiconductor, it can disperse the electric field in the epoxy resin, reduce the local electric field intensity, thereby reducing the risk of corona discharge and improving the insulation reliability.

[0019] The application also discloses a preparation method of the above-mentioned epoxy resin for high voltage direct current based on in-situ generated Cu2S nanoparticles modification, by selecting a suitable solvent (a mixed solvent of DMF and NMP) to dissolve the epoxy resin, providing a basis for the subsequent steps. By adding copper N,N-dibutyl dithiocarbamate and under the action of high-speed stirring and ultrasonic dispersion, ensure its uniform distribution in the epoxy resin, provide conditions for the subsequent reaction to generate Cu2S nanoparticles. By heating reaction, N,N-dibutyl dithiocarbamate decomposes and in-situ generates Cu2S nanoparticles. Subsequently, the solvent is completely volatilized by heating and stirring to obtain an epoxy resin containing Cu2S nanoparticles. By adding a curing agent, an accelerator and Al2O3 microparticles, and after uniform stirring, vacuum degassing and high-temperature curing, the desired modified epoxy resin is finally obtained. By in-situ generation technology, the uniform dispersion of Cu2S nanoparticles in the epoxy resin is realized, avoiding the problem of easy agglomeration of nanoparticles in the traditional addition method, thereby improving the insulation performance of the composite material. As carrier traps, Cu2S nanoparticles can effectively enhance the direct current resistivity and improve the insulation performance. At the same time, as a semiconductor material, it can also disperse the electric field in the epoxy resin, reduce the local electric field intensity, thereby reducing the risk of corona discharge. Through the above modification method, the epoxy resin for high voltage direct current based on in-situ generated Cu2S nanoparticles modification has higher insulation performance and reliability, and is suitable for high voltage direct current transmission and other application scenarios that require high insulation performance. DETAILED DESCRIPTION

[0020] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0021] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than those described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to the clearly listed steps or units, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0022] The present application will be further described in detail below in conjunction with the embodiments:

[0023] The present application discloses a kind of Cu2S nanoparticles modified epoxy resin for high voltage direct current based on in-situ generation, comprising: epoxy resin, filler, curing agent and accelerator;Filler includes basic filler and reinforcing filler;Basic filler is Al2O3 microparticle;Reinforcing filler is Cu2S nanoparticles;Cu2S nanoparticles are prepared by in-situ reduction of copper N,N-dibutyl dithiocarbamate in epoxy resin.

[0024] Wherein, epoxy resin (90-110 parts), Al2O3 micron basic filler (100-200 parts), copper N,N-dibutyl dithiocarbamate (3-15 parts), curing agent (60-80 parts), accelerator (1 part).

[0025] Epoxy resin is bisphenol A type epoxy resin, and any one of E51 and E42 is selected.

[0026] Curing agent is any one of acid anhydride curing agent, tetrahydrophthalic acid, hydrogenated phthalic acid and maleic anhydride.

[0027] Accelerator is 2,4,6-tris (dimethylaminomethyl) phenol.

[0028] Wherein, Cu2S nanoparticles reinforcing filler is generated in-situ, including the following steps:

[0029] 1) Dissolve the epoxy resin in a mixed solvent of DMF and NMP, keep the temperature at 70-100℃, and fully stir until the epoxy resin is dissolved in the solution;

[0030] 2) Add copper N,N-dibutyldithiocarbamate to the obtained epoxy resin solution, first disperse uniformly by high-speed stirring machine, and then disperse again by sharp-end ultrasonic instrument;

[0031] 3) Put the obtained mixed solution of epoxy resin and copper N,N-dibutyldithiocarbamate into a reaction kettle, heat to 160-200℃ at a heating rate of 1-2℃ / min, and then keep at 160-200℃ for 3-6h to make the reaction complete;

[0032] 4) After the above reaction is completed, stir the mixed solution at 70-90℃ under a nitrogen atmosphere until the solvent is completely volatilized, to obtain an epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler.

[0033] In step 1), the volume ratio of DMF to NMP is (80-120):(80-120), and the stirring temperature is 70-100℃.

[0034] In step 2), copper N,N-dibutyldithiocarbamate can be completely reacted, and 1 mol of copper N,N-dibutyldithiocarbamate generates 1 mol of Cu2S nanoparticles.

[0035] In step 3), the reaction time is 3-6h, the reaction temperature is 160-200℃, and the heating rate is 1-2℃ / min.

[0036] Then, the epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler, a curing agent and an accelerator are placed in a high-speed stirring machine, Al2O3 microparticle filler is added, and stirring is performed at 70-90℃ until the mixture is uniformly dispersed. Then, the mixture is placed in a mold, degassed at 100-120℃ for 25-45min, vacuum degassed; kept at 110-130℃ for 70-110min, then heated to 155-175℃ for 90-130min, and finally heated to 185-205℃ for 80-120min for high-temperature curing; then demolded to obtain an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, and the resistivity is tested.

[0037] Example 1

[0038] A preparation method of an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, comprising the following steps:

[0039] Firstly, 90 parts of epoxy resin E51, 100 parts of Al2O3 micron base filler, 3 parts of N,N-dibutyl dithiocarbamic acid copper, 60 parts of tetrahydrophthalic acid, 1 part of 2,4,6-tris(dimethylaminomethyl) phenol are prepared.

[0040] The Cu2S nanoparticle enhanced filler generated in situ is prepared by the following steps:

[0041] 1) Dissolve the epoxy resin in a mixed solvent of DMF and NMP (volume ratio 100:100), keep the temperature at 80°C, and fully stir until the epoxy resin is dissolved in the solution;

[0042] 2) Add N,N-dibutyl dithiocarbamic acid copper to the obtained epoxy resin solution, first disperse uniformly by high-speed stirring machine, and then disperse again by sharp-end ultrasonic instrument;

[0043] 3) Put the obtained mixed solution of epoxy resin and N,N-dibutyl dithiocarbamic acid copper into a reaction kettle, heat to 180°C at a heating rate of 1°C / min, and then keep at 180°C for 3h to make the reaction complete;

[0044] 4) After the above reaction is completed, stir the above mixed solution at 80°C under a nitrogen atmosphere until all the solvent is volatilized, and obtain an epoxy resin containing Cu2S nanoparticle enhanced filler generated in situ.

[0045] Then, the epoxy resin containing Cu2S nanoparticle enhanced filler generated in situ, a curing agent and an accelerator are placed in a high-speed stirring machine, Al2O3 micron filler is added, and the mixture is stirred uniformly at 80°C. Then, whether the mixture is uniformly dispersed is observed. Then, the mixture is placed in a mold, degassed at 110°C for 30min, vacuum degassed; kept at 120°C for 90min, then heated to 165°C for 110min, and finally heated to 195°C for 100min for high-temperature curing. Then, the mold is removed to obtain an epoxy resin for high-voltage direct current modified based on Cu2S nanoparticles generated in situ, and the resistivity is tested.

[0046] Example 2

[0047] A preparation method of an epoxy resin for high-voltage direct current modified based on Cu2S nanoparticles generated in situ, comprising the following steps:

[0048] Firstly, 110 parts of epoxy resin E42, 200 parts of Al2O3 micron base filler, 5 parts of N,N-dibutyl dithiocarbamic acid copper, 70 parts of hydrogenated phthalic acid, and 1 part of 2,4,6-tris(dimethylaminomethyl) phenol are prepared.

[0049] The Cu2S nanoparticle enhanced filler generated in situ is prepared by the following steps:

[0050] 1) Dissolve the epoxy resin in a mixed solvent of DMF and NMP (volume ratio 100:100) at a temperature of 80°C, and fully stir until the epoxy resin is dissolved in the solution;

[0051] 2) Add copper N,N-dibutyldithiocarbamate to the obtained epoxy resin solution, first disperse uniformly by high-speed stirring machine, and then disperse again by using a pointed ultrasonic instrument;

[0052] 3) Put the obtained mixed solution of epoxy resin and copper N,N-dibutyldithiocarbamate into a reaction kettle, heat to 180°C at a heating rate of 1.5°C / min, and then keep at 180°C for 6h to make the reaction complete;

[0053] 4) After the above reaction is completed, stir the mixed solution at 80°C under a nitrogen atmosphere until all the solvent is volatilized, to obtain an epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler.

[0054] Subsequently, the epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler, a curing agent, and an accelerator are placed in a high-speed stirring machine, Al2O3 microparticle filler is added, and stirring is performed at 80°C until the mixture is uniformly dispersed. Then, the mixture is placed in a mold, degassed at 110°C for 30min, vacuum degassed; kept at 120°C for 90min, then heated to 165°C for 110min, and finally heated to 195°C for 100min for high-temperature curing, then demolded to obtain an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, and the resistivity is tested.

[0055] Example 3

[0056] A preparation method of an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, comprising the following steps:

[0057] First, prepare 100 parts of epoxy resin E51, 150 parts of Al2O3 microparticle basic filler, 7 parts of copper N,N-dibutyldithiocarbamate, 80 parts of maleic anhydride, and 1 part of 2,4,6-tris(dimethylaminomethyl)phenol.

[0058] An in-situ generated Cu2S nanoparticle reinforced filler, which is prepared by the following steps:

[0059] 1) Dissolve the epoxy resin in a mixed solvent of DMF and NMP (volume ratio 1:1) at a temperature of 80°C, and fully stir until the epoxy resin is dissolved in the solution;

[0060] 2) In the obtained epoxy resin solution, N,N-dibutyl dithiocarbamic acid copper was added, first dispersed uniformly by high-speed mixer, and then dispersed again by a pointed ultrasonic instrument;

[0061] 3) The obtained mixed solution of epoxy resin and N,N-dibutyl dithiocarbamic acid copper was placed in a reaction kettle, heated to 180°C at a heating rate of 2°C / min, and then kept at 180°C for 5h to make the reaction complete;

[0062] 4) After the above reaction was completed, the mixed solution was stirred at 80°C under a nitrogen atmosphere until all the solvent was volatilized, to obtain an epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler.

[0063] Then the epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler, a curing agent and an accelerator were placed in a high-speed mixer, Al2O3 microparticle filler was added, and stirring was performed at 80°C until the mixture was uniformly dispersed. Then the mixture was placed in a mold, degassed at 110°C for 30min, vacuum degassed; kept at 120°C for 90min, then heated to 165°C for 110min, and finally heated to 195°C for 100min for high-temperature curing, then demolded to obtain an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, and resistivity testing was performed.

[0064] Example 4

[0065] A preparation method of an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, comprising the following steps:

[0066] First, 100 parts of epoxy resin E51, 150 parts of Al2O3 microparticle basic filler, 15 parts of N,N-dibutyl dithiocarbamic acid copper, 80 parts of maleic anhydride, and 1 part of 2,4,6-tris(dimethylaminomethyl) phenol were prepared.

[0067] The in-situ generated Cu2S nanoparticle reinforced filler was prepared by the following steps:

[0068] 1) The epoxy resin was dissolved in a mixed solvent of DMF and NMP (volume ratio 1:1), the temperature was kept at 80°C, and stirring was performed until the epoxy resin was dissolved in the solution;

[0069] 2) In the obtained epoxy resin solution, N,N-dibutyl dithiocarbamic acid copper was added, first dispersed uniformly by high-speed mixer, and then dispersed again by a pointed ultrasonic instrument;

[0070] 3) The obtained mixture solution of epoxy resin and copper N,N-dibutyl dithiocarbamate is placed in a reaction kettle, heated to 180°C at a heating rate of 2°C / min, and then kept at 180°C for 5h to complete the reaction;

[0071] 4) After the above reaction is completed, the above mixture solution is stirred at 80°C under a nitrogen atmosphere until all the solvent is completely volatilized, to obtain an epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler.

[0072] Then the epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler and the curing agent and accelerator are placed in a high-speed stirrer, Al2O3 microparticle filler is added, and stirred uniformly at 80°C, and then the mixture is observed for uniform dispersion. Then the mixture is placed in a mold, degassed at 110°C for 30min, vacuum degassed; kept at 120°C for 90min, then heated to 165°C for 110min, and finally heated to 195°C for 100min for high-temperature curing, then demolded to obtain an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, and the resistivity is tested.

[0073] Example 5

[0074] A preparation method of an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, comprising the following steps:

[0075] First, 110 parts of epoxy resin E42, 200 parts of Al2O3 microparticle basic filler, 5 parts of copper N,N-dibutyl dithiocarbamate, 70 parts of hydrogenated phthalic acid, and 1 part of 2,4,6-tris(dimethylaminomethyl) phenol are prepared.

[0076] The in-situ generated Cu2S nanoparticle reinforced filler is prepared by the following steps:

[0077] 1) The epoxy resin is dissolved in a mixed solvent of DMF and NMP (volume ratio 80:90) with the temperature kept at 70°C, and stirred thoroughly until the epoxy resin is dissolved in the solution;

[0078] 2) Copper N,N-dibutyl dithiocarbamate is added to the obtained epoxy resin solution, first dispersed uniformly in a high-speed stirrer, and then secondarily dispersed by a pointed ultrasonic instrument;

[0079] 3) The obtained mixture solution of epoxy resin and copper N,N-dibutyl dithiocarbamate is placed in a reaction kettle, heated to 160°C at a heating rate of 1.5°C / min, and then kept at 160°C for 6h to complete the reaction;

[0080] 4) After the reaction, the mixture is stirred at 70°C under nitrogen atmosphere until the solvent is completely evaporated, obtaining an epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler.

[0081] Subsequently, the epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler and the curing agent and accelerator are placed in a high-speed blender, Al2O3 microparticle filler is added, and stirring is performed at 70°C until the mixture is uniformly dispersed. Then, the mixture is placed in a mold, degassed at 100°C for 45 min, vacuum degassed; 110°C for 110 min, then heated to 155°C for 130 min, and finally heated to 185°C for 120 min for high-temperature curing, then demolded, obtaining an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, and the resistivity is tested.

[0082] Example 6

[0083] A method for preparing an in-situ generated Cu2S nanoparticle modified epoxy resin for high-voltage direct current, comprising the following steps:

[0084] First, 110 parts of epoxy resin E42, 200 parts of Al2O3 microparticle basic filler, 5 parts of copper N,N-dibutyl dithiocarbamate, 70 parts of hydrogenated phthalic acid, and 1 part of 2,4,6-tris(dimethylaminomethyl) phenol are prepared.

[0085] The in-situ generated Cu2S nanoparticle reinforced filler is prepared by the following steps:

[0086] 1) Dissolve the epoxy resin in a mixed solvent of DMF and NMP (volume ratio 110:120), keep the temperature at 90°C, and fully stir until the epoxy resin is dissolved in the solution;

[0087] 2) Add copper N,N-dibutyl dithiocarbamate to the obtained epoxy resin solution, first disperse uniformly in a high-speed blender, and then disperse again with a sharp ultrasonic instrument;

[0088] 3) Put the obtained mixed solution of epoxy resin and copper N,N-dibutyl dithiocarbamate into a reaction kettle, heat to 200°C at a heating rate of 1.5°C / min, then keep at 200°C for 6h to make the reaction complete;

[0089] 4) After the reaction, the mixture is stirred at 90°C under nitrogen atmosphere until the solvent is completely evaporated, obtaining an epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler.

[0090] Subsequently, the epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler and the curing agent and accelerator are placed in a high-speed blender, the Al2O3 micron filler is added, and the mixture is stirred uniformly at 90°C. Then, whether the mixture is uniformly dispersed is observed. Then, the mixture is placed in a mold, degassed at 120°C for 25 min, vacuum degassed; 130°C for 70 min, then heated to 175°C for 90 min, and finally heated to 205°C for 80 min for high-temperature curing, then demolded to obtain an epoxy resin for high-voltage direct current modified based on in-situ generated Cu2S nanoparticles, and the resistivity is tested.

[0091] Example 7

[0092] A preparation method of an epoxy resin for high-voltage direct current modified based on in-situ generated Cu2S nanoparticles, comprising the following steps:

[0093] First, 110 parts of epoxy resin E42, 200 parts of Al2O3 micron base filler, 5 parts of copper N,N-dibutyl dithiocarbamate, 70 parts of hydrogenated phthalic acid, and 1 part of 2,4,6-tris(dimethylaminomethyl) phenol are prepared.

[0094] The in-situ generated Cu2S nanoparticle reinforced filler is prepared by the following steps:

[0095] 1) Dissolve the epoxy resin in a mixed solvent of DMF and NMP (volume ratio 120:110) with the temperature maintained at 100°C, and fully stir until the epoxy resin is dissolved in the solution;

[0096] 2) In the obtained epoxy resin solution, copper N,N-dibutyl dithiocarbamate is added, first dispersed uniformly in a high-speed blender, and then dispersed again with a sharp ultrasonic instrument;

[0097] 3) The mixed solution of the obtained epoxy resin and copper N,N-dibutyl dithiocarbamate is placed in a reaction kettle, heated to 190°C at a heating rate of 1.5°C / min, and then kept at 190°C for 5 h to make the reaction complete;

[0098] 4) After the above reaction is completed, the mixed solution is stirred at 85°C under a nitrogen atmosphere until all the solvent is volatilized, and an epoxy resin containing in-situ generated Cu2S nanoparticle reinforced filler is obtained.

[0099] Then the epoxy resin containing in-situ generated Cu2S nanoparticles reinforced filler and curing agent and accelerator were placed in a high-speed blender, Al2O3 micron filler was added, and the mixture was stirred evenly at 85°C. Then the mixture was placed in a mold, degassed at 105°C for 35 min, vacuum degassed, cured at 115°C for 100 min, then heated to 160°C for 120 min, and finally heated to 200°C for 110 min for high-temperature curing, then demolded to obtain an epoxy resin for high-voltage direct current based on in-situ generated Cu2S nanoparticles modified, and the resistivity was tested.

[0100] Comparative Example 1

[0101] 100 parts of epoxy resin E51, 150 parts of Al2O3 micron basic filler, 80 parts of maleic anhydride, and 1 part of 2,4,6-tris(dimethylaminomethyl) phenol.

[0102] A measured amount of epoxy resin E51 and curing agent and accelerator were placed in a high-speed blender, Al2O3 micron basic filler was added, and the mixture was stirred evenly, then the mixture was placed in a mold, vacuum degassed and high-temperature cured, then demolded to obtain an epoxy resin containing only Al2O3 micron basic filler without in-situ generated Cu2S nanoparticles reinforced filler, and the resistivity was tested.

[0103] Table 1 Performance comparison of products prepared in Examples 1-4 and Comparative Example 1

[0104]

[0105] Table 1 is a performance comparison of products prepared in Examples 1-4 and Comparative Example 1. As can be seen from Table 1, in-situ generated Cu2S nanoparticles reinforced filler in the epoxy resin can enhance the electrical and mechanical properties of the epoxy resin, and the comprehensive performance is good, which is suitable for high-voltage direct current applications.

[0106] The above content only illustrates the technical idea of the present application and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical solution falls within the protection scope of the claims of the present application.

Claims

1. An epoxy resin mixture for high voltage direct current based on in situ generated Cu2S nanoparticle modification, characterized by, The epoxy resin, Al2O3 microparticles, copper N,N-dibutyl dithiocarbamate, curing agent and accelerator are in a mass ratio of (90-110):(100-200):(3-7):(60-80):

1. The curing agent is any one of an acid anhydride curing agent, tetrahydrophthalic acid and hydrogenated phthalic acid. The epoxy resin is any one of bisphenol A type epoxy resin E51 and bisphenol A type epoxy resin E42.

2. The epoxy resin mixture for high voltage direct current based on in-situ generated Cu2S nanoparticle modification according to claim 1, characterized in that, The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

3. The epoxy resin mixture for high voltage DC based on in-situ generated Cu2S nanoparticle modification according to claim 1, characterized in that, The method comprises the following steps:

4. The method for preparing the epoxy resin mixture for high voltage direct current based on in-situ generated Cu2S nanoparticles modification according to any one of claims 1-3, characterized in that, The epoxy resin is dissolved in a mixed solvent of DMF and NMP, and stirred sufficiently until dissolved; copper N,N-dibutyl dithiocarbamate is added, and stirred at high speed until uniform, and then subjected to secondary dispersion by ultrasonic; after warming and reaction, heating and stirring are performed until the solvent is completely volatilized, to obtain an epoxy resin containing in-situ generated Cu2S nanoparticle reinforcing filler; then, a curing agent, an accelerator and Al2O3 microparticles are added, and stirred until uniform, and then placed in a mold, to perform vacuum degassing and high-temperature curing, and then demolded, to obtain an epoxy resin mixture for high-voltage direct current, which is modified based on in-situ generated Cu2S nanoparticles. The epoxy resin, Al2O3 microparticles, copper N,N-dibutyl dithiocarbamate, curing agent and accelerator are in a mass ratio of (90-110):(100-200):(3-7):(60-80):1; the volume ratio of the DMF and NMP is (80-120):(80-120); and the stirring temperature is 70-100℃.

5. The method of claim 4, wherein the method is characterized by, The warming and reaction are performed at a warming rate of 1-2℃ / min to 160-200℃, and the temperature is maintained for 3-6h.

6. The method of claim 4, wherein the method is characterized by, The heating and stirring are performed at a temperature of 70-90℃; the vacuum degassing is performed at 100-120℃ for 25-45min; and the high-temperature curing is performed at 110-130℃ for 70-110min, then at 155-175℃ for 90-130min, and finally at 185-205℃ for 80-120min.

7. The method of claim 4, wherein the method is characterized by, ​

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