Preparation method of insulating modified epoxy paint

Abstract

The invention belongs to the technical field of epoxy paint, and mainly relates to a preparation method of insulating modified epoxy paint, which comprises the following steps: adding 230-260 parts by weight of basic resin material into a first solvent, and mixing to prepare an epoxy resin material; processing the surface of the modified nano filling material by adding a second solvent into the modified nano filling material; pouring the modified nano filler into an epoxy resin material to form a solution, and further preparing an insulating modified epoxy paint material; by means of the preparation method, the insulativity and stability of the epoxy paint material are improved, and the technical defect that the insulativity of the epoxy paint material cannot be effectively improved through an existing preparation process is overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy paint, and in particular relates to a preparation method of insulating modified epoxy paint. Background Art

[0002] Epoxy resin is widely used as an insulation material for electrical equipment due to its excellent mechanical properties, electrical insulation properties and chemical stability. However, with the trend of high voltage and high temperature of electrical equipment, the insulation performance of traditional epoxy resin has gradually exposed its shortcomings. Commonly used fillers such as silica powder and alumina contribute greatly to increasing the mechanical strength of the material, but due to their poor dispersibility in the resin, they often lead to unstable insulation performance.

[0003] In the prior art, although there are many modification methods, such as adding different types of fillers and using different solvents, problems such as weak interfacial bonding of fillers and easy generation of bubbles are usually encountered, which affect the electrical and mechanical properties of the final product.

[0004] Based on this, there is an urgent need for a preparation method of an insulating modified epoxy paint to improve the insulation and stability of the epoxy paint and solve the above-mentioned technical defects. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing an insulating modified epoxy paint which can improve the insulation and stability of the epoxy paint in view of the shortcomings of the prior art.

[0006] In order to achieve the above technical objectives, this application implements the following technical solutions:

[0007] A method for preparing an insulating modified epoxy paint, the preparation method comprising the following steps:

[0008] S101, weighing 230-260 parts by weight of a basic resin material, transferring the basic resin material to a four-necked flask, and adding a first solvent to the four-necked flask;

[0009] The four-necked flask was placed in a water bath at 40° C., and the solution in the four-necked flask was stirred at a speed of 300 rpm for 30 minutes using a mechanical stirrer to prepare an epoxy resin material;

[0010] S201, adding 25-55 parts by weight of a modified nanofiller material and a second solvent to a beaker in sequence, and treating the material with an ultrasonic processor for 30 minutes while adding the material, thereby treating the surface of the modified nanofiller;

[0011] S301, pouring the modified nano filler prepared in step S201 into the epoxy resin material prepared in step S101 to form a solution, and using a high-speed shear disperser to continuously stir the solution at a speed of 3000 rpm for 15 to 20 minutes;

[0012] S401, during the stirring process of the solution in step S301, adding a second solvent, and after the stirring is completed, allowing the prepared solution to stand;

[0013] After standing, transfer the solution to a vacuum degasser, set the vacuum to -0.08 MPa, and maintain for 15 to 20 minutes;

[0014] S501, adding 25-40 parts by weight of a curing agent to the de-vacuumed solution, stirring the solution at 150 rpm for 20 minutes, and then pouring and curing the solution;

[0015] The first solvent is used for dissolving the resin and dispersing the solute; the second solvent is used for surface treatment of the filler and enhancing the interface bonding force.

[0016] The above technical solution produces the following technical effects:

[0017] The modified epoxy paint prepared by the present invention not only has excellent performance in dielectric strength and heat resistance, but also has significant improvements in mechanical properties and process operability through rationally designed nanofiller surface modification and optimized solvent system. The nanofiller in the modified system has enhanced the bonding force with the substrate through surface modification, reduced interface defects, and provided excellent insulation performance.

[0018] As a further improvement to the method for preparing an insulating modified epoxy paint of the present invention, the basic resin material in step S101 is prepared from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, and epoxy phenolic amine.

[0019] As a further improvement to the preparation method of the insulating modified epoxy paint of the present invention, the basic resin material is modified by reacting with 5%-10%wt of terminal carboxyl polybutadiene acrylonitrile liquid rubber or the basic resin material is modified by reacting with 0.5%-2%wt of trimethylolethane triacrylate material.

[0020] As a further improvement to the preparation method of an insulating modified epoxy paint of the present invention, the first solvent includes one or more of ethyl acetate, acetone, and toluene; the second solvent includes one or more of γ-aminopropyltriethoxysilane and isopropanol.

[0021] As a further improvement to the method for preparing an insulating modified epoxy paint of the present invention, the first solvent in step S101 includes: 80-120 parts by weight of ethyl acetate, 20-45 parts by weight of acetone and 15-35 parts by weight of toluene.

[0022] As a further improvement to the method for preparing an insulating modified epoxy paint of the present invention, the second solvent in step S201 includes: 2-10 parts by weight of γ-aminopropyltriethoxysilane and 20-50 parts by weight of isopropanol.

[0023] As a further improvement to the method for preparing an insulating modified epoxy paint of the present invention, the second solvent in step S401 includes: 5-10 parts by weight of γ-aminopropyltriethoxysilane and 20-30 parts by weight of isopropanol.

[0024] As a further improvement to the method for preparing an insulating modified epoxy paint of the present invention, the modified nano-filling material in step S201 is modified nano-aluminum oxide and / or modified boron nitride.

[0025] As a further improvement to the preparation method of the insulating modified epoxy paint of the present invention, the modified nano-alumina is modified by surface silanization reaction of the alumina material and γ-aminopropyltriethoxysilane;

[0026] Among them, γ-aminopropyltriethoxysilane undergoes hydrolysis and condensation reaction with the hydroxyl groups on the surface of nano-alumina through its ethoxy groups to form a stable Si-O-Al bond, and the reaction equation is as follows:

[0027] Al-OH+(EtO)3Si(CH2)3NH2→Al-O-Si(CH2)3NH2+3EtOH

[0028] Et represents an ethoxy group, and NH2 represents an amino group.

[0029] As a further improvement to the preparation method of the insulating modified epoxy paint of the present invention, the modified boron nitride is modified by surface silanization reaction of hydroxylated boron nitride and γ-aminopropyltriethoxysilane;

[0030] Among them, γ-aminopropyltriethoxysilane undergoes a condensation reaction with the hydroxyl groups on the surface of hydroxylated boron nitride through its ethoxy groups, and combines with the active sites on the surface of boron nitride. The reaction equation is as follows:

[0031] BN-OH+(EtO)3Si(CH2)3NH2→BN-O-Si(CH2)3NH2+3EtOH

[0032] Et represents an ethoxy group, and NH2 represents an amino group. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. 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 ordinary technicians in the field without making creative work are within the scope of protection of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0034] Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the claims. Any technical personnel in this field may make several possible changes and modifications without departing from the concept of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

[0035] The present invention is further described in detail below in conjunction with specific implementation methods, but the embodiments of the present invention are not limited thereto.

[0036] The preparation method of the insulating modified epoxy paint of the present application comprises the following steps:

[0037] S101, weighing 230-260 parts by weight of a basic resin material, transferring the basic resin material to a four-necked flask, and adding a first solvent to the four-necked flask; (the mass fraction in this application is uniformly 1 g as 1 mass fraction, and the following content of this article will be directly explained in terms of mass fractions, and there is no insufficient disclosure)

[0038] The four-necked flask was placed in a water bath at 40° C., and the solution in the four-necked flask was stirred at a speed of 300 rpm for 30 minutes using a mechanical stirrer to prepare an epoxy resin material;

[0039] Wherein, the epoxy resin material is prepared, wherein the equipment is a four-necked flask, a water bath pot, and a mechanical stirrer, and the preparation conditions are: the temperature is controlled at 20-25°C, and the relative humidity is controlled at ≤60%. Further, after the preparation environment is prepared, 230-260 parts by weight of the basic resin material are weighed. In the specific implementation process, the mass fractions of the basic resin material weighed at 230-260 parts by weight are any value among 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 348, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, and 260. Specifically, the basic resin material can be prepared from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, and epoxy phenolic amine. Among them, the epoxy phenolic amine can be specifically prepared from the epoxy resin phenolic amine curing agent of Zhangjiagang Yarui Chemical Co., Ltd.

[0040] Among them, bisphenol A epoxy resin (such as E-51): commonly used in situations where high strength and high heat resistance are required. Bisphenol F epoxy resin: has lower viscosity and good chemical resistance than bisphenol A. Phenolic epoxy resin: provides excellent heat resistance and mechanical properties, suitable for high temperature applications. Epoxy phenolic amine: by adding amine compounds, the epoxy system is given better flexibility and impact strength. Because the epoxy resin itself has good dielectric properties. As a matrix material, it provides good electrical insulation, which is the basis of the insulation system. In addition, its highly cross-linked network structure will further enhance the electrical insulation capacity of the material after curing. Therefore, in this application, epoxy paint is prepared based on bisphenol A epoxy resin (E-51), the optimal choice, but the scope of protection of this application is not limited to bisphenol A epoxy resin (E-51).

[0041] Further, the basic resin material is modified by reacting with 5%-10%wt of carboxyl-terminated polybutadiene acrylonitrile liquid rubber or the basic resin material is modified by reacting with 0.5%-2%wt of trimethylolethane triacrylate material. The specific reason is that the modification of the base resin is usually achieved by chemical reaction and physical doping to improve its performance adaptability.

[0042] The preferred method for modifying the basic resin material is to modify it with a toughening agent. Taking bisphenol A epoxy resin as the basic resin material as an example, its toughening agent is liquid rubber-terminated carboxyl polybutadiene acrylonitrile liquid rubber (CTBN). The specific toughening agent modification is: dissolve an appropriate amount of epoxy resin in a water bath at 60°C. Add 5%-10%wt liquid rubber-terminated carboxyl polybutadiene acrylonitrile liquid rubber (CTBN) and stir with a high-speed stirrer for at least 1 hour to ensure uniform dispersion. Finally, the mixture is vacuum degassed to remove dissolved air, and the treated resin is cooled to room temperature to obtain a basic resin material (bisphenol A epoxy resin) modified with a toughening agent.

[0043] In addition, the basic resin material modification method can also be modified with a crosslinking agent, taking bisphenol F type epoxy resin as the basic resin material as an example. The crosslinking agent is trimethylolethane triacrylate (TMPTA). The specific implementation process of the modification method is: at room temperature, add 0.5%-2%wt. of TMPTA to the epoxy resin, and use a mechanical stirrer to stir at a medium speed for 30 minutes to ensure that the crosslinking agent is evenly mixed. Then heat the solution to 50°C for slow curing, and maintain this temperature until the viscosity increases. Then put the mixture into a mold and completely cure it at 80°C to form a modified basic resin material (bisphenol F type epoxy resin) with a network structure.

[0044] Furthermore, the matrix resin can be modified by using nano materials for reinforcement, wherein the matrix resin material is phenolic epoxy resin as an example, and the nano filler is nano silicon dioxide or nano clay. The modification method is as follows: the phenolic epoxy resin is heated to 60°C to reduce the viscosity, and then nano silicon dioxide or clay is added at a ratio of 0.5%-3% wt., and ultrasonic stirring is performed to ensure the dispersibility. The mixed system is degassed to reduce the agglomeration of fillers, and a coating is formed on the substrate by spin coating or extrusion, and cured under specified conditions to complete the reinforcement.

[0045] Furthermore, the matrix resin can also be modified by a multifunctional modification method, wherein the matrix resin material is epoxy phenolic amine as an example, and the modifier is a multifunctional epoxy compound (such as a diepoxy compound). Specifically, the multifunctional epoxy compound is added to the epoxy resin at 2%-5% wt. at room temperature. Use low-speed stirring to maintain uniform dispersion, and degassing treatment under high vacuum conditions to improve purity. Finally, the system is further heat-treated in an environment of 150°C to achieve customized physical properties.

[0046] Further, in the specific implementation process, 240-255 grams of E-51 epoxy resin is selected and added, transferred to a four-necked flask, and the outside of the flask is kept clean to prevent contamination. At this time, the first solvent has been added to the flask in advance, and its amount is adjusted according to the type of basic resin material and the expected product characteristics to ensure that the two can be fully mixed and dissolved.

[0047] The first solvent includes one or more of ethyl acetate, acetone, and toluene; the weight percentage of ethyl acetate is 80-120 parts; the weight percentage of acetone is 20-45 parts; and the weight percentage of toluene is 15-35 parts. In the specific implementation process, in order to further improve the mixing degree of the first solvent and the matrix resin material, and thus improve the chemical stability of the epoxy paint of the present application, the weight percentage of ethyl acetate in the first solvent is 90-110 parts; the weight percentage of acetone is 30-40 parts; and the weight percentage of toluene is 20-30 parts.

[0048] S201, add 25-55 parts by weight of modified nano filler material and second solvent to a beaker in turn, and use an ultrasonic processor to treat for 30 minutes when adding the material, thereby treating the surface of the modified nano filler; wherein, the modified nano filler material is modified nano alumina and / or modified boron nitride. The modified nano alumina is selected considering that the modified substrate nano alumina is a high dielectric strength material, and as a nano filler, it can greatly improve the overall dielectric constant of the composite material. At the same time, due to its particle size at the nanometer level, the alumina after silanization treatment on the surface can be well combined with the epoxy resin to form a uniform interface, thereby improving the insulation uniformity of the material and reducing the possibility of breakdown. Similarly, nano boron nitride has high thermal conductivity and excellent electrical insulation. Its introduction improves the thermal management ability of the material and reduces the resistance change caused by the temperature increase. In addition, the lamellar structure of boron nitride can prevent the formation of conductive channels, thereby improving the insulation performance.

[0049] Furthermore, nano-alumina particles are usually difficult to disperse in organic solvents and polymer matrices due to their high surface energy and polar hydroxyl surface. In order to solve this problem, we use silane coupling agents for surface modification to improve the insulation and other properties of nano-alumina particles. Among them, the modified nano-alumina is modified by surface silanization reaction of alumina material and γ-aminopropyltriethoxysilane; wherein γ-aminopropyltriethoxysilane hydrolyzes and condenses with the hydroxyl group on the surface of nano-alumina through its ethoxy group to form a stable Si-O-Al bond, and the reaction equation is as follows:

[0050] Al-OH+(EtO)3Si(CH2)3NH2→Al-O-Si(CH2)3NH2+3EtOH

[0051] Et represents an ethoxy group, and NH2 represents an amino group.

[0052] Specifically, the modified nano-alumina process is:

[0053] First, weigh a certain amount of nano-alumina particles (such as 20 grams), put them into a 500ml beaker, add an appropriate amount of anhydrous ethanol, and clean them with ultrasonic oscillation for 10 minutes to remove impurities adsorbed on the surface. Sadly, use γ-aminopropyltriethoxysilane (APTES) as a coupling agent, dissolve 2 parts by weight of APTES in 50 parts by weight of isopropanol to prepare a silanization solution. The silanization solution is added to the nano-alumina suspension, and the temperature is maintained at 70°C, and ultrasonic treatment is performed for 30 minutes to ensure that the coupling agent is evenly coated on the surface of the nano-alumina to achieve a surface silanization reaction. After the reaction is completed, the modified alumina is collected by centrifugation or filtration, and is washed with isopropanol several times to remove the unreacted coupling agent. The modified particles are dried in a vacuum oven at 50°C to constant weight to obtain the final modified nano-alumina.

[0054] Furthermore, due to its inert chemical properties, boron nitride usually has little surface reactivity. However, through special functionalization treatment, functional groups can be introduced on the surface to enhance compatibility with the resin matrix and improve the performance of boron nitride (mainly reflected in its inert chemical properties). Specifically, the modified boron nitride is modified by surface silanization reaction of hydroxylated boron nitride and γ-aminopropyltriethoxysilane; wherein γ-aminopropyltriethoxysilane condenses with the hydroxyl groups on the surface of hydroxylated boron nitride through its ethoxy group, and combines with the active sites on the surface of boron nitride, and the reaction equation is as follows:

[0055] BN-OH+(EtO)3Si(CH2)3NH2→BN-O-Si(CH2)3NH2+3EtOH

[0056] Et represents an ethoxy group, and NH2 represents an amino group.

[0057] Specifically, the modified boron nitride process is:

[0058] First, 15 grams of boron nitride nanoparticles were added to a beaker and preliminarily treated (oxidized) with a mixed solution of concentrated sulfuric acid and concentrated nitric acid to introduce hydroxyl and carboxyl groups on the surface of boron nitride to increase its surface activity. Secondly, the same APTES solution as alumina was used for further treatment, and 2 grams of γ-aminopropyltriethoxysilane (APTES) was added to the mixed solution. The solvent system (isopropanol) was adjusted to make the silane evenly dispersed. In the reactor, the temperature was adjusted to 80°C, and continuous stirring and ultrasonic oscillation were performed for 1 hour to ensure that the silanization reaction was fully carried out. Surface silanization. Finally, the impurities were removed by filtration and drying methods as with alumina to obtain the modified product.

[0059] These modification steps enhance the compatibility of filler particles with the polymer matrix, significantly improving the dispersion, electrical insulation and mechanical stability of the material. In addition, the dispersion and stability of the material in the matrix are enhanced, and the insulation and thermal stability are also improved.

[0060] Furthermore, the second solvent includes one or more of γ-aminopropyltriethoxysilane and isopropanol. Among them, γ-aminopropyltriethoxysilane can not only be used as a coupling agent to achieve modification of the above-mentioned nanofiller material, but also further optimize the dispersibility and interface characteristics of the filler by further mixing with the modified nanofiller material, reduce the weak points of electrical performance, and enhance the electric field uniformity and insulation tolerance of the material. The low viscosity and good volatility of isopropanol make it exhibit excellent performance when used as a medium to disperse nanofillers such as nanoalumina and boron nitride. Through mechanical stirring and ultrasonic oscillation, it is ensured that the nanoparticles can be effectively dispersed in the solution.

[0061] Furthermore, in step S202, the amount of the second solvent added is: 2-10 parts by weight of γ-aminopropyltriethoxysilane and 30-50 parts by weight of isopropanol. Among them, 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol are the best choices for adding the second solvent in step S201.

[0062] S301, pouring the modified nano filler prepared in step S201 into the epoxy resin material prepared in step S101 to form a solution, and using a high-speed shear disperser to continuously stir the solution at a speed of 3000 rpm for 15 to 20 minutes;

[0063] S401. During the stirring process of the solution in step S301, a second solvent is added, wherein the amount of the second solvent added is: 5-10 parts by weight of γ-aminopropyltriethoxysilane and 20-30 parts by weight of isopropanol; after the stirring is completed, the prepared solution is allowed to stand; wherein, in step S401, the optimal solution for the second solvent is: 7 parts by weight of γ-aminopropyltriethoxysilane and 20 parts by weight of isopropanol.

[0064] After standing, transfer the solution to a vacuum degasser, set the vacuum to -0.08 MPa, and maintain for 15 to 20 minutes;

[0065] S501, adding 25-40 parts by weight of a curing agent to the de-vacuumed solution, stirring the solution at 150 rpm for 20 minutes, and then pouring and curing the solution.

[0066] Furthermore, in the preparation process of S501, the curing agent is 28-35 grams of modified phenolic amine material; stir at 150rpm for 20 minutes to ensure that the curing agent and the mixture are completely and evenly blended, and confirm that the color is uniform and there is no stratification. (Be careful to avoid adding all at once to cause local overheating.)

[0067] Among them, the pouring and curing process uses molds and ovens; the environmental conditions are clean and dust-free environment, avoiding direct sunlight; the steps of pouring and curing are: pour the prepared solution (mixture) into the pre-treated mold to ensure that the liquid surface is smooth. Let it stand at room temperature for 1 hour for preliminary curing to reduce the generation of bubbles. Then transfer it to the oven and increase the temperature through the program, first to 85°C for 2 hours, then to 120°C for 3 hours, and finally cool it naturally to complete the curing process.

[0068] Furthermore, after all the processes of online steps S101-501, the cured sample is taken out and processed to a standard test size using a cutting machine to minimize cutting marks. The cutting device is a cutting machine; at the same time, a polishing machine is used to perform surface treatment on the sample to ensure the certainty of the test.

[0069] In order to further reflect the insulating performance of the epoxy paint prepared in the present application, the present application uses an electrical strength tester to measure the insulating strength of the epoxy paint prepared by Examples 1-5 according to the preparation process of the present application and the epoxy paint prepared by Comparative Examples 1-3 not manufactured according to the preparation process of the present application in accordance with the IEC 60243-1 standard, and analyzes and records the experimental data.

[0070] Example 1

[0071] In this embodiment, the basic resin material added in step S101 is 250 parts by mass of E-51 epoxy resin, and the first solvent includes: 100 parts by mass of ethyl acetate, 35 parts by mass of acetone, and 25 parts by mass of toluene;

[0072] The modified nano-filling material added in step S201 is: 23 parts by weight of modified nano-alumina and 16 parts by weight of modified nano-boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0073] In step S401, the amount of the second solvent added is: 7 parts by weight of γ-aminopropyltriethoxysilane and 20 parts by weight of isopropanol;

[0074] In step S501, the amount of curing agent added is 30 parts by weight.

[0075] Example 2

[0076] In this embodiment, the basic resin material added in step S101 is 245 parts by mass of E-51 epoxy resin, and the first solvent includes: 95 parts by mass of ethyl acetate, 30 parts by mass of acetone, and 20 parts by mass of toluene;

[0077] The modified nano-filling material added in step S201 is: 22 parts by weight of modified nano-alumina and 18 parts by weight of modified nano-boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0078] In step S401, the amount of the second solvent added is: 7 parts by weight of γ-aminopropyltriethoxysilane and 20 parts by weight of isopropanol;

[0079] In step S501, the amount of curing agent added is: 28 parts by weight.

[0080] Example 3

[0081] In this embodiment, the basic resin material added in step S101 is 255 parts by mass of E-51 epoxy resin, and the first solvent includes: 110 parts by mass of ethyl acetate, 35 parts by mass of acetone, and 30 parts by mass of toluene;

[0082] The modified nano-filling material added in step S201 is: 21 parts by weight of modified nano-alumina and 14 parts by weight of modified nano-boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0083] In step S401, the amount of the second solvent added is: 7 parts by weight of γ-aminopropyltriethoxysilane and 20 parts by weight of isopropanol;

[0084] In step S501, the amount of curing agent added is 35 parts by weight.

[0085] Example 4

[0086] In this embodiment, the basic resin material added in step S101 is 248 parts by mass of E-51 epoxy resin, and the first solvent includes: 100 parts by mass of ethyl acetate, 40 parts by mass of acetone, and 20 parts by mass of toluene;

[0087] The modified nano-filling material added in step S201 is: 20 parts by weight of modified nano-alumina and 14 parts by weight of modified nano-boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0088] In step S401, the amount of the second solvent added is: 7 parts by weight of γ-aminopropyltriethoxysilane and 20 parts by weight of isopropanol;

[0089] In step S501, the amount of curing agent added is 32 parts by weight.

[0090] Example 5

[0091] In this embodiment, the basic resin material added in step S101 is 250 parts by mass of E-51 epoxy resin, and the first solvent includes: 85 parts by mass of ethyl acetate, 45 parts by mass of acetone, and 15 parts by mass of toluene;

[0092] The modified nano-filling material added in step S201 is: 25 parts by weight of modified nano-alumina and 10 parts by weight of modified nano-boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0093] In step S401, the amount of the second solvent added is: 7 parts by weight of γ-aminopropyltriethoxysilane and 20 parts by weight of isopropanol;

[0094] In step S501, the amount of curing agent added is 33 parts by weight.

[0095] Comparative Example 1

[0096] In this embodiment, the basic resin material added in step S101 is 220 parts by mass of E-51 epoxy resin, and the first solvent includes: 80 parts by mass of ethyl acetate, 40 parts by mass of acetone, and 14 parts by mass of toluene;

[0097] The modified nano-filler material added in step S201 is: 23 parts by weight of aluminum oxide and 16 parts by weight of boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0098] In step S501, the amount of curing agent added is 30 parts by weight.

[0099] Comparative Example 2

[0100] In this embodiment, the basic resin material added in step S101 is 360 parts by mass of E-51 epoxy resin, and the first solvent includes: 80 parts by mass of ethyl acetate, 40 parts by mass of acetone, and 14 parts by mass of toluene;

[0101] The modified nano-filler material added in step S201 is: 23 parts by weight of aluminum oxide and 16 parts by weight of boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0102] In step S501, the amount of curing agent added is 30 parts by weight.

[0103] Comparative Example 3

[0104] In this embodiment, the basic resin material added in step S101 is 220 parts by mass of E-51 epoxy resin, and the first solvent includes: 40 parts by mass of ethyl acetate, 20 parts by mass of acetone, and 4 parts by mass of toluene;

[0105] The modified nano-filler material added in step S201 is: 23 parts by weight of aluminum oxide and 16 parts by weight of boron nitride; the amount of the second solvent added is: 2 parts by weight of γ-aminopropyltriethoxysilane and 50 parts by weight of isopropanol;

[0106] In step S501, the amount of curing agent added is 30 parts by weight.

[0107] Among them, in order to further reflect the technical effect of the present application, the present application determines the insulation strength of the epoxy paint of Examples 1-5 and Comparative Examples 1-3 according to the IEC 60243-1 standard, analyzes and records the experimental data;

[0108] At the same time, the present application also tests the wear resistance of epoxy paints in Examples 1-5 and Comparative Examples 1-3. The test standards for building materials and coatings are used as the benchmark, and the standard is "Technical Specifications for Building Coatings" (GB / T18451).

[0109] The degree of cracks that can be detected in epoxy paint can be divided into the following categories, and each type is defined as follows:

[0110] No cracks: The surface is smooth with no visible cracks or defects. The coating is even and maintains a good appearance.

[0111] Minor Cracks: Tiny cracks on the surface that are usually not noticeable. These cracks do not affect the protective properties or appearance of the coating and are considered early wear.

[0112] Moderate cracks: The cracks are more obvious and may affect the aesthetics of the coating. At this time, the cracks can be seen, but the protective performance of the coating is still good. It is suitable for observation to prevent further deterioration.

[0113] Severe cracks: Severe cracks may cause coating peeling, damage or leakage. In this case, the protective performance of the coating is greatly reduced and needs to be repaired or repainted.

[0114] The experimental data table 1 of Examples 1-5 and Comparative Examples 1-3 is as follows:

[0115]

[0116] Table 1

[0117] As can be seen from the above Table 1, the insulation performance of the modified epoxy paint of the present application is significantly better than that of the traditional formula. In Examples 1 to 5, by finely adjusting the ratio of epoxy resin, solvent, modified nanofiller and curing agent, not only the insulation strength is improved, but also a low wear rate is maintained. Some examples even show excellent performance without cracks in the wear test. In particular, Example 5 has an insulation strength of 130 kV / mm, showing extremely high insulation safety performance.

[0118] Comparative Examples 1 and 2 show that at the same curing agent addition amount, if the basic resin material content is too low or too high, the insulation strength will be significantly reduced. The low epoxy resin content in Comparative Example 1 may lead to insufficient paint film thickness or incomplete curing, thereby reducing the insulation performance; while the excessive epoxy resin content in Comparative Example 2 may cause the solvent to be unable to fully dissolve the resin, resulting in uneven paint film quality, which also affects the insulation effect. In addition, Comparative Example 3 further verifies the important role of the solvent in dissolving the resin, promoting the reaction and forming a uniform paint film by reducing the amount of solvent used. Its insulation strength and wear resistance are significantly lower than those of the embodiment group.

[0119] In summary, the insulating modified epoxy paint of the present invention achieves a dual improvement in insulation performance and wear resistance by optimizing the proportion of each component, and provides an efficient and reliable solution for insulation protection of electrical equipment. At the same time, the preparation method is simple in process, easy to operate, and has a high prospect for industrial application.

[0120] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing an insulating modified epoxy paint, characterized in that: The preparation method comprises the following steps: S101, weighing 230-260 parts by weight of a basic resin material, transferring the basic resin material to a four-necked flask, and adding a first solvent to the four-necked flask; The four-necked flask was placed in a water bath at 40° C., and the solution in the four-necked flask was stirred at a speed of 300 rpm using a mechanical stirrer for 30 minutes, thereby preparing an epoxy resin material; S201, adding 25-55 parts by weight of a modified nanofiller material and a second solvent in a beaker, and treating the material with an ultrasonic processor for 30 minutes, thereby treating the surface of the modified nanofiller; S301, pouring the modified nanofiller prepared in step S201 into the epoxy resin material prepared in step S101 to form a solution, and using a high-speed shear disperser to continuously stir the solution at a speed of 3000 rpm for 15 to 20 minutes; S401, during the stirring of the solution in step S301, adding the second solvent, and after the stirring is completed, allowing the prepared solution to stand; After standing, the solution was transferred to a vacuum degasser, and the vacuum was set to -0.08 MPa for 15 to 20 minutes; S501, adding 25-40 parts by weight of a curing agent to the de-vacuumed solution, stirring the solution at 150 rpm for 20 minutes, and then pouring and curing the solution; The first solvent is used for dissolving the resin and dispersing the solute; the second solvent is used for surface treatment of the filler and enhancing the interface bonding force.

2. The method for preparing an insulating modified epoxy paint according to claim 1, characterized in that: The basic resin material in step S101 is prepared from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, and epoxy novolac amine.

3. The method for preparing an insulating modified epoxy paint according to claim 1, characterized in that: The basic resin material is modified by reacting with 5%-10%wt of carboxyl-terminated polybutadiene acrylonitrile liquid rubber or the basic resin material is modified by reacting with 0.5%-2%wt of trimethylolethane triacrylate material.

4. The method for preparing an insulating modified epoxy paint according to claim 1, characterized in that: The first solvent includes one or more of ethyl acetate, acetone, and toluene; the second solvent includes one or more of γ-aminopropyltriethoxysilane and isopropanol.

5. The method for preparing an insulating modified epoxy paint according to claim 4, characterized in that: In the step S101, the first solvent includes: 80-120 parts by weight of ethyl acetate, 20-45 parts by weight of acetone, and 15-35 parts by weight of toluene.

6. The method for preparing an insulating modified epoxy paint according to claim 4, characterized in that: In the step S201, the second solvent includes: 2-10 parts by weight of γ-aminopropyltriethoxysilane and 30-50 parts by weight of isopropanol.

7. The method for preparing an insulating modified epoxy paint according to claim 4, characterized in that: In the step S401, the second solvent includes: 5-10 parts by weight of γ-aminopropyltriethoxysilane and 20-30 parts by weight of isopropanol.

8. The method for preparing an insulating modified epoxy paint according to claim 1, characterized in that: The modified nano-filling material in step S201 is modified nano-aluminum oxide and / or modified boron nitride.

9. The method for preparing an insulating modified epoxy paint according to claim 8, characterized in that: The modified nano-alumina is modified by surface silanization reaction of alumina material and γ-aminopropyltriethoxysilane; The γ-aminopropyltriethoxysilane undergoes hydrolysis and condensation reaction with the hydroxyl groups on the surface of the nano-alumina through its ethoxy groups to form a stable Si-O-Al bond, and the reaction equation is as follows: Al-OH+(EtO)3Si(CH2)3NH2→Al-O-Si(CH2)3NH2+3EtOH Et represents an ethoxy group, and NH2 represents an amino group.

10. The method for preparing an insulating modified epoxy paint according to claim 8, characterized in that: The modified boron nitride is modified by surface silanization reaction of hydroxylated boron nitride and γ-aminopropyltriethoxysilane; The γ-aminopropyltriethoxysilane undergoes a condensation reaction with the hydroxyl groups on the surface of the hydroxylated boron nitride through its ethoxy groups, and combines with the active sites on the surface of the boron nitride. The reaction equation is as follows: BN-OH+(EtO)3Si(CH2)3NH2→BN-O-Si(CH2)3NH2+3EtOH Et represents an ethoxy group, and NH2 represents an amino group.

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