Search

CN-122011883-A - Epoxy resin-based high-voltage-resistance powder coating and preparation method thereof

CN122011883ACN 122011883 ACN122011883 ACN 122011883ACN-122011883-A

Abstract

The invention belongs to the technical field of manufacturing of epoxy resin powder coatings, and particularly relates to an epoxy resin-based high-voltage-resistant high-resistance powder coating and a preparation method thereof. According to the invention, the alicyclic epoxy resin and the glycidyl ether epoxy resin are compounded, the charge migration is inhibited through the rigid alicyclic group, the breakdown field intensity is improved, the toughness of the resin is regulated through the glycidyl ether epoxy resin, the firm combination of the coating and the base material is ensured, the chemical activity of the surface of the flexible insulating polyamide fiber is enhanced through dopamine modification, the dispersibility in the epoxy resin is improved, the flexible insulating polyamide fiber can be combined with the insulating filler through hydrogen bonds to form a compact network, the occurrence of partial discharge and breakdown phenomena is effectively inhibited, and the adhesive force and the impact resistance of the powder coating are improved. The epoxy resin-based high-voltage-resistant high-resistance powder coating prepared by the invention has excellent insulativity and adhesive force, and is suitable for the field of new energy automobiles.

Inventors

  • WANG SHIYONG
  • DAI ZHENHUA
  • KANG XIAOBING

Assignees

  • 广东桑瑞斯环保新材料有限公司

Dates

Publication Date
20260512
Application Date
20260302

Claims (9)

  1. 1. The epoxy resin-based high-voltage-resistant high-resistance powder coating is characterized by being prepared from, by mass, 40-50 parts of alicyclic epoxy resin, 30-40 parts of glycidyl ether epoxy resin, 8-10 parts of flexible insulating polyamide fibers, 5-8 parts of insulating filler, 15-25 parts of curing agent, 0.5-2 parts of leveling agent, 0.5-2 parts of defoaming agent and 1-5 parts of curing accelerator.
  2. 2. The epoxy resin-based high-voltage-resistant high-resistance powder coating according to claim 1, wherein the epoxy equivalent of the alicyclic epoxy resin is 190-210, the glycidyl ether epoxy resin is any one of E51, E20 and E44, the curing agent is an anhydride curing agent, and the curing accelerator is a tertiary amine accelerator.
  3. 3. The epoxy resin-based high voltage-resistant high-resistance powder coating according to claim 1, wherein the preparation method of the flexible insulating polyamide fiber comprises the following steps: S11, adding 1, 4-bis (4-aminophenoxy) benzene and N, N-dimethylacetamide into a reaction kettle in a nitrogen atmosphere, dropwise adding isophthaloyl dichloride at a low temperature for reaction, adding deionized water after the reaction is finished for precipitation, adding sodium bicarbonate for neutralization, filtering, collecting solids, washing and drying to obtain aromatic polyamide; S12, adding aromatic polyamide into concentrated sulfuric acid for wet spinning to obtain aramid fiber, adding the aramid fiber into a modifying solvent for heating modification, filtering and collecting the fiber, washing and vacuum drying to obtain modified aramid fiber; And S13, adding the modified aramid fiber into dimethyl sulfoxide and oxalic acid, ball-milling to obtain dispersion, adding acetone for precipitation, filtering, collecting the precipitate, washing and drying in vacuum to obtain the flexible insulating polyamide fiber.
  4. 4. The epoxy resin-based high-voltage-resistant high-resistance powder coating according to claim 3, wherein the mass ratio of 1, 4-bis (4-aminophenoxy) benzene, N-dimethylacetamide and isophthaloyl dichloride in S11 is 29-31:100-150:20-22, and the isophthaloyl dichloride is dropwise added at-5 to-10 ℃ for reaction for 0.5-1 h.
  5. 5. The epoxy resin-based high-pressure-resistant high-resistance powder coating according to claim 3, wherein the aromatic polyamide in S12 is prepared by adding 250-300 mL of deionized water into 1.2-1.4 g of tris-hydroxymethyl aminomethane, dropwise adding hydrochloric acid to adjust the pH to 8.5, adding 0.5-0.8 g of dopamine for dissolution, reacting for 12-24 h at a temperature of between 3 and 5:60 and a temperature of between 40 and 50 ℃, spinning with deionized water to be neutral at room temperature, adding deionized water for solidification, collecting with a drawing roller at a temperature of between 60 and 120 ℃, ball-milling for 40-60 min, adding 0.5-0.8 g of dopamine for dissolution, and washing with deionized water for an average diameter ratio of between 200 and 300nm, wherein the mass ratio of the modified aramid fiber, dimethyl sulfoxide and oxalic acid in S13 is between 1:2.5 and 0.1 and 0.15, the modified aramid fiber is obtained by ball-milling for an average diameter ratio of between 200 and 300nm, and the average diameter of the modified polyamide is obtained by vacuum-600, and the average diameter ratio of the modified polyamide is between 200 and 300 nm.
  6. 6. The epoxy resin-based high-voltage-resistant high-resistance powder coating according to claim 1, wherein the preparation method of the insulating filler comprises the following steps: S21, adding boron nitride and ethanol into a ball mill for ball milling to prepare a suspension, centrifugally filtering the suspension, and then taking supernatant and drying to prepare the boron nitride nanosheets; S22, adding tannic acid and deionized water into a reaction kettle, stirring and dissolving, adding the nano boron nitride sheets into ethanol, performing ultrasonic dispersion, then adding the nano boron nitride sheets into the reaction kettle, reacting at room temperature, filtering, taking out solids, washing and drying to obtain the insulating filler.
  7. 7. The epoxy resin-based high-voltage-resistant high-resistance powder coating according to claim 6, wherein the mass ratio of boron nitride to ethanol in S21 is 1-2:7-10, ball milling is carried out for 12-16 h at a rotation speed of 400-500 rpm, centrifugal filtration is carried out for 20-30 min at a rotation speed of 1000-3000 rpm, drying is carried out at 80-100 ℃, the average thickness of boron nitride nano-sheets is 7-10 nm, the average diameter is 5-10 mu m, the mass ratio of tannic acid, deionized water, nano-boron nitride sheets and ethanol in S22 is 2-3:50-60:3-5:20-30, room temperature reaction is carried out for 20-24 h, washing is carried out with deionized water, and vacuum drying is carried out at 80-100 ℃.
  8. 8. The method for preparing the epoxy resin-based high-voltage-resistant high-resistance powder coating according to any one of claims 1 to 7, comprising the following steps: s1, dehydrating and drying raw materials for later use; s2, adding the alicyclic epoxy resin and the glycidyl ether epoxy resin into a stirring kettle, adding a leveling agent and a defoaming agent, stirring for 5-10 min at a rotating speed of 300-500 rpm, adding an insulating filler and flexible insulating polyamide fiber, stirring for 3-5 min at a rotating speed of 2000-3000 rpm, finally adding a curing agent and a curing accelerator, stirring for 2-3 min at a rotating speed of 500-800 rpm at a temperature of 30-40 ℃, carrying out melt extrusion granulation at a temperature of 140-150 ℃, and grinding and sieving with a 300-mesh sieve to obtain the epoxy resin-based high-pressure-resistant high-resistance powder coating.
  9. 9. The application of the epoxy resin-based high-voltage-resistant high-resistance powder coating according to any one of claims 1 to 7, wherein the powder coating is sprayed and then heated to 100 to 120 ℃ for curing for 1 to 2 hours, and then heated to 130 to 140 ℃ for curing for 3 to 4 hours, so as to prepare the insulating coating.

Description

Epoxy resin-based high-voltage-resistance powder coating and preparation method thereof Technical Field The invention belongs to the technical field of manufacturing of epoxy resin powder coatings, and particularly relates to an epoxy resin-based high-voltage-resistant high-resistance powder coating and a preparation method thereof. Background The powder coating is solid powder formed by mixing solid resin, a curing agent, pigment, filler and an auxiliary agent, is adhered to the surface of a workpiece in a mode of electrostatic spraying and the like, is baked, melted, leveled and cured at high temperature to form a layer of firm and compact coating, is essentially different from the traditional liquid coating in form, construction and curing principle, has extremely strong adhesive force, high hardness and excellent chemical corrosion resistance and electrical insulation, and is a common coating for high-voltage electrical equipment. At present, although the yield of the epoxy resin in China is in the front of the world, the production and research are always concentrated on common-grade general epoxy products, and the general epoxy resin is used in high-power electronic devices and cannot bear electric damage and mechanical damage caused by the action of multiple physical fields such as high temperature and high pressure, and insulating filler substances are required to be added to modify the insulating property and the mechanical property of the epoxy resin. Therefore, the development of the epoxy resin composite insulating material with excellent insulating property and mechanical property has important significance. The Chinese patent publication No. CN117384528B discloses a formula of a high-temperature-resistant and high-pressure-resistant insulating coating and a preparation method thereof, wherein the formula of the high-temperature-resistant and high-pressure-resistant insulating coating comprises, by mass, 60-100 parts of epoxy resin, 20-80 parts of polyester imide resin, 20-80 parts of bismaleimide resin, 20-40 parts of curing agent, 40-80 parts of color filler, 2-10 parts of leveling agent and 2-20 parts of accelerator, and the epoxy resin, the polyester imide resin and the bismaleimide resin are mixed to serve as film forming base materials. According to the invention, the epoxy resin is used as a main film-forming base material, the polyester imide resin and the bismaleimide resin are used as film-forming base materials in a mixed mode, the surface of the insulating coating is smooth and flat after spraying and curing, the defects of scratch, breakage, falling and the like are avoided, the coating thickness can meet the construction requirement of 100-150 mu m, and the insulating coating has excellent high-temperature and high-pressure resistance. However, the prior art has the technical problem that the resistivity and the high voltage resistance of the coating are further improved by further improving the composition of the insulating powder. Disclosure of Invention The invention aims to provide an epoxy resin-based high-voltage-resistant high-resistance powder coating and a preparation method thereof, which are used for solving the technical problem that the resistivity and the high-voltage resistance of the coating are further improved without further improvement on the components of epoxy resin in the prior art. In order to achieve the above purpose, the present invention adopts the following technical scheme: the epoxy resin-based high-voltage-resistant high-resistance powder coating is prepared from the following raw materials, by mass, 40-50 parts of alicyclic epoxy resin, 30-40 parts of glycidyl ether epoxy resin, 8-10 parts of flexible insulating polyamide fibers, 5-8 parts of insulating fillers, 15-25 parts of curing agents, 0.5-2 parts of leveling agents, 0.5-2 parts of defoaming agents and 1-5 parts of curing accelerators. The epoxy equivalent of the alicyclic epoxy resin is 190-210, and the glycidyl ether epoxy resin is any one of E51, E20 and E44; The curing agent is an anhydride curing agent, and the curing accelerator is a tertiary amine accelerator. Preferably, the preparation method of the flexible insulating polyamide fiber comprises the following steps: S11, adding 1, 4-bis (4-aminophenoxy) benzene and N, N-dimethylacetamide into a reaction kettle in a nitrogen atmosphere, dropwise adding isophthaloyl dichloride at a low temperature for reaction, adding deionized water after the reaction is finished for precipitation, adding sodium bicarbonate for neutralization, filtering, collecting solids, washing and drying to obtain aromatic polyamide; S12, adding aromatic polyamide into concentrated sulfuric acid for wet spinning to obtain aramid fiber, adding the aramid fiber into a modifying solvent for heating modification, filtering, collecting the fiber, washing and drying in vacuum to obtain modified aramid fiber; And S13, adding the modified aramid fiber into dimethyl sulfoxi