Coating as well as preparation method and application thereof

Abstract

The invention discloses a coating as well as a preparation method and application thereof. The coating comprises the following raw material components in parts by weight: 50-70 parts of basic powder, 30-50 parts of heat dissipation insulating powder and 1-5 parts of an auxiliary additive. The coating provided by the invention has the characteristics of high heat dissipation efficiency, high temperature resistance, high insulation and voltage resistance and wide application range. The coating can quickly conduct heat out, so that the operation efficiency and reliability of the equipment are improved; the coating can keep stable performance in a high-temperature environment, and the service life of equipment is prolonged; the coating can meet the insulation and voltage resistance requirements of the metal conductor and can improve the safety performance of the metal conductor; after the coating is coated on the surface of the metal conductor, the insulating and voltage-resisting capability of the metal conductor can be improved, and the surface heat dissipation capability of the metal conductor can be improved, so that the current-carrying capability of the metal conductor is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and specifically relates to a coating and a preparation method and application thereof, and more specifically, to a high temperature resistant, insulating and pressure resistant coating for metal conductors. Background Art

[0002] The charging and discharging module is an important component of new energy vehicles, and the metal conductor is the core of the charging and discharging module. In order to improve the insulation and withstand voltage of the metal conductor, the commonly used method is to wrap the surface of the metal conductor with insulating materials. Although the treatment method of wrapping insulating materials can improve the insulation and withstand voltage of the metal conductor, its own thermal conductivity is poor, which affects the heat dissipation of the metal conductor.

[0003] Metal conductors are prone to overheating under high load conditions, but because the metal conductors are wrapped in insulating materials, the generated heat cannot be dissipated in time, causing the temperature of the metal conductors to rise abnormally, resulting in reduced equipment efficiency and even possible safety accidents.

[0004] Some existing insulating materials of metal conductors may not be able to maintain their mechanical and electrical properties in high temperature environments. Long-term high temperature exposure may cause the insulating materials of metal conductors to age, oxidize or deform, thereby affecting the normal operation and life of the equipment. Summary of the invention

[0005] The purpose of the present invention is to address the above shortcomings and provide a coating and a preparation method and application thereof. After the coating is coated on the surface of a metal conductor (such as a copper busbar), it can not only improve the insulation withstand voltage capability of the metal conductor, but also improve the surface heat dissipation capability of the metal conductor, thereby increasing the current carrying capacity of the metal conductor.

[0006] To achieve the above object, the present invention is implemented by the following technical solutions: In a first aspect, the present invention provides a coating, wherein the raw materials of the coating include the following components: 50-70 parts by weight of base powder, 30-50 parts by weight of heat dissipation and insulation powder, and 1-5 parts by weight of auxiliary additives.

[0007] Furthermore, the coating is formed by the coating solution made from the raw materials being attached to the metal conductor through heat or chemical energy.

[0008] Furthermore, the base powder is a high-adhesive polymer, including any one of epoxy resin, polyurethane, acrylate or silicone polymer, etc., and has good adhesiveness.

[0009] Furthermore, the heat dissipating insulating powder is a nano-particle mixture of graphene, thermally conductive ceramic powder and alumina, and the mass ratio of the graphene, thermally conductive ceramic powder and alumina is (1-3): (6-9): 1, preferably 2:7:1. Through dispersion technology, it is integrated into the coating base powder to improve the heat dissipation coefficient and insulation withstand voltage capability of the coating.

[0010] Furthermore, the auxiliary additives include a curing agent, an accelerator and a pigment, and the mass ratio of the curing agent, the accelerator and the pigment is (5~6): (3~4): 1.

[0011] Furthermore, the curing agent is a diethanolamine curing agent, which is used to enhance the adhesion of the coating; The accelerator is an organic anhydride accelerator, which can improve the heat resistance and chemical resistance of the cured product and enhance the oxidation resistance and durability of the coating; The pigment is a titanate-based pigment used to change the color of the coating. Titanate-based pigments have excellent chemical stability and weather resistance, can resist the erosion of chemical substances such as acids, alkalis, salts, and can resist the erosion of harsh environments such as ultraviolet rays, high temperature, and humidity, and maintain the long-term stability of the pigment.

[0012] Furthermore, the pigment may be a titanate-based black pigment, and the color of the coating may be modulated to black to further improve the heat dissipation performance of the coating. Other colors may also be used as required.

[0013] Further, the coating is: A heat dissipation coating, wherein the thickness of the heat dissipation coating is less than 100 μm; or a heat dissipation and pressure-resistant coating, wherein the thickness of the heat dissipation and pressure-resistant coating is 100 μm to 450 μm; Or a high pressure resistant coating, wherein the thickness of the high pressure resistant coating is greater than 450 μm.

[0014] That is, the thickness of the coating attached to the surface of the metal conductor can be implemented according to the heat dissipation requirements and the insulation withstand voltage level: when the thickness is less than 100μm, the coating only plays a heat dissipation role and has no voltage withstand capability; the coating thickness of 100μm-450μm can meet the 940V-3300V voltage withstand requirements and has a heat dissipation effect; the coating thickness is greater than 450μm, meets the voltage withstand performance requirements of greater than 3300V, and the heat dissipation performance of the coating is reduced.

[0015] In a second aspect, the present invention further provides a method for preparing the coating according to the first aspect, comprising: adding the base powder into an organic solvent to obtain a prepolymer solution; Adding heat dissipation insulation powder to the prepolymer solution, adding auxiliary additives after dispersion, and obtaining a coating solution; The coating solution is applied to the substrate by dipping or spraying.

[0016] Furthermore, the organic solvent is ethanol or methyl ethyl ketone, which is used to adjust the viscosity and fluidity of the prepolymer solution to adapt to different coating processes.

[0017] Furthermore, the dispersion includes high-speed stirring dispersion, grinding dispersion or ultrasonic dispersion.

[0018] Further, the dip coating method comprises: Heat the substrate to 180-210°C and keep it warm, and heat the coating solution to 200-210°C; The heat-insulated substrate is immersed in the heated coating solution for coating; The substrate coated with the coating is dried and cured; the curing method is heat treatment or ultraviolet irradiation.

[0019] Furthermore, the spraying method includes: Place coating solution in spray gun; Fix the substrate and keep the distance between the spray gun and the substrate surface; Starting from one side of the substrate, spray by moving the gun in a straight line at a constant speed.

[0020] Furthermore, the distance between the spray gun and the workpiece surface is 15 to 30 centimeters.

[0021] In the third aspect, the present invention also provides an application of the coating described in the first aspect on the metal conductor of the charging and discharging module, that is, the coating is applied to the metal conductor (such as a copper busbar) of the charging and discharging module. The thermal conductivity of the coating is much higher than that of the metal conductor, and the heat can be quickly conducted away from the metal body, thereby achieving the purpose of efficient heat dissipation and improving the operating efficiency and reliability of the equipment; at the same time, the coating has strong insulation and voltage resistance, can meet the insulation and voltage resistance requirements of the metal conductor, and can improve the safety performance of the copper busbar.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The coating provided by the present invention has the characteristics of efficient heat dissipation, high temperature resistance, strong insulation and voltage resistance, and a wide range of applications. The coating can quickly conduct heat away, improving the operating efficiency and reliability of the equipment; the coating can maintain stable performance in a high temperature environment, extending the service life of the equipment; the coating can meet the insulation and voltage resistance requirements of the metal conductor, and can improve the safety performance of the metal conductor; The coating of the present invention is not only applicable to general new energy charging and discharging equipment, but also can be applied to special environments such as high temperature and corrosive media; The preparation method of the coating of the present invention is simple, easy to operate and effectively reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the current carrying performance of the black coating prepared in Example 1 for a copper bus; Figure 2 Schematic diagram of the voltage resistance test of the black coating prepared in Example 1. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention will be described in more detail below in conjunction with the accompanying drawings and specific examples.

[0025] Example 1 This embodiment provides a coating, which is made of the following components: Basic powder: 50kg epoxy resin; High heat dissipation insulation powder: 6kg of nano-graphene powder, 21kg of nano-thermal conductive ceramic powder, 3kg of nano-alumina powder; Auxiliary additives: 5kg diethanolamine, 3kg organic acid anhydride accelerator, 1kg titanate black pigment.

[0026] The preparation method and application process of the coating described in this embodiment include the following steps: (1) Material preparation: Weigh and prepare the raw materials according to the above amounts.

[0027] (2) Preparation of coating: Add the above base powder to 150L of ethanol to obtain a prepolymer solution, add the above high heat dissipation insulating powder to the prepolymer solution; then add the above auxiliary additives, and then add ethanol to adjust the viscosity and fluidity of the solution to obtain a coating solution with a viscosity of 100 cPd.

[0028] (3) Pretreatment of metal conductors: Clean and pretreat the surface of the copper busbar, such as degreasing and polishing, to improve the adhesion of the coating.

[0029] (4) Dip coating: First, heat the copper busbar to 180-210°C and perform heat preservation treatment to ensure that the copper busbar is heated evenly; heat the coating solution to 200-210°C, immerse the copper busbar in the coating solution, keep it for 30 minutes, stop heating, take out the workpiece, and clean the surface.

[0030] (5) Drying and curing: The coated copper busbar is placed in a drying oven for drying and curing. After drying, a heat treatment curing process is performed to firmly bond the coating to the copper busbar to form a stable structure.

[0031] The performance of the coating prepared by the method described in this example was verified: 1. For 140mm 2The bare copper product and the product coated with the black coating prepared in this example were subjected to current at room temperature. The results are as follows Figure 1 As shown, its current carrying performance is as follows: (1) The temperature rise of the black coated copper busbar at room temperature is lower than that of the bare copper product; (2) The temperature rise of the connection points and copper busbar surface of the black coating product is about 4.6~10.1K lower than that of the bare copper product.

[0032] 2. The copper busbar samples (of different thicknesses) coated with the coating prepared in this embodiment were subjected to a pressure resistance test. The pressure resistance performance is as follows: Figure 2 As shown in the figure, it can be seen that when the coating thickness is less than 100μm, the voltage resistance of the coating is less than 940V, the voltage resistance is weak and cannot meet the conventional voltage resistance requirements; the coating thickness of 100μm-450μm can meet the voltage resistance requirements of 940V-3300V and has a heat dissipation effect; the coating thickness is greater than 450μm, which meets the voltage resistance performance requirements of greater than 3300V.

[0033] Example 2 This embodiment provides a coating, which is made of the following components: Basic powder: 60kg epoxy resin; High heat dissipation insulation powder: 6kg of nano-grade graphene powder, 26kg of nano-grade thermal conductive ceramic powder, and 3kg of nano-grade alumina powder; Auxiliary additives: 3kg diethanolamine, 2kg organic acid anhydride accelerator, 0.5kg titanate black pigment.

[0034] The preparation method and application process of the coating described in this embodiment include the following steps: (1) Material preparation: Weigh and prepare the raw materials according to the above amounts.

[0035] (2) Preparation of coating: Add the above base powder to 150L methyl ethyl ketone to obtain a prepolymer solution, add the above high heat dissipation insulating powder to the prepolymer solution; then add the above auxiliary additives, and then add ml methyl ethyl ketone to adjust the viscosity and fluidity of the solution to obtain a coating solution with a viscosity of 25 cP.

[0036] (3) Pretreatment of metal conductors: Clean and pretreat the surface of the copper busbar, such as degreasing and polishing, to improve the adhesion of the coating.

[0037] (4) Spray coating: Place the coating solution in the spray gun; keep the distance between the spray gun and the surface of the copper busbar (usually 15-30 cm) and move the spray gun at a constant speed to ensure uniform coating; start from one side of the copper busbar and move the spray gun in a straight line to spray; if a thicker coating is required, multiple layers can be sprayed, but sufficient drying time should be left between each layer to avoid sagging due to excessive coating.

[0038] (5) Drying and curing: The coated copper busbar is placed in a drying oven for drying and curing. After drying, an ultraviolet irradiation curing process is performed to firmly bond the coating to the copper busbar to form a stable structure.

[0039] Comparative Example 1 No auxiliary additives are included, and the rest is the same as in Example 1.

[0040] The coating prepared in this comparative example has been verified to lack the required hardness, wear resistance and scratch resistance, and is easily damaged by external forces, shortening its service life. Comparative Example 2 Without nano-alumina powder, the rest is the same as in Example 1.

[0041] It has been verified that the coating prepared in this comparative example has low insulation performance and is not suitable for charge and discharge modules.

[0042] Comparative Example 3 The raw material composition is: 50 kg of basic powder, high heat dissipation insulating powder: 4 kg of nano-graphene powder, 14 kg of nano-thermal conductive ceramic powder, 2 kg of nano-alumina powder, 5 kg of auxiliary additives, and the rest is the same as Example 1.

[0043] It has been verified that the coating prepared in this comparative example is relatively thick, and although it meets the insulation performance requirements, its heat dissipation performance is relatively poor.

[0044] Comparative Example 4 The composition of the high heat dissipation insulating powder is: 15 kg of nano-scale graphene powder, 10 kg of nano-scale thermal conductive ceramic powder, and 5 kg of nano-scale alumina powder. The rest is the same as in Example 1.

[0045] It has been verified that the coating prepared in this comparative example has low overall insulation performance and is not suitable for charge and discharge modules.

[0046] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Without departing from the scope and technical principles of the described embodiments, many modifications and changes are obvious to those of ordinary skill in the art, and these modifications and changes should also be regarded as the scope of protection of the present invention.

Claims

1. A coating, characterized in that: The raw materials of the coating include the following components: 50-70 parts by weight of base powder, 30-50 parts by weight of heat dissipation and insulation powder, and 1-5 parts by weight of auxiliary additives.

2. The coating according to claim 1, characterized in that The coating is formed by a coating solution made of the raw materials being attached to the metal conductor by heat or chemical energy.

3. The coating according to claim 1, characterized in that The base powder is a high-adhesive polymer, including one of epoxy resin, polyurethane, acrylate or silicone polymer.

4. The coating according to claim 1, characterized in that The heat dissipation insulating powder is a nano-scale particle mixture of graphene, thermal conductive ceramic powder and aluminum oxide, and the mass ratio of the graphene, thermal conductive ceramic powder and aluminum oxide is (1-3): (6-9):

1.

5. The coating according to claim 1, characterized in that The auxiliary additives include a curing agent, an accelerator and a pigment, and the mass ratio of the curing agent, the accelerator and the pigment is (5-6): (3-4):

1.

6. The coating according to claim 5, characterized in that The curing agent is diethanolamine curing agent; And / or, the accelerator is an organic anhydride accelerator; And / or, the pigment is a titanate-based pigment.

7. The coating according to claim 1, characterized in that The coating is: A heat dissipation coating, wherein the thickness of the heat dissipation coating is less than 100 μm; or a heat dissipation and pressure-resistant coating, wherein the thickness of the heat dissipation and pressure-resistant coating is 100 μm to 450 μm; Or a high pressure resistant coating, wherein the thickness of the high pressure resistant coating is greater than 450 μm.

8. A method for preparing a coating according to any one of claims 1 to 7, characterized in that: include: adding the base powder into an organic solvent to obtain a prepolymer solution; Adding heat dissipation insulation powder to the prepolymer solution, adding auxiliary additives after dispersion, and obtaining a coating solution; The coating solution is applied to the substrate by dipping or spraying.

9. The method for preparing the coating according to claim 8, characterized in that: The dip coating method comprises: Heat the substrate to 180-210°C and keep it warm, and heat the coating solution to 200-210°C; The heat-insulated substrate is immersed in the heated coating solution for coating; The coated substrate is dried and cured.

10. Use of the coating according to any one of claims 1 to 7 on a metal conductor of a charging and discharging module.

Images