Insulating powder coating with improved substrate adhesion, preparation method and application thereof

Abstract

The present invention belongs to the field of coating technology, and particularly relates to an insulating powder coating for improving substrate adhesion, and a preparation method and application thereof. An insulating powder coating for improving substrate adhesion comprises an epoxy resin, a modified terminal hydroxyl phenolic resin, a curing agent, and an adhesion promoter; the modified terminal hydroxyl phenolic resin is an organosilicon-modified terminal hydroxyl phenolic resin; the curing agent comprises a dicyandiamide curing agent and a phenolic hydroxyl resin curing agent. The present invention modifies the phenolic resin with organosilicon, and at the same time, compounding dicyandiamide and phenolic hydroxyl resin curing agents and adding an adhesion promoter, so that the prepared insulating powder coating is applied to nickel-plated and tin-plated substrates, while taking into account the anti-corrosion performance, and has good adhesion, impact performance, cold and hot shock resistance, double 85 moisture and heat resistance, insulation pressure resistance, and flame retardancy.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to an insulating powder coating for improving substrate adhesion, a preparation method and an application thereof. Background Art

[0002] At present, insulating powder coatings are widely used in motors, transformers, electronic components, and electromagnetic wire products. With the rise of new energy and other industries, the demand for the application of powder coatings in busbars, energy storage systems, uninterruptible power supplies and other related products has also been greatly increased. Most of these products require coating of special nickel-plated and tin-plated substrates. Since metallic nickel has a strong passivation ability, a very thin passivation film is quickly generated on the surface of the substrate, which can resist corrosion from the atmosphere, alkali and some acids, making the nickel-plated substrate highly stable, and the hardness of the nickel coating is relatively high, which can improve the wear resistance of the product surface. The tin-plated substrate is non-toxic and has good ductility and corrosion resistance. In particular, the good ductility allows the tin-plated metal sheet to be processed into various shapes without destroying the tin-plated layer.

[0003] Conventional insulating powder coatings have been widely used on bare copper substrates, but the application of insulating powder coatings on tin-plated and nickel-plated substrates still has defects such as adhesion, high and low temperature impact, double 85 test performance, and compatibility issues between nickel-plated and tin-plated substrates and insulating powder coatings.

[0004] Therefore, it is urgent to provide an insulating powder coating which, after being applied to a nickel-plated or tin-plated substrate, has good adhesion, impact resistance and double 85 moisture and heat resistance (85° C. / 85% humidity). Summary of the invention

[0005] The present invention aims to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions. The present invention provides an insulating powder coating for improving substrate adhesion, which has good adhesion, impact resistance and double 85 moisture and heat resistance after being applied to a nickel-plated or tin-plated substrate.

[0006] The inventive concept of the present invention: the insulating powder coating of the present invention comprises epoxy resin, modified terminal hydroxyl phenolic resin, curing agent, and adhesion promoter; the modified terminal hydroxyl phenolic resin is organosilicon-modified terminal hydroxyl phenolic resin; the curing agent comprises dicyandiamide curing agent and phenolic hydroxyl resin curing agent. The present invention improves its physical and chemical properties by modifying the phenolic resin with organosilicon and introducing alkoxy groups, and at the same time, by compounding dicyandiamide and phenolic hydroxyl resin curing agent and adding adhesion promoter, the prepared powder coating has good adhesion, impact performance, and double 85 moisture and heat resistance after being applied to nickel-plated and tin-plated substrates. In addition to improving the adhesion of the coating, the adhesion promoter can also make the coating have good impact performance.

[0007] Therefore, a first aspect of the present invention provides an insulating powder coating having improved substrate adhesion.

[0008] Specifically, an insulating powder coating for improving substrate adhesion includes epoxy resin, modified hydroxy-terminated phenolic resin, curing agent, and adhesion promoter;

[0009] The modified hydroxyl-terminated phenolic resin is an organosilicon-modified hydroxyl-terminated phenolic resin;

[0010] The curing agent includes a dicyandiamide curing agent and a phenolic hydroxyl resin curing agent.

[0011] Preferably, the insulating powder coating comprises, by weight, 140-270 parts of epoxy resin, 55-160 parts of modified terminal hydroxyl phenolic resin, 27-90 parts of curing agent, and 0.9-11 parts of adhesion promoter.

[0012] Further preferably, the insulating powder coating comprises, by weight, 150-250 parts of epoxy resin, 60-150 parts of modified terminal hydroxyl phenolic resin, 30-80 parts of curing agent, and 1-10 parts of adhesion promoter.

[0013] Preferably, in the curing agent, the mass ratio of the dicyandiamide curing agent to the phenolic hydroxyl resin curing agent is 1:0.45-1.1.

[0014] More preferably, in the curing agent, the mass ratio of the dicyandiamide curing agent to the phenolic hydroxyl resin curing agent is 1:0.5-1.0.

[0015] Preferably, the insulating powder coating further comprises at least one of a leveling agent, a filler, an imidazole accelerator, a breathable agent, and a pigment.

[0016] Preferably, the insulating powder coating also includes a leveling agent, a filler, an imidazole accelerator, a breathable agent, and a pigment; and in parts by weight, the insulating powder coating includes 140-270 parts of epoxy resin, 55-160 parts of modified terminal hydroxy phenolic resin, 27-90 parts of curing agent, 0.9-11 parts of adhesion promoter, 0.9-5.5 parts of leveling agent, 45-220 parts of filler, 0.9-11 parts of imidazole accelerator, 0.9-11 parts of breathable agent, and 0.9-11 parts of pigment.

[0017] Further preferably, the insulating powder coating includes, by weight, 150-250 parts of epoxy resin, 60-150 parts of modified terminal hydroxyl phenolic resin, 30-80 parts of curing agent, 1-10 parts of adhesion promoter, 1-5 parts of leveling agent, 50-200 parts of filler, 1-10 parts of imidazole promoter, 1-10 parts of breathable agent, and 1-10 parts of pigment.

[0018] Specifically, the breathable agent can eliminate pores during the coating curing process to obtain a dense coating, thereby improving the coating's adhesion, resistance to the double 85 test and other properties.

[0019] Preferably, the epoxy resin is selected from at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0020] Preferably, the epoxy equivalent of the epoxy resin is 450-1000 g / eq and the softening point is 70-110°C.

[0021] More preferably, the epoxy equivalent of the epoxy resin is 500-950 g / eq and the softening point is 80-100°C.

[0022] Preferably, the imidazole accelerator is selected from at least one of 2,4-dimethylimidazole, 2-methylimidazole, 2-ethylimidazole and heptadecylimidazole.

[0023] More preferably, the imidazole accelerator is selected from at least one of 2-methylimidazole and 2-ethylimidazole.

[0024] Preferably, the leveling agent is an acrylic leveling agent.

[0025] Further preferably, the leveling agent is selected from at least one of polyethyl acrylate, polybutyl acrylate, and butyl acrylate-ethyl acrylate copolymer.

[0026] Preferably, the filler is selected from at least one of glass fiber, mica powder, silica powder and barium sulfate.

[0027] Preferably, the adhesion promoter is a high molecular weight copolymer containing basic groups adsorbed on silica.

[0028] Preferably, the breathable agent is benzoin.

[0029] Preferably, the pigment is selected from at least one of rutile titanium dioxide, red iron oxide, yellow iron oxide, carbon black, ultramarine, iron yellow, phthalocyanine blue and phthalocyanine green.

[0030] Preferably, the D50 particle size of the powder coating is 35-45 μm.

[0031] Further preferably, the D50 particle size of the powder coating is 37-43 μm.

[0032] The second aspect of the present invention provides a method for preparing the insulating powder coating for improving substrate adhesion according to the first aspect of the present invention.

[0033] Specifically, the method for preparing the insulating powder coating for improving substrate adhesion comprises the following steps:

[0034] The raw material components are mixed, extruded and powdered to obtain the insulating powder coating for improving substrate adhesion.

[0035] Preferably, the extrusion is carried out using a twin-screw extruder.

[0036] Preferably, the temperature of zone I of the twin-screw extruder is 85-100°C, and the temperature of zone II is 95-110°C.

[0037] Further preferably, the temperature of zone I of the twin-screw extruder is 90-95°C, and the temperature of zone II is 100-105°C.

[0038] Preferably, the extrusion further includes a process of tableting and cooling.

[0039] Preferably, the powder making comprises a process of pulverizing and screening.

[0040] Preferably, the preparation method of the modified hydroxy-terminated phenolic resin comprises the following steps:

[0041] The phenolic resin, polysilsesquioxane and a coupling agent are mixed and heated to obtain the organosilicon-modified hydroxy-terminated phenolic resin.

[0042] Preferably, the mass ratio of the phenolic resin, polysilsesquioxane and coupling agent is 1:(0.18-0.33):(0.045-0.11).

[0043] Further preferably, the mass ratio of the phenolic resin, polysilsesquioxane and coupling agent is 1:(0.2-0.3):(0.05-0.1).

[0044] Preferably, the heating temperature is 90-130°C; more preferably, the heating temperature is 100-120°C.

[0045] Preferably, stirring is performed during the heating process, and the stirring speed is 180-380 r / min; the stirring time is 9-22 min; further preferably, the stirring speed is 200-350 r / min; the stirring time is 10-20 min.

[0046] Preferably, the heating process also includes cooling, tableting and crushing.

[0047] Preferably, the temperature after cooling is 27-55°C; more preferably, the temperature after cooling is 30-50°C.

[0048] Preferably, the phenolic resin is a hydroxyl-terminated linear phenolic resin.

[0049] Preferably, the hydroxyl value of the hydroxyl-terminated linear phenolic resin is 0.35-0.65 mol / 100 g, and the softening point is 70-110° C.

[0050] More preferably, the hydroxyl value of the hydroxyl-terminated linear phenolic resin is 0.4-0.6 mol / 100 g, and the softening point is 80-100° C.

[0051] Preferably, the polysilsesquioxane is POSS-cage polysilsesquioxane.

[0052] Preferably, the POSS-cage polysilsesquioxane is selected from at least one of methacrylated cage polysilsesquioxane, trisilane isobutylated cage polysilsesquioxane, and methacrylate nano-silica dispersion.

[0053] Preferably, the coupling agent is selected from at least one of 3-aminopropyltrimethoxysilane and γ-aminopropylmethyldimethoxysilane.

[0054] A third aspect of the present invention provides a tin-plated or nickel-plated substrate.

[0055] Specifically, the tin-plated or nickel-plated substrate includes a coating formed by the insulating powder coating for improving substrate adhesion as described in the first aspect of the present invention.

[0056] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0057] (1) The insulating powder coating of the present invention modifies the phenolic resin with organic silicon, and compounding dicyandiamide and phenolic hydroxyl resin curing agent and adding adhesion promoter, so that the prepared insulating powder coating is applied to nickel-plated and tin-plated substrates, while taking into account the anti-corrosion performance, and has good adhesion, impact performance, double 85 moisture and heat resistance, insulation pressure resistance, and flame retardancy. In addition, the adhesion promoter can not only improve the adhesion of the coating, but also make the coating have good impact performance.

[0058] (2) When the present invention performs organosilicon modification on the phenolic resin, the raw materials are not simply mixed directly, but the modification is completed by heating the resin at a certain temperature to make it molten, thereby improving the comprehensive properties of the coating, such as adhesion, corrosion resistance, resistance to double 85 moisture and heat, and flame retardancy.

[0059] (3) The preparation process of the present invention is simple and convenient for large-scale production and application. DETAILED DESCRIPTION

[0060] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0061] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0062] The manufacturers and models of raw materials in the embodiments of the present invention are as follows:

[0063] The epoxy resin is selected from at least one of GESR-903 and GESR-903H of Guangzhou Hongchang Electronic Materials Industry Co., Ltd. and DER 662E and DER 664UE of Dow Chemical Company.

[0064] The dicyandiamide curing agent is selected from at least one of HT 2632 of Ciba Specialty Chemicals, DEH 40 and DEH41 of Dow Chemical.

[0065] The phenolic hydroxyl resin curing agent is selected from at least one of V-205, V-2051W and V-2081 of Shaanxi Jinchen Yongyue New Materials Co., Ltd.

[0066] The hydroxyl-terminated linear phenolic resin is selected from at least one of Amanda 969 and Amanda 999 of Daqing Qinglu Langrun Technology Co., Ltd.

[0067] The manufacturers, models and equipment of the raw materials used in Examples 1-3 and Comparative Examples 1-4 of the present invention are as follows:

[0068] Twin-screw extruder: JFY-30 crawler-type twin-screw extruder.

[0069] Epoxy resin: DER 662E from Dow Chemical Company, USA, with an epoxy equivalent of 600 g / eq and a softening point of 90°C.

[0070] Hydroxyl-terminated linear phenolic resin: Amanda 969 from Daqing Qinglu Langrun Technology Co., Ltd., with a hydroxyl value of 0.52 mol / 100 g and a softening point of 86°C.

[0071] Trisilane isobutylated cage-shaped silsesquioxane: Xi'an Qiyue Biology.

[0072] Dicyandiamide curing agent: DEH 40 from Dow Chemical.

[0073] Phenolic hydroxyl resin curing agent: V-2051W from Shaanxi Jinchen Yongyue New Materials Co., Ltd.

[0074] Leveling agent: BYK 360P from BYK Chemical.

[0075] Accelerator: 2-Methylimidazole from Hubei Changyao Biotechnology Co., Ltd.

[0076] Adhesion promoter: BYK-3942P from BYK.

[0077] Glass fiber: Wuhe County Weijia Composite Materials Co., Ltd.

[0078] Benzoin: MIWON BENZOIN.

[0079] The raw material components and amounts of the insulating powder coatings of Examples 1-3 of the present invention are shown in Table 1.

[0080] Table 1: Raw material components and dosages of insulating powder coatings of Examples 1-3 of the present invention

[0081] Components Example 1 Example 2 Example 3 Example 4 Epoxy resin DER 662E 170 180 180 180 Silicone modified hydroxyl-terminated phenolic resin 60 75 60 60 Curing agent DEH 40 40 40 35 35 Curing agent V-2051W 25 35 35 35 Leveling agent BYK 360P 3 3 3 3 Fiberglass 150 100 120 120 2-Methylimidazole 5 5 3 3 Adhesion promoter BYK-3942P 6 5 4 Benzoin 3 3 3 3 Carbon Black 3 5 5 5

[0082] Example 1

[0083] An insulating powder coating for improving substrate adhesion, wherein the raw materials for its preparation are the raw material components and amounts shown in Table 1 in parts by weight.

[0084] A method for preparing an insulating powder coating for improving substrate adhesion comprises the following steps:

[0085] (1) placing each raw material component by weight in a mixing tank, fully mixing and crushing for 10 minutes to obtain a mixed material;

[0086] (2) melt-extrude the mixture obtained in step (1) using a twin-screw extruder, wherein the temperature of zone I of the twin-screw extruder is 95° C., and the temperature of zone II is 105° C.; after being pressed by a tablet press, the mixture is cooled to 30° C., crushed, and sieved to obtain an insulating powder coating with a D50 particle size of 37 μm.

[0087] The preparation method of the organosilicon-modified hydroxy-terminated phenolic resin comprises the following steps:

[0088] 50 parts of linear phenolic resin Amanda 969, 10 parts of trisilane isobutylated cage-type silsesquioxane and 3 parts of γ-aminopropylmethyldimethoxysilane were mixed, stirred at a constant temperature of 110° C. and a stirring speed of 250 r / min for 15 minutes, and then cooled to 40° C. and then tableted and crushed to obtain an organosilicon-modified terminal hydroxyl phenolic resin.

[0089] Example 2

[0090] An insulating powder coating for improving substrate adhesion, wherein the raw materials for its preparation are the raw material components and amounts shown in Table 1 in parts by weight.

[0091] A method for preparing an insulating powder coating for improving substrate adhesion comprises the following steps:

[0092] (1) placing each raw material component by weight in a mixing tank, fully mixing and crushing for 10 minutes to obtain a mixed material;

[0093] (2) melt-extrude the mixture obtained in step (1) using a twin-screw extruder, wherein the temperature of zone I of the twin-screw extruder is 95° C., and the temperature of zone II is 105° C. After tableting by a tablet press, the mixture is cooled to 35° C., crushed, and sieved to obtain an insulating powder coating with a D50 particle size of 38 μm.

[0094] Wherein, the preparation method of the modified hydroxy-terminated phenolic resin is the same as that of Example 1.

[0095] Example 3

[0096] An insulating powder coating for improving substrate adhesion, wherein the raw materials for its preparation are the raw material components and amounts shown in Table 1 in parts by weight.

[0097] A method for preparing an insulating powder coating for improving substrate adhesion comprises the following steps:

[0098] (1) placing each raw material component by weight in a mixing tank, fully mixing and crushing for 10 minutes to obtain a mixed material;

[0099] (2) melt-extrude the mixture obtained in step (1) using a twin-screw extruder, wherein the temperature of zone I of the twin-screw extruder is 95° C., and the temperature of zone II is 105° C. After tableting by a tablet press, the mixture is cooled to 30° C., crushed, and sieved to obtain an insulating powder coating with a D50 particle size of 38 μm.

[0100] Wherein, the preparation method of the modified hydroxy-terminated phenolic resin is the same as that of Example 1.

[0101] Comparative Example 1

[0102] The difference between Comparative Example 1 and Example 3 is that Comparative Example 1 uses an equal amount of terminal hydroxyl linear phenolic resin Amanda 969 to replace the modified terminal hydroxyl phenolic resin, and the rest is the same as Example 3.

[0103] Comparative Example 2

[0104] The difference between Comparative Example 2 and Example 3 is that the adhesion promoter BYK-3942P is not added in Comparative Example 2, and the other parts are the same as Example 3.

[0105] Comparative Example 3

[0106] The only difference between Comparative Example 3 and Example 3 is that in Comparative Example 3, 50 parts of linear phenolic resin Amanda969, 10 parts of trisilane isobutylated cage-type silsesquioxane, and 3 parts of γ-aminopropylmethyldimethoxysilane are directly added in equal amounts, without first mixing the three and then stirring them at a constant temperature of 250 r / min at 110° C. for 15 minutes to obtain the organosilicon-modified terminal hydroxyl phenolic resin before adding them. The rest is the same as Example 3.

[0107] Comparative Example 4

[0108] The difference between Comparative Example 4 and Example 3 is that Comparative Example 4 uses an equal amount of curing agent DEH 40 to replace curing agent V-2051W, that is, curing agent V-2051W is not added, and the rest is the same as Example 3.

[0109] Comparative Example 5

[0110] The difference between Comparative Example 5 and Example 3 is that Comparative Example 5 uses an equal amount of curing agent V-2051W to replace curing agent DEH 40, that is, curing agent DEH 40 is not added, and the rest is the same as Example 3.

[0111] Performance Testing

[0112] Using a high-voltage electrostatic spray gun, the insulating powder coatings prepared in Examples 1-3 and Comparative Examples 1-5 were sprayed on a tin-plated substrate (tin-plated busbar workpiece) and a nickel-plated substrate (nickel-plated busbar workpiece), respectively, with a spraying thickness of 200 μm, and placed in a high-temperature curing furnace for curing at a curing temperature of 160°C for 10 min to obtain the coatings required for the tin-plated and nickel-plated substrates, and then relevant tests were carried out. The test results are shown in Table 2.

[0113] Table 2: Performance test results of insulating powder coatings of Examples 1-3 and Comparative Examples 1-5

[0114]

[0115] It can be seen from Table 2 that after the insulating powder coating of the present invention is applied to nickel-plated and tin-plated special substrates, the coating has excellent adhesion, impact resistance, hot and cold shock resistance, insulation performance, flame retardancy, double 85 moisture and heat resistance, and corrosion resistance, indicating that the insulating powder coating of the embodiment of the present invention can achieve low-temperature rapid curing under the condition of 160°C / 10min.

[0116] Comparative Example 1 uses an equal amount of terminal hydroxyl linear phenolic resin Amanda 969 to replace the modified terminal hydroxyl phenolic resin, so that the coating adhesion, impact resistance, thermal shock resistance, flame retardancy, insulation pressure resistance, double 85 moisture and heat resistance, and corrosion resistance are all worse than those of Example 3.

[0117] Comparative Example 2 did not add the adhesion promoter BYK-3942P, so the adhesion, impact resistance, and thermal shock resistance of the coating were worse than those of Example 3.

[0118] Comparative Example 3 directly added linear phenolic resin Amanda 969, γ-aminopropylmethyldimethoxysilane, and trisilane isobutylated cage-type silsesquioxane, and the linear phenolic resin Amanda 969 was not modified in advance with γ-aminopropylmethyldimethoxysilane and trisilane isobutylated cage-type silsesquioxane, so that the adhesion, corrosion resistance, double 85 moisture and heat resistance, and flame retardancy of the coating were all worse than those in Example 3.

[0119] Comparative Example 4 does not add the phenolic hydroxyl resin curing agent V-2051W, making it difficult to achieve low-temperature rapid curing (160°C / 10min). As a result, under the curing condition of 160°C / 10min, the various properties of the coating are poor, all of which are significantly worse than those of Example 3.

[0120] Comparative Example 5 does not add dicyandiamide curing agent DEH 40, making it difficult to achieve low-temperature rapid curing (160°C / 10min). As a result, under the curing condition of 160°C / 10min, the various properties of the coating are poor, all of which are significantly worse than those of Example 3.

[0121] In summary, the present invention modifies the linear phenolic resin with POSS-cage polysilsesquioxane and uses an adhesion promoter, so that the coating made of the insulating powder coating can better wet special substrates such as nickel-plated and tin-plated substrates, improve adhesion, and because of the introduction of Si-O bonds, the moisture and heat resistance, flame retardancy and impact resistance of the coating are improved; in addition, by using a dicyandiamide curing agent and a phenolic hydroxyl resin curing agent at the same time, the insulating powder coating can be quickly cured at low temperature, and after being applied to special nickel-plated and tin-plated substrates, the coating has excellent adhesion, impact resistance, resistance to electrolyte immersion, impact resistance, cold and hot shock, insulation performance, flame retardancy, and resistance to double 85 moisture and heat.

[0122] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An insulating powder coating, characterized in that: In parts by weight, the insulating powder coating comprises 140-270 parts of epoxy resin, 55-160 parts of modified terminal hydroxyl phenolic resin, 27-90 parts of curing agent, and 0.9-11 parts of adhesion promoter; The modified hydroxyl-terminated phenolic resin is an organosilicon-modified hydroxyl-terminated phenolic resin; The curing agent includes a dicyandiamide curing agent and a phenolic hydroxyl resin curing agent; The adhesion promoter is a high molecular weight copolymer containing basic groups adsorbed on silica; The preparation method of the modified hydroxy-terminated phenolic resin comprises the following steps: The phenolic resin, polysilsesquioxane and coupling agent are mixed and heated to obtain the modified hydroxy-terminated phenolic resin; The mass ratio of the phenolic resin, polysilsesquioxane and coupling agent is 1: (0.18-0.33): (0.045-0.11); In the curing agent, the mass ratio of the dicyandiamide curing agent to the phenolic hydroxyl resin curing agent is 1:0.45-1.

1.

2. The insulating powder coating according to claim 1, characterized in that: The insulating powder coating further comprises at least one of a leveling agent, a filler, an imidazole accelerator, a breathable agent, and a pigment; The filler is selected from at least one of glass fiber, mica powder, silica powder and barium sulfate; The pigment is selected from at least one of rutile titanium dioxide, red iron oxide, carbon black, ultramarine, iron yellow, phthalocyanine blue and phthalocyanine green.

3. The insulating powder coating according to claim 2, characterized in that: The insulating powder coating also includes a leveling agent, a filler, an imidazole accelerator, a breathable agent, and a pigment; and by weight, the insulating powder coating includes 140-270 parts of epoxy resin, 55-160 parts of modified terminal hydroxyl phenolic resin, 27-90 parts of curing agent, 0.9-11 parts of adhesion promoter, 0.9-5.5 parts of leveling agent, 45-220 parts of filler, 0.9-11 parts of imidazole accelerator, 0.9-11 parts of breathable agent, and 0.9-11 parts of pigment.

4. The method for preparing the insulating powder coating according to any one of claims 1 to 3, characterized in that: The following steps are involved: The insulating powder coating is obtained by mixing various raw material components, extruding and powdering.

5. The preparation method according to claim 4, characterized in that: The extrusion is performed using a twin-screw extruder; the temperature of zone I of the twin-screw extruder is 85-100°C, and the temperature of zone II is 95-110°C.

6. A tin-plated or nickel-plated substrate, characterized in that: A coating formed by the insulating powder coating according to any one of claims 1 to 3.

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