Polyvinylidene fluoride self-adhesive paint with self-lubricating property for coating enameled wire and preparation method of polyvinylidene fluoride self-adhesive paint

Abstract

The invention discloses polyvinylidene fluoride self-adhesive paint with a self-lubricating property for coating an enameled wire and a preparation method of the polyvinylidene fluoride self-adhesive paint. Comprising the following materials in parts by weight: 392 to 551 parts of dimethyl sulfoxide, 92 to 196 parts of dimethyl formamide (DMF), 160 to 350 parts of dimethyl tetrahydrofuran, 200 parts of polyvinylidene fluoride resin, 10 to 40 parts of phenolic epoxy resin, 6 to 24 parts of tert-butyl phenolic resin and 0.2 to 1.2 parts of a fluorocarbon modified polypropylene flatting agent. The invention aims to realize the manufacturing method of the novel self-adhesive coating material with high chemical / physical corrosion resistance suitable for harsh use environments, and the product fully meets various technical performance indexes, and can be widely applied to current new energy automobile winding wires, aerospace electronic wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires, marine aircraft electrical winding wires and the like. And coating fabrication of other electrical winding wires with chemical and material corrosivity.

Description

Technical Field

[0001] This invention pertains to self-adhesive enameled wire coatings, specifically relating to a polyvinylidene fluoride self-adhesive coating for enameled wires with self-lubricating properties. Background Technology

[0002] Self-adhesive enameled wire varnish is the core material for the outer coating of self-adhesive enameled wire. Due to its environmentally friendly and convenient characteristics, eliminating the need for impregnation, it is increasingly used in the manufacturing of modern high-quality electrical windings. Traditional self-adhesive varnishes, such as polyester (PE), polyvinyl butyral (PVB), and polyamide (PA), are used differently in the manufacture of coil winding self-adhesive materials for various applications due to their respective adhesive properties. With the continuous development of industrial technology and the expansion of new application areas, various new technical requirements have been placed on enameled wires. For example, electrical equipment used in marine vessels, high-quality submersible motors, petroleum machinery, aerospace, and new energy oil-immersed drive motors are subjected to harsh and long-term high-temperature, high-humidity, and highly corrosive environments, placing new requirements on the corrosion resistance of self-adhesive enameled wire varnishes. Due to material defects, the aforementioned traditional self-adhesive enameled wire varnishes cannot withstand the harsh environmental requirements of high temperature, high humidity, and high corrosion (they cannot meet the requirements of GB / T4074.4-2024 Winding Wire Test Methods Part 4: Chemical Performance Standard Test Requirements). Therefore, developing a novel self-adhesive enameled wire varnish with high resistance to physical / chemical corrosion is of great significance. Patent CN108690415A discloses a road marking paint manufactured by reprocessing waste PVDF resin for marking road lines. This patent primarily utilizes waste polyvinylidene fluoride hollow fiber membranes to prepare the road marking paint, taking full advantage of the excellent anti-aging, corrosion resistance, weather resistance, and lightfastness properties of polyvinylidene fluoride. Summary of the Invention

[0003] Objective of the Invention: To address the problems existing in the prior art, this invention provides a self-lubricating polyvinylidene fluoride (PVDF) self-adhesive varnish for coating enameled wire. This invention prepares a novel hot-melt self-adhesive varnish for heat-resistant enameled wire production coating with excellent physical / chemical corrosion resistance. This varnish possesses suitable physicochemical properties, good process adaptability, and is suitable for high-speed coating processes using felt or mold methods. The film formed exhibits ideal thermal adhesion characteristics, excellent corrosion resistance, resistance to chemical solvents, oil, and water, self-lubricating properties, a low coefficient of friction, and wear resistance. Furthermore, it meets the requirements of green manufacturing throughout the entire process (phenol-free). The finished product can fully meet the performance requirements of wires under harsh operating environments, ultimately endowing the formed coil windings with excellent corrosion resistance.

[0004] The present invention also provides a method for preparing and applying a self-lubricating polyvinylidene fluoride self-adhesive varnish for coating enameled wire.

[0005] Technical solution: To achieve the above objectives, the present invention provides a self-lubricating polyvinylidene fluoride self-adhesive varnish for coating enameled wire, comprising the following materials in parts by weight:

[0006] Dimethyl sulfoxide: 392–551 parts

[0007] Dimethylformamide (DMF): 92–196 parts

[0008] Dimethyltetrahydrofuran: 160–350 parts

[0009] Polyvinylidene fluoride resin: 200 parts

[0010] Phenolic epoxy resin: 10-40 parts

[0011] tert-butylphenol resin: 6-24 parts

[0012] Fluorocarbon modified polypropylene leveling agent: 0.2 to 1.2 parts.

[0013] In this process, polyvinylidene fluoride resin is used as the main film-forming material, combined with heat-resistant phenolic epoxy resin, curing agent tert-butylphenolic resin, and leveling agent fluorocarbon modified polypropylene. These are dissolved in a mixed multi-boiling-range solvent system composed of dimethyl sulfoxide, dimethylformamide, and dimethyltetrahydrofuran, which are compatible with the above materials.

[0014] The method for preparing the self-lubricating polyvinylidene fluoride self-adhesive varnish for coating enameled wire according to the present invention includes the following steps:

[0015] Step a: Mix dimethyl sulfoxide, dimethylformamide (DMF), and dimethyltetrahydrofuran evenly to prepare solution A;

[0016] Step b: Take the prepared solution A, and take out a portion of solution A and label it solution Aa and solution Ab respectively;

[0017] Step c: Add polyvinylidene fluoride (PVDF) resin to the remaining solution A, stir and heat, keep warm until fully dissolved to form a homogeneous solution B, then cool and keep warm for later use.

[0018] Step d: Similarly, using solution Aa from step b, dissolve tert-butylphenol resin at room temperature to prepare tert-butylphenol resin solution C; similarly, using solution Ab from step b, dilute fluorocarbon modified polypropylene at room temperature to prepare homogeneous liquid solution D.

[0019] Step e: Add phenolic epoxy resin, and liquids C and D prepared according to step d to liquid B obtained in step c, and stir thoroughly to form a homogeneous liquid to obtain the finished polyvinylidene fluoride self-adhesive paint.

[0020] In step b, solution Aa and solution Ab account for 8-10% and 2-5% of the total mass of solution A, respectively.

[0021] In step c, the temperature is gradually increased to 80±5℃ while stirring, and kept at this temperature for 2-3 hours until the solution is fully dissolved into a homogeneous solution B. Then the temperature is reduced to 50±5℃ and kept at this temperature for later use.

[0022] In step e, phenolic epoxy resin, and liquids C and D prepared in step d are sequentially added to the reaction vessel containing liquid B obtained in step c. The temperature of the materials in the vessel is maintained at 45±5℃ and stirred thoroughly for 2-3 hours to form a homogeneous liquid.

[0023] The homogeneous liquid is filtered through a 200-250 mesh stainless steel filter to obtain a finished polyvinylidene fluoride self-adhesive paint.

[0024] The self-lubricating polyvinylidene fluoride self-adhesive varnish for enameled wire coating described in this invention is used in the coating manufacturing of winding wires for new energy vehicles, aerospace electronic wires, electrical winding wires for marine vehicles, and other electrical winding wires with chemical and material corrosive properties.

[0025] Unlike road marking paints made from recycled PVDF resin, this invention is for coating self-adhesive layers on electromagnetic wires. The resulting wire is bonded into coil windings after being heated by hot air or energized. This invention provides a novel method for preparing self-adhesive paint for enameled wire coating, particularly a method for preparing a heat-resistant, hot-melt self-adhesive enameled wire paint using polyvinylidene fluoride (PVDF) as the main film-forming material. This invention relates to a novel self-adhesive enameled wire paint prepared using PVDF as the main film-forming material, combined with epoxy resin, a suitable curing agent, and a leveling agent, with a polar solvent as a good solvent.

[0026] The novel polyvinylidene fluoride (PVDF) self-adhesive enameled wire coating prepared by this invention is based on the synergistic effect between its components. PVDF resin, as the main film-forming material, is a first in the industry. The auxiliary function of modified resin enhances the mechanical strength and adhesion of the coating film, reduces the coefficient of friction, and compensates for the shortcomings of PVDF. This invention aims to achieve a novel method for manufacturing a self-adhesive coating material with high chemical / physical corrosion resistance suitable for harsh operating environments. The product fully meets various technical performance indicators and can be widely used in the coating manufacturing of winding wires for new energy vehicles, aerospace electronic wires, electrical winding wires for marine vehicles, and other electrical winding wires subject to chemical and material corrosion.

[0027] Technical design concept of the present invention:

[0028] 1. It is the first to use polyvinylidene fluoride (PVDF) resin as the main film-forming material for self-adhesive enameled wire coating. The hot melt bonding properties of PVDF give the film excellent bonding performance under ideal hot air / thermal resistance conditions. Its excellent chemical / corrosion resistance gives the formed winding excellent chemical resistance (such as oil / water resistance) to adapt to harsh operating environments. In addition, due to the self-lubricating properties of PVDF, the wire has an excellent low coefficient of friction, reducing mechanical damage to the wire during high-speed winding.

[0029] 2. To improve the heat resistance and chemical corrosion resistance of PVDF, a thermosetting phenolic epoxy resin with high chemical corrosion resistance is used, along with tert-butylphenolic resin, as a high-temperature curing agent. After curing, the two further improve the overall mechanical strength (high-temperature creep resistance) of PVDF, giving the wire coating a molecular structure that combines rigidity and flexibility after secondary curing, ensuring the formation of ideal deformation resistance of the coil winding.

[0030] 3. To meet the requirements of high-speed production of self-adhesive enameled wire and prevent defects during the coating process, a high-efficiency matching leveling agent has been appropriately added, which is beneficial to improving the surface quality of the coated wire.

[0031] 4. Based on the characteristics of PVDF material and taking into account the compatibility of the matching modified resins (phenolic epoxy resin, tert-butylphenolic resin and fluorocarbon modified polypropylene leveling agent), and combined with the coating requirements of enameled wire production, a polar combined solvent system (dimethyl sulfoxide, dimethyl acetamide and dimethyl tetrahydrofuran mixed solvent) with good solubility is preferred. While having good solubility, it also gives the entire formulation system good storage stability.

[0032] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows:

[0033] The novel polyvinylidene fluoride self-adhesive enameled wire varnish prepared by this invention not only possesses excellent hot-melt bonding performance but also outstanding chemical corrosion resistance, especially oil and water resistance, and resistance to "double 85" (temperature and humidity 85%). The finished varnish has a transparent and homogeneous appearance and good storage stability. Tests on the coated self-adhesive enameled wire have proven that the wire surface is smooth and uniform, with excellent low-friction performance. The hot-melt bonded winding has excellent appearance and dimensional stability, fully meeting the various technical requirements in chemically corrosive environments. This invention adds a novel hot-melt self-adhesive enameled wire varnish to the current series of self-adhesive varnishes in the industry.

[0034] The self-adhesive paint prepared by the method of this invention achieves the following physicochemical properties: A. Appearance: Clear and transparent, free of mechanical impurities, homogeneous liquid. B. Viscosity: 100–700 mPa·s (rotational viscometer / 30℃). C. Solid content: 8–28% (180℃ / 1g / 1h). It has broad market application value. Attached Figure Description

[0035] Figure 1 This is a test diagram of the adhesion strength of a finished polyvinylidene fluoride self-adhesive paint product. Detailed Implementation

[0036] The present invention will be further described below with reference to the embodiments.

[0037] The raw materials and reagents used in the examples are all commercially available.

[0038] The following raw materials were specifically used in the examples:

[0039] Polyvinylidene fluoride resin is used in the acoustic field of Zhejiang Juhua Co., Ltd. (product model JHS-7010);

[0040] The phenolic epoxy resin was produced by Sinochem Xingchen (commercial model F-44);

[0041] tert-butylphenol resin is produced by Hunan Yoshida Technology Co., Ltd. (trade name FQ2402);

[0042] Fluorocarbon modified polypropylene leveling agent (trade name: BASF substrate wetting agent Efka FL 3772).

[0043] All other solvent materials are commercially available industrial-grade products. As they are all highly polar solvents, the purity is controlled to be ≥98% and the moisture content to be ≤0.5%.

[0044] Example 1

[0045] Step a: Take 392 parts by weight of dimethyl sulfoxide, 196 parts by weight of dimethylformamide (DMF), and 196 parts by weight of dimethyltetrahydrofuran, add them to a reaction vessel equipped with a reflux and stirring device, and stir to mix evenly to obtain solution A;

[0046] Step b: Take the prepared solution A, and separately take out 8% of the total mass (62 parts, standard Aa solution) and 2% of the total mass (16 parts, standard Ab solution) for later use;

[0047] Step c: Add 200 parts by weight of polyvinylidene fluoride (PVDF) resin to the remaining solution A in the reactor in batches, while stirring and heating, gradually raising the temperature to 80°C, and keeping it at that temperature for 3 hours until it is fully dissolved into a homogeneous solution (solution B). Then cool it down to 50°C and keep it at that temperature for later use.

[0048] Step d: Similarly, using solution Aa from step b, dissolve 6 parts by weight of tert-butylphenol resin at room temperature to prepare a tert-butylphenol resin solution (solution C); similarly, using solution Ab from step b, dilute 0.2 parts by weight of fluorocarbon modified polypropylene leveling agent at room temperature to prepare a homogeneous liquid (solution D).

[0049] Step e: According to the mass fraction, add 10 parts of phenolic epoxy resin, and the C and D liquids prepared according to step d into the reaction vessel of liquid B obtained in step c in sequence. Keep the temperature of the materials in the vessel at 45℃ and stir thoroughly for 3 hours to form a uniform liquid. Measure the physicochemical parameters (viscosity / solid content), filter with a 200-250 mesh stainless steel filter screen, and obtain the finished polyvinylidene fluoride self-adhesive paint.

[0050] The adhesive strength of the finished product prepared in this embodiment is as follows: Figure 1 As shown, the self-adhesive varnish of enameled wire was coated onto the wire, wound into a coil, and baked at different temperatures for 10 minutes. The adhesion strength was then tested, and adhesion strength curves were obtained. The polyvinylidene fluoride self-adhesive varnish prepared in this embodiment of the invention has good adhesion characteristics. It begins to bond at 160°C, and the adhesion strength continues to increase with the baking temperature, reaching its maximum at 250°C, and then gradually decreasing from 260°C. This indicates that the product prepared in this embodiment has a wide bonding temperature range, strong adhesion, a wide range of winding process options, and a high yield of finished products.

[0051] Example 2

[0052] Step a: Take 445 parts by weight of dimethyl sulfoxide, 162 parts by weight of dimethylformamide (DMF), and 162 parts by weight of dimethyltetrahydrofuran, add them to a reaction vessel equipped with a reflux and stirring device, and stir to mix evenly to obtain solution A;

[0053] Step b: Take the prepared solution A, and separately take out 8% of the total mass (61 parts, standard Aa solution) and 2% of the total mass (15 parts, standard Ab solution) for later use;

[0054] Step c: Add 200 parts by weight of polyvinylidene fluoride (PVDF) resin to the remaining solution A in the reactor in batches, while stirring and heating, gradually raising the temperature to 80°C, and keeping it at that temperature for 2 hours until it is fully dissolved into a homogeneous solution (solution B). Then cool it down to 50°C and keep it at that temperature for later use.

[0055] Step d: Similarly, using solution Aa from step b, dissolve 12 parts by weight of tert-butylphenol resin at room temperature to prepare a tert-butylphenol resin solution (solution C); similarly, using solution Ab from step b, dilute 0.4 parts by weight of fluorocarbon modified polypropylene leveling agent at room temperature to prepare a homogeneous liquid (solution D).

[0056] Step e: According to the mass fraction, add 20 parts of phenolic epoxy resin, and the C and D liquids prepared according to step d into the reaction vessel of liquid B obtained in step c in sequence. Keep the temperature of the materials in the vessel at 45℃ and stir thoroughly for 2 hours to form a uniform liquid. Measure the physicochemical parameters (viscosity / solid content), filter with a 200-250 mesh stainless steel filter screen, and obtain the finished polyvinylidene fluoride self-adhesive paint.

[0057] Example 3

[0058] Step a: Take 495 parts by weight of dimethyl sulfoxide, 129 parts by weight of dimethylformamide (DMF), and 129 parts by weight of dimethyltetrahydrofuran, add them to a reaction vessel equipped with a reflux and stirring device, and stir to mix evenly to obtain solution A;

[0059] Step b: Take the prepared solution A, and separately take out 8% of the total mass (60 parts, standard Aa solution) and 2% of the total mass (15 parts, standard Ab solution) for later use;

[0060] Step c: Add 200 parts by weight of polyvinylidene fluoride (PVDF) resin to the remaining solution A in the reactor in batches, while stirring and heating, gradually raising the temperature to 80°C, and keeping it at that temperature for 3 hours until it is fully dissolved into a homogeneous solution (solution B). Then cool it down to 50°C and keep it at that temperature for later use.

[0061] Step d: Similarly, using solution Aa from step b, dissolve 18 parts by weight of tert-butylphenol resin at room temperature to prepare a tert-butylphenol resin solution (solution C); similarly, using solution Ab from step b, dilute 0.8 parts by weight of fluorocarbon modified polypropylene leveling agent at room temperature to prepare a homogeneous liquid (solution D).

[0062] Step e: According to the mass fraction, add 30 parts of phenolic epoxy resin, and the C and D liquids prepared according to step d into the reaction vessel of liquid B obtained in step c in sequence. Keep the temperature of the materials in the vessel at 45℃ and stir thoroughly for 2 hours to form a uniform liquid. Measure the physicochemical parameters (viscosity / solid content), filter with a 200-250 mesh stainless steel filter screen, and obtain the finished polyvinylidene fluoride self-adhesive paint.

[0063] Example 4

[0064] Step a: Take 551 parts by weight of dimethyl sulfoxide, 92 parts by weight of dimethylformamide (DMF), and 92 parts by weight of dimethyltetrahydrofuran, add them to a reaction vessel equipped with a reflux and stirring device, and stir to mix evenly to obtain solution A;

[0065] Step b: Take the prepared solution A, and separately take out 8% of the total mass (59 parts, standard Aa solution) and 2% of the total mass (14 parts, standard Ab solution) for later use;

[0066] Step c: Add 200 parts by weight of polyvinylidene fluoride (PVDF) resin to the remaining solution A in the reactor in batches, while stirring and heating, gradually raising the temperature to 80°C, and keeping it at that temperature for 3 hours until it is fully dissolved into a homogeneous solution (solution B). Then cool it down to 50°C and keep it at that temperature for later use.

[0067] Step d: Similarly, using solution Aa from step b, dissolve 24 parts by weight of tert-butylphenol resin at room temperature to prepare a tert-butylphenol resin solution (solution C); similarly, using solution Ab from step b, dilute 1.2 parts by weight of fluorocarbon modified polypropylene leveling agent at room temperature to prepare a homogeneous liquid (solution D).

[0068] Step e: According to the mass fraction, add 40 parts of phenolic epoxy resin, and the C and D liquids prepared according to step d into the reaction vessel of liquid B obtained in step c in sequence. Keep the temperature of the materials in the vessel at 45℃ and stir thoroughly for 2 hours to form a uniform liquid. Measure the physicochemical parameters (viscosity / solid content), filter with a 200-250 mesh stainless steel filter screen, and obtain the finished polyvinylidene fluoride self-adhesive paint.

[0069] Comparative Example 1

[0070] Step a: Take 400 parts by weight of dimethyl sulfoxide and 200 parts by weight of dimethylformamide (DMF).

[0071] 200 parts of dimethyltetrahydrofuran were added to a reaction vessel equipped with a reflux and stirring device and stirred until homogeneous.

[0072] Step b: Add 200 parts of polyvinylidene fluoride (PVDF) resin in batches, while stirring and heating, gradually raising the temperature to 80°C, and keeping it at that temperature for 3 hours until it is fully dissolved to form a homogeneous PVDF solution. Then cool it to room temperature, measure the physicochemical parameters (viscosity / solid content), and filter it with a 200-250 mesh stainless steel filter to obtain the finished product.

[0073] Experimental Example 1

[0074] 1. The physicochemical data of the polyvinylidene fluoride self-adhesive enameled wire coating prepared according to Examples 1-4 and Comparative Example 1 of the present invention are shown in Table 1 below.

[0075] Table 1

[0076]

[0077] The test items are the physical and chemical standards of self-adhesive varnish, including: appearance, solid content, viscosity, and copper sheet coating test of enameled wire self-adhesive varnish.

[0078] As can be seen from Table 1, according to embodiments 1 to 4 of the technical solution of the present invention, the products have good physical and chemical properties, all of which can meet the product design target requirements, the manufacturing formula and process are reliable, and the product quality is stable.

[0079] 2. The polyvinylidene fluoride self-adhesive enameled wires prepared in Examples 1-4 and Comparative Example 1 were coated to form self-adhesive enameled wires, and their performance was tested. The results are shown in Table 2 below:

[0080] Table 2

[0081]

[0082]

[0083] The test standard in Table 2 is GB / T6109-2008 enameled round winding wire.

[0084] *The bottom insulation of the wire is PAI (polyamide-imide);

[0085] *The test method refers to GB / T4074-2024 Test Method for Winding Wires;

[0086] *Oil and water resistance test: The sample coil was prepared by the spiral method and immersed in transmission oil containing 0.5% water at 100℃ for 168h. The amount of self-adhesive performance degradation was compared.

[0087] As shown in Table 2, the polyvinylidene fluoride self-adhesive enameled wire coated sample obtained using the technical solution of this invention has the following characteristics:

[0088] 1. It has good adaptability to coating processes, can meet the requirements of enameled wire production processes, and the performance of the products meets the expected results;

[0089] 2. Comparative Example 1 shows that the polyvinylidene fluoride self-adhesive paint product prepared using this technical solution has better overall performance than the comparative example product prepared with pure PVDF resin. Reasonable modification has obtained material advantages that exceed those of PVDF.

[0090] In contrast, the self-adhesive paint made from the formulation without modified resin in Comparative Example 1, when coated with wires, failed to meet the requirements for oil and water resistance, solvent resistance, coefficient of friction, and surface quality.

Claims

1. A self-adhesive polyvinylidene fluoride varnish for coating enameled wires with self-lubricating properties, characterized in that, Materials including the following parts by weight composition: Dimethyl sulfoxide: 392–551 parts Dimethylformamide (DMF): 92–196 parts Dimethyltetrahydrofuran: 160–350 parts Polyvinylidene fluoride resin: 200 parts Phenolic epoxy resin: 10-40 parts tert-butylphenol resin: 6-24 parts Fluorocarbon modified polypropylene leveling agent: 0.2 to 1.2 parts.

2. The self-lubricating polyvinylidene fluoride self-adhesive varnish for enameled wire coating according to claim 1, characterized in that, Polyvinylidene fluoride resin is used as the main film-forming material, combined with heat-resistant phenolic epoxy resin, curing agent tert-butylphenolic resin, and leveling agent fluorocarbon modified polypropylene, and dissolved in a mixed multi-boiling-range solvent system composed of dimethyl sulfoxide, dimethylformamide, and dimethyltetrahydrofuran, which are good solvents that are compatible with the above materials.

3. A method for preparing the self-lubricating polyvinylidene fluoride self-adhesive varnish for enameled wire coating as described in claim 1, characterized in that, Includes the following steps: Step a: Mix dimethyl sulfoxide, dimethylformamide (DMF), and dimethyltetrahydrofuran evenly to prepare solution A; Step b: Take the prepared solution A, and take out a portion of solution A and label it solution Aa and solution Ab respectively; Step c: Add polyvinylidene fluoride (PVDF) resin to the remaining solution A, stir and heat, keep warm until fully dissolved to form a homogeneous solution B, then cool and keep warm for later use. Step d: Similarly, using solution Aa from step b, dissolve tert-butylphenol resin at room temperature to prepare tert-butylphenol resin solution C. Similarly, using the Ab solution from step b, the fluorocarbon-modified polypropylene is diluted at room temperature to form a homogeneous liquid D solution. Step e: Add phenolic epoxy resin, and liquids C and D prepared according to step d to liquid B obtained in step c, and stir thoroughly to form a homogeneous liquid to obtain the finished polyvinylidene fluoride self-adhesive paint.

4. The preparation method according to claim 3, characterized in that, In step b, solution Aa and solution Ab preferably account for 8-10% and 2-5% of the total mass of solution A, respectively.

5. The preparation method according to claim 3, characterized in that, In step c, while stirring, the temperature is gradually increased to 80±5℃ and kept at this temperature for 2-3 hours until the solution is fully dissolved into a homogeneous solution B. Then, the temperature is lowered to 50±5℃ and kept at this temperature for later use.

6. The preparation method according to claim 3, characterized in that, In step e, phenolic epoxy resin, and liquids C and D prepared in step d are added sequentially to the reaction vessel containing liquid B obtained in step c. The temperature of the materials in the vessel is maintained at 45±5℃ and stirred thoroughly for 2-3 hours to form a homogeneous liquid.

7. The preparation method according to claim 6, characterized in that, The homogeneous liquid is filtered through a 200-250 mesh stainless steel filter to obtain a finished polyvinylidene fluoride self-adhesive paint.

8. The application of the self-lubricating polyvinylidene fluoride self-adhesive varnish for enameled wire coating as described in claim 1 in the coating manufacturing of winding wires for new energy vehicles, aerospace electronic wires, electrical winding wires for marine vehicles, and other electrical winding wires with chemical and material corrosive properties.

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