Anti-salt-mist high-temperature-resistant friction-resistant coating as well as preparation method and application thereof

Abstract

The invention provides a salt-spray-resistant high-temperature-resistant friction-resistant coating as well as a preparation method and application thereof. The coating comprises the following components in parts by weight: 75-88 parts of mineral oil, 2-8 parts of an anti-rust additive, 0.1-0.5 part of an anti-oxidation additive, 0.8-4.4 parts of a drier, 8-18 parts of a solid lubricating additive, 22-35 parts of film-forming resin, 15-18 parts of flaky metal pigment and 4-14 parts of a solvent, the mineral oil is selected from a mixture of dearomatized solvent oil, hydrogenated base oil and propylene glycol methyl ether acetate; the solid lubricating additive is selected from at least one of graphene or PEEK powder; the film-forming resin is selected from polyurethane resin; the flaky metal pigment is selected from non-floating neutral aluminum paste. The coating system provided by the invention is simple, pretreatment such as electroplating does not need to be carried out on the disc spring substrate, an effective protective layer can be formed through a simple coating process, the salt spray corrosion resistance, high temperature resistance and friction resistance of the semi-open flexible crimping type IGBT device are remarkably improved, and the long-term use reliability of the device is improved.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically providing an anti-salt spray, high-temperature resistant, and friction-resistant coating, its preparation method, and its application. Background Technology

[0002] Offshore wind power bases are undergoing large-scale planning and construction. The load centers are part of ultra-high-voltage transmission and long-distance flexible direct current transmission networks (VSC~HVDC) built to efficiently transmit clean energy from the west and offshore wind power to the east and central regions. The submarine cable landing points and onshore converter stations are concentrated in the eastern coastal areas, resulting in critical power facilities being exposed to harsh environments of high humidity and high salinity for extended periods. This causes irreversible corrosion to the precision semiconductor devices inside power electronic equipment and seriously affects the transmission security and long-term reliability of the power grid. Therefore, the ability of press-fit IGBT power semiconductors, the core power devices in converters and converter valves, to withstand long-term corrosion from salt spray environments is a fundamental hardware foundation and an inevitable choice for supporting energy security and ensuring the stable operation of major projects throughout their entire lifecycle.

[0003] For semi-open, flexible press-fit IGBT power semiconductor devices, the disc springs and their power components, as core components for balancing mechanical pressure, are directly related to the long-term reliability and service safety of the entire module due to their corrosion resistance. Disc springs typically use high-performance disc spring steel as the base material, which is prone to corrosion under long-term salt spray conditions. On the one hand, corrosion products can affect the elastic properties of the disc springs, leading to pressure relaxation or uneven pressure, thereby increasing chip contact resistance and internal thermal management. On the other hand, rust falling into other locations within the module can cause electrical insulation failure and continuously promote corrosion of metal components at the locations where the rust fell.

[0004] Therefore, rust prevention of disc springs and their power components is of paramount importance for internal protection. However, existing coatings cannot meet the special requirements of the disc spring's unique environment, thus necessitating improvements to coatings suitable for disc springs. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in the prior art. Therefore, one objective of this invention is to provide a salt spray resistant, high-temperature resistant, and abrasion-resistant coating, its preparation method, and its application, thereby meeting the special requirements of disc springs in semiconductor devices.

[0006] In complex environments, semi-open flexible press-fit IGBT devices are susceptible to corrosion from the gaps between the housing and sub-components, and between the housing and the gate PCB. As the core component for pressure regulation, the disc springs used in the main circuit elastic force application unit are highly susceptible to corrosion, which affects pressure stability and the rust debris can easily lead to device failure.

[0007] In view of this, in a first aspect, the present invention provides a salt spray resistant, high temperature resistant, and abrasion resistant coating, comprising: 75-88 parts by weight mineral oil, 2-8 parts by weight rust inhibitor, 0.1-0.5 parts by weight antioxidant, 0.8-4.4 parts by weight drier, 6-8 parts by weight solid lubricant, 35-42 parts by weight film-forming resin, 5-8 parts by weight flake metal pigment, 5-14 parts by weight true solvent and 5-14 parts by weight diluent; The mineral oil is selected from a mixture of dearomatized solvent oil, hydrogenated base oil, and propylene glycol methyl ether acetate; The solid lubricant additive is selected from at least one of graphene or PEEK powder; The film-forming resin is selected from polyurethane resin; The flake-shaped metallic pigment is selected from non-floating neutral aluminum silver paste.

[0008] The salt spray resistant, high-temperature resistant, and abrasion-resistant coating provided by this invention, through the specific selection of raw materials for each component and the adjustment of the mass fraction of each component, fully leverages the synergistic effect of each component, thereby significantly improving the coating's performance. It enhances the corrosion resistance of flexible press-fit IGBT power semiconductor devices in highly corrosive environments such as marine environments, particularly improving the rust prevention of disc spring assemblies with low corrosion resistance. Furthermore, the coating does not affect the device's pressure characteristics, thus significantly improving the device's abrasion resistance. In addition, the coating formed by this method exhibits excellent high-temperature resistance, helping the device maintain excellent performance in high-temperature environments, thereby ensuring the long-term operational reliability of the device in extreme environments.

[0009] In some embodiments of the present invention, the mass ratio of the dearomatic solvent oil, the hydrogenated base oil, and the PMA is (10-12):(1-3):(5-8). The dearomatic solvent oil can better dissolve and dilute highly polar rust inhibitors such as sulfonates, forming a homogeneous and stable solution. The hydrogenated base oil can serve as a non-volatile or slowly volatile continuous phase to ensure long-term use. PMA, as a key additive, can form a homogeneous and stable solution, avoiding the risk of precipitation. Using a mixture of dearomatic solvent oil, hydrogenated base oil, and propylene glycol methyl ether acetate as the mineral oil significantly improves the stability and uniformity of the coating.

[0010] In some embodiments of the present invention, the dearomatized solvent oil is selected from aliphatic hydrocarbon solvents with a distillation range of 160°C-250°C. Further, the aromatic content is less than 0.5%, preferably less than 0.1%.

[0011] In some embodiments of the present invention, the hydrotreated base oil has a kinematic viscosity of 15-50 cSt at 40°C. Preferably, it is a deeply hydrotreated Group III base oil, more preferably with a saturated hydrocarbon content greater than 98% and a sulfur content less than 5 ppm.

[0012] In some embodiments of the present invention, the rust-inhibiting additive is selected from a mixture of sulfonates, alkenyl succinic acid, and sulfonated castor oil, preferably in a mass ratio of (8-15):(1-3):(3-8). The use of the above-mentioned rust-inhibiting additive in the present invention can effectively improve the rust-inhibiting ability of the coating. The rust-inhibiting additive components can form a dense chemical adsorption film and a thicker physical barrier film: sulfonates provide an alkaline reserve, which can neutralize acidic corrosives in the environment and protect the molecular structure of alkenyl succinic acid from damage, allowing it to function effectively for a long time; sulfonated castor oil can also improve the solubility of the components and make the oil film more resilient and spreadable.

[0013] In some embodiments of the present invention, the drying agent is selected from a mixture of manganese, calcium, and zirconium, preferably in a mass ratio of zirconium, calcium, and manganese of (5-15):(2-8):(1-5). The use of the above-mentioned drying agent in the present invention can enhance the adhesion and strength of the polymer film, making it suitable for the functional requirements and applications of disc springs and their power components. Manganese soap is a powerful drying agent that can catalyze the oxidative polymerization reaction of base oil molecules on the metal surface, promoting slight cross-linking of unsaturated components in the base oil on the metal substrate surface; calcium soap, as an auxiliary drying agent, assists the main drying agent, zirconium soap, in promoting the intra-film cross-linking reaction, and can also synergistically provide alkaline reserves with sulfonates, enhancing resistance to acidic corrosive media.

[0014] In some embodiments of the present invention, the antioxidant additive is selected from a mixture of 2,6-di-tert-butyl-p-cresol (BHT) and tris(nonylphenyl) phosphite (TNPP), preferably in a mass ratio of (2-5):(1-3) of the 2,6-di-tert-butyl-p-cresol and the tris(nonylphenyl) phosphite. The present invention utilizes the above-mentioned classic antioxidant additive combination to significantly improve the antioxidant properties of coatings.

[0015] In some embodiments of the present invention, the hydroxyl value of the polyurethane resin is 50-150 mg KOH / g, preferably 80-120 mg KOH / g.

[0016] In some embodiments of the present invention, the flake metal of the flake metal pigment has a D 50 The particle size should be between 10μm and 25μm. Using flake-shaped metallic pigments within this range allows for the formation of overlapping and interwoven barriers within the coating during the curing process. During use, the disc spring is compressed, posing a risk of cracking to the anti-rust coating. When the coating is locally damaged, the exposed aluminum powder is preferentially corroded, and its byproducts can, to some extent, block the damaged area, achieving a degree of "self-healing" effect. A particle size D50 < 10μm results in an overly smooth coating surface that can affect the fit of the disc spring, while excessively large particle sizes can easily expose the substrate, hindering protection.

[0017] In some embodiments of the present invention, the true solvent is selected from ethyl acetate. Compared with other solvents, the present invention uses ethyl acetate as the true solvent, which serves two purposes: firstly, it completely dissolves the polyurethane resin as a solvent, ensuring the system's solubility, and works synergistically with the PMA to ensure the compatibility of solvent systems with large polarity differences, preventing turbidity and stratification after mixing; secondly, it can form a continuous evaporation gradient with the dearomatic solvent oil and the PMA, ensuring good leveling and allowing sufficient time for the aluminum powder to form a dense shielding layer under the action of surface tension.

[0018] In some embodiments of the present invention, the diluent is selected from butyl acetate. Compared to other solvents, the present invention uses butyl acetate as the diluent because it evaporates more slowly, provides a longer leveling time, makes the paint film surface smoother, and prevents the surface from cooling and condensing due to excessive evaporation.

[0019] Preferably, the coating comprises: 75-88 parts by weight of mineral oil, 2-8 parts by weight of rust inhibitor, 0.1-0.5 parts by weight of antioxidant, 0.8-4.4 parts by weight of drier, 6-8 parts by weight of solid lubricant, 35-42 parts by weight of film-forming resin, 5-8 parts by weight of flake metallic pigment, 5-14 parts by weight of true solvent, and 5-14 parts by weight of diluent; wherein the solid lubricant is selected from at least one of graphene or PEEK powder; the film-forming resin is selected from polyurethane resin; the flake metallic pigment is selected from non-floating neutral aluminum silver paste; and the mineral oil is selected from dearomatic solvent oil. The mixture comprises a hydrotreated base oil and propylene glycol methyl ether acetate (PMA), wherein the mass ratio of the dearomatic solvent oil, the hydrotreated base oil and the propylene glycol methyl ether acetate is (10-12):(1-3):(5-8); the rust inhibitor is selected from a mixture of sulfonates, alkenyl succinic acid and sulfonated castor oil, wherein the mass ratio of the sulfonates, the alkenyl succinic acid and the sulfonated castor oil is (8-15):(1-3):(3-8); the drier is selected from a mixture of manganese, calcium and zirconium, wherein the mass ratio of the zirconium, the calcium and the manganese is (5-15):(2-8):(1-5); the antioxidant is selected from a mixture of 2,6-di-tert-butyl-p-cresol and tris(nonylphenyl) phosphite, wherein the mass ratio of the 2,6-di-tert-butyl-p-cresol and the tris(nonylphenyl) phosphite is (2-5):(1-3).

[0020] In a second aspect, the present invention provides a method for preparing the above-mentioned anti-salt spray, high-temperature resistant, and abrasion-resistant coating, comprising: (1) Propylene glycol methyl ether acetate and the dearomatic solvent oil are stirred and mixed evenly at low speed, then heated slightly, and then the antioxidant additive and the rust inhibitor are added. After they are completely dissolved, the hydrogenated base oil is slowly added. After cooling to room temperature, the drier is added, and the mixture is dispersed evenly at high speed. The mixture is then filtered to obtain component A. (2) The ethyl acetate and the butyl acetate are slowly added to the polyurethane resin under low speed stirring, and then the stirring speed is increased until it is completely transparent. The solid lubricant is added slowly and evenly after the speed is reduced, and then the flake metal pigment is added slowly. After the addition is completed, the stirring speed is increased for at least 30 minutes to obtain component B. (3) Mix and stir the components A and B, and let them stand for at least 20 minutes to mature.

[0021] Therefore, the above method can be used to prepare coatings with excellent anti-salt spray, high temperature resistance and abrasion resistance.

[0022] Preferably, the first temperature is ≤50℃, and more preferably 40-50℃; Preferably, the maturation and standing time is not less than 20 minutes.

[0023] In a third aspect, the present invention proposes the application of the above-mentioned anti-salt spray, high temperature resistant and abrasion resistant coating in semiconductor devices, preferably the semiconductor device being the disc spring of a semi-open press-fit IGBT device.

[0024] In some embodiments of the present invention, the process of coating the disc spring with the coating material includes: immersing the disc spring in the coating material for 8-12 minutes, removing it and spinning it dry, and then drying it after 1-2 minutes.

[0025] Preferably, the spin dryer used for spin drying has a rotation speed of 800-1000 r / min; Preferably, the drying process is divided into four stages, in chronological order, with temperatures of 40°C, 60°C, 80°C, and 100°C for each stage, and a holding time of 2-4 hours for each stage. Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: (1) The anti-salt spray coating provided by the present invention achieves the dual functions of chemical protection and physical barrier. Its solvent and rust-preventive additives can actively neutralize acidic media and inhibit electrochemical corrosion by forming a passivation film and adsorption layer, and repel moisture and salt; at the same time, the added flake aluminum silver paste can build a dense physical barrier, effectively blocking the penetration of corrosive substances such as water, oxygen, and chlorine.

[0026] (2) This invention introduces graphene or PEEK powder as a solid lubricant and reinforcing material, which works synergistically during the repeated compression and rebound process of the disc spring, greatly reducing wear and friction. This not only prevents the protective film from failing due to damage, but also ensures long-term pressure stability. In addition, the solid lubricant can also improve the toughness and impact resistance of the film layer. Furthermore, the antioxidants in the coating, the solid lubricant, and the polyurethane resin together enhance the oxidation resistance and high-temperature resistance of the coating, essentially ensuring the stability and reliability of the device under harsh operating conditions.

[0027] (3) The coating technology proposed in this invention has both process simplicity and functional reliability: on the one hand, it adopts environmentally friendly materials and simple coating process (spin-drying + step drying), which is easy to mass-produce and forms an ultra-thin anti-rust layer only on the surface of the disc spring; on the other hand, the coating can effectively suppress volatilization and gas release, ensure the stability of semi-open devices, and does not affect electrical connection and pressure characteristics, ultimately greatly improving the corrosion resistance of power components and the long-term operational reliability in corrosive environments such as sea breeze. Detailed Implementation

[0028] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the invention in any way.

[0029] The materials used in the embodiments and comparative examples of this invention are as follows: The aromatics-free solvent oil is an aliphatic hydrocarbon solvent with a distillation range of 160°C-250°C; The hydrotreated base oil is a Group III base oil that has been hydrotreated, and its kinematic viscosity at 40°C is 35 cSt. The polyurethane resin is an aromatic polyurethane resin containing hydroxyl functional groups, and its hydroxyl value (based on solids) is 100 mg KOH / g. The sulfonate rust inhibitor is a highly alkaline calcium sulfonate with a total alkalinity of 300 mg KOH / g; The flake-shaped metallic pigment is a non-floating aluminum silver paste with a median particle size D. 50 It has a diameter of 18 μm and a pH value of 7.

[0030] Example 1 (1) This embodiment provides a coating, the specific components of which are as follows, by weight: Mineral oil: 45 parts of dearomatic solvent oil, 6 parts of hydrogenated base oil, and 28 parts of PMA; Rust inhibitor: 3.5 parts sulfonate, 0.5 parts alkenyl succinic acid, 1 part sulfonated castor oil; Antioxidant additives: BHT 0.2 parts, TNPP 0.1 parts; Drying agent: 1.4 parts zirconium, 0.7 parts calcium, 0.4 parts manganese; Solid lubricant additive: 7 parts graphene; Film-forming resin: 38.5 parts of polyurethane resin; True solvent: 12.5 parts of ethyl acetate; Diluent: 12.5 parts butyl acetate; Flake metallic pigment: 6.5 parts aluminum silver paste; (2) This embodiment provides a preparation process for the above-mentioned coating. The PMA and the dearomatic solvent oil are mixed evenly by low-speed stirring, then slightly heated (45°C) and the antioxidant (BHT, TNPP) and the rust inhibitor are added. After complete dissolution, the hydrotreated base oil is slowly added. After cooling to room temperature, the drier is added and dispersed evenly at high speed. The mixture is then filtered to obtain component A. The ethyl acetate and butyl acetate were slowly added to the polyurethane resin under low-speed stirring. Then the stirring speed was increased until the mixture was completely transparent. The solid lubricant was then slowly and evenly added at a reduced speed. The aluminum silver paste was then slowly added. After the addition was completed, the stirring speed was increased for 35 minutes to obtain component B. Mix and stir the components A and B, and let them mature and stand for 30 minutes.

[0031] (3) This embodiment provides a process for applying the above-mentioned coating to a disc spring. After dipping the disc spring sheet in the coating for 10 minutes, remove it and spin dry at a speed of 900 r / min. After 1 minute, remove it and place it in a dryer, and dry it by gradually increasing the temperature at 40℃, 60℃, 80℃ and 100℃ every 3 hours.

[0032] Example 2 The only difference between Example 2 and Example 1 is that the solid lubricant additive in Example 2 is PEEK powder.

[0033] Example 3 The difference between Example 3 and Example 1 is in step (1), where the composition of the coating is different, as detailed below: Mineral oil: 53 parts of dearomatic solvent oil, 5 parts of hydrogenated base oil, and 27 parts of PMA; Rust inhibitor: 4.6 parts sulfonate, 0.9 parts alkenyl succinic acid, 2.4 parts sulfonated castor oil; Antioxidant additives: BHT 0.32 parts, TNPP 0.18 parts; Drying agent: 2.4 parts zirconium, 1.2 parts calcium, 0.7 parts manganese; Solid lubricant additive: 8 parts graphene; Film-forming resin: 42 parts polyurethane resin; True solvent: 12 parts of ethyl acetate; Diluent: 14 parts butyl acetate; Flake metallic pigment: 8 parts aluminum silver paste.

[0034] Example 4 The only difference between Example 4 and Example 3 is that the solid lubricant additive in Example 4 is 8 parts of PEEK powder.

[0035] Example 5 The difference between Example 5 and Example 1 is in step (1), where the composition of the coating is different, as detailed below: Mineral oil: 43 parts of dearomatic solvent oil, 8 parts of hydrogenated base oil, and 29 parts of PMA; Rust inhibitor: 4.6 parts sulfonate, 0.9 parts alkenyl succinic acid, 2.4 parts sulfonated castor oil; Antioxidant additives: BHT 0.32 parts, TNPP 0.18 parts; Drying agent: 2.4 parts zirconium, 1.2 parts calcium, 0.7 parts manganese; Solid lubricant additive: 1 part graphene, 7 parts PEEK powder; Film-forming resin: 42 parts polyurethane resin; True solvent: 12 parts of ethyl acetate; Diluent: 14 parts butyl acetate; Flake metallic pigment: 8 parts aluminum silver paste.

[0036] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no solid lubricant additives are added to the coating of Comparative Example 1.

[0037] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the coating of Comparative Example 2 does not contain flake metallic pigments.

[0038] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the rust-preventive additives and solvents in the coating are different from those in Example 1. The rust-preventive additive is 5 parts of neutral sulfonate, the true solvent is 18 parts of acetone, and the diluent is 13 parts of 150# solvent oil.

[0039] The coatings prepared in each embodiment and comparative example were applied to disc springs and then assembled into power components for testing.

[0040] (1) Device pressure test: Standard pressure graph of press-fit power semiconductor device; (2) Load test: GB / T 1972, <3%-5%; (3) Fatigue test: JB / T 7366; (4) Adhesion of the grid: GB / T 9286; (5) Salt spray test: GB / T 4937.13-2018, Part 13: Salt spray; (6) Temperature shock: GB / T 2423.22-2012, Test method Test N: Temperature change; (7) Bending test: GB / T 1731; (8) Impact resistance: GB / T 1732-1993, ≥50 kg·cm; (9) Abrasion resistance: GB / T 1768-2006, <30mg.

[0041] The test results are shown in Table 1. Table 1

[0042] As can be seen from the data in Table 1, the addition of solid lubricant additives and flake metal pigments effectively improves the reliability and corrosion resistance of disc springs and their power components. Appropriate coating system components can ensure the long-term corrosion resistance and service reliability of the film layer.

[0043] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 50-90, in this specification it means specifically listing values ​​such as 51-89, 52-88… and 69-71 and 70-71, etc. For non-integer values, it may be appropriately considered that a unit is 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0044] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A salt spray resistant, high temperature resistant, and abrasion resistant coating, characterized in that, include: 75-88 parts by weight mineral oil, 2-8 parts by weight rust inhibitor, 0.1-0.5 parts by weight antioxidant, 0.8-4.4 parts by weight drier, 6-8 parts by weight solid lubricant, 35-42 parts by weight film-forming resin, 5-8 parts by weight flake metal pigment, 5-14 parts by weight true solvent and 5-14 parts by weight diluent; The mineral oil is selected from a mixture of dearomatized solvent oil, hydrogenated base oil, and propylene glycol methyl ether acetate; The solid lubricant additive is selected from at least one of graphene or PEEK powder; The film-forming resin is selected from polyurethane resin; The flake-shaped metallic pigment is selected from non-floating neutral aluminum silver paste.

2. The coating according to claim 1, characterized in that, The mass ratio of the dearomatic solvent oil, the hydrogenated base oil, and the propylene glycol methyl ether acetate is (10-12):(1-3):(5-8). And / or, the dearomatic solvent oil is selected from aliphatic hydrocarbon solvents with a distillation range of 160°C-250°C; And / or, the kinematic viscosity of the hydrotreated base oil at 40°C is 15-50 cSt.

3. The coating according to claim 1, characterized in that, The rust inhibitor is selected from a mixture of sulfonates, alkenyl succinic acid and sulfonated castor oil, preferably in a mass ratio of (8-15):(1-3):(3-8).

4. The coating according to any one of claims 1-3, characterized in that, The drying agent is selected from a mixture of manganese, calcium and zirconium, preferably the mass ratio of zirconium, calcium and manganese is (5-15):(2-8):(1-5).

5. The coating according to any one of claims 1-3, characterized in that, The antioxidant additive is selected from a mixture of 2,6-di-tert-butyl-p-cresol and tris(nonylphenyl) phosphite, preferably in a mass ratio of (2-5):(1-3) between the 2,6-di-tert-butyl-p-cresol and the tris(nonylphenyl) phosphite. And / or, the hydroxyl value of the polyurethane resin is 50-150 mg KOH / g, preferably 80-120 mg KOH / g.

6. The coating according to any one of claims 1-3, characterized in that, The flake metal of the flake metal pigment 50 The thickness is 10μm-25μm, preferably 15μm to 20μm; And / or, the pH value of the flake-shaped metallic pigment is 6-8.

7. The coating according to any one of claims 1-3, characterized in that, The true solvent is selected from ethyl acetate; And / or, the diluent is selected from butyl acetate.

8. A method for preparing an anti-salt spray, high-temperature resistant, and abrasion-resistant coating according to any one of claims 1-7, characterized in that, include: (1) Mix propylene glycol methyl ether acetate with dearomatic solvent oil until uniform, then heat and add antioxidant and rust inhibitor. After complete dissolution, add hydrogenated base oil. After cooling to room temperature, add drier, disperse evenly, and filter to obtain component A. (2) Add ethyl acetate and butyl acetate to polyurethane resin under stirring, and then stir until completely transparent. Add solid lubricant and flake metal pigment. After the addition is complete, stir for at least 30 minutes to obtain component B. (3) Mix and stir the components A and B, and let them mature and stand. The preferred step (1) involves heating to a temperature ≤50℃, preferably 40-50℃; Preferably, the maturation and standing time is not less than 20 minutes.

9. The application of the anti-salt spray, high temperature and friction resistant coating according to any one of claims 1-7 in semiconductor devices, wherein the semiconductor device is preferably a disc spring of a semi-open press-fit IGBT device.

10. The application according to claim 9, characterized in that, The process of coating the disc spring with the coating includes: immersing the disc spring in the coating for 8-12 minutes, then removing it and spinning it dry, and then drying it after 1-2 minutes; Preferably, the spin dryer used for spin drying has a rotation speed of 800-1000 r / min; Preferably, the drying process is divided into four stages, in chronological order, with temperatures of 40°C, 60°C, 80°C and 100°C for each stage, and a holding time of 2-4 hours for each stage.

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