Coating, preparation method and application and air conditioner

Abstract

The invention discloses a coating, a preparation method and application thereof and an air conditioner, and relates to the technical field of anti-corrosion coatings. The coating comprises a hydrophilic layer and a corrosion-resistant layer, and the corrosion-resistant layer is arranged on at least one surface of a base material and is arranged between the hydrophilic layer and the base material; wherein the raw materials of the corrosion-resistant layer comprise a magnetic modified filler, and the magnetic modified filler comprises a two-dimensional nanofiller and magnetic nanoparticles loaded on at least one surface of the two-dimensional nanofiller through an in-situ chemical reaction. The corrosion-resistant layer is effectively combined with the hydrophilic layer or the corrosion-resistant layer is effectively combined with the hydrophilic layer and the lubricating layer, so that the composite coating has good heat conduction performance while having corrosion resistance and weather resistance, the service life of the heat exchanger is greatly prolonged, and the energy-saving long-term effect of the heat exchanger is greatly improved. In addition, the composite coating provided by the invention is simple in preparation process and relatively low in cost, and has extremely high market application value.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coating technology, and particularly to a coating, its preparation method and application, and an air conditioner. Background Technology

[0002] Heat exchangers are the core material components in air conditioner manufacturing. The mainstream heat exchangers are tube-fin structures, with large-area metal heat dissipation fins wrapped around the refrigerant pipes. Corrosion products and stains accumulate on the surface of the fins and refrigerant pipes, which increases thermal resistance and reduces the air passage area, resulting in reduced heat exchange efficiency and a significant increase in air conditioning energy consumption. Summary of the Invention

[0003] The main objective of this invention is to develop an organic composite coating for heat exchanger fins. When applied to the surface of the heat exchanger fins, the coating provides both corrosion resistance and weather resistance while exhibiting excellent thermal conductivity, thereby significantly improving the service life and long-term energy efficiency of the heat exchanger.

[0004] To achieve the above objectives, the present invention proposes a coating comprising: a hydrophilic layer; and a corrosion-resistant layer, wherein the corrosion-resistant layer is disposed on at least one surface of a substrate and between the hydrophilic layer and the substrate; wherein the raw material of the corrosion-resistant layer comprises a magnetically modified filler, the magnetically modified filler comprising a two-dimensional nanofiller, and magnetic nanoparticles loaded on at least one surface of the two-dimensional nanofiller.

[0005] In one embodiment, the two-dimensional nanofiller includes at least one of graphene-based nanosheets, nanosheet silicates, nanosheet phosphates, nanosheet sulfides, nanosheet oxides, and nanosheet nitrides.

[0006] In one embodiment, the magnetic nanoparticles include at least one of elemental iron, cobalt, nickel, and alloy nanoparticles, nano-iron oxide particles, nano-sized ferrite particles, and nano-sized neodymium iron boron particles.

[0007] In one embodiment, the magnetic nanoparticles in the magnetically modified filler have a particle size of 10 nm to 50 nm.

[0008] In one embodiment, the magnetically modified filler has a sheet diameter of 0.5 μm to 10 μm.

[0009] In one embodiment, the weight ratio of the two-dimensional nanofiller to the magnetic nanoparticles in the magnetic modified filler is 1:(1~10).

[0010] In one embodiment, the surface of the magnetically modified filler is further coated with at least one layer of polymer shell material.

[0011] In one embodiment, the polymer shell material includes at least one of polydopamine and polysiloxane.

[0012] In one embodiment, the weight ratio of the polymer shell material to the magnetically modified filler is (5~20):(2~11).

[0013] In one embodiment, the thickness of the polymer shell material is 2 nm to 10 nm.

[0014] In one embodiment, the lamellar filler in the corrosion-resistant layer is disposed at an angle close to the surface of the substrate, and the two-dimensional plane of the lamellar filler forms a first angle with the surface of the substrate.

[0015] In one embodiment, the first angle formed between the two-dimensional plane of the sheet-like filler and the surface of the substrate is no greater than 45°.

[0016] In one embodiment, the two-dimensional plane of the lamellar filler, which constitutes not less than 80% of the amount in the corrosion-resistant layer, forms the first included angle with the surface of the substrate.

[0017] In one embodiment, the raw material of the corrosion-resistant layer includes 0.05wt% to 2wt% of the magnetically modified filler and the balance matrix material; the matrix material includes an aqueous resin.

[0018] In one embodiment, the waterborne resin includes at least one of waterborne fluorocarbon resin, waterborne polyester resin, waterborne silicone resin, waterborne acrylic resin, polyurethane resin, modified polyurethane resin, epoxy resin, modified epoxy resin, and polyamide resin.

[0019] In one embodiment, the raw material of the hydrophilic layer includes a first acrylate monomer, which contains a polar group.

[0020] In one embodiment, the first acrylate monomer includes at least one of hydroxyacrylate monomer and carboxyacrylate monomer.

[0021] In one embodiment, the hydrophilic layer comprises the following raw materials in parts by weight: first acrylate monomer: 10 to 40 parts; auxiliary agent: 0.5 to 2 parts; initiator: 0.5 to 3 parts.

[0022] In one embodiment, the hydrophilic layer further includes 5 to 40 parts by weight of a second acrylate monomer; the second acrylate monomer includes at least one of amino acrylate monomer, phosphate acrylate monomer, amide acrylate monomer, and epoxy acrylate monomer.

[0023] In one embodiment, the substrate includes any one of pure aluminum, aluminum alloy, zinc alloy, pure copper, copper alloy, and stainless steel.

[0024] In one embodiment, the coating amount of the corrosion-resistant layer is 0.3 g / m². 2 ~0.8g / m 2 ; and / or, the dry film thickness of the corrosion-resistant layer is 1μm~2μm.

[0025] In one embodiment, the coating further includes a lubricating layer disposed on the surface of the hydrophilic layer away from the substrate.

[0026] In one embodiment, the coating amount of the hydrophilic layer is 0.5 g / m². 2 ~1.3g / m 2 ; and / or, the coating amount of the lubricating layer is 0.05 g / m 2 ~0.5g / m 2 .

[0027] The present invention also proposes a method for preparing the coating, comprising the following steps: S1. A corrosion-resistant layer is formed by coating at least one surface of the substrate; S2. A hydrophilic layer is coated on the surface of the corrosion-resistant layer formed in step S1 to complete the preparation of the coating.

[0028] In one embodiment, the method for preparing the magnetically modified filler in the corrosion-resistant layer in step S1 includes the following steps: dispersing two-dimensional nanomaterials in a solvent, adding a magnetic precursor and stirring, adjusting the pH to 7-10 under a protective atmosphere, reacting at 20℃-80℃, filtering, washing the filter residue, and obtaining the magnetically modified filler.

[0029] In one embodiment, during step S1, at least two magnetic fields with different strengths are applied to the corrosion-resistant layer during the curing process.

[0030] In one embodiment, during step S1, at least three magnetic fields with different strengths are applied to the corrosion-resistant layer during the curing process, and the magnetic field strengths of the magnetic fields exhibit a gradient change trend.

[0031] In one embodiment, in step S1, the corrosion-resistant layer is pre-cured by applying a first magnetic field during the curing process, and then thermally cured by applying a second magnetic field to form the corrosion-resistant layer.

[0032] In one embodiment, the magnetic field direction of the first magnetic field and the magnetic field direction of the second magnetic field are parallel to the surface of the substrate.

[0033] In one embodiment, the first magnetic field is a uniform magnetic field with a field strength of 0.5T to 1T, and the second magnetic field is a uniform magnetic field with a field strength of 0.1T to 0.5T.

[0034] In one embodiment, the pre-curing temperature is 20℃~50℃, and the pre-curing time is 0.01h~1h.

[0035] In one embodiment, the thermosetting temperature is 200℃~300℃, and the thermosetting time is 0.01h~0.5h.

[0036] The present invention also proposes the application of the coating in heat exchangers.

[0037] The present invention also proposes an air conditioner, which includes the heat exchanger described above.

[0038] The technical solution of this invention designs a composite coating and its corresponding preparation process. A magnetic filler with a specific structure is added to the corrosion-resistant layer of the composite coating. Magnetic iron oxide nanoparticles are loaded onto the surface of two-dimensional nanoparticles and coated with a polymer layer. After coating the material containing the magnetic filler into a film, a specific magnetron orientation curing method is used to achieve high dispersion stability and planar oriented arrangement of the two-dimensional nanofiller in the resin matrix, forming a dense "brick-and-mortar" layered structure. This effectively blocks the corrosion of the substrate by water and oxygen, while having no significant impact on the thermal conductivity of the substrate. Secondly, this invention effectively combines the corrosion-resistant layer with a hydrophilic layer and a lubricating layer, enabling the composite coating to have good thermal conductivity while maintaining corrosion resistance and weather resistance, thus significantly improving the service life and long-term energy efficiency of the heat exchanger. Furthermore, the preparation process of the composite coating in this invention is simple and low-cost, possessing extremely high market application value. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the coating structure in one embodiment of the present invention; Figure 2 This is a schematic diagram of the coating structure in another embodiment of the present invention; Explanation of reference numerals in the attached figures: 100, Substrate; 201, First corrosion-resistant layer; 202, Second corrosion-resistant layer; 301, First hydrophilic layer; 302, Second hydrophilic layer; 401, First lubricating layer; 402, Second lubricating layer.

[0041] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0044] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0045] The technical problem addressed in this application is as follows: Heat exchangers are core material components in air conditioner manufacturing. The mainstream heat exchanger is a tube-fin structure, with large-area metal heat dissipation fins covering the refrigerant piping. Corrosion products and stains accumulate on the fin surface, increasing thermal resistance and reducing airflow area, leading to reduced heat exchange efficiency and significantly increased air conditioning energy consumption. Related technologies employ an epoxy-based organic coating on the metal heat dissipation fins; however, epoxy systems have poor resistance to light aging and their corrosion resistance rapidly degrades during service. Another related technology uses a fluorine-containing organic coating, but fluorine-containing systems are expensive and not suitable for large-scale application. Furthermore, the fluorine-containing base coat is highly hydrophobic, resulting in poor compatibility with the hydrophilic top coat, leading to poor performance balance. In addition, the thermal conductivity of organic coatings is significantly lower than that of metal substrates; thicker coatings increase air conditioning energy consumption, leading to energy waste.

[0046] To address the aforementioned technical problems, this application proposes a coating comprising: a hydrophilic layer and a corrosion-resistant layer, wherein the corrosion-resistant layer is disposed on at least one surface of a substrate and between the hydrophilic layer and the substrate; wherein the raw material of the corrosion-resistant layer comprises a magnetically modified filler, the magnetically modified filler comprising a two-dimensional nanofiller, and magnetic nanoparticles loaded on at least one surface of the two-dimensional nanofiller.

[0047] It should be noted that the present invention uses an in-situ synthesis method to load magnetic nanoparticles onto the surface of two-dimensional nanofillers, i.e., nanosheets, to obtain magnetically modified fillers. These fillers can respond to magnetic fields and can be arranged under the guidance of magnetic fields. By controlling the direction of the magnetic field, most of the sheet structures of the magnetically modified fillers form an angle with the substrate surface, making the overall sheet structure formed by the magnetically modified fillers in the corrosion-resistant layer difficult to be corroded by water and oxygen, thus protecting the substrate surface.

[0048] In one specific embodiment, refer to Figure 1 The coating includes a first corrosion-resistant layer 201, a second corrosion-resistant layer 202, a first hydrophilic layer 301, and a second hydrophilic layer 302; wherein the first corrosion-resistant layer 201 and the second corrosion-resistant layer 202 are disposed on two opposing surfaces of the substrate 100; the first hydrophilic layer 301 is disposed on the surface of the first corrosion-resistant layer 201 away from the substrate 100, and the second hydrophilic layer 302 is disposed on the surface of the second corrosion-resistant layer 202 away from the substrate 100.

[0049] It should be noted that the coating in this invention adopts a structure combining a corrosion-resistant layer and a hydrophilic layer, which has excellent anti-corrosion and hydrophilic properties, and can extend its service life. The inventors have discovered that by setting a hydrophilic layer on the surface of the corrosion-resistant layer, the hydrophilic effect and long-term hydrophilicity of the coating can be improved, and the detergency can be enhanced; it can also reduce the roughness of the side of the coated aluminum foil, reducing the adhesion of oil fumes and dust.

[0050] In one embodiment, the two-dimensional nanofiller includes at least one of graphene-based nanosheets, nanosheet silicates, nanosheet phosphates, nanosheet sulfides, nanosheet oxides, and nanosheet nitrides; wherein the graphene-based nanosheets can be graphene, graphene oxide, reduced graphene oxide, aminated graphene, fluorinated graphene, hydrogenated graphene, etc.; the two-dimensional nanofiller also includes other two-dimensional sheet materials that can be surface modified.

[0051] In one embodiment, the magnetic nanoparticles include at least one of elemental iron, cobalt, nickel, and alloy nanoparticles, nano-iron oxide particles, nano-sized ferrite particles, and nano-sized neodymium iron boron particles.

[0052] In one embodiment, the magnetic nanoparticles in the magnetically modified filler have a particle size of 10 nm to 50 nm. It is understood that the particle size of the magnetic nanoparticles can be any of 10 nm, 11 nm, 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, or 50 nm, and any particle size falling within the above range is acceptable.

[0053] In one embodiment, the two-dimensional nanofiller in the magnetically modified filler has a sheet diameter of 0.5 μm to 10 μm. It is understood that the sheet diameter of the two-dimensional nanofiller refers to the size of the filler in the two-dimensional planar direction. The sheet diameter of the two-dimensional nanofiller can be any one of 0.5 μm, 0.6 μm, 1 μm, 1.5 μm, 2 μm, 3 μm, 5 μm, 7 μm, or 10 μm, and any size falling within the above range is acceptable.

[0054] In one embodiment, the weight ratio of two-dimensional nanofiller to magnetic nanoparticles in the magnetically modified filler is 1:(1~10).

[0055] It should be noted that the two-dimensional nanofiller in this invention is used for loading magnetic nanoparticles and for them to contact and overlap on the substrate surface to form an effective sheet structure. By limiting the particle size of the magnetic nanoparticles, the sheet size of the two-dimensional nanofiller, and the ratio of their amounts, each two-dimensional nanofiller can more uniformly load magnetic nanoparticles, thereby making the magnetization intensity of each magnetically modified filler more similar and improving the uniformity of the corrosion-resistant layer.

[0056] In one embodiment, the surface of the magnetically modified filler is further coated with at least one polymer shell. In a specific embodiment, the polymer shell includes at least one of polydopamine and polysiloxane. It should be noted that the present invention forms a core-shell structure filler by coating the surface of magnetically modified particles with a polydopamine shell or a polysiloxane shell through in-situ polymerization or solution blending. Polydopamine has abundant polar groups such as hydroxyl and amino groups, which can form hydrogen bonds or covalent bonds with polar matrices such as epoxy resin and polyurethane, reducing interfacial energy and exhibiting adhesion and secondary reaction activity. It can be further grafted with functional molecules such as conductive polymers and flame retardants to achieve multifunctionality; the formed shell has good hydrophilicity. Polysiloxane contains silicon-oxygen bonds, exhibiting strong hydrophobicity and stability, giving the filler good high-temperature resistance and improving the thermal stability of the composite material.

[0057] In one embodiment, the weight ratio of polymer shell material to magnetically modified filler is (5~20):(2~11).

[0058] In one embodiment, the thickness of the polymer shell is 2 nm to 10 nm.

[0059] By defining the above technical features, a functional shell of suitable thickness is formed on the surface of the magnetically modified filler of the polymer shell material, which can isolate moisture, oxygen or corrosive media, prevent the magnetic particles from oxidizing or degrading, and extend the service life of the material without affecting the magnetization performance.

[0060] In one embodiment, the lamellar filler in the corrosion-resistant layer is inclined close to the surface of the substrate, and the two-dimensional plane of the lamellar filler forms a first angle with the surface of the substrate.

[0061] By adopting the above technical solution, when the two-dimensional plane of the lamellar filler forms an angle with the substrate surface, on the one hand, it effectively extends the corrosion path, greatly increases the total resistance of the corrosion circuit, and leads to a significant reduction in corrosion current; on the other hand, due to the labyrinth effect, oxygen is difficult to reach the substrate surface, resulting in strong cathodic polarization, and the corrosion potential of the entire system will shift negatively, greatly delaying the activation time of the metal under the coating.

[0062] In one embodiment, the first angle formed between the two-dimensional plane of the sheet-like filler and the surface of the substrate is no greater than 45°.

[0063] In one embodiment, the two-dimensional plane of the lamellar filler, which accounts for no less than 80% of the amount in the corrosion-resistant layer, forms the first included angle with the surface of the substrate.

[0064] In a preferred embodiment, the first angle formed between the two-dimensional plane of the lamellar filler, which accounts for no less than 80% of the amount in the corrosion-resistant layer, and the surface of the substrate is no greater than 45°.

[0065] It should be noted that by controlling the angle between the sheets of most magnetically modified fillers and the macroscopic surface of the substrate to be less than 45°, the transmission path of corrosive media can be made longer and more tortuous, thereby enhancing the labyrinth effect. It can also greatly compress the thickness of the corrosion-resistant layer, thereby significantly reducing the overall thickness of the coating, which is beneficial to maximizing the preservation of the thermal conductivity of the substrate.

[0066] In one embodiment, the raw material for the corrosion-resistant layer includes 0.05 wt% to 2 wt% of magnetically modified filler and the balance being a matrix material; the matrix material includes an aqueous resin. In a specific embodiment, the aqueous resin includes at least one of an aqueous fluorocarbon resin, an aqueous polyester resin, an aqueous silicone resin, an aqueous acrylic resin, a polyurethane resin, a modified polyurethane resin, an epoxy resin, a modified epoxy resin, and a polyamide resin.

[0067] It is understood that the coating in this invention only requires 0.05wt%~2wt% of magnetically modified filler for a low load to achieve a high level of magnetron-controlled directional barrier coating, resulting in lower raw material and preparation costs. Furthermore, the substrate material of the corrosion-resistant layer is a water-based resin containing a large number of polar groups, exhibiting good compatibility and adhesion with the hydrophilic layer, further enhancing the coating's protective effect on the substrate.

[0068] In one embodiment, the raw material for the hydrophilic layer includes a first acrylate monomer containing a polar group.

[0069] It is understandable that the base material of the hydrophilic layer is an acrylate copolymer, and the acrylate monomers that form the copolymer all contain polar groups, so the acrylate copolymer has extremely strong polarity.

[0070] In one specific embodiment, the first acrylate monomer includes at least one of hydroxyacrylate monomers and carboxyacrylate monomers. It is understood that in this embodiment, the base material of the hydrophilic layer is obtained by copolymerization of hydroxyacrylate monomers and / or carboxyacrylate monomers.

[0071] Furthermore, the hydroxyacrylate monomer can be at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyhexyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, including but not limited to the hydroxyacrylate monomers listed above. Furthermore, the carboxyacrylate monomer includes at least one of acrylic acid and methacrylic acid, including but not limited to the carboxyacrylate monomers listed above. By adopting the above technical solution, strong hydrophilic functional groups and reactive active sites are introduced into the hydrophilic layer. Through chemical means, strong hydrophilic groups are anchored in the coating, and a high-strength cross-linked network is constructed, resulting in a high-performance, long-life hydrophilic coating.

[0072] In one embodiment, the hydrophilic layer comprises the following raw materials in parts by weight: first acrylate monomer: 10 to 40 parts; additives: 0.5 to 2 parts; initiator: 0.5 to 3 parts.

[0073] It is understood that initiators include, but are not limited to, persulfates or azo compounds. Additives include at least one of surfactants, defoamers, leveling agents, and dispersants. By adding these additives, the surface tension and uniformity of the coating formed by the paint can be improved, thereby forming a high-quality coating. In a specific embodiment, the surfactant can be sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, or sodium dodecyl sulfate, including but not limited to the surfactants listed above. In a specific embodiment, the defoamer can be a silicone defoamer or a polyether defoamer, including but not limited to the defoamers listed above. In a specific embodiment, the dispersant can be a sodium polycarboxylate dispersant, an ammonium polyacrylate dispersant, or a silicone dispersant, including but not limited to the dispersants listed above.

[0074] Further, the hydrophilic layer comprises the following raw materials in parts by weight: a first acrylate monomer: 10 to 40 parts; a second acrylate monomer: 5 to 40 parts; an auxiliary agent: 0.5 to 2 parts; an initiator: 0.5 to 3 parts; and water: 30 to 50 parts; wherein the second acrylate monomer comprises at least one of amino acrylate monomer, phosphate acrylate monomer, amide acrylate monomer, and epoxy acrylate monomer.

[0075] It should be noted that the second acrylate monomer introduces new, more reactive polar groups into the polymerization system, which can play a synergistic role, significantly improve the performance of the hydrophilic layer, and also facilitate further cross-linking between the hydrophilic layer and the waterborne resin matrix material in the corrosion-resistant layer.

[0076] In one embodiment, the substrate includes any one of pure aluminum, aluminum alloy, zinc alloy, pure copper, copper alloy, and stainless steel.

[0077] In one embodiment, the coating amount of the corrosion-resistant layer is 0.3 g / m². 2 ~0.8g / m 2 For example, the coating amount of the corrosion-resistant layer can be 0.3 g / m². 2 0.31g / m 2 0.4g / m 2 0.5g / m 2 0.8g / m 2 This invention does not impose specific limitations; anything falling within the above scope is acceptable.

[0078] In one embodiment, the coating amount of the hydrophilic layer is 0.5 g / m². 2 ~1.3g / m 2For example, the coating amount of the hydrophilic layer can be 0.5 g / m². 2 0.51g / m 2 0.6g / m 2 0.8g / m 2 1g / m 2 1.3g / m 2 This invention does not impose specific limitations; anything falling within the above scope is acceptable.

[0079] In one embodiment, the dry film thickness of the corrosion-resistant layer is 1μm to 2μm; for example, the dry film thickness of the corrosion-resistant layer can be 1μm, 1.1μm, 1.2μm, 1.5μm, or 2μm. The present invention does not make specific limitations, and any thickness within the above range is acceptable.

[0080] In a preferred embodiment, in the corrosion-resistant layer, magnetically modified filler is deposited on the side close to the substrate to form a lamellar structure. By controlling the proportion of magnetically modified filler with an angle of less than 45° between the two-dimensional nanofiller and the macroscopic surface of the substrate to exceed 80%, the dry film thickness of the corrosion-resistant layer is maintained at 0.8 μm to 1.6 μm. By employing the above-mentioned technical means, the corrosion resistance of the coating can be further enhanced, while the overall thickness of the coating can be significantly reduced, which is beneficial to maximizing the preservation of the thermal conductivity of the heat exchanger fin substrate.

[0081] In one embodiment, the coating further includes a lubricating layer disposed on the surface of the hydrophilic layer away from the anti-corrosion layer. (See reference...) Figure 2 The coating includes a first corrosion-resistant layer 201, a second corrosion-resistant layer 202, a first hydrophilic layer 301, a second hydrophilic layer 302, a first lubricating layer 401, and a second lubricating layer 402; wherein the first corrosion-resistant layer 201 and the second corrosion-resistant layer 202 are disposed on two opposing surfaces of the substrate 100; the first hydrophilic layer 301 is disposed on the surface of the first corrosion-resistant layer 201 away from the substrate 100, and the second hydrophilic layer 302 is disposed on the surface of the second corrosion-resistant layer 202 away from the substrate 100; the first lubricating layer 401 is disposed on the surface of the first hydrophilic layer 301 away from the substrate 100, and the second lubricating layer 402 is disposed on the surface of the second hydrophilic layer 302 away from the substrate 100.

[0082] In one specific embodiment, the material of the lubricating layer can be a conventional paint used for surface coatings on metal substrates. In this embodiment, a water-based self-lubricating hydrophilic coating, specifically model HW6550, purchased from Guangdong Huigu Chemical Co., Ltd., is used. After being stirred evenly, it is coated on the surface of the hydrophilic layer away from the substrate. After curing and cross-linking, a lubricating layer is formed.

[0083] In one embodiment, the coating amount of the lubricating layer is 0.05 g / m. 2 ~0.5g / m 2For example, the coating amount of the lubricating layer can be 0.05 g / m. 2 0.1g / m 2 0.2g / m 2 0.3g / m 2 0.5g / m 2 This invention does not impose specific limitations; anything falling within the above scope is acceptable.

[0084] It should be noted that the lubricating layer needs to have a specific thickness to better protect the hydrophilic and anti-corrosion layers, thereby extending the service life of the substrate. When the coating amount on one side of the lubricating layer is too low, the lubrication effect of the lubricating layer is relatively poor; when the coating amount on one side of the lubricating layer is too high, the thickness of the lubricating layer is relatively thick, which will reduce the hydrophilicity of the coating and result in relatively poor performance.

[0085] In one embodiment, the lubricating layer includes at least one of an ultraviolet absorber, a light stabilizer, and a quencher. In a specific embodiment, the lubricating layer includes at least one of 0.1 wt% to 1 wt% of an ultraviolet absorber, 0.1 wt% to 1 wt% of a light stabilizer, and 0.1 wt% to 1 wt% of a quencher.

[0086] It is understandable that adding the above-mentioned amount of anti-aging agent to the corrosion-resistant layer, lubrication layer or hydrophilic layer can significantly improve the weather resistance of the coated aluminum foil, make the coated aluminum foil have better continuous hydrophilicity or corrosion resistance, and significantly extend its service life.

[0087] The present invention also proposes a method for preparing the above-mentioned coating, comprising the following steps: S1. A corrosion-resistant layer is formed by coating at least one surface of the substrate; S2. A hydrophilic layer is coated on the surface of the corrosion-resistant layer formed in step S1 to complete the preparation of the coating.

[0088] In one specific embodiment, the method for preparing the above coating includes the following steps: S1. A corrosion-resistant layer is formed by coating at least one surface of the substrate; S2. A hydrophilic layer is formed by coating the surface of the corrosion-resistant layer formed in step S1. S3. A lubricating layer is formed by coating the surface of the hydrophilic layer formed in step S2, thus completing the preparation of the coating.

[0089] In one embodiment, the method for preparing the magnetically modified filler in the corrosion-resistant layer includes the following steps: dispersing two-dimensional nanomaterials in a solvent, adding a magnetic precursor and stirring, adjusting the pH to 7-10 under a protective atmosphere, reacting at 20°C-80°C, filtering, washing the filter residue, and obtaining the magnetically modified filler.

[0090] It should be noted that in this embodiment, magnetically modified fillers are prepared by in-situ co-precipitation, which hydrolyzes metal ions and co-precipitates them into magnetic oxides, thereby growing magnetic nanoparticles in-situ on the surface of two-dimensional nanosheets to form magnetically modified fillers.

[0091] In one specific embodiment, the magnetic precursor comprises an ferric salt and a ferrous salt, wherein the molar ratio of ferric ions in the ferric salt to ferrous ions in the ferrous salt is (2~4):1. It is understood that by controlling the ratio of ferric ions to ferrous ions in the magnetic precursor, the crystal structure and phase purity can be further controlled, the formation of Fe(OH)₂ impurity phase can be suppressed, and the Fe content can be reduced. 2+ Oxidation loss during the reaction process; secondly, it can also regulate the particle size of magnetically modified particles. The inventors discovered during their research that Fe... 2+ An excessively high proportion will result in larger magnetically modified particles, increasing magnetic saturation strength but decreasing coercivity; Fe 3+ Increasing the proportion helps to obtain a smaller and more uniform particle size distribution.

[0092] In a preferred embodiment, the method for preparing the magnetically modified filler includes the following steps: Two-dimensional nanomaterials were dispersed in deionized water, a magnetic precursor was added and stirred, and ammonia was added dropwise under nitrogen protection to adjust the pH to 7-10. The reaction was carried out at 20℃-80℃ for 1-5 hours. The mixture was filtered, and the filter residue was washed to obtain magnetically modified filler. The magnetically modified filler was placed in an alkaline buffer solution, dopamine hydrochloride was added, and the mixture was stirred and reacted for 5-24 hours. The mixture was filtered, and the filter residue was washed to obtain polydopamine-coated magnetically modified filler.

[0093] It is understandable that a polydopamine shell is generated on the surface of the magnetically modified filler through the self-polymerization reaction of dopamine hydrochloride, which has good hydrophilicity and good compatibility with the matrix material of the corrosion-resistant layer.

[0094] In one embodiment, step S1, the method for preparing the corrosion-resistant layer includes the following steps: A corrosion-resistant coating is prepared by mixing magnetically modified filler with water-based resin, stirring, and degassing; the corrosion-resistant coating is then applied to the surface of a substrate and cured to form a corrosion-resistant layer.

[0095] In one specific embodiment, in step S1, at least two magnetic fields with different magnetic field strengths are applied to the corrosion-resistant layer during the curing process.

[0096] In another preferred embodiment, in step S1, during the curing process of the corrosion-resistant layer, at least three magnetic fields with different magnetic field strengths are applied, and the magnetic field strengths of the magnetic fields exhibit a gradient change trend.

[0097] It should be noted that the present invention mixes magnetically modified filler with water-based resin matrix to form a coating and applies it to form a coating layer; under the action of gradient magnetic field, the lamellar filler is induced to oriented and form a specific macroscopic angle with the substrate surface, and after curing, a dense "brick-mud" layered structure is constructed, so that the coating has excellent water vapor barrier, heat exchange performance and corrosion resistance.

[0098] In one embodiment, in step S1, during the curing process of the corrosion-resistant layer, a first magnetic field is applied for pre-curing, and then a second magnetic field is applied for thermal curing to complete the curing and form the coating.

[0099] In one embodiment, in step S1, the magnetic field direction of the first magnetic field and the magnetic field direction of the second magnetic field are parallel to the surface of the substrate to be coated.

[0100] In a preferred embodiment, the method for preparing the corrosion-resistant layer includes the following steps: A corrosion-resistant coating is applied to the surface of a substrate. A first magnetic field parallel to the surface of the substrate is applied and controlled to a magnitude of 0.5T~1T. The coating is then pre-cured at 20℃~50℃ for 0.1h~1h. Subsequently, a second magnetic field parallel to the surface is applied and controlled to a magnitude of 0.1T~0.5T. The coating is then heat-cured at 200℃~300℃ for 0.01h~0.5h to form a coating.

[0101] It is understood that this invention employs a staged curing mechanism: the pre-curing stage maintains the mobility of the filler, while the thermosetting stage locks the orientation structure through resin cross-linking; simultaneously, a strong magnetic field is applied during the pre-curing stage to achieve rapid orientation, and the magnetic field strength is reduced during the thermosetting stage to maintain coating stability. This keeps the included angle generally at a low level, fully utilizing the excellent barrier properties of two-dimensional materials to improve the shielding and barrier effects and labyrinth effect of the coating, further enhancing its corrosion resistance.

[0102] In one embodiment, step S2, the method for preparing the hydrophilic coating includes the following steps: mixing a first acrylate monomer, an additive and water, then mixing it with a second acrylate monomer, adding an initiator, heating to react, and then adjusting the solid content with water to obtain the hydrophilic coating.

[0103] In one specific embodiment, the hydrophilic coating is prepared by the following method: mixing a first acrylate monomer, an additive, and water at 50°C to 70°C, then mixing with a second acrylate monomer, adding an initiator, reacting at 80°C to 90°C for 30 to 50 minutes, and then adjusting the solid content to 20% to 40% with water to obtain the hydrophilic coating.

[0104] According to an embodiment of the present invention, when preparing a coating on a substrate surface, a corrosion-resistant coating is first applied as a base coat and cured to form a corrosion-resistant layer, followed by a hydrophilic coating and cured to form a hydrophilic layer, thereby forming a coating. The corrosion-resistant coating is cured under the influence of a magnetic field, while the hydrophilic coating undergoes thermal curing at a temperature of 215°C to 255°C, until the hydrophilic layer is completely hardened, thus completing the curing process.

[0105] In one specific embodiment, a lubricating layer coating is applied to the surface of the cured hydrophilic layer and then heat-cured until the lubricating layer is completely hardened, thus completing the curing process.

[0106] The present invention also proposes the application of the above coating in the field of heat exchangers, which can extend the service life of heat exchangers, improve the hydrophilicity effect and long-term hydrophilicity performance of heat exchangers, and improve the decontamination ability.

[0107] The present invention also proposes an air conditioner that includes the above-mentioned heat exchanger.

[0108] In one specific embodiment, the coating of the present invention is applied to the surface of heat exchanger fins and / or refrigerant pipes, especially the surface of heat exchanger fins of air conditioners. After long-term operation, the performance degradation of the air conditioner is smaller, resulting in a better user experience.

[0109] The present invention will be further illustrated below through specific embodiments: The raw materials, reagents, or devices used in the embodiments of this invention are all commercially available. Unless otherwise specified, this invention does not impose any restrictions on the source of raw materials.

[0110] Preparation Example 1 Example 1 shows a fin coated with a corrosion-resistant layer, with aluminum foil as the fin substrate.

[0111] The method for preparing the corrosion-resistant layer of the fins in Example 1 includes the following steps: 1g of filler was mixed with water-based silicone resin at a mass ratio of 5:9995, mechanically stirred at 800r / min for 20min, and allowed to stand for 12h to obtain a corrosion-resistant coating layer. The corrosion-resistant coating layer was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 30℃ for 0.3h while simultaneously applying a uniform magnetic field of 0.5T parallel to the substrate direction, followed by heat curing at 280℃ for 0.05h while simultaneously applying a uniform magnetic field of 0.3T parallel to the substrate direction, forms a corrosion-resistant layer with a thickness of approximately 0.9μm on the fin surface.

[0112] The preparation method of the filler in Preparation Example 1 includes the following steps: 1 g of graphene was dispersed in 200 mL of deionized water and sonicated at 200 W for 20 min. 0.8 g of FeCl2·4H2O and 2.16 g of FeCl3·6H2O were added, and ammonia was added dropwise under nitrogen protection until the pH was about 10. The mixture was reacted at 70 °C for 2 hours and then washed with magnetic separation to obtain Fe3O4-supported graphene oxide. The product was dispersed in Tris buffer and the pH was controlled to be about 8.5. 2 g of dopamine hydrochloride was added and the mixture was stirred for 12 hours to obtain polydopamine-coated magnetically modified filler.

[0113] The magnetic separation washing parameters are as follows: magnetic field strength is 0.1T, and rising water velocity is 0.5cm / s to 1cm / s.

[0114] Preparation Example 2 Preparation Example 2 is a fin with only a corrosion-resistant coating on the bottom, and the fin substrate is aluminum foil.

[0115] The method for preparing the corrosion-resistant layer of the fins in Example 2 includes the following steps: 1g of filler was mixed with water-based silicone resin at a mass ratio of 1:999, mechanically stirred at 800r / min for 20min, and allowed to stand for 12h to obtain a corrosion-resistant coating layer. The corrosion-resistant coating layer was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 30℃ for 0.3h while simultaneously applying a uniform magnetic field of 0.5T parallel to the substrate direction, followed by heat curing at 280℃ for 0.05h while simultaneously applying a uniform magnetic field of 0.3T parallel to the substrate direction, forms a corrosion-resistant layer with a thickness of approximately 1.1μm on the fin surface.

[0116] The packing material in Preparation Example 2 was prepared using the same method as in Preparation Example 1.

[0117] Preparation Example 3 Preparation Example 3 is a fin with only a corrosion-resistant coating on the bottom, and the fin substrate is aluminum foil.

[0118] The method for preparing the corrosion-resistant layer of the fins in Example 3 includes the following steps: 1g of filler was mixed with water-based silicone resin at a mass ratio of 1:99, mechanically stirred at 800r / min for 20min, and allowed to stand for 12h to obtain a corrosion-resistant coating layer. The corrosion-resistant coating layer was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 30℃ for 0.3h while simultaneously applying a uniform magnetic field of 0.5T parallel to the substrate direction, followed by heat curing at 280℃ for 0.05h while simultaneously applying a uniform magnetic field of 0.3T parallel to the substrate direction, forms a corrosion-resistant layer with a thickness of approximately 1.3μm on the fin surface.

[0119] The packing material in Preparation Example 3 was prepared using the same method as in Preparation Example 1.

[0120] Preparation Example 4 Preparation Example 4 is a fin with only a corrosion-resistant coating on the bottom, and the fin substrate is aluminum foil.

[0121] The method for preparing the corrosion-resistant layer of the fins in Example 4 includes the following steps: Filler and water-based silicone resin were mixed at a mass ratio of 1:49, mechanically stirred at 800 r / min for 20 min, and allowed to stand for 12 h to obtain a corrosion-resistant coating layer. The corrosion-resistant coating layer was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5 g / m². 2 Pre-curing at 30℃ for 0.3h while simultaneously applying a uniform magnetic field of 0.5T parallel to the substrate direction, followed by heat curing at 280℃ for 0.05h while simultaneously applying a uniform magnetic field of 0.3T parallel to the substrate direction, forms a corrosion-resistant layer with a thickness of approximately 1.3μm on the fin surface.

[0122] The packing material in Preparation Example 4 was prepared using the same method as in Preparation Example 1.

[0123] Preparation Example 5 Preparation Example 5 is a fin with only a corrosion-resistant coating on the bottom, and the fin substrate is aluminum foil.

[0124] The method for preparing the corrosion-resistant layer of the fins in Preparation Example 5 is the same as that in Preparation Example 4.

[0125] The preparation method of the filler in Example 5 includes the following steps: 1g of graphene was dispersed in 200 mL of deionized water and sonicated at 200W for 20 min. 0.8g of FeCl2·4H2O and 2.16g of FeCl3·6H2O were added, and ammonia was added dropwise under nitrogen protection until the pH was about 10. The reaction was carried out at 70℃ for 2 hours, followed by magnetic separation and washing to obtain the magnetically modified filler.

[0126] Preparation of Comparative Example 1 The method for preparing the corrosion-resistant layer of the fins in Comparative Example 1 includes the following steps: 1000g of water-based silicone resin was ultrasonically treated (200W, 20 minutes), mechanically stirred at 800r / min for 20 minutes, and allowed to stand for 12 hours to obtain a coating. The coating was then roller-coated onto a substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 40℃ for 0.5 hours, followed by heat curing at 280℃ for 0.1 hours, yields the coating.

[0127] Preparation of Comparative Example 2 Comparative Example 2 is a fin with only a corrosion-resistant coating on the bottom. The fin substrate is aluminum foil. The method for preparing the corrosion-resistant coating of the fin in Comparative Example 2 includes the following steps: 1g of graphene and water-based organosilicon resin were mixed at a mass ratio of 5:9995, mechanically stirred at 800 rpm for 20 minutes, and allowed to stand for 12 hours to obtain a corrosion-resistant coating layer. The corrosion-resistant coating layer was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 40℃ for 0.5 hours and heat curing at 280℃ for 0.1 hours forms a corrosion-resistant layer with a thickness of about 1.5μm on the fin surface.

[0128] Preparation of Comparative Example 3 Comparative Example 3 is a fin with only a corrosion-resistant coating on the bottom. The fin substrate is aluminum foil. The method for preparing the corrosion-resistant coating of the fin in Comparative Example 3 includes the following steps: 1g of graphene and water-based silicone resin were mixed at a mass ratio of 1:999, mechanically stirred at 800r / min for 20min, and allowed to stand for 12h to obtain a corrosion-resistant coating layer. The corrosion-resistant coating layer was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 40℃ for 0.5 hours and heat curing at 280℃ for 0.1 hours forms a corrosion-resistant layer with a thickness of approximately 2.8μm on the fin surface.

[0129] Preparation of Comparative Example 4 Comparative Example 4 shows a fin with only a corrosion-resistant coating on the underside. The fin substrate is aluminum foil. The method for preparing the corrosion-resistant coating of the fin in Comparative Example 4 includes the following steps: 1g of graphene and water-based silicone resin were mixed at a mass ratio of 1:99, mechanically stirred at 800r / min for 20min, and allowed to stand for 12h to obtain a corrosion-resistant coating. The corrosion-resistant coating was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 40℃ for 0.5 hours and heat curing at 280℃ for 0.1 hours forms a corrosion-resistant layer with a thickness of approximately 5.5μm on the fin surface.

[0130] Preparation of Comparative Example 5 Comparative Example 5 is a fin with only a corrosion-resistant coating on the bottom. The fin substrate is aluminum foil. The method for preparing the corrosion-resistant coating of the fin in Comparative Example 5 includes the following steps: 1g of graphene and water-based silicone resin were mixed at a mass ratio of 1:49, mechanically stirred at 800r / min for 20min, and allowed to stand for 12h to obtain a corrosion-resistant coating layer. The corrosion-resistant coating layer was then roller-coated onto the substrate, with the coating thickness controlled at approximately 0.5g / m². 2 Pre-curing at 40℃ for 0.5 hours and heat curing at 280℃ for 0.1 hours forms a corrosion-resistant layer with a thickness of approximately 11.2 μm on the fin surface.

[0131] Example 1 Example 1: A hydrophilic layer was coated on the surface of the corrosion-resistant layer of Preparation Example 1.

[0132] The hydrophilic layer in Example 1 comprises the following parts by weight of raw materials: Hydroxyethyl acrylate: 15 parts by weight; Acrylic acid: 5 parts by weight; Methyl methacrylate: 10 parts by weight; Sodium persulfate: 1 part by weight; Sodium dodecylbenzenesulfonate: 1 part by weight; Water: 30 parts by weight.

[0133] The method for preparing the hydrophilic layer of the coating in Example 1 includes the following steps: Hydroxyethyl acrylate, acrylic acid, N-hydroxymethylacrylamide, and sodium dodecylbenzenesulfonate were mixed at 50°C, followed by the addition of sodium persulfate. The mixture was reacted at 80°C for 30 minutes, and then water was added and stirred to obtain a hydrophilic coating layer. The hydrophilic coating layer was then roller-coated onto the surface of the corrosion-resistant layer, with the coating thickness controlled at approximately 0.5 g / m². 2 The hydrophilic layer was prepared by curing at 220℃ for 15 seconds.

[0134] Example 2 Example 2: A hydrophilic layer was coated on the surface of the corrosion-resistant layer of Example 2.

[0135] The hydrophilic layer in Example 2 comprises the following parts by weight of raw materials: Hydroxyethyl acrylate: 15 parts by weight; Acrylic acid: 5 parts by weight; N-hydroxymethylacrylamide: 5 parts by weight; Sodium persulfate: 1 part by weight; Sodium dodecylbenzenesulfonate: 1 part by weight; Water: 30 parts by weight.

[0136] The preparation method of the hydrophilic layer of the coating in Example 2 is the same as that in Example 1.

[0137] Example 3 In Example 3, a hydrophilic layer and a lubricating layer were sequentially coated on the surface of the corrosion-resistant layer of Example 3.

[0138] The composition ratio and preparation method of the hydrophilic layer in Example 3 are the same as those in Example 1.

[0139] The coating of the lubricating layer in Example 3 includes 1 wt% UV-9, 1 wt% benzotriazole and the balance of a base material, wherein the base material is HW6550 from Guangdong Huigu Chemical Co., Ltd.

[0140] The method for preparing the lubricating layer of the coating in Example 3 includes the following steps: The above raw materials were mixed at 50°C to obtain a lubricating coating; the lubricating coating was then roller-coated onto the surface of the hydrophilic layer, with the coating thickness controlled at approximately 0.2 g / m². 2 The lubricating layer is prepared by curing at 220℃ for 10 seconds.

[0141] Example 4 In Example 4, a hydrophilic layer and a lubricating layer were sequentially coated on the surface of the corrosion-resistant layer of Preparation Example 4.

[0142] The composition ratio and preparation method of the hydrophilic layer in Example 4 are the same as those in Example 2.

[0143] The composition ratio and preparation method of the lubricating layer in Example 4 are the same as those in Example 3.

[0144] Comparative Example 1 Comparative Example 1: A hydrophilic layer was coated on the surface of the corrosion-resistant layer used to prepare Comparative Example 1.

[0145] The composition ratio and preparation method of the hydrophilic layer in Comparative Example 1 are the same as those in Example 1.

[0146] Comparative Example 2 Comparative Example 2: A hydrophilic layer was coated on the surface of the corrosion-resistant layer used to prepare Comparative Example 2.

[0147] The composition ratio and preparation method of the hydrophilic layer in Comparative Example 2 are the same as those in Example 1.

[0148] Comparative Example 3 Comparative Example 3: A hydrophilic layer was coated on the surface of the corrosion-resistant layer used to prepare Comparative Example 3.

[0149] The composition ratio and preparation method of the hydrophilic layer in Comparative Example 3 are the same as those in Example 2.

[0150] Comparative Example 4 In Comparative Example 4, a hydrophilic layer and a lubricating layer were sequentially coated on the surface of the corrosion-resistant layer used to prepare Comparative Example 4.

[0151] The composition ratio and preparation method of the hydrophilic layer in Comparative Example 4 are the same as those in Example 1.

[0152] The composition ratio and preparation method of the lubricating layer in Comparative Example 4 are the same as those in Example 3.

[0153] Comparative Example 5 In Comparative Example 5, a hydrophilic layer and a lubricating layer were sequentially coated on the surface of the corrosion-resistant layer used to prepare Comparative Example 5.

[0154] The composition ratio and preparation method of the hydrophilic layer in Comparative Example 5 are the same as those in Example 2.

[0155] The composition ratio and preparation method of the lubricating layer in Comparative Example 5 are the same as those in Example 3.

[0156] Performance testing: (1) The low-frequency impedance values ​​(|Z|) of the corrosion-resistant layers prepared in Preparation Examples 1-4 and Comparative Examples 1-5 were measured respectively. 10 mHz / Ω·cm 2 The measurement results are shown in Table 1. (2) The salt spray corrosion resistance of the coatings prepared in Examples 1-4 and Comparative Examples 1-5 was determined in accordance with the standard GB / T 1771-2007 "Determination of the resistance of paints and varnishes to neutral salt spray". The percentage of corrosion area of ​​each group of coatings after 2000h of neutral salt spray was determined. The results are shown in Table 2.

[0157] Table 1

[0158] Table 2

[0159] Analysis of the data in Table 1 shows that, under the same addition amount, the electrochemical impedance value of the coating in the preparation example is significantly higher than that of the preparation comparison example by an order of magnitude, indicating that the corrosion-resistant layer prepared in this application has high barrier performance.

[0160] Analysis of the data in Table 2 shows that the coating prepared in this application has strong salt spray resistance and can effectively extend the service life of the heat exchanger when applied to the surface of the heat exchanger.

[0161] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A coating characterized in that, The corrosion-resistant layer is arranged between the hydrophilic layer and the substrate. The corrosion-resistant layer is arranged between the hydrophilic layer and the substrate. The magnetic modified filler includes at least one of graphene-based nanosheet, nanosheet-layer silicate, nanosheet-layer phosphate, nanosheet-layer sulfide, nanosheet-layer oxide, and nanosheet-layer nitride. The magnetic nanoparticles include at least one of elemental and alloy nano-powder particles of iron, cobalt, and nickel, nano-iron oxide particles, nano-sized ferrite powder particles, and nano-sized neodymium-iron-boron powder particles.

2. The coating of claim 1, wherein, The magnetic nanoparticles in the magnetic modified filler have a particle size of 10 nm to 50 nm. The two-dimensional nanofiller in the magnetic modified filler has a sheet size of 0.5 μm to 10 μm.

3. The coating of claim 1, wherein, The weight ratio of the two-dimensional nanofiller to the magnetic nanoparticles in the magnetic modified filler is 1: (1-10). The magnetic modified filler is further coated with at least one layer of polymer shell material. The polymer shell material includes at least one of polydopamine and polysiloxane.

4. The coating of claim 1, wherein, The weight ratio of the polymer shell material to the magnetic modified filler is (5-20):(2-11).

5. The coating of claim 4, wherein, The sheet-layer filler in the corrosion-resistant layer is arranged close to the surface of the substrate and is inclined, and the two-dimensional plane of the sheet-layer filler forms a first included angle with the surface of the substrate. The first included angle formed by the two-dimensional plane of the sheet-layer filler with the surface of the substrate is not greater than 45°.

6. The coating of claim 1, wherein, The two-dimensional plane of the sheet-layer filler with the surface of the substrate forms the first included angle, and the number of the sheet-layer filler accounts for not less than 80% of the total number of the sheet-layer filler in the corrosion-resistant layer.

7. The coating of claim 6, wherein, The raw material of the corrosion-resistant layer includes 0.05wt%-2wt% of the magnetic modified filler and a balance of base material.

8. The coating of claim 6, wherein, The base material includes water-based resin.

9. The coating of claim 1 wherein, The water-based resin includes at least one of water-based fluorocarbon resin, water-based polyester resin, water-based silicone resin, water-based acrylic resin, polyurethane resin, modified polyurethane resin, epoxy resin, modified epoxy resin, and polyamide resin. The raw material of the hydrophilic layer includes first acrylate monomer containing polar group.

10. The coating of claim 9, wherein, The first acrylate monomer includes at least one of hydroxyl acrylate monomer and carboxyl acrylate monomer.

11. The coating of claim 1 wherein, The raw material of the hydrophilic layer includes the following weight parts:

12. The coating of claim 11, wherein, The first acrylate monomer: 10 parts to 40 parts; 13. The coating of claim 11, wherein, The auxiliary: 0.5 parts to 2 parts; The initiator: 0.5 parts to 3 parts. The hydrophilic layer further includes 5 parts to 40 parts of second acrylate monomer. The second acrylate monomer includes at least one of amino acrylate monomer, phosphoric acid group acrylate monomer, amide group acrylate monomer, and epoxy group acrylate monomer.

14. The coating of claim 13, wherein, The substrate includes any one of pure aluminum, aluminum alloy, zinc alloy, pure copper, copper alloy, and stainless steel. The dry film thickness of the corrosion-resistant layer is 1 μm to 2 μm.

15. The coating of claim 1 wherein, ​ 16. The coating of claim 1 wherein, The coating film amount of the corrosion-resistant layer is 0.3 g / m 2 0.8 g / m 2 ; ​ 17. The coating of claim 1 wherein, The coating further comprises a lubricating layer disposed on the surface of the hydrophilic layer away from the substrate.

18. The coating of claim 17, wherein, The coating film amount of the hydrophilic layer is 0.5 g / m 2 ~1.3 g / m 2 The coating film amount of the lubricant layer is 0.05 g / m 2 ~0.5 g / m 2 .

19. A method of producing the coating according to any one of claims 1 to 18, characterized in that, The preparation method of the coating comprises the following steps: S1, coating a corrosion-resistant layer on at least one surface of the substrate; S2, coating a hydrophilic layer on the surface of the corrosion-resistant layer formed in the step S1 to complete the preparation of the coating.

20. The method of claim 19, wherein the coating is prepared by In the step S1, the preparation method of the magnetic modified filler in the corrosion-resistant layer comprises the following steps: Disperse the two-dimensional nanofiller in a solvent, add a magnetic precursor and stir uniformly, adjust the pH to 7-10 in a protective atmosphere, react at 20-80℃, filter, and wash the filter residue to obtain the magnetic modified filler.

21. The method of claim 19, wherein the coating is prepared by In the step S1, at least two magnetic fields with different magnetic field strengths are applied during the curing process of the corrosion-resistant layer.

22. The method of claim 19, wherein the coating is prepared by In the step S1, at least three magnetic fields with different magnetic field strengths are applied during the curing process of the corrosion-resistant layer, and the magnetic field strengths of the magnetic fields show a gradient change trend.

23. The method of claim 19, wherein the coating is prepared by In the step S1, a first magnetic field is applied for pre-curing during the curing process of the corrosion-resistant layer, and then a second magnetic field is applied for thermal curing to form the corrosion-resistant layer.

24. The method of claim 23, wherein the coating is prepared by The magnetic field direction of the first magnetic field and the magnetic field direction of the second magnetic field are parallel to the surface of the substrate; And / or, the first magnetic field is a uniform magnetic field with a field strength of 0.5-1T, and the second magnetic field is a uniform magnetic field with a field strength of 0.1-0.5T; And / or, the pre-curing temperature is 20-50℃, and the pre-curing time is 0.01-1h; And / or, the thermal curing temperature is 200-300℃, and the thermal curing time is 0.01-0.5h.

25. Use of the coating according to any one of claims 1-18 in a heat exchanger.

26. An air conditioner characterized by comprising: The air conditioner comprises the heat exchanger according to claim 25.

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