Aluminum fin material, heat exchanger, air conditioner, and method for manufacturing aluminum fin material

Abstract

A method for manufacturing an aluminum fin material, a heat exchanger, an air conditioner, and an aluminum fin material with excellent hydrophilicity and antifouling properties is provided. The aluminum fin material (10) comprises: an aluminum plate (1); a corrosion-resistant film layer (3) formed on the surface of the aluminum plate (1); and a hydrophilic film layer (4) formed on the surface of the corrosion-resistant film layer (3). The corrosion-resistant film layer (3) contains acrylic resin (3b) and fluororesin particles (3a), and the film weight of the corrosion-resistant film layer (3) is 0.05 mg / dm³. 2 Above and 8.00 mg / dm 2 The content of fluoropolymer particles (3a) in the corrosion-resistant coating layer (3) is 0.05% by mass or more and 8.00% by mass or less.

Description

TECHNICAL FIELD

[0001] The present application relates to an aluminum fin material, a heat exchanger, an air conditioner, and a manufacturing method of an aluminum fin material. BACKGROUND

[0002] A heat exchanger is used for products in various fields such as indoor air conditioners, packaged air conditioners, refrigerated display cases, refrigerators, oil coolers, radiators, and the like.

[0003] Therefore, an aluminum fin material used as a fin of such a heat exchanger has a hydrophilic film formed on the surface from the viewpoint of reducing the air resistance and preventing splashing.

[0004] However, if the heat exchanger is driven for a long period of time, dust floating in the atmosphere can adhere to the surface of the hydrophilic film of the aluminum fin material. As a result, various problems can occur, such as an increase in air resistance, the occurrence of mold growth from the starting point of the adhered dust, and a decrease in comfort if the heat exchanger is installed in a living environment.

[0005] Therefore, with respect to the aluminum fin material, a technology has been proposed from the viewpoint of preventing dust adhesion.

[0006] For example, in Patent Literature 1, an aluminum fin material having fluororesin particles contained in a baked coating film (hydrophilic film) is disclosed.

[0007] PRIOR ART DOCUMENTS

[0008] PATENT LITERATURE

[0009] Patent Literature 1: Japanese Patent Application Publication No. 2016-90105 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] The technology of Patent Literature 1 is a configuration in which fluororesin particles are contained in a baked coating film (hydrophilic film). However, with such a configuration, the hydrophilicity of the hydrophilic film is reduced due to the hydrophobicity of the fluororesin particles themselves, and it is difficult to ensure a high level of hydrophilicity.

[0012] The present application is proposed in view of the above-described problems, and aims to provide an aluminum fin material, a heat exchanger, an air conditioner, and a manufacturing method of an aluminum fin material that exhibit excellent hydrophilicity and stain resistance.

[0013] MEANS FOR SOLVING THE PROBLEMS

[0014] The aluminum fin material of the present invention has: an aluminum plate; a corrosion-resistant film layer formed on the surface of the aluminum plate; and a hydrophilic film layer formed on the surface of the corrosion-resistant film layer, the corrosion-resistant film layer containing an acrylic resin and fluororesin particles, the film amount of the corrosion-resistant film layer being 0.05 mg / dm 2 0.05 mg / dm and 8.00 mg / dm 2 0.05 mg / dm and 8.00 mg / dm

[0015] Further, the heat exchanger of the present invention is provided with a fin formed of the aluminum fin material of the present invention.

[0016] Further, the air conditioner of the present invention is provided with the heat exchanger of the present invention.

[0017] Further, the method for manufacturing the aluminum fin material of the present invention includes the following steps: forming a corrosion-resistant film layer containing an acrylic resin and fluororesin particles on the surface of an aluminum plate, the film amount of the corrosion-resistant film layer being 0.05 mg / dm 2 0.05 mg / dm and 8.00 mg / dm 2 0.05 mg / dm and 8.00 mg / dm

[0018] Effects of the Invention

[0019] The aluminum fin material, the heat exchanger, and the air conditioner of the present invention can exhibit excellent hydrophilicity and antifouling properties.

[0020] Further, the method for manufacturing the aluminum fin material of the present invention can manufacture an aluminum fin material that can exhibit excellent hydrophilicity and antifouling properties. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic view of a cross section of the fin material of the present embodiment.

[0022] Figure 2 is a schematic view of a top view of the fin material of the present embodiment.

[0023] Figure 3 is a schematic view of a heat exchanger of the present embodiment.

[0024] Figure 4 is a schematic view of an air conditioner of the present embodiment.

[0025] Figure 5 is a schematic view for explaining a measurement method of a contact angle in the evaluation of hydrophilicity. DETAILED DESCRIPTION

[0026] The following describes in detail the methods of manufacturing aluminum fins (hereinafter, appropriately referred to as "fins"), heat exchangers, air conditioners, and aluminum fins used in carrying out the present invention.

[0027] [Aluminum finned sheet]

[0028] like Figure 1 As shown, the fin material 10 of this embodiment includes: an aluminum plate 1; a corrosion-resistant film layer 3 formed on the surface of the aluminum plate 1; and a hydrophilic film layer 4 formed on the surface of the corrosion-resistant film layer 3. Additionally, the fin material 10 of this embodiment may also include a lubricating film layer 5 formed on the surface of the hydrophilic film layer 4. Furthermore, the fin material 10 of this embodiment may also include a substrate treatment layer 2 between the aluminum plate 1 and the corrosion-resistant film layer 3.

[0029] Furthermore, the corrosion-resistant coating layer 3 of the fin material 10 in this embodiment includes fluoropolymer particles 3a. These fluoropolymer particles 3a, such as... Figure 2 As shown, a portion of it protrudes from the surfaces of the hydrophilic film layer 4 and the lubricating film layer 5. In other words, as... Figure 1 As shown, the corrosion-resistant film layer 3 is presumably formed from an undulating layer containing fluoropolymer particles 3a and acrylic resin 3b. Furthermore, it is believed that a hydrophilic film layer 4 is formed on top of this corrosion-resistant film layer 3, exposing a portion of the fluoropolymer particles 3a. In other words, it can be assumed that the fluoropolymer particles 3a are present in the corrosion-resistant film layer 3 and also penetrate the hydrophilic film layer 4.

[0030] Furthermore, in this embodiment, each film layer of the fin material 10 is typically formed on both sides of the aluminum plate 1, but it is also possible that some or all of the film layers are formed only on one side of the aluminum plate 1.

[0031] The following is a detailed explanation of each component.

[0032] [Aluminum Plate]

[0033] The aluminum sheet is formed from pure aluminum or an aluminum alloy. Furthermore, from the viewpoint of thermal conductivity and workability, aluminum of the 1000 series as specified in JIS H 4000:2014 is preferred as the aluminum sheet. More specifically, aluminum of alloy numbers 1050, 1070, and 1200 is more preferred as the aluminum sheet.

[0034] However, aluminum alloys from the 2000 series to the 9000 series can also be used as aluminum sheets.

[0035] The thickness of the aluminum sheet is appropriately determined in accordance with the use and the specifications of the fin material, and the like. Specifically, the thickness of the aluminum sheet is preferably 0.08 mm or more and 0.3 mm or less from the viewpoint of appropriately ensuring the processability for the fin, the strength of the fin, the thermal conductivity, and the like. If the thickness of the aluminum sheet is 0.08 mm or more, the strength required to the extent of a general fin material can be ensured. On the other hand, if the thickness of the aluminum sheet is 0.3 mm or less, the processability for the fin can be ensured.

[0036] [Corrosion-resistant film layer]

[0037] The corrosion-resistant film layer is a layer that functions to prevent the penetration of moisture (condensed water and the like), oxygen, ion species including chloride ions, and the like to the aluminum sheet side, and to suppress the corrosion of the aluminum sheet and the generation of odor-causing aluminum oxides, and the like.

[0038] Furthermore, the corrosion-resistant film layer contains acrylic resin and fluororesin particles.

[0039] (Acrylic resin in corrosion-resistant film layer)

[0040] The acrylic resin contained in the corrosion-resistant film layer is a resin obtained by polymerizing acrylic acid, methacrylic acid, and derivatives thereof.

[0041] The corrosion-resistant film layer is mainly composed of acrylic resin if the fluororesin particles described later are removed. Furthermore, the content of the acrylic resin in the corrosion-resistant film layer is, for example, preferably 80% by mass or more, and more preferably 90% by mass or more.

[0042] (Fluororesin particles in corrosion-resistant film layer)

[0043] The fluororesin particles contained in the corrosion-resistant film layer are pieces of fluororesin, and the fluororesin is a synthetic resin obtained by polymerizing an olefin containing fluorine.

[0044] The content of the fluororesin particles in the corrosion-resistant film layer is 0.05% by mass or more, and is preferably 0.25% by mass or more, and 0.30% by mass or more. By the content of the fluororesin particles being equal to or more than the prescribed value, excellent stain resistance can be exerted.

[0045] In addition, the content of the fluororesin particles in the corrosion-resistant film layer is 8.00% by mass or less, and is preferably 6.00% by mass or less, 4.00% by mass or less, 2.50% by mass or less, and 1.50% by mass or less. If the content of the fluororesin particles is higher than the prescribed value, the hydrophobicity based on the fluororesin particles excessively increases, and the hydrophilicity decreases.

[0046] While there is no particular limitation on the average particle size (particle size is the area equivalent circle diameter) of the fluoropolymer particles, it is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

[0047] Furthermore, the particle size of fluoropolymer particles can be measured using scanning electron microscopy (SEM) and electron probe microanalysis (EPMA).

[0048] (Corrosion-resistant coating layer: coating amount)

[0049] The corrosion-resistant coating thickness is 0.05 mg / dm³. 2 The above is preferably 0.08 mg / dm³. 2 Above, 0.10 mg / dm 2 The above. Because the amount of corrosion-resistant coating is above the specified value, it can exert excellent anti-fouling properties.

[0050] In addition, the corrosion-resistant coating thickness is 8.00 mg / dm³. 2 The preferred dosage is 6.00 mg / dm³. 2 Below, 5.00 mg / dm 2 The following applies. If the amount of corrosion-resistant coating exceeds the specified value, the hydrophilicity decreases, and a high level of hydrophilicity cannot be ensured.

[0051] Furthermore, since the corrosion-resistant coating is mostly composed of acrylic resin and fluororesin particles, the amount of the corrosion-resistant coating can also be referred to as the amount of acrylic resin and fluororesin particles formed.

[0052] The amount of corrosion-resistant film can be adjusted by factors such as the concentration of the coating composition used in film formation and the selection of the number of the doctor blade coater used for film formation. Furthermore, the amount of corrosion-resistant film can be measured using methods such as fluorescence X-rays, infrared thickness gauges, and film peeling quality measurements.

[0053] Furthermore, the methods for adjusting and measuring the amount of the hydrophilic and lubricating film layers, as described later, are the same as those for the corrosion-resistant film layer.

[0054] [Hydrophilic membrane layer]

[0055] The hydrophilic coating layer is used to enhance the hydrophilicity of the fin material. By applying this layer, the contact angle of condensation water adhering to the fin surface decreases, making it less likely for the heat exchanger's efficiency to deteriorate. Furthermore, the increased hydrophilicity also improves the fluidity of the condensation water adhering to the fin surface. Therefore, even if contaminants adhere to the fin surface, they are easily washed away by the condensation water, improving contaminant removal.

[0056] Furthermore, the hydrophilic film layer preferably contains acrylic resin.

[0057] (Hydrophilic film layer: acrylic resin)

[0058] The so-called hydrophilic coating layer contains acrylic resin, which, like the acrylic resin in the corrosion-resistant coating layer, is made by polymerizing acrylic acid, methacrylic acid, and their derivatives.

[0059] The hydrophilic film layer is mainly composed of acrylic resin. Moreover, the content of acrylic resin in the hydrophilic film layer is preferably 80% by mass or more, and more preferably 90% by mass or more.

[0060] (Hydrophilic membrane layer: membrane thickness)

[0061] The preferred amount of hydrophilic film is 0.5 mg / dm³. 2 The above, more preferably 1 mg / dm 2 Above, 2mg / dm 2 Above, 3mg / dm 2 The above. The amount of hydrophilic film layer is above the specified value to ensure good hydrophilicity.

[0062] In addition, the preferred amount of hydrophilic film is 10 mg / dm³. 2 The following is more preferably 8 mg / dm 2 Below, 6mg / dm 2 The following applies. When the amount of hydrophilic film layer is below the specified value, the film-forming properties are good, defects such as cracks are reduced, and because the thermal resistance is suppressed, the heat exchange efficiency of the fins is less likely to be damaged.

[0063] Furthermore, the hydrophilic film layer is mostly composed of acrylic resin, so the amount of the hydrophilic film layer can also be referred to as the amount of acrylic resin film (formation amount).

[0064] [Lubricating film layer]

[0065] A lubricating film layer is a layer used to improve the lubricity of the fin surface. By setting a lubricating film layer, the coefficient of friction of the fin surface is reduced, improving the stamping formability when processing the fin into fins.

[0066] The lubricating film layer is composed of a resin composition containing one or more resins selected from the group consisting of polyethylene glycol, carboxymethyl cellulose, and alkali metal salts of carboxymethyl cellulose. However, the resin used for the lubricating film layer is not limited to these. Examples of alkali metal salts of carboxymethyl cellulose include sodium salts, potassium salts, and calcium salts. These resins can also be modified in a known manner, such as polyurethane modification or alkyl modification, by copolymerization with other monomers. A particularly preferred resin is a mixture of polyethylene glycol and sodium carboxymethyl cellulose. The mass ratio of polyethylene glycol to sodium carboxymethyl cellulose is preferably in the range of 5:5 to 9:1. A resin with such a composition exhibits better film-forming properties and lubricity.

[0067] (Lubricating film layer: film amount)

[0068] The amount of lubricating film is preferably 0.1 mg / dm³. 2 The above, more preferably 0.3 mg / dm 2 Above, 0.5 mg / dm 2 Above, 0.8mg / dm 2 The above. When the amount of lubricating film is above the specified value, good lubricity can be obtained.

[0069] In addition, the amount of lubricating film layer is preferably 5 mg / dm³. 2 The following is more preferably 3 mg / dm 2 Below, 2mg / dm 2 Below, 1.5 mg / dm 2 The following applies: When the amount of lubricating film is below a specified value, thermal resistance can be suppressed to a low level.

[0070] [Substrate Treatment Layer]

[0071] The substrate treatment layer is formed from inorganic oxides or inorganic-organic composite compounds. By applying a substrate treatment layer to the aluminum plate, the corrosion resistance of the aluminum plate is improved. In addition, the aluminum plate exhibits good adhesion to the coating layer applied to the outer side.

[0072] As an inorganic oxide, the main component preferably contains chromium (Cr) or zirconium (Zr). Specific examples of such inorganic oxides include those formed by treatment with chromate phosphate, zirconium phosphate, chromate chromate, zinc phosphate, and titanate phosphate. However, the types of inorganic oxides are not limited to those formed by these treatments.

[0073] Examples of inorganic-organic composite compounds include those formed by coating-type chromate treatment and coating-type zirconium treatment. Specific examples of such inorganic-organic composite compounds include, for instance, acrylic-zirconium composites.

[0074] The adhesion amount of the substrate treatment layer (converted to the mass of metallic elements such as Cr and Zr) is preferably 1 mg / m³. 2 The above, more preferably 5 mg / m² 2 The above demonstrates that good corrosion resistance is achieved when the adhesion amount of the substrate treatment layer is above a specified value. Furthermore, the adhesion amount of the substrate treatment layer is preferably 100 mg / m³. 2 The following is more preferably 80 mg / m² 2 the following.

[0075] Furthermore, the thickness of the substrate treatment layer can be adjusted according to the intended use of the fin material, preferably between 1 nm and 100 nm.

[0076] The amount of substrate treatment layer attached can be adjusted by regulating the concentration of the formation solution used for film formation and the film formation time. Furthermore, the amount and thickness of the substrate treatment layer can be measured using X-ray fluorescence, infrared film thickness gauges, dissolution mass measurements, etc.

[0077] [Heat Exchanger]

[0078] The heat exchanger of this embodiment has fins made of the fin material.

[0079] Moreover, such as Figure 3 As shown, the structure of the heat exchanger 30 in this embodiment can be any structure of a conventional heat exchanger. For example, a structure that includes heat transfer tubes 20 in addition to fins 10 can be listed.

[0080] Furthermore, the heat exchanger of this embodiment can be applied, for example, to air conditioners, freezer display cases, refrigerators, oil coolers, radiators, etc., as described later.

[0081] [Air conditioner]

[0082] The air conditioner of this embodiment includes the heat exchanger described above.

[0083] Moreover, such as Figure 4 As shown, the structure of the air conditioner 100 in this embodiment can be any structure of a conventionally known air conditioner. For example, in addition to the heat exchanger 30, it may also include a crossflow fan 40, a drain pan 50, louvers 60, and a housing 90 with an intake 70 and an exhaust 80.

[0084] [Manufacturing method of aluminum fins]

[0085] Next, the manufacturing method of the aluminum fin material of this embodiment will be described.

[0086] The method for manufacturing aluminum fins in this embodiment includes a substrate manufacturing process and a film layer formation process.

[0087] (Substrate manufacturing process)

[0088] In the substrate manufacturing process, aluminum sheets made of aluminum or aluminum alloys are produced. For example, ingots are melted and the molten metal is solidified into an arbitrary shape to obtain an ingot containing a specified amount of chemical components such as Al. Then, the surface of the ingot is machined as needed, and an aluminum sheet is obtained by hot rolling and cold rolling. Furthermore, when manufacturing the aluminum sheet, the ingot can be subjected to homogenization heat treatment, or intermediate annealing can be performed during rolling. Additionally, the rolled sheet can be subjected to solution heat treatment, quenching and tempering, etc.

[0089] (The process of forming the skin layer)

[0090] In the film layer formation process, a film layer is formed on the surface of the aluminum plate. Specifically, after cleaning and degreasing the surface of the aluminum plate as needed, various film layers are formed in sequence on the clean aluminum plate surface, including a film base treatment layer, a corrosion-resistant film layer, a hydrophilic film layer, and a lubricating film layer.

[0091] The substrate treatment layer can be formed by applying a formation treatment solution by spraying or immersing the aluminum plate in the formation treatment solution, followed by heating and drying.

[0092] Furthermore, the corrosion-resistant film layer, hydrophilic film layer, and lubricating film layer can be formed by dispersing the resins used for each film layer in a solvent to obtain a coating composition, applying the coating composition using a coating device such as a doctor blade coater or a roller coater, and then baking it to form a film. Also, in order to manufacture the aluminum fin material with the aforementioned structure, the coating composition for the corrosion-resistant film layer contains fluoropolymer particles. On the other hand, the presence of fluoropolymer particles in the coating composition for the hydrophilic film layer is avoided.

[0093] Furthermore, the coating baking temperature for each film layer is generally within the range of 100°C to 300°C. However, since fluoropolymer particles are blended into the coating composition for the corrosion-resistant film layer, a coating baking temperature at which the fluoropolymer particles will not decompose is preferred (e.g., 100°C to 280°C).

[0094] Furthermore, the coating compositions used in the process of forming the ground film layer to form each film are not limited to the aforementioned resins and microparticles, but may also include various water-based solvents and coating additives, taking into account coating properties, workability, and film properties. For example, water-soluble organic solvents, crosslinking agents, surfactants, surface modifiers, wetting and dispersing agents, anti-settling agents, antioxidants, defoamers, rust inhibitors, antibacterial agents, mildew inhibitors, and other solvents and additives may be added individually or in combination.

[0095] The aluminum fin material of this embodiment can be manufactured through the above processes.

[0096] Example

[0097] Next, by comparing embodiments that satisfy the requirements of the present invention with comparative examples that do not satisfy the requirements of the present invention, the aluminum fin material of the present invention will be specifically described. Furthermore, the present invention is not limited to these embodiments.

[0098] [Preparation of experimental materials]

[0099] The aluminum sheet used is alloy number 1070 as specified in JIS H 4000:2014, with a thickness of 0.1 mm. The surface of this aluminum sheet is treated with chromate phosphate to form a base treatment layer. Furthermore, the adhesion amount of the base treatment layer is 30 mg / m². 2 .

[0100] Then, a corrosion-resistant film layer, a hydrophilic film layer, and a lubricating film layer are formed sequentially on the surface of the substrate treatment layer.

[0101] The corrosion-resistant coating layer is formed by applying the coating composition to the surface of the substrate treatment layer using a doctor blade coater in the amount of coating shown in the table, and baking it at a temperature below 250°C.

[0102] Furthermore, the coating compositions used as test materials No. 2, 5 to 15 were compositions obtained by mixing acrylic resin and fluoropolymer particles (average particle size: about 0.1 to 1.0 μm) in a manner that resulted in the content of the layer after formation being as shown in the table. On the other hand, the coating compositions of test materials No. 1, 3, and 4 differed from those of test materials No. 2, 5 to 15 only in that they avoided the presence of fluoropolymer particles.

[0103] The hydrophilic film layer is formed by applying the coating composition to the surface of the corrosion-resistant film layer using a doctor blade coater in the amount of film shown in the table, and baking at 250°C.

[0104] Furthermore, the coating compositions used as test materials No. 1, 2, 4 to 15 were compositions in which acrylic resin was mixed with a solvent. On the other hand, the coating composition of test material No. 3 differs from that of test materials No. 1, 2, 4 to 15 only in that it contains fluoropolymer particles (average particle size: about 0.1 to 1.0 μm) in such a manner that the content after layer formation is as shown in the table.

[0105] The lubricating film layer is formed by applying the coating composition to the surface of the hydrophilic film layer using a doctor blade coater in the amount of film shown in the table, and baking at 250°C.

[0106] Furthermore, the coating compositions used for test materials No. 1 to 3 and 5 to 15 were compositions in which a resin containing polyethylene glycol was mixed with the solvent. On the other hand, the coating composition for test material No. 4 differs from that for test materials No. 1 to 3 and 5 to 15 only in that it contains fluoropolymer particles in a manner that ensures the content after layer formation is as shown in the table.

[0107] Next, the following evaluation will be conducted on the prepared test materials.

[0108] [Hydrophilicity evaluation]

[0109] For the prepared test material, the following cycle was repeated for a total of 14 cycles: immersion in a water tank overflowing with tap water at a flow rate of 0.1 L / min for 8 hours, followed by drying at 80°C for 16 hours, constituted one cycle. Afterward, the test material was allowed to return to room temperature, placed horizontally with the evaluation surface facing upward, and approximately 0.5 μL of pure water was dripped onto the evaluation surface. The contact angle was measured using a contact angle measuring instrument (Kyowa Surface Science Co., Ltd.: CA-05 type).

[0110] Also, such as Figure 5 As shown, the contact angle θ is the angle between the test material T and the water droplet W.

[0111] Then, hydrophilicity is determined according to the following evaluation criteria.

[0112] (Hydrophilicity: Evaluation Criteria)

[0113] Good: Contact angle is below 40°.

[0114] △ Generally good: Contact angle above 40° and below 60°.

[0115] × Defective: Contact angle is above 60°.

[0116] [Fouling Resistance Evaluation]

[0117] The surface of the prepared test material was coated with 11 types of test powders (Kanto loam) and 12 types of test powders (carbon black) as specified in JIS Z8901:2006.

[0118] After each powder adheres to the surface of the test material, an image of the surface of each test material is taken. Based on the obtained images, the adhesion amount of Kanto soil and carbon black is evaluated on a 5-point scale (5 points: very high adhesion amount, 1 point: very low adhesion amount).

[0119] Then, regarding antifouling properties, those with a carbon black related point count and a Kanto soil related point count of 3 or less are judged as good, and those with other counts are judged as poor.

[0120] Table 1 shows the composition of the test materials and the evaluation results.

[0121] Furthermore, the coating thickness of each film layer shown in Table 1 is the value measured by X-ray fluorescence. Additionally, the fluoropolymer particle content shown in Table 1 is a value calculated based on the amount of acrylic resin and fluoropolymer particles added to the coating composition used for each film layer. Furthermore, the particle size of the fluoropolymer particles used is the value measured by SEM.

[0122] [Table 1]

[0123]

[0124] Regarding test materials No. 2, 5-9, and 11-14, they meet the requirements specified in this invention. Therefore, test materials 2, 5-9, and 11-14 can achieve optimal results in terms of both "hydrophilicity" and "fouling resistance".

[0125] On the other hand, since test materials No. 1, 3, 4, 10, and 15 do not meet the requirements specified in this invention, at least one of hydrophilicity and antifouling properties will result in a less than preferred outcome.

[0126] Test material No. 1 has poor antifouling properties because it does not contain fluoropolymer particles in its corrosion-resistant coating layer.

[0127] Test material No. 3 contains 0.35% by mass of fluoropolymer particles in the hydrophilic film layer and no fluoropolymer particles in the corrosion-resistant film layer. Moreover, due to the large amount of fluoropolymer particles in the hydrophilic film layer near the surface, it has good antifouling properties, but this is a result of poor hydrophilicity.

[0128] Test material No. 4 contained 0.35% by mass of fluoropolymer particles in the lubricating film layer and no fluoropolymer particles in the corrosion-resistant film layer. Furthermore, due to the large amount of fluoropolymer particles in the lubricating film layer near the surface, it exhibited poor hydrophilicity.

[0129] Test material No. 10 exhibits poor hydrophilicity due to an excessive content of fluororesin particles in its corrosion-resistant coating.

[0130] Test material No. 15 exhibited poor hydrophilicity due to an excessive amount of corrosion-resistant coating.

[0131] Furthermore, when both the corrosion-resistant coating layer and the hydrophilic coating layer contain a large amount of fluoropolymer particles, considering the results of test material No. 3, it is believed that the presence of fluoropolymer particles in the hydrophilic coating layer near the surface will lead to poor hydrophilicity. However, if the hydrophilic coating layer contains only a trace amount of fluoropolymer particles, it is believed that the hydrophilicity will not decrease significantly.

[0132] The above is with reference to the appendix. Figure 1 Various embodiments have been described, but the present invention is certainly not limited to such examples. Those skilled in the art will undoubtedly conceive of various modifications and alterations within the scope of the patent claims, and these are naturally understood to fall within the technical scope of the present invention. Furthermore, the constituent elements of the above embodiments can be combined arbitrarily without departing from the spirit of the invention.

[0133] Furthermore, this application is based on Japanese Patent Application No. 2020-012661, filed on January 29, 2020, the contents of which are incorporated herein by reference.

[0134] Symbol Explanation

[0135] 1 Aluminum plate

[0136] 2. Substrate treatment layer

[0137] 3. Corrosion-resistant coating layer

[0138] 3a Fluoropolymer particles

[0139] 4. Hydrophilic membrane layer

[0140] 5. Lubricating film layer

[0141] 10 Finned Material

[0142] 30 Heat Exchanger

[0143] 100 air conditioner

Claims

1. A method for manufacturing aluminum fins, characterized in that, The process includes the following steps: The process of forming a substrate treatment layer composed of inorganic oxides or inorganic-organic composite compounds on the surface of an aluminum plate; It contains acrylic resin and fluoropolymer particles, with a film weight of 0.05 mg / dm³. 2 Above and 8.00 mg / dm 2 The following process involves forming a corrosion-resistant film layer on the surface of the substrate treatment layer, wherein the content of the fluoropolymer particles is 0.05% by mass or more and 8.00% by mass or less. The process of forming a hydrophilic film layer on the surface of the corrosion-resistant film layer using a coating composition for a hydrophilic film layer that does not contain fluorine resin particles.

2. The method for manufacturing aluminum fins according to claim 1, characterized in that, The corrosion-resistant coating layer has a coating thickness of 0.05 mg / dm³. 2 Above and 2.00 mg / dm 2 the following.

3. An aluminum fin material, characterized in that, The aluminum fin material manufactured by the method of manufacturing aluminum fin material according to claim 1 comprises: an aluminum plate; a substrate treatment layer formed of an inorganic oxide or an inorganic-organic composite compound disposed on the surface of the aluminum plate; a corrosion-resistant film layer formed on the surface of the substrate treatment layer; and a hydrophilic film layer formed on the surface of the corrosion-resistant film layer. The corrosion-resistant coating layer comprises acrylic resin and fluoropolymer particles. The corrosion-resistant coating layer has a coating thickness of 0.05 mg / dm³. 2 Above and 8.00 mg / dm 2 the following, The content of the fluororesin particles in the corrosion-resistant coating layer is more than 0.05% by mass and less than 8.00% by mass.

4. The aluminum fin material according to claim 3, characterized in that, The hydrophilic film layer contains acrylic resin.

5. The aluminum fin material according to claim 3 or claim 4, characterized in that, It also possesses a lubricating film layer formed on the surface of the hydrophilic film layer. The lubricating film layer is formed from a resin composition containing one or more resins selected from the group consisting of polyethylene glycol, carboxymethyl cellulose and alkali metal salts of carboxymethyl cellulose.

6. The aluminum fin material according to claim 3 or claim 4, characterized in that, The corrosion-resistant coating layer has a coating thickness of 0.05 mg / dm³. 2 Above and 2.00 mg / dm 2 the following.

7. A heat exchanger, characterized in that, It has fins formed from aluminum fins as described in any one of claims 3 to 6.

8. An air conditioner, characterized in that, It has the heat exchanger as described in claim 7.

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