JP5859895B2 - Aluminum fin material - Google Patents

Description

  The present invention relates to an aluminum fin material used for a heat exchanger such as an air conditioner.

  In general, in air conditioners and the like, demands for improving the performance of air conditioners such as high efficiency and miniaturization are increasing due to the emergence of global warming and the problem of soaring resources. Because of such demands, aluminum fins are widely used in heat exchangers such as air conditioners because they are excellent in thermal conductivity, workability, corrosion resistance, and the like. And in order to perform heat exchange efficiently and to suppress a space compactly, as shown in FIG. 3, in the heat exchanger 21, a plurality of aluminum fins (hereinafter referred to as the copper pipes 23) through which the refrigerant flows are provided. , Referred to as fins) 22 are arranged in parallel at a narrow interval. For this reason, when the temperature of the fin surface becomes equal to or lower than the dew point of the air during the operation of the heat exchanger 21, the condensed water W adhering to the fin surface is condensed, blocking between adjacent fins, and increasing the ventilation resistance. May end up. At this time, when the heat exchanger 21 is operated for a long time, the water contact angle becomes large if the hydrophilicity of the fin surface is low. The state is further deteriorated (see (a) and (b) of FIG. 4). As a result, the problem that the ventilation resistance of the heat exchanger 21 is further increased and the heat exchange function is hindered is conventionally known.

  Further, in recent years, hydrophilic deterioration has become a problem when contaminants adhere to the fin surface. In an environment where an air conditioner or the like is used, various indoor pollutants float and frequently adhere to the fin surface to greatly deteriorate the hydrophilicity. Examples of such contaminants include higher alcohol substances such as hexadecanol. When these contaminants adhere to the fin surface, the hydrophilicity of the fin surface is lowered, and the dew condensation water W becomes a bridge between adjacent fins. This accumulated dew condensation water W is a problem because it causes a phenomenon of scattering into the room (hereinafter referred to as a water splash phenomenon) during operation of the heat exchanger 21.

  In order to solve such a problem, Patent Document 1 includes a substrate made of aluminum and one or more coating films formed on the surface of the substrate, and the outermost layer of the coating film has a saponification degree. The surface roughness Ra after being exposed to flowing water at a temperature of 25 ° C. at a flow rate of 5 L / hour for 24 hours, containing 90% or more of polyvinyl alcohol resin in an amount exceeding 50% in terms of solid content by mass is 0.2 μm or less. There has been proposed an aluminum fin material for heat exchangers characterized by comprising a hydrophilic coating film.

JP 2011-94873 A

However, even with the aluminum fin material of Patent Document 1, it cannot be said that the effect of suppressing the occurrence of water splashing from the heat exchanger in an environment where hexadecanol or the like floats is sufficient.
The present invention has been made in view of the above problems, and there is no occurrence of water splashing from the heat exchanger even in an environment where hexadecanol or the like is floating, and the heat exchanger has been used for a long time. In particular, it is an object to provide an aluminum fin material that does not increase ventilation resistance.

In order to solve the above problems, an aluminum fin material according to the present invention includes an aluminum plate and a coating film formed on the surface of the aluminum plate, and the coating film has a hydrophilic coating on the outermost surface. Or an aluminum fin material comprising a plurality of coatings, wherein the hydrophilic coating comprises a hydrophilic resin having at least one of a hydroxyl group, a carboxyl group and a sulfonic acid group, and a silicone compound, The adhesion amount is 10 to 10000 mg / m ² , and the average value of the silicon content when the region within a depth of 0.1 μm from the outermost surface of the coating film is measured by high frequency glow discharge optical emission spectrometry is 0.01 to was 10 atomic%, the hydrophilic film is greater than the contact angle of 25 degrees at the time of liquid paraffin dropped, and the contact angle at the time under water droplets Ri der less than 50 degrees, wherein said hydrophilic coating is, the A first coating part formed on the surface of the ruminium plate and containing a hydrophilic first resin having at least one of a hydroxyl group, a carboxyl group and a sulfonic acid group; and formed on the surface of the first coating part, a hydroxyl group and a carboxyl group And a second film portion having at least one kind of sulfonic acid group and containing a hydrophilic second resin different from the hydrophilic first resin .

  As described above, in the aluminum fin material according to the present invention, the hydrophilic film contains a hydrophilic resin and a silicone compound, and the silicon-containing content of the hydrophilic film measured by high-frequency glow discharge emission spectrometry is measured. The contact angle at the time of liquid paraffin dropping of the hydrophilic film is specified. As a result, the surface free energy of the hydrophilic film is reduced by the silicone-based compound, the contact angle when hexadecanol or the like adheres is increased, the adhesion of hexadecanol or the like to the hydrophilic film is suppressed, Even when it adheres, it can be easily removed. Thereby, when a fin material is used for a heat exchanger, a bridge of condensed water does not occur between adjacent fins, and the occurrence of a water splash phenomenon can be prevented.

In the aluminum fin material according to the present invention, the content of the silicone compound and the contact angle at the time of dropping liquid paraffin are specified, and at the same time, the adhesion amount of the hydrophilic film and the functional group of the hydrophilic resin constituting the hydrophilic film. And the contact angle at the time of water dripping of a hydrophilic film is specified. As a result, when the fin material is used in a heat exchanger, the hydrophilicity of the hydrophilic film constituting the fin surface is maintained for a long time, and no bridge of condensed water is generated between adjacent fins, resulting in an increase in ventilation resistance. Can be prevented. Moreover, in the aluminum fin material according to the present invention, the hydrophilic film is composed of the first film part and the second film part, so that it is possible to further prevent the occurrence of water splashing and further prevent the increase in ventilation resistance.

  In the aluminum fin material according to the present invention, it is preferable that the coating film further has a hydrophobic coating containing a hydrophobic resin between the aluminum plate and the hydrophilic coating. Thus, in the aluminum fin material according to the present invention, the corrosion resistance of the aluminum fin material is further improved by the coating film having a hydrophobic film.

  The aluminum fin material according to the present invention preferably further contains an antibacterial agent in the hydrophobic film. Thus, in the aluminum fin material according to the present invention, the antibacterial property of the aluminum fin material is improved by further containing the antibacterial agent in the hydrophobic film.

  The aluminum fin material according to the present invention preferably further includes a chemical conversion film between the aluminum plate and the coating film. Thus, in the aluminum fin material which concerns on this invention, the corrosion resistance of an aluminum fin material improves by further providing a chemical conversion film between an aluminum plate and a coating film.

  The aluminum fin material according to the present invention preferably further contains an antibacterial agent in the hydrophilic film. Thus, in the aluminum fin material according to the present invention, the antibacterial property of the aluminum fin material is improved by further containing the antibacterial agent in the hydrophilic film.

  According to the aluminum fin material of the present invention, when the fin material is used in a heat exchanger, there is no occurrence of a water jump phenomenon from the heat exchanger even in an environment where hexadecanol or the like is floating. As a result, the cleanliness of the indoor environment where an air conditioner or the like equipped with a heat exchanger is used is improved. At the same time, the aluminum fin material according to the present invention does not increase the ventilation resistance even when the heat exchanger is used for a long time. As a result, the heat exchange performance of the heat exchanger can be maintained in an excellent state for a long time. Moreover, according to the aluminum fin material which concerns on this invention, the outstanding corrosion resistance and antibacterial property are added.

(A) is a schematic diagram of the cross section of the aluminum fin material which concerns on embodiment of this invention, (b)-(e) is a schematic diagram of the cross section of the aluminum fin material which concerns on another embodiment of this invention. (A), (b) is a schematic diagram of the cross section of the aluminum fin material which concerns on another embodiment of this invention. It is a schematic diagram which shows the heat exchange part of a heat exchanger. (A), (b) is a schematic diagram which shows the adhesion state of the dew condensation water to the fin surface. It is a figure which shows the measurement result of the silicon content rate by a high frequency glow discharge emission spectroscopic analysis.

  Hereinafter, embodiments of an aluminum fin material according to the present invention will be described in detail with reference to the drawings as appropriate. An aluminum fin material (hereinafter referred to as fin material) according to the present invention includes an aluminum plate and a coating film formed on the surface of the aluminum plate, and the coating film has one or more hydrophilic coatings on the outermost surface. It consists of a film. Here, the coating film means a hydrophilic film or a film composed of a hydrophilic film and a hydrophobic film as described later, and the chemical conversion film is not included in the coating film. In FIG. 1 to FIG. 2, the components already described are assigned the same reference numerals and description thereof is omitted.

<Aluminum fin material>
[First Embodiment]
As shown in FIG. 1A, the fin material 10 </ b> A includes an aluminum plate 1 and a hydrophilic film 2 (coating film) formed on the surface of the aluminum plate 1.

(Aluminum plate)
The aluminum plate 1 is made of pure aluminum or an aluminum alloy and is excellent in thermal conductivity and workability. Therefore, 1000 series aluminum defined by JIS H4000 is preferable, and aluminum of alloy number 1200 is more preferable.
The plate thickness of the aluminum plate 1 is preferably about 0.06 to 0.3 mm. If the plate thickness is less than 0.06 mm, the strength required for the aluminum plate 1 cannot be ensured, while if it exceeds 0.3 mm, the workability as a fin material decreases.

(Hydrophilic film)
The hydrophilic film 2 contains a hydrophilic resin and a silicone compound, and the adhesion amount is 10 to 10,000 mg / m ² . The hydrophilic film 2 is formed by applying a hydrophilic paint containing a hydrophilic resin and a silicone compound to the aluminum plate 1.

If the adhesion amount of the hydrophilic film 2 is less than 10 mg / m ² , the film thickness of the hydrophilic film 2 is too thin, and the contact angle at the time of water dripping of the hydrophilic film 2 is 50 degrees or more. Hydrophilicity decreases. As a result, when the fin material 10A is used for the heat exchanger 21 (see FIG. 3), a bridge of condensed water W occurs between adjacent fins after a long operation (see FIG. 4 (b)). Ventilation resistance increases. Moreover, when the adhesion amount of the hydrophilic film | membrane 2 exceeds 10000 mg / m < ² >, the film thickness of the hydrophilic film | membrane 2 is too thick and coating workability | operativity falls. In particular, when the aluminum plate 1 is in a coil state, the hydrophilic film 2 cannot be formed on the aluminum plate 1.

  The hydrophilic resin is a synthetic resin having at least one of a hydroxyl group, a carboxyl group, and a sulfonic acid group. Here, polyethylene oxide, polyethylene glycol, carboxymethyl cellulose, polyvinyl alcohol and the like are preferable as those having a hydroxyl group. As what has a carboxyl group, polyacrylic acid, carboxymethylcellulose, etc. are preferable. As those having a sulfonic acid group, sulfoethyl acrylate and the like are preferable. Moreover, as what has the said 2 types of functional group, the copolymer etc. of a sulfoethyl acrylate and acrylic acid are preferable.

  In the hydrophilic paint, the silicone compound is preferably present in a dispersed state in the hydrophilic resin in view of coating workability. Accordingly, the silicone compound is preferably a water-dispersed silicone compound. Examples of such water-dispersed silicone compounds include X-52-2162 made by Shin-Etsu Silicone, KM903 made by Shin-Etsu Silicone, and Zymac US-480 made by Toagosei.

  The content of the silicone compound in the hydrophilic film 2 is specified by the silicon content of the hydrophilic film 2. Specifically, when a region within a depth of 0.1 μm from the outermost surface of the hydrophilic film 2 is measured by high-frequency glow discharge emission spectrometry, the average value of silicon content is 0.01 to 10 atomic%. When the silicon content is less than 0.01 atomic%, the content of the silicone compound contained in the hydrophilic film 2 is reduced, and the contact angle at the time of dropping liquid paraffin of the hydrophilic film 2 is 25 degrees or less, Hexadecanol or the like easily adheres to the hydrophilic film 2. As a result, when the fin material 10A is used in a heat exchanger, a bridge of condensed water is formed between adjacent fins, and a water splash phenomenon from the heat exchanger occurs. On the other hand, when the silicon content exceeds 10 atomic%, the hydrophilicity of the hydrophilic coating 2 is lowered, the contact angle when the hydrophilic coating 2 is dripped with water is 50 degrees or more, and the ventilation resistance of the heat exchanger is increased. .

Here, measuring a region within a depth of 0.1 μm from the outermost surface means that the adhesion amount of the hydrophilic film 2 is 10 mg / m ² or more and less than 100 mg / m ² (0.01 μm or more and 0.1 μm in terms of film thickness). Less), it means that the entire hydrophilic film 2 is measured in the film thickness direction. However, the adhesion amount of the hydrophilic film 2 is 10 mg / m ² or more and less than 100 mg / m ² , and the hydrophobic film 4 (FIG. 1 (c), (See (e)) means that a region in which the total depth of all the coatings of the hydrophilic coating 2 and the depth of the hydrophobic coating 4 in the film thickness direction is 0.1 μm is measured. Further, when the adhesion amount of the hydrophilic film 2 is 100 mg / ^{m 2} or more 10000 mg / ^{m 2} or less (0.1 [mu] m or more 10μm or less in terms of film thickness), the depth from the outermost surface in the thickness direction of 0. It means to measure the area of 1 μm.

  Thus, the contact angle at the time of the liquid paraffin dripping of the hydrophilic membrane | film | coat 2 is controlled by specifying the silicon content rate of the whole membrane | film | coat or a 0.1 micrometer depth area | region. In addition, such a silicon content is obtained by using a water-dispersible silicone compound as a silicone compound and dispersing it in the hydrophilic resin to form a hydrophilic paint. It is suitably controlled by coating and baking on the surface of 1.

  Specifically, the method for measuring the silicon content is performed as follows. Using a high-frequency glow discharge optical emission spectrometer, argon sputtering is performed in a pulse mode, and the silicon content is measured by spectroscopic analysis of emission lines in the argon plasma of silicon in the sputtered region. Argon sputtering is continuously performed until the aluminum plate 1 is reached or until the depth in the film thickness direction of the hydrophilic coating 2 reaches 0.1 μm, and an integrated average value of the measured silicon content is calculated. . In addition, when the coating film has the hydrophobic coating 4 under the hydrophilic coating 2, the total depth of the entire coating of the hydrophilic coating 2 and the depth of the hydrophobic coating 4 in the film thickness direction is 0.1 μm. Continue argon sputtering until it reaches.

  The hydrophilic coating 2 has a contact angle of more than 25 degrees when dropping liquid paraffin and a contact angle of less than 50 degrees when dropping water. When the contact angle of the hydrophilic coating 2 when dropping liquid paraffin is 25 degrees or less, hexadecanol or the like is likely to adhere to the hydrophilic coating 2. As a result, when the fin material 10A is used in a heat exchanger, a bridge of condensed water W is formed between adjacent fins, and a phenomenon of water splashing from the heat exchanger occurs. Moreover, when the contact angle at the time of water dripping of the hydrophilic film 2 is 50 degrees or more, a bridge of condensed water is formed between adjacent fins when the heat exchanger is operated for a long time, and the ventilation resistance is increased. To do. The contact angle of the hydrophilic film 2 is determined by appropriately changing the adhesion amount of the hydrophilic film 2, the kind of the hydrophilic resin, the kind of the silicone compound, and the silicon content in a predetermined region. .

  In addition to the hydrophilic resin and the silicone compound, the hydrophilic paint used for forming the hydrophilic film 2 is added with various aqueous solvents and paint additives in order to improve paintability, workability, coating film properties, etc. For example, various solvents and additives such as water-soluble organic solvents, crosslinking agents, surfactants, surface conditioners, wetting and dispersing agents, anti-settling agents, antioxidants, antifoaming agents, and rust inhibitors. May be blended alone or in combination.

[Second Embodiment]
As shown in FIG. 1B, the fin material 10B has a hydrophilic film 2 composed of a first film part 2a and a second film part 2b.

  The first film portion 2 a includes a hydrophilic first resin having at least one of a hydroxyl group, a carboxyl group, and a sulfonic acid group, and applies a hydrophilic first coating material including the hydrophilic first resin to the surface of the aluminum plate 1. Formed by. In addition, the second film part 2b is a first film part 2a made of a hydrophilic second paint having at least one of a hydroxyl group, a carboxyl group, and a sulfonic acid group and containing a hydrophilic second resin different from the hydrophilic first resin. It is formed by applying to the surface.

  For example, when the 1st membrane | film part 2a contains the hydrophilic 1st resin which has a hydroxyl group, the 2nd membrane | film part 2b contains the hydrophilic 2nd resin which has at least 1 sort (s) of a carboxylic acid group and a sulfonic acid group. Moreover, when the 1st membrane | film part 2a contains the hydrophilic 1st resin which has a carboxylic acid group, the 2nd membrane | film part 2b contains the hydrophilic 2nd resin which has at least 1 sort (s) of a hydroxyl group and a sulfonic acid group. Furthermore, when the 1st film part 2a contains the hydrophilic 1st resin which has a sulfonic acid group, the 2nd film part 2b contains the hydrophilic 2nd resin which has at least 1 sort (s) of a hydroxyl group and a carboxylic acid group. As described above, by using different hydrophilic resins for the first film portion 2a and the second film portion 2b, the contact angle of the hydrophilic film 2 can be easily controlled. The increase can be further prevented. Specific examples of the hydrophilic first resin and the hydrophilic second resin are the same as those given as the hydrophilic resin of the fin material 10A.

The silicone compound contained in the hydrophilic film 2 is preferably contained only in the second film part 2b. The coating weight of the first coating unit 2a 100-1000 mg / ^{m 2,} the adhesion amount of the second coating portion 2b is preferably from 50 to 1000 mg / ^{m 2.}

[Third Embodiment]
As shown in FIGS. 1C to 1E, the fin materials 10C to 10E further include a corrosion-resistant film between the aluminum plate 1 and the hydrophilic film 2 (coating film). The corrosion resistant film is composed of at least one of the hydrophobic film 4 (coating film) and the chemical conversion film 3. Specifically, as shown in FIG. 1C, the fin material 10 </ b> C further includes a hydrophobic film 4 (coating film) between the aluminum plate 1 and the hydrophilic film 2 (coating film). As shown in FIG. 1D, the fin material 10D further includes a chemical conversion film 3 between the aluminum plate 1 and the hydrophilic film 2 (coating film). As shown in FIG. 1 (e), the fin material 10E further includes a chemical conversion film 3 and a hydrophobic film 4 (coating film) between the aluminum plate 1 and the hydrophilic film 2 (coating film). 3 is formed on the aluminum plate 1 side, and a hydrophobic film 4 is formed on the hydrophilic film 2 side.

(Hydrophobic film)
The hydrophobic film 4 contains a hydrophobic resin and is formed by applying a hydrophobic paint containing the hydrophobic resin to the surface of the aluminum plate 1 or the surface of the chemical conversion film 3 formed on the aluminum plate 1. (See FIGS. 1C and 1E). Examples of the hydrophobic resin used in the hydrophobic paint include polyester, polyolefin, epoxy, and urethane resins, and one or a mixture of two or more of these resins is used. Examples of the polyester-based resin include “Nichiko Polyester (registered trademark) WR-960” manufactured by Nippon Synthetic Chemical, and examples of the urethane-based resin include “Hitech (registered trademark) S-6254” manufactured by Toho Chemical Industry.

The adhesion amount of the hydrophobic film 4 of the fin materials 10C and 10E is not particularly limited, but is preferably 10 to 8000 mg / m ² . If it is less than 10 mg / m ² , the corrosion resistance of the fin materials 10C and 10E cannot be secured, and if it exceeds 8000 mg / m ² , the hydrophobic coating 4 becomes a heat insulating layer, which may deteriorate the efficiency of heat exchange. Because there is. More preferably 50~4000mg / ^{m 2.}

  The formation of the hydrophobic coating 4 improves the corrosion resistance of the fin materials 10C and 10E, so that the durability of the heat exchanger can be increased. Moreover, since the hydrophobic film | membrane 4 is hydrophobic, it can suppress that water osmose | permeates the aluminum plate 1 and generate | occur | produces an odor by subfilm corrosion.

  In addition to the hydrophobic resin, the hydrophobic paint used for forming the hydrophobic film 4 may be added with various aqueous solvents and paint additives in order to improve paintability, workability, etc. Well, for example, various solvents and additives such as water-soluble organic solvents, cross-linking agents, surfactants, surface conditioners, wetting and dispersing agents, anti-settling agents, antioxidants, antifoaming agents, rust inhibitors, etc. Or in combination.

(Chemical conversion film)
The chemical conversion film 3 is formed by subjecting the surface of the aluminum plate 1 to a known chemical conversion treatment such as a phosphoric acid chromate treatment, an inorganic oxide treatment such as a coating-type zirconium treatment, or a treatment with an organic-inorganic composite compound. It is. By forming the chemical conversion film 3, the corrosion resistance of the fin materials 10D and 10E is improved. Moreover, as for the adhesion amount of the chemical conversion film 3, 1-100 mg / m < ² > is preferable in conversion of Cr. Further, these chemical conversion treatments are performed before forming other films (hydrophobic film 4 and hydrophilic film 2) (see FIGS. 1D and 1E).

[Fourth Embodiment]
As shown in FIGS. 2A and 2B, the fin materials 10 </ b> F and 10 </ b> G are those in which an antibacterial agent is further contained in the hydrophobic film 4 or the hydrophilic film 2. By containing an antibacterial agent, antibacterial properties are imparted to the fin materials 10F and 10G.

  As the antibacterial agent, known antibacterial agents can be used, but it is preferable to use zinc pyrithione which has a broad antibacterial spectrum and is effective against both bacteria and fungi. The average particle diameter of zinc pyrithione is preferably 0.01 to 1.0 μm. Those having an average particle size of less than 0.01 μm are difficult to produce and are not practical. When the average particle diameter exceeds 1.0 μm, thermal decomposition due to heat in forming (coating or baking) the hydrophobic film 4 or the hydrophilic film 2 is likely to be promoted, and the antibacterial property is likely to be lowered. Moreover, it is easy to generate a bad odor from the thermal decomposition product itself. Furthermore, when the average particle size is large, the antimicrobial properties of the fin materials 10F and 10G are difficult to be sustained due to falling off from the hydrophobic coating 4 or the hydrophilic coating 2 during long-time operation.

  The content of zinc pyrithione is preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the hydrophobic resin or the hydrophilic resin. When the content is less than 0.1 part by weight, the content of zinc pyrithione is small, and the antibacterial properties of the fin materials 10F and 10G are likely to be lowered. When the content exceeds 100 parts by weight, zinc pyrithione has an extremely low solubility in water, and thus adversely affects the hydrophilicity of the hydrophilic film 2. Moreover, the film-forming property of the hydrophobic film 4 is also reduced.

Although not shown, the fin material according to the present invention may further include a lubricating film on the surface of the hydrophilic film.
The lubricating film contains a lubricating resin and is formed by applying a lubricating paint containing the lubricating resin to the surface of the hydrophilic film. The adhesion amount of the lubricating film is preferably 10 to 1000 mg / m ² . Examples of the lubricating resin include those containing at least one selected from the group consisting of polyethylene glycol, carboxymethyl cellulose, and alkali metal salts of carboxymethyl cellulose.

  Since the friction coefficient of the fin material is reduced by the formation of the lubricating film, the press formability at the time of manufacturing the heat exchanger is further improved. Even if the lubricating film is formed on the surface of the hydrophilic film, since the lubricating film has hydrophilicity, the function exhibited by the hydrophilic film (preventing the occurrence of water splashing phenomenon and ventilation resistance) (Preventing increase) is not reduced.

  The fin material according to the present invention is not limited to a configuration (see FIGS. 1 to 2) including the hydrophilic coating 2 and the like only on one surface of the aluminum plate 1, and includes a hydrophilic coating 2 and the like on both surfaces of the aluminum plate 1 ( (Not shown).

<Fin material manufacturing method>
As a manufacturing method of a fin material, according to the film | membrane structure shown to FIGS. 1-2, for example, the hydrophobic coating material and the hydrophilic coating material with respect to the aluminum plate 1 or the aluminum plate 1 in which the chemical conversion film 3 is formed in the surface The hydrophobic coating 4 and the hydrophilic coating 2 are formed by repeatedly applying and drying (including those added with an antibacterial agent) using a bar coater or a roll coater. Fin materials 10A to 10G having equivalent performance can be produced by using either a bar coater or a roll coater, but from the viewpoint of productivity, a roll coater etc. It is preferable to apply and continuously perform degreasing, painting, heating, winding and the like. In addition, the manufacturing method of fin material 10A-10G is not restricted to these methods.

  Examples in which the effects of the present invention are confirmed will be described below. In addition, this invention is not limited to this Example.

(Fin material production method)
First, a fin material was produced by the following method.
An aluminum plate (plate thickness 0.10 mm) made of pure aluminum-based A1200 (JIS H4000) was manufactured by a conventionally known manufacturing method. Next, degreasing was performed for 5 seconds by immersing the aluminum plate in an alkaline agent (“Surf Cleaner (registered trademark) 360” manufactured by Nippon Paint Co., Ltd.). Further, it was immersed in a phosphoric acid chromate solution to form a phosphoric acid chromate film (30 mg / m ^{2 in} terms of Cr) on the surface of the aluminum plate. Then, a hydrophilic paint containing the hydrophilic resin and silicone compound shown in Table 1 was applied and baked on the aluminum plate subjected to the phosphoric acid chromate treatment with a bar coater.

In addition, the resin kind of the hydrophilic film | membrane in Table 1 was as follows.
(A): Polyethylene oxide (manufactured by Sumitomo Seika, PEO-1 (registered trademark))
(B): Carboxymethylcellulose (Serogen PR, manufactured by Daiichi Kogyo Seiyaku)
(C): Acrylic acid / sulfonic acid monomer copolymer salt (Nippon Shokubai Co., Ltd., Aqualic GL)
(D): Polyvinyl alcohol (Nippon Synthetic Chemical Co., Ltd., completely saponified type, NM11 (registered trademark)), resin used in Patent Document 1 (E): Polyethylene glycol (manufactured by Sanyo Kasei, PEG6000S (registered trademark)) )
(U): urethane-modified resin emulsion, Hitec (registered trademark) S-6254)
(V): polyacrylic ester copolymer, Jurimer (registered trademark) AT-210)
(W): polyester-based resin paint (manufactured by Nippon Synthetic Chemical Co., Ltd., water-dispersed tape polyester resin, Nichiko Polyester (registered trademark) WR-960)

  About the produced fin material (sample Nos. 1 to 18), the silicon content, the contact angle at the time of dropping water, and the contact angle at the time of dropping liquid paraffin were measured by the following procedure, and the results are shown in Table 1.

(Silicon content)
The silicon content in the hydrophilic film was measured by argon sputtering in a pulse mode (frequency: 300 Hz, duty cycle: 0.3125) with a high-frequency glow discharge emission spectroscopic analyzer (manufactured by Horiba, Ltd., JY-5000RF). . Here, when the adhesion amount of the hydrophilic film is less than 100 mg / m ² , the silicon content of the entire film is measured, and when the adhesion amount is 100 mg / m ² or more, the film thickness direction from the outermost surface is measured. The silicon content in a region having a depth of 0.1 μm was measured. Table 1 shows the integrated average values of the measured silicon contents. 5 shows an example of the result of high-frequency glow discharge emission spectroscopic analysis (analysis result of sample No. 3 described later), and the integrated average value of silicon content was 0.6 atomic%.

<Contact angle>
The fin material was immersed in running water of ion exchange water having a flow rate of 0.1 liter / min for 8 hours, and then the process of drying at 80 ° C. for 16 hours was defined as 5 cycles for 5 cycles. Thereafter, the fin material is returned to room temperature, about 0.5 μL of pure water or 0.5 μL of liquid paraffin is dropped on the surface, and a contact angle measuring device (Kyowa Interface Science Co., Ltd .: CA-05 type) is used. The contact angle was measured. The evaluation criteria are as follows.

(When dripping water)
○ (Good): Contact angle of 40 degrees or less Δ (Generally good): Contact angle of more than 40 degrees and less than 50 degrees × (Bad): Contact angle of 50 degrees or more (during liquid paraffin dropping)
○ (Good): Contact angle is 30 degrees or more Δ (Generally good): Contact angle is more than 25 degrees and less than 30 degrees × (Bad): Contact angle is 25 degrees or less

  About the produced fin material (sample No. 1-18), the following procedure evaluated the ventilation resistance and the contamination | pollution resistance (the presence or absence of a water splash phenomenon). For these evaluations, fin press was first performed to produce fins. Specifically, it was produced with a fin pattern having two rows and 10 stages by drawless processing (metal mold manufactured by Hidaka Seiki: φ7 drawless method). Then, it expanded through the copper pipe, produced the heat exchanger, and implemented various evaluations. The results are shown in Table 1.

(Ventilation resistance)
A heat exchanger as shown in FIG. 3 was produced using the produced fin material. The heat exchanger was installed in the wind tunnel facility, and air-conditioning operation was performed for a predetermined time, and the occurrence of a bridge of condensed water (see FIG. 4B) between adjacent fins was confirmed.
○ (Good): During the operation for a long time (condensation for 3 hours and 3 cycles of drying for 1 hour), the occurrence of two or less bridges continued.
Δ (generally good): During the operation for a long time (condensation for 3 hours and drying for 3 hours for 1 hour), more than two bridges were generated.
X (Bad): During the operation for normal time (condensation for 3 hours and drying for 1 hour for 1 cycle), more than two bridges were generated.

(Contamination resistance)
The prepared heat exchanger is put in a sealed container, and hexadecanol is heated to 100 ° C. or more below it to generate mist of hexadecanol for 1 hour in an environment where hexadecanol is forcibly attached. Exposed. After that, an exposed heat exchanger was installed in the wind tunnel facility and air-cooling operation was performed. Condensed water jumping out of the heat exchanger was confirmed.
○ (Good): Condensate water containing mist-like water droplets does not jump out △ (Generally good): Condensed water containing mist-like water droplets jumps out slightly × (Poor): Condensed water pops out frequently

As shown in Table 1, the reference examples (Sample Nos. 1 to 7) were excellent in ventilation resistance, excellent in contamination resistance, and no dew condensation was confirmed.

  On the other hand, since the comparative examples (sample Nos. 8 to 10) do not have a hydrophilic film, the contact angle at the time of dripping water exceeds the upper limit value, so the ventilation resistance is inferior and the contamination resistance is inferior. Condensed water jumping out was confirmed. In Comparative Example (Sample No. 11), the silicon content rate exceeded the upper limit value, and the contact angle at the time of water dropping exceeded the upper limit value, so the ventilation resistance was inferior.

  In the comparative example (sample No. 12), the silicon content was less than the lower limit value, and the contact angle at the time of dropping liquid paraffin was less than the lower limit value. In the comparative example (Sample No. 13), since the adhesion amount of the hydrophilic film exceeded the upper limit value, blocking occurred when the coil was raised, and the plate could not be passed. In Comparative Example (Sample No. 14), the adhesion amount of the hydrophilic film was less than the lower limit value, and the contact angle at the time of dropping the water exceeded the upper limit value, so the ventilation resistance was inferior. In Comparative Example (Sample No. 15), the hydrophilic film was likely to be eluted, and the contact angle at the time of dropping water exceeded the upper limit value, so the ventilation resistance was inferior.

  In the comparative example (sample No. 16), since a silicone compound having a contact angle at the time of dropping liquid paraffin of less than the lower limit value was used, the contamination resistance was inferior and dew condensation was confirmed. In the comparative examples (Sample Nos. 17 and 18), since the hydrophilic film does not contain a silicone compound, the contact angle at the time of dropping liquid paraffin is less than the lower limit value. confirmed. The comparative example (Sample No. 18) corresponds to Patent Document 1.

  Next, in the production of the fin material, a hydrophobic coating containing a hydrophobic resin as shown in Table 2 was applied and baked with a bar coater, a two-layer hydrophilic film was formed, and the hydrophobic resin was antibacterial. The same procedure as in Example 1 was performed except that the agent was added. The produced fin material was measured for the silicon content and the contact angle in the same manner as in Example 1, and the results are shown in Table 2.

The types of the hydrophilic film and the hydrophobic resin in Table 2 are the same as in Table 1. Moreover, as an antibacterial agent, 10 mass% of zinc pyrithione (Tomside ZPT50 manufactured by API Corporation) having an average particle size of 0.3 μm was added.
Next, the produced fin material (Sample Nos. 18 to 23) was evaluated for ventilation resistance and contamination resistance in the same manner as Example 1, and the results are shown in Table 2. Furthermore, corrosion resistance and antibacterial properties were evaluated by the following procedure, and the results are shown in Table 2.

(Corrosion resistance)
The produced fin material was left in an environment where the surface of the fin material was condensed at 40 ° C. for 500 hours. The surface of the fin material after being left was checked for corrosion.
○ (Good): No corrosion occurred △ (Generally good): Corrosion occurred, but relatively minor x (defect): Corrosion occurred significantly

(Antibacterial)
Using the prepared fin material, an antibacterial evaluation test specified in JISZ2801 was performed by a film adhesion method, and the expression of antibacterial properties was confirmed.
○ (good): antibacterial is expressed, x (poor): no antibacterial

  As shown in Table 2, in Example (Sample No. 19), since two hydrophilic films were formed on the surface of the chemical conversion film, the ventilation resistance was excellent, the contamination resistance was excellent, and the jumping out of condensed water was also confirmed. It was also excellent in corrosion resistance. In the examples (Sample Nos. 20 and 21), since two hydrophilic films were formed on the surface of the hydrophobic film or the corrosion-resistant film (chemical conversion film and hydrophobic film), the ventilation resistance was excellent and the contamination resistance was improved. In addition, no jumping of condensed water was confirmed, and the corrosion resistance was also excellent. In Examples (Sample Nos. 22 and 23), since the antibacterial agent was contained in the hydrophilic film or the hydrophobic film, the antibacterial property was also excellent.

DESCRIPTION OF SYMBOLS 1 Aluminum plate 2 Hydrophilic film 3 Chemical conversion film 4 Hydrophobic film 6 Antibacterial agent 10A, 10B, 10C, 10D, 10E, 10F, 10G Fin material

Claims (5)

An aluminum fin material comprising an aluminum plate and a coating film formed on the surface of the aluminum plate, wherein the coating film comprises one or a plurality of coatings having a hydrophilic coating on the outermost surface,
The hydrophilic film includes a hydrophilic resin having at least one of a hydroxyl group, a carboxyl group, and a sulfonic acid group, and a silicone compound,
The adhesion amount of the hydrophilic film is 10 to 10000 mg / m ² ,
The average value of the silicon content when the region within a depth of 0.1 μm from the outermost surface of the coating film is measured by high frequency glow discharge emission spectrometry is 0.01 to 10 atomic%,
The hydrophilic film is greater than the contact angle of 25 degrees at the time of liquid paraffin dropped, and the contact angle at the time under water droplets Ri der less than 50 degrees,
The hydrophilic film is formed on the surface of the aluminum plate, and includes a first film part including a hydrophilic first resin having at least one of a hydroxyl group, a carboxyl group, and a sulfonic acid group; and a surface of the first film part. An aluminum fin material , comprising: a second film portion that is formed and has at least one of a hydroxyl group, a carboxyl group, and a sulfonic acid group, and includes a hydrophilic second resin different from the hydrophilic first resin . The aluminum fin material according to claim 1, wherein the coating film further includes a hydrophobic coating containing a hydrophobic resin between the aluminum plate and the hydrophilic coating. The aluminum fin material according to claim 2 , wherein the hydrophobic film further contains an antibacterial agent. The aluminum fin material according to any one of claims 1 to 3 , further comprising a chemical conversion film between the aluminum plate and the coating film. Aluminum fin stock according to any one of claims 1 to claim 4, characterized in that the antimicrobial agent is further contained in the hydrophilic coating.

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