JP2007040686A - Aluminum fin material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum fin material which can maintain hydrophilic property and antimicrobial and antibacterial properties over a long period. <P>SOLUTION: The aluminum fin material 1 comprises a substrate 20 of aluminum or an aluminum alloy, an anticorrosive film 3 of inorganic oxide or organic-inorganic composite compound formed on the substrate 2, a resin anticorrosive film 4 0.5-10 μm thick formed on the film 3, and a hydrophilic film 5 0.1-10 μm thick of hydrophilic resin formed on the film 4. The resin anticorrosive film 4 is formed of at least one resin selected from urethane resin, epoxy resin, polyester resin and vinyl chloride resin, and it contains, to 100 pts.wt. of the resin, 0.1-100 pts.wt. of zinc pyrithione having an average diameter of 0.01-1.0 μm. Otherwise, this material comprises a water-soluble film 8 0.1-10 μm thick formed on the hydrophilic film 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is an aluminum fin material made of aluminum or an aluminum alloy having a coating film formed on its surface, particularly excellent in suppressing the growth of mold and bacteria, and suitable for use in fins of heat exchangers such as room air conditioners. The present invention relates to an aluminum fin material for an exchanger.

  Heat exchangers are used in various fields such as room air conditioners, packaged air conditioners, refrigeration showcases, refrigerators, oil coolers and radiators. In heat exchangers such as room air conditioners and packaged air conditioners, aluminum materials are used for the fins because of their excellent thermal conductivity and workability.

The surface of the fin for the heat exchanger is subjected to anticorrosion treatment for the purpose of preventing corrosion. Moreover, in order to prevent the condensed water at the time of air_conditionaing | cooling operation from staying between fins, the surface treatment for the hydrophilic improvement which improves the fall property of a granular water droplet is given to the fin surface.
When the surface treatment for enhancing hydrophilicity is performed on the surface of the aluminum material, the contact angle of water droplets attached to the fin made of the aluminum material can be reduced. FIG. 2 is a schematic view showing a contact angle of water drops on a plane, and FIG. 3 is a perspective view schematically showing a heat exchange part of the heat exchanger. As shown in FIG. 2, the contact angle θ is an angle formed by the plane 10 and the tangent 11 of the water drop W at the point A rising from the plane 10 on the surface of the water drop W, and the lower the contact angle θ, the water film (water droplet). Becomes thinner and the hydrophilicity becomes better. In the heat exchange part of the heat exchanger as shown in FIG. 3, the coolant flows in the direction indicated by the arrow through the copper pipe 7 passing through the fin 6, so that water droplets are condensed on the surface of the fin 6. However, when the hydrophilicity is good, the dropability of the water drops is good. As a result, it is possible to prevent the resistance at the time of air blowing from being increased due to water droplets or a water film adhering to the fins 6 and to obtain excellent heat exchanger characteristics.

  4 (a) to 4 (c) are schematic views showing the state of water droplet adhesion on the fin surface. In FIG. 4 (a), the length of the downward arrow is proportional to the distance at which a water drop falls in a certain time. As shown in FIG. 4A, in the case of the fin 6a having good hydrophilicity, since the contact angle of the water droplet W is small, the water droplet W easily falls along the fin 6a. As a result, since the water droplet W does not block the blowing, the blowing resistance is reduced. On the other hand, in the heat exchanger composed of fins having poor hydrophilicity, the water droplets W stay on the fins 6b as shown in FIG. 4B, or the water droplets W are adjacent to the adjacent fins 6c and 6c as shown in FIG. In order to stay in contact with both, the water droplet W interrupts ventilation, and ventilation resistance increases remarkably.

  Here, various pollutants present in the environment where air conditioners are used, such as plasticizers such as diisooctyl phthalate, plastic lubricants such as palmitic acid, stearic acid, paraffins, etc., adhere to the fins, making them hydrophilic. It becomes easy to deteriorate. Therefore, a hydrophilic surface treatment (hydrophilic film) that does not deteriorate the hydrophilicity even if these contaminants adhere is desirable. In addition, when inorganic fine particles such as silica are present in the hydrophilic film, tool wear during fin molding processing is likely to occur, and a strange odor peculiar to the silica film is generated. Is desirable.

  As a means for solving all of these problems, Patent Document 1 discloses that a corrosion-resistant film made of an inorganic oxide or an organic-inorganic composite compound is formed on a substrate made of aluminum or an aluminum alloy, and on the molecule, A hydrophilic film made of polyacrylic acid or polyacrylate containing a water-soluble resin having a hydroxyl group is formed, and a water-soluble resin film having a hydroxyl group in the molecule is formed on the hydrophilic film. An aluminum fin material for heat exchangers having excellent hydrophilic sustainability is described.

  On the other hand, air conditioners during cooling are susceptible to mold growth because the interior of the indoor unit is kept in a high humidity atmosphere for a long time due to condensation of heat exchangers (“Nobuo Hamada, Akio Yamada: Air conditioner mold contamination, (Refer to antibacterial fungi, Vol. 21, No. 7, 385-389, 1993)). In addition, it has been pointed out that mold spores propagated inside the indoor unit are released from the air conditioner (“Abe Keiko: Mold Index and Mold Contamination During Air Conditioning Cooling, Journal of Indoor Environment Society, Vol. 1, No. .1, 41-50, 1998 "). It has been pointed out that release of mold spores from this air conditioner may cause allergies (“B. Crook, J. Lacey: Enumeration of Airborne Micro-Organisms in Work Environments, Environ. Technol. Lett., Vol. 9 , Pp. 515-520 (1988) ”,“ Kosuke Takashima: Mold and Health Disorders in Living Environments, J. Natl. Inst. Public Health, Vol. 47, pp. 13-18, 1998 ”), use of air conditioner There is a problem that comfort in time is impaired. In addition, it has been reported that volatile organic compounds derived from microorganisms are generated by the growth of mold, which may cause odor of air conditioners (“Pak Shun-Shi, Koichi Ikeda, Shuji Fujii: Regarding fungi-derived chemicals in air conditioners” Research, Air Conditioning and Sanitary Engineering Society Annual Lecture Collection, 1273-1276, 2001 ”).

In order to solve the above-mentioned problems, Patent Document 2 describes a fin material for a heat exchanger in which a fungus antibacterial property is provided by providing a hydrophilic film containing a zinc substance powder and an antibacterial agent on the surface of an aluminum substrate. ing. Also, an aqueous resin film containing bis (2-pyridylthio) -zinc-1,1′-dioxide (so-called zinc pyrithione) having a particle diameter of 1 to 10 μm, which is one of the mold antibacterial agents, on the surface of the aluminum substrate. Patent Document 3 describes an aluminum alloy fin material in which a hydrophilic film is formed on the surface of the water-based resin film.
Japanese Patent No. 3383914 (Claim 1, paragraph number 0035, FIG. 4) Japanese Patent No. 2934917 (Claim 1, paragraph numbers 0024 and 0049, FIG. 3) JP 2000-171191 A (paragraph numbers 0009 to 0013, FIG. 1)

  However, as shown in Patent Document 2, in the case where the antifungal antibacterial agent is contained in the hydrophilic film, in general, when the hydrophilic film is imparted with a good hydrophilicity, the hydrophilic film dissolves in water in a small amount. For this reason, there is a problem in that the antifungal antibacterial agent easily flows out due to the dew condensation water generated during the cooling operation, and the antifungal antibacterial property does not continue. In addition, when a curing agent or the like is added in order to suppress outflow, there is a problem that hydrophilicity, which is an important characteristic as a fin material for an air conditioner, easily deteriorates. This is because an antifungal antibacterial agent that can be retained in the film generally has a very low solubility in water, and thus adversely affects hydrophilicity.

  Moreover, in the fin material of patent document 3, since the particle diameter of zinc pyrithione is large, there exists a problem that zinc pyrithione is easy to drop | omit from a fin material surface with a state of a particle | grain by long-term cooling operation, and mold | fungi antibacterial property does not continue. In addition, the thermal decomposition of zinc pyrithione is accelerated by the heat during the formation (coating and baking) of the hydrophilic film, and the antibacterial and antifungal properties are liable to deteriorate, and it also causes a bad odor problem generated from the thermal decomposition product itself. .

  This invention is made | formed in view of the said problem, and it aims at providing the aluminum fin material with which hydrophilic property and antifungal antibacterial property continue over a long period of time.

  As a result of intensive research, the present inventors have selected zinc pyrithione as an antifungal antibacterial agent, and do not include this zinc pyrithione in the hydrophilic film, but instead provide the hydrophilic film independently after providing the film having zinc pyrithione. Was found to be effective.

  That is, the aluminum fin material according to the present invention is formed on a substrate made of aluminum or an aluminum alloy, a corrosion-resistant film made of an inorganic oxide or an organic-inorganic composite compound formed on the substrate, and the corrosion-resistant film. In the aluminum fin material provided with the formed resin corrosion-resistant film having a film thickness of 0.5 to 10 μm and the hydrophilic film having a film thickness of 0.1 to 10 μm made of a hydrophilic resin formed on the resin corrosion-resistant film, The resin corrosion resistant film is a resin composed of at least one of a urethane resin, an epoxy resin, a polyester resin, and a vinyl chloride resin, and the average particle diameter is 0.01 to 1 with respect to 100 parts by weight of the resin. 0.1 to 100 parts by weight of zinc pyrithione of 0.0 μm is contained (claim 1).

  According to the said structure, the mold antibacterial property of a fin material improves by forming the resin corrosion-resistant film | membrane containing a zinc pyrithione. By forming a hydrophilic film on the resin corrosion-resistant film, zinc pyrithione does not flow out easily even if dew condensation water is generated on the surface of the aluminum fin material. Is independent of the resin corrosion resistant film, and zinc pyrithione is prevented from adversely affecting the hydrophilicity of the hydrophilic film. By defining the film thickness of the resin corrosion resistant film and the content of zinc pyrithione within a predetermined range, zinc pyrithione having an average particle diameter of 0.01 to 1.0 μm is not exposed from the surface of the resin corrosion resistant film having a film thickness of 0.5 to 10 μm. It tends to concentrate near the surface of the film. This is promoted by heat in forming the hydrophilic film. The resin corrosion-resistant film is composed of a resin having no predetermined hydrophilicity, so that zinc pyrithione contained in the resin having no hydrophilicity is gradually released. By defining the average particle size of zinc pyrithione within a predetermined range, thermal decomposition and sublimation of zinc pyrithione due to heat during the formation of the hydrophilic film are prevented, and zinc pyrithione remains in the particle state from the resin corrosion resistant film during long-term cooling operation. It becomes difficult to drop off, and it is possible to dissolve gradually. By forming a corrosion-resistant film between the substrate and the resin corrosion-resistant film, the adhesion between the substrate and the resin corrosion-resistant film is improved, and zinc pyrithione is further prevented from falling off in the form of particles, and the fin material Is given corrosion resistance. By forming a hydrophilic film having a predetermined thickness on the outermost surface of the fin material, hydrophilicity is imparted to the fin material.

  Further, the aluminum fin material according to the present invention is characterized in that the hydrophilic resin has at least one of a carboxyl group, a hydroxyl group, a sulfonic acid group, an amide bond, an ether bond and a salt thereof. (Claim 2). According to the said structure, the hydrophilic property of a fin material improves further.

  The aluminum fin material according to the present invention includes a water-soluble film having a film thickness of 0.1 to 10 μm formed on the hydrophilic film, and the water-soluble film has a water-soluble resin having a hydroxyl group in the molecule. (Claim 3). According to the above configuration, since the water-soluble film is gradually dissolved at the time of dew condensation during the cooling operation, the processing oil remaining on the fin surface is washed away in the press working at the time of fin production. Therefore, the hydrophilicity of the fin material is further improved. Further, the moisture absorption of the hydrophilic film makes it possible to suppress a problem that the press mold and the fin material (hydrophilic film) adhere to each other during press working.

  According to the aluminum fin material of claim 1, hydrophilicity and antifungal antibacterial properties last for a long time. Moreover, according to the aluminum fin material of Claim 2, the hydrophilicity of a fin material improves further. Furthermore, according to the aluminum fin material of the third aspect, the hydrophilicity of the fin material is further improved and the workability is improved.

An embodiment of the present invention will be described. 1A and 1B are cross-sectional views schematically showing a cross section of an aluminum fin material.
As shown in FIG. 1A, an aluminum fin material (hereinafter referred to as a fin material) 1 includes a substrate 2 and a corrosion-resistant film 3 formed on the substrate 2. A resin corrosion resistant film 4 formed on the corrosion resistant film 3 and a hydrophilic film 5 formed on the resin corrosion resistant film 4 are provided. As shown in FIG. 1B, the aluminum fin material 1 may include a water-soluble film 8 formed on the hydrophilic film 5. Here, the top of the substrate 2 means one side or both sides (not shown) of the substrate 2. Each configuration will be described below.

(substrate)
The substrate 2 is a plate material made of aluminum or an aluminum alloy, and since it has excellent thermal conductivity and workability, 1000 series aluminum defined by JIS H4000, preferably aluminum of alloy number 1200 is used. In addition, in the aluminum fin material for heat exchangers, those having a thickness of about 0.08 to 0.3 mm are used in consideration of strength, thermal conductivity, workability, and the like.

(Corrosion resistant coating)
The corrosion resistant coating 3 is made of an inorganic oxide or an organic-inorganic composite compound. The inorganic oxide preferably contains chromium (Cr) or zirconium (Zr) as a main component, and is formed by, for example, phosphoric acid chromate treatment, zirconium phosphate treatment, or chromate chromate treatment. . However, in this invention, if it is a film | membrane which shows corrosion resistance, it will not be limited to this, For example, the corrosion-resistant film | membrane 3 can be formed also by performing a zinc phosphate process and a phosphoric acid titanate process. The organic-inorganic composite compound is formed by performing a coating type chromate treatment or a coating type zirconium treatment, and examples thereof include an acryl-zirconium composite.

The corrosion-resistant film 3 preferably contains Cr or Zr in the range of 1 to 100 mg / m ² , and the film thickness of the corrosion-resistant film 3 is preferably 10 to 1000 mm, depending on the purpose of use, etc. Needless to say, it can be changed as appropriate. The formation of the corrosion-resistant coating 3 improves the adhesion between the substrate 2 and the resin corrosion-resistant coating 4, prevents zinc pyrithione from falling off the resin corrosion-resistant coating 4, and the mold material 1 has a fungicidal antibacterial property. At the same time, corrosion resistance is imparted to the fin material 1.

(Resin corrosion resistant film)
The resin corrosion resistant film 4 is made of at least one of urethane resin, epoxy resin, polyester resin, and vinyl chloride resin, and has an average particle diameter of 0.01 to 1.0 μm with respect to 100 parts by weight thereof. The film thickness is 0.5 to 10 μm containing 0.1 to 100 parts by weight of zinc pyrithione. The formation of the resin corrosion resistant film 4 imparts antifungal properties to the fin material 1.

  The resin corrosion-resistant film 4 is made of at least one of urethane-based resin, epoxy-based resin, polyester-based resin, and vinyl chloride-based resin having no hydrophilicity, for example, urethane-based resin, epoxy-based resin, or epoxy-based resin By being made of a mixture of polyester resin and zinc pyrithione, which will be described later, is gradually released from the resin corrosion-resistant film 4 to the hydrophilic film 5.

  Zinc pyrithione is an antibacterial agent with a broad antibacterial spectrum and is effective against both bacteria and fungi ("Original Editor: John J Kabbalah, Translated by: Koichi Yoshimura, Hirofumi Takikawa, Cosmetics Drugs, Antiseptic / Sterilization Pharmaceutical Science, Publisher: Fragrance Journal, pages 93-104 (1990) ").

  The reason why the average particle size of zinc pyrithione is specified to be 0.01 to 1.0 μm is as follows. 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 during the formation (application, baking) of the hydrophilic film 5 tends to be promoted, and zinc pyrithione itself is sublimated. This is particularly noticeable when the content of zinc pyrithione is increased. This not only reduces the antifungal property of the mold, but also causes the thermal decomposition product to stay in the resin corrosion-resistant film 4 and cause a bad odor defect generated from the thermal decomposition product itself. On the other hand, if the average particle size is large, the fin material 1 (resin corrosion-resistant film 4) will fall off during long-term cooling operation, and the antifungal property of the fin material 1 will not be sustained.

  The reason why the content of zinc pyrithione is defined as 0.1 to 100 parts by weight with respect to 100 parts by weight of at least one of urethane resin, epoxy resin, polyester resin and vinyl chloride resin is as follows. It is. That is, when the content is less than 0.1 parts by weight, the content of zinc pyrithione is small, and the antifungal property of the fin material 1 is lowered. If the content exceeds 100 parts by weight, the solubility of zinc pyrithione in water is extremely low, which adversely affects the hydrophilicity of the hydrophilic film 5 formed on the resin corrosion-resistant film 4, and the hydrophilicity of the fin material 1 descend. Moreover, since zinc pyrithione itself is expensive, the manufacturing cost is increased. Furthermore, the film formability of the resin corrosion resistant film 4 is also reduced. In addition, the preferable content of zinc pyrithione is 0.1 to 50 parts by weight, and the more preferable content is 0.1 to 25 parts by weight. By such content, the hydrophilic property and antifungal property of the fin material 1 are further enhanced.

  The reason why the thickness of the resin corrosion resistant coating 4 is specified to be 0.5 to 10 μm is as follows. That is, when the film thickness is less than 0.5 μm, the amount of zinc pyrithione present in the resin corrosion-resistant coating 4 is reduced, so that the antifungal property of the fin material 1 is reduced. In addition, zinc pyrithione having an average particle diameter of 0.01 to 1.0 μm is easily exposed from the surface of the resin corrosion resistant coating 4. As a result, during the long-term cooling operation, zinc pyrithione tends to fall off from the resin corrosion-resistant film 4 in the form of particles, and the antifungal property of the fin material 1 does not continue. If the film thickness exceeds 10 μm, zinc pyrithione is buried in the resin corrosion-resistant film 4 and it is difficult to concentrate on the surface. Thereby, the amount of zinc pyrithione released to the hydrophilic film 5 decreases, and the antifungal property of the fin material 1 decreases. In addition, the preferable film thickness of the resin corrosion-resistant film 4 is 0.5 to 5 μm, and the more preferable film thickness is 0.8 to 3 μm. With such a film thickness, the antifungal property of the fin material 1 is further enhanced.

(Hydrophilic film)
The hydrophilic film 5 has a film thickness of 0.1 to 10 μm made of a hydrophilic resin. The hydrophilic resin preferably has at least one of a carboxyl group, a hydroxyl group, a sulfonic acid group, an amide bond, an ether bond, and a salt thereof. Here, polyacrylic acid has a carboxyl group, polyvinyl alcohol or carboxymethylcellulose has a hydroxyl group, polyacrylamide has an amide bond, and sulfoethyl acrylate and acrylic acid have a sulfonic acid group. Polyethylene glycol and the like are preferable as the polymer and those having an ether bond. Furthermore, in order to improve the adhesion with the resin corrosion resistant film 4 and prevent the hydrophilicity from deteriorating even when adhering contaminants such as the plasticizer and plastic lubricant, the hydrophilic resin has a carboxyl group. What has is more preferable. By forming the hydrophilic film 5, hydrophilicity is imparted to the fin material 1.

  The reason why the thickness of the hydrophilic film 5 is specified to be 0.1 to 10 μm is as follows. That is, if the film thickness is less than 0.1 μm, the hydrophilicity of the fin material 1 is lowered. When the film thickness exceeds 10 μm, further improvement in hydrophilicity is not recognized, and zinc pyrithione contained in the resin corrosion-resistant film 4 is not released through the hydrophilic film 5. In addition, the preferable film thickness of the hydrophilic membrane | film 5 is 0.1-5 micrometers, and a more preferable film thickness is 0.1-1 micrometer. By such a film thickness, the hydrophilic property and antifungal property of the fin material 1 are further enhanced.

(Water-soluble film)
The water-soluble film 8 has a film thickness of 0.1 to 10 μm made of a water-soluble resin having a hydroxyl group in the molecule. The water-soluble resin is not particularly limited as long as it has a hydroxyl group in the molecule, and examples thereof include sodium carboxymethyl cellulose, polyvinyl alcohol, and polyethylene glycol. And in this invention, a water-soluble film | membrane means what is 95 mass% or more melt | dissolves in 24 hours after being immersed in a tap water. Therefore, even if the water-soluble resin has a hydroxyl group in the molecule, a functional group that forms a cross-linked structure in the water-soluble film 8 by coating baking at the time of forming the water-soluble film 8 described later, For example, it is preferable not to contain an isocyanate group or an epoxy group. This is because if the water-soluble resin has the functional group described above, the solubility of the water-soluble film 8 is lowered due to the crosslinked structure. Further, as the water-soluble resin, the above-described resins may be used alone or in combination of two or more.

  The water-soluble film 8 preferably has a thickness of 0.1 to 10 μm. When the film thickness is less than 0.1 μm, the amount of the water-soluble film 8 dissolved during cooling operation (condensation) decreases in the fin produced from this fin material by press working or the like, and the processing oil adhered to the fin surface It becomes difficult to wash off and the hydrophilicity is not improved. In addition, the hydrophilic film 5 which is the lower layer of the water-soluble film 8 is likely to absorb moisture, and the fin material sticks to the mold during press working, and the workability is likely to be lowered. When the film thickness exceeds 10 μm, the coating property of the fin material is likely to be lowered during the baking process.

Next, the manufacturing method of the fin material 1 which concerns on this invention is demonstrated. The fin material 1 is manufactured by the following method.
(1) Corrosion-resistant film made of inorganic oxide or organic-inorganic composite compound by subjecting one side or both sides (not shown) of substrate 2 made of aluminum or aluminum alloy to phosphoric acid chromate treatment, zirconium phosphate treatment, etc. 3 is formed. Here, the phosphoric acid chromate treatment, the zirconium phosphate treatment, and the like are performed by applying a chemical conversion treatment solution to the substrate 2 by spraying or the like. The coating amount is preferably 1 to 100 mg / m ^{2 in} terms of Cr or Zr, and the formed film thickness is preferably 10 to 1000 mm. Moreover, before forming the corrosion-resistant film 3, it is preferable to degrease the surface of the substrate 2 in advance by spraying an alkaline aqueous solution or the like on the surface of the substrate 2. The adhesion between the substrate 2 and the corrosion-resistant coating 3 is improved by degreasing.

(2) On the formed corrosion-resistant coating 3, at least one resin solution of urethane-based resin, epoxy-based resin, polyester-based resin and vinyl chloride-based resin containing zinc pyrithione is applied and baked. A resin corrosion resistant film 4 is formed on the substrate.

  Here, the coating is performed by a conventionally known coating method such as a bar coder or a roll coater, and the coating amount is appropriately set so that the thickness of the resin corrosion-resistant film 4 is 0.5 to 10 μm. The baking temperature is appropriately set depending on the resin solution to be applied, but is performed at a baking temperature at which zinc pyrithione is not decomposed. In addition, before forming the resin corrosion resistant coating 4, it is preferable to degrease the surface of the substrate 2 in advance by spraying an alkaline aqueous solution on the surface of the substrate 2. The adhesion between the substrate 2 and the resin corrosion-resistant film 4 is improved by degreasing.

(3) A resin solution of a hydrophilic resin is applied to the surface of the formed resin corrosion-resistant film 4 and baked to form a hydrophilic film 5 on the resin corrosion-resistant film 4 to obtain the fin material 1. Here, the application is performed by a conventionally known application method such as a bar coder or a roll coater, and the application amount is appropriately set so that the thickness of the hydrophilic film 5 is 0.1 to 10 μm. The baking temperature promotes the concentration of zinc pyrithione on the surface of the resin corrosion-resistant film 4 by baking higher than the baking temperature of the resin corrosion-resistant film 4. In addition, zinc pyrithione concentrated on the surface on the hydrophilic film 5 side is released through the hydrophilic film 5 to impart antifungal property to the fin material 1. Moreover, although it is necessary to set suitably by the (hydrophilic) resin solution to apply | coat, it carries out at the baking temperature which a zinc pyrithione does not decompose | disassemble.

When the fin material 1 has the water-soluble film 8, the following (4) is performed after the formation of the hydrophilic film 5 of (3).
(4) A resin solution of a water-soluble resin is applied to the surface of the formed hydrophilic film 5 and baked to form a water-soluble film 8 on the hydrophilic film 5. Here, the coating is performed by a conventionally known coating method such as a bar coder or a roll coater, and the coating amount is appropriately set so that the film thickness of the water-soluble film 8 is 0.1 to 10 μm. And it is preferable to bake by baking temperature as low as possible. This is because when the baking temperature is high, the water-soluble film 8 (water-soluble resin) and the hydrophilic film 5 (hydrophilic resin) undergo a condensation reaction, and the water-soluble film 8 dissolves during cooling operation (condensation). Because it becomes difficult. Therefore, the baking temperature is preferably 200 ° C. or less.

Although the best mode for carrying out the present invention has been described above, examples in which the effects of the present invention have been confirmed will be described below.
In order to confirm the effect of Examples 1-5, the fin material 1 shown to Fig.1 (a), (b) was produced. And the board | substrate 2 used the aluminum plate with a plate | board thickness of 0.1 mm which consists of aluminum of the alloy number 1200 prescribed | regulated to JISH4000.

The surface of this aluminum plate was subjected to a phosphoric acid chromate treatment for forming a corrosion-resistant film 3. As the chemical conversion treatment liquid, Alsurf (registered trademark) 401/45, phosphoric acid, and chromic acid manufactured by Nippon Paint Co., Ltd. were used. At this time, the film thickness of the corrosion-resistant film 3 was 400 mm (Cr conversion value measured by the fluorescent X-ray method was 20 mg / m ² ).

  And, on the corrosion-resistant film 3, a urethane-based resin paint (manufactured by Toho Chemical Co., Ltd., urethane-modified resin emulsion, Hitech (registered trademark) S-6254) is used as a resin-corrosion-resistant paint, and the parts by weight shown in Table 1 are used. A predetermined amount of zinc pyrithione (average particle size 0.37 μm) was applied, followed by baking. The baking temperature was 160 ° C. at the temperature reached by the aluminum plate. In addition, the average particle diameter of zinc pyrithione was measured using a laser diffraction / scattering type particle size dispersion measuring apparatus (SEISIN company SK LAASER MICRON SIZER LMS-24), using water as a dispersion and screw dispersion as a dispersion method. In this way, a resin corrosion resistant film 4 having a film thickness shown in Table 1 was formed.

  Then, on the resin corrosion-resistant film 4, polyacrylic acid (molecular weight: 100,000) as a resin having a carboxyl group, polyethylene glycol (molecular weight: 6,000) as a resin containing an ether group, and polyvinyl alcohol (ken) as a resin containing a hydroxyl group. A predetermined amount of a resin aqueous solution mixed with poly (acrylic acid 30% by mass, polyethylene glycol 30% by mass, polyvinyl alcohol 40% by mass) was applied and then baked. The baking temperature was 240 ° C. at the temperature reached by the aluminum plate. In this way, a hydrophilic film 5 having a film thickness shown in Table 1 was formed.

  Moreover, about Example 4 and Example 5, 50 mass% each of sodium carboxymethylcellulose (molecular weight 100,000) and polyethyleneglycol (molecular weight 6,000) are mixed on the hydrophilic film 5 as a water-soluble resin having a hydroxyl group. A predetermined amount of the aqueous resin solution was applied, and then baked. The baking temperature was 150 ° C. at the temperature reached by the aluminum plate. Thus, the water-soluble film 8 having the film thickness shown in Table 1 was formed. In addition, the solubility of the water-soluble film | membrane 8 was 99 mass% or more in 24 hours after being immersed in tap water.

  In addition, the fin material of Comparative Examples 1-6 was also produced as a control | contrast of an Example. Comparative Examples 1 and 2 satisfied the film thickness of the resin corrosion resistant film 4, Comparative Example 3 satisfied the zinc pyrithione content (parts by weight), and Comparative Example 4 satisfied the film thickness of the hydrophilic film 5 within the scope of the present invention. A fin material was produced in the same manner as in the above example except that it was not. In Comparative Example 5, a fin material was produced in the same manner as in Example except that zinc pyrithione was contained in the hydrophilic film 5 instead of the resin corrosion-resistant film 4. Moreover, the comparative example 6 produced the fin material like the Example except having used the zinc pyrithione whose average particle diameter exceeds 1 micrometer (= 4 micrometer).

  Next, after immersing the fin materials of Examples 1-5 and Comparative Examples 1-6 in running tap water (1000 cc / min) for 240 hours assuming long-term cooling operation, the method shown below, The hydrophilicity and antifungal properties were evaluated. The results are shown in Table 1. Moreover, about the fin material before being immersed in a tap water flow, the presence or absence of workability and an initial stage odor was confirmed by the method shown below, and the result is shown in Table 1.

(Hydrophilic)
1 μl of pure water is dropped on the fin material after immersion, and the contact angle θ of the resulting water droplet is measured with a goniometer (Kyowa Interface Science Co., Ltd. CA-X250 type). It was.
(Anti-fungal)
According to the test by the glass ring method described in “Sadako Yamada et al .: Rapid antifungal activity test method on solid material surface, antibacterial fungus, Vol.31, No.11, pages 711 to 717 (2003)”. evaluated. The mold used was a mixture of three types of mold, black mold (Aspegillus niger), blue mold (Penicillium chrysogenum), and black mold (Cladosporium cladosporioides). The evaluation results were evaluated according to the 6 levels shown in Table 2.
(Processability)
A press test was conducted using a drawless mold (manufactured by Hidaka Seiki Co., Ltd.), and the press molding speed at which molding defects occurred during processing was confirmed. The higher the press molding speed (spm), the better the workability, and usually about 200 spm is sufficient.
(Initial odor)
Panelists who passed the olfactory test established by the Odor / Odor Environment Association judged whether or not odor was felt from the prepared fin material, and determined the presence or absence of odor.

  From the results shown in Table 1, the fin materials of Examples 1 to 5 were excellent in all of hydrophilicity, antifungal property, processability and initial odor in order to satisfy the claims. In addition, the fin material of Example 4 was formed with a water-soluble film having a film thickness satisfying a predetermined range on the hydrophilic film, so that the press molding speed was improved and the workability was further improved. It was. In addition, although the fin material of Example 5 formed the water-soluble film | membrane, since the film thickness of the water-soluble film | membrane was less than the predetermined range, the improvement of the press molding speed was not seen.

  On the other hand, the fin materials of Comparative Examples 1 and 2 had good hydrophilicity, processability and initial odor because the film thickness of the resin corrosion-resistant film 4 was outside the scope of the claims. It was inferior. Since the content of zinc pyrithione was less than the lower limit of the claims, the fin material of Comparative Example 3 was good in hydrophilicity, processability and initial odor, but was inferior in antifungal property. It was. In the fin material of Comparative Example 4, since the film thickness of the hydrophilic film 5 was less than the lower limit of the claims, the processability, antifungal property and initial odor were good, but the hydrophilicity was poor. It was a thing. Since the fin material of Comparative Example 5 contained zinc pyrithione in the hydrophilic film 5, the workability and the initial odor were good, but both the hydrophilic property and the antifungal property were inferior. The fin material of Comparative Example 6 was inferior in all of hydrophilicity, antifungal antibacterial properties and initial odor other than processability because the particle size of zinc pyrithione exceeded 1 μm.

(A) is sectional drawing which shows typically the cross section of the aluminum fin material which concerns on this invention, (b) is sectional drawing of another aluminum fin material. It is a schematic diagram which shows the contact angle of the water drop on a plane. It is a perspective view which shows typically the heat exchange part of a heat exchanger. (A) thru | or (c) is a schematic diagram which shows the water droplet adhesion state on the fin surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fin material 2 Substrate 3 Corrosion-resistant film 4 Resin corrosion-resistant film 5 Hydrophilic film 8 Water-soluble film J Zinc pyrithione particles

Claims (3)

A substrate made of aluminum or an aluminum alloy;
A corrosion-resistant film made of an inorganic oxide or an organic-inorganic composite compound formed on the substrate;
A resin corrosion resistant film having a film thickness of 0.5 to 10 μm formed on the corrosion resistant film;
In an aluminum fin material provided with a hydrophilic film having a film thickness of 0.1 to 10 μm made of a hydrophilic resin formed on this resin corrosion-resistant film,
The resin corrosion-resistant film is a resin composed of at least one of a urethane resin, an epoxy resin, a polyester resin, and a vinyl chloride resin, and an average particle diameter is 0.01 to 100 parts by weight of the resin. An aluminum fin material comprising 0.1 to 100 parts by weight of 1.0 μm zinc pyrithione.   The aluminum fin material according to claim 1, wherein the hydrophilic resin has at least one of a carboxyl group, a hydroxyl group, a sulfonic acid group, an amide bond, an ether bond, and a salt thereof.   2. A water-soluble film having a thickness of 0.1 to 10 μm formed on the hydrophilic film, wherein the water-soluble film is made of a water-soluble resin having a hydroxyl group in the molecule. The aluminum fin material according to claim 2.

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