JP2013180496A - Aluminum coating material and precoated aluminum fin member using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum coating material including a hydrophilic coating film excellent in hydrophilicity, contamination resistance, coating film adhesion, moldability, odorant adsorption capacity and anti-bacterial and mildew-proof properties, and a precoated aluminum fin member formed of the material.SOLUTION: An aluminum coating material includes a substrate of aluminum, an underlying film on a surface thereof, and a hydrophilic coating film thereon. The hydrophilic coating film contains 65.0-94.80 wt.% of a hydrophilic resin, 0.1-5.0 wt.% of an oolong tea component, 5.0-25.0 wt.% of an anti-bacterial and mildew-proof agent, and 0.1-5.0 wt.% of titanium oxide fine particles (D), and its deposit is 0.05-2.0g/m. The hydrophilic resin contains α% of resin having at least one of a carboxyl group and its salt, β% of resin having an amide bond and γ% of resin having an ether bond wherein γ≥α+β is satisfied. A precoated aluminum fin member is formed of the material.

Description

  The present invention forms a highly hydrophilic coating film excellent in hydrophilicity, stain resistance, coating film adhesion, moldability, odorous substance adsorption / desorption, and antibacterial and antifungal properties on the surface of an aluminum material or an aluminum alloy material. The present invention relates to an aluminum coating material and a precoated aluminum fin material that is processed and formed from the coating material, for example, used in a heat exchanger.

  Since the surface of a metal material is poor in hydrophilicity, a fin material of a heat exchanger or a printing lithographic printing plate material having a surface coated with a hydrophilic coating is used. Hereinafter, the case of the fin material of the heat exchanger will be described by taking an air conditioner as an example.

  Recent heat exchangers for air conditioners are required to have improved thermal efficiency and compactness in order to reduce weight, and incorporate a design that makes the fin spacing as narrow as possible. In the heat exchanger for an air conditioner, moisture in the air adheres to the surface of the aluminum fin as condensed water during the cooling operation. Since the surface of the metal material is generally poorly hydrophilic, moisture existing in the atmosphere adheres to the fin surface and freezes as frost in the outdoor unit during heating, preventing air flow between the fins. As a result, the ventilation resistance increases.

  Therefore, in order to melt the frost adhering to the outdoor heat exchanger, a defrosting operation in which a high-temperature refrigerant is passed through the outdoor heat exchanger is necessary. In this case, the temperature of the indoor heat exchanger decreases, and air that warms the room cannot be obtained. Therefore, it is necessary to quickly remove frost attached to the fin surface.

  As a method for quickly eliminating frost on the fin surface, (1) a method of forming a highly hydrophilic coating film on the surface of the aluminum fin material and allowing the melted frost to flow down, (2) a water-repellent coating on the surface of the aluminum fin material Although a method of forming a film and preventing frost from adhering to the surface is conceivable, the method (2) is extremely difficult at present. On the other hand, in the method (1), a coating film is formed on the surface in order to obtain hydrophilicity. With such a highly hydrophilic coating film, frost on the surface of the aluminum fin is quickly eliminated.

  Various methods for forming hydrophilic coating films have been proposed and put into practical use. For example, a method of forming an alkali silicate + resin coating film on the surface of an aluminum material (Patent Document 1 below), a method of forming a hydrophilic coating film containing a hydrophilic acrylic resin, hydrophobic acrylic and colloidal silica (Patent Document below) 2) etc. have been proposed.

  However, in order to impart hydrophilicity, the method of forming an alkali silicate + lubricating coating and the method of forming a hydrophilic coating containing colloidal silica are poor in the sustainability of hydrophilicity over time, In addition, when applied to the material and processed into fins, there is a problem that the wear of the mold is large due to the high hardness of the lubricating coating film, and cracks are likely to occur in the fin material.

  There has also been proposed a paint for forming a lubricious coating film free from such defects as mold wear and cracking (Patent Documents 3 to 7 below). As such a coating composition, for example, a hydrophilic coating composition containing a water-soluble hydrophilic resin such as polyvinyl alcohol resin, polyacrylamide resin, polyacrylic acid resin, and cellulose resin, and carbon black as an additive. The material etc. which provided the coating film to contain are mentioned.

Japanese Patent No. 3335285 Japanese Patent No. 2880308 JP 63-173632 A JP-A-5-302042 Japanese Patent Laid-Open No. 9-14889 JP 2008-001080 A JP 2009-2104017 A

  However, in outdoor units equipped with a fin material formed with an organic hydrophilic coating film composed of polyvinyl alcohol resin, etc., contaminants floating in the atmosphere adhere to the coating film surface or in sunlight. The resin deteriorated due to ultraviolet rays, etc., and high hydrophilicity could not be maintained.

  Organic hydrophilic coatings composed of cellulosic resins and the like have insufficient formability because there are few specific ether bonds exposed on the surface, and if they do not contain specific carbon black, hydrophilicity is insufficient. I could not withstand long-term use.

  In addition, in organic hydrophilic coatings composed of polyacrylic acid-based resins containing carbon black, etc., only a part of the carbon black is exposed on the surface, so that the adsorbability of odorous substances can be maintained for a long time. I could not do it. Furthermore, organic hydrophilic coatings composed of polyacrylamide resins and the like have not been able to satisfy odor absorption and desorption.

  The present inventors are aluminum materials for heat exchangers such as pre-coated fin materials, which are excellent in hydrophilicity, stain resistance, coating film adhesion, moldability, odorous substance adsorption / desorption properties, and antibacterial and antifungal properties. We have intensively studied the development of coating materials. As a result, an aluminum coating material provided with a hydrophilic coating film containing a specific resin, a specific plant-derived component, a specific antibacterial agent and specific oxide fine particles on at least one surface of an aluminum or aluminum alloy base material However, the inventors have found that it exhibits excellent performance in all of hydrophilicity, stain resistance, coating film adhesion, moldability, adsorption / desorption of odorous substances, and antibacterial and antifungal properties, and completed the present invention.

  The object of the present invention is to provide hydrophilicity on the surface of the base material of aluminum or aluminum alloy, which exhibits excellent performance in hydrophilicity, stain resistance, coating film adhesion, formability, adsorption / desorption of odorous substances, and antibacterial and antifungal properties. An object of the present invention is to provide an aluminum coating material provided with a coating film and a pre-coated aluminum fin material using such an aluminum coating material, for example, for a heat exchanger.

The present invention is the aluminum coating material according to claim 1, comprising an aluminum base material, a base film formed on at least one surface of the aluminum base material, and a hydrophilic coating film formed on the base film, The hydrophilic coating film comprises 65.0 to 94.80% by weight of the hydrophilic resin (A), 0.1 to 5.0% by weight of the oolong tea component (B), and bis- (2-pyridylthio-1). -Oxide) -5.0 to 25.0% by weight of antibacterial / antifungal agent (Z) containing zinc, and 0.1 to 0.1% of titanium oxide fine particles (D) having an average particle diameter of 0.001 to 0.050 μm A resin (a1) containing 5.0% by weight, having an adhesion amount of 0.05 to 2.0 g / m ² , and wherein the hydrophilic resin (A) has at least one of a carboxyl group and a salt thereof. Α% of the resin, β% of the resin (a2) having an amide bond, The aluminum coating material is characterized in that α, β and γ satisfy the relationship of γ ≧ α + β including γ% of the resin (a3) having a tellurium bond.

  In the present invention, the hydrophilic coating film according to the second aspect is preferably 0.01 to 1.0% by weight, with the hydrophilic coating (A) content being 64.0 to 94.79% by weight. At least one of the green tea component and the black tea component (E) was further included.

  The present invention according to claim 3 is the invention according to claim 1 or 2, wherein (a1) includes a polyacrylic resin, (a2) includes a polyacrylamide resin, and (a3) includes a polyethylene glycol resin. α: β: γ = 5-25: 5-25: 50-90 was satisfied.

  In the fourth aspect of the present invention, a precoated aluminum fin material using the aluminum coating material according to any one of the first to third aspects is used.

  The aluminum coated plate of the present invention and the precoated aluminum fin material using the same are hydrophilic, stain resistant, paint film adhesion, formability, odorous material adsorption / desorption, antibacterial protection Excellent performance in inertia.

(Aluminum paint plate)
The aluminum coating material according to the present invention includes a base material made of aluminum or an aluminum alloy, a base film formed on at least one surface of the base material, and a hydrophilic coating film formed on the base film.

(1) Aluminum base material The base material used by this invention is a base material which consists of aluminum or aluminum alloy. Hereinafter, a base material made of aluminum and an aluminum alloy is simply referred to as “aluminum material”. In addition, metals other than aluminum can also be used for a base material.

(2) Base film A corrosion-resistant base film is formed on the aluminum material. Examples of the corrosion-resistant undercoating film include a chemical conversion treatment film, a corrosion-resistant organic film, an anodized film, and a boehmite film, and any corrosion-resistant undercoating film may be used. From the viewpoint of corrosion resistance, adhesion, and economy, it is preferable to use a chemical conversion treatment film and an organic corrosion resistance film.

As the chemical conversion coating, chromium-based, zirconium-based, titanium-based and chemical conversion coatings in which these elements are mixed are used, and chromium-based chemical conversion coatings are preferable from the viewpoint of corrosion resistance and coating adhesion. As a method for forming the chemical conversion treatment film, a coating type, electrolytic type, reaction type chemical conversion treatment method, or the like is used, but any method may be used. The drying temperature is also arbitrary. Among the methods for forming the chemical conversion coating, it is preferable to use a coating type chromate method excellent in moldability, coating adhesion, and corrosion resistance. The adhesion amount of the chemical conversion film in this case is ² to 50 mg / m ² in terms of Cr element. If the coating amount is less than 2 mg / m ^{2 in} terms of Cr element, sufficient corrosion resistance and film adhesion may not be obtained. Moreover, even if it exceeds 50 mg / m < ² >, the effect of a corrosion resistance or film | membrane adhesiveness improvement cannot be expected, but it lacks economical efficiency. A preferable coating amount is 5 to 15 mg / m ² in terms of Cr element.

Since the organic corrosion-resistant film is composed of an organic resin, the thickness can be adjusted and high corrosion resistance can be maintained. As the organic resin, urethane resin, epoxy resin, polyester resin, acrylic resin, or the like is used, but any resin may be used. In this case, the adhesion amount of the organic corrosion-resistant film is 0.5 to 10.0 g / m ² . If it is less than 0.5 g / m ² , sufficient corrosion resistance may not be obtained, and if it exceeds 10.0 g / m ² , improvement in corrosion resistance cannot be expected, which is uneconomical.

(3) Hydrophilic coating film The hydrophilic coating film used for this invention is demonstrated. The hydrophilic coating film contains a hydrophilic resin (A), oolong tea component (B), antibacterial and antifungal agent (C), and fine titanium oxide particles (D), and the adhesion amount of the hydrophilic coating film is 0.05-2. 0.0 g / m ² . Such a hydrophilic coating film is excellent in hydrophilicity, stain resistance, coating film adhesion, moldability, absorption and desorption of odorous substances, and antibacterial and antifungal properties. The above performance can be satisfied.

A. Hydrophilic resin The hydrophilic resin in the hydrophilic coating film is composed of a resin containing at least one of a carboxyl group and a salt thereof, an amide bond, and an ether bond. These functional groups and bonds can exhibit hydrophilicity, coating film adhesion, moldability, and odorous substance adsorption / desorption. Particularly in the case of hydrophilicity, it is considered that the wettability between water and the resin is improved by these functional groups and bonds, and the hydrophilicity can be improved. As such a hydrophilic resin, it is preferable to use a mixture of a resin (a1) having at least one of a carboxyl group and a salt thereof, a resin (a2) having an amide bond, and a resin (a3) having an ether bond. . Here, at least one of the carboxyl group and its salt, the amide bond, and the ether bond may be contained in the resin (a1), (a2), and the resin (a3), respectively. It is preferable. Moreover, resin (a1), (a2) and resin (a3) may have another functional group and a coupling | bonding.
Instead of such a mixed system, a copolymer comprising a monomer unit having at least one of a carboxyl group and a salt thereof, a monomer unit having an amide bond, and a monomer unit having an ether bond may be used.
The content of the hydrophilic resin in the hydrophilic coating film is 65.0 to 94.80% by weight in a dry state. If it is less than 65.0% by weight, it is difficult to obtain sufficient hydrophilicity, and if it exceeds 94.80% by weight, antibacterial and antifungal properties and odor resistance cannot be satisfied.

First, the case where the hydrophilic resin is a mixed system of the resin (a1), the resin (a2), and the resin (a3) will be described.
As said resin (a1), it is the polymer which polymerized the monomer containing the carboxyl group which has an ethylenically unsaturated double bond, Comprising: What has at least one of a carboxyl group and its salt can be used. . As such a resin (a1), as a monomer, a polymer obtained by radical polymerization of an acrylic acid monomer, a methacrylic acid monomer, an itaconic acid monomer, a maleic acid monomer, a fumaric acid monomer, and the like, and A copolymer obtained by radical polymerization of these monomers and other ethylenically unsaturated monomers can be used.

  The monomer containing a carboxyl group having an ethylenically unsaturated double bond is not particularly limited, but acrylic esters (methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, acrylic 2-ethylhexyl acid, decyl acrylate, isooctyl acrylate, 2-ethylbutyl acrylate, octyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, 3-ethoxypropyl acrylate, etc.); methacrylate esters (methyl methacrylate, Ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, decyloctyl methacrylate, stearyl methacrylate, 2-methylhexyl methacrylate, methacrylate It can be suitably used Le acid 3-methoxy-butyl) and the like.

  Ethylenically unsaturated monomers that can be copolymerized with these monomers include styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, ethylene, toluene, propylene, hydroxypropyl acrylate, 2-hydroxyethyl acrylate, Dihydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid and the like are used. Among these, acrylic acid and methacrylic acid are preferable from the viewpoint of further improving hydrophilicity and adhesion.

  A commercially available resin may be used as the resin (a1) used in the present invention. The weight average molecular weight of the resin (a1) is preferably in the range of 2,000 to 300,000, more preferably 3,000 to 200,000.

  A polyacrylamide resin can be used as the resin (a2). As the polyacrylamide-based resin, an acrylamide homopolymer or a copolymer of acrylamide and another copolymerizable monomer having an amide bond can be used.

  Acrylamide, other copolymerizable monomers include acrylic acid, methacrylic acid, styrene sulfonic acid, ethylene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, dimethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, dimethyl Aminoethyl acrylate, dimethylaminopropyl acrylate, diallyldimethylammonium chloride and quaternary salts thereof; C1-24 alkyl esters of acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, etc. And so on.

  The weight average molecular weight of the resin (a2) used in the present invention is preferably in the range of 10,000 to 800,000.

  As the resin (a3), a polyethylene glycol resin can be used. As the polyethylene glycol-based resin, a polyethylene glycol homopolymer, an ethylene glycol / propylene glycol copolymer, or the like having an ether bond can be used. The weight average molecular weight of the resin (a3) used in the present invention is preferably in the range of 1,000 to 40,000, more preferably 8,000 to 25,000.

  In the present invention, the blending ratio of the resin (a1), the resin (a2), and the resin (a3) determines the hydrophilicity of the hydrophilic coating film, the stain resistance, the coating film adhesion, the moldability, and the adsorption / desorption properties of odorous substances. In order to satisfy, it is necessary to satisfy γ ≧ α + β. Here, α is the content (%) of the resin (a1) in the hydrophilic resin, β is the content (%) of the resin (a2), and γ is the content of the resin (a3). (%). When γ <α + β, the above characteristics cannot be satisfied.

  Specific values of α, β, and γ may be appropriately selected according to the performance desired for the resulting composition, but α: β: γ = 5-25: 5-25: 50-90. It is preferable to satisfy. Thereby, hydrophilicity, stain resistance, moldability, and coating film adhesion can be further satisfied. The reason is that at least one of a carboxyl group and a salt thereof, an amide bond and an ether bond are excellent in hydrophilicity, and these effectively adsorb various odorous substances and take them into the coating film, which is an excellent odorous substance. In addition, it is possible to further improve the adsorptivity of odorous substances due to the excellent hydrophilicity of the hydrophilic resin itself.

  Next, a copolymer composed of a monomer unit having at least one of a carboxyl group and a salt thereof, a monomer unit having an amide bond, and a monomer unit having an ether bond will be described.

  As the monomer unit having at least one of a carboxyl group and a salt thereof, the above-mentioned acrylic acid monomer, methacrylic acid monomer, itaconic acid monomer, maleic acid monomer, fumaric acid monomer, and the like, and these monomer units and Other ethylenically unsaturated monomer units described above can be used.

  As the monomer unit having an amide bond, acrylamide monomer or acrylamide monomer and the above-mentioned other copolymerizable monomer can be used. In addition, as the monomer unit having an ether bond, a polyethylene glycol monomer, an ethylene glycol monomer and a propylene glycol monomer, or the like having an ether bond can be used.

  The weight average molecular weight of such a copolymer is preferably in the range of 2,000 to 500,000, more preferably 3,000 to 300,000.

B. Oolong tea component In the present invention, an Oolong tea component is added to the coating composition in addition to the resin component. Oolong tea component has a function of adsorbing odorous substances such as acetaldehyde.

  The content of the Oolong tea component in the hydrophilic coating film is 0.1 to 5.0% by weight, preferably 1.0 to 3.0% by weight in a dry state. If the oolong tea component is less than 0.1% by weight, it is difficult to obtain sufficient adsorption of the odor component, and if it exceeds 5.0% by weight, the effect of improving the adsorption property of the odor component cannot be expected. Cannot be obtained.

  The manufacturing method of the oolong tea component used for this invention is not specifically limited. For example, when oolong tea leaves and stems are heated from room temperature to a predetermined temperature, with a solvent such as water, acidic aqueous solution, aqueous ethanol, ethanol, aqueous methanol, methanol, acetone, ethyl acetate or glycerin aqueous solution or a mixed solvent thereof. The extracted extract is used. In addition to using an extract obtained by removing the solvent from the extract, it can also be used as an extract obtained by extraction (consisting of an oolong tea extract component and an extract solvent) or as a concentrate of the extract. In particular, a method of adding room temperature water or an extract extracted with warm water to the coating composition is preferable from the viewpoint of odor component adsorptivity.

  Oolong tea components obtained by such extraction include catechins (catechin, gallocatechin, epicatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, epigallocatechin gallate); tannins. Other flavonoids such as kaempferol, quercetin and myricetin; polyphenols such as GOD polyphenol (excluding catechins); organic acids such as malonic acid, succinic acid and gallic acid; caffeine; amino acids; sugars; vitamins; Various components are contained.

  Inclusion of oolong tea components such as catechins in the hydrophilic coating film enhances the adsorptivity of odor components. Among oolong tea components, catechins (catechin, gallocatechin, epicatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, epigallocatechin gallate) greatly contribute to the adsorptivity of odor components. In particular, a multimer in which these catechins are associated, preferably a catechin dimer and a trimer, effectively acts to enhance the adsorptivity of odor components. Since catechin dimers and trimers are contained in oolong tea in particular among teas, it is preferable that the oolong tea component is contained in a hydrophilic coating film in order to ensure adsorptivity of odor components. In the present invention, it is preferable to use catechins and oolong tea in which the total amount of dimers and trimers of catechins is 0.5 to 20% by weight of the oolong tea component.

  The oolong tea component used in the present invention can be used not only for adsorption of ammonia, acetaldehyde, and acetic acid, but also for aldehydes such as butyraldehyde and benzaldehyde, and other types of odor components.

C. Antibacterial / antifungal agent In the present invention, an antibacterial / antifungal agent is added for the purpose of imparting antibacterial / antifungal properties to the resulting hydrophilic coating film. The antibacterial and antifungal agent in the present invention has at least one of antibacterial and antifungal properties, and preferably has both antibacterial and antifungal properties. As the antibacterial / antifungal agent, it is preferable to use bis- (2-pyridylthio-1-oxide) -zinc in order to ensure antibacterial / antifungal properties, hydrophilicity, and heat resistance during coating formation.

  By blending this antibacterial and antifungal agent into the hydrophilic resin, the antibacterial and antifungal agent is uniformly dispersed in the hydrophilic coating film of the present invention, and the antibacterial and antifungal agent is deposited on the surface of the coating film, It becomes possible to achieve both hydrophilicity and antibacterial / antifungal properties.

  The content of the antibacterial / antifungal agent in the hydrophilic coating film is 5.0 to 25.0% by weight, preferably 10.0 to 20.0% by weight in a dry state. If it is less than 5.0% by weight, the content of the antibacterial / antifungal agent is small, and sufficient antibacterial / antifungal properties cannot be obtained. On the other hand, if the amount of the antibacterial / antifungal agent exceeds 25.0% by weight, the physical properties of the coating such as hydrophilicity are deteriorated and cannot be used as a fin material.

D. Titanium oxide fine particles In the invention, the hydrophilic coating film contains fine particles, and the fine particles contain 50% by weight or more, preferably 70% by weight or more of titanium oxide fine particles. When titanium oxide fine particles are contained in the hydrophilic coating film, the hydrophilicity is improved by being dispersed on the coating film surface. As the titanium oxide component, an amorphous titanium oxide, anatase-type titanium oxide, brookite-type titanium oxide, rutile-type titanium oxide, titanium peroxide, or a combination of two or more types is suitably used.

  By blending the titanium oxide fine particles with a hydrophilic resin, the hydrophilicity can be further improved. In addition to the hydrophilicity of the titanium oxide fine particles themselves, the fine particles are exposed on the surface by adding fine fine particles to the hydrophilic resin, and the hydrophilicity can be further improved.

  By combining the titanium oxide fine particles with the zinc oxide component in addition to the titanium oxide component, the hydrophilicity can be further improved.

  The titanium oxide fine particles used in the present invention can be easily produced by the following known production method. That is, a liquid phase method such as a precipitation method (coprecipitation method); a gas phase method such as a sputtering method; a solid phase in which raw material powders are mixed and heated and reacted in a non-oxidizing atmosphere or an oxidizing atmosphere. It can be produced by various methods.

  Of these production methods, the precipitation method is preferred because the synthesis is relatively simple. For example, titanium oxide fine particles are produced by heat hydrolysis or neutralization of a titanium compound such as a water-soluble inorganic titanium compound such as titanium sulfate. In order to contain the zinc oxide component, titanium oxide / zinc oxide fine particles can be produced by further adding an aqueous solution containing a zinc component such as nitrate or sulfate.

  The content of fine titanium oxide particles in the hydrophilic coating film is 0.1 to 5.0% by weight, preferably 1.0 to 3.0% by weight in a dry state. If it is less than 0.1% by weight, the hydrophilicity will be insufficient, and if it exceeds 5.0% by weight, the mold wear will be severe when forming an aluminum coated plate into a fin material, etc., and cracks will occur during molding, so it can withstand use. I can't.

  The average particle diameter of the titanium oxide fine particles is 0.001 to 0.050 μm. If the average particle size is less than 0.001 μm, it is difficult to produce from the viewpoint of industrial production, and fine particles are buried in the coating film during the formation of the coating film, and the amount of titanium oxide fine particles on the surface of the hydrophilic coating film Therefore, there is a possibility that hydrophilicity cannot be maintained. On the other hand, when the average particle size exceeds 0.050 μm, the exposed surface area of the oxidized fine particles is reduced, so that the hydrophilicity is lowered.

E. Further, in the present invention, it is preferable to add at least one of the green tea component and the black tea component as a component of the hydrophilic coating film in addition to the oolong tea component. These green tea components and black tea components have a function of fixing the odor component adsorbed by the oolong tea component in the coating film. Therefore, by adding a green tea component or a black tea component as a hydrophilic coating film component, the desorption rate of the adsorbed odor component is reduced, thereby improving the fixability. As a result, the adsorption / desorption properties of the hydrophilic coating film are further improved.

  In the hydrophilic coating film, the content of the hydrophilic resin (A) is 64.0 to 94.79% by weight, and at least one of the green tea and black tea components is 0.01 to 1.0% by weight, preferably Is contained in an amount of 0.05 to 0.5% by weight. If it is less than 0.01% by weight, it is difficult to obtain the adsorption / desorption property of the odor component, and if it exceeds 1.0% by weight, an improvement in the effect cannot be expected, which is uneconomical.

  In addition, these contents are things as a single content, respectively, in the case of the green tea ingredient alone or the black tea ingredient alone, and when using both the green tea ingredient and the black tea ingredient, they are the sum of the contents. is there.

  The methods for producing the green tea component and black tea component used in the present invention are not particularly limited. As a method for producing these green tea components and black tea components, the same method as the method for extracting the oolong tea components is used. Among green tea components and black tea components, polyphenols are particularly excellent in odor component fixing, and therefore it is preferable to add green tea components and black tea components containing more polyphenols. In the present invention, it is preferable to use green tea or black tea containing 5 to 50% by weight of polyphenols.

  The green tea component and black tea component used in the present invention can be used not only for fixing ammonia, acetaldehyde, and acetic acid, but also for fixing aldehydes such as butyraldehyde and benzaldehyde, and other types of odor components.

  Conventionally, adsorption of odorous substances has been compensated by holding a solid substance such as carbon black in the resin coating. However, when used over a long period of time, carbon black and the like in the resin coating film fall off, and it has been impossible to avoid a decrease in the adsorptivity of odorous substances. In the present invention, Oolong tea component that adsorbs odor, more preferably green tea component, black tea component is incorporated into the hydrophilic resin, and the hydrophilic resin itself in the hydrophilic coating film is considered to be an adsorbent of the odor substance. It is done. As a result, each functional group and the oolong tea component, more preferably the green tea component and the black tea component in the hydrophilic resin adsorb the odorous substance, and the hydrophilicity of the hydrophilic resin itself further improves the adsorption of the odorous substance and strengthens it. It is thought that it will continue to retain odorous substances.

F. Other Additives The hydrophilic coating film of the present invention has, as necessary, rust preventives such as tannic acid, gallic acid, phytic acid, and phosphinic acid; leveling agents such as alkyl esters of polyalcohols; Additives such as a colorant such as a phthalocyanine compound added within a range not impaired; a surfactant such as an alkyl sulfate ester salt and an alkyl sulfosuccinate salt can be added.

G. Formation of hydrophilic coating film The hydrophilic coating film used in the present invention can be formed by coating (coating) a liquid coating composition for a hydrophilic coating film on an aluminum substrate surface and baking it.

  The coating composition for forming the hydrophilic coating film used in the present invention is prepared by dissolving and dispersing each component in a solvent. Such a solvent is not particularly limited as long as each component can be dissolved or dispersed. For example, an aqueous solvent such as water, a ketone solvent such as acetone, an alcohol solvent such as ethanol, ethylene glycol, etc. Ethylene glycol alkyl ether solvents such as monoethyl ether, diethylene glycol alkyl ether solvents such as diethylene glycol monobutyl ether, propylene glycol alkyl ether solvents such as propylene glycol monomethyl ether, and a series of glycol alkyl ethers such as ethylene glycol monoethyl ether acetate Examples include esterified products of system solvents, among which aqueous solvents are preferable, and water is particularly preferable.

  The coating composition is applied by a roll coater method, roll squeeze method, chemicoater method, air knife method, dipping method, spray method, electrostatic coating method, etc. However, a roll coater method is preferable. As the roll coater method, a gravure roll method with easy coating amount management, a natural coating method suitable for thick coating, a reverse coating method suitable for giving an aesthetic appearance to the coated surface, and the like can be employed. Moreover, a general heating method, a dielectric heating method, etc. are used for drying of a coating film.

  Baking at the time of forming the coating film is preferably performed under the conditions that the baking temperature (reached surface temperature) is 180 to 300 ° C. and the baking time is 1 to 60 seconds. When the baking temperature in forming the coating film is less than 180 ° C. or when the baking time is less than 1 second, the coating film is not sufficiently formed, and the adhesion of the coating film is lowered. When the baking temperature exceeds 300 ° C. or the baking temperature exceeds 60 seconds, the coating film component is modified and the hydrophilicity is remarkably lowered.

The adhesion amount as the coating film thickness is 0.05 to 2.0 g / m ² , preferably 0.1 to 1.5 g / m ² . Is less than deposition amount 0.05 g / m ^2, the desired hydrophilicity, moldability, adsorption and desorption of odor material without antimicrobial antifungal property can be obtained, further the respective characteristic exceeds 2.0 g / m ² It becomes uneconomical because there is no improvement.

  The aluminum coating material produced in this way is precoated with a desired fin shape by applying volatile press oil for press forming to the surface and then performing forming such as slitting and corrugating. Molded into aluminum fin material. Such a pre-coated aluminum fin material is preferably used as, for example, a fin material of a heat exchanger for an air conditioner, but is limited to a heat exchanger for an air conditioner as long as it is used to prevent condensation between the fin materials. It is not a thing.

Hereinafter, preferred embodiments of the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to these Examples.
Examples 1-31 and Comparative Examples 1-24
As shown in Tables 1 to 9, hydrophilic resin (A), oolong tea component (B), antibacterial and antifungal agent (C), titanium oxide fine particles (D), green tea component and black tea component (E), other additives The coating composition for hydrophilic coating films containing this was prepared. In Examples 1 to 16 and Comparative Examples 1 to 24, the green tea component and the black tea component (E) were not added. In Examples 17, 18, 20 to 24, either one of green tea component and black tea component (E) was added. In Example 19, both the green tea component and black tea component (E) were added. As for other additives, carbon black was added only in Comparative Examples 9 and 10.

The polyacrylic resin is polyacrylic acid (weight average molecular weight 30,000), the polyacrylamide resin is polyacrylamide (weight average molecular weight 20,000), and the polyethylene glycol resin is polyethylene glycol (weight average molecular weight 20). , 000) was used. In the table, PVA represents a polyvinyl alcohol resin. Bis- (2-pyridylthio-1-oxide) -zinc (ZPT) and 2- (4-thiazolyl) benzimidazole (TBZ) were used as the antibacterial and antifungal agent (C). As the titanium oxide fine particles, those having an average particle size shown in each table were used. The carbon black was used primary particle size 0.03 .mu.m, DBP oil absorption of 100 cm ^3/100 g, those of nitrogen adsorption specific surface area 80 cm ² / g.

  As Oolong tea component, green tea component and black tea component, an extract containing the components shown in Table 10 was used. Oolong tea extract is a commercially available Oolong tea extract, green tea extract is a commercially available green tea extract, and black tea extract is an extract from commercially available tea leaves. Each component such as polyphenol was measured by high performance liquid chromatography. The polyphenols, catechins, caffeine, and other tea components shown in Table 10 are extracts obtained by removing water as an extraction solvent from the extract, and the weight% of each component is based on 100% of the entire extract. Represents a numerical value. Moreover, content of each tea component shown to Tables 1-9 is content as an extract.

  The compounding amount of each component shown in Tables 1-9 (the compounding amount of the resin, the compounding amount of the oolong tea component, the compounding amount of the antibacterial and antifungal agent, the compounding amount of the titanium oxide fine particles, the green tea component and the black tea component, and other additives) It was shown as parts by weight relative to a total of 100 parts by weight of these components contained in the coating composition for hydrophilic coating. In other words, these compounding amounts represent the weight% of each component in the hydrophilic coating film in a dry state. The coating composition was prepared by dissolving or dispersing 100 g of each component in 1 liter of water as a solvent.

  A hydrophilic coating film was formed on the aluminum substrate surface as follows. An aluminum alloy plate (1100-H24 material, 0.100 mm thickness), which is an aluminum base material, was weakly alkaline degreased, washed with water, and then dried. Next, a coated chromate film, an epoxy resin corrosion-resistant organic film, or a boehmite film was formed as a base film on the surface of the aluminum alloy plate thus treated. Next, each hydrophilic coating composition was applied onto the undercoat with a roll coater and baked at a final plate surface temperature (PMT) of 200 ° C. for 20 seconds to obtain an aluminum coated plate. In Example 2, a hydrophilic coating composition was similarly applied and baked on an aluminum alloy plate without forming a base film.

  The aluminum coated plate sample thus obtained was measured for hydrophilicity (initial and sustainability), stain resistance, coating film adhesion, moldability, antibacterial and antifungal properties, and odor resistance by the methods described below. The results are shown in Tables 1-7.

  In each of the above measurements, the sample was first pretreated as follows. Each sample was immersed in volatile press oil (Daphni AF-2A manufactured by Idemitsu Kosan Co., Ltd.) for 1 minute. After removing the sample, the sample was held vertically at room temperature for 30 seconds to cut off the oil. Next, the mixture was placed in a hot blast furnace (atmosphere) at 180 ° C. for 2 minutes and then cooled to room temperature.

Hydrophilic (initial, hydrophilic sustainability)
The contact angle of pure water was measured with a goniometer. The initial hydrophilicity, which is hydrophilic immediately after the aluminum coated plate was produced, and the hydrophilic durability after the wet and dry cycle were evaluated. In the dry / wet cycle, the manufactured aluminum coated plate was immersed in tap water having a flow rate of 1 liter / min for 8 hours, and then dried at 80 ° C. for 16 hours, and this was performed 20 cycles. The meanings of the symbols in each table are as follows, and ●, ◎ and ○ are acceptable to satisfy the performance, and Δ and × are unacceptable.
●: Indicates that the contact angle is 10 ° or less, which is very excellent.
(Double-circle): It shows that a contact angle exceeds 10 degrees and is 20 degrees or less, and is very favorable.
◯: The contact angle exceeds 20 ° and is 30 ° or less, indicating that it is good.
(Triangle | delta): A contact angle exceeds 30 degrees and is 40 degrees or less, and it shows that it is inferior.
X: Indicates that the contact angle exceeds 40 ° and is very poor.

(Contamination resistance)
The prepared aluminum coated plate was pretreated and then subjected to a contamination cycle treatment. The contamination cycle treatment is to adsorb palmitic acid in the gas phase by exposing the aluminum coating plate to air at 50 ° C. containing palmitic acid vapor for 1 hour, then immersing in tap water for 6 hours and then drying in a dryer. Was one cycle and this was carried out for 10 cycles. The contact angle on the surface of the hydrophilic coating film after 10 cycles was measured by the same method as the hydrophilicity evaluation. The meanings of the symbols in each table are as follows, where ◎ and ○ are acceptable to satisfy the performance, and Δ and × are unacceptable.
(Double-circle): A contact angle is 20 degrees or less, and shows that it is very favorable.
A: The contact angle exceeds 20 ° and is 40 ° or less, indicating that it is good.
(Triangle | delta): A contact angle exceeds 40 degrees and is 60 degrees or less, and it shows that it is inferior.
X: Indicates that the contact angle exceeds 60 ° and is very poor.

Coating Film Adhesion An adhesion test according to JIS H4001 was performed, and the remaining number after peeling of the tape at the grid was measured. In each table, the case where all remained (25/25) was determined to be acceptable (◯), and the others were regarded as unacceptable (x).

Formability Evaluated in a situation where drawless molding was performed with an actual fin press. The molding conditions are as follows. Volatile press oil: AF-2C (Idemitsu Kosan) was used, the ironing rate was 58%, and the molding speed was 250 spm. The meanings of the symbols in each table which are the evaluation results are as follows, and “◎” and “◯” are acceptable and “Δ” and “x” are unacceptable.
(Double-circle): It shows that it is very favorable.
◯: Indicates that it is good.
(Triangle | delta): It shows that a crack generate | occur | produces on the inner surface of a color part and is unsatisfactory.
X: Indicates that buckling or color jump occurs and is defective.

Antibacterial and antifungal properties Antibacterial test An antibacterial test (film adhesion method) according to JIS Z2801 was performed using the prepared aluminum coated plate, and an antibacterial activity value was obtained using the following formula.
R = log (A / B)
R: Antibacterial activity value A: Average number of viable cells after culturing of blank test piece B: Meaning of symbols in each table, which is an average evaluation result of viable cell number after culturing of antibacterial processed test piece, is as follows , ○ is a pass that satisfies the performance, and × is a failure.
○: R is 2.0 or more, indicating that it is good.
X: R is less than 2.0, indicating a failure.

2. Antifungal test Using the prepared aluminum coated plate, a fungus resistance test was conducted according to JIS Z2911, and the growth of mycelia was examined with the naked eye.
The meanings of the symbols in each table which are the evaluation results are as follows, with 0 being acceptable to satisfy the performance and 1 and 2 being unacceptable.
0: No hyphal growth was observed in the inoculated part of the test piece.
1: The area of the growing part of the mycelium observed in the inoculated part of the test piece did not exceed 1/3 of the total surface area.
2: The area of the growth part of the mycelium recognized in the inoculated part of the test piece exceeded 1/3 of the total surface area.

Odor resistance The aluminum coated plate was evaluated using a sample subjected to a hydrophilic wet and dry cycle immediately after the aluminum coated plate was produced.
1-1. Acetaldehyde adsorption test Each aluminum coating plate was placed in a container in an acetaldehyde atmosphere, and the acetaldehyde concentration (Ca) in the container after adsorbing acetaldehyde was measured. Ca is a concentration corresponding to the amount of unadsorbed acetaldehyde. The measurement conditions were as follows. In addition, the density | concentration (Cb) which deducted the said acetaldehyde density | concentration Ca from the following initial acetaldehyde density | concentration (20 ppm) is a density | concentration corresponding to the acetaldehyde adsorption amount by an aluminum coating board. The adsorption rate (%) of acetaldehyde is represented by (Cb / 20) × 100.
Sample area: 100 × 200 mm ²
Sample container: 5 liter desiccator Gas amount of container: 5 liter Initial gas concentration: acetaldehyde 20 ppm
Gas measurement method: Acetaldehyde detector tube Laboratory temperature: 20 ° C
Measurement time: 24 hours The meanings of the symbols in each table are as follows, and ◎ and ○ are acceptable to satisfy the performance, and Δ and × are unacceptable.
A: Adsorption rate exceeding 70%, indicating that it is very good.
○: The adsorption rate exceeds 55% and is 70% or less, which indicates that it is good.
Δ: Adsorption rate exceeds 40% and is 55% or less, indicating that it is defective.
X: Adsorption rate is 40% or less, indicating that it is very poor.

1-2. Acetaldehyde Desorption Test Each aluminum coated plate adsorbed with acetaldehyde was placed in a container in an air atmosphere, and the acetaldehyde concentration (Cc) in the container after desorption of acetaldehyde was measured. The measurement conditions were as follows. A concentration (Cd) obtained by subtracting the acetaldehyde concentration Cc from the acetaldehyde concentration Cb is a concentration corresponding to the amount of acetaldehyde fixed by the aluminum coating plate. Therefore, the fixing ratio (%) of acetaldehyde is represented by (Cd / Cb) × 100.
Sample area: 100 × 200 mm ²
Sample container: 5 liter desiccator Gas amount of container: 5 liter Initial gas concentration: Acetaldehyde 0 ppm
Gas measurement method: Acetaldehyde detector tube Laboratory temperature: 20 ° C
Measurement time: 24 hours The meanings of the symbols in each table are as follows, and 及 び and ○ are acceptable to satisfy the performance, and Δ and × are unacceptable.
A: The fixing rate exceeds 95%, indicating that it is very good.
A: The fixing rate exceeds 90% and is 95% or less, indicating that it is good.
(Triangle | delta): A fixing rate exceeds 60% and is 90% or less, and shows that it is inferior.
X: The fixing rate is 60% or less, indicating that the fixing ratio is very poor.

2-1 Ammonia adsorption test Each aluminum coating plate was placed in an ammonia atmosphere container, and the ammonia concentration (Ca) in the container after ammonia was adsorbed was measured. Ca is a concentration corresponding to the amount of unadsorbed ammonia. The measurement conditions were as follows. In addition, the density | concentration (Cb) which deducted said ammonia density | concentration Ca from the following ammonia initial density | concentration (20 ppm) is a density | concentration corresponding to the ammonia adsorption amount by an aluminum coating plate. The adsorption rate (%) of ammonia is represented by (Cb / 20) × 100.
Sample area: 100 × 200 mm ²
Sample container: 5 liter desiccator Gas amount of container: 5 liter Initial gas concentration: 20 ppm of ammonia
Gas measurement method: ammonia detector tube Laboratory temperature: 20 ° C
Measurement time: 24 hours The meanings of the symbols in each table are as follows, and ◎ and ○ are acceptable to satisfy the performance, and Δ and × are unacceptable.
A: Adsorption rate exceeding 45%, indicating that it is very good.
A: The adsorption rate exceeds 35% and is 45% or less, indicating that it is good.
Δ: Adsorption rate exceeds 25% and is 35% or less, indicating a failure.
X: The adsorption rate is 25% or less, which indicates that it is very poor.

2-2 Ammonia desorption test Each aluminum coating plate that adsorbed ammonia was placed in a container in an air atmosphere, and the ammonia concentration (Cc) in the container after ammonia was desorbed was measured. The measurement conditions were as follows. The concentration (Cd) obtained by subtracting the ammonia concentration Cc from the ammonia concentration Cb is a concentration corresponding to the ammonia fixing amount by the aluminum coating plate. Therefore, the ammonia fixing rate (%) is expressed by (Cd / Cb) × 100.
Sample area: 100 × 200 mm ²
Sample container: 5 liter desiccator Gas amount in container: 5 liter Gas initial concentration: Ammonia 0 ppm
Gas measurement method: ammonia detector tube Laboratory temperature: 20 ° C
Measurement time: 24 hours The meanings of the symbols in each table are as follows, and ◎ and ○ are acceptable to satisfy the performance, and Δ and × are unacceptable.
A: The fixing rate exceeds 90%, indicating that it is very good.
A: The fixing ratio exceeds 80% and is 90% or less, indicating that the fixing ratio is good.
(Triangle | delta): A fixing rate exceeds 70% and is 80% or less, and shows that it is inferior.
X: The fixing rate is 70% or less, indicating that the fixing ratio is very poor.

  As shown in Tables 1 to 5, all of Examples 1 to 31 had good initial hydrophilicity and hydrophilic durability, stain resistance, coating film adhesion, moldability, antibacterial and antifungal properties, and odor resistance. It was. Moreover, by blending the green tea component and the black tea component, the odor resistance was remarkably excellent.

  On the other hand, in Comparative Example 1, since the oolong tea component, the antibacterial and antifungal agent and the titanium oxide fine particles were not contained in the hydrophilic coating film, hydrophilicity (sustained), antibacterial and antifungal properties, and odor resistance (initial and The acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property in sustainability) could not be satisfied.

  In Comparative Example 2, since the content ratio of the hydrophilic resin in the hydrophilic coating film was too large and the content ratio of the antibacterial / antifungal agent was too small, the antibacterial / antifungal property, odor resistance (acetaldehyde in the initial stage and the sustained stage) Adsorption / desorption properties and ammonia adsorption / desorption properties) could not be satisfied.

  In Comparative Example 3, since the resins (a2) and (a3) were not contained in the hydrophilic resin, the contamination resistance, moldability, and odor resistance (initial acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property) I was not satisfied.

  In Comparative Example 4, since the resins (a1) and (a3) were not contained in the hydrophilic resin, stain resistance, moldability, and odor resistance (initial and sustained acetaldehyde adsorption / desorption properties and ammonia adsorption / desorption properties) were obtained. I was not satisfied.

  In Comparative Example 5, since the resins (a1) and (a2) were not contained in the hydrophilic resin, hydrophilicity (sustained), contamination resistance, coating film adhesion, odor resistance (acetaldehyde adsorption / desorption in the initial stage and duration) And ammonia adsorption / desorption property) could not be satisfied.

  In Comparative Example 6, since the resin (a3) was not contained in the hydrophilic resin, moldability and odor resistance (acetaldehyde desorption property and ammonia desorption property in the initial stage, acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property in the continuous period) were obtained. I was not satisfied.

  In Comparative Example 7, since the resin (a2) was not contained in the hydrophilic resin, contamination resistance and odor resistance (initial acetaldehyde desorption property and ammonia desorption property, sustained acetaldehyde adsorption property and ammonia adsorption property) Could not be satisfied.

  In Comparative Example 8, since a polyvinyl alcohol-based resin was used instead of the resin (a1), contamination resistance and odor resistance (initial acetaldehyde desorption property and ammonia desorption property, acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property in duration) Could not be satisfied.

  In Comparative Example 9, since the polyvinyl alcohol resin was used instead of the resin (a1) and carbon black was added, the odor resistance (acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property in duration) could not be satisfied.

  In Comparative Example 10, since carbon black was added to the hydrophilic coating film instead of the oolong tea component, odor resistance (sustained acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property) could not be satisfied.

  In Comparative Examples 11 and 12, since the relationship of γ ≧ α + β in the hydrophilic resin was not satisfied, moldability and odor resistance (acetaldehyde desorption property and ammonia desorption property in the initial stage, acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property in the sustained period) ) Could not be satisfied.

  In Comparative Example 13, since the content ratio of the hydrophilic resin in the hydrophilic coating film was too low and the content ratio of the oolong tea component was too high, the hydrophilicity (initial and sustained) and stain resistance could be satisfied. could not.

  In Comparative Example 14, since the content ratio of the oolong tea component in the hydrophilic coating film was too low, odor resistance (acetaldehyde desorption property and ammonia desorption property in the initial stage, acetaldehyde adsorption / desorption property and ammonia adsorption / desorption property in the continuous period) was satisfied. I couldn't.

  In Comparative Example 15, since the content ratio of the oolong tea component in the hydrophilic coating film was too high, hydrophilicity (sustained) and stain resistance could not be satisfied.

  In Comparative Example 16, since the antibacterial / antifungal agent was not contained, the antibacterial / antifungal properties could not be satisfied.

  In Comparative Example 17, the content of the antibacterial / antifungal agent was too low, so that the antibacterial / antifungal property could not be satisfied.

  In Comparative Example 18, since the content ratio of the antibacterial / antifungal agent was too high, hydrophilicity (initial and sustained) and stain resistance could not be satisfied.

  In Comparative Example 19, since bis- (2-pyridylthio-1-oxide) -zinc was not contained as an antibacterial and antifungal agent, the stain resistance and antibacterial properties could not be satisfied.

  In Comparative Example 20, since the particle diameter of the titanium oxide fine particles was too large, the hydrophilicity (sustained) and stain resistance could not be satisfied.

  In Comparative Example 21, since titanium oxide fine particles were not contained, hydrophilicity (sustained) and contamination resistance could not be satisfied.

  In Comparative Example 22, since the content ratio of the titanium oxide fine particles was too low, hydrophilicity (sustained) and contamination resistance could not be satisfied.

  In Comparative Example 23, since the content ratio of the titanium oxide fine particles was too high, the moldability could not be satisfied.

  In Comparative Example 24, the coating amount of the hydrophilic coating film was too small, so hydrophilicity (sustained), stain resistance, antibacterial and antifungal properties, and odor resistance (acetaldehyde desorption property and ammonia desorption property at the initial stage, Desorption and ammonia adsorption / desorption properties) could not be satisfied.

  According to the present invention, an aluminum coating material having a hydrophilic coating film on the surface that exhibits excellent performance in hydrophilicity, stain resistance, coating film adhesion, moldability, odorous substance adsorption / desorption properties, and antibacterial and antifungal properties. In addition, a precor and an aluminum fin material using the same can be obtained.

Claims (4)

An aluminum coating material comprising an aluminum substrate, a base coating formed on at least one surface of the aluminum base, and a hydrophilic coating formed on the base coating,
The hydrophilic coating film comprises 65.0 to 94.80% by weight of the hydrophilic resin (A), 0.1 to 5.0% by weight of the oolong tea component (B), and bis- (2-pyridylthio-1). -Oxide) -5.0 to 25.0% by weight of antibacterial / antifungal agent (Z) containing zinc, and 0.1 to 0.1% of titanium oxide fine particles (D) having an average particle diameter of 0.001 to 0.050 μm 5.0 contains a weight%, the adhesion amount is 0.05 to 2.0 g / ^{m 2,}
The hydrophilic resin (A) is composed of α% of a resin (a1) having at least one of a carboxyl group and a salt thereof, β% of a resin (a2) having an amide bond, and a resin (a3) having an ether bond. An aluminum coating material characterized in that α, β, and γ satisfy a relationship of γ ≧ α + β.   In the hydrophilic coating film, the content of the hydrophilic resin (A) is set to 64.0 to 94.79% by weight, and 0.01 to 1.0% by weight of at least one of green tea component and black tea component (E) is added. The aluminum coating material according to claim 1, further comprising:   The (a1) contains a polyacrylic resin, the (a2) contains a polyacrylamide resin, the (a3) contains a polyethylene glycol resin, and α: β: γ = 5-25: 5-25: The aluminum coating material of Claim 1 or 2 satisfy | filling the relationship of 50-90.   The precoat aluminum fin material using the aluminum coating material as described in any one of Claims 1-3.