JP2021162164A - Aluminum fin material - Google Patents

Abstract

To provide an aluminum fin material that combines a good hydrophilicity with an oil repellency that can suitably suppress the attachment of contaminants, while suppressing the occurrence of an odor.SOLUTION: An aluminum fin material is provided with an aluminum sheet, a hydrophilic film, and a functional film in the indicated sequence. The hydrophilic film comprises a surfactant and a hydrophilic resin; the functional film comprises a silicone component; the surfactant has an alkyl chain as a lipophilic group; and the number of carbon atoms in the alkyl chain is equal to or more than 17.SELECTED DRAWING: Figure 1

Description

The present invention relates to an aluminum fin material, and more particularly to an aluminum fin material preferably used for a heat exchanger such as an air conditioner.

Heat exchangers are used in products in various fields such as room air conditioners, packaged air conditioners, freezing showcases, refrigerators, oil coolers, and radiators. As a material for fins of a heat exchanger, aluminum or an aluminum alloy having excellent thermal conductivity, workability, corrosion resistance, etc. is generally used. Plate fin type and plate and tube type heat exchangers have a structure in which fins are arranged side by side at narrow intervals.

When the surface temperature of the fins of the heat exchanger falls below the dew point, dew condensation water adheres to the fins. When the hydrophilicity of the surface of the fin is low, the contact angle of the adhering dew condensation water becomes large, so that the water splashes in the living environment called water splash. Further, when the condensed water is combined and becomes large, a bridge is formed between the adjacent fins, the ventilation path between the fins is blocked, and the ventilation resistance is increased.
For the purpose of preventing such water splashing and reducing ventilation resistance, for example, Patent Document 1 proposes a technique of applying and forming a hydrophilic film on the surface of fins.

On the other hand, the fins may have pollutants mainly composed of oily components derived from suspended matter volatilized and scattered from building materials, foods, daily necessities, etc., adhering to the surface. Since such pollutants are water-repellent substances, their hydrophilicity deteriorates when they adhere to the surface of fins.
In order to make it difficult for such a water-repellent substance to adhere to the surface of the fin, it is effective to impart hydrophilicity and oil repellency to the fin material at the same time. For example, Patent Document 2 discloses an aluminum fin material having a coating film having both hydrophilicity and oil repellency by containing a predetermined amount of a polyvinyl alcohol-based resin having a saponification degree of 90% or more in a hydrophilic resin. ..

Japanese Patent No. 2520308 Japanese Unexamined Patent Publication No. 2011-94873

However, according to the technique according to Patent Document 2, if the content of the polyvinyl alcohol-based resin having a saponification degree of 90% or more is increased in order to improve the oil repellency, the hydrophilicity is lowered. Thus, there was a limit to obtaining the desired high potency for both oil repellency and hydrophilicity.

As a result of diligent studies by the present inventors in view of the above situation, oil repellency capable of suitably suppressing the adhesion of pollutants by providing a hydrophilic film containing a hydrophilic resin and a surfactant and a functional film. It was newly found that both good hydrophilicity and good hydrophilicity can be achieved. However, it was also found that an odor may be generated depending on the components used.

Therefore, an object of the present invention is to provide an aluminum fin material that has both oil repellency that can suitably suppress the adhesion of pollutants and good hydrophilicity and that suppresses the generation of odor.

The present invention relates to the following [1] to [6].
[1] An aluminum plate, a hydrophilic film, and a functional film are provided in this order. The hydrophilic film contains a surfactant and a hydrophilic resin, and the functional film contains a silicone component. The surfactant is an aluminum fin material having an alkyl chain as a lipophilic group and having 17 or more carbon atoms in the alkyl chain.
[2] The aluminum fin material according to the above [1], wherein the surfactant is an anionic surfactant.
[3] The anionic surfactant contains at least one compound selected from the group consisting of polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl ether sulfate, and polyoxyethylene alkyl sulfosuccinate. , The aluminum fin material according to the above [2].
[4] The silicone component comprises a modified polydimethylsiloxane derivative having at least one functional group selected from the group consisting of an epoxy group, a methacryl group, a phenyl group, and a hydrogen group in its structure [1]. The aluminum fin material according to any one of [3].
[5] The aluminum fin material according to any one of [1] to [4], wherein the amount of the silicone component adhered to the functional film is 0.0010 to 1.0 g / m ^2.
[6] The aluminum fin according to any one of [1] to [5], wherein a corrosion-resistant film is further provided between the aluminum plate and the hydrophilic film, and the corrosion-resistant film contains a hydrophobic resin. Material.

According to the present invention, it is possible to provide an aluminum fin material that has both good oil repellency and hydrophilicity and suppresses the generation of odor. As a result, it is possible to use an aluminum fin material that can prevent water splashing and reduce ventilation resistance while suitably suppressing the adhesion of pollutants without causing an unpleasant odor.

FIG. 1 is a schematic cross-sectional view showing an aspect of the structure of an aluminum fin material.

Hereinafter, a mode for carrying out the aluminum fin material according to the present invention will be described in detail. Note that "~" indicating a numerical range is used to mean that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.

<Aluminum fin material>
As shown in FIG. 1, the aluminum fin material 10 (hereinafter, may be simply referred to as a fin material) according to the present embodiment includes an aluminum plate 1, a hydrophilic film 2, and a functional film 3. It prepares in order. A corrosion-resistant film may be provided between the aluminum plate 1 and the hydrophilic film 2, and a base treatment layer may be further provided between the aluminum plate 1 and the corrosion-resistant film. The functional film 3 is preferably formed on the hydrophilic film 2.
At least one surface of the aluminum plate 1 may have the above configuration, and both sides of the aluminum plate 1 may have the above configuration. Further, when both sides of the aluminum plate 1 have the above configuration, both sides do not have to have the same mode.

The hydrophilic film 2 contains a surfactant and a hydrophilic resin, and the surfactant has an alkyl chain as a lipophilic group. The alkyl chain has 17 or more carbon atoms. Further, the functional film 3 contains a silicone component.
By providing the hydrophilic film 2 and the functional film 3, the properties such as oil repellency that can suitably suppress the adhesion of pollutants to the fin material and hydrophilicity that can prevent water splashing and reduce ventilation resistance are mutually inhibited. It can be compatible and improved without doing anything.

The oil-repellent effect of the functional film is maintained even in the absence of dew condensation. Therefore, the fin material can suppress the deterioration of hydrophilicity by suppressing the adhesion of pollutants containing an oily component as a main component, regardless of whether or not it is in the cooling operation.

(Aluminum plate)
The aluminum plate is a concept including a plate made of aluminum and a plate made of an aluminum alloy, and an aluminum plate conventionally used for an aluminum fin material can be used.
As the aluminum plate, 1000 series aluminum specified in JIS H 4000: 2014 is preferable because it is excellent in thermal conductivity and workability. More specifically, aluminum having alloy numbers 1050, 1050, and 1200 is more preferable as the aluminum plate. However, the above description does not exclude the use of 2000 to 9000 series aluminum alloys or other aluminum plates as the aluminum plate.

The thickness of the aluminum plate is appropriately desired according to the application and specifications of the fin material. The fin material for the heat exchanger preferably has a thickness of 0.08 mm or more, more preferably 0.1 mm or more, from the viewpoint of fin strength and the like. On the other hand, from the viewpoint of processability to fins, heat exchange efficiency, etc., the thickness is preferably 0.3 mm or less, more preferably 0.2 mm or less.

(Hydrophilic film)
The hydrophilic film is a film that imparts hydrophilicity to the surface of the fin material, and contains a hydrophilic resin and a surfactant. As a result, even when a functional film is provided on the hydrophilic film, good hydrophilicity can be achieved as well as oil repellency due to the functional film. This is considered to be due to the expression action of the surfactant.
The hydrophilic film is formed by applying a resin coating material containing a hydrophilic resin and a surfactant on an aluminum plate, or when a base treatment layer or a corrosion-resistant film is provided on the aluminum plate, applying, drying, etc. on the layer or film. It can be formed by solidifying with.

Surfactants have a hydrophilic group and a lipophilic group, and have an alkyl chain having 17 or more carbon atoms as the lipophilic group. Surfactants have different volatility depending on their molecular weight, and when the number of carbon atoms is small, the molecular weight also decreases. Therefore, it is considered that the surfactant is easily volatilized and odor is easily generated. When the number of carbon atoms in the alkyl chain is 17 or more, the volatility is low and the generation of odor is suppressed.

The number of carbon atoms in the alkyl chain may be 17 or more, but 18 or more is preferable. The upper limit is not particularly limited, but the carbon number is preferably 25 or less, more preferably 22 or less, from the viewpoint of preventing the lipophilicity from being too strong and inhibiting the hydrophilic function.
Further, the alkyl chain may be linear or branched.

As the surfactant, any of an anion type, cation type and nonionic type can be applied, but an anion type surfactant is preferable from the viewpoint of easy dispersion in the hydrophilic film.

The anionic surfactant may include, for example, at least one compound selected from the group consisting of polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl ether sulfate, and polyoxyethylene alkyl sulfosuccinate. , More preferable from the viewpoint of improving hydrophilicity.

Adhesion amount of the surfactant in the hydrophilic coating, from the viewpoint of obtaining sufficient hydrophilicity, preferably from 0.0003 g / ^{m 2} or more, more preferably 0.0005 g / ^{m 2} or more, 0.001 g / ^{m 2} or more More preferred. Further, from the viewpoint of preventing the oil repellency of the functional film from being hindered due to being too hydrophilic, the amount of the surfactant adhered ^{is preferably 0.7 g / m 2} or less, more preferably 0.5 g / m ² or less. It is preferably 0.05 g / m ² or less, and more preferably 0.05 g / m 2 or less.

The hydrophilic resin may have a hydrophilic group and may contain one kind of resin or two or more kinds of resins. Examples of the hydrophilic group include a hydroxyl group (hydroxy group), a carboxyl group, a sulfonic acid group, a polyether group and the like.
Examples of those having a hydroxyl group include polyethylene glycol (PEG, PEO) and polyvinyl alcohol (PVA). Examples of those having a carboxyl group include polyacrylic acid (PAA) and the like. Examples of those having a hydroxy group and a carboxyl group include carboxymethyl cellulose (CMC). Examples of those having a sulfonic acid group include sulfoethyl acrylate. Examples of those having a polyether group include polyethylene glycol (PEG, PEO) and modified compounds thereof.

In addition to these, two or more copolymers of monomers having a hydrophilic group can also be applied, and for example, a copolymer of acrylic acid and sulfoethyl acrylate is preferable.
In the case of a copolymer, the method of arranging the monomers such as an alternating copolymer, a block copolymer, a graft copolymer, and a random copolymer is not particularly limited.

Adhesion amount of the hydrophilic resin in the hydrophilic coating is sufficient from the viewpoint of obtaining a hydrophilic 0.05 g / ^{m 2} or more preferably, 0.1 g / ^{m 2} or more preferably, 0.3 g / ^{m 2} or more and more preferable. Further, from the viewpoint of preventing the hydrophilic resin from eluting when the surface of the fin material gets wet with water and inhibiting the oil repellency of the functional film, the amount of the hydrophilic resin adhered ^{is preferably 5 g / m 2} or less. 1 g / m ² or less is more preferable, and 0.8 g / m ² or less is further preferable.

In addition to the hydrophilic resin and the surfactant, the hydrophilic film may contain other optional components as long as the effects of the present invention are not impaired. Examples of the optional component include various aqueous solvents and paint additives for improving the paintability, workability, and physical properties of the film.
Examples of the paint additive include a water-soluble organic solvent, a cross-linking agent, a surface conditioner, a wet dispersant, an antioxidant, an antioxidant, an antifoaming agent, a rust preventive, an antibacterial agent, and an antifungal agent. .. These paint additives may contain one kind or two or more kinds.

The thickness of the hydrophilic film is not particularly limited, but ^{assuming that the density of the hydrophilic film is 1 g / cm 3} , the thickness is preferably 0.01 μm or more, more preferably 0.1 μm or more from the viewpoint of obtaining good hydrophilicity. It is preferable, and 0.3 μm or more is more preferable. Further, from the viewpoint of obtaining good coating workability at the time of film formation, 5 μm or less is preferable, 1 μm or less is more preferable, and 0.8 μm or less is further preferable.
The film thickness of the hydrophilic film is determined by the concentration of the coating composition used for forming the hydrophilic film and the bar coater No. 1 used for forming the film. It can be adjusted by selecting.

(Functional film)
The functional film contains a silicone component.
The functional film formed on the outermost surface of the fin material to suppress the adhesion of pollutants contains a silicone component that has low surface free energy and is considered to have low substance adhesion, so that pollutants centered on oily components Adhesion can be reduced.

When the functional film is a lubricating film that enhances the lubricity of the surface of the fin material, it is preferable to further contain a resin that enhances the lubricity (hereinafter, may be referred to as a functional resin). When the lubricating film contains a functional resin, the friction coefficient on the surface of the fin material is reduced, and the press formability when the fin material is processed into fins is improved.
The functional film can be formed by applying a coating material containing a silicone component and, if necessary, a functional resin, onto the hydrophilic film, and solidifying the coating by drying or the like.

The silicone component is a polymer of a silicon compound, and is a compound having a siloxane bond as a skeleton. The silicone component is one or more functional groups selected from a polyether group, an epoxy group, a methacryl group, an amino group, a phenyl group, a hydrogen group, and a hydroxyl group because of its high dispersibility in a coating material and high fixability in a resin film. It is preferable to contain a modified polydimethylsiloxane derivative having the above in the structure, and the modified polydimethylsiloxane having one or more functional groups selected from the group consisting of an epoxy group, a methacryl group, a phenyl group and a hydrogen group in the structure. More preferably, it contains a derivative. Silicone containing a long-chain alkyl group is also preferable.
As the modified polydimethylsiloxane derivative or the silicone containing a long-chain alkyl group, any of nonionic, anionic and cationic properties can be used, and among them, nonionic property is preferable.

Adhesion amount of the silicone component in the functional coating, sufficient oil repellency was obtained, and preferably from 0.0010 g / ^{m 2} or more from the viewpoint of suppressing the adhesion of oil components, 0.006 g / ^{m 2} or more, and 0 More preferably, it is 0.01 g / m ^{2 or more.} On the other hand, since the silicone component exhibits both oil repellency and hydrophobicity, the amount of the silicone component adhered is 1.0 g / m ² or less from the viewpoint of preventing the hydrophilic function of the hydrophilic film from being impaired. Preferably, 0.3 g / m ² or less is more preferable, and 0.1 g / m ² or less is further preferable.

When the functional film is a lubricating film, examples of the functional resin include resins having a hydrophilic group. The resin may contain one kind or two or more kinds. Examples of the hydrophilic group include a hydroxyl group (hydroxy group), a carboxyl group, a sulfonic acid group, a polyether group and the like.
Examples of those having a hydroxyl group include polyethylene glycol (PEG, PEO) and polyvinyl alcohol (PVA). Examples of those having a carboxyl group include polyacrylic acid (PAA) and the like. Examples of those having a hydroxy group and a carboxyl group include carboxymethyl cellulose (CMC). Examples of those having a sulfonic acid group include sulfoethyl acrylate. Examples of those having a polyether group include polyethylene glycol (PEG, PEO) and modified compounds thereof. In addition to these, two or more copolymers of monomers having a hydrophilic group can also be applied.
Among them, those having a hydroxyl group are preferable, and polyethylene glycol (PEG, PEO) is more preferable.

In addition to the above, the functional film may contain other optional components as long as the effects of the present invention are not impaired. Examples of the optional component include various aqueous solvents and paint additives for improving the paintability, workability, and physical properties of the film.
Paint additives include, for example, water-soluble organic solvents, cross-linking agents, surfactants, surface conditioners, wet dispersants, anti-settling agents, antioxidants, defoamers, rust inhibitors, antibacterial agents, and antifungal agents. And so on. These paint additives may contain one kind or two or more kinds.

Adhesion amount of the functional resin in the functional coating is preferably from 0.01 g / ^{m 2} or more from the viewpoint of obtaining sufficient lubricity, 0.03 g / ^{m 2} or more preferably, 0.05 g / ^{m 2} or more and more preferable. On the other hand, when the surface of the fin material gets wet with water, the amount of adhesion is 5 g / g from the viewpoint of suppressing the elution of the functional resin and inhibiting the oil repellency and the deterioration of the application workability of the functional film. m ² or less, and more preferably at most 0.5 g / ^{m 2,} 0.3 g / ^{m 2} or less is more preferred.

The thickness of the functional film is not particularly limited, but ^{assuming that the density of the functional film is 1 g / cm 3} , 0.001 μm or more is preferable, 0.01 μm or more is more preferable, and 0 is obtained from the viewpoint of obtaining good oil repellency. It is more preferably .03 μm or more. Further, from the viewpoint of obtaining good coating workability at the time of film formation, 5 μm or less is preferable, 1 μm or less is more preferable, and 0.5 μm or less is further preferable.
The film thickness of the functional film is determined by the concentration of the coating composition used for forming the functional film and the bar coater No. used for the film formation. It can be adjusted by selecting.

The total film thickness of the hydrophilic film and the functional film is preferably 5 μm or less from the viewpoint of suppressing a decrease in heat exchange efficiency of the fin material.

(Base treatment layer)
The base treatment layer can be provided between the aluminum plate and the hydrophilic film, if desired. When the fin material further includes a corrosion-resistant film, the base treatment layer can be provided between the aluminum plate and the corrosion-resistant film.
By providing the base treatment layer, the corrosion resistance of the aluminum plate can be enhanced, and the adhesion between the aluminum plate and the hydrophilic film, and when the corrosion resistant film is provided, the adhesion between the aluminum plate and the corrosion resistant film can be improved. Can be enhanced.

As the base treatment layer, a conventionally known one can be used as long as it can impart corrosion resistance to the aluminum plate. For example, a layer made of an inorganic oxide or an inorganic-organic composite compound can be used.
As the inorganic material constituting the inorganic oxide or the inorganic-organic composite compound, chromium (Cr), zirconium (Zr) or titanium (Ti) is preferable as the main component.

For the layer made of inorganic oxide to be the base treatment layer, for example, an aluminum plate is subjected to phosphoric acid chromate treatment, zirconium phosphate treatment, zirconium oxide treatment, chromic acid chromate treatment, zinc phosphate treatment, titanium phosphate treatment, or the like. Can be formed by However, the types of inorganic oxides are not limited to those formed by these treatments.

The layer made of an inorganic-organic composite compound to be a base treatment layer can be formed, for example, by subjecting an aluminum plate to a coating type chromate treatment, a coating type zirconium treatment, or the like. Specific examples of such an inorganic-organic composite compound include an acrylic-zirconium complex and the like.

The film thickness of the base treatment layer is not particularly limited and may be set as appropriate, but it is formed so that the ^{amount of adhesion per unit area is 1 to 100 mg / m 2 in terms of metal (Cr, Zr, Ti).} The film thickness is preferably 1 to 100 nm.
The amount of adhesion and the film thickness of the base treatment layer can be adjusted by adjusting the concentration of the chemical conversion treatment liquid used for film formation of the base treatment layer and the film formation treatment time.

Before forming the base treatment layer, the surface of the aluminum plate may be degreased in advance with an alkaline degreasing liquid, which improves the reactivity of the base treatment and further improves the adhesion of the formed base treatment layer. improves.

(Corrosion resistant film)
The corrosion-resistant film is a layer that may be provided between the aluminum plate and the hydrophilic film mainly in order to enhance the corrosion resistance of the aluminum plate, and preferably contains a hydrophobic resin. When the base treatment layer is formed on the surface of the aluminum plate, the corrosion resistant film is provided between the base treatment layer and the hydrophilic film.
The corrosion-resistant film can be formed, for example, by applying a resin coating material containing a hydrophobic resin on an aluminum plate or an undercoat layer and solidifying it by drying or the like.

The corrosion-resistant film makes it difficult for moisture such as condensed water and ionic species such as oxygen and chloride ions to penetrate into the aluminum plate, and suppresses corrosion of the aluminum plate and formation of aluminum oxide that generates odor. ..

As the hydrophobic resin in the corrosion-resistant film, conventionally known ones can be used. For example, various resins such as polyester-based, polyolefin-based, epoxy-based, urethane-based, and acrylic-based resins can be mentioned, and one or a mixture of two or more of these resins can be applied.

In addition to the above, the corrosion-resistant film may contain other optional components as long as the effects of the present invention are not impaired. Examples of the optional component include various aqueous solvents and paint additives for improving the paintability, workability, and physical properties of the film.
Paint additives include, for example, water-soluble organic solvents, cross-linking agents, surfactants, surface conditioners, wet dispersants, anti-settling agents, antioxidants, defoamers, rust inhibitors, antibacterial agents, and antifungal agents. And so on. These paint additives may contain one kind or two or more kinds.

Adhesion amount of the hydrophobic resin in the corrosion barrier coating is not particularly limited, from the viewpoint of imparting sufficient corrosion resistance to the aluminum plate, 0.01 g / m ² or more preferably, 0.05 g / m ² or more is more preferable. On the other hand, from the viewpoint of suppressing reduction in heat exchanging efficiency of the fins, the adhesion amount of the hydrophobic resin is preferably 8 g / m ² or less, 4g / m ² or less is more preferable.
The film thickness of the corrosion-resistant film is preferably 0.05 μm or more from the viewpoint of obtaining good corrosion resistance, and the film-forming property is good, defects such as cracks are reduced, and the heat transfer resistance of the corrosion-resistant film is suppressed to a low level. It is preferably 4 μm or less from the viewpoint of obtaining good heat exchange efficiency of fins.
The film thickness of the corrosion-resistant film and the amount of the hydrophobic resin attached are determined by the concentration of the coating composition used for forming the corrosion-resistant film and the bar coater No. used for the film formation. It can be adjusted by selecting.

(Characteristics of aluminum fin material)
The surface of the aluminum fin material according to the present embodiment is excellent in hydrophilicity and oil repellency, and can suppress the generation of odor due to the surfactant.
When the use of the fin material is continued, the contact angle when n-tetradecane is dropped on the surface of the fin material is 15 ° or more, and the contact angle when pure water is dropped is less than 50 °. It is preferable from the viewpoint of achieving both hydrophilicity and oil repellency. The contact angle when n-tetradecane is dropped is more preferably 25 ° or more, and the contact angle when pure water is dropped is more preferably less than 40 °. The contact angle can be measured with a goniometer, for example.

The odor of the fin material is based on sensory evaluation, but when the fin material is brought close to the subject's nose in a room under normal conditions where the environment is not controlled, no odor is felt, or even if it is felt, the odor is slight. It is more preferable that no odor is felt at all.

The thickness of the fin material varies depending on the application and is not particularly limited, but when used in a heat exchanger, for example, it is preferably 0.08 mm or more, more preferably 0.1 mm or more from the viewpoint of strength that can withstand processing. Further, from the viewpoint of workability and heat exchange efficiency, the thickness is preferably 0.3 mm or less, more preferably 0.2 mm or less.

<Manufacturing method of aluminum fin material>
An example of a method for producing an aluminum fin material according to the present embodiment will be described, but the present invention is not limited to this aspect, and can be produced by another production method as long as the effects of the present embodiment are not impaired.

A base treatment layer or a corrosion-resistant film is formed on the aluminum plate by a known method, if desired, and then a coating composition containing a hydrophilic resin and a surfactant is applied and dried to form the hydrophilic film. Next, a coating composition containing a silicone component and, if desired, a functional resin is applied and dried to form a functional film.

When forming a hydrophilic film, a functional film is provided while suppressing the generation of odor by containing a surfactant having an alkyl chain having 17 or more carbon atoms as a lipophilic group in the coating composition. Even in this case, good hydrophilicity can be achieved as well as oil repellency due to the functional film.
Further, by incorporating a silicone component in the coating composition when forming the functional film, good oil repellency can be imparted, and adhesion of pollutants centering on the oily component can be suppressed.

The hydrophilic film, the functional film, and the corrosion-resistant film are formed by preparing a coating composition for forming each film, applying the coating composition to the object to be coated by a bar coater, a roll coating method, or the like, and subjecting the coating to a baking treatment. In particular, if the aluminum plate has a coil shape, it is preferable in terms of productivity to continuously perform degreasing, painting, heating, winding, etc. by applying a roll coating device or the like. The baking temperature of the hydrophilic film, the functional film, and the corrosion-resistant film may be set according to the components of the resin or the like used, and is preferably in the range of 120 to 270 ° C., for example.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples, and is modified to the extent that it can be adapted to the gist thereof. It is also possible to carry out, all of which are within the technical scope of the invention.

(Example 1)
As the aluminum plate, the standard of alloy number 1200 specified in JIS H 4000: 2014 with a thickness of 0.1 mm was used. A base treatment layer was formed on one surface of the aluminum plate by phosphoric acid chromate treatment. Next, a coating composition containing a corrosion-resistant film resin (acrylic resin, manufactured by Toagosei Co., Ltd.) was applied with a bar coater and baked to form a corrosion-resistant film having ^{an adhesion amount of 4 mg / dm 2.}
Next, a resin composition containing an anionic surfactant (polyoxyethylene alkyl ether phosphoric acid ester) having 18 carbon atoms in the alkyl chain and a sulfonic acid group-containing acrylic resin as a hydrophilic resin is applied to the film. The coating was applied to the surface of the corrosion-resistant film using a bar coater so that the amount of the hydrophilic resin attached and the amount of the surfactant attached were the values shown in Table 1. Subsequently, it was baked at 200 ° C. to form a hydrophilic film having a thickness of 0.65 μm.
Finally, a coating composition containing a nonionic epoxy / polyether-modified silicone emulsion as a silicone component and polyethylene glycol as a functional resin was applied to the surface of the obtained hydrophilic film, and the amount of the functional resin adhered to the film and the amount of the functional resin adhered to the film. The silicone component was applied to the surface of the hydrophilic film using a bar coater so that the amount of the silicone component adhered was as shown in Table 1. Subsequently, a functional film was formed by baking at 160 ° C. to obtain an aluminum fin material.

(Comparative Example 1)
Made of aluminum in the same manner as in Example 1 except that the surfactant in the hydrophilic film was changed to an anionic surfactant (polyoxyethylene alkyl ether phosphoric acid ester) having 12 to 13 carbon atoms in the alkyl chain. Obtained fin material.

(Comparative Example 2)
An aluminum fin material in the same manner as in Example 1 except that the surfactant in the hydrophilic film was changed to an anionic surfactant (polyoxyethylene lauryl ether phosphoric acid ester) having 12 carbon atoms in the alkyl acid. Got

(Comparative Example 3)
An aluminum fin material in the same manner as in Example 1 except that the surfactant in the hydrophilic film was changed to an anionic surfactant (polyoxyethylene alkyl ether phosphoric acid ester) having 8 carbon atoms in the alkyl acid. Got

(Comparative Example 4)
Aluminum fins in the same manner as in Example 1 except that the surfactant in the hydrophilic film was changed to an anionic surfactant (polyoxyethylene tridecyl ether phosphoric acid ester) having 13 carbon atoms in the alkyl acid. I got the wood.

(Comparative Example 5)
An aluminum fin material was obtained in the same manner as in Example 1 except that the surfactant in the hydrophilic film was changed to a cationic surfactant (lauryldimethylethylammonium ethyl sulfate) having 12 carbon atoms in the alkyl acid. rice field.

(Example 2)
An aluminum fin material was obtained in the same manner as in Example 1 except that the silicone component in the functional film was changed to a nonionic epoxy-modified silicone emulsion.

(Example 3)
An aluminum fin material was obtained in the same manner as in Example 1 except that the silicone component in the functional film was changed to an anionic epoxy-modified silicone emulsion.

(Example 4)
An aluminum fin material was obtained in the same manner as in Example 1 except that the silicone component in the functional film was changed to a nonionic long-chain alkyl group-containing silicone emulsion.

(Examples 5 to 17)
In the same manner as in Example 1 except that the amount of the functional resin adhered to the functional film and the amount of the silicone component adhered to the surface of the hydrophilic film were applied to the surface of the hydrophilic film using a bar coater so as to have the values shown in Table 3. An aluminum fin material was obtained.

The obtained aluminum fin material was evaluated for hydrophilicity, oil repellency showing the ability to suppress the adhesion of contaminants, and odor by the methods shown below.

(Hydrophilic)
The operation of immersing the aluminum fin material in running water for 8 hours and then drying it in a heater set at 80 ° C. for 16 hours was defined as one cycle. After carrying out such a cycle for 5 cycles, the aluminum fin material was placed horizontally so that the evaluation surface faced upward, and 1 to 3 μL of ion-exchanged water was dropped on the evaluation surface. The contact angle of the dropped water droplet was measured by a contact angle measuring device (Drop Master manufactured by Kyowa Surface Chemistry Co., Ltd.). The evaluation criteria are as follows, and the results are shown in Tables 1 to 3.
A Very good: Contact angle is less than 40 ° B Good (pass): Contact angle is 40 ° or more and less than 50 ° C Bad (failure): Contact angle is 50 ° or more

(Oil repellent)
The aluminum fin material was immersed in running water for 1 minute and then dried in a heater set at 80 ° C. for 1 hour. The aluminum fin material was placed horizontally so that the evaluation surface faced upward, and 1 to 3 μL of n-tetradecane was dropped on the evaluation surface. The contact angle of the dropped droplet was measured by a contact angle measuring device (manufactured by Kyowa Surface Chemistry Co., Ltd., CA-X150 type). The evaluation criteria are as follows, and the results are shown in Tables 1 to 3.
A Very good: Contact angle is 25 ° or more B Good (pass): Contact angle is 15 ° or more and less than 25 ° C Bad (failure): Contact angle is less than 15 °

(Odor)
In a normal room where the environment was not controlled, an aluminum fin material was brought close to the subject's nose, and the sensory evaluation of the odor felt from the surface was performed. The evaluation criteria are as follows, and the results are shown in Table 1.
A Good (pass): No odor is felt, or even if it is felt, odor is slight C Bad (fail): Odor is felt

From the above results, it was found that by incorporating a surfactant having an alkyl chain as a lipophilic group in the hydrophilic film, the hydrophilicity and the oil repellency related to the effect of suppressing the adhesion of pollutants are excellent, but odor is also generated. However, by setting the number of carbon atoms of the alkyl chain to 17 or more, it is possible to suppress the generation of odor while exhibiting good hydrophilicity and oil repellency. Odor is a problem that occurs for the first time when a hydrophilic film contains a surfactant, and the problem is solved by using a surfactant having an alkyl chain having 17 or more carbon atoms as a lipophilic group. can do.
Further, the hydrophilic and oil-repellent effects were confirmed in Examples 1 to 4 regardless of the type of silicone component. Further, by finely adjusting the balance between the amount of the functional resin attached to the functional film and the amount of the silicone component attached, both hydrophilicity and oil repellency can be made very good.

1 Aluminum plate 2 Hydrophilic film 3 Functional film 10 Aluminum fin material

Claims (6)

An aluminum plate, a hydrophilic film, and a functional film are provided in this order.
The hydrophilic film contains a surfactant and a hydrophilic resin, and
The functional film contains a silicone component and has a silicone component.
The surfactant is an aluminum fin material having an alkyl chain as a lipophilic group and having 17 or more carbon atoms in the alkyl chain. The aluminum fin material according to claim 1, wherein the surfactant is an anionic surfactant. Claimed that the anionic surfactant comprises at least one compound selected from the group consisting of polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl ether sulfate, and polyoxyethylene alkyl sulfosuccinate. 2. The aluminum fin material according to 2. Any of claims 1 to 3, wherein the silicone component comprises a modified polydimethylsiloxane derivative having at least one functional group in its structure selected from the group consisting of an epoxy group, a methacryl group, a phenyl group, and a hydrogen group. The aluminum fin material according to item 1. The aluminum fin material according to any one of claims 1 to 4, wherein the amount of the silicone component adhered to the functional film is 0.0010 to 1.0 g / m ^2. A corrosion-resistant film is further provided between the aluminum plate and the hydrophilic film.
The aluminum fin material according to any one of claims 1 to 5, wherein the corrosion-resistant film contains a hydrophobic resin.

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