JP6061755B2 - Aluminum fin material and manufacturing method thereof - Google Patents

Description

  The present invention relates to an aluminum fin material for a heat exchanger used for an indoor unit or the like of an air conditioner and a method for manufacturing the same.

  Heat exchangers are used in various fields such as room air conditioners, packaged air conditioners, refrigeration showcases, refrigerators, oil coolers, and radiators. Generally, aluminum or an aluminum alloy (hereinafter collectively referred to as aluminum) is applied to the fins of the heat exchanger because of its excellent thermal conductivity and workability. In the heat exchanger, if dew condensation water during cooling operation accumulates between the fins, it becomes a resistance during blowing and deteriorates the heat exchanger characteristics. Therefore, in order to impart hydrophilicity or water repellency so that condensed water does not accumulate on the fin surface, such fins made of aluminum are subjected to surface treatment before coating the fin (such as a coating film). Hereinafter, it is applied to the fin material). That is, the surface of the fin is made hydrophilic to increase the fluidity of the condensed water, or it is made water-repellent and dropped before the water droplets of the condensed water become large, depending on the use of the heat exchanger and the like. For example, for a heat exchanger mounted on an indoor unit of an air conditioner such as a room air conditioner, it is preferable to use a hydrophilic property in which water uniformly spreads on the fin surface, rather than water repellency in which condensed water is easily scattered. is there.

  On the other hand, the hydrophilicity of the fin deteriorates when a water-repellent substance derived from floating substances volatilized or scattered from building materials, food, daily necessities, etc. adheres to the surface. On the fin surface, the water-repellent substance is removed to some extent by condensed water constantly generated during the cooling operation, but is easily fixed in an operation mode such as a heating operation and a blowing operation. In particular, when a new air conditioner is installed or when the period from the last cooling operation is a long period of time, the water-repellent substance adhering to the fin surface is accumulated without being removed, and the hydrophilicity deterioration becomes remarkable. There is a risk that problems may occur during the cooling operation. In addition, the fin surface may become water repellent, and a water splash phenomenon may occur in which condensed water is scattered as water droplets during cooling operation.

  Therefore, it is effective for the fin to have a water-repellent substance at the same time, that is, to have oil repellency at the same time, in order to suppress the water-repellent surface and maintain the hydrophilicity. For example, Patent Document 1 discloses an aluminum fin material provided with a coating film having both hydrophilicity and oil repellency by containing a predetermined amount of a polyvinyl alcohol resin having a saponification degree of 90% or more in a hydrophilic resin. ing.

JP 2011-94873 A

  When both components imparting hydrophilicity and oil repellency are contained in the coating film as in Patent Document 1 of the prior art, the degree of saponification is 90 to improve one property, for example, to increase oil repellency. When the content of the polyvinyl alcohol resin of at least% is increased, the other characteristic, that is, the hydrophilicity tends to be lowered. Therefore, there is a limit to improving the two characteristics at the same time.

  The present invention has been made in view of the above problems, and for the purpose of providing an aluminum fin material for a heat exchanger suitable for an indoor unit of an air conditioner, etc., having high surface hydrophilicity and hardly deteriorated. It is an object to make both hydrophilicity and oil repellency sufficiently high.

  In order to solve the above-mentioned problems, the present inventors have come up with the idea of providing a two-layer coating to impart hydrophilicity to one and oil repellency to the other.

That is, the aluminum fin material according to the present invention includes a substrate made of aluminum or an aluminum alloy, a first functional film formed on the substrate, and a second functional film formed on the surface of the first functional film. And a functional film. In the aluminum fin material, at least the second functional film of the first functional film and the second functional film is selected from a hydroxyl group, a carboxyl group, a sulfonic acid group, and a polyether group. a hydrophilic resin having the above species in the structure, contained in the adhesion amount 0.05-5 g / m ^2, the first functional coating contains silicone component in coating weight 0.001 to 1 g / m ² , under 25 ° C. circumstances, the contact angle when dropped n- tetradecane onto the surface is at 15 ° or more and the contact angle when dropped pure water and less than 50 °.

  The aluminum fin material is a modified polydimethylsiloxane derivative in which the silicone component has in its structure one or more selected from a polyether group, an epoxy group, a methacryl group, an amino group, a phenyl group, a hydrogen group, and a hydroxyl group. It is preferable that

  In this way, one of the two-layer coatings contains a hydrophilic resin and the other contains a silicone component that imparts oil repellency, so that hydrophilicity and oil repellency can both be improved without interfering with each other. it can.

Alternatively, in the aluminum fin material according to the present invention, at least one of the first functional film and the second functional film contains the hydrophilic resin in an adhesion amount of 0.05 to 5 g / m ² , and at least The other may contain a silicone component in an adhesion amount of 0.001 to 1 g / m ² , and at this time, the silicone component has one or more types selected from an epoxy group, a methacryl group, a phenyl group, and a hydrogen group. The modified polydimethylsiloxane derivative is contained therein. In the aluminum fin material, the first functional film contains the hydrophilic resin in an adhesion amount of 0.05 to 5 g / m ² , and the second functional film has an adhesion amount of 0. It is preferable to contain by 001-1 g / m < ² >, and it is more preferable that the said 2nd functional film | membrane contains the said hydrophilic resin with the adhesion amount of 0.05-5 g / m < ² >.

  Thus, when the outermost film has oil repellency, the surface oil repellency is maintained even in the absence of condensed water, and the deterioration of hydrophilicity when the cooling is not used is suppressed.

  In the aluminum fin material according to the present invention, it is preferable that the substrate further includes a corrosion-resistant film made of a hydrophobic resin on a surface on which the first functional film is formed.

  Thus, the corrosion resistance of the substrate (aluminum) is improved by forming the corrosion-resistant film on the substrate surface.

  In the method for producing an aluminum fin material according to the present invention, the first functionality containing the silicone component is applied by applying a coating composition comprising an aqueous emulsion containing 0.05 to 70% by mass of the silicone component. A film or the second functional film is formed.

  Thus, the aluminum fin material which has oil repellency is obtained by applying the coating material which adjusted content of the silicone component, and forming the functional membrane | film | coat containing a silicone component.

  The aluminum fin material according to the present invention can be a heat exchanger suitable for an indoor unit of an air conditioner in which condensed water does not accumulate during subsequent cooling operation even if the cooling non-use period extends for a long time. .

[Aluminum fin material]
Hereinafter, the form for implement | achieving the aluminum fin material which concerns on this invention is demonstrated.
The aluminum fin material is a plate material before being formed into a fin, and is cut into a predetermined size and formed by press working to be manufactured into a heat exchanger fin. An aluminum fin material according to the present invention is formed on a substrate, a first functional film (first functional film) formed on one or both sides of the substrate, and the first functional film. And a second functional film (second functional film) to be coated. As described above, the aluminum fin material according to the present invention has a film having a two-layer structure in which the first and second functional films are laminated on the surface. The surface of the substrate on which the first and second functional coatings are formed may be either one surface or both surfaces, as long as it is formed on at least the surface on which the condensed water may come into contact when assembled in the heat exchanger. Hereinafter, for the aluminum fin material and the substrate, the surface on which the first and second functional films are formed is simply referred to as the surface.

(Hydrophilic and oil-repellent surface of aluminum fin material)
The surface of the aluminum fin material according to the present invention has hydrophilicity and oil repellency. Specifically, the aluminum fin material has a contact angle of 15 ° or more when n-tetradecane is dropped on the surface in an environment of 25 ° C., and a contact angle of 50 ° when water (pure water) is dropped. Less than. Due to such surface properties, the surface of the aluminum fin material has good water wettability, and the water repellent substance does not easily adhere to the surface, so that the hydrophilicity does not deteriorate and the water wettability is maintained for a long time. The contact angle on the surface of the aluminum fin material can be measured, for example, with a goniometer.

(substrate)
The substrate is formed of aluminum or an aluminum alloy (hereinafter collectively referred to as aluminum) applied to a fin material for a normal heat exchanger, and 1000 series aluminum specified in JIS H4000 is used from the viewpoint of thermal conductivity and workability. Preferably, aluminum with alloy number 1200 is used. These materials are produced into a plate material having a desired thickness by a known method such as casting, hot rolling, cold rolling, and tempering. The thickness of the substrate is not particularly specified, and may be a thickness that can meet the required thermal conductivity, strength, corrosion resistance, etc. according to the specifications of the heat exchanger to be manufactured. Is preferably a plate material having a thickness of about 0.06 to 0.3 mm.

It is preferable that a chemical conversion treatment film is formed on the surface of the substrate by chemical conversion treatment. The substrate made of aluminum is given corrosion resistance by the chemical conversion treatment film, and adhesion with a film such as a first functional film formed thereon is improved. The chemical conversion treatment film is made of an inorganic oxide or an organic-inorganic composite compound containing chromium (Cr), zirconium (Zr), or titanium (Ti) as an inorganic substance, and is formed by chemical conversion treatment of the substrate. The chemical conversion coating is not particularly limited as long as it imparts corrosion resistance to the substrate, and may be appropriately set according to the purpose of use, but the amount of adhesion per area is metal (Cr, Zr). , Ti), preferably in the range of 1 to 100 mg / m ^{2 in} terms of film thickness, and preferably 1 to 100 nm in terms of film thickness. Further, when the first and second functional coatings are provided only on one side, the chemical conversion coating may be formed on the opposite side, that is, on both sides of the substrate.

  The inorganic oxide film applied to the chemical conversion coating is applied to a substrate such as a phosphate chromate treatment, a zirconium phosphate treatment, a zirconium oxide treatment, a chromate chromate treatment, a zinc phosphate treatment, or a phosphate titanate treatment. It is processed and formed on the surface. The organic-inorganic composite compound film is formed by applying a coating type chromate treatment or a coating type zirconium treatment to the substrate, and examples thereof include an acrylic-zirconium composite. Before forming these chemical conversion coatings, it is preferable to degrease the surface of the substrate in advance with an alkaline degreasing solution, thereby improving the reactivity of the chemical conversion treatment and further improving the adhesion of the formed chemical conversion coating. To do.

(First functional film, second functional film)
In the aluminum fin material according to the present invention, one of the first and second functional films has at least a hydrophilic property of hydrophilicity and oil repellency, and the other has at least an oil repellency property of hydrophilicity and oil repellency. Have That is, one or both of the first and second functional films may have both hydrophilicity and oil repellency. In any case, regardless of whether the first or second functional film is used, the hydrophilic film is a hydrophilic film, the oil-repellent film is an oil-repellent film, and both the hydrophilic and oil-repellent films are used. It is called a hydrophilic / oil-repellent film.

  As will be described later, the first functional film and the second functional film define the adhesion amount of a predetermined component as a hydrophilic film and an oil-repellent film, respectively, and the film thickness ranges from 0.001 to 5 μm. Preferably it is formed. If the first and second functional coatings are too thin, sufficient hydrophilicity and oil repellency cannot be obtained. On the other hand, if the first and second functional coatings are too thick, the coating workability at the time of formation decreases, and in particular, the substrate is a coiled aluminum plate ( In the case of a strip material, it is difficult to form a film. In particular, when the second functional film is too thick, the hydrophilicity and oil repellency of the first functional film provided thereunder are hardly exhibited. Further, when the aluminum fin material is thick in the first and second functional films made of resin, the efficiency of heat exchange decreases. Therefore, it is particularly preferable that the first and second functional coatings have a total thickness of two layers of 5 μm or less. The first functional film is formed by applying a coating material as the first functional film on a substrate and solidifying it by baking, drying, or the like. Similarly, the second functional film is the second functional film. The coating material is applied to the surface of the formed first functional film and solidified.

(Hydrophilic film)
The hydrophilic film is a film that imparts hydrophilicity to the surface of the aluminum fin material, and contains a hydrophilic resin. The hydrophilic resin has in the structure one or more selected from a hydroxyl group (hydroxy group), a carboxyl group, a sulfonic acid group, and a polyether group, which are hydrophilic groups. Specifically, as those having a hydroxy group, polyethylene glycol (PEG, PEO), polyvinyl alcohol (PVA) having a carboxyl group, and polyacrylic acid (PAA) having a hydroxy group and a carboxyl group Examples of the carboxymethyl cellulose (CMC) having a sulfonic acid group include sulfoethyl acrylate. In addition, a copolymer of two or more monomers having a hydrophilic group, for example, a copolymer of acrylic acid and sulfoethyl acrylate can be applied. The hydrophilic film is formed by applying a resin paint of these hydrophilic resins and drying.

The hydrophilic film is formed so that the adhesion amount of the hydrophilic resin is 0.05 to 5 g / m ² in both cases of the first functional film and the second functional film in the aluminum fin material. If the adhesion amount of the hydrophilic resin is less than 0.05 g / m ² , the hydrophilic film is too thin or the hydrophilic resin per area is insufficient and sufficient hydrophilicity cannot be obtained. On the other hand, a coating with an adhesion amount of hydrophilic resin exceeding 5 g / m ² elutes when the surface of the aluminum fin material gets wet with water and inhibits the oil repellency of the oil-repellent coating. There is a risk that even the upper second functional film may be eluted. Moreover, such a film is too thick, and as described above, the coating workability is lowered, and if it is the second functional film, it is difficult to develop the characteristics of the first functional film. The hydrophilic film is preferably 0.1 to 1 g / m ^{2 in} terms of the adhesion amount of the hydrophilic resin.

(Oil repellent film)
The oil-repellent film is a film that imparts oil repellency to the surface of the aluminum fin material and contains a silicone component. As the silicone component, it is preferable to apply a modified polydimethylsiloxane derivative having in its structure one or more selected from a polyether group, an epoxy group, a methacryl group, an amino group, a phenyl group, a hydrogen group, and a hydroxyl group. Silicones having these characteristic groups have particularly high dispersibility in paints and fixability in resin films.

The oil-repellent film is formed so that the amount of the silicone component attached is 0.001 to 1 g / m ² in both cases of the first functional film and the second functional film in the aluminum fin material. When the adhesion amount of the silicone component is less than 0.001 g / m ² , sufficient oil repellency cannot be obtained. On the other hand, the silicone component contained in the oil-repellent film has both oil repellency and water repellency (hydrophobicity). Therefore, when a film exceeding 1 g / m ^{2 in} terms of the adhesion amount of the silicone component is formed, the hydrophilic property of the hydrophilic film is increased. Property is hindered, and the hydrophilicity of the surface of the aluminum fin material is insufficient. The oil-repellent film is preferably 0.02 to 0.3 g / m ^{2 in} terms of the amount of silicone component deposited. Such an oil-repellent film can be formed by applying and solidifying a coating composition comprising an aqueous emulsion containing 0.05 to 70% by mass of a silicone component.

  As described above, in the aluminum fin material according to the present invention, either the first or second functional film may be a hydrophilic film or an oil-repellent film, and is selected according to required characteristics. Specifically, in the aluminum fin material, the characteristics of the second functional film formed on the outermost surface are more strongly expressed. On the other hand, the first functional film formed in the lower layer is baked by forming each of the first functional film and the subsequent second functional film. Increases nature. However, even if the hydrophilic film is applied to the first functional film, the condensed water adheres to the surface of the fin (second functional film), so that the hydrophilic resin contained in the first functional film is Hydrophilicity can be expressed on the outermost surface by penetrating through the second functional film. On the other hand, the oil repellency is desirably expressed in a state where there is no condensed water on the surface of the heat exchanger (fin), and therefore the surface of the aluminum fin material, that is, the second functional film is preferably an oil repellant film. Furthermore, it is more preferable that the second functional film is a hydrophilic / oil-repellent film that also has hydrophilicity, for example, since hydrophilicity is exhibited even when dew condensation water is generated at the start of cooling operation. The hydrophilic / oil-repellent film can be formed of a coating obtained by adding the silicone component of the oil-repellent film or an aqueous emulsion containing the silicone component to the hydrophilic resin in the hydrophilic film. Also in the hydrophilic / oil-repellent film, the hydrophilic resin and the silicone component are formed so as to have the same adhesion amounts as the hydrophilic film and the oil-repellent film, respectively.

(Corrosion resistant coating)
The aluminum fin material according to the present invention is preferably provided with a corrosion-resistant film made of a hydrophobic resin on the substrate surface, that is, as a base of the first functional film. The aluminum fin material is further improved in corrosion resistance by not only forming the chemical conversion coating on the substrate made of aluminum but also coating the surface with a corrosion-resistant coating. Similarly to the chemical conversion coating on the substrate, the corrosion resistant coating may be formed on the opposite surface, that is, on both surfaces of the substrate, when the first and second functional coatings are provided only on one surface.

The corrosion-resistant film is a film made of a hydrophobic resin that coats the surface of the substrate in order to impart corrosion resistance to the substrate made of aluminum (aluminum fin material). Like the first and second functional films, a coating material is used as a base material. It is formed by applying to the surface. Examples of the hydrophobic resin used in the paint include various resins such as polyester, polyolefin, epoxy, and urethane, and a mixture of one or more of these resins is used. Corrosion barrier coating is not the film thickness and the like is particularly limited, in order to impart sufficient corrosion resistance to the substrate, 0.01 g / m ² or more preferably at a coverage per area, 0.05 g / m ² or more preferable. On the other hand, as in the first, second functional film, the corrosion barrier coating made of a resin is lowered the efficiency of a thick heat exchange, preferably 8 g / m ² or less at a coverage, more preferably 4g / m ² or less . The film thickness is preferably 0.05 to 4 μm.

[Method of manufacturing aluminum fin material]
As described above, the aluminum fin material according to the present invention can be manufactured by sequentially applying the coating materials for forming the first and second functional films on the surface of the substrate. Furthermore, before forming the first functional film, a hydrophobic resin coating may be applied to the surface of the substrate to form a corrosion-resistant film, and before forming these films, the substrate is formed as described above. Chemical conversion treatment may be performed on the surface.

  The first and second functional films, or further the corrosion-resistant film, are formed by adjusting the coating material for forming the film, applying the coating object (substrate) by a bar coater, a roll coating method, or the like, and performing a baking treatment. The In particular, if the substrate is a coiled aluminum plate, it is preferable in terms of productivity to apply a roll coater or the like and continuously perform degreasing, painting, heating, winding, and the like. Moreover, it is preferable to make the baking temperature of a 1st, 2nd functional film and a corrosion-resistant film into the range of 120-270 degreeC according to each kind of resin.

  The coating material for forming each film is not limited to the above-mentioned resin or the like for any of the hydrophilic film, oil-repellent film, hydrophilic / oil-repellent film, or corrosion-resistant film. In order to improve the physical properties of the coating film, various aqueous solvents and paint additives may be added, for example, water-soluble organic solvents, crosslinking agents, surfactants, surface conditioners, wetting and dispersing agents, anti-settling agents. Various solvents and additives such as antioxidants, antifoaming agents, rust preventives, antibacterial agents, and fungicides may be used alone or in combination.

  As mentioned above, although the form for implementing this invention was described, the Example which confirmed the effect of this invention is demonstrated concretely compared with the comparative example which does not satisfy | fill the requirements of this invention below. In addition, this invention is not limited to this Example.

[Production of test materials]
(Substrate, chemical conversion treatment)
A JIS H4000 A1200 aluminum plate having a thickness of 0.10 mm was applied as a substrate in the test material of the aluminum fin material. The surface of this substrate is degreased with an alkaline agent (Surf Cleaner (registered trademark) EC370, manufactured by Nippon Paint Co., Ltd.) and phosphoric acid is used as a chemical conversion treatment solution using Alsurf (registered trademark) 401KB-2 / 45KB manufactured by Nippon Paint Co., Ltd. A chromate treatment was applied to form a chemical conversion coating. The Cr conversion value of the chemical conversion film measured with a wavelength dispersive X-ray fluorescence apparatus (manufactured by Shimadzu Corporation, LAB CENTER XRF-1800) was 20 mg / m ² , and the film thickness was about 20 nm.

(Corrosion-resistant film formation)
As a material for the corrosion-resistant film, a resin coating of the types shown in Tables 1 to 5 was applied to the substrate with a bar coater, baked at a substrate reaching temperature of about 200 ° C. in a hot air drying furnace, and air-cooled to form a corrosion-resistant film. . However, in Tables 1 to 5, the corrosion resistant film was not formed for the test materials with “-” in the column of the corrosion resistant film. The material of the corrosion-resistant film (hydrophobic resin) is as follows.

(Hydrophobic resin)
Epoxy system: DIC, Epicron (registered trademark) 840
Acrylic system: Made by Enomoto Kasei, Neokrill (registered trademark) A-614
Urethane system: Made by Enomoto Kasei, Neoreds (registered trademark) R-9660
Polyolefin-type: Toho Chemical Industries, Hitech (registered trademark) S3148
Polyester type: manufactured by Toyobo, Vylonal (registered trademark) MD-1200

(Formation of first functional film and second functional film)
A coating prepared by adjusting the types of hydrophilic resins and silicones shown in Tables 1 to 5 is prepared, and a first functional film is formed on the substrate by a bar coater and then baked, and a second functional film is formed thereon. Furthermore, it formed and it was set as the test material of the aluminum fin material. The baking conditions were the same as for the corrosion-resistant film, and the upper film was formed after the substrate was cooled to room temperature, including the corrosion-resistant film. Moreover, the application quantity of the coating material was adjusted so that it might become each adhesion amount of the hydrophilic resin described in Tables 1-5, and silicone. Moreover, as an aluminum fin material according to the invention of Patent Document 1, a test material was produced in which water-repellent polyvinyl alcohol (PVA99) having a high saponification degree was applied to the second functional coating instead of the hydrophilic resin. In addition, the coating material for oil-repellent films contains the following silicone components, is a water-based emulsion adjusted with pure water according to the adhesion amount shown in Tables 1 to 5, and is further hydrophilic containing both hydrophilic resin and silicone. The water / oil-repellent film was a water-based emulsion in which hydrophilic resin materials were mixed in accordance with the ratios of the adhesion amounts shown in Tables 1 to 5. The materials of the first and second functional films are as follows.

(Hydrophilic resin and its comparative example)
Polyethylene glycol (PEG): manufactured by Sanyo Chemical Industries, PEG-6000S (registered trademark)
Polyacrylic acid (PAA): manufactured by Toagosei Co., Ltd., Jurimer (registered trademark) AC-10S
Polyvinyl alcohol (PVA): manufactured by Nippon Synthetic Chemical Co., Ltd., Gohsenol (registered trademark) GL-05
Copolymer of acrylic acid and sulfonic acid group-containing monomer (AASF): manufactured by Nippon Shokubai, Aquaric (registered trademark) GL
Water repellent polyvinyl alcohol (PVA99): manufactured by Nippon Synthetic Chemical Co., Ltd., Gohsenol (registered trademark) NM-11

(Silicone component)
Epoxy-polyether group-containing silicone: manufactured by Shin-Etsu Chemical Co., Ltd., Polon-MF-13
Epoxy group-containing silicone: X-51-1264, manufactured by Shin-Etsu Chemical Co., Ltd.
Methacrylic group-containing silicone: X-52-8145X, manufactured by Shin-Etsu Chemical Co., Ltd.
Amino group-containing silicone: manufactured by Shin-Etsu Chemical Co., Ltd., Polon-MF-52
Phenyl group-containing silicone: KM-9739, manufactured by Shin-Etsu Chemical Co., Ltd.
Hydrogen group-containing silicone: manufactured by Shin-Etsu Chemical, Polon-MWS

  The prepared test material was simulated for adhesion of condensed water to the fins, washed with water for 1 minute and dried, and then the surface on which the first and second functional films were formed was evaluated and observed as a water contact surface. The angle and the tetradecane contact angle were measured, and water wettability (hydrophilicity), oil repellency, and corrosion resistance were evaluated. Each contact angle and evaluation result are shown in Tables 1-5.

(Water contact angle, tetradecane contact angle)
In an environment of 25 ° C., the test material is placed horizontally with the surfaces on which the first and second functional films are formed, and about 0.5 μL of ion exchange water is dropped on the surface to measure the contact angle. The contact angle was measured using a container (Kyowa Interface Science Co., Ltd .: CA-05 type). Similarly, about 0.5 μL of n-tetradecane was dropped and the contact angle was measured.

[Evaluation]
(Water wettability)
Ion exchange water was sprayed on the surface of the specimen placed vertically, and the wetted area ratio was measured visually. A water wettability ratio of 70% or more is regarded as acceptable for water wettability, 95% or more is particularly excellent as “◎”, 90% or more and less than 95% as “good”, and 70% or more and less than 90% as “Good” ". Moreover, less than 70% is shown as “x” as failure.

(Oil repellency)
The oil repellency is defined as the ratio of the area where the salad oil adheres after the test material is immersed in the salad oil and pulled up, and left to stand for 30 seconds with the evaluation surface vertical. Measured visually. If the adhesion area ratio of salad oil is less than 50%, the oil repellency is acceptable, less than 5% is particularly excellent, “◎”, 5% or more but less than 20% is “◯”, 20% or more and less than 50% is “△” ". Moreover, 50% or more is shown as “x” as rejected.

(Corrosion resistance)
Corrosion resistance was evaluated based on the degree of corrosion of the specimen after a salt spray test according to JIS Z2371 for 480 hours. A 5 mass% sodium chloride aqueous solution was used as the spray solution, the spray environment temperature was 35 ° C., the spray amount was 80 cm ² , and the amount was 1.5 ml per hour. Quantified according to the rating number method for quantifying the degree of corrosion according to the corrosion area ratio, the rating number is 9.3 or higher, and 9.8 or higher is particularly excellent. Less than .8 is shown as "Good", and 9.3 or more and less than 9.5 is shown as "Good". Moreover, less than 9.3 is shown as "x" as a failure.

Table 1, Table 2, Table 3, Table 4, and Table 5 show the specifications of the second functional film.
Specimen No. shown in Table 1 Nos. 1 to 18 and 101 to 104 were extremely excellent in water wettability because the second functional coating on the surface was a hydrophilic coating. On the other hand, the oil repellency was in the vicinity of the acceptance criteria, and was not affected by the adhesion amount of the silicone component of the lower first functional film. Furthermore, the test material No. of the comparative example in which the silicone component of the first functional film was insufficient. 201 and 205 lacked oil repellency. However, the test sample No. of the comparative example in which the silicone component of the first functional film is excessive is used. Nos. 202 and 206 are deficient because the hydrophilicity of the second functional film is inhibited.

  On the other hand, the test material No. In No. 203, the hydrophilic resin in the second functional film was insufficient, so that sufficient water wettability could not be obtained. On the other hand, the test material No. In 204 and 207, since the hydrophilic resin in the second functional film is excessive, the oil repellency of the first functional film is not sufficiently expressed or inhibited, and the surface oil repellency becomes insufficient. In addition, specimen No. In 208, since the water-repellent polyvinyl alcohol was applied to the second functional film instead of the hydrophilic resin, the hydrophilicity of the first functional film was not sufficiently developed.

Specimen Nos. Shown in Tables 2 and 3 Nos. 21 to 50, 105 and 106 were excellent in oil repellency since the second functional film on the surface was an oil repellant film, and particularly those having an adhesion amount of the silicone component of 0.1 g / m ² or more were extremely excellent. . On the other hand, the test material No. Since No. 209 lacked the silicone component of the second functional film, sufficient oil repellency could not be obtained.

  In addition, specimen No. Nos. 21 to 50, 105, and 106 exhibited water wettability despite having a hydrophilic film or a hydrophilic / oil-repellent film on the lower first functional film. In particular, the first functional film is a hydrophilic film, and the test material No. 1 has a well-balanced adhesion amount between the hydrophilic resin and the silicone component of the second functional film. Nos. 26, 31 to 40 and 105 were sufficiently excellent in both water wettability and oil repellency. In addition, the test material No. whose water wettability is near the acceptance criteria. In Nos. 27 to 30, it is presumed that the hydrophilicity of the first functional film was inhibited to some extent due to the large amount of the silicone component of the second functional film. On the other hand, similarly, the test material No. 2 containing a large amount of the silicone component of the second functional film was used. Nos. 31 and 32 maintained hydrophilicity due to the large amount of hydrophilic resin adhering to the first functional film. However, the test material No. No. 212 has an excess of the hydrophilic resin of the first functional film, so that the oil repellency of the second functional film is inhibited and the oil repellency becomes insufficient. On the other hand, the test material No. Since 211 and 215 lacked the hydrophilic resin in the first functional film, sufficient water wettability could not be obtained. Moreover, the test material No. of the comparative example in which the silicone component of the second functional film is excessive. Nos. 210 and 213 were insufficient because the hydrophilicity of the first functional film was not sufficiently exhibited.

  On the other hand, the test material No. Nos. 41 to 50 and 106 are presumed that the hydrophilicity of the first functional film was inhibited to some extent by the silicone component in the same film and the silicone component of the second functional film. Furthermore, sample No. In No. 214, since the silicone component was excessive in the first functional film, the hydrophilicity was hindered and the surface hydrophilicity was insufficient.

  Specimen Nos. Shown in Tables 4 and 5 Nos. 51-94 and 107-110 exhibited both water wettability and oil repellency since the second functional coating on the surface was a hydrophilic / oil repellent coating. In particular, the first functional film is a hydrophilic film, and the silicone component of the second functional film is a test material No. having an appropriate amount of adhesion. 51, 53, 54, 75 to 80, 107 were relatively excellent in both water wettability and oil repellency.

  On the other hand, the test material No. In No. 216, the first functional film was a hydrophilic film, and the silicone component in the second functional film was insufficient, so Similar to 209, no oil repellency was obtained. On the other hand, the test material No. Nos. 217, 219, and 222 have the silicone component in the second functional film, so that the hydrophilic resin in the film or the hydrophilicity of the first functional film is further inhibited, and the samples in Tables 2 and 3 are used. Material No. As with 210 and 213, sufficient hydrophilicity was not obtained.

  Specimen No. In No. 220, the first functional film was an oil-repellent film, and the hydrophilic resin in the second functional film was insufficient. Similar to 203, hydrophilicity was not obtained. On the other hand, the test material No. In 218, since the hydrophilic resin was excessive in the second functional film, the oil repellency of the silicone component in the same film was inhibited, and sufficient oil repellency was not obtained. In addition, specimen No. Since 221 and 223 applied water-repellent polyvinyl alcohol instead of hydrophilic resin to the second functional film, the test materials No. Similar to 208, hydrophilicity was not obtained.

  Sample Nos. Shown in Tables 1-5. 101-110 is a specification which does not have a corrosion-resistant film | membrane, and compared with the test material provided with the corrosion-resistant film | membrane, although the influence on water wettability and oil repellency was not observed, it was inferior to corrosion resistance.

Claims (7)

An aluminum fin material comprising: a substrate made of aluminum or an aluminum alloy; a first functional film formed on the substrate; and a second functional film formed on a surface of the first functional film. Because
At least the second functional film of the first functional film and the second functional film has in its structure one or more selected from a hydroxyl group, a carboxyl group, a sulfonic acid group, and a polyether group. Containing a hydrophilic resin at an adhesion amount of 0.05 to 5 g / m ² ;
It said first functional skin film, the silicone component is contained in the adhesion amount 0.001 to 1 g / m ^2,
Under 25 ° C. environment aluminum fin stock in contact angle when dropped n- tetradecane onto the surface is 15 ° or more and the contact angle when dropped pure water and less than 50 °.   The silicone component is a modified polydimethylsiloxane derivative having in its structure one or more selected from a polyether group, an epoxy group, a methacryl group, an amino group, a phenyl group, a hydrogen group, and a hydroxyl group. The aluminum fin material according to claim 1. An aluminum fin material comprising: a substrate made of aluminum or an aluminum alloy; a first functional film formed on the substrate; and a second functional film formed on a surface of the first functional film. Because
At least one of the first functional film and the second functional film is attached with a hydrophilic resin having at least one selected from a hydroxyl group, a carboxyl group, a sulfonic acid group, and a polyether group in the structure. Amount 0.05 to 5 g / m ² Contained in
At least the other of the first functional film and the second functional film has a silicone component deposited in an amount of 0.001-1 g / m. ² Contained in
The silicone component is a modified polydimethylsiloxane derivative having in its structure one or more selected from an epoxy group, a methacryl group, a phenyl group, and a hydrogen group,
An aluminum fin material characterized by having a contact angle of 15 ° or more when n-tetradecane is dropped on the surface in an environment of 25 ° C. and a contact angle of less than 50 ° when pure water is dropped. The first functional film contains the hydrophilic resin in an adhesion amount of 0.05 to 5 g / m ² ;
The second functional coating, aluminum fin stock according to claim 3, characterized in that it contains the silicone component in coating weight 0.001 to 1 g / m ^2. The second functional coating, aluminum fin stock according to claim 4, characterized in that it contains further a hydrophilic resin coating weight 0.05-5 g / m ^2. On the surface of the substrate, further comprising a corrosion-resistant film comprising a hydrophobic resin, any one of claims 1 to 5, wherein the first functional coating on the corrosion barrier coating is formed Aluminum fin material described in 1. It is a manufacturing method of the aluminum fin material according to any one of claims 1 to 6 ,
Applying a coating composition comprising an aqueous emulsion containing 0.05 to 70% by mass of a silicone component to form the first functional film or the second functional film containing the silicone component The manufacturing method of the aluminum fin material characterized by these.