JP2002161377A - Fin material for heat exchanger having non-chromate coating type underlayer and heat exchanger having the same - Google Patents

Abstract

(57) [Problem] An object of the present invention is to provide a heat treatment which has excellent hydrophilicity, is less likely to cause a decrease in heat exchange efficiency due to adhesion of coagulated water, and does not cause a problem in corrosion resistance. An object is to provide a fin material for an exchanger. The present invention relates to a metal substrate made of aluminum or an aluminum alloy, a non-chromate coating type underlayer formed on the metal substrate, and a hydrophilic film formed on the underlayer. Wherein the underlayer is Ti
Or, formed by a coating type base treatment method in which Zr is an essential component, a coating liquid layer applied on the metal substrate is heated and dried, and a part of the coating liquid layer is reacted with the metal substrate. It is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fin material for a heat exchanger having a hydrophilic film having good adhesion and excellent corrosion resistance, and a heat exchanger having the same.

[0002]

2. Description of the Related Art As heat exchangers incorporated in air conditioners, those made of aluminum or an aluminum alloy have been widely used because they are required to be lightweight and have excellent heat exchange characteristics. In these heat exchangers, for example, during a cooling operation or the like, moisture in the air around the heat exchanger adheres to the surfaces of the fins of the heat exchanger as coagulated water.

As one method of preventing the adhesion of the coagulated water, it is conceivable to coat the surface of the fin with a water-repellent resin film to make the surface of the fin water-repellent. However,
When the surface of the fin is made water-repellent, moisture attached to the surface of the fin becomes hemispherical water droplets and adheres between the fins, impairing the air permeability around the fins and reducing the heat exchange efficiency of the fins. There is a risk. In addition, aluminum or aluminum alloy is generally used as a material having excellent corrosion resistance, but in the use state where coagulated water is constantly adhered to the surface of the fin, a kind of concentration battery is formed on the surface of the fin. This causes a problem that the corrosion of the fins is accelerated more than expected. From the above background, the inventor of the present application considers that it is necessary to form a hydrophilic film on the surface of the fin of the heat exchanger, and to further improve the corrosion resistance of the fin itself.

[0004] A chromate film has been widely studied as a hydrophilic film formed on the surface of this type of heat exchanger. However, this chromate film is C
Since the composition is mainly composed of r, there is a possibility that hexavalent chromium, which is regarded as a problem in terms of toxicity, must be used. The use of this hexavalent chromium film is likely to cause environmental problems. Even if this hexavalent chromium film is replaced with trivalent chromium, which is considered to be highly safe, it may be oxidized or the like. There is a risk that trivalent chromium will change to hexavalent chromium over time, and even if trivalent chromium is used, there is a need for waste liquid treatment, and there is a possibility of causing environmental chromium contamination problems. .

[0005]

Therefore, the inventor of the present application has
Research and development of technology that can be applied to fins for heat exchangers by non-chromate coating type processing without using chromium which may cause such environmental problems, and reached the present invention .

[0006] Based on the above background, the present invention has a hydrophilic film on the surface, has excellent hydrophilicity, is less likely to cause a decrease in heat exchange efficiency due to the adhesion of coagulated water, It is an object of the present invention to provide a fin material for a heat exchanger which does not cause a problem in corrosion resistance even when used in an environment where water is constantly adhered. It is another object of the present invention to provide a fin material for a heat exchanger which has these various properties and also has excellent adhesion of a hydrophilic film. A further object of the present invention is to provide a heat exchanger provided with a fin material having these excellent characteristics.

[0007]

In order to solve the above-mentioned problems, the present invention provides a metal substrate made of aluminum or an aluminum alloy, and a non-chromate coating type formed on the metal substrate by a coating type base treatment method. And a hydrophilic film formed on the underlayer, wherein the underlayer contains Ti or Zr as an essential component, and heats a coating liquid layer applied on a metal substrate. It is characterized by being formed by a coating type base treatment method in which a part of the coating liquid layer is dried and reacted with the metal base material. A part of the components of the coating solution containing Ti or Zr as an essential component was heated and dried to volatilize and dry the components in the coating solution, and at the same time, formed by the reaction between the components in the coating solution and the metal substrate. Since it has an underlayer and a hydrophilic film on it, Ti or Z
A non-chromate coating type underlayer containing r and not containing chromium can be used, and a fin material which does not cause a problem in terms of environmental pollution can be provided. Further, a hydrophilic film provided on the underlayer imparts hydrophilicity to the fin material,
Prevents adhesion of hemispherical flocculated water.

In the present invention, Ti or Zr as an essential component in the underlayer is 1 mg / m ² or more and 300 mg / m ² or more.
m ² or less is preferable. Containing 1 mg / m ² or more of Ti or Zr as an essential component;
When the content is not more than mg / m ² , good adhesion as the underlayer can be secured, excellent corrosion resistance can be secured, and hydrophilicity required for the fin material can be secured.

In the present invention, the underlayer may contain at least one or more of C, O, Si, F, and P in addition to Ti or Zr as an essential component. it can. In the present invention, the underlayer may contain an oxide of at least one or more of Ti, Zr, C, Si, and P.

In the present invention, 5 mg
/ M ² or more and 100 mg / m ² or less, Ti or Zr may be contained. When Ti or Zr as an essential component is contained in such a range, better adhesion can be secured as an underlayer, and excellent corrosion resistance and hydrophilicity required for the fin material are secured.

According to the present invention, there is provided a heat exchanger including the fin material described above.
If the heat exchanger is provided with the fin material, the surface of the fin material has hydrophilicity, so that even if flocculated water adheres during cooling operation of the heat exchanger or the like, air permeability around the fin material is impaired. There is little fear.

[0012]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following embodiments. FIG. 1 shows a first embodiment of a fin material for a heat exchanger according to the present invention. A fin material A of the first embodiment includes a plate-shaped metal substrate 1 made of aluminum or an aluminum alloy, Substrate 1
And a non-chromate coating type underlayer 2 formed on the surface of the substrate, and a hydrophilic film 3 coated on the underlayer 2 to form a thin plate.

The metal substrate 1 is made of aluminum or an aluminum alloy.
1100, JIS1200 and other JIS1000-based alloys or JIS7000-based alloys, but the constituent material of the metal substrate 1 is not limited to these types, and various materials used as constituent materials of fin materials for heat exchangers are used. Of course, the pure aluminum type or aluminum alloy type can be applied.

The underlayer 2 is formed by applying a coating type non-chromate treatment method described later to the metal substrate 1. The underlayer 2 contains at least one of Ti and Zr as an essential component, and further contains one or more of C, O, Si, F, and P as an additional component. Among these elements, O (oxygen) is contained in the form of an oxide of an essential component (Ti or Zr) or an oxide of another additive component element (Si, C, V, P). .

The underlayer 2 preferably contains Ti or Zr as an essential component in the range of 1 to 300 mg / m ² . More preferably, Ti or Zn is contained as an essential component of the underlayer ^{2 in} a range of 5 to 100 mg / m ² . It is preferable that these essential components constitute 0.1 to 50% by weight of the total amount of the underlayer 2. Further, in the underlayer 2, Zr or Ti as an essential element
In addition, as additional components, C is 10 to 90% by weight, O is 5 to 30% by weight, Si is 1 to 30% by weight, and F is 1 to 30%.
% Of P and 1 to 30% by weight of P, it is preferable that these are contained singly or in combination of two or more kinds in the range.

In the underlayer 2, Zr and Ti are essential components, and if they are not contained, adhesion to the metal substrate 1 cannot be obtained, and the corrosion resistance of the metal substrate 1 also decreases. In the underlayer 2, C, O, Si, F, and P are components that can be added as needed. In the above-mentioned elements, C is contained as a component of the organic resin constituting the base layer 2, and an acrylic resin or the like is preferably used. The elements constituting the underlayer 2 include Zr and Ti in a compound state, and the detailed structure will be described later.

The hydrophilic film 3 is located on the surface of the fin material to ensure hydrophilicity.
As the water glass hydrophilic film, organic hydrophilic film,
Any of the composite hydrophilic films may be used.

The water glass-based hydrophilic film mainly comprises an alkali silicate as a main component and an aqueous resin as a binder. Among them, for example, those mainly containing an alkali silicic acid and a low molecular weight organic compound having a carbonyl group can be used. Further, a composition in which a water-soluble organic polymer compound is added to these main components can be used. The alkali silicate constitutes a main component for imparting hydrophilicity to the film.
a ratio represented by iO ₂ / M ₂ O (where M represents an alkali metal such as lithium, sodium, or potassium) is 1 or more;
For example, those having 2 to 5 are preferable. The low-molecular-weight organic compound is, for example, a low-molecular-weight organic compound having a carbonyl group in a molecule, and stabilizes a film of the alkali silicate, improves hydrophilicity, and gives flexibility to the film. is there. Specific examples of such low-molecular-weight organic compounds include aldehydes, esters, and amides. The water-soluble organic polymer compound,
It is added in order to further improve the hydrophilicity of the film formed from the alkali silicate and the low molecular weight organic compound having a carbonyl group, and also to improve the flexibility. Specific examples of such a water-soluble organic polymer compound include polysaccharide-based natural polymers, water-soluble protein-based natural polymers, anionic, nonionic, or cationic addition-polymerized water-soluble synthetic polymers,
Examples include polycondensation-based water-soluble polymers.

The organic hydrophilic film is composed mainly of a hydrophilic resin such as a polyvinyl alcohol type, a cellulose type and an acrylic type. Among these, for example, a conjugated monomer having a nitrile group (a), a conjugated and / or non-conjugated monomer having a hydroxy group (b),
Conjugated monomer (c) having a carbonyl group, having 1 to 1 carbon atoms
The conjugated monomer (d) having a saturated linear and / or alicyclic alkyl group of No. 6 and the acid group of the copolymer (A) constituted by using the phosphate compound (f) have a base It may be a film of a hydrophilic resin (a) constituted by partial neutralization or neutralization with a hydrophilic compound. Further, an alkali resistance imparting agent (b) constituted by neutralizing an acid group of a diester dibasic acid (B) composed of polyethylene glycol and an organic dibasic oxyacid (h) with an organic amine compound (γ). ) And at least one curing agent (C) selected from the group of polyglycidyl ethers (C) is applied to a resin of the above-described component and applied with a coating material to form an organic hydrophilic film. May be.

In the above composition, acrylonitrile and methacrylonitrile can be exemplified as the monomer (a), and 2-hydroxyethyl methacrylate and 2-hydroxyethyl methacrylate as the conjugated and / or non-conjugated monomer (b). -Hydroxyethyl methacrylate, 2-hydroxypropylethyl vinyl vinyl ether, 3-hydroxypropyl vinyl ether, and the like.
Further, examples of the conjugated monomer (c) include acrylic acid, methacrylic acid, and crotonic acid, and examples of the conjugated monomer (d) include methyl methacrylate, methyl acrylate, and ethyl methacrylate. it can.

As the composite hydrophilic film, those composed of a hydrophilic resin and colloidal silica are widely known. For example, it contains alumina sol, a water-soluble acrylic resin and polyethylene glycol, a modified product of polyethylene glycol, a copolymer of ethylene oxide and propylene, and a copolymer of ethylene oxide and propylene oxide and a modified product thereof. Can be exemplified. In the composition constituting the composite hydrophilic film, the alumina sol is an example of a water medium in which alumina hydrate particles are dispersed in water, and the water-soluble acrylic resin is a sulfonic acid group. Examples thereof include an acrylic copolymer having a polar group such as a valent salt, a hydroxyl group, and a carboxyl group.

Any of the various water glass-based hydrophilic coatings, organic hydrophilic coatings, and composite hydrophilic coatings described above may be used alone, or may be mixed as necessary, or may be used as the hydrophilic coating 3 as a multilayer. it can.

Next, a method of manufacturing the non-chromate coating type underlayer 2 by the above-described non-chromate coating type underlayer treatment method for forming the underlayer 2 will be described. Basically, the non-chromate coating type base treatment method is to apply a coating solution having a necessary composition on the metal base material 1 to a thickness of about 1 to 10 μm by a coating method and to dry the coating solution. Then, the resin in the resin is solidified by removing the moisture in the resin or the resin is made overseas, and a part of the components of the coating liquid is reacted with the metal substrate 1 on the surface of the metal substrate 1 to form a partial reaction product layer at the interface. This is a method of forming the underlayer 2. The method of applying the above-mentioned coating solution on the metal substrate 1 may be any of a roll coating method, a dipping method, a brush coating method, and a spray coating method.

The treatment liquid applied here is zirconium or titanium, tannic acid, polyacrylic acid, and various polyvinylphenol derivatives, that is, water-soluble polymers such as polyalkenephenol, and substituted polyvinylphenol / polyhydroxyamino. Can be used. Here, the application and treatment of the application type treatment liquid may be performed in a short time, and the application method may be appropriately selected from any of the above application methods. Examples of the coating type treatment liquid that can be used here include a mixture of polyacrylic acid and (NH ₄ ) ₂ ZrF _6, a mixture of polyacrylic acid and H ₂ ZrF _{6, and} a mixture of polyacrylic acid and H ₂ TiF _6. can do.

To form the underlayer 2 more specifically,
As an example, the following steps can be adopted. First,
A rolled Al thin plate having a thickness of about 100 μm is prepared, and is subjected to an alkali-based degreasing treatment to wash the surface, followed by washing with water to remove the alkaline solution. Here, for example, an alkali degreasing treatment is performed by immersing an Al thin plate in an alkaline solution for several seconds at a temperature of 50 to 70 ° C., and then pulling it out.

Next, this Al thin plate is heated to 100 to 120 ° C.
To remove moisture on the surface. Next, a non-chromate coating type treatment liquid is applied to the dried Al thin plate with a coating device such as a roll coat coating device to a required thickness. Subsequently, a process of heating to a temperature in the range of 120 ° C. to 200 ° C., drying and baking is performed for several seconds to 30 seconds, and a coating type non-chromate process for forming the underlayer 2 is performed.

The underlayer 2 formed by the above-described non-chromate treatment method contains Ti or Zr as an essential component, and in addition to those essential components, any one of C, O, Si, F, and P or Since it contains two or more elements, the adhesion of the underlayer 2 to the metal substrate 1 can be improved, and the corrosion resistance of the metal substrate 1 can be improved. Further, since the hydrophilic film 3 formed on the underlayer 2 exhibits good hydrophilicity, the hydrophilic film 3 is excellent in hydrophilicity, and no hemispherical water droplets adhere to the hydrophilic film 3 and the fin material. There is no risk of impairing the surrounding air permeability.

Next, one embodiment of the heat exchanger B provided with the fin material having the above-described structure is shown in FIG. FIG. 2 shows an example of a heat exchanger for an air conditioner provided with fins obtained using the fin material A according to the present invention.
A meandering tube 13 is arranged so as to penetrate a plurality of fins A having a configuration in which a large number of fin materials A are stacked at fine intervals (interval of about 1 mm to several mm). The heat exchanger B having this structure is configured such that the fins 14 are formed by plastically processing the fin material A described above.

When the fins 14 of the heat exchanger B are made of the fin material A, the hydrophilic film 2 is uniformly provided on the entire surface of the fins 14, so that the fins 1 of the heat exchanger B are provided.
4 can exhibit uniform hydrophilicity on the entire surface, and if the heat exchanger B is provided in the air conditioner and the cooling operation is performed, coagulated water may be generated on the surface portion of the fin material A. However, since the coagulated water does not adhere in the form of droplets on the entire surface of the fins 14 and the coagulated water is formed on the surface of the fin material 14 in a thin film, the fin material A has a structure in which many fin materials A are stacked. Even so, it is possible to eliminate the possibility that the coagulated water closes or narrows the gap between the fin members 14. Further, since the base layer 2 having excellent adhesion to the metal substrate 1 is used, there is little possibility that the base layer 2 is peeled off, and the adhesion between the hydrophilic film 3 and the base layer 2 is also improved. The heat exchanger B with the fin material which can be provided.

Therefore, if the heat exchanger B has the fin material A, good heat exchange characteristics can be maintained even when coagulated water is generated during the cooling operation. Further, since the fin material A has the base layer 2,
It has excellent adhesion and excellent corrosion resistance.

[0031]

[Example] JIS-specified pure aluminum alloy (JIS1
050) made of aluminum with a thickness of 100 μm
A plurality of metal substrates were prepared. Alkali removal of these metal substrates
Fat (3% solution of Nippon Paint Surf Cleaner 330,
(Immersed in 50 ° C for several seconds), washed with water at normal temperature,
And dried. Next, roll these metal substrates after drying.
Various amounts of Zr compound-based coating solution can be applied by coater
Apply various amounts of the applied one and Ti-based compound coating solution
And various amounts of the coating solution mixed with Zr and Ti.
Three types were prepared. Coating liquid used here
Is based on a compound of Zr or Ti,
Polyacrylic acid and H_TwoZrF₆Blend of
Compound, polyacrylic acid and H _TwoTiF₆Was used.
In addition, in the case of a composition containing Si in addition to these, H _TwoS
iF₆In the case of using P-added components and containing P
Is Zr_Three(PO_Four)_FourIs added individually in the required amount
Using.

The metal substrate coated with the processing solution is
The substrate was dried and baked by heating to a temperature of ° C. to form an underlayer formed on the metal substrate by reaction with the resin solution. next,
A hydrophilic resin was applied on the underlayer. The hydrophilic resin is an inorganic resin. As the inorganic hydrophilic film, a water glass-based paint (trade name: Surf Coat 131, manufactured by Nippon Paint Co., Ltd.) is applied in an amount of 200 mg in terms of SiO ₂ .
/ M ² and oven oven at 260 ° C x 30
Baked for seconds.

The content of Ti or Zr as an essential component contained in the underlayer of each of the obtained samples was measured, and the hydrophilicity and adhesion (adhesion of the hydrophilic film) and corrosion resistance (metallic base) of those samples were measured. Table 1 below shows the results of the test for the corrosion resistance of the material. In Table 1, the term "weight in the coating" means the weight% of Ti or Zr as an essential component contained in the coating of the underlayer after drying. The coating contains additional elements such as C, O, Si, F, and P in addition to Zr and Ti. Although only the essential components Zr and Ti are shown in Table 1, for example, in an underlayer containing 11% by weight of Zr, O is 12% by weight, Si is 0.5% by weight, and C is 6%.
5.5% by weight, F is 11% by weight, and the remaining unavoidable impurities. In the underlayer having 18% by weight of Zr, 20% by weight of O, 0.5% by weight of Si, 50% by weight of C and 50% by weight of F Is 11
% By weight. In the sample to which Ti was added, Ti was 1.4% by weight, O was 30% by weight, and Si was 12% by weight.
% By weight, C by 51% by weight, and P by 3% by weight. Further, in the sample in which Zr and Ti are mixed and added, O
5% by weight, 0.5% by weight of Si, 49% by weight of C, and 11% by weight of F. In each of these compositions, only the amount of Ti and the amount of Zr are shown in Tables 1 and 2 below. The amount of Ti and the amount of Zr in the film are equivalent to the amount of Ti and the amount of Zr contained in the coating solution.

In Table 1, hydrophilicity A indicates the result of immersing a sample in a volatile press oil for 60 seconds, heat-treating it at 150 ° C. for 3 minutes, and measuring the contact angle of a water droplet. The measurement results of the contact angle of water droplets after immersion in water for 8 hours, drying in an oven at 80 ° C. for 16 hours, and repeating the above cycle for 14 cycles are shown. As the criteria for determining the hydrophilicity, the mark ◎ was less than 20 °, the mark ゜ was less than 30 °,
Δ indicates less than 40 °, and X indicates 40 ° or more. In Table 1, the term “adhesion” refers to a test in which a dry “Crecia product name: Kim towel” is placed on a hydrophilic film, and a tile is rubbed 50 times while a load of 500 g is applied. ◎ for those that do not, 〇 for those with only a few damages,
The symbol Δ indicates damage at two or three portions, and the symbol × indicates damage at more than two portions. Table 1
The corrosion resistance A is a salt spray test (SST: 240 hours) specified in JISZ2371, and the corrosion resistance B
Is a moisture resistance test (240 hours) specified in JIS4001. The mark x indicates that corrosion marks were found in many places, the mark Δ indicates that corrosion marks were found in multiple places, the mark Δ indicates that corrosion marks were found in one or two places, and the mark ◎ indicates corrosion. Shows no trace at all.

[0035]

[Table 1]

From the results shown in Table 1, 1.0 to 300 mg of Zr or Ti as an essential component was contained in the dried underlayer.
It was found that a sample containing these elements in the range of / m ² had excellent hydrophilicity, good adhesion, and excellent corrosion resistance. In addition, even within this range, especially 5 to 100 mg
/ M ² has also been found to be particularly preferred.

Next, the results of equivalent tests using the organic hydrophilic film having the following composition in place of the inorganic hydrophilic film used in the previous test are shown in Table 2 below. Here, as the organic hydrophilic film, the hydrophilic film of Example 1 described in JP-A-08-81650 was used. That is, in order to form a hydrophilic film, first, [Copolymer A-1] is produced, and after the [Copolymer A-1] is subjected to the treatment described below, a curing agent for imparting alkali resistance described later. Was added, and then a curing agent and ion-exchanged water were mixed by weight as described below to obtain an organic hydrophilic film.

Production of [Copolymer A-1] 400 g of ion-exchanged water, sodium hypophosphite were placed in a 1 L four-necked flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas inlet tube. 8.1 g, potassium persulfate 5.0 g, light acrylate CN (manufactured by Kyoeisha Chemical Co., Ltd., 2-cyanoethyl acrylate) 80 g, light ester HO
(Kyoeisha Chemical Co., Ltd., 2-hydroxyethyl methacrylate) 28 g, crotonic acid 20 g, maleic acid 10
0 g, methacrylic acid 72 g, methyl methacrylate 8
g, light acrylate CH (manufactured by Kyoeisha Chemical Co., Ltd.
Cyclohexyl acrylate) 4 g, AS (Nissei Chemical Industry Co., Ltd., sodium arylsulfonate) 40 g, and AT
48 g of BS-K (manufactured by Toa Gosei Chemical Industry Co., Ltd., potassium 2-acrylamido-2-methylpropane-1-sulfonate) was charged, and the polymerization temperature was adjusted to 47 to under nitrogen gas flow.
As a result of performing a redox polymerization reaction at 50 ° C. for 16 hours,
Copolymer A-1 having an average molecular weight of 12,000 and a concentration of 51.1% was obtained.

Preparation of [Hydrophilic Resin A-1] Triethylamine and aqueous ammonia were added to this copolymer A-1, stirred at 40 to 45 ° C. for 1 hour, adjusted to pH with 25% aqueous ammonia, and then subjected to ion exchange. Adjust the concentration by adding water,
The mixture was further stirred and mixed for 1 hour to obtain a liquid resin.

Preparation of [Alkali resistance-imparting agent B-1] This was prepared by adding PEG @ 600 to a 500 mL four-necked flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser.
200 g of polyethylene glycol molecular weight (manufactured by Lion Corporation) and 87 g of RIKACID SA (succinic anhydride manufactured by Nippon Rika Co., Ltd.) were charged at 80 ° C.
Reaction at 100 ° C. for 1 hour and 110 ° C. for 2 hours,
A colorless liquid diester dibasic oxyacid was obtained. 44 g of triethylamine and 4% of 25% aqueous ammonia
3.5 g was added, and the mixture was stirred and mixed at 40 to 45 ° C. for 1 hour. Thereafter, the concentration was adjusted to 40% by adding ion-exchanged water to obtain an alkali resistance imparting agent B-1.

[Curing Agent C-3] This is Yukicoat E-394 (manufactured by Kyoeisha Chemical Co., Ltd., polyethylene glycol (ethylene glycol chain n = 14) diglycidyl ether, viscosity 160 cps, light yellow transparent liquid). . These were prepared, and 100 parts by weight of [hydrophilic resin A-1], 60 parts by weight of [alkali resistance imparting agent b-1], 25 parts by weight of [curing agent C-3], and 160 parts by weight of ion-exchanged water were added. After mixing, an organic hydrophilic film used in the present invention was obtained. This organic hydrophilic film was used in place of the above-mentioned inorganic hydrophilic film and subjected to a test equivalent to that shown in Table 1.

[0042]

[Table 2]

As shown in Table 2, even with the fin material provided with the organic hydrophilic film, the same results were obtained as with the fin material provided with the inorganic hydrophilic film.

[0044]

As described above, according to the present invention, since the coating liquid layer containing Ti or Zr as an essential component is provided with a dried or heated base layer and a hydrophilic film formed thereon, the T
A non-chromate type underlayer containing i or Zr and no Cr can be used, and a fin material which does not cause a problem of environmental pollution can be provided. Further, the hydrophilic film provided on the underlayer imparts hydrophilicity to the fin material, and prevents adhesion of hemispherical aggregated water. Next, in the present invention,
When Ti or Zr as an essential component contained in the underlayer is contained in an amount of 1 mg / m ² or more and 300 mg / m ² or less, good adhesion as the underlayer can be secured,
Excellent corrosion resistance can be secured, and the hydrophilicity required for the fin material is secured. In the present invention, 5 mg / m
^When Ti or Zr is contained in an amount of ² or more and 100 mg / m ² or less, better adhesion as an underlayer can be ensured, and excellent corrosion resistance and hydrophilicity required for the fin material are ensured.

Next, the present invention may be a heat exchanger including the fin material described above. If the fin material is a provided heat exchanger,
Since the surface of the fin material has a hydrophilic property, even if coagulated water adheres during cooling operation of the heat exchanger, there is little possibility that air permeability around the fin material is impaired.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a fin material according to a first embodiment of the present invention.

FIG. 2 is a front view showing an example of a heat exchanger including fins made of a fin material according to the present invention.

[Explanation of symbols]

A: Fin material, 1: Base material, 2: Underlayer, 3: Hydrophilic film, B: Heat exchanger, 13: Tube, 14: Fin.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Fumio Mihara 85, Hiramatsu, Susono-shi, Shizuoka Prefecture F-term in the Technology Development Center of Mitsubishi Aluminum Co., Ltd. DA16 EB02 EB08 4K044 AA06 AB02 BA12 BA20 BA21 BB03 BC02 BC05 CA16 CA53

Claims (6)

[Claims] A metal substrate made of aluminum or an aluminum alloy, a non-chromate coating type underlayer formed on the metal substrate, and a hydrophilic film formed on the underlayer. A coating layer in which the underlayer contains Ti or Zr as an essential component, and the coating liquid layer applied on the metal base is heated and dried, and a part of the coating liquid layer reacts with the metal base. A fin material for a heat exchanger, which is formed by a base treatment method. 2. An underlayer comprising Ti or Z as an essential component.
r is 1 mg / m ² or more, the heat exchanger fin stock according to claim 1, characterized by being contained 300 mg / m ² or less. 3. The underlayer contains at least one or more of C, O, Si, F, and P in addition to Ti or Zr as an essential component. The fin material for a heat exchanger according to 1. 4. The heat exchanger according to claim 3, wherein the underlayer contains an oxide of at least one or more of Ti, Zr, Si and P. Fin material. 5. The method according to claim 1, wherein the underlayer has a thickness of 5 mg / m ² or more.
Heat exchanger fin stock according to claim 2, 0 mg / m ² or less of Ti or Zr are characterized by comprising been contained. 6. A heat exchanger comprising the fin material according to claim 1. Description: