JP2936259B1 - Surface treatment agent for heat exchanger fin, surface treatment method and surface treatment coating - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a hydrophilic surface treating agent for a fin of a heat exchanger, which is very excellent in hydrophilicity, does not deteriorate with time, and has excellent corrosion resistance, water resistance and workability, and a surface treatment method. Providing a surface-treated coating. SOLUTION: A monomer (a) represented by the following general formula (1)
1) and a copolymer (A) having a monomer (a2) represented by the general formula (2) as an essential constituent unit; and a functional group (b1) capable of reacting with active hydrogen, and / or A cross-linking agent (B) having a functional group (b2) capable of reacting with active hydrogen upon heating; General formula R ¹ -O-[(C ₂ H ₄ O) _m / (C ₃ H ₆ O) _n ] -H (1) In the formula, R ¹ is an alkenyl group having 2 to 5 carbon atoms. m
Is an integer of 1 to 50, and n is an integer of 0 to 10. [(C ₂ H
₄ O) _m / (C ₃ H ₆ O) _n ] indicates random addition or block addition. } General formula ^{Z 1 -R 2 -COOM 1 (2} ) { wherein, Z ¹ is a hydrogen atom or a -COOM ² group. M
¹ and M ² are a hydrogen atom, an alkali metal, an alkaline earth metal,
It is an ammonium group or an organic amine salt. R ² is an alkenylene group having 2 to 5 carbon atoms. ｝

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treating agent for heat exchanger fins, in particular, a surface treating agent for imparting a hydrophilic film to an aluminum material of a heat exchanger; a surface treating method using the same; Surface treatment film to be obtained.

[0002]

2. Description of the Related Art It has been proposed to coat a fin surface of a heat exchanger with a hydrophilic treating agent to form a hydrophilic film in order to prevent adhesion of coagulated water. For example, a hydrophilic film containing a predetermined amount of alkali silicic acid and a hydrophilic polymer (Japanese Patent Application Laid-Open No. 5-125555, etc.), and a hydrophilic polymer film containing a predetermined amount of polyethylene chains (Japanese Patent Application Laid-Open No.
2189), a hydrophilic polymer film containing a predetermined amount of polyglutamic acid (Japanese Patent Application Laid-Open No. 7-102188, etc.), and a hydrophilic polymer film containing a specific amount of a neutralized salt of methylolacrylamide and carboxymethylcellulose. JP-A-2-258874).

[0003]

However, there is a problem that the odor is poor and the odor is good, but the corrosion resistance is inferior, and the hydrophilicity deteriorates with time.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors diligently provide a hydrophilic surface treatment agent which is excellent in hydrophilicity, corrosion resistance and excellent in durability in which the hydrophilicity does not deteriorate with time. As a result of repeated studies, the present invention has been reached.

That is, the present invention provides a copolymer comprising a monomer (a1) represented by the following general formula (1) and a monomer (a2) represented by the following general formula (2) as essential constitutional units. (A); and a functional group (b1) capable of reacting with active hydrogen, and / or a functional group (b) capable of reacting with active hydrogen by heating
A surface treating agent for heat exchanger fins comprising a crosslinking agent (B) having 2). General formula R ¹ -O-[(C ₂ H ₄ O) _m / (C ₃ H ₆ O) _n ] -H (1) In the formula, R ¹ is an alkenyl group having 2 to 5 carbon atoms. m
Is a number from 1 to 50 and n is a number from 0 to 10. [(C ₂ H ₄ O)
_m / (C ₃ H ₆ O) _n ] indicates random addition or block addition. } General formula ^{Z 1 -R 2 -COOM 1 (2} ) { wherein, Z ¹ is a hydrogen atom or a -COOM ² group. M
¹ and M ² are a hydrogen atom, an alkali metal, an alkaline earth metal,
It is an ammonium group or an organic amine salt. R ² is an alkenylene group having 2 to 5 carbon atoms. ｝

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The copolymer (A) containing an active hydrogen group in the present invention is useful from the viewpoint of imparting coating film adhesion and imparting corrosion resistance.

The copolymer (A) is a copolymer derived from the monomer (a1) represented by the general formula (1) and the monomer (a2) represented by the general formula (2). . General formula R ¹ -O-[(C ₂ H ₄ O) _m / (C ₃ H ₆ O) _n ] -H (1) In the formula, R ¹ is an alkenyl group having 2 to 5 carbon atoms. m
Is a number from 1 to 50 and n is a number from 0 to 10. [(C ₂ H ₄ O)
_m / (C ₃ H ₆ O) _n ] indicates random addition or block addition. } General formula ^{Z 1 -R 2 -COOM 1 (2} ) { wherein, Z ¹ is a hydrogen atom or a -COOM ² group. M
¹ and M ² are a hydrogen atom, an alkali metal, an alkaline earth metal,
It is an ammonium group or an organic amine salt. R ² is an alkenylene group having 2 to 5 carbon atoms.に お い て In the monomer (a1), R ¹ is an alkenyl group having 2 to 5 carbon atoms, specifically, CH ₂ ＣＨCH—, CH ₃ CH
= CH- group, CH ₂ = CHCH ₂ - group, CH ₂ = C (C
H ₃ ) —, CH ₃ CH ＝ CHCH ₂ —, CH ₃ CH ＝ C
HCH ₂ CH ₂ — groups, CH ₂ ＣＨCHCH ₂ CH ₂ CH ₂ — groups,
CH ₂ ＣC (CH ₃ ) CH ₂ CH ₂ — and the like.
[(C ₂ H ₄ O) _m / (C ₃ H ₆ O) _n ] may be random addition or block addition when n is not 0, but is preferably block addition. [(C ₂ H ₄ O) _m /
The ratio of m / n in (C ₃ H ₆ O) _n ] is usually 10/0 to 4
/ 6, preferably 8/2 to 5/5. m is 1
N is an integer of 0 to 10, and n is a number of 0 to 10, and preferably m is a number of 5 to 25 and n is a number of 0 to 5 from the viewpoint of water resistance, durability, and hydrophilicity.

Specific examples of the monomer (a1) include an allyl alcohol ethylene oxide 10 mol block adduct and allyl alcohol ethylene oxide 10
Mole and propylene oxide 1 mol block adduct, allyl alcohol ethylene oxide 10 mol and propylene oxide 1 mol random adduct, allyl alcohol ethylene oxide 8 mol and propylene oxide 2 mol block adduct, allyl alcohol Alkylene oxide adducts of allyl alcohol such as a random adduct of 8 mol of ethylene oxide and 2 mol of propylene oxide; block adducts of 6 mol of methallyl alcohol and 2 mol of propylene oxide, and ethylene oxide of methallyl alcohol Alkylene oxide adduct of methallyl alcohol such as random adduct of 6 mol and 2 mol of propylene oxide; 12 mol of ethylene oxide of crotyl alcohol and An alkylene oxide adduct of crotyl alcohol such as a block-like adduct of 1 mol of pyrene oxide and a random adduct of 12 mol of ethylene oxide of crotyl alcohol and 1 mol of propylene oxide; ethylene oxide of 2-butene-1,4 diol Addition of alkylene oxide of 2-butene-1,4 diol such as block adduct of 8 mol and 1 mol of propylene oxide, random adduct of 8 mol of ethylene oxide of 2 butene-1,4 diol and 1 mol of propylene oxide Objects and the like.

In the monomer (a2), Z ¹ is a hydrogen atom or a —COOM ¹ group. M ¹ and M ² are a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic amine salt. R ² is an alkenyl group having 2 to 5 carbon atoms, specifically, a CH ₂ ＣＨCH— group, CH ₃ CHＣＨ
CH— group, CH ₂ ＣＨCHCH ₂ — group, CH ₂ ＣC (CH ₃ )
— Group, CH ₃ CH ＝ CHCH ₂ — group, CH ₃ CH ＝ CHC
H ₂ CH ₂ — group, CH ₂ ＣＨCHCH ₂ CH ₂ CH ₂ — group, CH
₂ ＣC (CH ₃ ) CH ₂ CH ₂ — and the like.

Specific examples of the monomer (a2) include acrylic acid, methacrylic acid, maleic acid, itaconic acid, crotonic acid, mesaconic acid, fumaric acid, citraconic acid, maleic anhydride, itaconic anhydride, and itaconic anhydride. Mesaconic acid, citraconic anhydride and the like. The monomer (a1) and the monomer (a2) may be used alone, or two or more monomers may be used as constituent units.

The copolymer (A) of the present invention may be obtained by copolymerizing another unsaturated monomer in an amount not impairing the performance of the present invention, in addition to the above-mentioned essential structural units. Can also. Examples of such monomers include (1) olefins [α-olefins having 2 to 20 carbon atoms, etc.], (2) conjugated dienes [butadiene, isoprene, etc.], and (3) vinyl aromatic [styrene, α -Methylstyrene and the like], (4) vinyl ester [vinyl acetate and the like], (5) (meth) acrylate [alkyl (meth) acrylate having 2 to 20 carbon atoms and the like],
(6) (meth) acrylic acid, (7) vinyl lactam [N-vinyl pyrrolidone, 3-methyl-N-vinyl pyrrolidone, etc.], (8) vinyl imidazole [N-imidazole,
-Methyl-2-imidazole etc.), (9) vinylpyridine [N-vinylpyridine etc.], (10) alkenyl alcohol [allyl alcohol, methallyl alcohol, crotyl alcohol, 3-butenyl alcohol, 4-pentenyl alcohol, 3-methyl-3-butenyl alcohol and the like],
(12) (meth) acrylamide; (13) alkenyl alcohol sulfate; and mixtures of two or more of these.

The monomer (a1) / (a) in the copolymer (A)
The content ratio of the structural unit represented by 2) is usually 10/90 to 90/10 in terms of molar ratio, and preferably 40/60 to 60/40 from the viewpoint of adhesion and hydrophilicity.

The solubility parameter of the copolymer (A) is 11.0 or more, preferably 12.0 to 50.0, from the viewpoint of imparting film adhesion and imparting hydrophilicity. The solubility parameter was determined by the Fedors method [Polym. En
g. Sci. 14 (2) 152, (1974)].

The weight average molecular weight of the copolymer (A) is 1,
It is preferably from 000 to 500,000. 1,0
If it is less than 00, the hydrophilicity may deteriorate over time, and 5
When it exceeds 000, the workability at the time of coating is poor.

The method for producing the copolymer (A) is not particularly limited, and any conventionally known method can be applied. For example, radical polymerization is generally used as a reaction type, and water or alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, benzene, toluene, xylene, and n-hexane are used as solvents. And hydrocarbons such as cyclohexane. As the polymerization initiator, peroxides such as benzoyl peroxide and hydrogen peroxide, azo compounds represented by azobisisobutyronitrile, and persulfates can be used. Polymerization average molecular weight, mercaptoethanol, mercaptopropionic acid, laurylmercaptan, to control the molecular weight distribution,
A chain transfer agent such as triethylene glycol dimercaptan may be used. Although the reaction temperature varies depending on the solvent and the polymerization initiator, the reaction can be usually performed at 50 to 200 ° C.

The crosslinking agent (B) having a functional group (b1) capable of reacting with active hydrogen and / or a functional group (b2) capable of reacting with active hydrogen by heating according to the present invention is used in view of imparting water resistance. Useful.

The functional group (b1) contained in the crosslinking agent (B)
Is not particularly limited as long as it is a functional group capable of reacting with active hydrogen, and examples thereof include a functional group that generates isocyanate, epoxy, and formalin. Further, the functional group (b2) also
If it is a functional group that can react with active hydrogen by heating,
There is no particular limitation, for example, an amine imide group [1,1-dimethyl-1- (2-hydroxypropyl) amine imide group or the like], an alkylolmethyl amide group [butyrol methyl amide group or the like], a hydroxymethyl amide group, an aldehyde group, Blocked isocyanate groups [e.g., methanol block isocyanate], and blocked epoxy groups [e.g., blocked epoxy group]. Among these functional groups, from the viewpoint of workability, a functional group (b2) capable of reacting with active hydrogen by heating is preferable, and more preferably an amine imide group, an alkylolmethylamide group, a hydroxymethylamide group, and an aldehyde group It is.

The total number of the functional groups (b1) and (b2) in one molecule of the crosslinking agent (B) is usually 2 or more, preferably 3 or more, from the viewpoint of water resistance. The weight-average molecular weight of the crosslinking agent (B) is not particularly limited, but is preferably 50 from the viewpoint of workability.
Preferably less than 000.

The functional group containing the crosslinking agent (B) [(b1) +
(B2)] and the equivalent ratio [(b1) + (b2)] / (a) of the active hydrogen (a) containing the copolymer (A) are usually 0.1 or more, and are preferably water-resistant. Is 0.5 or more.

The following additives may be added to the hydrophilic surface treating agent of the present invention according to each function. For example, when imparting smoothness and lubricity, a hydrophilic solvent (methylpyrrolidone, isopropyl alcohol, etc.), a hydrophilic polymer lubricant (polyacrylic acid, polyacrylamide, polyurethane, colloidal silica, polyoxyalkylene, etc.)
May be added.

In order to impart antibacterial and fungicidal properties, a fungicide (1,2-benzisothiazolin-3-one and the like) and a fungicide {2-thiazole-4- (methylsulfonyl) pyridine are used. Equal amounts may be added.

In order to improve workability during coating,
Nonionic activators such as polyoxyethylene alkyl phenyl ether; anionic activators such as polyoxyethylene alkyl ether sulfate; cationic activators such as alkylamine salts; N, N, N-trialkyl-N-sulfoalkylene ammonium betaine May be added.

In order to further impart corrosion resistance, an inhibitor (a zirconium compound such as hexafluorozirconic acid, a chromium compound such as chromium persulfate) may be added.

In the case of coloring, pigments and dyes may be added.

In the surface treatment method of the present invention, a degreased substrate is subjected to a corrosion-resistant film treatment such as a chromate treatment as required, and then a surface treatment agent is applied. The coating method is not particularly limited, and examples thereof include a roll coating method, a bar coating method, a dipping method, a spray method, and a brush coating method. After application,
The substrate is heat-treated. Heating temperature is usually 150 to 280
° C, preferably 180-260 ° C.

The surface-treated film of the present invention is usually used in an amount of 0.1.
A film thickness of ² to 5.0 g / m ² , preferably 0.3 to ² g / m ² is desirable.

[0027]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In addition,
The following surface treatment method and evaluation test were performed in common with the examples and comparative examples.

<Surface treatment method> After degreasing, an aqueous solution containing a treating agent was applied to an aluminum plate previously treated with phosphoric acid chromate with a bar coder, and then heated and dried (245 ° C, 6 ° C).
0 second) to form a coating having a dry weight of 0.3 g / m ² .

<Evaluation Test> (1) Hydrophilicity A cycle (warming cycle) consisting of immersing a sample of each of the above-treated aluminum plates in running water at room temperature for 8 hours and then drying at 80 ° C. for 16 hours is as follows. After repeating 15 times and 15 times, the contact angle with water was measured. For the measurement, 2 μl of water was dropped and FACE-CA- manufactured by Kyowa Interface Science Co., Ltd. was used.
A Z-type automatic contact angle meter was used. [Evaluation criteria] A: Contact angle of less than 10 ° O: Contact angle of 10 ° or more and less than 20 ° Δ: Contact angle of 20 ° or more and less than 30 ° ×: Contact angle of 30 ° or more

(2) Water resistance A sample of each of the aluminum plates treated as described above was measured for 150 m.
Cut out into a size of mx 75 mm and put in running water at room temperature.
After soaking for a time, the change in weight of the sample was measured. [Evaluation criteria] ◎: Weight loss of less than 10% ○: Weight loss of 10% or more and less than 15% △: Weight loss of 15% or more and less than 20% ×: Weight loss of 20% or more

(3) Corrosion resistance A sample of each aluminum plate treated as described above was 150 m
Cut out to the size of mx75mm, JIS-Z-291
The test was performed for 500 hours according to the salt spray test method 1, and the state of the coating film was observed. [Evaluation criteria] A: No change B: White turbidity B: Swelling occurred X: Rust occurred

(4) Adhesion A sample of each aluminum plate treated as above was wetted (4
(0 ° C., 98% RH) for 24 hours, and rubbed 30 times with gauze moistened with water to observe the degree of peeling of the coating. [Evaluation criteria] ◎: No peeling ○: Slight peeling ×: Full peeling

(5) Workability A sample of each of the aluminum plates treated as described above was placed in a 6 mm
The friction coefficient under a load of 100 g was measured with a steel ball. In addition,
The measurement was performed by HFR2 manufactured by PCS Instruments.
A mold lubricity / erosion testability tester was used. [Evaluation criteria]: Friction coefficient less than 0.1 ０．１: Friction coefficient 0.1 or more and less than 0.2 ×: Friction coefficient 0.2 or more

[Copolymer (A)] <Production Example> Allyl alcohol alkylene oxide adduct (block adduct of 10 mol of ethylene oxide and 1 mol of propylene oxide: EP1) to a 4-necked corbene equipped with a reflux condenser 496 parts and 284.8 parts of water were added and heated to 95 ° C. while stirring. 290 parts of a 40% aqueous solution of maleic acid and 23.8 parts of sodium persulfate were added to 90.4 parts of water.
And the solution diluted in 1 part were added dropwise over 2 hours. After stirring for 4 hours under the same conditions, a solution obtained by diluting 0.1 part of sodium persulfate with 5.0 parts of water was added, and the mixture was further stirred for 1 hour to complete the reaction, thereby obtaining the copolymer (A-1) of the present invention. Was obtained. Further, an aqueous solution 100 of the obtained copolymer (A-1) was prepared.
The solution was neutralized with 166.6 parts of a 48% aqueous solution of sodium hydroxide to obtain an aqueous solution of the copolymer (A-2) of the present invention.
Similarly, the amounts of the monomers and sodium hydroxide were changed to those shown in Table 1 to obtain copolymer (A-3 to A-7) component aqueous solutions.

[Cross-Linking Agent (B)] <Production Example> Water is added to a four-necked kolben equipped with a reflux condenser.
Parts, 250 parts of isopropanol and stirring and 80 parts.
Heated to ° C. 250 parts of the reactive monomer described in Table 2,
A mixture of 10 parts of 2,2-azobis (2-amidipropane) hydrochloride (hereinafter AHC) and 250 parts of water was added dropwise over 3 hours. After stirring for 2 hours under the same conditions, AHC0.
One part was added and stirred for an additional hour. Then, isopropanol was removed under reduced pressure to obtain an aqueous solution of a crosslinking agent (B-1). Similarly, the amount of the monomer was changed to the amount shown in Table 2 and the crosslinking agent (B
-2) A component aqueous solution was obtained.

[0036]

[Table 1]

EP1: CH ₂ ＣＨCHCH ₂ O (C ₂ H
₄ O) ₁₀ (C ₃ H ₆ O) H EP2: CH ₂ ＣＨCHCH ₂ O (C ₂ H ₄ O) ₂₀ H MA: Maleic acid AA: Acrylic acid MNA: Maleic acid sodium salt ANA: Sodium arylate

[0038]

[Table 2]

AMI: 1,1-dimethyl-1- (2-
(Hydroxypropyl) amine methacrylamide [Imid-100 manufactured by Inui Corporation] MOA: Methylol acrylamide AAM: Acrylamide MMA: Methacrylic acid

Examples 1 to 11 Using the copolymer (A) and the crosslinking agent (B) shown in Table 3, the functional group [(b1) + (b2)] containing the crosslinking agent (B) and the copolymer ( A) Equivalent ratio to the contained active hydrogen group (a) [(b1)
+ (B2)] / (a) was mixed with a 10% by weight aqueous solution of a surface treatment agent, and their performance was evaluated. Table 3 shows the results.

Example 12 Using the copolymer (A) and the crosslinking agent (B) shown in Table 3, the functional group [(b1) + (b2)] containing the crosslinking agent (B) and the copolymer (A) were used. Equivalent ratio with the active hydrogen group (a) contained [(b1)
+ (B2)] / (a) was mixed with a 10% by weight aqueous solution of a surface treatment agent to evaluate its performance. Table 3 shows the results.

Example 13 Using the copolymer (A) and the crosslinking agent (B) shown in Table 3, the functional group [(b1) + (b2)] containing the crosslinking agent (B) and the copolymer (A) were used. Equivalent ratio with the active hydrogen group (a) contained [(b1)
+ (B2)] / (a) = 5.0 A 10% by weight aqueous solution surface treatment agent was blended, and the performance was evaluated. Table 3 shows the results.

Comparative Examples 1 to 4 Using the components shown in Table 3, the performance was evaluated under the same conditions as in the examples. Table 3 shows the results.

[0044]

[Table 3]

B-3: Glyoxal B-4; Symmer 350 C-1 manufactured by Mitsui Cyanamid; Polyethylene glycol (weight average molecular weight 8,
000)

[0046]

EFFECT OF THE INVENTION The surface treating agent for heat exchanger fins of the present invention,
According to the surface treatment method and the surface treatment film, a film having the following effects can be obtained. (1) It is very excellent in hydrophilicity. (2) Since it is a crosslinked structure, the hydrophilicity does not deteriorate over time. (3) Very excellent in corrosion resistance, water resistance, workability and adhesion. Due to the above effects, the hydrophilic surface treatment agent of the present invention is used not only for fins of heat exchangers but also for applications where dew condensation prevention is required, for example, building materials (glass, slate, inorganic materials such as ceramics, Interior / exterior treatment agents for metal materials such as aluminum, wood, plastic materials, etc., treatment agents for vehicles (top coat, etc.), treatment agents for vehicle parts, treatment agents for plastics, treatment agents for cans, treatment agents for PVC sheets, It is extremely useful as a treatment agent for preventing dew condensation such as a treatment agent for paper and a treatment agent for plastic film.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C23C 28/00 C23C 28/00 F28F 1/32 F28F 1/32 H 13/18 13/18 B (56) References JP JP-A-6-280809 (JP, A) JP-A-6-80852 (JP, A) JP-A-5-223483 (JP, A) JP-A-5-223482 (JP, A) JP-A-3-74417 (JP, A) A) JP-A-3-60798 (JP, A) JP-A-2-202580 (JP, A) JP-A-62-286098 (JP, A) JP-A-62-268806 (JP, A) JP-A-59 -176312 (JP, A) JP-A-57-57706 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09D 129/10 C09D 5/00 C09D 133/02 C09D 135/00 C23C 22/56 C23C 28/00 F28F 1/32 F28F 13/18

Claims (6)

(57) [Claims] A monomer (a) represented by the following general formula (1)
1) and a copolymer (A) having a monomer (a2) represented by the general formula (2) as an essential constituent unit, and a functional group (b1) capable of reacting with active hydrogen and / or activated by heating A surface treating agent for a heat exchanger fin comprising a crosslinking agent (B) having a functional group (b2) capable of reacting with hydrogen. General formula R ¹ -O-[(C ₂ H ₄ O) _m / (C ₃ H ₆ O) _n ] -H (1) In the formula, R ¹ is an alkenyl group having 2 to 5 carbon atoms. m
Is a number from 1 to 50 and n is a number from 0 to 10. [(C ₂ H ₄ O)
_m / (C ₃ H ₆ O) _n ] indicates random addition or block addition. } General formula ^{Z 1 -R 2 -COOM 1 (2} ) { wherein, Z ¹ is a hydrogen atom or a -COOM ² group. M
¹ and M ² are a hydrogen atom, an alkali metal, an alkaline earth metal,
It is an ammonium group or an organic amine salt. R ² is an alkenylene group having 2 to 5 carbon atoms. ｝ 2. The heat treating fin surface treating agent according to claim 1, wherein the molar ratio of the monomer (a1) / the monomer (a2) is from 10/90 to 90/10. 3. The surface treating agent for heat exchanger fins according to claim 1, wherein the crosslinking agent (B) has a group (b2) capable of reacting with active hydrogen by heating. 4. The heat according to claim 1, wherein said functional group (b2) is at least one group selected from the group consisting of an amine imide group, an alkylolmethylamide group, a hydroxymethylamide group, and an aldehyde group. Surface treatment agent for exchanger fins. 5. A surface treatment method, comprising applying the heat treatment fin surface treating agent according to claim 1 to a heat exchanger fin base material, followed by heat treatment. 6. A surface treatment film obtained by subjecting the heat treatment fin surface treatment agent according to any one of claims 1 to 5 to a heat treatment.