JP2011032309A - Hydrophilic treatment composition for heat exchanger fin material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrophilic treatment composition for a heat exchanger fin material capable of making a film excellent in stain resistance and corrosion resistance because of good self-cleaning performance using condensed water generated on the surface of the heat exchanger fin material. <P>SOLUTION: This hydrophilic treatment composition for the heat exchanger fin material includes 1.0-5.0 pts.mass of a specific epoxy compound (C) and 100 pts.mass of the total solids amount of: at least one polymer component (A) selected from among polyglycerol and polyvinyl alcohol; and a high acid value acrylic resin (B) having a resin acid value of ≥300 mgKOH/g. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydrophilic treatment composition for a heat exchanger fin material that can form a film having good self-cleaning properties by condensed water generated on the surface of the heat exchanger fin material and excellent in contamination resistance and corrosion resistance.

  Since materials such as aluminum and aluminum alloys are lightweight and have excellent workability and thermal conductivity, they are widely used in various parts of heat exchangers such as car air conditioners and room air conditioners. A fin-made material (hereinafter sometimes abbreviated as “fin material”) is often used.

  When an air conditioner incorporating the fin material (hereinafter sometimes referred to as an “air conditioner”) is cooled, moisture in the air condenses on the surface of the fin material, causing clogging between the fins and reducing the cooling capacity. Let Therefore, in order to remove this condensed water, the fin surface is generally subjected to a hydrophilic treatment.

By this hydrophilization treatment, the fin surface is always wet with condensed water. For this reason, a bridge of water is formed between the fins to narrow the air ventilation path, which increases the resistance to ventilation and causes problems such as power loss, noise generation, water droplet scattering, and fin material corrosion. There is.
As a measure for preventing such a phenomenon, the improved hydrophilized composition prevents the condensed water from forming bridges and prevents a decrease in thermal efficiency. However, even if an improved hydrophilizing agent is applied to the surface of the fin material, by operating the air conditioner, contaminants derived from floor wax, wall cloth adhesive, cigarettes, etc., may be present on the surface of the fin material of the air conditioner. Adhering and the durability of contamination resistance was not sufficient.

  As countermeasures against this, for example, Patent Document 1 discloses (A) polyglycerin and (B) 300 mgKOH / g as a hydrophilization treatment composition capable of forming a film excellent in hydrophilic durability, corrosion resistance, odor and the like. It contains a high acid value acrylic resin having the above resin acid value, the resin solid content of the hydrophilic treatment composition has a resin acid value of 200 mgKOH / g or more and a hydroxyl value of 100 mgKOH / g or more. A hydrophilization composition for a heat exchanger fin material is disclosed.

  In addition, Patent Document 2 discloses that (A) polyvinyl alcohol having a saponification degree of 87% or higher and (B) a carboxyl group of a high acid value acrylic resin having a resin acid value of 300 mgKOH / g or higher. A hydrophilization treatment composition for heat exchanger fins, comprising a neutralizing resin having a boiling point of less than 180 ° C. and forming a salt with a basic compound that does not decompose at less than 180 ° C., Is disclosed.

  However, the composition described in Patent Document 1 or Patent Document 2 has insufficient self-cleaning ability to remove contaminants by condensed water generated on the surface of the heat exchanger fin material.

JP 2001-323257 A JP 2001-329377 A

  The problem to be solved by the invention is a hydrophilic treatment composition for a heat exchanger fin material that is capable of forming a film having excellent self-cleaning property due to condensed water generated on the surface of the heat exchanger fin material and excellent in contamination resistance. Is to provide things.

The inventors include at least one polymer component (A) selected from polyglycerin and polyvinyl alcohol, a high acid value acrylic resin (B) having a resin acid value of 300 mgKOH / g or more, and a specific epoxy compound (C). It has been found that the above-mentioned problems can be solved by the hydrophilization composition for heat exchanger fin material, and the present invention has been completed.
That is, the present invention
1. For at least one polymer component (A) selected from polyglycerin and polyvinyl alcohol, and a total acid content of 100 parts by mass of the high acid value acrylic resin (B) having a resin acid value of 300 mgKOH / g or more, the following formula (1) And / or a hydrophilic treatment composition for a heat exchanger fin material, comprising 1.0 to 5.0 parts by mass of the epoxy compound (C) represented by the formula (2),

Formula (1)
(Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which may be the same or different, and is the number of repeating units of the alkylene oxide structure part, m and n are m + n = 1. Represents an integer of ~ 20)

式（２）
（式（２）中、Ｙの繰り返しにおいてＲ^２は同一又は相異なってもよい、水素原子、水酸基、炭素数１〜６のアルキル基、式（３）で表される基を表し、Ｘは１〜９、Ｙは１〜５０となる整数を表す）

Formula (2)
(In the formula (2), in the repetition of Y, R ² may be the same or different, and represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a group represented by the formula (3), and X is 1 to 9, Y represents an integer of 1 to 50)

Formula (3)
2. Furthermore, the hydrophilization treatment composition for heat exchanger fin materials according to claim 1, containing lithium hydroxide,
3. 1 to 20 masses of a natural polymer compound having a carboxyl group and / or a hydroxyl group or a derivative thereof (D) with respect to 100 mass parts of the total solid content of the polymer component (A) and the high acid value acrylic resin (B). Hydrophilic composition for heat exchanger fin material according to 1 or 2, which is partly contained,
4.1. The hydrophilic treatment composition for a heat exchanger fin material according to any one of items 1 to 3 is coated on an aluminum fin material surface and dried by heating to form a film having a dry film thickness of 0.2 to 5 μm. Forming a heat exchanger aluminum fin material hydrophilization treatment, characterized by:
The present invention relates to an aluminum fin material obtained by the hydrophilization method described in Section 5.4.

  The fin material coated with the film of the hydrophilic treatment composition of the present invention has good self-cleaning property by condensed water generated on the surface of the fin material, and is excellent in stain resistance and corrosion resistance. Specifically, the obtained film is excellent in adhesion between the film and the aluminum material, even if a large amount of water vapor is condensed on the surface of the fin due to air cooling.

  Further, since the condensed water does not become large droplets, the fin material in the heat exchanger is excellent in thermal efficiency without causing clogging. Furthermore, by using lithium hydroxide as a neutralizing agent, the effect of improving the hydrophilicity of the aluminum fin material can be obtained, and clogging and scattering due to the condensed water can be reduced.

  The present invention contains at least one polymer component (A) selected from polyglycerin and polyvinyl alcohol, a high acid value acrylic resin (B) having a resin acid value of 300 mgKOH / g or more, and a specific epoxy compound (C). It is the hydrophilization treatment composition for heat exchanger fin materials. Details will be described below.

Polymer component (A)
The polymer component (A) is at least one selected from polyglycerin and polyvinyl alcohol.

  The above polyglycerin is a polyether product of glycerin, and usually has a number average molecular weight of 200 to 30,000, preferably 300 to 3,000. To preferred.

  Polyvinyl alcohol plays a role as a film-forming component and has a high affinity with water due to the presence of a large amount of secondary hydroxyl groups in the molecule. Further, water resistance and hydrophilicity are obtained by esterification of this hydroxyl group with other components. Shows the effect of maintaining sexual persistence. The polyvinyl alcohol is a polyvinyl alcohol having a saponification degree of 87% or more, preferably a so-called completely saponified polyvinyl alcohol having a saponification degree of 98% or more, and an average polymerization degree in the range of 500 to 2,000. It is suitable for obtaining the viscosity at the time of coating.

Completely saponified polyvinyl alcohol has a low solubility in water at room temperature, and exhibits desirable properties as a film material for a heat exchanger fin material used at room temperature or lower. As polyvinyl alcohol, so-called modified polyvinyl alcohol reacted with other organic compounds (for example, a copolymer with acrylamide, unsaturated carboxylic acid, sulfonic acid monomer, cationic monomer, unsaturated silane monomer, etc.) should be used. Can do.
In the present specification, the number average molecular weight or weight average molecular weight of the resin is a value calculated based on the molecular weight of standard polystyrene from a chromatogram measured by gel permeation chromatography. As the gel permeation chromatograph, “HLC8120GPC” (manufactured by Tosoh Corporation) was used. As the columns, four columns of “TSKgel G-4000HXL”, “TSKgel G-3000HXL”, “TSKgel G-2500HXL”, “TSKgel G-2000HXL” (both manufactured by Tosoh Corporation, trade name) were used, Mobile phase: Tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 ml / min, detector: under the conditions of RI.

High acid value acrylic resin (B)
The high acid value acrylic resin (B) is a polymer of a carboxyl group-containing ethylenically unsaturated monomer or a copolymer of the carboxyl group-containing ethylenically unsaturated monomer and other monomers, and has a resin acid value of 300 mgKOH / g. As described above, it is preferably within the range of 500 to 800 mgKOH / g, and the number average molecular weight is usually within the range of 500 to 300,000, preferably 800 to 250,000.

  Examples of the carboxyl group-containing ethylenically unsaturated monomer include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, crotonic acid, and itaconic acid. These can be used alone or in combination of two or more.

  When the acrylic resin is a copolymer, examples of other monomers copolymerized with the carboxyl group-containing ethylenically unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl ( (Meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate , Tridecyl (meth) acrylate, octadecyl (meth) acrylate, isostearyl (meth) acrylate and other C1-24 alkyl (meth) acrylates; 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate Monoesterified product of polyhydric alcohol and acrylic acid or methacrylic acid, such as acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and polyethylene glycol mono (meth) acrylate; Hydroxyl-containing monomers such as a compound obtained by ring-opening polymerization of ε-caprolactone to a monoesterified product of alcohol and acrylic acid or methacrylic acid; styrene, acrylonitrile, methacrylonitrile, vinyl acetate and the like. These compounds can be used alone or in combination of two or more. In the present invention, “(meth) acrylate” means acrylate or methacrylate. Among the high acid value acrylic resins (B), polyacrylic acid is preferable.

As a blending ratio of the high acid value acrylic resin (B) to the polymer component (A),
The polymer component (A) is 50 to 95 parts by mass, preferably 60 to 90 parts by mass, and the high acid value acrylic resin (B) is 5 to 50 parts by mass, preferably 10 parts per 100 parts by mass of the total solid content of both components. -40 mass parts is preferable for the corrosion resistance of a fin material.

Epoxy compound (C )
The epoxy compound (C) in the hydrophilic treatment composition for the heat exchanger fin material of the present invention is a compound (1) represented by the formula (1) and / or a compound (2) represented by the formula (2). Can be used.

Compound (1)

Formula (1)
(In the formula (1), R ¹ is the same or different hydrogen atom or alkyl group having 1 to 6 carbon atoms and the number of repeating units of the alkylene oxide structure part, and m and n are m + n = 1 to 1. Represents an integer such as 20.)
Compound (2)

式（２）
（式（２）中、Ｙの繰り返しにおいてＲ^２は同一又は相異なってもよい、水素原子、水酸基、炭素数１〜６のアルキル基、式（３）で表される基を表し、Ｘは１〜９、Ｙは１〜５０となる整数を表す）

Formula (2)
(In the formula (2), in the repetition of Y, R ² may be the same or different, and represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a group represented by the formula (3), and X is 1 to 9, Y represents an integer of 1 to 50)

Formula (3)
In addition, the compound (1) represented by the above formula (1) or the compound (2) represented by the formula (2) includes Denacol EX-313, Denacol EX-850, Denacol EX-821, Denacol EX-830, Denacol EX-841, Denacol EX-861, Denacol EX-941, Denacol EX-920, Denacol EX-931 (Nagase ChemteX Corporation), Glicier PP-300P, BPP-350 (Sanyo Chemical Industries Co., Ltd.) It is done. Moreover, a compound (1) and a compound (2) can also be mixed and used for an epoxy compound (C).

  The hydrophilic treatment composition for the heat exchanger fin material of the present invention has an epoxy compound (C) of 1.0 with respect to 100 parts by mass of the total solid content of the polymer (A) and the high acid value acrylic resin (B). -5.0 parts by mass, preferably 2.0-4.0 parts by mass, it is excellent in self-cleaning property by condensed water generated on the surface of the fin material of the heat exchanger and hydrophilic (water wettability) ) And an aluminum fin material excellent in contamination resistance can be obtained. Furthermore, the hydrophilicity and stain resistance are excellent in sustainability. The composition of the present invention essentially comprises the polymer component (A), the high acid value acrylic resin (B) and the epoxy compound (C), and further has a natural property having a carboxyl group and / or a hydroxyl group as necessary. A polymer compound or a derivative thereof (D), a nonionic surfactant, and the like can be added.

Natural polymer having carboxyl group and / or hydroxyl group or derivative thereof (D)
A natural polymer compound having a carboxyl group and / or a hydroxyl group or a derivative thereof (D) (hereinafter sometimes referred to as “component (D)”) is polyvinylpyrrolidone, N-methylol (meth) acrylamide, etc. Examples include polymers of (meth) acrylamide derivatives.

  The component (D) includes carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl cellulose (MC), ethyl cellulose (EC), cellulose derivatives such as ethyl hydroxyethyl cellulose (EHEC), and the like. Sodium salt, potassium salt, and ammonium salt.

  The hydrophilization treatment composition for the heat exchanger fin material of the present invention comprises 1 to 20 components (D) with respect to 100 parts by mass of the solid content of the polymer component (A) and the high acid value acrylic resin (B). It is preferable to contain 2 parts by mass, preferably 2 to 18 parts by mass, and more preferably 3 to 15 parts by mass for improving hydrophilicity.

  The nonionic surfactant in the composition of the present invention is blended as needed for the purpose of facilitating the expansion and wetting without moisture adhering to the obtained film forming water droplets. Such nonionic surfactants include, for example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene derivatives, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters. , Polyoxyethylene alkylamine, alkylalkanolamide, and the like. Among these, polyoxyethylene alkyl ether, especially polyoxyethylene heptadecyl ether is preferable from the viewpoint of improving hydrophilicity and improving self-cleaning properties by condensed water.

  The compounding amount of these nonionic surfactants is usually 20 parts by mass or less, preferably 0.5 parts per 100 parts by mass of the total solid content of the polymer component (A) and the high acid value acrylic resin (B). -10 parts by mass, more preferably 1-8 parts by mass.

  The composition of the present invention comprises the polymer component (A), a high acid value acrylic resin (B), an epoxy compound (C), a natural polymer compound having a carboxyl group and / or a hydroxyl group or a derivative thereof (D), and a nonionic type. In addition to surfactants, basic compounds, crosslinking agents, colloidal silica, antibacterial agents, colored pigments, known antirust pigments (for example, chromate-based, lead-based, molybdic acid-based) , Antirust agents (eg, phenolic carboxylic acids such as tannic acid and gallic acid and salts thereof, organic phosphoric acids such as phytic acid and phosphinic acid, metal salts of heavy phosphoric acid, nitrite, etc.) and an aqueous medium are added. be able to.

  The aqueous medium may be water or a mixed solvent of water and a small amount of an organic solvent or a basic compound. In the mixed solvent, the content of water is usually 80% by mass or more. The basic compound acts as a neutralizing agent for the carboxyl group of the high acid value acrylic resin (B) and can form a salt to contribute to the improvement of water-solubility of the resin.

  Examples of such basic compounds include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide; ammonia; ethylamine And amine compounds such as butylamine, benzylamine, monoethanolamine, diethanolamine, diisopropanolamine, N-methylethanolamine, N, N-dimethylaminoethanol, triethylamine, triethanolamine, and diethylenetriamine. Among these, lithium hydroxide is particularly effective for improving the hydrophilicity of the obtained film.

  The cross-linking agent is blended for the purpose of improving the water-solubility of the resulting film, such as melamine resin, urea resin, phenol resin, blocked polyisocyanate compound, metal chelate compound such as titanium chelate, etc. Can be mentioned. In general, the crosslinking agent preferably has water solubility or water dispersibility.

  The colloidal silica is blended for the purpose of imparting hydrophilicity to the resulting film and reducing the water contact angle of the film, and the colloidal silica is so-called silica sol or finely divided silica, A particle diameter of 5 nm to 10 μm, preferably 7 nm to 1 μm, and those usually supplied as an aqueous dispersion can be used as they are, or finely divided silica can be used by dispersing in water.

  The antibacterial agent is blended as necessary for the purpose of preventing the generation and propagation of microorganisms in the resulting film, and is known as an aliphatic or aromatic type having a known antibacterial and bactericidal action. Organic compounds such as haloallylsulfone, iodopropargyl, N-haloalkylthio, benzthiazole, nitrile, pyridine, 8-oxyquinoline, benzothiazole, isothiazoline And antibacterial agents such as those based on phenol, quaternary ammonium salts, triazines, thiazines, anilides, adamantanes, dithiocarbamates, and bromindanone.

  Specific examples of the antibacterial agent include 2- (4-thiazolyl) -benzimidazole, N- (fluorodichloromethylthio) phthalimide, N-dimethyl-N′-phenol-N- (fluorodichloromethylthio) -sulfamide, O -Phenylphenol, 10,10'-oxybisphenoxyarsine, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, 2,4,5,6-tetrachloroisophthalonitrile, diiodomethyl-p -Toluylsulfone, methyl 2-benzimidazolecarbamate, bis (dimethylthiocarbamoyl) disulfide, N- (trichloromethylthio) -4-cyclohexene-1,2-dicarboximide and the like can be mentioned. Further, inorganic salt-based antibacterial agents can also be used, for example, barium metaborate, copper borate, zinc borate, zeolite (aluminosilicate) and the like.

  The hydrophilic treatment composition for heat exchanger fin material of the present invention is applied to the surface of the fin material and dried to maintain the hydrophilicity (water droplet contact angle, whole surface wettability), heat exchanger fin material. The self-cleaning property by the condensed water generated on the surface of the is good. Therefore, a hydrophilic film excellent in contamination resistance and corrosion resistance can be formed on the surface of the heat exchanger fin material.

Method of hydrophilizing aluminum fin material for heat exchanger The aluminum fin material used in the heat exchanger is an upper layer film of the hydrophilic treatment composition of the present invention as a lower layer film mainly for corrosion resistance of the raw material aluminum fin material. It is something that is painted over.

  In order to improve corrosion resistance, the lower layer film preferably contains chromium or zirconium as a metal element. Specifically, the lower layer film is treated with phosphoric acid chromate, chromate chromate, zirconium phosphate or the like to form the lower layer film. Although it forms, it is preferable that it is a processing agent which does not contain chromium from an environmental viewpoint.

Examples of the formation of the hydrophilic film by the hydrophilic treatment composition for the heat exchanger fin material of the present invention include a roll coating method, a bar coating method, a dipping method, a spray method, and a brush coating method. Among these coating methods, for example, in the case of a roll coating method, a hydrophilic film can be obtained by baking and drying at a temperature of 150 ° C. or higher and 270 ° C. or lower for 5 seconds to 1 minute after application. . The film thickness of the hydrophilic film is preferably 0.5 to 5.0 g / m ² , more preferably 0.5 to ² g / m ² .

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In the examples, “parts” represents parts by mass, and “%” represents mass%.

Preparation of chemical conversion treatment plate Aluminum fin material (JIS-A1100) is cut into 200 × 250 mm, degreased using a degreasing agent having a concentration of 2% by mass (Chem Cleaner 561B, manufactured by Nippon Seabee Chemical Co., Ltd.), and then chromated. A chemical conversion treatment plate was obtained by performing treatment (metal chromium equivalent coating amount 30 mg / m ² ) with an agent (Alchrome 712, manufactured by Nihon Parker Rising Co., Ltd.).

Production Example 1 Polyvinyl alcohol aqueous solution No. 1 1 Denkapoval K-05 (manufactured by Denki Kagaku Kogyo Co., Ltd., saponification degree 99%, polymerization degree 550) was dissolved in water, and a polyvinyl alcohol aqueous solution No. 1 having a solid content of 14% was dissolved. 1 was obtained.

Production Example 2 Polyvinyl alcohol aqueous solution No. 1 Preparation of Denkapoval B-05 (manufactured by Denki Kagaku Kogyo Co., Ltd., saponification degree 88%, polymerization degree 550) in water, polyvinyl alcohol aqueous solution No. 1 having a solid content of 14%. 2 was obtained.

Production Example 3 Production of aqueous acrylic resin solution (for comparison)
A four-necked flask equipped with a reflux tube, a thermometer, a dropping funnel, and a stirrer was charged with 406 parts of ethylene glycol monobutyl ether, heated and held at 100 ° C. under a nitrogen stream, and “110 parts of methacrylic acid, n -A mixture of 135 parts of butyl acrylate, 35 parts of ethylene glycol monobutyl ether and 14 parts of 2,2'-azobisisobutyronitrile "was dropped from the dropping funnel over 3 hours. Stirring was continued for a period of time, followed by cooling to obtain an acrylic resin solution having a solid content of 35%. The obtained resin (solid content) had a resin acid value of 293 mgKOH / g and a weight average molecular weight of 25,000. To the obtained 35% acrylic resin solution, N, N-dimethylaminoethanol and water in an amount corresponding to 1 equivalent of neutralization equivalent were gradually added and stirred to obtain an acrylic resin aqueous solution having a solid content of 13%.

Preparation of hydrophilization composition for heat exchanger fin material
Example 1
Poval JF-10 (Note 1) 30 parts (solid content), Polyglycerin # 750 (Note 2) 30 parts (solid content), Jurimer AC-10L (Note 3) 38 parts (solid content), Jurimer AC-10LHP ( Note 4) 2 parts (solid content), Denacol EX-313 (Note 5) 2.5 parts (solid content), Nonion S220 (Note 7) 8.0 parts, Lithium hydroxide 7.0 parts (0.3 equivalents) ) Was added and stirred, and a 3% n-butanol aqueous solution was added to adjust the solid content. 1 was obtained.

Examples 2-13
Except for the blending contents shown in Tables 1 and 2, the same as in Example 1, the hydrophilic treatment composition No. 10 having a solid content of 10% was used. 2-No. 13 was obtained.

(Note 1) Poval JF-10: manufactured by Nippon Vinegar Poval, trade name, polyvinyl alcohol, component A (Note 2) Polyglycerin # 750: manufactured by Sakamoto Pharmaceutical Co., Ltd., trade name, decaglycerin as the main component Polyglycerin, hydroxyl value of about 900 mg KOH / g, solid content of 100% by mass, component A (Note 3) Jurimer AC-10L: manufactured by Nippon Pure Chemical Co., Ltd., trade name, polyacrylic acid, number average molecular weight 2,500 , Acid value 779 mg KOH / g, B component (Note 4) Jurimer AC-10LHP: manufactured by Nippon Pure Chemical Co., Ltd., trade name, polyacrylic acid, number average molecular weight 25,000, acid value 745 mg KOH / g, B component (Note 5) Denacol EX-313: manufactured by Nagase ChemteX Corporation, trade name, epoxy resin, epoxy equivalent 141, component C (Note 6) Denacol EX-821: Nagase Chemte Product name, epoxy resin, epoxy equivalent 185, C component (Note 7) Glicier PP-300P: Sanyo Chemical Industries, product name, epoxy resin, epoxy equivalent 296, C component (Note 8) jER828EL: Japan Product name, epoxy resin, epoxy equivalent 190, number average molecular weight 380, manufactured by Epoxy Resin Co., Ltd.
(Note 9) Cellogen 7A: Daiichi Kogyo Seiyaku Co., Ltd., trade name, carboxymethyl cellulose, component D (Note 10) Serogen NB: Daiichi Kogyo Seiyaku Co., Ltd., trade name, carboxymethyl cellulose, D component (Note 11) Nonion S220 : Nippon Oil & Fats Co., Ltd., trade name, nonionic surfactant, polyoxyethylene heptadecyl ether.

Comparative Examples 1-7
Except for the blending contents shown in Table 3, the same procedure as in Example 1 was carried out. 14-No. 20 was obtained.

Preparation of test plate Using the chemical conversion treatment plate prepared as described above, each hydrophilic treatment composition was applied so that the dry film weight was 1.2 g / m ^2, and the material arrival temperature was 220 ° C. for 10 seconds. Each test plate was obtained by baking. Tables 4 to 6 show the results of the test using the test plate obtained as described above according to the following test method.

(Note 12) Hydrophilicity: The test plate and test plate are immersed in running tap water (flow rate is 15 kg / hour per square meter of coated plate) for 7 hours, and the wet and dry process of lifting and drying in 17 hours is defined as 5 cycles. About each performed test board, a coating board is immersed in the beaker containing tap water for 10 second, and the water swell state of the coating board surface when it pulls up is visually determined.
◎ indicates that the entire surface of the coated plate is wet with water and there is no bias in water even after 30 seconds of pulling. ○ indicates that the entire surface of the coated plate is wet with water and there is no bias in water even after 10 seconds of pulling. Immediately after that, the entire surface of the coated plate is wet, but after 10 seconds of pulling, water has come to the center from the edge of the coated plate. × indicates that polka dots are formed immediately after lifting and the entire coated plate is not wet.

(Note 13) Contamination resistance: Palmitic acid was heated to 70 ° C. and exposed to palmitic acid vapor for 24 hours, and then 0.03 cc of deionized water was dropped onto the coated surface of each test plate with a syringe. The contact angle of the water droplet was measured with a contact tangle meter DCAA type manufactured by Kyowa Chemical Co., Ltd.
◎ is a contact angle of 30 degrees or less 〇 is a practical range where the contact angle exceeds 30 degrees and 35 degrees or less △ is a contact angle of more than 35 degrees and 40 degrees or less × is a contact angle Over 40 degrees.

(Note 14) Water wettability at the time of condensation: A stainless steel container of 20 × 15 × 5 cm was placed in a thermostatic bath at 30 ° C. and 75% RH, and a test coating plate was attached to this side surface. Subsequently, an antifreeze solution at 0 ° C. was circulated in the stainless steel container, and the water leakage state due to the dew condensation water on the surface of the test coating plate after 10 hours of circulation was visually observed and evaluated according to the following criteria.
◯ is a state where the entire surface of the coated plate is wet with water. △ is a state where 50 to 100% of the surface of the coated plate is wet with water.
X is a state in which the wet area on the surface of the coated plate is less than 50%.

(Note 15) Corrosion resistance: According to JIS-Z-2371 salt spray test method. The test time was 500 hours and was evaluated according to the following criteria.
◎ indicates that no white rust or swelling is observed on the paint surface.
◯ indicates that at least one of white rust or bulge is slightly generated, but there is no problem as a current product. △ indicates that at least one of white rust or bulge is generated. × indicates that white rust or bulge is significantly generated.

  Even in a short heat exchanger where the distance between fins is short, it is possible to prevent an increase in ventilation resistance due to water droplet bridging, generation of noise due to water droplet resonance, and scattering of white powder due to corrosion of the aluminum plate. Therefore, it is useful as a fin material for heat exchangers such as condensers, radiators and evaporators.

Claims (5)

For at least one polymer component (A) selected from polyglycerin and polyvinyl alcohol, and a total acid content of 100 parts by mass of the high acid value acrylic resin (B) having a resin acid value of 300 mgKOH / g or more, the following formula (1) And / or 1.0 to 5.0 parts by mass of the epoxy compound (C) represented by the formula (2), and a hydrophilic treatment composition for a heat exchanger fin material.

Formula (1)
(Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which may be the same or different, and is the number of repeating units of the alkylene oxide structure part, m and n are m + n = 1. Represents an integer of ~ 20)

Formula (2)
(In the formula (2), in the repetition of Y, R ² may be the same or different, and represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a group represented by the formula (3), and X is 1 to 9, Y represents an integer of 1 to 50)

Formula (3) Furthermore, the hydrophilization treatment composition for heat exchanger fin materials of Claim 1 containing lithium hydroxide. 1 to 20 masses of a natural polymer compound having a carboxyl group and / or a hydroxyl group or a derivative thereof (D) with respect to 100 mass parts of the total solid content of the polymer component (A) and the high acid value acrylic resin (B). The hydrophilic treatment composition for a heat exchanger fin material according to claim 1 or 2, wherein the composition is contained. The hydrophilic composition for heat exchanger fin material according to any one of claims 1 to 3 is coated on an aluminum fin material surface and dried by heating to form a film having a dry film thickness of 0.2 to 5 µm. A hydrophilic treatment method for a heat exchanger aluminum fin material. An aluminum fin material obtained by the hydrophilization method according to claim 4.