JPH0680852A - Hydrophilization composition, hydrophilization method, and hydrophilization heat exchanger fin - Google Patents

Abstract

(57) [Summary] (Correction) [Structure] (A) (i) 100 parts by weight of water-dispersible silica (solid content) (ii) Hydrolyzable alkoxysilane group-containing polymerizable vinylsilane monomer 0 1 to 10 parts by weight of the polymerizable vinyl group-containing aqueous silica dispersion is reacted with (iii) another polymerizable unsaturated monomer, an organic-inorganic composite reactant, (B) a curing agent, It contains (C) a hydroxyl group-containing polyester resin, (D) a pyrithione-based antibacterial / antifungal agent, and (E) a silicone-based emulsion, and the mixing ratio of the components (A) and (B) is 99 by solid content weight ratio. ~
50: 1 to 50 The mixing ratio of component (C) is from component (A) to
Similarly, 5 to 60% by weight of the solid content of (C) component (D) is 3
˜50% by weight Component (E) is 0.3 to 3% by weight of the solid content of components (A) to (D), and the coating film is formed on the surface of the hydrophilic treatment aluminum heat exchange. Bowl fins. [Effect] The formed film is odorless, has a long-lasting hydrophilicity, and has excellent antibacterial and antifungal properties.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a hydrophilic treatment composition, a hydrophilic treatment method and a hydrophilic heat exchanger fin.

[0002]

2. Description of the Related Art In a heat exchanger of an air conditioner, condensed water generated during cooling forms water droplets between fins to form a water bridge between fins, which narrows an air passage to increase ventilation resistance. Loss, noise, water droplets, and other problems will occur. As a measure to prevent such a phenomenon, the surface of aluminum fins (hereinafter abbreviated as "fins") is made hydrophilic to prevent formation of water drops and bridges due to water drops.

As a method for hydrophilizing the surface of such a heat exchanger, an aluminum plate is molded to form fins, which are then assembled and then a surface treatment agent is applied thereto by dipping, spraying, showering or the like. The so-called after-coating method of applying by a means and the so-called pre-coating method of applying a surface treatment agent to an aluminum plate in advance by a roll coater or the like to form a surface treatment film and then press-molding the aluminum plate to form fins. There are two ways.

In the former method, the method of making the surface of the fin hydrophilic makes it practically used.
(1) A method of applying water glass represented by the general formula mSiO ₂ / nNa ₂ O (for example, Japanese Patent Laid-Open No. 59-13078), and (2) mainly composed of an organic polymer resin such as a water-soluble polyamide resin. To form a resin film by applying the prepared solution (for example, JP-A-61-250495)
However, these methods are not fully satisfactory even if they are put to practical use, and the hydrophilicity of the treated plate is maintained (water droplet contact angle, overall water wettability), corrosion resistance, odor, There are still problems to be improved in terms of press workability and stability of processing liquid. For example, if the water drop contact angle is 2
Regarding the method using the water glass (1), which has a good hydrophilic persistence of 0 ° or less, the fin treated with this material shows a powdery surface on the treated coating surface over time, and the fins are treated with this powder during ventilation. Particles scatter and produce a cement odor or chemical odor. In addition, water glass is hydrolyzed by the condensed water generated during the operation of the heat exchanger, and the fin surface becomes alkaline, so pitting corrosion easily occurs, and aluminum hydroxide powder (white powder), which is a corrosion product, scatters. There are also environmental conservation problems. On the other hand, in the method (2) using the treating agent, the water resistance of the coating film is not sufficient, and the coating film is easily dissolved by the condensed water, so that there is a problem that the hydrophilicity of the fin surface is persistent and the corrosion resistance is lowered. Moreover, there is a problem that the cost is high.

In addition, air conditioners have become smaller and lighter in recent years, and the heat exchanger is also designed to be compact, so that the fin spacing becomes smaller. Therefore, higher hydrophilicity is required, and the contact angle with water is 30. It is becoming essential to be below °.

Further, recently, since a comfortable living space is required, generation of odor by an air conditioner is regarded as a problem. As a countermeasure against the odor of the coating film at the beginning of use and the unpleasant odor at the start of operation due to the microorganisms generated in the air conditioner, the use of a treating agent mixed with an antibacterial agent and an antifungal agent has been proposed (JP-A-58-58). No. 10051, JP-A-61-16867
No. 5, etc.) is still insufficient and its improvement is required.

As described above, the methods currently in practical use do not sufficiently meet such demands, are more excellent in hydrophilicity and corrosion resistance, and have no odor problem. And development of the hydrophilization heat exchanger fin is desired.

[0008]

Means for Solving the Problems As a result of intensive studies aimed at solving the above problems, the present inventors have found that an inorganic fine silica powder is used as a core as a fining agent hydrophilic treatment agent,
A hydrophilization treatment in which an organic-inorganic composite reaction product having a structure in which an organic polymerizable unsaturated monomer is reacted to form a shell is used as a main component, and a curing agent and a hydroxyl group-containing polyester resin are further added to the reaction product. It has been found that the composition is very effective. And, it is possible to give extremely excellent antibacterial / fungal properties to the film obtained by further adding a pyrithione antibacterial / antifungal agent to this treatment composition, which is caused by the generation of bacteria / fungi over time. It can solve the problem of unpleasant odor and the problem of hygiene. At the same time, by using a pyrithione-based antibacterial / antifungal agent dispersed in a fine particle diameter, minute and sharp-angled irregularities are generated on the surface of the obtained film, and by using such a surface shape, It becomes easy to wet with water, and in addition to the hydrophilic property inherent to the resin composition, a film having extremely high hydrophilicity and water wettability can be obtained. Further, in the case of a surface treatment bath when the hydrophilic treatment composition containing the above-mentioned pyrithione-based antibacterial / antifungal agent is applied by dip coating, the pyrithione-based antibacterial / antifungal agent does not aggregate or precipitate. , It is important that they are stably dispersed in the bath, and in order to achieve this purpose, it is extremely effective to add a silicone emulsion with excellent water dispersibility, and the defoaming of the surface treatment liquid The present invention has been completed by improving the property and finding that it is suitable for the above-mentioned fin after-coating method.

That is, according to the present invention, (A) (i) 100 parts by weight of water-dispersible silica (solid content), (ii) a polymerizable vinylsilane monomer containing a hydrolyzable alkoxysilane group 0.1 to 10 An organic-inorganic composite reaction product obtained by reacting a polymerizable vinyl group-containing aqueous silica dispersion obtained by reacting in a proportion of parts by weight with (iii) a polymerizable unsaturated monomer other than (ii) above, (B) A hydrophilic treatment composition comprising: a curing agent, (C) a hydroxyl group-containing polyester resin, (D) a pyrithione-based antibacterial / antifungal agent, and (E) a silicone-based emulsion; A method for hydrophilizing a heat exchanger fin, which comprises coating an aluminum heat exchanger fin with an aqueous dispersion or aqueous solution having a solid content concentration of 2 to 30% by weight, and then heat-drying; and the composition. table It relates to an aluminum-made heat exchanger fins characterized by being applied to.

In the hydrophilic treatment composition of the present invention,
The water-dispersible silica (i) used as the component (A) is so-called colloidal silica and has a particle size of about 3 to 500 mμ,
It is preferably about 5 to 100 mμ, and the one usually supplied as an aqueous dispersion can be used as it is.

The vinylsilane monomer (ii) used as the component (A) is represented by the following general formulas (I) and (I)
I):

[0012]

[Chemical 1]

[Wherein R ₁ represents an alkyl group or an alkoxyalkyl group having 1 to 10 carbon atoms, and R ₂
Represents a hydrogen atom or a methyl group, m represents an integer of 0 or 1, and n represents an integer of 1 to 8], for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl. Dimethoxymethylsilane, γ- (meth) acryloxyethyltrimethoxysilane, γ- (meth) acryloxyethyltriethoxysilane, γ- (meth) acryloxyethyldimethoxymethylsilane, γ- (meth) acryloxypropyltrimethoxy Examples thereof include silane and γ- (meth) acryloxypropyltriethoxysilane. Among these, γ- (meth) acryloxypropyltrimethoxysilane is particularly preferable.

The above-mentioned water-dispersible silica (i) and vinylsilane monomer (ii) are 0.1 parts by weight of vinylsilane monomer (ii) per 100 parts by weight (solid content) of water-dispersible silica (i).
The polymerizable vinyl group-containing aqueous silica dispersion is obtained by reacting at a ratio of 10 to 10 parts by weight, preferably 0.2 to 7 parts by weight.

Here, if the blending ratio of the vinylsilane monomer is less than 0.1 part by weight, the amount of the polymerizable vinyl group contained in the obtained aqueous silica dispersion becomes insufficient, while if it exceeds 10 parts by weight. However, it is not preferable because it causes thickening and gelation during the reaction between the water-dispersible silica and the vinylsilane monomer.

The reaction between the water-dispersible silica and the vinylsilane monomer is carried out by stirring the mixture of both at a temperature of 40 ° C. or higher and a boiling point (usually 100 to 110 ° C.) or lower for 2 to 8 ° C.
This is achieved by heating continuously for hours. The polymerizable unsaturated vinyl monomer-containing aqueous silica dispersion thus obtained is reacted with the polymerizable unsaturated monomers (iii) to obtain an organic-inorganic composite reaction product which is the component (A).

The polymerizable unsaturated monomer (iii) used for the synthesis of the component (A) is a monomer containing at least one monomer having a functional group selected from an amide group, a hydroxyl group and a carboxyl group in the molecule. The shell comprises the above-mentioned aqueous silica dispersion as a core.

Among the polymerizable unsaturated monomers, the above-mentioned functional group-containing monomers include (a) unsaturated amide monomer, (b) hydroxyl group-containing unsaturated monomer and (c) carboxyl group-containing unsaturated monomer. Further, if necessary, these monomers may be used in combination with (d) a polymerizable unsaturated monomer other than (a) to (c).

The monomer (a) has the following general formula (III):

[0020]

[Chemical 2]

[In the formula, R ₂ represents a hydrogen atom or a methyl group, and R ₃ and R ₄ are a hydrogen atom and a carbon number 1 respectively.
Represents an alkyl group or a methylol group of 6; However,
Both R ₃ and R ₄ are hydrogen atoms or at least one of both is a methylol group. ], And typical examples thereof include acrylamide, methacrylamide, N-methylol acrylamide, and N-methylol methacrylamide.

The monomer (b) has the following general formula (I
Examples thereof include those represented by V), (V) and (VI).

[0023]

[Chemical 3]

[In the formula, R ₂ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 4. ] As typical examples represented by the formula (IV), 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate,
4-hydroxy butyl acrylate etc. can be mentioned, These can be used individually or in mixture of 2 or more types.

[Chemical 4]

[Wherein R ₂ is a hydrogen atom or a methyl group, and n is
Represents an integer of 2 to 100. As typical examples represented by the above (V) and (VI), polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polyethylene glycol monoallyl ether and the like in which n is 2 to 100, preferably 10 to 40 are mentioned. These may be used alone or in combination of two or more. Moreover, acrylic acid, methacrylic acid, etc. can be mentioned as a (c) monomer.

The polymerizable unsaturated monomers used for synthesizing the component (A) may be only the monomer components (a), (b) and (c), but if necessary, other polymerizable polymerizable monomers may be used. The unsaturated monomer (d) may be used in combination.

Typical examples of the polymerizable unsaturated monomer (d) are, for example, methyl acrylate, ethyl acrylate,
Propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, soypropyl methacrylate, butyl methacrylate, Hexyl methacrylate, 2-methacrylic acid
Glycidyl acrylate, glycidyl methacrylate; ethylhexyl methacrylate, octyl methacrylate, C ₁ -C ₁₈ alkyl esters of (meth) acrylic acid lauryl methacrylate methoxybutyl acrylate, methacrylic acid methoxybutyl, methoxyethyl acrylate, methoxyethyl methacrylate C ₂ of (meth) acrylic acid such as ethoxybutyl acrylate and ethoxybutyl methacrylate.
C ₁₈ alkoxyalkyl ester; C of (meth) acrylic acid such as allyl acrylate and allyl methacrylate
Alkenyl esters of ₂ -C _3; dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, aminoalkyl esters of (meth) acrylic acid and mono- -t- butyl aminoethyl methacrylate; dimethylaminopropyl acrylamide And acrylic unsaturated monomers such as (meth) acrylamide monomers such as dimethylaminopropyl methacrylamide.

Further, as the (d) monomer other than the acrylic unsaturated monomer, styrene, α-methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, acrolein, methacrolein, butadiene, isoprene and the like can be mentioned.

These (d) monomers can be blended appropriately depending on the desired performance.

The proportions of the monomers (a) to (d) constituting the above-mentioned polymerizable unsaturated monomers (iii) are not particularly limited, but usually 10 to 80% by weight of the monomer (a), preferably 20 to 60. % By weight, (b) monomer 10-60
%, Preferably 20 to 40% by weight, (c) monomer 2 to 20% by weight, (d) monomer 50% by weight or less, preferably 30% by weight or less. If the amount of these monomer components is out of the above range, the hydrophilicity or curability of the coating film tends to decrease.

The above-mentioned reaction between the polymerizable vinyl group-containing aqueous silica dispersion and the polymerizable unsaturated monomer (iii) is carried out according to a solution polymerization method which is a method known per se when producing an acrylic resin. be able to. Specifically, in the presence of a polymerization catalyst such as an azo compound, a peroxide compound, sulfides, and sulfines, it is 4 to 4 at 40 to 180 ° C.
It can be carried out by reacting for 10 hours. Here, the compounding ratio of the polymerizable vinyl group-containing aqueous silica dispersion and the polymerizable unsaturated monomer is not strictly limited, but in general, the former ratio: the latter ratio is 10: solid weight ratio. 90 to 90:10, preferably 10:90 to 70:30. The former aqueous silica dispersion is 10
If it is less than 100%, the hydrophilizing effect of the hydrophilic treatment composition is generally not sufficient, and if it exceeds 90%, the film-forming property tends to decrease.

The curing agent (B) used in combination with the thus obtained organic-inorganic composite reactant (A) is a curing agent having a functional group capable of undergoing a crosslinking reaction with the hydroxyl group in the organic-inorganic composite reactant. Agents can be used. Typical examples are amino resins such as melamine resin, urea resin and guanamine resin; polyisocyanate having two or more isocyanate groups is blocked with phenol, cresol, aromatic secondary amine, tertiary alcohol, lactam, oxime, etc. A block polyisocyanate compound obtained by the following: organic coordinating alkoxide compound (chelate compound) of an element selected from titanium (Ti), zirconium (Zr) and aluminum (Al), and the like. They can be used alone or in combination of two or more.

In the present invention, the mixing ratio of the organic-inorganic composite reaction product (A) and the curing agent (B) is not particularly limited, but (A) :( B) is 99-50 in terms of solid content weight ratio. : 1
˜50, and more preferably 90 to 70:10 to 30. If the amount of the curing agent is less than 1%, crosslinking and curing of the hydrophilic treatment composition will be insufficient, and the water resistance of the resulting coating will tend to be poor. On the other hand, when the amount of the curing agent exceeds 50%, it tends to cause a decrease in water wettability of the obtained coating film and an increase in the contact angle with water.

In the hydrophilic treatment composition of the present invention, a hydroxyl group-containing polyester resin (C) is blended for the purpose of improving the wettability of the resulting coating film and reducing the contact angle with water.

The hydroxyl group-containing polyester resin (C) is a mono- or polyether diol (hereinafter, abbreviated as "polyether diol") having two hydroxyl groups in one molecule as a polyhydric alcohol component and one molecule. Inside 3
A mono- or polyether polyol having one or more hydroxyl groups (hereinafter, this is abbreviated as “polyether polyol”) is used, and a C _{3 to} C ₉ aliphatic dibasic acid and / or a fat is used as a polybasic acid component. It is obtained by condensation using a cyclic dibasic acid.

The polyether diol has one or more ether bonds in the molecule, preferably 1 to 200, more preferably 1 to 100, and each of the ends of the main chain of the molecule has a primary or secondary bond. It is a chain compound having a hydroxyl group. Specifically, the following general formula (VII):

[0037]

[Chemical 5] Polyethylene glycol represented by

General formula (VIII):

[0039]

[Chemical 6]

Polypropylene glycol represented by
As a constituent unit formula,

[0041]

[Chemical 7]

And the above unit formulas (IX) and (X) may be repeated individually or mutually, and the unit formula (I)
Examples include polyethylene-propylene glycol in which the sum of (X) and (X) is n.

N in the above general formulas (VII) and (VIII) and the total number of unit formulas (IX) and (X), n is 2 to 20.
It is an integer of 0, preferably 2 to 100. If the value of n is less than 2, a coating film having excellent hydrophilicity cannot be formed.
If it exceeds 0, water resistance and corrosion resistance are deteriorated, which is not preferable.

As the type of hydroxyl group possessed by the polyether diol, a primary hydroxyl group is preferable from the viewpoint of easiness of synthesis of the hydroxyl group-containing polyester resin.

The polyether polyol has one or more ether bonds in one molecule, preferably 1 to 600, more preferably 3 to 300, and a branched chain having 3 or more hydroxyl groups in one molecule. It is a chain compound. If the number of ether bonds is less than 1, a film having excellent hydrophilicity cannot be formed. Further, if the number exceeds 600, water resistance, corrosion resistance and the like decrease, so it is preferable to set it within this range.

As the polyether polyol, for example, one obtained by addition polymerization of a cyclic ether using a polyhydric alcohol having a valence of 3 or more as a raw material can be used.

The trihydric or higher polyhydric alcohol has three or more hydroxyl groups in the molecule capable of polymerizing with a cyclic ether, and specific examples thereof include glycerin, trimethylolpropane, trimethylolethane, diglycerin and triglycerin. , 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol and the like. Among the above, trimethylolpropane, trimethylolethane, glycerin, pentaerythritol and the like are preferable. The above polyhydric alcohol is 1
They can be used alone or in combination of two or more.

The cyclic ether is a compound having one ether bond in the cyclic structure, and specific examples thereof include ethylene oxide, propylene oxide and butylene oxide. These can be used alone or in combination of two or more. Of these, ethylene oxide and propylene oxide are preferable.

Specific examples of the polyether polyol include, for example, the general formula (XI):

[0050]

[Chemical 8]

An ethylene oxide or propylene oxide addition polymer of trimethylolethane represented by the general formula (XII):

[0052]

[Chemical 9]

An ethylene oxide or propylene oxide addition polymer of trimethylolpropane represented by the general formula (XIII):

[0054]

[Chemical 10]

An ethylene oxide or propylene oxide addition polymer of glycerin represented by the general formula (XIV):

[0056]

[Chemical 11]

Pentaerythritol ethylene oxide or propylene oxide addition polymers represented by the following are preferable examples.

In the general formulas (XI) to (XIV), n ₁ ,
n ₂ , n ₃ and n ₄ are each an integer of 1 to 200, preferably an integer of 1 to 100. Then, the total number of n ₁ ~n ₃ and n ₁ ~n ₄ is 1 to 200, respectively.

On the other hand, the polybasic acid component is a saturated or unsaturated aliphatic dibasic acid or alicyclic dibasic acid having two carboxyl groups in one molecule or one acid anhydride group in one molecule. Is.

The dibasic acid is represented by the following general formula (XV): HOOC C _n H _2n COOH (XV) (n represents an integer of 1 to 7, preferably 1 to 4), for example, malonic acid. Saturated succinic acid, glutaric acid, adipic acid, suberic acid, and other saturated aliphatic dibasic acids and their anhydrides (such as succinic anhydride);
(XVI): HOOC C _n H _2n-2 COOH (XVI) (n is an integer of 1 to 7, preferably 1 to 4), for example, unsaturated aliphatic such as fumaric acid or itaconic acid Dibasic acids and their anhydrides (such as maleic anhydride); and alicyclic dibasic acids such as tetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 3-methyltetrahydrophthalic acid and the like Anhydrous and the like are included.

If the carbon number n of the above polybasic acid exceeds 7, a coating film having excellent hydrophilicity cannot be formed.

The hydroxyl group-containing polyester resin (C) used in the present invention is produced by subjecting the polyhydric alcohol component and an aliphatic dibasic acid or an alicyclic dibasic acid to an esterification reaction.

In the esterification reaction of the polyhydric alcohol component and the dibasic acid component, the mixing ratio of both components is 15 to 85% by weight, preferably 20% by weight of the polyhydric alcohol component.
The amount of the dibasic acid component is 15 to 85% by weight, preferably 25 to 80% by weight, relative to 75% by weight. When the proportion of the polyhydric alcohol component is more than 85% by weight and the proportion of the dibasic acid component is less than 15% by weight, the water resistance and corrosion resistance of the hydrophilic composition are deteriorated, while the proportion of the polyhydric alcohol component is Is less than 15% by weight, and the proportion of the dibasic acid component is more than 85% by weight, the hydrophilicity decreases, which is not preferable. Further, the mixing ratio of the polyether diol and the polyether polyol in the polyhydric alcohol component is
A suitable range is 5 to 70% by weight, preferably 10 to 60% by weight, based on 30 to 95% by weight, preferably 40 to 90% by weight, of polyether diol. 30% by weight of polyether diol
, And the proportion of polyether polyol is 70
If the amount exceeds 100% by weight, the production stability of polyester decreases,
On the other hand, if the proportion of the polyether diol exceeds 95% by weight and the proportion of the polyether polyol is less than 5% by weight, the hydrophilicity of the hydrophilic composition and the like decrease, which is not preferable.

In the hydroxyl group-containing polyester resin (C) used in the present invention, a polyhydric alcohol other than the above-mentioned polyether diol and polyether polyol can be blended as the polyhydric alcohol component, if necessary. Examples of the polyhydric alcohol component include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, butylene glycol, pentanediol, dimethylpropanediol, hexanediol, hydrogenated bisphenol A, cyclohexanedimethanol, trimethylene glycol and tetra. Methylene glycol, hexamethylene glycol, trimethylolethane, trimethylolpropane, glycerin, diglycerin, dipentaerythritol, sorbitol, diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, cyclohexyldiisopropanolamine, methyldiethanolamine, methyldi Isopropanol amine etc. can be mentioned.

Further, in the hydroxyl group-containing polyester resin (C) used in the present invention, a polybasic acid other than the above-mentioned aliphatic or alicyclic dibasic acid can be blended as a polybasic acid component, if necessary. . Examples of the polybasic acid component include aliphatic saturated dibasic acids such as azelaic acid, sebacic acid, dodecynylsuccinic acid and their anhydrides.
Aromatic polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid and their anhydrides, methylcyclohexene tricarboxylic acid, het acid, tetrachlorophthalic acid, hexahydrotrimellitic acid and these Alicyclic polybasic acids such as anhydrides are included.

In the hydroxyl group-containing polyester resin (C) used in the present invention, a monobasic acid other than a fatty acid, such as benzoic acid or P-, is used depending on the adjustment of the molecular weight and the required coating film performance.
Aromatic monobasic acids such as tert-benzoic acid can be included.

The hydroxyl group-containing polyester resin (C) is used under the same conditions as in the production of ordinary polyester resins, for example, 15
It is produced by reacting at 0 to 250 ° C. for 1 to 15 hours. The hydroxyl group-containing polyester resin is 30 to 2
It preferably has a hydroxyl value of 50, preferably 30 to 200. If the hydroxyl value is less than 30, the crosslink density of the coating of the hydrophilic treatment composition will be low, and it will be difficult to obtain a hydrophilic coating having excellent durability. On the other hand, if the hydroxyl value is greater than 250, the water resistance of the coating will be reduced.

The hydroxyl group-containing polyester resin (C) is about 500 from the viewpoint of the durability and hydrophilicity of the film.
~ 20,000, preferably about 1,000 to 15,000
It is advantageous to have an average molecular weight in the range 0. Furthermore,
The polyester resin may contain a carboxyl group as required, and the content thereof is, for example, in the range of an acid value of about 300 or less.

Since the hydroxyl group-containing polyester resin (C) thus obtained forms a linear structure having an ether bond by the reaction of the polyether diol component and the aliphatic or alicyclic dibasic acid component, the hydrophilicity of the coating film is improved. Excellent in
In addition, since a branched structure having an ether bond is formed by the reaction between the polyether polyol component and the aliphatic or alicyclic dibasic acid component, it is presumed that the action of improving the hydrophilic durability of the coating is exerted. . Furthermore, the ether bond contained in the resin imparts hydrophilicity, is chemically stable, and is not hydrolyzed, so that the hydrophilicity of the coating film can be maintained for a long period of time. Further, the dibasic acid component used in combination with the polyether diol and the polyether polyol is an aliphatic dibasic acid or an alicyclic dibasic acid having a relatively small number of carbon atoms, and since it itself has relatively high hydrophilicity. It has a good effect on the hydrophilicity of the coating.

The mixing ratio of the above-mentioned component (C) is 5 to 60% by weight in terms of solid content in the composition consisting of the organic-inorganic composite reaction product (A), the curing agent (B) and (C), preferably. 10
It is necessary to blend in the range of -40% by weight.
When the proportion of the component (C) is less than 5% by weight, the hydrophilicity of the coating becomes insufficient, while when it exceeds 60% by weight, the water resistance of the obtained coating is lowered, and swelling and dissolution of the coating occur, which is not preferable. .

In the hydrophilic treatment composition of the present invention, a pyrithione-based anti-fouling agent is used for the purpose of imparting antibacterial and antifungal properties to the resulting coating, and at the same time, improving the wettability of the coating and reducing the contact angle with water. A fungus / mold inhibitor (D) is added. Antibacterial
Various types of antifungal agents are known, and the heat-drying temperature of the water-insoluble and hydrophilic treatment composition is 150.
The pyrithione type antibacterial / antifungal agent is most suitable because it is excellent in heat stability at 200 ° C and antibacterial / antifungal properties.

The pyrithione antibacterial / antifungal agent (D) is a compound represented by the following general formulas (XVII) and (XVIII).

[Chemical 12] (In the formula, M represents Na, Mg, or Zn, and n is a number corresponding to the valence of M.)

[Chemical 13] Among the compounds represented by the above general formula, zinc pyrithione having the following structural formula, that is, bis- (2-pyridylthio-1-oxide) zinc, is preferable because it is water-insoluble and excellent in thermal stability.

[Chemical 14]

The compounding amount of the component (D) is 3 with respect to 100 parts by weight of the total solid content of the organic-inorganic composite reactant (A), the curing agent (B), and the hydroxyl group-containing polyester resin (C). -50 parts by weight, preferably 10-30 parts by weight. When the amount of the component (D) is less than 3 parts by weight, sufficient antibacterial and antifungal properties cannot be obtained. On the other hand, when the amount of the component (D) exceeds 50 parts by weight, the brittleness of the obtained coating increases and the adhesion to the fin material is increased. It is not preferable because it decreases.

When the component (D) is blended, it is desirable to disperse it in advance to a particle size of 10 μm or less, preferably 5 μm or less. By doing so, a film obtained by the fine particles of the component (D) is obtained. Minute irregularities are generated on the surface, and the irregularities on the surface improve the wettability of the coating film and further reduce the contact angle with water.

When the heat exchanger fins are subjected to dip coating using a surface treatment bath having a solid content concentration of 2 to 30% by weight, which comprises the hydrophilic treatment composition composed of the components (A) to (D) described above, pyrithione is used. Stable dispersion of the antibacterial / antifungal agent (D) without aggregation or settling is required from the viewpoint of performance and workability of the coating, and the defoaming property and defoaming duration of the bath liquid are required. The performance is also a performance that is particularly required for practical use.

In the present invention, the stable dispersion of the component (D),
A specific silicone emulsion (E) is added for the purpose of breaking the bath liquid.

The silicone-based emulsion (E) was prepared by dispersing fine silica in silicone oil to obtain a silicone compound and adding the compound of the general formula R ₁ OCOCH ₂ CH ₂ O.
A nonionic ethylene glycol fatty acid ester represented by COR ₂ (R ₁ and R ₂ represent a C _13-19 alkyl group) was added to form an emulsion. The fine silica added to the silicone oil may be either dry silica or wet silica known as a silica-based filler, and the particle diameter is preferably 0.1 μm or less. For example, Aerosil (product name of Nippon Aerosil Co., Ltd.),
Cabosil (trade name of Cabot Corporation in the United States) and the like are exemplified. The amount of finely divided silica added is silicone oil 100.
It is 5 to 30 parts by weight with respect to parts by weight. By adding 5 to 20 parts by weight of nonionic ethylene glycol fatty acid ester to 100 parts by weight of the silicone compound and emulsifying the resulting silicone compound, the present invention has excellent stability and extremely good water dispersibility. The silicone emulsion (E) used is obtained.

The amount of the silicone emulsion (E) blended is such that the organic-inorganic composite reaction product (A), the curing agent (B), the hydroxyl group-containing polyester resin (C), and the pyrithione antibacterial and antifungal agent (D). The solid content is 0.3 to 3 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight.

In the case of dip coating in a surface treatment bath having a solid content concentration of 2 to 30% by weight, which is composed of the hydrophilic treatment composition composed of the components (A) to (D), the component (E) is added in the above-mentioned blending amount. By adding it, the pyrithione antibacterial / antifungal agent (D) can be stably dispersed, and the defoaming property and defoaming durability of the bath liquid can be obtained. It is considered that this is due to the excellent foam-breaking property of the silicone compound and the stable dispersibility of the pyrithione-based antibacterial / antifungal agent due to the presence of the ethylene glycol fatty acid ester.

In the hydrophilic treatment composition of the present invention, in addition to the components (A), (B), (C), (D) and (E) described above, known surfactants, antifoaming agents and alcohols are further added. A system solvent, a pH adjuster (acid, alkali) and the like can be contained as necessary.

The hydrophilizing composition of the present invention is applied to a plastic film or molded product, a ceramic molded product, a concrete structure, a container, etc. in addition to hydrophilizing fins to form a film for preventing dew condensation and preventing snow and ice. It can also be used as an agent.

In the method for hydrophilizing a heat exchanger fin using the composition of the present invention, first, the composition is appropriately adjusted to a concentration suitable as a hydrophilizing agent for an aluminum fin,
It is carried out by applying it to a heat exchanger fin molded by a conventional coating method such as dip coating, shower coating, spray coating, roll coating, and then heating and drying.

Of the above-mentioned hydrophilic treatment methods, dip coating is particularly suitable. When the hydrophilic treatment is carried out by such a dip coating method, the solid content concentration of the hydrophilic treatment composition is usually 2 to.
An aqueous bath adjusted to a range of 30% by weight, preferably 5 to 10% by weight, in which a preformed and assembled aluminum heat exchanger fin is immersed and pulled up, then appropriate baking conditions, For example, it can be performed by baking at 120 to 200 ° C. for 10 to 30 minutes.

The hydrophilic treatment method of the present invention forms a practical hydrophilic film even when applied to fins that have been degreased and washed only. Chromate phosphate treatment, which is a surface treatment,
Alternatively, it is preferable to apply chromic acid chromate treatment or the like after applying, from the viewpoint of forming a hydrophilic coating having excellent corrosion resistance.

The hydrophilic film thus formed has a thickness of 0.2 to 5 μm, preferably 0.5 to 3 μm.
If the film thickness is less than 0.2 μm, the hydrophilicity is insufficiently maintained, while if it exceeds 5 μm, the heat dissipation efficiency of the fins may decrease.

[0086]

The hydrophilic treatment composition of the present invention mainly comprises an organic-inorganic composite reaction product having an inorganic silica fine powder dispersed in water as a core and a copolymer of organic monomers as a shell. By adding a curing agent and a hydroxyl group-containing polyester resin to this as a component, excellent hydrophilic durability (overall wettability and a contact angle with water of 20 ° or less), which has been a problem in the past, is excellent. Since it has a good thermosetting property, there is almost no water elution from the coating film, and as a result, a coating film having an extremely small odor can be formed. Furthermore, by adding a pyrithione-based antibacterial / antifungal agent, in order to impart an excellent antibacterial / antifungal function to the film, bacteria over time,
Odor and hygiene problems caused by mold can be solved all at once, and in addition, to increase the surface roughness of the coating,
The hydrophilicity can be further improved. Further, by incorporating a silicone-based emulsion, the stable dispersion of the pyrithione-based antibacterial / antifungal agent and the defoaming property of the bath solution can be satisfied at the same time, and the present invention has excellent coating performance and surface treatment workability. The fin formed by the hydrophilization treatment method using the above composition is very excellent in hydrophilicity and corrosion resistance, and exerts a remarkable effect of suppressing the generation of odor in the initial stage and with the passage of time.

[0087]

EXAMPLES Examples and comparative examples will be shown below. These examples are intended to explain the invention in more detail,
It does not impose any limitation on the present invention. "Parts" and "%" indicate "parts by weight" and "% by weight".

Synthesis of Organic-Inorganic Composite Reactant (A) Synthesis Example 1 333 parts of deionized water and 166 parts of isopropyl alcohol are placed in a 1-liter four-necked flask equipped with a thermometer, a stirrer, a condenser and a dropping funnel. was placed, with stirring "Kyataroido S-20L" (catalyst chemical Industries Ltd., aqueous colloidal silica dispersion, SiO ₂ content 20%) 166 parts,
Then γ-methacryloxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., trade name "KBM-503")
0.3 part was added dropwise, heated to about 70 ° C., and kept at the same temperature for 2 hours to obtain an aqueous dispersion of an aqueous silica dispersion. The following formulation solution was added dropwise to this solution over about 3 hours with sufficient stirring.

Acrylamide 13.4 parts N-methylol acrylamide 6.7 parts 2-Hydroxyethyl methacrylate 26.8 parts Polyethylene glycol monomethacrylate 20.1 parts Ammonium persulfate 1.7 parts Deionized water 266 parts About 80 after the dropping. Hold at ℃ for about 2 hours to react.
A milky white organic-inorganic composite reactant aqueous dispersion having a solid content of 10% was obtained.

Synthesis Examples 2 to 5 Synthesis Example 1 except that the composition of each component is as shown in Table-1.
In the same manner as above, an aqueous dispersion of the organic-inorganic composite reaction product was obtained. In addition, the compounding amount of Table 1 is a solid content in parts by weight.

[0091]

[Table 1]

Synthesis of Hydroxyl Group-Containing Polyester Resin (C) Synthesis Example 6 Polyethylene glycol 200 (weight average molecular weight 20
0) A mixture of 28.8 parts, 51.1 parts by weight of a 10-mole ethylene oxide adduct of glycerin, 20.1 parts of maleic anhydride and 3 parts of xylene was stirred at 160 to 230 ° C. in a nitrogen gas atmosphere while stirring. After reacting for about 8 hours, a polyester resin was obtained. Regarding the resin, the hydroxyl value was 128, the acid value was 30, and the polybasic acid component / polyhydric alcohol component (molar ratio) was 0.85.

Synthesis Example 7 Polyethylene glycol 400 (weight average molecular weight 40
0) 51.7 parts, 29.5 parts of a 20-mole propylene oxide adduct of pentaerythritol, adipic acid 18.
A mixture of 8 parts and 3 parts of xylene was prepared as in Synthesis Example 6 above.
A polyester resin was prepared by reacting in the same manner as in. With respect to the resin, the hydroxyl value was 74, the acid value was 20, and the polybasic acid component / polyhydric alcohol component (molar ratio) was 0.85.

Synthesis Example 8 Polypropylene glycol 200 (weight average molecular weight 20
0) A mixture of 27.4 parts, 45.8 parts of a 15 mol adduct of trimethylolethane with ethylene oxide, 268 parts of tetrahydrophthalic anhydride and 3 parts of xylene was reacted in the same manner as in Synthesis Example 6 to give a polyester resin. Created. With respect to the resin, the hydroxyl value was 117, the acid value was 60, and the polybasic acid component / polyhydric alcohol component (molar ratio) was 0.9.

Synthesis Example 9 Polyethylene glycol 400 (weight average molecular weight 40
0) A mixture of 70.2 parts, pentaerythritol 4.2 parts, adipic acid 25.6 parts and xylene 3 parts was reacted in the same manner as in Synthesis Example 6 to prepare a polyester resin for a comparative example.

Synthesis Example 10 A mixture of 26.7 parts of ethylene glycol, 10.4 parts of pentaerythritol, 62.9 parts of adipic acid and 3 parts of xylene was reacted under the same conditions as in Synthesis Example 6 to obtain a polyester resin for comparison. Created.

Example 1 500 parts of an organic-inorganic composite reaction product aqueous dispersion having a solid content of 10% obtained in Synthesis Example 1 was treated with 70% solid content to obtain "Nikalac M".
S-20U "(manufactured by Sanwa Chemical Co., Ltd., water-soluble urea resin liquid)
21.4 parts, 25 parts of the polyester resin obtained in Synthesis Example 6,
20 parts of a 50% aqueous dispersion of zinc pyrithione was added under stirring, then 1.5 parts of "BYK-080" (manufactured by BYK Chemie, silicone emulsion) was added, and after stirring well, the solid content was further diluted with water. A hydrophilic treatment composition of 7% was obtained.

Then, the aluminum plate (A-1050, plate thickness 0.1 mm) was heated to 70 ° C. After soaking in an acidic liquid (10% sulfuric acid, 5% nitric acid aqueous solution) for 3 minutes, 50 with a chromate treatment agent (manufactured by Nippon Parker Rising Co., Ltd., trade name "Alodine 407" and "Alodine 47" mixed solution) It was immersed at 90 ° C. for 90 seconds to carry out chromate treatment (chromium conversion adhesion amount 120 mg / m ² ).
Then, this is used as an article to be coated by dip coating so as to have a dry film thickness of 1 μm in the above hydrophilic treatment composition solution.
The coating was formed by baking at 0 ° C. for 20 minutes.

The hydrophilically treated plate thus obtained was tested for hydrophilicity, corrosion resistance, antibacterial property and the like. The test results are shown in Table 3.

Examples 2 to 7 and Comparative Examples 1 to 4 In the same manner as in Example 1 except that the formulations shown in Table 2 were used, a hydrophilic treatment composition having a solid content of 7% was obtained. To form a hydrophilic treatment film. The blending amount in Table 2 is the solid content.

The obtained hydrophilized plate was tested in the same manner as in Example 1, and the test results are shown in Table 3. Next, the hydrophilic treatment composition solution having a solid content of 7% was tested for the sedimentation state of the antibacterial / antifungal agent and the defoaming property, and the test results are shown in Table 4.

[0102]

[Table 2]

[0103]

[Table 3]

[0104]

[Table 4]

The test method in Table 3 was carried out by the following method.

(* 1) Water wettability: The water wettability was evaluated by the water wetted area ratio when the test plate was immersed in tap water for 30 seconds and pulled up.

◎: 100% wetted area rate ○: 〃 90 to less than 100% △: 〃 50 to less than 90% ×: 〃 less than 50%

(* 2) Contact angle: about 0.03 cc on the test plate
Water droplets of deionized water are formed, and the contact angle of the water droplets at 20 ° C is measured by Kyowa Kagaku Co., Ltd.
It was measured with a mold. Note that the water wettability and contact angle were determined by immersing the initial test plate and tap water in running water for 500 hours and pulling it up.
The test piece was immersed in running water for 24 hours in an environment of 20 ° C., 75% R, H and was also tested.

(* 3) Corrosion resistance: JIS Z 2371 salt spray test The area ratio of white rust generation on the flat surface after 300 hours was evaluated.

◎: White rust occurrence area ratio less than 1% ○: 〃 less than 1 to 10% △: 〃 less than 10 to 30% ×: 〃 more than 30% (* 4) Antibacterial property: According to JIS-Z-2911 . The mixed spore suspension of the test bacteria described below was sprayed onto each coated plate and allowed to stand at a temperature of 27 ° C. for 28 days, after which the degree of mold growth on the coated plate surface was visually observed. The case where no mold was generated or adhered on the coated surface was evaluated as good (○). The occurrence of mold on the painted surface,
The state in which there was adhesion was regarded as poor (x).

Aspergillus Penicillium Alternaria Cladosporium Mixture of

(* 5) Impact resistance: A DuPont type impact tester was used, and a weight of 500 g was applied to a 1/2 inch diameter impact core at 30 cm.
The state of the coating film when dropped from the height of was evaluated.

○: No abnormality ×: Cracks occurred

The test method in Table 4 was carried out by the following method.

(* 6) Sedimentation property of antibacterial / antifungal agent: 100 ml of the treatment liquid was placed in a glass 100 ml measuring cylinder, tightly capped, and allowed to stand at 30 ° C. for 5 days, and then the sedimentation state was examined.

◯: There is no sedimentation and the transparent liquid volume is within 10 ml from the upper part. (Triangle | delta): Some sedimentation is recognized and 30-50 ml of liquid has transparency. X: Most of the antibacterial / antifungal agents settle out, and 90 ml or more of the liquid is transparent.

(* 7) Defoaming property: 100 ml of the treatment liquid was dropped through a hole having a diameter of 4 mm into a measuring cylinder 1 m below, and the time until the bubbles generated at that time disappeared was measured.

◯: Completely disappears in 0 to 20 seconds. (Triangle | delta): It disappears completely in 40 to 60 seconds. X: It takes 3 minutes or more.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C08L 67:02 83:04) (72) Inventor Tatsuyuki Kinoshita 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya Mitsubishi Heavy Industry Co., Ltd. Nagoya Research Institute (72) Inventor Masateru Masachi, Aichi Prefecture Nishi Kasugai-gun, Nishibiwajima-cho, Asahi-cho 3 chome 1 No. 1 in Kansai Paint Co., Ltd. (72) Yutaka Inoue 4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture Kansai Paint Co., Ltd. (72) Hiromi Haragawa 4-171, Higashi-Hachiman, Hiratsuka City, Kanagawa Prefecture Kansai Paint Co., Ltd.

Claims (4)

[Claims] 1. A polymerizable vinylsilane monomer 0.1 to 10 containing (ii) a hydrolyzable alkoxysilane group, based on 100 parts by weight of (A) (i) water-dispersible silica (solid content).
An organic-inorganic composite reaction product obtained by reacting a polymerizable vinyl group-containing aqueous silica dispersion obtained by reacting at a ratio of parts by weight with (iii) a polymerizable unsaturated monomer other than (ii), (B) A hydrophilic treatment composition comprising a curing agent, (C) a hydroxyl group-containing polyester resin, (D) a pyrithione-based antibacterial / antifungal agent, and (E) a silicone-based emulsion. 2. A method for coating an aluminum heat exchanger fin with an aqueous dispersion or aqueous solution of the hydrophilic treatment composition according to claim 1 having a solid content concentration of 2 to 30% by weight, followed by heating and drying. Hydrophilic treatment method for heat exchanger fins. 3. A method for hydrophilizing a heat exchanger fin, wherein the coating of the hydrophilizing composition is dip coating. 4. A heat exchanger fin made of aluminum, characterized in that the composition according to claim 1 is applied to the surface thereof.