JPH11349893A - Coating composition capable of forming planing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating compsn. suitable for coating an aluminum fin material by incorporating a specific hydroxylated vinyl polymer, a specific epoxy-terminated siloxane polymer, a specific crosslinker, and a specified amt. of a sulfonic acid compd. into the same. SOLUTION: This compsn. contains a hydroxylated vinyl polymer obtd. by the copolymn. of a hydroxylated vinyl monomer and other copolymerizable unsatd. monomers; an epoxy-terminated siloxane polymer represented by the formula; a sulfonic acid compd. (e.g. methanesulfonic acid); and a crosslinker comprising an optionally blocked polyisocyanate compd. and/or a melamine resin in an equivalent ratio of the epoxy groups of the siloxane polymer to the sulfo groups of the sulfonic acid compd. of (1/1)-(10/1). In the formula, the mean value of m is 6-150; n is 0-6; and R<1> is a 1-6C alkyl. Thus are obtd. such advantages that the growth of mildew on the surface of a fin and the freezing in winter can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition capable of forming a water-slidable film from which attached water droplets can easily slide off, and a method for coating an aluminum fin material using the coating composition.

[0002]

2. Description of the Related Art
As aluminum fins for heat exchangers such as air conditioners, fins with a hydrophilic coating have been put into practical use.
In this fin, it is known that water condensed during cooling does not form a water droplet bridge between the fins, and is excellent in heat exchange efficiency.

[0003] However, the fin having a hydrophilic coating film easily retains water on the surface, so that mold is easily generated on the surface of the fin. In winter, when the temperature falls to 0 ° C. or lower, frost on the fin surfaces of the heat exchanger of the outdoor unit freezes, which grows and lowers the heat exchange efficiency.

Further, in order to make the surface of the aluminum fin of the heat exchanger hard to wet, that is, to impart water repellency, the surface may be coated with a hydrophobic material such as a silicone resin, a fluorine-based resin, or a polyolefin-based resin. Are being considered. When water adheres to a surface coated with a hydrophobic material, the water is repelled into spherical water droplets.Large water droplets fall under their own weight, while small water droplets remain attached to the surface and tilt the attached surface vertically. The phenomenon that it does not fall is often seen.

[0005] Therefore, various studies have been made on the development of highly hydrophobic materials that make it easy to roll off attached water droplets by increasing the contact angle with water by increasing the hydrophobicity of the surface as much as possible. Further, a physical method for forming a roughened surface or a hairy projection on the surface has been studied.

[0006] However, the above-mentioned proposed hydrophobic materials and hydrophobic methods are insufficient in the ease of falling of water droplets, have poor mechanical properties, and are difficult to form. However, no practical one has been found.

[0007] The inventors of the present invention have found that, in a fin on which a hydrophilic coating film is formed without forming a water droplet bridge between the fins, generation of fungi due to moisture adhering to the coating film and the fin surface in winter. The present inventors have intensively studied to obtain a coating composition capable of forming a film capable of solving the icing of the above, and a coated aluminum fin using the composition.

As a result, a hydroxyl group-containing vinyl polymer,
The present invention has been completed by finding that a coating composition containing a specific epoxy-terminated siloxane polymer, a sulfonic acid compound, and a crosslinking agent component can form a film in which water droplets are easily tumbled and the above object can be achieved, and the present invention has been completed. .

[0009]

That is, the present invention provides:
(A) a hydroxyl group-containing vinyl polymer obtained by copolymerization of a hydroxyl group-containing vinyl monomer and another unsaturated monomer copolymerizable therewith, (B) the following formula (1)

[0010]

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(Wherein, the average number of m is from 6 to 150,
n is a number of 0 to 6, and R ¹ is an alkyl group having 1 to 6 carbon atoms), (C) a sulfonic acid compound and (D) a blocked siloxane polymer. Containing at least one crosslinking agent component selected from a polyisocyanate compound and a melamine resin,
The amount of the sulfonic acid compound (C) is such that the equivalent ratio of the epoxy group in the epoxy-terminated siloxane polymer (B) / the sulfonic acid group in the sulfonic acid compound (C) is 1/1 to 10/1.
And a coating composition capable of forming a water-slidable film.

Further, the present invention is characterized in that the above-mentioned coating composition is applied on an aluminum fin material with or without a primer coating film to form a water-sliding film as an uppermost coating film. An object of the present invention is to provide a method of coating an aluminum fin material.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A coating composition capable of forming a water-slidable film of the present invention will be described in detail below.

The coating composition capable of forming the water-sliding film of the present invention (hereinafter, may be abbreviated as “water-sliding composition”) is
A hydroxyl group-containing vinyl polymer (A), an epoxy-terminated siloxane polymer (B), a sulfonic acid compound (C),
It is a coating composition containing a crosslinking agent component (D) as an essential component.

Hydroxyl-containing vinyl polymer (A) The hydroxyl-containing vinyl polymer (A) in the present invention comprises a hydroxyl-containing vinyl monomer and other unsaturated monomers copolymerizable with this monomer (hereinafter referred to as "other monomers").
(May be abbreviated as).

Examples of the hydroxyl group-containing vinyl monomer used for producing the hydroxyl group-containing vinyl polymer (A) include hydroxyl group-containing vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxypentyl vinyl ether, and hydroxyhexyl vinyl ether. s; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, hydroxybutyl acrylate, C ₂ -C ₁₂ acrylic acid or methacrylic acid such as 2-hydroxybutyl methacrylate
-Alkyl esters and the like.

Other monomers copolymerized with the hydroxyl group-containing vinyl monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate,
C1-C1 such as propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, and dodecyl (meth) acrylate
(Meth) acrylic acid alkyl esters having an alkyl group of 18; alkyl groups such as methyl, ethyl, propyl, n-butyl, isobutyl, hexyl, octyl, decyl, and lauryl; and fatty acids such as cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and bornyl Vinyl ethers having a cyclic group; aromatic vinyl monomers such as styrene and α-methylstyrene; hexafluoropropene, tetrafluoroethylene, monochlorotrifluoroethylene,
Fluoroolefins such as dichlorodifluoroethylene, 1,2-difluoroethylene, vinylidene fluoride and monofluoroethylene; perfluorobutylethyl (meth)
Acrylate, perfluoroisononylethyl (meth)
Perfluoroalkyl (meth) acrylates such as acrylate and perfluorooctylethyl (meth) acrylate; Silaprene FM-0701 and FM-071
1. Polymerizable unsaturated compounds having a dimethyl silicon chain, such as FM-0721 and FM-0725 (all of which are manufactured by Chisso Corporation); carboxyl groups such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid Containing polymerizable unsaturated monomer; glycidyl (meth) acrylate,
Epoxy group-containing polymerizable unsaturated monomers such as 3,4-epoxycyclohexylmethyl (meth) acrylate; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl laurate, vinyl versatate, and cyclohexanecarboxylic acid Vinyl esters such as vinyl acid; and α-olefins such as ethylene, propylene, isobutylene and butene-1. The other monomer preferably contains a fluoroolefin as a part thereof.

In the hydroxyl group-containing vinyl polymer (A), the copolymerization ratio of the hydroxyl group-containing vinyl monomer and the other monomer is generally desirably within the following range based on the total amount of both.

Hydroxyl-containing vinyl monomer: 1 to 80 mol%, particularly 5 to 70 mol%, and other monomers: 20 to 99 mol%, especially 25 to 95 mol%.

When the other monomer contains a fluoroolefin, the hydroxyl group-containing vinyl polymer (A)
In the above, the copolymerization ratio of the hydroxyl group-containing vinyl monomer, fluoroolefin and other monomer other than fluoroolefin is generally preferably within the following range based on the total amount of the above three.

Hydroxyl-containing vinyl monomer: 1-80 mol%, especially 5-70 mol%, fluoroolefin: 19-80 mol%, especially 25-7
5 mol%, other monomers except fluoroolefin: 1 to 80 mol%, particularly 5 to 70 mol%.

The copolymerization of the above monomers to obtain the hydroxyl group-containing vinyl polymer (A) is usually carried out in an organic solvent.
In the presence of about 0.01 to about 5 parts by weight of the polymerization initiator per 100 parts by weight of the total of the monomer components, from about -20 ° C to about 15
At a temperature of 0 ° C., at normal pressure or optionally about 30 kg / cm
^The reaction can be carried out under a pressure of up to ² G.

As the hydroxyl group-containing vinyl polymer (A), the copolymer obtained as described above is further reacted with a dibasic acid anhydride to introduce a carboxyl group into a part of the hydroxyl group of the copolymer. Modified copolymers can also be used.

The hydroxyl group-containing vinyl polymer (A) thus obtained can have a number average molecular weight in the range of generally 2,000 to 100,000, preferably 5,000 to 60,000. Further, the hydroxyl group-containing vinyl polymer (A) generally contains 30 to 400 mg KOH / g,
It may have a hydroxyl value preferably in the range of 40 to 300 mg KOH / g. Further, it is preferable to have a carboxyl group from the viewpoint of the adhesion of the obtained coating film,
0.1-40 mgKOH / g, further 1-20 mgK
It is preferred to have an acid number in the range of OH / g.

As the hydroxyl group-containing vinyl polymer (A), monochlorotrifluoroethylene,
A modified copolymer obtained by reacting a copolymer of hydroxybutyl vinyl ether and ethyl vinyl ether with a dibasic acid anhydride to introduce a carboxyl group into a part of the hydroxyl groups of the copolymer is preferred.

Epoxy-terminated siloxane polymer (B) The epoxy-terminated siloxane polymer (B) used in the present invention has the following formula (1)

[0027]

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Wherein m represents the average degree of polymerization of the dimethylsiloxane unit, and 6 to 15
0, preferably a number in the range of 6 to 70, and n
Is an integer of 0 to 6, preferably 1 to 5, and R ¹ is an alkyl group having 1 to 6, preferably 1 to 4 carbon atoms.

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ¹ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and hexyl. Among them, methyl group, n-
Butyl groups are preferred.

The siloxane polymer (B) generally contains 53
It may have a number average molecular weight in the range of 0 to 11,400, preferably 540 to 5,500.

Sulfonic acid compound (C) The sulfonic acid compound (C) used in the present invention comprises:
Formula R ² -SO ₃ H (wherein, R ² is an organic residue, for example, represents an aliphatic hydrocarbon group, and an aromatic hydrocarbon group,
The aliphatic hydrocarbon group and the aromatic hydrocarbon group may be optionally substituted by a halogen atom or the like), and specifically, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid , P-toluenesulfonic acid, 2,4- or 2,5-dimethylbenzenesulfonic acid, naphthalene-α-sulfonic acid, naphthalene-β-sulfonic acid and the like, among which methanesulfonic acid is preferred.

Crosslinking Agent Component (D) In the present invention, as the crosslinking agent component for crosslinking and curing the fluoropolymer (A), at least one selected from a polyisocyanate compound which may be blocked and a melamine resin is used. Can be

As the above polyisocyanate compound,
For example, aliphatic, alicyclic or aromatic such as tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, bis (isocyanatomethyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate and diphenylmethane diisocyanate. Polyisocyanate compounds, and isocyanate-terminated prepolymers obtained by reacting excess amounts of these polyisocyanate compounds with low-molecular-weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, trimethylolpropane, hexanetriol, and castor oil. Is mentioned.

These polyisocyanate compounds may be used as they are, or, if necessary, in a form in which isocyanate groups are blocked by a blocking agent.

Examples of the isocyanate blocking agent include phenols such as phenol, m-cresol, xylenol and thiophenol; methanol, ethanol, butanol, 2-ethylhexanol, cyclohexanol,
Alcohols such as ethylene glycol monoethyl ether; oximes such as acetoxime, methyl ethyl ketoxime, benzophenone oxime and cyclohexanone oxime; and active hydrogen-containing compounds such as ε-caprolactam, ethyl acetoacetate and diethyl malonate. Blocking of the polyisocyanate compound using these blocking agents can be performed according to a method known per se.

As the melamine resin, the number of triazine rings is 1 to 5, and the molecular weight is in the range of 300 to 3,000, particularly 500 to 2,000. Or a completely methylolated product, or a partial alkyl etherification in which part or all of the methylol group is further etherified with a monohydric alcohol having 1 to 8 carbon atoms, for example, methanol, ethanol, propanol, n-butanol, isobutanol, or the like. A completely alkyl etherified methylol melamine resin or the like can be used.

Coating capable of forming a water-slidable film according to the present invention
Composition The water-sliding composition of the present invention comprises the above-mentioned hydroxyl-containing vinyl polymer (A), epoxy-terminated siloxane polymer (B), sulfonic acid compound (C) and crosslinking agent component (D).
And an organic solvent as appropriate.

In the water-sliding composition of the present invention, the mixing ratio of the hydroxyl group-containing vinyl polymer (A), the siloxane polymer (B) and the crosslinking agent component (D) is not particularly limited. ) For 100 parts by weight of the components,
It is preferable that the component (B) is in the range of 2 to 30 parts by weight, preferably 2 to 20 parts by weight, and the component (D) is in the range of 4 to 100 parts by weight, preferably 4 to 60 parts by weight. The amount of the sulfonic acid compound (C) is such that the equivalent ratio of the epoxy group in the siloxane polymer (B) / the sulfonic acid group in the sulfonic acid compound (C) is 1/1 to 10/1, and preferably 1.5 to 10/1. It is preferable that the ratio be in the range of / 1 to 8/1.

The epoxy-terminated siloxane polymer (B) and the sulfonic acid compound (C) are liable to react with each other. During the production of the water-sliding composition of the present invention, these are mixed and reacted in advance before mixing with other components. And may be separately mixed with other components. Even if mixed separately, the epoxy-terminated siloxane polymer (B) and the sulfonic acid compound (C) easily react in a short time in the water-sliding composition.

In the water-sliding composition of the present invention, the mixing ratio of the epoxy-terminated siloxane polymer (B) and the sulfonic acid compound (C) is such that the epoxy groups are equivalent to or larger than the sulfonic acid groups. From the epoxy-terminated siloxane polymer (B) and the sulfonic acid compound (C),
An adduct of the siloxane polymer (B) and the sulfonic acid compound (C) and an unreacted epoxy-terminated siloxane polymer (B) are obtained. Although the unreacted sulfonic acid compound (C) may remain, it is preferable that the unreacted sulfonic acid compound (C) is not substantially contained.

When the siloxane polymer (B) and the sulfonic acid compound (C) are mixed and reacted in advance,
The reaction can be performed, for example, by mixing both the siloxane polymer (B) and the sulfonic acid compound (C) at room temperature in the presence of an organic solvent, if necessary. Of course, both may be mixed and heated. As the organic solvent, those capable of dissolving or dispersing the siloxane polymer (B), the sulfonic acid compound (C), and the adduct of the component (B) and the component (C) can be suitably used. Toluene, xylene, cyclohexane, petroleum ether, gasoline, kerosene, naphtha, chloroform, carbon tetrachloride, ethylene dichloride, 2-ethylhexanol, diethyl ether, methyl ethyl ketone,
Examples thereof include methyl isobutyl ketone, isopropyl alcohol, butanol, dioxane, and mineral oil.

As an example of an adduct of the siloxane polymer (B) and the sulfonic acid compound (C), an epoxy group in the siloxane polymer (B) and a sulfonic acid group in the sulfonic acid compound (C) are shown below. Adducts obtained by an equimolar reaction of

[0043]

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As an example of an adduct of the siloxane polymer (B) and the sulfonic acid compound (C), an adduct obtained by further adding the siloxane polymer (B) to the above adduct obtained by the equimolar reaction is shown below. (An adduct of 2 mol of siloxane polymer (B) and 1 mol of sulfonic acid compound (C)).

[0045]

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Further, as an example of an adduct of the siloxane polymer (B) and the sulfonic acid compound (C), the hydroxyl group of the adduct of the siloxane polymer (B) 2 mol and the sulfonic acid compound (C) 1 mol Further, an adduct to which the siloxane polymer (B) is added (an adduct of 3 mol of the siloxane polymer (B) and 1 mol of the sulfonic acid compound (C)) can be considered.

According to the study of the present inventors, the adduct of the siloxane polymer (B) and the sulfonic acid compound (C) is
Although it depends on the raw materials used, the equimolar addition of the siloxane polymer (B) and the sulfonic acid compound (C) is usually determined from the results of gel permeation chromatography (gel permeation chromatography) of both addition products. And optionally a mixture of equimolar and 2 mole to 1 mole adduct.

In the present specification, the composition of the present invention comprises:
The term "containing the components (A), (B), (C) and (D)" means that in the composition of the present invention, the components (B) and (C) are each independently present. It means both the case and the case where the component (B) and the component (C) are present in an adducted state by reacting.

As the crosslinking agent component (D), like a polyisocyanate compound having a free isocyanate group,
In the case of using a polymer which is relatively easily reacted with the hydroxyl group-containing vinyl polymer (A), the water-sliding composition of the present invention comprises a mixture of the components (A), (B) and (C) and the component (C). It is desirable to prepare a two-pack type separated from D) and mix both components immediately before use.

The water-sliding composition of the present invention may optionally contain
Furthermore, for example, organic solvents, coloring pigments, extender pigments, rust-preventive pigments, dyes, fungicides, surfactants, organic solvents, and other additives known per se that are commonly used in paints can be added.

The water-sliding composition of the present invention usually contains an organic solvent for viscosity adjustment and the like. As the organic solvent, those capable of dissolving or dispersing each component of the water-sliding composition of the present invention can be suitably used. Specific examples include, for example, toluene, xylene, cyclohexane, petroleum ether, gasoline, Kerosene, naphtha, petroleum hydrocarbon solvents, chloroform, carbon tetrachloride, ethylene dichloride, 2-ethylhexanol, diethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, isopropyl alcohol, butanol, dioxane, mineral oil, etc. it can.

The water-sliding composition of the present invention thus obtained comprises:
For example, a molded article having a surface with excellent water-sliding property (here, the molded article is formed by injecting into an appropriate mold or applying to an appropriate substrate surface to form a film and then crosslinking and curing the film. Molded articles in the form of a film coated on a substrate).

The water-sliding composition of the present invention may be used as a coating composition, particularly as a glass (for example, a vehicle windshield, a window glass, a window glass, a mirror, etc.), a metal (for example, a glass).
Automobiles, vehicles, aluminum fins, road sign boards, microwave antennas, large water pipes, traffic lights, etc.), plastics (films or sheets for the extension of greenhouses, artificial organs, toilets, washbasins, etc.), inorganic materials (toiletries, It is useful for application to the surface of a substrate such as a bathtub, a roof tile, and wood.

The application of the water-sliding composition of the present invention to these substrates is carried out by a method known per se such as, for example, spray coating, brush coating, roller coating, roll coating, dip coating, curtain flow coater coating and the like. It can be carried out.

The thickness of the applied film can be varied depending on the use of the object to be coated, etc., and is generally 0.5 to 100 μm, particularly 1 to 50 μm, after curing.
The degree is preferred.

The conditions for crosslinking and curing of the water-sliding composition of the present invention are as follows:
It is determined according to the type of the hydroxyl group-containing vinyl polymer (A) and the crosslinking agent component (D) used in the preparation of the composition, and is usually from room temperature to about 300 ° C., preferably from 80 to 300 ° C.
Conditions at a temperature of 250 ° C. for about 15 seconds to 40 minutes can be used.

The surface of the film formed by using the water-sliding composition of the present invention is excellent in water-sliding property. For example, the surface of an object coated with a conventional fluorinated ethylene-based resin is treated with water droplets. Has a contact angle of about 108 degrees, but a mass of 1
Even if the film on which 0 mg of water droplets are placed is tilted at 90 degrees, the water droplets remain stopped and do not fall by their own weight, but the film formed from the water-sliding composition of the present invention has a contact angle of the water droplets of
Usually, it is in the range of about 65 to 85 degrees, and although not so large, the water droplet of 10 mg attached to the film starts to slip under its own weight only by tilting the film at an angle within 30 degrees from the horizontal plane, and falls. It shows excellent slipperiness. Further, when water droplets having a mass of 10 mg adhered to the film formed from the water-sliding composition of the present invention, when the air was blown while keeping the film horizontal, the velocity of the air was 1 m.
Per second or less and can slide down.

Hereinafter, as an example of a method of forming a water-slidable film, a method of forming a water-slidable film on an aluminum fin material using the water-slidable composition of the present invention will be described.

A coated aluminum fin having a water-slidable film as the uppermost film can be produced by coating the above-mentioned water-slidable composition on an aluminum fin material with or without a primer coating film.

Examples of the aluminum fin material include known aluminum fin materials conventionally used as fin materials for heat exchangers, regardless of whether the surface is chemically treated or not. Although a coated aluminum fin having sufficient coating film adhesion and corrosion resistance can be obtained without any treatment, a chemical conversion treatment is preferable when a high degree of coating film adhesion or corrosion resistance is required. The chemical conversion treatment includes a phosphoric acid chromate treatment,
Coating type chromate treatment may be used.

The primer coating for forming the primer coating is not particularly limited as long as it has good coating properties such as adhesion to a fin material and a water-slidable coating, corrosion resistance, workability, etc., and good coating properties. Can be used without. As the primer coating, for example, acrylic-amino resin, epoxy-amino resin, epoxy-urethane resin, polyester-amino resin, acrylic-urethane resin, ethylene-unsaturated carboxylic acid copolymer, ethylene ionomer resin, vinyl chloride resin, etc. Resin-based paints.

The primer paint usually has a dry film thickness of 0.2.
It is coated so as to have a thickness of about 20 μm, preferably about 0.5 to 10 μm, and is cured by baking or the like. Curing conditions can be appropriately set according to the type of coating material, coating method, and the like.

The method of coating the water-sliding composition on the aluminum fin material can be appropriately selected according to the shape of the aluminum fin material. When the aluminum fin material is in the form of a sheet, it can be coated with a roll coater or drawn. A method such as painting is suitable. On the other hand, when the aluminum fin material is molded into a fin and assembled, a method such as dip coating, spray coating, or shower coating is suitable.

The amount of the water-sliding composition to be applied is not particularly limited, but is generally preferably in the range of about 0.5 to 50 μm, especially about 1 to 15 μm in terms of dry film thickness.

When the aluminum fin material is in the form of a sheet, a water-slidable composition is applied on the fin material with or without a primer coating film and cured to form a water-slidable film. Thus, a coated aluminum fin can be manufactured by molding. The method of forming the fin is not particularly limited, and examples thereof include a drawless method using a mold and a draw method. When the aluminum fin material is in the form of a sheet and is continuously coated by roll coating, etc.,
The curing conditions of the water-sliding composition are usually such that the maximum temperature at which the material reaches is 8
The conditions of 0 to 250 ° C and the baking time of about 15 seconds to about 90 seconds are suitable.

When the aluminum fin material is molded into a fin and assembled, the one coated with the water-sliding composition and cured can be used as it is as a coated aluminum fin.

The coated aluminum fin obtained as described above has a water-slidable film from the water-slidable composition of the present invention as the uppermost layer, and the surface shows excellent water-slidability. Even if water droplets adhere to the surface of the painted aluminum fins, they immediately fall off the fin surface, so that the formation of water droplet bridges between the fins can be eliminated, and the fins are suitable as heat exchanger fins.

Thus, the water-sliding composition of the present invention is extremely useful as an object which is less likely to adhere to water droplets or a surface treatment material thereof.

[0069]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Hereinafter, parts and percentages are by weight unless otherwise specified.

Production Example 1 of Hydroxyl-Containing Vinyl Polymer Preparation Example 1 53.8 parts of xylene and 28 parts of methyl isobutyl ketone were charged into a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer and a dropping device, and heated under stirring. And kept at 115 ° C. Next, at the same temperature, “Siraprene FM-071
1 "(manufactured by Chisso Corporation, a monomer containing a polysiloxane chain having a methacryloyl group, molecular weight of about 1,000), 5 parts, 2-
Hydroxyethyl methacrylate 14 parts, styrene 30
, 20 parts of n-butyl methacrylate, 30 parts of isobutyl methacrylate, 1 part of acrylic acid and 4.2 parts of azobisisobutyronitrile were added dropwise over 3 hours. After completion of the dropwise addition, the mixture was aged at 115 ° C. for 2 hours to obtain a hydroxyl group-containing vinyl polymer (A) -1 solution having a nonvolatile content of 55%. The obtained resin had a number average molecular weight of 12,000 and a hydroxyl value of 60 KOHmg / g.

Production Example 2 In Production Example 1, 5 parts of “Silaprene FM-071
In the same manner as in Production Example 1 except that 5 parts of methyl methacrylate was used instead of "1", a hydroxyl group-containing vinyl polymer (A) -2 solution having a nonvolatile content of 55% was obtained. The obtained resin had a number average molecular weight of about 11,000 and a hydroxyl value of 60K.
OH mg / g.

Preparation of Preliminary Reaction Product Preparation Example 3 In 100 parts of toluene, in the above formula (1), R ¹ is n
An epoxy-terminated siloxane polymer having a butyl group, m is 63.9 and n is 5 (epoxy group equivalent weight of about 5,000
98.1 parts in Table 1 (abbreviated as "(B) -1" in Table 1) were mixed, stirred and dissolved. When the mixture became homogeneous, 1.9 parts of methanesulfonic acid was added thereto, and the mixture was stirred at room temperature ( 2
(0 ° C.) for 1 hour to obtain a 50% active ingredient preliminary reaction product (BC) -1 solution.

Production Examples 4 to 14 Production Example 4 was carried out in the same manner as in Production Example 3 except that the type and amount of the epoxy-terminated siloxane polymer and the amount of methanesulfonic acid were as shown in Table 1 below.
Pre-reaction product (BC) -2 to (B) having a solid content of about 50%
C) -12 solution was obtained. The preliminary reaction products (BC) -9 to (BC) -12 obtained in Production Examples 11 to 14 are all reaction products for comparison.

Table 1 also shows the equivalent ratio of epoxy group in siloxane polymer / sulfonic acid group in methanesulfonic acid in the composition. Epoxy-terminated siloxane polymers (B) -2 to (B) -6 in Table 1 are epoxy-terminated siloxane polymers in which R ¹ , m, and n in Formula (1) are as shown in Table 2 below.

[0075]

[Table 1]

[0076]

[Table 2]

Production Example 1 of Water- Sliding Composition Zeffle GK-510 (manufactured by Daikin Industries, Ltd., containing hydroxyl groups containing fluoroolefins, hydroxyl group-containing vinyl monomers and other unsaturated monomers as monomer components constituting the polymer) Fluoropolymer solution, solid content 50%, hydroxyl value 60 mg in polymer solid content
KOH / g, acid value 10 mg KOH / g) 200
Department, Takenate B-820NSU (Takeda Pharmaceutical Co., Ltd.)
Made, block polyisocyanate compound, solid content 60
%) 104.5 parts, Formate K (manufactured by Takeda Pharmaceutical Co., Ltd., organotin-based blocking agent dissociation catalyst, solid content 10)
%), 0.57 parts of methanesulfonic acid and, in the above formula (1), R ¹ is an n-butyl group, m is 63.9 and n is 5, an epoxy-terminated siloxane polymer (epoxy equivalent of about 5, 000, in Table 1, this siloxane polymer is abbreviated as "(B) -1") 29.43
Parts, and toluene / cyclohexanone = 1 /
The mixed solvent of 1 is added in such an amount that the solid content becomes 40%, and the mixture is stirred.
A water-sliding composition was obtained.

Examples 2 to 34 and Comparative Examples 1 to 9 Epoxy-terminated siloxane polymers shown in Table 2 were used. In Example 1, the components were blended according to the respective compositions shown in Table 3 below. A mixed solvent of cyclohexanone = 1/1 was added in such an amount that the solid content became 40%, followed by stirring to obtain each water sliding composition. The water-sliding compositions obtained in Comparative Examples 2 and 6 had poor paint stability and gelled immediately after production. In addition, the water-sliding compositions obtained in Comparative Examples 5 and 9 separated immediately after production.

Preparation of Coated Plates Examples 1-34 and Comparative Examples 1, 3, 4, 7 and 8
Each slipping composition obtained in the above was used as an alkaline degreasing agent (trade name "Chem Cleaner 561", manufactured by Nippon CB Chemical Co., Ltd.)
B ") is applied to a degreased aluminum plate (A1050, plate thickness 0.1 mm) using a 2% concentration aqueous solution in which a dry film thickness of 10 μm is obtained, and baked at 140 ° C. for 30 minutes. Each coated plate was obtained.

Each of the obtained coated plates was tested for adhesion and water slip of the coating film. The test results are shown in Table 1 below. The test was performed based on the following test method.

Test Method Adhesion of coating film: JIS K5400 8.5.2 (19
90) According to the grid-tape method, 100 squares of 1 mm x 1 mm were prepared, and a cellophane adhesive tape was adhered to the surface thereof, and the squares left without being peeled off the coated surface after being rapidly peeled off. The number was recorded.

Water slippage of water droplets: C manufactured by Kyowa Interface Science Co., Ltd.
Using an AX-type contact angle meter, about 10 mg of deionized water is dropped on a coated surface of a tilted coated plate using a microsyringe under an atmosphere of 23 ° C. and 65% RH, and a horizontal surface on which water droplets slide down The minimum angle from was investigated. The angle of inclination of the painted plate was set every 5 degrees from the horizontal plane. When sliding down even at 5 degrees, 5> is displayed, and when sliding down even at 90 degrees is displayed as 90 <. As the painted plate for which the inclination angle is to be examined, a painted plate immediately after painting (initial painted plate) and 16% in deionized water at 25 ° C. after painting.
An immersion-treated plate immersed for 8 hours and a dry / wet cycle test after painting (immersion in running tap water at 25 ° C. for 7 hours—pulling up to 80
(A step of drying at 17 ° C. for 17 hours is regarded as one cycle).

[0083]

[Table 3]

[0084]

[Table 4]

[0085]

[Table 5]

[0086]

[Table 6]

Further, (Note) in Table 3 has the following meanings.

(* 1) Lumiflon LF-554: Hydroxyl group-containing fluoropolymer solution, solid content 40%, hydroxyl value of polymer 53 mg KOH / g, acid value 5 mg KOH / g
g. (* 2) Takenate B-870N: Takeda Pharmaceutical Company Limited
Made, block polyisocyanate compound, solid content 60
%.

(* 3) Cymel 303: a methyl etherified melamine resin manufactured by Mitsui Cytec Co., Ltd. (* 4) Cymel 325: manufactured by Mitsui Cytec Co., Ltd., imino group-containing methyl etherified melamine resin, solid content: about 8
0%.

(* 5) Catalyst 4040: manufactured by Mitsui Cytec Co., Ltd., aromatic sulfonic acid catalyst solution, solid content 4
0%. (* 6) Catalyst 269-9: manufactured by Mitsui Cytec Co., Ltd., phosphoric acid-based catalyst solution, solid content 50%.

[0091]

As described above, the water-sliding composition of the present invention can form a water-slidable film having an excellent water drop sliding property.

Further, coated aluminum fins having a water-slidable coating film on the uppermost layer obtained by applying the water-slidable composition of the present invention are likely to slide down from the fin surface even if water droplets adhere to the fin surface. It is a coated aluminum fin which does not form a water droplet bridge between the fins and has excellent durability, and is suitable as a fin of a heat exchanger. Moreover, the heat exchanger using the coated aluminum fin obtained by the present invention has an advantage that no mold is generated on the fin surface and there is no freezing in winter.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F28F 19/04 F28F 19/04 A // (C09D 157/10 161: 28)

Claims (4)

[Claims] (A) a hydroxyl group-containing vinyl monomer obtained by copolymerizing a hydroxyl group-containing vinyl monomer and another unsaturated monomer copolymerizable therewith; (B) a hydroxyl group-containing vinyl polymer represented by the following formula (1): (Wherein, the average number of m is 6 to 150, n is a number of 0 to 6, and R ¹ is an alkyl group having 1 to 6 carbon atoms) C) a sulfonic acid compound and (D) at least one crosslinking agent component selected from a polyisocyanate compound which may be blocked and a melamine resin, and the amount of the sulfonic acid compound (C) is an epoxy-terminated siloxane polymer. The water-slidable film can be formed, wherein the equivalent ratio of the epoxy group in (B) / the sulfonic acid group in the sulfonic acid compound (C) is in the range of 1/1 to 10/1. Coating composition. 2. The coating composition according to claim 1, wherein the hydroxyl-containing vinyl polymer (A) is a fluorine-containing hydroxyl-containing vinyl polymer using a fluoroolefin as a part of the other unsaturated monomer. 3. A hydroxyl group-containing vinyl polymer (A) 100
The amount of the epoxy-terminated siloxane polymer (B) is 2 to 30 parts by weight based on the weight of the crosslinking agent component (D).
3. The coating composition according to claim 1, wherein the amount is from 4 to 100 parts by weight. 4. An aluminum film, wherein the composition according to claim 1 is coated on an aluminum fin material with or without a primer coating film to form a water-slidable film as an uppermost film. Fin coating method.