JP2000026796A - Coating composition capable of forming waterslipping coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a coating composition capable of forming a coating film having excellent slipping property of water droplets after the lapse of time as well as at the initial stage and suitable for the coating of a fin of a heat- exchanger, or the like by including respectively specific hydroxyl containing vinyl polymer, siloxane polymer, or the like, and a crosslinking agent component. SOLUTION: The objective composition is produced by compounding (A) 100 pts.wt. of a hydroxyl-containing vinyl polymer produced by the copolymerization of a hydroxyl-containing vinyl monomer and other unsaturated monomer copolymerizable with the vinyl monomer with (B) preferably 2-30 pts.wt. of a siloxane polymer having a functional group on one terminal and expressed by formula I (R1 is a 1-6C alkyl; R2 is amino, carboxyl or the like; (m) is 6-150; (n) is 0-6), (C) preferably l-30 pts.wt. of a hydroxyl-containing siloxane polymer of formula II (R3 is a 1-6C alkyl or the like; R4 is a 1-12C hydroxy-containing organic group; (k) is 6-210) and (D) preferably 4-100 pts.wt. of one or more crosslinking agent components selected from a (blocked) polyisocyanate compound and melamine resin.

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 surface of the heat exchanger of the outdoor unit freezes and grows, which causes a problem that the heat exchange efficiency is reduced.

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 the water droplets have good sliding properties both in the initial stage and over time, and do not form water droplet bridges between the fins. The present inventors have conducted intensive studies to obtain a coating composition capable of forming a film capable of solving the occurrence of mold and freezing of the fin surface in winter due to the attached water, and a coated aluminum fin using this composition.

As a result, a coating composition containing a hydroxyl group-containing vinyl polymer, a functional group one-terminal siloxane polymer having a specific functional group at one end, a hydroxyl group-containing siloxane polymer and a crosslinking agent component can form water droplets even at the initial stage and over time. The inventors have found that a film that easily falls down can be formed 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 R ¹ represents an alkyl group having 1 to 6 carbon atoms, R ² represents an amino group, a carboxyl group or a glycidyloxy group; the average number of m is 6 to 150; A siloxane polymer having one functional group at one end, represented by the following formula (2):

[0012]

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(Wherein, R ³ represents an alkyl group having 1 to 6 carbon atoms or a hydroxyl group-containing organic group having 1 to 12 carbon atoms, and R ⁴ represents a hydroxyl group-containing organic group having 1 to 12 carbon atoms. , K is an average number of 6 to 210), and (D) at least one crosslinking agent component selected from a polyisocyanate compound which may be blocked and a melamine resin. An object of the present invention is to provide a coating composition capable of forming a characteristic 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-slidable film as an uppermost film. An object of the present invention is to provide a method of coating an aluminum fin material.

[0015]

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-slidable film of the present invention (hereinafter, may be abbreviated as “water-sliding composition”) is
Hydroxyl-containing vinyl polymer (A) and siloxane polymer having a specific functional group at one terminal and a siloxane polymer having one terminal at one end
And a hydroxyl group-containing siloxane polymer (C) and a crosslinking agent component (D) as essential components.

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, for example, 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 above-mentioned 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 preferably 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%, particularly 25 to 95 mol%.

When the other monomer contains a fluoroolefin, the copolymerization ratio of the hydroxyl group-containing vinyl monomer, the fluoroolefin and the other monomer other than the fluoroolefin in the hydroxyl group-containing vinyl polymer (A) is the total amount of the above three. In general, it is desirable to set the value in the following range based on the above.

Hydroxy group-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.

Functional Group One-Terminal Siloxane Polymer (B) The functional group one-terminal siloxane polymer (B) used in the present invention is a component for improving the water-sliding property of a coating film.
The following equation (1)

[0029]

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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 0 to
6, preferably an integer of 1 to 5, R ¹ is an alkyl group having 1 to 6, preferably 1 to 4 carbon atoms, and R ² is an amino group, a carboxyl group or a glycidyloxy group.

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.

As a commercially available product of the siloxane polymer having one functional group terminal (B), those having a carboxyl group (—COOH group) are referred to as SILAPLANE.
FM-0611, FM-0621, FM-0625
(All of which are manufactured by Chisso Corporation).

[0034]

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As a product having thyraprene FM-
0511, FM-0521 and FM-0525 (all manufactured by Chisso Corporation) and the like.

Hydroxyl-Containing Siloxane Polymer (C) The hydroxyl-containing siloxane polymer (C) used in the present invention is blended for the purpose of, for example, improving the retention of water slippage over time. )

[0037]

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(Wherein, the average number of k is 6 to 210, preferably 6 to 110, R ³ is an alkyl group having 1 to 6 carbon atoms, and R ⁴ is a hydroxyl group having 1 to 12 carbon atoms. A hydroxyl group-containing siloxane polymer represented by the following formula:

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ³ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and hexyl. Among them, an n-butyl group is preferred.

Examples of the hydroxyl group-containing organic group having 1 to 12 carbon atoms represented by R ⁴ include groups represented by the following formulas (3), (4) and (5).

[0041]

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The above-mentioned hydroxyl-containing siloxane polymer (C)
Commercially available products include, for example, Siraprene FM-041
1, the same FM-0421, the same FM-0425, the same FM-D
411, FM-D421, FM-D425, FM
-DA11, FM-DA21, FM-DA25, and FM-DA26 (all manufactured by Chisso Corporation) and the like.

Crosslinking agent component (D) In the present invention, the hydroxyl group-containing vinyl polymer (A)
As a crosslinking agent component for crosslinking and curing, at least one selected from a polyisocyanate compound which may be blocked and a melamine resin is used.

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), a functional group terminal siloxane polymer (B), a functional group terminal siloxane polymer (C) and a crosslinking agent component (D). It is an essential component.

In the water-sliding composition of the present invention, the mixing ratio of the hydroxyl group-containing vinyl polymer (A), the functional group terminal siloxane polymer (B), the functional group terminal siloxane polymer (C) and the crosslinking agent component (D) is as follows: Although not particularly limited, usually, based on 100 parts by weight of the component (A),
Component (B) is 2 to 30 parts by weight, preferably 2 to 20 parts by weight, and component (C) is 1 to 30 parts by weight, preferably 2 to 20 parts by weight.
Parts by weight, and the component (D) is suitably in the range of 4 to 100 parts by weight, preferably 4 to 60 parts by weight.

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

The water-sliding composition of the present invention may optionally contain
For example, organic solvents, surfactants, coloring pigments, extender pigments,
Rust-preventing pigments, dyes, fungicides, and other additives known per se, which are commonly used in paints, can also 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 surfactant which can be added to the water-sliding composition of the present invention, if necessary, is added for the purpose of improving the surface water-sliding property in a state where fine dew water is adhered. , For example,

[0054]

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(Wherein u is an integer of 0 to 100, and v is 1 to 100)
An integer of 10, w is an integer of 0 to 10, a is an integer of 3 to 45, b is an integer of 0 to 15, h is an integer of 2 to 12, R ⁵ is a lower alkyl group having 1 to 6 carbon atoms. And G is -Si
OR ⁶ (wherein, R ⁶ represents an alkyl group having 1 to 6 carbon atoms), a hydroxyl group, a carboxyl group or a glycidyl group),

[0056]

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(Wherein x is an integer of 5 to 20, and a, b and R ⁵ have the same meanings as described above),

[0058]

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Wherein y is an integer of 5 to 20, and z is 1 to 2
An integer of 0, c is an integer of 3 to 45, d is an integer of 0 to 15,
R ⁷ represents a lower alkyl group having 1 to 6 carbon atoms, R ⁸
And R ⁹ are the same or different and each represent a direct bond or a lower alkylene group having 1 to 6 carbon atoms;
⁵ has the same meaning as above) or

[0060]

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(Wherein R ¹⁰ and R ¹¹ are the same or different and represent an alkyl group having 1 to 18 carbon atoms, M ¹ is an alkali metal such as lithium, sodium or potassium,
Or an ammonium group or an amine), and a dialkyl sulfosuccinate salt.

Commercially available surfactants represented by the above formula include, for example, SILWET L-7
7, L-720, L-722, FZ-2161,
SS-2801, FZ-2222, MAC-2101
(All of these are alkylene oxide silane compounds manufactured by Nippon Unicar Co., Ltd.);
0K, 290P (all above, Japan Emulsifier Co., Ltd.)
And dialkyl sulfosuccinates). When blending the above surfactant,
The blending amount is 100 parts of the hydroxyl-containing vinyl polymer (A).
Suitably, it is in the range of 0.02 to 30 parts by weight, preferably 0.1 to 15 parts by weight, based on parts by weight.

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, in particular, as a coating composition for a glass (for example, a 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 water-sliding composition of the present invention can be applied to these substrates by a method known per se, 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 changed according to the use of the object to be coated, etc., and generally, the film thickness after curing is 0.5 to 100 μm, particularly 1 to 50 μm.
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 using the water-sliding composition of the present invention has excellent water-sliding properties. For example, the surface of an object coated with a conventional fluorinated ethylene-based resin may 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-sliding film as an uppermost film can be produced by coating the above-mentioned water-sliding 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 the fin material and the water-slidable coating, corrosion resistance, workability, etc., and good coatability. 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 preferably in the range of about 0.5 to 50 μm, particularly about 1 to 15 μm in 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 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.

In the case where the aluminum fin material is molded into a fin and assembled, the coated and cured water-slidable composition can be used as a coated aluminum fin as it is.

The coated aluminum fin obtained as described above has a water-sliding film of the water-sliding composition of the present invention as the uppermost layer, and the fin surface exhibits excellent water-sliding properties. 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 a coating material for an object which is difficult to adhere to water droplets, or as a surface treatment agent for the object.

[0080]

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.

Production of Water-Sliding Composition Example 1 Zeffle GK-510 (manufactured by Daikin Industries, Ltd., containing hydroxyl group containing fluoroolefin, hydroxyl group-containing vinyl monomer and other unsaturated monomer 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)
%) 10 parts, and in the formula (1), R ¹ is an n-butyl group, R ² is a glycidyloxy group, the average number of m is 64.0, and n is 5, one end of a functional group 30 parts of a siloxane polymer (epoxy equivalent: about 5,000, and in Tables 1 and 3, this siloxane polymer is abbreviated as “(B) -1”), and in the above formula (2), R ³ and R ⁴ are All are 2-hydroxyethyloxypropyl groups represented by the formula (3), and the average number of k is 9.9.
(A number average molecular weight of about 1,000, and in Tables 2 and 3, this siloxane polymer is abbreviated as “(C) -1”), and toluene / cyclohexanone = 1/1 Was added in such an amount that the solid content became 40%, followed by stirring to obtain a water-slidable composition.

Examples 2 to 19 and Comparative Examples 1 to 7 The siloxane polymer having one functional end group shown in Table 1 below was used, and the siloxane polymer having a hydroxyl group shown in Table 2 below was used. Each water-sliding composition was obtained in the same manner except that the components were blended in each composition as shown in Table 3. The water slip compositions obtained in Comparative Examples 4 and 7 were separated immediately after production. In Table 3 below, the blending amount in each composition is indicated by parts by weight of solid content.

The siloxane polymers (B) -2 to (B) -6 at both ends of the functional group in Table 1 have the same R ¹ , R ² m and n in the formula (1) as shown in Table 1 below. Certain functional groups are siloxane polymers at both ends.

[0086]

[Table 1]

The hydroxyl group-containing siloxane polymers (C) -2 to (C) -6 in Table 2 are each represented by the formula (2)
Wherein R ³ , R ⁴ and k are as shown in Table 2 below.

[0088]

[Table 2]

Preparation of Coated Plate Each of the water-sliding compositions obtained in Examples 1 to 19 and Comparative Examples 1 to 3 and 5 to 6 was used as an alkaline degreasing agent (trade name "Chem Cleaner", manufactured by Nippon CV Chemical Co., Ltd.). 561B ”) 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 3 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 are prepared in a room at 20 ° C, and a cellophane adhesive tape is adhered to the surface thereof, and the cell surface is peeled off rapidly and then peeled off. The number of squares remaining was recorded.

Slipping property of water droplet: 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 defined as one cycle).

[0093]

[Table 3]

[0094]

[Table 4]

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

(* 1) Lumiflon LF-554: Hydroxyl-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%.

(* 7) Newcol 290M: manufactured by Nippon Emulsifier Co., Ltd., a surfactant which is a dialkyl sulfosuccinate represented by the formula (5).

(* 8) Silwet L-77: a surfactant which is an alkylene oxide silane compound represented by the formula (4), manufactured by Nippon Unicar Co., Ltd.

[0101]

EFFECTS OF THE INVENTION The water-sliding composition of the present invention has an unprecedented excellent water-drop sliding property, and can form a film having excellent water-drop sliding properties not only at the initial stage but also over time.

The coated aluminum fin having a water-sliding coating film on the uppermost layer obtained by coating the water-sliding composition of the present invention can be used immediately after water droplets adhere to the fin surface in the initial stage and over time. Since it slides down, the formation of a water droplet bridge between the fins can be eliminated, which is suitable as a fin of a heat exchanger. Further, the heat exchanger using the coated aluminum fin obtained by the present invention,
The fin surface has an advantage that there is no generation of mold and no freezing in winter.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 183/04 C09D 183/04 F-term (Reference) 4D075 CA36 DA23 DB07 DC16 EB16 EB19 EB32 EB37 EB38 EB43 4J038 CE051 CG141 CH121 DA162 DG262 DG302 DL052 DL082 GA03 GA06 GA07 KA03 NA07 PA07 PC02

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, R ¹ represents an alkyl group having 1 to 6 carbon atoms, R ² represents an amino group, a carboxyl group or a glycidyloxy group, the average number of m is 6 to 150, and n is a number of 0 to 6. (C) a siloxane polymer having one end of a functional group represented by the following formula: (C) (Wherein, R ³ represents an alkyl group having 1 to 6 carbon atoms or a hydroxyl group-containing organic group having 1 to 12 carbon atoms; R ⁴ represents a hydroxyl group-containing organic group having 1 to 12 carbon atoms; (An average number is 6 to 210), and (D) at least one crosslinking agent component selected from a polyisocyanate compound which may be blocked and a melamine resin. A coating composition capable of forming a water-slidable film. 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 functional group one-terminal siloxane polymer (B) is 2 to 30 parts by weight, the amount of the hydroxyl group-containing siloxane polymer is 1 to 30 parts by weight, and the amount of the crosslinking agent component (D) is 4 to 100 parts by weight. The coating composition according to claim 1, wherein the coating composition is a part. 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.