JP2012025820A - Hydrophilic treatment agent composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrophilic treatment agent composition which enables a film to be formed, the film being excellent in hardly frost forming property and defrosting property and maintaining the excellent performances over a long period, and to provide heat exchanger parts having a hydrophilic cured film obtained by being coated with the hydrophilic treatment composition and being baked.SOLUTION: The hydrophilic treatment agent composition contains: (A) an acrylic resin obtained by copolymerizing (a1) at least one of amphoteric ion group-containing polymerizable unsaturated monomer selected from a polymerizable unsaturated monomer with a betaine structure and a polymerizable unsaturated monomer with a phosphorylcholine structure, (a2) at least one of polymerizable unsaturated monomer selected from a carboxyl group-containing polymerizable unsaturated monomer and a hydroxy group-containing polymerizable unsaturated monomer, and (a3) the other polymerizable unsaturated monomer; (B) hydrophilic crosslinked polymer particles; and (C) a crosslinking agent.

Description

  The present invention is characterized by delaying frost formation by applying to the surface of an object to be coated or suppressing the growth of adhering frost (hereinafter, this characteristic is referred to as difficult frost formation), and adhering frost. A hydrophilizing agent composition that forms a hydrophilic cured film with excellent properties (hereinafter referred to as defrosting properties) that make it easy to drain water generated when melted from the surface, and the hydrophilic The present invention relates to a heat exchanger component having a hydrophilic cured film formed by coating a chemical treatment composition.

  In air conditioner heat exchanger parts, fins made of aluminum or aluminum alloy are designed to be mounted with a very narrow gap between the fins in order to increase the surface area per unit volume in order to improve heat exchange efficiency. . The fins of the heat exchanger parts provided in the outdoor unit of the air conditioner tend to frost on the surface during heating operation at low temperatures. This tendency is particularly strong in heat pump air conditioners that have been widely used in recent years. Since the fin interval is very narrow, if the operation is continued as it is, the attached frost grows and eventually the frost is connected and closed between the fins, and the heat exchange efficiency is remarkably lowered. In order to recover the heat exchange efficiency, an operation (defrosting operation) for removing frost attached to the fins must be performed. In general, since the heating operation is stopped during the defrosting operation, the person in the room is uncomfortable, and electric energy is consumed for purposes other than the original purpose.

  Further, in this defrosting operation, it is known that when the fin material surface has a high hydrophobicity, water droplets generated by melting of frost are isolated and become large and remain in a form connecting fins. When water droplets exist between the fins, when the heating operation is restarted, the water droplets freeze, partially closing the space between the fins, and further, the phenomenon that the frost grows faster at the icing site occurs. Will increase the number of times. In order to solve the above-mentioned problems related to the defrosting operation, the surface of the fin material is made hydrophilic so that the water generated by the melting of the frost is thinly spread on the surface of the fin material to be removed and easily evaporated. In order to prevent water droplets from remaining on the surface of the fin material.

  As a method of hydrophilizing the fin material surface, there is a method of forming a hydrophilic inorganic coating using a hydrophilizing material mainly composed of high molecular weight water glass. However, this inorganic coating has the problem that the water glass of the component is hydrolyzed by the moisture generated on the fins, causing outflow or peeling of the coating, resulting in a decrease in hydrophilicity over time. As a method for solving such problems of inorganic coatings, a method of forming a hydrophilic organic-inorganic composite coating on a fin material has been studied. So far, hydrophilic inorganic particle components such as colloidal silica and hydrophilic properties have been studied. A composition comprising a combination of organic resin components has been put into practical use. However, in the case of a method (preheating method) in which a fin film is formed by applying a press forming process to this plate after forming the hydrophilic film by coating this composition on an aluminum plate by means such as a roll coater. In some cases, the mold used in the above is easily worn, and the use of the worn mold may cause problems such as poor molding of the fin material and reduced corrosion resistance due to the destruction of the hydrophilic film. Therefore, a method using hydrophilic crosslinked polymer particles instead of hydrophilic inorganic particles was proposed in Patent Document 1 to solve the above-described problems of mold wear, molding failure, and film destruction in the pre-coating method. When applied to aluminum fin materials for heat exchangers, it has become possible to maintain excellent defrosting properties for a long time. On the other hand, from the idea that frost formation should be made difficult in the first place, in addition to the defrosting property due to the hydrophilization, it has been demanded to provide a new characteristic of difficult frosting property. However, even in the method of Patent Document 1, the difficulty of frost formation is insufficient.

  As a method for forming a hydrophilic organic coating, Patent Document 2 discloses a composition for a heat exchanger coating comprising an aqueous thermosetting acrylic aminoplast resin and / or an aqueous emulsion silicone resin, resin particles having zwitterionic groups, and an alkali metal salt. Is disclosed. When the coating was applied to a fin material for a heat exchanger, it was excellent in hydrophilicity at the beginning of use, but it was difficult to maintain the hydrophilicity for a long time. Moreover, the difficulty frost formation is inadequate from the beginning of use, and when it was used for a long period of time, there existed a problem that defrostability fell with the fall of hydrophilicity.

  Patent Document 3 discloses a hydrophilic film forming composition containing a zwitterionic group-containing polymer having a betaine structure. Since the coating obtained from this composition has a crosslinked structure, it is possible to maintain hydrophilicity for a long period of time. However, when the composition is applied to a fin material for a heat exchanger, it has a defrosting property. Was insufficient.

JP 2009-149715 A JP 61-238864 A JP 2008-308659 A

  An object of the present invention is to provide a hydrophilizing agent composition that is excellent in difficult frost formation and defrosting properties and can form a film capable of maintaining the excellent performance for a long period of time, and the hydrophilizing agent composition. It is to provide a heat exchanger component having a hydrophilic cured coating formed by painting and baking.

As a result of intensive studies to achieve the above object, the present inventors have found that a copolymer of a monomer mixture containing a zwitterionic group-containing polymerizable unsaturated monomer having a specific structure, a hydrophilic cross-linked polymer particle, and a cross-linking agent In order to disclose the present invention, it has been found that by using a hydrophilic treatment composition comprising: a coating excellent in both anti-frosting and defrosting properties can be obtained, and the performance can be maintained for a long period of time. It came. That is, the present invention comprises the following items.
1. At least one zwitterionic group-containing polymerizable unsaturated monomer (a1) selected from the group consisting of a polymerizable unsaturated monomer having a betaine structure and a polymerizable unsaturated monomer having a phosphorylcholine structure, a carboxyl group-containing polymerizable unsaturated monomer And an acrylic resin (A) obtained by copolymerizing at least one polymerizable unsaturated monomer (a2) selected from the group consisting of a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer (a3), A hydrophilic treatment agent composition comprising hydrophilic crosslinked polymer particles (B) and a crosslinking agent (C).
2. 2. The hydrophilic treatment composition according to 1, wherein the crosslinking agent (C) is at least one selected from the group consisting of a melamine resin, an oxazoline compound, a carbodiimide compound, an epoxy compound, an isocyanate compound, and a blocked isocyanate compound.
3. A heat exchanger component coated with the hydrophilic treatment composition according to 1 or 2.

  According to the composition of the present invention, a film excellent in difficult frost formation and defrosting properties can be obtained, and further a film capable of maintaining the performance for a long period of time, which has been a conventional problem, can be obtained. Thus, by using a heat exchanger part coated with the composition of the present invention in an air conditioner, energy saving and a comfortable operating environment can be achieved.

  Hereinafter, the hydrophilic treatment composition of the present invention will be described in more detail. The hydrophilic treatment agent composition of the present invention comprises an acrylic resin (A), hydrophilic crosslinked polymer particles (B) and a crosslinking agent (C).

Acrylic resin (A)
The acrylic resin (A) comprises at least one zwitterionic group-containing polymerizable unsaturated monomer (a1) selected from the group consisting of a polymerizable unsaturated monomer having a betaine structure and a polymerizable unsaturated monomer having a phosphorylcholine structure, a carboxyl group It is obtained by copolymerizing at least one polymerizable unsaturated monomer (a2) selected from the group consisting of a polymerizable polymerizable unsaturated monomer and a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer (a3). . The monomer (a1) is a zwitterionic group-containing polymerizable unsaturated monomer having a betaine structure represented by the following formula (1) or a phosphorylcholine structure represented by the following formula (2).

(R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 1 to 8 carbon atoms, and R ³ and R ⁴ are linear chains having 1 to 4 carbon atoms that may be independently substituted with a hydroxyl group. Represents a linear or branched alkyl group, and R ⁵ represents a linear or branched alkylene group having 1 to 15 carbon atoms which may be substituted with a hydroxyl group, or a phenylene group which may be substituted with a hydroxyl group, Z represents an oxygen atom or an imino group, X ^- represents a sulfonic acid anion, carboxylic acid anion group, any one group of phosphoric acid anion group).

(R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ represents an alkylene group having 1 to 8 carbon atoms.)
The polymerizable unsaturated monomer (a1) which is a betaine compound represented by the formula (1) is a “carboxybetaine monomer” when X ⁻ in the formula (1) is a carboxylate anion group, and X is a sulfonate anion group. In the present specification, the term “sulfobetaine monomer” may be referred to as “phosphobetaine monomer” when X is a phosphate anion group. Specific examples of the carboxybetaine monomer include dimethyl (2-methacryloyloxyethyl) (2-carboxylatoethyl) aminium, dimethyl (2-acryloyloxyethyl) (2-carboxylatoethyl) aminium, dimethyl (2-methacryloyloxy). Ethyl) (3-carboxylatopropyl) aminium, dimethyl (2-acryloyloxyethyl) (3-carboxylatopropyl) aminium, dimethyl (2-methacryloyloxyethyl) (4-carboxylatobutyl) aminium, dimethyl (2-acryloyl) Oxyethyl) (4-carboxylatobutyl) aminium, dimethyl (2-methacryloyloxyethyl) (carboxylatomethyl) aminium, dimethyl (2-acryloyloxyethyl) (carboxy Tomechiru) aminium, and the like. The carboxybetaine monomer can be produced by a known method, and for example, the method described in JP-A-2008-63334 or JP-A-9-95474 can be used. Of the above, dimethyl (2-methacryloyloxyethyl) (carboxylatomethyl) aminium may be referred to as methacryloyloxyethyl-N, N-dimethylammonium-α-methylcarboxybetaine in this specification.

  Specific examples of the sulfobetaine monomer include dimethyl (2-methacryloyloxyethyl) (2-sulfonatoethyl) aminium, dimethyl (2-acryloyloxyethyl) (2-sulfonatoethyl) aminium, dimethyl (2-methacryloyloxy). Ethyl) (3-sulfonatopropyl) aminium, dimethyl (2-acryloyloxyethyl) (3-sulfonatopropyl) aminium, dimethyl (2-methacryloyloxyethyl) (4-sulfonatobutyl) aminium, dimethyl (2-acryloyloxyethyl) ) (4-sulfonatobutyl) aminium, dimethyl (2-methacryloyloxyethyl) (sulfonatomethyl) aminium, dimethyl (2-acryloyloxyethyl) (sulfonatomethyl) aminium, and the like.The sulfobetaine monomer can be produced by a known method, for example, a method described in JP-A-2008-63334 can be used. Of the above, dimethyl (2-methacryloyloxyethyl) (3-sulfonatopropyl) aminium is referred to as methacryloyloxyethyl-N, N-dimethyl-N- (3-sulfopropyl) ammonium betaine in this specification. Sometimes.

  Specific examples of the phosphobetaine monomer include dimethyl (2-methacryloyloxyethyl) (2-phosphonatoethyl) aminium, dimethyl (2-acryloyloxyethyl) (2-phosphonatoethyl) aminium, dimethyl (2-methacryloyloxyethyl) (3 -Phosphonatopropyl) aminium, dimethyl (2-acryloyloxyethyl) (3-phosphonatopropyl) aminium, dimethyl (2-methacryloyloxyethyl) (4-phosphonatobutyl) aminium, dimethyl (2-acryloyloxyethyl) (4- Phosphonatobutyl) aminium, dimethyl (2-methacryloyloxyethyl) (phosphonatomethyl) aminium, dimethyl (2-acryloyloxyethyl) (phosphonatomethyl) aminium, and the like.The phosphobetaine-based monomer can be produced by a known method, and for example, the method described in JP-A-2008-63334 can be used.

  As the polymerizable unsaturated monomer having a phosphorylcholine structure, a known compound can be used. Examples of the compound include JP-A-54-63025, JP-A-58-154591, JP-A-6-345787, and JP-A-7. -10892, JP-A-11-43496, and the like. Specific examples of the polymerizable unsaturated monomer having a phosphorylcholine structure include methacryloyloxyethyl phosphorylcholine, acryloyloxyethyl phosphorylcholine, methacryloyloxybutylphosphorylcholine, acryloyloxybutylphosphorylcholine, and the like.

  The above-mentioned polymerizable unsaturated monomers (a1) can be used alone or in admixture of two or more.

  Betaine is a general name for an inner salt having a quaternary ammonium and an anion of an acid as a cation in one molecule (Chemical Dictionary 8, Reprinted Edition 38, 319, October 1, 2003). Japan, Kyoritsu Publishing Co., Ltd. In the present specification, a polymerizable unsaturated monomer having a betaine structure is a compound of the formula 1 having a quaternary ammonium as a cation and any one of a carboxylate anion, a sulfonate anion and a phosphate anion. Called. On the other hand, phosphorylcholine is an important compound as an intermediate of lecithin metabolism (Chemical Dictionary 8, Reprinted Edition 38, 677, October 1, 2003, Kyoritsu Shuppan Co., Ltd.). In this specification, phosphorylcholine The compound of formula 2 which is an ester compound is referred to as a polymerizable unsaturated monomer having a phosphorylcholine structure. This is also an intramolecular salt having a cation and an anion in one molecule. In the present specification, a polymerizable unsaturated monomer that is an intramolecular salt having a cation and an anion in one molecule is referred to as a zwitterionic group-containing polymerizable unsaturated monomer.

  Among the at least one monomer (a2) selected from the group consisting of a carboxyl group-containing polymerizable unsaturated monomer and a hydroxyl group-containing polymerizable unsaturated monomer, as the carboxyl group-containing polymerizable unsaturated monomer, (meth) acrylic acid, It is an ester of crotonic acid, itaconic acid, maleic acid, fumaric acid, 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 5-carboxypentyl (meth) acrylate, hydroxyethyl methacrylate and succinic anhydride. 2-Methacryloyloxyethyl succinate (product name: NK Ester SA, Shin-Nakamura Chemical Co., Ltd. product), a hydroxyl group-containing unsaturated monomer, which is a reaction product of a hydroxyl group-containing unsaturated monomer and an acid anhydride compound, anhydrous Maleic acid and hydroxyl group-containing compounds And the like compounds obtained by half-esterification reaction. The carboxyl group of the above-described monomer may form a salt with a basic substance.

  Among the monomers (a2), as the hydroxyl group-containing polymerizable unsaturated monomer, carbon number of acrylic acid or methacrylic acid such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, etc. Mention may be made of 2-8 hydroxyalkyl esters. Moreover, the adduct of the hydroxyalkyl ester of acrylic acid or methacrylic acid and (epsilon) -caprolactone is also mentioned. As a commercial item of this adduct, for example, “PLAXEL FM-3” (trade name, manufactured by Daicel Chemical Industries, Ltd.) and the like can be mentioned.

  Examples of the other polymerizable unsaturated monomer (a3) include the following compounds.

  (Meth) acrylamide monomer: (Meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn- Butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) Acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, diacetone (meth) acrylamide, (meth) acryloylmorpholine and the like.

  Nitrogen-containing heterocyclic compound monomers: 2-vinylpyridine, 1-vinyl-2-pyrrolidone, 4-vinylpyridine and the like.

  Amino group-containing monomers: N, N-dimethylaminoethyl (meth) acrylate, Nt-butylaminoethyl (meth) acrylate, and the like.

  Nitrile group-containing monomer: acrylonitrile, methacrylonitrile, etc.

  (Meth) acrylic acid ester monomer: methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth ) I-butyl acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate, (meth C1-30 alkyl ester or cycloalkyl ester of acrylic acid or methacrylic acid such as lauryl acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, and the like. C2-C18 alkoxyalkyl ester of acrylic acid or methacrylic acid such as methoxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxybutyl (meth) acrylate, or acetoacetoxy (meth) acrylate Ethyl etc.

  Polymerizable unsaturated monomer having a polyoxyalkylene chain: a compound having a structure represented by the following formula (2) or a compound obtained by reaction with a polymerizable unsaturated monomer having a functional group capable of reacting with a polyoxyalkylene compound.

(R ⁸ represents a hydrogen atom or a methyl group, R ⁹ represents an alkylene group having 2 to 5 carbon atoms, all of which may be the same or different, among the n repeating units, and the alkylene The group may be linear or branched, and R ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, and n is an integer of 2 to 300)
Aromatic monomers: styrene, α-methylstyrene, vinyltoluene, hydroxystyrene and the like.

  Fluorinated alkyl group-containing monomer: Perfluoroalkyl ester of acrylic acid or methacrylic acid such as perfluorobutylethyl (meth) acrylate, perfluoroisononylethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, and the like.

  Olefin monomers: ethylene, propylene, butylene, pentene, etc.

  Fluoroolefin monomers: trifluoroethylene, tetrafluoroethylene, vinylidene fluoride, etc.

  Vinyl ester monomers: vinyl esters and propenyl esters of fatty acids having 1 to 20 carbon atoms such as vinyl acetate, vinyl propionate, vinyl caprate, and isopropenyl acetate. Examples of such commercially available vinyl esters include “VeoVa” monomer (trade name, manufactured by Shell Chemical Co., Ltd., vinyl ester of branched higher fatty acid).

  Hydrolyzable alkoxysilyl group-containing monomer: vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (methoxyethoxy) silane, γ-methacryloyloxypropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, p-styryltrimethoxysilane etc.

  Sulfonic acid group-containing monomers: sulfonic acid group-containing monomers such as vinyl sulfonic acid, methallyl sulfonic acid, sulfoethyl (meth) acrylate, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, and salts thereof.

  Phosphoric acid group-containing monomer: esterified product of a hydroxyl group-containing monomer such as 2- (meth) acryloyloxyethyl acid phosphate and a phosphoric acid compound, or a compound obtained by adding a phosphoric acid compound to an epoxy group such as glycidyl (meth) acrylate .

  Monomers having a plurality of unsaturated bonds in one molecule: allyl (meth) acrylate, 1,6-di (methacryloyloxy) hexane, divinylbenzene and the like.

  1 type (s) or 2 or more types can be used for the above-mentioned other polymerizable unsaturated monomer (a3).

  The use amount of the zwitterionic group-containing polymerizable unsaturated monomer (a1) is preferably 10% by mass to 90% by mass, more preferably 20% by mass, with respect to the total amount of the monomers (a1), (a2) and (a3). The range is preferably 80% by mass. When the use amount of the polymerizable unsaturated monomer (a1) is less than 10% by mass, the hardened frosting property and the defrosting property of the obtained cured film may be insufficient. If it exceeds 90% by mass, the resulting cured film may have insufficient water resistance.

  The monomer (a2) can introduce a carboxyl group and / or a hydroxyl group into the acrylic resin (A) by copolymerizing with the monomer (a1) and the monomer (a3). These carboxyl groups and hydroxyl groups can be used as a crosslinking reactive functional group with the crosslinking agent (C) or used to adjust the hydrophilicity of the acrylic resin (A). The total value of the acid value or the hydroxyl value per solid content of the acrylic resin (A) is preferably in the range of 20 to 200 mgKOH / g, and more preferably in the range of 40 to 180 mgKOH / g. The carboxyl group-containing polymerizable unsaturated monomer and the hydroxyl group-containing polymerizable unsaturated monomer of the monomer (a2) are each independently such that the sum of the acid value and the hydroxyl value of the acrylic resin (A) is in the above-described range. Or both can be used. When the total value of the acid value and the hydroxyl value per solid content of the acrylic resin (A) is less than 20 mgKOH / g, the processability of the coating film may be inferior due to insufficient crosslinking of the coating film after baking. . If the total value of the acid value and the hydroxyl value per solid content of the acrylic resin (A) is greater than 200 mgKOH / g, the water resistance of the cured coating film after baking becomes insufficient, resulting in difficult frost formation and defrosting. It may be difficult to maintain sex for a long time.

  The weight average molecular weight of the acrylic resin (A) is preferably in the range of 2,000 to 300,000, more preferably 3,000 to 200,000.

  In this specification, the weight average molecular weight is the retention time (retention capacity) of a standard polystyrene having a known molecular weight measured under the same conditions as the retention time (retention capacity) measured using a gel permeation chromatograph (GPC). Is a value obtained by converting to a molecular weight of polystyrene. Specifically, “HLC8120GPC” (trade name, manufactured by Tosoh Corporation) is used as a gel permeation chromatograph, and “TSKgel G-4000HXL”, “TSKgel G-3000HXL”, “TSKgel G-2500HXL” are used as columns. ”And“ TSKgel G-2000HXL ”(trade names, all manufactured by Tosoh Corporation), a differential refractometer is used as a detector, mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: It can be measured under the condition of 1 mL / min.

  The acrylic resin (A) is at least one polymerizable unsaturated selected from the group consisting of an amphoteric ion group-containing polymerizable unsaturated monomer (a1), a carboxyl group-containing polymerizable unsaturated monomer, and a hydroxyl group-containing polymerizable unsaturated monomer. It is obtained by copolymerizing the monomer (a2) and other polymerizable unsaturated monomer (a3). As the polymerization method, for example, a known method such as homogeneous polymerization (solution polymerization) or dispersion polymerization in a solvent, or bulk polymerization without using a solvent can be used. Among these, the solution polymerization method is most suitable. During the polymerization, the molecular weight can be adjusted using a chain transfer agent. A conventionally known method can be used as a method for introducing the monomer and the polymerization initiator into the polymerization system.

  Solvents used in the solution polymerization include, for example, water; aromatic solvents such as toluene, xylene, “Swazole 1000” (trade name, high-boiling petroleum solvent) manufactured by Cosmo Oil Co., Ltd .; ethyl acetate, 3-methoxy Ester solvents such as butyl acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propyl propionate, butyl propionate, and ethoxyethyl propionate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone An alcohol solvent such as ethylene glycol monobutyl ether, propylene glycol monopropyl ether, and butanol. These solvents can be used alone or in combination of two or more. Moreover, it is also possible to mix and use the above-mentioned solvent and water as necessary.

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, di-t-amyl peroxide, t-butyl peroctoate, 2,2 Well-known radical polymerization initiators, such as' -azobis (2-methylbutyronitrile), can be mentioned. About 0.01-30 mass% is preferable with respect to the total amount of the monomer to superpose | polymerize, and, as for the usage-amount of a polymerization initiator, about 0.1-20 mass% is more preferable. As the chain transfer agent, known compounds such as n-dodecyl mercaptan, t-dodecyl mercaptan, and α-methylstyrene dimer can be used. Copolymerization by solution polymerization is performed by, for example, dissolving or dispersing a mixture of a monomer and a polymerization initiator in a solvent and stirring the mixture for about 1 to 20 hours while usually heating to about 50 ° C. to 200 ° C. Can do.

  The acrylic resin (A) may be used together with a basic compound, and a part or all of the carboxyl group in the acrylic resin (A) may be an alkali metal salt, alkaline earth metal salt, or ammonium salt. The acrylic resin (A) can be used by neutralizing with an alkali metal hydroxide or an alkaline earth metal hydroxide.

Hydrophilic crosslinked polymer particles (B)
As the hydrophilic crosslinked polymer particles (B) in the composition of the present invention, those obtained by a known method can be used. From the viewpoint of excellent frost formation and defrosting properties, for example, JP 2000-328038 A Those obtained by the methods described in JP-A Nos. 2002-302644 and 2009-149715 can be preferably used. Specifically, it can be obtained by the method described below.

  The hydrophilic crosslinked polymer particles (B) are composed of a hydrophilic polymerizable unsaturated monomer (b1), a (meth) acrylamide monomer (b2), a crosslinkable unsaturated monomer (b3), and other polymerizable unsaturated monomers (b4). ) Hydrophilic cross-linked polymer particles.

  Examples of the hydrophilic polymerizable unsaturated monomer (b1) include a compound having at least one polymerizable unsaturated group and a polyoxyalkylene chain or a polyvinylpyrrolidone chain in one molecule. Typical examples of the compound Examples thereof include a polymerizable unsaturated monomer having a polyoxyalkylene chain represented by the above formula (3) or a polymerizable unsaturated monomer having a polyvinylpyrrolidone chain represented by the formula (4).

(In the formula, R ¹¹ represents a hydrogen atom or a methyl group, R ¹² represents a hydrogen atom or a polymer end group such as a polymerization initiator segment, and X represents a carbon atom that may contain an O, S, or N atom. Represents a divalent organic group of formula 5-10, m is an integer of 10-100)
In the above formula (4), X is a divalent organic group having 5 to 10 carbon atoms which may contain O, S or N atoms. As a specific example, an organic compound represented by the following formula (5) is used. The group can be mentioned. The hydrophilic polymerizable unsaturated monomer (b1) is preferably a compound of the formula (3) or (4) in which n is 50 to 200 from the viewpoint of dispersion stability and the like.

  The (meth) acrylamide monomer (b2) is at least one compound selected from the compounds represented by the following formula (6) or (7).

(Wherein R ¹³ represents a hydrogen atom or a methyl group, R ¹⁴ and R ¹⁵ are the same or different, each represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ¹⁴ and R ¹⁵ The sum of the number of carbon atoms is 5 or less.)

(In the formula, R ¹⁶ represents a hydrogen atom or a methyl group.)
In the above formula (6), the “alkyl group having 1 to 5 carbon atoms” represented by R ¹⁴ or R ¹⁵ may be either linear or branched, methyl, ethyl, Examples thereof include n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and amyl. Representative examples of the monomer (b2) represented by the general formula (6) include acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, Nn-propylacrylamide, Nn-propylmethacrylamide, N-isopropylacrylamide, N-isopropylmethacrylamide, Nn-butylacrylamide and the like can be mentioned.

  The crosslinkable unsaturated monomer (b3) is a component that contributes to the cross-linking of particles, a compound having two or more polymerizable unsaturated groups in one molecule, a hydrolyzable silyl group, and an epoxy group in one molecule. And at least one compound selected from compounds having at least one functional group selected from an N-methylol group and an N-alkoxymethyl group and one polymerizable unsaturated group. Among the crosslinkable unsaturated monomer (b3), examples of the compound having two or more polymerizable unsaturated groups in one molecule include methylene bisacrylamide, ethylene glycol di (meth) acrylate, and triethylene glycol di (meta). ) Acrylate, tetraethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, divinylbenzene, allyl ( And (meth) acrylate. Of these, methylene bisacrylamide and methylene bismethacrylamide are preferred from the viewpoints of dispersion stability and hydrophilicity of the polymer particles obtained.

  Of the crosslinkable unsaturated monomer (b3), at least one functional group selected from a hydrolyzable silyl group, an epoxy group, an N-methylol group and an N-alkoxymethyl group in one molecule and one polymerizable property. Typical examples of the compound having an unsaturated group include the following compounds.

  Polymerizable unsaturated monomer having hydrolyzable silyl group: γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, 2-styrylethyltrimethoxysilane, vinyltris (Methoxyethoxy) silane and the like. Polymerizable unsaturated monomer having an epoxy group: glycidyl (meth) acrylate, allyl glycidyl ether and the like. Polymerizable unsaturated monomer having an N-methylol group: N-methylolacrylamide, N-methylolmethacrylamide and the like. Polymerizable unsaturated monomer having N-alkoxymethyl group: N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, N-ethoxymethyl acrylamide, N-ethoxymethyl methacrylamide, N-butoxymethyl acrylamide, N-butoxymethyl methacryl Amides etc. Among these monomers, a polymerizable unsaturated monomer having an N-methylol group or an N-alkoxymethyl group having 1 to 7 carbon atoms is preferable from the viewpoint of stability of polymer particles in an organic solvent. In the present specification, the “hydrolyzable silyl group” means a silicon-containing group that generates a silanol group by hydrolysis.

  The other polymerizable unsaturated monomer (b4) is a monomer used as necessary, and has one polymerizable unsaturated group in one molecule, and the monomers (b1), (b2) and (b3) Monomers (a2) to (a3) that can be used to produce the above-mentioned acrylic resin A, which are compounds other than the monomers (b1), (b2), and (b3) that can be copolymerized with ), It is possible to use compounds other than the monomers (b1), (b2) and (b3).

  When the functional group in the monomer (b3) is a hydrolyzable silyl group, an N-methylol group or an N-alkoxymethyl group, these groups can also be crosslinked by reacting with each other. Further, when a compound having a functional group that reacts complementarily with the functional group in the monomer (b3) is used as the monomer (b4), the reaction between the functional group in the monomer (b3) and the functional group in the monomer (b4) It is also possible to crosslink the inside of the particles. When the functional group in the monomer (b3) is a hydrolyzable silyl group, N-methylol group, or N-alkoxymethyl group, the functional group of (b4) that reacts complementarily with the functional group includes a hydroxyl group When the functional group in the monomer (b3) is an epoxy group, the functional group in (b4) that reacts in a complementary manner with the functional group can include a carboxyl group, and reacts in a complementary manner as appropriate. A polymerizable unsaturated monomer having a functional group can be selected and used.

  The hydrophilic cross-linked polymer particles (B) include, for example, the above-described hydrophilic polymerizable unsaturated monomer (b1), (meth) acrylamide monomer (b2), cross-linkable unsaturated monomer (b3), and other polymerizations. The water-miscible organic solvent / water-miscible organic solvent / b which dissolves the monomer but does not substantially dissolve the resulting copolymer in the presence or absence of the dispersion stabilizer. It can be produced by copolymerization in a water mixed solvent.

  The use ratio of each monomer in that case is the polymerizable unsaturated monomer (b1) having a polyoxyalkylene chain or polyvinylpyrrolidone chain with respect to the total amount of (b1) to (b4): 2 to 50% by mass, preferably 2 -40 mass%, (meth) acrylamide monomer (b2): 20-97 mass%, preferably 30-96 mass%, crosslinkable unsaturated monomer (b3): 1-30 mass%, preferably 2-20 mass% %, Other polymerizable unsaturated monomer (b5): 0 to 77% by mass, preferably 0 to 66% by mass, from the viewpoint of hydrophilic sustainability.

  When the amount of the hydrophilic polymerizable unsaturated monomer (b1) having a polyoxyalkylene chain or a polyvinylpyrrolidone chain is less than 2% by mass, it may be difficult to stabilize the polymer particles to be produced. Aggregates are likely to be generated during or during storage. On the other hand, when the amount exceeds 50% by mass, the polymer particles to be generated are easily dissolved in the reaction solvent, and many of the polymers may be dissolved. When the amount of the (meth) acrylamide monomer (b2) is less than 20% by mass, generally, the polymer produced by the polymerization is easily dissolved in the reaction solvent, and it may be difficult to form polymer particles. If it exceeds 97 mass%, the stability of the polymer particles during polymerization and over time may be insufficient, and aggregates may be easily formed. When the amount of the crosslinkable unsaturated monomer (b3) is less than 1% by mass, when used in a composition containing an organic solvent other than water as a solvent, the composition is swollen by the organic solvent during storage and the viscosity of the composition increases. On the other hand, if it exceeds 30% by mass, the mold may be easily worn during press molding of an aluminum plate on which a film of a composition containing the same is formed.

  In the production of the hydrophilic crosslinked polymer particles (B), the polymer particles produced by the copolymerization of the hydrophilic polymerizable unsaturated monomer (b1) have a hydrophilic polyoxyalkylene chain or polyvinylpyrrolidone chain. Since the polyoxyalkylene chain or polyvinylpyrrolidone chain contributes to the dispersion stabilization of the polymer particles, the polymer particles (B) can be produced without using a dispersion stabilizer.

  A water-miscible organic solvent or a water-miscible organic solvent / water mixed solvent that dissolves the raw material monomer mixture but does not substantially dissolve the resulting copolymer is used as a reaction solvent in the production of the polymer particles (B). used. Here, “water miscible” or “miscible with water” means that it can be dissolved in water at an arbitrary ratio at a temperature of 20 ° C.

  As the water-miscible organic solvent, any solvent can be used as long as the above requirements are satisfied. In particular, the solubility parameter (SP) value is generally 9 to 11, particularly 9.5 to 10.7. A solvent containing at least 50% by weight, particularly 70% by weight or more of an organic solvent within the range is preferable from the viewpoint of polymerization stability. The “solubility parameter (SP) value” in this specification is described in Journal of Paint Technology Vol. 42, No. 541, pages 76 to 118 (February 1970). Is based.

  Examples of water-miscible organic solvents having an SP value within the above range include alkylene glycol monoalkyl ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. Among these, ethylene glycol monobutyl ether or propylene glycol monomethyl ether is particularly preferable.

  The water-miscible organic solvent can contain other water-miscible or water-immiscible organic solvents in addition to the organic solvent having an SP value in the range of 9 to 11 as described above. As such an organic solvent, a water-miscible organic solvent such as methanol, ethanol, isopropyl alcohol and the like are suitable. These other water-miscible or water-immiscible organic solvents are desirably used in an amount of 50% by mass or less, particularly 30% by mass or less of the total amount of the organic solvent.

  Further, when a water-miscible organic solvent / water mixed solvent is used as the reaction solvent, the water content in the mixed solvent is usually 100 parts by mass of the water-miscible organic solvent from the viewpoint of polymerization stability and the like. It is preferably 60 parts by mass or less, particularly 40 parts by mass or less.

  The copolymerization of the monomer mixture is usually performed in the presence of a radical polymerization initiator. As the radical polymerization initiator, those known per se can be used, and the amount used is preferably in the range of 0.2 to 5% by mass relative to the total amount of monomers.

  The polymerization temperature can be varied depending on the type of polymerization initiator used and the like. Usually, a temperature within the range of about 50 to about 160 ° C., more preferably 90 to 160 ° C. is appropriate, and the reaction time is 0.5. About 10 hours. Moreover, in order to advance the bridge | crosslinking by a monomer (b3) after a polymerization reaction, you may heat to higher temperature. Furthermore, a cross-linking reaction catalyst may be added as necessary to allow the intra-particle cross-linking reaction to proceed more rapidly during or after the polymerization reaction. Examples of the crosslinking reaction catalyst include strong acid catalysts such as dodecylbenzenesulfonic acid and p-toluenesulfonic acid; base catalysts such as triethylamine and the like, and may be appropriately selected according to the crosslinking reaction species. The particle diameter of the polymer particles (B) produced as described above is not particularly limited, but generally, from the viewpoints of stability of the polymer particles (B), suppression of the generation of aggregates, and the like. It is appropriate to have an average particle size in the range of 0.03 to 1 μm, preferably 0.05 to 0.6 μm. This average particle diameter can be measured by a particle diameter measuring apparatus, for example, a submicron particle analyzer N5 (manufactured by Beckman Coulter, Inc.) and can be obtained by monodisperse mode analysis.

  The polymer particles (B) are oriented outward with the polyoxyalkylene chain or polyvinylpyrrolidone chain derived from the hydrophilic polymerizable unsaturated monomer (b1) chemically bonded to the polymer particle surface. Therefore, even in the absence of a dispersion stabilizer, polymerization stability and dispersion stability over time (storage stability) are extremely excellent, and the surface is rich in hydrophilicity.

  In addition, the polymer particles (B) are crosslinked in the particles due to the presence of the monomer (b3) component, and maintain their form even in the organic solvent-type paint, and are not easily melted by heating. The form can be maintained.

  In the composition of the present invention, the ratio of the solid content mass of the acrylic resin (A) to the solid content mass of the hydrophilic crosslinked polymer particles (B) is in the range of 97/3 to 55/45, particularly 95/5 to 60/40. Is preferred. When the solid content mass ratio of the above (A) and (B) is larger than 97/3, the defrosting property of the resulting film may be insufficient. On the other hand, if it is smaller than 55/45, the coating workability may be lowered, and the film thickness may be difficult to control.

Cross-linking agent (C)
The cross-linking agent (C) in the composition of the present invention is used for the purpose of improving the water resistance of the hydrophilic coating obtained after baking or maintaining long-lasting frost resistance and defrosting properties. Examples of the crosslinking agent include melamine resin, urea resin, polyaldehyde compound, phenol resin, epoxy compound, isocyanate compound, blocked polyisocyanate compound, metal compound (metal salt, metal complex, metal oxide, metal hydroxide, etc. ), Oxazoline compounds, carbodiimide compounds, hydroxyalkylamide compounds, silicate compounds and the like.

  As said melamine resin, the methylolation amino resin obtained by reaction of a melamine and an aldehyde is mention | raise | lifted. Examples of the aldehyde include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like. In addition, those obtained by etherifying this methylolated amino resin with an appropriate alcohol can be used. Examples of alcohols used for etherification include methyl alcohol, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, and n-butyl alcohol. I-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol and the like. As the melamine resin, a methylolated melamine resin in which at least a part of the methylol group is methyl etherified is particularly preferable. When using a melamine resin, the usage-amount is 0.5-100 mass parts with respect to 100 mass parts of acrylic resin (A) of this invention, Preferably it is 1-45 mass parts.

  The polyaldehyde compound is a compound having at least two aldehyde groups in one molecule, and specific examples thereof include glyoxal and glutaraldehyde.

  The polyepoxy compound is a compound having at least two epoxy groups in one molecule, and typical examples thereof include ethylene glycol diglycidyl ether, hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, Multivalents such as glycerin diglycidyl ether, glycerin triglycidyl ether, diglycerin triglycidyl ether, sorbitol polyglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol A diglycidyl ether, phenol novolac polyglycidyl ether or cresol novolac polyglycidyl ether Polyglycidyl ethers of alcohols or polyphenols; glycidyl esters of p-oxybenzoic acid and glycidyl ether Polyglycidyl esters of polycarboxylic acids such as diglycidyl phthalate, diglycidyl hexaphthalate or (meth) acrylic acid glycidyl ester copolymers; polyepoxies containing nitrogen-containing heterocycles such as hydantoin rings Compound: Epoxy resin which is an adduct of a compound having two or more epoxy groups in one molecule and a polyhydric alcohol, polyhydric phenol or polybasic acid; Modified epoxy such as fatty acid-modified epoxy resin, amine-modified epoxy resin Examples of the resin include vinyl polymers having an epoxy group in the side chain. When the epoxy compound is blended, the blending amount is 0.05 to 3 mol of the epoxy group in the epoxy compound with respect to a total of 1 mol of the carboxyl group and the hydroxyl group contained in the acrylic resin (A) of the present invention. It is desirable to adjust so that it may become in the range of 0.1-2 mol preferably.

  The said isocyanate compound is a compound which has two or more isocyanate groups in 1 molecule, and what is conventionally used for manufacture of a polyurethane can be used. Examples thereof include aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, aromatic polyisocyanates, and derivatives of these polyisocyanates.

  Examples of the alicyclic polyisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name: Isophorone diisocyanate), 4,4'-methylenebis (cyclohexyl isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane ( Common name: hydrogenated xylylene diisocyanate) or mixtures thereof, alicyclic diisocyanates such as norbornane diisocyanate, for example 1,3,5-triisocyanatocyclohexane, 1, , 5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 2- (3-isocyanatopropyl) -2 , 6-Di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 3- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 6- (2-isocyanatoethyl) -2-isocyanate Natomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyana Propyl) -bicyclo (2.2.1) -heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, etc. And alicyclic triisocyanate.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3- Aliphatic diisocyanates such as butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, such as lysine ester triisocyanate, 1,4,8- Triisocyanatooctane, 1,6,11-triisocyanatoundecane, 1,8-diisocyanato-4-isocyanatomethyloctane, 1,3,6-triisocyanatohexane, 2 5,7 and aliphatic triisocyanates such as trimethyl-1,8-diisocyanato-5-isocyanatomethyl octane and the like.

  Examples of the araliphatic polyisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω, ω′-diisocyanato-1,4-diethylbenzene, 1,3- or 1,4-bis ( 1-isocyanato-1-methylethyl) benzene (common name: tetramethylxylylene diisocyanate) or an aromatic aliphatic diisocyanate such as a mixture thereof, for example, an araliphatic triisocyanate such as 1,3,5-triisocyanatomethylbenzene And so on.

  Examples of the aromatic polyisocyanate include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 2,4′- or 4,4′-diphenylmethane diisocyanate or a mixture thereof. 2,4- or 2,6-tolylene diisocyanate or mixtures thereof, aromatic diisocyanates such as 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate, for example, triphenylmethane-4,4 ′, 4 Aromatic triisocyanates such as '' '-triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, such as 4,4'-diphenylmethane-2,2', 5 , 5'- Or the like can be mentioned aromatic tetracarboxylic isocyanates such as tiger isocyanate.

  Examples of the polyisocyanate derivative include dimer, trimer, biuret, allophanate, carbodiimide, uretdione, uretoimine, isocyanurate, oxadiazine trione, polymethylene polyphenyl polyisocyanate (crude MDI, polymeric). MDI) and a crude product of tolylene diisocyanate (crude TDI).

  The above-mentioned polyisocyanate compound may be used by modifying a part of the isocyanate group with a compound containing 1 to 5 active hydrogens such as a hydroxyl group or an amino group as needed.

  Said polyisocyanate compound may be used independently and may be used together 2 or more types.

  The blocked polyisocyanate compound as a crosslinking agent is a compound obtained by blocking the isocyanate group of the polyisocyanate compound with a blocking agent.

  The reaction between the polyisocyanate compound and the blocking agent can be carried out under known conditions. Moreover, it is preferable that the ratio of both components is set so as to be a slightly excessive amount of the blocking agent with respect to all isocyanate groups in the polyisocyanate compound so that isocyanate groups do not remain. When blocking (reacting the blocking agent), a solvent can be added as necessary. As the solvent used for the blocking reaction, those not reactive to isocyanate groups are preferable. For example, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, and solvents such as N-methylpyrrolidone (NMP). Can be mentioned.

  The blocking agent is a compound that blocks the isocyanate group. When the blocked isocyanate group is heated to, for example, 100 ° C. or higher, preferably 130 ° C. or higher, the blocking agent is dissociated to regenerate the isocyanate group and can be easily reacted with a hydroxyl group or the like.

  Examples of the blocking agent include phenols such as phenol and cresol; lactams such as ε-caprolactam and δ-valerolactam; aliphatics such as methanol, ethanol, propyl alcohol, butyl alcohol and lauryl alcohol; ethylene glycol monomethyl ether Ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and diethylene glycol monoethyl ether; benzyl alcohol; glycolic acid esters such as methyl glycolate and ethyl glycolate; lactic acid such as lactic acid, methyl lactate, ethyl lactate and butyl lactate Esters: Alcohols such as methylol urea and diacetone alcohol; Acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzoph Oximes such as enone oxime and cyclohexane oxime; active methylenes such as diethyl malonate, ethyl acetoacetate, methyl acetoacetate and acetylacetone; butyl mercaptan, t-butyl mercaptan, hexyl mercaptan, t-dodecyl mercaptan, thiophenol, ethylthiophenol Mercaptans such as acetanilide, acetanisidide, acid amides such as methacrylamide, acetic acid amide and benzamide; imides such as phthalimide and maleic imide; amines such as diphenylamine, phenylnaphthylamine, carbazole, aniline, naphthylamine and butylamine; Imidazoles such as imidazole and 2-ethylimidazole; Ureas such as urea, thiourea, ethyleneurea and diphenylurea; N Carbamate esters such as phenyl phenylcarbamate; Imines such as ethyleneimine and propyleneimine; Sulphites such as sodium bisulfite and potassium bisulfite; 3,5-dimethylpyrazole, 3-methylpyrazole, 4-nitro- Examples include pyrazole-based compounds such as 3,5-dimethylpyrazole and 4-bromo-3,5-dimethylpyrazole. The above blocking agents can be used alone or in combination of two or more.

  Of the above blocking agents, oxime and pyrazole compounds can be suitably used from the viewpoint of curability and yellowing of the coating film.

  The blocked polyisocyanate compound can be used alone or in combination of two or more. When blending the blocked polyisocyanate compound, the blending amount is usually 0.05 to 3 moles, preferably 0.05 to 3 moles, preferably 1 to 3 moles of the hydroxyl group contained in the acrylic resin (A) of the present invention. It is desirable to adjust so that it may become in the range of 0.1-2 mol.

  Examples of the polyoxazoline compound include compounds having two or more oxazoline groups in the molecule, 2,2′-p-phenylene-bis- (1,3-oxazoline), 2,2′-tetramethylene- Low molecular weight poly (1,3-oxazoline) compounds such as bis- (1,3-oxazoline), 2,2′-octamethylene-bis- (2-oxazoline); A homopolymer of a 1,3-oxazoline group-containing vinyl monomer such as oxazoline or 2-isopropenyl-1,3-oxazoline, or various vinyl monomers copolymerizable therewith is copolymerized. Examples thereof include a vinyl polymer containing a 1,3-oxazoline group.

  Commercially available oxazoline group-containing compounds include “Epocross K-1000”, “Epocross K-1020E”, “Epocross K-1030E”, “Epocross K-2010E”, “Epocross K-2020E”, “Epocross K-2030E”. "Epocross WS-500" (above, trade name, manufactured by Nippon Shokubai Chemical Industry Co., Ltd.). When blending the polyoxazoline compound, the blending amount is usually 0.05 to 3 mol of the oxazoline group in the polyoxazoline compound with respect to 1 mol of the carboxyl group contained in the acrylic resin (A) of the present invention. It is desirable to adjust so that it may become in the range of 0.1-2 mol preferably.

  Examples of the carbodiimide compound include compounds having two or more carbodiimide groups in the molecule. Specific examples thereof include “carbodilite V-02”, “carbodilite V-04”, “carbodilite V-06” (and above). Commercial products such as trade names, manufactured by Nisshinbo Industries, Inc.) can be mentioned. These can be used alone or in a mixture of two or more. When the carbodiimide compound is blended, the amount of the carbodiimide compound in the carbodiimide compound is usually 0.05 to 3 mol, preferably 0, with respect to 1 mol of the carboxyl group contained in the acrylic resin (A) of the present invention. It is desirable to adjust so that it may become in the range of 1-2 mol.

  As a 2-hydroxyalkylamide compound, for example, N, N, N ′, N′-tetrakis (2-hydroxyethyl) adipamide (trade name: PrimidXL552) is used as a tetrafunctional type having a structure in which dialkanolamine is condensed at both ends of adipic acid. CAS 6334-25-4) and N, N, N ′, N′-tetrakis (2-hydroxypropyl) adipamide (trade name: PrimidQM1260; CAS 57843-53-5) (all manufactured by EMS) . When the 2-hydroxyalkylamide compound is blended, the amount of the hydroxy group in the 2-hydroxyalkylamide compound is usually 0.00 with respect to 1 mol of the carboxyl group contained in the acrylic resin (A) of the present invention. It is desirable to adjust so that it may be in the range of 05 to 3 mol, preferably 0.1 to 2 mol.

  As the hydrazide compound, a compound having two or more hydrazide groups and / or semicarbazide groups in one molecule can be suitably used. For example, saturated fatty acid dihydrazides having 2 to 18 carbon atoms such as succinic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, etc .; maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide Unsaturated dicarboxylic acid dihydrazide, phthalic acid, terephthalic acid or isophthalic acid dihydrazide, and pyromellitic acid dihydrazide, trihydrazide or tetrahydrazide; nitrilotrihydrazide, citric acid trihydrazide, 1,2,4-benzenetrihydrazide, ethylenediaminetetrazide Low polymer having two or more acetic acid tetrahydrazide, 1,4,5,8-naphthoic acid tetrahydrazide, carboxylic acid lower alkyl ester group in one molecule Hydrazine or hydrazine hydrate (hydrazine human Dorado) and reacted and becomes polyhydrazide (see JP-B 52-22878), polyhydrazide compounds such as carbonate dihydrazide. The hydrazide compound described above can be used as a crosslinking agent when the acrylic resin (A) of the present invention contains a carbonyl group. The acrylic resin (A) can be obtained by using a monomer having a carbonyl group in the molecule such as diacetone (meth) acrylamide as the other polymerizable unsaturated monomer described above during the production thereof. When the hydrazide compound is blended, the amount of the hydrazide compound is usually 0.05 to 3 mol, preferably 0 with respect to 1 mol of the carbonyl group contained in the acrylic resin (A) of the present invention. It is desirable to adjust so that it may become in the range of 1-2 mol.

  Examples of the semicarbazide compound include a polyisocyanate compound obtained by reacting a diisocyanate such as hexamethylene diisocyanate and isophorone diisocyanate and a polyisocyanate compound derived therefrom with hydrazine or a monoalkyl-substituted hydrazine, and the polyisocyanate compound containing diisocyanate. Isocyanates in modified polyisocyanate compounds obtained from the reaction of polyhydrazide compounds obtained by reacting dihydrazide compounds and polyhydrazide compounds, polyisocyanate compounds and polyethers and polyols having active hydrogen such as polyethylene glycol monoalkyl ethers A polysemicarbazide compound obtained by reacting a group with hydrazine or a monoalkyl-substituted hydrazine; Poly hydrazide compound to the isocyanate groups obtained by reacting the above-exemplified dihydrazide or polyhydrazide and the like of Aneto compounds which alone or can be used together as a mixture as required. The semicarbazide compound described above can be used as a crosslinking agent when the acrylic resin (A) of the present invention contains a carbonyl group. The acrylic resin (A) can be obtained by using a monomer having a carbonyl group in the molecule such as diacetone (meth) acrylamide as the other polymerizable unsaturated monomer described above during the production thereof. When the semicarbazide compound is blended, the amount of the semicarbazide compound is usually 0.05 to 3 mol, preferably 0, based on 1 mol of the carbonyl group contained in the acrylic resin (A) of the present invention. It is desirable to adjust so that it may become in the range of 1-2 mol.

As a silicate compound, general formula: (R _< ¹⁷ _> ) _n- Si- (OR _< ¹⁸ _> ) _4-n (In formula, R _< ¹⁷ _> is C1-C18 alkyl which may be substituted by the epoxy group or the mercapto group.) A group or a phenyl group, and n is 0 or 1. OR ¹⁸ is an alkoxy group having 1 to 6 carbon atoms.) And / or a condensate thereof. The organosilicate and / or condensate thereof can be suitably used as a crosslinking agent when the acrylic resin (A) contains a hydroxyl group or a silyl group. From the viewpoint of crosslinking efficiency, the organosilicate is more preferably a condensate. Specific examples of R ¹⁷ in the above general formula include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, pentyl, hexyl, heptyl, n-octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, Examples include tetradecyl, hexadecyl, octadecyl, glycidyl, methylglycidyl, mercaptomethyl, 2-mercaptoethyl, 2-mercaptopropyl, 3-mercaptopropyl, 4-mercaptobutyl, phenyl, and p-mercaptophenyl groups.

  Specific examples of the organosilicate include tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraisobutoxysilane; methyltrimethoxysilane, methyltriethoxysilane, Methyltripropoxysilane, methyltriisopropoxysilane, methyltrin-butoxysilane, methyltriisobutoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane, phenyltrin-butoxysilane , Phenyltriisobutoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, lauryltrimethoxysilane, lauryltriethoxysilane It includes trifunctional silanes of. Examples of the condensate of the organosilicate include a condensate of one or a combination of two or more of these tetrafunctional or trifunctional silanes.

  The organosilicate condensate can be produced by a conventional method. For example, MKC silicate MS51, MS56, MS57, MS56S, MS56SB5, MS58B15, MS58B30, ES40, EMS31, BTS (all of which are Mitsubishi Chemical) (Trade name), methyl silicate 51, ethyl silicate 40, ethyl silicate 40T, ethyl silicate 48 (all of which are trade names, manufactured by Colcoat Co., Ltd.), KR500, KR9218, X-41-1805, X -41-1810, X-41-1818, X-41-1053, X-41-1056 (all are trade names manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. Alternatively, these organosilicate condensates can be obtained by single hydrolysis or by partial hydrolysis condensation using a combination of two or more. The organosilicate condensate is a branched or linear condensate, preferably having a condensation degree of 2 to 100, more preferably 2 to 20. Here, the degree of condensation is the average value of the number of silicon atoms contained per molecule of the organosilicate condensate. In the hydrophilic treatment composition of the present invention, the above-described organosilicate or organosilicate condensate may be used alone or in combination of two or more.

  Examples of crosslinking agents that can crosslink by reacting with carboxyl groups or hydroxyl groups contained in the acrylic resin (A) include Ba, B, Fe, Ca, Mg, Cu, Al, Zn, Ti, Zr, Pd, Pt, and Mn. The metal compound more than bivalence of these can be mentioned. As the metal compound, known compounds such as metal salts, metal complexes, metal oxides and metal hydroxides can be used. These can be used alone or in combination of two or more.

  The crosslinking agent (C) may react with the functional group of the hydrophilic crosslinked polymer particle (B) depending on the type of the functional group of the acrylic resin (A) as described above. It is preferable to use alone or select a plurality of types of crosslinking agents (C). As the crosslinking agent (C), the melamine resin, the oxazoline compound, the carbodiimide compound, the epoxy compound, the isocyanate compound, and the blocked isocyanate compound are particularly difficult to obtain from the hydrophilic treatment agent composition of the present invention. It is suitable from the viewpoint of satisfying both the frosting performance and the defrosting performance.

Hydrophilization treatment composition
The composition of the present invention comprises an acrylic resin (A), hydrophilic crosslinked polymer particles (B) and a crosslinking agent (C) as essential components. It is considered that the use of the hydrophilic crosslinked polymer particles (B) in combination with the acrylic resin (A) in the composition of the present invention led to the performance of both excellent frost resistance and defrostability. The reason is not clear, but the acrylic resin (A) is obtained by copolymerizing an unsaturated polymerizable monomer containing an amphoteric ion group-containing polymerizable unsaturated monomer. It is presumed that the fine irregularities on the surface of the coating formed by the addition of hydrophilic crosslinked polymer particles are the result of more effectively exerting this hydrophilic property. Further, since the acrylic resin (A) is obtained by copolymerizing a carboxyl group-containing polymerizable unsaturated monomer and / or a hydroxyl group-containing polymerizable unsaturated monomer, a crosslinking agent using these functional groups. It is possible to carry out a crosslinking reaction with (C). The film formed from the composition of the present invention is considered to be able to maintain the non-frosting property and the defrosting property for a long time by forming a three-dimensional network structure by this crosslinking reaction.

  The composition of the present invention comprises acrylic resin (A), hydrophilic cross-linked polymer particles (B) and cross-linking agent (C) as essential components, and usually a solvent for dissolving or dispersing these components. And, if necessary, curing catalysts, surfactants, antibacterial agents, antiseptics, antifungal agents, coloring pigments, dyes, per se known antirust pigments (for example, chromate-based, lead-based, Molybdic acid-based), rust preventives and antioxidants (for example, phenolic hydroxyl group-containing aromatic carboxylic acids such as tannic acid and 3,4,5-trihydroxybenzoic acid and their salts and esters, polyphenols, 2,2 '-Methylenebis (4-methyl-6-t-butylphenol), organic phosphoric acid such as phytic acid and phosphinic acid, metal salts of heavy phosphoric acid, nitrite, etc.), antistatic agent, flame retardant, rheology Troll, ultraviolet absorbers, known additives which can be used in paints, such as light stabilizer may be contained in a range that does not impair the desired performance of the cured coating of the composition of the present invention.

  Moreover, you may mix | blend a well-known water-soluble resin and silica particle further as needed to the composition of this invention. Examples of the water-soluble resin include polyvinyl pyrrolidone, polyvinyl alcohol, poly (meth) acrylic acid, polyethylene glycol, polyglycerin, N-alkyl substituted or N-unsubstituted (meth) acrylamide copolymer, poly (N-vinyl). Acetamide), water-soluble nylon, oxidized starch, dextrin, carboxymethyl starch, carboxymethylcellulose, hydroxymethyl starch, hydroxymethylcellulose, hydroxyethylcellulose and the like. As the silica particles, so-called silica sol or finely divided silica, usually having a particle size of about 5 nm to 10 μm, preferably 5 nm to 1 μm, and usually supplied as an aqueous dispersion is used as it is, or Fine powder silica can be used by dispersing in water. The aforementioned water-soluble resin or silica particles are used for the purpose of adjusting the hydrophilicity and physical properties of the cured film of the composition of the present invention. These water-soluble resins or silica particles can be contained as long as the desired performance of the cured film of the composition of the present invention is not impaired.

  The curing catalyst is not particularly limited as long as it promotes a crosslinking reaction with the acrylic resin (A) and the crosslinking agent (C), and a known one can be used. Examples include proton acid compounds, neutral salts of proton acid compounds and basic compounds, metal salt compounds, metal oxides, metal hydroxides, organometallic compounds, onium salt compounds such as ammonium salts and sulfonium salts, amine compounds, and the like. be able to.

  The solvent for dissolving or dispersing the acrylic resin (A), the hydrophilic cross-linked polymer particles (B), the cross-linking agent (C), and other components used as necessary is a solution polymerization of the acrylic resin (A). The above-mentioned organic solvent that can be used in the production may be used, or water or a mixed solvent of the organic solvent and water may be used.

  In the composition of the present invention, a surfactant may be used as necessary for the purpose of lowering the water contact angle on the coating surface. The surfactant may be any of anionic, cationic, zwitterionic and nonionic surfactants as long as it has a wetting action on the surface of the cured coating. Representative examples of surfactants that can be used include dialkylsulfosuccinic acid ester salts and alkylene oxide silane compounds. These surfactants can be used alone or in combination of two or more.

In the composition of the present invention, the antibacterial agent is blended as necessary for the purpose of inhibiting the generation and propagation of microorganisms in the resulting coating, and as the antibacterial agent, the following (1) to What has the conditions of (5) is suitable.
Toxic and high safety;
Stable against heat, light, acid, alkali, etc., soluble in water, and excellent in sustainability;
Have bactericidal properties at low concentrations or have the ability to inhibit the growth of bacteria;
When added to the paint, the efficacy does not decrease and the stability of the paint is not impaired;
Do not inhibit the hydrophilicity and corrosion resistance of the formed coating.
The antibacterial agent that meets such conditions can be selected from among known aliphatic and aromatic organic compounds having antibacterial and bactericidal activity, such as haloallylsulfone, iodopropargyl, N-haloalkylthio, benzthiazole, nitrile, pyridine, 8-oxyquinoline, benzothiazole, isothiazoline, phenol, quaternary ammonium salt, triazine, thiazine, anilide, adamantane And antibacterial agents such as dithiocarbamate and bromindanone.

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

  These antibacterial agents may be used alone or in combination, and the amount of the antibacterial agent can be changed according to the type of the antibacterial agent, etc., but generally the stability of the composition of the present invention, In consideration of the film forming property, the hydrophilicity of the coating, and the corrosion resistance of the article to be coated, the solids of the acrylic resin (A), the hydrophilic crosslinked polymer particles (B) and the crosslinking agent (C) are usually used. It is preferable to set it as 20 mass parts or less with respect to a total of 100 mass parts, and it is more preferable to set it as the range of 3-15 mass parts.

  The composition of the present invention comprises, for example, an acrylic solvent (A), hydrophilic cross-linked polymer particles (B), a cross-linking agent (C), and an organic solvent or an organic solvent and water together with the above-described components blended as necessary. It can be prepared by dissolving or dispersing in a mixed solvent. The hydrophilic treatment agent composition of the present invention is formed on the surface of the heat exchanger fin material, for example, by applying the hydrophilic treatment agent composition to the surface of the heat exchanger fin material and drying it, and thereby forming a cured film having excellent anti-frosting and defrosting properties. Can do.

Heat exchanger component of the present invention The heat exchanger component of the present invention has a cured coating formed by coating and baking the hydrophilic treatment agent composition of the present invention. From the viewpoint of maintaining long-lasting frost formation and defrosting properties while suppressing a decrease in thermal conductivity, it is preferable to apply the coating so that the amount of the cured coating is 0.3 to 5 g / m ² . More preferably, the coating is performed so as to be 5 to 3 g / m ² . The heat exchanger component is preferably used by using a metal material having good thermal conductivity such as aluminum, iron, copper, etc., among which aluminum material is particularly preferable.

  In the case where the heat exchanger component is, for example, an aluminum fin, an aluminum plate (which may be assembled in a heat exchanger) whose surface of the aluminum material is degreased and subjected to chemical conversion treatment as necessary is preferably used. It is done. The surface of the fin made of aluminum is particularly preferably subjected to a chemical conversion treatment from the viewpoints of adhesion of the hydrophilic treatment agent composition film, corrosion resistance, and the like. As the chemical conversion treatment, a conventionally known method can be used.

  The hydrophilic treatment composition can be applied by a method known per se, for example, a flow coating method, dip coating, shower coating, spray coating, electrostatic spray coating, roll coating, electrophoretic coating, or the like. Baking after coating is preferably performed at a baking temperature (maximum material arrival temperature) of 60 to 300 ° C. and a baking time of 5 seconds to 30 minutes. When the maximum material reaching temperature is lower than 60 ° C or the baking time is shorter than 5 seconds, the resulting coating has insufficient cross-linking reaction, resulting in long-lasting performance of difficult frost formation and defrosting. It may not be possible. In addition, when the baking temperature is higher than 300 ° C. or when the baking time is longer than 30 minutes, the partial heat deterioration of the organic component in the cured coating film occurs, and the long-lasting performance of difficult frost formation and defrosting properties is achieved. It may not be obtained. When the cured film of the hydrophilizing agent composition of the present invention is formed on the surface of the aluminum plate, it can be processed after forming the film to obtain a heat exchanger component.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the following, “parts” and “%” mean “parts by mass” and “% by mass”, respectively.

Production example of acrylic resin (Production Example 1)
A reaction vessel equipped with a thermometer, thermostat, reflux condenser, monomer tank, stirrer, etc. was charged with 85 parts of propylene glycol monomethyl ether and 85 parts of deionized water, heated to 80 ° C. and held under a nitrogen stream. 100 parts of the monomer having the composition described in 1 (methacryloyloxyethyl-N, N-dimethylammonium-α-methylcarboxybetaine 25 parts, acrylic acid 10 parts, 2-hydroxyethyl acrylate 10 parts, methyl acrylate 30 parts, ethyl acrylate 25 Part), radical polymerization initiator 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate 0.7 part, and deionized water 50 part in a monomer tank. The mixture was dropped into the reaction vessel over 2 hours. After completion of the dropwise addition, the mixture was further maintained at the same temperature for 0.5 hour, and then 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate 0.5 part and deionized water. The mixture with 5 parts was added dropwise over 0.5 hours. Then, it hold | maintained at the same temperature for 1 hour, and obtained acrylic resin solution A-1 of 33% of solid content. The obtained resin had a resin acid value of 78 mgKOH / g and a hydroxyl value of 48 mgKOH / g.

(Production Examples 2 to 10)
In the manufacture example 1, it manufactured like the manufacture example 1 except having set it as the mixing | blending which described the monomer composition in Table 1, and obtained acrylic resin solution A-2 to A-10. The acid value and hydroxyl value of the obtained resin are shown together in Table 1.

  The methacryloyloxyethyl-N, N-dimethyl-N- (3-sulfopropyl) ammonium betaine of Production Example 4 was obtained from Journal of Applied Polymer Science, Vol. 30, (1885). It was synthesized by the following method described on page 4697. After adding 35 parts of N, N-dimethylaminoethyl methacrylate and 80 parts of acetone to a reaction tank equipped with a thermometer, thermostat, reflux condenser, monomer tank, stirrer, etc., 1,3-propane sultone was stirred. 27.2 parts were dissolved in 12 parts of acetone and added dropwise over 30 minutes. After reacting at 30 ° C. for 4 hours, the precipitate was filtered, and the resulting white crystals were washed twice with dehydrated acetone, dried under reduced pressure, and then methacryloyloxyethyl-N, N-dimethyl-N- (3-sulfopropyl). Ammonium betaine was obtained.

The methacryloyloxyethyl phosphorylcholine of Production Example 5 was synthesized by the following method described in JP-A No. 58-154591.
13 parts of 2-hydroxyethyl methacrylate and 9.35 parts of triethylamine were placed in 150 ml of dry diethyl ether, and 14.25 parts of 2-chloro-1,3,2-dioxaphosphorane was added dropwise while cooling to -20 ° C. did. During the dropwise addition, the reaction temperature was kept at -20 to -10 ° C, and after completion of the dropwise addition, the mixture was stirred for 2 hours under ice cooling. After further stirring for 30 minutes at room temperature, triethylamine hydrochloride was removed, and diethyl ether was distilled off under reduced pressure to obtain methacryloyloxyethyl-1,3,2-dioxaphospholane (Compound 1).
9.44 parts (0.04 mol) of Compound 1, 11.8 parts (0.2 mol) of trimethylamine and 80 ml of acetonitrile were placed in a pressure-resistant reaction tube and shaken at 50 ° C. for 10 hours. Concentrated immediately after the reaction and stored in a cold place to obtain white crystals. The crude crystals were dissolved in dehydrated chloroform and reprecipitated with dehydrated acetone to obtain methacryloyloxyethyl phosphorylcholine.

(* 1) Made by Osaka Organic Chemical Industry (* 2) Methoxypolyethylene glycol monomethacrylate, the number of repeating units of oxyethylene group is about 45, solid content 50%, made by Evonik Degussa Japan
Production example of hydrophilic crosslinked polymer particles
Production of hydrophilic crosslinked polymer particles (B-1)
200 parts of propylene glycol monomethyl ether was placed in a flask equipped with a thermometer, thermostat, reflux condenser, monomer tank, stirrer, etc., and heated to 80 ° C. Next, a mixture of the following polymerizable unsaturated monomer, organic solvent, deionized water, and polymerization initiator is dropped into the flask over 5 hours, and after completion of the dropwise addition, the mixture is kept at 80 ° C. for 2 hours to obtain a hydrophilic crosslinked polymer. A dispersion liquid of particles (B-1) was obtained.
BLEMMER PME-4000 (methoxypolyethylene glycol monomethacrylate, oxyethylene group repeat unit number about 90, solid content 100%, manufactured by NOF Corporation) 20 parts acrylamide 50 parts N-methylol acrylamide 15 parts acrylic acid 10 parts methylene bisacrylamide 5 parts propylene glycol monomethyl ether 150 parts deionized water 50 parts ammonium persulfate 1.5 parts The resulting dispersion is a milky white, stable 20% solids dispersion with a polymer particle size of 320 nm It was measured with a micron particle analyzer N5 (manufactured by Beckman Coulter) and determined by monodisperse mode analysis).

Production of hydrophilic crosslinked polymer particles (B-2)
170 parts of propylene glycol monomethyl ether was put into a flask equipped with a thermometer, a thermostat, a reflux condenser, a monomer tank, a stirrer and the like, and the temperature was raised to 80 ° C. Next, a mixture of the following polymerizable unsaturated monomer, organic solvent, deionized water, and polymerization initiator is dropped into the flask over 5 hours, and after completion of the dropwise addition, the mixture is kept at 80 ° C. for 2 hours to obtain a hydrophilic crosslinked polymer. A dispersion of particles (B-2) was obtained.
Bremer PME-4000 (methoxypolyethylene glycol monomethacrylate, oxyethylene group repeat unit number about 90, solid content 100%, manufactured by NOF Corporation) 30 parts acrylamide 45 parts acrylic acid 15 parts glycidyl methacrylate 10 parts propylene glycol monomethyl ether 150 Part deionized water 80 parts Ammonium persulfate 1.5 parts The resulting dispersion is a milky white, stable dispersion with a solid content of 20%, and the particle size of the resin particles is 163 nm (submicron particle analyzer N5 (Beckman Coulter And obtained by monodisperse mode analysis).

Production of hydrophilizing agent composition (Example 1)
Acrylic resin solution A-2 obtained in Production Example 1 in a solid amount of 64 parts, hydrophilic cross-linked polymer particle B-1 in a solid amount of 16 parts, Cymel 701 (manufactured by Nippon Cytec Industries, methyl etherified melamine resin, The solid content was 20 parts by weight, and deionized water was added as a solvent and stirred to obtain a hydrophilic treatment composition 1 having a solid content of 15%.

(Examples 2 to 15 and Comparative Examples 1 to 3)
In the same manner as in Example 1 with the formulation shown in Table 2-1 and Table 2-2, hydrophilic treatment compositions 2 to 18 having a solid content of 15% were obtained. In addition, the compounding quantity in a table | surface is solid content.

(* 3) Methyl etherified melamine resin, solid content 82%, manufactured by Nippon Cytec Industries, Ltd. (* 4) Oxazoline group-containing acrylic polymer, solid content 25%, manufactured by Nippon Shokubai Co., Ltd. (* 5) Polyepoxy compound, solid content 100 %, Nagase ChemteX Corp. (* 6) Blocked polyisocyanate compound, solid content 80%, Asahi Kasei Chemicals Corp. (* 7) Polyisocyanate compound, solid content 100%, manufactured by Sumika Bayer Urethane Co., Ltd.
Preparation of paint test plate
The hydrophilic treatment composition obtained in Examples 1 to 15 and Comparative Examples 1 to 3 was dissolved in an alkaline degreasing agent (manufactured by Nippon CB Chemical Co., Ltd., trade name “Chem Cleaner 561B”) with a concentration of 2%. After degreasing using an aqueous solution, an aluminum plate (A1050, made by chromate treatment (made by Nippon Parkerizing Co., Ltd., trade name “Alchrome 712”) and subjected to chromate treatment (metal chromium equivalent coating amount 30 mg / m ² ) A coating test plate was obtained by applying to a thickness of 0.1 mm) so that the amount of the cured coating was 1 g / m ² and baking for 10 seconds under the condition that the final material arrival temperature was 220 ° C. The obtained coated test plate was tested according to the following test method. The test results are shown in Tables 2-1 and 2-2.

Test method
Difficult frost formation: A coating test plate is cut into 5 cm × 10 cm, pasted on a Peltier element, and the Peltier element is cooled to −10 ° C. in a booth where the room temperature is 8 ° C. and the room humidity is 70%. Evaluation was made by visually comparing the time until frost formation in a state where the coating test plate was set up vertically. The difficulty frost formation property was evaluated as “◎” when the time until the frost formation could be visually confirmed was 5 minutes or more, and “x” when the time was less than 5 minutes. Note that the Peltier element refers to a plate-like semiconductor element that utilizes the Peltier effect that heat is transferred from one metal to the other when a current is passed through a joint between two kinds of metals. When direct current is passed, one surface absorbs heat and the other surface generates heat. When the polarity of the current is reversed, high-precision temperature control is possible by utilizing the fact that the relationship is reversed.

  Defrosting property: In the above-described difficult frosting property test, after the surface of the coating test plate was frosted, the Peltier device was kept at -10 ° C for 30 minutes, and then the coating test plate was set up in a vertical state. Was heated to 5 ° C. to melt the frost. When water (condensation water) generated by melting of frost remains on the test plate surface in the state where the paint test plate is set up vertically, the proportion of the area occupied by the water droplets on the test plate surface (%). Condensation water droplet ratio is calculated by reading the image of the test plate obtained by photographing the test plate with the camera into the image processing software (WinROOF, Mitani), and the other part where the water droplets are attached on the test plate. It distinguished on the image and the ratio for which the area which the water droplet on the test plate adhered occupied was calculated | required as a dew condensation water droplet ratio. In the case where water droplets were not observed on the test plate surface because the dew condensation water spread on the test plate surface and dropped from the test plate surface, the dew condensation water droplet ratio was 0%, and the evaluation was the best “◎”. If the water droplets remain on the surface of the test plate and the condensed water droplet ratio is less than 5%, the evaluation is “◯”. If the condensed water droplet ratio is 5% or more and less than 10%, the evaluation is “△”, and the condensed water droplet ratio is 10%. In the above case, the evaluation was “x”. The defrosting property is a level where evaluation of “◯” or more is practical.

Persistence of hard frost formation and defrosting: The test plate is dipped in running tap water (flow rate is 15 kg / hr per m ^{2 of} test plate) for 72 hours and dried in an atmosphere at 80 ° C. for 15 minutes. The above-mentioned difficult frost formation test and defrosting test were performed using the coated test plate.

Claims (3)

At least one zwitterionic group-containing polymerizable monomer selected from the group consisting of a polymerizable unsaturated monomer having a betaine structure represented by the following formula (1) and a polymerizable unsaturated monomer having a phosphorylcholine structure represented by the following formula (2): At least one polymerizable unsaturated monomer (a2) selected from the group consisting of a saturated monomer (a1), a carboxyl group-containing polymerizable unsaturated monomer, and a hydroxyl group-containing polymerizable unsaturated monomer, and other polymerizable unsaturated monomers (a3 ), An acrylic resin (A) obtained by copolymerization, hydrophilic cross-linked polymer particles (B), and a cross-linking agent (C).

(R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 1 to 8 carbon atoms, and R ³ and R ⁴ are linear chains having 1 to 4 carbon atoms that may be independently substituted with a hydroxyl group. Represents a linear or branched alkyl group, and R ⁵ represents a linear or branched alkylene group having 1 to 15 carbon atoms which may be substituted with a hydroxyl group, or a phenylene group which may be substituted with a hydroxyl group, Z represents an oxygen atom or an imino group, X ^- represents a sulfonic acid anion, carboxylic acid anion group, any one group of phosphoric acid anion group).

(R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ represents an alkylene group having 1 to 8 carbon atoms.) The hydrophilic treatment composition according to claim 1, wherein the crosslinking agent (C) is at least one selected from the group consisting of a melamine resin, an oxazoline compound, a carbodiimide compound, an epoxy compound, an isocyanate compound, and a blocked isocyanate compound. A heat exchanger component coated with the hydrophilic treatment composition according to claim 1 or 2.