JP2009179811A5 - - Google Patents

Description

Crosslinkable fine particles, hydrophilic treatment agent, hydrophilic film coating method and hydrophilic film

The present invention relates to crosslinkable fine particles, a hydrophilic treatment agent, a hydrophilic film coating method, and a hydrophilic film.

Various surface treatments are performed on the surface of the metal material. In particular, aluminum and its alloys are widely used in heat exchangers because they are lightweight and have excellent workability and thermal conductivity.

In heat exchanger fins such as air conditioners, moisture in the air adheres to the fin surface as condensed water during cooling operation. As a result of clogging due to water droplets, ventilation resistance is increased and heat exchanger exchange efficiency is reduced. In addition, there are problems such as generation of noise and contamination due to scattering of water droplets. In order to prevent such a problem from occurring, it has been conventionally performed that the fin surface is subjected to a hydrophilic treatment.

In recent years, as a required performance for the hydrophilization treatment, the persistence of hydrophilicity when contaminants adhere has become important. This is because the environment where air conditioners are used has various indoor suspended substances such as plastic lubricants such as palmitic acid, stearic acid and paraffinic acid, and pollutants such as diisooctyl phthalate. This is because it adheres to and significantly deteriorates the hydrophilicity.

As a hydrophilization treatment, a polymer composition for hydrophilization treatment containing a polymer such as a polyacrylic acid polymer and a polymer such as polyethylene oxide that forms hydrogen bonds with the polymer has been proposed (see, for example, Patent Document 1). .) This is a technique for improving the sustainability of hydrophilicity, but it is not a technique assuming the sustainability when a pollutant such as palmitic acid adheres, and it is insufficient for the sustainability of the pollutant. Further, the adhesion in a state where moisture is attached is also insufficient.

Hydrophilic surface treating agent containing carboxymethylcellulose salt, N-methylolacrylamide, polyacrylic acid and polyethylene oxide, and hydrophilic polymer containing polyoxyalkylene chain, aqueous resin, and hydrophilic surface containing N-methylolacrylamide Treatment aqueous solutions have been proposed (see, for example, Patent Documents 2 and 3). Since these are blended with N-methylolacrylamide as a monomer, they are insufficient in sustainability when contaminants adhere to them.

Obtained from a crosslinkable unsaturated monomer having a polyoxyalkylene chain, a (meth) acrylamide monoethylenic monomer, an N-methylol group such as N-methylolacrylamide and a polymerizable double bond, and other monomers Hydrophilic crosslinked polymer fine particles have been proposed (see, for example, Patent Documents 4 to 6).

The technique disclosed here is not a technique assuming the sustainability of hydrophilicity when contaminants such as palmitic acid adhere. Moreover, since N-methylol acrylamide etc. are only mix | blended as a component which contributes to bridge | crosslinking of particle | grains, the compounding quantity of N-methylol acrylamide etc. is a comparatively little thing, As a result, it is obtained. The hydrophilic crosslinked polymer fine particles are not satisfactory in hydrophilic sustainability when contaminants adhere to them.

JP-A-6-322292 (2nd page) Japanese Patent Application Laid-Open No. 6-322552 (second page) JP 7-102189 A (page 2) JP-A-8-120003 (page 2) JP 2000-248225 A (page 2) JP 2002-302644 A (second page)

In view of the above, the present invention can be suitably used for metals, particularly aluminum and alloys thereof, and has excellent hydrophilicity, particularly hydrophilic sustainability after adhesion of contaminants, and excellent adhesion. An object of the present invention is to provide crosslinkable fine particles and a hydrophilic treatment agent capable of forming a hydrophilic film.

The present invention provides the following formula (1);

(In the formula, R ¹ represents hydrogen or a methyl group. R ² represents CH ₂ or C ₂ H _4. )
40 to 95% by mass of the monomer (a), 5 to 60% by mass of the monomer (b) having a polyoxyalkylene chain and a polymerizable double bond, and 0 to 30 % by mass of the other polymerizable monomer (c). % of a monomer component consisting of copolymerization-obtained water swelling ratio at a polymerization temperature of 95 to 105 ° C. in a substantially undissolved water-miscible organic solvent copolymer monomers used to produce dissolves 1 .3 or less crosslinkable fine particles (excluding those in which the other polymerizable monomer (c) contains (meth) acrylic acid).

The monomer (b) has the following formula (2):

(In the formula, R ³ and R ⁴ are the same or different and each represents hydrogen or a methyl group. R ⁵ represents hydrogen, a methyl group, SO ₄ H, SO ₄ Na, or SO ₄ NH ₄ . Represents an integer of 6 to 300), and / or the following formula (3);

(In the formula, R ⁶ and R ⁸ are the same or different and each represents hydrogen or a methyl group. R ⁹ represents hydrogen, a methyl group, SO ₄ H, SO ₄ Na, or SO ₄ NH _4. R ⁷ represents R ^7. CH ₂ or

Represents. m represents an integer of 6 to 300. It is preferable that it is a compound represented by this.

The monomer (b) is preferably a compound containing 50% by mass or more of a polyoxyalkylene chain .

The present invention is a hydrophilic treatment agent containing the crosslinkable fine particles and a hydrophilic resin.

The hydrophilic resin is preferably at least one selected from the group consisting of acrylic resins having an acid value of 200 or more or a hydroxyl value of 200 or more, polyvinyl alcohol, carboxymethyl cellulose, and modified resins thereof.

The mixing ratio of the crosslinkable fine particles to the hydrophilic resin is preferably 1/99 to 80/20.
The present invention is a method for coating a hydrophilic film, comprising the step of applying the hydrophilic treatment agent.

The present invention also provides a hydrophilic film formed by the above-described hydrophilic film coating method.
Hereinafter, the present invention will be described in detail.

Since the crosslinkable fine particles of the present invention have the above-described configuration, the hydrophilic film formed using the hydrophilic treatment agent containing the crosslinkable fine particles is contaminated with a contaminant such as palmitic acid. Even so, the hydrophilicity is maintained and the adhesiveness is also excellent. Accordingly, the crosslinkable fine particles of the present invention can be suitably used for, for example, fins of aluminum heat exchangers used in air conditioners and the like.

The crosslinkable fine particles of the present invention are obtained from the monomer (a) represented by the above formula (1), the monomer (b) having a polyoxyalkylene chain and a polymerizable double bond, and other polymerizable monomers (c). It is the resin particle which consists of a copolymer obtained by copolymerizing the monomer component which becomes. In the crosslinkable fine particles, the methylol group or ethylol group in (a) reacts with a functional group such as a carboxyl group or a hydroxyl group in (b), a methylol group or an ethylol group undergoes a condensation reaction, or ( Since it reacts with the carboxyl group and hydroxyl group of c), when used as a component of a hydrophilic treatment agent, a strong water-insoluble hydrophilic film can be formed. In addition, since the crosslinkable fine particles have high hydrophilicity and have a relatively large number of unreacted functional groups, when used as a component of a hydrophilic treatment agent, they react with other hydrophilic resins, and the hydrophilicity is not impaired and contamination. Later hydrophilic sustainability can be greatly improved. Furthermore, since the crosslinkable fine particles have a relatively low swelling rate with respect to water, the hydrophilic film formed is also prevented from dissolving in water.

The monomer (a) represented by the above formula (1) is N-methylolacrylamide, N-methylolmethacrylamide, N-hydroxyethylacrylamide or N-hydroxyethylmethacrylamide. In the case where the monomer (a) represented by the above formula (1) is used, a coating excellent in hydrophilic sustainability and adhesion can be formed by using a hydrophilic treatment agent containing the resulting crosslinkable fine particles. . These may be used alone or in combination of two or more.

The crosslinkable fine particles are obtained by copolymerizing a monomer component containing the lower limit of 30% by mass and the upper limit of 95% by mass of the monomer (a) represented by the formula (1). Since the monomer (a) represented by the above formula (1) is blended in the above range, it not only functions as a crosslinking component but also functions as a main component of a hydrophilic film forming component. That is, when it is blended in order to express only the function as a crosslinking component, it is usually used as a blending amount smaller than the above range. By using the monomer (a) in a blending amount within the above range, methylol groups and ethylol groups remain in the crosslinkable fine particles even after copolymerization. For this reason, when a hydrophilic film is formed using the hydrophilic treatment agent containing the crosslinkable fine particles, it reacts with other hydrophilic resins to obtain strong adhesion and hydrophilic durability. Accordingly, the hydrophilicity can be sufficiently maintained even after the formed hydrophilic film is adhered with a lubricant for plastics such as palmitic acid, stearic acid and paraffinic acid, and a contaminant such as diisooctyl phthalate.

In addition, the crosslinkable fine particles obtained by blending the monomer (a) represented by the above formula (1) have a high degree of crosslinking due to the blended amount. For this reason, it is suppressed that the hydrophilic film to be formed is dissolved by moisture, and a film having excellent adhesion (adhesion when the film is exposed to moisture) can be formed.

It is preferable that the compounding quantity of the monomer (a) represented by the said Formula (1) is a minimum of 30 mass% and an upper limit of 90 mass% with respect to 100 mass% of monomer components. If it is less than 30% by mass, the sustainability of hydrophilicity after contamination of the hydrophilic film may be reduced. If it exceeds 90% by mass, production may be difficult. The lower limit is more preferably 40% by mass, and the upper limit is more preferably 80% by mass.

The monomer (b) is not particularly limited as long as it is a monomer having a polyoxyalkylene chain and a polymerizable double bond, but may be a compound represented by the above formula (2) and / or the above formula (3). preferable. Thereby, crosslinkable fine particles having excellent hydrophilicity and stable in water dispersion can be obtained.

In the above formula (2), R ³ and R ⁴ are the same or different and represent hydrogen or a methyl group. R ⁵ represents hydrogen, a methyl group, SO ₄ H, SO ₄ Na, or SO ₄ NH ₄ .

In the above formula (2), n represents an integer having a lower limit of 6 and an upper limit of 300. When it is less than 6, dispersion stability and hydrophilicity are insufficient, and when it exceeds 300, production becomes difficult. The lower limit is more preferably 30, and the upper limit is preferably 200.

In the above formula (3), R ⁶ and R ⁸ are the same or different and each represents hydrogen or a methyl group. It said ^{R 9} represents hydrogen, _methyl, SO 4 H, the _SO 4 Na or _SO 4 NH _4. R ⁷ represents CH ₂ or a benzene ring (already represented by the chemical formula).

In the above formula (3), m represents an integer having a lower limit of 6 and an upper limit of 300. When it is less than 6, dispersion stability and hydrophilicity are insufficient, and when it exceeds 300, production becomes difficult. The lower limit is more preferably 30, and the upper limit is preferably 200.

The monomer (b) is not particularly limited. For example, in addition to the compounds represented by the formula (2) and the formula (3), methoxypolyethylene glycol monomethacrylate, methoxypolyethylene glycol monoacrylate, octoxypolyethylene glycol- A polypropylene glycol monoacrylate etc. can also be mentioned. These may be used alone or in combination of two or more.

The monomer (b) is preferably a compound containing 50% by mass or more of a polyoxyalkylene chain. Here, 50 mass% or more means that the total solid mass of the polyoxyalkylene chain portion is 50 mass% or more in the total solid mass 100 mass% of the monomer (b) used. If it is less than 50% by mass, the hydrophilicity of the hydrophilic film may decrease. The monomer (b) more preferably contains a polyoxyalkylene chain at a lower limit of 80% by mass and an upper limit of 99% by mass.

The blending amount of the monomer (b) is a lower limit of 5% by mass and an upper limit of 60% by mass with respect to 100% by mass of the monomer component. If it is less than 5% by mass, the dispersibility of the crosslinkable fine particles in the hydrophilic treatment agent may be lowered, and the hydrophilicity of the hydrophilic film may be lowered. When it exceeds 60 mass%, the adhesiveness of the hydrophilic film is insufficient and the sustainability of hydrophilicity after contamination may be lowered. The lower limit is preferably 10% by mass, and the upper limit is preferably 40% by mass.

The other polymerizable monomer (c) has a polymerizable unsaturated bond in one molecule and can be copolymerized with the monomer (a) represented by the formula (1) and the monomer (b). if compound is not particularly limited, for example, Lee itaconic acid, carboxylic acid such as maleic acid, vinyl monomers such as vinyl acetate group, 2-hydroxyethyl acrylate, a hydroxyl group, such as hydroxypropyl acrylate, N- vinyl acetamide , N-vinylformamide, N-vinylpyrrolidone, N-vinylimidazole, acrylonitrile, methyl acrylate, methyl methacrylate, styrene, unsaturated double bond-containing surfactant, acrylamide, methacrylamide, N-methylacrylamide, N-vinyl Sulfonic acid, N-allyl sulfonic acid, styrene sulfonic acid soda, 2 acrylic Amide 2-methylpropane sulfonic acid, and the like. Moreover, unsaturated monomers used for normal radical polymerization, such as methyl acrylate, acrylic esters other than methyl methacrylate, and methacrylic esters, can also be used . These may be used alone, or may be used in combination of two or more thereof.

The blending amount of the other polymerizable monomer (c) is 0% by mass for the lower limit and 50% by mass for the upper limit with respect to 100% by mass of the monomer component. If it exceeds 50% by mass, the hydrophilicity and crosslinkability of the resulting crosslinkable fine particles may be lowered, and the hydrophilicity of the hydrophilic film after contamination may be lowered. The upper limit is more preferably 30% by mass.

The crosslinkable fine particles of the present invention preferably have a water swelling ratio of 1.5 or less. Thereby, when forming a hydrophilic film | membrane, even if it expose | bleaches to a water | moisture content, it is suppressed that the adhesiveness of a film | membrane falls. The water swelling ratio of 1.5 or less is determined by appropriately changing the reaction conditions of the monomer (a) represented by the above formula (1), the monomer (b) and the other polymerizable monomer (c) with the above-mentioned mixing ratio. It can be obtained by setting. The water swelling rate is more preferably a lower limit of 1.0 and an upper limit of 1.3. In addition, the water swelling ratio in this specification is a value calculated as water swelling ratio = particle diameter in aqueous solution / particle diameter in solvent. The particle diameter is a value measured using an electrophoretic light scattering photometer photo ELS-800 (manufactured by Otsuka Electronics Co., Ltd.).

The crosslinkable fine particles of the present invention include, for example, 30 to 95% by mass of the N-methylol (meth) acrylamide, 5 to 60% by mass of the monomer (b) having a polyoxyalkylene chain and a polymerizable double bond, and the other Polymerizable monomer (c) in an amount of 0 to 50% by weight in a water-miscible organic solvent that dissolves the monomer used but does not substantially dissolve the resulting copolymer in the absence of a dispersion stabilizer. It can be produced by polymerization in an organic solvent / water mixed solvent.

In the polymerization in the production of the crosslinkable fine particles, a dispersant may be used in combination. Examples of the dispersant include dispersion resins such as polyvinyl pyrrolidone, polyvinyl alcohol, and polycarboxylic acid, and anionic, cationic, and nonionic surfactants.

In the production of the crosslinkable fine particles of the present invention, the copolymerization of the monomer component comprising the above (a), (b) and (c) is an ether such as alkylene glycol monoalkyl ether (for example, ethylene glycol monobutyl ether). The reaction can be carried out in a solvent such as a system solvent, methoxypropanol, and a mixed solvent of these with water.

The copolymerization of the monomer component consisting of (a), (b) and (c) is usually performed in the presence of a radical polymerization initiator. It does not specifically limit as said radical polymerization initiator, All can be used normally. For example, peroxides such as benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, t-butyl peroctoate, t-butylperoxy 2-ethylhexanoate; 2,2′-azobis Isobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisiso Azo compounds such as butyrate and 4,4'-azobis (4-cyanopentanoic acid); 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (N-N'- Dimethylene isobutylamidine), 2,2'-azobis (N-N'-dimethyleneisobutylamidine) dihydrochloride and other amidines Compounds; potassium persulfate, persulfate-based initiator or sodium thiosulfate to such ammonium persulfate, can be given in combination with the system, such as an amine or the like. These may be used alone or in combination of two or more. The amount used can usually be in the range of 0.2 to 5 mass% with respect to the total amount of monomers.

The polymerization temperature in the above copolymerization can be changed depending on the type of polymerization initiator used, but a temperature within the range of a lower limit of 70 ° C. and an upper limit of 140 ° C. is usually appropriate. If it is less than 70 ° C, the crosslinkability becomes insufficient, and if it exceeds 140 ° C, it is difficult to control the reaction. The lower limit is more preferably 90 ° C, and the upper limit is more preferably 120 ° C. The reaction time is usually 0.2 to 5 hours. If it is less than 0.2 hours, the crosslinkability becomes insufficient, and even if it exceeds 5 hours, the reaction does not change, which is economically disadvantageous. By setting the polymerization temperature to 90 ° C. or higher, the intraparticle crosslinking can be advanced. When the polymerization temperature is less than 70 ° C., the intra-particle crosslinking reaction usually hardly proceeds during the polymerization. Therefore, after the polymerization reaction, the resulting polymer is usually heated at a temperature of 90 ° C. or more for 0.2 to 5 hours. An operation for advancing intra-particle crosslinking is performed.

In addition, a crosslinking reaction catalyst may be added to the polymerization reaction system as necessary in order to advance the intraparticle crosslinking reaction of the polymer particles during or after the polymerization reaction more quickly. Examples of the crosslinking reaction catalyst include strong acid catalysts such as dodecylbenzenesulfonic acid and paratoluenesulfonic acid; and polymerizable double bond-containing strong acid catalysts such as sulfoethyl methacrylate.

The particle diameter of the crosslinkable fine particles obtained as described above is not particularly limited, but is generally within the range of 0.03 to 1 μm, preferably 0.05 to 0.6 μm, from the viewpoint of the stability of the crosslinkable fine particles. is there.

The hydrophilic treatment agent containing the above-mentioned crosslinkable fine particles and hydrophilic resin can form a hydrophilic film excellent in hydrophilic durability and adhesion, and such a hydrophilic treatment agent is also one of the present inventions. It is. The said hydrophilic processing agent can form the hydrophilic film excellent in hydrophilic sustainability and adhesiveness, when using with respect to a metal, especially aluminum, or its alloy.

The hydrophilic resin is not particularly limited as long as it is a hydrophilic resin. For example, the unsaturated polymerizable monomer or unsaturated polymerizable aqueous polymer compound containing a carboxyl group and / or a hydroxyl group, a carboxyl group and / or Examples thereof include natural polymer compounds containing hydroxyl groups or derivatives thereof, aqueous alkyd resins, aqueous polyester resins, aqueous polybutadiene resins, aqueous polyamide resins, aqueous epoxy resins, aqueous polyurethane resins, aqueous phenol resins, aqueous amino resins, and the like. .

Examples of the unsaturated polymerizable monomer or unsaturated polymerizable aqueous polymer compound containing a carboxyl group and / or a hydroxyl group include poly (meth) acrylic acid, (meth) acrylic acid / (meth) acrylic ester copolymer Products, styrene / (meth) acrylic copolymer, polyvinyl alcohol partially saponified with polyvinyl acetate resin, polyvinyl pyrrolidone and the like. Here, the poly (meth) acrylic acid and the (meth) acrylic acid / (meth) acrylic acid ester copolymer contribute to improvement of alkali resistance and corrosion resistance. Further, polyvinyl alcohol obtained by partially saponifying polyvinyl acetate resin has an effect of preventing odor and imparting hydrophilicity. Polyvinyl pyrrolidone has the effect of slightly improving hydrophilic sustainability. In addition, a polyvinyl acetate resin, a polyvinyl chloride resin, a vinyl chloride / vinyl acetate copolymer, a polymer of (meth) acrylamide, and the like may be added as long as the effects of the present invention are not impaired.

Examples of the natural polymer compound or derivative thereof containing a carboxyl group and / or a hydroxyl group include carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl cellulose (MC), ethyl cellulose (EC ), Cellulose derivatives such as ethyl hydroxyethyl cellulose (EHEC), methyl cellulose derivatives and the like. The cellulose derivative is not limited to this, and may be carboxymethyl ether, carboxyethyl ether, hydroxymethyl ether, hydroxyethyl ether of cellulose, starch acetate or phosphate starch. The methyl cellulose derivative is not limited to this, and an adduct obtained by adding a hydroxyethyl group or a hydroxypropyl group to methyl cellulose may be used. Further, gums containing a carboxyl group, or added with ethylene oxide (EO) or propylene oxide (PO), or polysaccharide derivatives may be used. Further, tannic acid, lignin sulfonic acid, alginic acid, hyaluronic acid and the like may be used. Further, polyglutamic acid (PGA) may be used, and when polyglutamic acid is used, the hydrophilic durability is remarkably improved. Polyglutamic acid includes γ-PGA and α-PGA, and either may be used.

Examples of the aqueous alkyd resin include polyols such as glycerol, pentaerythritol, ethylene glycol, and trimethylol ethane, and higher fatty acids obtained from fats and oils such as dibasic acids such as palmitic acid, phthalic anhydride, and maleic anhydride. Can be obtained by condensing.

Examples of the aqueous polyester resin include those obtained by subjecting the hydroxyl group in the polyester resin to a half-esterification reaction with trimellitic anhydride and neutralizing the remaining carboxylic acid group with an amine or the like to make it aqueous. Can do. In addition, there is a polyester resin obtained by reacting polyethylene glycol with a polybasic acid.

Examples of the aqueous polybutadiene resin include those obtained by polymerizing butadiene using a catalyst, and include 1,2-bond type and 1,4-bond type, which can be used together. These can be formed into a film by heat, peroxide, sulfur or the like.

Examples of the aqueous polyamide resin include (1) by ring-opening polymerization of ε-caprolactam (2) by condensation polymerization of hexamethylenediamine and adipic acid (3) by condensation polymerization of hexamethylenediamine and sebacic acid (4) Examples include those obtained by condensation polymerization of 11-aminoundecanoic acid (5) those obtained by ring-opening polymerization of ω-ralium lactam or those obtained by condensation polymerization of 12-aminododecanoic acid.

Examples of the aqueous epoxy resin include, as water-soluble epoxy resins, di- or polyglycidyl ethers of aliphatic polyhydric alcohols, dicarboxylic acid diglycidyl esters, and epoxy compounds containing nitrogen-containing heterocycles. In addition, as water acidic epoxy resin, suitable emulsifier is added to water or a mixture of water and organic solvent, epoxy resin is dispersed and emulsified, and epoxy resin is modified or dissolved or dispersed and emulsified in water Specifically, a hydrophilic group is introduced into an epoxy resin, or an anionic group such as a carboxyl group or a cationic group such as an amino group is introduced, and this is neutralized with a hydroxyl group or an acid to make the polymer electrolyte aqueous. Can be mentioned.

Examples of the aqueous polyurethane resin include those obtained by introducing an anion or a cationic group into the molecule to make it aqueous. In addition, a bisulfite is added to a urethane prepolymer having an isocyanate group as a terminal group to block with an isocyanate group, and the water is made water-based due to the hydrophilicity of the sulfonate. In addition, the polyurethane prepolymer may be forcibly emulsified and dispersed after blocking with a blocking agent.

Examples of the aqueous phenol resin include those having a phenolic-OH group such as phenol, xylenol, p-alkylphenol, p-phenylphenol, chlorophenol, bisphenol A, phenolsulfonic acid, resorcin, formalin, furfural and the like. Examples thereof include a polymer obtained by adding and condensing aldehydes to an aqueous solution. These are generally classified as phenol / formalin resin, cresol / formalin resin, phenol / furfural resin, resorcin resin and the like. The aqueous phenol resin forms a cross-link between the resins and acts to improve the film forming property.

Examples of the aqueous amino resin include water-soluble melamine resins such as n-butylated melamine resins and isobutylated melamine resins, and urea resins. These resins are usually obtained by etherifying an amino compound such as melamine or benzoguanamine with an addition reaction or addition condensation reaction of an aldehyde such as formaldehyde or paraformaldehyde with a monohydric alcohol having 1 to 4 carbon atoms. . The aqueous amino resin forms a cross-link between the resins and acts to improve the film forming property. As said melamine resin, the alkoxymethyl melamine resin whose alkoxy group is a methoxy group, an ethoxy group, n-butoxy group, i-aqueous butoxy group etc. can be mentioned, for example.

The hydrophilic resin is preferably at least one selected from the group consisting of an acrylic resin having an acid value of 200 mgKOH / g or more or a hydroxyl value of 200 mgKOH / g or more, polyvinyl alcohol, carboxymethylcellulose, and modified resins thereof. Thereby, the hydrophilic sustainability and adhesiveness of the formed hydrophilic film can be further improved.

If the acrylic resin having an acid value of 200 mgKOH / g or more has an acid value of less than 200 mgKOH / g, the hydrophilic durability and adhesion of the hydrophilic film may be lowered. The acid value is more preferably a lower limit of 200 mgKOH / g and an upper limit of 800 mgKOH / g.

If the acrylic resin having a hydroxyl group of 200 mgKOH / g or more has a hydroxyl value of less than 200 mgKOH / g, the hydrophilic durability and adhesion of the hydrophilic film may be lowered. The hydroxyl value is more preferably a lower limit of 200 mgKOH / g and an upper limit of 1500 mgKOH / g.

In the hydrophilic treatment agent, the mixing ratio of the crosslinkable fine particles and the hydrophilic resin is preferably 1/99 to 80/20. If it is less than 1/99, the hydrophilic durability of the hydrophilic film may decrease. When it exceeds 80/20, workability may be reduced. More preferably, it is 5/95 to 50/50.

A pigment can be added to the hydrophilic treatment agent for the purpose of forming a colored hydrophilic film. There is a market need for a colored hydrophilic film, and conventionally a colored hydrophilic film was formed by adding a pigment to the hydrophilic treatment agent. However, a hydrophilic film obtained by a conventional hydrophilic treatment agent is a hydrophilic resin water. As the pigment dissolves as it dissolves, the film loses color. In addition, since pigments are generally hydrophobic, there is a problem that hydrophilicity deteriorates when added to a hydrophilic treatment agent. On the other hand, in the colored hydrophilic treatment agent obtained by adding a pigment to the hydrophilic treatment agent containing the crosslinkable fine particles, the hydrophilic film is firmly adhered, so that the pigment is extremely difficult to dissolve and hardly loses color. In addition, since the hydrophilic film has high hydrophilicity, there is almost no hydrophilic inhibition due to the addition of pigment. Therefore, by using the hydrophilic treatment agent containing the crosslinkable fine particles and the pigment, a colored hydrophilic film in which the color fading of the film is sufficiently suppressed can be obtained. The pigment to be added is not particularly limited, and commonly used color pigments such as inorganic pigments and organic pigments can be used. Especially, the organic water dispersion disperse | distributed with dispersing agents, such as resin and surfactant, is preferable.

The hydrophilic treatment agent may be added with a necessary amount of other components depending on the function to be added. For example, surfactants, colloidal silica, titanium oxide, saccharides and other hydrophilic additives; tannic acid, imidazoles, triazines, triazoles, guanines, hydrazines, phenol resins, zirconium compounds, silane coupling agents, etc. Rust additives; crosslinkers such as melamine resin, epoxy resin, blocked isocyanate, amine, phenol resin, silica, aluminum, zirconium; antibacterial agent, dispersant, lubricant, deodorant, solvent, and the like.

A hydrophilic film coating method comprising the step of applying the hydrophilic treatment agent is also one aspect of the present invention. By using the hydrophilic film coating method, it is possible to form a hydrophilic film excellent in hydrophilicity, in particular, hydrophilic sustainability after adhesion of contaminants, and excellent in adhesion. In particular, the method can be suitably applied to aluminum or an alloy thereof.

In the hydrophilic film coating method of the present invention, first, a metal plate such as aluminum or aluminum alloy is first degreased. Next, if necessary, a chemical conversion treatment, which is a pretreatment for anticorrosion, or application of a corrosion resistant resin primer is performed.

The degreasing treatment may be any of solvent degreasing such as trichloroethylene, perchlorethylene, gasoline, and normal hexane, and alkali degreasing with an alkali solution such as sodium hydroxide, sodium carbonate, sodium silicate, sodium phosphate, and the like. Examples of the chemical conversion treatment include phosphoric acid chromate treatment, coating type chromate treatment, acrylic, epoxy, phenol or urethane resin primer treatment, non-chromate treatment, and the like. The phosphoric acid chromate treatment can be performed with a treatment liquid obtained by adding an additive to chromic anhydride and phosphoric acid. The phosphoric acid chromate treatment can be performed by dipping in the treatment liquid, spraying of the treatment liquid, or the like.

The rust preventive film obtained by the phosphoric acid chromate treatment is preferably ³ to 50 mg / m ² in terms of chromium (Cr). When it is less than 3 mg / m ² , the rust prevention property is insufficient, and when it exceeds 50 mg / m ² , a reaction with the hydrophilic film occurs and the hydrophilicity is lowered. A metal such as aluminum or aluminum alloy on which a rust preventive film is formed is usually washed with water. In this case, the water washing is preferably performed in about 10 to 30 seconds.

The coating-type chromate treatment agent is a chromate treatment agent using a coating treatment such as a roll coater. In this case, the coating chromium amount is preferably 5 to 30 mg / m ² .

The non-chromate treatment is a treatment agent that does not contain chromium, and examples thereof include a zirconium-based treatment agent. Examples of the zirconium-based treatment agent include a mixture of polyacrylic acid and zircon fluoride.

The amount of Zr in the film obtained by the zirconium-based treatment agent is preferably 0.1 to 40 mg / m ² . If it is less than 0.1 mg / m ² , the corrosion resistance is not sufficient, and if it exceeds 40 mg / m ² , it is uneconomical. When the zirconium-based treatment is performed on the chromate treatment, the effect is even greater.

Moreover, after apply | coating a resin primer, baking is performed for 10 second-1 minute at the temperature of 180-280 degreeC. The range of 0.5-2 g / m < ² > is preferable for a coating film. When the coating film is less than 0.5 g / m ² , the antirust property is insufficient, and when it exceeds ² g / m ² , the cost may increase.

The pretreatment in the hydrophilic film coating method of the present invention is usually performed by combining any one of the above degreasing treatment and, if necessary, the above chemical conversion treatment.

The hydrophilic film coating method of the present invention comprises a step of applying the above-mentioned hydrophilic treatment agent on a metal surface such as aluminum or aluminum alloy which has been subjected to the above pretreatment. Examples of the coating method include a roll coating method, a bar coating method, a dipping method, a spray method, a brush coating method, and the like, which are used for pre-coating. After coating, it is preferable to obtain a hydrophilic film by drying and baking at a temperature of 120 to 300 ° C. for 3 seconds to 60 minutes. If the baking temperature is less than 120 ° C., sufficient film-forming property cannot be obtained, and the film may be dissolved after immersion in water. If it exceeds 300 ° C., the resin may be dissolved and the hydrophilicity may be impaired.

In view of the above, the hydrophilic film formed by the above-described hydrophilic film coating method is a film formed on the surface of a metal, particularly aluminum and its alloy, and has hydrophilicity, in particular, hydrophilicity after adhesion of contaminants. It is a film with excellent sustainability and excellent adhesion. Such a hydrophilic film is also one aspect of the present invention.

The film thickness of the hydrophilic coating, is preferably 0.05 g / ^{m 2} or more, more preferably 0.1-2 g / ^{m 2.} When the film thickness is less than 0.05 g / m ² , the hydrophilic sustainability and processability of the film are insufficient.

The crosslinkable fine particles of the present invention comprise a monomer (a) represented by the above formula (1) 30 to 95% by mass, a monomer (b) 5 to 60% by mass having a polyoxyalkylene chain and a polymerizable double bond, and And a copolymer obtained by copolymerizing a monomer component comprising 0 to 50% by mass of other polymerizable monomer (c). That is, the crosslinkable fine particles are used not as a comparatively small amount of the monomer (a) represented by the above formula (1) but as a main component of the constituent components of the crosslinkable fine particles. Therefore, it is highly hydrophilic and has a relatively large number of unreacted functional groups. Therefore, when a hydrophilic film is formed on a metal surface such as aluminum or an alloy thereof using the hydrophilic treatment agent containing the crosslinkable fine particles, the formed film is hydrophilic, particularly palmitic acid, stearic acid, paraffinic acid, etc. Even after being contaminated with contaminants such as plastic lubricants and diisooctyl phthalate, it exhibits excellent hydrophilic durability and adhesion. In addition, since the crosslinkable fine particles have a relatively low water swelling rate, it is possible to prevent the formed hydrophilic film from being dissolved in water. Therefore, the crosslinkable fine particles can be suitably used as a component of a hydrophilic treatment agent.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited only to these examples.

Production Example 1 Preparation of Crosslinkable Fine Particle A monomer solution in which 70 parts by mass of N-methylolacrylamide and 30 parts by mass of methoxypolyethylene glycol monomethacrylate (polyethylene chain having 100 repeating units) were dissolved in 200 parts by mass of methoxypropanol, and methoxypropanol A solution in which 1 part by mass of “ACVA” (azo-based initiator manufactured by Otsuka Chemical Co., Ltd.) is dissolved in 50 parts by mass is added dropwise to 150 parts by mass of methoxypropanol at 105 ° C. in a nitrogen atmosphere over 3 hours. The mixture was further heated and stirred for 1 hour for polymerization. In the obtained dispersion liquid, the average particle diameter of the crosslinkable fine particles was 250 nm, the water swelling ratio of the crosslinkable fine particles was 1.10, the viscosity Ford Cup Nо. 4 was 17 seconds and the solid content concentration was 20% by mass. In addition, the average particle diameter of the crosslinkable fine particles was measured with photal ELS-800 (electrophoretic light scattering photometer manufactured by Otsuka Electronics Co., Ltd.) (the same measurement was performed hereinafter).

Production Example 2 Preparation of Crosslinkable Fine Particles Using 60 parts by mass of N-methylolacrylamide, 20 parts by mass of methoxypolyethylene glycol monomethacrylate (polyethylene chain having 100 repeating units), 10 parts by mass of acrylic acid, and 10 parts by mass of acrylamide The same procedure as in Production Example 1 was carried out except that. In the obtained dispersion, the average particle diameter of the crosslinkable fine particles was 350 nm, the water swelling ratio of the crosslinkable fine particles was 1.15, the viscosity Ford Cup N o. 4 was 18 seconds and the solid content concentration was 20% by mass.

Production Example 3 Preparation of Crosslinkable Fine Particles 200 parts by mass of methoxypropanol 50 parts by mass of N-methylolacrylamide, 20 parts by mass of N-hydroxyethylacrylamide and 20 parts by mass of methoxypolyethylene glycol monomethacrylate (polyethylene chain having 100 repeating units) A dissolved monomer solution and a solution prepared by dissolving 1 part by mass of “ACVA” (an azo-based initiator manufactured by Otsuka Chemical Co., Ltd.) in 50 parts by mass of methoxypropanol are respectively connected to methoxypropanol 140 at 95 ° C. in a nitrogen atmosphere. The mixture was added dropwise over 3 hours to a mixture of parts by weight and 10 parts by weight of a 50% by weight aqueous solution of polyvinyl pyrrolidone (weight average molecular weight 20000), and further heated and stirred for 1 hour for polymerization. In the obtained dispersion, the average particle diameter of the crosslinkable fine particles was 310 nm, the water swelling ratio of the crosslinkable fine particles was 1.13, the viscosity Ford Cup Nо. 4 was 16 seconds and the solid content concentration was 21% by mass. In addition, the average particle diameter of the crosslinkable fine particles was measured with photo ELS-800 (electrophoretic light scattering photometer manufactured by Otsuka Electronics Co., Ltd.).

Production Example 4 Preparation of Crosslinkable Fine Particles The ion-exchanged water was added to the dispersion obtained in Production Example 1, and desalted under reduced pressure to 70 mmHg at 60 ° C. to obtain crosslinkable fine particles having a solid content of 10% by mass.

Comparative Production Example 5
Neutralized with a mixture of 21 parts of N vinylpyrrolidone, 4 parts of N methylol acrylamide and 5 parts of methyl phthalate polyethylene oxide ester (MA50 manufactured by Nippon Emulsifier Co., Ltd.) having 5 repeating units, and 0.5 part of dimethylethanolamine to give water. A solution prepared by dissolving 1 part of an azo-based initiator (ACVA manufactured by Otsuka Chemical Co., Ltd.) in 20 parts of ion-exchanged water was added dropwise to 50 parts of ion-exchanged water at 80 ° C. in a nitrogen atmosphere over 3 hours. The mixture was further heated and stirred for 2 hours for polymerization. To this, 500 parts of ion exchange water was added and diluted to adjust the solid content concentration.

Comparative Production Example 6
The monomer component was 20 parts by mass of Blemmer PME-4000 [Nippon Yushi Co., Ltd. methoxypolyethylene glycol monomethacrylate (polyethylene chain having 98 repeating units)], 50 parts by mass of acrylamide, 20 parts by mass of N-methylolacrylamide, and 10 parts by mass of acrylic acid. Parts, propylene glycol monomethyl ether 200 parts by weight, 2,2′-azobis (2-methylbutyronitrile) 1.5 parts by weight were used. In the obtained dispersion, the average particle diameter of the crosslinkable fine particles was 270 nm, the water swelling ratio of the crosslinkable fine particles was 1.41, the viscosity Ford Cup Nо. 4 was 16 seconds and the solid content concentration was 20% by mass.

Production Example 7
A monomer solution in which 80 parts by mass of acrylic acid and 20 parts by mass of 2-hydroxyethyl acrylate are dissolved in 300 parts by mass of pure water is separated from a solution in which 1 part by mass of ammonium persulfate is dissolved in 50 parts by mass of pure water. From an opening, it was dripped over 90 minutes at 70 degreeC in nitrogen atmosphere over 90 minutes, and also it superposed | polymerized by heating and stirring for 1 hour, ion-exchange water was added, and the acrylic resin with a solid content of 10 mass% was prepared. . The obtained acrylic resin had a solid content acid value of 620 and a solid content hydroxyl value of 110.

Production Example 8
A monomer solution in which 60 parts by mass of acrylic acid and 40 parts by mass of sodium styrenesulfonate are dissolved in 300 parts by mass of pure water and a solution in which 1 part by mass of ammonium persulfate is dissolved in 50 parts by mass of pure water are separately used. The mixture was added dropwise to 300 parts by mass of ion-exchanged water at 80 ° C. in a nitrogen atmosphere over 90 minutes, and further heated and stirred for 1 hour for polymerization, and ion-exchanged water was added to prepare an acrylic resin having a solid content of 10% by mass. The obtained acrylic resin had a solid content acid value of 470.

Example 1,3～5,7,8,10～12, Reference Examples 2, 6, 9 and Comparative Examples 1 to 7
The components obtained in Production Examples and Comparative Production Examples were mixed at the blending ratio shown in Table 1 to prepare a hydrophilic treatment agent.

[Preparation of test plate]
A 1000 series aluminum material of 150 mm × 200 mm × 0.13 mm was degreased for 5 seconds at 70 ° C. with a 1% solution of Surf Cleaner EC370 manufactured by Nippon Paint, and 60 ° C. using a 10% solution of Alsurf 4130 manufactured by Nippon Paint. Treated with zirconium for 5 seconds. Next, the solid content of the hydrophilic treatment agent was adjusted to 5%, applied with a bar coater # 4, and heated and dried at 220 ° C. for 20 seconds to prepare a test plate.

The obtained test plate was evaluated for hydrophilicity, WET adhesion, workability, and color fading after contamination by the following methods. The results are shown in Table 2.
(Hydrophilic durability evaluation after contamination)
The obtained test plate was immersed in running tap water (flowing amount: 15 kg / hr) for 30 minutes, pulled up and dried. 3 parts by mass of stearic acid, 3 parts by mass of 1-octadecanol, 3 parts by mass of palmitic acid and 3 parts by mass of bis (2-ethylhexyl) phthalate are put in a container, heated at 150 ° C. and evaporated, and applied to a sample for 8 hours. The cycle was repeated 20 times to evaluate the water contact angle and wettability. The water contact angle was measured using a FACE automatic contact angle meter (CA-Z type; conditions: room temperature, measured 30 seconds after dropping). For wettability, the test plate was cooled to 5 ° C., and the wet state of condensation after 15 minutes was visually evaluated (the wet area is expressed in%).

(WET adhesion)
Pure water was sprayed on the test plate, and the film was rubbed with paper at a weight of about 500 g. One round trip was defined as one, and the number of times until the substrate was exposed was evaluated.

(Processability)
The dynamic friction coefficient of the test plate was measured at a load of 50 g, a 5 mmφ hard ball, and 300 mm / min.

(Color fading)
Pure water was sprayed on the test plate, and the film was rubbed once and again at a load of about 500 g with paper, and the color and rubbing surface of the paper were judged according to the following criteria.
◎: No color adherence ○: Slight color adherence △: Color adheres to paper, but no undercoat is exposed ×: Color adheres to paper, undercoat is exposed

From Table 2, the hydrophilic film obtained in the examples was excellent in all of hydrophilicity after contamination, WET adhesion, workability, and color fading. On the other hand, those obtained in Comparative Examples were inferior.

Claims (8)

Following formula (1);

(In the formula, R ¹ represents hydrogen or a methyl group. R ² represents CH ₂ or C ₂ H _4. )
40 to 95% by mass of the monomer (a), 5 to 60% by mass of the monomer (b) having a polyoxyalkylene chain and a polymerizable double bond, and 0 to 30 % by mass of the other polymerizable monomer (c). % of a monomer component consisting of copolymerization-obtained water swelling ratio at a polymerization temperature of 95 to 105 ° C. in a substantially undissolved water-miscible organic solvent copolymer monomers used to produce dissolves 1 .3 or less crosslinkable fine particles (excluding those in which the other polymerizable monomer (c) contains (meth) acrylic acid). The monomer (b) has the following formula (2):

(In the formula, R ³ and R ⁴ are the same or different and each represents hydrogen or a methyl group. R ⁵ represents hydrogen, a methyl group, SO ₄ H, SO ₄ Na, or SO ₄ NH ₄ . Represents an integer of 6 to 300.)
And / or the following formula (3);

(In the formula, R ⁶ and R ⁸ are the same or different and each represents hydrogen or a methyl group. R ⁹ represents hydrogen, a methyl group, SO ₄ H, SO ₄ Na, or SO ₄ NH _4. R ⁷ represents R ^7. CH ₂ or

Represents. m represents an integer of 6 to 300. )
The crosslinkable fine particle according to claim 1, which is a compound represented by the formula: The crosslinkable fine particles according to claim 1 or 2, wherein the monomer (b) is a compound containing 50% by mass or more of a polyoxyalkylene chain. A hydrophilic treatment agent comprising the crosslinkable fine particles according to claim 1, 2 or 3 and a hydrophilic resin. The hydrophilic treatment agent according to claim 4 , wherein the hydrophilic resin is at least one selected from the group consisting of an acrylic resin having an acid value of 200 or more or a hydroxyl value of 200 or more, polyvinyl alcohol, carboxymethylcellulose, and a modified resin thereof. The hydrophilic treatment agent according to claim 4 or 5 , wherein a mixing ratio of the crosslinkable fine particles and the hydrophilic resin is 1/99 to 80/20. Hydrophilic coating coating method characterized by comprising the step of applying the hydrophilic treatment agent according to claim 4, 5 or 6, wherein. A hydrophilic film formed by the method for coating a hydrophilic film according to claim 7 .