TW202233766A - Hydrophilized coating composition - Google Patents

Abstract

The present invention relates to a hydrophilized coating composition that contains a hydrophilic resin (A), a sulfonic acid surfactant (B), a hydrophobic resin (C), and a crosslinking agent (D), the total solids fraction of the hydrophilic resin (A) and the sulfonic acid surfactant (B) being 10-35 mass% relative to the total solids fraction of the hydrophilic resin (A), the sulfonic acid surfactant (B), the hydrophobic resin (C), and the crosslinking agent (D).

Description

Hydrophilized coating composition

The present invention relates to a hydrophilized coating composition excellent in hydrophilicity, corrosion resistance and water resistance.

Surface treatments intended to impart various properties are applied to various materials such as vehicles, vehicle parts, building materials, and home appliance parts, cast products, and various materials such as sheets, coils, or molded products. As such performance, corrosion resistance, hydrophilicity, water repellency, etc. are mentioned, for example. Among them, light metals (especially aluminum or the alloy materials, hereinafter referred to as aluminum materials) are also widely used in home appliances and automobiles because of their light weight and excellent workability.

In particular, aluminum is used for various metal materials due to its high thermal conductivity, and requires hydrophilicity, corrosion resistance, moisture resistance, and durability.

For example, when using aluminum fins for air conditioners and other air conditioners, the hydrophilicity and corrosion resistance of the surface become necessary. Persistent). In addition, it is required that the hydrophilized coating film formed by the surface treatment also has excellent water resistance to dissolve and prevent flow-out.

As a hydrophilization treatment composition excellent in hydrophilicity (sustainability), corrosion resistance, etc., for example, Patent Document 1 discloses a hydrophilization treatment agent combining polyglycerol and a high acid value acrylic resin.

Moreover, Patent Document 2 discloses a composition for hydrophilization treatment containing (A) water-dispersible silica, (B) water-soluble or water-dispersible organic polymer resin, and (C) crosslinking agent. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2001-323257 [Patent Document 2] Japanese Patent Laid-Open No. 2001-247822

[Problems solved by the invention]

However, among these surface treatment compositions proposed in the past, sufficient hydrophilicity (sustainability) and corrosion resistance cannot be obtained and a hydrophilic coating film satisfying the water resistance cannot be obtained, and an effective hydrophilizing surface treatment agent has not been developed yet. status quo.

The present invention was made to solve the above-mentioned problems, and the object is to provide a coating film capable of forming a hydrophilic coating film having excellent hydrophilicity (sustainability) and corrosion resistance on the surfaces of various materials such as substrates, and also excellent in water resistance. Hydrophilized coating composition. [Means to solve the problem]

The inventors of the present invention conducted detailed examinations in order to solve the above-mentioned problems, and found that the hydrophilic resin (A), the sulfonic acid-based surfactant (B), the hydrophobic resin (C), and the crosslinking agent (D) are contained, and are relatively hydrophilic relative to the hydrophilic resin (A). In terms of the total solid content of the hydrophilic resin (A), the sulfonic acid-based surfactant (B), the hydrophobic resin (C) and the crosslinking agent (D), the hydrophilic resin (A) and the sulfonic acid-based surfactant If the total solid content of (B) is a hydrophilic coating composition of 10 to 35 mass %, the above-mentioned problems can be solved, and the present invention has been completed.

That is, the present invention relates to the following.

1. Contains hydrophilic resin (A), sulfonic acid-based surfactant (B), hydrophobic resin (C) and crosslinking agent (D), compared to hydrophilic resin (A), sulfonic acid-based surfactant ( B) In terms of the total solid content of the hydrophobic resin (C) and the crosslinking agent (D), the total solid content of the hydrophilic resin (A) and the sulfonic acid-based surfactant (B) is 10-35 Mass % of the hydrophilic coating composition.

2. In the hydrophilic resin (A), with respect to the total amount of the monomer components constituting the polyacrylamide resin and the polymer, the total amount of the monomers containing an amide group is 50% by mass or more of hydrophilicity At least one type of acrylic polymer is the hydrophilized coating composition described in the above item 1.

3. The hydrophilic resin (A) having a weight-average molecular weight of 5,000 to 350,000 as described in the above-mentioned item 1 or 2, the hydrophilized paint composition.

4. The hydrophobic resin (C) containing at least one selected from the group consisting of acrylic resin (C1), polyurethane resin (C2), and epoxy resin (C3) as described in any one of the above items 1 to 3 The described hydrophilized coating composition.

5. Relative to the total solid content of the hydrophilic resin (A), sulfonic acid-based surfactant (B), hydrophobic resin (C) and cross-linking agent (D), according to the total solid content of each component , the hydrophilic resin (A) is 5-25 mass %, the sulfonic acid-based surfactant (B) is 5-15 mass %, the hydrophobic resin (C) is 20-60 mass %, and the crosslinking agent (D) is 20 to 60 mass % of the hydrophilized paint composition according to any one of the above items 1 to 4. [Effect of invention]

Since the hydrophilic coating composition of the present invention contains a hydrophilic resin (A), a sulfonic acid-based surfactant (B), a hydrophobic resin (C) and a crosslinking agent (D), hydrophilicity and corrosion resistance can be obtained. Excellent coating film. Moreover, unlike the conventional hydrophilization surface treatment agents in which the amount of the hydrophilization-imparting component is large, the content of the hydrophilic resin (A) and the sulfonic acid-based surfactant (B) of the hydrophilicity-imparting component can be at least as high as possible. Since it is hydrophilic, a coating film excellent in water resistance can be obtained.

As described above, according to the present invention, it is possible to provide a hydrophilic coating composition which can form a coating film having excellent hydrophilicity (sustainability) and corrosion resistance, and also excellent water resistance on various materials such as substrates.

[Type of carrying out the invention]

The present invention relates to the following hydrophilized paint composition (hereinafter, also referred to as the paint in some cases), which contains a hydrophilic resin (A), a sulfonic acid-based surfactant (B), and a hydrophobic resin (C) ) and cross-linking agent (D), relative to the total solid content of hydrophilic resin (A), sulfonic acid-based surfactant (B), hydrophobic resin (C) and cross-linking agent (D), hydrophilic The total solid content of the resin (A) and the sulfonic acid-based surfactant (B) is 10 to 35% by mass.

The content of the present invention will be described in detail below.

<Hydrophilic coating composition> Hydrophilic resin (A) The hydrophilic resin (A) in the hydrophilized coating composition of the present invention is a resin having a hydrophilic group, and the so-called hydrophilic group refers to a functional group that is ionized in water to form ions, or a functional group that undergoes hydration by hydrogen bonding without ionization. . Specific examples of the hydrophilic group include a carboxyl group, a hydroxyl group, an amino group, an amide group, a sulfuric acid group, a sulfonic acid group, an oxyalkylene group, a functional group serving as the precursor, and the like.

For the present invention, the hydrophilic resin (A) is defined as follows.

The hydrophilic resin (A) refers to a resin that satisfies any one of the requirements of 1. and 2. below.

1. The content of the hydrophilic group in the resin is more than 4000 mmol/kg 2. The repeating unit in the resin is 5 or more epoxide [(RO) _n ; n≧5, R is the content of the alkylene group] constituent unit Amount of 5 mass % or more Specific hydrophilic resins include vinyl alcohol-based polymers such as polyvinyl alcohol and polyvinyl vinyl alcohol, polyvinyl pyrrolidone-based polymers such as polyvinyl pyrrolidone, and fibers. cellulose, cellulose acetate, carboxymethyl cellulose, cellulose-based polymers such as cellulose triacetate, polyethylene glycol-based polymers such as polyethylene glycol and polyethylene oxide, polyacrylic acid, Acrylic polymers such as sodium polyacrylate, sodium polyvinyl sulfonate, polystyrene sulfonic acid, polyacrylic acid amide resin, and acrylic acid having at least one selected from polyoxyalkylene chain, amide group, hydroxyl group and acid group type polymer (hereinafter simply referred to as hydrophilic acrylic type polymer) and the like.

These can be used alone or in combination of two or more.

Among the above-mentioned hydrophilic resins, from the viewpoint of having both hydrophilicity and corrosion resistance, polyacrylamide resins and hydrophilic acrylic polymers are preferable. In particular, the hydrophilic resin (A) is hydrophilic in which the total amount of the amide group-containing monomer is 50% by mass or more in terms of the polyacrylamide resin and the total amount of the monomer components constituting the polymer. At least one type of acrylic polymer is preferred.

In addition, in the present invention, if the total amount of (meth)acrylamide is 70% by mass relative to the total amount of the monomer components constituting the polymer, the polyacrylic acid amide resin and the hydrophilic acrylic polymer are As mentioned above, it is defined as a polyacrylamide resin, and when it is less than 70 mass %, it is defined as a hydrophilic acrylic polymer.

In addition, "(meth)acrylate" described in this specification means "acrylate or methacrylate". In addition, "(meth)acrylamide" means "acrylamide or methacrylamide".

・Polyacrylic acid amide resin As the polyacrylamide resin, a polymer obtained by radical polymerization containing 70% by mass or more of (meth)acrylamide based on the total amount of radical polymerizable monomers constituting the resin can be used. A polymer obtained by polymerizing a mixture of free-radical monomers, such as a homopolymer of (meth)acrylamide, or a copolymer of (meth)acrylamide and other radically polymerizable monomers. one.

Specifically, the polyacrylamide resin can be prepared by, for example, a mixture of (meth)acrylamide and other radically polymerizable monomers as necessary in a polymerization initiator (azo-based, peroxide-based, redox-based) etc.) in the presence of water, organic solvents and other solvents for polymerization. The usage-amount of a polymerization initiator is preferably in the range of 0.2-5 mass % with respect to the total amount of monomers normally. The above-mentioned polymerization temperature can be changed according to the type of polymerization initiator used, etc., but it is usually 50 to 200°C, more preferably 90 to 160°C, and the reaction time is about 0.5 to 10 hours.

As the polyacrylamide resin, commercially available products may be used, for example, Haricoat G-50, Haricoat G-51, Haricoat 1057 (above, Harima Chemicals, trade name), Polymerset 305, Polymerset 500, Polymerset 512 (above, Arakawa Chemical Industry Co., Ltd.) , trade name) etc.

Examples of other radical copolymerizable monomers that can be used in the production of the above-mentioned polyacrylamide resin include cationic vinyl monomers, anionic vinyl monomers, and N-substituted (meth)acryloyl amides. Amines and other vinyl monomers, etc.

As said cationic vinyl monomer, N,N- dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, , N-dimethylaminopropyl (meth)acrylamide, N,N-diethylaminopropyl (meth)acrylamide and other vinyl monomers with tertiary amine groups or the like salts such as diallylamine, allylamine-based compounds such as diallylamine, triallylamine, and allylamine, or salts thereof, and the like.

Examples of the anionic vinyl monomers include monocarboxylic acids such as (meth)acrylic acid and crotonic acid; maleic acid, fumaric acid, itaconic acid, muconic acid, citraconic acid, and the like. Dicarboxylic acids; organic sulfonic acids such as vinylsulfonic acid, styrenesulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid; or sodium salts, potassium salts, etc. of these various organic acids.

As the above-mentioned N-substituted (meth)acrylamides, any N-substituted (meth)acrylamides other than cationic vinyl monomers may be used, and there are no particular limitations, and well-known ones can be used, for example, N,N-Dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N-methyl (Meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-t-butyl (meth) acrylamide, N-methoxy Methyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-isopropoxymethyl (methyl) base) acrylamide, N-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, N-hexyloxymethyl (meth) acrylamide amine, N-isohexyloxymethyl(meth)acrylamide, etc.

As the above-mentioned other vinyl monomers, vinyl monomers other than cationic vinyl monomers, anionic vinyl monomers, and N-substituted (meth)acrylamides can be used, and known ones can also be used without particular limitation. For example, alkyl acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, etc.; allyl alcohol containing allyl groups such as allyl alcohol Monomers; (meth)acrylonitrile; bisacrylamide monomers such as methylenebis(meth)acrylamide and ethylidene bis(meth)acrylamide; ethylene glycol bis(methyl) ) acrylate, diethylene glycol di(meth)acrylate and other diacrylate monomers; divinylbenzene; 1,3,5-tricycloarylhexahydro-S-triazine, triallyl Polyfunctional vinyl monomers such as methyl isocyanurate and tetramethylolmethane tetraacrylate.

"(meth)acrylic acid" in this specification means "acrylic acid or methacrylic acid".

Regarding the polyacrylamide resin, from the viewpoint of hydrophilicity, the total amount of (meth)acrylamide is 80% by mass or more, particularly preferably 90% by mass, relative to the total amount of monomer components constituting the polymer. % or more.

・Hydrophilic acrylic polymer As the hydrophilic acrylic polymer, a polymer obtained by subjecting a mixture of radically polymerizable monomers to a polymerization reaction can be used, and examples of the radically polymerizable monomers include the following monomers.

M1. Polymerizable unsaturated monomer having polyoxyalkylene chain or polyvinylpyrrolidone chain M2. (Meth) acrylamide, N-methylol (meth) acrylamide or N-alkoxymethyl (meth) acrylamide M3. Polymerizable unsaturated monomer containing an acidic group M4. Hydroxyl-containing polymerizable unsaturated monomer M5. Monomers having two or more polymerizable unsaturated double bonds in one molecule M6. Polymerizable unsaturated monomers other than the above M1 to M5 The said M1 is a compound which has at least 1 polymerizable double bond in 1 molecule, and a polyoxyalkylene chain or a polyvinylpyrrolidone chain.

As the N-alkoxymethyl (meth)acrylamide of the above-mentioned M2, for example, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)propylene can be mentioned. amide, N-propoxymethyl (meth) acrylamide, N-isopropoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N- - isobutoxymethyl(meth)acrylamide, N-hexyloxymethyl(meth)acrylamide, N-isohexyloxymethyl(meth)acrylamide.

As said M3, if it is a compound having at least one acidic group and one polymerizable unsaturated group in one molecule, it can be used without particular limitation. Specifically, acrylic acid, methyl acrylate, crotonic acid, Itaconic acid, maleic acid, fumaric acid and other polymerizable unsaturated monomers containing carboxyl groups; vinylsulfonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, etc. containing sulfonic acid groups The polymerizable unsaturated monomers; or the sodium salts, potassium salts, etc. of these various organic acids. The acid group-containing polymerizable unsaturated monomer can impart hardenability to the hydrophilic coating composition.

Specific examples of M4 include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl C2-C8 hydroxyalkyl esters of acrylic acid or methacrylic acid such as (meth)acrylates, and the like. The hydroxyl-containing polymerizable unsaturated monomer can impart hardenability to the hydrophilic coating composition.

Specific examples of M5 include methylenebisacrylamide, methylenebismethacrylamide, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, Tetraethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate base) acrylate, divinylbenzene, allyl (meth)acrylate, and the like. Among these, methylenebisacrylamide and methylenebismethacrylamide are applicable from the viewpoints of dispersion stability and hydrophilicity when used as polymer fine particles.

Specific examples of M6 include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, and octyl (meth)acrylate. C 1-24 alkyl or cycloalkyl esters of acrylic acid or methacrylic acid such as acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate; polymerization of acrylonitrile, methacrylonitrile, etc. Sexually unsaturated nitrile; aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene; N,N-dimethylaminoethyl (meth)acrylate, N , N-dimethylaminopropyl (meth)acrylate and other nitrogen-containing alkyl esters of acrylic acid or methacrylic acid with 2 to 8 carbon atoms; α-olefins such as ethylidene and propylidene; butadiene , isoprene and other diene compounds; vinyl acetate, vinyl propionate and other vinyl esters; ethyl vinyl ether, n-propyl vinyl ether and other vinyl ethers; -Methyl Methacrylamide, N,N-Dimethacrylamide, N,N-Dimethyl Methacrylamide, N-Ethyl Methacrylamide, N-Ethyl Methacrylamide , N-n-propyl acrylamide, N-n-propyl methyl acrylamide, N-isopropyl acrylamide, N-isopropyl methyl acrylamide, N-n-butyl acrylamide, etc. (methyl ) acrylamide-based unsaturated compounds; γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane , Unsaturated compounds with hydrolyzable silicon groups such as 2-styrene ethyl trimethoxy silane, vinyl bis(methoxyethoxy) silane, glycidyl (meth)acrylate, allyl glycidyl Unsaturated compounds having epoxy groups such as base ethers and the like.

For the hydrophilic acrylic polymer, from the viewpoint of hydrophilicity, the total amount of the amide group-containing monomer is 50% by mass or more, particularly preferably 60% by mass, relative to the total amount of the monomer components constituting the polymer. % or more.

The above-mentioned monomers may be used alone or in combination of two or more.

The synthesis of the hydrophilic acrylic polymer is usually carried out in the presence of a radical polymerization initiator. As a radical polymerization initiator, the self-known thing can be used, and the usage-amount is preferably in the range of 0.2-5 mass % with respect to the total amount of monomers normally.

The polymerization temperature varies depending on the type of polymerization initiator to be used and the like, but is usually 50 to 160°C, more preferably 90 to 160°C, and the reaction time can be set to about 0.5 to 10 hours.

In the hydrophilic resin (A), the content of the hydrophilic group in the resin is preferably 4000 mmol/kg or more, 6000 mmol/kg or more, particularly 8000 mmol/kg or more, from the viewpoint of hydrophilicity.

The weight average molecular weight of the hydrophilic resin (A) is in the range of 5,000 to 350,000, particularly preferably 15,000 to 350,000, and more particularly preferably 15,000 to 200,000 from the viewpoint of corrosion resistance or hydrophilicity.

In this specification, the weight-average molecular weight is the molecular weight of polystyrene by converting the retention time measured using a gel permeation chromatograph to the retention time of standard polystyrene whose molecular weight is known under the same conditions. the requested value. As a specific gel permeation chromatograph apparatus, "HLC-8120GPC" (trade name, manufactured by Tosoh Corporation) was used, and as columns, "TSKgel G4000HXL", "TSKgel G3000HXL", "TSKgel G2500HXL", and "TSKgel G2000HXL" were used (trade name, all manufactured by Tosoh Co., Ltd.) in total, a differential refractometer was used as a detector, and the mobile phase: tetrahydrofuran, the measurement temperature: 40°C, and the flow rate: 1 mL/min. .

The hydrophilic resin (A) preferably contains a functional group having reactivity with the crosslinking agent (D) from the viewpoint of the crosslinking reaction with the crosslinking agent (D) described later. Specifically, for example, when the crosslinking agent (D) is a melamine resin or a polyisocyanate resin, it is preferable to contain a hydroxyl group having reactivity with these.

The hydrophilic resin (A) can be dissolved or dispersed in water by adding a neutralizing agent as necessary.

When the hydrophilic resin (A) is used as an aqueous dispersion, when the average particle diameter is 30 to 700 nm, particularly preferably 40 to 600 nm, and more preferably 120 to 500 nm, the dispersion stability, coating workability, etc. Good point of view.

The average particle diameter can be measured by a particle diameter measuring apparatus, for example, a coulter model N4MD (manufactured by Beckman Coulter, trade name).

Sulfonic acid-based surfactant (B) The sulfonic acid-based surfactant is an anion-based surfactant having a -SO ₃ - group in its molecular structure. Specific examples thereof include surfactants such as sulfonate-based, sulfate-ester-based, and sulfosuccinate-based surfactants.

As a sulfonate type surfactant, surfactant, such as an alkyl diphenyl ether disulfonate type and an alkylbenzene sulfonate type, is mentioned.

As the surfactant of the alkyl diphenyl ether disulfonate type, alkyl diphenyl ether disulfonic acid or the metal salt thereof can be mentioned. Among these, the use of alkyldiphenyl ether disulfonic acid sodium salt is particularly suitable also from the viewpoint of improving the hydrophilicity.

Examples of commercial products of alkyl diphenyl ether disulfonic acid-based surfactants include PerexSS-L, PerexSS-H (Kao Co., Ltd.), NewCall261-A, and NewCall271-A (Japan Emulsifier Co., Ltd.) company), etc.

As the surfactant of the alkylbenzenesulfonate type, alkylbenzenesulfonic acid or a metal salt thereof can be mentioned. Among these, it is particularly suitable to use an alkylbenzenesulfonic acid sodium salt from the viewpoint of improving the hydrophilicity sustainability.

Examples of commercially available alkylbenzenesulfonate-based surfactants include NewCall210, NewCall220-L (Japan Emulsifier Co., Ltd.), Neo PerexG-15, Neo PerexG-25 (Kao Co., Ltd.), and the like .

Surfactants such as polyoxyethylene alkyl ether sulfate salt-based surfactants are exemplified as the sulfate-based surfactant.

As a surfactant of a polyoxyethylene alkyl ether sulfate salt system, polyoxyethylene alkyl ether sulfate or its metal salt is mentioned. Among these, the polyoxyethylene alkyl ether sulfate sodium salt is particularly preferred from the viewpoint of improvement of the hydrophilicity sustainability.

Examples of commercial products of polyoxyethylene alkyl ether sulfate-based surfactants include NewCall707SN, NewCall714SF, NewCall2308SF, NewCall2360SN (Japan Emulsifier Co., Ltd.), Latemul E-118B, Lateum E-150, Latemul WX, Latemul PD-140 (Kao Co., Ltd.), LevenorWX (Kao Chemical Co., Ltd.), etc.

Dialkylsulfosuccinic acid or its metal salt etc. are mentioned as surfactant of a sulfosuccinate type.

For example, specific examples include monoalkyl sulfosuccinate, dialkyl sulfosuccinate, alkyl sulfosuccinate, polyoxyethylene alkyl sulfosuccinate, and alkylamine oxide. Ditridecyl Sodium Sulfosuccinate, Sodium Dioctyl Sulfosuccinate, Sodium Dihexyl Sulfosuccinate, Sodium Dicyclohexyl Sulfosuccinate, Sodium Diamyl Sulfosuccinate, Diisobutyl Sodium Sodium sulfosuccinate, disodium isodecyl sulfosuccinate, disodium N-octadecyl sulfosuccinate, N-(1,2-dicarboxyethyl)-N-octadecane Tetrasodium sulfosuccinate, etc. Among these, the dialkylsulfosuccinic acid sodium salt is particularly suitable for use from the viewpoint of improvement of the hydrophilicity persistence.

Examples of commercially available sulfosuccinate-based surfactants include PerexOT-P, PerexTR, PerexCS, PerexTA (Kao Co., Ltd.), NewCall290-A, NewCall290-M, NewCall291-M, NewCall291-PG , NewCall291-GL, NewCall292-PG, NewCall293 (Japan Emulsifier Co., Ltd.), NeocallSW-C, NeocallYSK, NeocallP (First Industrial Pharmaceutical Co., Ltd.).

Among the sulfonic acid-based surfactants, those using alkyldiphenyl ether disulfonic acid-based and sulfosuccinate-based surfactants are preferred from the viewpoint of hydrophilicity and corrosion resistance. Also, it is better to use both.

When using an alkyl diphenyl ether disulfonic acid-based surfactant and a sulfosuccinate-based surfactant in combination, the total solid content of the two is used as a basis, and the alkyl diphenyl ether disulfonic acid-based surfactant/ Sulfosuccinate-based surfactant = 80/20 to 50/50 (mass ratio), especially in the range of 70/30 to 55/45 (mass ratio), from the viewpoint of hydrophilic persistence good.

Hydrophobic resin (C) The hydrophobic resin (C) in the hydrophilized coating composition of the present invention does not have a hydrophilic group, or the content thereof is small. The hydrophilic group refers to a functional group that is ionized in water to become an ion, or a functional group that undergoes hydration by hydrogen bonding without being ionized. Specific examples of the hydrophilic group include a carboxyl group, a hydroxyl group, an amino group, an amide group, a sulfuric acid group, a sulfonic acid group, an oxyalkylene group, a functional group serving as the precursor, and the like.

For the present invention, the hydrophobic resin (C) is defined as follows.

The hydrophobic resin (C) means a resin satisfying the requirements of 1. and 2. below at the same time.

1. The content of the hydrophilic group in the resin is less than 4000mmol/kg 2. The repeating unit in the resin is an epoxide [(RO) _n ; n≧5, R is an alkylene group] with 5 or more constituent units The amount is less than 5 mass %. Examples of the specific hydrophobic resin (C) include polyolefin resins, polyester resins, epoxy resins, polyurethane resins, acrylic resins, polystyrene resins, polystyrene resins, and polyolefin resins. Carbonate resin, etc.

These can be used alone or in combination of two or more.

Among the above-mentioned resins, from the viewpoint of corrosion resistance or hot water resistance, those using an acrylic resin (C1), a polyurethane resin (C2), and an epoxy resin (C3) are preferable. That is, the hydrophilized coating composition of the present invention contains, as the hydrophobic resin (C), at least one selected from the group consisting of acrylic resin (C1), polyurethane resin (C2) and epoxy resin (C3). better.

Acrylic resin (C1) The acrylic resin (C1) is a hydrophobic acrylic resin, and can be used without particular limitation as long as it satisfies the requirements 1 and 2 of the above-mentioned hydrophobic resin (C). As a comonomer, the thing similar to what was described in the hydrophilic acrylic polymer of the said hydrophilic resin (A) can be used, and it can synthesize|combine by the same method as described in the hydrophilic acrylic polymer.

Polyurethane resin (C2) Polyurethane resin (C2) can generally be made of acrylic polyol, polyester polyol, polyether polyol and other polyols and diisocyanate into polyurethane, optionally with diol, It is synthesized by chain extension in the presence of a chain extension agent of a low molecular weight compound having two or more active hydrogens such as diamine. Those that can be stably dispersed or dissolved in water are preferred.

The polyurethane resin (C2) can be stably dispersed or dissolved in water, for example, by the following method.

(1) The method of dispersing or dissolving in water by self-emulsifying and imparting hydrophilicity by introducing ionic groups such as hydroxyl groups, amine groups, and carboxyl groups to the side chains or terminals of the polyurethane polymer (2) The polymer that has completed the reaction or the terminal isocyanate group is blocked with a blocking agent such as oxime, alcohol, phenol, thiol, amine, soda bisulfite, etc., and is forced by an emulsifier or mechanical shearing force. method for dispersing in water (3) A method of simultaneously dispersing and polymerizing a urethane prepolymer having a terminal isocyanate group with water, an emulsifier and an elongator, and using a mechanical shearing force (4) A method of dispersing or dissolving in water as a water-soluble polyurethane using a water-soluble polyol such as polyethylene glycol as the polyol as the main raw material of the polyurethane

Examples of commercially available urethane resins (C2) include HydranHW-330, HydranHW-340, HydranHW-350 (all manufactured by Dainippon Ink Chemical Co., Ltd.), Super flex 100, Super flex 110, Super flex flex150, Super flexF-8438D, Super flex420 (all manufactured by Daiichi Pharmaceutical Co., Ltd.), ADEKA BontiterHUX-232, ADEKA BontiterHUX-260, ADEKA BontiterHUX-320, ADEKA BontiterHUX-350, ADEKA BontiterHUX-540, ADEKA BontiterUX-206 ( All are manufactured by Asahi Denka Corporation), etc.

Epoxy resin (C3) Typical examples of the epoxy resin (C3) include a copolymer of a polyphenol compound and an epihalohydrin (Epihalohydrin), for example, a resin obtained by reacting a polyphenol compound and epichlorohydrin. Examples of the above-mentioned polyphenol compound include bis(4-hydroxyphenyl)-2,2-propane (also referred to as "bisphenol A"), 4,4-dihydroxybenzophenone, bis(4- hydroxyphenyl)methane (also known as "bisphenol F"), 4,4-dihydroxydiphenylene (also known as "bisphenol S"), and the like. From the viewpoint of corrosion resistance, it is preferable to use a bisphenol A type epoxy resin.

Bisphenol A epoxy resin can be obtained by the polymerization of bisphenol A and epichlorohydrin. Moreover, a bisphenol A type epoxy resin can also be obtained by a two-stage polymerization method in which bisphenol A is added to a bisphenol A type epoxy resin having a relatively low epoxy equivalent weight.

The above-mentioned bisphenol A epoxy resin having a relatively low epoxy equivalent is generally one with an epoxy equivalent of about 160 to 2,000. Examples of such commercial products include jER828EL, jER1001, jER1004, and jER1007 manufactured by Japan Epoxy Resin; Asahi AralditeAER250, AralditeAER260, AralditeAER6071, AralditeAER6004, AralditeAER6007 manufactured by Kasei Epoxy Co., Ltd.; EpomicR140, EpomicR301, EpomicR304, EpomicR307 manufactured by Mitsui Chemicals, Adeka ResinEP-4100, Adeka ResinEP-510 manufactured by Asahi Chemical Corporation, etc.

In addition, the bisphenol A epoxy resin may be a denatured epoxy resin obtained by denaturing the bisphenol A epoxy resin with a dibasic acid. In this case, as the bisphenol A-type epoxy resin to be reacted with the dibasic acid, it is preferable to use one having a number average molecular weight of 2,000 to 8,000 and an epoxy equivalent within the range of 1,000 to 4,000.

Examples of the above-mentioned dibasic acid include compounds represented by the following general formula: HOOC-(CH ₂ ) _n -COOH (in the formula, n is an integer of 1 to 12), and specific examples thereof include succinic acid and adipic acid. , Pimelic acid, azelaic acid, sebacic acid, dodecanedioic acid, hexahydrophthalic acid, etc.

The above-mentioned bisphenol A-type modified epoxy resin can be prepared by mixing the above-mentioned bisphenol A-type epoxy resin with a dibasic acid, for example, in the presence of an esterification catalyst such as tri-n-butylamine, an organic solvent, and the like. The reaction temperature is 120 to 180° C. to carry out the reaction for 1 to 4 hours.

The acrylic modified epoxy resin (C3a) is an epoxy resin modified with an acrylic resin, and can be produced by, for example, the following methods (1) to (3).

(1) A graft polymerization method in which an epoxy resin and a polymerizable unsaturated monomer, such as an acrylic monomer, are subjected to a hydrogen extraction reaction (Hydrogen extraction reaction) (2) The epoxy group of the epoxy resin is esterified with a polymerizable unsaturated monomer containing a carboxyl group, such as an acrylic monomer containing a carboxyl group, and the acrylic monomer is used for the double bond introduced into the epoxy resin. Method for obtaining acrylic modified epoxy resin after polymerization reaction (3) A method for obtaining an acrylic modified epoxy resin by reacting an epoxy resin with an acrylic resin containing a carboxyl group Among these, the acrylic modified epoxy resin produced by the method (3) is preferable from the viewpoint of being able to form a coating film having excellent hydrophilicity and corrosion resistance.

The manufacture of the acrylic modified epoxy resin by the method (3) is as follows.

The bisphenol-type epoxy resin used for the production of acrylic modified epoxy resin (C3a) has a number average molecular weight of 2,000 from the viewpoint of dispersion stability in the aqueous medium of the obtained acrylic modified epoxy resin (C3a). -30,000, particularly preferably in the range of 5,000 - 30,000, and epoxy equivalent is in the range of 1,000 - 10,000, particularly preferably in the range of 2,500 - 10,000.

The carboxyl group-containing acrylic resin used for the production of the above-mentioned acrylic modified epoxy resin (C3a) reacted with the epoxy resin is a carboxyl group-containing polymer of acrylic acid, methyl acrylate, maleic acid, itaconic acid, fumaric acid, etc. An acrylic copolymer containing a sexually unsaturated monomer as a monomer backbone.

The above-mentioned acrylic copolymer has a weight average molecular weight of 5,000 to 100,000, particularly preferably 10,000 to 100,000, and an acid value of 150 to 700 mgKOH/g from the viewpoints of stability in an aqueous medium and corrosion resistance of a coating film. Particularly preferably, it is within the range of 200 to 500 mgKOH/g.

Examples of monomers other than the carboxyl group-containing polymerizable unsaturated monomer used for producing the carboxyl group-containing acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, propyl ( Meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, C1-22 alkyl esters of acrylic acid or methacrylic acid such as lauryl (meth)acrylate, benzyl (meth)acrylate, and stearyl (meth)acrylate; cyclohexyl (methyl) ) acrylate, isobornyl (meth)acrylate; aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene; for 2-hydroxyethyl (meth)acrylate, hydroxyl Hydroxyalkyl (meth)acrylates such as propyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, and hydroxyhexyl (meth)acrylate, and hydroxy 1 mol of hydroxyalkyl (meth)acrylate such as ethyl (meth)acrylate, and a caprolactone-modified alkyl group ( Acrylic monomers containing hydroxyl groups such as meth)acrylates; acrylamide, methacrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)propylene amide, N-n-propoxymethyl (meth) acrylamide, N-isopropoxymethyl (meth) acrylamide, N-n-butoxymethyl (meth) acrylamide, N- -sec-butoxymethyl (meth)acrylamide, N-tert-butoxymethyl (meth)acrylamide and other acrylamide monomers; acrylonitrile, methacrylonitrile, vinyl acetate Ester, ethyl ester, butadiene, etc.

The carboxyl group-containing acrylic resin can be obtained by mixing the above-mentioned carboxyl group-containing polymerizable unsaturated monomer with the above-mentioned other monomers in a monomer mixture, for example, in an organic solvent, in the presence of a radical polymerization initiator and/or a chain transfer agent It is obtained by performing copolymerization at 80-150° C. for 1-10 hours under the following conditions.

As said polymerization initiator, an organic peroxide type initiator, an azo type initiator, etc. are mentioned, for example. Examples of the above-mentioned organic peroxide-based initiator include benzyl peroxide, t-butylperoxy 2-ethylhexanoate, di-t-butyl peroxide, and t-butyl peroxide. Peroxybenzoate, t-amylperoxy 2-ethylhexanoate, etc. As the azo initiator, for example, azobisisobutyronitrile, azodimethylvaleronitrile, etc. can be mentioned . As said chain transfer agent, (alpha)-methylstyrene dimer, thiols, etc. are mentioned, for example.

Acrylic modified epoxy resin (C3a) can be prepared by combining bisphenol epoxy resin with acrylic resin containing carboxyl group, such as in organic solvent, in esterification catalyst, such as in triethylamine, dimethylethanolamine, etc. It is obtained by performing esterification at 80 to 120° C. for 0.5 to 8 hours in the presence of tertiary amines and trialkyl phosphines such as triphenylphosphine.

For acrylic modified epoxy resin (C3a), the mass ratio of bisphenol epoxy resin to carboxyl group-containing acrylic resin can be appropriately selected only in accordance with hydrophilicity, corrosion resistance, etc. The solid content mass ratio of the acrylic resin is in the range of 10/90 to 95/5, particularly preferably in the range of 20/80 to 90/10.

For the hydrophobic resin (C), the content of the hydrophilic group in the resin is preferably less than 4000 mmol/kg, less than 3000 mmol/kg, especially less than 2000 mmol/kg, from the viewpoint of hydrophilicity and water resistance. .

The weight average molecular weight of the hydrophobic resin (C) is in the range of 8,000 to 200,000, particularly preferably 10,000 to 150,000, from the viewpoint of corrosion resistance.

The hydrophobic resin (C) preferably has a functional group reactive with the crosslinking agent (D) from the viewpoint of the crosslinking reaction with the crosslinking agent (D) described later. For example, when the crosslinking agent (D) is a melamine resin or a polyisocyanate resin, it is preferable to include a hydroxyl group having reactivity with these.

A neutralizer may be added to the hydrophobic resin (C) as necessary, and it may be dissolved or dispersed in water.

When the hydrophobic resin (C) is used as an aqueous dispersion, the average particle diameter is 100 to 1000 nm, particularly 110 to 900 nm, more particularly 120 to 800 nm, from the viewpoints of dispersion stability, coating workability, etc. Look good.

Crosslinker (D) The crosslinking agent (D) is a compound having a functional group that reacts with the hydrophilic resin (A) and/or the hydrophobic resin (C). Usually, it has two or more functional groups which react with hydrophilic resin (A) or hydrophobic resin (C) in a molecule|numerator.

The hardenability of the hydrophilized coating composition of the present invention can be improved, and the coating film properties such as corrosion resistance and water resistance of the obtained coating film can be improved, especially water resistance can be improved.

Examples of the crosslinking agent (D) include amino resins, phenol resins, polyisocyanate compounds, block polyisocyanate compounds, oxazoline group-containing resins, polyepoxy compounds, and carbodiimide compounds.

Among these crosslinking agents (D), it is preferable to use at least one selected from the group consisting of amino resins and phenol resins, particularly from the viewpoint of water resistance.

As the amino resin, a melamine resin, a benzoguanamine resin, a urea resin, and the like can be mentioned. Among them, it is particularly preferable to use a melamine resin (D1) from the viewpoint of hydrophilicity and corrosion resistance.

For the melamine resin, for example, a melamine resin in which the methylol group of the methylolated melamine resin is etherified with a monohydric alcohol having 1 to 8 carbon atoms can be used. The above-mentioned etherified melamine resin may be a methylolated melamine resin in which all the methylol groups are etherified, or may be partially etherified to leave methylol groups or imino groups.

Specific examples of amine-based resins include fully alkyl methyl/butyl mixed etherified melamine resins, methylol type methyl/butyl mixed etherified melamine resins, and imide methyl/butyl mixed etherified melamine resins. Etherified melamine resin, fully alkyl methylated melamine resin, imino type methylated melamine resin, methylated urea resin, butylated urea resin, methylated benzoguanamine resin, butylated benzene And guanamine resin and so on. These amino resins can be used alone or in combination of two or more.

Examples of the above-mentioned amine-based resins for sale include Cymel232, Cymel232S, Cymel235, Cymel236, Cymel238, Cymel266, Cymel267, Cymel285 and other complete alkyl methyl/butyl mixed etherified melamine resins; Cymel272 and other methylolated melamine resins. Type methyl/butyl mixed etherified melamine resin; Cymel202, Cymel207, Cymel212, Cymel253, Cymel254 and other imide methyl/butyl mixed etherified melamine resin; Cymel300, Cymel301, Cymel303, Cymel350 and other completely alkyl methyl Cymel325, Cymel327, Cymel701, Cymel703, Cymel712, Cymel254, Cymel253, Cymel212, Cymel1128 and other imino-type methylated melamine resins (above, manufactured by Daicel Ornex, trade name), Uban20SE60 (Mitsui Cytec Co., Ltd. Co., Ltd., butyl etherified melamine resin), methylated benzoguanamine resin such as NicarakBL-60 (manufactured by Sanwa Chemical Co., Ltd.), Super Beccamin TD-126, Super Beccamin 15-594 (above, manufactured by DIC Corporation), etc. Methylated benzoguanamine resins, methylated urea resins such as CymelU-65 (manufactured by Daicel or Ornex), NicarakMX-270, NicarakMX-280, NicarakMX-290 (above, manufactured by Sanwa Chemical Co., Ltd.), NicarakMX-279 Butylated urea resins such as (manufactured by Sanwa Chemical Co., Ltd.), Uban10S60, Uban10R (above, made by Mitsui Cytec Co., Ltd.), Beccamin P-138, Beccamin P-196-M, Beccamin G-1850 (above, made by DIC Corporation), etc.

Phenolic resins are generally resins that condense phenolic compounds such as phenol, cresol, and bisphenol A with aldehydes such as formaldehyde in the presence of an acidic catalyst or a basic catalyst, and the condensation will also be carried out in the presence of an acidic catalyst. Those who are condensed under the novolak type phenol resin and alkaline catalyst are called resol type phenol resins.

In the hydrophilized coating composition of the present invention, any of a novolac-type phenol resin and a resol-type phenol resin can be used. In addition, a methylol group-introduced resin is also included, and a part of the further-introduced methylol group or a phenol resin whose owner is alkyl-etherified with an alcohol having 6 or less carbon atoms may be used.

Examples of phenolic resins sold include SUMILITERESIN PR-HF-3, SUMILITERESIN PR-HF-6, SUMILITERESIN PR-53194, SUMILITERESIN PR-53195, SUMILITERESIN PR-54869, SUMILITERESIN PR-16382, SUMILITERESIN PR-51939, SUMILITERESIN PR-53153, SUMILITERESIN PR-53364, SUMILITERESIN PR-53365, SUMILITERESIN PR-50702 (above, manufactured by "Sumitomo Bakelite"); PHENOLITE TD-2131, PHENOLITE TD-2106, PHENOLITE TD-2093, PHENOLITE TD-2091, PHENOLITE TD-2090, PHENOLITE VH-4150, PHENOLITE VH-4170, PHENOLITE VH-4240, PHENOLITE KH-1160, PHENOLITE KH-1163, PHENOLITE KH-1165, PHENOLITE TD-2093-60M, PHENOLITE TD-2090-60M, PHENOLITE Shonor BKM -262, Shonor BRG-555, Shonor BRG-556, Shonor BRG-558, Shonor CKM-923, Shonor CKM-983, Shonor BKM-2620, Shonor BRL-2854, Shonor BRG-5590M, Shonor CKS-3898, Shonor CKS -3877A, Shonor CKM-937 (above, manufactured by Showa Polymer Co., Ltd.), etc.

The polyisocyanate compound is a compound having two or more isocyanate groups in one molecule, and specific examples thereof include aromatic diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, and naphthalene diisocyanate; Aliphatic diisocyanates such as methyl diisocyanate, hexamethylene diisocyanate, dimer acid diisocyanate, lysine diisocyanate; methylene bis(cyclohexyl isocyanate), isophorone diisocyanate, methyl ring Alicyclic diisocyanates such as hexane diisocyanate, cyclohexane diisocyanate and cyclopentane diisocyanate; Viewlet type adduct adducts and isocyanuric cyclic adducts of the polyisocyanates; these Prepolymers containing free isocyanate groups obtained by reacting polyisocyanates with low molecular weight or high molecular weight polyol compounds (such as acrylic polyols, polyester polyols, polyether polyols, etc.) in excess of isocyanate groups.

Blocked polyisocyanate compounds are obtained by combining the free isocyanate groups of the above-mentioned polyisocyanate compounds with phenol compounds, oxime compounds, active methylene compounds, lactamide compounds, alcohol compounds, thiol compounds, acid amide compounds, and amide compounds. A polyisocyanate compound that is blocked by blocking agents such as amine-based compounds, amine-based compounds, imidazole-based compounds, urea-based compounds, urethane-based compounds, and imine-based compounds.

The crosslinking agent (D) may be used alone or in combination of two or more.

From the viewpoint of the hydrophilicity and corrosion resistance of the obtained coating film, the hydrophilized coating composition of the present invention is more stable than the hydrophilic resin (A), the sulfonic acid-based surfactant (B), and the hydrophobic resin (C). ) and the total solid content of the crosslinking agent (D), the total solid content of the hydrophilic resin (A) and the sulfonic acid-based surfactant (B) is 10 to 35 mass %, particularly preferably 12 to 30 mass % , more preferably 15 to 28 mass %.

In addition, (A) component, (B) component, (C) component and (D) component, the content of each component is relative to the hydrophilic resin (A), sulfonic acid-based surfactant (B), hydrophobic resin ( The total solid content of C) and the crosslinking agent (D), the total solid content of each component in the hydrophilic resin (A) is 5 to 25 mass %, particularly preferably 7 to 20 mass %, more particularly preferably 9 to 15% by mass, the sulfonic acid-based surfactant (B) is 5 to 15% by mass, particularly preferably 7 to 13% by mass, more preferably 9 to 11% by mass, and the hydrophobic resin (C) is 20 to 60% by mass mass %, particularly preferably 25 to 55 mass %, more preferably 30 to 50 mass %, and the crosslinking agent (D) is 20 to 60 mass %, particularly preferably 25 to 55 mass %, more preferably 30 to 50 mass % The coating film obtained by 50 mass % is preferable from the viewpoints of hydrophilicity, corrosion resistance, and water resistance of the coating film.

Furthermore, the total solid content of the hydrophobic resin (C) is 25 to 65 mass %, particularly preferably 30 to 60 mass %, relative to the total solid content of the hydrophobic resin (C) and the crosslinking agent (D). More preferably, it is a coating film obtained by 35-55 mass %, and it is more preferable from a viewpoint of the hydrophilicity or corrosion resistance of a coating film.

other ingredients The hydrophilized coating composition of the present invention contains, as other components, a pigment, a rust inhibitor, a surfactant (other than the sulfonic acid-based surfactant (B)), a rheology control agent, and a surface conditioner as appropriate as necessary. , ionic liquids, defoaming agents, film-forming aids and other components commonly used in coatings, and as a diluting solvent, water or an appropriate organic solvent can be used.

As the pigment, a coloring pigment, an extender pigment, an antirust pigment, etc. are mentioned. As a coloring pigment, titanium dioxide, red iron oxide, an aluminum paste, an azo type pigment, a phthalocyanine type pigment, etc. are mentioned, for example.

As an extender pigment, a talc, a silica, calcium carbonate, barium sulfate, a zinc flower (zinc oxide) etc. are mentioned, for example.

As the rust preventive pigment, from the viewpoint of preventing environmental pollution, those that do not contain harmful metals such as lead and chromium are preferable, and examples thereof include zinc phosphate, zinc phosphite-zinc oxide complex, aluminum phosphate, calcium phosphate, phosphoric acid Phosphate-based compounds such as magnesium, and molybdate-based compounds such as calcium molybdate and zinc molybdate. Each of these pigments can be used alone or in combination of two or more.

Examples of the rust inhibitor include organic phosphoric acid such as phytic acid and phosphonic acid, metal salts of diphosphoric acid, and nitrite, and further include tannin, gallic acid, ascorbic acid, and salts thereof.

The hydrophilic coating composition of the present invention, for example, can be prepared by mixing the hydrophilic resin (A), the sulfonic acid-based surfactant (B), the hydrophobic resin (C), the crosslinking agent (D), and other necessary Components are prepared by dissolving or dispersing in an aqueous medium.

The water content of the hydrophilized coating composition of the present invention in the total solvent in the coating is 80 to 97% by mass, preferably 85 to 95% by mass.

In addition to water, the whole medium may further contain an organic solvent, a neutralizing agent, or the like.

The hydrophilized coating composition of the present invention can be applied to various substrates that require surface treatment to be hydrophilized. Examples of the substrate include metals, various plastics, such films, glass, paper, and wood.

Examples of the metal substrate include zinc plated steel sheets, aluminum-zinc plated steel sheets, aluminum sheets, aluminum alloy sheets, electrical steel sheets, copper sheets, and stainless steel sheets used in automobiles, home appliances, and building materials.

As the aforementioned plastic substrate, it is generally used as a raw material for plastic moldings such as mobile phones, home appliances, interior and exterior materials of automobiles, and OA machines. Carbonate resin (PC resin), ABS/PC resin, polystyrene resin (PS resin), polymethyl methacrylate resin (PMMA resin), acrylic resin, polypropylene resin, polyethylene resin, etc.

Examples of the plastic film base material include polyethylene terephthalate film, polyester film, polyethylene film, polypropylene film, TAC (triacetyl cellulose) film, polycarbonate film, polyethylene film Vinyl chloride film, etc.

The hydrophilic coating composition of the present invention can be applied to, for example, vehicles and vehicle parts; building components such as outer walls and roofs; civil engineering components such as guardrails, soundproof walls, and drains; home appliances; aluminum fins; industrial machinery; castings; Fog film sheet, anti-fog glass and other anti-fog materials; mirrors; medical equipment; surface coating of various items such as sheets, coils, or molded products.

It is especially suitable for vehicles, building materials, machine materials, etc. which use light metal materials such as aluminum or its alloy materials, its formed products, and the formed products as parts.

The above-mentioned substrates and objects to be coated may be those whose surfaces have been degreased and, if necessary, chemically treated. In addition, it is preferable that the surface is chemically treated from the viewpoints of adhesion, corrosion resistance, and the like. As chemical conversion treatment, phosphate treatment, zirconium treatment, chromate treatment, etc. are mentioned.

Moreover, the said base material and to-be-coated object may be formed by the primer coating film.

Examples of the primer coating composition used for the formation of the above-mentioned primer coating film include acrylic resins, epoxy resins, acrylic modified epoxy resins, urethane resins, polyester resins, and polyoxyalkylene resins. , ethylene and unsaturated carboxylic acid copolymer, ethylene-extended ionomer resin, chlorinated vinyl resin, etc. as the primer coating composition of the matrix resin. The primer coating composition may be either water-based coating or organic solvent-based coating. In addition, the primer coating composition may be an inorganic compound-based primer coating composition.

The coating of the primer coating composition can be carried out by methods known in itself, for example, by dip coating, shower coating, spray coating, roller coating, electrophoretic coating, etc., usually applied to a dry film The thickness is 0.2 to 20 μm, preferably 0.5 to 10 μm, and the primer coating film is formed by setting at room temperature, baking and drying, or the like.

For the baking and drying of the above-mentioned primer coating film, the maximum temperature of the raw materials is usually 80 to 250°C, preferably 120 to 240°C, and the baking time is 6 seconds to 30 minutes, preferably 8 seconds to 10 minutes. conduct.

The hydrophilic coating composition of the present invention can be applied by the self-known method, for example, by dip coating, shower coating, spray coating, roll coater coating, curtain coater coating Coating, flow coater coating, electrophoretic dynamic coating (electric coating), etc. are carried out, and among them, spray coating or roll coater coating is preferred.

The film thickness can be appropriately set according to the object to be coated and the properties of the coating film required. Usually, it is applied to a cured film thickness of 0.2 to 20 μm, preferably 0.4 to 18 μm, more preferably 0.6 to 15 μm, and a hydrophilic coating film can be formed by setting at room temperature or baking and drying.

For the baking and drying of the above-mentioned hydrophilic coating film (hardening of the hydrophilic coating composition of the present invention), suitable curing conditions can be selected according to the composition. 240°C, and the baking time is 6 seconds to 20 minutes, preferably 8 seconds to 15 minutes. [Example]

Hereinafter, the present invention will be described in more detail by way of examples. Wherein, "parts" and "%" respectively represent "mass parts" and "mass %". In addition, the mass part of the raw material in the following Production Examples, Examples and Comparative Examples represents the mass part of the solid content (or the active ingredient in some cases) of the raw material.

The raw materials in the table are shown below.

Hydrophilic resin (A) (Note 1) Polyacrylamide resin No. 1: weight average molecular weight of about 80,000, hydrophilic group content of about 14,000 mmol/kg, total acrylamide of 90% by mass or more (acrylamide 96% by mass, acrylic acid 1 mass%, HEMA3 mass%, hydrophilic group content about 14000mmol/kg) (Note 2) Polyacrylamide resin No. 2: weight average molecular weight of about 40,000, hydrophilic group content of about 14,000 mmol/kg, total acrylamide of 90 mass % or more (acrylamide 96 mass %, acrylic acid 1 mass%, HEMA3 mass%, hydrophilic group content about 14000mmol/kg) (Note 3) Polyacrylamide resin No. 3: weight average molecular weight of about 8,000, hydrophilic group content of about 14,000 mmol/kg, total acrylamide of 90 mass % or more (acrylamide 96 mass %, acrylic acid 1 mass%, HEMA3 mass%, hydrophilic group content about 14000mmol/kg) (Note 4) Haricoat1057: manufactured by Harima Chemicals, trade name, weight average molecular weight of about 300,000, nonionic polyacrylamide resin, hydrophilic group content of about 14,000 mmol/kg, total acrylamide of 90% by mass or more

(Note 5) Hydrophilic acrylic resin No. 1: As shown below, the synthesized acrylic resin latex has a hydrophilic group content of about 14,600 mmol/kg, a total of 40% by mass of acrylamide, and a monoamide group-containing 52% by mass of the total body In a four-necked flask equipped with a stirring device, a thermometer, a cooling tube, and a nitrogen gas inlet, 25 parts of isopropanol and 250 parts of deionized water were put, and the temperature was raised to 80°C. Next, a mixture of the following monomer, solvent and initiator was dropped into the flask over a period of 4 hours, and after the dropping was completed, the mixture was kept at 80° C. for a further 2 hours to obtain a hydrophilic acrylic resin No. 1 with a solid content of 15% by mass. Dispersions. The weight-average molecular weight of the hydrophilic acrylic resin No. 1 is 250,000, the average particle size of the resin in the dispersion is 50 nm, the hydroxyl value of the resin is 80 mgKOH/g, and the acid value of the resin is 168 mgKOH/g.

Hydrophilic acrylic resin No.1 dispersion BLEMMERPME-400(*) 20 parts Acrylamide 40 parts N-methylol acrylamide 10 parts Acrylic acid 21 parts 2-hydroxyethyl methacrylate 7 parts methylenebis 2 parts of acrylamide, 1.5 parts of ammonium persulfate, 290 parts of deionized water ₂ CH ₂ O) repeating units n=9 (average)

(Note 6) Hydrophilic acrylic resin No. 2: As shown below, a synthesized acrylic resin latex, a hydrophilic group content of about 16,400 mmol/kg, a total amount of acrylamide 20 mass %, a monoamide group-containing monolayer 36 mass% of the total body In a four-necked flask equipped with a stirring device, a thermometer, a cooling pipe, and a nitrogen gas inlet, 25 parts of isopropanol and 250 parts of deionized water were put, and the temperature was raised to 80°C. Next, a mixture of the following monomer, solvent and initiator was dropped into the flask over a period of 4 hours, and after the drop was completed, the mixture was kept at 80° C. for 2 hours to obtain a dispersion of hydrophilic acrylic resin No. 2 with a solid content of 15% by mass. liquid. The weight-average molecular weight of the hydrophilic acrylic resin No. 2 is 250,000, the average particle diameter of the resin in the dispersion is 55 nm, the hydroxyl value of the resin is 87 mgKOH/g, and the acid value of the resin is 164 mgKOH/g.

Dispersion of hydrophilic acrylic resin No.2 BLEMMERPME-400(※) 40 copies 20 parts of acrylamide 15 parts of N-methylol acrylamide Acrylic 21 copies 2-hydroxyethyl methacrylate 3 parts Methylenebisacrylamide 1 part 1.5 parts of ammonium persulfate Deionized water 290 parts

(Note 7) Cellogen F-7A: manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., trade name, weight average molecular weight about 30,000, sodium carboxymethyl cellulose compound, hydrophilic group content about 18,500 mmol/kg (Note 8) PEG-20000: manufactured by Sanyo Chemical Industry Co., Ltd., trade name, weight average molecular weight of about 20,000, polyoxyalkylene compound and hydrophilic group content of about 23,000 mmol/kg (Note 9) JE-04: manufactured by Japan Vam & Poval, trade name, weight average molecular weight about 17000, polyvinyl alcohol compound, hydrophilic group content about 7700 mmol/kg

Sulfonic acid-based surfactant (B) (Note 10) NewCall290-A: Nippon Emulsifier Co., Ltd., trade name, sulfosuccinic acid-based negative ionic surfactant (Note 11) NewCall271-A: Nippon Emulsifier Co., Ltd., trade name, anionic surfactant based on alkyl diphenyl ether disulfonic acid (Note 12) LevenorWX: Kao Corporation, a polyoxyethylene alkyl ether sodium sulfate-based negative ionic surfactant (Note 13) PrisurfM208F: manufactured by Daiichi Industrial Pharmaceutical Co., Ltd., phosphate ester type anion surfactant (Note 14) NewCall2308: manufactured by Nippon Emulsifier, trade name, polyoxyethylene alkyl ether, nonionic surfactant, HLB=13.2 (Note 15) Anhitor20AB: Kao Corporation, amphoteric surfactant of lauric acid amidopropyl betaine series

In addition, (Note 13) to (Note 15) non-sulfonic acid-based surfactants were used as comparative examples.

Hydrophobic resin (C) (Note 16) Hydrophobic acrylic resin No. 1: acrylic resin latex (St/MMA/2HEA/HEMA/Aac=10/60/25/4/1 (mass ratio)), resin hydroxyl value 138 mgKOH/g, resin acid The price is 8mgKOH/g, and the hydrophilic group content is about 2600mmol/kg

In addition, each of the above-mentioned abbreviations is as follows. St; Styrene, MMA; Methyl Methacrylate, 2HEA; 2-Hydroxyethyl Acrylate, HEMA; 2-Hydroxyethyl Methacrylate, Aac; Acrylic (Note 17) Polyurethane resin No. 1: As shown below, the synthetic urethane resin latex has a hydrophilic group content of about 300 mmol/kg Put 115.5 parts of polybutene adipic acid with a number average molecular weight of 2000, 115.5 parts of polycaprolactone diol with a number average molecular weight of 2000, 23.2 parts of dimethylolpropionic acid, and 1,4-butanediol into the reaction vessel 14.5 parts of isophorone diisocyanate and 120.1 parts of isophorone diisocyanate were reacted at 85° C. for 7 hours in a nitrogen stream with stirring to obtain a prepolymer with an NCO (isocyanate group) content of 4.0%.

Next, the prepolymer was cooled to 50°C, 165 parts of acetone was added to dissolve it uniformly, 15.7 parts of triethylamine was added under stirring, and 600 parts of deionized water was added while keeping the temperature below 50°C. The aqueous dispersion was kept at 50°C for 2 hours. After the water elongation reaction was completed, the acetone was distilled off under reduced pressure at below 70°C, and the pH was adjusted to 8.0 with triethylamine and deionized water to obtain a solid with an acid value of 17 mgKOH/ g, latex of urethane resin No. 1 with a solid content of 30% by mass and an average particle diameter of 150 nm.

(Note 18) Epoxy resin No. 1: As shown below, synthesized acrylic modified epoxy resin, hydrophilic group content of about 2700 mmol/kg Production of carboxyl group-containing acrylic resin No. 1 solution 850 parts of n-butanol was heated at 100°C under nitrogen flow, and the monomer mixture and polymerization initiator "450 parts of methacrylic acid, 450 parts of styrene, 100 parts of ethyl acrylate, t- 40 parts of butyl peroxy-2-ethylhexanoate" was dripped and aged for 1 hour. Next, a mixed solution of 10 parts of t-butylperoxy-2-ethylhexanoate and 100 parts of n-butanol was dripped over 30 minutes, and aged for 2 hours after the dripping.

Next, 933 parts of n-butanol and 400 parts of ethylene glycol monobutyl ether were added to obtain a solution of carboxyl group-containing acrylic resin No. 1 with a solid content of about 30%. The obtained resin had a resin acid value of 300 mgKOH/g and a weight average molecular weight of about 17,000.

Manufacture of Aqueous Dispersion of Acrylic Modified Epoxy Resin In a reaction vessel, 513 parts of jER828EL (manufactured by Mitsubishi Chemical Corporation, epoxy resin, epoxy equivalent of about 190, number average molecular weight of about 380), 287 parts of bisphenol A, 0.3 part of tetramethylammonium chloride, and methyl isoform were charged. 89 parts of butyl ketones were heated at 140° C. under nitrogen flow, and reacted for about 4 hours to obtain an epoxy resin solution. The obtained epoxy resin had an epoxy equivalent of 3700 and a number average molecular weight of about 17000.

Next, in the obtained epoxy resin solution, 667 parts of the above-obtained acrylic resin No. 1 solution containing a carboxyl group with a solid content of about 30% was placed, heated at 90° C. to dissolve uniformly, and then heated at the same temperature. Next, 40 parts of deionized water was added dropwise over 30 minutes, followed by adding 30 parts of dimethylethanolamine, and stirring was performed for 1 hour to react.

Further, 2380 parts of deionized water was added over 1 hour to obtain an aqueous dispersion of epoxy resin No. 1 of acrylic modified epoxy resin with a solid content of about 25%. The obtained resin had a number average molecular weight of about 22,000 and a resin acid value of 48 mgKOH/g. The average particle diameter of the resin in the dispersion was 190 nm.

(Note 19) jER W2821R70: manufactured by Mitsubishi Chemical Corporation, trade name, bisphenol A epoxy resin latex, solid content about 70%, epoxy equivalent about 230, hydrophilic group content about 3500mmol/kg Crosslinker (D) (Note 20) Cymel327: manufactured by Daicel Ornex, brand name, imino type methylated melamine resin, solid content 90% (Note 21) Cymel350: Daicel Ornex, brand name, fully alkyl methylated melamine resin, solid content 100% (Note 22) Cymel303: Daicel Ornex Co., Ltd., brand name, fully alkyl methylated melamine resin, solid content 100% (Note 23) NicarakMX-290: manufactured by Sanwa Chemical Co., Ltd., trade name, methylated urea resin (Note 24) Shonor BKM-262: Showa Polymer Co., Ltd., trade name, phenol resin

＜Manufacture of hydrophilic coating composition＞ Example 1 Production of Hydrophilized Coating Composition No.1 5 parts (solid content) of polyacrylamide resin No. 1 (Note 1), 5 parts (solid content) of NewCall290-A (Note 10), and 55 parts of polyurethane resin No. 1 (Note 17) Part (solid content) and 35 parts (solid content) of Cymel327 (Note 20) were mixed and stirred, and adjusted with deionized water to obtain a hydrophilic coating composition No. 1 with a solid content of 10%.

Examples 2 to 37 and Comparative Examples 1 to 12 Production of Hydrophilized Paint Compositions No. 2 to No. 49 Except for the composition shown in Tables 1 to 4, in the same manner as in Example 1, each of the hydrophilic coating compositions No. 2 to No. 49 with a solid content of 10% was obtained.

In addition, the hydrophilized coating composition No. 38 to No. 49 were used in the comparative example. The numerical values in Tables 1 to 4 represent the compounding part (parts by mass) of each component.

<Preparation of the test coated sheet> Preparation of test board (1) The aluminum plate (A1050, plate thickness 0.1 mm) was degreased using a 2% aqueous solution of an alkali degreaser (manufactured by Japan CB Chemistry Company, trade name "Chemi Cleaner 561B"), followed by zirconium conversion treatment. Next, each hydrophilized coating composition was applied until the film thickness of the dry coating film was 0.7 μm, and baked for 10 seconds under the condition that the raw material reached a maximum temperature of 220° C. to obtain each test panel (1).

Preparation of test board (2) Each of the hydrophilic coating compositions was coated on the steel sheet coated with the electrocoating film until the film thickness of the dry coating film was 10 μm, and each test plate (2) was obtained after baking at 140° C. for 10 minutes.

Each test was performed according to the following test method with respect to each test-coated board obtained by the above. The combined test results are shown in Tables 1-4.

Water resistance: Using each test plate (1), when 3 sheets of overlapping gauze were immersed in water and rubbed, the number of times of reciprocating rubbing until the base material was exposed was evaluated according to the following criteria. ◎ and ○ were judged as acceptable levels. ◎ means more than 30 times without problems. ○ means more than 20 times and less than 30 times, which is within the practical range △ means more than 10 times and less than 20 times, there is a slight problem × means less than 10 times, which is significantly insufficient.

Hydrophilic: Each test panel (1) and each test panel (2) were dripped with 10 μL of water on the coated surface at room temperature of 20°C, and the contact angle between the water droplet and the coated surface was measured using the “Automatic” manufactured by Kyowa Interface Science Co., Ltd. After measuring with a contact angle meter DM-501" (trade name), hydrophilicity was evaluated. ◎ and 〇 indicate the qualified level. ◎ indicates that the contact angle is less than 15°, and the hydrophilicity persistence is a remarkably good level. ○ indicates that the contact angle is 15° or more and less than 30°, and the hydrophilicity persistence is a good level. △ indicates that the contact angle is 30° or more and less than 50°, which means that the hydrophilicity persistence is insufficient. × indicates that the contact angle is 50° or more, which means that the hydrophilicity persistence is significantly insufficient.

Hydrophilic persistence: Each test panel (1) and each test panel (2) were immersed in running water of tap water (the flow rate was 15 kg/hour per 1 m ² of the coated surface) for 72 hours, at 80°C for 5 minutes After drying, 10 μL of water was dropped into the coated surface at room temperature of 20°C, and the contact angle between the water droplet and the coated surface was measured using "Automatic Contact Angle Meter DM-501" (trade name) manufactured by Kyowa Interface Science Co., Ltd. After the assay, the hydrophilicity persistence was assessed. ◎ and 〇 are judged to be acceptable levels. ◎ indicates that the contact angle is less than 15°, and the hydrophilicity persistence is a remarkably good level. ○ indicates that the contact angle is 15° or more and less than 30°, which is a good level of hydrophilic persistence. △ indicates that the contact angle is 30° or more and less than 50°, which means that the hydrophilicity persistence is insufficient. × indicates that the contact angle is 50° or more, which means that the hydrophilicity persistence is remarkably insufficient.

Hydrophilic persistence after heating cycle test: Using each test panel (1), immerse "in running water of tap water (the flow rate is 15 kg/hour per 1 m ² of the coated surface) for 17 hours, and carry out 7 hours at 80°C. "Drying" was taken as 1 cycle, and the cycle was repeated 5 times. Then, 10 μL of water was dropped on the coated surface at room temperature of 20°C, and the contact angle between the water drop and the coated surface was measured using "Automatic Contact Angle Meter DM-501" (trade name) manufactured by Kyowa Interface Science Co., Ltd. Measurements were performed to evaluate heating cyclability. ◎ and ○ were judged as acceptable levels. ◎ indicates that the contact angle is less than 15°, which is a remarkably good level of hydrophilic persistence. ○ indicates that the contact angle is 15° or more and less than 30°, which is a good level of hydrophilic persistence. △ indicates that the contact angle is 30° or more and less than 50°, which means that the hydrophilicity persistence is insufficient. × indicates that the contact angle is 50° or more, which means that the hydrophilicity persistence is remarkably insufficient.

Water leaching resistance: Using each test plate (1), according to the following steps 1 to 3, the coating film weight loss ratio (%) was obtained, and the evaluation was performed according to the following criteria. ◎ and ○ were judged as acceptable levels.

Step 1: Determine the quality of the aluminum plate･･･A Step 2: Determination of the quality of the coated plate coated with the hydrophilizing agent on the aluminum plate･･･B Step 3: Determination of the quality of the coated board after immersing the coated board in deionized water for 72 hours and drying at 80°C for 30 minutes･･･C Coating film reduction ratio (%)={[B mass-C mass]/[B mass-A mass]}×100 ◎ indicates that the coating film weight loss ratio (%) is 5% or less. ○ indicates that the coating film weight loss ratio (%) exceeds 5% and is 10% or less. △ indicates that the coating film weight loss ratio (%) exceeds 10% and is less than 15%. × indicates that the coating film weight loss ratio (%) exceeds 15%.

Corrosion resistance: Using each test plate (1), the test was performed according to the salt spray test method of JIS-Z-2371. The test time was set to 500 hours, and the evaluation was performed according to the following criteria. ◎ and ○ were judged as acceptable levels. ◎: White rust and blisters have not been confirmed on the coated surface 〇: White rust and blisters are generated on a part of the coated surface △: White rust or blisters are slightly generated on the entire surface ×: White rust or blisters were remarkably generated on the entire surface.

Corrosion and odor resistance: Using each test panel (1), the corrosion resistance test was carried out for 500 hours in accordance with JIS-Z-2371 salt spray test method, and then the corrosion odor level of exhaled aluminum was evaluated according to the following criteria. ◎ and ○ were judged as acceptable levels. ◎: No odor is felt 〇: Slight smell △: odor is felt ×: Remarkable odor is felt

Hot water resistance: Using each test panel (2), after being immersed in hot water of 80° C. for 2 hours, the appearance was evaluated by the following criteria, and ⊚ and ◯ were judged as acceptable levels. ◎: No change was observed in the appearance of the coated surface 〇: The coated surface is only slightly whitish △: Whitening on the coated surface ×: Remarkably whitened on the coated surface.

[產業上可利用性]

[Industrial availability]

The present invention can provide a hydrophilized coating composition which can obtain a coating film having excellent hydrophilicity (sustainability) and corrosion resistance on the surfaces of various materials such as substrates, and also excellent in water resistance.

The present invention will be described in detail with reference to specific embodiments, but it will be apparent to those skilled in the art that various changes or corrections can be made without departing from the spirit and scope of the present invention. The present application is based on Japanese Patent Application (Japanese Patent Application No. 2020-182598) filed on October 30, 2020, the contents of which are incorporated herein by reference.

Claims (5)

A hydrophilized coating composition, which contains a hydrophilic resin (A), a sulfonic acid-based surfactant (B), a hydrophobic resin (C) and a crosslinking agent (D), relative to the aforementioned hydrophilic resin (A), In terms of the total solid content of the sulfonic acid-based surfactant (B), the hydrophobic resin (C) and the crosslinking agent (D), the hydrophilic resin (A) and the sulfonic acid-based surfactant ( The total solid content of B) is 10 to 35% by mass. The hydrophilized coating composition according to claim 1, wherein in the hydrophilic resin (A), with respect to the total amount of the monomer components constituting the polyacrylamide resin and the polymer, a monomer containing an amide group The total amount is 50 mass % or more of at least one of the hydrophilic acrylic polymers. The hydrophilized coating composition according to claim 1 or 2, wherein the weight-average molecular weight of the aforementioned hydrophilic resin (A) is 5,000 to 350,000. The hydrophilized coating composition according to any one of claims 1 to 3, wherein the hydrophobic resin (C) contains a composition selected from the group consisting of acrylic resin (C1), polyurethane resin (C2) and epoxy resin (C3) ) at least one of them. The hydrophilized coating composition according to any one of claims 1 to 4, wherein the hydrophilic resin (A), the sulfonic acid-based surfactant (B), the hydrophobic resin (C), and the cross-linked In terms of the total solid content of the agent (D), the hydrophilic resin (A) is 5 to 25 mass %, and the sulfonic acid-based surfactant (B) is 5 to 25 mass % in terms of the total solid content of each component. 15 mass %, the said hydrophobic resin (C) is 20-60 mass %, and the said crosslinking agent (D) is 20-60 mass %.