KR101852314B1 - Coating agent and coating film - Google Patents

Abstract

The coating agent is a coating agent containing metal fine particles, a dispersion medium, a metal fine particle dispersant and a binder, wherein the metal fine particle dispersant contains a monomer or oligomer having at least two active energy curing groups and at least one carboxyl group, (Meth) acrylic resin binder having a (meth) acryloyl group and the (meth) acrylic resin binder contains no anionic group-containing monomer or contains an anionic group-containing monomer in a proportion of less than 5% It is the reactant of the monomer component.

Description

[0001] COATING AGENT AND COATING FILM [0002]

More particularly, the present invention relates to a coating agent comprising metal fine particles dispersed by a fine metal particle dispersing agent, and a coating film obtained by curing the coating agent.

Conventionally, various coating agents are added to coating films obtained by coating and curing the coating agents, for example, in order to impart various physical properties such as mechanical properties, chemical resistance, high refractive index, antistatic property, ultraviolet ray / infrared ray blocking property, , And further various pigments and the like are dispersed in various kinds of metal fine particles.

Further, in such a coating agent, metal fine particles may aggregate depending on the kinds of the metal fine particles, the solvent, and the binder resin to be blended. Therefore, it has been proposed to add a dispersant to the coating agent in order to disperse the fine metal particles well.

Specifically, for example, by reacting a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (containing 67 mol% of dipentaerythritol pentaacrylate) with pyromellitic dianhydride It has been proposed to prepare an active energy ray curable coating composition by mixing the resulting composition (I) with a copolymer of methyl methacrylate and hydroxyethyl acrylate and colloidal silica containing isopropyl alcohol as a dispersion medium Patent Document 1 (Example 10)).

Japanese Patent Laid-Open No. 07-286115

On the other hand, the coating film of the resin composition for coating as described above is required to have adhesion with a substrate, and is required to have hardness and durability (alkali resistance and light resistance).

In addition, as the resin composition for coating, it is required to improve the dispersibility and dispersion stability of the further layer, and the coating film thereof is required to have excellent transparency depending on the use.

An object of the present invention is to provide a coating agent which is excellent in dispersibility and dispersion stability of metal fine particles and can improve the transparency, adhesion, hardness and durability (alkali resistance and light resistance) of the coating film, And to provide a coating film.

The present invention [1] is a coating agent containing metal fine particles, a dispersion medium, a metal fine particle dispersant and a binder, wherein the metal fine particle dispersant contains a monomer or oligomer having at least two active energy curing groups and at least one carboxyl group Wherein the binder contains a (meth) acrylic resin binder having a (meth) acryloyl group in a side chain, and the (meth) acrylic resin binder does not contain an anionic group-containing monomer or a ratio , Which is a reactant of a monomer component containing an anionic group-containing monomer.

In the present invention [2], the metal fine particle dispersant further comprises a (meth) acrylic resin dispersant having a (meth) acryloyl group in its side chain, and the (meth) acrylic resin dispersant is contained in a proportion of 5% And a coating agent according to the above [1], which is a reactant of a monomer component containing an anionic group-containing monomer.

In the present invention [3], the (meth) acrylic resin dispersant comprises the coating material according to the above [2], which is a reactant of a monomer component containing an anionic group-containing monomer in a proportion of 10 mass% or more.

The present invention [4] includes the coating agent according to any one of [1] to [3], wherein the anionic group of the anionic group-containing monomer is a carboxyl group or a phosphoric acid group.

The present invention [5] includes the coating agent according to any one of the above [1] to [4], wherein the (meth) acrylic resin binder is a reactant of a monomer component containing an aromatic ring-containing monomer.

The present invention [6] includes the coating agent according to [5], wherein the content of the aromatic ring-containing monomer in the (meth) acrylic resin binder is 20% by mass or more based on the total amount of the monomer components.

The present invention [7] includes the coating agent according to any one of the above [1] to [6], wherein the (meth) acrylic resin binder has a weight average molecular weight of 3000 to 50000.

The present invention [8] includes the coating agent according to any one of [2] to [7], wherein the (meth) acrylic resin dispersant is a reactant of a monomer component containing an aromatic ring-containing monomer.

The present invention [9] includes the coating agent according to the above [8], wherein the content of the aromatic ring-containing monomer in the (meth) acrylic resin dispersant is 20% by mass or more based on the total amount of the monomer components.

The present invention [10] includes the coating agent according to any one of the above-mentioned [2] to [9], wherein the (meth) acrylic resin dispersant has a weight average molecular weight of 3000 to 50000.

The present invention [11] is a process for producing a metal fine particle dispersion according to any one of [2] to [10], wherein the metal fine particle dispersant further comprises a caprolactone adduct of (meth) acrylic acid represented by the following formula And a coating agent.

CH ₂ = C (R ¹ ) CO [O (CH ₂ ) ₅ CO] _n OH (1)

(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and n represents 1 to 10.)

The present invention [12] includes a coating film which is a cured product of the coating agent according to any one of [1] to [11].

The coating agent of the present invention can provide a coating film excellent in dispersibility and dispersion stability of metal fine particles and excellent in transparency, adhesion, hardness and durability (alkali resistance and light resistance).

Therefore, the coating film of the present invention is excellent in transparency, adhesion, hardness and durability (alkali resistance and light resistance).

The coating agent of the present invention comprises a fine metal particle dispersion in which metal fine particles are dispersed in a dispersion medium. Specifically, the coating agent contains metal fine particles, a dispersion medium, a metal fine particle dispersant, and a binder.

Examples of the metal fine particles include, but are not limited to, aluminum oxide (alumina), titanium oxide (titania), zinc oxide, zirconium oxide (zirconia), tin oxide, yttrium oxide (yttria), bismuth oxide, Such as gallium, antimony, tin, fluorine, phosphorus, aluminum, or the like, may be added to fine particles of metal oxides such as cerium oxide, indium oxide, silicon oxide And a fine particle of a hetero-element-doped metal oxide obtained by doping a different kind of element of the above-mentioned element. The crystal structure of these metal oxides is not particularly limited and may be, for example, a cubic system, a tetragonal system, an orthorhombic system, a monoclinic system, a trinary system, a hexagonal system, a three-system system or the like.

As the metal fine particles, aluminum oxide, titanium oxide and zirconium oxide are preferable.

The metal fine particles may be surface-treated by a known method, if necessary.

These metal fine particles may be used alone or in combination of two or more.

The shape of the metal fine particles is not particularly limited, and examples thereof include bulk, spherical, hollow, porous, rod-shaped, plate-like, fibrous, irregular shape, and mixtures thereof.

The particle diameter of the metal fine particles is measured as a primary particle diameter of the metal fine particles themselves and is, for example, 200 nm or less, preferably 90 nm or less, more preferably 50 nm or less, usually 1 nm or more, and preferably 3 nm or more.

When the primary particle diameter of the metal fine particles is within the above range, it is easy to obtain fine metal particles, and the storage stability of the coating agent and the transparency of the coating film (described later) can be improved.

Examples of the dispersion medium include, but are not limited to, petroleum hydrocarbon solvents such as hexane and mineral spirit, aromatic hydrocarbon solvents such as benzene, toluene and xylene, for example, acetone, methyl ethyl ketone , Ketone solvents such as methyl isobutyl ketone, diisobutyl ketone and cyclohexanone, and ester solvents such as methyl acetate, ethyl acetate, butyl acetate,? -Butyrolactone and propylene glycol monomethyl ether acetate , Organic solvents such as aprotic polar solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone and pyridine have.

Examples of the dispersion medium include water, for example, alcohol solvents such as methanol, ethanol, propanol, isopropanol and butanol, glycol solvents such as ethylene glycol monoethyl ether and propylene glycol monomethyl ether And water-based solvents such as ether-based solvents.

Specific examples of the petroleum hydrocarbon solvents include AF Solvent Nos. 4 to 7 (manufactured by Shin-Nihon Petroleum K.K.) and the like, and as the aromatic hydrocarbon solvents, there may be mentioned, for example, For example, ink solvent No. 0, Solvesso 100, 150, 200 (manufactured by Shin-Nippon Petroleum K.K.), manufactured by Exxon Chemical Co., Ltd., and the like.

These dispersion media may be used alone or in combination of two or more.

The metal fine particle dispersant is an additive for improving the dispersibility of the metal fine particles in the dispersion medium. As the essential component, a monomer or an oligomer having at least two active energy curing groups and at least one carboxyl group (hereinafter collectively referred to as a monomer and an oligomer) ).

The active energy curing unit is a group which is cured by forming a crosslinked structure by irradiation of an active energy ray (described later), and examples thereof include (meth) acryloyl group, glycidyl group and the like. As the active energy curing agent, a (meth) acryloyl group is preferably exemplified.

On the other hand, the term "(meth) acryloyl group" is defined as "acryloyl group" and / or "methacryloyl group".

Acrylate " and " methacrylate " are also defined as " acrylate " &Quot;

Examples of the compound having two or more (meth) acryloyl groups and at least one carboxyl group include compounds obtained by modifying a compound having two or more (meth) acryloyl groups and at least one hydroxyl group with an acid anhydride And the like.

As such a modifier, more specifically, for example, a polyfunctional (meth) acrylic compound having two or more (meth) acryloyl groups and at least one hydroxyl group (hereinafter referred to as a hydroxyl group- (Hereinafter sometimes referred to as (A) a modified product of an acid anhydride of a polyfunctional (meth) acrylic compound) in the presence of a (meth) acrylic compound.

The hydroxyl group-containing polyfunctional (meth) acrylic compound is, for example, a polyol such as glycerin (hydroxyl group number 3), trimethylol propane (hydroxyl number 3), tris (2- (Hydroxyl group number 4), ditrimethylol propane (hydroxyl number 4), pentaerythritol (hydroxyl number 4), and the like. , Known polyfunctional alcohols such as dipentaerythritol (hydroxyl group number 6), and tri pentaerythritol (hydroxyl group number 8)), and (meth) acrylic acid having less than equimolar number of hydroxyl groups in the polyol This is an added adduct (adduct).

Examples of the hydroxyl group-containing polyfunctional (meth) acrylic compound include pentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) Acrylate, pentaerythritol penta (meth) acrylate, trimethylol propane di (meth) acrylate, ditrimethylolpropane di (meth) acrylate, ditrimethylol propane tri (meth) (Meth) acrylate, glycerin di (meth) acrylate, diglycerin di (meth) acrylate, diglycerin tri (meth) acrylate, and alkylene oxides thereof Oxides, propylene oxide, etc.) adducts (including random adducts and block adducts), and mixtures thereof.

These hydroxyl group-containing polyfunctional (meth) acrylic compounds may be used alone or in combination of two or more.

As the hydroxyl group-containing polyfunctional (meth) acrylic compound, dipentaerythritol pentaacrylate and pentaerythritol tri (meth) acrylate are preferable, and from the viewpoint of the hardness of the coating film (described later) And preferably dipentaerythritol pentaacrylate.

On the other hand, the hydroxyl group-containing polyfunctional (meth) acrylic compound may be used in an appropriate ratio with the hydroxyl group-free polyfunctional (meth) acrylic compound described below.

Examples of the acid anhydride include a dicarboxylic acid monoanhydride, a tricarboxylic acid monoanhydride, and a tetracarboxylic acid dianhydride.

Examples of the dicarboxylic acid monoanhydride include anhydrides such as oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, anhydrous 2-alkyl (C 12 -C 18) succinic acid, anhydrous tetrahydrophthalic acid, hymic acid anhydride, hexahydrophthalic acid anhydride, Tetrabromophthalic anhydride, tetrachlorophthalic anhydride and the like.

Examples of the tricarboxylic acid monoanhydride include trimellitic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride and the like.

Examples of the tetracarboxylic acid dianhydride include pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 5- (2,5-oxotetrahydrofuryl) -3- Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride and the like.

These acid anhydrides may be used alone or in combination of two or more.

As the acid anhydride, preferably dicarboxylic acid monoanhydride or tetracarboxylic acid dianhydride can be given, and more preferred examples thereof include succinic anhydride, phthalic anhydride and pyromellitic anhydride. As the acid anhydride, a dicarboxylic acid monoanhydride is preferably used, and from the viewpoint of the hardness of the coating film (described later), more preferable examples thereof include succinic anhydride and phthalic anhydride, particularly preferably phthalic anhydride .

In order to obtain the acid anhydride modified product of the hydroxyl group-containing polyfunctional (meth) acrylic compound, for example, the hydroxyl group-containing polyfunctional (meth) acrylic compound and the acid anhydride are mixed, , And reacted by heating.

The compounding ratio of the hydroxyl group-containing polyfunctional (meth) acrylic compound and the acid anhydride is, for example, an equivalent ratio of an anhydride carboxylic acid group of an acid anhydride to a hydroxyl group of a hydroxyl group-containing polyfunctional (meth) (Anhydrous carboxylic acid group / hydroxyl group) is, for example, not less than 0.5, preferably not less than 0.67, such as not more than 1, preferably not more than 0.91.

As the solvent, for example, the above organic solvent (organic solvent as the dispersion medium) and the above-mentioned aqueous solvent (aqueous solvent as the dispersion medium) and the like can be mentioned. These solvents may be used alone or in combination of two or more. As the solvent, an organic solvent, more preferably a ketone solvent, and more preferably methyl isobutyl ketone can be mentioned.

In this reaction, a catalyst may be added as required.

Examples of the catalyst include metals, organic metal compounds, metal halides and amine compounds.

Examples of the metal include alkali metals such as sodium and potassium.

Examples of the organometallic compound include alkali metal alkoxides (alkali metal alkoxides) and derivatives thereof, for example, alkylaluminum compounds such as triethylaluminum and derivatives thereof such as tetrabutyl titanate Organic tin compounds such as alkoxy titanium compounds, tin 2-ethylhexanoate, tin octylate, and dibutyltin laurate.

Examples of the metal halide include tin halides such as tin chloride (specifically, tin dichloride: SnCl ₂ ).

Examples of the amine compound include N, N-dimethylbenzylamine, triethylamine, tributylamine, triethylenediamine, benzyltrimethylammonium chloride, benzyltriethylammonium bromide, tetramethylammonium bromide, Methyl ammonium bromide and the like.

These catalysts may be used alone or in combination of two or more.

As the catalyst, an amine compound is preferable, and N, N-dimethylbenzylamine, triethylamine and tributylamine are more preferable, and triethylamine is more preferable.

The compounding ratio of the catalyst is, for example, not less than 0.0001 part by mass, preferably not less than 0.01 part by mass relative to 100 parts by mass of the total amount of the hydroxyl group-containing polyfunctional (meth) acrylic compound and the acid anhydride, 5 parts by mass or less, preferably 0.5 parts by mass or less.

In this reaction, if necessary, a polymerization inhibitor may be added.

Examples of the polymerization inhibitor include p-methoxyphenol, hydroquinone, hydroquinone monomethyl ether, catechol, tert-butylcatechol, 2,6-di-tert-butyl-hydroxytoluene, 4- Phenol compounds such as benzyl-1,2-dihydroxybenzene, 2,2'-methylene-bis (4-methyl-6-tert- butylcatechol), phenothiazine, diphenylphenylene Aromatic amines such as diamine, dynaphthylphenylenediamine, p-aminodiphenylamine and N-alkyl-N'-phenylenediamine, for example, 4-hydroxy-2,2,6,6 -Tetramethylpiperidine, 4-acetoxy-1-oxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-1-oxy-2,2,6,6- 4-alkoxy-1-oxy-2,2,6,6-tetramethylpiperidine, bis (1-oxy-2,2,6,6-tetramethylpiperidin- Oxides of 2,2,6,6-tetramethylpiperidine, N-nitrosodiphenylamine, diethyldithiothiocarbamic acid P-benzoquinone, and the like.

These polymerization inhibitors may be used alone or in combination of two or more.

As the polymerization inhibitor, p-methoxyphenol is preferably exemplified.

The mixing ratio of the polymerization inhibitor is, for example, not less than 0.0001 part by mass, preferably not less than 0.01 part by mass based on 100 parts by mass of the total amount of the hydroxyl group-containing polyfunctional (meth) acrylic compound and the acid anhydride, Is not more than 1.0 part by mass, preferably not more than 0.1 part by mass.

The reaction conditions include a heating temperature of, for example, 60 ° C or higher, preferably 80 ° C or higher, for example, 140 ° C or lower in an oxygen atmosphere or an inert gas-oxygen gas mixture atmosphere Lt; 0 > C. The heating time is, for example, 4 hours or more, preferably 8 hours or more, for example, 20 hours or less, preferably 12 hours or less.

Thereby, the hydroxyl group-containing polyfunctional (meth) acrylic compound can be modified with an acid anhydride, and (A) an acid anhydride modified product of the polyfunctional (meth) acrylic compound can be obtained.

As the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A), more specifically, for example, a phthalic acid modified product of dipentaerythritol pentaacrylate, a phthalic acid modified product of pentaerythritol triacrylate, Succinic acid modified products of pentaerythritol pentaacrylate, succinic acid modified products of pentaerythritol triacrylate, and the like.

The acid value of the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A) is, for example, 20 mgKOH / g or more, preferably 73 mgKOH / g or more, more preferably 80 mgKOH / g or more, G or less, preferably 300 mgKOH / g or less.

The hydroxyl value of the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A) is, for example, more than 0 mgKOH / g, preferably not less than 1 mgKOH / g, such as not more than 350 mgKOH / g , Preferably not more than 230 mg KOH / g.

On the other hand, the compound having two or more (meth) acryloyl groups and at least one carboxyl group is not limited to the acid anhydride modified product of the above-mentioned (A) polyfunctional (meth) acrylic compound, ) Acrylate may also be used.

As the compound having two or more (meth) acryloyl groups and at least one carboxyl group, from the viewpoints of dispersibility, dispersion stability and film hardness, it is preferable to use an acid anhydride modified product of the polyfunctional (meth) acrylic compound (A) .

The compounding ratio of the compound having two or more (meth) acryloyl groups and at least one carboxyl group (preferably the modified product of the acid anhydride of the (A) polyfunctional (meth) acrylic compound) For example, not less than 1 part by mass, preferably not less than 5 parts by mass, more preferably not less than 7 parts by mass, for example, not more than 200 parts by mass, preferably not more than 100 parts by mass, more preferably not more than 70 Or less, particularly preferably 50 parts by mass or less.

In addition, the metal fine particle dispersant may further contain (B) a monomodal (meth) acrylic compound.

The monofunctional (meth) acrylic compound (B) is specifically a compound having one (meth) acryloyl group and contains at least one of the compounds represented by the following (b1) to (b3).

(b1) a caprolactone adduct of (meth) acrylic acid represented by the following formula (1).

CH ₂ = C (R ¹ ) CO [O (CH ₂ ) ₅ CO] _n OH (1)

(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and n represents 1 to 10.)

(b2) An acid anhydride-modified product of a caprolactone adduct of hydroxyalkyl (meth) acrylate represented by the following formula (2).

CH ₂ = C (R ¹ ) COOR ² O [CO (CH ₂ ) ₅ O] _n H (2)

(In the formula (2), R ¹ represents a hydrogen atom or a methyl group, R ² represents at least one kind selected from the group consisting of an ethylene group, a propylene group and a tetramethylene group, and n represents an integer of 1 to 10.)

(b3) An acid anhydride-modified product of an alkylene oxide adduct of (meth) acrylic acid represented by the following formula (3).

CH ₂ = C (R ¹ ) COO (C _m H _{2 m} O) _n H (3)

(In the formula (3), R ¹ represents a hydrogen atom, a methyl group, m represents 2 to 4, and n represents 1 to 10.)

Hereinafter, each of the compounds represented by the above-mentioned (b1) to (b3) will be described in detail.

(b1) is a caprolactone adduct of (meth) acrylic acid represented by the following formula (1).

CH ₂ = C (R ¹ ) CO [O (CH ₂ ) ₅ CO] _n OH (1)

(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and n represents 1 to 10.)

In the above formula (1), R ¹ represents a hydrogen atom and / or a methyl group, preferably a hydrogen atom.

In the above formula (1), n is an average number of moles of caprolactone added per mole of (meth) acrylic acid, and is 1 or more, preferably 2 or more, and 10 or less, preferably 5 or less, Is 3 or less.

Such a caprolactone adduct of (meth) acrylic acid can be obtained by subjecting (meth) acrylic acid to an addition reaction (ring-opening addition) with? -Caprolactone.

(Meth) acrylic acid is acrylic acid and / or methacrylic acid, preferably acrylic acid.

? -caprolactone is not particularly limited, and a commercially available product can be used as it is.

(Meth) acrylic acid and? -Caprolactone is not particularly limited and a known method (for example, a method described in JP-A-62-135521, JP-A-60-67446 ) Can be employed.

More specifically, for example, (meth) acrylic acid and epsilon -caprolactone are combined and, if necessary, heated and stirred in the presence of a catalyst and a solvent.

The mixing ratio of (meth) acrylic acid and epsilon -caprolactone is suitably set in accordance with the molecular weight of the object (the compound represented by the formula (1)), that is, the average addition mole number n of? -Caprolactone to (meth) acrylic acid .

For example, 竜 -caprolactone may be used in an amount of 1 mole or more, preferably 2 moles or more, such as 10 moles or less, and preferably 5 moles or less, per mole of (meth) Preferably 3 mol or less.

For example, the amount of? -Caprolactone is, for example, 50 parts by mass or more, preferably 150 parts by mass or more, for example, 100 parts by mass or less, preferably 100 parts by mass or less, based on 100 parts by mass of (meth) Is not more than 2000 parts by mass.

The reaction conditions include a reaction temperature of, for example, 80 DEG C or higher, preferably 120 DEG C or higher, for example, 240 DEG C or lower in an inert gas or an inert gas- Lt; / RTI > The reaction time is, for example, 4 hours or more, preferably 6 hours or more, for example, 20 hours or less, preferably 12 hours or less.

Examples of the catalyst include acid catalysts such as Lewis acids such as aluminum chloride and tin chloride, for example, Bronsted acid such as sulfuric acid, para toluenesulfonic acid, benzenesulfonic acid, sulfonic acid type ion exchange resin, etc. .

These catalysts may be used alone or in combination of two or more.

As the catalyst, sulfuric acid, para-toluenesulfonic acid, and benzenesulfonic acid are preferably used from the viewpoint of solubility in the reaction solution.

The mixing ratio of the catalyst is, for example, not less than 0.1 part by mass, preferably not less than 1 part by mass, for example, not more than 50 parts by mass, preferably not more than 20 parts by mass, relative to 100 parts by mass of (meth) .

Examples of the solvent include aromatic hydrocarbons such as benzene, toluene and xylene.

The blending ratio of the solvent is not particularly limited and is suitably set according to the purpose and use.

The? -Caprolactone adduct of (meth) acrylic acid can also be prepared as a non-solvent.

On the other hand, in the reaction, the above-mentioned polymerization inhibitor may be added, if necessary.

As the polymerization inhibitor, p-methoxyphenol is preferably exemplified.

The blending ratio of the polymerization inhibitor is, for example, not less than 0.0001 parts by mass, preferably not less than 0.01 parts by mass, for example, not more than 1.0 parts by mass relative to 100 parts by mass of the total amount of (meth) acrylic acid and epsilon -caprolactone , Preferably not more than 0.1 part by mass.

The caprolactone adduct of (meth) acrylic acid can also be obtained by, for example, an esterification reaction (polycondensation reaction) of ω-oxycaproic acid in which (meth) acrylic acid and caprolactone are ring-opened.

Further, the caprolactone adduct of (meth) acrylic acid may be also available as a commercial product. Examples of such commercially available products include ARONIX M-5300 (omega -carboxyl caprolactone monoacrylate, DOA synthesizer) and the like.

(b1) The acid value of the caprolactone adduct of (meth) acrylic acid represented by the above formula (1) is, for example, 45 mgKOH / g or more, preferably 135 mgKOH / g or more and, for example, 310 mgKOH / g or less .

(b2) is an acid anhydride-modified product of a caprolactone adduct of hydroxyalkyl (meth) acrylate represented by the following formula (2).

CH ₂ = C (R ¹ ) COOR ² O [CO (CH ₂ ) ₅ O] _n H (2)

(In the formula (2), R ¹ represents a hydrogen atom or a methyl group, R ² represents at least one kind selected from the group consisting of an ethylene group, a propylene group and a tetramethylene group, and n represents an integer of 1 to 10.)

In the formula (2), R ¹ represents a hydrogen atom and / or a methyl group, preferably a hydrogen atom.

In the above formula (2), R ² represents at least one kind selected from the group consisting of an ethylene group, a propylene group and a tetramethylene group, preferably an ethylene group.

In the formula (2), n is an average addition mole number of caprolactone relative to 1 mole of hydroxyalkyl (meth) acrylate, and is 1 or more, preferably 2 or more, and 10 or less, preferably 5 or less to be.

(meth) acrylate and epsilon -caprolactone (ring-opening addition) to obtain a compound represented by the formula (b2), for example, a hydroxyalkyl (Meth) acrylate is obtained. Thereafter, the caprolactone adduct of the hydroxyalkyl (meth) acrylate represented by the above formula (2) is reacted with the acid anhydride.

Examples of the hydroxyalkyl (meth) acrylate include hydroxyalkyl (meth) acrylates having a hydroxyalkyl group having 2 to 4 carbon atoms. Specific examples thereof include 2-hydroxyethyl (meth) acrylate, Acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like.

These hydroxyalkyl (meth) acrylates may be used alone or in combination of two or more.

As the hydroxyalkyl (meth) acrylate, a hydroxyalkyl (meth) acrylate having a hydroxyalkyl group preferably having 2 carbon atoms can be given, and more preferred is 2-hydroxyethyl (meth) acrylate .

? -caprolactone is not particularly limited, and a commercially available product can be used as it is.

The method of reacting the hydroxyalkyl (meth) acrylate with epsilon -caprolactone (ring-opening addition) is not particularly limited, and a known method (for example, the method described in Japanese Patent Application Laid-Open No. 10-7774 or the like) .

Specifically, for example, hydroxyalkyl (meth) acrylate and epsilon -caprolactone are combined and, if necessary, heated and stirred in the presence of the catalyst and the above-mentioned solvent.

The blending ratio of hydroxyalkyl (meth) acrylate and epsilon -caprolactone is preferably such that the molecular weight of the object (the compound represented by the formula (2)), that is, the average of? -Caprolactone with respect to the hydroxyalkyl (meth) Is appropriately set in accordance with the addition mole number n.

For example, 1 mole or more, preferably 2 moles or more, for example, 10 moles or less, and preferably 5 moles or less of 竜 -caprolactone per mole of hydroxyalkyl (meth) acrylate. Mole.

For example, 竜 -caprolactone is, for example, at least 90 parts by mass, preferably at least 190 parts by mass, and more preferably at least 1000 parts by mass, for example, with respect to 100 parts by mass of hydroxyalkyl (meth) Or less, preferably 500 parts by mass or less.

The reaction conditions include a reaction temperature of, for example, 60 ° C or higher, preferably 90 ° C or higher, for example, 140 ° C or lower in an oxygen gas or an inert gas- Lt; / RTI > The reaction time is, for example, 4 hours or more, preferably 8 hours or more, for example, 20 hours or less, preferably 12 hours or less.

On the other hand, in the reaction, the above-mentioned polymerization inhibitor may be added, if necessary.

As the polymerization inhibitor, p-methoxyphenol is preferably exemplified.

The blending ratio of the polymerization inhibitor is, for example, not less than 0.0001 part by mass, preferably not less than 0.01 part by mass, relative to 100 parts by mass of the total amount of hydroxyalkyl (meth) acrylate and? -Caprolactone, 1.0 part by mass or less, preferably 0.1 part by mass or less.

On the other hand, caprolactone adducts of hydroxyalkyl (meth) acrylates can also be commercially available. Examples of such commercially available products include commercially available products such as Flachels FA-1, Flaxel FA-2, Flaxel FA-2D, Flaxel FA-3, Flaxel FA-4, Flaxel FA- (PLACCEL) (all manufactured by Daicel Chemical Industries, Ltd.) (manufactured by Daicel Chemical Industries, Ltd.), 10 L, FLACCEL FM-1, FLACCEL FM-2, FLACCEL FM-2D, FLACCEL FM- And the like).

These caprolactone adducts of hydroxyalkyl (meth) acrylates may be used alone or in combination of two or more.

The caprolactone adduct of hydroxyalkyl (meth) acrylate is reacted with the acid anhydride to obtain an acid anhydride-modified product of the caprolactone adduct of hydroxyalkyl (meth) acrylate (that is, (b2) Compound to be displayed) can be obtained.

Examples of the acid anhydride include the above-mentioned acid anhydride (acid anhydride used in the production of the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A)), preferably dicarboxylic acid monoanhydride, From the viewpoint of the hardness of the coating film (described later), more preferable examples include anhydrous succinic acid and phthalic anhydride, and more preferably, succinic anhydride.

In the reaction of the caprolactone adduct of hydroxyalkyl (meth) acrylate with the acid anhydride, for example, a caprolactone adduct of hydroxyalkyl (meth) acrylate and an acid anhydride are mixed and, if necessary, In the presence of a solvent, a catalyst or the like.

As the solvent, for example, the above organic solvent (organic solvent as the dispersion medium) and the above-mentioned aqueous solvent (aqueous solvent as the dispersion medium) and the like can be mentioned. These solvents may be used alone or in combination of two or more. As the solvent, an organic solvent, more preferably a ketone solvent, and more preferably methyl isobutyl ketone can be mentioned.

As the catalyst, there can be mentioned, for example, the above catalyst (a catalyst used in the production of the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A)). These catalysts may be used alone or in combination of two or more. As the catalyst, an amine compound is preferable, and N, N-dimethylbenzylamine, triethylamine and tributylamine are more preferable, and triethylamine is more preferable.

The mixing ratio of the caprolactone adduct of hydroxyalkyl (meth) acrylate to the acid anhydride is, for example, the ratio of the anhydride carboxylic acid group in the acid anhydride to the hydroxyl group in the caprolactone adduct of hydroxyalkyl (meth) For example, not less than 0.5, preferably not less than 0.67, for example, not more than 1, preferably not more than 0.91, in terms of an equivalent ratio (anhydrous carboxylic acid group / hydroxyl group)

The reaction conditions include a heating temperature of, for example, 60 占 폚 or higher, preferably 80 占 폚 or higher, for example, 140 占 폚 or lower in an oxygen gas or an inert gas- Lt; / RTI > The heating time is, for example, 4 hours or more, preferably 8 hours or more, for example, 20 hours or less, preferably 12 hours or less.

Thereby, an acid anhydride-modified product of the caprolactone adduct of hydroxyalkyl (meth) acrylate (that is, a compound represented by (b2)) is obtained.

(b2) The acid value of the acid anhydride modified product of the caprolactone adduct of hydroxyalkyl (meth) acrylate represented by the above formula (2) is, for example, 40 mgKOH / g or more, preferably 60 mgKOH / g or more, For example, 280 mgKOH / g or less, preferably 150 mgKOH / g or less.

(b3) is an acid anhydride-modified product of an alkylene oxide adduct of (meth) acrylic acid represented by the above formula (3).

CH ₂ = C (R ¹ ) COO (C _m H _{2 m} O) _n H (3)

(In the formula (3), R ¹ represents a hydrogen atom, a methyl group, m represents 2 to 4, and n represents 1 to 10.)

In the formula (3), R ¹ represents a hydrogen atom and / or a methyl group, preferably a hydrogen atom.

In the above formula (3), m is 2 or more and 4 or less, preferably 3 or less.

That is, the alkylene oxide adduct of (meth) acrylic acid represented by the formula (3) has an oxyalkylene (C _m H _2m O) having 2 to 4 carbon atoms.

Examples of the oxyalkylene having 2 to 4 carbon atoms include oxyethylene (-CH ₂ CH ₂ O-), oxytrimethylene (-CH ₂ CH ₂ CH ₂ O-), oxytetramethylene (-CH ₂ CH ₂ CH ₂ CH ₂ O-), straight chain oxyalkylene such as oxypropylene (-CH ₂ CH (CH ₃ ) O-), oxybutylene (-CH ₂ CH (CH ₂ CH ₃ ) O-, -CH CH ₃ ) CH (CH ₃ ) O-), and the like. Of these, straight-chain oxyalkylene is preferable, and oxyethylene is more preferable.

In the formula (3), n is an average number of moles of alkylene oxide added per mole of (meth) acrylic acid, and is 1 or more, preferably 2 or more, and 10 or less, preferably 5 or less.

(meth) acrylic acid and an alkylene oxide are reacted (ring-opening addition) to obtain a compound represented by the formula (b3), for example, the alkylene oxide adduct of the (meth) acrylic acid represented by the formula (3) Get water. Thereafter, an alkylene oxide adduct of (meth) acrylic acid represented by the above formula (3) is reacted with an acid anhydride.

(Meth) acrylic acid is acrylic acid and / or methacrylic acid, preferably acrylic acid.

Examples of the alkylene oxide include alkylene oxides having 2 to 4 carbon atoms. Specific examples thereof include cyclic ether compounds having 2 to 4 carbon atoms such as ethylene oxide, propylene oxide, trimethylene oxide (oxetane), and butylene oxide. .

These alkylene oxides may be used alone or in combination of two or more.

On the other hand, when two or more kinds of alkylene oxides are used in combination, the addition form thereof is not particularly limited and may be, for example, random addition, block addition or the like.

As the alkylene oxide, ethylene oxide and propylene oxide are preferable, and ethylene oxide is more preferable.

The method of adding the alkylene oxide to the (meth) acrylic acid is not particularly limited and a known method can be employed.

More specifically, for example, (meth) acrylic acid and an alkylene oxide are combined and, if necessary, heated and stirred in the presence of the catalyst and the above-mentioned solvent.

The blending ratio of the (meth) acrylic acid and the alkylene oxide is appropriately set in accordance with the molecular weight of the target product (the compound represented by the formula (3)), that is, the average addition mole number n of the alkylene oxide to the (meth) acrylic acid.

For example, the alkylene oxide is, for example, at least 1 mole, preferably at least 2 moles, for example, at most 10 moles, preferably at most 5 moles per mole of (meth) acrylic acid.

For example, the alkylene oxide may be used in an amount of, for example, 50 parts by mass or more, preferably 100 parts by mass or more, for example, 5000 parts by mass or less, 1500 parts by mass or less.

The reaction conditions include a reaction temperature of, for example, 40 DEG C or higher, preferably 100 DEG C or higher, for example, 240 DEG C or lower, preferably 200 DEG C or lower in an inert gas- to be. The reaction time is, for example, 1 hour or more, preferably 3 hours or more, for example, 20 hours or less, preferably 12 hours or less.

Thereby, an alkylene oxide adduct of (meth) acrylic acid represented by the above formula (3) is obtained.

Specific examples of the alkylene oxide adduct of (meth) acrylic acid include polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polytrimethylene glycol mono (meth) acrylate, (Meth) acrylate, poly (ethyleneglycol-tetramethyleneglycol) mono (meth) acrylate, poly (ethylene glycol-propylene glycol) mono (Meth) acrylate such as (mono) ethylene glycol mono (meth) acrylate, (mono) propylene glycol mono (meth) acrylate such as poly (propylene glycol-tetramethylene glycol) mono Glycol mono (meth) acrylate, (mono) trimethylene glycol mono (meth) acrylate, (mono) Call mono (meth) acrylate, and (mono), polytetramethylene glycol mono (meth) acrylate, hydroxyl group-terminated mono-alkylene glycol mono (meth) acrylate.

These alkylene oxide adducts of (meth) acrylic acid may be used alone or in combination of two or more.

The alkylene oxide adduct of (meth) acrylic acid is preferably a hydroxyl group-terminated polyalkylene glycol mono (meth) acrylate, and more preferably polyethylene glycol mono (meth) acrylate.

On the other hand, the alkylene oxide adduct of (meth) acrylic acid can be also available as a commercial product. Such commercially available products include, for example, blemmers PE series, blemish AE series, blemish PP series, blemish AP series, blemish PEP series, blemish AEP series, blemmer PET series, Blemmer PPT series, and Blemmer APT series (both manufactured by Nippon Oil & Fats Co., Ltd.). These may be used alone or in combination of two or more.

Then, an acid anhydride-modified product of the alkylene oxide adduct of (meth) acrylic acid (that is, a compound represented by (b3)) is obtained by reacting the alkylene oxide adduct of (meth) acrylic acid with the acid anhydride .

Examples of the acid anhydride include the above-mentioned acid anhydride (acid anhydride used in the production of the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A)), preferably dicarboxylic acid monoanhydride, From the viewpoint of the hardness of the cured product (described later), more preferable examples include anhydrous succinic acid and phthalic anhydride, and more preferably, succinic anhydride.

In the reaction of an alkylene oxide adduct of (meth) acrylic acid with an acid anhydride, for example, an alkylene oxide adduct of (meth) acrylic acid and an acid anhydride are mixed and, if necessary, .

As the solvent, for example, the above organic solvent (organic solvent as the dispersion medium) and the above-mentioned aqueous solvent (aqueous solvent as the dispersion medium) and the like can be mentioned. These solvents may be used alone or in combination of two or more. As the solvent, an organic solvent, more preferably a ketone solvent, and more preferably methyl isobutyl ketone can be mentioned.

As the catalyst, there can be mentioned, for example, the above catalyst (a catalyst used in the production of the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A)). These catalysts may be used alone or in combination of two or more. As the catalyst, an amine compound is preferable, and N, N-dimethylbenzylamine, triethylamine and tributylamine are more preferable, and triethylamine is more preferable.

The mixing ratio of the caprolactone adduct of an alkylene oxide adduct of (meth) acrylic acid to an acid anhydride is, for example, an equivalent ratio of an anhydride carboxylic acid group in the acid anhydride to the hydroxyl group in the alkylene oxide adduct of (meth) (Anhydrous carboxylic acid group / hydroxyl group) is, for example, not less than 0.5, preferably not less than 0.67, such as not more than 1, preferably not more than 0.91.

The reaction conditions include a heating temperature of, for example, 60 ° C or higher, preferably 80 ° C or higher, for example, 140 ° C or lower in an oxygen atmosphere or an inert gas-oxygen gas mixture atmosphere Lt; 0 > C. The heating time is, for example, 4 hours or more, preferably 8 hours or more, for example, 20 hours or less, preferably 12 hours or less.

Thereby, an acid anhydride-modified product of the alkylene oxide adduct of (meth) acrylic acid (that is, a compound represented by (b3)) is obtained.

(b3) The acid value of the acid anhydride modified product of the alkylene oxide adduct of (meth) acrylic acid represented by the above formula (3) is, for example, 55 mgKOH / g or more, preferably 95 mgKOH / g or more, , Not more than 400 mg KOH / g, preferably not more than 300 mg KOH / g.

These (B) monofunctional (meth) acrylic compounds may be used alone or in combination of two or more.

The monofunctional (meth) acrylic compound (B) is preferably a compound represented by (b1) from the viewpoint of improving the dispersion stability of the coating agent, more preferably (B) (Meth) acrylate compound containing a caprolactone adduct of (meth) acrylic acid represented by the above formula (1) and n is 1 to 3.

When the (B) monofunctional (meth) acrylic compound is used as the metal fine particle dispersant, the content thereof is, for example, not less than 2% by mass, preferably not less than 5% by mass relative to the total amount of the metal fine particle dispersant, For example, 60 mass% or less, preferably 40 mass% or less.

Further, the metal fine particle dispersant preferably further contains (meth) acrylic resin dispersant having (meth) acryloyl group in the side chain (C).

(Meth) acrylic resin dispersant having a (meth) acryloyl group in the side chain (C) is a reactant obtained by reacting a monomer component containing an anionic group-containing monomer by the following method.

The anionic group-containing monomer is a monomer having at least one anionic group and at least one polymerizable unsaturated group.

Examples of the anionic group include a carboxyl group, a phosphoric acid group, and a sulfonic acid group, and these may be used alone or in combination. As the anionic group, in view of the hardness of the coating film (described later), a carboxyl group and a phosphoric acid group are preferable, and a carboxyl group is more preferable.

The polymerizable unsaturated group is a group having a polymerizable unsaturated bond and includes, for example, an ethylenic unsaturated group. Specific examples thereof include a (meth) acryloyl group, a vinylaryl group, a vinyloxy group, an allyl group And these may be used alone or in combination. As the polymerizable unsaturated group, a (meth) acryloyl group is preferable from the viewpoint of availability.

Specific examples of the anionic group-containing monomer include carboxyl group-containing monomers such as an?,? -Unsaturated carboxylic acid or a salt thereof such as (meth) acrylic acid, itaconic acid, maleic acid and fumaric acid, (Meth) acrylate such as a phosphoric acid group-containing (meth) acrylate such as polyoxypropylene glycol mono (meth) acrylate, acid phosphoxyethyl (meth) acrylate and mono (2-hydroxyethyl Containing monomers, for example, sulfonic acid group-containing monomers such as 2-acrylamido-2-methylpropanesulfonic acid and the like.

These anionic group-containing monomers may be used alone or in combination of two or more.

As the anionic group-containing monomer, from the viewpoint of the hardness of the coating film (described later), a carboxyl group-containing monomer and a phosphoric acid group-containing monomer are preferable, and a carboxyl group-containing monomer is more preferable. More preferably, ,? -unsaturated carboxylic acid, and particularly preferably (meth) acrylic acid.

On the other hand, in the (meth) acrylic resin dispersant, a (meth) acrylic resin containing an anionic group is obtained as the (meth) acrylic resin since the monomer component contains an anionic group-containing monomer.

In addition, the monomer component may contain other monomers copolymerizable with the anionic group-containing monomers.

Specific examples of other monomers include alkyl (meth) acrylates, aromatic ring-containing monomers, hydroxyl group-containing monomers, and isocyanate group-containing monomers.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) (Meth) acrylate, isoamyl (meth) acrylate, isoamyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (Meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Decyl (meth) acrylate (Meth) acrylate (stearyl (meth) acrylate), isostearyl (meth) acrylate, eicosyl (meth) acrylate, docosyl (Meth) acrylate), tetracosyl (meth) acrylate, triacontyl (meth) acrylate, cyclohexyl (meth) acrylate and isobornyl (Meth) acrylate of cyclic alkyl, and the like.

Examples of the aromatic ring-containing monomer include phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol Containing (meth) acrylates such as phenoxybenzyl (meth) acrylate and phenoxybenzyl (meth) acrylate, and styrene-based monomers such as styrene and? -Methylstyrene.

On the other hand, when the monomer component contains an aromatic ring-containing monomer, a (meth) acrylic resin containing an aromatic ring as a (meth) acrylic resin is obtained.

Examples of the hydroxyl group-containing monomer include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (Meth) acrylate having a hydroxyl group such as ethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate, Hydroxyethyl (meth) acrylate.

On the other hand, when the monomer component contains a monomer containing a hydroxyl group, a (meth) acrylic resin containing a hydroxyl group as a (meth) acrylic resin is obtained.

Examples of the isocyanate group-containing monomer include isocyanatoethyl (meth) acrylate, 2-isocyanatoethyl (meth) acrylate, 3-isocyanatopropyl (meth) (Meth) acrylates such as 1-methyl-2-isocyanatoethyl (meth) acrylate, 2-isocyanatopropyl (meth) acrylate and 4-isocyanatobutyl (Meth) acrylic monomers, and the like.

On the other hand, when the monomer component contains an isocyanate group-containing monomer, a (meth) acrylic resin containing an isocyanate group is obtained as the (meth) acrylic resin.

Examples of other monomers include glycidyl group-containing monomers such as glycidyl (meth) acrylate and allyl glycidyl ether, vinyl ester monomers such as vinyl acetate and vinyl propionate, and the like. .

These other monomers may be used alone or in combination of two or more.

As other monomers, preferred are monomers containing an alkyl (meth) acrylate, an aromatic ring-containing monomer, a hydroxyl group-containing monomer, and an isocyanate group, and more preferably an alkyl (meth) Containing monomer, a monomer containing a hydroxyl group, and a monomer containing an isocyanate group.

If the monomer component contains an aromatic ring-containing monomer (that is, the (meth) acrylic resin is a (meth) acrylic resin containing an aromatic ring), the adhesion of the coating film (described later) can be improved.

When the monomer component contains a hydroxyl group-containing monomer and an isocyanate group-containing monomer, the (meth) acryloyl group can be easily introduced into the side chain of the (meth) acrylic resin by the method described later, The adhesion of the coating film (described later) can be improved.

When the monomer component contains alkyl (meth) acrylate, the content thereof is, for example, not less than 10% by mass, preferably not less than 20% by mass relative to the total amount of the monomer components, for example, not less than 90% Or less, preferably 80 mass% or less.

When the monomer component contains an aromatic ring-containing monomer, the content thereof is, for example, not less than 10% by mass, preferably not less than 20% by mass, more preferably not less than 20% by mass with respect to the total amount of monomer components from the viewpoint of adhesion of the coating film % Or more, for example, 90 mass% or less, preferably 80 mass% or less.

When the monomer component contains a hydroxyl group-containing monomer, the content thereof is, for example, not less than 0.1% by mass, preferably not less than 1% by mass, relative to the total amount of the monomer component, % Or less, preferably 30 mass% or less.

When the monomer component contains an isocyanate group-containing monomer, the content thereof is, for example, not less than 0.1% by mass, preferably not less than 1% by mass, based on the total amount of the monomer components, 20 mass% or less, preferably 10 mass% or less.

When the monomer component (monomer other than the anionic group-containing monomer) is contained in the monomer component, the content of the anionic group-containing monomer in the monomer component is preferably 5% by mass or more, more preferably 10% , For example, not more than 40 mass%, preferably not more than 20 mass%.

When the content of the anionic group-containing monomer relative to the total amount of the monomer components is 5 mass% or more, the (meth) acrylic resin dispersant obtained by the reaction of the monomer component can disperse the fine metal particles well. Particularly, when the monomer component contains an anionic group-containing monomer in a proportion of 10 mass% or more, the (meth) acrylic resin dispersant obtained by polymerization of the monomer component can improve the dispersibility and dispersion stability of the metal fine particles .

On the other hand, when the content of the anionic group-containing monomer relative to the total amount of the monomer components is 5 mass% or more, the (meth) acrylic resin obtained by the reaction of the monomer components is used as the (meth) acrylic resin dispersant. When the content of the anionic group-containing monomer relative to the total amount of the monomer components is less than 5% by mass, the (meth) acrylic resin obtained by the reaction of the monomer components is used as the (meth) acrylic resin binder do. Thus, the (meth) acrylic resin dispersant and the (meth) acrylic resin binder (described later) are distinguished from each other.

The (meth) acrylic resin dispersant having a (meth) acryloyl group in the side chain (C) is synthesized by the following reaction.

That is, in this method, first, a part of the monomer component is polymerized to obtain a (meth) acrylic resin having no (meth) acryloyl group in its side chain. Then, the resulting (meth) acrylic resin is reacted with the remainder of the monomer component to introduce the (meth) acryloyl group into the side chain of the polymer.

As a part of the monomer component, an anionic group-containing monomer, an alkyl (meth) acrylate, an aromatic ring-containing monomer, a hydroxyl group-containing monomer (concretely, a monomer other than an isocyanate group-containing monomer) have.

The content of the anionic group-containing monomer in a part of the monomer component is 5% by mass or more, preferably 10% by mass or more, for example, 40% by mass or less, preferably 20% by mass or less, Or less.

When a part of the monomer component contains alkyl (meth) acrylate, the content thereof is, for example, not less than 10% by mass, preferably not less than 20% by mass, based on the total amount of the monomer components, , 90 mass% or less, preferably 80 mass% or less.

When a part of the monomer component contains an aromatic ring-containing monomer, the content thereof is, for example, not less than 10% by mass, preferably not less than 10% by mass, 20 mass% or more, for example, 90 mass% or less, preferably 80 mass% or less.

When a part of the monomer component contains a hydroxyl group-containing monomer, the content thereof is, for example, not less than 0.1% by mass, preferably not less than 1% by mass with respect to the total amount of the monomer components, 50 mass% or less, preferably 30 mass% or less.

The method of polymerizing a part of the monomer components is not particularly limited. For example, a method of polymerizing a part of the above monomer components (preferably an anionic group-containing monomer, an alkyl (meth) acrylate, an aromatic ring- , A hydroxyl group-containing monomer) are mixed in the above proportions and heated in the presence of a known radical polymerization initiator (for example, an azo-based compound, a peroxide-based compound, etc.).

The polymerization conditions vary depending on the formulation of the monomer component and the kind of the radical polymerization initiator. For example, the polymerization temperature is 30 DEG C or higher, preferably 60 DEG C or higher, for example, 150 DEG C or lower, Or less. The polymerization time is, for example, 2 hours or longer, preferably 4 hours or longer, for example, 20 hours or shorter, preferably 8 hours or shorter.

Thereby, a (meth) acrylic resin for obtaining a dispersant is obtained.

The weight average molecular weight (GPC measurement: in terms of polystyrene) of the (meth) acrylic resin for obtaining the dispersant is, for example, 2000 or more, preferably 3000 or more, for example 100000 or less, preferably 50000 or less And preferably 15,000 or less.

When the weight average molecular weight is within the above range, a coating film (to be described later) excellent in transparency, adhesion, hardness and durability (alkali resistance and light resistance) can be obtained.

In the above method, when the monomer component as the raw material of the (meth) acrylic resin contains a monomer containing a hydroxyl group, the (meth) acrylic resin obtained by the above polymerization has a hydroxyl group.

Thus, in this method, the polymer obtained above (i.e., the (meth) acrylic resin having a hydroxyl group) is reacted with the remainder of the monomer component.

As the remainder of the monomer component, for example, there can be mentioned an isocyanate group-containing monomer, preferably an isocyanate group-containing (meth) acryl monomer. More preferably, the remainder of the monomer component is composed of an isocyanate group-containing (meth) acrylic monomer.

(Meth) acrylic monomer having an isocyanate group is used as the remainder of the monomer component, the remaining part of the monomer component is reacted with the (meth) acrylic resin having a hydroxyl group as described below to obtain the (meth) (Meth) acryloyl group may be introduced.

In order to react the (meth) acrylic resin having a hydroxyl group with the (meth) acrylic monomer containing an isocyanate group, there is no particular limitation, and for example, a (meth) acrylic resin having a hydroxyl group and an isocyanate (Meth) acrylate monomer having a carboxyl group and a (meth) acrylate monomer, and if necessary, heating in the presence of a known catalyst and a solvent.

The mixing ratio of the (meth) acrylic resin having a hydroxyl group to the isocyanate group-containing (meth) acrylic monomer is such that the isocyanate group-containing (meth) For example, not less than 0.1 mol, preferably not less than 0.8 mol, such as not more than 2.0 mol, and preferably not more than 1.2 mol, of the (meth) acrylic monomer.

The reaction conditions are, for example, a reaction temperature in an air atmosphere of, for example, 40 ° C or higher, preferably 60 ° C or higher, for example, 200 ° C or lower, preferably 150 ° C or lower. The reaction time is, for example, 1 hour or more, preferably 2 hours or more, for example, 20 hours or less, preferably 12 hours or less.

On the other hand, in the reaction, the above-mentioned polymerization inhibitor may be added, if necessary.

As the polymerization inhibitor, p-methoxyphenol is preferably exemplified.

The blending ratio of the polymerization inhibitor is, for example, not less than 0.0001 part by mass, preferably not less than 0.01 part by mass, per 100 parts by mass of the total amount of the (meth) acrylic monomer having an isocyanate group and the (meth) For example, 1.0 part by mass or less, preferably 0.1 part by mass or less.

Thereby, the hydroxyl group of the (meth) acrylic resin having a hydroxyl group reacts with the isocyanate group of the (meth) acrylic monomer containing an isocyanate group.

As a result, an isocyanate group-containing (meth) acryl monomer is bonded to the side chain of the (meth) acrylic resin, and a (meth) acryloyl group is introduced at the side chain end.

Thereby, a (meth) acrylic resin dispersant having a (meth) acryloyl group in its side chain is obtained.

On the other hand, the method of introducing a (meth) acryloyl group into the side chain of the (meth) acrylic resin is not limited to the above method, and a known method can be employed.

For example, when the monomer component contains an isocyanate group-containing monomer, the (meth) acrylic resin has an isocyanate group. Therefore, a (meth) acryloyl group is introduced into the side chain of the (meth) acrylic resin by reacting the (meth) acrylic resin having an isocyanate group with the (meth) acrylate containing a hydroxyl group It is possible.

Further, for example, when the monomer component contains an anionic group-containing monomer (e.g., a carboxyl group-containing monomer or the like), the (meth) acrylic resin has an anionic group (e.g., a carboxyl group or the like). Therefore, a (meth) acryloyl group may be introduced into the side chain of the (meth) acrylic resin by esterifying the (meth) acrylic resin having an anionic group with the glycidyl group-containing (meth) acrylate.

Further, for example, when the monomer component contains a glycidyl group-containing monomer, the (meth) acrylic resin has a glycidyl group. Therefore, by esterifying the (meth) acrylic resin having a glycidyl group with an anionic group-containing (meth) acrylate (such as a carboxyl group-containing (meth) acrylate) (Meth) acryloyl group may be introduced into the side chain of the polymer.

When the (meth) acrylic resin dispersant has a (meth) acryloyl group in the side chain, the adhesion of the coating film (described later) can be improved.

The weight average molecular weight (GPC measurement: in terms of polystyrene) of the (meth) acrylic resin dispersant having a (meth) acryloyl group in the side chain (C) is, for example, 2000 or more, preferably 3000 or more, 100000 or less, preferably 50000 or less, and more preferably 15000 or less.

When the weight average molecular weight is within the above range, a coating film (to be described later) excellent in transparency, adhesion, hardness and durability (alkali resistance and light resistance) can be obtained.

The (meth) acryloyl group equivalent of the (meth) acryloyl group dispersant having a (meth) acryloyl group in the side chain (C) is, for example, 400 or more, preferably 800 or more, Or less, preferably 10000 or less.

On the other hand, the (meth) acryl group equivalent is defined as the polymer mass (double bond equivalent) per 1 mol of the double bond (the same applies hereinafter).

When the (meth) acrylic resin dispersant having a (meth) acryloyl group in the side chain (C) is contained in the metal fine particle dispersant, it is possible to improve the dispersibility and dispersion stability of the metal fine particles, A coating film (to be described later) excellent in adhesion, hardness and durability (alkali resistance and light resistance) can be obtained.

(Meth) acrylic resin dispersant having a (meth) acryloyl group in its side chain (C) is, for example, not less than 5% by mass, preferably not less than 10% by mass, based on the total amount of the metal fine particle dispersant, For example, 80 mass% or less, preferably 50 mass% or less.

The binder is an additive for improving various physical properties such as hardness, adhesion, durability (alkali resistance, light resistance) and the like of a coating film (to be described later) and contains a (meth) acryl resin binder having a (meth) acryloyl group in its side chain .

The (meth) acryl resin binder having a (meth) acryloyl group in its side chain is a reactant obtained by reacting the monomer components shown below by the following method.

More specifically, examples of the monomer contained in the monomer component include an alkyl (meth) acrylate, an aromatic ring-containing monomer, a hydroxyl group-containing monomer, and an isocyanate group-containing monomer.

Examples of the alkyl (meth) acrylate include the same alkyl (meth) acrylates as the alkyl (meth) acrylates exemplified as the raw materials of the (meth) acrylic resin dispersant.

Examples of the aromatic ring-containing monomer include the same aromatic ring-containing monomers as the aromatic ring-containing monomers exemplified as the raw materials of the (meth) acrylic resin dispersant. On the other hand, when the monomer component contains an aromatic ring-containing monomer, a (meth) acrylic resin containing an aromatic ring as a (meth) acrylic resin is obtained.

Examples of the hydroxyl group-containing monomer include hydroxyl group-containing monomers similar to the hydroxyl group-containing monomers exemplified as the raw materials of the (meth) acrylic resin dispersant. On the other hand, when the monomer component contains a monomer containing a hydroxyl group, a (meth) acrylic resin containing a hydroxyl group as a (meth) acrylic resin is obtained.

Examples of the isocyanate group-containing monomer include the same isocyanate group-containing monomers as the isocyanate group-containing monomers exemplified as the raw materials of the (meth) acrylic resin dispersant. On the other hand, when the monomer component contains an isocyanate group-containing monomer, a (meth) acrylic resin containing an isocyanate group is obtained as the (meth) acrylic resin.

In the (meth) acrylic resin binder, examples of the monomer contained in the monomer component include the above-mentioned glycidyl group-containing monomer, vinyl ester monomer, and the like.

These monomers may be used alone or in combination of two or more.

As the monomer, monomers containing an alkyl (meth) acrylate, an aromatic ring-containing monomer, a hydroxyl group-containing monomer, and an isocyanate group are preferable, and alkyl (meth) acrylate, Containing monomer, a monomer containing a hydroxyl group, and an isocyanate group-containing monomer.

If the monomer component contains an aromatic ring-containing monomer (that is, the (meth) acrylic resin is a (meth) acrylic resin containing an aromatic ring), the adhesion of the coating film (described later) can be improved.

When the monomer component contains a hydroxyl group-containing monomer and an isocyanate group-containing (meth) acryl monomer, the (meth) acryloyl group is easily introduced into the side chain of the (meth) And the adhesion of the coating film (described later) can be improved.

When the monomer component contains alkyl (meth) acrylate, the content thereof is, for example, not less than 10% by mass, preferably not less than 20% by mass relative to the total amount of the monomer components, for example, not less than 90% Or less, preferably 80 mass% or less.

When the monomer component contains an aromatic ring-containing monomer, the content thereof is, for example, not less than 10% by mass, preferably not less than 20% by mass with respect to the total amount of the monomer components from the viewpoint of the hardness of the coating film % Or more, for example, 95 mass% or less, preferably 80 mass% or less.

When the monomer component contains a hydroxyl group-containing monomer, the content thereof is, for example, not less than 0.1% by mass, preferably not less than 1% by mass, relative to the total amount of the monomer component, % Or less, preferably 30 mass% or less.

When the monomer component contains an isocyanate group-containing monomer, the content thereof is, for example, not less than 0.1% by mass, preferably not less than 1% by mass, based on the total amount of the monomer components, 20 mass% or less, preferably 10 mass% or less.

In the (meth) acrylic resin binder, the monomer component does not contain an anionic group-containing monomer or contains an anionic group-containing monomer in a proportion of less than 5% by mass based on the total amount of the monomer component.

In the case of containing an anionic group-containing monomer, examples of such an anionic group-containing monomer include the same anionic group-containing monomer as the anionic group-containing monomer in the above-mentioned (meth) acrylic resin dispersant.

These anionic group-containing monomers may be used alone or in combination of two or more.

As the anionic group-containing monomer, in view of the hardness of the coating film (described later), a carboxyl group-containing monomer is preferably used, more preferably an?,? - unsaturated carboxylic acid, Acrylic acid.

In the (meth) acrylic resin binder, the monomer component may not contain the above-mentioned anionic group-containing monomer, but preferably contains an anionic group-containing monomer in a proportion of less than 5% by mass based on the total amount thereof.

When the monomer component contains an anionic group-containing monomer, the (meth) acrylic resin binder obtained by the reaction of the monomer component can improve the adhesion of the coating film (described later).

When the monomer component contains an anionic group-containing monomer, the content of the anionic group-containing monomer in the monomer component is, for example, not less than 1% by mass, preferably not less than 2% by mass relative to the total amount of the monomer component, %, Preferably not more than 4.5 mass%.

On the other hand, when the content of the anionic group-containing monomer relative to the total amount of the monomer components is less than 5 mass% (including 0 mass%), the (meth) acrylic resin obtained by the reaction of the monomer components is Resin binder. When the content of the anionic group-containing monomer relative to the total amount of the monomer components is 5% by mass or more as described above, the (meth) acrylic resin dispersant is a (meth) acrylic resin obtained by the reaction of the monomer components . Thus, the (meth) acrylic resin binder is distinguished from the (meth) acrylic resin dispersant.

The (meth) acrylic resin binder having a (meth) acryloyl group in its side chain is synthesized by the following reaction.

That is, in this method, first, a part of the monomer component is polymerized to obtain a (meth) acrylic resin having no (meth) acryloyl group in its side chain. Then, the resulting (meth) acrylic resin is reacted with the remainder of the monomer component to introduce the (meth) acryloyl group into the side chain of the polymer.

As a part of the monomer component, an anionic group-containing monomer, an alkyl (meth) acrylate, an aromatic ring-containing monomer, and a hydroxyl group-containing monomer are preferable.

When a part of the monomer component contains an anionic group-containing monomer, the content thereof is less than 5% by mass, preferably 4.5% by mass or less, for example, 1% by mass or more, Is not less than 2% by mass.

When a part of the monomer component contains alkyl (meth) acrylate, the content thereof is, for example, not less than 10% by mass, preferably not less than 20% by mass, based on the total amount of the monomer components, , 90 mass% or less, preferably 80 mass% or less.

When a part of the monomer component contains an aromatic ring-containing monomer, the content thereof is, for example, not less than 10% by mass, preferably not less than 10% by mass, 20 mass% or more, for example, 95 mass% or less, preferably 80 mass% or less.

When a part of the monomer component contains a hydroxyl group-containing monomer, the content thereof is, for example, not less than 0.1% by mass, preferably not less than 1% by mass with respect to the total amount of the monomer components, 50 mass% or less, preferably 30 mass% or less.

The method of polymerizing a part of the monomer components is not particularly limited. For example, a method of polymerizing a part of the above monomer components (preferably an anionic group-containing monomer, an alkyl (meth) acrylate, an aromatic ring- , A hydroxyl group-containing monomer) are mixed in the above proportions and heated in the presence of a known radical polymerization initiator (for example, an azo-based compound, a peroxide-based compound, etc.).

The polymerization conditions vary depending on the formulation of the monomer component and the kind of the radical polymerization initiator. For example, the polymerization temperature is 30 DEG C or higher, preferably 60 DEG C or higher, for example, 150 DEG C or lower, Or less. The polymerization time is, for example, 2 hours or longer, preferably 4 hours or longer, for example, 20 hours or shorter, preferably 8 hours or shorter.

Thereby, a (meth) acrylic resin for obtaining a binder is obtained.

The weight average molecular weight (GPC measurement: in terms of polystyrene) of the (meth) acrylic resin for obtaining the binder is, for example, 2000 or more, preferably 3000 or more, for example 100000 or less, preferably 50000 or less And preferably 15,000 or less.

When the weight average molecular weight is within the above range, a coating film (to be described later) excellent in transparency, adhesion, hardness and durability (alkali resistance and light resistance) can be obtained.

In the above method, when the monomer component as the raw material of the (meth) acrylic resin contains a monomer containing a hydroxyl group, the (meth) acrylic resin obtained by the above polymerization has a hydroxyl group.

Thus, in this method, similarly to the (meth) acrylic resin dispersant, the polymer obtained above (that is, the (meth) acrylic resin having a hydroxyl group) is reacted with the remainder of the monomer component.

As the remainder of the monomer component, for example, there can be mentioned an isocyanate group-containing monomer, preferably an isocyanate group-containing (meth) acryl monomer. More preferably, the remainder of the monomer component is composed of an isocyanate group-containing (meth) acrylic monomer.

(Meth) acrylic monomer having an isocyanate group is used as the remainder of the monomer component, the remaining part of the monomer component is reacted with the (meth) acrylic resin having a hydroxyl group as described below to obtain the (meth) (Meth) acryloyl group may be introduced.

In order to react the (meth) acrylic resin having a hydroxyl group with the (meth) acrylic monomer containing an isocyanate group, there is no particular limitation, and for example, a (meth) acrylic resin having a hydroxyl group and an isocyanate (Meth) acrylate monomer having a carboxyl group and a (meth) acrylate monomer, and if necessary, heating in the presence of a known catalyst and a solvent.

The mixing ratio of the (meth) acrylic resin having a hydroxyl group to the isocyanate group-containing (meth) acrylic monomer is such that the isocyanate group-containing (meth) For example, not less than 0.1 mol, preferably not less than 0.8 mol, such as not more than 2.0 mol, and preferably not more than 1.2 mol, of the (meth) acrylic monomer.

The reaction conditions are, for example, a reaction temperature in an air atmosphere of, for example, 40 ° C or higher, preferably 60 ° C or higher, for example, 200 ° C or lower, preferably 150 ° C or lower. The reaction time is, for example, 1 hour or more, preferably 2 hours or more, for example, 20 hours or less, preferably 12 hours or less.

On the other hand, in the reaction, the above-mentioned polymerization inhibitor may be added, if necessary.

As the polymerization inhibitor, p-methoxyphenol is preferably exemplified.

The blending ratio of the polymerization inhibitor is, for example, not less than 0.0001 part by mass, preferably not less than 0.01 part by mass, per 100 parts by mass of the total amount of the (meth) acrylic monomer having an isocyanate group and the (meth) For example, 1.0 part by mass or less, preferably 0.1 part by mass or less.

Thereby, the hydroxyl group of the (meth) acrylic resin having a hydroxyl group reacts with the isocyanate group of the (meth) acrylic monomer containing an isocyanate group.

As a result, an isocyanate group-containing (meth) acryl monomer is bonded to the side chain of the (meth) acrylic resin, and a (meth) acryloyl group is introduced at the side chain end.

Thereby, a (meth) acrylic resin binder having a (meth) acryloyl group in its side chain is obtained.

On the other hand, the method of introducing a (meth) acryloyl group into the side chain of the (meth) acrylic resin is not limited to the above method, and a known method can be employed.

For example, when the monomer component contains an isocyanate group-containing monomer, the (meth) acrylic resin has an isocyanate group. Therefore, a (meth) acryloyl group is introduced into the side chain of the (meth) acrylic resin by reacting the (meth) acrylic resin having an isocyanate group with the (meth) acrylate containing a hydroxyl group It is possible.

Further, for example, when the monomer component contains an anionic group-containing monomer (e.g., a carboxyl group-containing monomer or the like), the (meth) acrylic resin has an anionic group (e.g., a carboxyl group or the like). Therefore, a (meth) acryloyl group may be introduced into the side chain of the (meth) acrylic resin by esterifying the (meth) acrylic resin having an anionic group with the glycidyl group-containing (meth) acrylate.

Further, for example, when the monomer component contains a glycidyl group-containing monomer, the (meth) acrylic resin has a glycidyl group. Therefore, by esterifying the (meth) acrylic resin having a glycidyl group with an anionic group-containing (meth) acrylate (such as a carboxyl group-containing (meth) acrylate) (Meth) acryloyl group may be introduced into the side chain of the polymer.

When the (meth) acrylic resin binder has a (meth) acryloyl group in the side chain, the adhesion of the coating film (described later) can be improved.

The weight average molecular weight (GPC measurement: in terms of polystyrene) of the (meth) acrylic resin binder having a (meth) acryloyl group in its side chain is, for example, 2000 or more, preferably 3000 or more, Preferably 50,000 or less, more preferably 15,000 or less.

When the weight average molecular weight is within the above range, a coating film (to be described later) excellent in transparency, adhesion, hardness and durability (alkali resistance and light resistance) can be obtained.

The (meth) acryloyl group equivalent of the (meth) acryloyl group binder having a (meth) acryloyl group in the side chain is, for example, 400 or more, preferably 800 or more, It is less than 10,000.

As the binder, other binders may be contained.

Examples of other binders include synthetic resins such as polyvinyl butyral resin, polyvinyl alcohol resin, vinyl acetate resin, and urethane resin. Other examples of the binder include (meth) acrylic resins other than the above-mentioned (meth) acrylic resin binders.

These other binders may be used alone or in combination of two or more.

The coating agent is obtained by collectively or sequentially mixing and mixing the metal fine particles, the dispersion medium, the metal fine particle dispersant, and the binder described above.

The blending ratio of each component in the coating agent is preferably 1 part by mass or more, preferably 5 parts by mass or more, for example, 200 parts by mass or less, and more preferably 1 part by mass or less for 100 parts by mass of the metal fine particles Is not more than 100 parts by mass, more preferably not more than 70 parts by mass. The amount of the fine metal particles is, for example, 0.5 parts by mass or more, preferably 2.5 parts by mass or more, for example, 50 parts by mass or less, and preferably 40 parts by mass or less, based on 100 parts by mass of the coating agent. The binder is, for example, 1 part by mass or more, preferably 5 parts by mass or more, for example, 50 parts by mass or less, preferably 30 parts by mass or less, based on 100 parts by mass of the coating agent.

On the other hand, the mixing ratio of the dispersion medium is appropriately set according to the purpose and use, but is, for example, 100 parts by mass or more, preferably 200 parts by mass or more, relative to 100 parts by mass of the metal fine particles, 2000 parts by mass or less, preferably 1000 parts by mass or less.

Further, the coating agent may further contain a crosslinking agent.

Examples of the crosslinking agent include polyfunctional (meth) acrylates (polyfunctional (meth) acrylates which are not modified with acid anhydrides) and the like.

The polyfunctional (meth) acrylate is a compound having two or more (meth) acryloyl groups in one molecule, and examples thereof include a hydroxyl group-containing polyfunctional (meth) acrylic compound, (Meth) acrylic compounds.

The hydroxyl group-containing polyfunctional (meth) acrylic compound is a polyfunctional (meth) acrylic compound having at least two (meth) acryloyl groups and at least one hydroxyl group as described above.

As the hydroxyl group-containing polyfunctional (meth) acrylic compound, the hydroxyl group-containing polyfunctional (meth) acrylic compound ((A) used in the production of the acid anhydride modified product of the polyfunctional (meth) A hydroxyl group-containing polyfunctional (meth) acrylic compound).

The hydroxyl group-free polyfunctional (meth) acrylic compound is a polyfunctional (meth) acrylic compound having two or more (meth) acryloyl groups and no hydroxyl group.

More specifically, the hydroxyl group-free polyfunctional (meth) acrylic compound is, for example, a polyol (for example, 1,3-butanediol (hydroxyl number 2) (Hydroxyl group number 2), ethylene glycol (hydroxyl group number 2), diethylene glycol (hydroxyl group number 2), neopentyl glycol (hydroxyl group number 2), triethylene glycol (Hydroxyl group number 2), tetraethylene glycol (hydroxyl group number 2), polyethylene glycol (hydroxyl group number 2), glycerin (hydroxyl group number 3), trimethylol propane (hydroxyl number 3) (Hydroxyl group number 3), diglycerin (hydroxyl number 4), ditrimethylol propane (hydroxyl number 4), pentaerythritol (hydroxyl group number 4) 4), dipentaerythritol (hydroxyl number 6), tripentaerythritol (hydroxyl number 8) To the action of a known alcohol), and that of the polyol hydroxyl groups with equimolar number of (meth) acrylic acid adduct addition product (adduct).

Examples of the polyfunctional (meth) acrylic compound that does not contain a hydroxyl group include dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylol propane tri (meth) (Meth) acrylate, and the like.

In addition to the above, examples of the cross-linking agent include monomolecular (meth) acrylic compounds (monomodal (meth) acrylic compounds other than the monomodal (meth) acrylic compound (B) described above). Examples of such mono-functional (meth) acrylic compounds include the above-mentioned alkyl (meth) acrylates, the above-mentioned aromatic ring-containing monomers, the above-mentioned hydroxyl group-containing monomers and the above-mentioned anionic group- .

These crosslinking agents may be used alone or in combination of two or more.

The compounding ratio of the cross-linking agent is suitably set according to the purpose and use.

The mixing method of the crosslinking agent is not particularly limited and may be added separately from the above-mentioned metal fine particle dispersing agent. For example, the mixing method of the above-mentioned (A) the acid anhydride modified product of the polyfunctional (meth) (Meth) acrylic compound is not denatured by an acid anhydride, and the hydroxyl group-containing polyfunctional (meth) acrylic compound is left unmodified by the hydroxyl group-containing polyfunctional (meth) A practical group-containing polyfunctional (meth) acrylic compound may be used as a crosslinking agent.

In the production of the acid anhydride modified product of the above-mentioned (A) polyfunctional (meth) acrylic compound, the hydroxyl group-containing polyfunctional (meth) acrylic compound and the hydroxyl group- Mixtures of compounds may also be used.

The mixture of the hydroxyl group-containing polyfunctional (meth) acrylic compound and the hydroxyl group-free polyfunctional (meth) acrylic compound is, for example, a polyol (for example, glycerin, trimethylol propane, diglycerin (Meth) acrylic acid with an equimolar amount of the hydroxyl group of the polyol to a known polyfunctional alcohol such as dibutyl ether, ditrimethylol propane, pentaerythritol, or dipentaerythritol.

Specifically, in this reaction, usually, equimolar (meth) acrylic acid is added to a part of the polyol with respect to the number of hydroxyl groups of the polyol to generate a hydroxyl group-free polyfunctional (meth) acrylic compound do.

Further, with respect to the remainder of the polyol, (meth) acrylic acid having an equimolar amount to the number of hydroxyl groups of the polyol is added to produce a hydroxyl group-containing polyfunctional (meth) acrylic compound.

As a result, a mixture of a hydroxyl group-containing polyfunctional (meth) acrylic compound and a hydroxyl group-free polyfunctional (meth) acrylic compound is obtained.

A mixture of the hydroxyl group-containing polyfunctional (meth) acrylic compound and the hydroxyl group-free polyfunctional (meth) acrylic compound was used in the production of (A) an acid anhydride modified product of a polyfunctional (meth) , The hydroxyl group-free polyfunctional (meth) acrylic compound remains unmodified by the acid anhydride. Then, the remaining hydroxyl group-free polyfunctional (meth) acrylic compound can be directly used as a crosslinking agent.

The blending ratio of the crosslinking agent is, for example, not less than 1 part by mass, preferably not less than 5 parts by mass, for example, not more than 1,500 parts by mass, preferably not more than 1,000 parts by mass, based on 100 parts by mass of the total amount of the metal fine particle dispersing agent More preferably 500 parts by mass or less, and even more preferably 200 parts by mass or less.

Further, the coating agent may contain a polymerization initiator, if necessary.

Examples of the polymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenylketone, 1-cyclohexylphenylketone, 2- Methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2- 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one, , Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4-methylbenzophenone, benzophenone, 2- And photopolymerization initiators such as 1- {4- [4- (2-hydroxy-2-methylpropionyl) -benzyl] phenyl} -2-methyl-propan-1-one.

These polymerization initiators may be used alone or in combination of two or more.

The mixing ratio of the polymerization initiator is, for example, not less than 1 part by mass, preferably not less than 3 parts by mass, relative to 100 parts by mass of the total amount of the fine metal particle dispersing agent (and the crosslinking agent to be incorporated as required) Or less, preferably 7 parts by mass or less.

On the other hand, the timing of blending the cross-linking agent and the polymerization initiator is not particularly limited and may be blended simultaneously at the time of mixing the metal fine particles, the solvent, the metal fine particle dispersant and the binder, or may be mixed with the metal fine particles, The crosslinking agent and the polymerization initiator may be added together or sequentially.

In the preparation of the coating agent, there is no particular limitation, and when mixing the fine metal particles, the solvent and the fine metal particle dispersing agent (in addition, the binder, the crosslinking agent and the polymerization initiator which are added as needed), for example, a paint shaker, , A ball mill, an attritor, a sand mill, a bead mill, and an ultrasonic dispersing machine.

From the viewpoint of improving the transparency and the like of the coating film, a ball mill and a bead mill are preferable, and a bead mill is more preferable.

When a bead mill is used as the dispersing unit, a known dispersion medium such as zirconia beads and glass beads can be used.

The bead diameter of the dispersion medium is not particularly limited, but is, for example, 10 占 퐉 or more, for example, 500 占 퐉 or less, preferably 100 占 퐉 or less. On the other hand, the filling rate of the dispersion medium is suitably set in accordance with the purpose and use.

When a bead mill or a ball mill is used as the dispersing machine, the metal fine particles may be pulverized by the above-mentioned dispersion medium to adjust the average particle diameter thereof to the above-mentioned range. In such a case, metal fine particles having an average particle size larger than the above range can be introduced into the dispersing machine.

Further, the coating agent may contain, for example, a pigment, a drying agent, a rust inhibitor, a plasticizer, a coating film surface conditioner, an antioxidant, an ultraviolet absorber and further a dispersant other than the metal fine particle dispersing agent (for example, sorbitan fatty acid ester, polyethylene glycol A nonionic surfactant such as a fatty acid ester), and the like can be added. On the other hand, the compounding ratio of the additive is suitably set according to the purpose and use.

The nonvolatile matter content of the coating agent is, for example, not less than 0.5% by mass, preferably not less than 3% by mass, for example not more than 70% by mass, preferably not more than 50% by mass.

In the coating agent, the particle size of the metal fine particles is measured as the average particle size (average particle size) of the metal fine particles because they exist as primary particles or secondary particles, and for example, 200 nm or less, preferably 90 nm or less Preferably 50 nm or less, and usually 1 nm or more, preferably 3 nm or more.

Since such a coating agent includes the metal fine particle dispersant, a coating film having excellent dispersibility and dispersion stability of the metal fine particles and excellent in transparency, adhesion, hardness and durability (alkali resistance and light resistance) can be obtained.

In order to obtain a coating film, for example, a coating agent is applied to a substrate by a known method using a coating agent, followed by drying, followed by irradiation with an active energy ray to cure the coating film.

Examples of the substrate include, but are not limited to, polycarbonate, polymethyl methacrylate, polystyrene, polyester (polyethylene terephthalate and the like), polyolefin, epoxy resin, melamine resin, triacetyl cellulose resin, , And norbornene resin, and metal such as metal, wood, paper, glass, and slate.

The application method is not particularly limited, and examples thereof include application using a device commonly used in application such as roll coater, bar coater, doctor blade, Meyer bar, air knife, etc., screen printing, offset printing, Known coating methods such as printing, brushing, spray coating, gravure coating, reverse gravure coating are employed.

The drying conditions are, for example, 40 ° C or higher, preferably 60 ° C or higher, for example, 180 ° C or lower, preferably 140 ° C or lower, and the drying time is, for example, 1 minute Preferably not less than 2 minutes, for example, not more than 60 minutes, preferably not more than 30 minutes.

The film thickness after drying is, for example, 50 nm or more, preferably 500 nm or more, for example, 10 μm or less, preferably 7 μm or less.

Examples of the active energy ray include ultraviolet rays and electron rays.

In the case of curing by ultraviolet rays, an ultraviolet irradiation apparatus having a xenon lamp, a high-pressure mercury lamp, a metal halide lamp or the like is used as a light source. The amount of ultraviolet radiation, the amount of ultraviolet light, the arrangement of light sources, and the like are appropriately adjusted as necessary. Specifically, in the case of using a high-pressure mercury lamp, for example, a substrate coated with a coating agent is transported at a transport speed of 5 to 50 m / min for 1 light having a light intensity of 80 to 1000 mW / cm ² or so. The dose of ultraviolet rays is, for example, 100 to 10000 mJ / cm ² . When curing is carried out by electron beams, the substrate coated with the coating agent is transported at an electron beam accelerating device having an acceleration voltage of 10 to 300 kV at a transporting speed of 5 to 50 m / min.

By irradiation of such active energy rays, the (meth) acryloyl group in the metal fine particle dispersant is crosslinked to form a three-dimensional structure. As a result, a coating film can be obtained as a cured product of the coating agent.

Since the obtained coating film is obtained by using the above-mentioned coating agent, transparency, adhesion, hardness and durability (alkali resistance and light resistance) are excellent.

Therefore, the coating film is a functional film such as a light-emitting diode (LED), a lens, and an optical device, such as a fine ceramic, for example, a conductive film or an optical film, It is suitably used in products.

Example

Next, the present invention will be described based on Examples and Comparative Examples, but the present invention is not limited by the following Examples. On the other hand, "part" and "%" are based on mass unless otherwise specified. Specific numerical values such as a mixing ratio (content ratio), a physical property value and a parameter to be used in the following description are the same as those described in the " Detailed Description of the Invention " (A value defined as "less than" or "less than") or a lower limit (a value defined as "greater than or equal to").

On the other hand, measurement methods used in the following will be described below.

≪ Weight average molecular weight &

The sample was dissolved in tetrahydrofuran to give a sample concentration of 3.5 g / L and measured by a gel permeation chromatograph (GPC) to obtain a molecular weight distribution of the sample.

Thereafter, the weight average molecular weight (Mw) of the sample was calculated from the obtained chromatogram (chart) using standard polystyrene as a calibration curve. The measurement apparatus and measurement conditions are shown below.

Data processing device: Part number HLC-8220GPC (manufactured by TOSOH CORPORATION)

Differential Refractive Index Detector: RI detector built in part number HLC-8220GPC

Column: TSKgel G2000HXL, G3000HXL, G4000HXL (manufactured by Tosoh Corporation, weight average molecular weight 20,000 or less), TSKgel GMHXL (manufactured by Tosoh Corporation, weight average molecular weight 20,000 or more)

Mobile phase: tetrahydrofuran

Column flow rate: 1 mL / min

Sample concentration: 3.5 g / L

Injection amount: 100 μL

Measuring temperature: 40 ° C

Molecular weight markers: Standard polystyrene (manufactured by POLYMER LABORATORIES LTD.) (Using POLYSTYRENE-MEDIUM MOLECULAR WEIGHT CALIBRATIO KIT)

<Modified acid anhydride of (A) polyfunctional (meth) acrylic compound>

  Synthesis Example 1

To a 1 L flask equipped with a stirrer, a thermometer, a reflux condenser and a mixed gas inlet tube, 327.2 parts of methyl isobutyl ketone (solvent), a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate 300 parts of dipentaerythritol pentaacrylate (Nippon Mitsubishi Chemical Co., Ltd., Niks M403, content of dipentaerythritol pentaacrylate: 50 to 60%), 0.33 part of triethylamine (catalyst) and 0.16 part of p-methoxyphenol (polymerization inhibitor) .

Then, 27.2 parts of phthalic anhydride was added, and a nitrogen-oxygen mixed gas (oxygen concentration: 7%) was introduced, and the mixture was maintained at 80 DEG C for 8 hours. Thereafter, the solution was cooled to obtain a solution of the acid anhydride modified product of the polyfunctional (meth) acrylic compound (A) having a solid content of 50% and an acid value of 23 mg KOH / g.

<(Meth) acrylic resin binder>

  Synthesis Example 2

A flask equipped with a stirrer, a condenser, a thermometer, a nitrogen inlet tube and a dropping funnel was charged with 100 parts of methyl isobutyl ketone, and the temperature was raised to 100 DEG C in a nitrogen atmosphere.

On the other hand, 4 parts of acrylic acid, 70 parts of methyl methacrylate, 10 parts of n-butyl acrylate, 16 parts of 2-hydroxyethyl methacrylate, and 2,2'-azobis-2 And 5 parts of methyl butyronitrile were mixed to prepare a monomer mixture solution.

Then, to the flask containing methyl isobutyl ketone, a monomer mixture liquid was added dropwise over 3 hours, followed by aging reaction for 3 hours.

Thus, a (meth) acrylic resin having a hydroxyl group ((meth) acrylic resin for obtaining a binder) was obtained.

Thereafter, the reaction temperature was set at 80 占 폚, the atmosphere was changed from a nitrogen atmosphere to an air atmosphere, and 2 parts of 2-isocyanatoethyl acrylate (Carens AOI, Showa Denko Co., Ltd.) , 5 parts of methyl isobutyl ketone and 0.1 part of p-methoxyphenol as a polymerization inhibitor were added and reacted for 4 hours.

As a result, a solution of a (meth) acrylic resin binder having a nonvolatile content of 50% and a (meth) acryloyl group in its side chain was obtained.

The weight average molecular weight of the obtained (meth) acrylic resin binder was 6500.

  Synthesis Examples 3 to 7 and Comparative Synthesis Examples 1 to 2

A solution of a (meth) acrylic resin binder having a (meth) acryloyl group in its side chain was obtained in the same manner as in Synthesis Example 2 except that the formulation was changed to the formulation shown in Table 1.

On the other hand, in Comparative Synthesis Example 1, a solution of a (meth) acrylic resin binder having no (meth) acryloyl group in the side chain was obtained.

In Comparative Synthesis Example 2, 8 parts of acrylic acid (7.8% of the total amount of monomer components) was used. That is, the obtained (meth) acrylic resin was a (meth) acrylic resin dispersant having a (meth) acryloyl group in its side chain.

<(Meth) acrylic resin dispersant>

  Synthesis Example 8

A flask equipped with a stirrer, a condenser, a thermometer, a nitrogen inlet tube and a dropping funnel was charged with 100 parts of methyl isobutyl ketone, and the temperature was raised to 100 DEG C in a nitrogen atmosphere.

On the other hand, as a part of the monomer component, 15 parts of acrylic acid, 10 parts of n-butyl acrylate, 5 parts of 2-hydroxyethyl methacrylate, 70 parts of isobornyl methacrylate, and 2,2'-azobis -6-methylbutyronitrile were mixed to prepare a monomer mixture.

Then, to the flask containing methyl isobutyl ketone, a monomer mixture liquid was added dropwise over 3 hours, followed by aging reaction for 3 hours.

Thus, a (meth) acrylic resin having a hydroxyl group (a (meth) acrylic resin for obtaining a dispersant) was obtained.

Thereafter, the reaction temperature was set at 80 占 폚, the atmosphere was changed from a nitrogen atmosphere to an air atmosphere, and 2 parts of 2-isocyanatoethyl acrylate (Carens AOI, Showa Denko Co., Ltd.) , 5 parts of methyl isobutyl ketone and 0.1 part of p-methoxyphenol as a polymerization inhibitor were added and reacted for 4 hours.

Thus, a solution of a (meth) acrylic resin dispersant having a nonvolatile content of 50% and a (meth) acryloyl group in its side chain was obtained.

The weight average molecular weight of the obtained (meth) acrylic resin dispersant was 6700.

  Synthesis Examples 9 to 13

A solution of a (meth) acrylic resin dispersant having a (meth) acryloyl group in its side chain was obtained in the same manner as in Synthesis Example 8, except that the formulation was changed to the formulation shown in Table 2.

<Modified acid anhydride of caprolactone adduct of (b2) hydroxyalkyl (meth) acrylate>

  Synthesis Example 14

143.5 parts of methyl isobutyl ketone (solvent), 40.0 parts of a caprolactone adduct of hydroxyethyl (meth) acrylate (di-tert-butyl alcohol FA-1 , 0.1 part of triethylamine (catalyst), and 0.07 part of p-methoxyphenol (polymerization inhibitor) were charged and heated to 80 ° C and stirred.

Subsequently, 43.5 parts of succinic anhydride was added, and a nitrogen-oxygen mixed gas (oxygen concentration: 7%) was introduced and maintained at 80 DEG C for 8 hours. Thereafter, the resultant solution was cooled to obtain a solution of an acid anhydride modified product of a caprolactone adduct of hydroxyethyl (meth) acrylate of (b2) having a solid content of 50% and an acid value of 85 mgKOH / g.

< (b3) Modified acid anhydride of alkylene oxide adduct of (meth) acrylic acid >

  Synthesis Example 15

In a 500 mL flask equipped with a stirrer, a thermometer, a reflux condenser and a mixed gas inlet tube, 137.0 parts of methyl isobutyl ketone (solvent), 200.0 parts of an ethylene oxide adduct of (meth) acrylic acid (Nippon Oil Blemish AE- (Average addition mol number of oxide: 4.5 moles), 0.14 part of triethylamine (catalyst) and 0.07 part of p-methoxyphenol (polymerization inhibitor) were charged and heated to 80 deg.

Then, 37.0 parts of succinic anhydride was added, and a nitrogen-oxygen mixed gas (oxygen concentration: 7%) was introduced and maintained at 80 DEG C for 8 hours. Thereafter, the solution was cooled to obtain a solution of an acid anhydride modified product of an ethylene oxide adduct of (b3) (meth) acrylic acid having a solid content of 50% and an acid value of 64 mgKOH / g.

<Coating agent and coating film>

Example 1

(Solid content) of the (meth) acrylic resin binder obtained in Synthesis Example 2 and the nonvolatile matter (solid content) of the acid anhydride modified product (metal fine particle dispersant) of the polyfunctional (meth) acrylic compound obtained in Synthesis Example 1 was 9, (Solid content) of 25 parts of zirconium oxide as a metal fine particle (Daichikigen retaining agent UEP-100, average primary particle diameter 15 nm), 56.1 parts of methyl isobutyl ketone as a dispersion medium and IRGACURE 907 (BASF 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one) was added in an amount of 0.9 part to obtain a coating agent.

Thereafter, the obtained coating material was applied to a polyethylene terephthalate (PET) film (Doresay UH-13, thickness 125 탆) as a substrate so that the film thickness after drying was 1 탆 with a bar coater and dried at 80 캜 for 2 minutes .

Subsequently, ultraviolet rays of 300 mJ / cm ² and 240 mW / cm ² were irradiated by a high-pressure mercury lamp of an ultraviolet irradiator (apparatus name CSOT-40 manufactured by Nippon Denshi Co., Ltd.) to cure the coating film to obtain a laminate of a substrate and a coating film.

Examples 2 to 23 and Comparative Examples 1 to 7

A layered product of a coating agent, a substrate and a coating film was obtained in the same manner as in Example 1 except that the formulation was changed to the formulation shown in Tables 3 to 5.

<Evaluation>

The coating agent and coating film obtained in Examples and Comparative Examples were evaluated by the following methods. The results are also shown in Tables 3 to 5.

(1) Dispersibility

The average particle size of the coating agent was measured by a dynamic light scattering particle size distribution measuring device (product name: "nanotrac wave", manufactured by Microtrac). The criteria for evaluation are described below.

A: average particle diameter less than 30 nm.

B: average particle diameter of 30 nm or more and less than 70 nm.

C: average particle diameter 70 nm or more.

(2) dispersion stability

The coating agent was allowed to stand at 23 占 폚 for 1 week to 6 months, and dispersion stability was confirmed by visual observation and particle size measurement. The criteria for evaluation are described below.

A +: There was no sediment and no change in average particle size after 6 months.

A: There was no sediment and no change in average particle size after 3 months.

B: There was no sediment after 3 months, but the average particle size increased.

C: The sediment was identified within 3 months.

(3) Transparency (haze)

The laminate of the substrate and the coating film was allowed to stand in a state (normal state, 23 ° C, 50% relative humidity) for 40 hours, and haze was measured with a haze meter (NDH5000 turbidimeter manufactured by Nippon Denshoku Industries Co., Ltd.). The measurement of haze is based on JIS K 7136, How to obtain haze of a transparent material (2000 edition).

On the other hand, in the measurement, light was irradiated from the surface on the coating film side and the measurement was made.

In addition, as a measurement sample, 10 samples of a 50 mm square coating film were prepared and measured 10 times in total each time. The average value in each measurement was regarded as a haze value. Then, transparency was evaluated from the obtained haze value. The criteria for evaluation are described below.

A ++: Haze value less than 1.0%.

A +: Haze value of 1.0% or more and less than 1.2%.

A: The haze value is 1.2% or more and less than 1.5%.

B: Haze value of 1.5% or more and less than 2.5%.

C: Haze value of 2.5% or more.

(4) Adhesion

The adhesion was evaluated in accordance with a checkerboard test (former standard) of JIS K 5400. On the other hand, a peel test was carried out at the same position up to five times. The criteria for evaluation are described below.

A ++: The adhesion test was conducted five times, and no peeling was observed.

A +: Peeling of the coating film from the 4th to 5th times.

A: There is peeling of coating film from 2nd to 3rd times.

A-: There is a small peeling in the lattice part of the mass eye.

B: The peeling area is less than 5% of the mass eye.

C: Peel area is more than 5% of mass eye.

(5) Hardness

The surface of the coating film was subjected to 10 reciprocating abrasions with a load described below so as to have a width of 40 mm or more with steel wool # 0000. Thereafter, a black tape was attached to the back surface of the substrate (PET film), and the presence of scratches was confirmed under a three-wavelength fluorescent lamp. The criteria for evaluation are described below.

A ++: No scratches were found with a load of 200 g / cm ² .

A +: 1 to 5 scratches were observed with a load of 200 g / cm ² .

A: No scratches were observed at a load of 100 g / cm ² . More than 6 scratches were observed with a load of 200 g / cm ² .

B: 1 to 5 scratches were observed at a load of 100 g / cm ² .

C: At least 6 scratches were observed under a load of 100 g / cm ² .

(6) Alkalinity

The film thickness of the coating film in the laminate was measured in advance and immersed in an aqueous 4% by mass NaOH solution at 40 캜 for 5 minutes. After the film was taken out, the film was rinsed with distilled water, and after drying, the film thickness was again measured to confirm a change in film thickness before and after the test. The evaluation criteria are described below.

A: The film thickness reduction rate was less than 15%.

B: The film thickness reduction rate was 15% or more and less than 30%.

C: The film thickness reduction rate was 30% or more.

(7) Light fastness

The coating film in the laminate was irradiated with ultraviolet rays of 500 mJ / cm ² and 400 mW / cm ² by a high-pressure mercury lamp of an ultraviolet irradiator (apparatus name CSOT-40 manufactured by Nippon Denshi Co., Ltd.). Thereafter, it was confirmed whether or not the coating film was peeled from the substrate.

When not peeled off, ultraviolet light was further irradiated as described above until the coating film peeled off from the substrate, and the number of times of irradiation was measured. This was the light resistance test. The evaluation criteria are described below.

A +: 10 times irradiation with ultraviolet ray, no peeling.

A: Peeling when 6th to 10th ultraviolet rays were irradiated.

B: Peeling when irradiated with ultraviolet rays for the third to fifth times.

C: Peeling off when ultraviolet light is irradiated for the first to second times.

Details of the abbreviations in the table are described below.

Zirconium oxide: Daichikigen agent UEP-100, average primary particle diameter 15 nm

Titanium oxide: TTO-51 manufactured by Ishihara Industries, average primary particle size 20 nm

Aluminum oxide: TM-300 manufactured by Daimei Chemical Industry, average primary particle diameter 10 nm

NK Ester CBX-0: manufactured by Shin Nakamura Chemical Industry Co., Ltd.

Disperson DA7301: Disperson DA-7301, manufactured by Kusumoto Chemical Co., Ltd., alkylcyclohexane of high molecular weight polyester acid

Aronix M-5300: Aronix M-5300, Doa synthetic agent,? -Carboxyl caprolactone monoacrylate

DPHA: crosslinking agent, dipentaerythritol hexaacrylate (content 95% or more)

Irgacure 907: a product name, a polymerization initiator, a polymerization initiator, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-

While the present invention has been described as an exemplary embodiment of the present invention, it is to be understood that the present invention is not limited thereto. Variations of the invention which will be apparent to those skilled in the art are included in the scope of the following claims.

The coating agent and coating film of the present invention are suitably used as functional coatings in various industrial products such as light emitting diodes (LEDs), lenses, optical devices, fine ceramics, conductive films and optical films.

Claims (12)

As a coating agent containing metal fine particles, a dispersion medium, a metal fine particle dispersant and a binder,
The metal fine particles are fine particles of a metal oxide,
Wherein the metal fine particle dispersant contains a monomer or an oligomer having at least two active energy curing groups and at least one carboxyl group,
The binder contains a (meth) acrylic resin binder having a (meth) acryloyl group in its side chain,
Wherein the (meth) acrylic resin binder does not contain an anionic group-containing monomer, or is a reaction product of a monomer component containing an anionic group-containing monomer in a proportion of less than 5%
&Lt; / RTI &gt; The method according to claim 1,
Wherein the metal fine particle dispersant further contains a (meth) acrylic resin dispersant having a (meth) acryloyl group in its side chain,
The (meth) acrylic resin dispersant is a reaction product of a monomer component containing an anionic group-containing monomer at a ratio of 5 mass%
&Lt; / RTI &gt; 3. The method of claim 2,
The (meth) acrylic resin dispersant is a reaction product of a monomer component containing an anionic group-containing monomer in a proportion of 10 mass% or more
&Lt; / RTI &gt; The method according to claim 1,
Wherein the anionic group of the anionic group-containing monomer is a carboxyl group or a phosphoric acid group. The method according to claim 1,
Wherein the (meth) acrylic resin binder is a reaction product of a monomer component containing an aromatic ring-containing monomer
&Lt; / RTI &gt; 6. The method of claim 5,
In the (meth) acrylic resin binder,
Wherein the content of the aromatic ring-containing monomer is 20 mass% or more based on the total amount of the monomer components
&Lt; / RTI &gt; The method according to claim 1,
Wherein the weight average molecular weight of the (meth) acrylic resin binder is from 3,000 to 50,000. 3. The method of claim 2,
Wherein the (meth) acrylic resin dispersant is a reaction product of a monomer component containing an aromatic ring-containing monomer
&Lt; / RTI &gt; 9. The method of claim 8,
In the (meth) acrylic resin dispersant,
Wherein the content of the aromatic ring-containing monomer is 20 mass% or more based on the total amount of the monomer components
&Lt; / RTI &gt; 3. The method of claim 2,
Wherein the (meth) acrylic resin dispersant has a weight average molecular weight of from 3,000 to 50,000. 3. The method of claim 2,
Wherein the metal fine particle dispersant further comprises a caprolactone adduct of (meth) acrylic acid represented by the following formula (1).
CH ₂ = C (R ¹ ) CO [O (CH ₂ ) ₅ CO] _n OH (1)
(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and n represents 1 to 10.) A coating film characterized by being a cured product of the coating agent according to claim 1.