JP6886585B2 - Aqueous resin compositions, coating agents and articles - Google Patents

Description

The present invention relates to an aqueous resin composition, a coating agent, and an article having a coating film of the coating agent.

The coating agent is required to be able to form a coating film capable of preventing deterioration of the surface of various base materials, to be able to impart designability to the surface of the base material, and the like. When used outdoors, it has hydrophilicity and adhesion to the base material, and further deteriorates the surface of the base material due to deterioration of hydrophilicity due to adhesion of chemicals such as water stains, oil stains, cleaning agents, acid rain, etc. It is required to be preventable. In recent years, in a wide variety of fields such as agriculture, manufacturing, construction, and industrial production, there has been a demand for a coating agent capable of forming a coating film having excellent hydrophilic durability, and metals such as steel sheets have been demanded. Demand is increasing for surface treatment applications of base materials, glass base materials including mirrors, and plastic base materials called poorly adherent base materials.

In particular, in the agricultural industry, house cultivation, tunnel cultivation, etc. are carried out in which plants are cultivated by ensuring sunlight irradiation while maintaining the internal temperature with agricultural films such as vinyl chloride resin film and polyolefin resin film. A surface coating is applied to such an agricultural film for the purpose of imparting antifogging property and the like.

The coating film of the coating agent used on the surface of the base material is an antifogging coating film formed from the composition containing the alkoxysilane compound on the lower layer coating film formed from the composition containing the synthetic resin binder and the inorganic colloid sol. A coating film in which is laminated has been proposed (see, for example, Patent Document 1). Further, an antifogging coating composition containing a (meth) acrylic acid-based copolymer, a hydrophilic inorganic substance and an aqueous resin has been proposed (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2008-07645 Japanese Unexamined Patent Publication No. 2005-248091

However, the coating films described in Patent Documents 1 and 2 may not have sufficient adhesion to the substrate and heat resistance. An object to be solved by the present invention is to provide an aqueous resin composition capable of forming a coating film having improved antifogging property and further improved heat resistance while maintaining adhesion to a base material. Is.

As a result of diligent research to solve the above problems, the present inventors have found that both the urethane resin and the hydrophilic acrylic polymer contained in the aqueous resin composition have a specific hydrolyzable silyl group and / or silanol group. It has been found that by incorporating metal oxide fine particles in the aqueous resin composition, it is possible to improve the antifogging property while maintaining the adhesion to the substrate, and further to improve the heat resistance and water resistance. , The present invention has been completed.

That is, the present invention comprises a urethane resin (A) having a group represented by the following general formula (1), a hydrophilic acrylic polymer (B) having a group represented by the following general formula (1), and metal oxidation. It is characterized by being formed from an aqueous resin composition characterized by containing fine particles (D) and an aqueous medium (C), a coating agent characterized by containing the aqueous resin composition, and the coating agent. The present invention relates to a coating film, an article characterized by having a coating film of the coating agent, and an agricultural film characterized by having a coating film of the coating agent.

［一般式（１）中、Ｒ¹は、水素原子又は炭素原子数１以上４以下のアルキル基を表す。Ｒ²は、炭素原子数１以上４以下のアルキル基を表す。ａは、１以上３以下の整数を表す。］

[In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 or more and 4 or less carbon atoms. R ² represents an alkyl group having 1 or more carbon atoms and 4 or less carbon atoms. a represents an integer of 1 or more and 3 or less. ]

By using the aqueous resin composition of the present invention, it is possible to provide a coating film capable of enhancing antifogging property while maintaining adhesion to a base material and further improving heat resistance and water resistance.
Examples of the base material to which the coating agent of the present invention can be applied include metal base materials such as zinc-plated steel plate, aluminum-zinc-plated steel plate, aluminum plate, aluminum alloy plate, electromagnetic steel plate, copper plate, and stainless steel plate; polyester resin and polycarbonate. Examples thereof include various plastics such as resins and ethylene-vinyl acetate copolymer resins (EVA resins) and films thereof; glass; paper; wood and the like. Further, since the coating agent of the present invention can form a coating film having excellent hydrophilicity durability and chemical resistance that can prevent deterioration of the surface of these base materials, agricultural films, aluminum fins, building members, home appliances, etc. It can be used for various articles such as automobile exterior materials, goggles, antifogging film sheets, antifogging glass, mirrors, and medical instruments.

The aqueous resin composition of the present invention includes a urethane resin (A) having a group represented by the general formula (1) (hereinafter, may be referred to as "urethane resin (A)") and the general formula (1). Hydrophilic acrylic polymer (B) having a group represented by (hereinafter, may be referred to as “hydrophilic acrylic polymer (B)”), metal oxide fine particles (D), and an aqueous medium (C). ) And.

［一般式（１）中、Ｒ¹は、水素原子又は炭素原子数１以上４以下のアルキル基を表す。Ｒ²は、炭素原子数１以上４以下のアルキル基を表す。ａは、１以上３以下の整数を表す。］

[In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 or more and 4 or less carbon atoms. R ² represents an alkyl group having 1 or more carbon atoms and 4 or less carbon atoms. a represents an integer of 1 or more and 3 or less. ]

Examples of the alkyl group having 1 or more and 4 or less carbon atoms represented by R ¹ or R ² include a methyl group, an ethyl group, a propyl group, a butyl group and the like, and a carbon atom such as a methyl group and an ethyl group. Alkyl groups having a number of 1 or more and 2 or less are preferable.

The urethane resin (A) is, for example, a urethane prepolymer (a1) having an isocyanate group at the terminal (hereinafter, may be referred to as "urethane prepolymer (a1)"); at least one active hydrogen and at least one. It can be obtained by reacting with a compound (s1) having a group represented by the general formula (1) (hereinafter, may be referred to as "silane compound (s1)"). Further, in the urethane resin (A), functional groups such as a hydroxyl group, a carboxy group, an epoxy group, and a (meth) acryloyl group are introduced into the urethane prepolymer (a1) or the urethane prepolymer (a2) having no isocyanate group. However, it can also be obtained by reacting with a silane coupling agent (s2).

As the urethane prepolymer (a1), one obtained by reacting a polyol (a1-1) with a polyisocyanate (a1-2) can be used.

As the polyol (a1-1), one kind or two or more kinds can be used, and examples thereof include a polyether polyol, a polyester polyol, a polycarbonate polyol, and a polyolefin polyol. Among these, it is preferable to include a polyester polyol and a polycarbonate polyol because a coating film having excellent substrate adhesion can be formed.
From the viewpoint of further improving the adhesion to the base material, the number average molecular weight of the polyol is preferably 500 or more and 3,000 or less.

Examples of the polyether polyol include those obtained by addition polymerization (ring-opening polymerization) of an alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator.

Examples of the initiator include ethylene glycol, diethylene glycol, triethylene glycol, trimethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, and 1,4-. Linear diols such as butanediol and 1,6-hexanediol; branched chain diols such as neopentyl glycol; triols such as glycerin, trimethylolethane, trimethylolpropane and pyrogallol; polyols such as sorbitol, citrus sugar and aconit sugar Tricarboxylic acids such as aconitic acid, trimellitic acid, hemimeric acid; phosphoric acid; polyamines such as ethylenediamine and diethylenetriamine; triisopropanolamine; phenolic acids such as dihydroxybenzoic acid and hydroxyphthalic acid; 1,2,3-propanetri Examples include thiol.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

As the polyether polyol, it is preferable to use polyoxytetramethylene glycol obtained by addition polymerization (ring-opening polymerization) of tetrahydrofuran to the initiator.

The polyester polyol is, for example, a polyester polyol obtained by esterifying a low molecular weight polyol (for example, a polyol having a molecular weight of 50 or more and 300 or less) and a polycarboxylic acid; and ring-opening polymerization of a cyclic ester compound such as ε-caprolactone. Polyester polyols obtained by reaction; examples thereof include these copolymerized polyester polyols.

As the low molecular weight polyol, a polyol having a molecular weight of about 50 or more and about 300 or less can be used, and for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol can be used. , 3-Methyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol and other aliphatic polyols having 2 to 6 carbon atoms; 1,4-cyclohexanediol, cyclohexane Alicyclic structure-containing polyols such as dimethanol; bisphenol compounds such as bisphenol A and bisphenol F, and aromatic structure-containing polyols such as alkylene oxide adducts thereof can be mentioned.

Examples of the polycarboxylic acid include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid and dodecandicarboxylic acid; aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid and naphthalenedicarboxylic acid; and the fat. Examples thereof include anhydrides or ester-forming derivatives of group polycarboxylic acids and aromatic polycarboxylic acids.

Examples of the polycarbonate polyol include a reaction product of a carbonic acid ester and a polyol; a reaction product of phosgene and bisphenol A and the like.

Examples of the carbonic acid ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like.

Examples of the polyol capable of reacting with the carbonic acid ester include the polyol exemplified as the low molecular weight polyol; the high molecular weight polyol (weight) such as a polyether polyol (polyethylene glycol, polypropylene glycol, etc.) and a polyester polyol (polyhexamethylene adipate, etc.). The average molecular weight is 500 or more and 5,000 or less).

Examples of the polyolefin polyol include polyisobutene polyols, hydrogenated (hydrogenated) polybutadiene polyols, hydrogenated (hydrogenated) polyisoprene polyols, and the like.

The total content of the polyether polyol, the polyester polyol, the polycarbonate polyol, and the polyolefin polyol contained in the polyol (a1-1) is preferably 30% by mass or more, more preferably 40% by mass, in the polyol (a1-1). % Or more, preferably 100% by mass or less.

Further, as the polyol (a1-1), it is preferable to use a polyol having a hydrophilic group in combination from the viewpoint of imparting good water dispersion stability to the urethane resin (A).

As the polyol having a hydrophilic group, for example, a polyol other than the above-mentioned polyether polyol, polyester polyol, polycarbonate polyol and polyolefin polyol can be used, and specifically, a polyol having an anionic group and a cationic group can be used. Polyol having and a polyol having a nonionic group can be used. Among these, it is preferable to use a polyol having an anionic group or a polyol having a cationic group.

Examples of the polyol having an anionic group include a polyol having a carboxy group and a polyol having a sulfonic acid group.

Examples of the polyol having a carboxy group include hydroxy acids such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid; Examples thereof include a reaction product of a polyol having a carboxy group and the polycarboxylic acid. As the hydroxy acid, 2,2-dimethylolpropionic acid is preferable.

When the polyol (a1-1) contains a polyol having a carboxy group, the content thereof is preferably 1 part by mass or more, more preferably 2 parts by mass or more, based on 100 parts by mass of the total of the polyol (a1-1). It is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less.

Examples of the polyol having a sulfonic acid group include a dicarboxylic acid having a sulfonic acid group such as 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, and 5- (4-sulfophenoxy) isophthalic acid; the dicarboxylic acid. Examples thereof include a polyester polyol obtained by reacting the salt of the above with the aromatic structure-containing polyol.

When the polyol having a carboxy group or the polyol having a sulfonic acid group is used, the acid value of the urethane resin (A) is preferably 2 mgKOH / g or more and 70 mgKOH / g or less, more preferably 10 mgKOH / g or more and 50 mgKOH / g. It is as follows.
The acid value referred to in the present invention is based on the amount of an acid group-containing compound such as a polyol having a carboxy group or a sulfonic acid group used in the production of the urethane resin (A), and 1 g of the urethane resin (A) is added. It is a theoretical value calculated as the number of mg of potassium hydroxide required for summing.

From the viewpoint of exhibiting good water dispersibility, it is preferable that a part or all of the anionic group is neutralized with a basic compound or the like.

Examples of the basic compound that can be used to neutralize the anionic group include organic amines such as ammonia, triethylamine, morpholine, monoethanolamine, and diethylethanolamine; sodium hydroxide, potassium hydroxide, and lithium hydroxide. And the like, including metal hydroxides and the like. From the viewpoint of improving the water dispersion stability of the urethane resin composition, the molar ratio (basic group / anionic group) of the basic compound to the anionic group is preferably 0.5 or more and 3.0 or less. It is preferably 0.8 or more and 2.0 or less.

Examples of the polyol having a cationic group include N-methyl-diethanolamine; a polyol having a tertiary amino group such as a polyol obtained by reacting a compound having two epoxies in one molecule with a secondary amine. Be done.

Part or all of the tertiary amino group as the cationic group is a carboxylic acid such as formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, adipic acid; a hydroxy acid such as tartaric acid; an acidic acid such as phosphoric acid. It is preferably neutralized with a compound.

It is preferable that a part or all of the tertiary amino group as the cationic group is quaternized. Examples of the quaternizing agent include dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride and the like. Among these, it is preferable to use dimethyl sulfate.

When the polyol having a cationic group is used, the amine value of the urethane resin (A) is preferably 2 mgKOH / g or more and 50 mgKOH / g or less, and more preferably 5 mgKOH / g or more and 30 mgKOH / g or less. The amine value referred to in the present invention is 1 g of the urethane resin (A) based on the amount of the tertiary amino group-containing compound such as the polyol having the tertiary amino group used in the production of the urethane resin (A). It is a theoretical value calculated as a product of the number of moles of hydrogen chloride (mmol) required for summing and the formula amount of potassium hydroxide (56.1 g / mol).

Examples of the polyol having a nonionic group include a polyol having a polyoxyethylene structure.

The content of the polyol having a hydrophilic group is preferably 0.3% by mass or more, more preferably 1% by mass or more, still more preferably 5% by mass or more, based on 100% by mass of the total of the polyol (a1-1). It is preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less.

As the polyol (a1-1), in addition to the above-mentioned polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, and polyol having a hydrophilic group, other polyols may be used if necessary.

Examples of the other polyol include ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, and 1,4-butanediol. , 1,5-Pentanediol, 3-Methyl-1,5-Pentanediol, 1,4-Cyclohexanediol, 1,6-Hexanediol, Cyclohexanedimethanol and the like with relatively low molecular weight (for example, molecular weight of 50 or more and 300 or less). ) Polyol.

As the polyisocyanate (a1-2) capable of reacting with the polyol (a1-1), one kind or two or more kinds can be used, for example, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate. , Carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylenediisocyanate, trienediisocyanate, naphthalenediocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate and other aromatic polyisocyanates; hexamethylene diisocyanate, lysine diisocyanate and other aliphatic polyisocyanates; cyclohexanediisocyanate , Hydroisocyanate containing an alicyclic structure such as hydrogenated xylylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

The urethane prepolymer (a1) having an isocyanate group is produced, for example, by reacting the polyol (a1-1) with the polyisocyanate (a1-2) in the absence of a solvent or in the presence of an organic solvent. be able to. If necessary, a chain extension reaction may be further carried out by adding a chain extender described later.

The equivalent ratio [isocyanate group / hydroxyl group] of the isocyanate group of the polyisocyanate (a1-2) to the hydroxyl group of the polyol (a1-1) is preferably 0.9 or more and 3 or less on a molar basis. , 0.95 or more and 2 or less is more preferable.

The reaction temperature of the polyol (a1-1) and the polyisocyanate (a1-2) is usually preferably 50 ° C. or higher and 150 ° C. or lower.

The isocyanate group equivalent of the urethane prepolymer (a1) obtained by the above reaction is preferably 3,500 g / eq. More than 100,000 g / eq. Hereinafter, more preferably 10,000 g / eq. More than 60,000 g / eq. It is as follows.

Examples of the organic solvent that can be used in producing the urethane prepolymer (a1) include ketone solvents such as acetone and methyl ethyl ketone; ether solvents such as tetrahydrofuran and dioxane; acetate solvents such as ethyl acetate and butyl acetate; acetonitrile and the like. Nitrile solvent; amide solvent such as dimethylformamide and N-methylpyrrolidone can be mentioned. These organic solvents can be used alone or in combination of two or more.

In order to reduce the burden on safety and the environment, a part or all of the organic solvent may be removed during or after the production of the urethane resin (A) by distillation under reduced pressure or the like.

Examples of the compound (s1) having a group represented by the general formula (1) include γ- (2-aminoethyl) aminopropylmethyldimethoxysilane and γ- (2-aminoethyl) aminopropyltrimethoxysilane. Amine group-containing alkoxysilane compounds such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane; γ-hydroxypropyltrimethoxysilane, γ Examples thereof include hydroxyl group-containing alkoxysilane compounds such as −hydroxypropyltriethoxysilane; and mercapto group-containing alkoxysilane compounds such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane.

As the urethane prepolymer (a2) having no isocyanate group, for example, the hydroxyl group of the polyol (a1-1) is the equivalent ratio of the isocyanate group of the polyisocyanate (a1-2) [isocyanate group / hydroxyl group]. Examples of the urethane prepolymer obtained by reacting with an excessive design and having a hydroxyl group remaining, the urethane prepolymer (a1), and a urethane prepolymer obtained by adding a chain extender can be mentioned as the chain extender. Can use polyamines, hydrazine compounds, other active hydrogen atom-containing compounds and the like.

As the polyamine, one kind or two or more kinds can be used, for example, ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4, Diamines such as 4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxy Propylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, triethylenetetramine and the like can be mentioned.

As the hydrazine compound, one kind or two or more kinds can be used, for example, hydrazine, N, N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; dihydrazide succinate, dihydrazide adipic acid, dihydrazide glutarate. , Sebasic acid dihydrazide, isophthalic acid dihydrazide; β-semicarbazide propionate hydrazide and the like.

As the other active hydrogen-containing compound, one kind or two or more kinds can be used, and for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1 , 4-Butanediol, hexamethylene glycol, saccharose, methylene glycol, glycerin, sorbitol and other glycols; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone, Examples thereof include hydrogenated bisphenol A, phenols such as hydroquinone, water and the like, and they can also be used within a range in which the storage stability of the aqueous resin composition of the present invention is not deteriorated.

As the silane coupling agent (s2), one kind or two or more kinds can be used, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxy. Contains epoxy groups such as propylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane Alkoxysilane compounds; γ-isocyanuppropyltrimethoxysilane, γ-isocyanuppropyltriethoxysilane, γ-isocyanuppropylmethyldimethoxysilane, γ-isocyanuppropylmethyldiethoxysilane, γ-isocyanaboethyldimethoxysilane, γ-isocyanuppropylethyl Isocyanate group-containing alkoxysilane compounds such as diethoxysilane and γ-isocyanoxide propyltrichlorosilane; γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-amino Amino group-containing alkoxysilane compounds such as propyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane; γ- (meth) acryloxipropyltrimethoxysilane, (Meta) acryloyl group-containing alkoxysilane compounds such as γ- (meth) acryloxylpropyltriethoxysilane, γ- (meth) acryloxipropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane; vinyltri Examples thereof include vinyl group-containing alkoxysilanes such as methoxysilane and vinyltriethoxysilane, and styryl group-containing alkoxysilanes such as p-styryltrimethoxysilane and p-styryltriethoxysilane.

The urethane resin (A) preferably has an alicyclic structure because it can form a coating film having excellent chemical resistance.

Examples of the ring contained in the alicyclic structure include monocycles such as cyclobutyl ring, cyclopentyl ring, cyclohexyl ring, cycloheptyl ring, cyclooctyl ring, and propylcyclohexyl ring; tricyclo [5.2.1.0.2. .6] Decyl ring, bicyclo [4.3.0] -nonyl ring, tricyclo [5.3.1.1] dodecyl ring, propyltricyclo [5.3.1.1] dodecyl ring, norbornyl ring, isobornyl Examples thereof include a ring, a crosslinked ring such as a dicyclopentanyl ring and an adamantyl ring. Among these, a monocyclic structure is preferable, and a cyclohexyl ring structure is preferable.

In the alicyclic structure, as a component forming the urethane prepolymer (a1) or the urethane prepolymer (a2), the alicyclic structure-containing polyol and / or the alicyclic structure-containing polyisocyanate (hereinafter, alicyclic structure) The structure-containing polyol and the alicyclic structure-containing polyisocyanate may be collectively referred to as "alicyclic structure-containing compound"), and by using the alicyclic structure-containing polyisocyanate. It is preferably the one that has been introduced.

The content of the alicyclic structure is preferably 10 mmol / kg or more and 6,000 mmol / kg or less, more preferably 10 mmol, in the entire urethane resin (A) from the viewpoint of forming a coating film having excellent chemical resistance. It is / kg or more and 5,000 mmol / kg or less, more preferably 1,000 mmol / kg or more and 3,000 mmol / kg or less.
The content of the alicyclic structure referred to in the present invention is the total mass of the polyol (a1-1) and the polyisocyanate (a1-2) used for producing the urethane resin (A) and the urethane resin (A). It is a value calculated based on the amount of substance of the alicyclic structure contained in the alicyclic structure-containing compound used for production.

The content of the group represented by the general formula (1) contained in the urethane resin (A) is preferably in the urethane resin (A) from the viewpoint of improving hydrophilicity persistence, chemical resistance and substrate adhesion. Is 5 mmol / kg or more, more preferably 10 mmol / kg or more, still more preferably 50 mmol / kg or more, even more preferably 100 mmol / kg or more, preferably 500 mmol / kg or less, more preferably 300 mmol / kg or less, still more preferably. Is 200 mmol / kg or less.

In the aqueous resin composition of the present invention, the content of the urethane resin (A) is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65, based on 100% by mass of the non-volatile content of the aqueous resin composition. It is 5% by mass or more, preferably 95% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass or less.
In the present specification, the "nonvolatile content of the aqueous resin composition" means an amount obtained by subtracting the content of the aqueous medium (C) from the total amount of the aqueous resin composition.

The hydrophilic acrylic polymer (B) having a group represented by the general formula (1) (hereinafter, may be referred to as “hydrophilic acrylic polymer (B)”) is an acrylic monomer (b1) having an amide group. -1) (hereinafter, may be referred to as "acrylic monomer (b1-1)") and an acrylic monomer (b1-2) having an oxyethylene group (hereinafter, "acrylic monomer (b1-2)" ) ”) And an acrylic monomer (b1-3) having a group represented by the general formula (1) (hereinafter, referred to as“ acrylic monomer (b1-3) ”. It is preferable that the unit contains a unit derived from).
In the present specification, the unit derived from each monomer means a group formed by polymerization of each monomer.

The "hydrophilicity" of the hydrophilic acrylic polymer (B) means that it exhibits an affinity with water, and 100 g of water (20 ° C.) of the hydrophilic acrylic polymer (B). ) Is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more.

As the acrylic monomer (b1-1) having an amide group, a compound represented by the following general formula (2) can be used.

[In the general formula (2), R ³ represents a hydrogen atom or an alkyl group having 1 or more and 3 or less carbon atoms. R ⁴ represents an alkyl group having 1 to 3 carbon atoms and a methyl chloride salt of _{− (CH 2} ) _3- N (CH ₃ ) ₂ or − (CH ₂ ) ₃ −N (CH ₃ ) _2. ]

As the compound represented by the general formula (2), one kind or two or more kinds can be used, for example, N-hydroxyethylacrylamide, N-methylolacrylamide, N-methoxyethylacrylamide, N, N-dimethyl. Examples thereof include acrylamide, N, N-diethylacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylaminopropylacrylamide, methyl chloride salt of N, N-dimethylaminopropylacrylamide, N-isopropylacrylamide and the like.

Further, as the acrylic monomer (b1-1) having an amide group, for example, a compound represented by the following general formula (3) can be used.

［一般式（３）中、Ｒ⁵及びＲ⁶は、互いに独立に、炭素原子数１以上３以下のアルキレン基を表す。］

[In the general formula (3), R ⁵ and R ⁶ represent alkylene groups having 1 or more and 3 or less carbon atoms independently of each other. ]

Examples of the compound represented by the general formula (3) include N-acryloyl morpholine and the like.

As the acrylic monomer (b1-2) having an oxyethylene group, one kind or two or more kinds can be used, and for example, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, and polyethylene glycol polypropylene glycol can be used together. Polymerized (meth) acrylate, methoxypolyethylene glycol polypropylene glycol copolymerized (meth) acrylate, polyethylene glycol polytetramethylene glycol copolymerized (meth) acrylate, methoxypolyethylene glycol polytetramethylene glycol copolymerized (meth) acrylate and the like can be mentioned.

As the acrylic monomer (b1-3) having a group represented by the general formula (1), one kind or two or more kinds can be used, for example, a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane. Containing alkoxysilane compound; styryl group-containing alkoxysilane compound such as p-styryltrimethoxysilane and p-styryltriethoxysilane; γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane , (Meta) acryloyl group-containing alkoxysilane compounds such as γ- (meth) acryloxypropylmethyldimethoxysilane and γ- (meth) acryloxypropylmethyldiethoxysilane.

The total content of the units derived from the acrylic monomers (b1-1), (b1-2) and (b1-3) is preferably 70% by mass based on 100% by mass of the hydrophilic acrylic copolymer (B). As mentioned above, it is more preferably 80% by mass or more, and further preferably 90% by mass or more.

The ratio ((b1-1) / (b1-2)) of the unit derived from the acrylic monomer (b1-1) having an amide group to the unit derived from the acrylic monomer (b1-2) having an oxyethylene group is From the viewpoint of maintaining hydrophilicity and hydrophilicity persistence at a high level, it is preferably 99/1 or more and 50/50 or less on a molar basis, and more preferably 90/10 from the viewpoint of obtaining even better hydrophilicity persistence. More than 70/30 or less.

The content of the unit derived from the acrylic monomer (b1-3) having a group represented by the general formula (1) is the unit derived from the acrylic monomer (b1-1) having an amide group and the oxyethylene group. It is preferably 0.1 mol or more, more preferably 0.3 mol or more, still more preferably 0.5 mol or more, and preferably 0.5 mol or more, based on a total of 100 mol of the units derived from the acrylic monomer (b1-2) having. It is 20 mol or less, more preferably 15 mol or less, still more preferably 10 mol or less.

The average number of moles of oxyethylene groups added to the acrylic monomer (b1-2) having an oxyethylene group is preferably 5 or more and 13 mol or less, and more preferably 8 or more and 10 mol or less from the viewpoint of hydrophilicity persistence. is there.

The hydrophilic acrylic polymer (B) may contain other acrylic monomers (b1-) in addition to the units derived from the acrylic monomers (b1-1), (b1-2) and (b1-3), if necessary. It may contain a unit derived from 4).

Examples of the other acrylic monomer include an acrylic monomer having a sulfonic acid group, an acrylic monomer having a carboxy group, an acrylic monomer having a hydroxyl group, an acrylic monomer having a quaternary ammonium group, an acrylic monomer having an amino group, and an acrylic having a cyano group. Examples thereof include a monomer, an acrylic monomer having an imide group, an acrylic monomer having a methoxy group, and other radically polymerizable monomers.

As the acrylic monomer having a sulfonic acid group, one kind or two or more kinds can be used, for example, sulfopropyl (meth) acrylate sodium, 2-sulfoethyl (meth) acrylate sodium, 2- (meth) acrylamide-2. -Sodium methylpropane sulfonate and the like can be mentioned.

As the acrylic monomer having a carboxy group, one kind or two or more kinds can be used, for example, (meth) acrylic acid, propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, crotonic acid, fumaric acid and the like. Can be mentioned.

As the acrylic monomer having a hydroxyl group, one type or two or more types can be used, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and the like. Examples thereof include 4-hydroxybutyl (meth) acrylate and glycerol mono (meth) acrylate.

As the acrylic monomer having a quaternary ammonium group, one kind or two or more kinds can be used, and examples thereof include tetrabutylammonium (meth) acrylate and trimethylbenzylammonium (meth) acrylate.

As the acrylic monomer having an amino group, one kind or two or more kinds can be used, for example, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert-butylaminoethyl (meth) acrylate. , (Meta) acryloxyethyltrimethylammonium chloride and the like.

As the acrylic monomer having a cyano group, one kind or two or more kinds can be used, for example, (meth) acrylonitrile, cyanomethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, cyanopropyl (meth) acrylate, and the like. 1-Cyanomethylethyl (meth) acrylate, 2-cyanopropyl (meth) acrylate, 1-cyanocyclopropyl (meth) acrylate, 1-cyanocycloheptyl (meth) acrylate, 1,1-dicyanoethyl (meth) acrylate, Examples thereof include 2-cyanophenyl (meth) acrylate, 3-cyanophenyl (meth) acrylate, 4-cyanophenyl (meth) acrylate, 3-cyanobenzyl (meth) acrylate, and 4-cyanobenzyl (meth) acrylate.

As the acrylic monomer having an imide group, one kind or two or more kinds can be used, and for example, (meth) acrylicimide, N-methylolmaleimide, N-hydroxyethylmaleimide, N-glycidylmaleimide, N-4- Examples thereof include chloromethylphenylmaleimide and N-acetoxyethylmaleimide.

As the acrylic monomer having a methoxy group, one kind or two or more kinds can be used, for example, 3-methoxybutyl (meth) acrylate), 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth). Examples thereof include acrylate and 2-methoxybutyl (meth) acrylate.

As the radically polymerizable monomer, one kind or two or more kinds can be used, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth). Acrylate, sec-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) Acrylate, n-octyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate, 3-methylbutyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl ( Aliphatic (meth) acrylates such as meta) acrylate, isostearyl (meth) acrylate, neopentyl (meth) acrylate, hexadecyl (meth) acrylate, isoamyl (meth) acrylate; isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydro Alicyclic (meth) acrylates such as furfuryl (meth) acrylates; aromatic (meth) acrylates such as benzyl (meth) acrylates, benzyl (meth) acrylates, phenoxyethyl (meth) acrylates, and phenyl (meth) acrylates; , Α-Methylstyrene, chlorostyrene, chloromethylstyrene, methylvinyl ether, ethylvinyl ether, vinyl compounds such as isobutylvinyl ether and the like.

The content of the group represented by the general formula (1) contained in the hydrophilic acrylic resin (B) is the acrylic resin (B) from the viewpoint of forming a coating film having excellent hydrophilic durability and substrate adhesion. ), More preferably 5 mmol / kg or more, more preferably 20 mmol / kg or more, more preferably 40 mmol / kg or more, still more preferably 50 mmol / kg or more, preferably 1000 mmol / kg or less, more preferably 600 mmol / kg or less. , More preferably 800 mmol / kg or less, and even more preferably 700 mmol / kg or less.

As a method for producing the hydrophilic acrylic polymer (B), a known radical polymerization method can be adopted, and polymerization of the acrylic monomers (b1-1), (b1-2) and (b1-3) is started. Examples thereof include a method of radical polymerization with the acrylic monomer (b1-4) used as needed in the presence of an agent and a reaction solvent.

As the polymerization initiator, one kind or two or more kinds can be used, for example, peroxides such as hydrogen peroxide, potassium persulfate, sodium persulfate, ammonium persulfate; benzoyl peroxide, t-butylperoxy-. Organic peroxides such as 2-ethylhexanoate and cumenehydroperoxide; 2,2'-azobis- (2-aminodipropane) dihydrochloride, 2,2'-azobis- (N, N'-dimethylene) Isobutyl amidine) dihydrochloride, azobisisobutyronitrile, azo compounds such as 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleric acid nitrile), etc. Can be mentioned.
The amount of the polymerization initiator used is the acrylic monomers (b1-1), (b1-2) and (b1-3) which are the raw materials of the hydrophilic acrylic polymer (B), and the acrylic monomers used as needed. It is preferably 0.001 part by mass or more and 5 parts by mass or less with respect to a total of 100 parts by mass of (b1-4).

As the reaction solvent, water and / or an organic solvent can be used. As the organic solvent, one kind or two or more kinds can be used, for example, methanol, ethanol, toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, hexane, acetone, cyclohexanone, etc. Examples thereof include 3-pentanone, acetonitrile, isopropyl alcohol, 1,2-propanediol, 1,3-butanediol and the like. The amount of the organic solvent used is, for example, 100 parts by mass in total of the acrylic monomers (b1-1), (b1-2) and (b1-3) and the acrylic monomers (b1-4) used as needed. On the other hand, it is preferably 10 parts by mass or more and 500 parts by mass or less.

The reaction temperature is preferably 40 ° C. or higher and 90 ° C. or lower, and the reaction time is preferably 1 hour or longer and 10 hours or lower.

The weight average molecular weight of the hydrophilic acrylic polymer (B) is preferably 10,000 or more and 100,000 or less, more preferably 15,000 or more and 50,000, from the viewpoint of affinity with the urethane resin (A). It is as follows. The weight average molecular weight of the hydrophilic acrylic polymer (B) shows a value obtained by measuring under the following conditions by a gel permeation chromatography (GPC) method.

Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation are connected in series for use.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSKgel G4000" (7.8 mm ID x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (Differential Refractometer)
Column temperature: 40 ° C
Eluent: tetrahydrofuran (THF)
Flow velocity: 1.0 mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: Prepare a calibration curve using the following standard polystyrene.

(Standard polystyrene)
"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

The content of the hydrophilic acrylic polymer (B) is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and further preferably 10 parts by mass or more with respect to 100 parts by mass of the urethane resin (A). Yes, preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less.

The metal oxide fine particles (D) are fine metal oxide fine particles, and in the present specification, the metal also includes a metalloid such as silicon, germanium, and antimony. As the metal oxide fine particles, silica fine particles, titanium oxide fine particles, aluminum oxide fine particles and zirconium oxide fine particles are preferable, and silica fine particles and aluminum oxide fine particles are more preferable.

The shape of the metal oxide fine particles (D) is preferably spherical, granular or lumpy, and more preferably spherical.

The metal oxide fine particles (D) may have a structure (independent structure) in which two or more metal oxide fine particles are independently present, and two or more metal oxide fine particles are connected in a row. It may form a structure (aggregate structure). Above all, it is preferable to form a structure (chain structure, pearl necklace structure, etc.) in which two or more metal oxide fine particles are connected in a row, and two or more metal oxide fine particles are joined in one plane. It is more preferable that a connected structure (pearl necklace structure) is formed. Specific examples of the structure include a chain structure or a pearl necklace structure, and a pearl necklace structure is preferable.
Examples of a structure in which two or more metal oxide fine particles are joined to form a structure connected in one plane include Snowtex (registered trademarks) ST-UP, ST-PS-S, and ST-PS-. Examples thereof include metal oxide fine particles contained in M, ST-OUP, ST-PS-SO, ST-PS-MO, and ST-AK-PS-S (all manufactured by Nissan Chemical Industries, Ltd.).

The average particle size of the metal oxide fine particles is preferably 1 nm or more, more preferably 5 nm or more, further preferably 10 nm or more, preferably 500 nm or less, more preferably 300 nm or less, still more preferably 200 nm or less, and more. It is more preferably 100 nm or less, particularly preferably 80 nm or less, and particularly preferably 50 nm or less. The average particle size of the metal oxide fine particles shall mean a 50% median diameter measured by a dynamic light scattering method.

The metal oxide fine particles (D) may be directly used for preparing an aqueous resin composition, or may be used as an aqueous dispersion containing the metal oxide fine particles and an aqueous medium in advance and then used for preparing an aqueous resin composition. .. As the aqueous medium, the same compounds as those exemplified as the aqueous medium (C) described later can be used.

From the viewpoint of improving the dispersibility in the aqueous resin composition, the metal oxide fine particles (D) may be surface-treated with the silane coupling agent or the like, and the aqueous dispersion may contain an acidic compound or a base. It may contain a sex compound. In particular, when the acrylic monomer (b1-4) contains an acrylic monomer having a sulfonic acid group, an acrylic monomer having a carboxy group, an acrylic monomer having a quaternary ammonium group, an acrylic monomer having an amino group, or the like, the metal oxide The fine particles (D) or the aqueous dispersion have the same charge as an acidic group (sulfonic acid group, carboxy group, etc.) or a basic group (quaternary ammonium group, amino group, etc.) derived from these monomers (acidic). It preferably contains a group or a basic group) or a compound (an acidic compound or a basic compound).

When the aqueous dispersion contains an acidic compound, the pH of the aqueous dispersion is preferably 1 or more and 6.5 or less, and more preferably 2 or more and 6 or less. When the aqueous dispersion contains a basic compound, the pH of the aqueous dispersion is preferably 8 or more and 12 or less, more preferably 9 or more and 11 or less.

The concentration of the metal oxide fine particles in the aqueous dispersion is preferably 10% by mass or more, more preferably 15% by mass or more, preferably 50% by mass or less, and more preferably 40% by mass or less.

The content of the metal oxide fine particles (D) is preferably 0.1 part by mass or more, more preferably 0.1 part by mass or more, based on 100 parts by mass of the total of the acrylic resin (A) and the hydrophilic acrylic polymer (B). It is 3 parts by mass or more, more preferably 5 parts by mass or more, preferably 50 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less.

Examples of the aqueous medium (C) include water, an organic solvent miscible with water, and a mixture thereof. As the organic solvent to be mixed with water, one kind or two or more kinds can be used, and for example, alcohols such as methanol, ethanol, n-propanol, isopropyl alcohol, 1,2-propylene glycol and 1,3-butylene glycol can be used. Solvents: Solvents such as acetone and methyl ethyl ketone; ethylene glycol-n-butyl ether, diethylene glycol-n-butyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene Glycol ether solvents such as glycol-n-butyl ether and tripropylene glycol methyl ether; lactam solvents such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; amide solvents such as N and N-dimethylformamide. Therefore, an alcohol solvent is preferable.

The aqueous medium (C) is preferably water alone or a mixture of water and an organic solvent miscible with water, and more preferably water alone, in consideration of safety and reduction of environmental load. The water content is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more in 100% by mass of the aqueous medium (C).

The content of the aqueous medium (C) is preferably 30% by mass or more and 80% by mass or less, and more preferably 50% by mass or more and 70% by mass or less, based on 100% by mass of the total amount of the aqueous resin composition.

The aqueous resin composition of the present invention further comprises a cross-linking agent, a surfactant, a plasticizer, an antistatic agent, a wax, a light stabilizer, a flow conditioner, a dye, a leveling agent, a rheology control agent, an ultraviolet absorber, and an antioxidant. , Photocatalytic compounds, inorganic pigments, organic pigments, extender pigments and other various additives may be contained.

By using the cross-linking agent, the durability of the coating film or film formed from the aqueous resin composition can be further improved. As the cross-linking agent, one kind or two or more kinds can be used, and examples thereof include amino resins, aziridine compounds, melamine compounds, epoxy compounds, oxazoline compounds, carbodiimide compounds and isocyanate compounds.

By using the surfactant, the dispersion stability of the aqueous resin composition can be further improved. When a surfactant is used, the content thereof is preferably 20 parts by mass or less with respect to 100 parts by mass of the urethane resin (A) from the viewpoint of maintaining the substrate adhesion and water resistance of the obtained coating film. , More preferably 10 parts by mass or less, still more preferably 1 part by mass or less.

The aqueous resin composition of the present invention may contain a curing agent and a curing catalyst, if necessary, as long as the effects of the present invention are not impaired.

Examples of the curing agent include a compound similar to the compound exemplified as the silane coupling agent (s2) (hereinafter, may be referred to as “silane coupling agent (s3)”), a polyepoxy compound, and a polycarbodiimide compound. , Polyoxazoline compounds, polyisocyanate compounds and the like.
The silane coupling agent (s3) is preferable as the curing agent from the viewpoint of forming a coating film having excellent durability, water resistance and substrate adhesion. When the aqueous resin composition of the present invention is used as a coating agent, the group represented by the formula (1) of the compound improves the adhesion to the substrate, and as a result, a coating film having excellent durability is obtained. Can be formed.

The silane coupling agent (s3) that can be used as the curing agent is γ-glycidoxypropyl from the viewpoint of improving the cross-linking density of the coating film and improving durability, water resistance and substrate adhesion. Trimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, Epoxy group-containing alkoxysilane compounds such as β- (3,4-epoxycyclohexyl) ethyltriethoxysilane; γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane , Γ-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane and other amino group-containing alkoxysilane compounds are preferable, and γ-glycidoxy One or more selected from the group consisting of propyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane is preferable.

The content of the curing agent (preferably the silane coupling agent (s3)) is from the viewpoint of obtaining the aqueous urethane resin composition of the present invention, which forms a coating film having excellent chemical resistance and has excellent storage stability. , 0.01% by mass or more and 10% by mass or less is preferable in 100% by mass of the total amount of the urethane resin (A).

Examples of the curing catalyst include lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methylate, tetraisopropyl titanate, tetra-n-butyl titanate, tin octylate, lead octylate, cobalt octylate, and zinc octylate. , Calcium octylate, zinc naphthenate, cobalt naphthenate, di-n-butyltin diacetate, di-n-butyltin dioctate, di-n-butyltin dilaurate, di-n-butyltin maleate, p-toluenesulfone Acids, trichloroacetic acid, phosphoric acid, monoalkyl phosphoric acid, dialkyl phosphoric acid, monoalkyl phosphite, dialkyl phosphite and the like can be used.

The aqueous resin composition of the present invention may contain an emulsifier, a dispersion stabilizer and a leveling agent, if necessary, but the water resistance of the coating film or film formed from the coating agent containing the aqueous resin composition of the present invention. From the viewpoint of suppressing deterioration of properties, it is preferably not contained as much as possible, and is preferably 0.5% by mass or less with respect to the non-volatile content of the aqueous resin composition.

The aqueous resin composition of the present invention includes a urethane resin (A), a hydrophilic acrylic polymer (B), metal oxide fine particles (D), an aqueous medium (C), and various additions used as necessary. It can be prepared by mixing an agent, a curing agent, a curing catalyst, or the like. After mixing the above components, the easily volatile components may be removed by vacuum distillation or the like.

The aqueous resin composition of the present invention can be used as a coating agent for the purpose of protecting the surface of various base materials and imparting design to various base materials.

Examples of the base material include metals, various plastics and films thereof, glass, paper, wood and the like.

Examples of the metal base material include galvanized steel sheets, aluminum-galvanized steel sheets, aluminum plates, aluminum alloy plates, phosphoric acid chromate-treated aluminum plates, electromagnetic steel plates, and copper plates used in applications such as automobiles, home appliances, and building materials. , Stainless steel plate and the like.

As the plastic base material, polyester resin and acrylonitrile-butadiene-styrene resin (ABS resin) are generally used as materials used for plastic molded products such as agricultural films, mobile phones, home appliances, automobile interior / exterior materials, and OA equipment. ), Polycarbonate resin (PC resin), ABS / PC resin, Polystyrene resin (PS resin), Polymethylmethacrylate resin (PMMA resin), Acrylic resin, Polypropylene resin, Polyethylene resin, Ethylene-vinyl acetate copolymer resin (EVA resin) ) And the like, and as the plastic film base material, a polyethylene terephthalate film, a polyester film, a polyethylene film, a polypropylene film, a TAC (triacetyl cellulose) film, a polycarbonate film, a polyvinyl chloride film and the like can be used.

The aqueous resin composition of the present invention can form a coating film having excellent hydrophilicity and heat resistance even when the film thickness is 5 μm or less, further 1 μm or less.

A coating film can be formed by applying the aqueous resin composition of the present invention and a coating agent containing the aqueous resin composition of the present invention onto a substrate, and drying and curing the obtained coating agent layer. The cured coating film thus obtained can be used as the film of the present invention.

In the drying step, the organic solvent volatilizes after the aqueous medium in the aqueous resin composition volatilizes. After volatilization of the aqueous medium, it is composed of an organic solvent, a urethane resin and a hydrophilic acrylic polymer, and the organic solvent promotes fusion of the urethane resin and the hydrophilic acrylic polymer, so that there are no coating defects. A coating film is formed.

Examples of the coating method include a spray method, a curtain coater method, a flow coater method, a roll coater method, a brush coating method, and a dipping method.

The drying may be natural drying at room temperature, but it may also be heat-dried. The heat drying is usually carried out at 40 ° C. or higher and 250 ° C. or lower for a time of about 1 second or longer and 600 seconds or lower.

When the base material is easily deformed by heat such as a plastic base material, the coating agent layer is preferably dried (cured) at a temperature of the glass transition temperature of the plastic base material or less, for example, 90 ° C. or less. It is preferable to dry at a drying temperature of 80 ° C. or lower, more preferably 60 ° C. or lower.

A film formed from a coating agent containing the aqueous resin composition of the present invention is also included in the technical scope of the present invention. The film thickness of the film is preferably 0.1 μm or more and 10 μm or less, more preferably 0.3 μm or more and 5 μm or less, and further preferably 0.5 μm or more and 3 μm or less.

Articles having a cured coating film of a coating agent using the aqueous resin composition of the present invention include, for example, agricultural films, aluminum fins, building materials, home appliances, automobile exterior materials, goggles, antifogging film sheets, and antifogging. Examples include glass, mirrors, medical instruments and the like.

Since the water-based resin composition of the present invention can form a cured coating film that can improve antifogging property and further improve heat resistance while maintaining adhesion to a base material, agricultural films, aluminum fins, and the like. It can be used for various articles such as building materials, home appliances, automobile exterior materials, goggles, antifogging film sheets, antifogging glass, mirrors, medical instruments, etc., and is particularly preferably used for agricultural films.

Hereinafter, the present invention will be described in more detail with reference to examples.

(Preparation Example 1: Preparation of Urethane Resin (A-1) Aqueous Dispersion)
A 4-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping device is charged with 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol and depressurized. It was dehydrated at 120 to 130 ° C. at 0.095 MPa. After dehydration, the mixture was cooled to 70 ° C., 50 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 26 parts by mass of 4,4'-dicyclohexylmethane diisocyanate (4,4'-H-MDI) and 0.1 part by mass of stannous octylate were added, and the mixture was reacted at 70 ° C. for 2 hours.

After completion of the reaction, 4 parts by mass of 2,2-dimethylolpropionic acid was added, the reaction was carried out for 4 hours, the mixture was cooled to 55 ° C., 36 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shinetsu Chemical Industry Co., Ltd.) 4 parts by mass of "KBE-903" manufactured by Co., Ltd.) was added and reacted for 1 hour to prepare a urethane prepolymer solution having a terminal isocyanate group.

Next, 3 parts by mass of triethylamine was added, and the mixture was held at 40 ° C. for 10 minutes, and then 291 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Next, 2 parts by mass of a 20 mass% ethylenediamine aqueous solution was added to the aqueous dispersion, and a chain extension reaction was carried out for 1 hour. By distilling this aqueous dispersion under reduced pressure, a urethane resin (A-1) aqueous dispersion having a non-volatile content of 30% by mass was obtained.

(Preparation Example 2: Preparation of Urethane Resin (A-2) Aqueous Dispersion)
A 4-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping device is charged with 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol and depressurized. It was dehydrated at 120 to 130 ° C. at 0.095 MPa. After dehydration, the mixture was cooled to 70 ° C., 47 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 16 parts by mass of hexamethylene diisocyanate and 0.1 part by mass of stannous octylate were added, and the mixture was reacted at 70 ° C. for 2 hours.

After completion of the reaction, 4 parts by mass of 2,2-dimethylolpropionic acid was added, and after reacting for 4 hours, the mixture was cooled to 55 ° C., 33 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shinetsu Chemical Industry Co., Ltd.) 4 parts by mass of "KBE-903" manufactured by Co., Ltd.) was added and reacted for 1 hour to prepare a urethane prepolymer solution having a terminal isocyanate group.

Next, 3 parts by mass of triethylamine was added, and the mixture was held at 40 ° C. for 10 minutes, and then 271 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Next, 2 parts by mass of a 20 mass% ethylenediamine aqueous solution was added to the aqueous dispersion, and a chain extension reaction was carried out for 1 hour. By distilling this aqueous dispersion under reduced pressure, a urethane resin (A-2) aqueous dispersion having a non-volatile content of 30% by mass was obtained.

(Preparation Example 3: Preparation of Urethane Resin (A-3) Aqueous Dispersion)
A 4-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping device is charged with 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol and depressurized. It was dehydrated at 120 to 130 ° C. at 0.095 MPa. After dehydration, the mixture was cooled to 70 ° C., 58 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 5 parts by mass of 1,4-cyclohexanedimethanol, 39 parts by mass of 4,4'-dicyclohexylmethane diisocyanate (4,4'-H-MDI) and 0.1 parts by mass of stannous octylate are added. , 70 ° C. for 2 hours.

After completion of the reaction, 5 parts by mass of 2,2-dimethylolpropionic acid was added, the reaction was carried out for 4 hours, the mixture was cooled to 55 ° C., 41 parts by mass of methylethylketone was added, and γ-aminopropyltriethoxysilane (Shinetsu Chemical Industry Co., Ltd.) "KBE-903" manufactured by Co., Ltd.) 12 parts by mass was added and reacted for 1 hour to prepare a urethane solution.

Next, 4 parts by mass of triethylamine was added, and the mixture was held at 40 ° C. for 10 minutes, and then 355 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. By distilling this aqueous dispersion under reduced pressure, a urethane resin (A-3) aqueous dispersion having a non-volatile content of 30% by mass was obtained.

(Preparation Example 4: Preparation of Urethane Resin (A-4) Aqueous Dispersion)
A 4-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping device is charged with 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol and depressurized. It was dehydrated at 120 to 130 ° C. at 0.095 MPa. After dehydration, the mixture was cooled to 70 ° C., 120 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 45 parts by mass of 1,4-cyclohexanedimethanol, 150 parts by mass of 4,4'-dicyclohexylmethane diisocyanate (4,4'-H-MDI) and 0.1 parts by mass of stannous octylate are added. , 70 ° C. for 2 hours.

After completion of the reaction, 14 parts by mass of 2,2-dimethylolpropionic acid was added, the mixture was reacted for 4 hours, cooled to 55 ° C., 86 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shinetsu Chemical Industry Co., Ltd.) 11 parts by mass of "KBE-903" manufactured by Co., Ltd.) was added and reacted for 1 hour to prepare a urethane prepolymer solution having a terminal isocyanate group.

Next, 10 parts by mass of triethylamine was added, and the mixture was held at 40 ° C. for 10 minutes, and then 690 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Next, 15 parts by mass of a 20 mass% ethylenediamine aqueous solution was added to the aqueous dispersion, and a chain extension reaction was carried out for 1 hour. By distilling this aqueous dispersion under reduced pressure, a urethane resin (A-4) aqueous dispersion having a non-volatile content of 30% by mass was obtained.

(Preparation Example 5: Preparation of Urethane Resin (A-5) Aqueous Dispersion)
A 4-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping device is charged with 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol and depressurized. It was dehydrated at 120 to 130 ° C. at 0.095 MPa. After dehydration, the mixture was cooled to 70 ° C., 178 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 84 parts by mass of 1,4-cyclohexanedimethanol, 252 parts by mass of 4,4'-dicyclohexylmethane diisocyanate (4,4'-H-MDI) and 0.1 parts by mass of stannous octylate were added. , 70 ° C. for 2 hours.

After completion of the reaction, 20 parts by mass of 2,2-dimethylolpropionic acid was added, the reaction was carried out for 4 hours, the mixture was cooled to 55 ° C., 127 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shinetsu Chemical Industry Co., Ltd.) 18 parts by mass of "KBE-903" manufactured by Co., Ltd.) was added and reacted for 1 hour to prepare a urethane prepolymer solution having a terminal isocyanate group.

Next, 15 parts by mass of triethylamine was added, and the mixture was held at 40 ° C. for 10 minutes, and then 1,025 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Next, 26 parts by mass of a 20 mass% ethylenediamine aqueous solution was added to the aqueous dispersion, and a chain extension reaction was carried out for 1 hour. By distilling this aqueous dispersion under reduced pressure, a urethane resin (A-5) aqueous dispersion having a non-volatile content of 30% by mass was obtained.

(Preparation Example 6: Preparation of Urethane Resin (A-6) Aqueous Dispersion)
A 4-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping device is charged with 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol and depressurized. It was dehydrated at 120 to 130 ° C. at 0.095 MPa. After dehydration, the mixture was cooled to 70 ° C., 50 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 25 parts by mass of 4,4'-dicyclohexylmethane diisocyanate (4,4'-H-MDI) and 0.1 part by mass of stannous octylate were added, and the mixture was reacted at 70 ° C. for 2 hours.

After completion of the reaction, 4 parts by mass of 2,2-dimethylolpropionic acid was added, the reaction was carried out for 4 hours, the mixture was cooled to 55 ° C., 36 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shinetsu Chemical Industry Co., Ltd.) 0.2 part by mass of "KBE-903" manufactured by Co., Ltd.) was added and reacted for 1 hour to prepare a urethane prepolymer solution having a terminal isocyanate group.

Next, 3 parts by mass of triethylamine was added, and the mixture was held at 40 ° C. for 10 minutes, and then 278 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Next, 3 parts by mass of a 20 mass% ethylenediamine aqueous solution was added to the aqueous dispersion, and a chain extension reaction was carried out for 1 hour. By distilling this aqueous dispersion under reduced pressure, a urethane resin (A-6) aqueous dispersion having a non-volatile content of 30% by mass was obtained.

(Comparative Preparation Example 1: Preparation of Urethane Resin (A'-1) Aqueous Dispersion)
A 4-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a dropping device is charged with 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol and depressurized. It was dehydrated at 120 to 130 ° C. at 0.095 MPa. After dehydration, the mixture was cooled to 70 ° C., 50 parts by mass of methyl ethyl ketone was added, and the mixture was sufficiently stirred and mixed while cooling to 50 ° C. After stirring and mixing, 25 parts by mass of 4,4'-dicyclohexylmethane diisocyanate (4,4'-H-MDI) and 0.1 part by mass of stannous octylate were added, and the mixture was reacted at 70 ° C. for 2 hours.

After completion of the reaction, 4 parts by mass of 2,2-dimethylolpropionic acid was added and reacted for 4 hours to prepare a urethane prepolymer solution having a terminal isocyanate group.

Next, 3 parts by mass of triethylamine was added, and the mixture was held at 40 ° C. for 10 minutes, and then 278 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Next, 3 parts by mass of a 20 mass% ethylenediamine aqueous solution was added to the aqueous dispersion, and a chain extension reaction was carried out for 1 hour. By distilling this aqueous dispersion under reduced pressure, a urethane resin (A'-1) aqueous dispersion having a non-volatile content of 30% by mass was obtained.

Table 1 shows the ratio of the alicyclic structure per non-volatile component of the urethane resin aqueous dispersions obtained in Preparation Examples 1 to 6 and Comparative Preparation Example 1 and the content of the group represented by the general formula (1).

(Preparation Example 7: Preparation of hydrophilic acrylic polymer (B-1))
30 parts by mass of isopropyl alcohol was charged into a 4-necked flask equipped with a thermometer, a stirrer, a reflux cooling tube and a dropping device, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.). 100 parts by mass of a mixture of "AM-90G" with an average addition molar number of oxyethylene groups of 9 mol) = 85/15 (molar ratio) and 2 parts by mass of γ-methacryloxypropyltriethoxysilane by 51 parts by mass of isopropyl alcohol. 20 parts by mass of the solution diluted with (1) and a 0.5 mass% isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) were added dropwise to a reactor at 80 ° C. for 4 hours. Radical polymerization was carried out to obtain a solution of the hydrophilic acrylic polymer (B-1) (nonvolatile content 50% by mass). The weight average molecular weight of the obtained hydrophilic acrylic polymer (B-1) was 20,000.

(Preparation Example 8: Preparation of Hydrophilic Acrylic Polymer (B-2))
30 parts by mass of isopropyl alcohol was charged into a 4-necked flask equipped with a thermometer, a stirrer, a reflux cooling tube and a dropping device, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.). "AM-90G", 100 parts by mass of a mixture of "AM-90G", an average addition molar number of oxyethylene groups of 9 mol) = 45/55 (molar ratio), and 2 parts by mass of γ-methacryloxypropyltriethoxysilane is 51 parts by mass of isopropyl alcohol. 20 parts by mass of the solution diluted with (1) and a 0.5 mass% isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) were added dropwise to a reactor at 80 ° C. for 4 hours. Radical polymerization was carried out to obtain a solution of the hydrophilic acrylic polymer (B-2) (nonvolatile content 50% by mass). The weight average molecular weight of the obtained hydrophilic acrylic polymer (B-2) was 20,000.

(Preparation Example 9: Preparation of hydrophilic acrylic polymer (B-3))
30 parts by mass of isopropyl alcohol was charged into a 4-necked flask equipped with a thermometer, a stirrer, a reflux cooling tube and a dropping device, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.). "AM-90G", 100 parts by mass of a mixture having an average addition molar number of oxyethylene groups of 9 mol) = 85/15 (molar ratio) and 25 parts by mass of γ-methacryloxypropyltriethoxysilane is 63 parts by mass of isopropyl alcohol. 20 parts by mass of the solution diluted with (1) and a 0.5 mass% isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) were added dropwise to a reactor at 80 ° C. for 4 hours. Radical polymerization was carried out to obtain a solution of the hydrophilic acrylic polymer (B-3) (nonvolatile content 50% by mass). The weight average molecular weight of the obtained hydrophilic acrylic polymer (B-3) was 20,000.

(Preparation Example 10: Preparation of hydrophilic acrylic polymer (B-4))
30 parts by mass of isopropyl alcohol was charged into a 4-necked flask equipped with a thermometer, a stirrer, a reflux cooling tube and a dropping device, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.). "AM-90G", 100 parts by mass of a mixture of "AM-90G", an average addition molar number of oxyethylene groups of 9 mol) = 85/15 (molar ratio), and 17 parts by mass of γ-methacryloxypropyltriethoxysilane is 59 parts by mass of isopropyl alcohol. 20 parts by mass of the solution diluted with (1) and a 0.5 mass% isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) were added dropwise to a reactor at 80 ° C. for 4 hours. Radical polymerization was carried out to obtain a solution of the hydrophilic acrylic polymer (B-4) (nonvolatile content 50% by mass). The weight average molecular weight of the obtained hydrophilic acrylic polymer (B-4) was 20,000.

(Preparation Example 11: Preparation of hydrophilic acrylic polymer (B-5))
30 parts by mass of isopropyl alcohol was charged into a 4-necked flask equipped with a thermometer, a stirrer, a reflux cooling tube and a dropping device, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.). 100 parts by mass of a mixture of "AM-90G", an average addition molar number of oxyethylene groups of 9 mol) = 95/5 (molar ratio), and 2 parts by mass of γ-methacryloxypropyltriethoxysilane is 51 parts by mass of isopropyl alcohol. 20 parts by mass of the solution diluted with (1) and a 0.5 mass% isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) were added dropwise to a reactor at 80 ° C. for 4 hours. Radical polymerization was carried out to obtain a solution (nonvolatile content: 50% by mass) of the hydrophilic acrylic polymer (B-5). The weight average molecular weight of the obtained hydrophilic acrylic polymer (B-5) was 20,000.

(Comparative Preparation Example 2: Preparation of Hydrophilic Acrylic Polymer (B'-1))
30 parts by mass of isopropyl alcohol was charged into a 4-necked flask equipped with a thermometer, a stirrer, a reflux cooling tube and a dropping device, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.). A solution obtained by diluting 100 parts by mass of a mixture of "AM-90G" with an average addition molar number of oxyethylene groups of 9 mol) = 85/15 (molar ratio) with 50 parts by mass of isopropyl alcohol and manufactured by Wako Pure Chemical Industries, Ltd. 20 parts by mass of a 0.5 mass% isopropyl alcohol solution of the azo polymerization initiator "V-59" was added dropwise to a reaction apparatus at 80 ° C. for 4 hours to carry out radical polymerization, and the hydrophilic acrylic polymer (B'-) was subjected to radical polymerization. A solution of 1) (nonvolatile content 50% by mass) was obtained. The weight average molecular weight of the obtained hydrophilic acrylic polymer (B'-1) was 20,000.

The molar ratios of the acrylic monomer (b1-1) and the acrylic monomer (b1-2) used in Preparation Examples 7 to 11 and Comparative Preparation Example 2 ((b1-1) / (b1-2)) and Preparation Examples 7 to 11 Table 2 shows the content of the group represented by the formula (1) of the hydrophilic acrylic polymer obtained in Comparative Preparation Example 2.

The abbreviations in Table 2 will be described.
"DMAA"; N, N-dimethylacrylamide "AM-90G"; methoxypolyethylene glycol acrylate ("AM-90G" manufactured by Shin Nakamura Chemical Industry Co., Ltd.)

(Examples 1 to 13, Comparative Examples 1 to 3: Preparation of aqueous resin compositions (1) to (13), (C1) to (C3))
A four-necked flask equipped with a thermometer, a stirrer, a reflux cooling tube, and a dropping device, an aqueous dispersion of urethane resin (A) (each having a non-volatile content of 30% by mass) and a hydrophilic acrylic weight shown in the table below. An aqueous dispersion of the solution of the coalescence (B) (each having a non-volatile content of 50% by mass) and the metal oxide fine particles (D), 30 parts by mass of 1,2-propylene glycol, and 30 parts by mass of 1,3-butylene glycol. An aqueous dispersion was obtained by adding 30 parts by mass of ion-exchanged water. The aqueous dispersion was distilled under reduced pressure to obtain aqueous resin compositions (1) to (13) and (C1) to (C3) having a non-volatile content of 30% by mass.

In Table 3, the types, structures, proportions and average particle diameters of the metal oxide fine particles (D-1) to (D-3) in the aqueous dispersions measured by the following methods are as follows. is there.

[Measurement method of average particle size of metal oxide fine particles]
An aqueous dispersion of metal oxide fine particles is diluted with water to obtain a diluted dispersion having a concentration of 0.1% by mass, and then the particle size measuring device (Nanotrack UPA-Ex150 manufactured by Nikkiso Co., Ltd.) is used. ": Calculated by dynamic light scattering method), and the 50% median diameter was taken as the average particle size.
There are two peaks in the particle size distribution of the aqueous dispersion of the metal oxide fine particles (D-1), and the numerical values in parentheses represent the mode of each peak.

[Evaluation method of substrate adhesion]
The aqueous resin compositions obtained in Examples and Comparative Examples were coated on each of the substrates shown below using a bar coater so that the film thickness after drying was about 1 μm. It was placed in a dryer at a temperature of 200 ° C. for 30 seconds to dry, and the plastic substrate was dried at 60 ° C. for 5 minutes to prepare a coating film. Then, it was cured at room temperature for 3 days to prepare a sample. A peeling test of 100 1 mm square cellophane tapes (registered trademark) was carried out on the surface of the obtained coating film according to JIS K-5400. The number of grids that did not peel off was measured and evaluated according to the following evaluation criteria. The metal base material used was an aluminum plate (AL plate) treated with phosphoric acid chromate, and the plastic base material used was a base material made of biaxially stretched polyethylene terephthalate resin (PET resin) and a polycarbonate resin (polycarbonate resin). A base material made of a PC resin) and a base material made of an ethylene-vinyl acetate copolymer resin (EVA resin).
A: The number of grids that did not peel off was 90 or more.
B: The number of non-peeling grids was 60 or more and less than 90. C: The number of non-peeling grids was 40 or more and less than 60.
D: The number of grids that did not peel off was less than 40.

[Evaluation method of anti-fog property]
The aqueous resin compositions obtained in Examples and Comparative Examples are coated on a base material made of biaxially stretched polyethylene terephthalate resin (PET resin) using a bar coater so that the film thickness after drying is about 1 μm. It was processed and dried at 60 ° C. for 5 minutes to prepare a coating film. Then, it was cured at room temperature for 3 days to prepare a sample. Next, the sample was placed at a position of 3 cm on the water surface of 90 ° C. so that the coating film surface of the obtained specimen faced downward, and the antifogging property was evaluated from the state of the coating film surface after 10 seconds. Evaluated according to criteria.
A: The surface of the coating film was not cloudy at all.
B: A slight cloudiness was observed on one mass part of the surface of the coating film, but it was at a level where there was no problem in practical use.
C: The surface of the coating film becomes cloudy as a whole, but when the specimen is removed from the water surface, it returns to transparent in less than 10 seconds.
D: The surface of the coating film is totally cloudy, and it takes 10 seconds or more for the cloudiness to disappear even if the sample is removed from the water surface.

[Evaluation method of heat resistance]
The aqueous resin compositions obtained in Examples and Comparative Examples are coated on a base material made of biaxially stretched polyethylene terephthalate resin (PET resin) using a bar coater so that the film thickness after drying is about 1 μm. It was processed and dried at 60 ° C. for 5 minutes to prepare a coating film. Then, it was cured at room temperature for 3 days to prepare a sample. Next, the water contact angle after being immersed in water at 60 ° C. for 8 hours and dried at room temperature for 1 day was evaluated according to the following evaluation criteria.
A: The water contact angle of the coating film was less than 20 °.
B: The water contact angle of the coating film was 20 ° or more and less than 30 °.
C: The water contact angle of the coating film was 30 ° or more and less than 40 °.
D: The water contact angle of the coating film was 40 ° or more.

[Evaluation method of blocking resistance]
The aqueous resin compositions obtained in Examples and Comparative Examples were dried using a bar coater on a base material made of a phosphoric acid chromate-treated aluminum plate (AL plate) so that the film thickness after drying was about 1 μm. The coating was applied and dried at 200 ° C. for 30 seconds to prepare a coating film. Then, it was cured at room temperature for 3 days to prepare a sample. Next, the coated surfaces of the obtained specimens were overlapped and held at a predetermined temperature for 5 minutes while ^{applying a pressure of 100 kg / cm 2 (10 MPa).} After cooling to room temperature, the blocking resistance temperature at which the specimens were not attached was evaluated according to the following evaluation criteria.
A: The blocking temperature of the coating film was 60 ° C. or higher.
B: The blocking resistance temperature of the coating film was 50 ° C. or higher and lower than 60 ° C.
C: The blocking resistance temperature of the coating film was 40 ° C. or higher and lower than 50 ° C.
D: The blocking resistance temperature of the coating film was less than 40 ° C.

Urethane resin (A) aqueous dispersion and hydrophilic acrylic polymer (B) in the aqueous resin compositions (1) to (13), (C1) to (C3) prepared in Examples 1 to 13 and Comparative Examples 1 to 3. Table 5 shows the non-volatile contents of the solution and the aqueous dispersion of the metal oxide fine particles (D), and the evaluation results of the aqueous resin compositions (1) to (13) and (C1) to (C3).

A urethane resin (A) having a group represented by the general formula (1), a hydrophilic acrylic polymer (B) having a group represented by the general formula (1), and metal oxide fine particles (D). When the aqueous resin compositions of Examples 1 to 13 containing the aqueous medium (C) are used, the antifogging property can be improved while maintaining the adhesion to the base material, and the heat resistance and water resistance can be further improved. It was confirmed that it is possible to form a coating film with improved blocking resistance.

The aqueous resin composition of Comparative Example 1 was an example in which an aqueous resin composition containing no metal oxide fine particles (D) was used, and it was confirmed that the aqueous resin composition was inferior in heat resistance and blocking resistance.

The aqueous resin composition of Comparative Example 2 is an example using an aqueous resin composition containing a hydrophilic acrylic polymer (B) having no group represented by the general formula (1), and has a substrate adhesion. It was confirmed that it was inferior in antifogging property and heat resistance and water resistance.

The aqueous resin composition of Comparative Example 3 is an example using an aqueous resin composition containing a urethane resin (A) having no group represented by the general formula (1), and has substrate adhesion and antifogging property. , It was confirmed that it was inferior in heat resistance and water resistance.

Claims (13)

A urethane resin (A) having a group represented by the following general formula (1), a hydrophilic acrylic polymer (B) having a group represented by the following general formula (1), and metal oxide fine particles (D). When, viewed contains an aqueous medium (C), wherein the content of groups represented by the above general formula (1) wherein the urethane resin (a) has is equal to or less than 5 mmol / kg or more 500 mmol / kg Aqueous resin composition.

[In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 or more and 4 or less carbon atoms.
R ² represents an alkyl group having 1 or more carbon atoms and 4 or less carbon atoms. a represents an integer of 1 or more and 3 or less. ] The aqueous resin composition according to claim 1, wherein the metal oxide fine particles (D) are one or more selected from the group consisting of silica fine particles, titanium oxide fine particles, aluminum oxide fine particles, and zirconium oxide fine particles. The aqueous resin composition according to claim 1 or 2, wherein the metal oxide fine particles (D) form a structure in which two or more metal oxide fine particles are joined to form a connected structure in one plane. The aqueous resin composition according to any one of claims 1 to 3, wherein the metal oxide fine particles (D) have an average particle size of 1 nm or more and 500 nm or less. The content of the metal oxide fine particles (D) is 0.1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass in total of the acrylic resin (A) and the hydrophilic acrylic polymer (B). The aqueous resin composition according to any one of claims 1 to 4. The hydrophilic acrylic polymer (B) is an acrylic monomer (b1-1) having an amide group.
A unit derived from, a unit derived from an acrylic monomer (b1-2) having an oxyethylene group, and a unit derived from an acrylic monomer (b1-3) having a group represented by the general formula (1). The aqueous resin composition according to any one of claims 1 to 5, which comprises. The molar ratio of the unit derived from the acrylic monomer (b1-1) having an amide group to the unit derived from the acrylic monomer (b1-2) having an oxyethylene group ((b1-1) / (b1-2)). The aqueous resin composition according to claim 6, wherein the amount is 99/1 or more and 50/50 or less. The content of the group represented by the general formula (1) contained in the hydrophilic acrylic polymer (B) is
The aqueous resin composition according to any one of claims 1 to 7, which is 5 mmol / kg or more and 600 mmol / kg or less in the hydrophilic acrylic polymer (B). A coating agent comprising the aqueous resin composition according to any one of claims 1 to 8. The coating agent according to claim 9, which is used for an agricultural film. A coating film formed from the coating agent according to claim 9 or 10. An article comprising a coating film of the coating agent according to claim 9 or 10. An agricultural film comprising a coating film of the coating agent according to claim 9 or 10.