JP2019011394A - Aqueous resin composition, coating agent and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous resin composition capable of improving antifogging property while maintaining the adhesiveness to a substrate, and further capable of forming a coating film having improved hot water resistance. To do. The aqueous resin composition of the present invention comprises a urethane resin (A) having a group represented by the following general formula (1) and a hydrophilic acrylic polymer having a group represented by the following general formula (1). It is characterized by containing a coalesced (B), metal oxide fine particles (D), and an aqueous medium (C). [In the general formula (1), R1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R2 represents an alkyl group having 1 to 4 carbon atoms. a represents an integer of 1 or more and 3 or less. ] [Selection diagram] None

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 capable of forming a coating film capable of preventing the deterioration of the surface of various base materials and to impart design properties to the surface of the base material. When used outdoors, it has hydrophilicity and adhesion to the base material, and further deteriorates the surface of the base material caused by water and oil stains, chemicals such as cleaning agents, and adhesion of acid rain. It must be preventable. In recent years, in various fields such as agriculture, manufacturing, construction, and industrial production, there has been a demand for a coating agent that can form a coating film with excellent hydrophilic sustainability. There is an increasing demand for surface treatment applications of base materials, glass base materials including mirrors, and plastic base materials referred to as hard-to-adhere base materials.

  In particular, in the agricultural industry, house cultivation, tunnel cultivation, etc., where plants are cultivated by securing sunlight irradiation while maintaining the internal temperature with agricultural films such as vinyl chloride resin film and polyolefin resin film, etc. are performed, Such agricultural films are surface-coated for the purpose of imparting antifogging properties and the like.

  As a coating film of the coating agent used on the substrate surface, an antifogging coating film formed from a composition containing an alkoxysilane compound on a lower layer coating film formed from a composition containing a synthetic resin binder and an inorganic colloid sol. Has been proposed (see, for example, Patent Document 1). Further, an antifogging coating composition containing a (meth) acrylic acid copolymer, a hydrophilic inorganic substance, and an aqueous resin has been proposed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 2008-067645 JP 2005-248091 A

  However, the coating films described in Patent Documents 1 and 2 sometimes have insufficient adhesion to the substrate and hot water resistance. The problem to be solved by the present invention is to provide an aqueous resin composition capable of improving the antifogging property while maintaining the adhesion to the substrate, and further capable of forming a coating film with improved hot water resistance. It is.

  As a result of intensive studies 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. Furthermore, it has been found that by adding metal oxide fine particles to the aqueous resin composition, the antifogging property can be improved while maintaining the adhesion to the base material, and the hot water resistance can also be improved. The present invention has been completed.

  That is, the present invention relates to 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. A water-based resin composition comprising fine particles (D) and an aqueous medium (C), a coating agent comprising the aqueous resin composition, and a coating agent comprising the aqueous resin composition It is related with the agricultural film characterized by having the coating film made from, the article | item characterized by having the coating film of the said coating agent, and the coating film of the said 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 General Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² represents an alkyl group having 1 to 4 carbon atoms. a represents an integer of 1 to 3. ]

By using the aqueous resin composition of the present invention, it is possible to provide a coating film that can improve the antifogging property while maintaining the adhesion to the base material and can also improve the hot water resistance.
Examples of the substrate to which the coating agent of the present invention can be applied include metal substrates such as galvanized steel sheets, aluminum-galvanized steel sheets, aluminum sheets, aluminum alloy sheets, electromagnetic steel sheets, copper sheets, and stainless steel sheets; polyester resins, polycarbonates Various plastics such as resin, ethylene-vinyl acetate copolymer resin (EVA resin) and films thereof; glass; paper; wood and the like. Moreover, since the coating agent of the present invention can form a coating film excellent in hydrophilic durability and chemical resistance capable of preventing the deterioration of the surface of these base materials, it is used for agricultural films, aluminum fins, building members, and home appliances. 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 sometimes referred to as “urethane resin (A)”), and a general formula (1). A hydrophilic acrylic polymer (B) having a group represented by the formula (hereinafter sometimes referred to as “hydrophilic acrylic polymer (B)”), metal oxide fine particles (D), and an aqueous medium (C ).

［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 General Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² represents an alkyl group having 1 to 4 carbon atoms. a represents an integer of 1 to 3. ]

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ¹ or R ² include a methyl group, an ethyl group, a propyl group, and a butyl group, and a carbon atom such as a methyl group and an ethyl group. An alkyl group having a number of 1 or more and 2 or less is preferred.

  The urethane resin (A) includes, for example, a urethane prepolymer (a1) having an isocyanate group at a terminal (hereinafter sometimes referred to as “urethane prepolymer (a1)”); at least one active hydrogen and at least one. It can be obtained by reacting two compounds (s1) having a group represented by the general formula (1) (hereinafter sometimes referred to as “silane compound (s1)”). The urethane resin (A) introduces a functional group such as a hydroxyl group, a carboxy group, an epoxy group, or a (meth) acryloyl group into the urethane prepolymer (a1) or the urethane prepolymer (a2) having no isocyanate group. It can also be obtained by reacting the silane coupling agent (s2).

  As said urethane prepolymer (a1), what was obtained by making a polyol (a1-1) and polyisocyanate (a1-2) react can be used.

As said polyol (a1-1), 1 type (s) or 2 or more types can be used, For example, polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol etc. are mentioned. Among these, it is preferable that polyester polyol and polycarbonate polyol are included because a coating film excellent in substrate adhesion can be formed.
From the viewpoint of further improving the substrate adhesion, the polyol has a number average molecular weight of preferably 500 or more and 3,000 or less.

  Examples of the polyether polyol include those obtained by addition polymerization (ring-opening polymerization) of 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, 1,4- Linear diols such as butanediol and 1,6-hexanediol; branched diols such as neopentyl glycol; triols such as glycerin, trimethylolethane, trimethylolpropane, and pyrogallol; polyols such as sorbitol, sucrose, and aconite sugar Tricarboxylic acids such as aconitic acid, trimellitic acid and hemimellitic acid; phosphoric acid; polyamines such as ethylenediamine and diethylenetriamine; triisopropanolamine; phenolic acids such as dihydroxybenzoic acid and hydroxyphthalic acid; Such as bread birds thiol, and the like.

  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.

  Examples of the polyester polyol include polyester polyols obtained by esterifying low molecular weight polyols (for example, polyols having a molecular weight of 50 to 300) and polycarboxylic acids; ring-opening polymerization of cyclic ester compounds such as ε-caprolactone. Polyester polyols obtained by reaction; these copolyester polyols and the like can be mentioned.

  As the low molecular weight polyol, a polyol having a molecular weight of about 50 to 300 can be used. For example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol Aliphatic polyols having 2 to 6 carbon atoms, such as 3-methyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol; 1,4-cyclohexanediol, cyclohexane Examples include 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.

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

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

  Examples of the carbonate 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 carbonate ester include polyols exemplified as the low molecular weight polyols; high molecular weight polyols (weight) such as polyether polyols (polyethylene glycol, polypropylene glycol, etc.), polyester polyols (polyhexamethylene adipate, etc.) Average molecular weight of 500 or more and 5,000 or less).

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

  The total content of the polyether polyol, polyester polyol, polycarbonate polyol and 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.

  Moreover, as said polyol (a1-1), it is preferable to use combining the polyol which has a hydrophilic group further from a viewpoint which provides favorable water dispersion stability to the said urethane resin (A).

  As the polyol having a hydrophilic group, for example, a polyol other than the polyether polyol, polyester polyol, polycarbonate polyol and polyolefin polyol can be used. Specifically, a polyol having an anionic group and a cationic group can be used. The polyol which has and the polyol which has 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; and Examples 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, in a total of 100 parts by mass of the polyol (a1-1). It is preferably 20 parts by mass or less, more preferably 10 parts by mass or less.

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

When using the polyol having a carboxy group or the polyol having a sulfonic acid group, 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 as used herein refers to 1 g of the urethane resin (A) based on the amount of the 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). It is a theoretical value calculated as the number of mg of potassium hydroxide necessary for summing.

  From the viewpoint of expressing good water dispersibility, part or all of the anionic group is preferably neutralized with a basic compound or the like.

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

  The tertiary amino group as the cationic group is partly or wholly composed of carboxylic acid such as formic acid, acetic acid, propionic acid, succinic acid, glutaric acid and adipic acid; hydroxy acid such as tartaric acid; acidic acid such as phosphoric acid It is preferably neutralized with a compound.

  The tertiary amino group as the cationic group is preferably a part or all of which 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 the 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, more preferably 5 mgKOH / g or more and 30 mgKOH / g or less. The amine value referred to in the present invention is based on the amount of the tertiary amino group-containing compound such as a polyol having a tertiary amino group used in the production of the urethane resin (A). This is a theoretical value calculated as the product of the number of moles of hydrogen chloride (mmol) necessary for the summation and the formula weight 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, and further preferably 5% by mass or more, in a total of 100% by mass of the polyol (a1-1). Preferably, it is 30 mass% or less, More preferably, it is 20 mass% or less, More preferably, it is 10 mass% or less.

  As said polyol (a1-1), you may use another polyol other than the said polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, and the polyol which has a hydrophilic group as needed.

  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, etc. (for example, molecular weight 50 to 300) ) Polyol.

  As the polyisocyanate (a1-2) capable of reacting with the polyol (a1-1), one or more kinds can be used. For example, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate. , Aromatic diisocyanates such as carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, triene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate; cyclohexane diisocyanate , Hydrogenated xylylene diisocyanate, isophorone diisocyanate, dicyclo Alicyclic structure-containing polyisocyanates such as cyclohexyl methane diisocyanate.

  The urethane prepolymer (a1) having the isocyanate group is produced, for example, by reacting the polyol (a1-1) and 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 for adding a chain extender described later may be performed.

  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 between 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 reaction is preferably 3,500 g / eq., Because a coating film having excellent durability can be formed. 100,000 g / eq. Or less, more preferably 10,000 g / eq. 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; Nitrile solvents; amide solvents such as dimethylformamide and N-methylpyrrolidone. These organic solvents can be used alone or in combination of two or more.

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

  Examples of the compound (s1) having a group represented by the general formula (1) include γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, amino group-containing alkoxysilane compounds such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane; γ-hydroxypropyltrimethoxysilane, γ Examples include hydroxyl group-containing alkoxysilane compounds such as hydroxypropyltriethoxysilane; 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 equivalent to the isocyanate group of the polyisocyanate (a1-2) [isocyanate group / hydroxyl group]. For example, a urethane prepolymer in which a hydroxyl group remains, a urethane prepolymer obtained by adding a chain extender and the like, and a urethane prepolymer obtained by adding a chain extender. Can use polyamines, hydrazine compounds, other active hydrogen atom-containing compounds, and the like.

  As said polyamine, 1 type (s) or 2 or more types 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 Examples include propylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, triethylenetetramine and the like.

  As said hydrazine compound, 1 type (s) or 2 or more types can be used, for example, hydrazine, N, N'-dimethylhydrazine, 1, 6-hexamethylene bishydrazine; succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide , Sebacic acid dihydrazide, isophthalic acid dihydrazide; β-semicarbazide propionic acid hydrazide and the like.

  As said other active hydrogen containing compound, 1 type (s) or 2 or more types can be used, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, , 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 phenols such as hydrogenated bisphenol A and hydroquinone, water, and the like, and they can be used within the range in which the storage stability of the aqueous resin composition of the present invention does not deteriorate.

  As said silane coupling agent (s2), 1 type (s) or 2 or more types can be used, for example, (gamma) -glycidoxypropyl trimethoxysilane, (gamma) -glycidoxypropyl triethoxysilane, (gamma) -glycidoxy Contains epoxy groups such as propylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane Alkoxysilane compounds; γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane Isocyanate group-containing alkoxysilane compounds such as lan, γ-isocyanatopropylethyldiethoxysilane, γ-isocyanatopropyltrichlorosilane; γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyl Amino group-containing alkoxysilane compounds such as trimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane; γ- (meth) Acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane (Meth) acryloyl group-containing alkoxysilane compounds such as vinyl; vinyl group-containing alkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane; styryl group-containing alkoxysilanes such as p-styryltrimethoxysilane and p-styryltriethoxysilane Etc.

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

  Examples of the ring included in the alicyclic structure include monocyclic rings such as a cyclobutyl ring, a cyclopentyl ring, a cyclohexyl ring, a cycloheptyl ring, a cyclooctyl ring, and a 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 include a ring, a bridged ring such as a dicyclopentanyl ring and an adamantyl ring. Among these, a monocyclic structure is preferable and a cyclohexyl ring structure is preferable.

  The alicyclic structure includes the alicyclic structure-containing polyol and / or the alicyclic structure-containing polyisocyanate (hereinafter referred to as alicyclic) as a component for forming the urethane prepolymer (a1) or the urethane prepolymer (a2). The structure-containing polyol and the alicyclic structure-containing polyisocyanate may be collectively referred to as “alicyclic structure-containing compound”), and the alicyclic structure-containing polyisocyanate may be used. It is preferable that it is 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 excellent in chemical resistance. / Kg to 5,000 mmol / kg, more preferably 1,000 mmol / kg to 3,000 mmol / kg.
The content of the alicyclic structure referred to in the present invention is the total mass of the polyol (a1-1) and polyisocyanate (a1-2) used in the production of the urethane resin (A), and the urethane resin (A). It is the value computed based on the substance amount of the alicyclic structure which the alicyclic structure containing compound used for manufacture has.

  The content of the group represented by the general formula (1) of the urethane resin (A) is preferably in the urethane resin (A) from the viewpoint of improving hydrophilic durability, chemical resistance, and substrate adhesion. Is at least 5 mmol / kg, more preferably at least 10 mmol / kg, even more preferably at least 50 mmol / kg, even more preferably at least 100 mmol / kg, preferably at most 500 mmol / kg, more preferably at most 300 mmol / kg, even 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, and still more preferably 65% in 100% by mass of the nonvolatile content of the aqueous resin composition. It is 95 mass% or more, Preferably it is 95 mass% or less, More preferably, it is 85 mass% or less, More preferably, it is 80 mass% or less.
In the present specification, the “nonvolatile content of the aqueous resin composition” refers to an amount obtained by removing 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 sometimes referred to as “hydrophilic acrylic polymer (B)”) is an acrylic monomer (b1) having an amide group. -1) (hereinafter sometimes referred to as “acrylic monomer (b1-1)”) and an acrylic monomer (b1-2) having an oxyethylene group (hereinafter referred to as “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.

  “Hydrophilic” of the hydrophilic acrylic polymer (B) means that it has an affinity for 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 still more preferably 20% by mass or more.

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

[In General Formula (2), R ³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ⁴ represents an alkyl group having 1 to 3 carbon atoms, — (CH ₂ ) ₃ —N (CH ₃ ) ₂ or — (CH ₂ ) ₃ —N (CH ₃ ) ₂ methyl chloride. ]

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

  Moreover, as an acrylic monomer (b1-1) which has the said amide group, the compound represented by following General formula (3) can be used, for example.

［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 General Formula (3), R ⁵ and R ⁶ each independently represent an alkylene group having 1 to 3 carbon atoms. ]

  Examples of the compound represented by the general formula (3) include N-acryloylmorpholine.

  As the acrylic monomer (b1-2) having the oxyethylene group, one or more kinds can be used. For example, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, polyethylene glycol polypropylene glycol Examples thereof include polymerization (meth) acrylate, methoxypolyethylene glycol polypropylene glycol copolymerization (meth) acrylate, polyethylene glycol polytetramethylene glycol copolymerization (meth) acrylate, and methoxypolyethylene glycol polytetramethylene glycol copolymerization (meth) acrylate.

  As an acrylic monomer (b1-3) which has group represented by the said General formula (1), 1 type (s) or 2 or more types can be used, for example, vinyl groups, such as vinyltrimethoxysilane and vinyltriethoxysilane -Containing alkoxysilane compounds; styryl group-containing alkoxysilane compounds such as p-styryltrimethoxysilane and p-styryltriethoxysilane; γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane And (meth) 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 100% by mass in 100% by mass of the hydrophilic acrylic copolymer (B). As mentioned above, More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more.

  The ratio ((b1-1) / (b1-2)) of the unit derived from the acrylic monomer (b1-1) having the amide group and the unit derived from the acrylic monomer (b1-2) having an oxyethylene group is From the viewpoint of maintaining a high level of hydrophilicity and hydrophilic sustainability, 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 hydrophilic sustainability. It is 70/30 or more.

  The content of the unit derived from the acrylic monomer (b1-3) having the group represented by the general formula (1) is the unit derived from the acrylic monomer (b1-1) having the amide group and the oxyethylene group. Preferably, it is 0.1 mol or more, more preferably 0.3 mol or more, still more preferably 0.5 mol or more, with respect to a total of 100 mol of 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.

  Moreover, the average addition mole number of the oxyethylene group in the acrylic monomer (b1-2) having the oxyethylene group is preferably 5 or more and 13 mol or less, more preferably 8 or more and 10 mol or less, from the viewpoint of hydrophilic sustainability. 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) as necessary. The unit derived from 4) may be included.

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

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

  As an acrylic monomer which has the said carboxy group, 1 type (s) or 2 or more types can be used, for example, (meth) acrylic acid, propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, crotonic acid, fumaric acid, etc. Is 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, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, etc. are mentioned.

  As the acrylic monomer having a quaternary ammonium group, one 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 or more kinds can be used. For example, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert-butylaminoethyl (meth) acrylate , (Meth) acryloxyethyltrimethylammonium chloride, and the like.

  As said acrylic monomer which has a cyano group, 1 type (s) or 2 or more types can be used, for example, (meth) acrylonitrile, cyanomethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, cyanopropyl (meth) acrylate, 1-cyanomethylethyl (meth) acrylate, 2-cyanopropyl (meth) acrylate, 1-cyanocyclopropyl (meth) acrylate, 1-cyanocycloheptyl (meth) acrylate, 1,1-dicyanoethyl (meth) acrylate, Examples include 2-cyanophenyl (meth) acrylate, 3-cyanophenyl (meth) acrylate, 4-cyanophenyl (meth) acrylate, 3-cyanobenzyl (meth) acrylate, 4-cyanobenzyl (meth) acrylate, and the like.

  As the acrylic monomer having an imide group, one or more kinds can be used. For example, (meth) acrylimide, N-methylol maleimide, N-hydroxyethyl maleimide, N-glycidyl maleimide, N-4- Examples include chloromethylphenylmaleimide and N-acetoxyethylmaleimide.

  As said acrylic monomer which has a methoxy group, 1 type (s) or 2 or more types can be used, for example, 3-methoxybutyl (meth) acrylate), 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) Examples include acrylate and 2-methoxybutyl (meth) acrylate.

  As said radically polymerizable monomer, 1 type (s) or 2 or more types 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, tri Aliphatic (meth) acrylates such as syl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, neopentyl (meth) acrylate, hexadecyl (meth) acrylate, and isoamyl (meth) acrylate; isobornyl (meth) acrylate , Cycloaliphatic (meth) acrylates such as cyclohexyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate; benzyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl (meth) acrylate, etc. Aromatic (meth) acrylates such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, etc. A vinyl compound etc. are mentioned.

  Content of group represented by the said General formula (1) which the said hydrophilic acrylic resin (B) has is the said acrylic resin (B from a viewpoint of forming the coating film excellent in hydrophilic sustainability and base-material adhesiveness. ), 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, it is 800 mmol / kg or less, and still 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. And a method of radical polymerization together with the acrylic monomer (b1-4) used as necessary in the presence of an agent and a reaction solvent.

As said polymerization initiator, 1 type (s) or 2 or more types 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 cumene hydroperoxide; 2,2′-azobis- (2-aminodipropane) dihydrochloride, 2,2′-azobis- (N, N′-dimethylene) Isobutylamidine) dihydrochloride, azo compounds such as azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleric acid nitrile), etc. Is mentioned.
The amount of the polymerization initiator used is the acrylic monomers (b1-1), (b1-2) and (b1-3), which are raw materials for the hydrophilic acrylic polymer (B), and the acrylic monomer used as necessary. It is preferable that it is 0.001 mass part or more and 5 mass parts or less with respect to a total of 100 mass parts of (b1-4).

  As the reaction solvent, water and / or an organic solvent can be used. As the organic solvent, one 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, Examples include 3-pentanone, acetonitrile, isopropyl alcohol, 1,2-propanediol, 1,3-butanediol. The amount of the organic solvent used is, for example, a total of 100 parts by mass of the acrylic monomers (b1-1), (b1-2) and (b1-3) and the acrylic monomers (b1-4) used as necessary. On the other hand, it is preferable that it is 10 to 500 mass parts.

  The reaction temperature is preferably 40 ° C. or more and 90 ° C. or less, and the reaction time is preferably 1 hour or more and 10 hours or less.

  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) is a value obtained by measurement under the following conditions by 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 used in series.
"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 Book “TSKgel G2000” (7.8 mm ID × 30 cm) × 1 Detector: RI (differential refractometer)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%)
Standard sample: A calibration curve is prepared 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, and still more preferably 40 parts by mass or less.

  The metal oxide fine particles (D) are metal oxide fine particles, and in the present specification, the metal includes semimetals 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 massive, 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 exist independently, and two or more metal oxide fine particles are joined together. The structure which formed the structure (gathering structure) may be sufficient. Among them, it is preferable to form a structure (chain structure, pearl necklace structure, etc.) in which two or more metal oxide fine particles are joined together in a single plane by joining two or more metal oxide fine particles. It is more preferable to form a connected structure (pearl necklace structure). Specific examples of the structure include a chain structure or a pearl necklace structure, and a pearl necklace structure is preferable.
As what forms the structure connected in one plane by joining two or more metal oxide fine particles, for example, Snowtex (registered trademark) ST-UP, ST-PS-S, ST-PS- Metal oxide fine particles contained in M, ST-OUP, ST-PS-SO, ST-PS-MO, ST-AK-PS-S (manufactured by Nissan Chemical Industries, Ltd.).

  The average particle diameter 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 More preferably, it is 100 nm or less, Especially preferably, it is 80 nm or less, Most preferably, it is 50 nm or less. The average particle diameter of the metal oxide fine particles means a 50% median diameter measured by a dynamic light scattering method.

  The metal oxide fine particles (D) may be directly used for preparation of an aqueous resin composition, or may be used for preparation of an aqueous resin composition after an aqueous dispersion containing metal oxide fine particles and an aqueous medium in advance. . As said aqueous medium, the compound similar to the compound illustrated as an aqueous medium (C) mentioned later can be used.

  From the viewpoint of improving 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 contains an acidic compound or a base. An organic compound may be contained. In particular, when the acrylic monomer (b1-4) includes 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, etc., the metal oxide The fine particles (D) or the aqueous dispersion are acidic groups (sulfonic acid groups, carboxy groups, etc.) derived from these monomers or groups (acidic groups) having the same charge as basic groups (quaternary ammonium groups, amino groups, etc.). Group or basic group) or a compound (an acidic compound or a basic compound) is preferable.

  When the aqueous dispersion contains an acidic compound, the pH of the aqueous dispersion is preferably 1 or more and 6.5 or less, 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, more preferably 40% by mass or less.

  The content of the metal oxide fine particles (D) is preferably 0.1 parts by mass or more, more preferably with respect to a total of 100 parts by mass 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, organic solvents miscible with water, and mixtures thereof. As the organic solvent miscible with water, one or more kinds can be used. For example, alcohols such as methanol, ethanol, n-propanol, isopropyl alcohol, 1,2-propylene glycol, and 1,3-butylene glycol Solvents; Ketone 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; N-methyl- - pyrrolidone, lactam solvent such as N- ethyl-2-pyrrolidone; N, N- such amide solvents such as dimethylformamide and the like, alcohol solvents are preferred.

  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 environmental load reduction. The content of water is preferably 50% by mass or more, more preferably 60% by mass or more, and 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, more preferably 50% by mass or more and 70% by mass or less in the total amount of 100% by mass of the aqueous resin composition.

  The aqueous resin composition of the present invention further comprises a crosslinking agent, a surfactant, a plasticizer, an antistatic agent, a wax, a light stabilizer, a flow regulator, a dye, a leveling agent, a rheology control agent, an ultraviolet absorber, and an antioxidant. And various additives such as a photocatalytic compound, an inorganic pigment, an organic pigment, and an extender pigment.

  By using the said crosslinking agent, durability of the coating film and film formed from an aqueous resin composition can be improved more. As said crosslinking agent, 1 type (s) or 2 or more types can be used, For example, an amino resin, an aziridine compound, a melamine compound, an epoxy compound, an oxazoline compound, a carbodiimide compound, an isocyanate compound etc. are mentioned.

  By using the surfactant, the dispersion stability of the aqueous resin composition can be further improved. When using a surfactant, the content 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 resulting coating film. More preferably, it is 10 mass parts or less, More preferably, it is 1 mass part or less.

  The aqueous resin composition of the present invention may contain a curing agent and a curing catalyst as necessary within a range not impairing the effects of the present invention.

Examples of the curing agent include compounds similar to those exemplified as the silane coupling agent (s2) (hereinafter sometimes referred to as “silane coupling agent (s3)”), polyepoxy compounds, and polycarbodiimide compounds. , Polyoxazoline compounds and polyisocyanate compounds.
From the viewpoint of forming a coating film excellent in durability, water resistance and substrate adhesion, the silane coupling agent (s3) is preferable as the curing agent. 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 with the substrate, and as a result, a coating film having excellent durability. 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 the 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-aminopropy Amino group-containing alkoxysilane compounds such as triethoxysilane, γ-aminopropylmethyldimethoxysilane, and γ-aminopropylmethyldiethoxysilane are preferred, such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxy. One or more selected from the group consisting of silane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane is preferred.

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

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 dioctoate, di-n-butyltin dilaurate, di-n-butyltin maleate, p-toluenesulfone Acid, trichloroacetic acid, phosphoric acid, monoalkyl phosphoric acid, dialkyl phosphoric acid, monoalkyl phosphorous acid, dialkyl phosphorous acid 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 as 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 the deterioration of the properties, it is preferable that it is not contained as much as possible, and it is preferably 0.5% by mass or less with respect to the nonvolatile content of the aqueous resin composition.

  The aqueous resin composition of the present invention comprises a urethane resin (A), a hydrophilic acrylic polymer (B), metal oxide fine particles (D), an aqueous medium (C), and various additives used as necessary. It can be prepared by mixing an agent, a curing agent, a curing catalyst and the like. After mixing the components, the readily 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 surface protection of various substrates and imparting design properties to various substrates.

  Examples of the substrate include metals, various plastics and films thereof, glass, paper, and wood.

  Examples of metal base materials include galvanized steel sheets and aluminum-galvanized steel sheets, aluminum sheets, aluminum alloy sheets, phosphoric acid chromate treated aluminum sheets, electrical steel sheets, and copper plates used in applications such as automobiles, home appliances, and building materials. And stainless steel plate.

  As a plastic substrate, polyester resin, acrylonitrile-butadiene-styrene resin (ABS resin), which is generally used for plastic molded products such as agricultural films, mobile phones, home appliances, automobile interior and exterior materials, OA equipment, etc. ), Polycarbonate resin (PC resin), ABS / PC resin, polystyrene resin (PS resin), polymethyl methacrylate resin (PMMA resin), acrylic resin, polypropylene resin, polyethylene resin, ethylene-vinyl acetate copolymer resin (EVA resin) ) And the like, and as a plastic film substrate, polyethylene terephthalate film, polyester film, polyethylene film, polypropylene film, TAC (triacetyl cellulose) film, polycarbonate film, It can be used polyvinyl chloride film or the like.

  The aqueous resin composition of the present invention can form a coating film having excellent hydrophilicity and hot water resistance even when the film thickness is 5 μm or less, and even 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 resulting coating agent layer. The cured coating film thus obtained can be used as the film of the present invention.

  In the drying step, after the aqueous medium in the aqueous resin composition is volatilized, the organic solvent is volatilized. After volatilization of the aqueous medium, it consists of an organic solvent, a urethane resin, and a hydrophilic acrylic polymer, and the organic solvent promotes the fusion of the urethane resin and the hydrophilic acrylic polymer, so that there is no coating film defect. A smooth coating 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 normal temperature, but may be heat-dried. The heat drying is preferably performed usually at 40 ° C. or more and 250 ° C. or less and for a time of about 1 second to 600 seconds.

  In addition, when a base material is a thing which is easy to deform | transform with heat like a plastic base material etc., it is preferable to dry (harden) a coating agent layer below the glass transition temperature of a plastic base material, for example, 90 degrees C or less The drying is preferably performed 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 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.

  Examples of 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 members, home appliances, automobile exterior materials, goggles, antifogging film sheets, and antifogging. Glass, a mirror, a medical instrument, etc. are mentioned.

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

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

(Preparation Example 1: Preparation of urethane resin (A-1) aqueous dispersion)
Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol was charged, and the pressure was reduced. Dehydration was performed at 120 to 130 ° C. at a degree of 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 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, then cooled to 55 ° C., 36 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd.) was added. 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 maintained at 40 ° C. for 10 minutes, and then 291 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Subsequently, 2 mass parts of 20 mass% ethylenediamine aqueous solution was added to the said water dispersion, and chain | strand extension reaction was performed for 1 hour. This aqueous dispersion was distilled under reduced pressure to obtain a urethane resin (A-1) aqueous dispersion having a nonvolatile content of 30% by mass.

(Preparation Example 2: Preparation of aqueous dispersion of urethane resin (A-2))
Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol was charged, and the pressure was reduced. Dehydration was performed at 120 to 130 ° C. at a degree of 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 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, followed by cooling to 55 ° C., addition of 33 parts by mass of methyl ethyl ketone, and γ-aminopropyltriethoxysilane (Shin-Etsu Chemical 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 maintained at 40 ° C. for 10 minutes, and then 271 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Subsequently, 2 mass parts of 20 mass% ethylenediamine aqueous solution was added to the said water dispersion, and chain | strand extension reaction was performed for 1 hour. This aqueous dispersion was distilled under reduced pressure to obtain a urethane resin (A-2) aqueous dispersion having a nonvolatile content of 30% by mass.

(Preparation Example 3: Preparation of urethane resin (A-3) aqueous dispersion)
Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol was charged, and the pressure was reduced. Dehydration was performed at 120 to 130 ° C. at a degree of 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 part by mass of stannous octylate were added. And reacted at 70 ° C. for 2 hours.

  After completion of the reaction, 5 parts by mass of 2,2-dimethylolpropionic acid was added and reacted for 4 hours, then cooled to 55 ° C., 41 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd.) was added. A urethane solution was prepared by adding 12 parts by mass and reacting for 1 hour.

  Next, after adding 4 parts by mass of triethylamine and maintaining at 40 ° C. for 10 minutes, 355 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. This aqueous dispersion was distilled under reduced pressure to obtain a urethane resin (A-3) aqueous dispersion having a nonvolatile content of 30% by mass.

(Preparation Example 4: Preparation of urethane resin (A-4) aqueous dispersion)
Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol was charged, and the pressure was reduced. Dehydration was performed at 120 to 130 ° C. at a degree of 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 part by mass of stannous octylate were added. And reacted at 70 ° C. for 2 hours.

  After completion of the reaction, 14 parts by mass of 2,2-dimethylolpropionic acid was added and reacted for 4 hours, followed by cooling to 55 ° C., addition of 86 parts by mass of methyl ethyl ketone, and γ-aminopropyltriethoxysilane (Shin-Etsu Chemical 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 held at 40 ° C. for 10 minutes, and then 690 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Subsequently, 15 mass parts of 20 mass% ethylenediamine aqueous solution was added to the said water dispersion, and chain extension reaction was performed for 1 hour. This aqueous dispersion was distilled under reduced pressure to obtain a urethane resin (A-4) aqueous dispersion having a nonvolatile content of 30% by mass.

(Preparation Example 5: Preparation of urethane resin (A-5) aqueous dispersion)
Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol was charged, and the pressure was reduced. Dehydration was performed at 120 to 130 ° C. at a degree of 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 part by mass of stannous octylate were added. And reacted at 70 ° C. for 2 hours.

  After completion of the reaction, 20 parts by mass of 2,2-dimethylolpropionic acid was added and reacted for 4 hours, then cooled to 55 ° C., 127 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd.) was added. 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 held at 40 ° C. for 10 minutes, and then 1025 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Subsequently, 26 mass parts of 20 mass% ethylenediamine aqueous solution was added to the said water dispersion, and chain extension reaction was performed for 1 hour. This aqueous dispersion was distilled under reduced pressure to obtain a urethane resin (A-5) aqueous dispersion having a nonvolatile content of 30% by mass.

(Preparation Example 6: Preparation of urethane resin (A-6) aqueous dispersion)
Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol was charged, and the pressure was reduced. Dehydration was performed at 120 to 130 ° C. at a degree of 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 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, then cooled to 55 ° C., 36 parts by mass of methyl ethyl ketone was added, and γ-aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd.) was added. "KBE-903" manufactured by Co., Ltd.) 0.2 parts by mass 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 held at 40 ° C. for 10 minutes, and then 278 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Subsequently, 3 mass parts of 20 mass% ethylenediamine aqueous solution was added to the said water dispersion, and chain | strand elongation reaction was performed for 1 hour. This aqueous dispersion was distilled under reduced pressure to obtain a urethane resin (A-6) aqueous dispersion having a nonvolatile content of 30% by mass.

(Comparative Preparation Example 1: Preparation of Urethane Resin (A′-1) Water Dispersion)
Into a four-necked flask equipped with a thermometer, a stirring device, a reflux condenser, and a dropping device, 100 parts by mass of a polycarbonate polyol (hydroxyl value 56.1 mgKOH / g) obtained using 1,6-hexanediol was charged, and the pressure was reduced. Dehydration was performed at 120 to 130 ° C. at a degree of 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 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 held at 40 ° C. for 10 minutes, and then 278 parts by mass of ion-exchanged water was added to prepare an aqueous dispersion. Subsequently, 3 mass parts of 20 mass% ethylenediamine aqueous solution was added to the said water dispersion, and chain | strand elongation reaction was performed for 1 hour. This aqueous dispersion was distilled under reduced pressure to obtain a urethane resin (A′-1) aqueous dispersion having a nonvolatile content of 30% by mass.

  Table 1 shows the ratio of the alicyclic structure per nonvolatile content 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))
Into a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping device, 30 parts by mass of isopropyl alcohol was charged, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) "AM-90G", 100 parts by mass of a mixture of oxyethylene groups with an average addition mole number of 9 mol) = 85/15 (molar ratio) and 2 parts by mass of γ-methacryloxypropyltriethoxysilane are added to 51 parts by mass of isopropyl alcohol. And 20 parts by mass of a 0.5% by mass isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) for 4 hours in a reactor at 80 ° C., Radical polymerization was performed 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))
Into a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping device, 30 parts by mass of isopropyl alcohol was charged, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) "AM-90G", 100 parts by mass of a mixture of oxyethylene group having an average addition mole number of 9 mol) = 45/55 (molar ratio), and 2 parts by mass of γ-methacryloxypropyltriethoxysilane are mixed with 51 parts by mass of isopropyl alcohol. And 20 parts by mass of a 0.5% by mass isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) for 4 hours in a reactor at 80 ° C., Radical polymerization was performed to obtain a hydrophilic acrylic polymer (B-2) solution (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))
Into a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping device, 30 parts by mass of isopropyl alcohol was charged, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) "AM-90G", 100 parts by mass of a mixture of oxyethylene groups with an average addition mole number of 9 mol) = 85/15 (molar ratio), and 25 parts by mass of γ-methacryloxypropyltriethoxysilane, 63 parts by mass of isopropyl alcohol And 20 parts by mass of a 0.5% by mass isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) for 4 hours in a reactor at 80 ° C., Radical polymerization was performed to obtain a hydrophilic acrylic polymer (B-3) solution (non-volatile 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))
Into a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping device, 30 parts by mass of isopropyl alcohol was charged, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) 100 parts by mass of a mixture of “AM-90G”, the average number of added moles of oxyethylene groups being 9 mol) = 85/15 (molar ratio), and 17 parts by mass of γ-methacryloxypropyltriethoxysilane are added to 59 parts by mass of isopropyl alcohol. And 20 parts by mass of a 0.5% by mass isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) for 4 hours in a reactor at 80 ° C., Radical polymerization was performed to obtain a hydrophilic acrylic polymer (B-4) solution (non-volatile 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))
Into a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping device, 30 parts by mass of isopropyl alcohol was charged, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) "AM-90G", 100 parts by weight of a mixture of 95/5 (molar ratio) of an average addition mole number of oxyethylene groups of 9 moles, and 2 parts by weight of γ-methacryloxypropyltriethoxysilane, 51 parts by weight of isopropyl alcohol And 20 parts by mass of a 0.5% by mass isopropyl alcohol solution (azo-based polymerization initiator “V-59” manufactured by Wako Pure Chemical Industries, Ltd.) for 4 hours in a reactor at 80 ° C., Radical polymerization was performed to obtain a hydrophilic acrylic polymer (B-5) solution (nonvolatile content: 50% by mass). 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))
Into a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping device, 30 parts by mass of isopropyl alcohol was charged, and then N, N-dimethylacrylamide / methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) A solution obtained by diluting 100 parts by mass of “AM-90G”, an average addition mole number of oxyethylene groups of 9 mol) = 85/15 (molar ratio) with 50 parts by mass of isopropyl alcohol, and Wako Pure Chemical Industries, Ltd. 20 parts by mass of a 0.5% by mass isopropyl alcohol solution of the azo polymerization initiator “V-59” was dropped into a reactor at 80 ° C. for 4 hours to carry out radical polymerization, and a hydrophilic acrylic polymer (B′- 1) solution (non-volatile content: 50% by mass) was obtained. The weight average molecular weight of the obtained hydrophilic acrylic polymer (B′-1) was 20,000.

  Molar ratio ((b1-1) / (b1-2)) of acrylic monomers (b1-1) and acrylic monomers (b1-2) used in Preparation Examples 7 to 11 and Comparative Preparation Example 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.

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

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

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

[Measuring method of average particle diameter of metal oxide fine particles]
After diluting the aqueous dispersion of metal oxide fine particles with water to obtain a diluted dispersion having a concentration of 0.1% by mass, this diluted dispersion was used to measure a particle size measuring device (“Nanotrack UPA-Ex150 manufactured by Nikkiso Co., Ltd.). ": Calculated by dynamic light scattering method), and the 50% median diameter was defined as the average particle diameter.
There are two peaks in the particle size distribution of the aqueous dispersion of metal oxide fine particles (D-1), and the numerical value in parentheses represents the mode value 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. The film was dried for 30 seconds in a drier at a temperature of 200 ° C., and a plastic substrate was dried at 60 ° C. for 5 minutes to prepare a coating film. Thereafter, it was cured at room temperature for 3 days to obtain a specimen. On the surface of the obtained coating film, a cellophane (registered trademark) peel test of 100 square 1 mm squares was carried out according to JIS K-5400. The number of grids not peeled was measured and evaluated according to the following evaluation criteria. The metal substrate used was an aluminum plate (AL plate) treated with phosphate chromate, and the plastic substrate used was a substrate made of a biaxially stretched polyethylene terephthalate resin (PET resin), a polycarbonate resin ( PC resin) and a base material made of ethylene-vinyl acetate copolymer resin (EVA resin).
A: The number of grids not peeled was 90 or more.
B: The number of grids not peeled was 60 or more and less than 90 C: The number of grids not peeled was 40 or more and less than 60.
D: The number of grids not peeled was less than 40.

[Anti-fogging evaluation method]
The aqueous resin compositions obtained in Examples and Comparative Examples were coated on a base material made of a biaxially stretched polyethylene terephthalate resin (PET resin) using a bar coater so that the film thickness after drying was about 1 μm. And dried at 60 ° C. for 5 minutes to prepare a coating film. Thereafter, it was cured at room temperature for 3 days to obtain a specimen. Next, at the position of the water surface of 90 ° C. water 3 cm so that the coating surface of the obtained specimen faced downward, the antifogging property was evaluated from the state of the coating surface after 10 seconds as follows. Evaluation was made according to criteria.
A: The surface of the coating film was not clouded at all.
B: Slight cloudiness was observed on one part by mass of the surface of the coating film, but it was at a level causing no problem in practice.
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 to disappear even if the specimen is removed from the water surface.

[Method for evaluating hot water resistance]
The aqueous resin compositions obtained in Examples and Comparative Examples were coated on a base material made of a biaxially stretched polyethylene terephthalate resin (PET resin) using a bar coater so that the film thickness after drying was about 1 μm. And dried at 60 ° C. for 5 minutes to prepare a coating film. Thereafter, it was cured at room temperature for 3 days to obtain a specimen. Next, the water contact angle after immersion in water at 60 ° C. for 8 hours and drying 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.

[Method for evaluating blocking resistance]
The aqueous resin compositions obtained in the examples and comparative examples were dried on a substrate made of an aluminum plate (AL plate) treated with phosphoric acid chromate using a bar coater so that the film thickness after drying was about 1 μm. It was coated and dried at 200 ° C. for 30 seconds to prepare a coating film. Thereafter, it was cured at room temperature for 3 days to obtain a specimen. Next, the coating surfaces of the obtained specimens were superposed 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 anti-blocking temperature at which the specimen was not bonded was evaluated according to the following evaluation criteria.
A: The anti-blocking temperature of the coating film was 60 ° C. or higher.
B: The anti-blocking temperature of the coating film was 50 ° C or higher and lower than 60 ° C.
C: The anti-blocking temperature of the coating film was 40 ° C. or higher and lower than 50 ° C.
D: The anti-blocking temperature of the coating film was less than 40 ° C.

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

  Urethane resin (A) having a group represented by the general formula (1), 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, It was confirmed that it was possible to form a coating film with improved blocking resistance.

  The aqueous resin composition of Comparative Example 1 is an example using an aqueous resin composition that does not contain metal oxide fine particles (D), and was confirmed to be inferior in hot water 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) that does not have a group represented by the general formula (1). It was confirmed that the antifogging property and hot water resistance were poor.

  The aqueous resin composition of Comparative Example 3 is an example using an aqueous resin composition containing a urethane resin (A) that does not have the group represented by the general formula (1). It was confirmed that the hot water resistance was poor.

Claims (14)

Urethane resin (A) having a group represented by the following general formula (1), hydrophilic acrylic polymer (B) having a group represented by the following general formula (1), and metal oxide fine particles (D) And an aqueous medium (C).

[In General Formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² represents an alkyl group having 1 to 4 carbon atoms. a represents an integer of 1 to 3. ]   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 together in a single plane.   The aqueous resin composition according to any one of claims 1 to 3, wherein an average particle size of the metal oxide fine particles (D) is 1 nm or more and 500 nm or less.   Content of the said metal oxide microparticles | fine-particles (D) is 0.1 to 30 mass parts with respect to a total of 100 mass parts of the said acrylic resin (A) and the said hydrophilic acrylic polymer (B). The aqueous resin composition of any one of Claims 1-4.   The hydrophilic acrylic polymer (B) is a unit derived from an acrylic monomer (b1-1) having an amide group, a unit derived from an acrylic monomer (b1-2) having an oxyethylene group, and the general formula ( The aqueous resin composition according to any one of claims 1 to 5, comprising a unit derived from an acrylic monomer (b1-3) having a group represented by 1).   Molar ratio ((b1-1) / (b1-2)) of units derived from the acrylic monomer (b1-1) having the amide group and units derived from the acrylic monomer (b1-2) having the oxyethylene group Is 99/1 or more and 50/50 or less, The aqueous resin composition of Claim 6.   The content of the group represented by the general formula (1) of the hydrophilic acrylic polymer (B) is 5 mmol / kg or more and 600 mmol / kg or less in the hydrophilic acrylic polymer (B). The aqueous resin composition according to any one of 1 to 7.   The content of the group represented by the general formula (1) of the urethane resin (A) is 5 mmol / kg or more and 300 mmol / kg or less in the hydrophilic acrylic polymer (B). The aqueous resin composition according to any one of the above.   A coating agent comprising the aqueous resin composition according to claim 1.   The coating agent according to claim 10, which is used for an agricultural film.   A coating film formed from the coating agent according to claim 10 or 11.   An article having a coating film of the coating agent according to claim 10 or 11.   An agricultural film comprising the coating film of the coating agent according to claim 10 or 11.