JP2018104535A - Aqueous resin composition, coating agent and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous resin composition that can form a coating having excellent antifouling and recoating properties, a coating agent, and an article having a coating of the coating agent.SOLUTION: An aqueous resin composition contains a urethane resin (A) as a reactant between polyol (a1) and polyisocyanate (a2), and an aqueous medium (B). In a nonvolatile content of the aqueous resin composition, the total concentration of polymerizable unsaturated bonds and aromatic rings is 3 mol/kg or more.SELECTED DRAWING: 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.

  Aqueous resin compositions, in particular aqueous urethane resin compositions, generally have good adhesion to substrates and can form flexible coatings, so they can be used in various applications including coating agents and adhesives. It is used.

  Generally as a coating agent using the said aqueous resin composition, the ability to form the coating film which can prevent deterioration of the surface of various base materials, the ability to provide the design property to the surface of a base material, etc. are calculated | required. In particular, in recent years, a coating agent having excellent antifouling properties has been demanded from the industry from the viewpoint of protecting design properties in addition to the hardness and durability of the formed coating film. The demand for coating agents having the above-described properties is increasing in surface treatment applications such as metal substrates such as steel plates, glass substrates, and plastic substrates.

  As a coating agent that can form a coating film having excellent antifouling properties, a coating agent containing fluorine or silicon is known (for example, see Patent Document 1).

  However, in the coating agent, fluorine or silicon migrates to the surface of the coating film, thereby reducing the adhesion of dirt and facilitating wiping off the dirt. In order to reduce the surface free energy and the adhesion, the application of the coating agent again causes a decrease in adhesion. Further, in applications where rewriting on the surface of a coating film is performed on a daily basis such as a white board, there has been a problem that water and oil-based inks are repelled and rewriting on the surface cannot be performed again.

  Therefore, there has been a demand for an aqueous resin composition capable of forming a coating film having antifouling properties and capable of being repainted.

JP 2005-60675 A

  The problem to be solved by the present invention is to provide an aqueous resin composition capable of forming a coating film having excellent antifouling properties and recoatability.

  As a result of intensive studies to solve the above problems, the inventors of the present invention are aqueous resin compositions containing a urethane resin (A) and an aqueous medium (B), wherein the non-volatile content of the aqueous resin composition It has been found that the above-mentioned problems can be solved by using an aqueous resin composition in which the total of the polymerizable unsaturated group concentration and the aromatic ring concentration is not less than a specific amount, and the present invention has been completed.

  That is, the present invention is an aqueous resin composition containing a urethane resin (A), which is a reaction product of polyol (a1) and polyisocyanate (a2), and an aqueous medium (B), wherein the aqueous resin composition The present invention relates to an aqueous resin composition, a coating agent, and an article characterized in that the total of the polymerizable unsaturated bond concentration and the aromatic ring concentration in the non-volatile content is 3 mol / kg or more.

  Since the aqueous resin composition of the present invention can form a coating film having excellent antifouling properties, for example, acrylonitrile-butadiene-styrene resin (ABS resin), polycarbonate resin (PC resin), ABS / PC resin, polystyrene resin (PS resin), polymethacrylic acid resin (PMMA resin), polyester resin (PET resin) and other plastic substrate coating agents and adhesives can be suitably used.

  The aqueous resin composition of the present invention is a urethane resin (A) and an aqueous medium (B). The total of the polymerizable unsaturated bond concentration and the aromatic ring concentration in the nonvolatile content of the aqueous resin composition is 3 mol. / Kg or more.

  As the urethane resin (A), a reaction product of polyol (a1) and polyisocyanate (a2) is used.

  As the polyol (a1), for the purpose of introducing two or more polymerizable unsaturated groups into the side chain of the main chain of the urethane resin (A) in which urethane bonds are mainly present, An alkylene diol (a1-1) having two or more polymerizable unsaturated groups represented by the general formula (1) or an oxyalkylene diol having two or more polymerizable unsaturated groups represented by the following general formula (2) What contains (a1-2) can be used.

(R ¹ in the general formula (1) represents a structure having two or more atomic groups containing a polymerizable unsaturated group in the side chain of a linear alkylene group having 1 to 9 carbon atoms.)

(R ¹ and R ³ in the general formula (2) represent a structure having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group. R ² represents an alkylene group having 1 to 5 carbon atoms. .)

  The polymerizable unsaturated group derived from the alkylene diol (a1-1) and the oxyalkylene diol (a1-2) undergoes radical polymerization when forming a coating film or the like. Thereby, the coating film excellent in hardness, elongation, and flexibility can be formed.

As said alkylene diol (a1-1), what has the structure shown by the said General formula (1) can be used. R ¹ in the general formula (1) represents a structure having two or more atomic groups containing a polymerizable unsaturated group in the side chain of a linear alkylene group having 1 to 9 carbon atoms. For example, pentaerythritol di (meth) acrylate has a structure in which R ¹ in the general formula (1) has two atomic groups containing a polymerizable unsaturated group in the side chain of a propylene group having 3 carbon atoms.

  As the alkylene diol (a1-1), those having 2 or more and 5 or less polymerizable unsaturated groups are preferably used, and those having 2 or more and 3 or less polymerizable unsaturated groups are used. It is more preferable to obtain a urethane resin composition capable of forming a coating film excellent in hardness, elongation and flexibility.

Examples of the alkylene diol (a1-1) include pentaerythritol di (meth) acrylate [dimethylolpropane di (meth) acrylate], dimethylolmethane di (meth) acrylate (R ¹ in the general formula (1) is , Those having 3 carbon atoms and two atomic groups having a polymerizable unsaturated group), diethylolmethane di (meth) acrylate, and diethylolpropane di (meth) acrylate (general formula (1 R ¹ is a group having 5 carbon atoms and having two atomic groups having a polymerizable unsaturated group.), Dipropanolmethane di (meth) acrylate, dipropanolpropanedi (meth) acrylate (formula (1) R ¹ in the intended 7 carbon atoms, is an atomic group having a polymerizable unsaturated group as it has two.) Di-butanol methane di (meth) acrylate, R ¹ in the di-butanol propane di (meth) acrylate (Formula (1) is of a carbon atoms 9 and has two atomic group having a polymerizable unsaturated group Etc.). Among these, pentaerythritol di (meth) acrylate and dimethylolmethane di (meth) acrylate are preferable because a urethane resin composition capable of forming a coating film excellent in hardness, elongation and flexibility is obtained. Moreover, these alkylene diols (a1-1) can be used alone or in combination of two or more. In the present invention, “(meth) acrylate” refers to either one or both of acrylate and methacrylate.

Moreover, as said oxyalkylene diol (a1-2), what has the structure shown by the said General formula (2) can be used. R ¹ and R ³ in the general formula (2) have a structure having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group. In the general formula (2), it has a total of two or more structures having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group, preferably in the range of 2 or more and 5 or less, More preferably, it has in the range of 2 or more and 3 or less.

R ² in the general formula (2) represents an alkylene group having 1 to 5 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentyl group.

Examples of the oxyalkylene diol (a1-2) include bis (3-acryloyloxy-2-hydroxypropoxy) methane (R ¹ and R ³ in the general formula (2) are those having 2 carbon atoms and are polymerizable. It has one atomic group having an unsaturated group, and R ² has 1 carbon atom.) 1,2-bis (3-acryloyloxy-2-hydroxypropoxy) ethane (general formula (2 And R ¹ and R ³ are those having 2 carbon atoms and having one atomic group having a polymerizable unsaturated group, and R ² is having 2 carbon atoms.), 1, 3-bis (3-acryloyloxy-2-hydroxypropoxy) propane (in the general formula (2), R ¹ and R ³ have 2 carbon atoms and have one atomic group having a polymerizable unsaturated group) in and, ^{R 2} is the number of carbon atoms Is of.), 1,4-bis (3-acryloyloxy-2-hydroxypropoxy) butane (formula (2) ^{R 1} and ^{R 3} in the intended 2 carbon atoms, a polymerizable unsaturated group And R ² has 4 carbon atoms.) 1,5-bis (3-acryloyloxy-2-hydroxypropoxy) pentane (in the general formula (2)) R ¹ and R ³ have 2 carbon atoms, have 1 atomic group having a polymerizable unsaturated group, and R ² has 5 carbon atoms). Among these, 1,4-bis (3-acryloyloxy-2-hydroxypropoxy) butane is preferable because a urethane resin composition capable of forming a coating film excellent in hardness, elongation and flexibility is obtained. Moreover, these oxyalkylene diols (a1-2) can be used alone or in combination of two or more.

  The said alkylene diol (a1-1) and the said oxyalkylene diol (a1-2) are used in the range of 0.1-49 mass% in total in the whole quantity of the raw material used for manufacture of the said urethane resin (A). Is preferable from the viewpoint of obtaining a urethane resin composition capable of forming a coating film excellent in hardness, elongation and flexibility, and more preferably in the range of 1 to 15% by mass. In addition, the total amount of the raw material used for manufacture of the said urethane resin (A) points out the total mass containing it, when a polyol (a1), polyisocyanate (a2), and a chain extender are used.

  As said polyol (a1), since the coating film excellent in antifouling property can be formed, aromatic polyester polyol (a1-3) can also be used further.

  Examples of the aromatic polyester polyol (a1-3) include those obtained by esterifying a low molecular weight polyol and an aromatic polycarboxylic acid.

  Examples of the low molecular weight polyol that can be used in the production of the aromatic polyester polyol include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,6-hexane. Diol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane and the like can be used alone or in combination of two or more. It is preferable to use a combination of propanediol, 1,3-butanediol, 1,4-butanediol, or the like, and 3-methyl-1,5-pentanediol, neopentyl glycol, or the like.

  Examples of the aromatic polycarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, and anhydrides or esterified products thereof.

  Moreover, as said polyol (a1), another polyol can be used in combination with the above-mentioned polyol as needed.

  Examples of the other polyol include a polyol having a hydrophilic group for the purpose of imparting excellent water dispersion stability to the urethane resin (A).

  Examples of the polyol having a hydrophilic group include a polyol having an anionic group, a polyol having a cationic group, and a polyol having a nonionic group. Of these, polyols having an anionic group are preferred.

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

  Examples of the polyol having a carboxyl group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolvaleric acid, and the like, among others, 2,2-dimethylol. Propionic acid is preferred. Moreover, the polyester polyol which has a carboxyl group obtained by making the polyol which has the said carboxyl group react with various polycarboxylic acids can also be used.

  Examples of the polyol having a sulfonic acid group include dicarboxylic acids such as 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, 5- (4-sulfophenoxy) isophthalic acid, and salts thereof; Polyester polyol obtained by reacting low molecular polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and the like, and the polyester polyol and γ-butyrolactone And polyester polyols obtained by reacting cyclic ester compounds such as δ-valerolactone and ε-caprolactone.

  The anionic groups are preferably partially or wholly neutralized with a basic compound or the like in order to exhibit good water dispersibility.

  Examples of basic compounds that can be used when neutralizing the anionic group include organic amines having a boiling point of 200 ° C. or higher, such as ammonia, triethylamine, morpholine, monoethanolamine, diethylethanolamine; sodium hydroxide, water Examples thereof include metal hydroxides including potassium oxide and lithium hydroxide. From the viewpoint of improving the water dispersion stability of the obtained urethane resin composition, the basic compound is [basic compound / (total amount of acid groups such as carboxyl groups)] = 0.5 to 3 (molar ratio). It is preferable to use in the range which becomes, and it is more preferable to use in the range used as 0.7-1.5 (molar ratio).

  Examples of the polyol having a cationic group include a polyol having a tertiary amino group. Specific examples include N-methyl-diethanolamine and polyols obtained by reacting a compound having two epoxies with a secondary amine.

  It is preferable that a part or all of the cationic group is neutralized with an acidic compound such as formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, tartaric acid, adipic acid, and phosphoric acid.

  Further, the tertiary amino group as the cationic group is preferably partly or entirely quaternized. Examples of the quaternizing agent include dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride and the like, and dimethyl sulfate is preferable.

  Examples of the polyol having a nonionic group include polyalkylene glycol having a structural unit derived from ethylene oxide.

  The polyol having a hydrophilic group is preferably used in the range of 1 to 20% by mass in the total amount of raw materials used for the production of the urethane resin (A), and further in hardness, elongation and flexibility. Since the urethane resin composition which can form the outstanding coating film is obtained, it is more preferable to use in 1-15 mass%.

  Examples of the other polyols include polyester polyols other than the aromatic polyester polyol (a1-3), polycarbonate polyols, polyphenols, for the purpose of forming a coating film having excellent hardness, elongation, and flexibility. Examples include ether polyols. Of these, polyester polyol and polycarbonate polyol are preferable.

  Examples of the polyester polyol include a polyester polyol obtained by reacting a low molecular weight polyol and a polycarboxylic acid; a polyester polyol obtained by a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone; Examples include polyester polyols obtained by polymerization. These polyester polyols can be used alone or in combination of two or more.

  Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 1,3-butanediol and the like having a molecular weight of about 50 to 300. Aliphatic polyols that are: polyols having an alicyclic structure such as cyclohexanedimethanol. Of these, 1,6-hexanediol and neopentyl glycol are preferable.

  Examples of the polycarboxylic acid include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid.

  The polycarbonate polyol is obtained by an esterification reaction of carbonic acid and a carbonate ester with a polyhydric alcohol. Examples of the polyhydric alcohol include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Etc. These polycarbonate polyols can be used alone or in combination of two or more.

  Examples of the polyether polyol include those obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator. Examples of the compound having two or more active hydrogen atoms include propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, diester, and the like. Examples include glycerin, trimethylolethane, trimethylolpropane, water, hexanetriol and the like. Examples of the alkylene oxide include propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran. These polyether polyols can be used alone or in combination of two or more.

  The polyester polyol, the polycarbonate polyol, and the polyether polyol are preferably used in the range of 1 to 70% by mass in the total amount of raw materials used for the production of the urethane resin (A), and in the range of 15 to 50% by mass. It is more preferable to use in the case of being able to form a coating film having excellent hardness, elongation and flexibility.

  Examples of the polyisocyanate (a2) used in the production of the urethane resin (A) include polyisocyanates having an aliphatic cyclic structure such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate; 4,4′-diphenylmethane Aromatic polyisocyanates such as diisocyanate, 2,4′-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate Aliphatic polyisocyanates such as isocyanate Sulfonate, and the like. Especially, it is preferable to use an aromatic polyisocyanate because a coating film excellent in hardness, elongation and flexibility can be formed. Moreover, these polyisocyanates (a2) can be used alone or in combination of two or more.

  As a method for producing the urethane resin (A) obtained by reacting the polyol (a1) and the polyisocyanate (a2), for example, in the absence of a solvent or in the presence of an organic solvent, the polyol (a1) and Examples include a method in which the polyisocyanate (a2) is mixed and reacted in a reaction temperature range of about 50 ° C to 150 ° C.

  In the reaction of the polyol (a1) and the polyisocyanate (a2), for example, the equivalent ratio of the isocyanate group of the polyisocyanate (a2) to the hydroxyl group of the polyol (a1) is in the range of 0.8 to 2.5. Preferably, it is carried out in the range of 0.9 to 1.5.

  Moreover, when manufacturing the said urethane resin (A), since the coating film excellent in hardness, elongation, and flexibility can be formed, in addition to the said polyol (a1) and the said polyisocyanate (a2), it is necessary. A chain extender can be used accordingly.

  Examples of the chain extender include polyamines, hydrazine compounds, and other active hydrogen atom-containing compounds.

  Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 3,3′-. Diamines such as dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N -Methylaminopropylamine; diethylenetriamine, dipropylenetriamine, triethylenetetramine and the like. Moreover, these polyamines can be used alone or in combination of two or more.

  Examples of the hydrazine compound include hydrazine, N, N′-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide; β-semicarbazide And propionic acid hydrazide. Moreover, these hydrazine compounds can be used alone or in combination of two or more.

  Examples of the other active hydrogen-containing compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, saccharose, Glycols such as methylene glycol, glycerin and sorbitol; bisphenol A, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, phenol such as hydroquinone, and water These can be used, and the aqueous resin composition of the present invention can be used alone or in combination of two or more within the range in which the storage stability does not deteriorate.

  Examples of the organic solvent that can be used in producing the urethane resin (A) 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 solvents of the following: amide solvents such as dimethylformamide and N-methylpyrrolidone. These organic solvents can be used alone or in combination of two or more.

  In addition, in order to reduce the burden on safety and the environment, the organic solvent removes part or all of the organic solvent by, for example, distilling under reduced pressure during or after the production of the urethane resin (A). May be.

  Since the urethane resin (A) obtained by the above method can form a coating film having excellent hardness, elongation and flexibility, it is preferable to use a resin having a weight average molecular weight in the range of 10,000 to 500,000. It is preferable to use those having a weight average molecular weight in the range of 20,000 to 200,000, and it is more preferable to use a weight average molecular weight in the range of 40,000 to 100,000.

  Moreover, as said urethane resin (A), since it can form the coating film excellent in hardness, elongation, and flexibility, it is preferable to use what has a urea bond.

  As the urethane resin (A), it is preferable to use a resin having a urea bond equivalent in the range of 500 to 50,000 because a coating film excellent in hardness, elongation and flexibility can be formed.

  Examples of the aqueous medium (B) used in the present invention include water, organic solvents miscible with water, and mixtures thereof. Examples of the organic solvent miscible with water include alcohol solvents such as methanol, ethanol, n-propanol and isopropanol; ketone solvents such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; Alkyl ethers; lactam solvents such as N-methyl-2-pyrrolidone and the like. In the present invention, only water may be used, a mixture of water and an organic solvent miscible with water may be used, or only an organic solvent miscible with water may be used.

  The aqueous medium (B) is preferably water alone or a mixture of water and an organic solvent miscible with water, particularly water alone, from the viewpoint of safety and environmental load.

  The ratio of the aqueous medium (B) is preferably in the range of 10 to 90% by mass and more preferably in the range of 30 to 70% by mass in the total amount of the aqueous resin composition.

  The aqueous resin composition of the present invention can be produced by dispersing the urethane resin (A) in an aqueous medium (B).

  The polymerizable unsaturated bond concentration in the nonvolatile content of the aqueous resin composition is preferably in the range of 0 to 14 mol / kg, and the aromatic ring concentration in the nonvolatile content of the aqueous resin composition is 0 to 6 mol / kg. It is preferably in the kg range. Furthermore, since the total of the polymerizable unsaturated bond concentration and the aromatic ring concentration in the non-volatile content of the aqueous resin composition is 3 mol / kg or more, a coating film having excellent antifouling properties and recoatability can be formed. More preferably, it is more preferably 4 mol / kg or more.

  Moreover, since the aqueous resin composition of this invention can form the coating film which has the outstanding antifouling property and recoat property, you may contain polyfunctional acrylate (C).

  Examples of the polyfunctional acrylate (C) include pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and trimethylolethylene. Oxide-modified triacrylate, diglycerin ethylene oxide modified (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane propylene oxide modified triacrylate, pentaerythritol tri (meth) acrylate, isocyanuric acid ethylene oxide modified triacrylate, glycerin Tri (meth) acrylate, glycerin propoxytriacrylate, pentaerythritol ethyl Emissions oxide modified tetraacrylate and the like. By using these, an aqueous resin composition capable of forming a coating film with higher hardness can be obtained. Of these, dipentaerythritol hexa (meth) acrylate is preferable. These polyfunctional acrylates can be used alone or in combination of two or more.

  The ratio of the polymerizable unsaturated bond in the polyfunctional acrylate (C) is preferably in the range of 0 to 12 mol / kg because a coating film having excellent antifouling properties and recoatability can be formed. The range of 11.8 mol / kg is more preferable.

  Moreover, it is preferable that the average functional group number per compound of the said polyfunctional acrylate (C) is 3 or more from the viewpoint that the coating film which has the outstanding antifouling property can be formed, and it is more preferable that it is 4 or more.

  Furthermore, when the aqueous resin composition of the present invention contains the polyfunctional acrylate (C), the ratio of polymerizable unsaturated bonds in the total of the urethane resin (A) and the polyfunctional acrylate (C) is 0. It is preferable that it is in the range of ˜9.5 mol / kg because a coating film having excellent antifouling properties and recoatability can be formed, more preferably in the range of 1.5 to 9 mol / kg, and 3-8. More preferably, it is in the range of 5 mol / kg.

  The polyfunctional acrylate (C) may be added before the urethane resin (A) is dispersed in the aqueous medium (B), and the urethane resin (A) is added to the aqueous medium (B). You may add after dispersing in.

  The aqueous resin composition of the present invention obtained by the method described above contains the urethane resin (A) and the polyfunctional acrylate (C) in the range of 5% by mass to 85% by mass in the total amount of the aqueous resin composition. It is preferable to contain, and it is more preferable to contain in 15 to 50 mass%.

  The aqueous resin composition may contain an additive as necessary. Examples of the additive include a film forming aid, a filler, a thixotropic agent, a tackifier, a pigment, an antibacterial agent, and the like. Can be used as long as the object of the present invention is not impaired.

  Examples of the film forming aid include an anionic surfactant (dioctylsulfosuccinic acid ester soda salt and the like), a hydrophobic nonionic surfactant (such as sorbitan monooleate) and silicone oil.

  Examples of the thixotropy-imparting agent include fatty acid, fatty acid metal salt, fatty acid ester, paraffin, resin acid, surfactant, polyacrylic acid and the like surface-treated filler, polyvinyl chloride powder, hydrogenated castor oil, Fine powder silica, organic bentonite, sepiolite and the like can be mentioned.

  As the pigment, known and commonly used inorganic pigments and organic pigments can be used.

  Examples of the inorganic pigment include titanium oxide, antimony red, bengara, cadmium red, cadmium yellow, cobalt blue, bitumen, ultramarine, carbon black, graphite and the like.

  Examples of the organic pigment include quinacridone pigment, quinacridone quinone pigment, dioxazine pigment, phthalocyanine pigment, anthrapyrimidine pigment, ansanthrone pigment, indanthrone pigment, flavanthrone pigment, perylene pigment, diketopyrrolopyrrole pigment, perinone pigment, Examples include quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, and azo pigments. These pigments can be used alone or in combination of two or more. These pigments may be surface-treated and have a self-dispersing ability with respect to an aqueous medium.

  Examples of the antibacterial agent include silver chloride, trifuranide, dichlorofluanide, fluorophorpet, zinc pyrithione, methyl 2-benzimidazole carbanate, 2- (4-thiazolyl) benzimidazole and the like.

  Examples of other additives include reaction accelerators (metal reaction accelerators, metal salt reaction accelerators, amine reaction accelerators, etc.), photopolymerization initiators, radical polymerization initiators, stabilizers (ultraviolet absorbers). , Antioxidants, heat stabilizers, etc.), water removal agents (4-paratoluenesulfonyl isocyanate, etc.), adsorbents (quick lime, slaked lime, zeolite, molecular sieves, etc.), adhesion-imparting agents, antifoaming agents, leveling agents, etc. And various additives.

  Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholino). Phenyl) -butanone, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl -Diphenyl-phosphine oxide etc. are mentioned. These photopolymerization initiators can be used alone or in combination of two or more.

  Examples of the radical polymerization initiator include azo compounds such as 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2-methylbutyronitrile), azobiscyanovaleric acid; Organics such as oxypivalate, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide Peroxides: inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate. These radical polymerization initiators can be used alone or in combination of two or more.

  The aqueous resin composition of the present invention can be suitably used, for example, as a coating agent that can impart surface protection and design properties to various substrates.

  As a base material which can apply | coat the said coating agent and can form a coating film, a glass base material, a metal base material, a plastic base material, paper, a wood base material, a fiber base material etc. are mentioned, for example. Moreover, it can also be used for a base material having a porous structure such as urethane foam.

  Examples of the metal substrate include plated steel plates such as galvanized steel plates and aluminum-zinc alloy steel plates, iron plates, aluminum plates, aluminum alloy plates, electromagnetic steel plates, copper plates, and stainless steel plates.

  Examples of the plastic substrate include a polycarbonate substrate, a polyester substrate, an acrylonitrile-butadiene-styrene substrate, a polyacryl substrate, a polystyrene substrate, a polyurethane substrate, an epoxy resin substrate, a polyvinyl chloride substrate, and a polyamide. Examples include base materials.

  The various base materials may be planar materials made of the above materials or may have curved portions, or may be base materials made of fibers such as nonwoven fabric.

  The coating agent of the present invention can be applied, for example, directly on the surface of the substrate or on the surface of a substrate on which a primer layer or the like has been previously provided, and dried to form a coating film. When the urethane resin (A) has a polymerizable unsaturated bond and / or when the aqueous resin composition of the present invention contains the polyfunctional acrylate (C), the aqueous resin composition of the present invention is used. The urethane-containing resin (A) and the polyfunctional acrylate (C) are coated directly on the surface of the base material or on the surface of the base material previously provided with a primer layer and the like, and then dried. A coating film can be formed by advancing radical polymerization of the polymerizable unsaturated bond group possessed by active energy rays or heat.

  In addition, a coating film is formed on the surface of the release paper by applying the coating agent on the release paper, then drying and curing, and a non-woven fabric obtained by applying an adhesive or an adhesive on the coating film. A film formed using the coating agent can be laminated on the surface of a desired substrate by laminating the substrate made of such fibers and peeling the release paper.

  Examples of the method for applying the coating agent on the substrate include a spray method, a curtain coater method, a flow coater method, a roll coater method, a brush coating method, and a dipping method.

  Examples of the method for curing the coating agent include a heating method and a method of irradiating active energy rays such as ultraviolet rays.

  The heating method varies depending on the type of radical polymerization initiator to be used. For example, by performing the heating at a temperature of about 100 ° C. to 150 ° C. for about 10 minutes to 30 minutes, the radical polymerization is advanced and cured. it can.

  In addition, as a method of irradiating the active energy ray, for example, a method using a known lamp such as a xenon lamp, a xenon-mercury lamp, a metal halide lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, or an LED lamp is used. Can be mentioned.

The exposure dose of the actinic energy ray is preferably in the range of ^{0.5J / cm 2 ~5J / cm 2} , more preferably in the range of ^{0.1J / cm 2 ~3J / cm 2} , 0. particularly preferably in the range of ^{1J / cm 2 ~1J / cm 2} . In addition, said ultraviolet irradiation amount is based on the value measured in the wavelength range of 300-390 nm using UV checker UVR-N1 (made by Nippon Battery Co., Ltd.).

  Although the thickness of the coating film that can be formed using the coating agent of the present invention can be appropriately adjusted according to the use of the substrate, it is usually preferably about 0.1 μm to 100 μm.

  Examples of the article having a coating film of the coating agent include optical members such as liquid crystal displays and flexible displays, mobile phones, various plastic products such as home appliances, metal products such as automobile exteriors and building materials.

  Hereinafter, the present invention will be specifically described by way of examples and comparative examples.

(Synthesis Example 1: Synthesis of polyester polyol (1))
While introducing nitrogen gas in a reaction vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 27.6 parts by mass of isophthalic acid, 27.6 parts by mass of terephthalic acid, 11.7 parts by mass of ethylene glycol, 19. 9 parts by mass and 0.03 parts by mass of dibutyltin oxide were charged, and a polycondensation reaction was performed at 230 ° C. for 24 hours until the acid value became 1 or less at 180 to 230 ° C., to obtain an aromatic polyester polyol (1).

(Synthesis Example 2: Synthesis of polyester polyol (2))
While introducing nitrogen gas in a reaction vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 35.1 parts by mass of isophthalic acid, 11.6 parts by mass of 1,6-hexanediol, 17.7 parts by mass of sebacic acid , Ethylene glycol 6.5 parts by mass, neopentyl glycol 21.4 parts by mass, adipic acid 7.7 parts by mass and dibutyltin oxide 0.04 parts by mass until the acid value becomes 1 or less at 180 to 230 ° C. A polycondensation reaction was carried out at 230 ° C. for 24 hours. After completion of the reaction, an aromatic polyester polyol (2) diluted with 20.0 parts by mass of methyl ethyl ketone was obtained.

(Example 1: Preparation of aqueous resin composition (1))
In a reaction vessel, 74.1 parts by mass of the aromatic polyester polyol (1) obtained in Synthesis Example 1 was dehydrated at 100 ° C. under reduced pressure, and after cooling to 80 ° C., 66.5 parts by mass of methyl ethyl ketone was added, stirred, and evenly mixed. Mixed. Next, 6 parts by mass of 2,2-dimethylolpropionic acid was added, and then 19.9 parts by mass of isophorone diisocyanate was added and reacted at 80 ° C. for 12 hours to carry out a urethanization step. After confirming that the isocyanate value was 0.1% or less, 0.29 parts by mass of n-butanol was added, and the reaction was further continued for 2 hours, followed by cooling to 50 ° C.

Next, 4.7 parts by mass of triethylamine was added, and 536 parts by mass of ion-exchanged water was slowly added to effect water solubilization. Subsequently, methyl ethyl ketone was removed under reduced pressure at 30 to 50 ° C. to obtain an aqueous resin composition (1) having a nonvolatile content of 23.5% by mass. This aqueous resin composition (1) had an aromatic ring concentration in the nonvolatile content of 3.2 mol / kg, and a polymerizable unsaturated bond concentration of 0 mol / kg.

(Example 2: Preparation of aqueous resin composition (2))
To a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.1 parts by mass, polycarbonate polyol (Polycarbonate polyol obtained by reacting 1,6-hexanediol, 1,5-pentanediol and diethyl carbonate, number average molecular weight 2000) 43.4 parts by mass, 1,6-hexanediol 0.06 parts by mass, Charge 0.002 parts by mass of methylhydroquinone and 0.024 parts by mass of 2,6-tert-butyl-p-cresol at 50 ° C. with stirring. Sei was.

  Next, 36.7 parts by mass of dicyclohexylmethane diisocyanate was supplied to the four-necked flask and reacted at 80 ° C. for about 3 hours. Then, 7.7 parts by mass of 2,2-dimethylolpropionic acid and 5.2% of methyl ethyl ketone were added. A part by mass was supplied and reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 163.1 parts by mass of dipentaerythritol hexaacrylate and 5.7 parts by mass of triethylamine were supplied, and 480 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, after feeding 10.9 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting, an aqueous resin having a nonvolatile content of 40% by mass is removed under reduced pressure. A composition (2) was obtained. The concentration of the aromatic ring in the non-volatile content of this aqueous resin composition (2) was 0 mol / kg, and the polymerizable unsaturated bond concentration was 6.5 mol / kg.

(Example 3: Preparation of aqueous resin composition (3))
To a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer and a reflux condenser, 42.9 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.2 parts by mass, polycarbonate polyol (Polycarbonate polyol obtained by reacting 1,6-hexanediol, 1,5-pentanediol and diethyl carbonate, number average molecular weight 2000) 38.2 parts by weight, 1,6-hexanediol 3.9 parts by weight, 0.002 part by mass of methylhydroquinone and 0.025 part by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring. It was.

  Next, after supplying 40.6 parts by mass of dicyclohexylmethane diisocyanate to the four-necked flask and reacting at 80 ° C. for about 3 hours, 5.1 parts by mass of 2,2-dimethylolpropionic acid, 23.8 of methyl ethyl ketone, A part by mass was supplied and reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 60.1 parts by mass of pentaerythritol tetraacrylate and 3.8 parts by mass of triethylamine were supplied, and 372.3 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, after supplying 11.9 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting, an aqueous resin having a non-volatile content of 37% by mass is removed under reduced pressure. A composition (3) was obtained. The concentration of the aromatic ring in the non-volatile content of this aqueous resin composition (3) was 0 mol / kg, and the polymerizable unsaturated bond concentration was 4.2 mol / kg.

(Example 4: Preparation of aqueous resin composition (4))
To a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer and a reflux condenser, 33.1 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.3 parts by mass, synthesis example 2 polyester polyol (2) 48.0 parts by mass (solid content 38.4 parts by mass), 1,6-hexanediol 2.6 parts by mass, methylhydroquinone 0.002 parts by mass, and 2,6-tert- 0.026 parts by mass of butyl-p-cresol was charged and adjusted at 50 ° C. with stirring.

  Next, 40.1 parts by mass of dicyclohexylmethane diisocyanate was supplied to the four-necked flask and reacted at 80 ° C. for about 3 hours, and then 6.6 parts by mass of 2,2-dimethylolpropionic acid, 23.8 methyl ethyl ketone. A part by mass was supplied and reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 45.6 parts by mass of dipentaerythritol hexaacrylate and 5.1 parts by mass of triethylamine were supplied, and 426.3 parts by mass of deionized water exchanged water was slowly added to carry out water solubilization.

  Next, 11.8 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender is supplied to the four-necked flask and reacted, and then the solvent is removed under reduced pressure, whereby an aqueous resin having a non-volatile content of 37% by mass is obtained. A composition (4) was obtained. The concentration of the aromatic ring in the non-volatile content of this aqueous resin composition (4) was 1.4 mol / kg, and the polymerizable unsaturated bond concentration was 3.8 mol / kg.

(Example 5: Preparation of aqueous resin composition (5))
A 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer and a reflux condenser was charged with 33.6 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.3 parts by mass, synthesis example 2 polyester polyol (2) 48.7 parts by mass (solid content 39 parts by mass), 1,6-hexanediol 1.9 parts by mass, methylhydroquinone 0.002 parts by mass, and 2,6-tert-butyl- 0.022 parts by mass of p-cresol was charged and adjusted at 50 ° C. with stirring.

  Next, 40 parts by mass of dicyclohexylmethane diisocyanate is supplied to the four-necked flask and reacted at 80 ° C. for about 3 hours, and then 6.7 parts by mass of 2,2-dimethylolpropionic acid and 22 parts by mass of methyl ethyl ketone are supplied. And reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 163.1 parts by mass of dipentaerythritol hexaacrylate and 5.2 parts by mass of triethylamine were supplied, and 491 parts by mass of deionized water exchanged water was slowly added to carry out water solubilization.

  Next, 12.3 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender is supplied to the four-necked flask and reacted, and then the solvent is removed under reduced pressure, whereby an aqueous resin having a nonvolatile content of 40% by mass is obtained. A composition (5) was obtained. The aromatic ring concentration in the non-volatile content of this aqueous resin composition (5) was 1.4 mol / kg, and the polymerizable unsaturated bond concentration was 6.5 mol / kg.

(Example 6: Preparation of aqueous resin composition (6))
To a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.1 parts by mass, polycarbonate polyol (Polycarbonate polyol obtained by reacting 1,6-hexanediol, 1,5-pentanediol and diethyl carbonate, number average molecular weight 2000) 43.4 parts by mass, 1,6-hexanediol 0.06 parts by mass, Charge 0.002 parts by mass of methylhydroquinone and 0.024 parts by mass of 2,6-tert-butyl-p-cresol at 50 ° C. with stirring. Sei was.

  Next, 36.7 parts by mass of dicyclohexylmethane diisocyanate was supplied to the four-necked flask and reacted at 80 ° C. for about 3 hours. Then, 7.7 parts by mass of 2,2-dimethylolpropionic acid and 5.2% of methyl ethyl ketone were added. A part by mass was supplied and reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 100 parts by mass of trimethylolpropane triacrylate and 5.7 parts by mass of triethylamine were supplied, and 345.1 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, after feeding 10.9 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting, an aqueous resin having a nonvolatile content of 40% by mass is removed under reduced pressure. A composition (6) was obtained. The concentration of the aromatic ring in the non-volatile content of this aqueous resin composition (6) was 0 mol / kg, and the polymerizable unsaturated bond concentration was 5.7 mol / kg.

(Example 7: Preparation of aqueous resin composition (7))
In a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 30.9 parts by mass of methyl ethyl ketone, 58.6 parts by mass of polyester polyol (2) of Synthesis Example 2 (solid content 46.9 parts by mass) Part) and 6.4 parts by mass of 1,6-hexanediol were prepared and adjusted at 50 ° C. with stirring.

  Next, after supplying 40 parts by mass of dicyclohexylmethane diisocyanate to the four-necked flask and reacting at 80 ° C. for about 3 hours, 6.7 parts by mass of 2,2-dimethylolpropionic acid, 23.8 parts by mass of methyl ethyl ketone And reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 22.3 parts by mass of dipentaerythritol hexaacrylate and 5 parts by mass of triethylamine were supplied, and 320.6 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, 11.8 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender is supplied to the four-necked flask and reacted, and then the solvent is removed under reduced pressure, whereby an aqueous resin having a non-volatile content of 35% by mass is obtained. A composition (4) was obtained. The aromatic ring concentration in the non-volatile content of this aqueous resin composition (4) was 1.7 mol / kg, and the polymerizable unsaturated bond concentration was 2.0 mol / kg.

(Example 8: Preparation of aqueous resin composition (8))
In a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 33.6 parts by mass of methyl ethyl ketone, pentaerythritol diacrylate (R ¹ in the general formula (1) has 3 carbon atoms) And having two atomic groups having a polymerizable unsaturated group.) 12.3 parts by mass, polyester polyol of Synthesis Example 2 (2) 48.8 parts by mass (solid content 39 parts by mass), 1 , 6-hexanediol 1.9 parts by weight, methylhydroquinone 0.002 parts by weight, and 2,6-tert-butyl-p-cresol 0.024 parts by weight were prepared and adjusted at 50 ° C. with stirring.

  Next, after supplying 40 parts by mass of dicyclohexylmethane diisocyanate to the four-necked flask and reacting at 80 ° C. for about 3 hours, 6.7 parts by mass of 2,2-dimethylolpropionic acid, 23.7 parts by mass of methyl ethyl ketone And reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 45.5 parts by mass of dipentaerythritol hexaacrylate and 5.0 parts by mass of triethylamine were supplied, and 288.5 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, after supplying 11.9 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting, an aqueous resin having a nonvolatile content of 40% by mass is removed under reduced pressure. A composition (8) was obtained. The aromatic ring concentration in the non-volatile content of this aqueous resin composition (8) was 1.4 mol / kg, and the polymerizable unsaturated bond concentration was 3.8 mol / kg.

(Comparative Example 1: Preparation of aqueous resin composition (C1))
In a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 30.8 parts by mass of methyl ethyl ketone, 58.5 parts by mass of the aromatic polyester polyol (2) of Synthesis Example 2 (solid content: 46. 9 parts by mass) and 6.4 parts by mass of 1,6-hexanediol were prepared and adjusted at 50 ° C. with stirring.

  Next, after supplying 40 parts by mass of dicyclohexylmethane diisocyanate to the four-necked flask and reacting at 80 ° C. for about 3 hours, 6.7 parts by mass of 2,2-dimethylolpropionic acid, 23.8 parts by mass of methyl ethyl ketone And reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 5 parts by mass of triethylamine was supplied, and 256.1 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, 11.8 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender is supplied to the four-necked flask and reacted, and then the solvent is removed under reduced pressure, whereby an aqueous resin having a non-volatile content of 35% by mass is obtained. A composition (C1) was obtained. The concentration of the aromatic ring in the non-volatile content of this aqueous resin composition (C1) was 1.7 mol / kg, and the polymerizable unsaturated bond concentration was 0 mol / kg.

(Comparative Example 2: Preparation of aqueous resin composition (C2))
Into a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 46.7 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.2 parts by mass, polycarbonate polyol (Polycarbonate polyol obtained by reacting 1,6-hexanediol, 1,5-pentanediol and diethyl carbonate, number average molecular weight 2000) 38 parts by mass, 4.5 parts by mass of 1,6-hexanediol, methylhydroquinone 0.003 part by mass and 0.026 part by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring. .

  Next, 40.4 parts by mass of dicyclohexylmethane diisocyanate was supplied to the four-necked flask and reacted at 80 ° C. for about 3 hours, and then 5 parts by mass of 2,2-dimethylolpropionic acid and 23.7 parts by mass of methyl ethyl ketone. And reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 10.1 parts by mass of dipentaerythritol hexaacrylate and 3.8 parts by mass of triethylamine were supplied, and 251.3 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, after supplying 12.0 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting, an aqueous resin having a nonvolatile content of 35% by mass is removed under reduced pressure. A composition (C2) was obtained. The aromatic ring concentration in the nonvolatile content of this aqueous resin composition (C2) was 0 mol / kg, and the polymerizable unsaturated bond concentration was 1.6 mol / kg.

(Comparative Example 3: Preparation of aqueous resin composition (C3))
To a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer and a reflux condenser, 42.9 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.2 parts by mass, polycarbonate polyol (Polycarbonate polyol obtained by reacting 1,6-hexanediol, 1,5-pentanediol and diethyl carbonate, number average molecular weight 2000) 38.2 parts by weight, 1,6-hexanediol 3.9 parts by weight, 0.002 part by mass of methylhydroquinone and 0.024 part by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring. It was.

  Next, after supplying 40.6 parts by mass of dicyclohexylmethane diisocyanate to the four-necked flask and reacting at 80 ° C. for about 3 hours, 5.1 parts by mass of 2,2-dimethylolpropionic acid, 23.8 of methyl ethyl ketone, A part by mass was supplied and reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 50 parts by mass of ethoxylated pentaerythritol tetraacrylate (“Aronix M460” manufactured by Toagosei Co., Ltd.) and 3.8 parts by mass of triethylamine are slowly added, and 372.3 parts by mass of deionized water-exchanged water is slowly added to make water-soluble. Carried out.

  Next, an aqueous resin composition having a nonvolatile content of 40% by mass is prepared by supplying 12 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting them. (C3) was obtained. The aromatic ring concentration in the non-volatile content of this aqueous resin composition (C3) was 0 mol / kg, and the polymerizable unsaturated bond concentration was 2.8 mol / kg.

(Comparative Example 4: Preparation of aqueous resin composition (C4))
To a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.1 parts by mass, polycarbonate polyol (Polycarbonate polyol obtained by reacting 1,6-hexanediol, 1,5-pentanediol and diethyl carbonate, number average molecular weight 2000) 43.4 parts by mass, 1,6-hexanediol 0.06 parts by mass, 0.002 part by mass of methylhydroquinone and 0.025 part by mass of 2,6-tert-butyl-p-cresol were charged and stirred at 50 ° C. Sei was.

  Next, after 36.7 parts by mass of dicyclohexylmethane diisocyanate was supplied to the four-necked flask and reacted at 80 ° C. for about 3 hours, 7.7 parts by mass of 2,2-dimethylolpropionic acid, methyl ethyl ketone 5.1 A part by mass was supplied and reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 163.1 parts by mass of dipentaerythritol hexaacrylate and 5.8 parts by mass of triethylamine were supplied, and 480.1 parts by mass of deionized water exchanged water was slowly added to effect water solubilization.

  Next, after supplying 10.8 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting, a silicon additive (“BYK-333” manufactured by Big Chemie Japan KK: poly Ether-modified polydimethylsiloxane) was added in an amount of 3.3 parts by mass, and the solvent was removed under reduced pressure to obtain an aqueous resin composition (C4) having a nonvolatile content of 40% by mass. The aromatic ring concentration in the non-volatile content of this aqueous resin composition (C4) was 0 mol / kg, and the polymerizable unsaturated bond concentration was 6.5 mol / kg.

(Comparative Example 5: Preparation of aqueous resin composition (C5))
To a 2 liter four-necked flask equipped with a heating device, a stirrer, a thermometer, and a reflux condenser, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2 R ₁ is ₂ carbon atoms, R ₂ is 4 carbon atoms, R ₃ is 2 carbon atoms, 2 atomic groups having a polymerizable unsaturated group) 12.1 parts by mass, polycarbonate polyol (Polycarbonate polyol obtained by reacting 1,6-hexanediol, 1,5-pentanediol and diethyl carbonate, number average molecular weight 2000) 43.4 parts by mass, 1,6-hexanediol 0.06 parts by mass, 0.002 part by mass of methylhydroquinone and 0.025 part by mass of 2,6-tert-butyl-p-cresol were charged and stirred at 50 ° C. Sei was.

  Next, after 36.7 parts by mass of dicyclohexylmethane diisocyanate was supplied to the four-necked flask and reacted at 80 ° C. for about 3 hours, 7.7 parts by mass of 2,2-dimethylolpropionic acid, methyl ethyl ketone 5.1 A part by mass was supplied and reacted at 80 ° C. for about 4 hours.

  Next, it cooled to 50 degreeC after reaction. After cooling, 163.1 parts by mass of dipentaerythritol hexaacrylate, 2.1 parts by mass of a fluorine additive (DIC Corporation “Megafac RS-56”), 5 parts by mass of triethylamine are supplied, and 487. 7 parts by mass was slowly added to effect water solubilization.

  Next, after supplying 10.8 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender to the four-necked flask and reacting, an aqueous resin having a nonvolatile content of 40% by mass is removed under reduced pressure. A composition (C5) was obtained. The aromatic ring concentration in the non-volatile content of this aqueous resin composition (C5) was 0 mol / kg, and the polymerizable unsaturated bond concentration was 6.8 mol / kg.

  The following evaluation was performed using the urethane resin composition obtained by said Example and comparative example.

[Preparation of test piece (1)]
The aqueous resin compositions obtained in Example 1 and Comparative Example 1 were each applied to the surface of a polycarbonate substrate so that the film thickness of the coating film was 15 μm. The coated material was dried at 70 ° C. for 5 minutes to obtain a test piece in which a coating film was laminated on the surface of the polycarbonate substrate.

[Preparation of test piece (2)]
4 parts by mass of photopolymerization initiator (mixture of 1-hydroxy-cyclohexyl-phenyl-ketone and benzophenone) with respect to 100 parts by mass of the solid content of the aqueous resin compositions obtained in Examples 2 to 8 and Comparative Examples 2 to 5 The compounded liquid obtained by blending was applied to the surface of the polycarbonate substrate so that the film thickness of the coating film was 15 μm. After the coated material is dried at 70 ° C. for 5 minutes, the surface of the polycarbonate substrate is irradiated with 0.5 J / cm ² of ultraviolet rays using a high-pressure mercury lamp (manufactured by GS Yuasa Co., Ltd.) for one pass. A test piece on which the coating film was laminated was obtained.

[Anti-fouling evaluation method]
The antifouling property of the coating film was evaluated by two methods, an aqueous type and an oily type.

  Preparation of the Test Specimen On the surface of each test specimen obtained by the method (1) or (2), an aqueous black marker (“Whiteboard Marker Black” manufactured by KOKUYO Co., Ltd.) and an aqueous blue marker (“White” manufactured by KOKUYO Co., Ltd.). A board marker blue ") was drawn each with a width of 10 mm, left for 4 hours, and then wiped with a dry cloth. The remaining color on the surface of the coating film after wiping was visually evaluated according to the following evaluation criteria.

A: No marker marks were left on the coating film surface.
○: A trace of the marker remained on the surface of the coating film.
Δ: Marker marks remained on the surface of the coating film by 5 mm or more.
X: All traces of markers remained on the coating film surface.

  A 10 mm wide line was drawn on the surface of the coating film with an oily black marker (“Mackey Care Black” manufactured by Zebra Co., Ltd.) and left for 4 hours, followed by wiping with a cloth soaked with a solvent (isopropyl alcohol). The remaining color on the surface of the coating film after wiping was visually evaluated according to the following evaluation criteria.

○: No marker marks were left on the surface of the coating film.
(Triangle | delta): The trace of the marker remained on the coating-film surface slightly.
X: Marker dyeing trace remained clearly about 10 mm on the coating film surface.

[Evaluation method of recoatability]
Preparation of Test Specimens On the coating surface of each test piece obtained by the method of (1) or (2), each aqueous resin composition obtained in Examples and Comparative Examples is coated with a film thickness of 15 μm. In addition, it was applied again, and the repellency of the surface when applied was visually evaluated according to the following evaluation criteria.

○: No repelling or liquid accumulation can be confirmed on the surface of the coating film.
(Triangle | delta): Although the repellency cannot be confirmed on the coating-film surface, the liquid pool was able to be confirmed.
X: Repelling and liquid accumulation were confirmed on the coating film surface.

  Table 1 shows the compositions and evaluation results of the aqueous resin compositions (1) to (8) prepared in Examples 1 to 8.

  Table 2 shows the compositions and evaluation results of the aqueous resin compositions (C1) to (C5) prepared in Comparative Examples 1 to 5.

  From the evaluation results of Examples 1 to 8 shown in Table 1, it was confirmed that the coating film obtained using the aqueous resin composition of the present invention was excellent in antifouling property and recoatability.

  On the other hand, Comparative Examples 1-2 is an example using the aqueous resin composition whose sum total of a polymerizable unsaturated bond density | concentration and an aromatic ring density | concentration is less than 3 mol / kg. Although the coating film obtained using the aqueous resin composition of Comparative Example 1 and Comparative Example 2 was excellent in recoatability, it was confirmed that the antifouling property was remarkably insufficient.

  Moreover, the comparative example 3 is an example using the aqueous resin composition whose sum total of a polymerizable unsaturated bond density | concentration and an aromatic ring density | concentration is less than 3 mol / kg. Although the coating film obtained using the aqueous resin composition of Comparative Example 3 is excellent in antifouling property (aqueous marker) and recoatability, it can be confirmed that the antifouling property (oil-based marker) is insufficient. It was.

  Comparative Example 4 is an example using an aqueous resin composition containing a silicon additive. Although the coating film obtained using the aqueous resin composition of Comparative Example 3 was excellent in antifouling property, it was confirmed that recoatability was extremely insufficient.

  Comparative Example 5 is an example using an aqueous resin composition containing a fluorine additive. Although the coating film obtained using the aqueous resin composition of Comparative Example 4 was excellent in antifouling property, it was confirmed that recoatability was extremely insufficient.

Claims (9)

  An aqueous resin composition containing a urethane resin (A) which is a reaction product of a polyol (a1) and a polyisocyanate (a2), and an aqueous medium (B), and polymerization in a nonvolatile content of the aqueous resin composition The aqueous resin composition, wherein the total of the unsaturated bond concentration and the aromatic ring concentration is 3 mol / kg or more.   The aqueous resin composition according to claim 1, further comprising a polyfunctional acrylate (C).   The aqueous resin composition according to claim 2, wherein the average number of functional groups per compound of the polyfunctional acrylate (C) is 4 or more. The polyol (a1) is an alkylene diol (a1-1) further having two or more polymerizable unsaturated groups represented by the following general formula (1) or two or more polymerizations represented by the following general formula (2) The aqueous resin composition according to claim 1, which contains an oxyalkylenediol (a1-2) having a polymerizable unsaturated group.

(R ¹ in the general formula (1) represents a structure having two or more atomic groups containing a polymerizable unsaturated group in the side chain of a linear alkylene group having 1 to 9 carbon atoms.)

(R ¹ and R ³ in the general formula (2) represent a structure having a total of two or more atomic groups containing a polymerizable unsaturated group in the side chain of the ethylene group. R ² has 1 to 5 carbon atoms. Represents an alkylene group.)   The aqueous resin composition according to claim 1, wherein the polyol (a1) further contains an aromatic polyester polyol (a1-3).   The aqueous resin composition according to claim 5, wherein the alkylene diol (a1-1) is pentaerythritol diacrylate.   The total mass of the said alkylene diol (a1-1) and the said oxyalkylene diol (a1-2) is the range of 0.1-49 mass% in the whole quantity of the raw material used for manufacture of the said urethane resin (A). The aqueous resin composition according to claim 5.   A coating agent comprising the aqueous resin composition according to claim 1.   An article comprising the coating film of the coating agent according to claim 8.