JP6988087B2 - Aqueous resin compositions, coatings and articles - Google Patents

Description

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

Aqueous resin compositions, especially aqueous urethane resin compositions, generally have good adhesion to a substrate and can form a flexible coating film, and thus are used in various applications such as coating agents and adhesives. in use.

As a coating agent using the aqueous resin composition, it is generally required to be able to form a coating film capable of preventing deterioration of the surface of various base materials, to be able to impart designability to the surface of the base material, and the like. In particular, in recent years, there has been a demand from the industrial world for a coating agent having excellent antifouling properties from the viewpoint of design protection in addition to the hardness and durability of the formed coating film. The coating agent having the above-mentioned characteristics is in increasing demand for surface treatment applications such as metal base materials such as steel sheets, glass base materials, and plastic base materials.

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

However, although the coating agent exhibits excellent antifouling properties by migrating fluorine or silicon to the surface of the coating film, reducing the adhesion of stains and making it easier to wipe off the stains, the surface of the coating film has excellent antifouling properties. In order to reduce the surface free energy and the adhesiveness, recoating with the coating agent causes a decrease in the adhesiveness. Further, in applications such as whiteboards where rewriting on the surface of a coating film is routinely performed, there is a problem that water-based 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 that has antifouling properties and can form a coating film that can be reapplied.

Japanese Unexamined Patent Publication No. 2005-60675

An object to be solved by the present invention is to provide an aqueous resin composition capable of forming a coating film having excellent antifouling property and recoating property.

As a result of diligent research to solve the above problems, the present inventors have obtained an aqueous resin composition containing a urethane resin (A) and an aqueous medium (B), and the non-volatile content of the aqueous resin composition. The present invention has been completed by finding that the above problems can be solved by using an aqueous resin composition in which the total concentration of the polymerizable unsaturated group and the concentration of the aromatic ring is equal to or more than a specific amount.

That is, the present invention is 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). The present invention relates to an aqueous resin composition, a coating agent and an article, wherein 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, and polystyrene resin. It can be suitably used as a coating agent and an adhesive for a plastic base material such as (PS resin), polymethacrylic acid resin (PMMA resin), and polyester resin (PET resin).

The aqueous resin composition of the present invention comprises a urethane resin (A) and an aqueous medium (B), and 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. It is characterized by being / kg or more.

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

The polyol (a1) is further described below 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 the urethane bond is 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). Those containing (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 an 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) is radically polymerized when forming a coating film or the like. This makes it possible to form a coating film having excellent hardness, elongation and flexibility.

As the alkylene diol (a1-1), one having a structure represented by the 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), it is preferable to use one having two or more and five or less polymerizable unsaturated groups, and one having two or more and three or less polymerizable unsaturated groups is used. This is more preferable because a urethane resin composition capable of forming a coating film having excellent hardness, elongation and flexibility can be obtained.

Examples of the alkylene diol (a1-1) include pentaerythritol di (meth) acrylate [dimethylol propandi (meth) acrylate] and dimethylol methanedi (meth) acrylate (R ¹ in the general formula (1) is , It has 3 carbon atoms and has two atomic groups having a polymerizable unsaturated group.), Diethylol methanedi (meth) acrylate, Diethylol propandi (meth) acrylate (general formula (1). ) R ¹ in the intended 5 carbon atoms, is an atomic group having a polymerizable unsaturated group as it has two.), di-propanol methane di (meth) acrylate, di propanol propane di (meth) ^{Acrylate (R 1} in the general formula (1) has 7 carbon atoms and has two atomic groups having a polymerizable unsaturated group), dibutanolmethane di (meth) acrylate, and di. Examples thereof include butanol propandi (meth) acrylate (R ¹ in the general formula (1) has 9 carbon atoms and has two atomic groups having a polymerizable unsaturated group). Of these, pentaerythritol di (meth) acrylate and dimethylolmethane di (meth) acrylate are preferable because they can obtain a urethane resin composition capable of forming a coating film having excellent hardness, elongation and flexibility. Further, these alkylene diols (a1-1) can be used alone or in combination of two or more. In the present invention, "(meth) acrylate" means either one or both of acrylate and methacrylate.

Further, as the oxyalkylene diol (a1-2), one having a structure represented by the 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), a total of two or more structures having an atomic group containing a polymerizable unsaturated group in the side chain of the ethylene group is provided, preferably in the range of two or more and five or less. More preferably, it has a range of 2 or more and 3 or less.

^{Further, 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.

As the oxyalkylene diol (a1-2), for example, bis (3-acryloyloxy-2-hydroxypropoxy) ^{R 1} and ^{R 3} in methane (formula (2) by way of 2 carbon atoms, polymerizable It has one atomic group having an unsaturated group, and R ² has one carbon atom.) 1,2-Bis (3-acryloyloxy-2-hydroxypropoxy) ethane (general formula (2). ), R ¹ and R ³ have 2 carbon atoms, have one atomic group having a polymerizable unsaturated group, and R ² has 2 carbon atoms.) 1, 1, 3- bis (3-acryloyloxy-2-hydroxypropoxy) propane (formula (2) R ¹ and R ³ in the intended 2 carbon atoms, having one atomic group having a polymerizable unsaturated group , R ² has 3 carbon atoms.) 1,4-Bis (3-acryloyloxy-2-hydroxypropoxy) butane (R ¹ and R ³ in the general formula (2) have carbon atoms. Of 2, it has one atomic group having a polymerizable unsaturated group, and R ² has 4 carbon atoms.) 1,5-bis (3-acryloyloxy-2-hydroxypropoxy). ^{) Pentan (R 1} and R ³ in the general formula (2) ^{have 2} carbon atoms and have one atomic group having a polymerizable unsaturated group, and R 2 has 5 carbon atoms. It is mentioned.) And the like. Of these, 1,4-bis (3-acryloyloxy-2-hydroxypropoxy) butane is preferable because it can obtain a urethane resin composition capable of forming a coating film having excellent hardness, elongation and flexibility. Further, these oxyalkylene diols (a1-2) can be used alone or in combination of two or more.

The alkylene diol (a1-1) and the oxyalkylene diol (a1-2) are used in a total amount of 0.1 to 49% by mass in the total amount of the raw materials used for producing the urethane resin (A). This is preferable because a urethane resin composition capable of forming a coating film having excellent hardness, elongation and flexibility can be obtained, and it is more preferable to use it in the range of 1 to 15% by mass. The total amount of the raw materials used for producing the urethane resin (A) refers to the total mass including the polyol (a1), the polyisocyanate (a2), and the chain extender when used.

As the polyol (a1), an aromatic polyester polyol (a1-3) can also be used because a coating film having excellent antifouling properties can be formed.

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 for producing 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, ethylene glycol, 1,2. -It is preferable to use a combination of propanediol, 1,3-butanediol, 1,4-butanediol and the like with 3-methyl-1,5-pentanediol, neopentyl glycol and the like.

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

Further, as the polyol (a1), other polyols can be used in combination with the above-mentioned polyol, if necessary.

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, a polyol having an anionic group is preferable.

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-dimethylolpropane valeric acid and the like, and among them, 2,2-dimethylol. Propionic acid is preferred. Further, a polyester polyol having a carboxyl group obtained by reacting the polyol having a carboxyl group 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, and 5- (4-sulfophenoxy) isophthalic acid, and salts thereof; with the dicarboxylic acid. , Ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol and other low molecular weight polyols, and further the polyester polyol and γ-butyrolactone. , Δ-Valerolactone, ε-caprolactone and the like can be mentioned as a polyester polyol obtained by reacting with a cyclic ester compound.

It is preferable that some or all of the anionic groups are neutralized with a basic compound or the like in order to exhibit good water dispersibility.

Examples of the basic compound that can be used for neutralizing the anionic group include organic amines having a boiling point of 200 ° C. or higher, such as ammonia, triethylamine, morpholine, monoethanolamine, and diethylethanolamine; sodium hydroxide and water. Examples thereof include metal hydroxides containing potassium oxide, lithium hydroxide and the like. 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 it in the range of 0.7 to 1.5 (molar ratio), and it is more preferable to use it in the range of 0.7 to 1.5 (molar ratio).

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

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, it is preferable that a part or all of the tertiary amino group as the cationic group is quaternized. Examples of the quaternizing agent include dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride and the like, 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 the raw material used for producing the urethane resin (A), and further, in terms of hardness, elongation and flexibility. Since a urethane resin composition capable of forming an excellent coating film can be obtained, it is more preferable to use it in the range of 1 to 15% by mass.

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

The polyester polyol may be, for example, a polyester polyol obtained by reacting a low molecular weight polyol with a polycarboxylic acid; a polyester polyol obtained by ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone; Examples thereof 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, and 1,3-butanediol having a molecular weight of about 50 to 300. An aliphatic polyol; a polyol having an alicyclic structure such as cyclohexanedimethanol can be mentioned. 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.

Further, the polycarbonate polyol is obtained by subjecting carbonic acid and carbonic acid ester to an esterification reaction 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. And so on. 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 an 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, trimethylolgluco, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, and di. Examples thereof 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 may 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, preferably in the range of 15 to 50% by mass, in the total amount of the raw materials used for producing the urethane resin (A). It is more preferable to use the above because it can form a coating film having excellent hardness, elongation and flexibility.

The polyisocyanate (a2) used for producing the urethane resin (A) is, for example, a polyisocyanate having an aliphatic cyclic structure such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, or isophorone diisocyanate; 4,4'-diphenylmethane. Aromatic polyisocyanates such as diisocyanate, 2,4'-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylenedi isocyanate, tolylene diisocyanate, naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate. Examples thereof include aliphatic polyisocyanates such as isocyanates. Of these, it is preferable to use an aromatic polyisocyanate because a coating film having excellent hardness, elongation and flexibility can be formed. Further, 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) with the polyisocyanate (a2), for example, with the polyol (a1) in the absence of a solvent or in the presence of an organic solvent. Examples thereof include a method of mixing with the polyisocyanate (a2) and reacting at a reaction temperature in the range of about 50 ° C. to 150 ° C.

In the reaction between 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. It is preferable to carry out in the range of 0.9 to 1.5, and it is more preferable to carry out in the range of 0.9 to 1.5.

Further, when the urethane resin (A) is produced, a coating film having excellent hardness, elongation and flexibility can be formed. Therefore, in addition to the polyol (a1) and the polyisocyanate (a2), it is necessary. Depending on the chain extender, a chain extender can be used.

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; examples include diaminetriamine, dipropylenetriamine, triethylenetetramine and the like. In addition, 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-hexamethylene bishydrazine; succinate dihydrazide, adipic acid dihydrazide, glutarate dihydrazide, sebacic acid dihydrazide, isophthalate dihydrazide; β-semicarbazide. Examples thereof include propionic acid hydrazide. In addition, these hydrazine compounds may be used alone or in combination of two or more.

Examples of the other active hydrogen-containing compound include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, and saccharose. Glycols such as methylene glycol, glycerin, sorbitol; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone, hydrogenated bisphenol A, phenols such as hydroquinone, and water. Etc., and can be used alone or in combination of two or more as long as the storage stability of the aqueous resin composition of the present invention is not deteriorated.

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

Further, in order to reduce the load on the safety and the environment, the organic solvent removes a 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 possible to use a urethane resin (A) having a weight average molecular weight in the range of 10,000 to 500,000. It is preferable to use one having a weight average molecular weight in the range of 20,000 to 200,000, and even more preferably to use one having a weight average molecular weight in the range of 40,000 to 100,000.

Further, as the urethane resin (A), it is preferable to use one having a urea bond because a coating film having excellent hardness, elongation and flexibility can be formed.

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

Examples of the aqueous medium (B) used in the present invention include water, an organic solvent miscible with water, and a mixture thereof. Examples of the organic solvent to be mixed 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; polyalkylene glycols. Alkyl ethers; examples include lactam solvents such as N-methyl-2-pyrrolidone. 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.

Further, as the aqueous medium (B), only water or a mixture of water and an organic solvent miscible with water is preferable, and only water is particularly preferable, from the viewpoint of safety and environmental load.

The proportion of the aqueous medium (B) is preferably in the range of 10 to 90% by mass, 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 non-volatile content of the aqueous resin composition is preferably in the range of 0 to 14 mol / kg, and the aromatic ring concentration in the non-volatile content of the aqueous resin composition is 0 to 6 mol / kg. It is preferably in the range of kg. Further, when 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 property and recoating property can be formed. More preferably, it is more preferably 4 mol / kg or more.

Further, the aqueous resin composition of the present invention may contain a polyfunctional acrylate (C) because it can form a coating film having excellent antifouling property and recoating property.

Examples of the polyfunctional acrylate (C) include pentaerythritol tetra (meth) acrylate, ditrimethylolpropanetetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and trimethylol ethylene. Oxide-modified triacrylate, diglycerin ethylene oxide-modified (meth) acrylate, trimethylolpropanetri (meth) acrylate, trimethylolpropanepropylene oxide-modified triacrylate, pentaerythritol tri (meth) acrylate, isocyanuric acid ethylene oxide-modified triacrylate, glycerin Examples thereof include tri (meth) acrylate, glycerin propoxytriacrylate, and pentaerythritol ethylene oxide-modified tetraacrylate. By using these, it is possible to obtain an aqueous resin composition capable of forming a coating film having even higher hardness. Of these, dipentaerythritol hexa (meth) acrylate is preferable. Further, these polyfunctional acrylates can be used alone or in combination of two or more.

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

Further, the average number of functional groups per compound of the polyfunctional acrylate (C) is preferably 3 or more because it can form a coating film having excellent antifouling properties, and more preferably 4 or more.

Further, when the aqueous resin composition of the present invention contains the polyfunctional acrylate (C), the ratio of the polymerizable unsaturated bond in the total of the urethane resin (A) and the polyfunctional acrylate (C) is 0. The range of ~ 9.5 mol / kg is preferable because a coating film having excellent antifouling property and recoating property can be formed, and the range of 1.5-9 mol / kg is more preferable. It is more preferable to have it 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), or the urethane resin (A) may be added in the aqueous medium (B). It may be added after being dispersed in.

The aqueous resin composition of the present invention obtained by the above method 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 preferably contained, and more preferably contained in the range of 15% by mass to 50% by mass.

The aqueous resin composition may contain an additive, if necessary, and the additive includes, for example, a film-forming aid, a filler, a thixotropy-imparting agent, an adhesive-imparting agent, 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 auxiliary include an anionic surfactant (dioctylsulfosuccinic acid ester soda salt and the like), a hydrophobic nonionic surfactant (sorbitan monooleate and the like), silicone oil and the like.

Examples of the thixotropy-imparting agent include the filler, polyvinyl chloride powder, hydrogenated castor oil, which has been surface-treated with fatty acid, fatty acid metal salt, fatty acid ester, paraffin, resin acid, surfactant, polyacrylic acid and the like. Examples thereof include fine powder silica, organic bentonite, and sepiolite.

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

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

Examples of the organic pigment include quinacridone pigment, quinacridone quinone pigment, dioxazine pigment, phthalocyanine pigment, anthrapyrimidine pigment, anthanthrone pigment, indanslon pigment, flavanthron pigment, perylene pigment, diketopyrrolopyrrole pigment, perinone pigment, and the like. Examples thereof 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. Further, these pigments may be surface-treated and have self-dispersing ability with respect to an aqueous medium.

Examples of the antibacterial agent include silver chloride, trifluanide, dichlorfluanide, fluorofolpet, zinc pyrithione, methyl 2-benzoimidazole carnate, 2- (4-thiazolyl) benzoimidazole and the like.

Examples of other additives include reaction accelerators (metal-based reaction accelerators, metal salt-based reaction accelerators, amine-based reaction accelerators, etc.), photopolymerization initiators, radical polymerization initiators, stabilizers (ultraviolet absorbers). , Antioxidants, heat-resistant stabilizers, etc.), Moisture removers (4-paratoluene sulfonyl isocyanate, etc.), Adsorbents (fresh lime, delime, zeolite, molecular sieve, etc.), Adhesive-imparting agents, antifoaming agents, leveling agents, etc. Various additives of the above are mentioned.

Examples of the photopolymerization initiator include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2-benzyl-2-dimethylamino-1- (4-morpholino). Phenyl) -butanone, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphinoxide, 2,4,6-trimethylbenzoyl -Diphenyl-phosphine oxide and the like can be mentioned. These photopolymerization initiators may 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), and azobiscyanovaleric acid; tert-butylper. Organics such as oxypivalate, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide, etc. Peroxides: Inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate and the like. 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 capable of imparting surface protection and designability to various base materials.

Examples of the base material to which the coating agent can be applied to form a coating film include a glass base material, a metal base material, a plastic base material, paper, a wood base material, and a fibrous base material. It can also be used as a base material having a porous structure such as urethane foam.

Examples of the metal base material 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, stainless steel plates and the like.

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

The various base materials may be a flat material made of the material, a material having a curved portion, or a base material made of fibers such as a non-woven 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 provided with a primer layer or the like in advance and dried to form a coating film. Further, 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 coating agent contained therein is applied directly to the surface of the base material or on the surface of the base material provided with a primer layer or the like in advance, and then dried, and then the urethane resin (A) and the polyfunctional acrylate (C) are obtained. A coating film can be formed by advancing the radical polymerization of the polymerizable unsaturated bond group of the resin by an active energy ray or heat.

Further, 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 then an adhesive or an adhesive is applied on the coating film to form a non-woven fabric. A coating film formed by using the coating agent can be laminated on the surface of a desired base material by adhering it to a base material made of such fibers and peeling off the paper pattern.

Examples of the method of 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.

In addition, examples of the method of curing the coating agent include a method of heating and a method of irradiating with active energy rays such as ultraviolet rays.

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

Further, as a method of irradiating the active energy ray, for example, in the case of ultraviolet rays, 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 can be 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} . The above-mentioned ultraviolet irradiation amount is based on a value measured in a wavelength range of 300 to 390 nm using a UV checker UVR-N1 (manufactured by Nippon Battery Co., Ltd.).

The thickness of the coating film that can be formed by using the coating agent of the present invention can be appropriately adjusted depending on the intended use of the substrate and the like, but is usually preferably about 0.1 μm to 100 μm.

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

Hereinafter, the present invention will be specifically described with reference to 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 introduction 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, and diethylene glycol 19. 9 parts by mass and 0.03 part by mass of dibutyltin oxide were charged and subjected to a polycondensation reaction at 230 ° C. for 24 hours at 180 to 230 ° C. until the acid value became 1 or less 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 introduction tube, and a stirrer, 35.1 parts by mass of isophthalic acid, 11.6 parts by mass of 1,6-hexanediol, and 17.7 parts by mass of sebacic acid. , 6.5 parts by mass of ethylene glycol, 21.4 parts by mass of neopentyl glycol, 7.7 parts by mass of adipic acid and 0.04 parts by mass of dibutyltin oxide, 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 the 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, then cooled to 80 ° C., 66.5 parts by mass of methyl ethyl ketone was added, and the mixture was stirred and uniform. Was mixed with. 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, the mixture was further reacted for 2 hours, and then cooled 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 carry out water solubilization. Then, under reduced pressure, methyl ethyl ketone was removed at 30 to 50 ° C. to obtain an aqueous resin composition (1) having a non-volatile content of 23.5% by mass. The aromatic ring concentration in the non-volatile content of this aqueous resin composition (1) was 3.2 mol / kg, and the polymerizable unsaturated bond concentration was 0 mol / kg.

(Example 2: Preparation of aqueous resin composition (2))
In a 2 liter 4-port flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 parts by mass of methylhydroquinone and 0.024 parts by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring.

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, and then 7.7 parts by mass of 2,2-dimethylolpropionic acid and 5.2 parts of methyl ethyl ketone. A mass portion was supplied and reacted at 80 ° C. for about 4 hours.

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized water exchanged water was slowly added to carry out water solubilization.

Next, 10.9 parts by mass of a 10% by mass piperazine aqueous solution was supplied to the four-necked flask as a chain extender, reacted, and then desolvated under reduced pressure to form an aqueous resin having a non-volatile content of 40% by mass. The composition (2) was obtained. The aromatic ring concentration 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))
In a 2 liter 4-mouth flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 42.9 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 mass, 1,6-hexanediol 3.9 parts by mass, 0.002 parts by mass of methylhydroquinone and 0.025 parts by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring.

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

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized water exchanged water was slowly added to carry out water solubilization.

Next, 11.9 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender was supplied to the four-necked flask to react, and then the solvent was removed under reduced pressure to cause an aqueous resin having a non-volatile content of 37% by mass. The composition (3) was obtained. The aromatic ring concentration 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))
In a 2 liter 4-neck flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 33.1 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxilo) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 and 23.8 parts by mass of methyl ethyl ketone. A mass portion was supplied and reacted at 80 ° C. for about 4 hours.

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized 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 was supplied to the four-necked flask to react, and then the solvent was removed under reduced pressure to cause an aqueous resin having a non-volatile content of 37% by mass. The composition (4) was obtained. The aromatic ring concentration 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))
In a 2 liter 4-neck flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 33.6 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxilo) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 was 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 methylethylketone were supplied. Then, the reaction was carried out at 80 ° C. for about 4 hours.

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized 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 was supplied to the four-necked flask to react, and then the solvent was removed under reduced pressure to cause an aqueous resin having a non-volatile content of 40% by mass. The 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))
In a 2 liter 4-port flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 parts by mass of methylhydroquinone and 0.024 parts by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring.

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, and then 7.7 parts by mass of 2,2-dimethylolpropionic acid and 5.2 parts of methyl ethyl ketone. A mass portion was supplied and reacted at 80 ° C. for about 4 hours.

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized water exchanged water was slowly added to carry out water solubilization.

Next, 10.9 parts by mass of a 10% by mass piperazine aqueous solution was supplied to the four-necked flask as a chain extender, reacted, and then desolvated under reduced pressure to form an aqueous resin having a non-volatile content of 40% by mass. The composition (6) was obtained. The aromatic ring concentration 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 and 58.6 parts by mass (solid content 46.9 mass) of the polyester polyol (2) of Synthesis Example 2 Part), 6.4 parts by mass of 1,6-hexanediol was charged and adjusted at 50 ° C. with stirring.

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

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized 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 was supplied to the four-necked flask to react, and then the solvent was removed under reduced pressure to cause an aqueous resin having a non-volatile content of 35% by mass. The 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 4-neck 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. It has 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 , 1.9 parts by mass of 6-hexanediol, 0.002 parts by mass of methylhydroquinone, and 0.024 parts by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring.

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

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized water exchanged water was slowly added to carry out water solubilization.

Next, 11.9 parts by mass of a 10% by mass piperazine aqueous solution was supplied to the four-necked flask as a chain extender, reacted, and then desolvated under reduced pressure to form an aqueous resin having a non-volatile content of 40% by mass. The 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 and 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 charged and adjusted at 50 ° C. with stirring.

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

Next, after the reaction, the mixture was cooled to 50 ° C. After cooling, 5 parts by mass of triethylamine was supplied, and 256.1 parts by mass of ionized 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 was supplied to the four-necked flask to react, and then the solvent was removed under reduced pressure to cause an aqueous resin having a non-volatile content of 35% by mass. The composition (C1) was obtained. The aromatic ring concentration 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))
In a 2 liter 4-mouth flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 46.7 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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, 1,6-hexanediol 4.5 parts by mass, methylhydroquinone 0.003 parts by mass and 0.026 parts 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 the mixture was reacted at 80 ° C. for about 3 hours, followed by 5 parts by mass of 2,2-dimethylolpropionic acid and 23.7 parts by mass of methyl ethyl ketone. Was supplied and reacted at 80 ° C. for about 4 hours.

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized water exchanged water was slowly added to carry out water solubilization.

Next, 12.0 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender was supplied to the four-necked flask to react, and then the solvent was removed under reduced pressure to cause an aqueous resin having a non-volatile content of 35% by mass. The composition (C2) was obtained. The aromatic ring concentration in the non-volatile 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))
In a 2 liter 4-mouth flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 42.9 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 mass, 1,6-hexanediol 3.9 parts by mass, 0.002 parts by mass of methylhydroquinone and 0.024 parts by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring.

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

Next, after the reaction, the mixture was cooled to 50 ° C. After cooling, 50 parts by mass of ethoxylated pentaerythritol tetraacrylate (“Aronix M460” manufactured by Toa Synthetic Co., Ltd.) and 3.8 parts by mass of triethylamine were supplied, and 372.3 parts by mass of ionized water exchanged water was slowly added to make it water-soluble. Was carried out.

Next, 12 parts by mass of a 10% by mass piperazine aqueous solution was supplied to the four-necked flask as a chain extender, reacted, and then desolvated under reduced pressure to form an aqueous resin composition having a non-volatile content of 40% by mass. (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))
In a 2 liter 4-port flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 parts by mass of methylhydroquinone and 0.025 parts by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring.

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 5.1 parts of methyl ethyl ketone. A mass portion was supplied and reacted at 80 ° C. for about 4 hours.

Next, after the reaction, the mixture was cooled to 50 ° C. 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 ionized water exchanged water was slowly added to carry out water solubilization.

Next, 10.8 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender was supplied to the four-necked flask and reacted, and then a silicon additive (“BYK-333” manufactured by Big Chemie Japan Co., Ltd .: poly). 3.3 parts by mass of ether-modified polydimethylsiloxane) was added and the solvent was removed under reduced pressure to obtain an aqueous resin composition (C4) having a non-volatile 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))
In a 2 liter 4-port flask equipped with a heating device, a stirrer, a thermometer and a reflux cooling tube, 61.5 parts by mass of methyl ethyl ketone, 1,4-bis (3-acryloyloxy-2-hydroxyproxy) butane (general formula (2). ), R _{1 has 2} carbon atoms, R 2 has 4 carbon atoms, R ₃ has 2 carbon atoms, and 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 parts by mass of methylhydroquinone and 0.025 parts by mass of 2,6-tert-butyl-p-cresol were charged and adjusted at 50 ° C. with stirring.

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 5.1 parts of methyl ethyl ketone. A mass portion was supplied and reacted at 80 ° C. for about 4 hours.

Next, after the reaction, the mixture was cooled to 50 ° C. After cooling, 163.1 parts by mass of dipentaerythritol hexaacrylate, 2.1 parts by mass of fluorine additive (DIC Corporation positive "Megafuck RS-56"), and 5 parts by mass of triethylamine were supplied, and ionized water exchanged water 487. 7 parts by mass was slowly added to carry out water solubilization.

Next, 10.8 parts by mass of a 10% by mass piperazine aqueous solution as a chain extender was supplied to the four-necked flask to react, and then the solvent was removed under reduced pressure to cause an aqueous resin having a non-volatile content of 40% by mass. The 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 evaluations were performed using the urethane resin compositions obtained in the above Examples and Comparative Examples.

[Preparation of test piece (1)]
The aqueous resin compositions obtained in Example 1 and Comparative Example 1 were applied to the surfaces of the 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 a 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 composition obtained in Examples 2 to 8 and Comparative Examples 2 to 5. The compounding solution obtained by compounding was applied to the surface of each polycarbonate substrate so that the film thickness of the coating film was 15 μm. After drying the coating film at 70 ° C. for 5 minutes, the surface of the polycarbonate substrate is exposed to 1 pass of ultraviolet rays of ^{0.5 J / cm 2} using a high-pressure mercury lamp (manufactured by GS Yuasa Co., Ltd.). A test piece having a laminated coating film was obtained.

[Evaluation method of antifouling property]
The antifouling property of the coating film was evaluated by two methods, a water-based type and an oil-based type.

Preparation of the test piece The surface of each test piece obtained by the method (1) or (2) has a water-based black marker (“whiteboard marker black” manufactured by KOKUYO Co., Ltd.) and a water-based blue marker (“white” manufactured by KOKUYO Co., Ltd.). A line with a width of 10 mm was drawn with a marker for board blue ”), left for 4 hours, and then wiped off with a dry cloth. The degree of color remaining on the surface of the coating film after wiping was visually evaluated according to the following evaluation criteria.

⊚: No marker marks remained on the surface of the coating film.
◯: A slight marker mark 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 marker marks remained on the surface of the coating film.

A line having a width of 10 mm was drawn on the surface of the coating film with an oil-based black marker (“McKee Care Black” manufactured by Zebra Co., Ltd.), left for 4 hours, and then wiped off with a cloth dampened with a solvent (isopropyl alcohol). The degree of color remaining on the surface of the coating film after wiping was visually evaluated according to the following evaluation criteria.

◯: No marker marks remained on the surface of the coating film.
Δ: A slight mark of a marker remained on the surface of the coating film.
X: A marker dyeing mark was clearly left on the surface of the coating film by about 10 mm.

[Evaluation method of recoatability]
Preparation of the test pieces On the coated surface of each test piece obtained by the method (1) or (2), each aqueous resin composition obtained in Examples and Comparative Examples was applied so that the film thickness of the coating film was 15 μm. Then, it was applied again, and the degree of repelling on the surface when applied was visually evaluated according to the following evaluation criteria.

◯: No repellency or liquid pool can be confirmed on the surface of the coating film.
Δ: No repelling was confirmed on the surface of the coating film, but liquid pool was confirmed.
X: Repellents and liquid pools could be confirmed on the surface of the coating film.

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 by using the aqueous resin composition of the present invention was excellent in antifouling property and recoating property.

On the other hand, Comparative Examples 1 and 2 are examples in which an aqueous resin composition having a total polymerizable unsaturated bond concentration and aromatic ring concentration of less than 3 mol / kg was used. It was confirmed that the coating films obtained by using the aqueous resin compositions of Comparative Example 1 and Comparative Example 2 were excellent in recoating property but significantly inadequate in antifouling property.

Further, Comparative Example 3 is an example using an aqueous resin composition in which the total of the polymerizable unsaturated bond concentration and the aromatic ring concentration is less than 3 mol / kg. It can be confirmed that the coating film obtained by using the aqueous resin composition of Comparative Example 3 is excellent in antifouling property (water-based marker) and recoating property, but insufficient in antifouling property (oil-based marker). rice field.

Further, Comparative Example 4 is an example using an aqueous resin composition containing a silicon additive. It was confirmed that the coating film obtained by using the aqueous resin composition of Comparative Example 3 was excellent in antifouling property, but the recoating property was remarkably insufficient.

Further, Comparative Example 5 is an example using an aqueous resin composition containing a fluorine additive. It was confirmed that the coating film obtained by using the aqueous resin composition of Comparative Example 4 was excellent in antifouling property but remarkably inadequate in recoating property.

Claims (7)

An aqueous resin composition containing a urethane resin (A) which is a reaction product of a polyol (a1) and a polyisocyanate (a2), an aqueous medium (B), and a polyfunctional acrylate (C). The total of the polymerizable unsaturated bond concentration and the aromatic ring concentration in the non-volatile content of the composition is 3 mol / kg or more, and the polyol (a1) is two or more polymerizable non-polymerizable compounds represented by the following general formula (1). alkylene diols having a saturated group (a1 - 1) or the following general formula polyoxyalkylene diol having two or more polymerizable unsaturated group represented by (2) (a1 - 2) are those containing, silicone additives or fluorine aqueous resin composition, wherein the additive is one which does not contain (provided that the polyfunctional acrylate is 9,9 - bis case containing the 4 - - (2-acryloyloxy ethoxy) phenyl] fluorene except).

^{(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 an ethylene group. R ² has 1 to 5 carbon atoms. Represents an alkylene group.)
The average functionality per compound of the polyfunctional acrylate (C) The aqueous resin composition according to claim 1, wherein 4 or more. The aqueous resin composition according to claim 1 or 2 , wherein the polyol (a1) further contains an aromatic polyester polyol (a1-3). The aqueous resin composition according to any one of claims 1 to 3, wherein the alkylene diol (a1-1) is pentaerythritol diacrylate. The total mass of the alkylene diol (a1-1) and the oxyalkylene diol (a1-2) is in the range of 0.1 to 49% by mass in the total amount of the raw materials used for producing the urethane resin (A). The aqueous resin composition according to any one of claims 1 to 4. A coating agent comprising the aqueous resin composition according to any one of claims 1 to 5. An article comprising a coating film of the coating agent according to claim 6.