JP2022060137A - Clear coating composition - Google Patents

Abstract

To provide a coating composition which enables formation of a coated film having good coated film appearance, and good antibacterial/antiviral performance.SOLUTION: A clear coating composition contains a silver-containing antibacterial/antiviral agent and a binder resin, in which a silver elution amount when a cured coated film of the clear coating composition is immersed in the water for 24 hours is 0.0008-0.003 mg/1 L per 1 cm2 on a surface area of the cured coated film, 20° specular glossiness of the cured coated film of the clear coating composition is 150 or more, and the binder resin contains an anionic resin.SELECTED DRAWING: None

Description

The present invention relates to a clear paint composition.

A coating film is formed on the surface of many articles such as various industrial products, building materials, and large structures for the purpose of surface protection, designability, and functionalization. Further, in recent years, a method for imparting antibacterial and antiviral performance to a coating film formed on the surface of such an article is being studied. As a method for imparting antibacterial and antiviral performance to a coating film, for example, a method of including an antiviral agent in a coating composition can be mentioned.

Japanese Unexamined Patent Publication No. 2018-024633 (Patent Document 1) describes an antimicrobial material in which silver, zinc, and copper metal ions are filled in synthetic zeolite, and a paint containing the same. It is stated that this antimicrobial material can be used in any paint.

Further, Japanese Patent No. 6534273 (Patent Document 2) includes a step of reacting a raw material containing a polyol, an organic isocyanate, a urethane catalyst, a foaming agent, and an antibacterial agent, which is a method for producing an antibacterial polyurethane foam. Described is a method for producing an antibacterial polyurethane foam, wherein the antibacterial agent contains a silver compound having a water solubility at 25 ° C. of 0.01 to 0.8 g in 100 g of a saturated aqueous solution in terms of silver atom. (Claim 1). Patent Document 2 describes that an antibacterial polyurethane foam exhibiting good antibacterial properties can be produced by this production method.

Japanese Unexamined Patent Publication No. 2018-024633 Japanese Patent No. 6534273

It is considered that antimicrobial performance can be imparted by including an antimicrobial material in which silver, zinc, and copper metal ions are filled in the synthetic zeolite as described in Patent Document 1 in the paint. On the other hand, it has been found that when the above materials are added to the coating composition, the appearance of the formed coating film may change, and the desired coating film appearance may not be obtained.

The production method described in Patent Document 2 is a method for producing a polyurethane foam (foam) using a foaming agent. Then, it is described that the polyurethane foam exhibiting antibacterial properties based on the antibacterial spectrum originally possessed by the silver compound can be produced by the production method of Patent Document 2. As described above, the foam described in Patent Document 2 has a different configuration from the clear coating film intended by the present disclosure.

It is an object of the present invention to provide a coating composition capable of forming a coating film having a desired coating film appearance and having good antibacterial and antiviral performance.

In order to solve the above problems, the present invention provides the following aspects.
[1]
A clear paint composition containing a silver-containing antibacterial antiviral agent and a binder resin.
The amount of silver elution when the cured coating film of the above clear coating film was immersed in water for 24 hours was 0.0008 to 0.003 mg / 1 L per 1 cm ² of the surface area of the cured coating film.
The 20 ° mirror surface gloss of the cured coating film of the above clear paint composition is 140 or more.
The binder resin contains an anionic resin.
Clear paint composition.
[2]
The silver-containing antibacterial antiviral agent comprises one or more of silver salts and silver complexes.
The clear paint composition of [1].
[3]
One or more of the above silver salts and silver complexes are silver carboxylate, silver nitrate, silver carbonate, silver sulfate, silver perchlorate, silver fluoride, silver chloride, silver chlorate, silver chromate, silver cyanide. , Silver bromide, silver bromide, silver iodide or silver nitrate,
The clear paint composition of [2].
[4]
The clear coating composition of [2] or [3], wherein the silver-containing antibacterial antiviral agent further contains a nitrogen-containing compound.
[5]
The clear coating composition according to any one of [1] to [4], wherein the anionic resin contains an aqueous dispersion of a resin having at least one of a hydroxyl group and an acid group.
[6]
The clear coating composition according to any one of [1] to [5], wherein the anionic resin contains a hydroxyl group-containing resin aqueous dispersion and an aqueous dispersible polyisocyanate.
[7]
The clear paint composition of [6], wherein the hydroxyl group-containing resin water dispersion is an acrylic resin emulsion.
[8]
The clear paint composition further contains a sulfur compound and contains
The sulfur compound comprises one or more selected from the group consisting of thiourea compounds, mercaptotriazine compounds and inorganic sulfur compounds.
The clear paint composition according to any one of [1] to [7].
[9]
A method for forming a clear coating film, which comprises a step of applying the above clear coating composition to an object to be coated to form a clear coating film.
When the clear coating film is immersed in water for 24 hours, the amount of silver elution is 0.0008 to 0.003 mg / 1 L per 1 cm ² of the surface area of the cured coating film.
The 20 ° mirror gloss of the clear coating film is 140 or more.
A method for forming a clear coating film.

By using the coating composition of the present invention, it is possible to form a clear coating film having a 20 ° mirror gloss of 140 or more and having antibacterial and antiviral performance.

The clear paint composition of the present disclosure contains a silver-containing antibacterial antiviral agent and a binder resin. Each component will be described below.

Binder Resin The clear paint composition of the present disclosure contains a binder resin. In the clear coating composition of the present disclosure, the binder resin contains an anionic resin. When the binder resin contains an anionic resin, a sufficient amount of silver can be eluted in the cured coating film of the above clear coating composition to exhibit antibacterial and antiviral performance, whereby a good antibacterial and antiviral property can be eluted. There is an advantage that the performance is exhibited. The "cured coating film of a clear coating composition" in the present disclosure means a coating film formed by coating a clear coating composition and drying or heating as necessary.

The anionic resin preferably contains an aqueous dispersion of a resin having at least one of a hydroxyl group and an acid group. Examples of the resin water dispersion include acrylic resin emulsion, acrylic resin dispersion, acrylic resin solution, fluororesin emulsion, acrylic silicone resin emulsion, urethane resin dispersion, polyester resin dispersion, and epoxy resin emulsion.

Acrylic resin emulsion Acrylic resin emulsion can be prepared by polymerizing various polymerizable monomers. As the polymerizable monomer, an ethylenically unsaturated monomer can be used. As the ethylenically unsaturated monomer, a mixture of a hydroxyl group-containing ethylenically unsaturated monomer, a carboxyl group-containing ethylenically unsaturated monomer, and other monomers can be used.

Examples of the hydroxyl group-containing ethylenically unsaturated monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and ε-caprolactone-modified (meth). Acrylic monomer and the like can be mentioned. Specific examples of the ε-caprolactone-modified (meth) acrylic monomer include Daicel FA-1, Praxel FA-2, Praxel FA-3, Praxel FA-4, Praxel FA-5, and Praxel FM-1 manufactured by Daicel Chemical Industries, Ltd. , Praxel FM-2, Praxel F
Examples thereof include M-3, Praxel FM-4 and Praxel FM-5. In addition, in this specification, (meth) acrylic acid means acrylic acid and methacrylic acid.

Examples of the carboxyl group-containing ethylenically unsaturated monomer include carboxylic acid monomers such as (meth) acrylic acid, 2-ethylpropenic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, or dicarboxylic acid monoester monomers thereof. Can be mentioned. Acrylic acid, methacrylic acid and the like are preferable as the carboxyl group-containing ethylenically unsaturated monomer. These may be used alone or in combination of two or more.

Other monomers include, for example, the following ethylenically unsaturated monomers;
Ethylene unsaturated carboxylic acid alkyl ester monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate;
Cycloalkyl group-containing polymerizable monomers such as cyclopentyl (meth) acrylate and cyclohexyl (meth) acrylate;
Ethylene unsaturated carboxylic acid aminoalkyl ester monomers such as (meth) aminoethyl acrylate, (meth) dimethylaminoethyl acrylate, (meth) butylaminoethyl acrylate;
Ethylene unsaturated carboxylic acid aminoalkylamide monomers such as aminoethyl (meth) acrylamide, dimethylaminomethyl (meth) acrylamide, and methylaminopropyl (meth) acrylamide;
Other amide group-containing ethylenically unsaturated carboxylic acid monomers such as acrylamide, methacrylamide, dimethylacrylamide, diethylacrylamide, acryloylmorpholine, isopropylacrylamide, N-methylolacrylamide, methoxybutylacrylamide, diacetoneacrylamide;
Unsaturated fatty acid glycidyl ester monomers such as glycidyl acrylate and glycidyl methacrylate;
(Meta) Vinyl cyanide-based monomers such as acrylonitrile and α-chloroacrylonitrile;
Saturated aliphatic carboxylic acid vinyl ester monomers such as vinyl acetate and vinyl propionate;
Styrene-based monomers such as styrene, α-methylstyrene, and vinyltoluene.

As the other monomer, it is preferable that a styrene-based monomer is contained. When the monomer mixture contains a styrene-based monomer, the content of the styrene-based monomer is preferably 1 to 10% by mass, for example, 2 to 8% by mass, based on the total amount of the monomer mixture used for synthesizing the acrylic resin emulsion. Is more preferable. When the monomer mixture contains a styrene-based monomer, there is an advantage that the gloss and water resistance of the obtained coating film can be designed in a good range.

The acrylic resin emulsion comprises, for example, a monomer mixture containing an ethylenically unsaturated carboxylic acid monomer and another monomer copolymerizable with the ethylenically unsaturated carboxylic acid monomer in the presence of an emulsifier and a polymerization initiator. It can be prepared by emulsion polymerization in a solvent.

Examples of the emulsifier that can be used for the emulsification polymerization include anionic emulsifiers such as soap, alkyl sulfonates and polyoxyethylene alkyl sulfates, and polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers and polypropylene glycols. Examples thereof include nonionic emulsifiers such as ethylene oxide adduct, polyethylene glycol fatty acid ester, and polyoxyethylene sorbitan fatty acid ester.

As the emulsifier, a surfactant having a radically polymerizable carbon-carbon double bond (hereinafter referred to as a reactive emulsifier) can also be used. Examples of the reactive emulsifier include an anionic surfactant containing a sulfonic acid group, a sulfonate group, a sulfate ester group, and / or an ethyleneoxy group and having a radically polymerizable carbon-carbon double bond.

A commercially available product may be used as the emulsifier. As commercially available emulsifiers, for example, Aqualon HS series such as Aqualon HS-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); Aquaron RN series (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.); Eleminor JS-2 (manufactured by Sanyo Kasei Kogyo Co., Ltd.); Latemuru series (manufactured by Kao) such as Latemuru S-120, S-180A, PD-104, and Emargen series (manufactured by Kao) such as Emulgen 109P; (Manufactured by Japan); Antox series (manufactured by Nippon Emulsifier Co., Ltd.) such as Antox MS-2N (2-sodium sulfoethyl methacrylate); Adecaria soap NE-10 (α- [1-[(allyloxy)) Adecaria soap series (manufactured by ADEKA) such as methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene); and the like.

Only one type of emulsifier may be used, or two or more types may be used in combination. When the emulsifier is used, the amount used is preferably 0.5 to 10 parts by mass as the solid content with respect to 100 parts by mass of the polymerizable monomer.

In the preparation of the acrylic resin emulsion by emulsion polymerization, it is preferable to use a polymerization initiator. The polymerization initiator is one that generates radicals by heat or a reducing substance to carry out addition polymerization of the monomer, and a water-soluble polymerization initiator or an oil-soluble polymerization initiator can be used. The water-soluble polymerization initiator is not particularly limited, and examples thereof include persulfate-based initiators such as ammonium persulfate, sodium persulfate, and potassium persulfate, and inorganic initiators such as hydrogen peroxide. can. The oil-soluble polymerization initiator is not particularly limited, and is, for example, benzoyl peroxide, t-butylperoxybenzoate, t-butylhydroperoxide, t-butylperoxy (2-ethylhexanoate), t-butyl. Organic peroxides such as peroxy-3,5,5-trimethylhexanoate, di-t-butyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4 Examples thereof include azobis compounds such as -dimethylvaleronitrile, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), and 1,1'-azobis-cyclohexane-1-carbonitrile. These may be used alone or in combination of two or more.

The amount of the polymerization initiator used is preferably 0.01 to 10% by mass with respect to the total amount of the monomers used for the polymerization. The polymerization temperature in emulsion polymerization is, for example, 30 to 90 ° C., and the polymerization time is, for example, 3 to 12 hours. The monomer concentration during the polymerization reaction is, for example, 30 to 70% by mass.

The acrylic resin emulsion may also be mixed with a mixture of polymerizable monomers, an emulsifier and an aqueous medium prior to emulsion polymerization to prepare a pre-reaction emulsified mixture. When preparing a pre-reaction emulsification mixture, emulsion polymerization can be carried out by mixing the pre-reaction emulsification mixture and the polymerization initiator in an aqueous medium.

The acrylic resin emulsion may have an acid group. When the acrylic resin emulsion has an acid group, the acid value is preferably 5 to 100 mgKOH / g, more preferably 5 to 70 mgKOH / g. When the acid value is within the above range, the stability of the resin emulsion in water and the water resistance of the coating film can be balanced. In the present specification, the acid value represents the solid content acid value and can be measured by a known method described in JIS K 0070.

The acrylic resin emulsion preferably has a hydroxyl group. When the acrylic resin emulsion has a hydroxyl group, the hydroxyl value is preferably 5 to 200 mgKOH / g, more preferably 10 to 150 mgKOH / g. In this specification, the hydroxyl value represents the solid content hydroxyl value, and can be measured by a known method described in JIS K 0070.

A commercially available acrylic resin emulsion may be used. It is not particularly limited as a commercially available product, and for example, DIC's Barnock WE series, Boncoat series; Henkel Japan's Yodosol AD series; Aica Kogyo's Ultrasol series; Nippon Zeon's NIPOL series; The Pegar series made by; etc. can be mentioned.

Acrylic resin dispersion As the acrylic resin dispersion, for example, an acrylic resin dispersion having a hydroxyl group is preferable. The acrylic resin dispersion has a hydroxyl value in the range of 5 to 200 mgKOH / g, an acid value in the range of 5 to 100 mgKOH / g, and a number average molecular weight in the range of 1,000 to 100,000. Is preferable. Such an acrylic resin dispersion can be prepared by polymerizing a monomer mixture containing an ethylenically unsaturated monomer. In the present specification, the number average molecular weight is a value obtained by converting the measurement result of gel permeation chromatography (GPC) as a polystyrene standard.

As the ethylenically unsaturated monomer, a mixture of the hydroxyl group-containing ethylenically unsaturated monomer, the carboxyl group-containing ethylenically unsaturated monomer and other monomers can be used.

The acrylic resin dispersion can be prepared by carrying out a polymerization reaction of the above-mentioned monomer mixture in the presence of no solvent or a suitable organic solvent, dropping and mixing in water, and removing excess solvent if necessary. ..
A polymerization initiator can be used in the polymerization reaction. As the polymerization initiator, for example, an initiator used in the art as a radical polymerization initiator can be used. Specific examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, t-butyl peroxide and cumene hydroperoxide, and organic azo compounds such as azobiscyanovaleric acid and azoisobutyronitrile.

The polymerization reaction can be carried out at a temperature of, for example, 80 to 140 ° C. The polymerization reaction time can be appropriately selected depending on the polymerization temperature and the reaction scale, and can be, for example, 1 to 8 hours. The polymerization reaction can be carried out by an operation usually performed by those skilled in the art. For example, polymerization can be carried out by dropping a monomer mixture containing an ethylenically unsaturated monomer and a polymerization initiator into a heated organic solvent. The organic solvent that can be used for the polymerization is not particularly limited, but a solvent having a boiling point of about 60 to 250 ° C. is preferable. Organic solvents that can be suitably used include, for example, water-insoluble organic solvents such as butyl acetate, xylene, toluene, methylisobutylketone, propylene glycol, dipropylene glycol dimethyl ether, methyl ether acetate; and tetrahydrofuran, ethanol, methanol, etc. Propanol, isopropanol, 2-butanol, t-butyl alcohol, dioxane, methyl ethyl ketone, ethylene glycol, ethylene glycol monobutyl ether, 2-methoxypropanol, 2-butoxypropanol, diethylene glycol monobutyl ether, butyl diglycol, N-methylpyrrolidone, ethylene carbonate And water-soluble organic solvents such as propylene carbonate.

A neutralizing agent may be added to the acrylic resin obtained by the polymerization to neutralize at least a part of the acid groups contained in the acrylic resin. By this step, water dispersibility can be satisfactorily imparted to the acrylic resin. The neutralizing agent is not particularly limited as long as it is generally used for neutralizing the acid group contained therein when preparing the water-dispersible resin composition. Examples include organic amines such as monomethylamine, dimethylamine, trimethylamine, triethylamine, diisopropylamine, monoethanolamine, diethanolamine and dimethylethanolamine, and inorganic bases such as sodium hydroxide, potassium hydroxide and lithium hydroxide. Be done. These neutralizers may be used alone or in combination of two or more.

If necessary, the acrylic resin dispersion can be prepared by mixing water with the neutralized acrylic resin or by mixing the acrylic resin with water. In the preparation of the acrylic resin dispersion, excess organic solvent may be removed before the addition of the neutralizing agent or after water dispersion, if necessary.

The acrylic resin dispersion preferably has a hydroxyl value in the range of 5 to 200 mgKOH / g. Further, the acrylic resin dispersion preferably has an acid value in the range of 5 to 100 mgKOH / g. When the hydroxyl value and / or acid value of the acrylic resin dispersion is within the above range, there is an advantage that the physical strength of the obtained coating film can be secured in a good range. In addition, in this specification, the acid value and the hydroxyl value are both the values in terms of solid content, and are the values measured by the method according to JIS K 0070.

A commercially available acrylic resin dispersion may be used. The commercially available product is not particularly limited, and for example, MACRYNAL series such as MACRYNAL VSM6299 / 42WA (manufactured by Surface Specialties), bihydrol series such as bihydrol A2470 (manufactured by Sumika Cobestlor Urethane), Vernock WD-551 and the like. Barnock series (manufactured by DIC), NeoCryl series (manufactured by DSM) such as NeoCryl XK-555, and the like can be mentioned.

Acrylic resin solution The acrylic resin solution can be prepared, for example, by neutralizing an acid group-containing acrylic resin, if necessary, and dissolving and dispersing it in an aqueous medium. The acrylic resin can be prepared, for example, by a method known to those skilled in the art as described above. When the acrylic resin contained in the acrylic resin solution is an acid group-containing acrylic resin, the acid value is preferably in the range of 5 to 100 mgKOH / g.

A commercially available acrylic resin solution may be used. The commercially available product is not particularly limited, and examples thereof include a water sol series (manufactured by DIC Corporation) and the like.

Fluororesin emulsion A fluororesin emulsion can be prepared, for example, by polymerizing a monomer containing at least one fluoroolefin in the presence of a surfactant. Preferred preparation examples of the fluororesin emulsion include, for example, a step of aqueous dispersion polymerization of a monomer containing at least one fluoroolefin to produce an aqueous dispersion of fluoropolymer particles, and an aqueous dispersion of fluoropolymer particles. Examples thereof include a step of seed-polymerizing an ethylenically unsaturated monomer onto fluoropolymer particles in a liquid to obtain a fluororesin emulsion.

The fluoroolefin is not particularly limited, and is, for example, a perfluoroolefin such as tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro (alkyl vinyl ether) (PAVE); chlorotrifluoroethylene (CTFE), foot. Non-perfluoroolefins such as vinyl dioxide (VF), vinylidene fluoride (VdF), trifluoroethylene, trifluoropropylene, pentafluoropropylene, tetrafluoropropylene and hexafluoroisobutene; can be mentioned. Specific examples of perfluoro (alkyl vinyl ether) (PAVE) include perfluoro (methyl vinyl ether) (PMVE), perfluoro (ethyl vinyl ether) (PEVE), perfluoro (propyl vinyl ether) (PPVE) and the like.

Further, as the fluoroolefin, a functional group-containing fluoroolefin monomer can also be used. Examples of the functional group contained in the functional group-containing fluoroolefin include a hydroxyl group, a carboxylic acid group, a sulfonic acid base, a carboxylic acid base, and an epoxy group.

These may be used alone or in combination of two or more. Further, a non-fluorine-based monomer copolymerizable with the fluoroolefin may be used in combination.

As the surfactant used for preparing the fluorine-containing polymer particles, either a fluorine-based surfactant or a non-fluorine-based surfactant can be used. As the fluorine-based surfactant, an anionic fluorine-based surfactant is preferable. As a fluorine-based surfactant, for example, partial fluorination having a hydrophobic group having a CH bond and a CF bond and a hydrophilic group such as a carboxylic acid group, a sulfonic acid group, a phosphoric acid group and salts thereof. A surfactant can be preferably used. As the non-fluorinated surfactant, an anionic non-fluorinated surfactant is preferable. As the non-fluorinated surfactant, for example, a surfactant having a hydrophobic group containing an unsaturated double bond group and a hydrophilic group such as a carboxylic acid group, a sulfonic acid group, a phosphoric acid group and salts thereof is preferable. Can be used. Specific examples of such a non-fluorinated surfactant include Aqualon HS-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and the like. Further, if necessary, a surfactant other than the above, which is usually used by those skilled in the art, may be contained.

The fluorine-containing polymer particles can be prepared by performing aqueous dispersion polymerization in the presence of the surfactant. The polymerization temperature is not particularly limited and can be selected according to the type of the polymerization initiator. The polymerization temperature is preferably, for example, 40 to 120 ° C, more preferably 50 to 100 ° C. In the polymerization, the supply of the monomers may be continuous or sequential.

As the polymerization initiator, a water-soluble radical polymerization initiator can be preferably used. Specific examples of the water-soluble radical polymerization initiator include persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, ammonium salt of percarbonate, potassium salt, sodium salt and the like, and ammonium persulfate and potassium persulfate. Especially preferable.

Next, the fluororesin emulsion can be suitably prepared by seed-polymerizing the ethylenically unsaturated monomer onto the fluorine-containing polymer particles in the obtained aqueous dispersion of the fluorine-containing polymer particles. As a seed polymerization method, for example, an ethylenically unsaturated monomer is added to an aqueous dispersion of fluorine-containing polymer particles, and the ethylenically unsaturated monomer is aqueously dispersed and polymerized with the fluorine-containing polymer particles (seed particles) as nuclei. Can be mentioned. As the ethylenically unsaturated monomer, the above-mentioned monomer can be used.

In seed polymerization, a surfactant may be used if necessary. As the surfactant, the above-mentioned surfactant can be preferably used. When a surfactant is used, the amount used is preferably, for example, 0.01 to 5% by mass with respect to the total amount of water as a medium.

A commercially available product can also be used as the fluororesin emulsion. Examples of commercially available products include the Zeffle series manufactured by Daikin Industries, Ltd.

Acrylic Silicone Resin Emulsion An acrylic silicone resin emulsion can be prepared, for example, by polymerizing a monomer mixture containing an alkoxysilyl group-containing ethylenically unsaturated monomer and another ethylenically unsaturated monomer.

The alkoxysilyl group-containing ethylenically unsaturated monomer is an ethylenically unsaturated monomer having an alkoxysilyl group. As the alkoxysilyl group, an alkoxysilyl group having 1 to 14 carbon atoms is suitable. One to three alkoxyl groups having 1 to 14 carbon atoms can be bonded to the silicon atom constituting the alkoxysilyl group having 1 to 14 carbon atoms. The alkoxyl group is likely to be hydrolyzed to form a silanol group, especially in an acidic environment. When the silanol group is dehydrated and bonded, a siloxane bond is formed to crosslink or increase the molecular weight, so that the film-forming property, blocking resistance and temperature change resistance of the obtained coating film are improved, which is particularly excellent. It has the advantage of being able to obtain weather resistance and temperature water resistance.

The alkoxysilyl group-containing ethylenically unsaturated monomer is not particularly limited as long as it is an ethylenically unsaturated monomer containing an alkoxysilyl group having 1 to 14 carbon atoms, and is, for example, trimethoxysilylpropyl (meth) acrylate, (. Triethoxysilylpropyl acrylate, (meth) tributoxysilylpropyl acrylate, dimethoxymethylsilylpropyl (meth) acrylate, methoxydimethylsilylpropyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl Examples thereof include dimethoxymethylsilane, vinylmethoxydimethylsilane, vinyltris (β-methoxyethoxy) silane and the like. These may be used alone or in combination of two or more.

Among the alkoxysilyl group-containing ethylenically unsaturated monomers, trimethoxysilylpropyl (meth) acrylate, triethoxysilylpropyl (meth) acrylate, vinyltrimethoxysilane or vinyltriethoxysilane are particularly preferable.

The amount of the alkoxysilyl group-containing ethylenically unsaturated monomer contained in the monomer mixture is preferably in the range of 0.1 part by mass at the lower limit and 3 parts by mass at the upper limit with respect to 100 parts by mass of the monomer mixture.

The monomer mixture may further contain an alkoxysilane compound having 1 to 14 carbon atoms. When the above alkoxysilane compound is contained, excellent weather resistance and water resistance can be imparted to the obtained coating film. The alkoxysilane compound is not particularly limited, and for example, tetramethoxysilane, trimethoxymethylsilane, dimethoxydimethylsilane, methoxytrimethylsilane, tetraethoxysilane, triethoxyethylsilane, diethoxydiethylsilane, ethoxytriethylsilane, and γ- Examples thereof include glycidoxypropyltrimethoxysilane and γ-aminopropyltrimethoxysilane. These can be used alone or in admixture of two or more. Of these, tetramethoxysilane, trimethoxymethylsilane, dimethoxydimethylsilane, methoxytrimethylsilane, and γ-glycidoxypropyltrimethoxysilane are preferable.

The alkoxysilane compound is preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the monomer mixture.

The monomer mixture contains other ethylenically unsaturated monomers in addition to the alkoxysilyl group-containing ethylenically unsaturated monomers. The ethylenically unsaturated monomer is not particularly limited, and for example, the above-mentioned ethylenically unsaturated monomer can be used.

The monomer mixture contains an alkoxysilyl group-containing ethylenically unsaturated monomer and other ethylenically unsaturated monomers, and the other ethylenically unsaturated monomers are derived from methyl methacrylate, n-butyl acrylate and 2-ethylhexyl acrylate. It is preferable to include one or more selected from the group.

The acrylic silicone resin emulsion can be prepared by polymerizing the above-mentioned monomer mixture in the presence of an emulsifier and a polymerization initiator as required by a method known to those skilled in the art. As the emulsifier and the polymerization initiator, emulsifiers and polymerization initiators known to those skilled in the art can be used.

Polyurethane resin dispersion and polyester resin dispersion The polyurethane resin dispersion uses, for example, a polyol compound, a compound having an active hydrogen group and a hydrophilic group in the molecule, an organic polyisocyanate, and if necessary, a chain extender and a polymerization terminator. The polyurethane resin prepared in the above can be prepared by dispersing it in water. As the polyester resin dispersion, for example, a polyester resin dispersion having two or more hydroxyl groups in one molecule, which is called a polyester polyol, can be preferably used. Commercially available products may be used as the polyurethane resin dispersion and the polyester resin dispersion.

Epoxy resin emulsion An epoxy resin emulsion can be prepared, for example, by emulsifying and dispersing a liquid or solid epoxy resin having two or more epoxy groups in one molecule using an emulsifier. As the epoxy resin, for example, one having a number average molecular weight of about 370 to 4000 and an epoxy equivalent of about 185 to 2000 can be preferably used. The epoxy resin emulsion preferably has a solid content of about 40 to 60% by weight. Examples of the epoxy resin that can be used for preparing the epoxy resin emulsion include bisphenol A type, bisphenol F type, bisphenol AD type, and modified ones thereof. As the emulsifier that can be used for preparing the epoxy resin emulsion, the above emulsifier can be appropriately used.

Water-dispersible polyisocyanate As a preferable example of this embodiment, there is an embodiment in which the anionic resin contains a hydroxyl group-containing resin water dispersion and a water-dispersible polyisocyanate. In this embodiment, the water-dispersible polyisocyanate functions as a curing agent for the hydroxyl group-containing resin water dispersion. The water-dispersible polyisocyanate is a polyisocyanate compound having water dispersibility and can be dispersed without separation when added to an aqueous medium. The water-dispersible polyisocyanate may be modified with a hydrophilic compound having a hydrophilic group, if necessary. The hydrophilic group may be an ionic hydrophilic group or a nonionic hydrophilic group.

The polyisocyanate compound contained in the water-dispersible polyisocyanate is not particularly limited as long as it does not deviate from the scope of the present invention. For example, aromatic diisocyanates such as tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), metaxylylene diisocyanate (MXDI); and aliphatic diisocyanates such as hexamethylene diisocyanate (HDI). Diisocyanates; alicyclic polyisocyanates such as isophorone diisocyanate (IPDI); and multimers thereof such as bullet type, nurate type, trimethylolpropane (TMP) adduct type and the like can be mentioned. It may be a mixture of these two or more polyisocyanates.

Preferably, the polyisocyanate is an aliphatic diisocyanate and / or an alicyclic polyisocyanate, and more preferably hexamethylene diisocyanate (HDI) and / or isophorone diisocyanate (IPDI). Such a polyisocyanate compound has lower reactivity than an aromatic isocyanate compound and can suppress side reactions with an aqueous medium such as water.

If desired, the polyisocyanate chain may be modified without departing from the scope of the present invention, and further, a crosslinking reaction may occur due to the isocyanate group contained in the polyisocyanate. Since the polyisocyanate compound which is a multimer is trifunctional or higher, at least one of a plurality of isocyanate groups may be modified, or at least two isocyanate groups may cause a crosslinking reaction.

A commercially available product may be used as the water-dispersible polyisocyanate compound. As commercially available products, for example, Aquanate 105, Aquanate 130, Aquanate 200 and Aquanate 210 (manufactured by Tosoh Corporation); Chemical Cobestro Urethane); Takenate WD-725, Takenate WD-726 and Takenate WD-730 (Mitsui Chemicals); Duranate WB40-100, Duranate WT20-100, Duranate WE50-100 (Asahi Kasei), etc. Can be mentioned.

When the anionic resin contains a hydroxyl group-containing resin water dispersion and a water-dispersible polyisocyanate, the content of the water-dispersible polyisocyanate is the isocyanate group of the water-dispersible polyisocyanate (B) and the hydroxyl group-containing resin. The equivalent ratio (NCO / OH) with the hydroxyl group of the aqueous dispersion is preferably in the range of 0.5 to 3.0, and is preferably in the range of 1.0 to 2.0. Is more preferable. When the equivalent ratio (NCO / OH) is within the above range, there is an advantage that the curing reactivity of the clear coating composition can be ensured in a good range. The above equivalent ratios are all converted into solid content.

Hydrazide compound, carbodiimide compound, aziridine compound As another preferable example of this embodiment, the anionic resin comprises an acid group-containing aqueous resin dispersion and at least one of a hydrazide compound, a carbodiimide compound and an aziridine compound. Examples include. In this embodiment, at least one of the hydrazide compound, the carbodiimide compound and the aziridine compound functions as a curing agent for the acid group-containing resin aqueous dispersion.

Hydrazide compounds include oxalate dihydrazide, malonic acid dihydrazide, succinate dihydrazide, glutarate dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanoic acid dihydrazide, carbonate dihydrazide, phthalic acid dihydrazide, terephthalic acid dihydrazide, terephthalic acid dihydrazide. Acid dihydrazide, polyacrylic acid polyhydrazide with 20-100 hydrazide groups, nitrilotriacetate trihydrazide, ethylenediaminetetraacetate tetrahydrazide, ditrihydrazine-triazine, trihydrazine-triazine, thiocarbohydrazide, N, N'-diamino Guanidin, 2-hydrazinopyridine-5-carboxylic acid hydrazide, 3-chlor-2-hydrazinopyridine-5-carboxylic acid hydrazide, 6-chlor-2-hydrazinopyridine-4-carboxylate hydrazide, 2,5- Dihydrazinopyridine-4-carboxylic acid, 1,4-dihydrazinobenzol, 1,3-dihydrazinobenzol, 2,3-dihydrazine naphthalin, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, 1, Examples thereof include 3-bis (hydrazinocarboethyl) -5-isopropylhydrantin. Among these, it is preferable to use adipic acid dihydrazide in terms of availability and 1,3-bis (hydrazinocarboethyl) -5-isopropylhydrantin in terms of high water solubility.

Examples of the carbodiimide compound include a modified polycarbodiimide compound. The modified polycarbodiimide compound has a polyalkylene oxide unit having at least two carbodiimide groups in one molecule and having one end blocked by a monoalkoxy group having 4 or more carbon atoms. The amount of the carbodiimide group contained in one molecule of the modified polycarbodiimide compound is at least two, and is preferably 20 or less in consideration of the reaction efficiency. Specific examples of the compound having two or more carbodiimide groups in one molecule include carbodilite V-02-L2 (polyvalent carbodiimide, manufactured by Nisshinbo Chemical Co., Ltd.) and carbodilite E-01 (polyvalent carbodiimide, Nisshinbo Chemical Co., Ltd.). (Made by company), etc.

Examples of the aziridine compound include bisphenylmethane-bis, 4,4'-N, N'-ethyleneurea and the like. Specific examples of the compound having two or more aziridine groups in one molecule include Chemitite DZ-22E (divalent aziridine, manufactured by Nippon Shokubai Co., Ltd.) and the like.

As another aspect of the clear coating composition of the present disclosure, there is a case where the binder resin is a cationic resin. As the cationic resin, a cationic acrylic resin can be preferably used.

The cationic acrylic resin can be prepared, for example, by a ring-opening addition reaction between an acrylic copolymer having a plurality of oxylan rings and a plurality of hydroxyl groups in the molecule and an amine. More specifically, for example, glycidyl (meth) acrylate and a hydroxyl group-containing acrylic monomer (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, etc. A cationic acrylic resin can be prepared by copolymerizing the hydroxyl group-containing (meth) acrylic ester (addition product of ε-caprolactone) with other acrylic and / or non-acrylic monomers.

The other acrylic monomers are not particularly limited, and are, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl. Examples thereof include (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth) acrylate.

The non-acrylic monomer is not particularly limited, and examples thereof include styrene, vinyltoluene, α-methylstyrene, (meth) acrylonitrile, (meth) acrylamide, and vinyl acetate.

The acrylic copolymer having an oxylan ring derived from the glycidyl (meth) acrylate is ring-opened by reacting all of the oxylan rings in the copolymer with a primary amine, a secondary amine, and a tertiary amine acid salt. However, it can be a cationic acrylic resin.

The cationic acrylic resin can also be prepared by a method of directly synthesizing an acrylic monomer having an amino group by copolymerizing it with another monomer. In the above method, an amino group-containing acrylic monomer such as N, N-dimethylaminoethyl (meth) acrylate or N, N-di-t-butylaminoethyl (meth) acrylate is used instead of the glycidyl (meth) acrylate. A cationic acrylic resin can be prepared by copolymerizing the amino group-containing acrylic monomer with the hydroxyl group-containing acrylic monomer and the other acrylic and / or non-acrylic monomers.

The cationic acrylic resin obtained by the above method can be obtained as a self-crosslinking cationic acrylic resin by introducing a blocked isocyanate group by an addition reaction with a half-block diisocyanate compound, if necessary.

The cationic acrylic resin may be in the form of an emulsion. One embodiment of the emulsion form includes an embodiment containing the above-mentioned cationic acrylic resin and a cross-linking agent. Examples of the cross-linking agent include blocked isocyanate and melamine resin. The blocked polyisocyanate is a compound in which the isocyanate group of a polyisocyanate having two or more isocyanate groups is protected with a blocking agent.

The polyisocyanate is not particularly limited, and for example, hydroxymethylene diisocyanate (including trimer), tetramethylene diisocyanate, aliphatic diisocyanate such as trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylenebis (cyclohexyl). Examples thereof include alicyclic polyisocyanates such as isocyanate), aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, and xylylene diisocyanate.

The blocking agent is not particularly limited, and for example, monohydric alkyl (or aromatic) alcohols such as n-butanol, n-hexyl alcohol, 2-ethylhexanol, lauryl alcohol, phenolcarbinol, and methylphenylcarbinol. Cellosolves such as ethylene glycol monohexyl ether and ethylene glycol mono2-ethylhexyl ether; phenols such as phenol, para-t-butylphenol and cresol; Oximes such as cyclohexanone oxime; lactams typified by ε-caprolactam and γ-butyrolactam can be mentioned. Oximes and lactams are more preferable from the viewpoint of resin curability because they dissociate at low temperatures.

In the case of an emulsion form containing a cationic acrylic resin and a cross-linking agent, the content of the cross-linking agent is within the range of 10 to 60 parts by mass as the resin solid content with respect to 100 parts by mass of the resin solid content of the cationic acrylic resin. Is preferable.

In the clear coating composition of the present disclosure, there is an advantage that a clear coating film having good antibacterial antiviral property, clear property and glossiness can be formed by using the binder resin. The binder resin (anionic resin) contained in the clear coating composition more preferably contains a hydroxyl group-containing resin water dispersion and a water-dispersible polyisocyanate, and the hydroxyl group-containing resin water dispersion is an acrylic resin emulsion. It is even more preferable to have it. Further, as another aspect, it is preferable that the binder resin contains one or more selected from an acrylic resin emulsion, an acrylic resin dispersion and an acrylic resin solution.

Silver-Containing Antibacterial Antiviral Agent The clear paint composition of the present disclosure comprises a silver-containing antibacterial antiviral agent. The silver-containing antibacterial antiviral agent preferably contains one or more of silver salts and silver complexes as silver.

One or more of the above silver salts and silver complexes are silver carboxylate, silver nitrate, silver carbonate, silver sulfate, silver perchlorate, silver fluoride, silver chloride, silver chlorate, silver chromate, silver cyanide. , Silver bromide, silver bromide, silver iodide or silver iodide is preferred.

It is more preferable that one or more of the silver salts and the silver complex is silver carboxylate. As used herein, "silver carboxylic acid" means either a silver salt of a carboxylic acid, a silver complex of a carboxylic acid, or both.

The carboxylic acid constituting the silver salt of the carboxylic acid and the silver complex of the carboxylic acid may be any of monocarboxylic acid, dicarboxylic acid, tricarboxylic acid and tetracarboxylic acid.
Examples of the monocarboxylic acid include monocarboxylic acids having 2 to 18 carbon atoms. Examples of the dicarboxylic acid include a dicarboxylic acid having 2 to 18 carbon atoms. Examples of the tricarboxylic acid include tricarboxylic acids having 6 to 18 carbon atoms. Examples of the tetracarboxylic acid include a tetracarboxylic acid having 7 to 18 carbon atoms. These may have substituents as needed. Examples of the substituent include a hydroxyl group, an amide group, an ester group, an acetyl group, a ketone group, a sulfo group and the like.

Specific examples of monocarboxylic acids having 2 to 18 carbon atoms include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, and pivalic acid. An aliphatic monocarboxylic acid having 2 to 18 carbon atoms such as isobutyric acid; an alicyclic monocarboxylic acid having 7 to 18 carbon atoms such as cyclohexanecarboxylic acid; benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β- Aromatic monocarboxylic acids with 7-18 carbon atoms such as naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid and phenylacetic acid; fats with 2-18 carbon atoms such as acetylglycine, acetoxyacetic acid, methoxyacetic acid, pyruvate and glycolic acid. Substituted derivatives of group monocarboxylic acids; substituted derivatives of aromatic monocarboxylic acids having 7 to 18 carbon atoms such as salicylic acid; and the like.

Amino acids and derivatives thereof can also be used as the monocarboxylic acid having 2 to 18 carbon atoms. Amino acids and their derivatives include, for example, glycine, N-acetylglycine, alanine, arginine, asparagine, cysteine, glutamine, glutamic acid, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine. , And derivatives thereof.

Specific examples of the dicarboxylic acid having 2 to 18 carbon atoms include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, tridecanoic acid, methylmalonic acid, and ethyl. An aliphatic dicarboxylic acid having 2 to 18 carbon atoms, such as malonic acid, dimethylmalonic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, tetramethylsuccinic acid, and fumaric acid; cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acids with 8 to 18 carbon atoms; phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sulfoisophthalic acid, 1,6-naphthalenedicarboxylic acid, 2,7- Aromatic dicarboxylic acids with 7-18 carbon atoms such as naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 3,4'-dicarboxybiphenyl and 4,4'-dicarboxyterphenyl, lutidic acid; apple acid , Substitute derivatives of aliphatic dicarboxylic acids having 2 to 18 carbon atoms such as tartrate; and the like.

Amino acids and derivatives thereof can also be used as the dicarboxylic acid having 2 to 18 carbon atoms. Examples of amino acids and their derivatives include aspartic acid, glutamic acid and derivatives thereof.

Specific examples of the tricarboxylic acid having 6 to 18 carbon atoms include, for example, 3-carboxymethyl glutaric acid, 1,2,4-butanetricarboxylic acid, cis-propen-1,2,3-tricarboxylic acid, and the like. ~ 18 aliphatic tricarboxylic acids; 1,2,4-cyclopentanetricarboxylic acid, 1,2,3-cyclohexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, etc. , Alicyclic tricarboxylic acid having 6 to 18 carbon atoms; benzenetricarboxylic acid (trimellitic acid, etc.), naphthalenetricarboxylic acid, 3,4,4'-benzophenonetricarboxylic acid, 3,4,4'-biphenyl ether tricarboxylic acid, Aromatic tricarboxylic acids having 8 to 18 carbon atoms, such as 3,4,4'-biphenyltricarboxylic acid, 2,3,2'-biphenyltricarboxylic acid, 3,4,4'-biphenylmethanetricarboxylic acid; the above tricarboxylic acid. , And carboxylic acid derivatives such as 2-phosphonobutane-1,2,4-sodium tricarboxylate; and the like.

Specific examples of tetracarboxylic acids having 7 to 18 carbon atoms include aliphatic tetracarboxylic acids having 7 to 18 carbon atoms, such as 1,2,3,4-butanetetracarboxylic acid; 2-carboxymethyl-1, 3,4-Cyclopentanetricarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclo Pentantetracarboxylic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,5,6-tricarboxynorbornan-2-acetic acid, 2,3,4,5-tetratetracarboxylic acid, 5- (2,5-) Dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, bicyclo [2.2.2] -oct-7-en-2,3,5,6-tetracarboxylic acid, etc. Alicyclic tetracarboxylic acid with 7 to 18 carbon atoms; aromatic tetra with 8 to 18 carbon atoms such as benzenetetracarboxylic acid (pyromellitic acid, etc.), benzophenone tetracarboxylic acid, naphthalenetetracarboxylic acid, furantetracarboxylic acid, etc. Carboxylic acid; a substituted derivative of the above tetracarboxylic acid; and a carboxylic acid derivative such as ethylenediamineacetic acid; and the like.

The above-mentioned carboxylic acid may be used alone or in combination of two or more. The carboxylic acid may be an intramolecular or intermolecular anhydride. Further, the carboxylic acid may be in the form of a salt.

The carboxylic acid is preferably fumaric acid, acetylglycine, acetoxyacetic acid, adipic acid, succinic acid, tartaric acid, phthalic acid, trimellitic acid, lutidic acid or pyromellitic acid. In the case of the above carboxylic acid, there is an advantage that a clear coating composition capable of forming a good clear coating film can be obtained.

The silver-containing antibacterial antiviral agent may further contain a nitrogen-containing compound, if necessary. The "nitrogen-containing compound" referred to in the present disclosure does not include a compound having a carboxylic acid group (for example, an amino acid). The nitrogen-containing compound is more preferably an imidazole ring-containing compound. In the present disclosure, the imidazole ring-containing compound means a compound having an imidazole ring structure and a derivative thereof. Specific examples of the imidazole ring-containing compound include, for example, 1,3-dimethyl-2-imidazolidinone, 2-amino-1-methyl-2-imidazolin-4-one, 2,2,5,5-tetraalkylimidazoline. -4-On and the like can be mentioned.

The silver-containing antibacterial antiviral agent can be prepared by mixing a silver compound such as silver, silver oxide and silver nitrate, an acid component such as a carboxylic acid, and a necessary nitrogen-containing compound in an aqueous medium. .. The mixing order of these components is not particularly limited, and for example, an acid component and a nitrogen-containing compound may be mixed in an aqueous medium, and then a silver compound may be added and mixed. The nitrogen-containing compound may be mixed in an aqueous medium, and then an acid component such as a carboxylic acid may be added and mixed. Examples of the aqueous medium include water, a mixture of water and a hydrophilic organic solvent (such as alcohol), and the like. In the above mixing, a pH adjuster may be used if necessary. Examples of the pH adjuster include alkali metals such as sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, sodium oxide, potassium oxide, calcium oxide, barium oxide and magnesium oxide, or alkaline earth metals. Hydroxide or oxide of.

A commercially available product may be used as the silver-containing antibacterial antiviral agent. Examples of commercially available products include the AG Alpha ^™ series manufactured by J-Chemical, Inc.

The amount of the silver-containing antibacterial antiviral agent contained in the clear coating composition is 0.02 to 1 mass in terms of Ag as the amount of the active ingredient in the coating film with respect to 100 parts by mass of the resin solid content of the binder resin. It is preferably in the range of 0.03 to 0.5 parts by mass, more preferably in the range of 0.03 to 0.2 parts by mass, and particularly preferably in the range of 0.03 to 0.2 parts by mass. When the silver-containing antibacterial antiviral agent is contained in the clear coating composition in an amount in the above range, good antibacterial antiviral properties can be obtained while ensuring the clearness and glossiness of the obtained coating film. There are advantages that can be done.

In the present disclosure, the antibacterial property refers to the property of inactivating bacteria, and can be evaluated by, for example, the antibacterial activity value of JIS Z 2801. Further, the antiviral property means a property of inactivating a virus, and can be evaluated by, for example, the antiviral activity value of JIS R 1756 (2020).

Sulfur Compounds The clear paint compositions of the present disclosure may contain sulfur compounds in addition to the above components. By containing the sulfur compound in the clear coating composition, there is an advantage that the weather resistance of the clear coating composition is further improved. In the present disclosure, the clear coating composition containing a sulfur compound has an advantage that it can be suitably used for applications requiring better weather resistance, such as coating compositions for outdoor coating.

Examples of the sulfur compound include thiourea compounds, mercaptotriazine compounds, and inorganic sulfur compounds. The above sulfur compounds may be used alone or in combination of two or more. It is more preferable that the sulfur compound is one or more selected from the group consisting of thiourea compounds and mercaptotriazine compounds.

Examples of the thiourea compound include thiourea, 1-methylthiourea, 1,3-dimethylthiourea, 1,3-diethylthiourea, trimethylthiourea, 1,3-diisopropylthiourea, ethylenethiourea, 1,3-diphenylthiourea and tributylthiourea. , 1,3-Dibutylthiourea, Tetramethylthiourea, 1-Phenylthiourea and the like.

Examples of the mercaptotriazine-based compound include 2,4,6-trimercapto-1,3,5-triazine, 2-methoxy-4,6-dimercaptotriazine, 2-hexylamino-4,6-dimercaptotriazine, 2-Diethylamino-4,6-dimercaptotriazine, 2-cyclohexaneamino-4,6-dimercaptotriazine, 2-dibutylamino-4,6-dimercaptotriazine, 2-anilino-4,6-dimercaptotriazine, Examples thereof include 2-phenylamino-4,6-dimercaptotriazine, and alkali metal salts thereof (monoalkali metal salt, dialkali metal salt, trialkali metal salt, etc.). Examples of the alkali metal constituting the salt include sodium and potassium. Among these, 2,4,6-trimercapto-1,3,5-triazine, 2,4,6-trimercapto-1,3,5-triazine monosodium salt, 2,4,6-trimercapto- It is more preferable to use 1,3,5-triazine trisodium salt.

Examples of the inorganic sulfur compound include sodium thiosulfate, sodium sulfide, potassium sulfide, ammonium sulfide and the like. Of these, it is more preferable to use sodium thiosulfate.

A commercially available product may be used as the sulfur compound. Examples of commercially available products include Sankyo Kasei Co., Ltd.'s Santhiol series and Jisnet series.

When the clear coating composition contains a sulfur compound, the amount of the sulfur compound contained in the clear coating composition is 0 as the amount of the active component in the coating film with respect to 100 parts by mass of the resin solid content of the binder resin. It is preferably in the range of .04 to 0.50 parts by mass, and more preferably in the range of 0.08 to 0.25 parts by mass. When the sulfur compound is contained in the clear coating composition in an amount in the above range, good weather resistance can be obtained while ensuring the antibacterial property, viral property, clear property and glossiness of the obtained coating film. There are advantages that can be done.

Other components, etc. The clear paint composition of the present disclosure may contain other components, if necessary, in addition to the above components, depending on the purpose and use. Other components include, for example, pigments, resin particles, resin emulsions other than the above, resin components, dispersants, curing catalysts, viscosity modifiers, film-forming aids, and additives commonly used in coating compositions (eg, UV absorption). Agents, light stabilizers, antioxidants, defoamers, surface conditioners, pinhole inhibitors, rust preventives, etc.) and the like. These components can be added in a manner that does not impair the physical characteristics of the coating composition of the present disclosure.

The clear coating composition may contain an organic solvent, if necessary. Examples of the organic solvent include butyl acetate, xylene, toluene, methyl isobutyl ketone, propylene glycol, dipropylene glycol dimethyl ether, methyl ether acetate, tetrahydrofuran, ethanol, methanol, propanol, isopropanol, 2-butanol, t-butyl alcohol, dioxane, and the like. Methyl ethyl ketone, ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate (butyl cellosolve acetate), propylene glycol monomethyl ether acetate, 2-methoxypropanol, 2-butoxypropanol, diethylene glycol monobutyl ether, butyl diglycol, N-methylpyrrolidone, ethylene Examples include carbonate and propylene carbonate. These organic solvents may be the organic solvents used in the preparation of the anionic resin and the like, or may be added separately in the preparation of the clear coating composition.

The clear coating composition may contain a viscosity modifier. Examples of the viscosity adjusting agent include urethane type viscosity adjusting agents (for example, ADEKA Adecanol UH series, San Nopco Ltd. NOPALL series, etc.), polyamide type viscosity adjusting agents (for example, Kusumoto Kasei Co., Ltd. Disparon series, etc.), and wax type. Viscosity adjusting agents (for example, AQUATIX series manufactured by BYK), urea type viscosity adjusting agents (for example, BYK-410, 415, 420, 425, etc. manufactured by BYK) and the like can be mentioned. As the viscosity adjusting agent, it is more preferable to use a urethane type viscosity adjusting agent, a wax type viscosity adjusting agent, or the like.

The clear coating composition may contain an adhesion-imparting agent, if necessary. Examples of the adhesion-imparting agent include silane coupling agents such as epoxy silane coupling agents. For example, when an epoxy silane coupling agent is used, the amount of the epoxy silane coupling agent contained in the clear coating composition is 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin solid content of the binder resin. Is preferable.

Method for Producing Clear Paint Composition and Clear Coating Film The clear paint composition of the present disclosure can be prepared by mixing the above components by a method known to those skilled in the art. As a method for preparing the coating composition, a method usually used by those skilled in the art can be used. For example, a method usually used by those skilled in the art, such as a kneading and mixing means using a kneader or a roll, or a dispersion and mixing means using a sand grind mill or a disper, can be used.

The clear paint composition may be a one-component type, a two-component type composed of a main agent and a curing agent, or a two-component type composed of a main agent and an additive (for example, an adhesion-imparting agent). You may. When the clear coating composition is, for example, a two-component type, the two-component may be mixed and coated by a usual coating method before use. Alternatively, a two-component mixing gun may be used to send each liquid to the gun and the two liquids may be mixed at the gun tip for painting.

By applying the clear paint to the object to be coated and curing it, a coating film can be formed on the object to be coated. Examples of the base material constituting the object to be coated include a metal base material, a plastic base material, a composite base material thereof, and wood, stone, glass, cloth, concrete, and ceramic materials. Examples of the metal base material include metals such as iron, steel, copper, aluminum, tin, and zinc, and alloys containing these metals. The metal substrate may be plated with zinc, copper, chromium or the like, or may be surface-treated with a surface treatment agent such as chromic acid, zinc phosphate or a zirconium salt. Examples of the plastic base material include polypropylene resin, polycarbonate resin, urethane resin, polyester resin, polystyrene resin, ABS resin, vinyl chloride resin, polyamide resin and the like. These plastic substrates may be primer-coated, if necessary.

The method for applying the clear coating composition is not particularly limited, and for example, commonly used coatings such as dipping, brushing, rollers, roll coaters, air sprays, airless sprays, curtain flow coaters, roller curtain coaters, and die coaters. The method etc. can be mentioned. In the above spray painting, a two-component mixing gun may be used if necessary. These can be appropriately selected depending on the object to be coated.

The coating of the clear coating composition is preferably carried out so that the film thickness after forming the coating film is, for example, 20 to 150 μm, more preferably 30 to 100 μm. The curing temperature of the clear coating composition is preferably in the range of 20 ° C to 150 ° C, more preferably in the range of 20 ° C to 100 ° C. The curing time can be appropriately selected depending on the curing temperature, and may be, for example, between 10 minutes and 7 days.

In the present disclosure, the cured coating film (clear coating film) formed by coating the above clear coating composition has a silver elution amount of 0.0008 to 0 per 1 cm ² of the surface area of the cured coating film when immersed for 24 hours. The condition is that the amount is .003 mg / 1 L and the 20 ° mirror gloss of the cured coating film (clear coating film) is 140 or more. The amount of silver eluted is preferably 0.0009 to 0.0025 mg / 1 L, more preferably 0.001 to 0.002 mg / 1 L.

The term "clear coating film" as used herein means a state in which the coating film formed by the clear coating film has visible light transmittance to the extent that the lower layer of the coating film is recognized. The clear coating film in the present disclosure preferably has a haze value of 4.0 or less, and more preferably 2.0 or less.
For the measurement of the haze value of the clear coating film, for example, a clear coating composition is coated on a glass plate to prepare a test piece having the clear coating film, and the haze meter NDH2000 (manufactured by Nippon Denshoku) is used for measurement. be able to.

In the above-mentioned cured coating film (clear coating film), the amount of silver elution when immersed for 24 hours is 0.0008 to 0.003 mg / 1 L per 1 cm ² of the surface area of the cured coating film, thereby exhibiting antibacterial and antiviral performance. A sufficient amount of silver can be eluted, which has the advantage of exhibiting good antibacterial and antiviral performance. In the clear coating composition of the present disclosure, there is an advantage that the elution of silver in the cured coating film (clear coating film) can be ensured by using the binder resin and the silver-containing antibacterial antiviral agent in combination.

When the 20 ° mirror surface gloss of the cured coating film (clear coating film) formed by painting the above clear coating composition is 140 or more, the glossiness of the clear coating film is strongly felt, and the appearance of the coating film is good. It can be said that it is a clear coating film having. The 20 ° specular gloss is an index generally called 20 ° gloss (Gs (20 °)), and the specular reflected luminous flux is measured by irradiating the coating film surface with light from a light source having an incident angle of 20 °. This is the value obtained. The 20 ° mirror glossiness can be measured according to JIS K 5600-4-7 (mirror glossiness). The 20 ° mirror surface gloss can be measured using, for example, a gloss meter such as MULTI GLOSS 268 PLUS manufactured by Konica Minolta.

The clear coating composition of the present disclosure can be used in combination with the binder resin and the silver-containing antibacterial antiviral agent in addition to the antibacterial antiviral performance and coating strength generally required for antibacterial antiviral coating materials. It has the advantages of achieving transparency (clear performance) and good gloss. Examples of the antiviral agent that can be added to the coating composition for the purpose of forming a coating film having antibacterial and antiviral performance include a photocatalyst containing titanium, a silver-supported zeolite, and quaternary ammonium salts. .. It is generally said that these components can exhibit excellent antibacterial and antiviral performance. However, when a coating film is formed by including these components in a clear coating composition as in the present disclosure, one or more performances are inferior in clear performance, stability, glossiness, antibacterial antiviral property, and the like. It was found by the experiments of the present inventors. This is considered to be related to the composition of the clear coating film and the functions required for the clear coating film.

The present inventors conducted experiments for the purpose of solving the above technical problems. As a result of these experiments, by using the above binder resin component in combination with the above silver-containing antibacterial antiviral agent, in addition to antibacterial antiviral performance and coating strength, transparency (clear performance) and good glossiness can be obtained. It was found by experiment that it was achieved. Since the clear coating film formed by the clear coating composition is generally applied to the outermost surface of the object to be coated, transparency (clear performance) and good glossiness are important in addition to the general coating film physical characteristics. It becomes an index. The clear coating composition of the present disclosure is characterized in that the antibacterial and antiviral performance and the performance in these clear coating films can be compatible with each other by the above-mentioned configuration. The reason why such performance can be achieved at the same time is not limited to the theory, but in the clear coating film formed by using the binder resin and the silver-containing antibacterial antiviral agent in combination. It is considered that the silver elution amount required for exerting the antibacterial antiviral performance can be secured, and the combination of the binder resin and the silver-containing antibacterial antiviral agent does not impair the clear performance and glossiness. Be done.

The clear paint composition includes, for example, various medical equipment, food supply equipment, educational environment equipment, vehicle equipment, outdoor facilities and equipment, commercial facilities, public equipment, housing equipment, touch panels for financial institutions and public information, and the like. These walls, floors, etc. can be painted.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. In the examples, "parts" and "%" are based on mass unless otherwise specified.

Example 1
To a 1 L metal container, 60.0 parts of Burnock WE-306 (hydroxyl-containing acrylic resin emulsion, manufactured by DIC, resin solid content 45%) and 25.5 parts of tap water were added and stirred with a disper. Next, TEGO Formex 800 (Evonik defoaming agent) 0.1 part, BYK-307 (Big Chemie surface conditioner) 0.3 part, AQUACER 515 (oxidized high density polyethylene wax, Big Chemie) 2.2 part, CF Add 2.5 parts of -04 (Aqueous solution of antibacterial antiviral agent manufactured by J-Chemical) and 4.5 parts of Bihydur 3100 (isocyanurate compound manufactured by Sumika Cobestrourethane) in sequence, and stir well with a disper to clear. A coating composition was obtained.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear coating composition is 0.040 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

Example 2
To a 1 L metal container, add 78.0 parts of Watersol S-745 (acid group-containing acrylic resin solution, manufactured by DIC, resin solid content 40%) and 18.0 parts of tap water, and stir with a disper. bottom. Next, TEGO Formex 800 (Ebonic defoaming agent) 0.1 part, BYK-307 (Big Chemie surface conditioner) 0.3 part, AQUASER515 (oxidized high density polyethylene wax, Big Chemie) 2.2 part, CF. Add 2.6 parts of -04 (aqueous solution of antibacterial antiviral agent manufactured by J-Chemical) and 1.0 part of KBM-403 (silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.) in sequence, and stir well with a disper to clear. A coating composition was obtained.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear paint composition is 0.042 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

Example 3
To a 1 L metal container, 60.0 parts of hydroxyl group-containing acrylic resin Barnock WE-306 (manufactured by DIC) and 25.5 parts of tap water were added and stirred with a disper. Next, TEGO Formex 800 (Ebonic defoaming agent) 0.1 part, BYK-307 (Big Chemie surface conditioner) 0.3 part, AQUACER515 (oxidized high density polyethylene wax, Big Chemie) 2.2 part, CF Add 5.0 parts of -04 (J-Chemical's antibacterial antiviral agent aqueous solution) and 4.5 parts of Bihidol 3100 (Isocyanurate compound manufactured by Sumika Cobestrourethane) in sequence, and stir well with a disper to clear. A coating composition was obtained.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear paint composition is 0.079 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

Example 4
To a 1 L metal container, 60.0 parts of Burnock WE-306 (hydroxyl-containing acrylic resin emulsion, manufactured by DIC, resin solid content 45%) and 25.5 parts of tap water were added and stirred with a disper. Next, TEGO Formex 800 (Ebonic defoaming agent) 0.1 part, BYK-307 (Big Chemie surface conditioner) 0.3 part, AQUACER 515 (oxidized high density polyethylene wax, Big Chemie) 2.2 part, CF. -04 (Aqueous solution of antibacterial antiviral agent manufactured by J-Chemical) 2.5 parts, Bihydur 3100 (Isocyanurate compound manufactured by Sumika Cobestrourethane) 4.5 parts, and Santhiol N-1 (manufactured by Sankyo Kasei Co., Ltd.) (Weather-resistant discoloration inhibitor) 3.3 parts of a 1% aqueous solution was sequentially added and sufficiently stirred with a disper to obtain a clear paint composition.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear coating composition is 0.040 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

Comparative Example 1
To a 1 L metal container, 60.0 parts of hydroxyl group-containing acrylic resin Barnock WE-306 (manufactured by DIC) and 25.5 parts of tap water were added and stirred with a disper. Next, TEGO Formex 800 (Ebonic defoaming agent) 0.1 part, BYK-307 (Big Chemie surface conditioner) 0.3 part, AQUACER515 (oxidized high density polyethylene wax, Big Chemie) 2.2 part, CF Add 0.8 parts of -04 (J-Chemical's antibacterial antiviral agent aqueous solution) and 4.5 parts of Bihidol 3100 (Isocyanurate compound manufactured by Sumika Cobestrourethane) in sequence, and stir well with a disper to clear. A coating composition was obtained.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear coating composition is 0.013 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

Comparative Example 2
To a 1 L metal container, 60.0 parts of hydroxyl group-containing acrylic resin Barnock WE-306 (manufactured by DIC) and 25.5 parts of tap water were added and stirred with a disper. Next, TEGO Formex 800 (Ebonic defoaming agent) 0.1 part, BYK-307 (Big Chemie surface conditioner) 0.3 part, AQUACER515 (oxidized high density polyethylene wax, Big Chemie) 2.2 part, Zeomic Add 2.5 parts of HD10N (Sinanenzeomic, zeolite-supported antibacterial antiviral agent) and 4.5 parts of Bihydur 3100 (isocyanurate compound manufactured by Sumika Cobestrourethane) in sequence, and stir well with a disper. A clear paint composition was obtained.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear coating composition is 0.119 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

Comparative Example 3
To a 1 L metal container, 78.0 parts of acrylic resin water sol S-745 (manufactured by DIC) and 18.0 parts of tap water were added, and the mixture was stirred with a disper. Next, TEGO Formex 800 (Evonik defoaming agent) 0.1 part, BYK-307 (Big Chemie surface conditioner) 0.3 part, AQUASER515 (oxidized high density polyethylene wax, Big Chemie) 2.2 part, Zeomic Add 2.6 parts of HD10N (Sinanen Zeomic, zeolite-supported antibacterial antiviral agent) and 1.0 part of KBM-403 (Silane coupling agent, Shin-Etsu Chemical Co., Ltd.) in sequence, and stir well with a disper. A clear paint composition was obtained.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear coating composition is 0.125 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

Comparative Example 4
In a reaction vessel equipped with a stirrer, cooler, nitrogen introduction tube and thermometer, 702 parts of epoxy resin with an epoxy equivalent of 188 synthesized from bisphenol A and epichlorohydrin, 269 parts of bisphenol A, 108 parts of dimer acid, and methyl isobutyl ketone (hereinafter referred to as "methyl isobutyl ketone"). (Referred to as "MIBK") 190 parts were charged and reacted at 117 ° C. in the presence of 1 part of benzyldimethylamine until the epoxy equivalent reached 1270. Then, 255 parts of a ketimine compound (73 mass% MIBK solution) of aminoethylethanolamine was added, and the mixture was reacted at 117 ° C. for 1 hour. Then, it was diluted with MIBK until the non-volatile content became 75% to obtain an epoxy-based polyamine resin having a number average molecular weight of 2400 and an amine equivalent of 1184. Further, acetic acid was added to bring the neutralization rate to 20.0% (neutralization rate of the resin with respect to the amine group), and ion-exchanged water was added to dilute the mixture. Then, the mixture of MIBK and water was removed under reduced pressure until the solid content became 40% by mass to prepare a cationic epoxy-based polyamine resin emulsion.
To 2960 parts of the obtained emulsion, 1000 parts of tap water and 118 parts of dipropylene glycol n-butyl ether (DPnB) were added while stirring with a disper, and then ethoxylated trimethylolpropane triacrylate (with stirring with a disper). EO 20 mol) (trade name “AT-20E” manufactured by Shin-Nakamura Chemical Co., Ltd.) and 296 parts of CF-04 (antibacterial antiviral agent aqueous solution manufactured by J-Chemical) were added and stirred for 10 minutes to obtain a clear coating composition. rice field.
The content of the silver-containing antibacterial antiviral agent in the coating film formed by using the above clear coating composition is 0.125 parts by mass in terms of Ag as the amount of the active ingredient with respect to 100 parts by mass of the resin solid content of the binder resin. It was the amount that became.

The following evaluation tests were carried out using the clear paint compositions prepared in the above Examples and Comparative Examples.

Silver elution amount The silver elution amount was evaluated using an ICP emission spectrophotometer. Specifically, the procedure was as follows.
The coating compositions obtained in each Example and Comparative Example were coated on a glass plate (length 50 mm, width 50 mm, thickness 2 mm) using a brush, dried at room temperature for 7 days, and cleared to a film thickness of 45 μm. A test piece having a coating film was prepared.
Next, the test piece was immersed in 12 ml of ion-exchanged water (water temperature 25 ° C.) for 24 hours with the coated surface on the upper surface and the coated surface completely immersed.
The test piece is pulled up from the ion-exchanged water, and the amount of silver elution (mg / 1 L) per 1 cm ² of the surface area of the cured coating film contained in the ion-exchanged water in which the test piece is immersed is measured by an ICP emission spectrophotometer (ICPE-). It was measured by inductively coupled plasma emission spectroscopy using 9000 (manufactured by Shimadzu Corporation). The measurement results are shown in the table below.

Anti-viral evaluation The anti-viral evaluation test was carried out in accordance with the provisions of JIS R 1756 "Fine ceramic-Anti-viral test method for visible light responsive photocatalytic material-Method using bacteriophage Qβ".
The coating compositions obtained in each Example and Comparative Example were coated on a glass plate (length 50 mm, width 50 mm, thickness 2 mm) using a brush, dried at room temperature for 7 days, and cleared to a film thickness of 45 μm. A test piece having a coating film was prepared.
Bacteriophage Qβ solution was added dropwise to the sample of the obtained test piece, covered with a film, and allowed to stand for 24 hours. Then, the bacteriophage remaining on the test piece was infected with Escherichia coli and allowed to stand overnight, and then the number of viruses retaining the infectivity was measured to determine the antiviral activity value. The higher the antiviral activity value (the higher the absolute value), the better the antiviral property is evaluated.
The obtained results were evaluated according to the following criteria.

◯: Antiviral activity value is 2 or more ×: Antiviral activity value is less than 2.

Antibacterial evaluation The antibacterial evaluation test was conducted in accordance with the provisions of JIS Z 2801.
The coating compositions obtained in each Example and Comparative Example were coated on a glass plate (length 50 mm, width 50 mm, thickness 2 mm) using a brush, dried at room temperature for 7 days, and cleared to a film thickness of 45 μm. A test piece having a coating film was prepared.
Next, an evaluation test was conducted using a test bacterial solution containing Staphylococcus aureus (NBRC12732) with a viable cell count of 1.4 × 10 ⁴ / mL. The clear coating film on the test piece was inoculated with 0.4 ml of the test bacterial solution, the surface of the inoculated coating film was covered with a polyethylene film and brought into close contact with each other, and the cells were cultured for 24 hours under the conditions of a temperature of 35 ° C. and a relative humidity of 90%.
As a standard sample (blank), a glass plate (length 50 mm, width 50 mm, thickness 2 mm) having no coating film was used.
The number of bacteria after culturing for 24 hours was measured, and the number obtained by subtracting A from the logarithmic value of the number of bacteria after culturing the standard sample (blank): U was defined as the antibacterial activity value: R. (R = UA).
The obtained results were evaluated according to the following criteria.

◯: Antibacterial activity value is 2 or more ×: Antibacterial activity value is less than 2.

Gloss measurement (20 ° gloss)
The coating compositions obtained in each Example and Comparative Example were coated on a glass plate (thickness 2 mm) using a 6 mil applicator, dried at room temperature for 7 days, and a test piece having a clear coating film having a film thickness of 45 μm. It was created. The obtained test piece was placed on a black portion of a black-and-white concealing paper, and the 20 ° glossiness was measured according to JIS K 5600-4-7 (mirror glossiness). For the measurement, MULTI GLOSS 268 PLUS (manufactured by Konica Minolta) was used. The results obtained are shown in the table below.

Measurement of haze value Haze was measured using a haze meter NDH2000 (manufactured by Nippon Denshoku) using the test piece used for the measurement of the gloss value. The results obtained are shown in the table below. The smaller the haze value, the higher the transparency (clearness) of the coating film.

An aluminum plate is used as the weather resistance test base material, and a two-component water-based paint (Nippe Clean Color U Water-based White manufactured by Nippon Paint Co., Ltd.) is applied on it with an air spray to a dry film thickness of 50 μm, dried for one day, and then coated. Obtained a membrane. The coating compositions obtained in each Example and Comparative Example were coated on this base coating film using a 6 mil applicator and dried at room temperature for 7 days to prepare a test piece having a clear coating film having a film thickness of 45 μm. .. The obtained test piece was subjected to an accelerated weather resistance test with a super xenon weather meter SX-120 (manufactured by Suga Test Instruments Co., Ltd.) according to the xenon lamp method described in JIS K 5600-7-7. The test time was 1000 hours, and the appearance of the coating film after the test time had elapsed was quantified by the Lab color system. A color difference meter (CR-400 manufactured by Konica Minolta Co., Ltd.) was used as the color difference meter. The difference (ΔE) from the hue after the test was evaluated based on the hue before the test.

◯: 3> ΔE
○ △: 7> ΔE ≧ 3
Δ: ΔE ≧ 7

It was confirmed that all the clear coating films formed by using the clear coating composition of the example had good antibacterial and antiviral properties, and were excellent in transparency (clearness) and glossiness. Was done.
Comparative Example 1 is an example in which the amount of silver elution is small and does not fall within the scope of the present disclosure. In this example, good antibacterial and antiviral performance could not be obtained.
Comparative Examples 2 and 3 are examples using a zeolite-supported antibacterial antiviral agent. In these examples, it was confirmed that the high glossiness of the coating film was low, the haze value was high, and the transparency was low.
Comparative Example 4 is an example in which a cationic epoxy-based polyamine resin is used as the binder resin. In this example, the amount of silver eluted was small, and antibacterial and antiviral performance could not be obtained.

By using the clear coating composition of the present disclosure, it is possible to form a clear coating film having high glossiness and antibacterial and antiviral performance. The clear coating composition of the present disclosure can be suitably applied to various objects to be coated, which are required to be imparted with antibacterial and antiviral performance.

Claims (9)

A clear paint composition containing a silver-containing antibacterial antiviral agent and a binder resin.
The amount of silver elution when the cured coating film of the clear coating film was immersed in water for 24 hours was 0.0008 to 0.003 mg / 1 L per 1 cm ² of the surface area of the cured coating film.
The cured coating film of the clear paint composition has a 20 ° mirror surface gloss of 140 or more.
The binder resin contains an anionic resin.
Clear paint composition. The silver-containing antibacterial antiviral agent comprises one or more of silver salts and silver complexes.
The clear paint composition according to claim 1. One or more of the silver salts and silver complexes are silver carboxylate, silver nitrate, silver carbonate, silver sulfate, silver perchlorate, silver fluoride, silver chloride, silver chlorate, silver chromate, silver cyanide. , Silver bromide, silver bromide, silver iodide or silver nitrate,
The clear paint composition according to claim 2. The clear coating composition according to claim 2 or 3, wherein the silver-containing antibacterial antiviral agent further contains a nitrogen-containing compound. The clear coating composition according to any one of claims 1 to 4, wherein the anionic resin contains an aqueous dispersion of a resin having at least one of a hydroxyl group and an acid group. The anionic resin contains a hydroxyl group-containing resin water dispersion and a water-dispersible polyisocyanate.
The clear paint composition according to any one of claims 1 to 5. The hydroxyl group-containing resin water dispersion is an acrylic resin emulsion.
The clear paint composition according to claim 6. The clear coating composition further contains a sulfur compound and contains
The sulfur compound comprises one or more selected from the group consisting of thiourea compounds, mercaptotriazine compounds and inorganic sulfur compounds.
The clear paint composition according to any one of claims 1 to 7. A method for forming a clear coating film, which comprises a step of coating the object to be coated with the clear coating composition according to any one of claims 1 to 8 to form a clear coating film.
The amount of silver elution when the clear coating film was immersed in water for 24 hours was 0.0008 to 0.003 mg / 1 L per 1 cm ² of the surface area of the cured coating film.
The 20 ° mirror surface gloss of the clear coating film is 140 or more.
A method for forming a clear coating film.