AU2022319170A1 - Coating composition and coating film - Google Patents

Abstract

Provided is a coating composition capable of forming coating films having antiviral and antibacterial properties, resistance to deterioration and discoloration by light, and crack resistance. The coating composition comprises an acrylic-resin emulsion, photocatalytic titanium oxide, and a pigment, wherein the acrylic resin of the acrylic-resin emulsion has a content of aromatic vinyl monomer units of 0-52 mass% and the photocatalytic titanium oxide includes metal-supported anatase-form titanium oxide, the content of the metal-supported anatase-form titanium oxide being 0.05-2.90 parts by mass per 100 parts by mass of all the solid components of the coating composition, the coating composition having a pigment volume concentration (PVC) of 35-65%.

Description

DESCRIPTION TITLE COATING COMPOSITION AND COATING FILM TECHNICAL FIELD

[0001] The present disclosure relates to a coating composition and a coating film.

BACKGROUND

[00021 Coating films formed using paints that contain photocatalytic titanium oxide are conventionally known to have excellent antibacterial property and antiviral property because the titanium oxide exhibits a strong oxidation reduction action when irradiated with light such as ultraviolet light (see, for example, JP 2019-011417 A (PTL 1) and JP 2019-011418 A (PTL 2)).

CITATION LIST Patent Literature

[0003] PTL 1: JP 2019-011417 A PTL 2: JP 2019-011418 A

SUMMARY (Technical Problem)

[00041 With such paint containing photocatalytic titanium oxide, however, the oxidation-reduction action of the titanium oxide irradiated with light facilitates degradation of the coating film and causes discoloration (including fading) of the coating film from the desired color.

[0005] Increasing the pigment volume concentration (PVC) of the paint reduces the amount of resin component in the coating film and increases the photocatalyst exposed without being sufficiently covered with the resin component, so that antibacterial property and antiviral property can be improved. In this case, however, since the amount of resin component in the coating film decreases, cracks tend to occur in the coating film during film formation. Such cracks not only impair the appearance of the coating film but also cause a decrease in the adhesion of the coating film to the coated matter. If the adhesion of the coating film to the coated matter decreases, the coating

Ref. No. P0224225-PCT-AU (1/30) film may fall off in the parts where the adhesion has decreased, and the photocatalytic effect cannot be achieved in the parts where the coating film has fallen off.

[0006] It could therefore be helpful to provide a coating composition capable of forming a coating film having antiviral property, antibacterial property, discoloration resistance against photodegradation of a photocatalytic titanium oxide-containing coating film (hereafter referred to as "photodegradation discoloration resistance"), and crack resistance.

[0007] It could also be helpful to provide a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance.

[0008] It could also be helpful to provide an article comprising a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance. (Solution to Problem)

[0009] A coating composition according to the present disclosure is a coating composition comprising: an acrylic resin emulsion; a photocatalytic titanium oxide; and a pigment, wherein a proportion of an aromatic vinyl monomer unit in an acrylic resin of the acrylic resin emulsion is 0 mass% to 52 mass%, the photocatalytic titanium oxide contains a metal-supporting anatase type titanium oxide, a content of the metal-supporting anatase type titanium oxide is 0.05 parts by mass to 2.90 parts by mass per 100 parts by mass of a total solid content of the coating composition, and a pigment volume concentration (PVC) of the pigment is 35 % to 65 %. The coating composition is thus capable of forming a coating film having antiviral property, antibacterial property, discoloration resistance against photodegradation of a photocatalytic titanium oxide-containing coating film, and crack resistance.

[0010] In one embodiment of the coating composition according to the present disclosure, the acrylic resin does not contain the aromatic vinyl monomer unit.

[0011] In one embodiment of the coating composition according to the present disclosure, the proportion of the aromatic vinyl monomer unit is 0 mass% to 16 mass% with respect to the total solid content of the coating composition.

[0012] In one embodiment of the coating composition according to the present disclosure, the photocatalytic titanium oxide further contains metal-supporting rutile type titanium oxide.

[0013] A coating film according to the present disclosure is a coating film Ref No. P0224225-PCT-AU (2/30) using the above-described coating composition. The coating film thus has antiviral property, antibacterial property, discoloration resistance against photodegradation of a photocatalytic titanium oxide-containing coating film, and crack resistance.

[0014] An article according to the present disclosure is an article comprising the above-described coating film. The article thus comprises a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance. (Advantageous Effect)

[0015] It is thus possible to provide a coating composition capable of forming a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance. It is also possible to provide a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance. It is also possible to provide an article comprising a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance.

DETAILED DESCRIPTION

[0016] Embodiments of the present disclosure will be described below. The following description is intended for illustrative purposes only and is not intended to limit the scope of the present disclosure in any way.

[0017] In the present disclosure, two or more embodiments may be freely combined.

[0018] In the present disclosure, the terms "paint" and "coating composition" can be used interchangeably.

[0019] In the present disclosure, the term "solid content" is a concept that includes solid content and nonvolatile content.

[0020] In this specification, each numerical range is intended to include the upper and lower limits of the range, unless otherwise specified. For example, 0 % to 52 % means 0 % or more and 52 % or less.

[0021] In this specification, the term "(meth)acrylic acid" means one or more selected from the group consisting of acrylic acid and methacrylic acid. In this specification, the term "(meth)acrylonitrile" means one or more selected from the group consisting of acrylonitrile and methacrylonitrile. In this specification, the term "(meth)acrylamide" means one or more selected from the group

Ref No. P0224225-PCT-AU (3/30) consisting of acrylamide and methacrylamide.

[0022] In this specification, the term "aromatic vinyl monomer unit" means a structural unit formed by polymerizing an aromatic vinyl monomer. In this specification, the term "(meth)acrylonitrile monomer unit" means a structural unit formed by polymerizing a (meth)acrylonitrile monomer. In this specification, the term "polyfunctional monomer unit" means a structural unit formed by polymerizing a polyfunctional monomer. A polyfunctional monomer is a monomer having two or more functional groups that can form a crosslinked structure during or after polymerization as a result of heating or irradiation with energy rays. In this specification, the term "(meth)acrylic acid ester monomer unit" means a structural unit formed by polymerizing a (meth)acrylic acid ester monomer. In this specification, the term "carboxy group-containing monomer unit" means a structural unit formed by polymerizing a monomer having a carboxy group.

[0023] In this specification, for an acrylic resin produced by copolymerizing two or more monomers, the proportion of a structural unit formed by polymerizing one monomer in the acrylic resin typically coincides with the ratio (charging ratio) of the mass of the monomer to the mass of all monomers, reactive emulsifiers, and polymerization initiators used for the polymerization of the acrylic resin, unless otherwise specified.

[0024] In this specification, titanium oxide whose crystal structure is anatase type is referred to as "anatase type titanium oxide", and titanium oxide whose crystal structure is rutile type is referred to as "rutile type titanium oxide".

[0025] In this specification, the term "titanium oxide" other than photocatalytic titanium oxide, metal-supporting anatase type titanium oxide, metal-supporting rutile type titanium oxide, and metal-supporting titanium oxide refers to not photocatalytic titanium oxide but titanium oxide as a pigment.

[0026] (Coating composition) A coating composition according to the present disclosure is a coating composition comprising: an acrylic resin emulsion; a photocatalytic titanium oxide; and a pigment, wherein a proportion of an aromatic vinyl monomer unit in an acrylic resin of the acrylic resin emulsion is 0 mass% to 52 mass%, the photocatalytic titanium oxide contains a metal-supporting anatase type titanium oxide, a content of the metal-supporting anatase type titanium oxide is 0.05 parts by mass to 2.90 parts by mass per 100 parts by mass of a total

Ref No. P0224225-PCT-AU (4/30) solid content of the coating composition, and a pigment volume concentration (PVC) of the pigment is 35 % to 65 %.

[0027] The acrylic resin emulsion, photocatalytic titanium oxide, and pigment in the coating composition according to the present disclosure will be described below.

[0028] - Acrylic resin emulsion The acrylic resin emulsion is a component containing an acrylic resin which is a coating film forming component.

[0029] The proportion of an aromatic vinyl monomer unit in the acrylic resin of the acrylic resin emulsion is 0 mass% to 52 mass%. As a result of the proportion of the aromatic vinyl monomer unit being 0 mass% to 52 mass%, the discoloration resistance of the coating film containing photocatalytic titanium oxide against photodegradation is improved.

[0030] Examples of aromatic vinyl monomers include styrene, C methylstyrene, styrene sulfonic acid, butoxystyrene, and vinylnaphthalene. In one embodiment, the aromatic vinyl monomer is styrene.

[0031] The proportion of the aromatic vinyl monomer unit in the acrylic resin is 0 mass% to 52 mass%. If the proportion of the aromatic vinyl monomer unit in the acrylic resin is more than 52 mass% with respect to the total mass of the acrylic resin, the discoloration resistance of the coating film containing photocatalytic titanium oxide against photodegradation cannot be improved. In one embodiment, the proportion of the aromatic vinyl monomer unit in the acrylic resin is 0 mass% or more, 10.0 mass% or more, 20.0 mass% or more, 30.0 mass% or more, or 40.0 mass% or more. In another embodiment, the proportion of the aromatic vinyl monomer unit in the acrylic resin is 52.0 mass% or less, 50.0 mass% or less, 40.0 mass% or less, 30.0 mass% or less, 25.0 mass% or less, 21.0 mass% or less, 20.0 mass% or less, or 10.0 mass% or less.

[0032] In the case where two or more acrylic resins that differ in the proportion of the aromatic vinyl monomer unit are used in combination, the weighted average value of their proportions of the aromatic vinyl monomer unit is 0 mass% to 52 mass%.

[0033] In one embodiment of the coating composition according to the present disclosure, the acrylic resin contains no aromatic vinyl monomer unit, that is, the proportion of the aromatic vinyl monomer unit in the acrylic resin is 0 mass%.

Ref No. P0224225-PCT-AU (5/30)

[0034] The proportion of the aromatic vinyl monomer unit to the total solid content of the coating composition may be adjusted as appropriate as long as the proportion of the aromatic vinyl monomer unit in the acrylic resin is 0 mass% to 52 mass%. For example, the proportion of the aromatic vinyl monomer unit is 0 mass% to 20 mass% with respect to the total solid content of the coating composition. In one embodiment, the proportion of the aromatic vinyl monomer unit is 0 mass% or more, 1.0 mass% or more, 2.0 mass% or more, 3.0 mass% or more, 4.0 mass% or more, 5.0 mass% or more, 6.0 mass% or more, 7.0 mass% or more, 8.0 mass% or more, 9.0 mass% or more, 10.0 mass% or more, or 15.0 mass% or more with respect to the total solid content of the coating composition. In another embodiment, the proportion of the aromatic vinyl monomer unit is 20.0 mass% or less, 16.0 mass% or less, 15.0 mass% or less, 10.0 mass% or less, 9.0 mass% or less, 8.0 mass% or less, 7.0 mass% or less, 6.0 mass% or less, 5.0 mass% or less, 4.0 mass% or less, 3.0 mass% or less, 2.0 mass% or less, or 1.0 mass% or less with respect to the total solid content of the coating composition.

[0035] In one embodiment of the coating composition according to the present disclosure, the proportion of the aromatic vinyl monomer unit is 0 mass% to 16 mass% with respect to the total solid content of the coating composition.

[0036] Examples of other monomers that can be contained in the acrylic resin include (meth)acrylic acid ester monomer units, carboxy group-containing monomers, polyfunctional monomers, (meth)acrylonitrile monomers, (meth)acrylamide monomers, vinyl chloride-based monomers, vinyl acetate based monomers, vinylamine-based monomers, vinylamide-based monomers, (meth)acrylic acid derivative monomers, unsaturated carboxylic acid anhydride monomers, maleimide derivative monomers, and diene-based monomers. The acrylic resin may contain a monomer derived from each of one or more monomers. In one embodiment, the acrylic resin contains a monomer unit derived from each of one or more selected from the group consisting of aromatic vinyl monomers, (meth)acrylic acid ester monomers, carboxy group containing monomers, polyfunctional monomers, (meth)acrylonitrile monomer units, vinyl chloride-based monomer units, vinyl acetate-based monomer units, vinylamine-based monomer units, vinylamide-based monomer units, (meth)acrylic acid derivatives, unsaturated carboxylic acid anhydride monomer units, maleimide derivative monomer units, and diene-based monomers. In another embodiment, the acrylic resin contains a monomer unit

Ref No. P0224225-PCT-AU (6/30) derived from each of one or more selected from the group consisting of aromatic vinyl monomers, (meth)acrylic acid ester monomers, carboxy group containing monomers, polyfunctional monomers, and (meth)acrylonitrile monomer units. In yet another embodiment, the acrylic resin contains a monomer unit derived from each of one or more selected from the group consisting of aromatic vinyl monomers and (meth)acrylic acid ester monomers. In yet another embodiment, the acrylic resin contains a (meth)acrylic acid ester monomer unit. In yet another embodiment, the acrylic resin contains a (meth)acrylic acid ester monomer unit, and further contains a monomer unit derived from each of one or more selected from the group consisting of carboxy group-containing monomers, polyfunctional monomers, (meth)acrylonitrile monomer units, vinyl chloride-based monomer units, vinyl acetate-based monomer units, vinylamine-based monomer units, vinylamide-based monomer units, (meth)acrylic acid derivatives, unsaturated carboxylic acid anhydride monomer units, maleimide derivative monomer units, and diene-based monomers. In yet another embodiment, the acrylic resin contains only a (meth)acrylic acid ester monomer unit.

[00371 Examples of (meth)acrylic acid ester monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, isopropyl acrylate, isopropyl methacrylate, propyl acrylate, propyl methacrylate, isobutyl acrylate, isobutyl methacrylate, butyl acrylate, butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, pentyl acrylate, pentyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, hexyl acrylate, hexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, myristyl acrylate, myristyl methacrylate, palmityl acrylate, palmityl methacrylate, glycidyl acrylate, glycidyl methacrylate, trifluoroethyl acrylate, trifluoroethyl methacrylate, isopentyl acrylate, isopentyl methacrylate, octyl acrylate, octyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, dodecenyl acrylate, dodecenyl methacrylate, octadecyl acrylate, octadecyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 4-tert butylcyclohexyl acrylate, 4-tert-butylcyclohexyl methacrylate, phenyl acrylate, phenyl methacrylate, isobornyl acrylate, isobornyl methacrylate, benzyl acrylate, benzyl methacrylate, 2-phenylethyl acrylate, 2-phenylethyl

Ref. No. P0224225-PCT-AU (7/30) methacrylate, 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate, 4 methoxybutyl acrylate, and 4-methoxybutyl methacrylate.

[0038] The proportion of the (meth)acrylic acid ester monomer unit in the acrylic resin may be adjusted as appropriate, and is, for example, 5 mass% to 100 mass%. In one embodiment, the proportion of the (meth)acrylic acid ester monomer unit in the acrylic resin is 5 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 100 mass%. In another embodiment, the proportion of the (meth)acrylic acid ester monomer unit in the acrylic resin is 100 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, or 10 mass% or less.

[0039] Examples of carboxy group-containing monomers include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid.

[0040] The proportion of the carboxy group-containing monomer unit in the acrylic resin may be adjusted as appropriate, and is, for example, 0 mass% to 95 mass%. In one embodiment, the proportion of the carboxy group-containing monomer unit in the acrylic resin is 0 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 95 mass%. In another embodiment, the proportion of the carboxy group containing monomer unit in the acrylic resin is 95 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, 10 mass% or less, or 0 mass%.

[0041] Examples of polyfunctional monomers include divinylbenzene, ethylene dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,3-butylene glycol diacrylate, allyl methacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, allyl glycidyl ether, and glycidyl methacrylate.

[0042] The proportion of the polyfunctional monomer unit in the acrylic resin may be adjusted as appropriate, and is, for example, 0 mass% to 95 mass%. In one embodiment, the proportion of the polyfunctional monomer unit in the acrylic resin is 0 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 95 mass%. In another

Ref No. P0224225-PCT-AU (8/30) embodiment, the proportion of the polyfunctional monomer unit in the acrylic resin is 95 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, 10 mass% or less, or 0 mass%.

[0043] Examples of (meth)acrylonitrile monomers include acrylonitrile, methacrylonitrile, and other (meth)acrylonitrile derivatives.

[0044] The proportion of the (meth)acrylonitrile monomer unit in the acrylic resin may be adjusted as appropriate, and is, for example, 0 mass% to 95 mass%. In one embodiment, the proportion of the (meth)acrylonitrile monomer unit in the acrylic resin is 0 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 95 mass%. In another embodiment, the proportion of the (meth)acrylonitrile monomer unit in the acrylic resin is 95 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, 10 mass% or less, or 0 mass%.

[0045] Examples of (meth)acrylamide monomers include acrylamide, methacrylamide, and diacetone acrylamide.

[0046] The proportion of the (meth)acrylamide monomer unit in the acrylic resin may be adjusted as appropriate, and is, for example, 0 mass% to 95 mass%. In one embodiment, the proportion of the (meth)acrylamide monomer unit in the acrylic resin is 0 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 95 mass%. In another embodiment, the proportion of the (meth)acrylamide monomer unit in the acrylic resin is 95 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, 10 mass% or less, or 0 mass%.

[0047] Examples of vinyl chloride-based monomers include vinyl chloride and vinylidene chloride.

[0048] Examples of vinyl acetate-based monomers include vinyl acetate.

[0049] Examples of vinylamine-based monomers include vinylamine.

[0050] Examples of vinylamide-based monomers include N-vinylformamide and N-vinylacetamide.

[0051] Examples of unsaturated carboxylic acid anhydride monomers include maleic anhydride.

Ref No. P0224225-PCT-AU (9/30)

[0052] Examples of diene-based monomers include 1,3-butadiene and isoprene.

[0053] The respective proportions of the vinyl chloride-based monomer unit, vinyl acetate-based monomer unit, vinylamine-based monomer unit, vinylamide-based monomer unit, unsaturated carboxylic acid anhydride monomer unit, and diene-based monomer unit in the acrylic resin are each, for example, 0 mass% to 95 mass%. In one embodiment, the respective proportions of the vinyl chloride-based monomer unit, vinyl acetate-based monomer unit, vinylamine-based monomer unit, vinylamide-based monomer unit, unsaturated carboxylic acid anhydride monomer unit, and diene-based monomer unit in the acrylic resin are each 0 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 95 mass%. In another embodiment, the respective proportions of the vinyl chloride-based monomer unit, vinyl acetate-based monomer unit, vinylamine-based monomer unit, vinylamide-based monomer unit, unsaturated carboxylic acid anhydride monomer unit, and diene-based monomer unit in the acrylic resin are each 95 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, 10 mass% or less, or 0 mass%.

[0054] The foregoing monomers in the acrylic resin may be used alone or in combination of two or more.

[0055] The glass transition temperature (Tg) of the acrylic resin may be adjusted as appropriate, and is, for example, -50 °C to 50 °C. In one embodiment, Tg of the acrylic resin is -50 °C or more, -40 °C or more, -30 °C or more, -20 °C or more, -10 °C or more, 0 °C or more, 10 °C or more, 20 °C or more, 30 °C or more, or 40 °C or more. In another embodiment, Tg of the acrylic resin is 50 °C or less, 40 °C or less, 30 °C or less, 20 °C or less, 10 °C or less, 0 °C or less, -10 °C or less, -20 °C or less, -30 °C or less, or -40 °C or less. In yet another embodiment, Tg of the acrylic resin is -35 °C to 30 °C.

[0056] In the present disclosure, Tg of the acrylic resin is calculated from the following formula: 1/Tg = Mi/Ti + M 2/T 2 + ... Mn/Tn where Mi, M 2 , ... , Mn are each mass% of the corresponding monomer, and Ti, T 2 , . . , Tn are each Tg (absolute temperature) of the homopolymer of the corresponding monomer. Here, mass% of each monomer is calculated from (the blending amount (parts by mass) of the monomer) x 100/(the total blending

Ref No. P0224225-PCT-AU (10/30) amount (parts by mass) of the monomers).

[0057] The molecular weight of the acrylic resin may be adjusted as appropriate. For example, the number average molecular weight of the acrylic resin is 5,000 to 300,000. In one embodiment, the number average molecular weight of the acrylic resin is 5,000 or more, 10,000 or more, 50,000 or more, 100,000 or more, 150,000 or more, 200,000 or more, or 250,000 or more. In another embodiment, the number average molecular weight of the acrylic resin is 300,000 or less, 250,000 or less, 200,000 or less, 150,000 or less, 100,000 or less, 50,000 or less, or 10,000 or less.

[0058] The number average molecular weight Mn is a value calculated from the molecular weight in terms of standard polystyrene, measured by gel permeation chromatography (GPC) using tetrahydrofuran or chloroform as a measurement solvent.

[0059] One acrylic resin may be used alone or two or more acrylic resins may be used in combination.

[0060] The amount of acrylic resin (solid content) in the coating composition is not limited and may be adjusted as appropriate as long as the predetermined content range of the metal-supporting anatase type titanium oxide and the predetermined range of the PVC of the pigment described later are satisfied. The amount of acrylic resin (solid content) in the coating composition is, for example, 5 parts by mass to 30 parts by mass per 100 parts by mass of the total solid content of the coating composition. In one embodiment, the amount of acrylic resin (solid content) is 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more per 100 parts by mass of the total solid content of the coating composition. In another embodiment, the amount of acrylic resin (solid content) is 30 parts by mass or less, 25 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, or 5 parts by mass or less per 100 parts by mass of the total solid content of the coating composition.

[00611 The acrylic resin emulsion may contain a solvent, a polymerization initiator, an emulsifier, a chain transfer agent, etc. in addition to the acrylic resin. These components may be used alone or in combination of two or more.

[0062] Examples of the solvent include water such as deionized water, ion exchange water, pure water, distilled water, purified water, and tap water; alcohols such as methanol, ethanol, 2-propanol, and 1-butanol; esters such as

Ref. No. P0224225-PCT-AU (11/30) ethyl acetate, butyl acetate, isobutyl acetate, ethyl propionate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; ethers such as diethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, dioxane, and tetrahydrofuran (THF); glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, pentamethylene glycol, and 1,3-octylene glycol; amides such as formamide, N-methylformamide, dimethylformamide (DMF), dimethylacetamide, dimethylsulfoxide (DMSO), and N-methylpyrrolidone (NMP); ketones such as acetone, methyl ethyl ketone (MEK), methyl propyl ketone, methyl isobutyl ketone, acetylacetone, and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, mesitylene, and dodecylbenzene; and halogen-based solvents such as chloroform and dichloromethylene. In one embodiment, the solvent contains water. In another embodiment, the solvent is water.

[0063] Examples of the polymerization initiator include ammonium persulfate and potassium persulfate. As the polymerization initiator, for example, the polymerization initiators described in JP 6058843 BI, JP HO1-098652 A, etc. may be used.

[0064] Examples of the emulsifier include sodium dodecylbenzene sulfonate, sodium lauryl sulfate, ammonium lauryl sulfate, sodium alkyl diphenyl ether disulfonate, and polyoxyethylene alkyl ester. As the emulsifier, for example, the emulsifiers described in JP 6058843 BI, JP HO1-098652 A, etc. may be used.

[00651 Examples of the chain transfer agent include lauryl mercaptan, n-butyl mercaptan, t-butyl mercaptan, dodecyl mercaptan, octyl mercaptan, 2 ethylhexyl thioglycolate, 2-methyl-5-t-butylthiophenol, carbon tetrabromide, and a-methylstyrene dimer. As the emulsifier, for example, the chain transfer agents described in JP 2015-193779 A, etc. may be used.

[00661 The method of preparing the acrylic resin emulsion is not limited as long as the proportion of the aromatic vinyl monomer unit in the acrylic resin is 0 mass% to 50 mass%, and a known preparation method may be used. Examples of the method of preparing the acrylic resin emulsion include the preparation method for aqueous emulsion (A) described in JP 2015-193779 A.

[0067] An example of the method of preparing the acrylic resin emulsion is as follows: A glass reactor equipped with a drop funnel, a reflux condenser, a

Ref. No. P0224225-PCT-AU (12/30) stirrer, and a thermometer is charged with deionized water and an emulsifier, and the temperature of the contents is set to 85 °C. A pre-emulsified liquid containing a monomer such as (meth)acrylic acid ester, an emulsifier, and deionized water and a polymerization initiator are added dropwise to the mixture using the drop funnel, and the mixture is reacted. The reaction temperature is kept at 85 °C. After the addition is completed, the product is kept at 85 °C for 3 hours. The product is then cooled to 30 °C and removed from the reactor to obtain an acrylic resin emulsion.

[0068] The coating composition may contain a resin emulsion other than the acrylic resin emulsion. Examples of resin emulsions other than the acrylic resin emulsion include vinyl acetate resin emulsions, vinyl chloride resin emulsions, epoxy resin emulsions, urethane resin emulsions, acrylic silicon resin emulsions, fluororesin emulsions, and synthetic resin emulsions consisting of resin components such as composites of these resin emulsions. Resin emulsions other than the acrylic resin emulsion may be used alone or in combination of two or more.

[0069] In one embodiment, one or more selected from the group consisting of vinyl acetate resin emulsions and urethane resin emulsions are used as resin emulsions other than the acrylic resin emulsion.

[0070] The amount of resin (solid content) other than acrylic resin in the coating composition is not limited and may be adjusted as appropriate as long as the predetermined content range of the metal-supporting anatase type titanium oxide and the predetermined range of the PVC of the pigment are satisfied. For example, the amount of resin (solid content) other than acrylic resin in the coating composition is 0 parts by mass to 35 parts by mass per 100 parts by mass of the total solid content of the coating composition.

[0071] - Photocatalytic titanium oxide The photocatalytic titanium oxide is a component that imparts antibacterial property or antiviral property to the coating film formed using the coating composition according to the present disclosure. In the present disclosure, the photocatalytic titanium oxide is not included in the below described pigment.

[0072] The photocatalytic titanium oxide contains a metal-supporting anatase type titanium oxide. For example, the metal component contained in the metal supporting anatase type titanium oxide is in contact with anatase type titanium oxide, and part of the metal component exists independently in a dispersed

Ref No. P0224225-PCT-AU (13/30) state. The crystal structure of the photocatalytic titanium oxide can be identified, for example, using powder X-ray diffraction.

[0073] As the metal supported by the metal-supporting anatase type titanium oxide, metals of known metal-supporting titanium oxides may be selected and used. Examples of the metal supported by the metal-supporting anatase type titanium oxide include metals such as vanadium V, iron Fe, cobalt Co, nickel Ni, copper Cu, zinc Zn, ruthenium Ru, rhodium Rh, palladium Pd, silver Ag, platinum Pt, and gold Au, silver compounds such as silver oxide (Ag20), and copper compounds such as Cu(OH)2, Cu20, and CuO. These metals or metal compounds may be used alone or in combination of two or more.

[0074] In one embodiment, the metal supported by the metal-supporting anatase type titanium oxide is one or more selected from the group consisting of silver, copper, silver compounds, and copper compounds. In another embodiment, the metal supported by the metal-supporting anatase type titanium oxide is one or more selected from the group consisting of silver, copper, silver oxide (Ag20), Cu(OH)2, Cu20, and CuO.

[0075] As the metal-supporting anatase type titanium oxide, commercial products may be used. Examples of commercially available metal-supporting anatase type titanium oxides include ST series such as trade names ST-01, ST 21, ST-31, and ST-41 produced by Ishihara Sangyo Kaisha, Ltd.; trade names AMT-100 andAMT-600 produced by Tayca Corporation; and trade names SSP N, SSP-20, and SPP-M produced by Sakai Chemical Industry Co., Ltd.

[0076] One metal-supporting anatase type titanium oxide may be used alone, or two or more metal-supporting anatase type titanium oxides may be used in combination.

[0077] The proportion of the metal-supporting anatase type titanium oxide in the photocatalytic titanium oxide is, for example, 0.5 mass% to 100 mass%. In one embodiment, the proportion of the metal-supporting anatase type titanium oxide in the photocatalytic titanium oxide is 0.5 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, or 90 mass% or more. In another embodiment, the proportion of the metal-supporting anatase type titanium oxide in the photocatalytic titanium oxide is 100 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, or 10 mass% or less. In a preferred embodiment, the proportion of the metal

Ref No. P0224225-PCT-AU (14/30) supporting anatase type titanium oxide in the photocatalytic titanium oxide is 10 mass% to 100 mass%.

[0078] The content of the metal-supporting anatase type titanium oxide is 0.05 parts by mass to 2.90 parts by mass per 100 parts by mass of the total solid content of the coating composition. As a result of the content of the metal supporting anatase type titanium oxide being 0.05 parts by mass or more, the antibacterial property or antiviral property of the coating film is enhanced. As a result of the content of the metal-supporting anatase type titanium oxide being 2.90 parts by mass or less, the discoloration resistance of the coating film containing photocatalytic titanium oxide against photodegradation can be suppressed.

[0079] The photocatalytic titanium oxide may further contain a metal supporting rutile type titanium oxide in addition to the metal-supporting anatase type titanium oxide. The metal component contained in the metal supporting rutile type titanium oxide may be in contact with the rutile type titanium oxide.

[0080] Examples of the metal supported by the metal-supporting rutile type titanium oxide include the metals listed as examples of the metal supported by the metal-supporting anatase type titanium oxide. The metals or metal compounds supported may be used alone or in combination of two or more.

[0081] In one embodiment, the metal supported by the metal-supporting rutile type titanium oxide is one or more selected from the group consisting of silver, copper, silver compounds, and copper compounds. In another embodiment, the metal supported by the metal-supporting rutile type titanium oxide is one or more selected from the group consisting of silver, copper, silver oxide (Ag20), Cu(OH)2, Cu20, and CuO. In yet another embodiment, the metal supported by the metal-supporting rutile type titanium oxide is at least one divalent copper compound.

[0082] In one embodiment, the copper compound supported by the metal supporting rutile type titanium oxide is a copper compound that is insoluble or poorly soluble in water. In another embodiment, the copper compound supported by the metal-supporting rutile type titanium oxide is a copper compound with a solubility product of less than 1.5 x 10-10. The solubility product is determined with reference to Chemical Experiment Handbook Editorial Committee, "Chemical Experiment Handbook, 4th Edition," Gihodo Shuppan,1984.

Ref No. P0224225-PCT-AU (15/30)

[0083] As the metal-supporting rutile type titanium oxide, for example, the metal-supporting rutile type titanium oxide described in PTL 1 may be used.

[0084] As the metal-supporting rutile type titanium oxide, commercial products may be used. Examples of commercially available metal-supporting rutile type titanium oxides include trade name Photopaque MPT-623 produced by Ishihara Sangyo Kaisha, Ltd.; and trade names STR-100C and STR-100W produced by Sakai Chemical Industry Co., Ltd.

[0085] One metal-supporting rutile type titanium oxide may be used alone, or two or more metal-supporting rutile type titanium oxides may be used in combination.

[0086] In the case where the photocatalytic titanium oxide contains metal supporting rutile type titanium oxide, the proportion of the metal-supporting rutile type titanium oxide in the photocatalytic titanium oxide is, for example, 1 mass% to 99.5 mass%. In one embodiment, in the case where the photocatalytic titanium oxide contains metal-supporting rutile type titanium oxide, the proportion of the metal-supporting rutile type titanium oxide in the photocatalytic titanium oxide is 1 mass% or more, 10 mass% or more, 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, or 90 mass% or more. In another embodiment, in the case where the photocatalytic titanium oxide contains metal-supporting rutile type titanium oxide, the proportion of the metal-supporting rutile type titanium oxide in the photocatalytic titanium oxide is 99.5 mass% or less, 90 mass% or less, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, 20 mass% or less, or 10 mass% or less. In a preferred embodiment, the proportion of the metal-supporting rutile type titanium oxide in the photocatalytic titanium oxide is 0 mass% to 90 mass%.

[0087] In one embodiment of the coating composition according to the present disclosure, the photocatalytic titanium oxide further contains metal-supporting rutile type titanium oxide.

[0088] The content of the photocatalytic titanium oxide per 100 parts by mass of the total solid content of the coating composition is, for example, 0.05 parts by mass to 2.85 parts by mass. In one embodiment, the content of the photocatalytic titanium oxide per 100 parts by mass of the total solid content of the coating composition is 0.1 parts by mass or more, 0.50 parts by mass or more, 1.00 part by mass or more, 1.10 parts by mass or more, 1.20 parts by

Ref No. P0224225-PCT-AU (16/30) mass or more, 1.30 parts by mass or more, 1.40 parts by mass or more, 1.50 parts by mass or more, 1.60 parts by mass or more, 1.70 parts by mass or more, 1.80 parts by mass or more, 1.90 parts by mass or more, 2.00 parts by mass or more, 2.10 parts by mass or more, 2.20 parts by mass or more, 2.30 parts by mass or more, 2.40 parts by mass or more, 2.50 parts by mass or more, 2.60 parts by mass or more, 2.70 parts by mass or more, or 2.80 parts by mass or more. In another embodiment, the content of the photocatalytic titanium oxide per 100 parts by mass of the total solid content of the coating composition is 2.85 parts by mass or less, 2.80 parts by mass or less, 2.70 parts by mass or less, 2.60 parts by mass or less, 2.50 parts by mass or less, 2.40 parts by mass or less, 2.30 parts by mass or less, 2.20 parts by mass or less, 2.10 parts by mass or less, 2.00 parts by mass or less, 1.90 parts by mass or less, 1.80 parts by mass or less, 1.70 parts by mass or less, 1.60 parts by mass or less, 1.50 parts by mass or less, 1.40 parts by mass or less, 1.30 parts by mass or less, 1.20 parts by mass or less, 1.10 parts by mass or less, 1.00 part by mass or less, or 0.50 parts by mass or less.

[0089] - Pigment The pigment is a component that imparts design to the coating film formed using the coating composition according to the present disclosure.

[0090] The pigment is not limited, and pigments in known coating compositions may be used. Examples of the pigment include color pigments, extender pigments, and matte materials. In the present disclosure, the term "pigment" is a concept that includes color pigments, extender pigments, and matte materials.

[0091] Examples of color pigments include organic color pigments and inorganic color pigments.

[0092] Examples of organic color pigments include azo lake-based pigments, insoluble azo-based pigments, condensed azo-based pigments, phthalocyanine based pigments, indigo-based pigments, perinone-based pigments, perylene based pigments, phthalone-based pigments, dioxazine-based pigments, quinacridone-based pigments, isoindolinone-based pigments, and metal complex pigments.

[0093] Examples of inorganic color pigments include yellow iron oxide, red iron oxide, carbon black, and titanium dioxide.

[0094] The color of the color pigment is not limited, and any known color, including white, can be used.

Ref No. P0224225-PCT-AU (17/30)

[0095] One color pigment may be used alone, or two or more color pigments may be used in combination.

[0096] Examples of extender pigments include baryta powder, precipitated barium sulfate, barium carbonate, gypsum, clay, white carbon, magnesium carbonate, alumina white, and gloss white.

[0097] A matte material is a component that contributes to increasing the surface area of the coating film. A coating film with a larger surface area can absorb more light, with it being possible to enhance the effect of photocatalytic titanium oxide.

[0098] Examples of matte materials include inorganic matte materials such as talc, silica, calcium carbonate, barium sulfate, feldspar, wollastonite, diatomaceous earth, zeolite, and nepheline syenite, and organic matte materials made of organic fine particles.

[0099] The matte material is preferably in the form of fine particles, and more preferably in the form of fine particles with an average particle size of 0.1 Pm to 100 pm. As a result of the average particle size being 0.1 Pm or more, the effect of increasing the surface area of the coating film can be easily achieved. As a result of the average particle size being 100 pm or less, the aesthetic appearance of the coating film is likely to be improved.

[0100] The matte material may be an inorganic or organic porous pigment. A preferable average particle size of the porous pigment is as described above. The diameter of the pores (pore size) of the porous pigment is, for example, 0.1 nm to 50 nm. In a preferred embodiment, the pore size of the porous pigment is 0.2 nm to 50 nm. In another preferred embodiment, the pore size of the porous pigment is 0.2 nm to 10 nm.

[0101] Examples of inorganic porous pigments include diatomaceous earth, zeolite, activated carbon, activated alumina, silica gel, hydroxyapatite, zirconium phosphate, titanium phosphate, potassium titanate, hydrous bismuth oxide, hydrous zirconium oxide, hydrotalcite, and mesoporous silica. In one embodiment, the inorganic porous pigment is one or more selected from the group consisting of diatomaceous earth and zeolite.

[0102] In one embodiment, the pigment contains an inorganic porous pigment.

[0103] The amount of porous pigment in the pigment may be adjusted as appropriate, and is, for example, 0.1 parts by mass to 50 parts by mass or 2.0 parts by mass to 22 parts by mass per 100 parts by mass of the pigment.

[0104] In one embodiment, the pigment contains an inorganic porous pigment,

Ref No. P0224225-PCT-AU (18/30) and the amount of the inorganic porous pigment is 0.1 parts by mass to 50 parts by mass per 100 parts by mass of the pigment.

[0105] In the present disclosure, the pigment volume concentration (PVC) represents the proportion of the volume of the pigment to the total solid volume of the resin component, photocatalytic titanium oxide, and pigment. In the present disclosure, the PVC is 35 % to 65 %. As mentioned above, even when the amount of photocatalyst is the same, increasing the PVC reduces the amount of resin component in the coating film and increases the photocatalyst exposed without being sufficiently covered with the resin component, so that antibacterial property and antiviral property can be improved. In this case, however, the crack resistance of the coating film decreases. Decreasing the PVC enhances the crack resistance of the coating film but reduces the exposed photocatalyst as a result of the photocatalyst being covered with the resin component, so that the antiviral property and antibacterial property of the coating film decrease. In the present disclosure, as a result of the PVC being 35 % to 65 %, the antiviral property, antibacterial property, and crack resistance of the coating film can be enhanced.

[0106] In one embodiment, the PVC is 35.0 % or more, 40.0 % or more, 45.0 % or more, 46.0 % or more, 47.0 % or more, 48.0 % or more, 49.0 % or more, 50.0 % or more, 51.0 % or more, 52.0 % or more, 53.0 % or more, 54.0 % or more, 55.0 % or more, or 60.0 % or more. In another embodiment, the PVC is 65.0 % or less, 60.0 % or less, 55.0 % or less, 54.0 % or less, 53.0 % or less, 52.0 % or less, 51.0 % or less, 50.0 % or less, 49.0 % or less, 48.0 % or less, 47.0 % or less, 46.0 % or less, 45.0 % or less, or 40.0 % or less.

[0107] For example, the PVC can be obtained by finding the respective volumes of the resin component, photocatalytic titanium oxide, and pigment from their solid densities and solid masses and calculating (the volume of the pigment) x 100/(the sum of the volume of the resin component, the volume of the photocatalytic titanium oxide, and the volume of the pigment). The density (specific gravity) of the resin component is measured, for example, as follows: The specific gravity of the emulsion solution is measured using a specific gravity cup. The emulsion NV is then measured. The specific gravity resulting from subtracting the proportion of water in the emulsion solution from the specific gravity of the emulsion solution measured using the specific gravity cup is taken to be the emulsion specific gravity. The emulsion NV is measured in accordance with JIS K 6833-1: 2008, under the conditions of sample amount:

Ref No. P0224225-PCT-AU (19/30)

1.0 ±0.2 g, drying temperature: 105± 2 C, and drying time: 60 minutes. The emulsion specific gravity is measured in accordance with JIS K 6833-1: 2008.

[0108] Alternatively, the PVC may be obtained by directly finding the respective solid volumes of the resin component, photocatalytic titanium oxide, and pigment and calculating (the volume of the pigment) x 100/(the sum of the volume of the resin component, the volume of the photocatalytic titanium oxide, and the volume of the pigment).

[0109] - Other components The coating composition may optionally contain components other than the acrylic resin emulsion, photocatalytic titanium oxide, and pigment. Examples of the other components include aggregates, fibers, plasticizers, preservatives, antifungal agents, antifoaming agents, viscosity modifiers, leveling agents, pigment dispersants, anti-settling agents, anti-sagging agents, ultraviolet absorbers, light stabilizers, antioxidants, antibacterial agents, and adsorbents. These components may be used alone or in combination of two or more.

[0110] The form of the coating composition is not limited, and may be one component type or two-component type.

[0111] - Method of preparing coating composition The method of preparing the coating composition involves mixing the foregoing acrylic resin emulsion, photocatalytic titanium oxide, and pigment so that the content of the metal-supporting anatase type titanium oxide and the PVC will be within the respective predetermined ranges, and a known coating composition preparation method may be used. For example, the coating composition may be prepared by mixing the resin emulsion, photocatalytic titanium oxide, and pigment and optionally other components using a disper, ball mill, SG mill, roll mill, planetary mixer, or the like.

[0112] (Coating film) A coating film according to the present disclosure is a coating film using the above-described coating composition.

[0113] The thickness of the coating film is not limited and may be adjusted as appropriate. The thickness (dry film thickness) of the coating film is, for example, 10 pm to 200 pm.

[0114] The method of forming the coating film is not limited, and a conventionally known coating method may be used. For example, coating may be performed using an applicator, bar coater, brush, spray, roller, roll coater,

Ref No. P0224225-PCT-AU (20/30) curtain coater, or the like. Alternatively, coating may be performed through immersion in a paint bath.

[0115] The drying temperature after the coating composition is applied may be adjusted as appropriate depending on the solvent and the like. For example, in the case where drying in a short time such as 10 seconds to 30 minutes is required, the drying temperature may be 30 °C to 200 °C, and is preferably 40 °C to 160 °C. In the case where drying in a short time is required, a two component curing reaction or energy rays such as ultraviolet rays may be used. In the case where drying in a short time is not required, drying may be performed at room temperature, for example.

[0116] (Article) An article according to the present disclosure is an article comprising the above-described coating film.

[0117] The article comprising the coating film is not limited, and examples thereof include vehicles such as cars, trains, buses, and taxis; vehicle tires; ships; aircraft such as airplanes and helicopters; buildings such as detached houses, apartment buildings such as condominiums, office buildings, public facilities, commercial facilities, research facilities, military facilities, and tunnels, or exterior and interior surfaces of buildings, such as walls, floors, ceilings, roofs, columns, signboards, digital signage, doors, and gates; bridges; vending machines; road signs; traffic lights; street lights; electronic bulletin boards such as LED, liquid crystal, and light bulb systems; operating machines, construction machines; stone monuments; tombstones; clothing; footwear such as shoes; rain gear such as umbrellas and raincoats; packaging materials; lenses such as eyeglasses; and mirrors.

[0118] Examples of the substrate of the article comprising the coating film include mortar, concrete, gypsum board, siding board, extruded plate, slate plate, asbestos cement plate, fiber-containing cement plate, calcium silicate plate, ALC plate, metal, wood, glass, ceramics, fired tile, porcelain tile, plastic plate, wallpaper, synthetic resin, and coating films formed on these substrates.

EXAMPLES

[0119] The presently disclosed techniques will be described in more detail below by way of examples. These examples are intended to be illustrative and do not limit the scope of the present disclosure in any way.

[0120] The materials and devices used in the examples are as follows:

Ref No. P0224225-PCT-AU (21/30)

Polyurethane resin emulsion: trade name "UCOAT@ UX-485" (UCOAT is a registered trademark in Japan, other countries, or both) produced by Sanyo Chemical Industries, Ltd., density 1.1 (g/cm 3

) Vinyl acetate emulsion: trade name "VINYBLAN@ A68J1" (VINYBLAN is a registered trademark in Japan, other countries, or both) produced by Nissin Chemical Co., Ltd., density 1.1 (g/cm 3

) Metal-supporting anatase type titanium oxide: photocatalytic titanium oxide, anatase type titanium oxide supporting silver oxide and copper oxide, density 4.1 (g/cm 3 )

Metal-supporting rutile type titanium oxide: photocatalytic titanium oxide, titanium oxide supporting a divalent copper compound with a solubility product of less than 1.5 x 10-10, density 4.1 (g/cm 3

) Titanium oxide: color pigment, trade name "TIPAQUE@ CR-97" (TIPAQUE is a registered trademark in Japan, other countries, or both) produced by Ishihara Sangyo Kaisha, Ltd., density 4.1 (g/cm 3

) Calcium carbonate: extender pigment, trade name "SPECIAL RICE SSS" produced by Maruo Calcium Co., Ltd., density 2.7 (g/cm 3

) Diatomaceous earth: inorganic porous pigment, trade name "RADIOLITE #100" produced by Marutou Co., Ltd., average particle size 12.8 pm, density 0.44 (g/cm 3 )

Zeolite: inorganic porous pigment, trade name "ZEORAM@ F-9" (ZEORAM is a registered trademark in Japan, other countries, or both) produced by Tosoh Corporation, X-type zeolite, pore size 0.9 nm, density 1.8 (g/cm 3 )

Reactive emulsifier: sodium alkyl diphenyl ether disulfonate, trade name "PELEX SS-H" produced by Kao Corporation, solid content 50 %

Polymerization initiator: ammonium persulfate, 5.0 % aqueous solution Substrate: soda glass plate, dimensions 50 mm x 50 mm x 2 mm, trade name "Float Glass" produced by TP Giken Co., Ltd. Substrate: mortar, dimensions 70 mm x 70 mm x 20 mm, trade name "Mortar" produced by TP Giken Co., Ltd., water: cement: sand = 0.6:1:2 (mass ratio) White fluorescent lamp: 20 W, trade name "NEOLINE FL20SW" produced by Toshiba Lighting & Technology Corporation Ultraviolet cut filter: acrylic resin plate produced by Nitto Jushi Kogyo Co., Ltd., trade name "CLAREX@ N-169" (CLAREX is a registered

Ref No. P0224225-PCT-AU (22/30) trademark in Japan, other countries, or both) Illuminometer: digital illuminometer, trade name "IM-5" produced by Topcon Corporation, used for antibacterial property and antiviral property evaluation Accelerated weathering machine: trade name "Super Xenon Weather Meter SX2-75" produced by Suga Test Instruments Co., Ltd. Color difference meter: trade name "CR-400" produced by Konica Minolta, Inc. Gypsum board: trade name "Tiger Board" produced by Yoshino Gypsum Co., Ltd., corresponding to gypsum board GB-R in JIS A 6901 Base conditioner: trade name "Field Putty" produced by Meikoh Corporation.

[0121] - Preparation of acrylic resin emulsions 1 to 4 A glass reactor equipped with a drop funnel, a reflux condenser, a stirrer, and a thermometer was charged with 50.50 parts by mass of deionized water and 1.50 parts by mass of a reactive emulsifier, and the temperature of the contents was set to 85 °C. A pre-emulsified liquid of the formation shown in Table 1 and a polymerization initiator were added dropwise to the mixture at a constant rate over 2 hours using the drop funnel to cause a reaction. After the addition was completed, the product was kept at 85 °C for 3 hours. The product was then cooled to 30 °C and removed from the reactor. Thus, each of acrylic resin emulsions 1 to 4 having a nonvolatile content of 47 % was obtained. Since the reactive emulsifier and the polymerization initiator were incorporated into each acrylic resin, the proportion of styrene unit in the acrylic resin is the proportion to the mass of the acrylic resin including the reactive emulsifier and the polymerization initiator.

[0122] [Table 1]

Ref No. P0224225-PCT-AU (23/30)

Formulation (parts by mass) Acrylic resin emulsion Solid content(%) 1 2 3 4 Styrene 100 0.00 20.65 51.63 56.79 2-ethylhexyl acrylate 100 32.13 29.33 16.73 12.46 Pre-emulsified Butyl methacrylate 100 42.87 25.02 19.14 18.25 liquid Methyl methacrylate 100 25.00 25.00 12.50 12.50 Reactive emulsifier 50 4.00 4.00 4.00 4.00 Deionized water 0 50.09 50.09 50.09 50.09

Polymerization Ammonium persulfate 5 10.00 10.00 10.00 10.00 initiator 5.0% aqueous solution

Proportion of styrene unit in acrylic resin (mass%) 0 20.0 50.0 55.0 Tg of acrylic resin (°C) -35 -10 20 30

[0123] (Examples I to 17 and Comparative Examples 1 to 6) Each coating composition was obtained by mixing the components in the corresponding formulation (parts by mass) shown in Tables 2 and 3.

[0124] - Preparation of test plate The coating composition was applied to the surface of a soda glass plate cleaned in advance using air spray so that the coating amount would be 200 g/m2 (dry film thickness 50 pm). After the coating, the glass plate was dried at 23 °C for 7 days to prepare a glass test plate.

[0125] - Preparation of test plate The coating composition was applied to the surface of a mortar plate using a trowel so that the coating amount would be 200 g/m 2 (dry film thickness 50 pm). After the coating, the mortar plate was dried at 23 °C for 7 days to prepare a mortar test plate.

[0126] - Antibacterial property evaluation Using the prepared glass test plate, an antibacterial test was conducted by use of Staphylococcus aureus in accordance with JIS R1752. Using a white fluorescent lamp as a light source, visible light of 380 nm or more was applied with 500 lux of illumination for 8 hours through an ultraviolet cut filter. Control was a soda glass plate not subjected to antibacterial treatment, i.e. not coated with a coating composition. The antibacterial activity value R was determined from R = Logio(UB/TB), where TB is viable bacteria count (cfu) per test plate after light irradiation and UB is viable bacteria count (cfu) per control after light irradiation. The antibacterial property of each coating film was then evaluated based on the following evaluation criteria. A higher score indicates better antibacterial property. A score of 3 to 5 is considered as pass.

Ref No. P0224225-PCT-AU (24/30)

The evaluation results are shown in Tables 2 and 3. (Evaluation criteria) Score 5: R is 4 or more. Score 4: R is 3 or more and less than 4. Score 3: R is 2 or more and less than 3. Score 2: R is 1 or more and less than 2. Score 1: R is less than 1.

[0127] - Antiviral property evaluation Using the prepared glass test plate, an antiviral test was conducted by use of bacteriophage Qp in accordance with JIS R 1756 (2013). Using a white fluorescent lamp as a light source, visible light of 380 nm or more was applied with 500 lux of illumination for 4 hours through an ultraviolet cut filter. The antiviral activity value V in light was determined from V = Logio(UV/TV), where TV is bacteriophage infectivity titer (pfu) per test plate after light irradiation and UV is bacteriophage infectivity titer (pfu) per control after light irradiation. The antiviral property of each coating film was then evaluated based on the following evaluation criteria. A higher score indicates better antiviral property. A score of 3 to 5 is considered as pass. The evaluation results are shown in Tables 2 and 3. (Evaluation criteria) Score 5: V is 4 or more. Score 4: V is 3 or more and less than 4. Score 3: V is 2 or more and less than 3. Score 2: V is 1 or more and less than 2. Score 1: V is less than 1.

[0128] - Photodegradation discoloration resistance evaluation Using the prepared mortar test plate, an accelerated weathering test was conducted by use of an accelerated weathering machine in accordance with the xenon lamp method described in JIS K 5600-7-7. The test time was 250 hours, and the appearance of the coating film after the test time was quantified in the L*a*b* color system using a color difference meter. The L* value, a* value, and b* value were measured, and the difference in brightness (AE) from the test plate before the test was evaluated based on the following evaluation criteria. A higher score indicates less discoloration of the coating film due to photodegradation and better photodegradation discoloration resistance. A score of 2 or more is considered as pass. The evaluation results are shown in Tables

Ref No. P0224225-PCT-AU (25/30)

2 and 3. (Evaluation criteria) Score 5: AE is less than 2. Score 4: AE is 2 or more and less than 4. Score 3: AE is 4 or more and less than 6. Score 2: AE is 6 or more and less than 8. Score 1: AE is 8 or more.

[0129] - Crack resistance evaluation A base conditioner was applied to a gypsum board to a thickness of 2 mm using a trowel and dried at room temperature for one day. After this, the coating composition was applied using a roller so that the coating amount would be 140 g/m2 , and dried at room temperature while blowing air. The degree of cracking in the coating film after dried completely was visually evaluated. A score of 5 indicates the coating film had no cracks, and a score of 1 indicates the coating film had cracks. Even slight cracks are considered cracks and a score of 1 is given. The evaluation results are shown in Tables 2 and 3.

Ref No. P0224225-PCT-AU (26/30)

101301 [Table 2] ~0 00

00

-4 0000

I~ uu

Cl Cl fl ~ C

Cl~ 2lA 00u

Re No. P0225-C-U 2/0

[0131] [Table 3] Comparative Example Formulation (parts by mass) 1 2 3 4 5 6 Acrylic resin emulsion 2 0 20 20 41 8 0 Acrylic resin emulsion 4 20 0 0 0 0 20 Photocatalytic titanium oxide Anatase type 1.00 0.01 1.84 1.00 1.00 1.84 Titanium oxide 20 20 20 20 20 20 Pigment Calcium carbonate 30 30 30 30 30 30 Proportion of styrene unit in acrylic resin (%) 55.0 20.0 20.0 20.0 20.0 55.0 Proportion of styrene unit in acrylic resin 9.32 4.31 4.17 7.96 1.82 9.18 to total solid content of paint(%) Proportion of photocatalytic titanium oxide 1.66 0.02 3.00 1.43 1.82 3.00 to total solid content of paint (%) Proportion of anatase type titanium oxide 1.66 0.02 3.00 1.43 1.82 3.00 to total solid content of paint (%) Proportion of inorganic porous pigment 0 0 0 0 0 0 to total pigment (%) PVC (%) 46.5 46.8 46.2 30.0 67.5 46.2 Antibacterialproperty 4 1 5 2 4 5 Antiviral property 4 1 5 2 4 5

Evaluation Photodegradation 1 5 1 4 3 1 discoloration resistance

Crack resistance 5 5 5 5 1 5

INDUSTRIAL APPLICABILITY

[0132] It is thus possible to provide a coating composition capable of forming a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance. It is also possible to provide a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance. It is also possible to provide an article comprising a coating film having antiviral property, antibacterial property, photodegradation discoloration resistance, and crack resistance.

Ref No. P0224225-PCT-AU (28/30)

Claims (6)

1. [Claim 1] A coating composition comprising: an acrylic resin emulsion; a photocatalytic titanium oxide; and a pigment, wherein a proportion of an aromatic vinyl monomer unit in an acrylic resin of the acrylic resin emulsion is 0 mass% to 52 mass%, the photocatalytic titanium oxide contains a metal-supporting anatase type titanium oxide, a content of the metal-supporting anatase type titanium oxide is 0.05 parts by mass to 2.90 parts by mass per 100 parts by mass of a total solid content of the coating composition, and a pigment volume concentration (PVC) of the pigment is 35 % to 65 %.
2. [Claim 2] The coating composition according to claim 1, wherein the acrylic resin does not contain the aromatic vinyl monomer unit.
3. [Claim 3] The coating composition according to claim 1 or 2, wherein the proportion of the aromatic vinyl monomer unit is 0 mass% to 16 mass% with respect to the total solid content of the coating composition.
4. [Claim 4] The coating composition according to claim 1 or 2, wherein the photocatalytic titanium oxide further contains a metal-supporting rutile type titanium oxide.
5. [Claim 5] A coating film using the coating composition according to any one of claims 1 to 4.
6. [Claim 6] An article comprising the coating film according to claim 5.

   Ref No. P0224225-PCT-AU (29/30)