Antibacterial composition and decorative sheet

Abstract

To provide an antibacterial composition capable of imparting good antibacterial properties without causing discoloration or sedimentation over time, and capable of forming a smooth coating film by uniform dispersion regardless of whether a solvent of an existing coating agent is water, an aqueous solvent, or an organic solvent, and also to provide an antibacterial additive, an antibacterial coating agent, and a decorative sheet employing the antibacterial composition.SOLUTION: Provided is an antibacterial composition containing an antibacterial agent carrying at least silver, an azole compound, an anionic surfactant or a nonionic surfactant, the antibacterial composition containing the azole compound in an amount of 0.01 mass% to 30 mass% relative to the antibacterial agent. Also provided are an antibacterial additive, an antibacterial coating agent, and a decorative sheet.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an antibacterial composition, an antibacterial additive, an antibacterial coating agent, and a decorative sheet. [Background technology]

[0002] Generally, decorative sheets are used as materials that can impart an appearance (design) similar to that of natural materials by being attached to the surface of plywood or the like for furniture, residential interiors, vehicle interiors, etc. Such decorative sheets are required to have a texture similar to that of real natural materials in addition to high durability and design, so a coating layer is provided on the base material in addition to a printed layer for design, achieving both high durability and texture.

[0003] Conventionally, coating agents used in such coating layers have been imparted with hygienic functions such as antibacterial, antifungal, antiviral, and deodorizing properties. Methods for imparting antibacterial properties to coating agents include a method of directly adding an antibacterial compound to the coating agent, and a method of pre-dispersing an antibacterial compound at a high concentration and then adding a small amount of an antibacterial additive to an existing coating agent, which has the effect of exhibiting antibacterial properties by simply adding a small amount of the antibacterial compound to the existing coating agent. Antibacterial additives are required to disperse uniformly regardless of the type of solvent used in existing coating agents (which may be water or aqueous solvents, or organic solvents), and to not cause aggregation or sedimentation in the coating agent.

[0004] Known antibacterial compounds include those in which antibacterial metal ions such as silver are supported on zeolite, zirconium phosphate, or the like (silver-based antibacterial agents). It is also known that compositions containing silver-based antibacterial agents are used as coating agents for antibacterial flooring materials and the like (see, for example, Patent Document 1). Patent Document 1 discloses a composition in which 3 to 80 wt. % of an inorganic antibacterial powder is dispersed in a medium containing a surfactant such as a phosphate ester copolymer or an organically modified organopolysiloxane, in order to maintain uniform dispersion of a high-specific-gravity silver-zeolite antibacterial agent over a long period of time. However, while this method can prevent discoloration of the dispersion medium by using a surfactant such as a phosphate ester copolymer or an organically modified organopolysiloxane, problems such as aggregation and precipitation of the silver-based antibacterial agent and discoloration due to silver ions can occur depending on the type of silver-based antibacterial agent used.

[0005] One known method for preventing discoloration of silver-based antibacterial agents is to use them in combination with an imidazole compound and / or a benzotriazole compound (see, for example, Patent Document 2). Patent Document 2 discloses that discoloration is prevented by using an imidazole compound and / or a benzotriazole compound, and that an antibacterial dispersion with excellent long-term storage stability is obtained by using 0.1 to 10 parts by mass of a thickener per 100 parts by mass of the silver zeolite-based antibacterial agent. However, since Patent Document 2 assumes water as the medium, the disclosed thickener exhibits a thickening effect in water, but not in organic solvents, and instead can cause problems such as aggregation.

[0006] That is, even if the solvent of an existing coating agent is water, an aqueous solvent, or an organic solvent, a composition that can be uniformly dispersed, can maintain stable dispersion without causing aggregation or sedimentation in the coating agent, and can prevent discoloration of the coating agent and antibacterial additive over time, and can also provide good antibacterial properties, has not yet been obtained. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 11-104218 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-83469 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention provides an antibacterial composition that provides good antibacterial properties without discoloration or sedimentation over time, and that can be uniformly dispersed to form a smooth coating film even when the solvent used in existing coating agents is water, an aqueous solvent, or an organic solvent; and an antibacterial additive, an antibacterial coating agent, and a decorative sheet that use the same.

[0009] That is, the present invention provides an antibacterial composition containing at least a silver-supported antibacterial agent, an azole compound, and an anionic surfactant or a nonionic surfactant, The antibacterial composition contains the azole compound in an amount of 0.01% by mass to 30% by mass relative to the antibacterial agent.

[0010] The present invention also provides an antibacterial additive comprising the above-described antibacterial composition.

[0011] The present invention also provides an antibacterial coating agent containing the antibacterial composition described above.

[0012] The present invention also provides a decorative sheet comprising a substrate and a coating layer of the antibacterial coating agent described above. [Effects of the Invention]

[0013] The present invention can provide an antibacterial composition that provides good antibacterial properties without discoloration or sedimentation over time, and that can be uniformly dispersed to form a smooth coating film even when the solvent used in existing coating agents is water, an aqueous solvent, or an organic solvent, as well as an antibacterial additive, an antibacterial coating agent, and a decorative sheet that use the same. DETAILED DESCRIPTION OF THE INVENTION

[0014] (Antibacterial composition) (Antibacterial agent carrying at least silver (antibacterial agent (A))) The antibacterial agent used in the present invention includes metal-supported antibacterial agents in which inorganic particles such as zeolite particles, silica gel particles, alumina particles, zirconium phosphate, phosphate particles, etc. are used as carriers and metals such as silver, zinc, copper, cobalt, etc. are supported alone or in combination of two or more kinds on these carrier particles. Among these, it is preferable to use antibacterial agents that support silver (silver-based antibacterial agents). It may also be a mixture of a silver-based antibacterial agent and an antibacterial agent carrying another metal, such as zinc, or a silver-zinc-carrying antibacterial agent carrying both silver and another metal, such as zinc. Note that "an antibacterial agent carrying at least silver" refers to an antibacterial agent carrying silver or silver and another metal. Hereinafter, "an antibacterial agent carrying at least silver" may be referred to as "antibacterial agent (A)." The antibacterial agent (A) may be used alone or in combination of two or more kinds.

[0015] The content of the antibacterial agent (A) used in the present invention is not particularly limited, but if it is too small, antibacterial properties are difficult to exhibit, and if it is too large, lumps (clusters) and sedimentation tend to occur easily. Therefore, the content of the antibacterial agent (A) is preferably in the range of 1% by mass to 80% by mass, more preferably 3% by mass to 80% by mass, and even more preferably 3% by mass to 60% by mass, based on the solid content of the antibacterial composition.

[0016] The average particle size of the antibacterial agent (A) used in the present invention is not particularly limited, but is preferably 0.1 μm to 10 μm, more preferably 0.1 μm to 5 μm, as measured using a scanning electron microscope in accordance with JIS H 7804. If the average particle size of the antibacterial agent (A) is too small, when added to a coating agent, the surface area of ​​the antibacterial agent (A) protruding from the coating agent decreases, making it difficult to exhibit antibacterial properties, while if the average particle size of the antibacterial agent (A) is too large, dispersibility decreases, making it more likely to cause sedimentation.

[0017] Furthermore, many of these antibacterial agents (A) have antiviral properties in addition to antibacterial properties, and can be preferably used as antiviral agents as well. Examples of such antibacterial and / or antiviral agents include "Zeomic" (manufactured by Sinanen Zeomic Co., Ltd.) and "Novalon" (manufactured by Toagosei Co., Ltd.).

[0018] In addition to the antibacterial agent (A), organic / inorganic hybrid antibacterial agents and / or organic antifungal agents can also be used, in which an organic antibacterial agent and / or organic antifungal agent is supported on an inorganic compound. These hybrid antibacterial and / or organic antifungal agents combine the immediate effectiveness of organic components with the heat resistance and long-lasting properties of inorganic components. Furthermore, by supporting multiple active ingredients, each active ingredient is effective against different types of bacteria / molds, which allows for antibacterial and antifungal performance in a wide range of fields. Examples of such organic antibacterial and / or organic antifungal agents include "Essenguard" (manufactured by Sinanen Zeomic Co., Ltd.), "Rasap" (manufactured by Rasa Kogyo Co., Ltd.), "Kabinon" (manufactured by Toagosei Co., Ltd.), and "Hybrid Ion Pure" (Ishizuka Glass Co., Ltd.).

[0019] (Azole compounds) Examples of azole compounds used in the present invention include imidazole compounds such as imidazole, pyrazole, oxazole, thiazole, triazole, and tetrazole; benzimidazole compounds such as benzimidazole, benzoxazole, benzisoxazole, benzothiazole, mercaptobenzimidazole, mercaptomethylbenzimidazole, mercaptobenzothiazole, benzotriazole, tolyltriazole, indazole, purine, imidazothiazole, pyrazoloxazole, and thiabendazole, as well as salts of these compounds. These compounds or salts may be used alone or in combination. The azole compound is preferably contained in an amount of 0.01% to 30% by weight, more preferably 0.1% to 20% by weight, and most preferably 0.1% to 10% by weight, based on the antibacterial agent.

[0020] In the present invention, imidazole and thiabendazole are preferred, with thiabendazole being particularly preferred. Thiabendazole is a compound that has traditionally been used as an antibacterial, antifungal agent, food additive, and wood preservative. In the present invention, when used in combination with the antibacterial agent (A), a synergistic effect of the functions as an antibacterial, antiviral, and antifungal agent can be expected. In addition, hydrogen bonding between thiabendazole molecules results in thixotropy, which simultaneously imparts anti-discoloration and anti-settling effects through complex formation. By incorporating thiabendazole in an amount of 0.01% by mass to 30% by mass relative to the antibacterial agent (A), an anti-settling effect can be achieved without the use of a thickener or the like, and long-term anti-discoloration effect can also be achieved. The content is preferably in the range of 0.1% by mass to 20% by mass, and even more preferably in the range of 0.1% by mass to 10% by mass.

[0021] (anionic surfactant or nonionic surfactant) The anionic surfactant or nonionic surfactant used in the present invention is not particularly limited, and any anionic surfactant or nonionic surfactant can be used.

[0022] Examples of such surfactants include anionic surfactants such as alkenyl succinates, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfates, higher alcohol sulfates, polyoxyethylene alkyl ether sulfates, dialkyl sulfosuccinates, alkyl phosphates, phosphate copolymers, and polycarboxylic acid-type polymer surfactants, and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyether-modified siloxane copolymers, and alcohol alkoxylates. These surfactants may be used alone or in combination of two or more.

[0023] Among these, anionic surfactants such as alkyl phosphate ester salts and phosphate ester copolymers, and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyether-modified siloxane copolymers, and alcohol alkoxylates are preferred because of their effect of preventing aggregation and sedimentation of the antibacterial agent (A) and because they can be easily dispersed uniformly when the antibacterial composition of the present invention is used as an antibacterial additive, regardless of the type of solvent used in existing coating agents (which may be water or an aqueous solvent, or an organic solvent).

[0024] The surfactant used in the present invention is preferably one whose balance between hydrophobicity and hydrophilicity is set within the range of HLB 12-18.

[0025] (Other ingredients) As described above, the antibacterial composition of the present invention is an antibacterial composition containing at least a silver-supported antibacterial agent (antibacterial agent (A)), an azole compound, and an anionic surfactant or a nonionic surfactant, and is characterized in that the azole compound is contained in an amount of 0.01% by mass to 30% by mass relative to the antibacterial agent, but other components may also be used as appropriate within a range that does not impair the effects of the present invention.

[0026] (Manufacturing method) The antibacterial composition of the present invention can be obtained by mixing and dispersing the antibacterial agent (A), an azole compound, and an anionic surfactant or a nonionic surfactant using a known disperser. The dispersion method is not particularly limited, and examples of the disperser that can be used include commonly used dispersers such as a roller mill, a ball mill, a pebble mill, an attritor, a sand mill, and a disperser. On the other hand, by using at least one selected from the group consisting of alkyl phosphate ester salts, phosphate ester copolymers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, alcohol alkoxylates, and organically modified organopolysiloxanes as the anionic surfactant or nonionic surfactant, a composition in a well-dispersed state can be obtained using a low-shear dispersion method such as Disper dispersion, rather than a high-shear dispersion method such as kneading.

[0027] (Antibacterial additive) The antibacterial additive of the present invention can use the antibacterial composition as it is. The antibacterial additive of the present invention can impart good antibacterial properties to a coating agent described below simply by adding it in an amount of 0.01% by mass to 20% by mass relative to the solid content of the coating agent. Specifically, the antibacterial agent is preferably added in an amount of 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, based on the solid content of the coating agent.

[0028] (coating agent) The antibacterial additive of the present invention can be used with existing coating agents commonly used for decorative sheets. Examples of coating agents used for decorative sheets include active energy ray-curable coating agents that cure with ultraviolet light or the like to form a film, thermosetting coating agents that cure with heat or the like to form a film, and coating agents that contain no curable components and are primarily composed of thermoplastic resins that form a film by drying the solvent after application. However, the antibacterial additive of the present invention is not limited to the method of film formation of the coating agent and can be used as an additive in any form of coating agent. Furthermore, while many coating agents are diluted with organic solvents, water, or aqueous solvents, the antibacterial additive of the present invention disperses uniformly even when the solvent is water, aqueous solvent, or organic solvent, and can therefore be used as an additive regardless of the type or presence of solvent in the coating agent.

[0029] (active energy ray curable coating agent) An example of a specific embodiment of the active energy ray-curable coating agent used in the decorative sheet used in the present invention is an active energy ray-curable coating agent containing a compound having a (meth)acryloyl group and a photopolymerization initiator.

[0030] (Compounds having a (meth)acryloyl group) Examples of compounds having a (meth)acryloyl group include monofunctional (meth)acrylates such as ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, isoamyl (meth)acrylate, isodecyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxydiethylene glycol. (meth)acrylate, nonylphenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, diethylaminoethyl (meth)acrylate, nonylphenoxyethyl tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, ethoxyethoxyethanol acrylic acid polymer ester, and the like.

[0031] Examples of bifunctional (meth)acrylates include 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropyl Examples of the di(meth)acrylate include di(meth)acrylates of dihydric alcohols such as ethylene glycol di(meth)acrylate and tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, di(meth)acrylate of tris(2-hydroxyethyl)isocyanurate, di(meth)acrylates of diols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol, and di(meth)acrylates of diols obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A.

[0032] Examples of the tri- or higher functional (meth)acrylate include poly(meth)acrylates of trihydric or higher polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and poly(meth)acrylate of dipentaerythritol; poly(meth)acrylates of polyoxyalkylene polyols such as triol tri(meth)acrylates obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of glycerin, di- or tri(meth)acrylates of triols obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane, and di(meth)acrylates of diols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A.

[0033] Furthermore, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (sometimes abbreviated as DPHA), which corresponds to a bifunctional or higher functional (meth)acrylate, ditrimethylolpropane tetraacrylate (sometimes abbreviated as DTMPTA), trimethylolpropane ethylene oxide adduct tri(meth)acrylate, which is a triol tri(meth)acrylate obtained by adding 3 moles or more of ethylene oxide to 1 mole of trimethylolpropane, etc. A representative example of the trimethylolpropane ethylene oxide adduct tri(meth)acrylate is trimethylolpropane ethylene oxide (hereinafter, ethylene oxide may be referred to as "EO")-modified (n≒3) triacrylate.

[0034] Furthermore, polymerizable oligomers or polymers may be used as needed. Examples of polymerizable oligomers include urethane (meth)acrylates, amine-modified polyether acrylates, amine-modified epoxy acrylates, amine-modified aliphatic acrylates, amine-modified polyester acrylates, amine-modified acrylates such as amino (meth)acrylates, polyester (meth)acrylates, polyether (meth)acrylates, polyolefin (meth)acrylates, polystyrene (meth)acrylates, and epoxy (meth)acrylates. Examples of polymerizable polymers include acrylic resins containing a (meth)acryloyl group.

[0035] (Photopolymerization initiator) The photopolymerization initiator is not particularly limited, and known radical polymerization type photopolymerization initiators can be used. Examples include α-hydroxyalkyl ketone photopolymerization initiators such as 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-(4-i-propylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, and 1-hydroxycyclohexylphenyl ketone, phenylglyoxolate photopolymerization initiators such as methylbenzoyl formate, and monoacylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,6-dimethoxybenzoyl-diphenylphosphine oxide, 2,6-dichlorobenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-phenylphosphinic acid methyl ester, 2-methylbenzoyl-diphenylphosphine oxide, and pivaloylphenylphosphinic acid isopropyl ester. These photopolymerization initiators may be used alone or in combination of two or more. The total amount of the photopolymerization initiators added is often in the range of 0.1 to 20% by mass based on the total amount of the coating agent. In addition, a tertiary amine compound selected from an aliphatic amine derivative and / or a benzoic acid amine derivative may also be used in combination as a sensitizer, etc.

[0036] (organic solvent) The active energy ray-curable coating agent may contain an organic solvent as a diluent. The antibacterial composition of the present invention is easily dispersed in both water and organic solvents, so it can be used without any problems even if it contains an organic solvent as a diluent. Examples of suitable organic solvents include aromatic hydrocarbons such as toluene and xylene, aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane, esters such as ethyl acetate, butyl acetate, and propyl acetate, alcohols such as methanol, ethanol, and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, and alkylene glycol monoalkyl ethers such as ethylene glycol monoethyl ether and propylene glycol monomethyl ether.

[0037] (Thermosetting coating agent) A specific example of a thermosetting coating agent used in the decorative sheet of the present invention is a composition that uses an isocyanate compound or an epoxy compound as a thermosetting agent and a polymeric compound having an active hydrogen group, which has a group reactive with an isocyanate group or an epoxy group and can serve as a binder resin. Polymeric compounds having active hydrogen groups are preferred because they can form a three-dimensional crosslinked structure after curing. Acrylic resins, acrylic alkyd resins, polyester resins, urethane resins, and the like, which have two or more functional groups selected from hydroxyl groups, amino groups, and carboxyl groups, are preferred. Acrylic resins (acrylic polyols) and acrylic alkyd resins (acrylic alkyd polyols) having two or more hydroxyl groups per molecule are particularly preferred.

[0038] As the heat curing agent, an isocyanate compound is preferred, and a polyisocyanate compound having two or more isocyanate groups in one molecule is preferred because it can form a three-dimensional crosslinked structure after curing. Examples of polyisocyanate compounds having two or more isocyanate groups per molecule that react with the functional groups of the thermosetting resin composition include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), and hydrogenated compounds thereof, as well as compounds having two isocyanate groups per molecule such as isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI), and trimer types, TMP adduct types, biuret types, etc., synthesized by known techniques from one or more compounds selected from these. Furthermore, a composition containing a mixture of one or more types selected from these different types of polyisocyanates can also be used.

[0039] Preferred are trimer type, TMP adduct type and biuret type synthesized by known techniques from one or more compounds selected from TDI, XDI, IPDI and HDI.

[0040] The content of the isocyanate compound relative to the resin component can be set arbitrarily, but generally the equivalent ratio of hydroxyl group / isocyanate is often 1 / 0.5 to 1 / 3.

[0041] (organic solvent) The thermosetting coating agent may also contain the above-mentioned organic solvent as a diluent, similar to the active energy ray-curable coating agent.

[0042] (Coating agent mainly composed of thermoplastic resin, etc.) Examples of thermoplastic resins used in the coating agent of the present invention, which contains a thermoplastic resin as a main component, include cellulose-based resins such as nitrocellulose, cellulose acetate propionate (CAP), and cellulose acetate butyronate (CAB), polyamide-based resins, urethane-based resins, acrylic resins, vinyl chloride-based resins such as vinyl chloride-vinyl acetate copolymer resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, and polyvinyl chloride resins, polyester resins, alkyd resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubber, chlorinated rubber, butyral, and petroleum resins. These thermoplastic resins can be selected appropriately depending on the type of substrate to be used.

[0043] Since many of the thermoplastic resins have high viscosities, most coating agents contain organic solvents, aqueous solvents, or water as diluents. The antibacterial additive of the present invention disperses uniformly even when the solvent is water, an aqueous solvent, or an organic solvent, and therefore can be used as an additive without being limited to the solvent of the coating agent.

[0044] (Coating agent using organic solvent as solvent) As a coating agent using an organic solvent as a solvent, a solvent in which the binder resin is appropriately dissolved can be used. Alternatively, the organic solvent used as a synthesis medium when synthesizing the binder resin can be used as is. The organic solvents used can be the same as those described above for the active energy ray-curable coating agent.

[0045] (Water or water-based coating agent) Known coating agents using water or an aqueous solvent as a medium include emulsions or aqueous dispersions of acrylic resins, styrene-acrylic resins, acrylic urethane resins, urethane resins, polyester resins, etc. While there are no particular limitations on the types of coating agents that can be used in the present invention, emulsions or aqueous dispersions of acrylic resins, styrene-acrylic resins, acrylic urethane resins, etc. are preferred. Furthermore, other resins, such as epoxy resins, alkyd resins, amino acid resins, polyester resins, polyvinyl chloride resins, cellulose derivatives, casein, etc., may also be included within the range that does not impair stability.

[0046] (acrylic resin) Examples of the acrylic resin include, as monomers, unsaturated carboxylic acids such as (meth)acrylic acid and (anhydrous) maleic acid, (meth)acrylic acid esters having an aliphatic hydrocarbon group such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, oleyl (meth)acrylate, and eicosyl (meth)acrylate, 2-hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and (meth)acrylate. These resins are obtained by polymerizing (meth)acrylic acid ester compounds having a hydroxyalkyl group such as 2-hydroxypropyl acrylate and 3-hydroxypropyl (meth)acrylate, (meth)acrylamide, acrylonitrile, olefin-based compounds, styrene-based monomers such as styrene, α-methylstyrene, vinyltoluene, dimethylstyrene, ethylstyrene, isopropylstyrene, t-butylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, fluorostyrene, and styrene, benzyl (meth)acrylate-based monomers such as benzyl (meth)acrylate, and phenyl (meth)acrylate-based monomers such as phenyl (meth)acrylate. These acrylic resins may be used alone or in combination of two or more.

[0047] (styrene acrylic resin) Styrene-acrylic resins (also called acrylic-styrene resins) are copolymers of styrenes with (meth)acrylic acid and (meth)acrylic acid alkyl esters. Known monomers that can be used as comonomers in acrylic resins, such as acrylamide and acrylonitrile, can be used as long as they do not impair the effects of the acrylic-styrene resins. The styrenes are those having a styrene skeleton, such as styrene, α-methylstyrene, p-chlorostyrene, and p-methylstyrene, and among them, styrene is preferred from the viewpoint of industrial use. As the (meth)acrylic acid and (meth)acrylic acid ester, those exemplified in the above acrylic resin can be used.

[0048] The glass transition temperature (Tg) of the acrylic resin or acrylic styrene resin is preferably 15 to 90°C, and more preferably 20 to 85°C.

[0049] (acrylic urethane resin) The acrylic urethane resin is preferably one obtained by mixing, for example, a keto group-containing acrylic resin and a hydrazide group-containing urethane resin. The acrylic resin and the urethane resin are crosslinked by the keto group and the hydrazide group, resulting in a composite of the acrylic resin and the urethane resin. In an aqueous emulsion of this composite resin (urethane / acrylic composite emulsion), particles of the resin are dispersed as composite particles with the acrylic resin component present inside the particle and the urethane resin component present outside the particle. The ratio of the acrylic resin component and the urethane resin component in the urethane / acrylic composite emulsion is not limited, but the urethane resin component is preferably 20 to 40% by weight of the total of the two components (100% by weight).

[0050] For coating agents using water or aqueous solvents as a medium, the degree of crosslinking can be increased by using a curing agent as needed. Examples include isocyanate-based curing agents, epoxy-based curing agents, melamine-based curing agents, aziridine-based curing agents, and carbodiimide-based curing agents. The amount of curing agent used will vary depending on the type of curing agent used, but it is usually about 20 to 70 parts by weight per 100 parts by weight of the acrylic urethane resin.

[0051] (aqueous solvent or water) As the medium, water or an aqueous solvent, in addition to water and alcohols such as isopropyl alcohol, glycols, glycol ethers, etc. can also be used.

[0052] (Other additives contained in the coating agent) The coating agent used in the present invention may also contain various additives, such as inorganic pigments, organic pigments, extender pigments, clay minerals, waxes, release agents, surfactants, stabilizers, flow adjusters, dyes, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, or plasticizers, as required. The thickness of the coating film formed by coating the coating agent of the present invention is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 0.3 to 50 μm, and particularly preferably 0.3 to 30 μm. If the thickness is within this range, the coating composition can form a cured coating film with excellent UV-shielding properties that protects the substrate and ink layer from UV light.

[0053] Specific examples of the application / printing method of the coating agent used in the present invention include a roll coater, gravure coater, flexo coater, air doctor coater, blade coater, air knife coater, squeeze coater, impregnation coater, transfer roll coater, kiss coater, curtain coater, cast coater, spray coater, die coater, offset printing machine, screen printing machine, etc., which can be appropriately used as the coating method.

[0054] (decorative sheet) The decorative sheet of the present invention comprises a substrate and a coating film layer containing the antibacterial composition of the present invention provided thereon. An example of a specific embodiment of the configuration envisioned for the decorative sheet of the present invention is shown below. Of course, this is not limited to this in the present invention. The "coating layer of antibacterial coating agent" referred to here is a coating layer of the antibacterial coating agent of the present invention. The "coating layer of antibacterial coating agent" may be one layer or multiple layers superimposed. When multiple layers are superimposed, all of the multiple layers may be solid printed layers, or may be printed layers printed using a cut-out printing block.

[0055] Antibacterial coating layer / pattern layer / substrate Antibacterial coating layer / transparent resin layer / adhesive layer / pattern layer / substrate Antibacterial coating layer / primer layer / pattern layer / substrate Antibacterial coating layer / primer layer / transparent resin layer / adhesive layer / pattern layer / substrate

[0056] (base material) The substrate used in the present invention is not particularly limited, and a substrate suitable for the desired purpose can be used as appropriate. Examples include film or sheet-like substrates made of polyolefin resins such as polyethylene (LLDPE: low-density polyethylene, HDPE: high-density polyethylene, MDOPE: uniaxially oriented polyethylene, OPE: biaxially oriented polyethylene), polypropylene (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene-butene copolymer, and polyolefin thermoplastic elastomer. Other examples include film or sheet-like substrates made of polyethylene terephthalate (PET), polystyrene, polyamide, polyacrylonitrile, ethylene vinyl alcohol copolymer, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and the like. These substrates may be single-layered or may be multi-layered substrates.

[0057] To produce a film or sheet-like substrate, for example, methods such as calendaring, inflation, T-die extrusion, etc. The thickness of these is not particularly limited and can be set depending on the product characteristics, but is usually about 40 to 150 μm, and preferably about 50 to 100 μm.

[0058] The base material may contain additives as needed. Examples of additives include fillers such as calcium carbonate and clay, flame retardants such as magnesium hydroxide, antioxidants, lubricants, foaming agents, colorants, etc. The amount of additives to be added can be appropriately determined depending on the product characteristics.

[0059] One or both sides of the substrate may be subjected to a surface treatment such as corona discharge treatment, ozone treatment, plasma treatment, ionizing radiation treatment, or dichromate treatment, as needed. For example, when corona discharge treatment is performed, the surface tension of the substrate surface may be set to 30 dyne or more, preferably 40 dyne or more. The surface treatment may be performed according to a conventional method for each treatment.

[0060] Substrates such as paper, wood, and leather can also be used without any problems. For example, any known paper substrate can be used without any particular limitation. Specifically, paper is produced using natural fibers for papermaking, such as wood pulp, on a known papermaking machine. Examples of natural fibers for papermaking include wood pulp, such as softwood pulp and hardwood pulp; non-wood pulp, such as Manila hemp pulp, sisal hemp pulp, and flax pulp; and chemically modified pulps of these pulps. Examples of pulp that can be used include chemical pulp produced by sulfate cooking, acidic, neutral, or alkaline sulfite cooking, soda cooking, ground pulp, chemi-ground pulp, and thermomechanical pulp. Various commercially available fine paper, coated paper, lined paper, impregnated paper, cardboard, and paperboard can also be used.

[0061] (Picture layer) The substrate used in the present invention may have a design layer. The design layer is usually provided by printing. The design layer may be a single layer, or multiple layers may be laminated. Furthermore, the design layer may be solid printed, or may be a design layer printed only on a portion of the substrate. A printed design layer may also be called a printed layer. The design layer can be printed on the substrate by a known coating or printing method, such as roll coating, gravure coating, or spray coating, or gravure printing, offset printing, letterpress printing, screen printing, or inkjet printing. The pattern to be imparted to the design layer may be freely determined, and examples include patterns imitating the surface of rock such as wood grain and marble, fabric patterns imitating the grain of fabric or patterns on fabric, tile patterns, etc., floral patterns consisting of flowers or bunches of flowers arranged at equal intervals, letters, etc. In addition, to make the pattern stand out, a solid print layer such as a white background may be provided under the pattern print layer.

[0062] The ink constituting the design layer may be any known ink, such as an oil-based ink, a water-based ink, or an active energy ray-curable ink. Alternatively, the ink may be selected from liquid printing inks such as flexographic printing inks and gravure printing inks, lithographic offset printing inks, inkjet inks, etc., depending on the printing method.

[0063] (Transparent resin layer) The transparent resin layer is preferably made of polyolefin, such as polypropylene, polyethylene, polybutene, or various α-olefin copolymers (copolymers of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, etc.). The transparent resin layer may contain various additives, such as an ultraviolet absorber, a heat stabilizer, a light stabilizer, an antiblocking agent, a catalyst scavenger, a colorant, a light scattering agent, and a gloss adjuster, as needed. The method for forming the transparent resin layer is not particularly limited, and a conventional method such as calender film formation or extrusion film formation can be used. The transparent resin layer may be provided with surface irregularities to impart design properties. Examples of methods for providing the irregularities include a method of subjecting the transparent resin layer to hot embossing after extrusion molding, and a method of subjecting the extrusion layer to embossing simultaneously with extrusion molding using a cooling roll provided with irregularities during extrusion molding.

[0064] (decorative materials) A decorative material can be obtained by laminating the decorative sheet of the present invention to wood, plywood, fiberboard, metal plate, etc. The decorative sheet of the present invention can also be used for residential interior materials, furniture, home appliances, office supplies, toys, vehicle interior materials, etc., which require antibacterial properties, and is particularly ideal for use in residential interior materials, furniture, and home appliances. [Example]

[0065] The present invention will be described in more detail below with reference to examples. In the examples, "parts" means "parts by mass" and "%" means "% by mass".

[0066] (Antibacterial Composition Examples and Comparative Examples) The silver-supported antibacterial agent, surfactant, and azole compound were mixed to obtain the compositions shown in Tables 1 and 2, and the mixture was stirred uniformly with a dispersing stirrer to prepare antibacterial compositions.

[0067] (Antibacterial composition evaluation method) The antibacterial compositions were evaluated for the following items.

[0068] (40℃ sedimentation) 200 g of each of the antibacterial compositions prepared above was weighed out and placed in a 400 mL glass bottle, and left to stand in a thermostatic chamber at 40° C. for 30 days. Thereafter, the condition of each composition was evaluated according to the following three-point scale. ○: No sedimentation △: Soft cake (can be redispersed by stirring) ×: Hard cake (cannot be redispersed)

[0069] (settling at room temperature) 200 g of each of the antibacterial compositions prepared above was weighed out and placed in a 400 mL glass bottle, and left to stand in a thermostatic chamber at 25° C. for 30 days. Thereafter, the condition of each composition was evaluated according to the following three-point scale. ○: No sedimentation △: Soft cake (can be redispersed by stirring) ×: Hard cake (cannot be redispersed)

[0070] (discoloration at 40℃) 200 g of each antibacterial composition prepared above was weighed out and placed in a 400 mL glass bottle, and then left to stand in a 40°C thermostatic chamber for 30 days while shielded from light with aluminum foil. After that, the condition of each composition was evaluated using the following three-point scale. 〇: No discoloration △: Slight discoloration ×: Clear discoloration

[0071] (Discoloration under fluorescent light) 200 g of each antibacterial composition prepared above was weighed out into a 400 mL glass bottle and exposed to fluorescent light in a thermostatic chamber at 25°C for 24 hours. After that, the condition of each composition was evaluated according to the following three-point scale. 〇: No discoloration △: Slight discoloration ×: Clear discoloration

[0072] Tables 1 and 2 show the compositions of the antibacterial compositions and the evaluation results (physical property values).

[0073] [Table 1]

[0074] [Table 2]

[0075] The abbreviations in Tables 1 and 2 are as follows: Silver-loaded antibacterial agents: AW10N: Zeomic AW10N (silver-supported zeolite antibacterial agent manufactured by Sinanen Zeomic Co., Ltd.) AJ10N: Zeomic AJ10N (silver-loaded zeolite antibacterial agent manufactured by Sinanen Zeomic Co., Ltd.) AW10D: Zeomic AW10D (silver-loaded zeolite antibacterial agent manufactured by Sinanen Zeomic Co., Ltd.) XAW10D: Zeomic XAW10D (silver-loaded zeolite antibacterial agent manufactured by Sinanen Zeomic Co., Ltd.) AG300: Novalon AG300 (silver-loaded zirconium phosphate antibacterial agent manufactured by Toagosei Co., Ltd.) Anionic or nonionic surfactants: TEGOWet 280: TEGO Wet 280 (polyether-modified siloxane copolymer manufactured by Evonik Japan Co., Ltd.) DYNWET 800: (Alcohol alkoxylate manufactured by BYK Japan Co., Ltd.) Azole compounds: Imidazole: (Special grade imidazole manufactured by Kanto Chemical Co., Ltd.) Thiabendazole: (2-(4-thiazolyl)benzimidazole manufactured by Tokyo Chemical Industry Co., Ltd.)

[0076] (Antibacterial Coating Agent Examples and Comparative Examples) Coating compositions containing a thermosetting resin, an active energy ray curable resin, or a thermoplastic resin as a main component were blended and uniformly stirred with a dispersing stirrer to obtain the compositions shown in Tables 3 to 5. To each prepared coating composition, the antibacterial composition shown in Table 1 was added in the blending amount shown in Tables 2 to 4, and the mixture was uniformly stirred with a dispersing stirrer to prepare an antibacterial coating.

[0077] (Antibacterial coating agent evaluation method) (Preparation of decorative sheet for evaluation) The antibacterial coating agent prepared above was applied to a substrate, Cosmoshine A4100 (50 μm thick, one-sided easy-adhesion treated PET), by Toyobo Co., Ltd., by bar coating to form a coating film. The antibacterial composition used to prepare each antibacterial coating agent was left to stand at room temperature for one month, and then stirred with a dispersing stirrer. The solvent-containing coating agent was dried at 100°C for approximately 60 seconds to volatilize the solvent. The coating was then cured as needed using the procedures described below and used in the various evaluations described below. The thickness of the cured coating was confirmed to be 4-8 μm by measuring the mass of the coating. Mass conversion was performed using 1 g / m² = 1 μm.

[0078] Active energy ray curable resin: Irradiated at a speed of 25 m / min under a light source of an air-cooled high-pressure mercury lamp of 120 W / cm. The integrated UV dose was measured at 50 mJ / cm using an integrated UV actinometer (GS Yuasa Corporation Industrial UV Checker UVR-N1). 2 I confirmed that it was. Thermosetting resin: left to stand in a thermostatic bath at 60°C for 3 days.

[0079] (Surface smoothness) The antibacterial coating agent was applied to a substrate, Cosmoshine A4100, using a bar coater. After application, the smoothness of the coated surface was visually evaluated using the following two-point scale. ◯: The surface is uniform and smooth. ×: There are aggregates and the surface is not smooth.

[0080] (Color difference ΔE after weathering test) The decorative sheet for evaluating the antibacterial coating composition prepared above was irradiated with UV light for 96 hours using a Super UV accelerated weather resistance tester (Eye Super UV Tester SUV-W261, manufactured by Iwasaki Electric) under the following settings: illuminance 60mW, irradiation temperature 63°C, resting temperature 50°C, irradiation humidity 50%, resting humidity 50%, irradiation time 20 hours, condensation time 4 hours, resting time 6 minutes, and shower time 10 seconds. A spectrophotometer CM-700d manufactured by Konica Minolta, Inc. was used to track the color difference (△(Delta)E) between a sample with no antibacterial composition added and a sample with the antibacterial composition added before and after UV irradiation, and the discoloration of the decorative sheet caused by the antibacterial composition was evaluated on the following three-point scale. ○: No yellowing at all, and the change in color difference value is less than 2, so there is almost no change. △: Slight yellowing is observed, and the change in color difference value is 2 or more and less than 5, with slight change observed. ×: Yellowing was observed, and the change in color difference value was 5 or more.

[0081] (Color difference ΔE after moist heat test) The decorative sheet for evaluating the antibacterial coating composition prepared above was left to stand for 5 days in a thermo-hygrostat chamber under conditions of 85% humidity and 85°C temperature, and a spectrophotometer CM-700d manufactured by Konica Minolta, Inc. was used to track the color difference (Δ(Delta)E) between a sample without the antibacterial composition and a sample with the antibacterial composition added before and after ultraviolet light irradiation, and the discoloration of the decorative sheet caused by the antibacterial composition was evaluated on the following three-point scale. ○: No yellowing at all, and the change in color difference value is less than 2, so there is almost no change. △: Slight yellowing is observed, and the change in color difference value is 2 or more and less than 5, with slight change observed. ×: Yellowing was observed, and the change in color difference value was 5 or more.

[0082] (Antibacterial test results) The antibacterial activity of the cured coating films of each coating composition in the Examples and Comparative Examples was evaluated according to JIS Z 2 801:2012 using the following procedure. The resulting cured coating films were cut into 50±2 mm squares to prepare test specimens. Escherichia coli and Staphylococcus aureus were used as test bacteria. The test bacteria were suspended in 1 / 500 NB nutrient bouillon medium to a concentration of 10 pfu / mL, which served as the test bacterial solution. 0.4 mL of the test bacterial solution was dropped onto the test specimen, covered with PE film to adhere the bacterial solution to the test specimen, and then cultured at 35±1°C and a relative humidity of 90% or higher for 24 hours. The inoculum was washed and recovered with 10 mL of SCDLP medium, and then cultured on agar medium at 35±1°C for 40 to 48 hours. The viable bacterial count was counted and calculated from the colonies that emerged. The antibacterial activity was calculated using the following formula. The reference example is a blank sample to which no antibacterial additive was added. Calculation of antibacterial activity value (R): R = UA U: Logarithm of viable bacteria count in unprocessed product after 24 hours A: Logarithm of the number of viable bacteria on antibacterial processed products after 24 hours The antibacterial activity was evaluated according to the following three levels. 〇: Antibacterial activity value 3 or more △: Antibacterial activity value 1 or more but less than 3 ×: Antibacterial activity value less than 1

[0083] Tables 3 to 5 show the compositions of the antibacterial coating agents and the evaluation results (physical property values).

[0084] [Table 3]

[0085] [Table 4]

[0086] [Table 5]

[0087] In Tables 3 to 5, the abbreviations are as follows: Table 3 Active energy ray curable resin: Urethane acrylate (urethane acrylate oligomer manufactured by IGM Resins BV) Trifunctional monomer (ethylene oxide modified trimethylolpropane triacrylate manufactured by MIWON) Bifunctional monomer (ethylene oxide-modified 1,6-hexanediol diacrylate manufactured by MIWON) Shiko UV-1700B (urethane acrylate manufactured by Mitsubishi Chemical Corporation) Omnirad 184 (1-hydroxycyclohexyl phenyl ketone, manufactured by IGM Resins BV) Table 4 ·Thermosetting resin: Acrylic polyol A (Taisei Fine Chemical Co., Ltd. acrylic polyol, molecular weight 31,000, Tg 70°C) Acrylic polyol B (Taisei Fine Chemical Co., Ltd. acrylic polyol, molecular weight 65,000, Tg 102°C) Sumidur N3200: Isocyanate-type curing agent (polyisocyanate manufactured by Sumika Covestro Urethane Co., Ltd.) Table 5 Paraloid A-11 (acrylic resin manufactured by Dow Chemical) Hi-Loss X·X-436 (styrene acrylic emulsion manufactured by Seiko PMC Corporation)

[0088] As a result, the antibacterial compositions of Examples 1 to 12 maintained stable dispersibility without discoloration or sedimentation even after being left standing for 30 days in a thermostatic chamber at 40° C. Furthermore, the antibacterial coating agents to which the antibacterial compositions of Examples 1 to 12 were added dispersed uniformly even when the solvent of the coating agent was water, an aqueous solvent, or an organic solvent, and the coated surface after application was smooth and showed good antibacterial properties. On the other hand, Comparative Examples 1 and 2 are examples that do not contain an azole compound. Despite the presence of a surfactant, sedimentation and discoloration occurred. Therefore, the antibacterial coating agents using the antibacterial compositions of Comparative Examples 1 and 2 also failed to obtain a smooth coating film after application due to the influence of aggregates caused by sedimentation.

[0089] The present invention can provide an antibacterial composition that is useful as an antibacterial additive that disperses uniformly in existing coating agents, even if the solvent is water, an aqueous solvent, or an organic solvent, maintains stable dispersion without causing aggregation or sedimentation in the coating agent, prevents discoloration of the coating agent and antibacterial additive over time, and imparts good antibacterial properties, as well as an antibacterial additive, antibacterial coating agent, and decorative sheet using the same. The obtained antibacterial coating agent and decorative sheet exhibit high antibacterial activity.

Claims

1. An antibacterial composition comprising at least a silver-carrying antibacterial agent, an azole compound, and an anionic surfactant or a nonionic surfactant, The antibacterial composition is characterized in that the azole compound is contained in an amount of 0.01% by mass to 30% by mass relative to the antibacterial agent.

2. 2. The antibacterial composition according to claim 1, wherein the azole compound is thiabendazole.

3. The antibacterial composition according to claim 1, wherein the anionic surfactant or nonionic surfactant is at least one selected from the group consisting of alkyl phosphate ester salts, phosphate ester copolymers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, alcohol alkoxylates, and organically modified organopolysiloxanes.

4. 2. The antibacterial composition according to claim 1, wherein the average particle size of the antibacterial agent carrying silver is in the range of 0.1 to 10 μm.

5. An antibacterial additive comprising the antibacterial composition according to any one of claims 1 to 4.

6. An antibacterial coating agent comprising the antibacterial composition according to any one of claims 1 to 4.

7. A decorative sheet comprising a substrate and a coating layer of the antibacterial coating agent according to claim 6 provided on the substrate.

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