JP2022147239A - Active energy ray-curable overprint varnish, and paper base material or plastic base material using the same - Google Patents

Abstract

To provide an active energy ray-curable overprint varnish having antibacterial and antiviral performance.SOLUTION: There are provided an active energy ray-curable overprint varnish containing an active energy ray-curable compound as a main component, wherein in an X-ray diffraction pattern obtained by plotting a diffraction line strength relative to a diffraction angle of 2θ by Cu-Kα rays, a titanium oxide containing a titanium oxide having a content of a crystalline rutile-type titanium oxide that is a titanium oxide having a full width at half maximum of the strongest diffraction peak corresponding to a rutile-type titanium oxide of 0.65 degrees or less of 50 mol% or more, and a divalent copper compound are contained in an amount of 0.05-15 mass% with respect to the total amount of a varnish content; and a paper base material or a plastic base material using the same.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to an active energy ray-curable overprint varnish containing an active energy ray-curable compound as a main component.

Overprint varnish (also referred to as overcoat varnish, hereinafter sometimes referred to as OP varnish) is used after printing for the purpose of improving the glossiness of the printed matter and protecting the film of the printed matter. Specifically, colorless and transparent OP varnish is printed after each color of printing ink is printed. As OP varnishes, active energy ray-curable OP varnishes are known in addition to solvent-type OP varnishes that contain an organic solvent and are dried to form a varnish film. (See Patent Documents 1 and 2, for example)

On the other hand, in recent years, there is a demand for the addition of functionality to the surface of various substrates, and it is necessary to improve the surface properties of not only printed matter, but also plastic materials, molded products, paper substrates, film substrates, packaging materials, etc. there is
Especially in recent years, in addition to physical functionality such as gloss improvement and film protection, hygienic functions such as antibacterial and antiviral functions are also desired. There is an urgent need for antiviral (virus inactivating) measures as measures against viral infections.

As an OP varnish composition having antiviral performance, for example, an OP varnish composition characterized by containing polytetrafluoroethylene particles and an antibacterial agent in OP varnish is known (see, for example, Patent Document 3). . However, active energy ray-curable OP varnishes with antibacterial and antiviral properties have not been known so far.

JP 2008-163293 A JP-A-07-196948 JP-A-11-80643

The problem to be solved by the present invention is to provide an active energy ray-curable overcoat varnish having antibacterial and antiviral properties.

The present inventors have solved the problem by providing an active energy ray-curable overprint varnish containing a specific amount of photocatalyst relative to the solid content of the varnish.

That is, the present invention provides an active energy ray-curable overprint varnish containing an active energy ray-curable compound as a main component, wherein the active energy ray-curable overprint varnish contains a photocatalyst, and the photocatalyst is crystalline rutile. The crystalline rutile-type titanium oxide contains titanium oxide containing type titanium oxide and a divalent copper compound, and the crystalline rutile-type titanium oxide is an X-ray diffraction pattern in which the diffraction line intensity is plotted against the diffraction angle 2θ by Cu-Kα rays. Titanium oxide in which the full width at half maximum of the strongest diffraction peak corresponding to titanium is 0.65 degrees or less, the content of the crystalline rutile-type titanium oxide in the titanium oxide is 50 mol% or more, and the anatase-type titanium oxide is contained. Provided is an active energy ray-curable overprint varnish containing 0.01 to 15% by mass of a photocatalyst with respect to the total solid content of the varnish.

The present invention also provides a printed matter comprising a substrate and a coating film of the active energy ray-curable overprint varnish according to any one of claims 1 to 3 disposed on the substrate.

The present invention also provides a paper substrate or a plastic substrate obtained by coating a paper substrate or a film with the active energy ray-curable overprint varnish described above.

The present invention also provides containers and packaging materials using the paper base material or plastic base material.

Since the active energy ray-curable overcoat varnish of the present invention has antibacterial and antiviral properties, it is possible to impart antibacterial and antiviral properties to paper or plastic substrates simply by coating them on paper substrates or films. can be done.

(Active energy ray-curable overprint varnish)
The active energy ray-curable overprint varnish used in the present invention contains an active energy ray-curable compound such as an active energy ray-curable monomer and/or oligomer as a main component.

(Monomer having an ethylenically unsaturated double bond)
The active energy ray-curable monomer and/or oligomer used in the present invention can be used without particular limitation as long as it is a monomer and/or oligomer used in the active energy ray-curable technical field. In particular, those having a (meth)acryloyl group, a vinyl ether group, or the like as a reactive group are preferred. The number of reactive groups and molecular weight are also not particularly limited, and the more reactive groups there are, the higher the reactivity but the higher the viscosity and crystallinity tend to be, and the higher the molecular weight, the higher the viscosity. They can be used in combination as appropriate depending on the desired physical properties. For example, in terms of suitable curing with low-energy irradiation such as UV-LED, it is necessary to combine more highly reactive trifunctional or higher active energy ray-curable monomers, depending on the application, adhesion to printing substrates, film In order to obtain necessary physical properties such as flexibility, it is preferable to use a monofunctional or difunctional monomer alone or in combination.

Examples of monofunctional (meth)acrylates include 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, butoxy Ethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 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, nonylphenoxyethyltetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl ( meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate and the like.

Bifunctional or higher (meth)acrylates include, for example, 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ) acrylate, neopentyl glycol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, tricyclodecanedi Methanol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, etc. dihydric alcohol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, 4 mol per 1 mol of neopentyl glycol Di(meth)acrylate of diol obtained by adding ethylene oxide or propylene oxide, di(meth)acrylate of diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A, trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, poly(meth)acrylate of dipentaerythritol, etc.; poly(meth)acrylates of polyhydric alcohols with a valence of 3 or more, tri(meth)acrylates of triols obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of glycerin, 3 mol or more of trimethylolpropane to 1 mol of trimethylolpropane Di or tri (meth) acrylate of triol obtained by adding ethylene oxide or propylene oxide, di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A Poly such as Examples include poly(meth)acrylates of oxyalkylene polyols.

Polymerizable oligomers include amine-modified (meth)acrylates such as amine-modified polyether (meth)acrylate, amine-modified epoxy (meth)acrylate, amine-modified aliphatic acrylate, amine-modified polyester (meth)acrylate, and amino (meth)acrylate. , thiol-modified polyester (meth)acrylate, thiol-modified (meth)acrylate such as thiol (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, polyolefin (meth)acrylate, polystyrene (meth)acrylate, epoxy ( meth)acrylates, urethane (meth)acrylates, and the like.

In addition, as the active energy ray-curable monomer and/or oligomer, a tetrafunctional or higher (meth)acrylate is used for printing on paper such as woodfree paper, coated paper, art paper, imitation paper, thin paper, and cardboard. It is preferable to use it because it greatly contributes to the improvement of strength, and it is preferable to use it in the range of 15 to 70% by mass based on the total solid content of the varnish. On the other hand, in printing applications on plastics, as the cross-linking density of the cured coating increases, the adhesion between the base material and the cured coating decreases, so the content of tetrafunctional or higher (meth)acrylates should be appropriately reduced. need to let In this case, the tetrafunctional or higher (meth)acrylate is preferably used in an amount of 0 to 50% by mass based on the total solid content of the ink.

In addition, the active energy ray-curable overprint varnish of the present invention can use resins, pigments, and various additives.

(resin)
As the resin, various known binder resins can be used. The binder resin mentioned here refers to resins in general that have appropriate pigment affinity and dispersibility and rheological properties required for printing inks. Resin, epoxy ester resin, polyurethane resin, polyester resin, petroleum resin, rosin ester resin, poly(meth)acrylic acid ester, cellulose derivative, vinyl chloride-vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, butadiene-acrylonitrile Examples include copolymers, and epoxy (meth)acrylate compounds, urethane (meth)acrylate compounds, polyester (meth)acrylate compounds, etc. having at least one or more polymerizable groups in the molecule can also be used. These binder resins may be used alone or in combination of one or more.

In the present invention, it is preferable to use a combination of polyester (meth)acrylate and diallyl phthalate resin.
The polyester (meth)acrylate is preferably a polyester (meth)acrylate having a glass transition temperature of 200° C. or higher. Among them, it is preferable that the glass transition temperature is 250° C. or higher.
The polyester (meth)acrylate content is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, based on the total amount of the active energy ray-curable overprint varnish.

The diallyl phthalate resin preferably has a glass transition temperature of 140°C to 160°C, more preferably 150°C to 160°C. Moreover, it is preferably contained in an amount of 5 to 30% by mass based on the total amount of the active energy ray-curable overprint varnish.

Among them, 10 to 35% by mass of polyester (meth)acrylate based on the total amount of active energy ray-curable overprint varnish, and 5 to 20% by mass of diallyl phthalate resin based on the total amount of active energy ray-curable overprint varnish. It is preferable to contain.

Moreover, it is preferable to contain both a polyester (meth)acrylate having a glass transition temperature of 250°C or higher and a diallyl phthalate resin having a glass transition temperature of 140 to 160°C. In that case, the total mass of the polyester acrylate having a glass transition temperature of 250° C. or higher and the diallyl phthalate resin having a glass transition temperature of 140 to 160° C. is 10 to 70% by mass with respect to the total amount of the active energy ray-curable overprint varnish. is preferably

(Photoinitiator)
As the photopolymerization initiator used in the present invention, any known photopolymerization initiator can be used without any particular limitation. For example, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone (184), 2-hydroxy-2-methyl-1-phenyl-propan-1-one ( 1173), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (2959), 2-hydroxy-1-{4-[4-( 2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one (127), 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropane Alkylphenone-based photopolymerization initiators such as noyl)phenoxy]phenyl]-2-methylpropan-1-one,

Phenyl Glyoxylic Acid Methyl Ester, Oxyphenylacetic Acid, Mixture of 2-[2-oxo-2-phenylacetoxyethoxy]ethyl Ester and Oxyphenylacetic Acid, 2-(2-Hydroxyethoxy)ethyl Ester, 1,2-octane dione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl) -butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone,2-benzyl-2-dimethylamino- 1-(4-piperidinophenyl)-butan-1-one, 1-([1,1′-biphenyl]-4-yl)-2-methyl-2-morpholinopropan-1-one, 1- compounds such as (4-methoxyphenyl)-2-methyl-2-(4-morpholinyl-1-propanone;

Also, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl- Examples include acylphosphine oxide compounds such as pentylphosphine oxide and ethyl-(2,4,6-trimethylbenzoyl)phenylphosphinate.

2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-isopropylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dichlorothioxanthone, 2-chlorothioxanthone , 1-chloro-4-propoxythioxanthone, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H thioxanthone-2-yloxy-N,N,N-trimethyl-1-propanamine hydrochloride and the like Thioxanthone compounds are mentioned.

In addition, 4,4'-bis-(dimethylamino)benzophenone, 4,4'-dialkylaminobenzophenones such as 4,4'-bis-(diethylamino)benzophenone, 4-benzoyl-4'-methyldiphenylsulfide and the like. Benzophenone compounds are mentioned.

Besides, for example benzophenone, 4-methyl-benzophenone, 2,4,6-trimethylbenzophenone, 2,3,4-trimethylbenzophenone, 4-phenylbenzophenone, 3,3′-dimethyl-4-methoxybenzophenone, 4 -(1,3-acryloyl-1,4,7,10,13-pentoxotridecyl)benzophenone, methyl-o-benzoylbenzoate, [4-(methylphenylthio)phenyl]phenylmethanone, diethoxyacetophenone, Dibutoxyacetophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin normal butyl ether and the like.

In the present invention, the general-purpose photopolymerization initiator may be used singly or in combination of several kinds.

[Sensitizer/photoinitiator aid]
In the present invention, a photoinitiator aid such as a photosensitizer or a tertiary amine may be used in combination with the general-purpose photopolymerization initiator, which is preferable. Examples of the photosensitizer include, but are not limited to, thioxanthone-based, benzophenone-based such as 4,4′-bis(diethylamino)benzophenone, anthraquinone-based, coumarin-based, and the like.

When a sensitizer or a photoinitiator is used in combination, it is preferably 0.05 to 10% by mass, more preferably 0.1 to 7.0% by mass, based on the total solid content of the ink. If it is less than 0.05% by mass, a sufficient effect of improving curability cannot be obtained, and if it exceeds 10% by mass, the hue of the cured coating film becomes unacceptably yellowish, or the sensitizer is used. It precipitates out or the fluidity of the ink is remarkably lowered.

On the other hand, as the tertiary amine, although not particularly limited, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-diethylaniline , N,N-dimethyl-p-toluidine, N,N-dihydroxyethylaniline, triethylamine and N,N-dimethylhexylamine, 2-ethylhexyl-4-(dimethylamino)benzoate, 2-butoxyethyl-4-(dimethyl amino) benzoate, etc., which reduce inhibition of polymerization by oxygen, react with thioxanthones and 4,4'-dialkylaminobenzophenones activated by ultraviolet rays, become active radical donors, and improve ink curing performance. or improve the solubility of the photopolymerization initiator. The tertiary amine is preferably used in combination within a range that does not impair the printing performance of the active energy ray-curable ink of the present invention. It is more preferable to use it in the mass% range.

In applications where high sanitation is required, a high-molecular-weight compound obtained by branching a plurality of photosensitizers or tertiary amines with a polyhydric alcohol or the like in one molecule can be used as appropriate.

(photocatalyst)
The photocatalyst used in the present invention is a photocatalyst containing titanium oxide containing crystalline rutile-type titanium oxide and a divalent copper compound, wherein the crystalline rutile-type titanium oxide has a diffraction angle 2θ of Cu-Kα rays. In an X-ray diffraction pattern in which diffraction line intensities are plotted, the strongest diffraction peak corresponding to rutile-type titanium oxide has a full width at half maximum of 0.65 degrees or less, and the crystalline rutile-type titanium oxide in the titanium oxide. is 50 mol% or more, and the content of anatase-type titanium oxide is less than 50 mol%.

A photocatalyst (visible A visible-light-responsive photocatalyst having photocatalytic activity such as antiviral properties in the light region can be obtained. Moreover, unlike monovalent copper compounds, divalent copper compounds are less susceptible to discoloration due to oxidation, so discoloration over time can be suppressed.

In the present invention, "bright place" means a place where visible light exists, and "dark place" means a place where light does not exist.

Here, photocatalytic activity means at least one selected from photoinduced decomposability and photoinduced hydrophilization. Photoinduced decomposability is the action of oxidatively decomposing organic substances adsorbed on the surface treated with titanium oxide. It is an effect that becomes This photo-induced hydrophilization is thought to be caused by the increase in hydroxyl groups on the surface of titanium oxide due to holes generated and diffused by photoexcitation.

Viruses mean DNA viruses and RNA viruses, but also include bacteriophages (hereinafter sometimes abbreviated as "phages"), which are viruses that infect bacteria.

Next, each component of the photocatalyst will be described.
(titanium oxide)
The titanium oxide used for the photocatalyst contains crystalline rutile-type titanium oxide.

In the present invention, crystalline rutile-type titanium oxide means that the full width at half maximum of the strongest diffraction peak corresponding to rutile-type titanium oxide in an X-ray diffraction pattern in which the diffraction line intensity is plotted against the diffraction angle 2θ by Cu-Kα rays is 0. It means titanium oxide of 0.65 degrees or less.

If the full width at half maximum is larger than 0.65 degrees, the crystallinity will be poor and the antiviral properties in the dark will be insufficient. From this viewpoint, the full width at half maximum is preferably 0.6 degrees or less, more preferably 0.5 degrees or less, still more preferably 0.4 degrees or less, and even more preferably 0.35 degrees. .

The content of crystalline rutile-type titanium oxide (hereinafter sometimes referred to as “rutilization rate”) in titanium oxide is 50 mol % or more. When the content is 50 mol% or more, the resulting photocatalyst has sufficient antiviral properties in bright and dark places, and also has sufficient organic compound degradability in bright places and, in particular, sufficient visible light responsiveness. become a thing. From this point of view, the rutilization rate is preferably 90 mol % or more, more preferably 94 mol % or more. This rutilization rate is a value measured by XRD as described later.

From the above viewpoint, the content of anatase-type titanium oxide in titanium oxide (hereinafter sometimes referred to as "anatase conversion rate") is preferably small, and the anatase conversion rate is less than 50 mol%, preferably 10 mol. %, more preferably less than 7 mol %, and still more preferably 0 mol % (that is, it does not contain anatase titanium oxide). This anatase rate is also a value measured by XRD, like the rutilization rate.

The specific surface area of titanium oxide is preferably 1 to 200 m2/g. When the specific surface area is 1 m2/g or more, the frequency of contact with viruses, bacteria, and organic compounds increases due to the large specific surface area, and the resulting photocatalyst has antiviral properties in bright and dark places, organic compound decomposing properties, and antibacterial properties. is superior. On the other hand, when it is 200 m<2>/g or less, the handleability is excellent. From these viewpoints, the specific surface area of titanium oxide is more preferably 3 to 100 m2/g, still more preferably 4 to 70 m2/g, and particularly preferably 8 to 50 m2/g. Here, the specific surface area is a value measured by the BET method using nitrogen adsorption.

Titanium oxide is classified into those produced by a vapor phase method and those produced by a liquid phase method, and both of them can be used, but the titanium oxide produced by a vapor phase method is more preferable.

The vapor phase method is a method of obtaining titanium oxide by a vapor phase reaction with oxygen using titanium tetrachloride as a raw material. Titanium oxide obtained by the gas phase method has a uniform particle size and high crystallinity because it is manufactured through a high-temperature process. As a result, the obtained photocatalyst has good antiviral properties in bright and dark places, organic compound decomposing properties, and antibacterial properties.

On the other hand, the liquid phase method is a method of obtaining titanium oxide by hydrolyzing or neutralizing a liquid in which titanium oxide raw materials such as titanium chloride and titanyl sulfate are dissolved. Titanium oxide produced by the liquid phase method tends to have low rutile crystallinity and a large specific surface area. , the vapor phase method is more suitable because it takes time and effort.

As the titanium oxide, it is more advantageous to use commercially available titanium oxide as it is in consideration of the catalyst preparation process.

(Divalent copper compound)
The photocatalyst contains a divalent copper compound. This divalent copper compound alone does not have antiviral properties in bright and dark places, organic compound degradability in bright places, and visible light responsiveness. And the antiviral properties in the dark, the organic compound degradability in the light, and the visible light responsiveness are fully expressed. In addition, since the divalent copper compound is less discolored by oxidation or the like than the monovalent copper compound, discoloration of the photocatalyst using the divalent copper compound is suppressed.

The divalent copper compound is not particularly limited, and includes one or two of divalent copper inorganic compounds and divalent copper organic compounds.

Divalent copper inorganic compounds include copper sulfate, copper nitrate, copper iodate, copper perchlorate, copper oxalate, copper tetraborate, copper ammonium sulfate, copper amidosulfate and copper ammonium chloride, copper pyrophosphate and copper carbonate. 1 selected from the group consisting of divalent copper inorganic acid salts, divalent copper halides consisting of copper chloride, copper fluoride and copper bromide, and copper oxide, copper sulfide, azurite, malachite and copper azide species or two or more species.

Divalent copper organic compounds include carboxylates of divalent copper. The divalent copper carboxylates include copper formate, copper acetate, copper propionate, copper butyrate, copper valerate, copper caproate, copper enanthate, copper caprylate, copper pelargonate, copper caprate, and mystic acid. Copper, copper palmitate, copper margarate, copper stearate, copper oleate, copper lactate, copper malate, copper citrate, copper benzoate, copper phthalate, copper isophthalate, copper terephthalate, copper salicylate, mellitic acid Copper, copper oxalate, copper malonate, copper succinate, copper glutarate, copper adipate, copper fumarate, copper glycolate, copper glycerate, copper gluconate, copper tartrate, copper acetylacetonate, copper ethylacetoacetate, copper isokyl One or two selected from the group consisting of copper formate, copper β-resorcylate, copper diacetoacetate, copper formylsuccinate, copper salicylate, copper bis(2-ethylhexanoate), copper sebacate and copper naphthenate species or more. Other divalent copper organic compounds selected from the group consisting of copper oxine, copper acetylacetone, copper ethylacetoacetate, copper trifluoromethanesulfonate, copper phthalocyanine, copper ethoxide, copper isopropoxide, copper methoxide, and copper dimethyldithiocarbamate. 1 type or 2 types or more are mentioned.

Among the above divalent copper compounds, preferably one or more of copper oxide, divalent copper halide, divalent copper inorganic acid salt and divalent copper carboxylate, for example, divalent copper They are one or more of halides, inorganic acid salts of divalent copper and carboxylates of divalent copper.

Moreover, as a bivalent copper compound, the bivalent copper compound represented with the following general formula (1) is mentioned.
Cu2(OH)3X (1)
In the general formula (1), X is an anion, preferably a halogen such as Cl, Br or I, a conjugate base of a carboxylic acid such as CH3COO, a conjugate base of an inorganic acid such as NO3, (SO4)1/2, etc. or OH.

Among these divalent copper compounds, a divalent copper inorganic compound is more preferable, and copper oxide is still more preferable, from the viewpoint of economy because it contains less impurities. A divalent copper compound represented by the general formula (1) is also preferred. The divalent copper compound may be either an anhydride or a hydrate.

The content of the divalent copper compound in terms of copper is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the titanium oxide. When the amount is 0.01 part by mass or more, good antiviral properties, organic compound decomposing properties, and antibacterial properties are obtained in bright and dark places. In addition, when the amount is 20 parts by mass or less, the surface of the titanium oxide is prevented from being coated, and the function as a photocatalyst (organic compound decomposability, antibacterial properties, etc.) is well expressed, and antiviral performance is achieved with a small amount. It can be improved and is economical. From this point of view, the content of the divalent copper compound in terms of copper is more preferably 0.1 to 20 parts by mass, more preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of titanium oxide, Even more preferably, it is 0.3 to 10 parts by mass.

Here, the copper-equivalent content of the divalent copper compound with respect to 100 parts by mass of titanium oxide can be calculated from the charged amounts of the raw material of the divalent copper compound and the raw material of titanium oxide. In addition, this content in terms of copper can also be specified by measuring the photocatalyst by ICP (inductively coupled plasma) emission spectrometry, which will be described later.

As described above, the photocatalyst contains titanium oxide including crystalline rutile-type titanium oxide and a divalent copper compound as essential components, but may contain other optional components within a range that does not impede the object of the present invention. may be However, from the viewpoint of improving the function as a photocatalyst and antiviral performance, the content of the essential component in the photocatalyst is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 99% by mass. % by mass or more, more preferably 100% by mass.

The photocatalyst can be produced by performing a mixing step of mixing titanium oxide containing crystalline rutile-type titanium oxide and a divalent copper compound raw material. Moreover, a heat treatment step of heat-treating the mixture obtained by this mixing step may be further performed to obtain a photocatalyst. A photocatalyst can also be obtained by suspending and adsorbing titanium oxide in an aqueous solution of a copper compound. Specifically, the photocatalyst can be produced by the method described in Japanese Patent No. 5343176.

A photocatalyst having a primary particle size of about 200 to 400 nm and a secondary particle size of about 3 to 10 μm is preferable because it can be dispersed in a coating agent and has excellent photocatalytic activity such as antiviral properties.
The method of measuring the primary particle size is a value obtained by directly measuring the size of primary particles from an electron micrograph using a transmission electron microscope (TEM).

The photocatalyst is used for the paper substrate or plastic substrate of the present invention in order to express photocatalytic activity such as antiviral properties within a range that does not impair various performances such as transparency, curability, printability, and gloss inherent in the overprint varnish. It is preferably contained in the range of 0.05% by mass or more and 15% by mass or less based on the total solid content of the coating agent for lumber. Furthermore, when high transparency is required for the overprint varnish, the content is preferably 0.05% by mass or more and 5% by mass or less, and more preferably 0.05% by mass or more and 2% by mass or less. . If it is less than 0.05% by mass, the desired antiviral and antibacterial properties cannot be obtained, while if it exceeds 15% by mass, the image in the lower part of the varnish becomes unclear and the cosmetic properties are significantly impaired. In addition, since titanium oxide significantly reflects the ultraviolet rays emitted from the ultraviolet irradiation device, the deterioration of the curing performance becomes remarkable. Furthermore, due to the increased amount of titanium oxide particles with a high specific gravity in the overprint varnish, the inherent rheological properties of the overprint varnish are significantly impaired, deteriorating the suitability for offset printing.

In the method of mixing the photocatalyst used in the present invention with the active energy ray-curable overprint varnish, the monomer, oligomer, resin solution, various additives, etc. used in the overprint varnish are mixed in a liquid. , powdery photopolymerization initiator, extender pigment and the photocatalyst are mixed and pre-dispersed with a known and public dispersing stirrer, and then using a kneading disperser such as a triple roll or a bead mill to form particles suitable for offset printing. It can also be produced by kneading and dispersing until the particle diameter is obtained, or by blending the photocatalyst at a high concentration in a binder component composed of a monomer, oligomer, and resin solution, and kneading until the particle diameter is suitable for offset printing. A thick high-concentration photocatalyst base is produced in advance, and the above-mentioned high-concentration photocatalyst base is blended in a photocatalyst-free overprint varnish produced in a separate process to a desired concentration. It is also possible to produce an active energy ray-curable overprint varnish containing a photocatalyst by mixing with a dispersion stirrer.

(Other additives)
Other additives include natural additives such as carnauba wax, Japan wax, lanolin, montan wax, paraffin wax, and microcrystalline wax, as additives that impart abrasion resistance, anti-blocking properties, slip properties, and scratch resistance. Examples include wax, Fischer-Tropsch wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax, and synthetic waxes such as silicone compounds.

Further, for example, additives that impart storage stability to ink include (alkyl)phenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, t-butylcatechol, t-butylhydroquinone, pyrogallol, 1,1-picryl, hydrazil, phenothiazine, p-benzoquinone, nitrosobenzene, 2,5-di-tert-butyl-p-benzoquinone, dithiobenzoyl disulfide, picric acid, cupferron, aluminum N-nitrosophenylhydroxylamine, tri-p-nitrophenylmethyl , N-(3-oxyanilino-1,3-dimethylbutylidene)aniline oxide, dibutyl cresol, cyclohexanone oxime cresol, guaiacol, o-isopropylphenol, butyraldoxime, methyl ethyl ketoxime, cyclohexanone oxime and the like.

In addition, additives such as ultraviolet absorbers, infrared absorbers, and antibacterial agents can be added according to required performance.

The active energy ray-curable overprint varnish of the present invention can be used without a solvent, or can be used with a suitable solvent as necessary. The solvent is not particularly limited as long as it does not react with each of the above components, and may be used alone or in combination of two or more.

The production of the active energy ray-curable overprint varnish of the present invention may be carried out by a method similar to the conventional one. and sensitizers such as amine compounds, photocatalysts and other additives used in the present invention are manufactured using kneading, mixing and adjusting machines such as kneaders, three rolls, attritors, sand mills and gate mixers. be.

(printed matter)
The printed matter of the present invention can be obtained by applying the overprint varnish composition described above directly onto a substrate or onto a printed matter printed by a lithographic offset printing machine using a printing ink composition. The overprint varnish composition may be applied to the entire surface of the printed matter, or may be applied to only a portion of the printed matter. The amount of coating may be appropriately adjusted depending on the purpose of coating the overprint varnish composition. As an example, the thickness of the coating film of the overprint varnish composition after drying is about 0.5 μm to 1.5 μm. adjust.

The coating method may be a so-called in-line method in which a coating apparatus is installed in a lithographic offset printing machine and the overprint varnish composition is applied subsequently to printing using the printing ink composition. A so-called off-line method in which the coating is performed by a coater equipped with a gravure or flexographic coating device after printing by an offset printing machine may also be used.

(Paper substrate)
The substrate is not particularly limited, and conventionally known substrates can be used, but it is particularly suitable for printing on paper substrates such as coated paper, matte coated paper, and woodfree paper. Backing paper, impregnated paper, cardboard, paperboard and the like can also be used.

(Plastic substrate)
Moreover, you may apply to a plastic base material. The plastic substrate may be a substrate used for substrates such as plastic materials, molded articles, film substrates, and packaging materials. Specifically, for example, polyamide resins such as nylon 6, nylon 66, nylon 46, polyethylene terephthalate (hereinafter sometimes referred to as PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, Polyester resins such as polybutylene naphthalate, polyhydroxycarboxylic acids such as polylactic acid, biodegradable resins such as aliphatic polyester resins such as poly(ethylene succinate) and poly(butylene succinate), polypropylene, polyethylene, etc. Polyolefin resins, polyimide resins, polyarylate resins, or films made of thermoplastic resins such as polyarylate resins or mixtures thereof, and laminates thereof. Among them, films made of polyethylene terephthalate (PET), polyester, polyamide, polyethylene, and polypropylene can be preferably used. These base films may be either unstretched films or stretched films, and the manufacturing method thereof is not limited. Also, the thickness of the base film is not particularly limited, but it is usually in the range of 1 to 500 μm. Further, the substrate film is preferably subjected to corona discharge treatment, and aluminum, silica, alumina, or the like may be deposited thereon. The base material is a laminate (sometimes referred to as a laminated film) having a laminated structure obtained by laminating the paper base material or film base material by a dry lamination method, a solventless lamination method, or an extrusion lamination method. I don't mind.

The paper substrate or plastic substrate may further have a printing ink layer. The printing ink used for the printing ink layer is not particularly limited, and offset lithographic ink, gravure printing ink, flexographic printing ink, inkjet printing ink, etc. can be applied onto the printing layer. In particular, as described above, the method of applying an offset printing ink composition onto a printed material printed by a lithographic offset printing machine is industrially preferable.

(containers, packaging materials)
The single-layer paper substrate or film substrate and the laminate having a laminated structure are functional films, flexible packaging films, shrink films, packaging films for daily necessities, pharmaceutical packaging films, food products, etc., depending on the industry and method of use. Packaging films, cartons, posters, flyers, CD jackets, direct mail, pamphlets, high-quality paper, coated paper, art paper, imitation paper, thin paper, cardboard, etc. used for packages of cosmetics, beverages, pharmaceuticals, toys, equipment, etc. paper, various synthetic papers, etc., but the overprint varnish of the present invention can be used without any particular limitation. These substrates coated with the overprint varnish of the present invention are molded into containers and packaging materials. It is preferably coated on the surface to be the surface layer.

EXAMPLES The contents and effects of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

<Preparation of photocatalyst>
First, the properties of the titanium oxide raw material (manufactured by Showa Denko Ceramics Co., Ltd.) to be used were measured as follows.

(BET specific surface area)
The BET specific surface area of the titanium oxide raw material was measured using a fully automatic BET specific surface area measuring device "Macsorb, HM model-1208" manufactured by Mountec Co., Ltd.
(Rutile content (rutilization ratio) and crystallinity (full width at half maximum) in titanium oxide raw material)
The content (rutilization ratio) and crystallinity (full width at half maximum) of rutile-type titanium oxide in the titanium oxide raw material were measured by powder X-ray diffractometry.

That is, for the dried titanium oxide raw material, using "X'pertPRO" manufactured by PANalytical as a measuring device, using a copper target, using Cu-Kα1 line, tube voltage 45 kV, tube current 40 mA, measurement range 2θ = 20 X-ray diffraction measurement was performed under the conditions of ~100 deg, a sampling width of 0.0167 deg, and a scanning speed of 3.3 deg/min.

Obtain the peak height (Hr) corresponding to the rutile crystal, the peak height (Hb) corresponding to the brookite crystal, and the peak height (Ha) corresponding to the anatase crystal, and use the following formula to calculate titanium oxide The content of rutile-type titanium oxide (rutilization rate) in the medium was determined.

Rutilization rate (mol%) = {Hr / (Ha + Hb + Hr)} x 100
Also, the content of anatase-type titanium oxide (anatase conversion rate) and the content of brookite-type titanium oxide (brookite conversion rate) in titanium oxide were determined by the following formulas.

Anatase rate (mol%) = {Ha / (Ha + Hb + Hr)} x 100
Brookite conversion rate (mol%) = {Hb/(Ha + Hb + Hr)} x 100
In the X-ray diffraction pattern obtained by the above X-ray diffraction measurement, the strongest diffraction peak corresponding to rutile-type titanium oxide was selected and the full width at half maximum was measured.

(Primary particle size)
The average primary particle diameter (DBET) (nm) is obtained by measuring the specific surface area S (m / g) of titanium oxide by the BET single point method, and using the following formula
DBET=6000/(S×ρ)
calculated from Here, ρ indicates the density of titanium oxide (g/cm3).

Table 1 shows the measurement results of the titanium oxide raw material used.

(Production example 1)
6 g (100 parts by mass) of titanium oxide raw material (manufactured by Showa Denko Ceramics Co., Ltd.) was suspended in 100 mL of distilled water, and 0.0805 g (0.5 parts by mass in terms of copper) of CuCl2.2H2O (manufactured by Kanto Chemical Co., Ltd.) was added. ) was added and stirred for 10 minutes. A 1 mol/L sodium hydroxide (manufactured by Kanto Kagaku Co., Ltd.) aqueous solution was added so that the pH was 10, and the mixture was stirred and mixed for 30 minutes to obtain a slurry. This slurry was filtered, and the obtained powder was washed with pure water, dried at 80° C., and pulverized with a mixer to obtain a sample (photocatalyst).

The resulting sample (photocatalyst) was heated in a hydrofluoric acid solution to completely dissolve, and the extract was quantified by ICP emission spectrometry. As a result, the amount of copper ions was 0.5 parts by mass with respect to 100 parts by mass of titanium oxide. That is, all of the charged copper ions (derived from CuCl2.2H2O) were supported on the titanium oxide surface.

The sample (photocatalyst) obtained in Production Example 1 was analyzed by the following method.

(Content of rutile-type titanium oxide (rutilization rate) and crystallinity (full width at half maximum))
With respect to the sample (photocatalyst) obtained in Production Example 1, the content of rutile-type titanium oxide in titanium oxide (rutilization ratio) and crystallinity (full width at half maximum) were measured by powder X-ray diffractometry.

That is, a powder obtained by grinding a dried photocatalyst with a mortar was used as a sample. For this sample, using "X'pertPRO" manufactured by PANalytical as a measuring device, using a copper target, using Cu-Kα1 wire, tube voltage 45 kV, tube current 40 mA, measurement range 2θ = 20 to 100 deg, sampling width 0 X-ray diffraction measurement was performed under the conditions of 0.0167 deg and a scanning speed of 3.3 deg/min.

Obtain the peak height (Hr) corresponding to the rutile crystal, the peak height (Hb) corresponding to the brookite crystal, and the peak height (Ha) corresponding to the anatase crystal, and use the following formula to calculate titanium oxide The content of rutile-type titanium oxide (rutilization rate) in the medium was determined.

Rutilization rate (mol%) = {Hr / (Ha + Hb + Hr)} x 100
In the X-ray diffraction pattern obtained by the above X-ray diffraction measurement, the strongest diffraction peak corresponding to rutile-type titanium oxide was selected and the full width at half maximum was measured.

(Identification of divalent copper compound)
The bivalent copper compound present in the sample (photocatalyst) obtained in Production Example 1 was identified by X-ray diffraction measurement using the above measuring apparatus and measuring conditions. Table 2 shows the results.

[Production of diallyl phthalate resin solution]
MIWON's Miramer M-600 (67.6% by mass) was placed in a metal container and heated to 80° C. while stirring. After reaching 80° C., 32.4% by mass of Daiso DAP-A, which had been pulverized in advance, was gradually added with stirring. After the addition of the resin was completed, the temperature was raised to 110° C. while blowing air, and stirring was continued for 1 hour in this state to completely dissolve the resin.
In Table 1, the decomposed composition is shown in order to clarify the blending amount of the diallyl phthalate resin.

[Production of Active Energy Ray Overprint Varnish]
Various ink compositions were obtained by kneading the inks of Examples 1 to 8 and Comparative Examples 1 and 2 according to the compositions shown in Table 3 using a three-roll mill. A blank in the table means that the product is not blended.

[Antibacterial evaluation method]
0.10 ml of the inks of Examples 1 to 8 and Comparative Examples 1 and 2 produced above were drawn uniformly on the rubber roll and metal roll of the RI tester using a simple color development machine (RI tester, manufactured by Houei Seiko Co., Ltd.), It was coated on a PET raw material (Lumirror film T60 #250 manufactured by Toray) so as to be uniformly coated over an area range of about 220 cm ² . Using a water-cooled UV-LED (central emission wavelength of 385 nm ± 5 nm UV-LED output 100%) and a UV irradiation device (manufactured by Eye Graphics Co., Ltd.) equipped with a belt conveyor, the exhibit is placed on the conveyor. and passed directly under the LED (irradiation distance 9 cm) at a conveyor speed of 100 m/min. Ultraviolet (UV) irradiation was performed on the color development product after applying the photocurable ink obtained by the above method, and the ink film was cured and dried. A bacterial solution was dropped on the coated surface of the cured overprint varnish obtained above, and the number of viable bacteria was measured after 24 hours at 35° C. and 90% humidity.
When the number of bacteria inoculated was 1/1000 or less, it was marked with ◯, when it was 1/100 or less, it was marked with Δ, and otherwise, it was marked with x. Two types of bacteria, Staphylococcus aureus and Escherichia coli, were evaluated.

[Antiviral evaluation method]
Cured products of the active energy ray overprint varnishes described in Examples 1 to 8 and Comparative Examples 1 and 2 were prepared by the method described in the antibacterial evaluation method. After that, the virus solution is dropped onto the coated surface of the hardened overprint varnish, and the number of viruses is measured after 24 hours at 25°C.
When the number of inoculated viruses was 1/1000 or less, it was marked with ◯, when it was 1/100 or less, it was marked with Δ, and other cases were marked with x.
Two types of viruses, influenza A virus and feline calicivirus, were evaluated.

[Method for confirming suitability for offset printing]
In order to control the print film thickness by color density, 95% by mass of the ink having the composition described in Examples 1 to 8 and Comparative Examples 1 and 2 was added in advance with 5% by mass of DC HRL SP-LK2 Indigo S from DIC Graphics. were mixed on a three roll mill and toned with indigo.
Using a Lithrone G40 manufactured by Komori Corporation equipped with a water-cooled metal halide lamp (output 160 W / cm, 3 lamps used) manufactured by Eye Graphics as an ultraviolet irradiation device,
Offset printing was performed at a printing speed of 10,000 sheets per hour. OK Top Coat Plus (57.5 kg, A size) manufactured by Oji Paper Co., Ltd. was used as printing paper.
The dampening water supplied to the printing plate was an aqueous solution obtained by mixing 97.5% by weight of tap water and 2.5% by weight of an etchant (Pressert SU, manufactured by DIC Graphics).
Next, the ink supply key was operated so that the indigo density of the solid area was 0.25 (measured with a SpectroEye densitometer manufactured by X-Rite), and when the density was stabilized, the ink supply key was fixed.
When the coating amount of each ink composition at the above indigo density was measured, it was 1 g/m2.
After printing 3,000 sheets under the above conditions, the degree of deposition of emulsified ink on the non-feeding portion of the compact in the offset printing machine was confirmed according to the following criteria, and suitability for offset printing was evaluated.
◯ No adhesion of emulsified ink was observed on the entire non-feeding portion of the impression cylinder.
Δ Emulsified ink adhered to less than 50% of the area of the non-feeding portion of the impression cylinder.
x Adhesion of emulsified ink was observed on 50% or more of the area of the non-feeding portion of the impression cylinder.

[Curability evaluation method]
For the curability, using the 3000th printed material subjected to offset printing by the above method, the solid portion surface in the printed material was evaluated for the degree of scratching by the nail scratch method as follows.
◯: No flaws caused by fingernail scratches, and the curability is the best.
Δ: Fingernail scratches are observed, but at a usable level.
x: Scratches are easily generated by fingernail scratches, and curability is the worst.

Measurement Method of [60° Gloss] Gloss was evaluated according to the following criteria using GM-268plus manufactured by Konica Minolta, using the 3000th print obtained by offset printing by the above method.
○: 30 or more △: 25 or more and less than 30 ×: less than 25

Tables 3 and 4 show the compositions and evaluation results of the active energy ray-curable overprint varnishes of the present invention. In addition, a blank represents unblending. Details of the raw materials shown in Tables 3 and 4 are shown in Table 5.

From the above results, it is clear that the active energy ray-curable overprint varnishes of Examples are excellent in antibacterial and antiviral activities.

Claims (7)

An active energy ray-curable overprint varnish containing an active energy ray-curable compound as a main component,
The active energy ray-curable overprint varnish contains a photocatalyst, the photocatalyst contains titanium oxide containing crystalline rutile-type titanium oxide and a divalent copper compound, and the crystalline rutile-type titanium oxide contains Cu- In the X-ray diffraction pattern obtained by plotting the diffraction line intensity with respect to the diffraction angle 2θ by Kα rays, titanium oxide in which the full width at half maximum of the strongest diffraction peak corresponding to rutile-type titanium oxide is 0.65 degrees or less, and in the titanium oxide A photocatalyst in which the content of the crystalline rutile-type titanium oxide is 50 mol% or more and the content of the anatase-type titanium oxide is less than 50 mol%, and the photocatalyst is 0.05 to 15 masses with respect to the total solid content of the varnish. % of active energy ray-curable overprint varnish. It contains a polyester (meth)acrylate having a glass transition temperature of 250°C or higher and a diallyl phthalate resin having a glass transition temperature of 140 to 160°C, wherein the polyester acrylate having a glass transition temperature of 250°C or higher and the diallyl having a glass transition temperature of 140 to 160°C 2. The active energy ray-curable overprint varnish according to claim 1, wherein the total weight of the phthalate resin and the active energy ray-curable overprint varnish is 10 to 70% by weight based on the total weight of the active energy ray-curable overprint varnish. 3. The active energy ray-curable overprint varnish according to claim 1, which contains an alkylphenone-based photopolymerization initiator as a photopolymerization initiator. A printed matter comprising a substrate and a coating film of the active energy ray-curable overprint varnish according to any one of Claims 1 to 3 disposed on the substrate. A paper substrate or a plastic substrate obtained by coating a paper substrate or a film with the active energy ray-curable overprint varnish according to any one of claims 1 to 3. 6. The paper or plastic substrate according to claim 5, wherein said paper or plastic substrate further comprises a printing ink layer. A container or packaging material using the paper base material or plastic base material according to claim 5 or 6.