JP2024008083A - Coating agent for paper substrates or plastic substrates, and paper substrate, plastic substrate, container, and packaging material each including coating layer of coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating agent for paper substrates or plastic substrates that utilizes a silver-containing inorganic compound, striking a balance between antibacterial, antifungal, or antiviral properties and rub resistance.

SOLUTION: The present invention provides a coating agent for paper substrates or plastic substrates that includes a binder resin (A), a silver-containing inorganic compound (B), a polyethylene wax (C), and an aqueous medium (D). The present invention also provides a paper substrate or a plastic substrate wherein the paper substrate or the film is coated with the coating agent, as well as a packaging material made using the same.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a coating agent for paper or plastic substrates that can be used as gravure ink or flexo ink for flexible packaging.

In recent years, there has been a demand for functionality to be imparted to the surfaces of various substrates, and it is necessary to improve the surface properties of plastic materials, molded products, paper substrates, film substrates, packaging materials, and the like. As a method of imparting these functions to the surface of a base material, a method of attaching a polymer film or the like having various functions to the surface is widely known. However, this method requires time and effort to apply the film, often has insufficient adhesion to the substrate and processability, and is also expensive. On the other hand, as a method of imparting functionality to the surface of these base materials, a method of expressing these functions by coating is also known. The coating method is highly convenient because it can be applied not only to the base material before molding or processing, but also to only desired parts of the base material after molding or processing.
Film base materials such as polyester film, nylon film, and polyolefin film, which are often used for food packaging and daily life coating consumer goods, have properties such as water repellency, oil repellency, stain resistance, antistatic, antireflection, and scratch prevention. In addition to physical functionality, hygienic functions such as antibacterial, antifungal, antiviral, and deodorizing properties are also desired recently.

Inorganic compounds in which silver compounds are supported on zeolite particles, silica gel particles, alumina particles, phosphate particles, etc. as carriers are known as compounds having antibacterial, antifungal, and deodorizing functions. When such an inorganic compound is used in a film, it is generally kneaded and extruded. However, with this method, it is difficult to efficiently cause the inorganic compound to exist on the film surface. As a result, the inorganic compounds present inside the film have no effect on functionality, and are a cause of overall cost increase. Although there is a method to solve this problem by laminating films, in reality, the process becomes complicated and it is difficult to expect a significant cost reduction (for example, see Patent Document 1).
Therefore, a method of printing and applying a coating agent in which an inorganic compound is dispersed in a binder resin is also known (see, for example, Patent Documents 2 and 3).

Patent No. 2809674 JP2009-203600A JP 2017-040013 Publication

The method of expressing the function of an inorganic compound having antibacterial properties etc. by coating as in Patent Documents 2 and 3 is simple and convenient. However, some inorganic compounds have a particle size of about 2 to 3 μm, and because they are relatively large, they are susceptible to contact such as rubbing, rubbing, rubbing, and friction, and the abrasion resistance of printed materials is said to be significantly reduced. There's a problem. Therefore, it has been difficult to achieve both antibacterial, antifungal, antiviral properties and abrasion resistance.
Therefore, an object of the present invention is to provide a coating agent for paper or plastic substrates that uses a silver-containing inorganic compound and is capable of achieving both antibacterial, antifungal, or antiviral properties and abrasion resistance. It is in.

The present invention provides a coating agent for paper or plastic substrates containing a binder resin (A), a silver-containing inorganic compound (B), a polyethylene wax (C), and water.

The present invention also relates to a paper base material or a plastic base material in which a paper base material or a film is coated with the above-mentioned coating agent.

The present invention also relates to containers and packaging materials using paper or plastic base materials.

According to the present invention, it is possible to provide a coating agent that can exhibit the antibacterial, antifungal, and antiviral properties of a silver-containing inorganic compound and has excellent abrasion resistance. .

(definition of word)
In the present invention, all "parts" refer to "parts by mass,""total amount of coating agent" refers to the total amount of ink containing all volatile components such as organic solvents, and "total amount of coating agent solids" refers to , indicates the total amount of solid content only, excluding volatile components such as solvents.

(Binder resin (A))
The binder resin (A) used in the coating agent for paper base materials or plastic base materials of the present invention is not particularly limited, and examples thereof include urethane resins, polyvinyl alcohols, polyvinylpyrrolidones, which are used in general water-based liquid printing inks, Acrylic copolymers such as polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer; styrene- Acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid- Styrene-acrylic acid resins such as acrylic acid alkyl ester copolymers; styrene-maleic acid; styrene-maleic anhydride; vinylnaphthalene-acrylic acid copolymers; vinylnaphthalene-maleic acid copolymers; vinyl acetate-ethylene copolymers Vinyl acetate-based copolymers such as vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleate ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer, and these Salt can be used. These can also be used in combination as appropriate depending on desired physical properties.

Among these, it is preferable to use at least one of acrylic resin and urethane resin as the binder resin because it is easily available.

(acrylic resin)
The acrylic resin is not particularly limited, and includes homopolymerization or copolymerization of (meth)acrylate, and copolymerization of (meth)acrylate and a copolymerizable vinyl monomer. Further, for the purpose of imparting water dispersibility and water solubility, a copolymer having an acid value is preferable.
In the present invention, "(meth)acrylate" refers to either or both of acrylate and methacrylate, and "(meth)acrylic" refers to either or both of acrylic and methacrylic.

Examples of (meth)acrylate and vinyl monomers copolymerizable with (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, t - Alkyl (meth)acrylates such as butyl (meth)acrylate, isopropyl (meth)acrylate, and isobutyl (meth)acrylate; Aromatic (meth)acrylates such as benzyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate , 2-hydroxypropyl (meth)acrylate; alkyl polyalkylene glycol mono(meth)acrylates such as methoxypolyethylene glycol mono(meth)acrylate, methoxypolypropylene glycol mono(meth)acrylate; perfluoroalkylethyl (meth)acrylate; ) Fluorinated (meth)acrylates such as acrylates; styrene, styrene derivatives (p-dimethylsilylstyrene, (p-vinylphenyl)methylsulfide, p-hexynylstyrene, p-methoxystyrene, p-tert-butyldimethylsiloxystyrene) , o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, α-methylstyrene, etc.), aromatic vinyl compounds such as vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene; glycidyl (meth)acrylate, Epoxy (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylene glycol tetra(meth)acrylate, 2-hydroxy-1,3-diacryloxy Propane, 2,2-bis[4-(acryloxymethoxy)phenyl]propane, 2,2-bis[4-(acryloxyethoxy)phenyl]propane, dicyclopentenyl (meth)acrylate tricyclodecanyl (meth) (Meth)acrylate compounds such as acrylate, tris (acryloxyethyl) isocyanurate, urethane (meth)acrylate; alkylaminos such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, etc. (meth)acrylates having groups; vinylpyridine compounds such as 2-vinylpyridine, 4-vinylpyridine, and naphthylvinylpyridine; 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1 , 3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-cyclohexadiene, and other conjugated dienes. These monomers can be used alone or in combination of two or more.

In addition, for the purpose of introducing one or more acidic groups selected from the group consisting of a carboxyl group and a carboxylate group in which the carboxyl group is neutralized with a basic compound, (meth)acrylic acid, crotonic acid, itaconic acid By copolymerizing (meth)acrylic monomers having a carboxyl group such as , maleic acid, fumaric acid, β-(meth)acryloyloxyethyl hydrogen succinate, β-(meth)acryloyloxyethylhydrogen phthalate, the acid value can be lowered. It is possible to obtain a copolymer with
When introducing an acidic group, it is preferable to appropriately adjust the amount of monomer so that the acid value falls within a desired range, as will be described in detail later.

The copolymer can be produced, for example, by polymerizing various monomers in the presence of a polymerization initiator in a temperature range of 50°C to 180°C, more preferably in a temperature range of 80°C to 150°C. Examples of polymerization methods include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. Moreover, examples of the polymerization mode include random copolymers, block copolymers, graft copolymers, and the like.

The copolymers used in the invention may be of core-shell type. In the present invention, the core-shell type resin refers to a state in which the polymer (a2) is dispersed in an aqueous medium by the polymer (a1), and usually, the presence of the polymer (a1) at the outermost part of the resin particles creates a shell. In many cases, a part or all of the polymer (a2) forms a core part. Hereinafter, in the present invention, the resin forming the shell portion will be referred to as a polymer (a1), and the resin forming the core portion will be referred to as a polymer (a2).

[Polymer (a1) constituting the shell part]
The core-shell type resin used in the present invention has one or more hydrophilic groups selected from the group consisting of a carboxyl group and a carboxylate group formed by neutralizing the carboxyl group in the polymer (a1) constituting the shell part. It is preferable that the material is made of an acrylic resin having the following properties. In this case, the acid value of the shell portion is preferably in the range of 40 mgKOH/g or more and 250 mgKOH/g or less, more preferably 120 mgKOH/g or less.

The carboxyl group of the polymer (a1) constituting the shell portion is preferably neutralized with a basic compound to form a carboxylate group.

As the basic compound that can be used for neutralization, for example, ammonia, triethylamine, morpholine, monoethanolamine, diethylethanolamine, etc. can be used, and it is preferable to use ammonia and triethylamine to improve the hot water resistance of the coating film. This is preferable for further improving properties, corrosion resistance, and chemical resistance.

The amount of the basic compound to be used is determined based on the total amount of carboxyl groups that the polymer (a1) has in order to further improve the water dispersion stability of the resulting core-shell resin [basic compound/carboxyl group] It is preferable to use it within the range of =0.2 to 2 (molar ratio).

Among the monomers having a polymerizable unsaturated double bond, those obtained by polymerizing (meth)acrylic monomers including (meth)acrylic monomers having a carboxyl group are preferably used. In particular, as the polymer (a1), methyl (meth)acrylate, butyl (meth)acrylate, It is more preferable to use a product obtained by polymerizing a combination of (meth)acrylic acid and the like in order to form a coating film that has excellent film-forming properties and is also excellent in hot water resistance, corrosion resistance, and chemical resistance.

[Polymer (a2) constituting the core part]
As the polymer (a2) constituting the core portion, a copolymer such as an acrylic monomer similar to the above-mentioned acrylic resin can be used.
At this time, the weight average molecular weight of the core portion is preferably in the range of 200,000 to 3,000,000, more preferably 800,000 or more. The Tg is preferably in the range of -30°C to 30°C.

As the polymer (a2) constituting the core portion, a copolymer such as an acrylic monomer similar to the acrylic resin described above can be used, but it is particularly preferable to produce it in an aqueous medium. Specifically, it can be produced by supplying the monomer, polymerization initiator, etc. to a reaction vessel containing an aqueous medium all at once or sequentially and polymerizing the monomers and polymerization initiators. At that time, a pre-emulsion is produced by mixing the monomer, an aqueous medium, and a reactive surfactant, etc. as necessary, and the pre-emulsion and a polymerization initiator, etc. are supplied to a reaction vessel containing the aqueous medium. May be polymerized.

Examples of polymerization initiators that can be used in producing the polymer (a2) include radical polymerization initiators such as persulfates, organic peroxides, and hydrogen peroxide, and 4,4'-azobis(4- Azo initiators such as cyanovaleric acid), 2,2'-azobis(2-amidinopropane) dihydrochloride, etc. can be used. Further, the radical polymerization initiator may be used as a redox polymerization initiator in combination with a reducing agent described below.

As the persulfate, for example, potassium persulfate, sodium persulfate, ammonium persulfate, etc. can be used. Examples of the organic peroxides include benzoyl peroxide, lauroyl peroxide, decanoyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, t-butyl peroxylaurate, and t-butyl peroxybenzoate. , cumene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide, etc. can be used.

In addition, examples of the reducing agent include ascorbic acid and its salts, erythorbic acid and its salts (such as sodium salts), tartaric acid and its salts, citric acid and its salts, metal salts of formaldehyde sulfoxylate, sodium thiosulfate, Sodium bisulfite, ferric chloride, etc. can be used.

The amount of polymerization initiator used may be such that the polymerization proceeds smoothly, but from the viewpoint of maintaining the excellent corrosion resistance of the resulting coating film, a smaller amount is preferable. The amount is preferably 0.01% by mass to 0.5% by mass based on the total amount of monomers used. Furthermore, when the polymerization initiator is used in combination with the reducing agent, it is preferable that the total amount used is also within the above range.

In addition, when producing the pre-emulsion, reactive surfactants, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. are used. Good too.

The acid value of the copolymer is preferably 20 mgKOH/g or more and 120 mgKOH/g or less, more preferably 25 mgKOH or more. If the acid value is 20 mgKOH/g or more, the abrasion resistance, water abrasion resistance, and scratch resistance of the laminate can be improved when the curing agent is added.

Note that the acid value herein refers to the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of resin.

The weight average molecular weight of the copolymer is preferably in the range of 5,000 to 100,000. When the weight average molecular weight is 5,000 or more, the heat resistance of the resin film does not deteriorate, and the laminate tends to maintain its abrasion resistance and water abrasion resistance. If it is 100,000 or less, the laminate tends to have both good adhesion to the base material and scratch resistance.

The glass transition temperature (Tg) of the copolymer is preferably in the range of 0°C to 55°C. If the Tg of the copolymer is 0°C or higher, the film strength is maintained and the water abrasion resistance of the laminate does not decrease, and if it is 55°C or lower, the compatibility with other printed layers will decrease. Therefore, the laminate tends to maintain good abrasion resistance, water abrasion resistance, and scratch resistance.

Note that the glass transition temperature (Tg1) refers to a so-called calculated glass transition temperature, and refers to a value calculated by the following method.
(Formula 1) 1/Tg(K)=(W1/T1)+(W2/T2)+...(Wn/Tn)
(Formula 2) Tg (°C) = Tg (K) - 273
In formula 1, W1, W2, ... Wn represent the mass % of each monomer with respect to the total mass of monomers used for the production of the polymer, and T1, T2, ... Tn represent the mass % of each monomer with respect to the total mass of monomers used for producing the polymer, and T1, T2, ... Tn represent the mass % of each monomer with respect to the total mass of monomers used for producing the polymer Represents glass transition temperature (K). Note that the values of T1, T2, . . . Tn are those described in Polymer Handbook (Fourth Edition, edited by J. Brandrup, E. H. Immergut, and E. A. Grulke).
In addition, although the glass transition temperature of the homopolymer of each monomer is not listed in the Polymer Hand Book, the glass transition temperature was determined in accordance with JIS K7121 using a differential scanning calorimeter "DSC Q-100" (manufactured by TA Instrument). It was measured using the same method. Specifically, we measured the change in calorific value of a polymer whose solvent had been completely removed by vacuum suction in the range of -100°C to +200°C at a heating rate of 20°C/min, and calculated the straight line as an extension of each baseline. The point where a straight line equidistant in the vertical axis direction intersects with the curve of the step-like change portion of the glass transition was defined as the glass transition temperature.

(Urethane resin)
The urethane resin has, for example, a polyol such as a polyether polyol, a polyester polyol, or a polycarbonate polyol, and a hydrophilic group such as an anionic group, a cationic group, a polyoxyethylene group, or a polyoxyethylene-polyoxypropylene group. Examples include urethane resins obtained by reacting polyols with polyisocyanates. Further, the weight average molecular weight of the urethane resin is not particularly limited, but generally it may be from 5,000 to 200,000, and preferably from 20,000 to 150,000.

Examples of the polyether polyol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, Glycerin, trimethylolethane, trimethylolpropane, sorbitol, sucrose, aconite sugar, femimellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydroxybenzoic acid, hydroxyphthalic acid, 1,2,3-propane Addition polymerization of a cyclic ether compound such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclophexylene, etc. to a compound having two or more active hydrogen groups such as trithiol, or the above-mentioned cyclic ether compound Examples include those obtained by ring-opening polymerization using a cationic catalyst, a protonic acid, a Lewis acid, etc. as a catalyst.

The polyester polyol is obtained by dehydration condensation reaction of diol compounds, dicarboxylic acids, hydroxycarboxylic acid compounds, etc., ring-opening polymerization reaction of cyclic ester compounds such as ε-caprolactone, and copolymerization of polyesters obtained by these reactions. It will be done. Examples of diol compounds that can be used as raw materials for this polyester polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5-pentanediol. Diol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1 , 4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone, and alkylene oxide adducts thereof.

In addition, examples of the dicarboxylic acid that is a raw material for the polyester polyol include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4 -Cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis Examples include (phenoxy)ethane-p,p'-dicarboxylic acid.

Examples of the hydroxycarboxylic acid serving as a raw material for the polyester polyol include p-hydroxybenzoic acid and p-(2-hydroxyethoxy)benzoic acid.

As the polycarbonate polyol, for example, one obtained by reacting a carbonate ester with a low molecular weight polyol, preferably a linear aliphatic diol can be used.

As the carbonate ester, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate, etc. can be used.

Examples of low molecular weight polyols that can react with the carbonate ester include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1 , 3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1, 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4 - Relatively low molecular weight dihydroxy compounds such as cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol-A, bisphenol-F, and 4,4'-biphenol, and polyether polyols such as polyethylene glycol, polypropylene glycol, and polyoxytetramethylene glycol. and polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate, and polycaprolactone.

The polycarbonate structure is preferably used in a range of 10% by mass to 90% by mass based on the total mass of the polyol and the polyisocyanate used for producing the polycarbonate-based urethane resin.

Further, the urethane resin has a hydrophilic group to provide dispersion stability in the coating agent. As the hydrophilic group, what is generally called an anionic group, a cationic group, or a nonionic group can be used, and among them, it is preferable to use an anionic group or a cationic group.

As the anionic group, for example, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, etc. can be used, and among them, a carboxylate group partially or completely neutralized with a basic compound, etc. The use of sulfonate groups is preferred in order to maintain good water dispersibility.

Examples of basic compounds that can be used to neutralize the carboxyl group or sulfonic acid group as the anionic group include organic amines such as ammonia, triethylamine, pyridine, and morpholine, alkanolamines such as monoethanolamine, Na, Examples include metal base compounds containing K, Li, Ca, and the like.

Further, as the cationic group, for example, a tertiary amino group or the like can be used. As the acid that can be used to neutralize some or all of the tertiary amino groups, for example, formic acid, acetic acid, etc. can be used. Moreover, as a quaternizing agent that can be used when quaternizing some or all of the tertiary amino groups, for example, dialkyl sulfates such as dimethyl sulfate and diethyl sulfate can be used.

In addition, examples of the nonionic group include polyoxyalkylene groups such as a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly(oxyethylene-oxypropylene) group, and a polyoxyethylene-polyoxypropylene group. can be used. Among them, it is preferable to use a polyoxyalkylene group having an oxyethylene unit in order to further improve hydrophilicity.

The hydrophilic group is preferably present in an amount of 0.5% to 30% by mass based on the entire urethane resin to provide even better water dispersibility, and is preferably in a range of 1% to 20% by mass. More preferred.

Further, crosslinking agents described below can be used depending on desired physical properties. When using the crosslinking agent, it is preferable to use a urethane resin having a functional group capable of crosslinking with the functional group of the crosslinking agent.

Examples of the functional group include a carboxyl group and a carboxylate group that can be used as the hydrophilic group. The carboxyl groups and the like contribute to the water dispersion stability of the urethane resin in an aqueous medium, and when they undergo a crosslinking reaction, they also act as the functional groups and can partially crosslink the crosslinking agent.

When a carboxyl group or the like is used as the functional group, it is preferable that the urethane resin has an acid value of 2 to 55, and it is preferable to use a resin that has an acid value of 15 to 50 because of its fastness. It is preferable to improve the The acid value in the present invention is a theoretical value calculated based on the amount of the acid group-containing compound such as the carboxyl group-containing polyol used in the production of the urethane resin.

The urethane resin can be produced, for example, by reacting a polyol, a polyisocyanate, and, if necessary, a chain extender.

As the chain extender, polyamines and other active hydrogen atom-containing compounds can be used.
Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'- Diamines such as dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid Dihydrazide, isophthalic acid dihydrazide; β-semicarbazide propionic acid hydrazide, 3-semicarbazide-propyl-carbazate, semicarbazide-3-semicarbazidomethyl-3,5,5-trimethylcyclohexane can be used, ethylenediamine It is preferable to use

Examples of the other active hydrogen-containing compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, neo Glycols such as pentyl glycol, sucrose, methylene glycol, glycerin, sorbitol; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, hydroquinone For example, the chain extender can be obtained by reacting the polyol and polyisocyanate such that the equivalent of the amino group and active hydrogen atom-containing group of the chain extender is It is preferable to use it in a range of 1.9 or less (equivalent ratio) with respect to the equivalent weight of isocyanate groups possessed by the urethane prepolymer obtained, and it should be used in a range of 0.0 to 1.0 (equivalent ratio). is more preferable, more preferably 0.5% by mass. The chain extender can be used when the polyol and polyisocyanate are reacted or after the reaction. Moreover, when dispersing the urethane resin obtained above in an aqueous medium to make it water-based, the chain extender can also be used.

In addition, examples of polyols other than those mentioned above include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1 , 6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol , bisphenol A, hydrogenated bisphenol A, hydroquinone and their alkylene oxide adducts, glycerin, trimethylolethane, trimethylolpropane, sorbitol, pentaerythritol, and other relatively low molecular weight polyols. These polyols can be used alone or in combination of two or more.

Examples of the polyisocyanate that reacts with the polyol to form a urethane resin include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, and dicyclohexylmethane. Aliphatic or aliphatic cyclic structure-containing diisocyanates such as diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate can be used alone or in combination of two or more.

The binder resin preferably accounts for 5 to 50% by mass in terms of solid content of the coating agent of the present invention. When the content is 5% by mass or more, the strength of the coating film does not decrease, and good adhesion to the substrate, water friction resistance, etc. are maintained. On the other hand, if the content is 50% by mass or less, deterioration of antiviral properties and antibacterial properties can be suppressed, high viscosity can be avoided, and workability does not decrease. Among these, it is more preferably 5 to 40% by mass, and most preferably 5 to 20% by mass.

(Silver-containing inorganic compound (B))
The silver-containing inorganic compound (B) used in the present invention has excellent antibacterial, antifungal, and antiviral properties. Preferred examples include a silver-supported antibacterial agent in which a silver compound is supported on carrier particles, and silver carbonate. Among them, silver-supported zeolite is preferred. Examples of such silver-containing inorganic compounds (B) include "Zeomic" (manufactured by Sinanen Zeomic Co., Ltd.), "Bactekiller" (manufactured by Fuji Chemical Co., Ltd.), "Novaron" (manufactured by Toagosei Co., Ltd.), etc. . One type of silver-containing inorganic compound (B) may be used alone, or two or more types may be used in combination.

The content of the silver-containing inorganic compound (B) in the coating agent of the present invention is not particularly limited, but if it is too small, it becomes difficult to exhibit antibacterial or antifungal properties. On the other hand, if the amount is too high, the viscosity of the coating agent will increase, and the antibacterial agent or antifungal agent will tend to form lumps in the coating agent, making it difficult to apply the coating agent uniformly to the film surface, and making it difficult to coat the coating layer. The abrasion resistance and gloss of the product decrease. Therefore, the content of the silver-containing inorganic compound (B) is preferably in the range of 1.0% by mass to 20.0% by mass, and even if it is 3.0% by mass to 15.0% by mass, based on the solid content of the coating agent. It is more preferable that the amount is 5.0% by mass to 10.0% by mass. If it is desired to enhance the antiviral effect, it is preferable to contain the coating agent in an amount of 5.0% by mass or more based on the solid content of the coating agent.

The average particle size of the silver-containing inorganic compound (B) is not particularly limited, but the average particle size measured according to JIS H 7804 method using a scanning electron microscope is preferably 0.5 μm or more and 4 μm or less, More preferably, it is 1 μm or more and 3 μm. If the average particle size of the silver-containing inorganic compound (B) is too small, the silver-containing inorganic compound (B) may not appear on the surface of the cured film of the coating agent, and sufficient antibacterial and antifungal properties may not be obtained. This is not desirable because of the If the average particle size of the silver-containing inorganic compound (B) is too large, coating with a gravure plate or a flexo plate tends to become difficult. Furthermore, if the average particle size of the silver-containing inorganic compound (B) is too large, the silver-containing inorganic compound (B) tends to settle in the coating agent, and the abrasion resistance and gloss tend to be poor.

(Polyethylene wax (C))
The coating agent of the present invention contains polyethylene wax. The polyethylene wax is preferably finely granular and water-dispersible, and commercially available waxes can be used as appropriate. The polyethylene waxes may be used alone or in combination of two or more. Examples of such waxes include Chemipearl W-400 (manufactured by Mitsui Chemicals, Inc.) and PA-60 (manufactured by Polycon Corporation).
The content of polyethylene wax (C) in the coating agent is not particularly limited, but if it is too small, the slipperiness of the coating layer will deteriorate and the friction resistance will decrease. On the other hand, if it is too large, the gloss of the coating layer will decrease. Therefore, the content of polyethylene wax (C) is preferably in the range of 3.0% to 20.0% by mass, and more preferably 5.0% to 15.0% by mass based on the solid content of the coating agent. It is preferably 6.0% by mass to 10.0% by mass.
Further, the mass ratio of the polyethylene wax (C) and the silver-containing inorganic compound (B) is preferably an antibacterial agent and/or antifungal agent (B): polyethylene wax (C) = 10:90 to 90:10. The ratio is preferably 30:70 to 70:30, even more preferably 40:60 to 60:40.

By using the above-mentioned silver-containing inorganic compound (B) and the above-mentioned polyethylene wax (C) together, the silver-containing inorganic compound (B) in the coating agent can be resistant to bacteria without impairing its antibacterial, antifungal, and antiviral properties. It is estimated that it becomes possible to achieve both frictional properties. In order to improve the abrasion resistance, it is preferable that the particle size of the silver-containing inorganic compound (B) and the particle size of the polyethylene wax (C) be closer to each other. The average particle size of the polyethylene wax (C) is not particularly limited, but it is preferably 0.5 μm or more and 5 μm or less, more preferably an average particle size measured according to JIS H 7804 method using a scanning electron microscope. It is 1 μm to 5 μm, more preferably 2 μm or more to 4 μm.

(Other waxes)
In the present invention, waxes other than polyethylene wax (C) may be added depending on desired physical properties. Other waxes are preferably carbon waxes, such as liquid paraffin, natural paraffin, synthetic paraffin, microcrystalline wax, fluorocarbon wax, ethylene-propylene copolymer wax, tetrafluoroethylene resin wax, and Fischer-Tropsch wax. Examples include wax. These waxes may be used alone or in combination of two or more. The total amount of waxes other than polyethylene wax (C) added is preferably 0.5 to 5% by mass of the total amount of the coating agent. If the total amount of other waxes added is 0.5% by mass or more based on the total amount of the ink, abrasion resistance, water resistance, abrasion resistance, and scratch resistance can be maintained, and the silver-containing inorganic compound (B ) can improve the dispersibility of When the total amount of wax added is 5% by mass or less of the total amount of the coating agent, adhesion to the substrate, abrasion resistance, water resistance, abrasion resistance, and scratch resistance can be maintained.

(Aqueous medium (D))
The aqueous medium (D) used in the coating agent of the present invention is an aqueous medium containing water as a main component, and may contain an organic solvent. In the present invention, water alone or a mixture of water and an organic solvent may be used, but from the viewpoint of reducing environmental impact and improving safety, it is preferable that the amount of organic solvent used is as small as possible. .
When an organic solvent is contained, it is preferably contained in an amount of 30% by mass or less, more preferably 5% by mass or less, based on the total amount of the coating agent.

There are no particular limitations on the organic solvent that can be used, but for example, organic solvents that are miscible with water are preferred, such as 1-butanol, isobutanol, 1-pentanol, 2-methyl-2-pentanol, 3-methyl-3 -Pentanol, methyl ethyl ketone,
Monofunctional alcohols such as methanol, ethanol, n-propyl alcohol (hereinafter also referred to as NPA), isopropyl alcohol (hereinafter also referred to as IPA), various diols, polyhydric alcohols such as glycerin,
Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane Diol, 1,12-dodecanediol, propylene glycol, 1,2-butanediol, 3-methyl-1,3-butanediol, 1,2-pentanediol, 2-methyl-1,3-propanediol, 1,2-hexanediol, Diols such as dipropylene glycol and diethylene glycol,

Bisphenol A, aromatic diols that are adducts of bisphenol A with alkylene oxides having 2 or 3 carbon atoms (average number of added moles of 1 to 16), alicyclic diols such as hydrogenated bisphenol A, polyoxypropylene-2,2- Bis(4-hydroxyphenyl)propane, polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane, cyclohexanediol, ethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl 3333 ether, ethylene glycol mono Isobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl Examples include ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, ethyl carbitol, γ-butyrolactone, and the like. These may be used alone or in combination, without any limitation.
Among them, 1-butanol, isobutanol, 1-pentanol, 2-methyl-2-pentanol, 3-methyl-3-pentanol, methyl ethyl ketone, methanol, ethanol, n-propyl alcohol (hereinafter also referred to as NPA). , isopropyl alcohol (hereinafter also referred to as IPA), propylene glycol, propylene glycol monomethyl ether (1-methoxy 2-propanol) (also referred to as PGM), and ethylene glycol are preferred.

(surfactant)
In the present invention, a surfactant may also be added depending on desired physical properties. The surfactant is not particularly limited and any surfactant commonly used in this technical field can be used, but acetylene surfactants and alcohol alkoxylate surfactants are particularly preferred.

Specifically, the acetylene surfactants include 2,5-dimethyl-3-hexyne-2,5-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9 -tetramethyl-5-decyne-4,7-diol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyne-3- Examples include ol, 3-hexyne-2,5-diol, 2-butyne-1,4-diol, and the like. Commercially available products include alkylene oxide non-modified acetylene glycol surfactants such as Surfynol 61, 82, and 104 (all manufactured by Air Products);

Surfynol 420, 440, 465, 485, TG, 2502, Dynor 604, 607, Surfynol SE, MD-20, Olfin E1004, E1010, PD-004, EXP4300, PD-501, PD-502, SPC (all , manufactured by Nissin Chemical Industry Co., Ltd.), acetylenol EH, E40, E60, E81, E100, E200 (all manufactured by Kawaken Fine Chemical Co., Ltd.), and alkylene oxide-modified acetylene glycol surfactants. . Among these, alkylene oxide-modified acetylene glycol surfactants are preferred.

In addition, specifically as alcohol alkoxylate surfactants,
One example is DYNWET800 (manufactured by BIC Chemie Japan).
These acetylene surfactants and alcohol alkoxylate surfactants may be used alone or in combination of two or more.

It is preferable that the total amount of these acetylene surfactants and/or alcohol alkoxylate surfactants added is 0.1 to 1% by mass of the total amount of the coating agent. These acetylene surfactants may be used alone or in combination of two or more, and the total amount of the acetylene surfactant and/or alcohol alkoxylate surfactant added is When the amount is 0.1% by mass or more based on the total amount of the coating agent, the coating property with the substrate is improved and the adhesion with the substrate can be maintained. If the total amount of acetylene surfactant and/or alcohol alkoxylate surfactant added is 1% by mass or less of the total amount of the coating agent, abrasion resistance, water resistance, abrasion resistance, and scratch resistance may decrease. Nor.

Furthermore, if necessary, other acrylic polymer surfactants (for example, Polyflow WS-314 manufactured by Kyoeisha Kagaku Co., Ltd.) or modified silicone surfactants (for example, Polyflow KL-401 manufactured by Kyoeisha Kagaku Co., Ltd.) may be used. You may.
For the reasons mentioned above, the total amount of surfactants used is preferably 0.1 to 1% by mass of the total amount of the coating agent.

(hardening agent)
In the present invention, a curing agent can also be added depending on desired physical properties. The curing agent is not particularly limited, and any known curing agent that can react with an acid group that can be used in an aqueous medium can be used. Examples include epoxy hardeners, carbodiimide hardeners, oxazoline hardeners, and the like.

The epoxy curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of the epoxy curing agent include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether.

The carbodiimide curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N=C=N-). As the carbodiimide curing agent, a polycarbodiimide compound having at least two carbodiimide groups is preferred.
The oxazoline curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the oxazoline curing agent include the Epocross series manufactured by Nippon Shokubai Co., Ltd.

The epoxy compounds include bisphenol A diglycidyl ether and its oligomer, hydrogenated bisphenol A diglycidyl ether and its oligomer, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid. Diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacate acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether , 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, Examples include diglycidylpropylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, and triglycidyl ether of glycerol alkylene oxide adducts.

The amount of the curing agent used in the present invention is preferably 0.1 to 10.0% by mass, more preferably 0.5 to 9.0% by mass in terms of solid content of the total amount of the coating agent.
If the amount added is 0.1% by mass or more, the effect as a curing agent can be obtained, while if it is 10.0% by mass or less, the adhesion to the substrate, abrasion resistance, and water friction resistance tend to be maintained. Become.

In the present invention, extender pigments, pigment dispersants, leveling agents, antifoaming agents, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, and the like may also be included. Among them, fatty acid amides such as oleic acid amide, stearic acid amide, and erucic acid amide to impart friction resistance and slipperiness, silicone-based and non-silicon-based antifoaming agents to suppress foaming during coating, and Various dispersants and the like are useful for improving the dispersibility of the silver-containing inorganic compound (B).
Moreover, the coating agent of the present invention may contain a coloring agent. Examples of the colorant include dyes, inorganic pigments, and organic pigments used in general inks, paints, and recording materials. Among them, pigments such as inorganic pigments and organic pigments are preferred.

(Production method of coating agent for paper base material or plastic base material)
The coating agent for paper substrates or plastic substrates of the present invention can be obtained by stirring and mixing the binder resin (A), silver-containing inorganic compound (B), etc. in an aqueous medium (C). As a dispersing machine, a bead mill, an Eiger mill, a sand mill, a gamma mill, an attritor, etc., which are commonly used in the production of gravure and flexo printing inks, are used.

The coating agent for paper base materials or plastic base materials of the present invention can be coated on base materials such as plastic materials, paper, molded products, film base materials, packaging materials, etc. by a general coating method. Specifically, , gravure roll coating (gravure coater), flexo roll coating (flexo coater), reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. can be adopted. Among them, from an industrial standpoint, it is preferable to use gravure roll coating (gravure coater) and flexo roll coating (flexo coater).

Furthermore, a coating layer may be provided on the substrate by impregnating the substrate with the overcoating agent of the present invention.

When the coating agent of the present invention is coated using a flexo coater, the viscosity should be 7 to 40 seconds, more preferably 10 to 20 seconds at 25°C using Rigosha Zahn cup #4. be.

On the other hand, when the coating agent of the present invention is coated using a gravure coater, the viscosity may be 14 to 30 seconds at 25°C using Rigosha Zahn Cup #3, more preferably 15 to 20 seconds. Seconds.

The thickness of the coating layer of the present invention can be adjusted as appropriate depending on the use and the material of the base material, but for example, it is preferably in the range of 0.1 μm to 5 μm, preferably in the range of 0.3 μm to 3 μm, and preferably in the range of 0.5 to 2 μm. preferable.

Since the coating agent of the present invention has excellent dispersibility, a coating layer formed using the coating agent tends to have a structure in which a part of the silver-containing inorganic compound (B) is exposed. Therefore, the coating layer in the present invention can exhibit the antiviral function to the maximum extent. Further, in order to improve the abrasion resistance of the coating layer, it is preferable that the coating layer contains (polyethylene) wax (C) and that a portion of the (polyethylene) wax (C) is also exposed from the coating layer.

(Coating agent for paper base material or plastic base material of the present invention)
The substrate used in the present invention is a paper substrate or a plastic substrate.

(Paper base material)
The paper base material is manufactured using a known papermaking machine using natural fibers for papermaking such as wood pulp, but the papermaking conditions are not particularly defined. Examples of natural fibers for papermaking include wood pulps such as softwood pulp and hardwood pulp, non-wood pulps such as Manila hemp pulp, sisal pulp, and flax pulp, and pulps obtained by chemically modifying these pulps. As for the type of pulp, chemical pulp produced by sulfate cooking method, acidic/neutral/alkaline sulfite cooking method, soda salt cooking method, etc., ground pulp, chemical ground pulp, thermomechanical pulp, etc. can be used.
Furthermore, various types of commercially available high-quality paper, coated paper, lined paper, impregnated paper, cardboard, paperboard, etc. can also be used.

(Plastic base material)
The plastic base material may be any base material used for plastic materials, molded products, film base materials, packaging materials, etc., but especially gravure roll coating (gravure coater), flexo roll coating (flexo coater) When using, film base materials commonly used in the gravure/flexo printing field can be used as they are.
Specifically, for example, polyamide resins such as nylon 6, nylon 66, and nylon 46, polyethylene terephthalate (hereinafter sometimes referred to as PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, Biodegradable resins such as polyester resins such as polybutylene naphthalate, polyhydroxycarboxylic acids such as polylactic acid, aliphatic polyester resins such as poly(ethylene succinate) and poly(butylene succinate), polypropylene, polyethylene, etc. Examples include films made of thermoplastic resins such as polyolefin resins, polyimide resins, polyarylate resins, or mixtures thereof, and laminates thereof, among which films made of polyethylene terephthalate (PET), polyester, polyamide, polyethylene, and polypropylene. can be suitably used. These base films may be unstretched films or stretched films, and the manufacturing method thereof is not limited. Further, the thickness of the base film is not particularly limited, but it is usually in the range of 1 to 500 μm. Further, the base film is preferably subjected to a corona discharge treatment, and aluminum, silica, alumina, etc. may be vapor-deposited thereon.

The base material is a laminate having a laminate structure (sometimes referred to as a laminate film) in which the paper base material or film base material is laminated by a dry lamination method, a solvent-free lamination method, or an extrusion lamination method. I don't mind. Further, the structure of the laminate may include a metal foil, a metal vapor deposited film layer, an inorganic vapor deposited film layer, an oxygen absorption layer, an anchor coat layer, a printed layer, a varnish layer, etc. There are many types of such laminates depending on the purpose, but the configuration currently most commonly used for food packaging and daily necessities is expressed as (F) for the paper base material or film base material, and has a printing or varnish layer. is expressed as (P), the metal or inorganic layer of the metal foil or vapor deposited film layer is expressed as (M), the adhesive layer is expressed as (AD), and the hot melt adhesive, heat sealing agent, or cold sealing agent is expressed as (AD2). ), the following configuration can be considered as a specific embodiment of the laminated film, but of course it is not limited to this.

(F)/(P)/(F)
(F)/(P)/(AD)/(F),
(F)/(P)/(AD)/(F)/(AD)/(F),
(F)/(P)/(AD)/(M)/(AD)/(F),
(F)/(P)/(AD)/(M),
(F)/(P)/(AD)/(F)/(AD)/(M)/(AD)/(F),
(F)/(P)/(AD)/(M)/(AD)/(F)/(AD)/(F),
(M)/(P)/(AD)/(M),
(M)/(P)/(AD)/(F)/(AD)/(M),
(P)/(F)
(P)/(F)/(P)
(P)/(F)/(AD)/(F),
(P)/(F)/(AD)/(F)/(AD)/(F)
(F)/(P)/(F)/(AD2)
(F)/(P)/(AD2)
(F)/(P)/(AD)/(M)/(AD2)

The single-layer paper base material, film base material, and laminate having a laminate structure may be used as functional films, flexible packaging films, shrink films, films for packaging daily necessities, films for packaging pharmaceuticals, and food products, depending on the industry and method of use. High quality paper, coated paper, art paper, imitation paper, thin paper, cardboard, etc. used for packaging films, cartons, posters, leaflets, CD jackets, direct mail, pamphlets, cosmetics, beverages, pharmaceuticals, toys, equipment, etc. The coating agent for paper base materials or plastic base materials of the present invention can be used without particular limitation. In this case, the coating agent for paper base material or plastic base material of the present invention is preferably coated on the surface that will be the outermost layer when a container or packaging material using these is made.

As mentioned above, there are many laminates having a laminate structure that have a printed layer on a paper base material or film base material, but the coating for paper base material or plastic base material of the present invention Of course, the agent can also preferably be coated onto the substrate having the printing ink layer.

The printing ink used in the printing ink layer is not particularly limited, and coating on the printing layer such as offset lithographic ink, gravure printing ink, flexographic printing ink, inkjet printing ink, etc. is possible. In particular, when using coating methods such as gravure roll coating (gravure coater) and flexo roll coating (flexo coater), it is possible to perform in-line printing, so combining it with gravure printing ink or flexographic printing ink is recommended for industrial applications. preferred.
Gravure printing ink and flexographic printing ink (hereinafter referred to as liquid printing ink) are formed from a printing ink consisting of a binder resin, a pigment, a solvent, and optionally additives.

(liquid printing ink)
Liquid printing inks used as gravure printing inks and flexographic printing inks are roughly divided into organic solvent-based liquid printing inks that use organic solvents as their main solvent, and water-based liquid printing inks that use water as their main solvent.

(Organic solvent-based liquid printing ink)
Organic solvent-based liquid printing ink is prepared by dispersing a mixture of the modified pigment used in the present invention, a binder resin, an organic solvent medium, a dispersant, an antifoaming agent, etc., which will be described later, using a dispersion machine to obtain a pigment dispersion. . It is obtained by adding a resin, an aqueous medium, and optionally additives such as a leveling agent to the obtained pigment dispersion, and stirring and mixing. As a dispersing machine, a bead mill, an Eiger mill, a sand mill, a gamma mill, an attritor, etc., which are commonly used in the production of gravure and flexo printing inks, are used.

The ink viscosity of organic solvent-based liquid printing ink, whether used as a gravure ink or a flexographic ink, is 10 mPa・s or more in order to prevent pigment sedimentation and ensure proper dispersion. From the viewpoint of work efficiency during ink production and printing, it is preferable that the pressure is in the range of 1000 mPa·s or less. Note that the above viscosity is a viscosity measured at 25° C. using a B-type viscometer manufactured by Tokimec.

The viscosity of the ink can be adjusted by appropriately selecting the types and amounts of raw materials used, binder resins, pigments, organic solvents, and the like. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

(Creation of printed matter)
Organic solvent-based liquid printing ink has excellent adhesion to various base materials and can be used for printing on paper, synthetic paper, thermoplastic resin film, plastic products, steel plates, etc., and can be used for electronic engraving intaglio etc. The ink is useful as an ink for gravure printing using a gravure printing plate, or for flexographic printing using a flexographic printing plate, such as a resin plate.

The film thickness of the printing ink formed by the gravure printing method or the flexographic printing method using the organic solvent type liquid printing ink of the present invention is, for example, 10 μm or less, preferably 5 μm or less.

(binder resin)
Binder resins for organic solvent-based liquid printing inks include polyurethane resins, acrylic resins, vinyl chloride-vinyl acetate copolymer resins, and vinyl chloride, which are used in general liquid printing inks without particular limitations. - Acrylic copolymer resin, chlorinated polypropylene resin, cellulose resin, polyamide resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, styrene resin, Dammar resin, styrene-maleic acid copolymer resin, polyester resin, Alkyd resin, polyvinyl chloride resin, rosin resin, rosin-modified maleic acid resin, terpene resin, phenol-modified terpene resin, ketone resin, cyclized rubber, chloride rubber, butyral, polyacetal resin, petroleum resin, and modified resins of these, etc. can be mentioned. These resins can be used alone or in combination of two or more.

Among the above, polyurethane resin, cellulose resin, polyamide resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, acrylic resin, styrene resin A binder resin containing at least one selected from the group consisting of , styrene-maleic acid copolymer resin, dammar resin, rosin-based resin, rosin-modified maleic acid resin, ketone resin, and cyclized rubber is preferred.
The content of the binder resin is in the range of 1 to 50% by mass, more preferably 2 to 40% by mass in terms of solid content of the aqueous liquid printing ink of the present invention.

(Organic solvent)
The organic solvent for organic solvent type liquid printing ink is not particularly limited, but includes, for example, aromatic hydrocarbon organic solvents such as toluene, xylene, Solvesso #100 and Solvesso #150, hexane, methylcyclohexane, heptane, octane, Examples include aliphatic hydrocarbon organic solvents such as decane, and various ester organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, amyl acetate, ethyl formate, and butyl propionate. In addition, water-miscible organic solvents include alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol, ketones such as acetone, methyl ethyl ketone, and cyclohaxanone, ethylene glycol (mono, di) methyl ether, and ethylene glycol (mono, di) ethyl. Ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) Examples include various glycol ether-based organic solvents such as di)methyl ether, propylene glycol (mono,di)methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono,di)methyl ether. These can be used alone or in combination of two or more.

Organic solvent-based liquid printing inks may also contain wax, chelate crosslinking agents, extender pigments, leveling agents, antifoaming agents, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc. as necessary. You can also do it.

(colorant)
The organic solvent-based liquid printing ink uses the above-mentioned modified pigment as a coloring agent, but in addition to that, organic pigments and/or inorganic pigments used in general inks, paints, recording materials, etc. may be used in combination. .
Examples of organic pigments include soluble azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, anthanthrone, dianthraquinonyl, anthrapyrimidine, perylene, perinone, quinacridone, Examples include thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethineazo-based, flavanthrone-based, diketopyrrolopyrrole-based, isoindoline-based, indanthrone-based, and carbon black-based pigments. Also, for example, Carmine 6B, Lake Red C, Permanent Red 2B, Disazo Yellow, Pyrazolone Orange, Carmine FB, Chromophthal Yellow, Chromophthal Red, Phthalocyanine Blue, Phthalocyanine Green, Dioxazine Violet, Quinacridone Magenta, Quinacridone Red, Indance. Examples include lon blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigments. Furthermore, both non-acid-treated pigments and acid-treated pigments can be used.

Examples of the inorganic pigment include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, lithobon, antimony white, and gypsum. Among the inorganic pigments, use of titanium oxide is particularly preferred. Titanium oxide is white and is preferred from the viewpoint of coloring power, hiding power, chemical resistance, and weather resistance. From the viewpoint of printing performance, the titanium oxide is preferably treated with silica and/or alumina.
Examples of inorganic pigments other than white include aluminum particles, mica (mica), bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine blue, deep blue, red iron oxide, yellow iron oxide, iron black, and zircon. Aluminum is in the form of powder or paste, but it is preferable to use it in paste form from the viewpoint of ease of handling and safety, and whether to use leafing or non-leafing is selected as appropriate from the viewpoint of brightness and density.
The average particle size of the pigment is preferably in the range of 10 to 200 nm, more preferably about 50 to 150 nm.
The pigment is used in an amount sufficient to ensure the concentration and coloring power of the water-based liquid printing ink, that is, 1 to 60% by mass based on the total mass of the ink, and 10 to 90% by mass in terms of solid content mass ratio in the ink. It is preferable that it is contained in a proportion. Further, these pigments can be used alone or in combination of two or more.

(Water-based liquid printing ink)
For the aqueous liquid printing ink, a pigment dispersion is obtained by dispersing a mixture containing the modified pigment used in the present invention, a binder resin, an aqueous medium, a dispersant, an antifoaming agent, etc., which will be described later, using a dispersing machine. It is obtained by adding a resin, an aqueous medium, and optionally additives such as a leveling agent to the obtained pigment dispersion, and stirring and mixing. As a dispersing machine, a bead mill, an Eiger mill, a sand mill, a gamma mill, an attritor, etc., which are commonly used in the production of gravure and flexo printing inks, are used.
When the water-based liquid printing ink is used as a flexographic ink, the viscosity thereof may be 7 to 25 seconds at 25° C. using a Zahn cup #4 manufactured by Rigosha, and more preferably 10 to 20 seconds. Further, the surface tension of the obtained flexographic ink at 25° C. is preferably 25 to 50 mN/m, more preferably 33 to 43 mN/m. The lower the surface tension of the ink, the better the wettability of the ink to a base material such as a film. However, if the surface tension is lower than 25 mN/m, the ink will wet and spread, causing adjacent halftone dots to overlap in midtone halftone dots. There is a tendency for the dots to connect easily, which tends to cause a stain on the printing surface called dot bridge. On the other hand, if the surface tension exceeds 50 mN/m, the wettability of the ink to a base material such as a film decreases, which is likely to cause repellency.

On the other hand, when a water-based liquid printing ink is used as a gravure ink, its viscosity may be 7 to 25 seconds at 25°C using Rigosha's Zahn Cup #3, and more preferably 10 to 20 seconds. . Further, the surface tension of the obtained gravure ink at 25° C. is preferably 25 to 50 mN/m, more preferably 33 to 43 mN/m, similar to the flexo ink. The lower the surface tension of the ink, the better the wettability of the ink to a base material such as a film. However, if the surface tension is lower than 25 mN/m, the ink will wet and spread, causing adjacent halftone dots to overlap in midtone halftone dots. There is a tendency for the dots to connect easily, which tends to cause a stain on the printing surface called dot bridge. On the other hand, if the surface tension exceeds 50 mN/m, the wettability of the ink to a base material such as a film decreases, which is likely to cause repellency.

(Creation of printed matter)
Water-based liquid printing ink has excellent adhesion to various base materials and can be used for printing on paper, synthetic paper, thermoplastic resin film, plastic products, steel plates, etc. It is useful as an ink for gravure printing using a printing plate or flexo printing using a flexographic printing plate such as a resin plate.

The film thickness of the printing ink formed by the gravure printing method or the flexographic printing method using the water-based liquid ink of the present invention is, for example, 10 μm or less, preferably 5 μm or less.

(binder resin)
Binder resins for water-based liquid printing inks are not particularly limited, and include urethane resins, polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymers, and acrylic acid, which are used in general water-based liquid printing inks. Acrylic copolymers such as potassium-acrylonitrile copolymer, acrylic ester polymer emulsion, polyester urethane dispersion, vinyl acetate-acrylic ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer; styrene- Acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid- Styrene-acrylic acid resins such as acrylic acid alkyl ester copolymers; styrene-maleic acid; styrene-maleic anhydride; vinylnaphthalene-acrylic acid copolymers; vinylnaphthalene-maleic acid copolymers; vinyl acetate-ethylene copolymers Vinyl acetate-based copolymers such as vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleate ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer, and these Salt can be used. These binder resins can be used alone or in combination of two or more.

Among these, it is preferable to use an acrylic resin or a urethane resin as the binder resin because they are easily available, and acrylic ester polymer emulsions and polyester urethane dispersions are particularly preferable.

The binder resin preferably accounts for 5 to 50% by mass in terms of solid content of the aqueous liquid printing ink of the present invention. When the amount is 5% by mass or more, the strength of the ink coating film does not decrease, and good adhesion to the substrate, water friction resistance, etc. are maintained. On the other hand, if the content is 50% by mass or less, it is possible to suppress a decrease in coloring power, avoid a high viscosity, and prevent a decrease in workability. Among these, it is more preferably 5 to 40% by mass, and most preferably 5 to 20% by mass.

(aqueous medium)
Aqueous media for aqueous liquid printing inks include, for example, water, water-miscible organic solvents, and mixtures thereof. Examples of organic solvents that are miscible with water include alcohol solvents such as methanol, ethanol, n-propanol, and isopropanol; ketone solvents such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol, and propylene glycol; alkyl ethers; lactam solvents such as N-methyl-2-pyrrolidone; and the like. In the present invention, water alone may be used, a mixture of water and a water-miscible organic solvent may be used, or only a water-miscible organic solvent may be used. Further, as the aqueous medium, from the viewpoint of safety and environmental impact, water alone or a mixture of water and an organic solvent miscible with water is preferable, and water alone is particularly preferable.

The water-based liquid printing ink can also contain the aforementioned colorants, extender pigments, pigment dispersants, leveling agents, antifoaming agents, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, and the like. Among them, fatty acid amides such as oleic acid amide, stearic acid amide, and erucic acid amide to impart friction resistance and slipperiness, and silicone-based and non-silicon-based antifoaming agents and pigments to suppress foaming during printing. Various dispersants and the like are useful to improve wetting.

The present invention will be explained in more detail with reference to Examples. Hereinafter, both "parts" and "%" are based on mass.

In the present invention, the weight average molecular weight (in terms of polystyrene) was measured by GPC (gel permeation chromatography) using HLC8220 system manufactured by Tosoh Corporation under the following conditions.
Separation columns: Four TSKgelGMHHR-N manufactured by Tosoh Corporation were used. Column temperature: 40°C. Mobile layer: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0ml/min. Sample concentration: 1.0% by mass. Sample injection volume: 100 microliters. Detector: Differential refractometer.

In addition, the acid value of acrylic resin indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of resin. Calculated from potentiometric titration with a potassium hydroxide/ethanol solution.

Further, the glass transition temperature (Tg) refers to a so-called calculated glass transition temperature, and refers to a value calculated by the following method.
(Formula 1) 1/Tg(K)=(W1/T1)+(W2/T2)+...(Wn/Tn)
(Formula 2) Tg (°C) = Tg (K) - 273
In formula 1, W1, W2, ... Wn represent the mass % of each monomer with respect to the total mass of monomers used for the production of the polymer, and T1, T2, ... Tn represent the mass % of each monomer with respect to the total mass of monomers used for producing the polymer, and T1, T2, ... Tn represent the mass % of each monomer with respect to the total mass of monomers used for producing the polymer Represents glass transition temperature (K). Note that the values of T1, T2, . . . Tn are those described in Polymer Handbook (Fourth Edition, edited by J. Brandrup, E. H. Immergut, and E. A. Grulke).
In addition, although the glass transition temperature of the homopolymer of each monomer is not listed in the Polymer Hand Book, the glass transition temperature was determined in accordance with JIS K7121 using a differential scanning calorimeter "DSC Q-100" (manufactured by TA Instrument). It was measured using the same method. Specifically, we measured the change in calorific value of a polymer whose solvent had been completely removed by vacuum suction in the range of -100°C to +200°C at a heating rate of 20°C/min, and calculated the straight line as an extension of each baseline. The point where a straight line equidistant in the vertical axis direction intersects with the curve of the step-like change portion of the glass transition was defined as the glass transition temperature.

[Synthesis Example 1: Preparation of shell acrylic resin (polymer a1)]
A reaction vessel is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 60.0 parts of n-propyl acetate is charged therein. The temperature was raised to 90°C while stirring under a nitrogen atmosphere. On the other hand, 36.0 parts of methyl methacrylate, 10.0 parts of ethyl methacrylate, 20.0 parts of n-butyl methacrylate, 10.0 parts of isobutyl methacrylate, 10.0 parts of 2-ethylhexyl acrylate, 14.0 parts of acrylic acid, and azobis. 1.0 part of isobutyronitrile was dissolved in 40.0 parts of n-propyl acetate, and the solution was added dropwise using a dropping funnel over 4 hours. After the dropwise addition was completed, the reaction was continued for an additional 6 hours. After the reaction was completed, it was cooled, and 8.0 parts of 30% ammonia water was added to the obtained acrylic resin solution to neutralize it. Further, ion-exchanged water was added and the solvent was replaced while heating to obtain an aqueous solution of acrylic resin with a solid content of 55%. The acid value was 105 mgKOH/g, the Tg was 65°C, and the weight average molecular weight was 16,000.

[Synthesis Example 2: Preparation of core-shell type acrylic emulsion (Ac1)]
A reaction vessel containing 121.2 parts of the acrylic resin aqueous solution prepared in Synthesis Example 1 is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 195.5 parts of ion-exchanged water is added thereto. The temperature was raised to 75°C while stirring under a nitrogen atmosphere. Subsequently, using a dropping funnel, 30.0 parts of methyl methacrylate, 20.0 parts of ethyl methacrylate, 25.0 parts of n-butyl acrylate, 25.0 parts of 2-ethylhexyl acrylate, and 3.3 parts of 30% ammonium persulfate were added for 4 hours. It dripped. After the dropwise addition was completed, the reaction was further carried out for 6 hours to obtain a core-shell type acrylic emulsion aqueous solution Ac1 having a solid content of 40%. The acid value was 42 mgKOH/g, the Tg was 10°C, and the weight average molecular weight was 1,200,000.

[Synthesis Example 3: Preparation of polyurethane resin solution (Pu)]
186.9 parts of PLACCEL 212 (manufactured by Daicel Chemical Industries, Ltd., polycaprolactone diol, hydroxyl value 90 mgKOH/g) and 100.0 parts of isophorodiisocyanate (abbreviated as IPDI) were charged. This was heated to 110°C while stirring. After 1 hour, it was cooled to 80°C, 20.1 parts of dimethylolpropionic acid (abbreviated as DMPA), 0.3 parts of dibutyltin dilaurate, and 76.8 parts of ethyl acetate were added, and the mixture was reacted at 80°C for 2 hours. I let it happen. To this were added 18.1 parts of Burnock DN-980S (manufactured by DIC Corporation, hexamethylene diisocyanate-based polyisocyanate, NCO content 20%) and 408 parts of methyl ethyl ketone (abbreviated as MEK). The NCO group content at this time was 4.9% in terms of solid content.
This was cooled to below 30° C., 15.2 parts of triethylamine was added, and then 1293 parts of ion-exchanged water were added to obtain an oil-in-water (O/W) emulsion. Subsequently, 234 parts of a 5% aqueous solution of diethylenetriamine was gradually added, and after the addition was completed, the temperature was raised to 60°C and stirring was continued for 30 minutes.
Distillation was then carried out under reduced pressure to remove a portion of the solvent and water.
This product is a slightly milky, semi-transparent liquid, and when a small amount of it is placed in a test tube and tetrahydrofuran (abbreviated as THF) is added, it becomes cloudy, indicating that it is cross-linked and insoluble. The nonvolatile content was 39.6%, the viscosity was 160 cps, the pH was 7.7, and the average particle size was 28.5 nm.

[Example 1]
As shown in Table 1, 72 parts of core-shell type acrylic emulsion (Ac1), 3.2 parts of Zeomic AJ-10N (manufactured by Sinanen Zeomic Co., Ltd.) as silver-supported zeolite, which is a silver-containing inorganic compound, and polyethylene wax. 15 parts of dispersion liquid 1 (average particle size 4 μm, solid content 40%), 0.1 part of antifoaming agent, 4.2 parts of water, mixed solvent 1 (ethanol/isopropyl alcohol at a mass ratio of 85:15) A coating agent composition (1) was obtained by uniformly mixing 5.0 parts of ethanolamine and 0.5 parts of ethanolamine using a dispersion stirrer (TK Homo Disper manufactured by Tokushu Kika Kogyo Co., Ltd.).

[Examples 2 to 7, Comparative Examples 1 to 3]
A coating agent composition was obtained in accordance with the formulation shown in Table 1 and in the same manner as in Example 1.

<Preparation of laminate having coating layer>
[Gravure coating creation]
The viscosity of the obtained coating agents of Examples and Comparative Examples was adjusted to 16 seconds (25°C) using a Zahn cup #3 (manufactured by Rigosha) with a mixed solvent of water/ethanol = 80/20 (mass ratio), and then plated. A laminate printed on coated cardboard or PET film using a gravure proofing machine equipped with a 35 μm deep gravure plate was left for one day to be used as a laminate for evaluation. The thickness of the coating layer was approximately 1.2 μm.

[Flexo coating creation]
The viscosity of the obtained coating agents of Examples and Comparative Examples was adjusted with water to 10 seconds (25°C) using a Zahn cup #4 (manufactured by Rigosha), and the viscosity was adjusted using a flexo proofing machine equipped with a 100 lines/cm anilox roll. The laminates printed on coated cardboard or PET film were left for one day and used as evaluation laminates. The thickness of the coating layer was approximately 1.0 μm.

Using the obtained laminate (base material having a coating layer), friction resistance, antiviral properties, gloss, and slipperiness were evaluated.

[Evaluation item 1: Friction resistance]
The abrasion resistance of the obtained laminate was evaluated using a robust Gakushin tester. Copy paper was used as the friction element, and after 100 reciprocations under a load of 500 g, the condition of the surface of the printed matter was visually judged in the following five stages.
5: The printed surface has not changed 4: There are few scratches on the printed surface 3: There are many scratches on the printed surface 2: Part of the coating agent has peeled off and the base material is visible 1: The coating agent has peeled off and the base material only

(Evaluation item 2: Antiviral evaluation)
The obtained laminate was subjected to an antiviral test against influenza virus (ATCC VR-1679).
1) After dropping 100 μL of an influenza virus (ATCC VR-1679) suspension of known concentration onto a 5 cm x 5 cm evaluation print, it was covered with a sterilized polyethylene film and brought into close contact. The test piece to which the virus solution was adhered was cultured for 24 hours at 25° C. and a relative humidity of 90% or more.
2) The virus suspension of the test piece was collected, diluted 100 times, and the virus infectivity titer (virus number) was measured by the plaque method. The antiviral activity value (R) was calculated by antiviral activity value (R)=UA.
U: Logarithmic value of the virus infectivity titer of the unprocessed product after 24 hours (Comparative Example 1, which does not contain an antiviral agent, was used as a blank product) A: Logarithm value of the virus infectivity titer of the antibacterial processed product after 24 hours 3) Antiviral efficacy was evaluated based on the following criteria. According to SIAA (Association for Antibacterial Products Technology) standards, a product is considered to have an antiviral effect when R is 2.0 or higher.
〇: Antiviral activity value (R) = 3.0 or more △: Antiviral activity value (R) = 2.0 or more but less than 3.0 ×: Antiviral activity value (R) = less than 2.0

(Evaluation item 3: Gloss)
Regarding the obtained laminate, the 60 degree specular gloss was measured at 20 points from the coated surface of the laminate in accordance with JIS Z8741:1997, and the average of the 60 degree specular gloss was calculated.

(Evaluation item 4: Slipperiness)
Using a sliding angle tester (manufactured by T.M.C. Japan), the sliding angle of printed surface x printed surface was measured. The measurement conditions were load: 1000 g, inclination angle: 2 degrees/second, and ground contact area: 6 cm x 10 cm (measured 5 times on the same sample, average value).

In the table, polyethylene wax dispersion 2 has an average particle size of 3.5 μm and a solid content of 40%. The paraffin wax dispersion has an average particle size of 3.8 μm and a solid content of 40%.
Furthermore, the organic antiviral antiviral agent is an antibacterial, antifungal, and antiviral organic composite agent containing diiodomethyl paratolyl sulfone as a main component.

As a result, the coating agent of the example was able to achieve both antiviral properties and anti-friction properties.
On the other hand, although Comparative Example 1 does not contain silver-supported zeolite, it did not exhibit antibacterial properties. Furthermore, Comparative Example 2 used an organic antiviral agent, and since it was an organic antiviral agent, the abrasion resistance was excellent, but no antiviral effect was exhibited.

Claims (9)

A coating agent for paper or plastic substrates containing a binder resin (A), a silver-containing inorganic compound (B), a polyethylene wax (C), and an aqueous medium (D). The coating agent according to claim 1, containing the polyethylene wax (C) in an amount of 3 to 20% by mass based on the total solid content of the coating agent. The coating agent according to claim 1 or 2, which contains the silver-containing inorganic compound (B) in an amount of 1 to 20% by mass based on the total solid content of the coating agent. The coating agent according to claim 1 or 2, wherein the binder resin (A) contains at least one of acrylic resin, styrene acrylic resin, and urethane resin. The coating agent according to claim 1 or 2, wherein the silver-containing inorganic compound (B) has an average particle size of 0.5 μm to 4.5 μm. The coating agent according to claim 1 or 2, wherein the polyethylene wax (C) has an average particle size of 1 μm to 5 μm. A paper base material or a plastic base material obtained by coating a paper base material or a film with the coating agent according to claim 1 or 2. The paper base material or plastic base material according to claim 6, wherein the paper base material or plastic base material further has a printing ink layer. A container or packaging material using the paper base material or plastic base material according to claim 1 or 2.