WO2020213413A1 - Water-based liquid ink and laminate - Google Patents

Abstract

The present invention addresses the problem of providing: a water-based liquid ink which has outstanding viscosity stability and which has both substrate adhesion as a cured coating and various types of coating strength; and a laminate that uses this water-based liquid ink. The present invention pertains to a water-based liquid ink characterized by comprising: a copolymer which is formed from one or more types of (meth)acrylate monomer and/or one or more types of vinyl monomer, and has an acid value constituting a glass transition temperature of 0-55°C; 0.1-1 mass% of an acetylene surfactant and/or an alcohol-alkoxylate surfactant relative to the total ink amount; and 0.5-5 mass% of wax relative to the total ink amount.

Description

Aqueous liquid ink and laminate

The present invention relates to a water-based gravure ink for laminating for flexible packaging, a water-based liquid ink such as a water-based flexo ink, and a laminate using the water-based liquid ink.
In particular, the present invention relates to a water-based liquid ink having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths, and a laminate using the water-based liquid ink.
Further, the present invention also relates to a water-based liquid ink having excellent viscosity stability, adhesion to the base material of the cured coating film, and various coating film strengths even in a system to which a curing agent is added, and a laminate using the water-based liquid ink. ..

Gravure inks and flexographic inks are widely used for the purpose of imparting cosmeticity and functionality to the printed material of the flexible packaging film. When the gravure- or flexographic-printed object is used as a flexible packaging material for foods and hygiene products among packaging materials, it is generally laminated. In this case, various printed materials and laminating processes are used depending on the type of contents and the purpose of use. Then, by laminating the printed matter and various films with an adhesive, it is possible to maintain the film surface strength, storage stability, boil / retort suitability, etc., which cannot be obtained only with the printed matter.
On the other hand, when laminating a printed matter, the printed matter itself is often intended to protect the contents. In this case, since the printed matter consisting of the base plastic and the printing ink layer and the sealant film are laminated using an adhesive, the printing ink layer does not come into direct contact with the contents, but the laminating suitability is required. .. Then, in order to maintain the laminating suitability, it is usual practice to improve the adhesion between the thermoplastic resin film of the base material and the printing ink layer by providing an anchor coat layer under the printing ink layer.

However, in response to recent efforts to save resources and simplify packaging forms, there is a demand to use gravure flexo printed matter itself as packaging material for the purpose of reducing the amount of film derived from petroleum resources and simplifying post-processing. The number is increasing, and in response to this, the printing ink layer itself is required to have high coating film characteristics such as film adhesion, abrasion resistance, water resistance, and blocking resistance.
In addition, the superiority or inferiority of the print design in the flexible packaging film packaging material has a great influence to the extent that it reminds us of the quality of the contents, and high image reproducibility that can correspond to advanced designs that are conscious of cosmetics is required. ..

In recent years, based on the perspective of sustainability against the backdrop of global expansion such as worsening air pollution due to VOCs and global warming, occupational safety and health, as well as flammability and explosiveness, have been added to the shift to de-oil resources. Therefore, it is expected to replace the organic solvent in the ink with water-based ink. For example, by combining a water-based acrylic resin-based color ink film layer and a water-based polyurethane resin-based white ink film layer, it is possible to obtain coating material properties and ink physical properties that could not be obtained so far. However, since the combination structure of these ink film layers requires an overprint varnish layer using a volatile organic compound or an aqueous polyurethane anchor coat varnish layer, it can be said that the productivity at the time of printing is sufficient. None (for example, Patent Document 1).
Further, although a printing ink laminate in which an acrylic resin or a polyurethane resin is used as a printing ink adjacent to a thermoplastic resin film has been invented, it is used in applications such as a body-wrapped shrink label that requires film adhesion and water resistance. , It cannot be said that the performance is still sufficient (for example, Patent Document 2).
Furthermore, when it is desired to add a curing agent to the water-based ink immediately before the printing operation, the substrate of the cured coating film is maintained in a constant viscosity for at least 6 hours after the addition of the curing agent in consideration of the workability. It cannot be said that it is easy to have both adhesion and various coating film strengths.

Japanese Unexamined Patent Publication No. 2005-225083 Japanese Unexamined Patent Publication No. 2016-155340

An object of the present invention is to provide a water-based liquid ink having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths, and a laminate using the water-based liquid ink.
Further, even in a system to which a curing agent is added, a water-based liquid ink having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths, and a laminate using the water-based liquid ink can be obtained. To provide.

The aqueous liquid ink of the present invention is formed from a (meth) acrylate-based monomer and / or a vinyl-based monomer, and is a copolymer having an acid value having a glass transition temperature of 0 ° C. to 55 ° C., an acetylene-based surfactant and / or It was found that it is effective to solve the problem by using an appropriate amount of alcohol alkoxylate-based surfactant and wax.

That is, the present invention is formed from one or more (meth) acrylate-based monomers and / or one or more vinyl-based monomers and has an acid value having a glass transition temperature of 0 ° C. to 55 ° C. A water-based liquid containing a copolymer, an acetylene-based surfactant and / or an alcohol alkoxylate-based surfactant in an amount of 0.1 to 1% by mass based on the total amount of ink, and a wax containing 0.5 to 5% by mass based on the total amount of ink. Provide ink.

Further, the present invention is a laminate having one or a plurality of printing layers on a base material, and at least one of the printing layers is a printing layer of the water-based liquid ink according to any one of claims 1 to 5. Provides a laminate that is.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a water-based liquid ink having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths, and a laminate using the water-based liquid ink.
Further, even in a system to which a curing agent is added, a water-based liquid ink having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths, and a laminate using the water-based liquid ink can be obtained. Can be provided.

The present invention will be described in detail. The "inks" used in the following description all refer to "water-based liquid inks". Further, "parts" mean "parts by mass", and "%" means "% by mass".

The water-based liquid ink of the present invention is an acid formed from one or more (meth) acrylate-based monomers and / or one or more vinyl-based monomers and having a glass transition temperature of 0 ° C. to 55 ° C. A copolymer having a value (hereinafter sometimes referred to as a copolymer (A)), an acetylene-based surfactant and / or an alcohol alkoxylate-based surfactant in an amount of 0.1 to 1% by mass based on the total amount of the ink, and a wax in the ink. It is essential to contain 0.5 to 5% by mass based on the total amount.

The copolymer (A) is a polymer or copolymer of one or more (meth) acrylate monomers, or a polymer or copolymer of one or more vinyl-based monomers, or one or more. It is a copolymer of the (meth) acrylate monomer and the vinyl-based monomer.
The "(meth) acrylate" refers to either or both of acrylate and methacrylate, and "(meth) acrylic" refers to either or both of acrylic and methacrylic.

The (meth) acrylate monomer is not particularly limited, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, 2 -Ethylhexyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, di Cyclopentanyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-pentafluoropropyl (meth) acrylate, Perfluorocyclohexyl (meth) acrylate, glycidyl (meth) acrylate, allyl glycidyl ether, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) acrylamide, N -Monoalkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide, N-methylol (meth) acrylamide, N-isopropoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-isobutoxymethyl Use (meth) acrylic monomers such as (meth) acrylamide, 2-aziridinyl ethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, achlorine, diacetone (meth) acrylamide, and acetoacetoxyethyl (meth) acrylate. Can be done. Each of these may be used alone, or two or more types may be used in combination.

Examples of the vinyl monomer include vinyl acetate, vinyl propionate, vinyl versatic acid, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, (meth) acrylonitrile, styrene, α-methylstyrene, divinylstyrene, isoprene, and chloroprene. Examples thereof include butadiene, ethylene, tetrafluoroethylene, vinylidene fluoride, N-vinylpyrrolidone and the like. Of these, it is preferable to use styrene-based monomers such as styrene, α-methylstyrene, and divinylstyrene. Each of these may be used alone, or two or more types may be used in combination.

Further, 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, It can be obtained by copolymerizing a (meth) acrylic monomer having a carboxyl group such as maleic acid, fumaric acid, β- (meth) acryloyloxyethyl hydrogen succinate, β- (meth) acryloyloxyethyl hydrogen phthalate.
When an acidic group is introduced, it is preferable to appropriately adjust the amount of the monomer so that the acid value is in a desired range, which will be described in detail later.

Among them, as the copolymer (A), a copolymer of two or more kinds of (meth) acrylate monomers or a copolymer of one or more kinds of (meth) acrylate monomers and a vinyl-based monomer is preferable. For example, (1) a copolymer of (meth) acrylate monomer having two or more kinds of carboxyl groups and (meth) acrylate monomer having a carboxyl group such as (meth) acrylic acid, having an acid value (meth). ) Acrylic copolymer (2) A copolymer of a (meth) acrylate monomer having two or more kinds of carboxyl groups, a styrene-based monomer, and a (meth) acrylate monomer having a carboxyl group such as (meth) acrylic acid. A styrene (meth) acrylic copolymer having an acid value is preferable.
More preferably, the (meth) acrylic monomer having no carboxyl group used in (1) and (2) is methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and iso-butyl. An aliphatic chain (meth) acrylate such as (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and hexyl (meth) acrylate is preferable.

The copolymer (A) can be produced, for example, by polymerizing various monomers in a temperature range of 50 ° C. to 180 ° C. in the presence of a polymerization initiator, and more if it is in a temperature range of 80 ° C. to 150 ° C. preferable. Examples of the polymerization method include a massive polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. In addition, examples of the polymerization mode include random copolymers, block copolymers, graft copolymers, and the like.

The copolymer (A) used in the present invention may be an emulsion forming a core-shell type. In the present invention, the core-shell type emulsion refers to a state in which the polymer (a2) is dispersed in an aqueous medium by the polymer (a1), and usually, the polymer (a1) is present on the outermost side of the resin particles to form a shell. In many cases, a portion is formed and a part or all of the polymer (a2) forms a core portion. 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 constituting the shell portion (a1)]
The core-shell emulsion used in the present invention is one or more hydrophilic groups selected from the group consisting of a carboxyl group and a carboxylate group formed by neutralizing the carboxyl group (a1) constituting the shell portion. It is preferably composed of one containing an acrylic copolymer having. At that time, the acid value of the shell portion is preferably in the range of 40 mgKOH / g or more and 250 mgKOH / g or less, and more preferably 120 mgKOH / g or less.

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

As the basic compound that can be used for the neutralization, for example, ammonia, triethylamine, morpholine, monoethanolamine, diethylethanolamine and the like can be used, and it is possible to use ammonia and triethylamine for the temperature resistance of the coating film. , It is preferable to further improve the corrosion resistance and the chemical resistance.

The amount of the basic compound used is [basic compound / carboxyl group] with respect to the total amount of the carboxyl group of the polymer (a1) in order to further improve the water dispersion stability of the obtained core-shell emulsion. It is preferably used in the range of = 0.2 to 2 (molar ratio).

Among the monomers having a polymerizable unsaturated double bond, it is preferable to use a monomer obtained by polymerizing a (meth) acrylic monomer containing a (meth) acrylic monomer having a carboxyl group. In particular, as the polymer (a1), methyl (meth) acrylate, butyl (meth) acrylate, in order to adjust the glass transition temperature (Tg1) of the polymer (a1) in the range of 20 ° C. to 100 ° C. It is more preferable to use a polymer obtained by combining and polymerizing (meth) acrylic acid or the like in order to form a coating film having excellent film-forming property and excellent temperature water resistance, corrosion resistance and chemical resistance.

[Polymer constituting the core portion (a2)]
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, and more preferably 800,000 or more. 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 above-mentioned acrylic resin can be used, but among them, it is preferably produced in an aqueous medium. Specifically, it can be produced by collectively supplying or sequentially supplying the monomer and the polymerization initiator or the like to a reaction vessel containing an aqueous medium for polymerization. At that time, a pre-emulsion is produced by mixing the monomer, an aqueous medium, and a reactive surfactant or the like in advance, and the polymerization initiator or the like is supplied to a reaction vessel containing the aqueous medium. It may be polymerized.

Examples of the polymerization initiator that can be used in producing the polymer (a2) include radical polymerization initiators such as persulfate, organic peroxide, and hydrogen peroxide, and 4,4'-azobis (4-cyano). Azo initiators such as valerate) and 2,2'-azobis (2-amidinopropane) dihydrochloride can be used. In addition, the radical polymerization initiator may be used as a redox polymerization initiator in combination with a reducing agent described later.

As the persulfate, for example, potassium persulfate, sodium persulfate, ammonium persulfate and the like can be used. Examples of the organic peroxide include benzoyl peroxide, lauroyl peroxide, decanoyyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, t-butyl peroxylaurate, and t-butyl peroxybenzoate. , Kumen hydroperoxide, paramentan hydroperoxide, t-butyl hydroperoxide and the like can be used.

Examples of the reducing agent include ascorbic acid and its salt, erythorbic acid and its salt (sodium salt, etc.), tartrate acid and its salt, citric acid and its salt, formaldehyde sulfoxylate metal salt, sodium thiosulfate, and the like. Sodium bicarbonate, ferric chloride, etc. can be used.

The amount of the polymerization initiator used may be an amount that allows the polymerization to proceed smoothly, but it is preferable that the amount used is as small as possible from the viewpoint of maintaining the excellent corrosion resistance of the obtained coating film, and is used for producing the vinyl polymer (a2). It is preferably 0.01% by mass to 0.5% by mass with respect to the total amount of the monomers used. When the polymerization initiator is used in combination with the reducing agent, the total amount of the polymerization initiator used is preferably within the above range.

In addition, when producing the pre-emulsion, a reactive surfactant, an anionic surfactant, a nonionic surfactant, a cationic surfactant, a zwitterionic surfactant and the like are used. May be good.

The acid value of the copolymer (A) is preferably 20 mgKOH / g or more, 120 mgKOH / g or less, and more preferably 25 mgKOH or more. When the acid value is 20 mgKOH / g or more, the friction resistance, water friction resistance, and scratch resistance of the laminate can be improved when the curing agent is added.
The acid value referred to here indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin.

The weight average molecular weight of the copolymer (A) 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 decrease, and the friction resistance and the water friction resistance of the laminate tend to be maintained. If it is 100,000 or less, the laminate tends to have both substrate adhesion and scratch resistance.

The glass transition temperature (sometimes referred to as Tg) of the copolymer (A) is preferably in the range of 0 ° C. to 55 ° C. When the Tg of the copolymer (A) is 0 ° C. or higher, the film strength is maintained, the water friction resistance of the laminate is not lowered, and when the Tg is 55 ° C. or lower, the compatibility with other printing layers is good. The friction resistance, water friction resistance, and scratch resistance of the laminate tend to be kept good without deterioration.
The glass transition temperature (Tg) refers to a so-called calculated glass transition temperature, and refers to a value calculated by the following method.
(Equation 1) 1 / Tg (K) = (W1 / T1) + (W2 / T2) + ... (Wn / Tn)
(Equation 2) Tg (° C.) = Tg (K) -273
W1, W2, ... Wn in the formula 1 represent the mass% of each monomer with respect to the total mass of the monomers used for producing the polymer, and T1, T2, ... Tn are the homopolymers of each monomer. Represents the glass transition temperature (K). As the values of T1, T2, ... Tn, the values described in Polymer Handbook (Fourth Edition, J. Brandrup, E.H. Immunogut, EA Grulke) are used.
Although the glass transition temperature of the homopolymer of each monomer is not described in the Polymer Hand Book, the glass transition temperature is based on JIS K7121 using a differential scanning calorimeter "DSC Q-100" (manufactured by TA Instrument). It was measured by the method described above. Specifically, the polymer from which the solvent has been completely removed by vacuum suction is measured for a change in calorific value in the range of -100 ° C to + 200 ° C at a heating rate of 20 ° C./min, and a straight line extending each baseline. The point where the straight line equidistant from the vertical axis direction and the curve of the stepwise change portion of the glass transition intersect was defined as the glass transition temperature.

The copolymer (A) is preferably contained in the aqueous liquid ink of the present invention in an amount of 5 to 50% by mass in terms of solid content. When the content of the copolymer (A) is 5% by mass or more, the strength of the ink coating film does not decrease, and the substrate adhesion, water friction resistance, and the like are kept good. On the other hand, if it is 50% by mass or less, the decrease in coloring power can be suppressed, the high viscosity can be avoided, and the workability does not decrease.

(Surfactant)
As the surfactant used in the present invention, an acetylene-based surfactant and / or an alcohol alkoxylate-based surfactant is preferable.
Specifically, as the acetylene-based surfactant used in the present invention, 2,5-dimethyl-3-hexyne-2,5-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2, 4,7,9-Tetramethyl-5-decine-4,7-diol, 3,5-dimethyl-1-hexyne-3-ol, 3-methyl-1-butyne-3-ol, 3-methyl-1 -Pentyne-3-ol, 3-hexyne-2,5-diol, 2-butyne-1,4-diol and the like can be mentioned. Commercially available products include alkylene oxide-non-modified acetylene glycol-based surfactants such as Surfinol 61, 82, and 104 (all manufactured by Air Products & Chemicals).

Surfinol 420, 440, 465, 485, TG, 2502, Dynol 604, 607 (all manufactured by Air Products & Chemicals), Surfinol SE, MD-20, Orfin E1004, E1010, PD-004, EXP4300, PD-501 , PD-502, SPC (all manufactured by Nisshin Kagaku Kogyo Co., Ltd.), acetylenol EH, E40, E60, E81, E100, E200 (all manufactured by Kawaken Fine Chemicals Co., Ltd.) and other alkylene oxide-modified acetylenes. Glycol-based surfactants and the like can be mentioned. Of these, an alkylene oxide-modified acetylene glycol-based surfactant is preferable.
Specific examples of the alcohol alkoxylate-based surfactant used in the present invention include alcohol ethoxylate and alcohol polyethoxylate, and commercially available products include DYNWET800 (manufactured by Big Chemie Japan).
These acetylene-based surfactants and alcohol alkoxylate-based surfactants may be used alone or in combination of two or more.

The total amount of the acetylene-based surfactant and / or the alcohol alkoxylate-based surfactant added is preferably 0.1 to 1% by mass of the total amount of the ink. These acetylene-based surfactants may be used alone or in combination of two or more, and the total amount of the acetylene-based surfactant and / or the alcohol alkoxylate-based surfactant added is When it is 0.1% by mass or more of the total amount of ink, the coatability with the base material is improved and the adhesion with the base material can be maintained. If the total amount of the acetylene-based surfactant and / or the alcohol alkoxylate-based surfactant added is 1% by mass or less of the total amount of the ink, the abrasion resistance, the water abrasion resistance, and the scratch resistance may decrease. Absent.
Further, if necessary, other acrylic polymer-based surfactants (for example, Polyflow WS-314 Kyoeisha Chemical Co., Ltd.) and modified silicone-based surfactants (for example, Polyflow KL-401 Kyoeisha Chemical Co., Ltd.) are used. You may.
For the above reasons, the total amount of the surfactant used is preferably 0.1 to 1% by mass of the total amount of the ink.

(wax)
As the wax used in the present invention, a hydrocarbon wax is preferable. Specific examples thereof include liquid paraffin, natural paraffin, synthetic paraffin, microcrystalline wax, polyethylene wax, fluorocarbon wax, ethylene-propylene copolymer wax, tetrafluoride ethylene resin wax, Fisher Tropsch wax and the like. Of these, polyethylene wax is preferable.
These waxes may be used alone or in combination of two or more, and the total amount of these waxes added is preferably 0.5 to 5% by mass of the total amount of the ink. When the total amount of wax added is 0.5% by mass or more of the total amount of ink, abrasion resistance, water abrasion resistance, and scratch resistance can be maintained. When the total amount of wax added is 5% by mass or less of the total amount of ink, adhesion to the substrate, abrasion resistance, water abrasion resistance, and scratch resistance can be maintained.

(Hardener)
In the present invention, a curing agent capable of reacting with an acid may be used in combination. The curing agent capable of reacting with the acid is not particularly limited, and a known curing agent that can be used in an aqueous medium can be used. For example, an epoxy-based curing agent, a carbodiimide-based curing agent, an oxazoline-based curing agent, and the like can be mentioned.

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

The carbodiimide-based 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-based curing agent, a polycarbodiimide compound having at least two or more carbodiimide groups is preferable.

The oxazoline-based curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the oxazoline-based curing agent include the Epocross series manufactured by Nippon Shokubai Co., Ltd.
Examples of the epoxy compound include bisphenol A diglycidyl ether and its oligomer, hydride bisphenol A diglycidyl ether and its oligomer, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, and p-oxybenzoic acid. Diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipate diglycidyl ester, sebacic 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, trimeric acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, Examples thereof include diglycidyl propylene urea, glycerol triglycidyl ether, trimethylol ethane triglycidyl ether, trimethylol propane triglycidyl ether, pentaerythritol tetraglycidyl ether, and triglycidyl ether as a glycerol alkylene oxide adduct.

The amount of the curing agent added 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 ink.
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 substrate adhesion, abrasion resistance, and water friction resistance tend to be maintained. Become.

(solvent)
As the solvent contained in the aqueous liquid ink of the present invention, water alone or an organic solvent miscible with water can be used. Examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and n-propyl alcohol, polyhydric alcohols such as propylene glycol and glycerin, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol mono n. -Ethers such as propyl ether and ethyl carbitol can be mentioned.

(Pigment)
The water-based liquid ink of the present invention becomes a transparent film after printing if it does not contain a coloring material, and is a colorless transparent ink (in the present technical field, it is used for the purpose of solid printing on the outermost layer of a color printing layer to protect the color printing layer. Therefore, it is also commonly referred to as overcoat varnish or OP varnish. In the present invention, it may be referred to as OP varnish). Of course, it also contains a coloring material and is used as an ink for so-called white, black, and color printing.
Specific examples of the coloring material include inorganic pigments and organic pigments used in general inks, paints, recording agents and the like. Organic pigments include soluble azo-based, insoluble azo-based, azo-based, phthalocyanine-based, halogenated phthalocyanine-based, anthraquinone-based, anthraslon-based, dianthraquinone-based, anthrapyrimidine-based, perylene-based, perinone-based, quinacridone-based, Pigments such as thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine-azo-based, flavanthlon-based, diketopyrrolopyrrole-based, isoindoline-based, indanslon-based, and carbon black-based pigments can be mentioned. Also, for example, Carmin 6B, Lake Red C, Permanent Red 2B, Disazo Yellow, Pyrazolone Orange, Carmin FB, Chromophtal Yellow, Chromophtal Red, Phthalocyanine Blue, Phthalocyanine Green, Dioxazine Violet, Quinacridone Magenta, Quinacridone Red, Indance. Examples thereof include lonblue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigment. Further, both unacidified treated pigments and acidic treated pigments can be used. Specific examples of preferable organic pigments are given below.

Examples of the black pigment include C.I. I. Pigment Black 1, C.I. I. Pigment Black 6, C.I. I. Pigment Black 7, C.I. I. Pigment Black 9, C.I. I. Pigment Black 20 and the like.

Examples of the indigo pigment include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 4, C.I. I. Pigment Blue 15: 5, C.I. I. Pigment Blue 15: 6, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 17: 1, C.I. I. Pigment Blue 22, C.I. I. Pigment Blue 24: 1, C.I. I. Pigment Blue 25, C.I. I. Pigment Blue 26, C.I. I. Pigment Blue 60, C.I. I. Pigment Blue 61, C.I. I. Pigment Blue 62, C.I. I. Pigment Blue 63, C.I. I. Pigment Blue 64, C.I. I. Pigment Blue 75, C.I. I. Pigment Blue 79, C.I. I. Pigment Blue 80 and the like.

Examples of green pigments include C.I. I. Pigment Green 1, C.I. I. Pigment Green 4, C.I. I. Pigment Green 7, C.I. I. Pigment Green 8, C.I. I. Pigment Green 10, C.I. I. Pigment Green 36 and the like.

Examples of the red pigment include C.I. I. Pigment Red 1, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 4, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 8, C.I. I. Pigment Red 9, C.I. I. Pigment Red 10, C.I. I. Pigment Red 11, C.I. I. Pigment Red 12, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 17, C.I. I. Pigment Red 18, C.I. I. Pigment Red 19, C.I. I. Pigment Red 20, C.I. I. Pigment Red 21, C.I. I. Pigment Red 22, C.I. I. Pigment Red 23, C.I. I. Pigment Red 31, C.I. I. Pigment Red 32, C.I. I. Pigment Red 38, C.I. I. Pigment Red 41, C.I. I. Pigment Red 43, C.I. I. Pigment Red 46, C.I. I. Pigment Red 48, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 48: 2, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 48: 4, C.I. I. Pigment Red 48: 5, C.I. I. Pigment Red 48: 6, C.I. I. Pigment Red 49, C.I. I. Pigment Red 49: 1, C.I. I. Pigment Red 49: 2, C.I. I. Pigment Red 49: 3, C.I. I. Pigment Red 52, C.I. I. Pigment Red 52: 1, C.I. I. Pigment Red 52: 2, C.I. I. Pigment Red 53, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 53: 2, C.I. I. Pigment Red 53: 3, C.I. I. Pigment Red 54, C.I. I. Pigment Red 57, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 58, C.I. I. Pigment Red 58: 1, C.I. I. Pigment Red 58: 2, C.I. I. Pigment Red 58: 3, C.I. I. Pigment Red 58: 4, C.I. I. Pigment Red 60: 1, C.I. I. Pigment Red 63, C.I. I. Pigment Red 63: 1, C.I. I. Pigment Red 63: 2, C.I. I. Pigment Red 63: 3, C.I. I. Pigment Red 64: 1, C.I. I. Pigment Red 68, C.I. I. Pigment Red 68, C.I. I. Pigment Red 81: 1, C.I. I. Pigment Red 83, C.I. I. Pigment Red 88, C.I. I. Pigment Red 89, C.I. I. Pigment Red 95, C.I. I. Pigment Red 112, C.I. I. Pigment Red 114, C.I. I. Pigment Red 119, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 136, C.I. I. Pigment Red 144, C.I. I. Pigment Red 146, C.I. I. Pigment Red 147, C.I. I. Pigment Red 149, C.I. I. Pigment Red 150, C.I. I. Pigment Red 164, C.I. I. Pigment Red 166, C.I. I. Pigment Red 168, C.I. I. Pigment Red 169, C.I. I. Pigment Red 170, C.I. I. Pigment Red 171 and C.I. I. Pigment Red 172, C.I. I. Pigment Red 175, C.I. I. Pigment Red 176, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 179, C.I. I. Pigment Red 180, C.I. I. Pigment Red 181 and C.I. I. Pigment Red 182, C.I. I. Pigment Red 183, C.I. I. Pigment Red 184, C.I. I. Pigment Red 185, C.I. I. Pigment Red 187, C.I. I. Pigment Red 188, C.I. I. Pigment Red 190, C.I. I. Pigment Red 192, C.I. I. Pigment Red 193, C.I. I. Pigment Red 194, C.I. I. Pigment Red 200, C.I. I. Pigment Red 202, C.I. I. Pigment Red 206, C.I. I. Pigment Red 207, C.I. I. Pigment Red 208, C.I. I. Pigment Red 209, C.I. I. Pigment Red 210, C.I. I. Pigment Red 211, C.I. I. Pigment Red 213, C.I. I. Pigment Red 214, C.I. I. Pigment Red 216, C.I. I. Pigment Red 215, C.I. I. Pigment Red 216, C.I. I. Pigment Red 220, C.I. I. Pigment Red 221 and C.I. I. Pigment Red 223, C.I. I. Pigment Red 224, C.I. I. Pigment Red 226, C.I. I. Pigment Red 237, C.I. I. Pigment Red 238, C.I. I. Pigment Red 239, C.I. I. Pigment Red 240, C.I. I. Pigment Red 242, C.I. I. Pigment Red 245, C.I. I. Pigment Red 247, C.I. I. Pigment Red 248, C.I. I. Pigment Red 251 and C.I. I. Pigment Red 253, C.I. I. Pigment Red 254, C.I. I. Pigment Red 255, C.I. I. Pigment Red 256, C.I. I. Pigment Red 257, C.I. I. Pigment Red 258, C.I. I. Pigment Red 260, C.I. I. Pigment Red 262, C.I. I. Pigment Red 263, C.I. I. Pigment Red 264, C.I. I. Pigment Red 266, C.I. I. Pigment Red 268, C.I. I. Pigment Red 269, C.I. I. Pigment Red 270, C.I. I. Pigment Red 271, C.I. I. Pigment Red 272, C.I. I. Pigment Red 279, etc.

Examples of purple pigments include C.I. I. Pigment Violet 1, C.I. I. Pigment Violet 2, C.I. I. Pigment Violet 3, C.I. I. Pigment Violet 3: 1, C.I. I. Pigment Violet 3: 3, C.I. I. Pigment Violet 5: 1, C.I. I. Pigment Violet 13, C.I. I. Pigment Violet 19 (γ type, β type), C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 25, C.I. I. Pigment Violet 27, C.I. I. Pigment Violet 29, C.I. I. Pigment Violet 31, C.I. I. Pigment Violet 32, C.I. I. Pigment Violet 36, C.I. I. Pigment Violet 37, C.I. I. Pigment Violet 38, C.I. I. Pigment Violet 42, C.I. I. Pigment Violet 50 and the like.

Examples of the yellow pigment include C.I. I. Pigment Yellow 1, C.I. I. Pigment Yellow 3, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, Pigment Yellow 17, C.I. I. Pigment Yellow 24, C.I. I. Pigment Yellow 42, C.I. I. Pigment Yellow 55, C.I. I. Pigment Yellow 62, C.I. I. Pigment Yellow 65, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 86, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 109, C.I. I. Pigment Yellow 110, C.I. I. Pigment Yellow 117, C.I. I. Pigment Yellow 120, Pigment Yellow 125, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 129, C.I. I. Pigment Yellow 137, C.I. I. Pigment, Yellow 138, C.I. I. Pigment Yellow 139, C.I. I. Pigment Yellow 147, C.I. I. Pigment Yellow 148, C.I. I. Pigment Yellow 150, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 153, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 166, C.I. I. Pigment Yellow 168, C.I. I. Pigment Yellow 174, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 185 and C.I. I. Pigment Yellow 213 and the like.

Examples of the orange pigment include C.I. I. Pigment Orange 5, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 16, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 36, C.I. I. Pigment Orange 37, C.I. I. Pigment O Orange 38, C.I. I. Pigment Orange 43, C.I. I. Pigment Orange 51, C.I. I. Pigment range 55, C.I. I. Pigment Orange 59, C.I. I. Pigment Orange 61, C.I. I. Pigment Orange 64, C.I. I. Pigment Orange 71, or C.I. I. Pigment Orange 74 and the like.

Examples of brown pigments include C.I. I. Pigment Brown 23, C.I. I. Pigment Brown 25, or C.I. I. Pigment Brown 26 and the like.

Among them, as a preferable pigment, as a black pigment, C.I. I. Pigment Black 7,
As an indigo pigment, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 4, C.I. I. Pigment Blue 15: 6,
As a green pigment, C.I. I. Pigment Green 7,
As a red pigment, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 48: 2, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 146, C.I. I. Pigment Red 242, C.I. I. Pigment Red 185, C.I. I. Pigment Red 122, C.I. I. Pigment Red 178, C.I. I. Pigment Red 149, C.I. I. Pigment Red 144, C.I. I. Pigment Red 166,
As a purple pigment, C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 37,
As a yellow pigment, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 139,
As an orange pigment, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 64,
Etc., and it is preferable to use at least one or two or more selected from these groups.

Examples of inorganic pigments 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, the use of titanium oxide is particularly preferable. Titanium oxide has a white color and is preferable from the viewpoints of coloring power, hiding power, chemical resistance and weather resistance, and from the viewpoint of printing performance, the titanium oxide is preferably treated with silica and / or alumina.

Examples of non-white inorganic pigments include aluminum particles, mica (mica), bronze powder, chrome vermilion, chrome yellow, cadmium yellow, cadmium red, ultramarine, dark blue, red iron oxide, yellow iron oxide, iron black, and zircon. Although aluminum is in the form of powder or paste, it is preferably used in the form of paste from the viewpoint of handleability and safety, and whether chrome yellow or non-leafing is used is appropriately selected from the viewpoint of brightness and density.

The average particle size of the pigment is preferably in the range of 1 to 300 nm, more preferably about 50 to 150 nm.
The amount of the pigment is sufficient to secure the concentration and coloring power of the water-based liquid printing ink, that is, 1 to 60% by weight based on the total weight of the ink composition, and 10 to 10 to 60% by weight of the solid content in the ink composition. It is preferably contained in a proportion of 90% by weight. In addition, these pigments can be used alone or in combination of two or more.

(Other ingredients)
The water-based liquid ink of the present invention may be used as a general-purpose resin other than the copolymer (A), a extender pigment, a pigment dispersant, a leveling agent, a defoaming agent, a plasticizer, an infrared absorber, an ultraviolet absorber, as required. It can contain a fragrance, a flame retardant, and the like. Among them, fatty acid amides such as oleic acid amide, stearic acid amide, and erucic acid amide for imparting abrasion resistance and slipperiness, and silicon-based and non-silicon-based defoamers for suppressing foaming during printing. It often contains various pigment dispersants and the like that improve the wetting of pigments.

(Production method)
In the water-based liquid ink of the present invention, a pigment, water alone, or a mixture containing water and an organic solvent mixed with water, a pigment dispersant, a defoaming agent, etc. is dispersed by a disperser to obtain a pigment dispersion. The aqueous liquid ink of the present invention can be obtained by adding an additive such as a resin, water, or an organic solvent miscible with water, and if necessary, a leveling agent, to the obtained pigment dispersion, and stirring and mixing. As the disperser, a bead mill, an Eiger mill, a sand mill, a gamma mill, an attritor, or the like, which are generally used for manufacturing gravure and flexographic printing inks, are used.

When the water-based liquid ink of the present invention is used as a flexo ink, its viscosity may be 7 to 25 seconds at 25 ° C., more preferably 10 to 20 seconds, using Zahn Cup # 4 manufactured by Rigosha. 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 the substrate such as a film. However, when the surface tension is less than 25 mN / m, the ink spreads and the halftone dots are adjacent to each other. Tend to be easily connected, which tends to cause stains on the printed surface called dot bridge. On the other hand, when the surface tension exceeds 50 mN / m, the wettability of the ink to a base material such as a film is lowered, which tends to cause repelling.

On the other hand, when the water-based liquid ink of the present invention is used as a gravure ink, its viscosity may be 7 to 25 seconds at 25 ° C. using Zahn Cup # 3 manufactured by Rigosha, more preferably 10 to 20 seconds. is there. 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, as with flexographic ink. The lower the surface tension of the ink, the better the wettability of the ink to the substrate such as a film. However, when the surface tension is less than 25 mN / m, the ink spreads and the halftone dots are adjacent to each other. Tend to be easily connected, which tends to cause stains on the printed surface called dot bridge. On the other hand, when the surface tension exceeds 50 mN / m, the wettability of the ink to a base material such as a film is lowered, which tends to cause repelling.

(Printed matter)
In the present invention, a printed matter is obtained by printing the water-based liquid ink of the present invention on a substrate and providing a printed layer. Usually, a printing layer is obtained by applying an ink to a base material using a gravure method or a flexographic printing method, drying the ink by drying in an oven, and fixing the ink. The drying temperature is usually about 40 to 60 ° C.

In the present invention, it is preferable to print the liquid printing ink by using the flexographic printing method from the viewpoints of high-speed printing suitability, print reproducibility, and the like.
Flexographic printing is a type of letterpress printing, in which a rubber plate is mainly used as a printing plate (letter plate), and a fine mesh engraving roll called anilox roll is used for a portion that supplies ink to the printing plate. Anilox roll receives ink from a chamber type doctor and applies ink on the printing plate, and has an advantage that the ink can be uniformly transferred to the printing plate via the anilox roll.

Specifically, ink is applied to the bulkhead and the surface of the anilox roll having many openings surrounded by the bulkhead, and the doctor is pressed against the surface of the anilox roll to scrape off the ink existing on the top surface of the bulkhead of the anilox roll. , Fill the recesses, which are the openings, with ink. Subsequently, the flexographic plate is pressed against the anilox roll to transfer the ink existing in the concave portion of the anilox roll to the convex portion (pattern portion) of the printing plate, and then the plate is brought into contact with the substrate and exists in the pattern portion of the plate. The ink to be used is transferred to a substrate to obtain a printed matter.

Further, a rotary printing method may be combined. For example, in the method for producing a rotary printed matter of a thermoplastic resin film, rotary printing is performed on the surface of a wound thermoplastic resin film using a water-based liquid ink. After printing, processes such as laminating, slitting (cutting unnecessary parts in the width portion), and bag making (cutting and heat-sealing to make a bag) can be performed. High-speed printing is possible and productivity is excellent by winding the liquid printing ink and rotating it on a thermoplastic resin film.
There are gravure rotation printing and flexo rotation printing in the rotation printing, and either method may be used. However, in the present application, it is preferable to print the water-based liquid printing ink by using the flexo printing method as described above. Rotational printing will be described in detail. In the present specification, the rotary printing means gravure rotary printing and flexographic rotary printing, and does not include ink jet printing and silk screen printing, which are other printing methods.

In flexographic rotary printing, ink is supplied directly from a container for storing liquid printing ink or via an ink supply pump or the like to an Anirox roller having an uneven shape on the surface, and the ink supplied to the Anirox roller is used on the plate surface. The contact with the convex portion transfers to the plate surface, and the contact between the plate surface and the thermoplastic resin film finally transfers to the thermoplastic resin film to form a pattern and / or characters.

When a water-based flexographic printing ink is used, the ink drying property is slightly inferior to that of the solvent-based flexographic printing ink, so that the ink film thickness is preferably as thin as possible. From this point of view, it is preferable that the amount of ink supplied to the Aronix roller is as small as possible. On the other hand, the print density tends to decrease as the film thickness decreases, so the pigment concentration of the water-based flexographic printing ink used may be appropriately controlled. Specifically, when the pigment concentration of the water-based flexographic printing ink is 1 to 5% by weight higher than the concentration of the solvent-type flexographic printing ink, an appropriate printing density can be obtained.

The take-up thermoplastic resin film is a roll-shaped thermoplastic resin film having a specified width, which is different from the sheet paper in which each sheet is separated in advance, and is a film for rotary printing. Is. The width of the film is appropriately selected based on the plate width of the rotary printing press to be used and the width of the image (picture) portion of the gravure plate.
When the colors are superimposed using the rotary printing inks of a plurality of colors, the printing order thereof is not particularly limited.

When performing front printing, it is common to print white ink first, and then color ink, if necessary. When there are a plurality of color inks, for example, yellow, magenta, cyan, and black can be printed in this order, but the printing is not particularly limited. In the case of a front print configuration, abrasion resistance, water resistance, and the like can be improved by applying an overcoat agent to the printed surface of the rotary printed matter as needed.
When the base material is white, that is, for example, a paper base material and a thermoplastic resin film kneaded with a white pigment, printing with only color ink is possible if necessary.

Further, in the case of back printing, it is common to print the color ink on the take-up thermoplastic resin film first, and then print the white ink. When the color ink has a plurality of colors, for example, black, cyan, magenta, and yellow can be printed in this order, but the printing is not particularly limited. In the large printing machine, special colors and the like can be used in addition to the basic colors. That is, the large-sized printing machine has a plurality of printing units corresponding to 5 to 10 colors, one printing unit is provided with one color of ink, and 5 to 10 colors can be overprinted at one time.
The printed matter obtained by back printing may be used as it is, or an anchor coating agent, an adhesive or the like may be applied to the printed surface of the rotary printed matter obtained by the above method, and if necessary, after drying, a film or the like may be used. It can also be laminated with.

The printed matter of the water-based liquid ink (A) of the present invention is excellent in coating film strength, particularly abrasion resistance and scratch resistance, and is therefore suitable for a form in which the printed layer is the outermost layer. In the front-printed matter and the back-printed matter, a printed matter having a printed layer of the water-based liquid ink (A) in the present invention on the surface that becomes the outermost layer at the time of distribution is preferable because the effect of the present invention can be maximized.

(Laminated body)
The laminate of the present invention may be a laminate that includes a printed matter having a printed layer of the water-based liquid ink of the present invention on a substrate by a printing method using a plate.

Examples of the base material include paper, synthetic paper, thermoplastic resin film, steel plate, aluminum foil, wood, woven cloth, knitted cloth, non-woven fabric, gypsum board, wood board and the like. Of these, paper, synthetic paper, thermoplastic resin film and the like are preferable. Further, a base material obtained by combining a plurality of types of these base materials may be used, for example, a base material in which paper and a thermoplastic resin film are laminated, or a base material in which a thermoplastic resin film and an aluminum foil are laminated. The laminating method is not particularly limited, and a general-purpose one-component adhesive, a two-component adhesive, or the like may be used for bonding, or if there are a plurality of thermoplastic resin films, the laminated body is bonded by extrusion molding. It may be.

The thermoplastic resin film is not particularly limited, and for example, polyamide resins such as nylon 6, nylon 66, and nylon 46, polyethylene phthalate (PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, and polybutylene. Biodegradable resins typified by polyester resins such as terephthalate and polybutylene naphthalate, polyhydroxycarboxylic acids such as polylactic acid, and aliphatic polyester resins such as poly (ethylene succinate) and poly (butylene succinate). Examples thereof include films made of polyolefin resins such as polypropylene (PP) and polyethylene, polyimide resins, polyarylate resins or thermoplastic resins such as mixtures thereof, and laminates thereof. Among them, polyester, polyamide, polyethylene and polypropylene are used. A film can be preferably used.
These films may be unstretched films or stretched films, and the production method thereof is not limited. Further, the thickness of the base film is not particularly limited, but usually it may be in the range of 1 to 500 μm.
Further, if the printed surface of the film is subjected to a corona discharge treatment, the adhesion to the base material can be further improved, which is preferable. Further, silica, alumina or the like may be vapor-deposited, or a gas barrier coat layer such as an oxygen gas barrier layer may be laminated.
I.

When paper is used as the base material, examples of the base paper include kraft paper, liner paper, art paper, coated paper, and carton paper. Moreover, you may use synthetic paper. The structure of the synthetic paper is not particularly limited and may be a single-layer structure or a multi-layer structure. As the multilayer structure, for example, there are a two-layer structure of a base material layer and a surface layer, a three-layer structure in which the base material layer and the front and back surfaces are present, and another resin film layer between the base material layer and the surface layer. A multi-layer structure can be exemplified. Further, each layer may or may not contain an inorganic or organic filler. Further, a microporous synthetic paper having a large number of fine voids can also be used.

A printing layer using the water-based liquid ink of the present invention is provided on the base material, and the printing layer may be one layer or a plurality of layers. During normal printing, white, process color (black (also referred to as black, blackish color), red (also referred to as magenta, reddish color), indigo (also referred to as cyan, bluish color) ), Yellow (also referred to as yellow, which is a yellowish color), and special color inks other than these basic colors are appropriately combined for printing. In the present invention, the water-based liquid of the present invention is applied to each of these color inks. An ink can be used, or a general-purpose water-based or oil-based liquid ink other than the water-based liquid ink of the present invention and the water-based liquid ink of the present invention, or an overcoat varnish can be used in combination. A commercially available overcoat varnish can be used, but as described above, it can also be used as an overcoat varnish in a form that does not contain a coloring material in the water-based liquid ink of the present invention.

More specific configurations of these print layers are listed below. Of course, the present invention is not limited to this configuration, and a printed matter and a laminate represented by a plurality of printing layers according to a desired design can be obtained.
As an abbreviation,
The printing layer using the water-based liquid ink of the present invention is referred to as "the present printing layer (color)".
"General-purpose printing layer (color)" is the printing layer using general-purpose water-based liquid ink.
The water-based liquid ink overcoat varnish of the present invention is referred to as "this OP".
"General-purpose OP" for general-purpose water-based liquid ink overcoat varnish
It is expressed as. Note that "/" means that they are adjacent to each other. For example, in the case of "base material / main printing layer (other than white) / main OP", the printing layer using the water-based liquid ink of the present invention is adjacent to the base material ( (Other than white) is provided, and the water-based liquid ink overcoat varnish of the present invention is provided adjacent to the print layer (other than white). It means that.

Base material / book OP
Base material / main printing layer (white) / main OP
Base material / main printing layer (white) / main printing layer (white)
Base material / main printing layer (white) / main printing layer (white) / main OP
Base material / main printing layer (other than white) / main OP
Base material / main printing layer (other than white) / main printing layer (white)
Base material / Main printing layer (other than white) / Main printing layer (white) / Main printing layer (white)
Base material / Main printing layer (other than white) / Main printing layer (white) / Main printing layer (white)
Substrate / Main printing layer (other than white) / Main printing layer (white) / Main printing layer (white) / Main OP
Base material / main printing layer (other than white) / main printing layer (white)
Base material / Main printing layer (other than white) / Main printing layer (white) / Main printing layer (color)
Base material / Main printing layer (other than white) / Main printing layer (white) / Main printing layer (color) / Main OP
Base material / Main printing layer (other than white) / Main printing layer (white) / Main printing layer (white) / Main printing layer (color)
Substrate / Main print layer (other than white) / Main print layer (white) / Main print layer (white) / Main print layer (color) / Main OP
Base material / general-purpose printing layer (other than white) / book OP
Base material / General-purpose printing layer (other than white) / Main printing layer (white)
Base material / General-purpose printing layer (other than white) / Main printing layer (white) / Main printing layer (white)
Base material / General-purpose printing layer (other than white) / Main printing layer (white) / Main printing layer (white)
Base material / General-purpose printing layer (other than white) / Main printing layer (white) / Main printing layer (white) / Main OP
Base material / main printing layer (other than white) / general-purpose OP
Base material / Main printing layer (other than white) / General-purpose printing layer (white)
Base material / Main printing layer (other than white) / General-purpose printing layer (white) / Main printing layer (white)
Base material / Main printing layer (other than white) / General-purpose printing layer (white) / Main printing layer (white)
Base material / Main printing layer (other than white) / General-purpose printing layer (white) / Main printing layer (white) / Main OP
Base material / Main printing layer (other than white) / Main printing layer (white) / General-purpose printing layer (white)
Base material / Main printing layer (other than white) / General-purpose printing layer (white) / General-purpose printing layer (white)
Base material / Main printing layer (other than white) / General-purpose printing layer (white) / General-purpose printing layer (white) / Main OP

In the above configuration, the base material is preferably a thermoplastic resin film. By having the thermoplastic film having a printed matter having a print layer other than white and a white print layer, preferable visibility can be obtained.

(Printing ink B)
A general-purpose water-based liquid ink is more preferably a printing ink containing a polyurethane resin or an acrylic polyurethane resin and a pigment. (Hereinafter, a printing ink containing a polyurethane resin or an acrylic polyurethane resin and a pigment may be referred to as a printing ink (B).)
In particular, when a thermoplastic resin film is used as the base material, by using a printing ink containing a polyurethane resin or an acrylic polyurethane resin as the ink in contact with the thermoplastic resin film, the coating film is more flexible than the acrylic resin. This is preferable because it has high adhesion to the thermoplastic resin film and high followability due to deformation of the film base material.
In addition, the polyurethane resin or acrylic polyurethane resin has the same or better performance as the acrylic resin in terms of pigment dispersibility, resolubility during printing, and color development when the pigment is dispersed, and is compatible with the pigment. ..
In particular, a printing ink containing an acrylic polyurethane resin is more preferable than a printing ink containing a polyurethane resin because it has better color development and resolubility and is less likely to cause stringing during printing. In the ink, both the polyurethane resin and the acrylic polyurethane resin may be mixed and used, or if necessary, the acrylic resin may be appropriately mixed and used.

The polyurethane resin used in the printing ink (B) preferably has a weight average molecular weight of 20,000 to 2,000,000 and an acid value of 10 to 50 mgKOH / g, more preferably a weight average molecular weight of 30, It is 000 to 1,500,000 and 20 to 50 mgKOH / g. If the weight average molecular weight is 20,000 or more, the friction resistance and the water friction resistance do not decrease, and if the weight average molecular weight is 2,000,000 or less, the decrease in substrate adhesion is suppressed. Can be done. Further, when the acid value is 10 mgKOH / g or more, the resolubility of the ink film in the aqueous solvent in printing is deteriorated, and the tone reproducibility of the printed matter is not deteriorated, and the image when the liquid printing ink laminate is formed. It is also possible to suppress a decrease in reproducibility. On the other hand, when the acid value is 50 mgKOH / g or less, the water resistance of the resin does not decrease, and the deterioration of the substrate adhesion and the water friction resistance of the printed layer can be suppressed. The acid value referred to here indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin.

The acrylic polyurethane resin used in the printing ink (B) preferably has a weight average molecular weight of 20,000 to 2,000,000 and an acid value of 10 to 60 mgKOH / g, more preferably a weight average molecular weight of 30. It is 000 to 1,500,000 and 20 to 50 mgKOH / g. If the weight average molecular weight is 20,000 or more, the friction resistance and the water friction resistance do not decrease, and if the weight average molecular weight is 2,000,000 or less, the decrease in substrate adhesion is suppressed. Can be done. Further, when the acid value is 10 mgKOH / g or more, the image reproducibility as a liquid printing ink laminate can be well maintained without deteriorating the tone reproducibility of the printed matter.
On the other hand, when the acid value is 60 mgKOH / g or less, the water resistance of the resin does not decrease, and the substrate adhesion and water friction resistance of the laminate can be kept good.

On the other hand, the printing layer of the water-based liquid ink (A) of the present invention is excellent in coating film strength, particularly abrasion resistance and scratch resistance, and is therefore the farthest from the outermost layer of the laminate, that is, the thermoplastic resin film which is the base material. By providing a printing layer of water-based liquid ink (A) on the upper layer, the strength of the laminated body becomes more sufficient, and basic coatings such as substrate adhesion, abrasion resistance, water friction resistance, and scratch resistance are applied. The film strength tends to be more retained. The printing layer at this time may be appropriately applied as a color ink containing a color material or as an overcoat varnish containing no color material depending on the desired design. The most commonly applied color ink containing a coloring material is a white ink containing a white pigment. Further, since a stronger print layer surface can be obtained by printing the water-based liquid ink (A) on top of each other and laminating a plurality of print layers, a print layer in which a plurality of layers of the same color (for example, white ink again on the white ink) are laminated. It may be. Further, a printing layer may be formed in which a plurality of layers of overcoat varnish containing no coloring material are laminated on a color ink (for example, white ink).

In a laminate having a printed layer printed by adding an appropriate amount of the curing agent to the water-based liquid ink (A), the viscosity stability of the ink is slightly lowered by the increase in the curing speed, but the substrate adhesion and resistance to the substrate. It is possible to obtain a tougher laminate having abrasion resistance, water friction resistance, and scratch resistance.

The laminate having the print layer of the water-based liquid ink (A) of the present invention is suitable for a form in which the print layer is the outermost layer because the print layer is excellent in coating film strength, particularly abrasion resistance and scratch resistance. There is. In the front-printed matter and the back-printed matter, a printed matter having a printed layer of the water-based liquid ink (A) in the present invention on the surface that becomes the outermost layer at the time of distribution is preferable because the effect of the present invention can be maximized. It can be applied to various applications such as plastic labels (corresponding to shrink labels and body-wrap labels) applied to beverage and food bottles, integrated packaging, and exterior packaging.

The present invention will be described in more detail with reference to the following examples. In the examples, "part" represents "parts by mass" and "%" represents "% by mass".

The weight average molecular weight (in terms of polystyrene) measured by GPC (gel permeation chromatography) in the present invention was measured using an HLC8220 system manufactured by Toso Co., Ltd. under the following conditions.
Separation column: Uses 4 TSKgelGMH _HR- N manufactured by Tosoh Corporation. Column temperature: 40 ° C. Moving layer: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow velocity: 1.0 ml / min. Sample concentration: 1.0% by mass. Sample injection volume: 100 microliters. Detector: Differential refractometer.
The acid value of the acrylic resin indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin, and each dried water-soluble resin was prepared according to JIS K2501. It was calculated from potentiometric titration with a potassium hydroxide / ethanol solution.
The glass transition temperature (Tg) refers to the so-called calculated glass transition temperature, and refers to a value calculated by the following method.
(Equation 1) 1 / Tg (K) = (W1 / T1) + (W2 / T2) + ... (Wn / Tn)
(Equation 2) Tg (° C.) = Tg (K) -273
W1, W2, ... Wn in the formula 1 represent the mass% of each monomer with respect to the total mass of the monomers used for producing the polymer, and T1, T2, ... Tn are the homopolymers of each monomer. Represents the glass transition temperature (K). As the values of T1, T2, ... Tn, the values described in Polymer Handbook (Fourth Edition, J. Brandrup, E.H. Immersut, EA Grulke) are used.
Although the glass transition temperature of the homopolymer of each monomer is not described in the Polymer Hand Book, the glass transition temperature is based on JIS K7121 using a differential scanning calorimeter "DSC Q-100" (manufactured by TA Instrument). It was measured by the method described above. Specifically, the polymer from which the solvent has been completely removed by vacuum suction is measured for a change in calorific value in the range of -100 ° C to + 200 ° C at a heating rate of 20 ° C./min, and an extended straight line of each baseline. The point where the straight line equidistant from the vertical axis direction and the curve of the stepwise change portion of the glass transition intersect was defined as the glass transition temperature.

[Synthesis Example 1: Preparation of Shell Acrylic Resin (Polymer a1)]
The 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. The temperature was raised to 90 ° C. while stirring in 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 added dropwise over 4 hours using a dropping funnel. After completion of the dropping, the reaction was carried out for another 6 hours. After completion of the reaction, the mixture was cooled and neutralized by adding 8.0 parts of 30% aqueous ammonia to the obtained acrylic resin solution. Further, ion-exchanged water was added and solvent substitution was carried out while heating to obtain an aqueous solution of an acrylic resin having a solid content of 55%. The acid value was 105 mgKOH / g, Tg was 65 ° C., and the weight average molecular weight was 16,000.

[Synthesis Example 2: Preparation of Core Shell Acrylic Emulsion (A1) Having Copolymer] Acid Value 42
A stirrer, a thermometer, a dropping funnel, and a reflux tube are provided in a reaction vessel containing 121.2 parts of the acrylic resin aqueous solution prepared in Synthesis Example 1, and 195.5 parts of ion-exchanged water is added. The temperature was raised to 75 ° C. while stirring in 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. Dropped over. After the dropping was completed, the reaction was further carried out for 6 hours to obtain a core-shell acrylic emulsion (A1) having a solid content of 40%. The acid value was 42 mgKOH / g, Tg was 10 ° C., and the weight average molecular weight was 1,200,000.

[Synthesis Example 3: Preparation of Core Shell Acrylic Emulsion (A2) Having Copolymer] Acid Value 42
A stirrer, a thermometer, a dropping funnel, and a reflux tube are provided in a reaction vessel containing 121.2 parts of the acrylic resin aqueous solution prepared in Synthesis Example 1, and 195.5 parts of ion-exchanged water is added. The temperature was raised to 75 ° C. while stirring in a nitrogen atmosphere. Subsequently, using a dropping funnel, 32.0 parts of methyl methacrylate, 28.0 parts of butyl acrylate, 10.0 parts of ethyl methacrylate, 30.0 parts of isobutyl methacrylate, and 3.5 parts of 30% ammonium persulfate were added dropwise over 4 hours. .. After the dropping was completed, the reaction was further carried out for 6 hours to obtain a core-shell acrylic emulsion (A2) having a solid content of 40%. The acid value was 42 mgKOH / g, Tg was 45 ° C., and the weight average molecular weight was 1,200,000.

[Synthesis Example 4: Preparation of Shell Styrene Acrylic Resin]
The reaction vessel is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 65.0 parts of n-propyl acetate is charged. The temperature was raised to 90 ° C. while stirring in a nitrogen atmosphere. On the other hand, 36.0 parts of styrene, 12.0 parts of ethyl methacrylate, 20.0 parts of 2-ethylhexyl acrylate, 32.0 parts of acrylic acid, 1.6 parts of azobisisobutyronitrile and 35.0 parts of n-propyl acetate. It was dissolved in and dropped over 4 hours using a dropping funnel. After completion of the dropping, the reaction was carried out for another 6 hours. After completion of the reaction, the mixture was cooled and neutralized by adding 20.0 parts of 30% aqueous ammonia to the obtained acrylic resin solution. Further, ion-exchanged water was added and solvent substitution was carried out while heating to obtain an aqueous solution of an acrylic resin having a solid content of 30%. The acid value was 250 mgKOH / g, Tg was 61 ° C., and the weight average molecular weight was 10,200.

[Synthesis Example 5: Preparation of Core-Shell Type Styrene Acrylic Emulsion (A3) Having Copolymer] Acid Value 100
A stirrer, a thermometer, a dropping funnel, and a reflux tube are provided in a reaction vessel containing 222.2 parts of the styrene acrylic resin aqueous solution prepared in Synthesis Example 4, and 119.6 parts of ion-exchanged water is added. The temperature was raised to 75 ° C. while stirring in a nitrogen atmosphere. Subsequently, using a dropping funnel, 32.0 parts of methyl methacrylate, 46.0 parts of butyl acrylate, 10.0 parts of ethyl methacrylate, 18.0 parts of isobutyl methacrylate, and 3.5 parts of 30% ammonium persulfate were added dropwise over 4 hours. .. After the dropping was completed, the reaction was further carried out for 6 hours to obtain a core-shell type styrene acrylic emulsion (A3) having a solid content of 38.5%. The acid value was 100 mgKOH / g, Tg was 42 ° C., and the weight average molecular weight was 1,200,000.

[Synthesis Example 6: Preparation of Copolymer (B)] Acid Value 220
The reaction vessel is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 65.0 parts of n-propyl acetate is charged. The temperature was raised to 90 ° C. while stirring in a nitrogen atmosphere. On the other hand, 45.0 parts of styrene, 10.0 parts of ethyl methacrylate, 20.0 parts of 2-ethylhexyl acrylate, 25.0 parts of acrylic acid, 1.6 parts of azobisisobutyronitrile and 35.0 parts of n-propyl acetate. It was dissolved in and dropped over 4 hours using a dropping funnel. After completion of the dropping, the reaction was carried out for another 6 hours. After completion of the reaction, the mixture was cooled and neutralized by adding 20.0 parts of 30% aqueous ammonia to the obtained acrylic resin solution. Further, ion-exchanged water was added and solvent substitution was carried out while heating to obtain a copolymer (B) which is an aqueous solution of an acrylic resin having a solid content of 30%. The acid value was 220 mgKOH / g, Tg was 60 ° C., and the weight average molecular weight was 10,000.

[Synthesis Example 7: Preparation of Polyurethane Resin (Pu)]
186.9 parts of PLACCEL 212 (polycaprolactone diol manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 90 mgKOH / g) and 100.0 parts of isophorone diisocyanate (abbreviated as IPDI) were charged. This was heated to 110 ° C. with stirring. After 1 hour, the mixture was cooled to 80 ° C., 20.1 parts of dimethylolpropionic acid (abbreviated as DMPA), 0.3 part of dibutyltin dilaurate and 76.8 parts of ethyl acetate were added, and the reaction was carried out at 80 ° C. for 2 hours. I let you. To this, 18.1 part of Bernock DN-980S (manufactured by DIC, hexamethylene diisocyanate polyisocyanate, NCO content 20%) and 408 parts of methyl ethyl ketone (abbreviated as MEK) were added. The NCO group content at this time was 4.9% in terms of solid content.
This was cooled to 30 ° C. or lower, 15.2 parts of triethylamine was added, and then 1293 parts of ion-exchanged water was added to obtain an oil droplet (O / W) type emulsion in water. 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. Then, distillation was carried out under reduced pressure to remove a part of the solvent and water to obtain an aqueous solution of polyurethane resin (Pu).
This is a translucent liquid that is slightly milky white, and when a small amount is taken in a test tube and tetrahydrofuran (abbreviated as THF) is added, it becomes turbid and cross-linked to be insoluble. The non-volatile content was 39.6%, the viscosity was 160 cps, the pH was 7.7, and the average particle size was 28.5 nm.

[Synthesis Example 8: Preparation of Acrylic Urethane Resin (Au)]
The reaction vessel is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 80.0 parts of n-propyl acetate is charged. The temperature was raised to 90 ° C. while stirring in a nitrogen atmosphere. On the other hand, 32.0 parts of styrene, 20.0 parts of 2-hydroxyethyl methacrylate, 40.0 parts of 2-ethylhexyl acrylate, 8.0 parts of acrylic acid, and 3.0 parts of azobisisobutyronitrile were added to n-propyl acetate. It was dissolved in 40.0 parts and added dropwise over 4 hours using a dropping funnel. After completion of the dropping, 1.6 parts of Burnock DN-980S (manufactured by DIC, hexamethylene diisocyanate polyisocyanate, NCO content 20%) was gradually added, and the mixture was further reacted for 6 hours. After completion of the reaction, the mixture was cooled and neutralized by adding 4.0 parts of 30% aqueous ammonia to the obtained acrylic resin solution. Further, ion-exchanged water was added and solvent substitution was carried out while heating to obtain an aqueous solution of acrylic urethane resin (Au) having a solid content of 25%. The acid value was 62 mgKOH / g, the Tg was 30 ° C., and the weight average molecular weight was 600,000.

[Example 1: Production of OP varnish]
35 parts of the core-shell type acrylic emulsion (A1) having the copolymer prepared in Synthesis Example 2 in terms of solid content, Surfinol 420 (Cas No .: 9014-), which is an alkylene oxide-modified acetylene glycol-based surfactant as an acetylene-based surfactant. 85-1 Nisshin Kagaku Kogyo Co., Ltd.) 0.1 parts, polyethylene wax 5 parts, normal propanol 4 parts, defoamer 0.1 parts, ammonia water 1.2 parts, water 54.6 parts are stirred. After mixing, the meat was kneaded with a bead mill to prepare an OP varnish. It was confirmed that the viscosity of the obtained aqueous varnish was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha).

(Examples 2 to 24, Comparative Examples 1 to 13: Production of OP varnish)
OP varnishes were obtained with the formulations shown in Tables 1 to 3 and Tables 5 and 6.

(Example 25: Production of water-based liquid ink]
20 parts of core-shell type acrylic emulsion (A1) having the copolymer prepared in Synthesis Example 2, 40 parts of titanium oxide (product name: JR-800 manufactured by TAYCA Corporation), 1 part of Surfinol 420, polyethylene wax 5 A total of 100 parts, 3 parts of normal propanol, 0.1 part of defoaming agent, 0.6 part of ammonia water, and 31.3 parts of water, were stirred and mixed, and then kneaded with a bead mill to prepare a white aqueous liquid ink. .. It was confirmed that the viscosity of the obtained aqueous liquid ink was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha).

(Examples 26 to 33: Production of water-based liquid ink)
Aqueous liquid ink was obtained by the formulation shown in Table 4.

The abbreviations in the table are as follows.
-Copolymer (A1): A core-shell acrylic emulsion (A1) having the copolymer prepared in Synthesis Example 2.
-Copolymer (A2): A core-shell acrylic emulsion (A2) having the copolymer prepared in Synthesis Example 3.
-Copolymer (A3): Core-shell type styrene acrylic emulsion (A3) having the copolymer prepared in Synthesis Example 5.
-Copolymer (B): The copolymer (B) prepared in Synthesis Example 6
-Core-shell acrylic emulsion (C) with copolymer: Emmapoly DG-197 (glass transition temperature -30 ° C, acid value 38 mgKOH / g, manufactured by Gifu Shellac Manufacturing Co., Ltd.)
-Acetylene-based surfactant: Surfinol 420 (alkylene oxide-modified acetylene glycol-based surfactant Cas No .: 9014-85-1 manufactured by Nisshin Chemical Industry Co., Ltd.)
-Alcohol alkoxylate-based surfactant: DYNWET800 Alcohol alkoxylate-based surfactant manufactured by Big Chemie Japan Co., Ltd.)
・ Water ・ Normal propanol ・ Polyethylene wax ・ Defoamer ・ Ammonia water ・ Epoxy curing agent: Denacol EX-612 (sorbitol polyglycidyl ether Nagase ChemteX Co., Ltd.)
-Polyurethane (Pu): Polyurethane resin (Pu) prepared in Synthesis Example 7.
-Acrylic urethane (Au): Acrylic urethane resin (Au) prepared in Synthesis Example 8
-Pigment dispersion resin: Styrene-maleic acid-based pigment dispersion resin-Titanium oxide (IV): JR-800 (manufactured by TAYCA)
-Indigo pigment: FASTPGEN BLUE LA5380 (manufactured by DIC Corporation)

Tables 1 to 7 show examples of each ink and varnish. The hollow column in the table indicates that the mixture is not blended.

　

The indigo inks of Reference Examples 1 and 2 shown in Table 7 indicate the printing ink B and the like used for the general-purpose printing layer described in the detailed description.

<Preparation of printing ink laminate>
[Example]
A solid pattern of 240 mm in length x 80 mm in width is printed on a corona-treated polypropylene biaxially stretched film (Piperen P2161 manufactured by Toyobo Co., Ltd., 20 μm in thickness) with a Flexoprof100 test printing machine (Testing Machines, Inc., Anilox 200 line / inch). ) Was used to print the OP varnish or water-based liquid ink obtained in Examples or Comparative Examples with an Anilox roll and a resin plate at a printing speed of 100 m / min, and the obtained printed matter was aged at 40 ° C. for 20 hours. This was carried out to obtain a printing ink laminate.
The printing order of the OP varnish or the water-based liquid ink was set to be in the order of the first printing layer → the second printing layer → the third printing layer → the fourth printing layer according to Tables 8 to 47.

Using the produced two-layer structure printing ink laminate (P1) and three-layer structure printing ink laminate (P2), the substrate adhesion, abrasion resistance, water friction resistance, and scratch resistance were evaluated, and also. The viscosity stability of the prepared acrylic resin-based ink and varnish of the present invention was also evaluated.

<Adhesion to base material>
A cellophane tape (manufactured by Nichiban Co., Ltd.) was attached to the ink-coated surface of the obtained printing ink laminate, and then the ink was strongly peeled off to visually determine the degree of ink peeling.
The practical level is ○ △ or higher.
◎: Ink did not peel off at all ○: Ink slightly peeled off from the film (less than 20%)
○ △: Ink peels off from the film (20% or more, less than 40%)
Δ: Ink peels off from the film (40% or more, less than 60%)
X: Ink peels significantly from the film (60% or more)

<Abrasion resistance>
The obtained printed ink laminate was rubbed with high-quality paper using a Gakushin-type friction resistance tester, and the degree of peeling of the ink layer was visually determined. (500 round trips with a load of 500 g)
The practical level is Δ or higher.
⊚: Ink did not peel off at all ○: Ink slightly peeled off from the film (less than 15%)
○ △: Ink peels off from the film (15% or more, less than 30%)
Δ: Ink peels off from the film (30% or more, less than 50%)
X: Ink peels significantly from the film (50% or more)

<Water friction resistance>
The obtained printed ink laminate was rubbed with a water-containing black cotton cloth using a Gakushin type friction resistance tester, and the degree of peeling of the ink layer was visually determined. (500 round trips with a load of 200 g)
The practical level is Δ or higher.
⊚: Ink did not peel off at all ○: Ink slightly peeled off from the film (less than 15%)
○ △: Ink peels off from the film (15% or more, less than 30%)
Δ: Ink peels off from the film (30% or more, less than 50%)
X: Ink peels significantly from the film (50% or more)

<Scratch resistance>
The ink-coated surface of the obtained printed ink laminate was scratched with a nail, and the scratch resistance was visually evaluated from the degree of damage to the coating film.
The practical level is ○ △ or higher.
◎: No scratches ○: Slight scratches ○ △: Medium scratches of ○ and △ △: Scratches ×: Significant scratches (even if the nail is vertical) Things that come off)

<Viscosity stability>
With respect to the prepared acrylic resin-based ink / varnish of the present invention, the viscosity after 6 hours at 25 ° C. for 15 seconds was evaluated using Zahn Cup # 4 (manufactured by Rigosha).
◎: Ink did not thicken at all (less than +1 second)
◯: Ink slightly thickened (less than +3 seconds)
○ △: Ink slightly thickened (less than +5 seconds)
Δ: Ink thickened (less than +10 seconds)
X: Ink is significantly thickened (+10 seconds or more)

Tables 8 to 47 show the composition of the obtained printing ink laminate and the evaluation results. In the table, blanks in "first print layer, second print layer, third print layer, fourth print layer" indicate that there is no print layer. For example, in Example 1 of the laminate shown in Table 8, indigo ink PU-indigo was printed as the first printing layer and then OP varnish A1-OP1 was printed as the second printing layer on the corona-treated polypropylene biaxially stretched film. It is a laminated body. Further, for example, in Example 8 of the laminate shown in Table 8, indigo ink PU-indigo is printed as the first printing layer on the corona-treated polypropylene biaxially stretched film, and then white ink A1-white 1 is printed as the second printing layer. It is a laminate obtained by printing and then printing OP varnish A1-OP1 as a third printing layer.

As a result, the following findings can be obtained.
-When a copolymer (A3) is used as a binder, it has excellent abrasion resistance. This is noticeable when the OP varnish of the present invention or the water-based ink of the present invention comes to the outermost layer.
-The effect of the printing layer of the OP varnish of the present invention or the water-based ink of the present invention is particularly remarkable in the case of a laminate having a plurality of printing layers, and the general-purpose ink AU-indigo, which has weak adhesion to the substrate, is used. Even in this case, the adhesion to the base material is particularly excellent.
-When a cross-linking agent is used in combination with the OP varnish of the present invention or the water-based ink of the present invention, the substrate adhesion, frictional property, and scratch property are particularly excellent.
-The white ink containing the pigment of the present invention is excellent in adhesion, friction, and scratch property regardless of whether or not it has a cross-linking agent.

From the above results, the water-based liquid ink of the present invention can provide a laminate having excellent viscosity stability, substrate adhesion of a cured coating film, and various coating film strengths.
Further, even in a system to which a curing agent is added, it is possible to provide a laminate having a viscosity stability comparable to that of the cured coating film, which further enhances the adhesion of the cured coating film to the substrate and the strength of various coating films.

The liquid printing ink laminate of the present invention can be widely used as various gravure and flexographic printed matter for industrial products such as food packaging materials, sanitary products, cosmetics, and electronic parts.

Claims (6)

1. A copolymer formed from one or more (meth) acrylate-based monomers and / or one or more vinyl-based monomers and having an acid value having a glass transition temperature of 0 ° C. to 55 ° C.
   The acetylene-based surfactant and / or the alcohol alkoxylate-based surfactant is contained in an amount of 0.1 to 1% by mass based on the total amount of the ink, and the wax is contained in an amount of 0.5 to 5% by mass based on the total amount of the ink. Aqueous liquid ink.
2. The water-based liquid ink according to claim 1, wherein the copolymer having an acid value is a (meth) acrylic copolymer having an acid value or a styrene (meth) acrylic copolymer having an acid value.
3. The aqueous liquid ink according to claim 1 or 2, wherein the acetylene-based surfactant is an alkylene oxide-modified acetylene glycol-based surfactant.
4. The aqueous liquid ink according to any one of claims 1 to 3, which contains a curing agent capable of reacting with an acid.
5. The water-based liquid ink according to any one of claims 1 to 4, which is applied to flexographic printing or gravure printing.
6. A laminate having one or a plurality of printing layers on a base material, wherein at least one of the printing layers is the printing layer of the water-based liquid ink according to any one of claims 1 to 5. Laminated body.