JP7354501B2 - Water-based printing ink composition - Google Patents

Description

The present invention relates to aqueous printing ink compositions.

Water-based flexographic letterpress printing is used in the field of printing packaging containers, mainly cardboard, for household goods and industrial materials. In recent years, environmental initiatives have become more active, and in the packaging industry, it is possible to reduce carbon dioxide emissions (carbon neutrality) by using raw materials that are not derived from fossil fuels, such as plant-derived and animal-derived raw materials. Increasingly, there is a growing demand for the creation of ink that is Prior to this request, the applicant used as a binder resin an aqueous polylactic acid resin dispersion in which a polylactic acid resin was dispersed in an aqueous medium in the presence of a poly(ethylene oxide/propylene oxide) block polymer. (For example, see Patent Document 1). However, this method had the problem of insufficient printability and coating film properties. Furthermore, when used as thin paper for food packaging, there has been a problem in that the physical properties of the coating film, such as printability, water resistance, abrasion resistance, heat resistance, oil resistance and abrasion resistance, are insufficient. Furthermore, when printing on paper food containers, for example, in environments where paper food containers are used, that is, in environments where water or oil adheres, in addition to the above properties, it is necessary to However, no printing ink composition with this property existed. Furthermore, when a large amount of carbon-neutral raw materials is used, there is a problem in that the physical properties and printability of conventional ink coatings deteriorate.
Further, Patent Document 2 states that the core resin contains a (meth)acrylic acid ester-derived structural unit having a hydrocarbon group having 2 to 18 carbon atoms in an amount of 40% by mass of the structural units constituting the core resin. The core-shell type resin particles (A) have an acid value of 50 mgKOH/g or more and 100 mgKOH/g or less, and contain two-layer core-shell type resin particles and glycol ether, and have excellent storage stability and substrate adhesion. An excellent gravure printing resin particle dispersion is described.

Japanese Patent Application Publication No. 2008-013657 JP 2019-116535 Publication

According to the description in Patent Document 1, even a water-based flexographic printing ink composition that uses many carbon-neutral raw materials can improve water and abrasion resistance, abrasion resistance, oil and abrasion resistance, and washability in a well-balanced manner. was not taken into account.
According to the description in Patent Document 2, when the resin particle dispersion is blended into an ink composition for gravure printing, it can be predicted that it will contribute to improving the storage stability and substrate adhesion of the ink composition. . However, with respect to such an ink composition film, no consideration has been given to improving the water and abrasion resistance, oil and abrasion resistance, and washability in a well-balanced manner.
Therefore, an object of the present invention is to obtain an aqueous printing ink composition that can improve both water and abrasion resistance, oil and abrasion resistance, and washability in an ink composition film.

The present inventors have discovered that the above problems can be solved by employing a specific core-shell structure emulsion type resin as the resin component in the aqueous printing ink composition.
That is, the present invention is as follows.
1. An aqueous printing ink composition comprising a colorant, a resin for pigment dispersion, a core-shell emulsion type resin with an average particle diameter of 30 to 200 nm having an intermediate layer between a core layer and a shell layer, and an aqueous medium.
2. 2. The aqueous printing ink composition according to 1, wherein the intermediate layer contains one or more of starch, rosin resin, modified rosin resin, and polyester resin.
3. A printed layer printed with the aqueous printing ink composition according to 1 or 2.

According to the present invention, in an ink composition film formed from an aqueous printing ink composition, it is possible to improve the degree of biomass, which is the ratio of using biologically derived materials. In addition, water resistance, abrasion resistance, oil resistance, and washability can be improved in a well-balanced manner.

The water-based printing ink composition of the present invention contains a colorant, an alkali-soluble water-soluble resin, a core-shell structure emulsion resin with an average particle diameter of 30 to 200 nm having an intermediate layer between a core layer and a shell layer, and an aqueous medium. It is a water-based printing ink composition, and will be specifically explained below.
The aqueous printing ink composition of the present invention contains a carbon-neutral raw material component derived from biomass, and the carbon-neutral raw material component can be contained in an amount of 10% by mass or more in the solid content of the aqueous printing ink composition. preferable. Furthermore, the aqueous printing ink composition of the present invention can be printed on thin paper for paper containers and food packages.
The aqueous printing ink composition of the present invention can be used for flexographic printing, gravure printing, or other uses. The following explanation is common to each of these printing methods.

<Colorant>
The colorant used in the aqueous printing ink composition of the present invention is not particularly limited. The colorant may be the known pigments and dyes commonly used in aqueous printing ink compositions. As an example, the colorant may be an inorganic pigment, and examples thereof include titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, deep blue, ultramarine blue, carbon black, graphite, and the like. The coloring agent may also be an organic pigment, and examples thereof include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments.

The content of the colorant is not particularly limited. The content of the colorant is preferably 4 to 11% by mass in the aqueous printing ink composition during printing. If the content is less than 4% by mass, it may be difficult to obtain printed matter with the desired print density. On the other hand, if the content exceeds 11% by mass, the resulting water-based printing ink composition tends to have a high viscosity and is difficult to handle.

<Pigment dispersion resin>
The pigment dispersing resin that may be used in the aqueous printing ink composition of the present invention is preferably an alkali-soluble water-soluble resin, and furthermore, it is preferable to use an (ethylene oxide/propylene oxide) block polymer in combination.
<Alkali-soluble water-soluble resin>
The alkali-soluble water-soluble resin is blended to improve the dispersibility of the vehicle and/or colorant. The alkali-soluble water-soluble resin is not particularly limited. The alkali-soluble water-soluble resin may be any conventionally known resin as long as it can be dissolved in an aqueous medium in the presence of a basic compound. Among them, alkali-soluble water-soluble resins are resins that contain one or more types of acid groups such as carboxyl groups, sulfonic acid groups, and phosphonic groups (-P(=O)(OH) ₂ ), and are basic. Those that can be dissolved in an aqueous medium in the presence of the compound are preferred.

The acid value of the alkali-soluble water-soluble resin is preferably 40 mgKOH/g or more, more preferably 60 mgKOH/g or more. Further, the acid value of the alkali-soluble water-soluble resin is preferably 300 mgKOH/g or less, more preferably 200 mgKOH/g or less.
When the acid value of the alkali-soluble water-soluble resin is less than 40 mgKOH/g, the dispersion stability of the aqueous pigment dispersion tends to decrease. On the other hand, when the acid value of the alkali-soluble water-soluble resin exceeds 300 mgKOH/g, the hydrophilicity becomes too high, and the storage stability and water resistance of the ink composition tend to decrease. Here, the acid value is determined by calculating the theoretical neutralization amount of KOH for the amount of each ethylenically unsaturated monomer theoretically required to obtain 1 g of copolymer, and calculating the neutralization amount. It can be calculated by considering the total amount in mg as the acid value (theoretical acid value) of the copolymer. The alkali-soluble water-soluble resin is preferably not a mixture of one with an acid value of less than 50 mgKOH/g and one with an acid value of 50 mgKOH/g or more.

Further, the weight average molecular weight of the alkali-soluble water-soluble resin is preferably 3,000 or more, more preferably 7,000 or more. Further, the weight average molecular weight of the alkali-soluble water-soluble resin is preferably 200,000 or less, more preferably 100,000 or less.
Note that in this specification, the weight average molecular weight can be measured by column chromatography. For example, it can be carried out using Water 2690 (manufactured by Waters Inc.) and PLgel 5 μm MIXED-D (manufactured by Polymer Laboratories Inc.), and can be determined as a weight average molecular weight in terms of polystyrene.
Examples of such alkali-soluble water-soluble resins include water-soluble acrylic resins copolymerized with acrylic acid or methacrylic acid and their alkyl esters, or styrene as the main monomer components, and water-soluble styrene-acrylic resins. Suitable examples include various binder resins such as water-soluble styrene-maleic acid-based resins, water-soluble styrene-acrylic-maleic acid-based resins, water-soluble polyurethane-based resins, and water-soluble polyester-based resins.

Alkali-soluble water-soluble resins are made from an ethylenically unsaturated monomer containing an acid group, a long-chain alkyl group having 8 to 20 carbon atoms, an alicyclic group, or an aromatic group, from the viewpoint of dispersion stability and stain resistance. A mixture of a monomer having a hydrophobic group such as a cyclic hydrocarbon group and other copolymerizable ethylenically unsaturated monomers with a common radical generator (for example, benzoyl peroxide, tert-butyl Peroxybenzoate, azobisisobutyronitrile, etc.) are preferably used.

Examples of acid group-containing ethylenically unsaturated monomers include (meth)acrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic anhydride, maleic acid, maleic acid monoester, 2-carboxyethyl (meth)acrylate, -Carboxypropyl (meth)acrylate, sulfoethyl methacrylate, phosphonoethyl methacrylate, etc. are exemplified.

Examples of monomers having hydrophobic groups such as long-chain alkyl groups having 8 to 20 carbon atoms, alicyclic or aromatic cyclic hydrocarbon groups include styrene, α-methylstyrene, vinyltoluene, and their like. Examples include styrenic monomers such as derivatives, and ethylenically unsaturated monomers containing a long chain alkyl group having 8 to 20 carbon atoms such as octyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate. .

Other monomers that can be contained in the alkali-soluble water-soluble resin include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, and (meth)acrylate. Examples include alkyl esters of (meth)acrylic acid having less than 8 carbon atoms, such as butyl acrylate and hexyl (meth)acrylate.
For example, Joncryl HPD-671 manufactured by BASF Japan, etc. can be used. In addition, from the viewpoint of coating film properties and resolubility required for thin paper applications, it is desirable to use volatile and nonvolatile basic compounds.
The amount of the alkali-soluble water-soluble resin used for the pigment is 10 to 30 parts by weight, preferably 12 to 28 parts by weight, based on 100 parts by weight of the pigment.

A basic compound may be used in combination with the alkali-soluble water-soluble resin in order to dissolve it in the aqueous resin dissolving medium described below. Examples of the basic compound include inorganic basic compounds such as sodium hydroxide and potassium hydroxide, ammonia, organic amines, and alkali metal hydroxides. Specifically, examples of the organic amine include alkylamines such as diethylamine, triethylamine, and ethylenediamine, and alkanolamines such as monoethanolamine, ethylethanolamine, diethylethanolamine, diethanolamine, and triethanolamine. Examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, and the like. Among these, amines with a low boiling point and high volatility are preferred from the viewpoint of improving drying properties, dew condensation resistance, and hexane resistance required for paper containers, etc., and amines with a boiling point of 150°C or less, more preferably 100°C or less, and even more preferably is 50°C or lower, particularly preferably 0°C or lower, such as ammonia. These basic compounds may be used in combination.

The basic compound may be added in an amount that can dissolve the alkali-soluble water-soluble resin in the aqueous resin-dissolving medium. For example, the amount of the basic compound generally ranges from 80 to 120% of the neutralization amount. The blending amount may be outside this range.

As the resin-dissolving aqueous medium for dissolving the alkali-soluble water-soluble resin, water or a mixture of water and a water-miscible organic solvent is preferably used. Examples of water-miscible organic solvents include lower alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-propyl alcohol, polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and glycerin, and ethylene glycol monomethyl. Ether, (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monoacetate, propylene glycol monoacetate, etc. Examples include monofatty acid esters of (poly)alkylene glycol. These water-miscible organic solvents may be used in combination.

(Ethylene oxide/propylene oxide) block polymer A (ethylene oxide/propylene oxide) block polymer used as a resin for pigment dispersion includes two or more blocks, and each block may be composed of polyethylene oxide or propylene oxide.
The (ethylene oxide/propylene oxide) block polymer can be synthesized by a known method. For example, a polyethylene oxide polymer can be reacted with propylene oxide to form a poly(propylene oxide/ethylene oxide/propylene oxide) block polymer; alternatively, a polypropylene oxide polymer can be reacted with ethylene oxide to form a poly(ethylene oxide/propylene oxide) block polymer. oxide/ethylene oxide) block polymers can be formed.
The (ethylene oxide/propylene oxide) block polymer that may be used in the present invention has a weight average molecular weight in the range of 5,000 to 100,000, and commercially available products include the ADEKA Pluronic series manufactured by ADEKA. etc.
Further, from the viewpoint of stability of the water-containing solvent, the HLB value of the (ethylene oxide/propylene oxide) block polymer is preferably 8 to 20.

Here, the HLB value represents the balance between the hydrophilic part and the lipophilic part of the molecule (Hydrophile-Lipophile Balance), which is used in the field of surfactants. It can be determined by applying the Griffin formula shown below (a formula based on experimental values obtained from measurements of emulsification efficiency for a certain oil and the weight fraction of the hydrophilic part).
[Griffin formula] HLB = (100/5) x hydrophilic group weight/(hydrophilic group weight + hydrophobic weight)
The amount of the (ethylene oxide/propylene oxide) block polymer used in the pigment is 0.5 to 10 parts by weight, preferably 0.5 to 8.0 parts by weight, based on 100 parts by weight of the pigment.
The total amount of the alkali-soluble water-soluble resin + (ethylene oxide/propylene oxide) block polymer relative to the pigment is preferably 10 to 30 parts by weight based on 100 parts by weight of the pigment.
Further, as the pigment dispersing resin, a pigment dispersing agent can be used in place of the above pigment dispersing resin, and the above pigment dispersing resin and the pigment dispersing agent can also be used together.

<Core-shell structure emulsion type resin>
The core-shell structure emulsion type resin used in the aqueous printing ink composition of the present invention has one or more intermediate layers between the core and the shell. It is preferable to have one layer as an intermediate layer.
This core-shell structure emulsion type resin is obtained, for example, using a polymer emulsifier for water-soluble acrylic resin.

The specific core-shell structure emulsion type resin of the present invention preferably has an acid value of 3 to 100 mgKOH/g.
In the present invention, it is preferable that the specific core-shell structure emulsion type resin has a surface tension of 20 to 40 mN/m (the surface tension is measured by diluting it with water to a solid content of 30%).
The average particle diameter of the emulsion resin having a specific core-shell structure in the present invention is 30 to 200 nm, preferably 50 to 170 nm, and more preferably 60 to 150 nm.
The amount of emulsion resin having a specific core-shell structure used in the present invention is preferably 5 to 40 parts by mass in terms of solid content of the emulsion in the aqueous printing ink composition.

(shell part)
The shell portion is made of a polymer emulsifier. Examples of the shell part include (meth)acrylic acid ester having an aliphatic hydrocarbon group having 4 to 24 carbon atoms in the shell part, (meth)acrylic acid ester compound having a hydroxyalkyl group, (meth)acrylamide, Contains structural units derived from acrylonitrile, olefin compounds, styrene monomers, benzyl (meth)acrylate monomers, phenyl (meth)acrylate, etc. For example, if the surface tension is lowered by containing 20 to 50 parts by mass of structural units derived from butyl acrylate in 100 parts by mass of the shell part, the amount of antifoaming agent or surfactant used may be reduced. It is also highly effective in preventing ink from dripping onto the printing plate and misting from occurring.
The shell portion preferably has a structural unit having a carboxylic acid group such as (meth)acrylic acid, and the theoretical acid value of the shell portion is 100 to 250 mgKOH/g. Furthermore, the carboxylic acid group is preferably neutralized with a basic compound.
As the basic compound, ammonia, triethylamine, morpholine, monoethanolamine, diethylethanolamine, etc. can be used, and it is preferable to use ammonia or triethylamine in order to further improve chemical resistance.
However, it is not necessary to contain (meth)acrylate having a polyester side chain as a structural unit.

(core part)
The core part is preferably a copolymer mainly consisting of a structural unit consisting of the following styrene monomer and a structural unit consisting of an acrylic monomer, and in order to provide water dispersibility or water solubility, it may contain the following other monomers. It is preferable to have.
It is desirable that the styrene-acrylic resin has a core-shell structure containing 70 parts by mass or more, preferably 90 parts by mass or more of structural units derived from a styrene monomer in 100 parts by mass of the core.

The styrene-acrylic resin constituting the styrene-acrylic resin emulsion having such a core-shell structure has mainly constituent units composed of styrene monomers and acrylic monomers in both the core and shell parts. It is preferable to use a copolymer of
Examples of the styrene monomer include styrene, α-methylstyrene, β-methylstyrene, 2,4-dimethylstyrene, α-ethylstyrene, α-butylstyrene, 4-methoxystyrene, vinyltoluene, and the like.

Acrylic monomers include acrylic esters and methacrylic esters such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and 3-ethoxypropyl acrylate. , acrylic acid ester derivatives and methacrylic acid ester derivatives such as 3-ethoxybutyl acrylate and hydroxyethyl methacrylate, acrylic acid aryl esters and acrylic acid aralkyl esters such as phenyl acrylate and benzyl acrylate, diethylene glycol, triethylene glycol, glycerin Examples include monoacrylic acid esters of polyhydric alcohols such as.

(middle class)
The specific core-shell structure emulsion type resin in the present invention has an intermediate layer between the core portion and the outermost shell portion. As the intermediate layer, a layer containing the following starch obtained using biomass-derived raw materials, rosin resin, modified rosin resin, polyester resin, etc. can be adopted.

[starch]
Examples of starch include corn starch, high amylose corn starch, wheat starch, potato starch, tapioca starch, etc., and these starches are subjected to low-grade esterification, etherification, oxidation, acid treatment, dextrinization, reduction, and enzymatic decomposition by known means. One or more types of processed starches can be used.

[Rosin resin and modified rosin resin]
Examples of the rosin resin that can form the intermediate layer include gum rosin, tall oil rosin, and wood rosin. Generally, rosin resin is an amber-colored, amorphous resin obtained from pine, and because it is obtained from nature, it is a mixture, but it is abietic acid, neoabietic acid, palustric acid, pimaric acid, isopimaric acid, sandaracopimaric acid. , dehydroabietic acid may be isolated and used, and these are also defined as rosin resins in the present invention.
The modified rosin resin that can form the intermediate layer is a compound obtained by modifying the above-mentioned rosin, and is specifically listed below.
(1) Hydrogenated rosin: A rosin with improved weather resistance by adding hydrogen to conjugated double bonds (hydrogenation).
(2) Disproportionated rosin: Disproportionation means that two molecules of rosin react, and two molecules of abietic acid with a conjugated double bond form, one forming an aromatic group and the other forming a single double bond. It is a denaturation that becomes a bonding molecule. Weather resistance is generally inferior to hydrogenated rosin, but better than untreated rosin.
(3) Rosin-modified phenolic resin: Rosin-modified phenolic resin is often used as the main binder in offset printing inks. Rosin-modified phenolic resin can be obtained by a known manufacturing method.
(4) Rosin ester: This is an ester resin derived from rosin, and has been used as a tackifier for adhesives and adhesives since ancient times.
(5) Rosin-modified maleic acid resin: A product obtained by addition-reacting maleic anhydride to rosin, and also includes a product obtained by esterifying and grafting a hydroxyl group-containing compound such as glycerin with an anhydride group as necessary.
(6) Polymerized rosin: A derivative containing a dimerized resin acid derived from a natural resin rosin.
In addition, known rosins and modified rosin resins can also be used, and these can be used not only alone but also in combination.

[Polyester resin]
As the polyester resin capable of forming the intermediate layer, a biopolyester polyol (biomass polyester polyol) obtained by reacting a short chain diol compound having 2 to 4 carbon atoms with a carboxylic acid component by a known method can be used. In the biopolyol component, at least one of the short chain diol compound and the carboxylic acid component is preferably derived from a plant, and even more preferably both are derived from a plant. Moreover, a part of each of the short chain diol compound and the carboxylic acid component may be derived from plants.
The plant-derived short chain diol compound having 2 to 4 carbon atoms is not particularly limited. For example, the short chain diol compound may be 1,3-propanediol, 1,4-butanediol, ethylene glycol, etc. obtained from plant materials by the following method. These may be used in combination.
1,3-propanediol can be produced from glycerol via 3-hydroxypropyl aldehyde (HPA) by a fermentation method in which glucose is obtained by decomposing plant resources (eg, corn, etc.). Compared to the 1,3-propanediol compound produced using the EO method, the 1,3-propanediol compound produced by biomethods such as the fermentation method described above does not produce useful by-products such as lactic acid due to safety concerns. Moreover, it is possible to keep manufacturing costs low. 1,4-butanediol can be produced by producing succinic acid obtained by producing glycol from plant resources and fermenting it, and hydrogenating this. Furthermore, ethylene glycol can be produced from bioethanol obtained by conventional methods via ethylene.

Plant-derived carboxylic acids are not particularly limited. For example, carboxylic acids include sebacic acid, succinic acid, lactic acid, glutaric acid, dimer acid, and the like. These may be used in combination. Among these, it is preferable that the carboxylic acid component contains at least one selected from the group consisting of sebacic acid, succinic acid, and dimer acid. Further, 0.05 to 0.5 parts by mass of malic acid may be contained per 100 parts by mass of sebacic acid.
The biopolyol component is produced as a 100% plant-derived biopolyester polyol by appropriately condensing a plant-derived short chain diol compound and a plant-derived carboxylic acid. Specifically, polytrimethylene sebacate polyol is obtained by direct dehydration condensation of plant-derived sebacic acid and plant-derived 1,3-propanediol. Furthermore, polybutylene succinate polyol can be obtained by direct dehydration condensation of plant-derived succinic acid and plant-derived 1,4-butanediol.
One or more of these biopolyol components may be used.

<Rosin resin>
In the aqueous printing ink composition of the present invention, the rosin resin that may be blended in addition to the core-shell emulsion is a rosin resin with an acid value of 0 mgKOH/g and/or 0 to 350 mgKOH/g, It may be either an emulsion or a water-soluble one.
The acid value when the rosin resin is an emulsion is 0 mgKOH/g and/or 0 to 150 mgKOH/g, and the acid value when it is a water-soluble rosin resin is 100 to 350 mgKOH/g.
Rosin-based resin emulsions are made by dispersing rosin derivatives such as rosin esters or rosin, which are made from materials extracted from plants, in water in the form of fine particles in the presence of a low-molecular emulsifier. is available. Specifically, Harima Kasei Co., Ltd.'s Harrierstar SK218NS, SK370N, SK385NS, SK501NS, LAWTER Co., Ltd.'s Snowpack XW-2442, XW-2551, XW-2561, XW-2582, SE780G, Examples include NS-121, NS-100H, and E-865NT.

As the water-soluble rosin resin, a rosin resin having an acid value of 100 to 350 mgKOH/g is used, with part or all of the acid value neutralized with a basic compound and dissolved in water. Specifically, Tespol 150, 154, 158 manufactured by Hitachi Chemical Co., Ltd., Harima Kasei Co., Ltd. Harimac T-80, Harriestar MSR-4, AS-5, Marquid 31, 32, 33 manufactured by Arakawa Chemical Co., Ltd., etc. can be exemplified. .
Examples of the basic compound include ammonia, organic amines, alkali metal hydroxides, and the like. Specifically, examples of the organic amine include alkylamines such as diethylamine, triethylamine, and ethylenediamine, and alkanolamines such as monoethanolamine, ethylethanolamine, diethylethanolamine, diethanolamine, and triethanolamine. Examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, and the like. Among these, it is desirable to use volatile and nonvolatile basic compounds in combination from the viewpoint of coating film properties and resolubility.
Among the acid values of rosin resins, preferred are rosin resins with an acid value of 0 to 200 mgKOH/g, and when water and abrasion resistance are required, rosin resins with an acid value of 0 to 100 mgKOH/g are preferred. It is an emulsion.
The content of the rosin resin in the aqueous printing ink composition of the present invention is preferably such that the carbon-neutral raw material component is contained in the solid content of the aqueous printing ink composition in an amount of 10% by mass or more. Note that the carbon-neutral raw material component refers to a raw material component derived from a vegetable material.

<Styrene-acrylic resin emulsion>
In addition to the core-shell type emulsion described above, a styrene-acrylic resin emulsion can be blended into the aqueous printing ink composition of the present invention. As such a styrene-acrylic resin emulsion, a styrene-acrylic resin emulsion having an acid value of 30 to 80 mgKOH/g and a glass transition temperature of -30 to 60° C. produced by a known method can be used. The lower limit of the glass transition temperature range is preferably -20°C, more preferably -10°C, and the upper limit is 40°C, more preferably 20°C.
Among such styrene-acrylic resin emulsions, in order to improve the printability of a water-soluble acrylic resin, preferably a rosin resin, the acrylic resin with an acid value of 150 to 250 mgKOH/g is neutralized with a basic compound. It is preferable to use a water-soluble acrylic resin as a polymer emulsifier to copolymerize a styrene monomer and, if necessary, an alkyl ester of (meth)acrylic acid, and to form a film at room temperature.
When a basic compound is used in the styrene-acrylic resin emulsion, examples of the basic compound include ammonia and organic amines. Specifically, examples of the organic amine include alkylamines such as diethylamine, triethylamine, and ethylenediamine, and alkanolamines such as monoethanolamine, ethylethanolamine, diethylethanolamine, diethanolamine, and triethanolamine. Among these, amines with a low boiling point and high volatility are preferred from the viewpoint of dew condensation resistance and hexane resistance, and amines with a boiling point of 150°C or lower, more preferably 100°C or lower, still more preferably 50°C or lower, and particularly preferably amines such as ammonia. The temperature is below 0°C.
As such a resin, Joncryl 309 (glass transition temperature 2° C., solid content 46%) manufactured by BASF Japan, etc. can be used.

<Wax resin fine particle dispersion>
The aqueous printing ink composition of the present invention may contain a commercially available dispersion of fine wax resin particles having an average particle diameter of 1 to 10 μm, preferably 2 to 5 μm, determined by the Coulter Counter method, for the purpose of improving the abrasion resistance of the coating film. The wax resin fine particle dispersion is preferably a polyethylene wax, and specific examples include Chemipearl W100, W200, W300, W310, W306, W400, W410, W500, and W800 manufactured by Mitsui Chemicals. The amount of the wax resin fine particle dispersion added is approximately 1 to 7% by mass in terms of solid content based on 100% by mass of the water-based printing ink composition, taking into account the balance between improving abrasion resistance in the physical properties of the coating film and adversely affecting the hue. It is preferable that

<Other materials>
Various additives can be used in the aqueous printing ink composition of the present invention, if necessary. Specifically, we use extender pigments such as calcium carbonate, kaolin, barium sulfate, aluminum hydroxide, clay, and talc to improve drying properties, and inorganic fine particles and adhesive resins (acrylic resins) to provide anti-slip properties. , vinyl acetate resin), a leveling agent to improve leveling properties, an antifoaming agent (manufactured by San Nopco, SN Deformer 777) to impart antifoaming properties, and a basic agent such as caustic soda to impart resolubility. Various additives such as compounds and film-forming emulsions can be mentioned.

(aqueous medium)
As the solvent used in the aqueous printing ink composition of the present invention, in addition to water, a water-soluble organic solvent is used within a range that does not cause a decrease in the performance of the aqueous printing ink composition of the present invention. There are no particular restrictions on the solvent other than water that may be used in the aqueous printing ink composition of the present invention, other than being compatible with water. It is preferable not to contain it. Such solvents include methanol, ethanol, propanol, butanol, hexanol, octanol, decanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monooctyl Ether, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, propylene glycol , propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, Examples include alcohols and polyhydric alcohol-based organic solvents such as propylene glycol, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether, dibutyl glycol, and glycerin. At least one type of solvent may be used, and two or more types may be used in combination, taking into consideration the solubility and drying properties of the binder resin.

Next, the aqueous printing ink composition and method for producing printed matter of the present invention will be explained.
The aqueous printing ink composition of the present invention can be produced by a conventional method by mixing a pigment, a pigment dispersing resin, and a water-containing solvent, and then using various kneading machines such as bead mills, pearl mills, and sand mills. The mixture is kneaded using a ball mill, attritor, roll mill, etc., and further, predetermined materials such as rosin resin emulsion, styrene-acrylic resin emulsion, and additives are mixed as necessary.
Next, if dilution is required during printing, a water-containing solvent is further added to obtain a water-based printing ink composition. The method for producing printed matter using this aqueous printing ink composition includes printing on the surface of paper or resin, particularly paper containers such as paper containers such as paper cups and paper plates, or printing on paper containers whose surfaces are coated with a resin layer. An example is a method of printing on paper containers, thin paper for food packages, or materials thereof using a printing machine using the above water-based printing ink composition.
At this time, the printing substrate includes food packages such as wrapping paper and paper bags, paper products such as paper containers having a resin layer such as polyolefin laminated on the surface, and a resin layer such as a resin coating layer of polyolefin or the like on the surface. Any of paper products such as paper containers and paper products such as uncoated paper containers that do not have a resin layer on the surface may be used.
As a method for producing paper having a layer of resin such as polyolefin by lamination or coating, known means can be employed.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples. In addition, unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass." In addition, the numbers for the quantities of each material in the table are also "parts by mass." The unit of acid value is mgKOH/g.

PB-15:3: Pigment Blue 15:3
Alkali-soluble water-based acrylic resin: (solid content 25% by mass) Joncryl HPD-671, manufactured by BASF EOPO block polymer: Poly(ethylene oxide/propylene oxide) block polymer: HLB value 14, weight average molecular weight 16,000
Rosin emulsion: (biomass degree 89%, solid content 50% by mass, softening point 100°C, nonionic surfactant included) Hariestar SK218NS, manufactured by Harima Kasei Styrene acrylic emulsion: Acid value 38mgKOH/g, glass transition temperature 9°C , solid content 38.50% by mass
Emulsions studied: In both cases, the core and shell are acrylic resin, and the respective intermediate layers are listed in Table 1. Examples 1 and 2: 160 nm, solid content 41%, biomass degree 40%
Example 4: 120 nm, solid content 40%, biomass degree 27%
Example 3: 60 nm, solid content 40%, biomass degree 20%
Example 5: 100 nm, solid content 45.4%, biomass degree 50%
Polyethylene wax: (solid content 35% by mass) Chemipearl W-100, manufactured by Mitsui Chemicals Defoaming agent: SN Deformer 777, manufactured by Sannopco

(Aqueous printing ink composition)
After kneading and dispersing a mixture of PB-15:3, alkali-soluble water-soluble resin (Joncryl HPD-671, manufactured by BASF Japan, solid content 25%), EOPO block polymer, dibutyl glycol, and water in a bead mill, rosin-based A resin, styrene-acrylic resin emulsion, polyethylene wax, and antifoaming agent were added and mixed in the proportions shown in Table 1 to obtain a water-based printing ink composition.

(Water and abrasion resistance)
The color was spread on base paper (K liner) using a 200-line hand proofer, and the color spread was evaluated using a Gakushin model rub fastness tester.
Evaluation conditions: 200g x 2 times, paper: 5 drops of water were dropped on a cloth. ◎: No paint film removed.
○: Ink slightly adhered to the paper. The ink from the exhibited color is slightly removed.
○△: Ink is thinly attached to the entire surface of the paper. The ink from the exhibited color is slightly removed.
△: Ink thinly adheres to the entire surface of the paper. The ink on the colored material has been removed and some of the original paper is visible.
×: Ink is thickly attached to the entire surface of the paper. The ink is removed even from colored objects, and most of the original paper is visible.

(wear resistance)
The color was spread on base paper (K liner) using a 200-line hand proofer, and the color spread was evaluated using a Gakushin model rub fastness tester.
Evaluation conditions: 200 g x 100 times, paper: Kanakin cloth ◎: No coating film removed.
◎○: A very small amount of ink adhered to the paper. A very small amount of ink has been removed from the color exhibit.
○: A slight amount of ink adheres to the paper. A small amount of ink has come off from the exhibited color.
〇△: Ink is thinly attached to the entire surface of the paper. A small amount of ink has come off from the exhibited color.
△: Ink adheres to the entire surface of the paper. The ink on the colored material has been removed and some of the original paper is visible.
×: Ink is thickly attached to the entire surface of the paper. The ink has also been removed from the colored objects, and most of the original paper is visible.

(Oil resistance and wear resistance)
The color was spread on base paper (K liner) using a 200-line hand proofer, and the color spread was evaluated using a Gakushin model rub fastness tester.
Evaluation conditions: 200g x 2 times, paper: 5 drops of salad oil was dropped on a cotton cloth ◎: No coating film removed.
◎○: A very small amount of ink adhered to the paper. A very small amount of ink has been removed from the color exhibit.
○: A slight amount of ink adheres to the paper. A small amount of ink has come off from the exhibited color.
〇△: Ink is thinly attached to the entire surface of the paper. A small amount of ink has come off from the exhibited color.
△: Ink adheres to the entire surface of the paper. The ink on the colored material has been removed and some of the original paper is visible.
×: Ink is thickly attached to the entire surface of the paper. The ink has also been removed from the colored objects, and most of the original paper is visible.

(Cleanability)
The color was spread on a printing plate using a φ0.10 wire bar, and after 15 minutes, it was wiped off with absorbent cotton soaked in water, and the removal of the coating film was visually evaluated.
Evaluation criteria ◎: The coating film is removed and most of the printing plate is visible.
◎○: The coating film was removed and a very small amount of ink remained on the printing plate.
○: The coating film was removed and a small amount of ink remained on the printing plate.
Δ: The coating film was slightly removed, and most of the ink remained on the printing plate.
×: The coating film cannot be removed.

According to the water-based printing ink compositions of Examples 1 to 5, which are examples in accordance with the present invention, since they have an intermediate layer, they have excellent abrasion resistance, and also have excellent oil and abrasion resistance and washability. It can be seen that it is possible to form a section.
On the other hand, according to Comparative Example 1, the cleaning performance was particularly poor because it did not have an intermediate layer.

Claims (4)

A coloring agent , a resin for pigment dispersion, a core-shell structure emulsion type resin with an average particle diameter of 30 to 200 nm having an intermediate layer containing a component obtained from a biomass-derived raw material between the core layer and the shell layer, and an aqueous medium. An aqueous printing ink composition comprising . The aqueous printing ink composition according to claim 1 , wherein the intermediate layer contains one or more of starch, rosin resin, modified rosin resin, and polyester resin. The aqueous printing ink composition according to claim 1 or 2, wherein the aqueous printing ink composition contains 10% by mass or more of a biomass-derived carbon-neutral raw material component in the solid content of the aqueous printing ink composition. A printed layer printed with the aqueous printing ink composition according to any one of claims 1 to 3 .