JP2023110271A - Ink set and printed matter - Google Patents

Abstract

To provide an ink set comprising a primer composition capable of forming a primer layer having excellent water resistance and an aqueous inkjet ink composition capable of forming an ink layer having excellent adhesion, solid image printability and bleeding resistance on the primer layer.SOLUTION: There is provided an ink set which comprises an aqueous inkjet ink composition comprising a pigment, a dispersant for the pigment, a water-soluble solvent and water and a primer composition comprising an agglutinating agent to agglutinate the aqueous inkjet ink composition, a resin emulsion and water, wherein the dispersant is a polyurethane resin and the agglutinating agent is a compound having a polyethyleneimine skeleton.SELECTED DRAWING: None

Description

The present invention relates to ink sets and printed matter.

A printing method using an ink set comprising an aqueous inkjet ink composition containing a pigment or the like and a primer composition containing an aggregation accelerator for promoting aggregation of the aqueous inkjet ink composition is known (Patent References 1-7). In these patent documents, when fine line printing is performed on a primer layer formed from the primer composition using a water-based inkjet ink composition, it is possible to form a good print image quality (print layer) without bleeding. disclosed.

JP 2017-61124 A JP 2017-88646 A JP 2018-12219 A Japanese Patent Application Laid-Open No. 2019-73608 JP 2019-111763 A WO2013/179838 JP 2019-166717 A

As described in Patent Documents 1 to 4 above, metal salts are often used as flocculants contained in primer compositions. However, it has been found that the use of metal salts lowers the water resistance of the primer layer itself. It is also known that a cationic polymer can be used as such a flocculant, as in Patent Documents 4 to 7 above.

In addition, since the pigment contained in the aqueous inkjet ink composition cannot normally be dispersed in the ink composition by itself, before blending each component of the ink composition, as in the above Patent Documents 1 to 7, It is known to use pigment dispersants to physically adsorb or chemically bind pigments. In particular, these documents specifically disclose that alkali-soluble resins such as (meth)acrylate copolymers are used as dispersants for pigments.

On the other hand, printed materials such as packaging containers for retort pouches are formed by forming a printed layer (printing ink) on a plastic film (base film) such as PET, and then printing on the surface of the printed layer and on the inside of the packaging container. It is produced by using a laminated film obtained by laminating two sealant films with an adhesive, sealing the sealant film with heat, and processing it into a bag shape. Plastic films such as PET films as described above have higher heat resistance than polypropylene films such as OPP films, but the substrate is hard, and there is a problem that it is difficult to ensure adhesion to the coating film (printing layer). .

The present invention has been made in view of the above-mentioned circumstances, and a primer composition capable of forming a primer layer having excellent water resistance, and a primer composition that has improved adhesion, solid image printability, and bleeding resistance on the primer layer. An object of the present invention is to provide an ink set having a water-based inkjet ink composition capable of forming an excellent ink layer.

Another object of the present invention is to provide a printed matter obtained by printing the ink set.

That is, the present invention includes a water-based inkjet ink composition containing a pigment, a dispersant for the pigment, a water-soluble solvent, and water, a flocculating agent for aggregating the water-based inkjet ink composition, a resin emulsion, and water. The ink set has a primer composition, wherein the dispersant is a polyurethane resin, and the flocculant is a compound having a polyethyleneimine skeleton.

The present invention also relates to a printed matter obtained by printing the ink set.

Although the details of the working mechanism of the effects of the ink set of the present invention are partly unknown, it is presumed as follows. However, the invention is not limited to this mechanism of action.

The ink set of the present invention comprises an aqueous inkjet ink composition containing a pigment, a dispersant for the pigment, a water-soluble solvent, and water; a flocculant for aggregating the aqueous inkjet ink composition; a resin emulsion; and water. wherein the dispersant is a polyurethane resin, and the flocculant is a compound having a polyethyleneimine skeleton. In the prior art document mentioned above, at least a polyurethane resin is used as a dispersant for the pigment contained in the water-based inkjet ink composition, and an ink set using a compound having a polyethyleneimine skeleton as a flocculant contained in the primer composition. is not specifically shown. The polyurethane resin used as the pigment dispersant has high adhesion, and the compound having a polyethyleneimine skeleton used as the coagulant is a polymer compound with excellent water resistance. and an aqueous inkjet ink composition capable of forming an ink layer having excellent adhesion, solid image printability, and bleeding resistance on the primer layer.

<Aqueous inkjet ink composition>
The water-based inkjet ink composition of the present invention contains a pigment, a dispersant for the pigment, a water-soluble solvent, and water.

<Pigment>
As the pigment, organic pigments and inorganic pigments used in aqueous inkjet ink compositions can be used. Examples of the organic pigment include dye lake pigments, azo pigments, benzimidazolone pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dioxazine pigments, indigo pigments, thioindico pigments, perylene pigments, Perinone pigments, diketopyrrolopyrrole pigments, isoindolinone pigments, nitro pigments, nitroso pigments, anthraquinone pigments, flavanthrone pigments, quinophthalone pigments, pyranthrone pigments, indanthrone pigments, etc. mentioned. Examples of the inorganic pigments include carbon black, titanium oxide, zinc white, red iron oxide, graphite, iron black, chromium oxide green, and aluminum hydroxide. The pigment may be surface-treated with a known surface-treating agent. The pigments may be used alone or in combination of two or more.

Specific examples for each typical hue of the pigment include the following.

Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 42, 73, 74, 75, 81, 83, 87, 93, 95, 97, 98, 108, 109, 114, 120, 128, 129, 138, 139, 150, 151, 155, 166, 180, 184, 185, 213 and the like.

Examples of magenta pigments include C.I. I. Pigment Red 5, 7, 12, 22, 38, 48:1, 48:2, 48:4, 49:1, 53:1, 57, 57:1, 63:1, 101, 102, 112, 122, 123, 144, 146, 149, 150, 168, 176, 177, 178, 179, 180, 184, 185, 190, 202, 209, 224, 242, 254, 255, 270, C.I. I. Pigment Violet 19 and the like.

Examples of cyan pigments include C.I. I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 18, 22, 27, 29, 60 and the like.

Examples of black pigments include carbon black (CI Pigment Black 7).

Examples of white pigments include titanium oxide and aluminum oxide, which may be surface-treated with various materials such as alumina and silica.

The proportion of the pigment in the water-based inkjet ink composition is preferably 1% by mass or more, more preferably 2% by mass or more, from the viewpoint of improving the printing density of printed matter, and is stable in ejection. From the viewpoint of improving properties, the content is preferably 10% by mass or less, more preferably 8% by mass or less. However, when the pigment is a white pigment, the proportion of the white pigment in the aqueous inkjet ink composition is preferably 4% by mass or more, more preferably 8% by mass or more, and It is preferably 30% by mass or less, more preferably 20% by mass or less.

<Pigment Dispersant>
The pigment dispersant is a polyurethane resin. Examples of the polyurethane resin include polyurethane resins obtained by reacting a diisocyanate compound and a diol compound, optionally with a chain extender or a reaction terminator. The polyurethane resins may be used alone or in combination of two or more.

Examples of the diisocyanate compounds include aliphatic diisocyanate compounds such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate; alicyclic diisocyanate compounds such as isophorone diisocyanate and hydrogenated xylylene diisocyanate; xylylene diisocyanate, α , α,α',α'-tetramethylxylylene diisocyanate, toluylene diisocyanate, diphenylmethane diisocyanate and other aromatic diisocyanate compounds. The diisocyanate compounds may be used alone or in combination of two or more.

Examples of the diol compound include low molecular weight diols such as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol and triethylene glycol; high molecular weight diols such as polyester diol compounds, polyether diol compounds, polycarbonate diol compounds and polybutadiene glycol compounds types are mentioned. The diol compounds may be used alone or in combination of two or more.

The polyurethane resin preferably has one or more skeletons selected from the group consisting of a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, and a polybutadiene skeleton, from the viewpoint of adhesion to plastic films, lamination suitability, and the like. preferable.

The polyurethane resin preferably has an ionic group in the molecule in order to easily disperse the pigment in water. preferably.

In order to easily introduce an anionic group into the polyurethane resin, for example, a diol compound having a carboxyl group, a sulfonic acid group, or the like may be used as the diol compound, and the general formula (1):
(In general formula (1), R ¹ represents a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms.), succinic acid, adipine Aliphatic carboxylic acid-containing polyols obtained by reacting an acid or the like with a polyol, aromatic carboxylic acid-containing polyols obtained by reacting a polyol with phthalic acid, trimellitic acid, pyromellitic acid or anhydride thereof, etc. is mentioned.

When the polyurethane resin has an anionic group, it preferably has an acid value of 5 to 100 mgKOH/g. If the acid value of the polyurethane resin is less than 5 mgKOH/g, the dispersibility in an aqueous medium described later may decrease, and if it is greater than 100 mgKOH/g, the drying property during printing and the water resistance of the resulting printed matter etc. may decrease. The acid value is more preferably 5 to 50 mgKOH/g from the viewpoint of suitably imparting lamination strength (peel strength between the base film and the sealant film). The acid value is a theoretical acid value, and it depends on the molecular weight of the anionic group-containing compound of the carboxyl group used as a synthetic component of the polyurethane resin, the compounding ratio, and the number of anionic groups of the carboxyl group contained in the molecule of the compound. The number of mg of potassium hydroxide theoretically required to neutralize 1 g of polyurethane resin calculated arithmetically based on the above.

As the chain extender, for example, a compound having two or more functional groups (amino group, hydroxyl group, etc.) capable of reacting with an isocyanate group in the molecule can be used. Compounds containing two or more amino groups in the molecule include, for example, diamines having two primary amino groups (ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, hexamethylenediamine, isophoronediamine, etc. ), diamines having one primary amino group and one secondary amino group (2-ethylaminoethylamine, etc.), polyamines having two primary amino groups and one or more secondary amino groups (diethylenetriamine, triethylene tetramine, etc.). Examples of hydroxyl group-containing compounds containing two or more hydroxyl groups in the molecule include low-molecular-weight diols (ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, etc.). Furthermore, compounds having two amino groups and one hydroxyl group in the molecule include, for example, aminoethylethanolamine, aminopropylethanolamine, and the like, and 1 mol of ethylene oxide is added to the diamines having two primary amino groups. things, etc. At least one chain extender may be used, and two or more thereof may be used in combination.

As the chain extender, for example, a compound having three or more functional groups such as amino groups and hydroxyl groups can be used from the viewpoint of introducing functional groups such as hydroxyl groups and amino groups into the molecule of the polyurethane resin. Examples of compounds having three or more functional groups such as amino groups and hydroxyl groups include glycerin and aminoethylethanolamine.

The reaction terminator can be, for example, a compound having one or more functional groups (amino group, hydroxyl group, etc.) capable of reacting with an isocyanate group in the molecule. Specifically, monoalcohols (methanol, ethanol, etc.) can be used. ), monoamines (n-butylamine, di-n-butylamine, etc.), alkanolamines having one amino group and one hydroxyl group in the molecule (monoethanolamine, ethylethanolamine, diethanolamine), and the like. Moreover, as the reaction terminator, the compounds exemplified as the chain elongation agent can also be used. From the viewpoint of introducing a functional group such as a hydroxyl group or an amino group into the molecule of the polyurethane resin, the reaction terminator is exemplified as alkanolamines having one amino group and one hydroxyl group in the molecule, or the chain extender. , diamines having two primary amino groups, and low-molecular-weight diols can be used. At least one type of the reaction terminator may be used, and two or more types may be used in combination.

Examples of the reaction terminator include polyaminohydrazide, hydrazine (hydrazine hydrate), and the following general formula (2): H ₂ N—NH—X—NH—NH ₂ (in formula (2), X is an alkylene dihydrazine or a saturated aliphatic diacid, represented by an alkylene group having 1 to 8 carbon atoms, or the residue of a saturated or unsaturated diacid having 1 to 10 carbon atoms, Dihydrazide compounds of unsaturated dibasic acids and the like can also be used. Specific examples of the alkylene dihydrazine include methylene dihydrazine, ethylene dihydrazine, butylene dihydrazine and the like. Specific examples of dihydrazide compounds of saturated aliphatic dibasic acids include dihydrazide oxalate, dihydrazide malonate, dihydrazide glutarate, dihydrazide adipic acid, dihydrazide sebacate, and dihydrazide compounds of unsaturated dibasic acids. Specific examples thereof include dihydrazide phthalate, dihydrazide fumarate, and dihydrazide itaconate.

If necessary, the polyurethane resin may be used as an aqueous resin varnish using a basic compound or the like. The basic compound is not particularly limited, and commonly used basic compounds can be used. Examples include alkylamines such as butylamine and triethylamine, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, morpholine, Ammonia water, sodium hydroxide, etc. can be mentioned. The amount of the basic compound to be blended is appropriately set according to the physical properties of the polyurethane resin to be used, the amount used, etc., and may be used singly or in combination of two or more.

From the viewpoint of improving the dispersibility of the pigment, the content of the polyurethane resin is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, relative to 100 parts by mass of the pigment. The content of the polyurethane resin is preferably 100 parts by mass or less, more preferably 60 parts by mass or less, relative to 100 parts by mass of the pigment, from the viewpoint of reducing the viscosity of the aqueous inkjet composition. , 50 parts by mass or less.

<Water-soluble solvent>
As the water-soluble solvent, known water-soluble solvents used in aqueous inkjet ink compositions can be used. Examples include monoalcohols, polyhydric alcohols, lower alkyl ethers of polyhydric alcohols, nitrogen-containing compounds, Ketones, ethers, esters and the like can be mentioned. The water-soluble solvents can be used alone or in combination of two or more.

Examples of the monoalcohols include methanol, ethanol, 1-propanol, 1-butanol, 3-methoxy-3-methyl-1-butanol and the like.

Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, glycerin, diethylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,2-pentanediol, 1,5-pentanediol, neopentyl glycol, 1 ,2-hexanediol, 1,6-hexanediol, 1,2-cyclohexanediol, heptanediol, 1,8-octanediol and the like.

Examples of the lower alkyl ethers of polyhydric alcohols include ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monopropyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, Ethylene glycol isobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono -n-butyl ether and the like.

Examples of the nitrogen-containing compound include pyrrolidone and N-methyl-2-pyrrolidone.

Examples of the ketones include acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diisopropyl ketone, cyclopentanone, cyclohexanone and the like.

Examples of the ethers include isopropyl ether, n-butyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane and the like.

Examples of the esters include propylene carbonate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, amyl acetate, ethyl lactate, ethyl butyrate, dibutyl phthalate, dioctyl phthalate; ε-caprolactone, ε. - Cyclic esters such as caprolactam and the like.

The water-soluble solvent includes monoalcohols, polyhydric alcohols, and polyhydric alcohols, from the viewpoint of suppressing drying of the ink composition in the inkjet nozzle and facilitating the formation of an ink layer (film) on the substrate. It preferably contains at least one selected from the group consisting of lower alkyl ethers of alcohol and nitrogen-containing compounds, propylene glycol, glycerin, diethylene glycol, ethylene glycol monobutyl ether and diethylene glycol monobutyl ether, 3-methoxy-3- More preferably, it contains at least one selected from the group consisting of methyl-1-butanol.

The proportion of the water-soluble solvent in the water-based inkjet ink composition is preferably 15% by mass or more, more preferably 20% by mass or more, from the viewpoint of improving ejection stability. From the viewpoint of improving film drying properties, the content is preferably 60% by mass or less, more preferably 50% by mass or less.

<Water>
The water of the present invention includes water as an aqueous medium contained in the pigment dispersion described below and water added for adjusting the concentration of the water-based inkjet ink composition of the present invention. Examples of the water include ion-exchanged water, pure water, distilled water, and industrial water. The water may be used alone or in combination of two or more.

The proportion of the water (including the water contained in each component) in the water-based inkjet ink composition is preferably 40% by mass or more, and 50% by mass or more, from the viewpoint of improving the drying property of the coating film. From the viewpoint of improving ejection stability, the content is preferably 70% by mass or less, and more preferably 60% by mass or less.

A resin emulsion may be used in the water-based inkjet ink composition from the viewpoint of improving bleeding resistance. As the resin emulsion, known resin emulsions used in aqueous inkjet ink compositions can be used. Examples include acrylic resin emulsion, styrene-acrylic resin emulsion, polyester resin emulsion, polyurethane resin emulsion, and polyvinyl acetate. system resin emulsion, polyvinyl chloride system resin emulsion, polybutadiene system resin emulsion, polyolefin system resin emulsion, and the like. The resin emulsion preferably has a glass transition temperature of 20° C. or less from the viewpoint of improving the drying property of the coating film of the printed matter and the adhesion to the substrate. The glass transition temperature is obtained by differential scanning calorimetry (DSC), and is usually calculated from the midpoint of the temperature range where glass transition occurs. The resin emulsions may be used alone or in combination of two or more.

The proportion of the resin solid content in the resin emulsion is preferably 1% by mass or more, preferably 3% by mass or more, in the water-based inkjet ink composition, from the viewpoint of improving print quality and scratch resistance. And, from the viewpoint of improving print quality and storage stability, the content is preferably 10% by mass or less, more preferably 8% by mass or less.

Furthermore, the water-based inkjet ink composition may contain optional components depending on the purpose. Examples include known resins, wax emulsions, pigment dispersants other than the pigment dispersants, surfactants, Additives such as antifungal agents, antirust agents, thickeners, antioxidants, ultraviolet absorbers, preservability improvers, antifoaming agents, and pH adjusters may also be added.

<Method for Preparing Aqueous Inkjet Ink Composition>
The method for preparing (manufacturing) the aqueous inkjet ink composition is not particularly limited, and the above components may be added in order or at the same time and mixed. For example, the polyurethane resin may be dissolved in water. After mixing the water-based resin varnish, pigment, and if necessary, a pigment dispersant, etc., a pigment dispersion (ink base) is prepared using various dispersing machines such as ball mills, attritors, roll mills, sand mills, agitator mills, etc. and then adding the remaining materials to prepare a water-based inkjet ink composition.

The aqueous inkjet ink composition has an initial viscosity after production of 2.0 to 15.0 mPa·s, preferably 3.0 to 12.0 mPa·s. The viscosity can be measured, for example, with an E-type viscometer (trade name “RE100L type viscometer”, manufactured by Toki Sangyo Co., Ltd.).

<Primer composition>
The primer composition of the present invention contains an aggregating agent for aggregating the aqueous inkjet ink composition, a resin emulsion, and water.

<Flocculant>
The flocculant is a compound having a polyethyleneimine skeleton. The compound having _a polyethyleneimine skeleton may have repeating units of ethyleneimine ( _{--CH.sub.2CH.sub.2NH--} ). A branched polyethyleneimine in which an imine unit is polymerized in a branched chain is exemplified. Polyethyleneimine may also be modified with a known modifier such as cycloalkyl. The compounds having a polyethyleneimine skeleton can be used alone or in combination of two or more.

Examples of commercially available products of compounds having a polyethyleneimine skeleton include trade name A-131-X (manufactured by Mica Corporation), trade name Epomin (manufactured by Nippon Shokubai), trade name Lupasol series (manufactured by BASF), and the like. .

The content of the aggregating agent is preferably 0.01% by mass or more, preferably 0.05% by mass or more, in the primer composition from the viewpoint of improving the clarity and bleeding resistance of printed matter. , more preferably 0.1% by mass or more, and from the viewpoint of improving bleeding resistance, it is preferably 10% by mass or less, more preferably 8% by mass or less in the primer composition. , 6% by mass or less.

<Resin emulsion>
As the resin emulsion, a known one contained in the primer composition used in the aqueous inkjet ink composition can be used. For example, acrylic resin emulsion, polyester resin emulsion, polyurethane resin emulsion, and polyvinyl acetate resin emulsion can be used. , polyvinyl chloride resin emulsion, polybutadiene resin emulsion, polyolefin resin emulsion, and the like. Among these, polyurethane-based resin emulsions and polyolefin-based resin emulsions are preferable from the viewpoint of improving the printability of solid images. The resin emulsions may be used alone or in combination of two or more.

The polyurethane-based resin emulsion is an emulsion in which a polyurethane resin is dispersed in water, and any of anionic, cationic, and nonionic properties can be used. Examples of the polyurethane resins include polyether-based polyurethane resins, polyester-based polyurethane resins, polyester/polyether-based polyurethane resins, and polycarbonate-based polyurethane resins.

The polyolefin resin emulsion is an emulsion in which a polyolefin resin is dispersed in water. Examples of the polyolefin resins include polyethylene resins, polypropylene resins, polybutylene resins, and polyolefin resins obtained by copolymerizing two or more of ethylene, propylene, and butylene. Further, the polyolefin resin includes a modified polyolefin resin obtained by introducing an amino group, a carboxyl group, a hydroxyl group, an acryloyl group, and other polymer chains into the polyolefin chain; an oxidized polyolefin resin obtained by oxidizing a part of the polyolefin chain; A halogenated polyolefin resin partially treated with halogen may also be used.

From the viewpoint of improving the printability of solid images, the resin solid content of the resin emulsion is preferably 0.5% by mass or more, more preferably 1% by mass or more, in the primer composition. And, from the viewpoint of improving bleeding resistance, it is preferably 10% by mass or less, more preferably 5% by mass or less, in the primer composition.

The water includes water contained in the resin emulsion, water added for adjusting the concentration of the primer composition of the present invention, and the like. Examples of the water include ion-exchanged water, pure water, distilled water, and industrial water. The water may be used alone or in combination of two or more.

The proportion of the water (including the water contained in each component) is preferably 70% by mass or more, more preferably 80% by mass or more, from the viewpoint of improving the drying property of the coating film. From the viewpoint of improving stability, the content is preferably 98% by mass or less, more preferably 95% by mass or less.

In addition to the components described above, the primer composition of the present invention may optionally contain optional components. Examples of optional components include water-soluble organic solvents and various additives. Examples of additives include surfactants such as silicone-based surfactants, acetylene-based surfactants, and fluorine-based surfactants; preservability improvers, antifoaming agents, adhesion-imparting agents, fillers, thickeners, and the like. be done.

<Manufacture of primer composition>
The primer composition is not particularly limited. For example, the resin emulsion, the flocculant, and, if necessary, the water-soluble organic solvent, the above various additives, etc. are added to water, and the mixture is stirred and mixed with a disper or the like. It can be manufactured by

<Ink set>
The ink set of the present invention comprises the aqueous inkjet ink composition and the primer composition.

<Printed Matter>
The printed matter of the present invention is obtained by printing an ink set comprising the aqueous inkjet ink composition and the primer composition. Specifically, the primer composition is applied to a substrate and dried to form a primer layer, and then the aqueous inkjet ink composition is printed on the primer layer using an inkjet printer to form an image ( forming a printed layer) method. The coating method of the primer composition includes coating methods using various coating devices such as a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a curtain coater, a die coater, and an inkjet. mentioned.

Conventionally known conditions can be suitably employed for the above-mentioned inkjet printing method. A method of ink-jet printing can be mentioned by installing a recording device and ejecting from a nozzle onto a base material.

Examples of the substrate include non-absorbent print media such as art paper, inkjet paper, coated paper such as inkjet glossy paper, and plastic substrates such as polyolefin film, polyester film, nylon film, and polyvinyl chloride sheet. uncoated paper such as plain paper and offset paper; fabrics such as cotton; among these, non-absorbent printing media are preferred from the viewpoint of good adhesion of the primer layer, and plastic-based substrates are more preferred. preferable.

In addition, as the printed material, food packaging containers such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polybutylene terephthalate, nylon-6, nylon-6,6, polyvinyl chloride, polyvinylidene chloride, etc. A laminate film in which a sealant film is laminated on a print layer provided on a base film used in the field is mentioned. The printed layer and the sealant film are usually laminated using a laminating adhesive. The application of the adhesive for lamination and the lamination of the sealant film can be performed using a known dry lamination processing apparatus equipped with various coating apparatuses such as a roll coater, bar coater, and gravure coater.

The laminate film preferably has a laminate strength (peel strength between the base film and the sealant film) of 50 g/15 mm or more, more preferably 100 g/15 mm or more.

The lamination strength is measured by cutting the laminate film to a width of 15 mm after 3 days at 40° C., creating a sample piece, and performing T-type peeling with a peel tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.). (dry laminate strength) is measured.

In order to form a bag from the laminated film, the sealant film side is center-folded toward the inside of the container, or the composite films are superimposed and the ends are thermally melted and crimped using a heat sealer or the like. can be used, and can be applied to packaging containers in the form of various heat seals such as three-side seal, four-side seal, envelope pasting, palm-to-palm pasting, and gusset pasting.

EXAMPLES The present invention will be described below with reference to Examples and the like, but the present invention is not limited to these.

<Manufacturing example>
<Production of water-based polyurethane resin varnish>
A four-necked flask equipped with a thermometer, stirrer, condenser, and nitrogen inlet tube was charged with 300 parts by weight of polyneopentyl adipate diol having a number average molecular weight of 1,000 and 133.2 parts by weight of isophorone diisocyanate. While introducing gas, reaction was carried out at 100 to 105°C for 4 hours while stirring. Then, 24.1 parts by mass of dimethylolpropionic acid was charged and reaction was carried out at 100 to 110°C for 2 hours. After confirming that the dimethylolpropionic acid has completely reacted, the mixture was cooled to 100° C., charged with 1128 parts by mass of water and 20.2 parts by mass of triethylamine to make it aqueous, and furthermore, 34.8 parts by mass of adipic acid dihydrazide was added to stop the reaction. to obtain an aqueous polyurethane resin varnish having a solid content of 30% and a resin acid value of 24 mgKOH/g.

<Preparation of pigment dispersion (color ink base)>
76.0 parts by mass of water was added to 12.0 parts by mass of the aqueous polyurethane resin varnish solution and mixed to prepare a resin varnish for pigment dispersion. To this varnish, 12 parts by mass of the following various color pigments are further added, and after stirring and mixing, kneading is performed with a wet circulation mill, and water-based color ink bases (BASE-UR-B, BASE-UR-Y, BASE-UR -M, BASE-UR-C) were prepared.
Black pigment: PBk7 (PRINTEX90, manufactured by Degussa)
Yellow pigment: PY17 (Graphtol Yellow GG, manufactured by Clariant)
Magenta pigment: PR146 (SYMULER Fast Red 4580, manufactured by DIC)
Cyan pigment: PB15:3 (HELIOGEN BLUE D 7088, manufactured by BASF)

<Preparation of pigment dispersion (white ink base)>
20.0 parts by mass of water was added to 40.0 parts by mass of the aqueous polyurethane resin varnish and mixed to prepare a resin varnish for pigment dispersion. To this varnish, 40 parts by mass of titanium oxide (trade name: R-960, manufactured by DuPont) was further added, stirred and mixed, and kneaded with a wet circulation mill to obtain a water-based white ink base (BASE-UR-W). was prepared.

<Comparative manufacturing example>
<Production of water-based (meth)acrylate copolymer resin varnish>
20 parts by mass of an acrylic acid/n-butyl acrylate/benzyl methacrylate/styrene copolymer having a glass transition temperature of 40°C, a weight average molecular weight of 30,000, and an acid value of 185 mgKOH/g; A water-based (meth)acrylate copolymer resin varnish having a solid content of 20% was obtained by dissolving in a mixed solution of 77.5 parts by mass.

<Preparation of pigment dispersion (black ink base)>
To 18.0 parts by mass of the water-based (meth)acrylate copolymer resin varnish, 70.0 parts by mass of water was added and mixed to prepare a resin varnish for pigment dispersion. To this varnish, 12 parts by mass of the above black pigment was further added, stirred and mixed, and kneaded with a wet circulation mill to prepare a water-based black ink base (BASE-AC-B).

<Examples 1 to 15, Comparative Examples 1 to 4>
<Production of Aqueous Inkjet Ink Compositions (I1 to I7)>
Each water-based inkjet ink composition was produced using each ink base obtained above and various raw materials so as to have the formulation shown in Table 1.

In Table 1, Neocryl A-1092 is a styrene-acrylic emulsion (solid content 48.5% by mass, manufactured by DSM, glass transition temperature 6 ° C.);
Olfine E1010 is an acetylenic surfactant (solid content: 100% by mass, HLB: 13, manufactured by Nissin Kagaku Kogyo Co., Ltd.);

<Manufacture of primer composition>
Each primer composition was produced using various raw materials so as to have the formulations shown in Tables 2 and 3.

The following evaluations were performed using each water-based inkjet ink composition obtained above and each primer composition. Results are shown in Tables 2 and 3.

<Evaluation of water resistance>
Each primer composition obtained above was printed on an OPP film (P2161, 25 μm, manufactured by Toyobo Co., Ltd.) using a 0.1 mm bar coater. After rubbing the printed primer coating film five times with a cotton swab moistened with water, the state of the coating film was visually observed. 0 was set as a pass.
[Evaluation criteria]
◯: No peeling of coating film.
Δ: The coating film was slightly peeled off.
x: The coating film was largely peeled off, and the base material was exposed at the rubbed portion.

<Evaluation of Adhesion>
Each primer obtained above was applied to the treated surface of a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., E-5102, thickness 12 μm, hereinafter referred to as PET film) that had been subjected to corona discharge treatment on one side. Each water-based inkjet ink composition thus prepared is packed in a cartridge of Epson's printer PX105 and printed, and then an isocyanate-based adhesive (Takeda Pharmaceutical Co., Ltd., Takenate A-385/Takelac A-50 ethyl acetate solution) is applied. Then, a CPP film was laminated using a dry laminator to obtain a laminated product. After these dry laminated products were aged at 40° C. for 3 days, samples were cut to a width of 15 mm and the T-peel strength was measured using a peel tester manufactured by Yasuda Seiki Seisakusho. 0 was set as a pass.
[Evaluation criteria]
◯: The strength when the laminated product is peeled off is 100 g/15 mm or more.
Δ: The strength when the laminated product is peeled off is 50 g/15 mm or more and less than 100 g/15 mm.
x: The strength when the laminated product is peeled off is less than 50 g/15 mm.

<Evaluation of Bleeding Resistance of Fine Lines>
Each primer composition obtained above was applied to the treated surface of a PET film which had been subjected to corona discharge treatment on one side, and each water-based inkjet ink composition obtained above was packed in a cartridge of a printer PX105 manufactured by Epson Corporation. A thin line of about 0.3 mm was printed, and thickening due to bleeding was observed and evaluated based on the following evaluation criteria. △ or ◯ is acceptable, and ◯ is preferable.
[Evaluation criteria]
◯: No blurring, printing is possible with the same thickness.
Δ: Partial thickening is observed, but double or more thickening is not observed.
x: Twice or more thickening is observed as a whole.

<Evaluation of solid image printability>
Each primer composition obtained above was applied to the treated surface of a PET film which had been subjected to corona discharge treatment on one side, and each water-based inkjet ink composition obtained above was packed in a cartridge of a printer PX105 manufactured by Epson Corporation. A solid image of 5 cm×5 cm was printed, and the resulting image formed product was visually observed to evaluate the image quality according to the following evaluation criteria. △ or ◯ is acceptable, and ◯ is preferable.
[Evaluation criteria]
◯: No bleeding, unevenness, or streaks.
Δ: Slight unevenness and streaks are observed.
x: Bleeding, unevenness, and streaks are visually observed.

In Tables 2 and 3, Lupasol G20 is polyethyleneimine (solid content 50% by mass, molecular weight 1,300, manufactured by BASF);
Lupasol G35 is polyethyleneimine (solid content 50% by mass, molecular weight 2,000, manufactured by BASF);
Lupasol G100 is polyethyleneimine (solid content 50% by mass, molecular weight 5,000, manufactured by BASF);
Polyurethane-based resin is a polycarbonate-based polyurethane emulsion (Superflex 650, solid content 26% by mass, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.);
The polyolefin resin is a chlorinated polypropylene emulsion (Superchron E-604, solid content 40% by mass, manufactured by Nippon Paper Industries Co., Ltd.);
Olfine E1010 is an acetylenic surfactant (solid content 100% by mass, HLB: 13, manufactured by Nissin Chemical Industry Co., Ltd.);
BYK-331 indicates a silicone surfactant (active ingredient 98%, Big Chemie);

Claims (6)

An ink comprising: an aqueous inkjet ink composition containing a pigment, a dispersant for the pigment, a water-soluble solvent, and water; and a primer composition containing an aggregating agent for aggregating the aqueous inkjet ink composition, a resin emulsion, and water. set and
The dispersant is a polyurethane resin,
The ink set, wherein the aggregating agent is a compound having a polyethyleneimine skeleton. 2. The ink set according to claim 1, wherein the polyurethane resin has at least one skeleton selected from the group consisting of a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, and a polybutadiene skeleton. 3. The ink set according to claim 1, wherein the compound having a polyethyleneimine skeleton is polyethyleneimine. 4. The ink set according to claim 1, wherein the resin emulsion is a polyurethane resin emulsion and/or a polyolefin resin emulsion. 5. The ink set according to claim 1, wherein the resin emulsion has a solid content of 1 to 10% by mass in the primer composition. A printed matter obtained by printing the ink set according to any one of claims 1 to 5.