JP2021091206A - Inkjet recording method and inkjet recording apparatus - Google Patents

Abstract

To provide an inkjet recording method capable of obtaining a cured product excellent in scratch resistance and beading suppression.SOLUTION: There is provided an inkjet recording method comprising a step of discharging an ink containing a dispersion having a polymerizable group and a polymerization initiator in a recording medium, which comprises: a step of irradiating an active energy ray to the ink dispersed in the recording medium after the step of dispersing an ink in the recording medium; and a step of drying with heat after irradiating an active energy ray.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inkjet recording method and an inkjet recording device.

Inkjet recording methods have rapidly become widespread in recent years because they can easily record color images and have low running costs.

As the ink for inkjet recording, an aqueous dye ink in which a dye is dissolved in an aqueous medium and a solvent-based ink in which an oil-soluble dye is dissolved in an organic solvent are used. Generally, from the viewpoint of environment and safety, water-soluble dyes dissolved in water or water and a water-soluble organic solvent are used in offices and homes.

In addition, water-based pigment inks in which pigments are made into fine particles and dispersed in water are attracting attention. Inkjet recording inks using water-dispersible pigments are known to have excellent water resistance and light resistance.

Further, in recent years, a pigment ink containing water as a main agent and containing a radically reactive polymerization material having an acrylate structure in a part of the structure can be used to form an ink film having scratch resistance by a radical reaction. Water-based pigment inks and the like have been proposed (see, for example, Patent Document 1).
In Patent Document 2, as an ink composition having excellent weather resistance, water resistance, moisture resistance, and chemical resistance, and also excellent fixability and surface drying property, pigments and photoreactive polymer fine particles are contained in an aqueous medium. , A water-soluble monomer, and an ink composition containing a photopolymerization initiator are disclosed.

An object of the present invention is to provide an inkjet recording method capable of obtaining a cured product having excellent scratch resistance and beading resistance.

The inkjet recording method of the present invention as a means for solving the above problems is
An inkjet recording method comprising a step of ejecting an ink containing a dispersion having a polymerizable group and a polymerization initiator into a recording medium.
An inkjet recording method comprising a step of ejecting the ink onto a recording medium, a step of irradiating the ink ejected onto the recording medium with active energy rays, and a step of irradiating the ink with active energy rays and then drying with heat. is there.

According to the present invention, it is possible to provide an inkjet recording method capable of obtaining a cured product having excellent scratch resistance and beading resistance.

FIG. 1 is a schematic view showing an example of an image forming apparatus according to the present invention.

The present invention is shown in the following (1), but the following (2) to (7) are also included in the embodiments thereof, and these will also be described.
(1) An inkjet recording method comprising a step of ejecting an ink containing a dispersion having a polymerizable group and a polymerization initiator into a recording medium.
An inkjet recording method comprising a step of ejecting the ink onto a recording medium, a step of irradiating the ink ejected onto the recording medium with active energy rays, and a step of irradiating the ink with active energy rays and then drying with heat.
(2) The inkjet recording method according to (1) above, wherein the polymerizable group is at least one of an acrylate group and a methacrylate group.
(3) As for the step of irradiating an active energy ray, the cumulative energy of the active energy ray is 300 mJ / cm ² to 1000 mJ / cm ^2, the ink jet recording method according to (1) or (2).
(4) The inkjet recording method according to (3) above, wherein the active energy ray is ultraviolet UV-A.
(5) The inkjet recording method according to any one of (1) to (4) above, wherein the ink contains 40% by mass or more and 70% by mass or less of water.
(6) The inkjet recording method according to any one of (1) to (5) above, wherein the dispersion having a polymerizable group contains a urethane dispersion.
(7) An inkjet recording apparatus having an ink ejection means for ejecting an ink containing a dispersion having a polymerizable group and a polymerization initiator into a recording medium.
After the ink ejection means for ejecting the ink to the recording medium, the active energy ray irradiating means for irradiating the ink ejected on the recording medium with active energy rays, and after the active energy ray irradiating means, drying by heat is performed. An ink-ink recording device having a drying means.

The present inventors examined an inkjet recording method having excellent scratch resistance, ejection property, and beading resistance, and obtained the following findings.
For example, in the conventional ink containing a water-soluble dye, there is a problem that the formed recorded image is inferior in water resistance and light resistance.
Further, for example, in the conventional water-based pigment ink, when printing on a non-absorbent medium or a non-absorbent medium, the ink dries slowly, so that the ink droplets on the media are united before being fixed on the medium, and the image quality is improved. There is a problem that the amount of ink decreases (beading).
As a means for solving the above problems, a method of applying a precoat liquid that reacts with the ink pigment and aggregates on the surface of the media is used.

In the method of irradiating the active energy rays after the ink is dried, the effect of pinning (sealing) the ink on the media when the ink droplets land on the media is weak. Therefore, when heat is applied rapidly, the viscosity of the ink droplets rapidly decreases due to the heat, so that there is a problem that the ink droplets spread and bleed. In particular, in addition to heat, a step of blowing wind is usually required to improve the drying efficiency and suppress the temperature rise of the media, and this wind causes a problem that ink droplets flow.
Therefore, in the inkjet recording method using an ink containing a dispersion having a polymerizable group and a polymerization initiator, the present inventors eject the ink to a recording medium, irradiate the ink with active energy rays, and further heat the ink. It was found that the drying by the above method is effective in beading resistance and scratch resistance even if the precoating liquid is not applied. After the ink droplets land on the media, they are irradiated with active energy rays before drying, so that the polymerizable groups on the surface of the resin particles are bonded and the resin particles are bonded to each other to form large particles. By aggregating the resin particles and settling on the media in this way, even if the resin particles are subsequently affected by heat or wind in the drying process, the resin particles have already settled and settled on the media, so that heat or heat is generated. The problem of ink droplets flowing due to the wind no longer occurs.

(ink)
The ink used in the present invention (hereinafter, also referred to as an active energy ray-curable composition) contains a dispersion having a polymerizable group and a polymerization initiator, and further contains other components as necessary. Examples of other components include organic solvents, water, resins, additives and the like.

<Polymerizable material>
The polymerizable material may contain a dispersion having a polymerizable group, and may contain other materials as necessary.
The polymerizable group is preferably at least one of an acrylate group, a methacrylate group and an acrylamide group.
In addition, examples of other polymerizable materials include amine compounds and polymerizable monomers.

<< Dispersion with acrylate group >>
The dispersion having an acrylate group is a reactive particle capable of polymerizing with other particles by a stimulus such as ultraviolet rays or heat. By incorporating a dispersion having an acrylate group into the ink, the cured film obtained by curing the ink can be made excellent in smoothness (glossiness), flexibility, and scratch resistance.

The dispersion having an acrylate group is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a dispersion having a water-dispersible acrylate group. Examples of the dispersion having a water-dispersible acrylate group include urethane dispersion containing reactive polyurethane particles. Examples of the reactive polyurethane particles include (meth) acrylicized polyurethane particles.

As the (meth) acrylicized polyurethane particles, for example, a commercially available product may be used. Examples of commercially available products include Ucecoat (registered trademark) 6558 (manufactured by Daicel Ornex), Ucecoat (registered trademark) 6559 (manufactured by Daicel Ornex), Ucecoat (registered trademark) 7571 (manufactured by Daicel Ornex), and Ebecryl. (Registered Trademark) 2002 (manufactured by Daicel Ornex), Ebecril (registered trademark) 2003 (manufactured by Daicel Ornex), Ucecoat (registered trademark) 7710 (manufactured by Daicel Ornex), Ucecoat (registered trademark) 7655 (Dycel) Ornex), NeoradR (registered trademark) 440 (Avecia), NeoradR (registered trademark) 441 (Avecia), NeoradR (registered trademark) 447 (Avecia), NeoradR (registered trademark) 448 (Avecia) , Bayhydr (registered trademark) UV2317 (manufactured by COVESTRO), Bayhydrol (registered trademark) UV VP LS2348 (manufactured by COVESTRO), Lux (registered trademark) 430 (manufactured by ALBERDING BOLEY), Lux (registered trademark) 399 BOLEY (registered trademark), Lux (registered trademark) 484 (ALBERDING BOLEY), Laromer (registered trademark) LR8949 (BASF), Laromer (registered trademark) LR8983 (BASF), Laromer (registered trademark) PE22WN (BASF) , Laromer (registered trademark) PE55WN (manufactured by BASF), Laromer (registered trademark) UA9060 (manufactured by BASF), and the like. Of these, Laromer (registered trademark) LR8949 (manufactured by BASF) and Laromer (registered trademark) LR8983 (manufactured by BASF) are preferable. With Laromer (registered trademark) LR8949 (manufactured by BASF) and Laromer (registered trademark) LR8983 (manufactured by BASF), scratch resistance can be improved.

The content of the dispersion having an acrylate group is preferably 2% by mass or more and 12% by mass or less, and more preferably 6% by mass or more and 12% by mass or less, based on the total amount of the ink. When the content of the dispersion having an acrylate group is 2% by mass or more and 12% by mass or less, the scratch resistance can be improved.

<< Polymerizable Monomer >>
The polymerizable monomer is not particularly limited as long as it has a reactive substituent capable of polymerizing, and can be appropriately selected depending on the intended purpose.
As the polymerizable monomer, for example, (meth) acrylate, (meth) acrylamide, vinyl ether and the like can be used in combination. More specifically, for example, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, γ-butyrolactone acrylate, isobornyl (meth) acrylate, formalized trimethylol propane mono (meth) acrylate, Polytetramethylene glycol di (meth) acrylate, trimethylolpropane (meth) acrylic acid benzoic acid ester, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol diacrylate [CH ₂ = CH- CO- (OC ₂ H ₄ ) n-OCOCH = CH ₂ (n ≒ 4)], polyethylene glycol diacrylate [CH ₂ = CH-CO- (OC ₂ H ₄ ) n-OCOCH = CH ₂ (n ≒ 9)) ], Polyethylene glycol diacrylate [CH ₂ = CH-CO- (OC ₂ H ₄ ) n-OCOCH = CH ₂ (n ≈ 14)], Polyethylene glycol diacrylate [CH ₂ = CH-CO- (OC ₂ H _4)] ) N-OCOCH = CH ₂ (n≈23)], dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol dimethacrylate [CH ₂ = C (CH ₃ ) -CO- (OC) ₃ H ₆ ) n-OCOC (CH ₃ ) = CH ₂ (n≈7)], 1,3-butanediol di (meth) acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol di ( Meta) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol diacrylate, tricyclodecanedimethanol diacrylate, propylene oxide modified bisphenol A di (meth) acrylate, polyethylene glycol di (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, (meth) acryloylmorpholine, propylene oxide-modified tetramethylolmethanetetra (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, caprolactone-modified dipentaerythritol hydroxypenta (meth) acrylate, ditrimethylol Propanetetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropanthria Crylate, ethylene oxide-modified trimethylol propantri (meth) acrylate, propylene oxide-modified trimethylol propanthry (meth) acrylate, caprolactone-modified trimethylol propanthry (meth) acrylate, pentaerythritol tri (meth) acrylate, tris (2-hydroxy) Ethyl) isocyanurate tri (meth) acrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol di (meth) acrylate, propylene oxide-modified neopentyl glycol di (meth) acrylate, propylene oxide-modified glyceryl tri (meth) acrylate, polyester. Di (meth) acrylate, polyester tri (meth) acrylate, polyester tetra (meth) acrylate, polyester penta (meth) acrylate, polyester poly (meth) acrylate, polyurethane di (meth) acrylate, polyurethane tri (meth) acrylate, polyurethane tetra. (Meta) acrylate, polyurethane penta (meth) acrylate, polyurethane poly (meth) acrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl (meth) acrylamide, N-vinylcaprolactam, N-vinylpyrrolidone, N-vinylformamide, cyclohexane Examples thereof include dimethanol monovinyl ether, cyclohexane dimethanol divinyl ether, hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, diethylene glycol divinyl ether, dicyclopentadiene vinyl ether, tricyclodecane vinyl ether, benzyl vinyl ether and ethyloxetane methyl vinyl ether. Among these, the solubility in water as a dispersion medium, the viscosity of the composition, the thickness of the cured film (coating film) on the substrate, and the like may be selected and added. In terms of solubility in water, acryloylmorpholine, dimethylaminopropylacrylamide, polyethylene glycol, polypropylene glycol-modified acrylate, and 4-hydroxybutyl acrylate are preferable. These may be used alone or in combination of two or more.

<Polymerization initiator>
The active energy ray-curable composition of the present invention may contain a polymerization initiator. The polymerization initiator may be one that can generate active species such as radicals and cations by the energy of the active energy ray and initiate the polymerization of the polymerizable compound (monomer or oligomer). As such a polymerization initiator, known radical polymerization initiators, cationic polymerization initiators, base generators and the like can be used alone or in combination of two or more, and among them, a radical polymerization initiator is used. Is preferable. Further, the polymerization initiator is preferably contained in an amount of 0.1 to 2% by mass with respect to the total mass (100% by mass) of the composition in order to obtain a sufficient curing rate.
Examples of the radical polymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, and the like. Examples thereof include ketooxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.
Further, in addition to the above-mentioned polymerization initiator, a polymerization accelerator (sensitizer) can also be used in combination. The polymerization accelerator is not particularly limited, but for example, trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, -2-ethylhexyl p-dimethylaminobenzoate, N, Amine compounds such as N-dimethylbenzylamine and 4,4'-bis (diethylamino) benzophenone are preferable, and the content thereof may be appropriately set according to the polymerization initiator used and the amount thereof.

A water-soluble polymerization initiator is particularly preferable, and a photopolymerization initiator having a hydroxyl group in the molecule is particularly preferable. As the photopolymerization initiator, those having an alkylphenone-based or monoacylphosphine oxide-based molecular skeleton are preferable. Particularly preferable examples include 2-hydroxy-2-methyl-1-phenylpropanone and 1- [4- (2-hydroxyethoxyl) -phenyl] -2-hydroxy-methylpropanone in the alkylphenone system, and acylphos. In the fin oxide system, an ionized product of Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and an EO adduct can be mentioned.

<< Amine compound >>
In the present invention, an amine compound can be added to the ink.
The amine compound can be added to the ink as a pH adjuster.
As the amine compound, it is preferable to add an amine compound having a boiling point of 120 ° C. or higher and 200 ° C. or lower and a molecular weight of 100 or lower. Further, when the content (mass standard) of the resin particles in the ink is 1, the content of the amine compound is more preferably 0.01 or more and 0.1 or less. As a result, even better maintainability is realized.

The amine compound may be any of primary, secondary, tertiary and quaternary amines and salts thereof. The quaternary amine means a compound in which a nitrogen atom is substituted with four alkyl groups.
As the amine compound, a compound represented by the following formula (I) or (II) is preferable.

［式中、Ｒ₁、Ｒ₂、Ｒ₃は水素原子、炭素数１〜４のアルコキシ基、炭素数１〜６のアルキル基、ヒドルキシエチル基を示す。但し、すべて水素原子である場合を除く。］

［式中、Ｒ₄、Ｒ₅、Ｒ₆は水素原子、メチル基、エチル基、ヒドロキシメチル基、炭素数１〜４のアルキル基を示す。］
（Ｉ）および（ＩＩ）式で表される化合物としては、例えば、１−アミノ−２−プロパノール、３−アミノ−１−プロパノール、Ｎ−メチルエタノールアミン、Ｎ，Ｎ−ジメチルエタノールアミン、１−アミノ−２−メチル−プロパノールなどが挙げられる。

[In the formula, R ₁ , R ₂ , and R ₃ represent a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, an alkyl group having 1 to 6 carbon atoms, and a hydroxyethyl group. However, this does not apply when all are hydrogen atoms. ]

[In the formula, R ₄ , R ₅ , and R ₆ represent a hydrogen atom, a methyl group, an ethyl group, a hydroxymethyl group, and an alkyl group having 1 to 4 carbon atoms. ]
Examples of the compounds represented by the formulas (I) and (II) include 1-amino-2-propanol, 3-amino-1-propanol, N-methylethanolamine, N, N-dimethylethanolamine, 1-. Amino-2-methyl-propanol and the like can be mentioned.

The content of the amine compound in the ink is not particularly limited, but is preferably 0.01% by mass to 5% by mass, particularly preferably 0.05% by mass to 2% by mass, from the viewpoint of adjusting the pH of the ink.

Further, the amine compound contained in the ink can be used in combination with another amine compound in addition to the amine compound.

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol , 2,4-Pentanediol, 1,5-Pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, Glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl- Polyhydric alcohols such as 1,3-pentanediol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl Polyhydric alcohol alkyl ethers such as ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone. , 1,3-Dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N- Amidos such as dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate and ethylene carbonate. And so on.
It is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because it not only functions as a wetting agent but also has good drying properties.

Polyol compounds having 8 or more carbon atoms and glycol ether compounds are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Ethers: Polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether can be mentioned.

A polyol compound having 8 or more carbon atoms and a glycol ether compound can improve the permeability of ink when paper is used as a recording medium.

The content of the organic solvent in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 60% by mass or less from the viewpoint of ink drying property and ejection reliability. More preferably, it is 20% by mass or more and 60% by mass or less.

<Water>
The content of water in the ink-curable composition is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of dryness and ejection reliability of the ink-curable composition, 40% by mass or more is 70. It is preferably mass% or less, more preferably 45% by mass to 60% by mass. When the amount of water is 40% by mass or more, the viscosity of the ink is suitable for ejection, and when the amount of water is 70% by mass or less, the solid content is appropriate and the required image density can be obtained. ..

<Color material>
The active energy ray-curable composition of the present invention may contain a coloring material. As the coloring material, various pigments and dyes that impart black, white, magenta, cyan, yellow, green, orange, glossy colors such as gold and silver, etc., depending on the purpose and required characteristics of the composition in the present invention. Can be used. The content of the coloring material may be appropriately determined in consideration of the desired color density, dispersibility in the composition, etc., and is not particularly limited, but is 0. It is preferably 1 to 20% by mass. The active energy ray-curable composition of the present invention may be colorless and transparent without containing a coloring material, and in that case, for example, it is suitable as an overcoat layer for protecting an image.
As the pigment, an inorganic pigment or an organic pigment can be used, and one type may be used alone or two or more types may be used in combination.
As the inorganic pigment, for example, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black, iron oxide, and titanium oxide can be used.
Examples of organic pigments include azo pigments such as insoluble azo pigments, condensed azo pigments, azolakes and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments and quinophthalones. Polycyclic pigments such as pigments, dye chelate (for example, basic dye type chelate, acidic dye type chelate, etc.), dyeing lake (basic dye type lake, acidic dye type lake), nitro pigment, nitroso pigment, aniline black, Daylight fluorescent pigments can be mentioned.
In addition, a dispersant may be further contained in order to improve the dispersibility of the pigment. The dispersant is not particularly limited, and examples thereof include dispersants commonly used for preparing pigment dispersions such as polymer dispersants.
As the dye, for example, an acid dye, a direct dye, a reactive dye, and a basic dye can be used, and one type may be used alone or two or more types may be used in combination.

<Pigment dispersion>
It is possible to obtain an ink by mixing a material such as water or an organic solvent with a pigment. It is also possible to produce an ink by mixing a material such as water or an organic solvent with a pigment dispersion obtained by mixing a pigment and other water or a dispersant.
The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and other components as necessary, and adjusting the particle size. It is preferable to use a disperser for dispersion.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of the maximum number because the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is also high. It is preferably 500 nm or less, more preferably 20 nm or more and 150 nm or less. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good ejection stability and increasing the image density, 0.1 mass is used. % Or more and 50% by mass or less are preferable, and 0.1% by mass or more and 30% by mass or less are more preferable.
If necessary, the pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifuge, or the like.

<Resin>
The type of resin contained in the ink is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, etc. Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
Resin particles made of these resins may be used. It is possible to obtain ink by mixing resin particles with a material such as a coloring material or an organic solvent in the state of a resin emulsion in which water is dispersed as a dispersion medium. As the resin particles, those synthesized as appropriate may be used, or commercially available products may be used. Further, these may be used alone or in combination of two or more kinds of resin particles.

The volume average particle diameter of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good fixability and high image hardness, 10 nm or more and 1,000 nm or less are preferable. More than 200 nm is more preferable, and 10 nm or more and 100 nm or less is particularly preferable.
The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

The content of the resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of fixability and storage stability of the curable composition, 1 mass with respect to the total amount of the curable composition. % Or more and 30% by mass or less are preferable, and 5% by mass or more and 20% by mass or less are more preferable.

The particle size of the solid content in the ink is not particularly limited and can be appropriately selected according to the purpose, but from the viewpoint of improving image quality such as ejection stability and image density, the maximum frequency in terms of the maximum number of inks. Is preferably 20 nm or more and 1000 nm or less, and more preferably 20 nm or more and 150 nm or less. The solid content includes resin particles, pigment particles, and the like. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

<Additives>
If necessary, a surfactant, a defoaming agent, an antiseptic / antifungal agent, a rust preventive, a pH adjuster, or the like may be added to the ink.

<Surfactant>
As the surfactant, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.
The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose.
Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, single-ended modified polydimethylsiloxane, and side chain double-ended modified polydimethylsiloxane. Those having an oxyethylene group and a polyoxyethylene polyoxypropylene group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the Si portion side chain of dimethylsiloxane.
Examples of the fluorine-based surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. The counterions of the salts in these fluorine-based surfactants are Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH). ₃ etc. can be mentioned.
Examples of the amphoteric tenside agent include laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, and lauryldihydroxyethylbetaine.
Examples of the nonionic surfactant include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include a fatty acid ester and an ethylene oxide adduct of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, and polyoxyethylene alkyl ether sulfate salt.
These may be used alone or in combination of two or more.

（但し、一般式（Ｓ−１）式中、ｍ、ｎ、ａ、及びｂは、それぞれ独立に、整数を表わし、Ｒは、アルキレン基を表し、Ｒ’はアルキル基を表わす。）
上記のポリエーテル変性シリコーン系界面活性剤としては、市販品を用いることができ、例えば、ＫＦ−６１８、ＫＦ−６４２、ＫＦ−６４３（信越化学工業株式会社）、ＥＭＡＬＥＸ−ＳＳ−５６０２、ＳＳ−１９０６ＥＸ（日本エマルジョン株式会社）、ＦＺ−２１０５、ＦＺ−２１１８、ＦＺ−２１５４、ＦＺ−２１６１、ＦＺ−２１６２、ＦＺ−２１６３、ＦＺ−２１６４（東レ・ダウコーニング・シリコーン株式会社）、ＢＹＫ−３３、ＢＹＫ−３８７（ビックケミー株式会社）、ＴＳＦ４４４０、ＴＳＦ４４５２、ＴＳＦ４４５３（東芝シリコン株式会社）などが挙げられる。 The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain-modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, side. Examples thereof include polydimethylsiloxane modified at both ends of the chain, and a polyether-modified silicone-based surfactant having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as modifying groups exhibits good properties as an aqueous surfactant, and is particularly effective. preferable.
As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. As commercially available products, for example, they can be obtained from Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd., and the like.
The above-mentioned polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the general formula (S-1) is dimethylpoly. Examples thereof include those introduced into the Si part side chain of siloxane.

(However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R'represents an alkyl group.)
Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.) and the like can be mentioned.

上記一般式（Ｆ−１）で表される化合物において、水溶性を付与するためにｍは０〜１０の整数が好ましく、ｎは０〜４０の整数が好ましい。
一般式（Ｆ−２）
Ｃ_nＦ_2n+1−ＣＨ₂ＣＨ(ＯＨ)ＣＨ₂−Ｏ−(ＣＨ₂ＣＨ₂Ｏ)_a−Ｙ
上記一般式（Ｆ−２）で表される化合物において、ＹはＨ、又はＣ_mＦ_2m+1でｎは１〜６の整数、又はＣＨ₂ＣＨ(ＯＨ)ＣＨ₂−Ｃ_mＦ_2m+1でｎは４〜６の整数、又はＣ_pＨ_2p+1でｐは１〜１９の整数である。ａは４〜１４の整数である。
上記のフッ素系界面活性剤としては市販品を使用してもよい。
この市販品としては、例えば、サーフロンＳ−１１１、Ｓ−１１２、Ｓ−１１３、Ｓ−１２１、Ｓ−１３１、Ｓ−１３２、Ｓ−１４１、Ｓ−１４５（いずれも、旭硝子株式会社製）；フルラードＦＣ−９３、ＦＣ−９５、ＦＣ−９８、ＦＣ−１２９、ＦＣ−１３５、ＦＣ−１７０Ｃ、ＦＣ−４３０、ＦＣ−４３１（いずれも、住友スリーエム株式会社製）；メガファックＦ−４７０、Ｆ−１４０５、Ｆ−４７４（いずれも、大日本インキ化学工業株式会社製）；ゾニール（Ｚｏｎｙｌ）ＴＢＳ、ＦＳＰ、ＦＳＡ、ＦＳＮ−１００、ＦＳＮ、ＦＳＯ−１００、ＦＳＯ、ＦＳ−３００、ＵＲ（いずれも、ＤｕＰｏｎｔ社製）；ＦＴ−１１０、ＦＴ−２５０、ＦＴ−２５１、ＦＴ−４００Ｓ、ＦＴ−１５０、ＦＴ−４００ＳＷ（いずれも、株式会社ネオス社製）、ポリフォックスＰＦ−１３６Ａ，ＰＦ−１５６Ａ、ＰＦ−１５１Ｎ、ＰＦ−１５４、ＰＦ−１５９（オムノバ社製）、ユニダインＤＳＮ-４０３Ｎ（ダイキン工業株式会社製）などが挙げられ、これらの中でも、良好な印字品質、特に発色性、紙に対する浸透性、濡れ性、均染性が著しく向上する点から、Ｃｈｅｍｏｕｒｓ社製のＦＳ−３００、ＦＳ−３４、ＦＳ−３００、株式会社ネオス製のＦＴ−１１０、ＦＴ−２５０、ＦＴ−２５１、ＦＴ−４００Ｓ、ＦＴ−１５０、ＦＴ−４００ＳＷ、オムノバ社製のポリフォックスＰＦ−１５１Ｎ及びダイキン工業株式会社製のユニダインＤＳＮ−４０３Ｎが特に好ましい。 As the fluorine-based surfactant, a compound having 2 to 16 carbon atoms substituted with fluorine is preferable, and a compound having 4 to 16 carbon atoms substituted with fluorine is more preferable.
Examples of the fluorine-based surfactant include a perfluoroalkyl phosphate compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain.
Among these, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain are preferable because they have low foaming property, and are particularly fluorine-based compounds represented by the general formulas (F-1) and (F-2). Surfactants are preferred.

In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility.
General formula (F-2)
C _n F _{2n + 1} −CH ₂ CH (OH) CH ₂ −O− (CH ₂ CH ₂ O) _a −Y
In the compound represented by the above general formula (F-2), Y is H, or C _m F _{2 m + 1} , and n is an integer of 1 to 6, or CH ₂ CH (OH) CH _2- C _m F _{2 m +. In 1} , n is an integer of 4 to 6, or C _p H _{2p + 1} and p is an integer of 1 to 19. a is an integer of 4 to 14.
Commercially available products may be used as the above-mentioned fluorine-based surfactant.
Examples of this commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Co., Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by Dainippon Ink and Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all) , DuPont); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.), etc. Among these, good print quality, especially color development and permeability to paper. FS-300, FS-34, FS-300 manufactured by The Chemours Company, FT-110, FT-250, FT-251, FT-400S manufactured by Neos Co., Ltd. , FT-150, FT-400SW, Polyfox PF-151N manufactured by Omniova Co., Ltd. and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

The content of the surfactant in the ink is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of excellent wettability and ejection stability and improvement in image quality, 0.001 mass is used. % Or more and 5% by mass or less are preferable, and 0.05% by mass or more and 5% by mass or less are more preferable.

<Other ingredients>
The active energy ray-curable composition of the present invention may contain other known components, if necessary. The other components are not particularly limited, but are, for example, conventionally known surfactants, polymerization inhibitors, leveling agents, antifoaming agents, fluorescent whitening agents, penetration promoters, wetting agents (moisturizers), and fixing agents. Agents, viscosity stabilizers, fungicides, preservatives, antioxidants, UV absorbers, chelating agents, pH regulators, thickeners and the like.

<Defoamer>
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because it has an excellent defoaming effect.

<Preservatives and fungicides>
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<Rust inhibitor>
The rust preventive is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

<Curing means>
Examples of the means for curing the curable composition of the present invention include heat curing or curing with active energy rays, and among these, curing with active energy rays is preferable.
The active energy rays used for curing the active energy ray-curable composition of the present invention include polymerizable components in the composition such as electron beams, α rays, β rays, γ rays, and X rays in addition to ultraviolet rays. It is not particularly limited as long as it can impart the energy required for advancing the polymerization reaction of. In particular, when a high-energy light source is used, the polymerization reaction can proceed without using a polymerization initiator. Further, in the case of ultraviolet irradiation, mercury-free is strongly desired from the viewpoint of environmental protection, and replacement with a GaN-based semiconductor ultraviolet light emitting device is very useful industrially and environmentally. Further, the ultraviolet light emitting diode (UV-LED) and the ultraviolet laser diode (UV-LD) are compact, have a long life, have high efficiency, and are low in cost, and are preferable as an ultraviolet light source.

In the case of electron irradiation, a low acceleration voltage type (80 kV to 120 kV) that is effective in curing the ink is preferable, and a nitrogen atmosphere is preferable. A specific example of the device is the EZCure series manufactured by Iwasaki Electric.
Cumulative energy amount of the active energy ray (integrated quantity of light) is preferably in the ^{300mJ / cm 2 ~1000mJ / cm 2} .

For UV irradiation, it is preferable that the integrated quantity of light UV-A in the step of irradiating ultraviolet rays is in ^{300mJ / cm 2 ~1000mJ / cm 2} . When the integrated light intensity is 300 mJ / cm ² or more, the curing is sufficient and the scratch resistance is good. When the integrated light intensity is 1000 mJ / cm ² or less, damage to the base material can be reduced, so that the base material does not deform or crack.

<Preparation of active energy ray-curable composition>
The active energy ray-curable composition of the present invention can be prepared by using the above-mentioned various components, and the preparation means and conditions thereof are not particularly limited. For example, a polymerizable monomer, a pigment, a dispersant and the like are used in a ball mill. It is put into a disperser such as a kitty mill, a disc mill, a pin mill, or a dyno mill, and dispersed to prepare a pigment dispersion liquid, and a polymerizable monomer, an initiator, a polymerization inhibitor, a surfactant, etc. are further mixed with the pigment dispersion liquid. It can be prepared by letting it.

<Viscosity>
The viscosity of the active energy ray-curable composition of the present invention may be appropriately adjusted according to the application and application means, and is not particularly limited. For example, when a discharge means for discharging the composition from a nozzle is applied. The viscosity in the range of 20 ° C. to 65 ° C., preferably the viscosity at 25 ° C. is preferably 3 to 40 mPa · s, more preferably 5 to 15 mPa · s, and particularly preferably 6 to 12 mPa · s. Further, it is particularly preferable that the viscosity range is satisfied without containing the organic solvent. For the above viscosity, a cone rotor (1 ° 34'x R24) was used with a cone plate type rotational viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd., the rotation speed was 50 rpm, and the temperature of constant temperature circulating water was 20 ° C. It can be appropriately set and measured in the range of ~ 65 ° C. VISCOMATE VM-150III can be used to adjust the temperature of the circulating water.

<Use>
The application of the active energy ray-curable composition of the present invention is not particularly limited as long as it is in a field in which an active energy ray-curable material is generally used, and can be appropriately selected depending on the intended purpose, for example, for molding. Examples thereof include resins, paints, adhesives, insulating materials, mold release agents, coating materials, sealing materials, various resists, and various optical materials.
Further, the active energy ray-curable composition of the present invention can be used as an ink to not only form two-dimensional characters and images and design coatings on various substrates, but also to form a three-dimensional three-dimensional image (three-dimensional model). It can also be used as a three-dimensional modeling material for forming. This three-dimensional modeling material may be used, for example, as a binder between powder particles used in a powder lamination method in which three-dimensional modeling is performed by repeatedly curing and laminating a powder layer.
As a three-dimensional modeling device for modeling a three-dimensional model using the active energy ray-curable composition of the present invention, a known one can be used, and the present invention is not particularly limited, but for example, a means for accommodating the composition. , A supply means, a discharge means, an active energy ray irradiation means, and the like.
The present invention also includes a cured product obtained by curing an active energy ray-curable composition and a molded product obtained by processing a structure in which the cured product is formed on a substrate. The molded product is, for example, a cured product or structure formed in a sheet shape or a film shape that has been subjected to molding processing such as heat stretching or punching, and is, for example, an automobile, OA equipment, or electricity. -Suitably used for applications that require molding after decorating the surface, such as electronic devices, meters for cameras, panels for operation units, and the like.
The base material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, or a composite material thereof and the like. From the viewpoint of processability, a plastic base material is preferable.

<Recording medium>
The recording medium used for recording is not particularly limited, and examples thereof include plain paper, glossy paper, special paper, cloth, film, transparency sheet, and general-purpose printing paper.

<Composition container>
The composition container of the present invention means a container in which an active energy ray-curable composition is contained, and is suitable for use in the above-mentioned applications. For example, when the active energy ray-curable composition of the present invention is used for ink, the container containing the ink can be used as an ink cartridge or an ink bottle, whereby ink transfer, ink replacement, etc. It is not necessary to directly touch the ink in the work, and it is possible to prevent the fingers and clothes from getting dirty. In addition, it is possible to prevent foreign substances such as dust from being mixed into the ink. The shape, size, material, etc. of the container itself may be suitable for the intended use and usage, and is not particularly limited, but the material is a light-shielding material that does not transmit light, or the container blocks light. It is desirable that it is covered with a sex sheet or the like.

<Inkjet recording method, recording device>
The inkjet recording method of the present invention is an inkjet recording method including a step of ejecting an ink containing a dispersion having a polymerizable group and a polymerization initiator into a recording medium, and is a step of ejecting the ink to the recording medium. Later, it has a step of irradiating the ejected ink with active energy rays and a step of irradiating the ejected ink with heat and then drying the ink.
The inkjet recording method of the present invention includes an irradiation step of irradiating an active energy ray to cure the ink with the active energy ray.
The inkjet recording apparatus of the present invention has a dispersion having a polymerizable group and an ink ejection means for ejecting ink containing a polymerization initiator into a recording medium. In the inkjet recording apparatus of the present invention, after the ink ejection means for ejecting the ink to the recording medium, the active energy ray irradiating means for irradiating the ink ejected on the recording medium with active energy rays and the active energy ray irradiation. It has a drying means for performing drying by heat after the means. The inkjet recording apparatus of the present invention includes an accommodating portion for accommodating ink, and the container may be accommodated in the accommodating portion. The method of ejecting ink is not particularly limited, and examples thereof include a continuous injection type and an on-demand type. Examples of the on-demand type include a piezo method, a thermal method, and an electrostatic method.

FIG. 1 is an example of an image forming apparatus provided with an inkjet ejection means. The ink is ejected to the recording medium 22 supplied from the supply roll 21 by the color printing units 23a, 23b, 23c, and 23d including the ink cartridges of the yellow, magenta, cyan, and black color-curable inks and the ejection head. Then, the light sources 24a, 24b, 24c, and 24d for curing the ink are irradiated with ultraviolet rays to cure the ink, and a color image is formed. After that, it is dried by heat by the drying means 27, and the recording medium 22 is conveyed to the processing unit 25 and the printed matter winding roll 26.
In the apparatus shown in FIG. 1, the drying means 27 is installed on the upstream side of the printed matter winding roll 26, but the drying means may be arranged on the downstream side of each of the light sources 24a, 24b, 24c, and 24d.

When the components in the ink aggregate while taking in the pigment when curing by the above activation energy ray irradiation, the aggregates settle in the ink, and the aggregates and water (solvent and / or water) are separated. (Hereinafter, this state is referred to as "solid-liquid separation"). In this case, it is possible to reduce the amount of heat required for drying and reduce power consumption by drying after reducing the water content, instead of immediately drying with heat after curing by irradiation with active energy rays. become.

Each printing unit 23a, 23b, 23c, 23d may be provided with a heating mechanism so that the ink is liquefied at the ink ejection portion. Further, if necessary, a mechanism for cooling the recording medium to about room temperature by contact or non-contact may be provided. Further, as an inkjet recording method, a serial method in which the head is moved to eject ink onto the recording medium or a recording medium is continuously moved with respect to a recording medium that moves intermittently according to the width of the ejection head. Any of the line methods of ejecting ink onto the recording medium from the head held at a fixed position can be applied.

The recording medium 22 is not particularly limited, and examples thereof include paper, film, ceramics, glass, metal, and composite materials thereof, and may be in the form of a sheet. Further, the configuration may be such that only single-sided printing is possible, or double-sided printing is also possible. Not limited to those used as general recording media, cardboard, building materials such as wallpaper and floor materials, cloth for clothing such as concrete and T-shirts, textiles, leather and the like can be appropriately used.
Further, the activation energy rays from the light sources 24a, 24b, and 24c may be weakened or omitted, and after printing a plurality of colors, the activation energy rays may be irradiated from the light source 24d. As a result, energy saving and cost reduction can be achieved.

The recorded material recorded by the inkjet recording method of the present invention includes not only those printed on a smooth surface such as ordinary paper or resin film, but also those printed on an uneven surface to be printed, metal or ceramic. It also includes those printed on the surface to be printed made of various materials such as. Further, by superimposing two-dimensional images, it is possible to form a partially three-dimensional image (an image composed of two-dimensional and three-dimensional) or a three-dimensional object.

There are methods such as warm air, halogen heaters, ceramic heaters, and heat drums for drying by heat, and any method that gives heat to the base material is acceptable, but it is preferable because there is little damage to the base material. The method of blowing warm air is good. The temperature of the warm air, 80 ° C. to 150 ° C., the air volume, and the drying time need to be appropriately adjusted depending on the number of hot air nozzles and the like, but the drying time is preferably in the range of 100 msec to 2000 msec at an ^{air volume of 20 m 3 / min.} In the case of a halogen heater, a wavelength of 1 um to 5 um and an irradiation time of 0.1 to 2 sec are preferable. If it is too dry, the image will become dry and rub off, and if it is too dry, the base material will be damaged and deformation or cracks may occur.

Image formation, recording, printing, printing, etc. in the terms of the present invention are all synonymous.

Recording media, media, and printed matter are all synonymous.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples.

-Preparation example of cyan pigment dispersion-
After sufficiently substituting nitrogen gas in a 1 L flask equipped with a mechanical stirrer, a thermometer, a nitrogen gas introduction tube, a perfusion tube, and a dropping funnel, 11.2 parts by mass of styrene and 2.8 parts by mass of acrylic acid. 12.0 parts by mass of lauryl methacrylate, 4.0 parts by mass of polyethylene glycol methacrylate, 4.0 parts by mass of styrene macromer, and 0.4 parts by mass of mercaptoethanol were mixed and heated to 65 ° C.
Next, 100.8 parts by mass of styrene, 25.2 parts by mass of acrylic acid, 108.0 parts by mass of lauryl methacrylate, 36.0 parts by mass of polyethylene glycol methacrylate, 60.0 parts by mass of hydroxylethyl methacrylate, and 36.0 parts by mass of styrene macromer. A mixed solution containing 3.6 parts by mass of mercaptoethanol, 2.4 parts by mass of azobismethylvaleronitrile, and 18 parts by mass of methyl ethyl ketone was added dropwise to the flask over 2.5 hours. After the dropping, a mixed solution of 0.8 parts by mass of azobismethylvaleronitrile and 18 parts by mass of methyl ethyl ketone was added dropwise to the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 parts by mass of azobismethylvaleronitrile was added, and the mixture was further aged for 1 hour. After completion of the reaction, 364 parts by mass of methyl ethyl ketone was added to the flask to obtain 800 parts by mass of the polymer solution A having a concentration of 50% by mass.

Next, 28 parts by mass of the obtained polymer solution A, 26 parts by mass of a phthalocyanine pigment (Dainichi Seika Kogyo Co., Ltd., Chromofine Blue A-220JC), and 13.6 parts by mass of a 1 mol / L potassium hydroxide aqueous solution. After sufficiently stirring 20 parts by mass of methyl ethyl ketone and 13.6 parts by mass of ion-exchanged water, the mixture was kneaded using a roll mill to obtain a paste. The obtained paste was poured into 200 parts by mass of pure water, stirred sufficiently, methyl ethyl ketone and water were distilled off using an evaporator, and this dispersion was subjected to polyvinylidene having an average pore size of 5.0 μm in order to further remove coarse particles. Pressure filtration was performed with a floride membrane filter to obtain a pigment-containing polymer fine particle dispersion having a pigment content of 15% by mass and a solid content of 20% by mass. _{The average particle size (D 50} ) of the polymer fine particles in the obtained pigment dispersion was measured. _{The average particle size (D 50} ) measured with a particle size distribution measuring device (Nanotrack UPA-EX150 manufactured by Nikkiso Co., Ltd.) was 56.0 nm.

-Preparation of ink jet ink 1-
The water-soluble organic solvent (wetting agent) shown in Table 1 below and water are mixed and stirred for 1 hour to be uniformly mixed. A polymerizable material (dispersion having a reactive group, polymerizable monomer) was added and stirred for 1 hour, and a pigment dispersion, a polymerization initiator, a surfactant, a urethane emulsion and a pH adjuster were added and stirred for 1 hour. This dispersion was pressure-filtered with a polyvinylidene fluoride membrane filter having an average pore size of 5.0 μm to remove coarse particles and dust to prepare an ink jet ink 1. “%” In Table 1 is “mass%”.

-Preparation of inkjet inks 2-9-
Inkjet inks 2 to 9 were obtained in the same manner as in Example 1 except that the composition was changed to that shown in Table 1.
The contents of the urethane dispersion, urethane emulsion, and pigment dispersion in Table 1 are the contents in terms of solid content.

(Examples 1 to 8 and Comparative Examples 1 to 6)
Next, using the obtained inkjet inks 1 to 9, a cured product was prepared as follows, and "beading resistance" and "scratch resistance" were measured and evaluated. The results are shown in Table 2.

<Printing equipment>
A flatbed type multipath printing apparatus equipped with a Ricoh head MH5220 was produced, and a solid image chart was printed. The UV irradiation device Subzero085 made by Integration technology is mounted on the left and right sides of the head carriage so that the printed ink can be irradiated with UV at the same time as the printing operation is performed. The printing conditions are a head gap of 2 mm, a discharge rate of 16 pl per drop, 600 dpi, 2 Pass, one-way printing, and an adhesion amount of 8.9 g / m ² , and the image pattern is a solid image of 5 cm x 20 cm. did.
In Examples 1 to 8 and Comparative Examples 1 to 4, UV irradiation was performed while printing, and then the product was dried with warm air for 30 seconds from a state separated by 20 cm with a plastic jet manufactured by Ishizaki Electric Mfg. Co., Ltd.
In Comparative Examples 5 and 6, UV irradiation was not performed at the time of printing, but UV irradiation was performed after drying with warm air.
Using an inkjet recording device under environmental conditions adjusted to 23 ± 0.5 ° C. and 50 ± 5% RH, drive the piezo element so that the same amount of ink adheres to a commercially available PET film (thickness 100 μm). The voltage was changed and set.
The prototype ink was tested by changing the time of the first UV irradiation after printing by arbitrarily changing the position of the filled head and the speed of the head carriage.

<Beading resistance>
The presence or absence of color unevenness in the 5 cm × 20 cm solid image produced by using the flatbed type multipath printing apparatus equipped with the Ricoh head MH5220 was evaluated as bead resistance.
[Evaluation criteria]
A: No beading B: Some beading is seen, but there is no problem (not visible at a distance of 1 m)
C: Intense beading can be seen (even 1m away)

<Scratch resistance>
Friction fastness tester RT-300 (manufactured by Daiei Kagaku Seiki Seisakusho) (dyeing fastness) for a 5 cm x 20 cm solid image produced using a flatbed type multi-pass printing device equipped with the Ricoh head MH5220. A cured product prepared on a friction tester type II (Gakushin type) specified in the degree test method (JIS L-0849) and a white cloth cotton (Kanakin No. 3) attached for a JIS L 0803 compliant test. And attached, a weighted weight of 500 g was attached, and the cured product was rubbed back and forth 100 times. The concentration of the cotton cloth after the test was measured by eXact Scan (manufactured by X-Rite), and the concentration difference from the untested cotton cloth was evaluated. The measurement results were evaluated based on the following evaluation criteria.
[Evaluation criteria]
A: 0.02 or less B: More than 0.02 0.2 or less C: More than 0.2

Details of each component shown in Table 1 are as follows.
-2-hydroxy-2-methyl-1-phenylpropanone: Hydroxyacetophenone-based water-soluble polymerization initiator-Omnirad 819 DW: Biacylphosphine oxide-based polymerization initiator aqueous dispersion (manufactured by IGM Resins)
-Surfinol 440: Nonionic surfactant-Laromer LR 8949: Reactive urethane dispersion (solid content 37.1%, manufactured by BASF)
-Ucecoat 7571: Reactive urethane dispersion (solid content 34.6%, (manufactured by Daicel Ornics))
-Permarin UA-3945: Urethane emulsion (manufactured by Sanyo Chemical Industries, Ltd.)

実施例８については、メディアの変形が見られた。

For Example 8, deformation of the media was observed.

21 Supply roll 22 Recording medium 23a, 23b, 23c, 23d Printing unit 24a, 24b, 24c, 24d Light source 25 Processing unit 26 Printed matter winding roll 27 Drying means

Japanese Unexamined Patent Publication No. 2018-83352 Japanese Unexamined Patent Publication No. 2001-115067

Claims (7)

An inkjet recording method comprising a step of ejecting an ink containing a dispersion having a polymerizable group and a polymerization initiator into a recording medium.
An inkjet recording method comprising a step of ejecting the ink onto a recording medium, a step of irradiating the ink ejected onto the recording medium with active energy rays, and a step of irradiating the ink with active energy rays and then drying with heat. The inkjet recording method according to claim 1, wherein the polymerizable group is at least one of an acrylate group and a methacrylate group. Wherein in the step of irradiating an active energy ray, the cumulative energy of the active energy ray is 300 mJ / cm ² to 1000 mJ / cm ^2, the ink jet recording method according to claim 1 or 2. The inkjet recording method according to claim 3, wherein the active energy ray is ultraviolet UV-A. The inkjet recording method according to any one of claims 1 to 4, wherein the ink contains 40% by mass or more and 70% by mass or less of water. The inkjet recording method according to any one of claims 1 to 5, wherein the dispersion having a polymerizable group contains a urethane dispersion. An inkjet recording apparatus having an ink ejection means for ejecting an ink containing a dispersion having a polymerizable group and a polymerization initiator into a recording medium.
After the ink ejection means for ejecting the ink to the recording medium, the active energy ray irradiating means for irradiating the ink ejected on the recording medium with active energy rays, and after the active energy ray irradiating means, drying by heat is performed. An ink-ink recording device having a drying means.

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