JP2007131793A - Colored dispersion, ink composition, image forming method using the same, and recorded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colored dispersion which contains a fine colorant excellent in dispersibility and its stability, can form high image quality images having clear color tone and high coloring force, can be cured by the irradiation of active energy rays, and is suitable for ink jet recording, to provide an ink composition, to provide an image forming method using the ink composition, and to provide a recorded article obtained by using an ink composition which can be cured by the irradiation of active energy rays and has clear color tone and high coloring force. <P>SOLUTION: This colored dispersion comprises at least a colorant, a compound represented by the general formula (1) (R<SB>1</SB>to R<SB>2</SB>are each independently an alkyl which may have one or more substituents, or an aryl which may have one or more substituents), and a polymerizable compound, wherein the content of the polymerizable compound is ≥50 mass%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a colored dispersion and an ink composition containing the same, and also relates to an ink composition suitably used for ink jet recording, an image forming method, and a recorded matter using the same. Specifically, an ink composition suitable for ink-jet recording capable of forming a high-quality image by being excellent in colorant dispersibility, excellent color developability, cured by irradiation with active energy rays, and the use thereof The present invention relates to an image forming method and recorded matter.

  As an image recording method for forming an image on a recording medium such as paper based on an image data signal, there are an electrophotographic method, a sublimation type and a melt type thermal transfer method, an ink jet method and the like. Among these, the ink jet method can be implemented with an inexpensive apparatus, and the ink can be efficiently used because the ink is ejected only on the required image portion to directly form the image on the recording medium. Running cost is low. Furthermore, there is little noise and it is excellent as an image recording method.

According to the inkjet system, printing is possible not only on plain paper but also on non-water-absorbing recording media such as plastic sheets and metal plates. However, high speed and high image quality are important issues for printing. The time required for drying and curing the droplets after printing has a property of greatly affecting the sharpness of the image.
As one of the ink jet methods, there is a recording method using an ink for ink jet recording that can be cured by irradiation with active energy rays. According to this method, a sharp image can be formed by irradiating active energy rays immediately after printing and curing the ink droplets.
As such a curable ink composition, for example, a composition in which a colorant is dispersed in a polymerizable compound is used in order to form a high-definition image having excellent color developability. Such a composition is required to have high pigment dispersibility and stability over time. In order to impart a clear color tone and high coloring power to the ink composition, it is essential to make the pigment finer. In particular, in the ink used for inkjet recording, since the ejected ink droplets greatly affect the sharpness of the image, the amount of ejected droplets is small, and the thickness of the ink cured film formed from the ink is small. It is essential to use finer particles. As described above, when the pigment particles are further miniaturized, aggregates are easily generated and dispersion of the fine particles becomes difficult. Moreover, the problem that the viscosity of a composition rises by addition of a dispersing agent also arises. The occurrence of pigment aggregates and the increase in viscosity of the ink composition both have an adverse effect on ink ejection properties, and are not preferred for use in ink compositions.

Further, when the ink composition is used for ink jet recording, the ink composition is stored in a cartridge, heated when ejected, and cooled during non-ejection and storage, and thus undergoes repeated heating-cooling temperature changes. This change in temperature also has an adverse effect on the pigment dispersibility, and the dispersibility of the pigment decreases with time, resulting in problems such as increased viscosity and aggregation.
Therefore, there is a need for a pigment dispersion that stably disperses a finely divided pigment in a polymerizable compound and that is excellent in fluid stability over time, and an ink composition containing the same. Various proposals have been made on dispersants for obtaining stable pigment dispersions.

In order to improve the affinity with the pigment, it is a base as a dispersant for an ink composition using a pigment derivative as a dispersant (for example, see Patent Documents 1 and 2) and specific pigments such as phthalocyanine and quinacridone series. Dispersing agents such as an ink composition using a polymer having a functional group (see, for example, Patent Document 3), poly (ethyleneimine) -poly (12-hydroxystearic acid) graft polymer, and a specific agent that dissolves the dispersing agent An ink composition containing a monomer and not using an organic solvent (for example, see Patent Document 4) has been proposed.
Although these ink compositions certainly have improved pigment dispersion stability over the conventional ones due to the function of the dispersant, they are insufficient to cope with the miniaturization of the pigments used, and are even smaller. It was necessary to improve the dispersibility of the pigment particles. Furthermore, the dispersion stability is still insufficient when the temperature change is repeated for a long time. Although a specific benzimidazolone compound has been proposed as a dispersant (see, for example, Patent Document 5), it is not related to the dispersion of fine pigment particles in a high-concentration polymerizable compound.

JP 2003-119414 A JP 2004-18656 A JP 2003-321628 A JP 2004-131589 A JP 2000-239954 A

The present invention is excellent in dispersibility and stability of a colorant containing a fine pigment, particularly a pigment, and can form a high-quality image having a clear color tone and high coloring power. An object of the present invention is to provide a curable color dispersion suitable for inkjet recording, an ink composition, and an image forming method using the ink composition.
Another object of the present invention is to provide a recorded matter obtained by using an ink composition that can be cured by irradiation with active energy rays and has a clear color tone and high coloring power.

As a result of intensive studies, the inventors of the present invention are excellent in pigment dispersibility by using a specific benzimidazolone compound, and also decrease in dispersion stability even after long-term storage or repeated temperature changes. The present inventors have found that a colored dispersion having excellent colorant dispersion stability effectively suppressed and an ink composition thereof can be obtained. That is, the present invention is as follows.
(1) Coloring characterized in that it is a dispersion containing at least a pigment, a compound represented by the following general formula (1), and a polymerizable compound, and the content of the polymerizable compound is 50% by mass or more. Dispersion.

〔一般式（１）中、Ｒ_１およびＲ_２はそれぞれ独立に置換基を有していてもよいアルキル基または置換基を有していてもよいアリール基を表す。〕
（２）前記一般式（１）で表される化合物がアミノ基を有する化合物であることを特徴とする（１）に記載の着色分散液。
（３）前記着色分散液がさらに高分子分散剤を含むことを特徴とする（１）または（２）に記載の着色分散液。
（４）前記重合性化合物の２５℃における粘度が３０ｍＰａ・ｓ以下であることを特徴とする（１）〜（３）のいずれか１項に記載の着色分散液。
（５）（１）〜（４）のいずれか１項に記載の着色分散液を含むインク組成物。
（６）重合開始剤を含むことを特徴とする（５）に記載のインク組成物。
（７）インクジェット用であることを特徴とする（５）または（６）に記載のインク組成物。
（８）（５）〜（７）のいずれか１項に記載のインク組成物を用いて被記録媒体に画像を記録する画像記録工程と、前記画像記録工程において記録媒体上に記録された画像に活性エネルギー線を照射して硬化させる画像硬化工程とを含むことを特徴とする画像形成方法。
（９）（５）〜（７）のいずれか１項に記載のインク組成物を硬化させてなることを特徴とする記録物。
（１０）被記録媒体上に、インク組成物をインクジェットプリンターにより記録したのち、活性エネルギー線を照射してインク組成物を硬化させてなる（９）に記載の記録物。

[In General Formula (1), R ₁ and R ₂ each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. ]
(2) The colored dispersion liquid according to (1), wherein the compound represented by the general formula (1) is a compound having an amino group.
(3) The colored dispersion according to (1) or (2), wherein the colored dispersion further contains a polymer dispersant.
(4) The colored dispersion liquid according to any one of (1) to (3), wherein the polymerizable compound has a viscosity at 25 ° C. of 30 mPa · s or less.
(5) An ink composition comprising the colored dispersion liquid according to any one of (1) to (4).
(6) The ink composition as described in (5), comprising a polymerization initiator.
(7) The ink composition as described in (5) or (6), which is for inkjet.
(8) An image recording step of recording an image on a recording medium using the ink composition according to any one of (5) to (7), and an image recorded on the recording medium in the image recording step And an image curing step of irradiating the active energy ray to cure.
(9) A recorded matter obtained by curing the ink composition according to any one of (5) to (7).
(10) The recorded matter according to (9), wherein the ink composition is recorded on a recording medium by an ink jet printer, and then the ink composition is cured by irradiation with active energy rays.

The colored dispersion of the present invention improves the dispersibility of the fine colorant and its stability, enables high-quality image formation with clear color tone and high coloring power, and can be cured by irradiation with active energy rays. An ink composition suitable for ink jet recording can be obtained, and an effective image forming method using the ink composition can be provided.
The colored dispersion of the present invention is an ink composition having a clear color tone and high coloring power, and can be cured by irradiation with an active energy ray after recording on a recording medium, resulting in a high-quality image. It can be set as the recorded matter formed as.
Furthermore, the ink composition of the present invention is not limited to being able to form a sharp image with excellent color developability when used in normal printing, and is also useful as a resist, a color filter, an optical disc, or an optical modeling material. It can be recorded.
Furthermore, by applying the image forming method of the present invention, a high-quality image can be directly formed on a non-absorbent recording medium based on digital data. It can also be suitably used for the production of recorded matter of area.

  The colored dispersion of the present invention contains at least a pigment, a compound represented by the following general formula (1), and a polymerizable compound, and the content of the polymerizable compound is 50% by mass or more.

〔一般式（１）中、Ｒ_１およびＲ_２はそれぞれ独立に置換基を有していてもよいアルキル基または置換基を有していてもよいアリール基を表す〕

[In General Formula (1), R ₁ and R ₂ each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent]

The colored dispersion of the present invention is preferably cured by applying some energy, more preferably polymerization, by the function of the polymerizable compound or when the ink composition is further added with a polymerization initiator. It contains an initiator and is cured by irradiation with active energy rays. Here, the active energy ray is not particularly limited as long as it can impart energy capable of generating a starting species in the ink composition by irradiation, and is widely α-ray, γ-ray, X-ray, ultraviolet ray, Visible light, electron beam, and the like are included, and among them, ultraviolet light, LED light, or electron beam are preferable from the viewpoint of curing sensitivity and device availability, and ultraviolet light and LED light are particularly preferable. Therefore, the colored dispersion or ink composition of the present invention is preferably one that can be cured by irradiation with ultraviolet rays or LED light.
Hereinafter, each component used for the colored dispersion of the present invention will be described in order.

[Compound represented by general formula (1)]
First, the compound represented by the general formula (1) will be described.
In general formula (1), R ₁ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. As an alkyl group, C1-C18 is preferable, 1-16 are more preferable, and 1-12 are especially preferable. Specifically, examples of the alkyl group include methyl group, ethyl group, n-butyl group, i-butyl group, t-butyl group, n-hexyl group, cyclohexyl group, n-octyl group, 2-ethylhexyl group, n- Examples include decyl group, n-dodecyl group, n-octadecyl group, 2-hydroxyethyl group, 6-hydroxyhexyl group, 8-hydroxyoctyl group, 7,8-dihydroxyoctyl group, 11,12-dihydroxydodecyl group and the like. . Moreover, as an aryl group, C6-C18 is preferable and 6-12 are especially preferable. Specifically, a phenyl group, a naphthyl group, a 2-methoxyphenyl group, a 4-methoxyphenyl group, a 2-octyloxynaphthyl group, and a dimethylaminophenyl group are preferable.

Also in the general formula (1), R ₂ represents an aryl group which may have an alkyl group or a substituted group which may have a substituent. The alkyl group preferably has 1 to 32 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 4 to 18 carbon atoms.
The alkyl group may have a substituent, and examples of the substituent include an aryl group, an alkoxy group, a phenoxy group, a hydroxy group, a sulfo group, a carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, an imidazolyl group, A pyridyl group etc. are mentioned.
Examples of the alkyl group include ethyl, n-butyl, i-butyl, t-butyl, n-hexyl, cyclohexyl, n-octyl, 2-ethylhexyl, n-decyl, and n-dodecyl. Group, n-octadecyl group, 2-hydroxyethyl group, 6-hydroxyhexyl group, 8-hydroxyoctyl group, 7,8-dihydroxyoctyl group, 11,12-dihydroxydodecyl group, 2-methoxyethyl group, 2-butoxy Ethyl group, 6-butoxyhexyl group, 8-butoxyoctyl group, 3-carboxypropyl group, 4-carboxybutyl group, 8-carboxyoctyl group, 3-sulfopropyl group, 4-sulfobutyl group, 2- (N, N -Dimethylamino) ethyl group, 3- (N, N-dimethylamino) propyl group, 6- (N, N-dimethylamino) he Preferred examples include syl group, 8- (N, N-methylamino) octyl group, 8- (N, N-diethylamino) octyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, n- Dodecyl group, n-octadecyl group, 8-hydroxyoctyl group, 7,8-dihydroxyoctyl group, 11,12-dihydroxydodecyl group, 6- (N, N-dimethylamino) hexyl group, 8- (N, N- A dimethylamino) octyl group and an 8- (N, N-diethylamino) octyl group are particularly preferred.
The aryl group preferably has 6 to 32 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 18 carbon atoms. Specific examples of the aryl group include a phenyl group, a naphthyl group, a 2-methoxyphenyl group, a 2-decyloxyphenyl group, a 4-methoxyphenyl group, a 2-octyloxynaphthyl group, a dimethylaminophenyl group, and 2-dodecylthiophenyl. Group, 4- (4-methylphenylthioxy) phenyl group, 2-methoxy-4-dodecylthiooxyphenyl group, 2-phenoxyethoxyphenyl group, 2-dodecyloxyphenyl group, 2-octadecyloxyphenyl group, 2, 5-dibenzyloxyphenyl group, 2,5-dicyclohexylmethyloxyphenyl group, 2-methoxy-4- (2-ethylhexanoylamino) phenyl group, 2-butoxy-4-benzyloxycarbonylaminophenyl group, 2-octyloxy-4-butyloxycarbonylaminophen Le group.

The compound represented by the general formula (1) particularly preferably has an amino group. Examples of the amino group include a dimethylamino group, a diethylamino group, a di-n-butylamino group, a di-n-hexylamino group, a dibenzylamino group, and a di (hydroxyethyl) amino group.
In the colored dispersion of the present invention, preferred specific examples of the compound represented by the general formula (1) include the following, but the present invention is not limited thereto.

  In the colored dispersion of the present invention, the content of the benzimidazolone compound represented by the general formula (1) is preferably 0.1 to 100 parts by mass, and 0.5 to 50 parts by mass with respect to 100 parts by mass of the pigment. Part is more preferable, and 1 to 30 parts by mass is particularly preferable. When the content is less than 0.1 parts by mass, the viscosity of the dispersion composition may increase. When the content exceeds 100 parts by mass, it may be difficult to obtain a desired colored ink.

[Polymerizable compound]
The polymerizable compound used in the colored dispersion in the present invention is not particularly limited as long as it is a compound that causes a polymerization reaction by being imparted with some energy and cures, and can be used regardless of the type of monomer, oligomer, or polymer. In particular, various polymerizable monomers known as a cationic polymerizable monomer and a radical polymerizable monomer that cause a polymerization reaction by an initiation species generated from a polymerization initiator added as desired are preferable. Of these, it is particularly preferable to use a polymerizable compound having a solubility parameter of 17 to 21 MPa ^1/2 . Further, a monomer having a viscosity at 25 ° C. of 30 mPa · s or less is preferable, and 20 mPa · s or less is particularly preferable. If this viscosity is too high, the viscosity of the dispersion composition may increase. The viscosity can be measured by, for example, a commercially available viscometer (B type viscometer, E type viscometer).

  The polymerizable compound used in the colored dispersion of the present invention can be used alone or in combination for the purpose of adjusting the reaction rate, ink physical properties, cured film physical properties and the like. The polymerizable compound may be a monofunctional compound or a polyfunctional compound.

(Cationically polymerizable monomer)
Examples of the cationic polymerizable monomer used as the polymerizable compound in the colored dispersion of the present invention include JP-A-6-9714, JP-A-2001-31892, JP-A-2001-40068, JP-A-2001-55507, Examples thereof include epoxy compounds, vinyl ether compounds, oxetane compounds and the like described in each publication such as 2001-310938, 2001-310937, and 2001-220526.

<Epoxy compound>
Examples of the epoxy compound include aromatic epoxides and alicyclic epoxides.
Examples of monofunctional epoxy compounds that can be used in the present invention include, for example, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monooxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide, 3 -Vinylcyclohexene oxide etc. are mentioned.

Examples of polyfunctional epoxy compounds include, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and brominated bisphenol. S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxy 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclo) Xylmethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6 '-Methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate) , Epoxyhexahydrophthalate dioctyl, epoxyhexahydrophthalate di-2-ethylhexyl, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether Glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,1,3-tetradecadiene dioxide, limonene dioxide, 1,2,7,8- Examples include diepoxyoctane and 1,2,5,6-diepoxycyclooctane.
Among these epoxy compounds, aromatic epoxides and alicyclic epoxides are preferable from the viewpoint of excellent curing speed, and alicyclic epoxides are particularly preferable.

<Vinyl ether compound>
Examples of monofunctional vinyl ethers include, for example, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, 4 -Methylcyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl D Ter, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloro Examples thereof include ethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxy polyethylene glycol vinyl ether and the like.

Examples of polyfunctional vinyl ethers include ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, and bisphenol F. Divinyl ethers such as alkylene oxide divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol Hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, propylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, propylene oxide addition Examples thereof include polyfunctional vinyl ethers such as pentaerythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.
As the vinyl ether compound, a di- or trivinyl ether compound is preferable from the viewpoints of curability, adhesion to a recording medium, surface hardness of the formed image, and the like, and a divinyl ether compound is particularly preferable.

<Oxetane compound>
The oxetane compound refers to a compound having an oxetane ring, and a normal oxetane compound is arbitrarily selected and used as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217. it can.
The compound having an oxetane ring that can be used in the ink composition of the present invention is preferably a compound having 1 to 4 oxetane rings in the structure. By using such a compound, it becomes easy to maintain the viscosity of the ink composition in a good handling property range, and it is possible to obtain high adhesion of the cured ink to the recording medium. .

  Examples of monofunctional oxetanes include, for example, 3-ethyl-3-hydroxymethyloxetane, 3- (meth) allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) methylbenzene, 4-fluoro -[1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, 4-methoxy- [1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, [1- (3-ethyl-3-oxetanyl) Methoxy) ethyl] phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl-3-oxetanylmethyl) Ether, 2-ethylhexyl (3-ethyl-3-oxetanyl) Til) ether, ethyl diethylene glycol (3-ethyl-3-oxetanylmethyl) ether, dicyclopentadiene (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, Dicyclopentenyl (3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tetrabromophenoxy Ethyl (3-ethyl-3-oxetanylmethyl) ether, tribromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tribromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, -Hydroxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, butoxyethyl (3-ethyl-3-oxetanylmethyl) ether, pentachlorophenyl (3- And ethyl-3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether, bornyl (3-ethyl-3-oxetanylmethyl) ether, and the like.

  Examples of the polyfunctional oxetane include, for example, 3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1,3- (2-methylenyl) propanediylbis (oxymethylene)) Bis- (3-ethyloxetane), 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1 , 3-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenylbis (3-ethyl-3-oxetanylmethyl) ether, Triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl -3-oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3- Ethyl-3-oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3 -Oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl) 3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol pentakis ( 3-ethyl-3-oxetanylmethyl) ether, ditrimethylolpropanetetrakis (3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified bisphenol A bis ( 3-ethyl-3-oxetanylmethyl) ether, EO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-ethyl) And polyfunctional oxetanes such as ru-3-oxetanylmethyl) ether and EO-modified bisphenol F (3-ethyl-3-oxetanylmethyl) ether.

The compound having such an oxetane ring is described in detail in the above-mentioned JP-A No. 2003-341217, paragraph numbers [0021] to [0084], and the compounds described herein can be preferably used.
In the colored dispersion of the present invention, when an oxetane compound is used as the polymerizable compound, it is particularly preferable to use a compound having 1 to 2 oxetane rings from the viewpoint of the viscosity and tackiness of the ink composition.

  In the ink composition of the present invention, these polymerizable compounds may be used alone or in combination of two or more. From the viewpoint of effectively suppressing shrinkage during ink curing. It is preferable to use at least one oxetane compound in combination with at least one compound selected from an epoxy compound and a vinyl ether compound.

(Radically polymerizable monomer)
In the present invention, it is also preferable to use various radically polymerizable monomers that cause a polymerization reaction by an initiating species generated from a photoradical initiator as the polymerizable compound.
Examples of the radical polymerizable monomer include (meth) acrylates, (meth) acrylamides, aromatic vinyls and the like. In the present specification, when referring to both or one of “acrylate” and “methacrylate”, when referring to both “(meth) acrylate” and “acryl” and / or “methacryl”, “(meth) acryl” And may be described respectively.

<(Meth) acrylates>
Examples of (meth) acrylates used in the present invention include the following.
Specific examples of monofunctional (meth) acrylates include hexyl group (meth) acrylate, 2-ethylhexyl (meth) acrylate, tert-octyl (meth) acrylate, isoamyl (meth) acrylate, decyl (meth) acrylate, isodecyl ( (Meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-n-butylcyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) Acrylate, 2-ethylhexylglycol (meth) acrylate, butoxyethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 4-bromobutyl (meth) acrylate, cyano Chill (meth) acrylate, benzyl (meth) acrylate, butoxymethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, alkoxymethyl (meth) acrylate, alkoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (Meth) acrylate, 2- (2-butoxyethoxy) ethyl (meth) acrylate, 2,2,2-tetrafluoroethyl (meth) acrylate, 1H, 1H, 2H, 2H perfluorodecyl (meth) acrylate, 4- Butylphenyl (meth) acrylate, phenyl (meth) acrylate, 2,4,5-tetramethylphenyl (meth) acrylate, 4-chlorophenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate Relate, glycidyl (meth) acrylate, glycidyloxybutyl (meth) acrylate, glycidyloxyethyl (meth) acrylate, glycidyloxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hydroxyalkyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate,

2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate , Dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) acrylate, trimethoxysilylpropyl (meth) acrylate, trimethylsilylpropyl (meth) acrylate, polyethylene oxide monomethyl ether (meth) acrylate, oligoethylene oxide monomethyl ether (meth) acrylate, Polyethylene oxide (meth) acrylate, oligoethylene oxide (meth) acrylate, oligoethyleneoxy Monoalkyl ether (meth) acrylate, polyethylene oxide monoalkyl ether (meth) acrylate, dipropylene glycol (meth) acrylate, polypropylene oxide monoalkyl ether (meth) acrylate, oligopropylene oxide monoalkyl ether (meth) acrylate, 2-methacrylate Leuoxytyl succinic acid, 2-methacryloyloxyhexahydrophthalic acid, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, butoxydiethylene glycol (meth) acrylate, trifluoroethyl (meth) acrylate, perfluorooctylethyl (meta ) Acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, EO-modified phenol (meth) acrylate, EO-modified Resole (meth) acrylate, EO-modified nonylphenol (meth) acrylate, PO-modified nonylphenol (meth) acrylate, EO-modified 2-ethylhexyl (meth) acrylate.

  Specific examples of the bifunctional (meth) acrylates include 1,6-hexanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2,4- Dimethyl-1,5-pentanediol di (meth) acrylate, butylethylpropanediol (meth) acrylate, ethoxylated cyclohexanemethanol di (meth) acrylate, polyethylene glycol di (meth) acrylate, oligoethylene glycol di (meth) acrylate , Ethylene glycol di (meth) acrylate, 2-ethyl-2-butyl-butanediol di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate Bisphenol F polyethoxydi (meth) acrylate, polypropylene glycol di (meth) acrylate, oligopropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 2-ethyl-2-butylpropanediol di (Meth) acrylate, 1,9-nonane di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, tricyclodecane di (meth) acrylate and the like.

  Specific examples of trifunctional (meth) acrylates include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane alkylene oxide modified tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, dipentaerythritol tri (meth) acrylate, trimethylolpropane tri ((meth) acryloyloxypropyl) ether, isocyanuric acid alkylene oxide modified tri (meth) acrylate, dipentaerythritol tri (meth) acrylate propionate, tri (( (Meth) acryloyloxyethyl) isocyanurate, hydroxypivalaldehyde-modified dimethylolpropane tri (meth) acrylate, sorbitol tri (meth) a Relate, propoxylated trimethylolpropane tri (meth) acrylate, and ethoxylated glycerin triacrylate.

  Specific examples of tetrafunctional (meth) acrylates include pentaerythritol tetra (meth) acrylate, sorbitol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate propionate, ethoxylation Examples include pentaerythritol tetra (meth) acrylate.

Specific examples of pentafunctional (meth) acrylates include sorbitol penta (meth) acrylate and dipentaerythritol penta (meth) acrylate.
Specific examples of hexafunctional (meth) acrylates include dipentaerythritol hexa (meth) acrylate, sorbitol hexa (meth) acrylate, phosphazene alkylene oxide modified hexa (meth) acrylate, captolactone modified dipentaerythritol hexa (meth) An acrylate etc. can be mentioned.

<(Meth) acrylamides>
Examples of (meth) acrylamides include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, Nn-butyl (meth) acrylamide, N -T-butyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl ( And (meth) acrylamide and (meth) acryloylmorpholine.

<Aromatic vinyls>
Specific examples of aromatic vinyls include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropyl styrene, chloromethyl styrene, methoxy styrene, acetoxy styrene, chloro styrene, dichloro styrene, bromo styrene, vinyl benzoic acid. Methyl ester, 3-methylstyrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3-hexylstyrene, 4- Hexyl styrene, 3-octyl styrene, 4-octyl styrene, 3- (2-ethylhexyl) styrene, 4- (2-ethylhexyl) styrene, allyl styrene, isopropenyl styrene, butenyl styrene, octenyl Styrene, 4-t-butoxycarbonyl styrene, 4-methoxystyrene, and a 4-t-butoxystyrene.

  Further, radically polymerizable monomers include vinyl esters [vinyl acetate, vinyl propionate, vinyl versatate, etc.], allyl esters [eg, allyl acetate], halogen-containing monomers [vinylidene chloride, vinyl chloride, etc.], vinyl ether [methyl Vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxy vinyl ether, 2-ethylhexyl vinyl ether, methoxyethyl vinyl ether, cyclohexyl vinyl ether, chloroethyl vinyl ether, etc.], vinyl cyanide [(meth) acrylonitrile, etc.], olefins [ethylene, propylene, etc.], etc. Can be mentioned.

Among these, when a radical polymerizable monomer is used as the polymerizable compound contained in the colored dispersion of the present invention, (meth) acrylates and (meth) acrylamides are preferred from the viewpoint of curing speed, and particularly, curing speed is pointed. To 4 or more functional (meth) acrylates are preferred. Further, from the viewpoint of the viscosity of the ink composition, it is preferable to use the above polyfunctional (meth) acrylates in combination with monofunctional or bifunctional (meth) acrylates and (meth) acrylamides.
50-95 mass% is preferable, as for content of the polymeric compound in the colored dispersion liquid of this invention, 60-92 mass% is more preferable, and it is especially preferable that it is the range of 70-90 mass%. If this amount is too large, the concentration of the colorant decreases, and if it is too small, the pigments aggregate.

[Pigment]
The colored dispersion of the present invention contains a pigment as an essential component.
At this time, the pigment is uniformly and stably dispersed in the ink composition by the function of the dispersant, so that a sharp image with excellent color developability can be formed.
There is no restriction | limiting in particular in the pigment which can be used here, According to a use, a various thing can be selected suitably and can be used. In particular, the colored dispersion of the present invention uses a pigment, so that an image printed as an ink composition has excellent weather resistance.

The pigment used in the colored dispersion of the present invention is not particularly limited, and all commercially available organic pigments and inorganic pigments, and those obtained by dyeing resin particles with a dye can be used. Furthermore, commercially available pigment dispersions and surface-treated pigments can be used as long as the effects of the present invention are not impaired.
Examples of these pigments include, for example, “Pigment Dictionary” (2000), edited by Seijiro Ito. Herbst, K.M. Hunger “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A, JP 2003-26978 A, and JP 2003-342503 A3.

  Specific examples of organic pigments and inorganic pigments include, for example, C.I. I. Pigment Yellow 1 (Fast Yellow G etc.), C.I. I. A monoazo pigment such as C.I. Pigment Yellow 74; I. Pigment Yellow 12 (disaji yellow AAA, etc.), C.I. I. Disazo pigments such as C.I. Pigment Yellow 17; I. Non-benzidine type azo pigments such as CI Pigment Yellow 180; I. Azo lake pigments such as C.I. Pigment Yellow 100 (eg Tartrazine Yellow Lake); I. Condensed azo pigments such as CI Pigment Yellow 95 (Condensed Azo Yellow GR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Yellow 115 (such as quinoline yellow lake); I. Basic dye lake pigments such as CI Pigment Yellow 18 (Thioflavin Lake, etc.), anthraquinone pigments such as Flavantron Yellow (Y-24), isoindolinone pigments such as Isoindolinone Yellow 3RLT (Y-110), and quinophthalone yellow Quinophthalone pigments such as (Y-138), isoindoline pigments such as isoindoline yellow (Y-139), C.I. I. Nitroso pigments such as C.I. Pigment Yellow 153 (nickel nitroso yellow, etc.); I. And metal complex salt azomethine pigments such as CI Pigment Yellow 117 (copper azomethine yellow, etc.).

  C. As a thing which exhibits red or magenta color, C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Disazo pigments such as C.I. Pigment Red 38 (Pyrazolone Red B, etc.); I. Pigment Red 53: 1 (Lake Red C, etc.) and C.I. I. Azo lake pigments such as C.I. Pigment Red 57: 1 (Brilliant Carmine 6B); I. Condensed azo pigments such as C.I. Pigment Red 144 (condensed azo red BR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Red 174 (Phloxine B Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Red 81 (Rhodamine 6G 'lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Red 177 (eg, dianthraquinonyl red); I. Thioindigo pigments such as C.I. Pigment Red 88 (Thioindigo Bordeaux, etc.); I. Perinone pigments such as C.I. Pigment Red 194 (perinone red, etc.); I. Perylene pigments such as C.I. Pigment Red 149 (perylene scarlet, etc.); I. Pigment violet 19 (unsubstituted quinacridone), C.I. I. Quinacridone pigments such as CI Pigment Red 122 (quinacridone magenta, etc.); I. Isoindolinone pigments such as CI Pigment Red 180 (isoindolinone red 2BLT, etc.); I. And alizarin lake pigments such as CI Pigment Red 83 (Mada Lake, etc.).

  As a pigment exhibiting blue or cyan, C.I. I. Disazo pigments such as C.I. Pigment Blue 25 (Dianisidine Blue, etc.); I. Phthalocyanine pigments such as C.I. Pigment Blue 15 (phthalocyanine blue, etc.); I. Acidic dye lake pigments such as C.I. Pigment Blue 24 (Peacock Blue Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Blue 1 (Viclotia Pure Blue BO Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Blue 60 (Indantron Blue, etc.); I. And alkali blue pigments such as CI Pigment Blue 18 (Alkali Blue V-5: 1).

As a pigment exhibiting green, C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. And azo metal complex pigments such as CI Pigment Green 8 (Nitroso Green).
As a pigment exhibiting an orange color, C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. And anthraquinone pigments such as CI Pigment Orange 51 (dichloropyrantron orange).

  Examples of the black pigment include carbon black, titanium black, and aniline black.

Specific examples of the white pigment include basic lead carbonate (2PbCO ₃ Pb (OH) ₂ , so-called silver white), zinc oxide (ZnO, so-called zinc white), titanium oxide (TiO ₂ , so-called titanium white), Strontium titanate (SrTiO ₃ , so-called titanium strontium white) can be used.
Here, titanium oxide has a smaller specific gravity than other white pigments, a large refractive index, and is chemically and physically stable, so that it has a large hiding power and coloring power as a pigment. Excellent durability against other environments. Therefore, it is preferable to use titanium oxide as the white pigment. Of course, other white pigments (may be other than the listed white pigments) may be used in combination as necessary.

  For dispersing the pigment, use a dispersing device such as a ball mill, sand mill, attritor, roll mill, jet mill, homogenizer, paint shaker, kneader, agitator, Henschel mixer, colloid mill, ultrasonic homogenizer, pearl mill, wet jet mill, etc. Can do.

The volume-based average particle diameter in the ink composition of the pigment used here is preferably about 0.01 to 0.4 μm, more preferably about 0.02 to 0.2 μm, because the finer the color development, the better the color developability. It is more preferable that the thickness is in the range of 0.02 to 0.1 μm. The pigment type, the dispersant, the selection of the dispersion medium, the dispersion conditions, and the filtration conditions are set so that the maximum particle size is 3 μm or less, preferably 1 μm or less. By controlling the particle size, clogging of the head nozzle can be suppressed when used as inkjet ink, and ink storage stability, ink transparency, and curing sensitivity can be maintained. In the colored dispersion of the present invention, a uniform and stable dispersion can be obtained by using the compound represented by the general formula (1) and a polymerizable compound even when a fine particle pigment is used. The pigment particles in the present invention are preferably primary particles.
The particle diameter of the pigment in the ink composition can be measured by an ordinary measurement method. Specifically, it can be measured by a centrifugal sedimentation light transmission method, an X-ray transmission method, a laser diffraction / scattering method, and a dynamic light scattering method. In the present invention, the particle diameter represents a value obtained by measurement using a laser diffraction / scattering method unless otherwise specified.
The pigment is preferably added in an amount of 1 to 20% by mass, more preferably 2 to 10% by mass in the dispersion. In the colored dispersion of the present invention, the above pigments may be used alone, or a plurality of types may be used in combination.

  In addition to the above essential components, the colored dispersion of the present invention may contain other compounds depending on the purpose, and various additives and the like can be added to form an ink composition. These optional components will be described.

[Polymer dispersant]
The colored dispersion of the present invention preferably further contains a polymer dispersant (in the present invention, the polymer dispersant refers to a polymer compound added in the pigment dispersion step). As the polymer dispersant, ordinary ones can be used. Specifically, “Ajispur PB821, PB822, PB817” manufactured by Ajinomoto Fine Techno Co., Ltd. “Solspers 24000GR, 32000” manufactured by Nippon Lubrizol Co., Ltd., Enomoto Kasei Co., Ltd. “Disparon DA-703-50, DA-705, DA-725” manufactured by BYK Chemie “Disperbyk-110, 130, 161, 162, 163, 164, 165, 166, 170”, “Efka Polymer” manufactured by Efka CHEMICALS 100, 150, 400, 401, 402, 403, 450, 451, 452, 453 (modified polyacrylate), “Floren TG-710” manufactured by Kyoeisha Chemical Co., Ltd. and the like.

The polymer dispersant used in the colored dispersion of the present invention is particularly preferably a polymer having a basic group. Specific examples of the basic group include primary amines, secondary amines, tertiary amines, anilines, guanidines, nitrogen-containing cyclic compounds, and the like. Group, methylamino group, dimethylamino group, ethylamino group, diethylamino group, butylamino group, dibutylamino group, hexylamino group, octylamino group, N-methyl-N-octylamino group, amino group and dicyclohexylcarbodiimide Degenerate products, degenerate products of amino group and diisopropylcarbodiimide, pyridinyl group, pyrrolidino group, piperidino group, morpholino group, functional group derived from diazabicycloundecene, and the like.
The polymer having the basic group may be a monomer having the basic group alone, or a radical polymerization, condensation polymerization of the monomer having the basic group and another monomer, or a polymer having no basic group. It is a homopolymer or copolymer obtained by functional group conversion.

More specifically, compounds described in JP-A-10-339949, JP-A-2000-234007, JP-A-2001-31885, polyethyleneimine, polyallylamine, amide amine salt of polyester acid, and the like can be mentioned. .
Among these, as the polymer having a basic group used in the colored dispersion of the present invention, an amine-containing polymer is preferable. The amine-containing polymer may be a homopolymer of a monomer having an amino group or a copolymer with another monomer. These modified products may be used, and are not particularly limited as long as at least an amino group is present as a repeating unit in the polymer.

  Examples of the monomer having an amino group include vinylamine, allylamine, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, 1- (N, N-dimethylamino) -1, 1-dimethylmethyl (meth) acrylate, N, N-dimethylaminohexyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diisopropylaminoethyl (meth) acrylate, N, N-di- n-butylaminoethyl (meth) acrylate, N, N-di-i-butylaminoethyl (meth) acrylate, morpholinoethyl (meth) acrylate, piperidinoethyl (meth) acrylate, 1-pyrrolidinoethyl (meth) acrylate, N , N-methyl-2-pyrrolidylami Ethyl (meth) acrylate or N, N-methylphenylaminoethyl (meth) acrylate (above (meth) acrylates); dimethyl (meth) acrylamide, diethyl (meth) acrylamide, diisopropyl (meth) acrylamide, di-n-butyl (Meth) acrylamide, di-i-butyl (meth) acrylamide, morpholino (meth) acrylamide, piperidino (meth) acrylamide, N-methyl-2-pyrrolidyl (meth) acrylamide or N, N-methylphenyl (meth) acrylamide ( (Meth) acrylamides); 2- (N, N-dimethylamino) ethyl (meth) acrylamide, 2- (N, N-diethylamino) ethyl (meth) acrylamide, 3- (N, N-diethylamino) propyl ( Meta) Rilamide, 3- (N, N-dimethylamino) propyl (meth) acrylamide, 1- (N, N-dimethylamino) -1,1-dimethylmethyl (meth) acrylamide and 6- (N, N-diethylamino) hexyl (Meth) acrylamide (above aminoalkyl (meth) acrylamides); vinylpyridine and the like can be mentioned. Among these, N, N-dimethylaminopropyl (meth) acrylate, 3- (N, N-diethylamino) propyl (meth) acrylamide, 6- (N, N-diethylamino) hexyl (meth) acrylamide, 1-pyrrolidinoethyl (Meth) acrylate and allylamine are preferred.

  Examples of the other monomers copolymerizable with the monomer having an amino group include aromatic vinyl compounds (for example, styrene, α-methylstyrene, vinyltoluene); (meth) acrylic acid alkyl esters (for example, methyl (meth)). Acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate); (meth) acrylic acid alkyl aryl ester (for example, benzyl (meth) acrylate, glycidyl (meth) acrylate); Acid vinyl esters (for example, vinyl acetate, vinyl propionate); vinyl cyanide (for example, (meth) acrylonitrile, α-chloroacrylonitrile); aliphatic conjugated dienes (for example, 1,3-butadiene, isoprene), Terminal methacryloylation Polyalkyl (meth) acrylates (for example, terminal methacryloylated polymethacrylate; trade name: AA-6, manufactured by Toa Gosei Co., Ltd.) can also be used, and a plurality of these can be used. Among these, styrene, n-butyl (meth) acrylate, benzyl (meth) acrylate, and terminal methacryloylated polyalkyl (meth) acrylate are preferable.

  When using the above-mentioned other monomers, the repeating unit derived from this monomer has a repeating unit derived from the monomer having an amino group in the range of 1 to 99% by mass of all repeating units. It is preferable to have in the range of 99 mass% (especially 5-50 mass%). Specific examples of the copolymer of the monomer having an amino group and other monomers include dimethylaminoethyl acrylate / methyl methacrylate copolymer, 3- (N, N-dimethylamino) propylmethacrylamide / benzyl methacrylate / AA. -6 copolymer, N, N-dimethylaminopropyl methacrylate / butyl methacrylate / AA-6 copolymer, and the like.

The weight average molecular weight (Mw) of the polymer dispersant contained in the colored dispersion of the present invention is preferably in the range of 2000 to 100,000, and particularly preferably in the range of 3000 to 20000. The said weight average molecular weight is a polystyrene conversion weight average molecular weight measured by gel permeation chromatography (carrier: tetrahydrofuran).
As content of the polymer dispersing agent in the colored dispersion liquid of this invention, 0.1-30 mass% is preferable, and 1-20 mass% is more preferable. When the content is less than 0.1% by mass, viscosity may increase during dispersion, and when it exceeds 30% by mass, viscosity may increase.

  In addition, in the colored dispersion of the present invention, when the mixing ratio of the compound represented by the general formula (1) and the polymer dispersing agent is mentioned, the polymer dispersing agent is converted into the compound represented by the general formula (1). On the other hand, the amount is preferably 0.5 to 50 times (mass), more preferably 1 to 20 times (mass), and particularly preferably 2 to 10 times (mass). Moreover, in the colored dispersion liquid of the present invention, the polymer dispersant may be used alone or in combination of two or more.

[Polymerization initiator]
The ink composition of the present invention preferably contains a polymerization initiator for radical polymerization or cationic polymerization, and particularly preferably contains a photopolymerization initiator.
A photopolymerization initiator is a compound that generates a chemical change through the action of light or interaction with the electronically excited state of a sensitizing dye to generate at least one of a radical, an acid, and a base. Of these, a radical or an acid is preferred.
The photopolymerization initiator is an actinic ray to be irradiated, for example, 400 to 200 nm ultraviolet ray, far ultraviolet ray, g ray, h ray, i ray, KrF excimer laser beam, ArF excimer laser beam, electron beam, X ray, molecular beam. Or what has a sensitivity to an ion beam etc. can be selected suitably, and can be used.

  Usual photopolymerization initiators can be used, and specific examples include, for example, Bruce M. et al. Monroe et al., Chemical Review, 93, 435 (1993). R. S. By Davidson, Journal of Photochemistry and biologic A: Chemistry, 73.81 (1993). J. P. Faussier “Photoinitiated Polymerization—Theory and Applications”: Rapra Review vol. 9, Report, Rapra Technology (1998). M. Tsunooka et al. , Prog. Polym. Sci. , 21, 1 (1996). Many are described. There are many chemical amplification type photoresists and compounds used for photocationic polymerization described in (Organic Electronics Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), pages 187-192). Has been. Further, F.I. D. Saeva, Topics in Current Chemistry, 156, 59 (1990). G. G. Maslak, Topics in Current Chemistry, 168, 1 (1993). H., et al. B. Shuster et al, JACS, 112, 6329 (1990). I. D. F. Eaton et al, JACS, 102, 3298 (1980). A group of compounds that undergo oxidative or reductive bond cleavage through interaction with the electronically excited state of a sensitizing dye as described in the above.

  Preferred photopolymerization initiators include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, (e) ketoxime ester compounds, f) borate compounds, (g) azinium compounds, (h) metallocene compounds, (i) active ester compounds, (j) compounds having a carbon halogen bond, and the like.

  (A) As a preferable example of aromatic ketones, “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” P. FOUASSIER J.M. F. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in RABEK (1993), p77-117. More preferable examples of (a) aromatic ketones include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, and JP-B-47-22326. Α-substituted benzoin compounds, benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, Benzoin ethers described in JP-A-60-26403, JP-A-62-81345, α-aminobenzophenones described in JP-B-1-34242, US Pat. No. 4,318,791, and European Patent 0284561A1 P-di (dimethylamino) described in JP-A-2-211452 Nzoyl) benzene, thio-substituted aromatic ketone described in JP-A-61-194062, acylphosphine sulfide described in JP-B-2-9597, acylphosphine described in JP-B-2-9596, JP-B-63-61950 And thioxanthones described in Japanese Patent Publication No. 59, and coumarins described in Japanese Patent Publication No. 59-42864.

  (B) As aromatic onium salts, elements of groups V, VI and VII of the periodic table, specifically nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth ( Bi), oxygen (O), sulfur (S), selenium (Se), tellurium (Te), or iodine (I) aromatic onium salts. For example, European Patent No. 104143, US Pat. No. 4,837,124, JP-A-2-150848, JP-A-2-96514, iodonium salts, European Patent Nos. 370693 and 233567, Sulphonium described in each specification of U.S. Pat. Nos. 297443, 297442, 279210, and 422570, U.S. Pat. Nos. 3,902,144, 4,933,377, 4760013, 4,734,444 and 2,833,827 Salts, diazonium salts (such as benzenediazonium optionally having substituents), diazonium salt resins (such as formaldehyde resin of diazodiphenylamine), N-alkoxypyridinium salts, etc. (for example, US Pat. No. 4,743,528) , JP 63- No. 38345, JP-A-63-142345, JP-A-63-142346, and JP-B-46-42363, specifically 1-methoxy-4-phenylpyridinium tetrafluoro And the compounds described in JP-B Nos. 52-147277, 52-14278, and 52-14279 are preferably used. Generates radicals and acids as active species.

  (C) The organic peroxide includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples thereof include 3,3 ′, 4,4′-tetra- (t -Butylperoxycarbonyl) benzophenone, 3,3 ', 4,4'-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (t-hexylperoxycarbonyl) benzophenone 3,3 ′, 4,4′-tetra- (t-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (cumylperoxycarbonyl) benzophenone, 3,3 ′, 4, Peroxyesters such as 4'-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone and di-t-butyldiperoxyisophthalate are preferred. .

  (D) Examples of hexaarylbiimidazoles include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4 ′, 5. , 5′-tetraphenylbiimidazole, 2,2′-bis (o-bromophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2, 2′-bis (o, o′-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-nitrophenyl) -4,4 ′, 5,5 ′ -Tet Phenylbiimidazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluorophenyl) -4,4 ′ , 5,5′-tetraphenylbiimidazole and the like.

  (E) As ketoxime esters, 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, 2-acetoxyiminopentane-3-one 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-p-toluenesulfonyloxyiminobutan-2-one, 2-ethoxycarbonyloxy Examples include imino-1-phenylpropan-1-one.

(F) Examples of the borate salt include compounds described in U.S. Pat. Nos. 3,567,453, 4,343,891, European Patents 109,772 and 109,773.
(G) Examples of azinium salt compounds include JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, JP-A-63-143537, and JP-B-46-42363. A compound group having an N—O bond described in the publication can be exemplified.

(H) Examples of the metallocene compounds are described in JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, and JP-A-2-4705. And the iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109.
Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3. 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- -2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) phenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopenta And dienyl) bis [2,6-difluoro-3- (N-butylbialoyl-amino) phenyl] titanium.

  (I) Examples of active ester compounds include European Patent Nos. 0290750, 046083, 156153, 271851, and 0388343, U.S. Pat. Nos. 3,901,710, and 4,181,531. Nitrobenzol ester compounds described in JP-A-60-198538 and JP-A-53-133022, European Patent Nos. 099672, 84515, 199672, 0441115, and 0101122. Iminosulfonates described in each specification, U.S. Pat. Nos. 4,618,564, 4,371,605, and 4,431,774, JP-A 64-18143, JP-A-2-245756, and JP-A-4-365048 Compound, JP-B-62-2223, JP Sho 63-14340, and include compounds described in JP-59-174831 each publication.

  (J) Preferred examples of the compound having a carbon halogen bond include those described in Wakabayashi et al., Bull. Chem. Soc. Examples include compounds described in Japan, 42, 2924 (1969), compounds described in British Patent No. 1388492, compounds described in JP-A-53-133428, compounds described in German Patent No. 3333724, and the like. Can do.

  F.F. C. J. Schaefer et al. Org. Chem. 29, 1527 (1964), compounds described in JP-A-62-258241, compounds described in JP-A-5-281728, and the like. A compound as described in German Patent No. 2641100, a compound described in German Patent No. 3333450, a compound group described in German Patent No. 3021590, or a compound described in German Patent No. 3021599 A compound group, etc. can be mentioned.

  Preferable specific examples of the compounds represented by the above (a) to (j) include the following, but the present invention is not limited thereto.

A polymerization initiator can be used individually or in combination of 2 or more types.
In the ink composition of the present invention, the content of the polymerization initiator in the ink composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and particularly preferably 1 to 7% by mass. %.

[Sensitizing dye]
In the ink composition of the present invention, a sensitizing dye may be added for the purpose of improving the sensitivity of the photopolymerization initiator. Examples of preferred sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region. For example, polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine), merocyanine (Eg, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones (eg, anthraquinone), squalium (eg, , Squalium), coumarins (for example, 7-diethylamino-4-methylcoumarin) and the like.

  More preferable examples of the sensitizing dye include compounds represented by the following general formulas (IX) to (XIII).

In general formula (IX), A ¹ represents a sulfur atom or NR ⁵⁰ , R ⁵⁰ represents an alkyl group or an aryl group, and L ² represents a basic nucleus of the dye in combination with adjacent A ¹ and an adjacent carbon atom. Represents a non-metallic atomic group to be formed, R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a monovalent non-metallic atomic group, and R ⁵¹ and R ⁵² are bonded to each other to form an acidic nucleus of the dye. Also good. W represents an oxygen atom or a sulfur atom.
In General Formula (X), Ar ¹ and Ar ² each independently represent an aryl group, and are linked via a bond with —L ³ —. Here, L ³ represents —O— or —S—. W is synonymous with that shown in the general formula (IX).
In the general formula (XI), A ² represents a sulfur atom or NR ⁵⁹ , L ⁴ represents a nonmetallic atomic group that forms a basic nucleus of the dye in combination with adjacent A ² and a carbon atom, R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ and R ⁵⁸ each independently represent a monovalent nonmetallic atomic group, and R ⁵⁹ represents an alkyl group or an aryl group.

In general formula (XII), A ³ and A ⁴ each independently represent —S— or —NR ⁶² — or —NR ⁶³ —, wherein R ⁶² and R ⁶³ each independently represent a substituted or unsubstituted alkyl group, substituted Or an unsubstituted aryl group, and L ⁵ and L ⁶ each independently represent a nonmetallic atomic group that forms a basic nucleus of a dye together with adjacent A ³ , A ⁴ and an adjacent carbon atom; ⁶⁰ and R ⁶¹ are each independently a hydrogen atom or a monovalent nonmetallic atomic group, or can be bonded to each other to form an aliphatic or aromatic ring.
In General Formula (XIII), R ⁶⁶ represents an aromatic ring or a hetero ring that may have a substituent, and A ⁵ represents an oxygen atom, a sulfur atom, or —NR ⁶⁷ —. R ⁶⁴ , R ⁶⁵ and R ⁶⁷ each independently represent a hydrogen atom or a monovalent non-metallic atomic group, R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ each represent an aliphatic or aromatic ring. Can be combined to form.

  Specific preferred examples of the compounds represented by the general formulas (IX) to (XIII) include the exemplified compounds (A-1) to (A-20) shown below, but the present invention is limited thereto. It is not something.

[Co-sensitizer]
Further, the ink composition of the present invention may contain a compound having a function of further improving sensitivity or suppressing polymerization inhibition by oxygen as a co-sensitizer.
Examples of such cosensitizers include amines such as M.I. R. Sander et al., “Journal of Polymer Society”, Vol. 10, 3173 (1972), Japanese Patent Publication No. 44-20189, Japanese Patent Publication No. 51-82102, Japanese Patent Publication No. 52-134692, Japanese Patent Publication No. 59-138205. No. 60-84305, JP-A 62-18537, JP-A 64-33104, Research Disclosure 33825, and the like. Specific examples include triethanolamine. P-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like.

Other examples include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, and JP-A-56-75643. Examples thereof include disulfide compounds, and specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene and the like.
Other examples include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), and hydrogen described in Japanese Patent Publication No. 55-34414. Donors, sulfur compounds described in JP-A-6-308727 (eg, trithiane), phosphorus compounds described in JP-A-6-250387 (diethylphosphite, etc.), Si-- described in JP-A-8-65779 H, Ge-H compound, etc. are mentioned.

  The ink composition of the present invention further includes various organic and metal complex anti-fading agents, and conductive materials such as potassium thiocyanate, lithium nitrate, ammonium thiocyanate, dimethylamine hydrochloride for the purpose of controlling ejection properties. In order to improve the adhesion to the volatile salts and the recording medium, a very small amount of an organic solvent can be added.

Various polymer compounds for adjusting physical properties can be added to the ink composition of the present invention. Examples of polymer compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylic resins. Rubber resins, waxes and other natural resins can be used. Two or more of these may be used in combination.
In addition, nonionic surfactants, cationic surfactants, organic fluoro compounds, and the like can be added to adjust the liquid properties of the ink composition of the present invention. Leveling additives, matting agents, waxes for adjusting film physical properties, tackifiers that do not inhibit polymerization, and the like can be contained in order to improve adhesion to recording media such as polyolefin and PET.

The ink composition of the present invention preferably has an ink viscosity of 30 mPa · s or less, more preferably 5 to 20 mPa · s at the temperature at the time of ejection in consideration of ejection properties, and is in the above range. It is preferable to adjust the composition ratio as appropriate. The temperature at the time of injection is generally 25 to 90 ° C, preferably 25 to 80 ° C, and particularly preferably 40 to 80 ° C.
The ink viscosity at 25 to 30 ° C. is preferably 200 mPa · s or less, and more preferably 7 to 100 mPa · s. By setting the viscosity at room temperature high, even when a porous recording medium is used, ink penetration into the recording medium can be prevented, uncured monomer can be reduced, and odor can be reduced. Dot bleeding at the time of landing can be suppressed, and as a result, the image quality is improved. When the ink viscosity at 25 to 30 ° C. is larger than 200 mPa · s, a problem occurs in the delivery of the ink liquid.

  The surface tension of the ink composition of the present invention is preferably 20 to 30 mN / m, more preferably 23 to 28 mN / m. When recording on various recording media such as polyolefin, PET, coated paper, and non-coated paper, 20 mN / m or more is preferable from the viewpoint of bleeding and penetration, and the wettability is preferably 30 mN / m or less.

The ink composition of the present invention thus prepared is suitably used as an ink for inkjet recording. That is, it is used in an image forming method in which an image is recorded on an ink jet recording medium by ejecting the ink composition of the present invention, and thereafter, the recorded image is cured by irradiation with active energy rays.
In the recorded matter obtained by the ink composition of the present invention, the image portion is cured by irradiation with active energy rays such as ultraviolet rays, and the strength of the image portion is excellent. It can be used for various purposes such as formation of an ink receiving layer (image portion) of a plate.
The irradiation dose of active energy is preferably ²⁰ to 2000 mJ / cm ² .

<Image forming method and recorded matter thereof>
The image forming method of the present invention includes an image recording step of recording an image on a recording medium using the ink composition of the present invention described above, and curing by irradiating the recorded image with active energy rays (active rays). And an image curing step to be provided. In the present invention, a polymerizable compound that contributes to imaging by using active energy rays in the image curing step, recording an image on a recording medium in the image recording step, and then irradiating the recorded image with active energy rays. As the polymerization and curing proceed, the image is cured well and an image having high fastness can be formed.
The recorded matter obtained with this ink has an image portion cured by irradiation with active energy rays such as ultraviolet rays and is excellent in strength of the image portion. For example, it is used as an ink receiving layer (image portion) of a lithographic printing plate. You can also

  In the image recording step, it is preferable to apply an ink jet recording method using an ink jet printer. Specifically, an aspect in which the image is inkjet-recorded by discharging an ink composition in the image recording step is preferable. In the ink jet recording method, image recording is performed on a recording medium using the ink composition of the present invention, but there are no particular restrictions on the ink discharge nozzles (for example, for an ink jet printer) used at that time, and the purpose and application It can be appropriately selected according to the like. There is no restriction | limiting in particular in an inkjet recording system, and it is as above-mentioned specifically.

  In the image curing step, an exposure process for accelerating polymerization and curing can be performed using a light source that emits active energy rays in a wavelength region corresponding to the sensitive wavelength of the ink composition. Specifically, a light source that emits active rays belonging to a wavelength region of 240 to 450 nm, for example, LD, LED, fluorescent lamp, low-pressure mercury lamp, high-pressure mercury lamp, metal halide lamp, carbon arc lamp, xenon lamp, chemical lamp, etc. It can be suitably performed. Preferred light sources include LEDs, high pressure mercury lamps, and metal halide lamps. What is necessary is just to select an exposure time and light quantity suitably according to the grade of the polymerization hardening of the polymeric compound which concerns on this invention.

[Inkjet recording method and inkjet recording apparatus]
Next, an ink jet recording method and an ink jet recording apparatus that can be suitably employed in the image forming method of the present invention will be described below.

  In the ink jet recording method, for example, it is preferable that the ink composition is heated to 40 to 80 ° C. to lower the viscosity of the ink composition to 30 mPa · s or less, and then ejected. Stability can be achieved. In general, an active energy ray-curable ink composition generally has a higher viscosity than an aqueous ink, and thus has a large viscosity fluctuation range due to temperature fluctuations during printing. This viscosity variation of the ink composition directly affects the droplet size and droplet ejection speed as it is, which causes image quality deterioration. Therefore, it is necessary to keep the ink composition temperature as constant as possible during printing. is there. The control range of the ink composition temperature is preferably set temperature ± 5 ° C., more preferably set temperature ± 2 ° C., and further preferably set temperature ± 1 ° C.

  One feature of the ink jet recording apparatus is that it includes a means for stabilizing the temperature of the ink composition, and the portion to be kept at a constant temperature is a piping system from an ink tank (an intermediate tank if there is an intermediate tank) to the nozzle ejection surface. All of the members are targeted.

  The temperature control method is not particularly limited, but for example, it is preferable to provide a plurality of temperature sensors in each piping portion and perform heating control according to the ink composition flow rate and the environmental temperature. Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside air. In order to shorten the printer start-up time required for heating or to reduce the loss of thermal energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

In the ink composition of the present invention, an active energy ray-curable ink composition can be obtained by adding a photopolymerization initiator as the polymerization initiator.
The irradiation conditions of active energy rays in such an ink composition will be described. A basic irradiation method is disclosed in JP-A-60-132767. Specifically, a light source is provided on both sides of the head unit, and the head and the light source are scanned by a shuttle method. Irradiation is performed after a certain period of time after ink landing. Further, the curing is completed by another light source that is not driven. In WO99 / 54415, as an irradiation method, a method using an optical fiber or a method in which a collimated light source is applied to a mirror surface provided on the side surface of the head unit to irradiate the recording unit with UV light is disclosed. These irradiation methods can be used in the image forming method of the present invention.

  In the present invention, the ink composition is heated to a constant temperature, and the time from landing to irradiation is preferably 0.01 to 0.5 seconds, and preferably 0.01 to 0.3 seconds. More preferably, it is particularly preferable to irradiate the active energy ray after 0.01 to 0.15 seconds. Thus, by controlling the time from landing to irradiation to an extremely short time, it is possible to prevent the landing ink from bleeding before being cured. Also, since the ink composition can be exposed to a porous recording medium before it penetrates deeper than the light source reaches, unreacted monomer remains, and as a result, odor can be reduced. Can do. By using the ink jet recording method described above in combination with the ink composition of the present invention described above, a great synergistic effect is brought about. In particular, when an ink composition having an ink viscosity of 200 mPa · s or less at 25 ° C. is used, a great effect can be obtained. By adopting such a recording method, the dot diameter of the landed ink can be kept constant even on various recording media having different surface wettability, and the image quality is improved. In addition, in order to obtain a color image, it is preferable to superimpose in order from the color with the lowest brightness. When inks with low lightness are stacked, it is difficult for the irradiation rays to reach the lower ink, and inhibition of curing sensitivity, increase of residual monomers, generation of odor, and deterioration of adhesion tend to occur. Irradiation can be performed by injecting all colors and exposing them together, but exposure for each color is preferable from the viewpoint of curing acceleration.

There is no restriction | limiting in particular as an inkjet recording device used for the image forming method of this invention, A commercially available inkjet recording device can be used. That is, in the present invention, recording can be performed on a recording medium using a commercially available inkjet recording apparatus.
According to the preferable ejection conditions, heating and cooling are repeated in the ink composition of the present invention. However, the colored dispersion of the present invention and the ink composition containing the same are generally used as a polymerizable compound. By combining with the compound represented by the formula (1), even when stored and used under conditions where such temperature changes are repeated, a decrease in pigment dispersibility is suppressed, and excellent color developability over a long period of time. Is obtained, and the pigment can be kept in a primary particle state, and it is possible to suppress a decrease in dischargeability due to aggregation.

[Recording medium]
The recording medium used in the image forming method of the present invention is not particularly limited, and examples thereof include an ink permeable recording material and an ink non-permeable recording material, any of which can be used.

  Examples of the ink-permeable recording material include plain paper, inkjet exclusive paper, coated paper, electrophotographic co-paper, cloth, non-woven fabric, porous film, and polymer absorber. These are described as “recording materials” in Japanese Patent Application Laid-Open No. 2001-181549.

  From the viewpoint of effectively expressing the effects of the present invention, it is preferable to use a non-ink-permeable (non-absorbing) recording material. Examples of the ink-impermeable recording material include art paper, synthetic resin, rubber, resin-coated paper, glass, metal, earthenware, and wood. In addition, in terms of adding each function, a base material obtained by combining a plurality of these materials can also be used.

As the synthetic resin, any synthetic resin can be used. For example, polyester resin (polyethylene terephthalate, polybutadiene terephthalate, etc.), polyolefin resin (polyvinyl chloride, polystyrene, polyethylene, polyurethane, polypropylene, etc.), acrylic resin, Examples include polycarbonate, acrylonitrile-butadiene-styrene copolymer, diacetate, triacetate, polyimide, cellophane, celluloid, and polyvinyl alcohol.
There is no restriction | limiting in particular about the shape of the base material using a synthetic resin, and its thickness, Any of a film form, a card | curd shape, or a block shape may be sufficient, and it can select suitably according to the desired objective. The synthetic resin may be either transparent or opaque.

  As the usage form of the synthetic resin, it is one of the preferred forms used in the form of a film used for so-called soft packaging, and various non-absorbable plastics and films thereof can be used. Various plastics films include, for example, PET (polyethylene terephthalate) film, OPS (stretched polystyrene) film, OPP (stretched polypropylene) film, ONy (biaxially stretched nylon) film, PVC (polyvinyl chloride) film, PE (Polyethylene) film, TAC (triacetylcellulose) film, etc. can be mentioned.

  Examples of the resin-coated paper include a paper support in which one side or both sides of the paper is coated with a polyolefin resin and the like, and a paper support in which both sides of the paper are laminated with a polyolefin resin is particularly preferable.

  The recording composition of the present invention can be obtained by recording the ink composition of the present invention on a recording medium using an inkjet printer, and then preferably irradiating the recorded ink composition with an active energy ray and curing. it can. The recorded matter of the present invention has a high-quality image excellent in color development and sharpness because the ink used for image formation contains fine pigments uniformly and stably dispersed, and the weather resistance of the image Therefore, it can be applied to a wide range of fields.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. Unless otherwise indicated, parts and% represent parts by mass and% by mass.

[Example 1]
The dispersant shown below is dissolved in a polymerizable compound, put into a motor mill M50 (manufactured by Eiger) together with the pigment, and dispersed for 6 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm. A dispersion (D-1) was obtained.
Pigment [Pigment Yellow [PY120]: manufactured by Clariant Co., Ltd.] 10.0 parts Dispersant [Exemplary Compound 1-4] 3.0 parts Polymerizable Compound Oxetane Compound (OXT-221: Toa Gosei Co., Ltd.) 37.0 parts)

[Example 2]
The dispersant shown below is dissolved in a polymerizable compound, put into a motor mill M50 (manufactured by Eiger) together with the pigment, and dispersed for 6 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm. A dispersion (D-2) was obtained.
Pigment [Pigment Yellow [PY120]: Clariant Co., Ltd.] 10.0 parts Dispersant [Exemplified Compound 1-4] 1.0 part Polymer Dispersant (weight average molecular weight 37000)
[Solsperse 32000: manufactured by Nihon Lubrizol Co., Ltd.] 3.0 parts Polymerizable compound Oxetane compound (OXT-221: manufactured by Toagosei Co., Ltd.) 36.0 parts

Example 3
A pigment dispersion (D-3) was obtained in the same manner as in Example 2, except that the polymer dispersant Solsperse 32000 in Example 2 was changed to byk168 ((by Big Chemie (weight average molecular weight 5400)).

Example 4
The polymer dispersant Solsperse 32000 in Example 2 was used as a graft copolymer (weight average molecular weight 23000) of N, N-dimethylaminopropylacrylamide and terminal methacryloylated polybutyl acrylate (AB-6: manufactured by Toagosei Co., Ltd.). A pigment dispersion (D-4) was obtained in the same manner as Example 2 except for the changes.

[Examples 5 and 6]
Except for changing the pigment (PY120) in Example 2 to Pigment Blue [PB15: 4] and Pigment Red [PR122] (both manufactured by Ciba Specialty Chemicals Co., Ltd.), all the same procedures as in Example 2 were performed. Pigment dispersions (D-5, D-6) were obtained.

Example 7
The following dispersant is dissolved in a polymerizable compound, put into a motor mill M50 (manufactured by Eiger) together with the pigment, and dispersed for 8 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm. A dispersion (D-7) was obtained.
Pigment [Pigment Yellow [PY120]: manufactured by Clariant Co., Ltd.] 10.0 parts Dispersant [Exemplary Compound 2-1] 1.0 part Polymer dispersing agent (weight average molecular weight 37000)
[Solsperse 32000: manufactured by Nippon Lubrizol Co., Ltd.] 3.0 parts; polymerizable compound [acrylate compound]
(HDDA: Daicel UCB Co., Ltd.) 36.0 parts

[Comparative Example 1]
A pigment dispersion (D-8) was obtained in the same manner as in Example 2 except that Example Compound 1-4 in Example 2 was not used.

[Comparative Examples 2-3]
A pigment dispersion (D-9, D-10) was obtained in the same manner as in Examples 5 and 6 except that Exemplified Compound 1-4 in Examples 5 and 6 was not used.

[Comparative Example 4]
A pigment dispersion (D-11) was obtained in the same manner as in Example 7 except that Example Compound 2-1 in Example 7 was not used.

[Characteristic test of pigment dispersion]
The characteristics of the obtained dispersions were measured according to the following method. The results are shown in Table 1.
(1. Viscosity)
The viscosity at 25 ° C. of each dispersion was measured with an E-type viscometer (trade name RE-810, manufactured by Toki Sangyo Co., Ltd.), and the results are shown in Table 1 as distinguished below.
A: Less than 100 mPas B: 100 mPas or more, less than 200 mPas C: 200 mPas or more (2. Stability)
The dispersion state after storage of each dispersion at 50 ° C. for 1 month was confirmed by visual observation and change in viscosity, and the results are shown in Table 1 as distinguished below.
A: No precipitate was generated and the viscosity was not increased B: No precipitate was generated and the viscosity was increased C: Generation of precipitate was observed (3. Average particle diameter)
About each dispersion liquid, the volume reference average particle diameter D50 was measured using the light-scattering diffraction type particle size distribution measuring apparatus (LA910, Horiba Ltd. make), and the result is distinguished as follows in Table 1. Described.
A: D50 is less than 100 nm B: D50 is 100 nm or more and less than 200 nm C: D50 is 200 nm or more

  As shown in Table 1, the colored dispersion in the present invention has a low viscosity and can provide a highly stable dispersion. Further, since the particle size can be reduced, it is possible to provide a colored dispersion liquid with low scattering and high coloring power.

Example 8
A polymerizable compound and a polymerization initiator were further added to the pigment dispersion of Example 1 and mixed gently, and then pressure filtered with a membrane filter to obtain an ink composition of the present invention.

Pigment dispersion (D-1) 20.0 parts Polymerizable compound Polymerizable compound: Epoxy compound (Celoxide 3000: manufactured by Daicel Chemical Industries, Ltd.) 45.0 parts Polymerizable compound: Oxetane compound (OXT-221: Toa Gosei Co., Ltd.) 30.0 parts Polymerization initiator: Triphenylsulfonium salt (UVI-6992, manufactured by Dow Chemical Co., Ltd.) 5.0 parts

[Examples 9 to 13]
Except that the pigment dispersion used in Example 8 was changed to pigment dispersions (D-2 to D-6), the ink compositions of the present invention of Examples 9 to 13 were used in the same manner as Example 8. Obtained.

Example 14
Further, a polymerizable compound and a polymerization initiator were added to the pigment dispersion D-7 and mixed gently, and then pressure-filtered with a membrane filter to obtain an ink composition of the present invention.
Pigment dispersion (D-7) 20.0 parts Polymerizable compound [hexanediol diacrylate]
(HDDA: manufactured by Daicel UCB, Ltd.) 45.0 parts, polymerizable compound [captolactone-modified dipentaerythritol hexaacrylate, DPCA-60: manufactured by Nippon Kayaku Co., Ltd.) 30.0 parts, polymerization initiator [Acylphosphine oxide compounds
(Lucirin TPO-L: manufactured by BASF) 5.0 parts

[Comparative Examples 5 to 7]
An ink composition for comparison was obtained in the same manner as in Example 8 except that the pigment dispersion D-1 used in Example 8 was changed to pigment dispersions D-8 to D-10, respectively.

[Comparative Example 8]
An ink composition for comparison was obtained in the same manner as in Example 8 except that the pigment dispersion D-7 used in Example 14 was changed to the pigment dispersion D-11.

[Characteristic test of ink composition]
The properties of the obtained ink composition were measured according to the following method. The results are shown in Table 2.
(4. Viscosity)
The viscosity of each inkjet ink at 40 ° C. was measured with an E-type viscometer (trade name RE-810, manufactured by Toki Sangyo Co., Ltd.), and the results were distinguished as described below and listed in Table 2 (note that (A is a level at which stable ejection is possible, B is a level causing problems in ejection, and C is a level having problems in ejection.)
A: Less than 30 mPas B: 30 mPas or more, less than 100 mPas C: 100 mPas or more

(5. Stability)
The dispersion state after each ink-jet ink was stored at 65 ° C. for 6 weeks was confirmed by visual observation and change in viscosity, and the results were distinguished as shown below and listed in Table 2 (Note that A is a level with no problem and B is ejection) C is a level that causes no problem in practical use, C is a level that causes a problem in practical use, and D is a level that causes a problem in practical use because the ejectability is impossible.)
A: No precipitate was generated and the viscosity was not increased. B: No precipitate was generated and the viscosity was slightly increased (less than 100%). C: No precipitate was generated and the viscosity was (100% or more). Increased D: Precipitation was observed

(6. Curability)
The obtained ink composition was printed on art paper with an ink jet printer (printing density 300 dpi, droplet ejection frequency 4 kHz, nozzle number 64), and then an energy of 100 mJ / cm ^{2 with} a Deep UV lamp (US-7, SP-7). The sample was exposed under the following conditions to obtain a print sample. The cured film was confirmed by touching with a finger, and the presence or absence of stickiness was distinguished as follows and listed in Table 2 (A is a level where there is no problem, B is a level that causes a problem in practice, and C is a problem in practice) A certain level.)
A: No stickiness B: Slightly sticky C: Remarkably sticky

(7. Heat cycle property)
The obtained ink composition was subjected to a temperature increase / decrease cycle of 25 ° C. to 60 ° C. 10 times, then printed with the ink jet printer, and observed for the absence of nozzles. (Note that A is a level where there is no problem, B is a level causing a problem in practice, and C is a level causing a problem in practice).
A: High quality image formed with no missing nozzles B: Some satellites generated and image defects observed C: Nozzle missing occurred and image defects were significant

(8. Repeatability)
The above (6. Curability) test was performed 100 times continuously, and the presence or absence of a nozzle missing was observed, and distinguished as follows and listed in Table 2 (where A is a problem-free level and B is a practical problem) Level C, which is a practically problematic level.)
A: High quality image formed with no missing nozzles B: Some satellites generated and image defects observed C: Nozzle missing occurred and image defects were significant

From Table 2, the ink composition of the present invention is cured with high sensitivity to radiation irradiation, can form a high-quality image without stickiness, and is subjected to long-term storage and repeated temperature changes. In the case of storage at 1, the viscosity did not increase due to a decrease in the dispersibility of the pigment, and both the dispersibility and dispersion stability of the pigment were good.
In addition, in the irradiation test using the LED separately performed, the ink characteristics were confirmed for similar items, and good results were obtained.
On the other hand, the comparative ink composition using a commercially available polymer dispersant has a relatively good initial pigment dispersibility, but it has particularly high temperature storage conditions and heat cycleability by repeated heating. The level was inferior and problematic in practice.

Claims (10)

A colored dispersion comprising at least a pigment, a compound represented by the following general formula (1), and a polymerizable compound, wherein the content of the polymerizable compound is 50% by mass or more .

[In General Formula (1), R ₁ and R ₂ each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. ]   The colored dispersion liquid according to claim 1, wherein the compound represented by the general formula (1) is a compound having an amino group.   The colored dispersion according to claim 1, wherein the colored dispersion further contains a polymer dispersant.   The colored dispersion liquid according to any one of claims 1 to 3, wherein the polymerizable compound has a viscosity at 25 ° C of 30 mPa · s or less.   An ink composition comprising the colored dispersion according to any one of claims 1 to 4.   The ink composition according to claim 5, further comprising a polymerization initiator.   The ink composition according to claim 5 or 6, wherein the ink composition is for inkjet.   An image recording process for recording an image on a recording medium using the ink composition according to claim 5, and an active energy ray on the image recorded on the recording medium in the image recording process An image forming method comprising: an image curing step of curing by irradiation.   A recorded matter obtained by curing the ink composition according to any one of claims 5 to 7. The recorded matter according to claim 9, wherein the ink composition is recorded on a recording medium by an ink jet printer, and then the active energy ray is irradiated to cure the ink composition.