JP2011208088A - Active energy ray curable composition, active energy ray curable ink composition, inkjet recording method, and printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy ray curable composition which can be sensitively cured even by the irradiation of a low-output active energy ray, is low in the exudation of a surfactant, and is excellent in temporal stability; an active energy ray curable ink composition; an inkjet recording method using the active energy ray curable ink composition; and printed matter.SOLUTION: The active energy ray curable composition comprises (A) a substantially water-insoluble polymerizable compound having an ethylenic unsaturated bond, (B) a surfactant having one or more groups selected from the group consisting of an acrylate, a methacrylate, acrylamide, and methacrylamide, (C) a polymerization initiator, and (D) water. The inkjet recording method and the printed matter use the active energy ray curable ink composition.

Description

  The present invention relates to an active energy ray-curable composition, an active energy ray-curable ink composition, an ink jet recording method, and a printed matter.

  As an image recording method for forming an image on a recording medium such as paper based on an image data signal, an inkjet method has been widely used. The ink jet method is an inexpensive device and ejects ink only to a required image portion to directly form an image on a recording medium. Therefore, the ink can be used efficiently and the running cost is low. Furthermore, there is little noise and it is excellent as an image recording method. In particular, an ink composition (radiation curable ink composition), which is one of the ink forms used in the ink jet method and can be cured by irradiation with active energy rays such as ultraviolet rays, is excellent in quick-drying properties and has a non-permeable group. It has features such as being able to record on materials.

  However, in the radiation curable ink composition, since all of the ink composition remains, a difference in thickness occurs between the image area and the non-image area, which may cause deterioration in image quality (roughness or loss of glossiness). As a solution to this problem, aqueous actinic radiation curable inks have been proposed (see, for example, Patent Documents 1 and 2), and it has been reported that image quality can be improved. Further, the water-based actinic radiation curable ink is a preferable form from the viewpoint of high environmental suitability.

The basic constituent materials of the water-based actinic radiation curable ink are water, a polymerizable compound, a polymerization initiator that generates radicals or the like by actinic radiation to initiate polymerization, and a coloring material (pigment or dye). Among these, the polymerizable compound and the polymerization initiator may be prepared in the form of emulsion particles or may be present in a solution state with water solubility imparted by appropriate substituents.
As an example of the active radiation curable ink in which the polymerizable compound is present in the form of emulsion particles, for example, Patent Document 1 can be cited. Curing excellent in color reproducibility, saturation, scratch resistance, glossiness and the like by light irradiation. Ink jet inks are described in which films are obtained. Here, in order to make the polymerizable compound exist in the form of emulsion particles, it is common to use a surfactant. However, after curing, the curability is lowered due to the surfactant, and the interface from the ink image is reduced. There is a concern that the activator oozes out and the surface of the ink image is sticky.

  In order to solve this problem, it has been proposed to use a reactive surfactant (see, for example, Patent Document 3). However, the surfactant introduced in Patent Document 3 has an allyl group or β-methylstyryl group with low radical reactivity used in other applications such as emulsion polymerization, and its effect is not sufficient.

JP 2004-285216 A JP 2004-58507 A JP 2002-275403 A

  An object of the present invention is to provide an active energy ray-curable composition and an active energy ray that are cured with high sensitivity even when irradiated with low-power active energy rays, have little leaching of a surfactant, and have excellent temporal stability. It is to provide a curable ink composition, an ink jet recording method using the active energy ray curable ink composition, and a printed matter.

  As a result of intensive studies, the present inventors have included a polymerizable compound that is substantially insoluble in water, and a surfactant having a specific group, so that the surfactant does not bleed out with high sensitivity. The inventors have found that an active energy ray-curable composition having excellent stability over time can be obtained, and the present invention has been completed.

That is, the means for solving the above problems are as follows.
<1> One selected from the group consisting of (A) a polymerizable compound having an ethylenically unsaturated bond and substantially insoluble in water, (B) an acrylate group, a methacrylate group, an acrylamide group, and a methacrylamide group An active energy ray-curable composition containing a surfactant having the above group, (C) a polymerization initiator, and (D) water.
<2> The active energy ray-curable composition according to <1>, wherein the polymerizable compound (A) is present in the form of emulsion particles.

<3> The active energy ray-curable composition according to <1> or <2>, wherein the (B) surfactant is a sulfonate salt or a sulfate monoester salt.
<4> The active energy ray-curable composition according to any one of <1> to <3>, wherein the (B) surfactant is a surfactant having an acrylate group or a methacrylate group.

<5> The active energy ray-curable composition according to any one of <1> to <4>, wherein the (B) surfactant is a surfactant further having an ethyleneoxy group.
<6> In any one of <1> to <5>, the content of the (B) surfactant is 1 part by mass to 20 parts by mass with respect to 100 parts by mass of the polymerizable compound (A). The active energy ray-curable composition as described.

<7> As described in any one of <1> to <6>, the polymerizable compound (A) includes a polymerizable compound having a molecular weight of 200 to 800 and a polymerizable compound having a weight average molecular weight of 800 to 10,000. Active energy ray-curable composition.
<8> The active energy ray-curable composition according to any one of <1> to <7>, further comprising (E) a colorant.
<9> The active energy ray-curable composition according to <8>, wherein the colorant (E) is a pigment.

<10> An active energy ray-curable ink composition comprising the active energy ray-curable composition according to any one of <1> to <9>.
<11> The active energy ray-curable ink composition according to <10>, which is for inkjet recording.

<12> A step of ejecting the active energy ray-curable ink composition according to <11> onto an ink-jet recording apparatus on a recording medium, and irradiating the ejected ink composition with active energy rays, A step of curing the ink composition.
<13> Printed matter recorded by the inkjet recording method according to <12>.

  ADVANTAGE OF THE INVENTION According to this invention, the active energy ray hardening-type composition which hardened | cured with high sensitivity also with irradiation of the low output active energy ray, there was little oozing-out of surfactant, and was excellent in stability with time, active energy ray A curable ink composition, an ink jet recording method using the active energy ray curable ink composition, and a printed material can be provided.

[Active energy ray curable composition, Active energy ray curable ink composition]
The active energy ray-curable composition of the present invention is (A) a polymerizable compound having an ethylenically unsaturated bond and substantially insoluble in water (hereinafter sometimes referred to as “specific polymerizable compound”), (B) a surfactant having one or more groups selected from the group consisting of an acrylate group, a methacrylate group, an acrylamide group, and a methacrylamide group (hereinafter sometimes referred to as “specific surfactant”), (C It is an active energy ray-curable composition containing a polymerization initiator) and (D) water.

  The active energy ray-curable composition of the present invention having the above-described composition is an emulsion that cures with high sensitivity even when irradiated with low-power active energy rays, has little leaching of a surfactant, and is stable over time. The active energy ray-curable composition of the mold.

  Here, the “active energy ray” as used in the present invention is not particularly limited as long as it can impart energy capable of generating an initiation species in the composition by irradiation, and widely used as α-ray, γ Including X-rays, X-rays, ultraviolet rays, visible rays, electron beams, and the like. Among these, ultraviolet rays and electron beams are preferable from the viewpoint of curing sensitivity and device availability, and ultraviolet rays are particularly preferable.

  The active energy ray-curable ink composition of the present invention is an ink composition containing the active energy ray-curable composition of the present invention, and after applying the ink composition to a recording medium, the active energy ray is irradiated. By doing so, a cured ink image is formed. In particular, the active energy ray-curable ink composition of the present invention can be suitably used as an ink composition for inkjet recording.

  Hereinafter, each component of the active energy ray-curable composition of the present invention will be described in detail together with the active energy ray-curable ink composition which is a preferred application mode thereof. In the following description, the active energy ray-curable composition and the active energy ray-curable ink composition of the present invention are appropriately referred to as “curable composition” and “ink composition”.

<(A) Specific polymerizable compound>
The specific polymerizable compound used in the curable composition and the ink composition of the present invention is a polymerizable compound having an ethylenically unsaturated bond. The specific polymerizable compound used in the present invention is a compound that is substantially insoluble in water. Here, “substantially insoluble in water” means that the solubility in water at 25 ° C. is less than 5 mass%.

  When the polymerizable compound is water-soluble and uniformly present in the ink containing water as a main component, the concentration of the polymerizable compound is lowered and the sensitivity is lowered. In addition, even when the polymerizable compound does not completely dissolve and exists in the form of emulsion particles, if it has a certain degree of solubility (specifically, the solubility in water at 25 ° C. is 5% by mass or more), Dispersion stability is lowered. From this point, it is preferable that the solubility of (A) the specific polymerizable compound in water is low. Specifically, the solubility of (A) the specific polymerizable compound in water at 25 ° C. is preferably less than 2% by mass, and more preferably less than 1% by mass.

(D) In the curable composition and ink composition of the present invention containing water, (A) the specific polymerizable compound is substantially insoluble in water. It is possible to exist in the state of When the (A) specific polymerizable compound is present in the form of emulsion particles, the concentration of the (A) specific polymerizable compound is increased, and this is preferable in that the sensitivity is increased.
(A) The presence of the specific polymerizable compound in the form of emulsion particles can be confirmed, for example, by observation with an optical microscope, an electron microscope, or the like, or a method such as a dynamic light scattering method. In the present invention, the particle size is measured with Nanotrack UPA manufactured by Nikkiso Co., Ltd., and is substantially insoluble in water existing in a dispersed state in the curable composition and ink composition of the present invention ( A) When the particles of the specific polymerizable compound could be confirmed, it was judged that the (A) specific polymerizable compound was present in the state of emulsion particles. The specific polymerizable compound (A) used in the present invention is substantially insoluble in water. Therefore, when it does not exist in the form of emulsion particles, it is precipitated in the curable composition and ink composition of the present invention. Present or free.
Further, the particle size of the emulsion particles in the curable composition and the ink composition of the present invention is arbitrary as long as it does not affect the ejection property.

(A) The specific polymerizable compound is not particularly limited as long as it has an ethylenically unsaturated bond and the solubility in water at 25 ° C. is less than 5% by mass. Polymerization sensitivity, viscosity, ejection stability, emulsion stability It can be selected as appropriate in consideration of the above. (A) As the specific polymerizable compound, a polymerizable compound having a molecular weight of 200 to 800 (more preferably 250 to 650) (hereinafter may be referred to as “low molecular weight polymerizable compound”), and a weight average molecular weight of 800 to 800. 10,000 (more preferably 1000 to 6000) polymerizable compounds (hereinafter may be referred to as “high molecular weight polymerizable compounds”).
Here, (A) molecular weight measurement of a specific polymeric compound measures a weight average molecular weight by GPC (gel permeation chromatography), when it is a compound with distribution in molecular weight like a high molecular weight polymeric compound. Specifically, Tosoh GPC HLC-8220GPC is used as the apparatus, the column is TSKgel SuperAWMMH from Tosoh, and the weight average molecular weight is measured using N-methylpyrrolidone (NMP) as the solvent. The molecular weight is calculated by comparison with standard polystyrene.

  The low molecular weight polymerizable compound may be a monofunctional polymerizable compound or a polyfunctional polymerizable compound. Examples of the low molecular weight polymerizable compound include the following acrylates, specifically monofunctional alkyl acrylates, monofunctional hydroxyalkyl acrylates, monofunctional halogen alkyl acrylates, and monofunctional ether alkyl acrylates. Acrylate is preferred.

(Monofunctional alkyl acrylate)
Examples of the monofunctional alkyl acrylate include acrylate substituted with an alkyl group. In this case, the alkyl group is preferably an alkyl group having 4 to 16 carbon atoms. Specifically, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate, lauryl acrylate, stearyl acrylate, isobornyl acrylate, cyclohexyl acrylate , Dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, benzyl acrylate, among which 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate, isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, benzyl Acrylate is preferred.

(Monofunctional hydroxyalkyl acrylate)
Examples of the monofunctional hydroxyalkyl acrylate include acrylate substituted with a hydroxyalkyl group. Examples of the alkyl in this case include the same groups as the alkyl group in the monofunctional alkyl acrylate. Specifically, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-chloropropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-allyloxypropyl acrylate, 2- Examples include acryloyloxyethyl-2-hydroxypropyl phthalate, among which 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate are preferable.

(Monofunctional halogenated alkyl acrylate)
Examples of the monofunctional halogenated alkyl acrylate include acrylate substituted with a halogenated alkyl group. Examples of the alkyl in this case include the same groups as the alkyl group in the monofunctional alkyl acrylate. Specifically, 2,2,2-trifluoroethyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, 1H-hexafluoroisopropyl acrylate, 1H, 1H, 5H-octafluoropentyl acrylate, 1H, 1H , 2H, 2H-heptadecafluorodecyl acrylate, 2,6-dibromo-4-butylphenyl acrylate, 2,4,6-tribromophenoxyethyl acrylate, 2,4,6-tribromophenol 3EO addition acrylate .

(Monofunctional ether alkyl acrylate)
Examples of the monofunctional ether alkyl acrylate include acrylate substituted with an ether alkyl group. Examples of the alkyl in this case include the same groups as the alkyl group in the monofunctional alkyl acrylate. Specifically, 2-methoxyethyl acrylate, 1,3-butylene glycol methyl ether acrylate, butoxyethyl acrylate, 2-ethylhexyl carbitol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, p-nonylphenoxyethyl Examples include acrylate and glycidyl acrylate. Among them, 2-methoxyethyl acrylate, tetrahydrofurfuryl acrylate, and phenoxyethyl acrylate are preferable.

(Other monofunctional acrylates)
Other monofunctional acrylates include N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate, morpholinoethyl acrylate, trimethylsiloxyethyl acrylate, diphenyl-2-acryloyloxyethyl phosphate, and 2-acryloyloxyethyl. Examples include acid phosphate and caprolactone-modified-2-acryloyloxyethyl acid phosphate. Among them, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate and morpholinoethyl acrylate are preferable.

(Bifunctional acrylate)
Bifunctional acrylates include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, and neopentyl glycol. Diacrylate, neopentyl glycol PO (propylene oxide) modified diacrylate, hydroxypivalic acid neopentyl glycol ester diacrylate, caprolactone adduct diacrylate of hydroxypivalic acid neopentyl glycol ester, 1,6-hexanediol bis (2-hydroxy -3-acryloyloxypropyl) ether, 1,9-nonanediol diacrylate, pentaerythris Tall diacrylate, pentaerythritol diacrylate monostearate, pentaerythritol diacrylate monobenzoate, bisphenol A diacrylate, EO (ethylene oxide) modified bisphenol A diacrylate, PO modified bisphenol A diacrylate, hydrogenated bisphenol A diacrylate, EO Modified hydrogenated bisphenol A diacrylate, PO modified hydrogenated bisphenol A diacrylate, bisphenol F diacrylate, EO modified bisphenol F diacrylate, PO modified bisphenol F diacrylate, EO modified tetrabromobisphenol A diacrylate, tricyclodecane dimethylol Examples include diacrylate and isocyanuric acid EO-modified diacrylate. Among these, 1,4- Tan diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, neopentyl glycol diacrylate are preferable.

(Trifunctional acrylate)
In addition, as trifunctional acrylate, glycerin PO modified triacrylate, trimethylolpropane triacrylate, trimethylolpropane EO modified triacrylate, trimethylolpropane PO modified triacrylate, isocyanuric acid EO modified triacrylate, isocyanuric acid EO modified ε-caprolactone modified Examples include triacrylate, 1,3,5-triacryloylhexahydro-s-triazine, pentaerythritol triacrylate, and dipentaerythritol triacrylate tripropionate. Among these, trimethylolpropane triacrylate and pentaerythritol triacrylate are preferable.

(Tetrafunctional or higher acrylate)
Examples of tetra- or higher functional acrylates include pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate monopropionate, dipentaerythritol hexaacrylate, tetramethylolmethane tetraacrylate, oligoester tetraacrylate, and tris (acryloyloxy) phosphate. Of these, pentaerythritol tetraacrylate is preferred.

  As mentioned above, specific examples of acrylate compounds have been given as specific examples of the low molecular weight polymerizable compounds, but methacrylate compounds having the same structure (compounds in which the acrylates mentioned as the above specific examples are replaced with methacrylates) can also be preferably used. . In the present invention, it is more preferable to use the acrylate compounds mentioned as specific examples.

(Acid amide)
An acid amide may be used as the low molecular weight polymerizable compound. Examples of the acid amide include acrylamide, N-methylolacrylamide, diacetoneacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-isopropylacrylamide, acryloylmorpholine, methacrylamide, N-methylolmethacrylamide, diacetone. Examples include methacrylamide, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide, N-isopropylmethacrylamide, and methacryloylmorpholine, among which N, N-dimethylacrylamide, N, N-diethylacrylamide, acryloylmorpholine, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide, and methacryloylmorpholine are preferred.

(Vinyl compound)
A vinyl compound may be used as the low molecular weight polymerizable compound. Examples of the vinyl compound include vinyl acetate, vinyl monochloroacetate, vinyl benzoate, vinyl pivalate, vinyl butyrate, vinyl laurate, divinyl adipate, vinyl methacrylate, vinyl crotonate, vinyl 2-ethylhexanoate, and N-vinyl. Examples thereof include carbazole and N-vinylpyrrolidone. Among these, vinyl acetate, N-vinylcarbazole and N-vinylpyrrolidone are preferable.

  (A) The specific polymerizable compound is preferably selected from acrylates, methacrylates, acrylamides, methacrylamides, and vinyl compounds, but other compounds having a polymerizable functional group may be used, specifically, arylate. And styrenes.

In the present invention, a polyfunctional polymerizable compound is preferably used as the low molecular weight polymerizable compound, but a monofunctional polymerizable compound may be used in combination. The ratio of the polyfunctional polymerizable compound in the entire low molecular weight polymerizable compound when the monofunctional polymerizable compound and the polyfunctional polymerizable compound are used in combination is 60% by mass or more from the viewpoint of obtaining high sensitivity. It is preferably 80% by mass or more, more preferably 95% by mass or more.
In addition, the polyfunctional polymerizable compound is preferably 2 to 4 functional in terms of achieving both mobility and crosslinking degree, that is, high sensitivity.
Furthermore, the polyfunctional polymerizable compound preferably has a boiling point of 150 ° C. or higher, more preferably 200 ° C. or higher, from the viewpoint of workability and ejection stability.

  The high molecular weight polymerizable compound is a group of compounds in which a radically polymerizable group is added to a polymer or oligomer containing a repeating unit (generally referred to as “polymerizable polymer” or “polymerizable oligomer”), and the weight average molecular weight is Those in the range of 800 to 10,000 are preferably used. Here, preferred radical polymerizable groups include acrylate groups and methacrylate groups, with acrylate groups being preferred.

Although it does not restrict | limit especially as said high molecular weight polymeric compound, For example, an acrylate polymer and an acrylate oligomer are mentioned. Among these, urethane acrylate polymer, urethane acrylate oligomer, polyester acrylate, ester acrylate oligomer, epoxy acrylate polymer, and epoxy acrylate oligomer are preferable, urethane acrylate polymer, urethane acrylate oligomer, polyester acrylate, and ester acrylate oligomer are more preferable, and urethane More preferred are acrylate polymers and urethane acrylate oligomers.
Further, the high molecular weight polymerizable compound may be any of a monofunctional polymerizable compound and a polyfunctional polymerizable compound, and is preferably a polyfunctional polymerizable compound, and is a bifunctional polymerizable compound. It is more preferable.

Examples of the high molecular weight polymerizable compound include the following products.
EBECRYL series (EBECRYL220: bifunctional urethane acrylate having an average molecular weight of 1000, EBECRYL1870: hexafunctional polyester acrylate having an average molecular weight of 1500, etc.) manufactured by Daicel-Cytec, Inc. UA series (UA-122P: bifunctional having an average molecular weight of 1100, etc.) Urethane acrylate), trade name: M-81000 (polyester acrylate, manufactured by Toagosei Co., Ltd.), and trade name: (polyester acrylate, manufactured by Toagosei Co., Ltd.). Among these, EBECRYL220, EBECRYL1870, and UA-122P are preferable, and EBECRYL220. Is more preferable. In addition, products in the form of emulsion, dispersion and the like can be preferably used. Specific examples include UCECOAT 7177 (urethane acrylate emulsion manufactured by Daicel-Cytec), UCECOAT7773 (urethane acrylate dispersion manufactured by Daicel-Cytech), and the like. It is done.

  In the present invention, it is preferable to use the high molecular weight polymerizable compound and the low molecular weight polymerizable compound in combination as the specific polymerizable compound (A) because high curing sensitivity can be obtained. By using two kinds of polymerizable compounds having different molecular weights in this way, the plastic effect of the remaining components is suppressed, and further, the polymerization reaction is also prevented from stopping in the middle, so that high curing sensitivity can be obtained.

  As a preferable combination when the high molecular weight polymerizable compound and the low molecular weight polymerizable compound are used in combination, it is preferable that the polymerizable functional groups are the same, and it is more preferable that both are acrylates. Further, it is preferable that the two are mixed with each other and become uniform.

  The ratio of the high molecular weight polymerizable compound to the low molecular weight polymerizable compound molecular weight (low molecular weight polymerizable compound: high molecular weight polymerizable compound, mass ratio) is preferably 20:80 to 95: 5, and 40:60. ~ 80: 20 is more preferred.

  The total content of the polymerizable compound (A) in the curable composition and the ink composition of the present invention may be appropriately determined, but is usually in the range of 3 to 50% by mass in terms of solid content. Preferably, it is in the range of 10 to 35% by mass.

<(B) Specific surfactant>
The curable composition and ink composition of the present invention contain (B) a surfactant having one or more groups selected from the group consisting of acrylate groups, methacrylate groups, acrylamide groups, and methacrylamide groups. (B) The specific surfactant has a function of allowing the (A) specific polymerizable compound that is insoluble in water to exist without being separated in water, and is a preferred embodiment in the state of emulsion particles of the (A) specific polymerizable compound. Enables the existence of At this time, one or more groups selected from the group consisting of an acrylate group, a methacrylate group, an acrylamide group, and a methacrylamide group have sufficiently high polymerization performance and copolymerize well with the polymerizable compound (A). Compared with the case where a compound having no radical reactive group or a surfactant having low reactivity is used, a composition having good curability can be obtained. In addition, (B) the specific surfactant is covalently linked to the polymer in the composition after exposure, so that it is difficult to ooze out of the composition and a composition with little environmental pollution can be obtained.

  (B) The specific surfactant has an acrylate group, a methacrylate group, an acrylamide group, or a methacrylamide group, but the total number of these groups is 1 to 4 in terms of brittleness and flexibility of the film after curing. Preferably, 1-2 is more preferable.

  The specific surfactant (B) preferably has an acrylate group or a methacrylate group in that it has high polymerization performance and is well copolymerized with the polymerizable compound (A).

  The specific surfactant (B) is preferably a so-called anionic surfactant which is a hydrophobic group and a sulfonic acid salt or a sulfuric monoester salt, from the viewpoint of emulsion stability. Furthermore, it is more preferable that the specific surfactant (B) has an ethyleneoxy group from the viewpoint of emulsion stability. The length of the ethyleneoxy group (chain) in this case is not limited, but from the viewpoint of achieving both stability and water resistance of the cured film, those containing 3 to 50 ethyleneoxy repeating units are preferable.

  Examples of the hydrophobic group include straight-chain, branched, or cyclic alkyl groups having 6 or more carbon atoms (which may have a benzene ring or a naphthyl ring), and aryl groups having 6 or more carbon atoms. An alkyl group having 8 to 20 carbon atoms and an aryl group having 8 to 20 carbon atoms are preferable.

  (B) Specific examples that can be preferably used as the specific surfactant include the following exemplified compounds: 1-1 to 1-8, but those used in the present invention are not limited thereto. In the following structural formula, m represents the length of the alkylene group, and n represents the length of the ethyleneoxy group. m and n each represents an integer of 1 or more, and a preferable range is that m is an average value of 3 to 20 (more preferably 5 to 15), and n is an average value of 3 to 50 (5 to 20). It is.

  Moreover, as (B) specific surfactant, Nippon Emulsifier Co., Ltd. Antox MS-60, Antox MS-2N etc. which are shown by the following structural formulas other than said exemplary compound can be mentioned. In the following structural formulas, R represents a hydrogen atom, an alkyl group, a benzyl group, or a styrene group, and X represents an alkali metal, an alkaline earth metal, an ammonium cation, or an amine cation. In the following structural formulae, m and n each represent an integer of 1 or more.

  (B) Although the manufacturing method of specific surfactant can be selected suitably, it can manufacture by the method of Unexamined-Japanese-Patent No. 1-227627 etc., for example.

  The content of the specific surfactant (B) in the curable composition and the ink composition of the present invention is preferably 1 part by mass to 20 parts by mass with respect to 100 parts by mass of the polymerizable compound (A). It is more preferable that it is 10 mass parts. When the content of the specific surfactant (B) is less than 1 part by mass with respect to 100 parts by mass of the polymerizable compound (A), the stability of the emulsion particles may be reduced, and when it exceeds 20 parts by mass. In some cases, elution from a cured film or sensitivity may decrease.

(Other surfactants)
In addition to (B) the specific surfactant, the curable composition and the ink composition of the present invention may further contain another surfactant. Other surfactants preferably used include anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols Nonionic surfactants such as polyoxyethylene / polyoxypropylene block copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. In particular, anionic surfactants and nonionic surfactants can be mentioned.

  In the present invention, a polymer surfactant can also be used as another surfactant, and the following water-soluble resins are listed as preferred polymer surfactants from the viewpoint of ejection stability. As the water-soluble resin, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-maleic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer are preferably used. Polymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-methacrylic acid copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer Etc.

  The content when the other surfactant is used in combination is a mass ratio, and is preferably 1/2 or less, more preferably 1/5 or less of the content of (B) the specific surfactant. Further, in the ink composition, it is preferably 5 parts by mass or less, preferably 2 parts by mass or less, with respect to 100 parts by mass of the polymerizable compound.

<(C) Polymerization initiator>
The curable composition and the ink composition of the present invention contain a polymerization initiator that is decomposed by active energy rays to generate radicals and initiate polymerization of the polymerizable compound.
(C) As the polymerization initiator, any compound generally known as a photopolymerization initiator, for example, (i) aromatic ketones, (ii) aromatic onium salt compounds, (iii) organic peroxides, (Iv) hexaarylbiimidazole compound, (v) ketoxime ester compound, (vi) borate compound, (vii) azinium compound, (viii) metallocene compound, (ix) active ester compound, (x) having a carbon halogen bond A compound or the like can be appropriately selected and used, but from the viewpoint of curing sensitivity, it preferably contains one or more polymerization initiators selected from the group consisting of α-aminoketones and acylphosphine oxides. -It is particularly preferred to contain both amino ketones and acylphosphine oxides.

  Specific examples of α-aminoketones and acylphosphine oxides preferably used as the polymerization initiator (C) in the present invention include compounds described in JP-A-2008-195926. In particular, the acylphosphine oxides [2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide] are available under the trade name Darocur TPO (manufactured by Ciba Specialty Chemicals) and [bis (2,4,6 -Trimethylbenzoyl) -phenylphosphine oxide] is available under the trade name Irgacure 819 (manufactured by Ciba Specialty Chemicals), and both are particularly preferably used.

  The content of the (C) polymerization initiator in the curable composition and ink composition of the present invention is preferably in the range of 0.1% by mass to 30% by mass in terms of solid content, and is 0.2% by mass. More preferably, it is in the range of ˜20% by mass.

In the curable composition and ink composition of the present invention, (A) the specific polymerizable compound is a compound that is substantially insoluble in water and exists as an emulsion in the ink. At this time, (C) the polymerization initiator may be present in the same phase as (A) the specific polymerizable compound, or may be present in the aqueous phase.
(C) When a polymerization initiator is present in the aqueous phase, the polymerization initiator has hydrophilic properties such as carboxyl groups (including salts thereof), sulfo groups (including salts thereof), and ethyleneoxy groups in the molecule. A water-soluble compound having the above substituents may be selected and used.
From the viewpoint of sensitivity, (C) the polymerization initiator is preferably present in the same phase as (A) the polymerizable compound.

  The curable composition and the ink composition of the present invention preferably contain at least one of the above α-amino ketones or acylphosphine oxides as (C) a photopolymerization initiator. In addition to these, other photopolymerization initiators may be used. Specific examples of other polymerization initiators include polymerization initiators described in JP-A-2008-195926, such as camphorquinone, benzophenone, benzophenone derivatives, acetophenone, acetophenone derivatives, such as α-hydroxycycloalkyl. Phenyl ketones or 2-hydroxy-2-methyl-1-phenyl-propanone, dialkoxyacetophenones, α-hydroxy- or 4-aroyl-1,3-dioxolanes, benzoin alkyl ethers and benzyl ketals, for example Benzyl dimethyl ketal, phenyl glyoxalate and its derivatives, dimer phenyl glyoxalate, peresters, eg benzophenone tetracarboxylic acid peresters (eg as described in EP 1126,541) Halomethyltriazines such as 2- [2- (4-methoxy-phenyl) -vinyl] -4,6-bis-trichloromethyl [1,3,5] triazine, 2- (4-methoxy-phenyl)- 4,6-bis-trichloromethyl [1,3,5] triazine, 2- (3,4-dimethoxy-phenyl) -4,6-bis-trichloromethyl [1,3,5] triazine, 2-methyl- 4,6-bis-trichloromethyl [1,3,5] triazine, hexaarylbisimidazole / co-initiator system such as ortho-chlorohexaphenyl-bisimidazole in combination with 2-mercaptobenzothiazole; ferrocenium compound or titanocene Titanocenes, for example, dicyclopentadienyl-bis (2,6-difluoro-3-pyrrolofur) Yl) titanium; for example, it is also possible to use mixtures of o- acyl oxime ester compounds as described in GB 2,339,571. A boric acid compound can also be used as a co-initiator.

  The total content of the (C) polymerization initiator in the curable composition and the ink composition of the present invention is preferably 0.01 to 35 parts by mass with respect to 100 parts by mass of the (A) specific polymerizable compound, More preferably, it is 0.1-30 mass parts, More preferably, it is the range of 0.5-30 mass parts.

<Sensitizing dye>
The curable composition and ink composition of the present invention preferably contain a sensitizing dye in order to accelerate the decomposition of the (C) polymerization initiator by irradiation with active energy rays. Generally, a sensitizing dye absorbs a specific active energy ray and enters an electronically excited state. The sensitizing dye in an electronically excited state is brought into contact with the polymerization initiator to cause actions such as electron transfer, energy transfer, and heat generation, thereby causing a chemical change of the polymerization initiator, that is, decomposition, radical, acid or base. The generation of active species such as these causes the active species generated here to cause and accelerate the polymerization and curing reaction of the polymerizable compound described later.

  As the sensitizing dye, a compound corresponding to the wavelength of the active energy ray that generates an initiation species in the polymerization initiator used in the curable composition or the ink composition may be used. Considering that it is used in the reaction, examples of preferred sensitizing dyes include those having an absorption wavelength in the 350 nm to 450 nm region. Examples of sensitizing dyes include benzophenone, thioxanthone, especially also isopropylthioxanthone, anthraquinone and 3-acylcoumarin derivatives, terphenyl, styryl ketone and 3- (aroylmethylene) thiazoline, camphorquinone, eosin, rhodamine and erythrosine. Can be mentioned. Specific examples of the sensitizing dye that can be used in the present invention include compounds described in JP-A-2008-195926. Further, thiochromanones described in JP-A-2008-195926 (compounds represented by the general formula (I) in the publication) are also particularly preferable examples.

The content of the sensitizing dye in the curable composition and the ink composition of the present invention is preferably 0.05% by mass to 30% by mass in terms of solid content with respect to the curable composition or the ink composition. The content is more preferably from 20% by mass to 20% by mass, and more preferably from 0.2% by mass to 10% by mass.
Since this sensitizing dye has almost no absorption in the visible light region, it has an advantage that there is no concern of affecting the hue of the ink composition even if an amount capable of producing the effect is added. When the content is described in relation to (C) the polymerization initiator, (C) polymerization initiator: sensitizing dye (mass ratio) is preferably 200: 1 to 1: 200, and 50: 1 to 1:50. Is more preferable, and 20: 1 to 1: 5 is still more preferable.

In the curable composition and ink composition of the present invention, (A) the specific polymerizable compound is present as an emulsion in the ink. At this time, the sensitizing dye is present in the same phase as the polymerizable compound. Or may be present in the aqueous phase.
When the sensitizing dye is present in the aqueous phase, hydrophilic substitution such as carboxyl group (including its salt), sulfo group (including its salt), ethyleneoxy group, etc. is present in the molecule of the sensitizing dye. In the present invention, the sensitizing dye is preferably present in the same phase as the specific polymerizable compound (A) from the viewpoint of sensitivity.

<(D) Water>
The curable composition and the ink composition of the present invention contain (D) water as a main solvent.
As water, it is preferable to use ion-exchanged water, distilled water or the like that does not contain impurities. The water content in the ink composition of the present invention can be appropriately selected, but is preferably 40 to 97% by mass, more preferably 55 to 90% by mass.

<Water-soluble organic solvent>
The curable composition and ink composition of the present invention contain (D) water as a main solvent, but a water-soluble organic solvent may be used in combination depending on the purpose. Examples of the water-soluble organic solvent that can be used in the present invention include alcohols (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl). Alcohol), polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol Etc.), polyhydric alcohol ethers (for example, ethylene glycol monomethyl ether, ethylene glycol) Ether monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether , Triethylene glycol monobutyl ether, ethylene glycol monophenyl ether, propylene glycol monophenyl ether, etc.), amines (for example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, mole) Phosphorus, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, etc.), amides (eg, formamide, N, N-dimethylformamide, N , N-dimethylacetamide, etc.), heterocyclic rings (for example, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, etc.), sulfoxides ( For example, dimethyl sulfoxide etc.), sulfones (for example, sulfolane etc.), urea, acetonitrile, acetone etc. are mentioned. Preferable water-soluble organic solvents include polyhydric alcohols. It is more preferable to use a polyhydric alcohol and a polyhydric alcohol ether in combination.

  The water-soluble organic solvent may be used alone or in combination. The addition amount of the water-soluble organic solvent in the curable composition or the ink composition is preferably 30% by mass or less, more preferably 15% or less in total.

<(E) Colorant>
When the curable composition or ink composition of the present invention is applied to an application such as image portion formation of a lithographic printing plate, it is not essential to form a colored image, and no colorant is particularly necessary. In order to improve the visibility of the image portion formed with the ink composition, or when forming a colored image using the curable composition or the ink composition, it may contain (E) a colorant. it can.

  The colorant that can be used in the present invention is not particularly limited. However, when the polymerizable compound (A) is present in the form of emulsion particles in water, the ink composition can be used as a mode of use of (E) the colorant. (1) A mode in which a pigment is used as a colorant and dispersed in an aqueous medium. (2) An oil-soluble dye is used as a colorant and dissolved in a polymerizable compound to form an emulsion phase formed of the polymerizable compound. It is possible to adopt any mode of the mode of being present, (3) a mode in which a water-soluble dye is used as a colorant and this is dissolved in the aqueous phase, and these can be used in combination. On the other hand, it is preferable to use a pigment as a colorant because of excellent weather resistance.

(Pigment)
As the pigment that can be used as the colorant in the present invention, conventionally known colored organic or colored inorganic pigments can be used.
For example, azo pigments such as azo lake, insoluble azo pigment, condensed azo pigment, chelate azo pigment, phthalocyanine pigment, perylene and perylene pigment, anthraquinone pigment, quinacridone pigment, dioxazine pigment, thioindigo pigment, isoindolinone pigment, quinophthalone pigment, etc. Examples include polycyclic pigments, dye lakes such as basic dye lakes, and acid dye lakes, organic pigments such as nitro pigments, nitroso pigments, aniline black, and daylight fluorescent pigments, and inorganic pigments such as carbon black.

  Examples of magenta or red pigments include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 170, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. Pigment red 194, C.I. I. Pigment red 209, C.I. I. Pigment red 222, C.I. I. And CI Pigment Red 224.

  Examples of orange or yellow pigments include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 138, pigment yellow 180, and the like.

  Examples of green or cyan pigments include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. Pigment green 7, C.I. I. And CI Pigment Green 36.

  Examples of the pigment for black include carbon black. Examples of the white pigment include Pigment White 6, 18, 21, and the like.

  For these pigments, a pigment dispersant may be used as necessary when preparing pigment particles. Examples of the pigment dispersant that can be used include higher fatty acid salts, alkyl sulfates, alkyl ester sulfates. Salt, alkyl sulfonate, sulfosuccinate, naphthalene sulfonate, alkyl phosphate, polyoxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester , Activators such as polyoxyethylene fatty acid amides, amine oxides, or styrene, styrene derivatives, vinyl naphthalene derivatives, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, fumaric acid Block copolymers of two or more monomers selected from derivatives, random copolymers and can be exemplified salts thereof.

  A self-dispersing pigment can also be used in the curable composition and ink composition of the present invention. The self-dispersing pigment as used in the present invention refers to a pigment that can be dispersed without a dispersant, and particularly preferably pigment particles having a polar group on the surface.

The pigment particles having a polar group on the surface as used in the present invention are a pigment whose surface is directly modified with a polar group, or an organic substance having an organic pigment mother nucleus, which is bonded directly or via a joint. (Hereinafter referred to as pigment derivative).
Examples of the polar group include a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a boric acid group, and a hydroxyl group, preferably a sulfonic acid group and a carboxylic acid group, and more preferably a sulfonic acid group.

  Examples of a method for obtaining pigment particles having a polar group on the surface include, for example, WO 97/48769, JP-A-10-110129, JP-A-11-246807, JP-A-11-57458, 11-189739, JP-A-11-323232, JP-A-2000-265094, etc., oxidize the pigment particle surface with an appropriate oxidizing agent, so that at least a part of the pigment surface has a sulfonic acid group or The method of introduce | transducing polar groups, such as the salt, is mentioned. Specifically, it is prepared by oxidizing carbon black with concentrated nitric acid or, in the case of color pigments, by oxidizing with sulfamic acid, sulfonated pyridine salt, amidosulfuric acid, etc. in sulfolane or N-methyl-2-pyrrolidone. can do. In these reactions, the pigment dispersion can be obtained by removing and purifying the substance that has been excessively oxidized and becomes water-soluble. Moreover, when a sulfonic acid group is introduced onto the surface by oxidation, the acidic group may be neutralized with a basic compound as necessary.

  As other methods for obtaining pigment particles having polar groups on the surface, the pigment particles described in JP-A-11-49974, JP-A-2000-273383, JP-A-2000-303014, etc. are treated with a treatment such as milling. Examples include a method of adsorbing to the surface, a method of dissolving the pigment described in Japanese Patent Application Nos. 2000-377068, 2001-1495, and 2001-234966 in a solvent together with a pigment derivative, and crystallizing in a poor solvent. In any method, pigment particles having a polar group on the surface can be easily obtained.

  The polar group on the surface of the pigment may be free or in a salt state, or may have a counter salt. Examples of the counter salt include inorganic salts (lithium, sodium, potassium, magnesium, calcium, aluminum, nickel, ammonium) and organic salts (triethylammonium, diethylammonium, pyridinium, triethanolammonium, etc.), preferably 1 A counter salt having a valence.

  As a method for dispersing the pigment, for example, various dispersing machines such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, and a paint shaker can be used. It is also preferable to use a centrifugal separator or a filter for the purpose of removing the coarse particles of the pigment dispersion.

  (E) A dye may be used as a colorant. As the dye, a water-soluble dye may be used, or an oil-soluble dye may be dissolved in a polymerizable compound present as an emulsion, but it is oil-soluble in that it can be uniformly fixed on a cured film. A method in which a dye is dissolved in a polymerizable compound present as an emulsion is preferred. Specific examples of the oil-soluble dye include dyes described in paragraphs 0097 to 0101 of the specification of JP-A-2008-195926. Specific examples of the water-soluble dye include the dyes described in paragraphs 0076 to 0080 of the specification of JP-A-2005-307199. When the oil-soluble dye or the water-soluble dye is used as a colorant, the preferable content (total amount of dye) in the curable composition or ink composition is based on the total amount of the curable composition or ink composition. It is in the range of 0.1 to 10% on a mass basis. The ink composition having a low dye concentration is suitably applied to, for example, a so-called light-color ink of density-modulated ink.

<Other additives>
In the curable composition and ink composition of the present invention, in addition to (A) a specific polymerizable compound, (B) a specific surfactant, (C) a polymerization initiator, and (E) a colorant, which are essential components. As long as the effects of the present invention are not impaired, known additives can be used in combination. Hereinafter, additives that can be used in the curable composition and the ink composition will be described.

(latex)
Latex can be added to the curable composition and ink composition of the present invention. Examples of the latex that can be used in the present invention include styrene-butadiene copolymer, polystyrene, acrylonitrile-butadiene copolymer, acrylic acid ester copolymer, polyurethane, silicon-acrylic copolymer, and acrylic-modified fluorine-fatting. Latex. The latex may be a polymer particle dispersed using an emulsifier, or a so-called soap-free latex dispersed without using an emulsifier. A surfactant is often used as an emulsifier, but a polymer having a water-soluble group such as a sulfonic acid group or a carboxylic acid group (for example, a polymer in which a solubilizing group is graft-bonded, a single group having a solubilizing group). It is also preferable to use a polymer obtained from a monomer and a monomer having an insoluble part.

  Soap-free latex is a latex that does not use an emulsifier and a polymer having a water-soluble group such as a sulfonic acid group or a carboxylic acid group (for example, a polymer in which a solubilizing group is graft-bonded, a solubilizing group) A polymer obtained from a monomer having an insoluble part and a monomer having an insoluble part).

  In recent years, as latex polymer particles, there are latexes in which core-shell type polymer particles with different compositions at the center and outer edge of the particles are dispersed, in addition to latex in which polymer particles that are uniform throughout the particle are dispersed. This type of latex can also be preferably used.

  The average particle size of the polymer particles in the latex used in the curable composition and the ink composition of the present invention is preferably 10 nm or more and 300 nm or less, and more preferably 10 nm or more and 100 nm or less. When the average particle size of the latex in the ink composition is in the above range, the glossiness of the image, the water resistance and the scratch resistance can be improved. The average particle size of the polymer particles in the latex can be determined by a commercially available particle size measuring instrument using a light scattering method, an electrophoresis method, or a laser Doppler method.

  In the curable composition and ink composition of the present invention, when latex is used, the addition amount is preferably 0.1% by mass or more and 20% by mass or less in terms of solid content, It is particularly preferable that the amount of the solid content of the latex be 0.5% by mass or more and 10% by mass or less. When the solid content of the latex is 0.1% by mass or more, the effect of improving water resistance can be exhibited. When the latex content is 20% by mass or less, the ink viscosity increases with time, the pigment dispersion particle size increases, etc. Thus, good ink storage stability can be maintained without causing problems caused by the effect of latex.

(Aqueous polymer)
An aqueous polymer can be added to the curable composition and the ink composition of the present invention.
Preferable examples of the aqueous polymer include natural polymers, and specific examples thereof include proteins such as glue, gelatin, casein, or albumin, natural rubbers such as gum arabic or gum tragacanth, and glucosides such as saponin. And alginic acid and propylene glycol alginate, triethanolamine alginate, or alginic acid derivatives such as ammonium alginate, and cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, or ethylhydroxylcellulose.

  Other preferable examples of the aqueous polymer include synthetic polymers such as polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, Acrylic resin such as vinyl acetate-acrylic acid ester copolymer or acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester Styrene acrylic resin such as copolymer, styrene-α-methylstyrene-acrylic acid copolymer, or styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-maleic acid copolymer, styrene -Maleic anhydride copolymer, vinyl naphth Talen-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-croton Examples include acid copolymers, vinyl acetate copolymers such as vinyl acetate-acrylic acid copolymers, and salts thereof. Among these, polyvinylpyrrolidones are particularly preferable examples.

  The molecular weight of the water-soluble polymer that can be used in the present invention is preferably 1,000 or more and 200,000 or less. Furthermore, 3,000 or more and 20,000 or less are more preferable. If it is less than 1,000, the effect of suppressing the growth and aggregation of pigment particles is reduced, and if it exceeds 200,000, problems such as an increase in viscosity and poor dissolution tend to occur.

  The addition amount of the water-soluble polymer is preferably 10% by mass or more and 1,000% by mass or less with respect to the dissolved pigment. Furthermore, 50 mass% or more and 200 mass% or less are more preferable. If it is less than 10% by mass, the effect of suppressing the growth and aggregation of the pigment particles is reduced, and if it exceeds 1000% by mass, problems such as an increase in viscosity and poor dissolution tend to occur.

  In addition to the above-described components, the ink according to the present invention is used for the purpose of improving ejection stability, print head and ink cartridge compatibility, storage stability, image storage stability, and other various performances as necessary. According to various known additives such as viscosity modifiers, surface tension modifiers, specific resistance modifiers, film forming agents, dispersants, surfactants, ultraviolet absorbers, antioxidants, fading inhibitors, polymerization prohibitions Agent, anti-corrosive agent, rust preventive agent, fragrance and the like can be appropriately selected and used. Oil droplet fine particles such as liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, JP-A-57-74193, the same UV absorbers described in 57-87988 and 62-261476, JP-A-57-74192, 57-87989, 60-72785, 61-146591, Antifading agents described in, for example, Kaihei 1-95091 and 3-13376, JP 59-42993, 59-52689, 62-280069, 61-242871, and JP 4-24 Examples thereof include fluorescent brighteners described in No. 219266, pH adjusters such as sulfuric acid, phosphoric acid, citric acid, sodium hydroxide, potassium hydroxide and potassium carbonate.

(Method for preparing curable composition and ink composition)
In the curable composition and ink composition of the present invention, it is preferable that (A) the specific polymerizable compound is present in the form of emulsion particles in the curable composition or the ink composition. In order to prepare the ink composition, first, a non-aqueous phase is prepared, and it is then dispersed in an aqueous medium by a conventional method to prepare an emulsion.

The formation of the emulsion can be performed using a known method or apparatus, and an ultrasonic dispersion method, a high-pressure emulsification method, or the like can be applied. Can be used as appropriate.
The particle size of the emulsion can be adjusted by appropriately adjusting the stirring conditions (shearing force / temperature / pressure) during emulsification, the use conditions of the dispersing device, the ratio of the non-aqueous phase to the aqueous medium phase, and the like. .

As described above, since the curable composition of the present invention is cured with high sensitivity by active energy rays, it can be suitably used as an ink composition.
Among these, the ink composition of the present invention, which is excellent in storage stability and has a relatively low viscosity with water as a main component, can be said to have a remarkable effect when used for inkjet recording applications.

  In order to use the ink composition of the present invention in an ink jet method, the viscosity is of course within an appropriate range, but the surface tension is also particularly high so that a high-quality, high-density image can be formed on plain paper. It is more preferable to optimize in view of the balance between curing and penetration.

The ink composition of the present invention preferably has a viscosity at 50 ° C. of 15 mPa · s or less, more preferably 5 to 15 mPa · s.
The ink viscosity (mPa · s) as used in the present invention is not particularly limited as long as it is tested with a standard solution for calibration of a viscometer specified in JIS Z 8809, and the viscosity measured at 50 ° C. according to a known method. As the viscosity measuring device, a rotary, vibration or capillary type viscometer can be used, for example, a Saybolt viscometer, a Redwood viscometer, etc., for example, a cone plate type manufactured by Tokimec E type viscometer, Toki Sangyo E Type Viscometer (rotary viscometer), Tokyo Keiki B type viscometer BL, Yamaichi Denki FVM-80A, Nametor Kogyo Viscoliner VISCO MATE MODEL VM-1A, DD-1 manufactured by Denki Co., Ltd. can be exemplified.

The ink composition of the present invention preferably has a surface tension of 35 mN / m or less, more preferably 20 to 35 mN / m.
Here, the surface tension (mN / m) of the ink composition is a value measured by a surface tension measured at 50 ° C., and is described in reference books on general surface chemistry and colloid chemistry. Laboratory Chemistry Volume 18 (Interface and Colloid), The Chemical Society of Japan, published by Maruzen Co., Ltd. 68-117 can be referred to, and specifically, it can be determined by using the ring method (Dunoi method) or the platinum plate method (Wilhelmy method), but in the present invention, it was measured by the platinum plate method. It can be measured using a surface tension meter CBVP-Z manufactured by Kyowa Interface Science, for example.

  In the ink composition, the viscosity or surface tension specified above is not particularly limited, but the type and concentration of the pigment, the type and concentration of the photopolymerizable monomer, the type and concentration of the surfactant, etc. are appropriately adjusted. By doing so, it can be adjusted to a desired value.

<Inkjet recording method>
An ink jet recording method of the present invention and an ink jet recording apparatus applicable to the method will be described.
The ink jet recording method of the present invention comprises: (a) a step of ejecting the ink composition of the present invention described above onto a recording medium by an ink jet recording apparatus; and (b) an active energy ray on the ejected ink composition. And a step of curing the ink composition.

  The recording medium used in the present invention is a metal such as aluminum, iron, copper, vinyl chloride, acrylic, polycarbonate, polyethylene terephthalate, acrylonitrile butadiene styrene copolymer, polyethylene, polypropylene and other plastics, ceramics such as glass, wood, Examples include paper, printing paper, and fiber.

In addition, as the recording medium used in the present invention, any of a non-absorbing medium and an absorptive medium can be used. From the viewpoint of curability and water resistance, the non-absorbing property that the ink does not absorb into the recording medium. A recording medium may be mentioned.
The base material of such a recording medium is also preferably non-ink-absorbing. Here, “non-ink-absorbing” means that the ink is absorbed by a fibrous material such as paper, or that a resin that swells by absorbing ink is used as an ink absorbing layer on the film, or a filler or resin particles are used. It means that it does not have an ink absorption layer in which a void is provided in the layer. Specifically, what is generally used as a flexible packaging material is preferable. The material of the flexible packaging material is polyester, polyolefin, polyamide, polyesteramide, polyether, polyimide, polyamideimide, polystyrene, polycarbonate, poly-p-phenylene sulfide, polyetherester, polyvinyl chloride, poly (meth) acrylic acid Esters, polyethylene, polypropylene and nylon are preferred. Moreover, these copolymers and blends, and also those crosslinked can be used. Among them, stretched polyethylene terephthalate, polystyrene, polypropylene, and nylon are preferable in terms of transparency, dimensional stability, rigidity, environmental load, and cost. The thickness of the film is 2 to 100 μm, preferably 6 to 45 μm, and more preferably 10 to 30 μm.

In the step (a) in the ink jet recording method of the present invention, an ink jet recording apparatus described in detail below can be used.
<Inkjet recording apparatus>
There is no restriction | limiting in particular as an inkjet recording device used for the inkjet recording method of this invention, The well-known inkjet recording device which can achieve the target resolution can be selected arbitrarily and can be used. That is, any known inkjet recording apparatus including a commercially available product can eject ink onto a recording medium in step (a) of the inkjet recording method of the present invention.

Examples of the ink jet recording apparatus that can be used in the present invention include an apparatus including an ink supply system, a temperature sensor, and an active energy ray source.
The ink supply system includes, for example, an original tank containing the ink composition of the present invention, a supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. The piezo-type inkjet head has a multi-size dot of 1 to 100 pl, preferably 8 to 30 pl, for example, 320 × 320 to 4000 × 4000 dpi, preferably 400 × 400 to 1600 × 1600 dpi, and more preferably 720 × 720 dpi. It can drive so that it can discharge with the resolution of. In the present invention, dpi represents the number of dots per 2.54 cm.

  As described above, since it is desirable that the radiation curable ink has a constant temperature for the ejected ink, heat insulation and heating can be performed from the ink supply tank to the inkjet head portion. The temperature control method is not particularly limited, but for example, it is preferable to provide a plurality of temperature sensors at each piping site and perform heating control according to the ink flow rate and the environmental temperature. The temperature sensor can be provided near the ink supply tank and the nozzle of the inkjet head. 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.

Next, step (b), that is, a step of curing the ink composition by irradiating the ejected ink composition with active energy rays will be described.
The ink composition ejected onto the recording medium is cured by irradiating with active energy rays. This is because (C) the polymerization initiator contained in the ink composition of the present invention is decomposed by irradiation with active energy rays to generate starting species such as radicals, acids, bases, etc. A) This is because the polymerization reaction of the specific polymerizable compound occurs and is accelerated and the ink composition is cured. At this time, if a sensitizing dye is present together with (C) the polymerization initiator in the ink composition, the sensitizing dye absorbs the active energy ray to be in an excited state, and comes into contact with (C) the polymerization initiator (C). It promotes decomposition of the polymerization initiator and achieves a more sensitive curing reaction.

Here, α-rays, γ-rays, electron beams, X-rays, ultraviolet rays, visible light, infrared rays, or the like can be used as active energy rays. The peak wavelength of the active energy ray depends on the absorption characteristics of the sensitizing dye, but is preferably 200 to 600 nm, more preferably 300 to 450 nm, and still more preferably 350 to 420 nm, for example.
In the present invention, the polymerization initiator (C) has sufficient sensitivity even with a low output active energy ray. Therefore, the output of the active energy ray is preferably 2,000 mJ / cm ² or less, more preferably 10 to 2,000 mJ / cm ² , and still more preferably 20 to 1,000 mJ / cm ² . Yes, and particularly preferably 50 to 800 mJ / cm ² .
The active energy ray exposure surface illuminance, for example, 10 to 2,000 mW / cm ^2, preferably, it is suitable to be irradiated at 20 to 1,000 mW / cm ^2.

  Mercury lamps and gas / solid lasers are mainly used as active energy ray sources, and mercury lamps and metal halide lamps are widely known as light sources used for curing UV photocurable ink jet recording inks. ing. However, from the viewpoint of environmental protection, mercury-free is strongly desired, and replacement with a GaN-based semiconductor ultraviolet light-emitting device is very useful industrially and environmentally. Furthermore, LED (UV-LED) and LD (UV-LD) are small, have a long life, have high efficiency, and are low in cost, and are expected as light sources for photocurable ink jets.

In addition, a light emitting diode (LED) and a laser diode (LD) can be used as an active energy ray source. In particular, when an ultraviolet light source is required, an ultraviolet LED and an ultraviolet LD can be used. For example, Nichia Corporation has introduced a purple LED whose main emission spectrum has a wavelength between 365 nm and 420 nm. If even shorter wavelengths are required, US Pat. No. 6,084,250 discloses an LED that can emit active energy rays centered between 300 nm and 370 nm. Other ultraviolet LEDs are also available and can emit radiation in different ultraviolet bands. A particularly preferable active energy ray source in the present invention is a UV-LED, and a UV-LED having a peak wavelength of 350 to 420 nm is particularly preferable.
It is preferable that maximum illumination intensity of the LED on a recording medium is 10 to 2,000 mW / cm ^2, more preferably 20 to 1,000 mW / cm ^2, particularly preferably 50 to 800 mW / cm ² .
Since the ink composition of the present invention contains a surfactant having a specific polymerizable group, it can be used with particularly improved sensitivity in the UV-LED light source.

The irradiation time of the active energy ray to the ink composition of the present invention is, for example, preferably 0.01 seconds to 120 seconds, and more preferably 0.1 seconds to 90 seconds.
The irradiation conditions of active energy rays and the basic irradiation method are disclosed in JP-A-60-132767. Specifically, the light source is provided on both sides of the head unit including the ink ejection device, and the head unit and the light source are scanned by a so-called shuttle method. Irradiation with active energy rays is performed for a certain period of time after ink landing (for example, 0.01 to 0.5 seconds, preferably 0.01 to 0.3 seconds, more preferably 0.01 to 0.15 seconds). It will be done after. In this way, by controlling the time from ink landing to irradiation to an extremely short time, it is possible to prevent the ink that has landed on the recording medium from spreading before curing. Further, since the ink can be exposed to the porous recording medium before the ink penetrates to a deep part where the light source does not reach, the residual unreacted monomer can be suppressed, and as a result, the odor can be reduced. .
Further, the curing may be completed by another light source that is not driven. WO99 / 54415 pamphlet discloses a method using an optical fiber and a method of applying a collimated light source to a mirror surface provided on the side surface of the head unit and irradiating the recording unit with UV light as an irradiation method. The curing method can also be applied to the recording method of the present invention.

By adopting the ink jet recording method as described above, 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. By superimposing the inks in the order of low lightness, the irradiation line can easily reach the lower ink, and good curing sensitivity, reduction of residual monomers, reduction of odor, and improvement of adhesion can be expected. In addition, irradiation can be performed by discharging all colors and collectively exposing, but exposure for each color is preferable from the viewpoint of promoting curing.
In this way, the ink composition of the present invention is cured with high sensitivity by irradiation with active energy rays, and forms a hydrophobic image on the surface of the recording medium.

Here, the active energy ray source used for curing the ink or preferred irradiation conditions thereof are also the same as those described in the ink jet recording method.
The ink composition of the present invention is cured with high sensitivity by active energy rays, and can form a hydrophobic region having excellent adhesion to the support and excellent film quality. For this reason, in addition to the formation of colored images, marking, etc., it can also be used, for example, for the formation of the image portion of a lithographic printing plate. By applying this application, a lithographic plate with high image quality and excellent printing durability It is also possible to obtain a printed version.
The ink composition of the present invention is excellent for ink jet recording for the reasons described above, but it is needless to say that it is also useful as a commonly used ink composition.

Since the ink composition of the present invention is a water-based ink using (D) water as a medium, it is preferable to provide a drying step after the curing step by irradiation with the active energy ray.
The drying method is not particularly limited, and a known drying means can be appropriately selected and used. For example, a method of blowing warm air with controlled temperature and humidity, a method of conveying on a heat plate, and a heater inside. The method etc. which pass between heating rolls can be mentioned.
An image formed by the ink jet recording method using the ink composition of the present invention has high image quality because the ink composition has excellent ejection stability and is cured with high sensitivity.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these.
<Example 1>
[Preparation of yellow ink composition]
<Preparation of pigment dispersion 1>
After mixing the compounds having the following composition, the mixture was dispersed using a horizontal bead mill (System Zeta Mini manufactured by Ashizawa Corporation) filled with 0.3 mm zirconia beads at a volume ratio of 60%. Next, after dilution with ion-exchanged water until the pigment concentration became 5% by mass, impurities were removed by ultrafiltration. Next, ion exchange treatment was performed, and the particle size was made uniform by centrifugation to prepare pigment dispersion 1.
(Composition of pigment dispersion 1)
C. I. Pigment Yellow 128 166g
・ High molecular dispersant (styrene / 2-ethylhexyl acrylate / n-butyl acrylate / styrene sulfonic acid = 64/16/15/5) 32 g
・ Diethylene glycol 180g
・ Ion exchange water 1000g

<Preparation of polymerizable compound dispersion 1>
Trimethylolpropane triacrylate (polymerizable compound, trifunctional monomer trimethylolpropane triacrylate (TMPT), molecular weight 296.3, manufactured by Shin-Nakamura Chemical Co., Ltd.) 70 g, EBECRYL220 (polymerizable compound, bifunctional urethane acrylate oligomer, Average molecular weight 1000, Daicel Cytec Co., Ltd. 30 g, and Darocur TPO (acylphosphine oxide initiator, Ciba Specialty Chemicals Co., Ltd.) 4.0 g were dissolved in 200 g of ethyl acetate, 500 ml and 5 g of Antox MS-60 (Nippon Emulsifier Co., Ltd.) corresponding to (B) a specific surfactant were added, and ultrasonic dispersion was performed. Next, after evaporating and removing ethyl acetate from the obtained polymerizable compound dispersion using an evaporator, purification and particle size distribution are adjusted by centrifugation and ultrafiltration to prepare a polymerizable compound dispersion 1. did. In the polymerizable compound dispersion 1, the polymerizable compound was present in the form of emulsion particles. When the particle size of the emulsion particles was measured by the method described above, the volume average particle size was 180 nm.

<Preparation of ink composition>
The pigment dispersion 1 is added to a solid content equivalent to 30 g, 330 g of the polymerizable compound dispersion 1 and 60 g of ethylene glycol are added, and Olfine E-1010 (manufactured by Nissin Chemical Industry Co., Ltd.) is added to the surface tension. Was adjusted to 1 liter with water to prepare a yellow ink composition in which the polymerizable compound was present in the form of emulsion particles.

<Evaluation of ink composition>
The obtained ink composition was printed on a polyvinyl chloride sheet using an ink jet recording apparatus, dried by blowing at 40 ° C., and then subjected to iron-doped ultraviolet lamp (power 120 W / cm ² ) under the light beam. Irradiation was performed by changing the transport speed so that the accumulated exposure amount shown in Table 1 was passed, and the ink was cured to obtain a printed matter. The following evaluation was performed on the ink composition and the printed matter. The results are shown in Table 1.

  Here, the ink supply system of the ink jet recording apparatus used for the evaluation consists of the original tank, the supply pipe, the ink supply tank immediately before the ink jet head, the filter, and the piezo ink jet head, and insulates from the ink supply tank to the ink jet head portion. And warmed. Temperature sensors were provided near the ink supply tank and the nozzles of the ink jet head, respectively, and temperature control was performed so that the nozzle portions were always 40 ° C. ± 2 ° C. The piezo-type inkjet head was driven so that 8 to 30 pl multi-size dots could be ejected at a resolution of 720 × 720 dpi. In the present invention, dpi represents the number of dots per 2.54 cm.

-Integrated exposure amount-
As an evaluation of the effect sensitivity, the exposure energy required for curing was measured with a light amount integrator (UV PowerMAP manufactured by EIT). As a result, the accumulated exposure amount of ultraviolet rays required for curing on the sheet was about 600 mJ / cm ² , and it was confirmed that curing was performed with high sensitivity. The confirmation of curing was determined by the presence or absence of stickiness on the surface of the printed material. Specifically, plain paper (Fuji Xerox Co., Ltd. copy paper C2) was pressed immediately after printing, and it was determined that the case where the color liquid did not transfer was cured.

-Dissolution rate of surfactant-
The obtained printed sheet was cut into 2 cm squares, 20 pieces were immersed in 100 mL of distilled water and stirred at 50 ° C. for 48 hours, and the amount of surfactant in water was quantified by gas chromatography. Table 1 shows the elution rate of the surfactant.

-Emulsion stability evaluation-
The obtained ink composition was allowed to stand at room temperature for 7 days, and the variation rate of the particle size of the emulsion was measured with a dynamic light scattering type particle size distribution measuring device to evaluate the stability of the emulsion. Table 1 shows the variation rate of the particle diameter of the obtained emulsion.

<Examples 2 to 5>
In Example 1, Antox MS-60 used in the preparation of the polymerizable compound dispersion 1 was replaced with the same amount of the surfactant described in Table 1, and a polymerizable compound dispersion was prepared. An ink composition was prepared in the same manner as in Example 1 except that the liquid was used, and the same evaluation as in Example 1 was performed. The results are shown in Table 1. In the polymerizable compound dispersions prepared in Examples 2 to 5, the polymerizable compound was present in the form of emulsion particles, and the particle size of the emulsion particles was measured by the method described above. 4 and 5, the volume average particle size was 180 nm, and in Example 3, it was 220 nm.

In Table 1, the addition amount of the surfactant means the addition amount of the surfactant with respect to 100 parts by mass of the polymerizable compound.
In addition, Example Compound 1-1 used in Example 2 is a mixture of a compound having n = 9 and a compound having n = 11, and the average value of m is 10. Exemplified compound 1-4 used in Example 4 is a mixture of a compound in which n is 9 and a compound in which n is 10, and the average value of m is 10. Exemplified compound used in Example 5: 1-6 is a mixture of a compound in which n is 9 and a compound in which n is 11, and the average value of m is 9.

<Examples 6 to 9>
In Example 1, a polymerizable compound dispersion was prepared by changing the addition amount of Antox MS-60 used in the preparation of the polymerizable compound dispersion 1 to the addition amount shown in Table 1, and then preparing the polymerizable compound dispersion. An ink composition was prepared in the same manner as in Example 1 except that was used, and the same evaluation as in Example 1 was performed. The results are shown in Table 1. In the polymerizable compound dispersions prepared in Examples 6 to 9, the polymerizable compound was present in the form of emulsion particles, and the particle size of the emulsion particles was measured by the method described above. The volume average particle size was 260 nm, 220 nm in Example 7, and 160 nm in Examples 8 and 9.

<Example 10>
In Example 1, a polymerizable compound dispersion was prepared by replacing 70 g of trimethylolpropane triacrylate and 30 g of EBECRYL220 used in the preparation of the polymerizable compound dispersion 1 with 100 g of trimethylolpropane triacrylate. An ink composition was prepared in the same manner as in Example 1 except that the dispersion was used, and the same evaluation as in Example 1 was performed. The results are shown in Table 1. In the polymerizable compound dispersion prepared in Example 10, the polymerizable compound was present in the form of emulsion particles. When the particle size of the emulsion particles was measured by the method described above, the volume average particle size was It was 180 nm.

<Example 11>
In Example 1, a polymerizable compound dispersion was prepared by replacing 70 g of trimethylolpropane triacrylate and 30 g of EBECRYL220 used in the preparation of the polymerizable compound dispersion 1 with 100 g of EBECRYL220, and using the polymerizable compound dispersion. Ink compositions were prepared in the same manner as in Example 1 except that the same evaluations were performed as in Example 1. The results are shown in Table 1. In the polymerizable compound dispersion prepared in Example 11, the polymerizable compound was present in the form of emulsion particles, and the particle size of the emulsion particles was measured by the method described above. It was 160 nm.

<Comparative Example 1>
In Example 1, Antox MS-60 used in the preparation of the polymerizable compound dispersion 1 was replaced with the same amount of Aqualon RN-20 (surfactant containing β-methylstyryl group, Daiichi Kogyo Kagaku Co., Ltd.) Ink composition was prepared in the same manner as in Example 1 except that a polymerizable compound dispersion was prepared instead of the above product and the polymerizable compound dispersion was used, and the same evaluation as in Example 1 was performed. The results are shown in Table 1. In the polymerizable compound dispersion prepared in Comparative Example 1, the polymerizable compound was present in the form of emulsion particles. When the particle size of the emulsion particles was measured by the method described above, the volume average particle size was It was 180 nm.

<Comparative example 2>
In Example 1, the Antox MS-60 used in the preparation of the polymerizable compound dispersion 1 was replaced with the same amount of sodium dodecyl sulfate to prepare a polymerizable compound dispersion, and the polymerizable compound dispersion was used. Except for the above, an ink composition was prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 1. In the polymerizable compound dispersion prepared in Comparative Example 2, the polymerizable compound was present in the form of emulsion particles. When the particle size of the emulsion particles was measured by the method described above, the volume average particle size was 220 nm.

  From the results described in Table 1, Examples 1 to 11 containing (A) a specific polymerizable compound and (B) a specific surfactant are cured with high sensitivity to irradiation with low-power active energy rays. It can be seen that the surfactant does not ooze out and is excellent in stability over time. On the other hand, (B) Comparative Examples 1 and 2, which do not use a specific surfactant, have both curing sensitivity to irradiation with low-power active energy rays, exuding property of the surfactant, and stability over time. It turns out that it is inferior to Examples 1-11.

Claims (13)

  (A) One or more groups selected from the group consisting of a polymerizable compound having an ethylenically unsaturated bond and substantially insoluble in water, (B) an acrylate group, a methacrylate group, an acrylamide group, and a methacrylamide group An active energy ray-curable composition containing a surfactant having (C) a polymerization initiator, and (D) water.   The active energy ray-curable composition according to claim 1, wherein the polymerizable compound (A) is present in the form of emulsion particles.   The active energy ray-curable composition according to claim 1 or 2, wherein the (B) surfactant is a sulfonate or a salt of a monoester sulfate.   The active energy ray-curable composition according to any one of claims 1 to 3, wherein the (B) surfactant is a surfactant having an acrylate group or a methacrylate group.   The active energy ray-curable composition according to any one of claims 1 to 4, wherein the (B) surfactant is a surfactant further having an ethyleneoxy group.   The activity according to any one of claims 1 to 5, wherein a content of the surfactant (B) is 1 part by mass to 20 parts by mass with respect to 100 parts by mass of the polymerizable compound (A). Energy ray curable composition.   The active energy according to any one of claims 1 to 6, comprising a polymerizable compound having a molecular weight of 200 to 800 and a polymerizable compound having a weight average molecular weight of 800 to 10,000 as the polymerizable compound (A). Line curable composition.   The active energy ray-curable composition according to any one of claims 1 to 7, further comprising (E) a colorant.   The active energy ray-curable composition according to claim 8, wherein the colorant (E) is a pigment.   An active energy ray-curable ink composition comprising the active energy ray-curable composition according to any one of claims 1 to 9.   The active energy ray-curable ink composition according to claim 10, which is for ink jet recording.   A step of ejecting the active energy ray-curable ink composition according to claim 11 onto a recording medium by an ink jet recording apparatus, and irradiating the ejected ink composition with an active energy ray, thereby the ink composition A step of curing the ink jet recording method.   A printed matter recorded by the ink jet recording method according to claim 12.