JP5215529B2 - Ink composition and inkjet recording method - Google Patents

Description

  The present invention relates to an ink composition and an ink jet recording method using the same.

  In recent years, printing using an inkjet printer that does not use a plate has come to be used for the production of printed materials with limited copies such as regional advertisements and large posters. As inks for inkjet printing, water-based inks, solvent-based inks, and ultraviolet curable inks are generally used. Water-based ink-jet inks have poor water resistance when printed on plain paper, are likely to bleed, and ink droplets adhere poorly when printed on non-water-absorbing recording media such as plastic. In addition, image formation defects are liable to occur, and the drying of the solvent is extremely slow, so that it is necessary to dry the printed matter without overlapping immediately after printing.

On the other hand, solvent-based inks are suitable for printing on non-water-absorbing recording media such as plastics, but since the solvent needs to be dried, not only does it take time to dry, but also volatilizes the organic solvent. Disposal facilities and solvent recovery mechanisms had to be provided.
Ultraviolet curable inks using polyfunctional monomers with excellent adhesion to recording media have been developed as suitable for recording on non-water-absorbing recording media. Slow and insufficient to form a full color image. In order to solve the drying property, a method using a volatile organic solvent as a solvent of the ink has been carried out. However, in order to dry quickly, highly flammable and volatile such as methyl ethyl ketone and ethanol are used. It was necessary to use a high solvent.

In order to solve these problems, inkjet inks that are cured and fixed by radiation rather than volatilization of the ink solvent have been developed. For example, Patent Documents 1 to 3 disclose inks containing a monomer having a polymerizable group and an oil-soluble dye. Patent Document 4 discloses a photopolymerizable composition containing a photopolymerizable compound and a photopolymerization initiator. However, since these inks are radical polymerization systems, the polymerization is hindered by oxygen, and poor curing tends to occur in the air, and improvement has been desired.
Therefore, an ink using cationic polymerization that is not inhibited by oxygen is disclosed. For example, Patent Document 5 discloses a liquid ink containing oxirane. When this was carried out, the ink containing styrene oxide had an odor in the ink, and the curability was insufficient, and an improvement was desired.
JP 2003-221528 A JP 2003-221532 A JP 2003-221530 A JP 2001-222105 A Japanese Patent Laid-Open No. 2004-2668

  The problem to be solved by the present invention is to provide an ink composition which is excellent in curability and stability and excellent in adhesion, flexibility and curl resistance when printed on various substrates. Another object of the present invention is to provide an ink jet recording method and a recorded matter using such an ink composition.

As a result of intensive studies to solve the above problems, the present inventors have used an oxirane compound represented by the following general formula ( 2 ), and compared with glycidyl ether and alicyclic oxirane which are widely used. It has been found that an ink having high reactivity and particularly excellent curability can be produced, and that the odor can be reduced by setting the molecular weight of the compound represented by the following general formula ( 2 ) to 130 or more.
Moreover, the cured film formed using the oxirane compound represented by the following general formula ( 2 ) has excellent adhesion and flexibility to various substrates, and the curl of the recorded material is small, and the recorded material printed on the film. It was found that cracking does not occur even when bending deformation is applied to the. Based on these findings, the present inventors have completed the present invention.
That is, the present invention
<1> A compound represented by the following general formula (2), an ink composition characterized by a molecular weight containing more than 130 compounds,

In (formula ^(2), are each R 7 ~ ^{R 9} independently represents a hydrogen atom, an alkyl group, the alkoxycarbonyl Motoma other represents a group these oxirane ring is substituted. ^R 10 ^{to R 14} is Each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a group having an oxirane ring substituted thereon, provided that at least one of R ^{7 to} R ¹⁴ is a substituent other than a hydrogen atom.
<2> the ^R 10 ^{to R 14} is a hydrogen atom, an alkyl Motoma other is characterized by oxirane ring an alkyl group is a group substituted ink composition according to <1>,
< 3 > The ink composition according to < 1 > or < 2 >, wherein any one of the groups R ^{7 to} R ^{14 is} a group substituted with an oxirane ring.
< 4 > The ink composition according to any one of < 1 > to < 3 >, wherein R ¹² is an alkyl group .
< 5 > The ink composition according to any one of < 1 > to < 4 >, wherein R ⁹ is an alkyl group having 1 to 5 carbon atoms.
< 6 > The compound represented by the general formula ( 2) is contained in an ink composition in an amount of 2% by mass to 70% by mass, and further contains a photoacid generator and a cationically polymerizable compound. <1> to the ink composition according to any one of < 5 >,
< 7 > Any one of <1> to < 6 >, further comprising a monofunctional oxirane compound and / or a monofunctional oxetane compound in a total amount of 25% by mass to 75% by mass as the cationic polymerizable compound Or an ink composition according to claim 1,
< 8 > The ink composition according to any one of <1> to < 7 >, which is for inkjet.
< 9 > A radiation curable ink comprising the ink composition according to any one of <1> to < 8 >,
< 10 > A step of ejecting the ink composition according to any one of <1> to < 8 > onto a recording medium using an ink jet printer, and curing the irradiated ink composition by irradiating active energy rays An inkjet recording method comprising the steps of:
< 11 > In the ink jet recording method according to < 10 >, a light emitting diode is used as a light source of the active energy ray to be irradiated, and < 12 > in the above <1> to < 8 > Recorded matter recorded using the ink composition according to any one of the above items ,
Is to provide.

The ink composition of the present invention is excellent in curability, adhesiveness, flexibility, and ejection stability.
In particular, since the ink composition of the present invention has good ink ejection stability, clogging is less likely and good characters or images can be recorded on a recording medium.
In addition, an ink jet recording method and a recorded matter using such an ink composition can be provided.

Details of the present invention will be described below.
The present invention is an ink composition comprising a compound represented by the general formula ( 2 ) and having a molecular weight of 130 or more.
First, the compound represented by the general formula (1) will be described.

Here, in the general formula (1), R ^{1 to} R ⁶ are each independently a hydrogen atom , alkyl group, alkenyl group, aryl group, alkoxy group, aryloxy group, oxycarbonyl group, acyloxy group, carbamoyl group, acyl Represents a group , an alkoxycarbonyl group, a sulfenyl group, a sulfamoyl group, a sulfinyl group, a heterocyclic group, a halogen atom, or a group in which an oxirane ring is substituted . R ⁵ may be linked to R ¹ or R ⁴ to form a ring, and R ² and R ³ or R ² and R ⁵ may be linked to each other with an alkylene group. In addition, when R ^{1 to} R ⁶ are substituents containing an oxirane ring, the compound represented by the general formula (1) may be a so-called polyfunctional monomer having two or more oxirane rings. .
The R ^{1, R} 2, ^{R 3} or ^{R 6,} among a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an oxycarbonyl group is preferably used. R ² and R ³ may be connected to each other through an alkylene group.

In the present invention, among the compounds represented by the general formula (1), using a compound represented by the following general formula (2).

In the general formula ^{(2), R 7 ~ R} 9 each independently represent a hydrogen atom, an alkyl group, alkoxycarbonyl Motoma other these oxirane ring is substituted group. R ^{10 to} R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a group in which an oxirane ring is substituted. However, at least one of R ^{7 to} R ¹⁴ must be a substituent other than a hydrogen atom. When all of R ^{7 to} R ¹⁴ are hydrogen atoms, since the molecular weight is small, concentration unevenness due to odor or volatilization may occur . The R ⁷ to R ^14, among them, a hydrogen atom, more preferably an alkyl ^group, the R 10 ^{to R 14,} and more preferably an alkoxy group in addition to. R ⁹ is preferably a hydrogen atom or an alkyl group, and particularly preferably an alkyl group having 1 to 5 carbon atoms. When R ^{7 to} R ¹⁴ are a substituent substituted with an oxirane ring, it becomes a so-called polyfunctional monomer and is preferably used from the viewpoint of improving curability.

The ink composition of the invention contains an oxirane compound represented by the general formula ( 2). Moreover, in addition to the compound represented by General formula ( 2), additives, such as a stabilizer other than a cationically polymerizable compound, a photo-acid generator, and a coloring agent, can be included. In this case, the total amount of the compound of the general formula (2) and the cationic polymerizable compound is preferably 70% by mass or more and 99% by mass or less, more preferably 75% by mass or more and 98% by mass or less, and 80% by mass with respect to the total amount of the ink. % To 95% by mass is most preferable. The content of the oxirane compound represented by the general formula ( 2) can be arbitrarily set, but is preferably 2% by mass or more and 70% by mass or less of the total amount of the ink composition from the viewpoints of viscosity and curability.

With a compound examples represented by general formula (1), shows a compound example of the general formula (2) of the present invention are shown below. However, in the present invention, any compound may be used as long as it is a compound represented by the general formula ( 2) and having a molecular weight of 130 or more, and is not limited to these compound examples.
The compounds (3) to (5) shown below and the compounds (10) and (15) in Table 1 are all reference examples.

The compound represented by the general formula ( 2) used in the present invention may be used not only alone but also as a mixture thereof or as a mixture with other cationically polymerizable compounds.
As other cationically polymerizable compounds that can be used in combination with the oxirane compound represented by the general formula ( 2 ), any kind of monomer, oligomer, or polymer may be used as long as it is a compound having a generally known cationically polymerizable group. Can be used. Examples of the cationic polymerizable compound include the compounds exemplified below, but the present invention is not limited to these, and any cationic polymerizable compound can be used without any problem. The cationically polymerizable compounds can be used alone or in combination as a mixture for the purpose of adjusting the reaction rate, ink properties, cured film properties, and the like.

Any cationic polymerizable compound is used as the cationic polymerizable compound, and in addition to the styrene compound and the vinyl ether compound, an oxirane compound, an oxetane compound, a tetrahydrofuran compound, a lactam compound, a lactone compound, and the like are used. Of these, oxirane compounds, oxetane compounds, vinyl ether compounds or styrene compounds are preferably used, and oxirane compounds and oxetane compounds are particularly preferred.
Moreover, 1 type may be used for an oxirane ring containing compound (oxirane compound, ie, epoxy compound), and an oxetane ring containing compound (oxetane compound), and it may use 2 or more types together. From the viewpoint of improving the curing rate and the degree of curing, it is preferable to use at least one oxetane compound and an oxirane compound in combination. In this case, the ratio of the oxirane compound and the oxetane compound is preferably 10:90 to 70:30. An ink composition having a good balance between curability and curing speed can be obtained by setting between these values.

  From the viewpoint of stably ejecting ink, the cationically polymerizable compound used in the present invention preferably has a low viscosity, and preferably contains a monofunctional cationically polymerizable compound. As the monofunctional cationically polymerizable compound, oxirane, oxetane, and vinyl ether are preferably used, and it is particularly preferable to use one or both of oxirane and oxetane. From the viewpoint of reducing the viscosity of the monofunctional cation polymerizable compound, the monofunctional oxirane compound and / or the monofunctional oxetane compound should be in a proportion of 25% by mass to 75% by mass of the total amount of the ink composition. The ratio is preferably 25% by mass to 60% by mass, and most preferably 25% by mass to 50% by mass.

[Oxirane compounds]
Examples of the oxirane compound include aromatic epoxides and alicyclic epoxides. Aromatic epoxides include di- or polyglycidyl ethers produced by the reaction of polyphenols having at least one aromatic nucleus or their alkylene oxide adducts and epichlorohydrin, such as bisphenol A or its alkylene oxides. Examples thereof include di- or polyglycidyl ethers of adducts, di- or polyglycidyl ethers of hydrogenated bisphenol A or alkylene oxide adducts thereof, and novolak type epoxy resins. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

Examples of the alicyclic epoxide include cyclohexene oxide obtained by epoxidizing a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring with an appropriate oxidizing agent such as hydrogen peroxide or peracid. Preferred examples include cyclopentene oxide-containing compounds.
Examples of the aliphatic epoxide include dihydric polyhydridyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, and typical examples thereof include diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol or 1,6. -Diglycidyl ether of alkylene glycol such as diglycidyl ether of hexanediol, polyglycidyl ether of polyhydric alcohol such as di- or triglycidyl ether of glycerin or its alkylene oxide adduct, diglycidyl of polyethylene glycol or its adduct of alkylene oxide Polyalkylene glycol diglycol represented by diglycidyl ether of ether, polypropylene glycol or its alkylene oxide adduct Jill ether, and the like. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.
Among these oxirane compounds, aromatic epoxides and alicyclic epoxides are preferable from the viewpoint of excellent curing speed, and alicyclic epoxides are particularly preferable.
Further, among the oxirane compounds, those having a small number of functional groups are preferable because they can simultaneously have solubility and viscosity adjusting effects as described above.

  Examples of monofunctional epoxides 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- Examples include vinylcyclohexene oxide.

  Examples of polyfunctional epoxides 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, 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′-epoxycyclohexanecarboxylate, 2 -(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexyl) Til) 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, Resin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,1,3-tetradecadiene dioxide, limonene dioxide, 1,2,7,8-di Examples thereof include epoxy octane, 1,2,5,6-diepoxycyclooctane and the like.

[Oxetane compounds]
The oxetane compound in the present invention refers to a compound having an oxetane ring, and arbitrarily selected from known oxetane compounds as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217. Can be used.
As the compound having an oxetane ring that can be used in the ink composition of the present invention, a compound having 1 to 4 oxetane rings in its structure is preferable, and as described above, the viscosity and tackiness of the ink composition are particularly preferable. From the viewpoint, it is preferable to use a compound having one or two oxetane rings. 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 the compound having 1 to 2 oxetane rings in the molecule include compounds represented by the following general formulas (i) to (iii).

R ^a1 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, a furyl group, or a thienyl group. When two R ^a1 are present in the molecule, they may be the same or different.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Preferred examples of the fluoroalkyl group include those in which any hydrogen of these alkyl groups is substituted with a fluorine atom.
R ^a2 is an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a group having an aromatic ring, an alkylcarbonyl group having 2 to 6 carbon atoms, or an alkoxycarbonyl having 2 to 6 carbon atoms. Group represents an N-alkylcarbamoyl group having 2 to 6 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the alkenyl group include a 1-propenyl group, a 2-propenyl group, a 2-methyl-1-propenyl group, and 2-methyl-2. -Propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group and the like. Examples of the group having an aromatic ring include phenyl group, benzyl group, fluorobenzyl group, methoxybenzyl group, phenoxyethyl group and the like. Can be mentioned. As the alkylcarbonyl group, an ethylcarbonyl group, a propylcarbonyl group, a butylcarbonyl group, etc., as an alkoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, etc., as an N-alkylcarbamoyl group, Examples thereof include an ethylcarbamoyl group, a propylcarbamoyl group, a butylcarbamoyl group, and a pentylcarbamoyl group.

R ^a3 represents a linear or branched alkylene group, a linear or branched poly (alkyleneoxy) group, a linear or branched unsaturated hydrocarbon group, an alkylene group containing a carbonyl group or a carbonyl group, a carboxyl group Represents an alkylene group containing, an alkylene group containing a carbamoyl group, or the following group. Examples of the alkylene group include an ethylene group, a propylene group, and a butylene group. Examples of the poly (alkyleneoxy) group include a poly (ethyleneoxy) group and a poly (propyleneoxy) group. Examples of the unsaturated hydrocarbon group include a propenylene group, a methylpropenylene group, and a butenylene group.

When R ^a3 is the above polyvalent group, R ^a4 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, a mercapto group, A lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group is represented.
R ^a5 represents an oxygen atom, a sulfur atom, a methylene group, NH, SO, SO ₂ , C (CF ₃ ) ₂ , or C (CH ₃ ) ₂ .
R ^a6 represents an alkyl group having 1 to 4 carbon atoms or an aryl group, and n is an integer of 0 to 2000. R ^a7 represents an alkyl group having 1 to 4 carbon atoms, an aryl group, or a monovalent group having the following structure. In the following formula, R ^a8 is an alkyl group having 1 to 4 carbon atoms or an aryl group, and m is an integer of 0 to 100.

  Examples of the compound having 3 to 4 oxetane rings include compounds represented by the following general formula (iv).

In general formula (iv), R ^a1 has the same ^meaning as in general formula (i). In addition, examples of R ^a9 that is a polyvalent linking group include branched alkylene groups having 1 to 12 carbon atoms such as groups represented by A to C below, and branched poly ( An alkyleneoxy) group or a branched polysiloxy group such as a group represented by E below. j is 3 or 4.

In the above A, R ^a10 represents a methyl group, an ethyl group, or a propyl group. Moreover, in said D, p is an integer of 1-10.

  Another embodiment of the oxetane compound that can be suitably used in the present invention includes a compound represented by the following general formula (v) having an oxetane ring in the side chain.

In the general formula (v), R ^a1 and R ^a8 have the same ^{meaning as} in the above formula. R ^a11 is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, or a trialkylsilyl group, and r is 1 to 4.

  Examples of monofunctional oxetanes include oxetane compounds used in the present invention, such as 3-ethyl-3-hydroxymethyloxetane, 3- (meth) allyloxymethyl-3-ethyloxetane, and (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-oxetanylmethoxy) ethyl] phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-Ethyl-3-oxetanylmethyl) ether, 2-ethyl Hexyl (3-ethyl-3-oxetanylmethyl) ether, ethyldiethylene 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-oxetanyl) Methyl) ether, 2-tetrabromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, tribromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tribromophenoxyethyl (3-ethyl) Ru-3-oxetanylmethyl) ether, 2-hydroxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, butoxyethyl (3-ethyl-3- Oxetanylmethyl) ether, pentachlorophenyl (3-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 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, tri Ethylene 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.

[Examples of vinyl ether]
Further, in the present invention, a compound having a vinyl ether group may be further contained in order to impart a degree of curing. In this case, the compound having a vinyl ether group can be present in the ink composition in the range of 1% by mass to 20% by mass from the viewpoint of adjusting the surface physical properties of the cured product and the solubility of the ink composition.
Examples of monofunctional vinyl ethers used in the present invention 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, Cyclohexylmethyl 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 , Methoxy polyethylene Recall vinyl ether, 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, Examples include chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxypolyethylene glycol vinyl ether, and the like.

  Examples of polyfunctional vinyl ethers include, for example, 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, bisphenol F alkylene oxide. Divinyl ethers such as divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hex Vinyl 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-added penta And polyfunctional vinyl ethers such as erythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.

  A known compound is used as the styrene compound, but a styrene compound in which at least one of the p-position and the o-position of the aromatic ring is substituted with an electron-donating functional group is preferable from the viewpoint of improving the electron density on the vinyl group. Used. Here, the electron-donating functional group means a group having a negative Hammett's rule substituent constant σ value, and examples of such a functional group include an amino group, a hydroxyl group, an alkoxy group, and an alkyl group. Among these, an alkoxy group, an alkyl group, and a dimethylamino group are preferably used because they hardly react with the active terminal during polymerization.

  Monofunctional styrene compounds include styrene, 2-methylstyrene, 4-methylstyrene, 2,6-methylstyrene, 2-ethylstyrene, 4-ethylstyrene, 2-ethylstyrene, 4-n-butylstyrene, 2 2-alkylstyrenes and 4-alkylstyrenes such as n-butylstyrene, 4-t-butylstyrene, 2-t-butylstyrene, 4-butenylstyrene, 4-octenylstyrene, 4-methoxystyrene, 2-alkoxystyrene such as 2-methoxystyrene and 4-t-butylstyrene, or 4-alkoxystyrenes, 4-acetoxystyrene, 4-dimethylaminostyrene, 4-dimethylaminomethylstyrene, 4-glycidylmethylstyrene, 4 -Hydroxystyrene, 2,4-dialkylstyrene, 2,4, - trialkyl styrene, 2,4-dialkoxy styrene, 2,4,6-alkoxy styrene.

  Examples of the polyfunctional styrene compound include divinylbenzene, bis (4-vinylphenyl) methane, bis (4-vinylphenyl) ethane, bis (4-vinylphenyl) butane, bis (4-vinylphenyl) hexane, and bis (4- Vinylphenyl) heptane, bis (4-vinylphenyl) octane, bis (4-vinylphenoxy) hexane, bis (4-vinylbenzyl) diethylene glycol, ethylene glycol bis (4-vinylphenyl) ether, propylene glycol bis (4-vinyl Phenyl) ether, 1,6-hexanediol bis (4-vinylphenyl) ether, 1,8-octanediol bis (4-vinylphenyl) ether, oligoethylene glycol bis (4-vinylphenyl) ether, polyethylene glycol (4 -Vinyl Phenyl ether), oligo propylene glycol bis (4-vinylphenyl) ether, polypropylene glycol bis (4-vinylphenyl) ether, glycerol tris (4-vinylphenyl) ether.

[Photocationic polymerization initiator]
The ink composition of the present invention preferably contains a photocationic polymerization initiator that generates an acid upon irradiation with radiation (also referred to as a photoacid generator as appropriate). As the cationic photopolymerization initiator that can be used in the present invention, it is used as a photoinitiator for photocationic polymerization, a photoinitiator for radical photopolymerization, a photodecolorant for dyes, a photochromic agent, a microresist, or the like. By irradiation with light (400-200 nm ultraviolet light, far ultraviolet light, particularly preferably g-line, h-line, i-line, KrF excimer laser beam), ArF excimer laser beam, electron beam, X-ray, molecular beam or ion beam A compound that generates an acid can be appropriately selected and used.

  Such photocationic polymerization initiators include onium salt compounds such as diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones that decompose upon irradiation with radiation to generate acids. And sulfonate compounds such as o-nitrobenzyl sulfonate.

  Other examples of the cationic photopolymerization initiator used in the present invention include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Bal et al, Polymer, 21, 423 (1980), U.S. Pat. Nos. 4,069,055, 4,069,056, Re 27,992, JP-A-3-140140 Ammonium salts described in the above, and the like. C. Necker et al, Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055, 4,069,056, and the like; V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent Nos. 104,143, 339,049, 410,201, JP-A-2-150848, JP-A-2-296514 and the like,

  J. et al. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al, J.A. PolymerSci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al, Polymer Bull. 14, 279 (1985), J. Am. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patent Nos. 370,693, 161,811, 410,201, 339,049, 233,567, 297,443, and 297,442. U.S. Pat.Nos. 3,902,114, 4,933,377, 4,760,013, 4,734,444, 2,833,827, German Patent 2, Nos. 904, 626, 3,604, 580, 3,604, 581, JP-A-7-28237, and 8-27102, and the like,

  J. et al. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), etc., selenonium salts, C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988) and other onium salts such as arsonium salts, US Pat. No. 3,905,815, Japanese Patent Publication No. 46-4605, Japanese Patent Publication No. 48-36281 JP 55-23070, JP 60-239736, JP 61-169835, JP 61-169837, JP 62-58241, JP 62-212401, JP 63- Organic halogen compounds described in JP-A-70243, JP-A-63-298339, and the like; Meier et al, J.A. Rad. Curing, 13 (4), 26 (1986), T.A. P. Gill et al, Inorg. Chem. , 19, 3007 (1980), D.M. Astruc, Acc. Chem. Res. , 19 (12), 377 (1986), and organometallic / organic halides described in JP-A-2-161445, etc.

  S. Hayase et al, J.A. Polymer Sci. 25, 753 (1987), E.I. Reichmanis et al. Polymer Sci. , Polymer Chem. Ed. , 23, 1 (1985), Q.M. Q. Zhu et al, J.A. Photochem. 36, 85, 39, 317 (1987), B.R. Amit et al, Tetrahedron Lett. , (24) 2205 (1973), D.M. H. R. Barton et al, J.A. Chem. Soc. , 3571 (1965), p. M.M. Collins et al, J.A. Chem. Soc. Perkin I, 1695 (1975), M .; Rudinstein et al, Tetrahedron Lett. , (17), 1445 (1975), J. MoI. W. Walker et al, J. et al. Am. Chem. Soc. 110, 7170 (1988), S.A. C. Busman et al, J.M. Imaging Technol. 11 (4), 191 (1985), H. et al. M.M. Houlihan et al, Macormolecules, 21, 2001 (1988), P.M. M.M. Collins et al, J.A. Chem. Soc. , Chem. Commun. 532 (1972), S.A. Hayase et al, Macromolecules, 18, 1799 (1985); Reichmanis et al. Electrochem. Soc. , Solid State Sci. Technol. , 130 (6), F.M. M.M. Houlihan et al, Macromolecules, 21, 2001 (1988), European Patents 0290,750, 046,083, 156,535, 271,851, 0,388,343, US Patent 3,901,710, 4,181,531, JP-A-60-198538, JP-A-53-133022 and the like, a photoacid generator having an O-nitrobenzyl type protecting group,

  M.M. TUNOOKA et al, Polymer Preprints Japan, 35 (8), G.M. Berner et al, J.A. Rad. Curing, 13 (4), W.M. J. et al. Mijs et al, Coating Technol. , 55 (697), 45 (1983), Akzo, H .; Adachi et al, Polymer Preprints, Japan, 37 (3), European Patent Nos. 0199,672, 84515, 044,115, 618,564, 0101,122, U.S. Pat. 371,605, 4,431,774, Japanese Patent Application Laid-Open No. 64-18143, Japanese Patent Application Laid-Open No. 2-245756, Japanese Patent Application Laid-Open No. 3-140109, and the like. Compounds that generate sulfonic acid, disulfone compounds described in JP-A Nos. 61-166544 and 2-71270, JP-A-3-103854, JP-A-3-103856, and JP-A-4-210960 The diazoketosulfone and diazodisulfone compound described can be mentioned.

  Further, a group which generates an acid by these light, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, E. Woodhouse et al., J. MoI. Am. Chem. Soc. 104, 5586 (1982), S .; P. Pappas et al. Imaging Sci. , 30 (5), 218 (1986), S .; Kondo et al, Makromol. Chem. , Rapid Commun. , 9, 625 (1988), Y. et al. Yamada et al, Makromol. Chem. 152, 153, 163 (1972), J. Am. V. Crivello et al, J.A. PolymerSci. , Polymer Chem. Ed. 17, 3845 (1979), U.S. Pat. No. 3,849,137, German Patent No. 3,914,407, JP-A 63-26653, JP-A 55-164824, JP-A 62- 69263, JP-A 63-146038, JP-A 63-163452, JP-A 62-153853, JP-A 63-146029, and the like can be used. For example, dicationium salt, ammonium salt, phosphonium salt, iodonium salt, sulfonium salt, selenonium salt, onium salt such as arsonium salt, organic halogen compound, organic metal / organic halide, photocationic polymerization having o-nitrobenzyl type protecting group Examples thereof include a compound capable of generating a sulfonic acid by photolysis, such as an initiator and iminosulfonate, a disulfone compound, a diazoketosulfone, and a diazodisulfone compound.

  Furthermore, V. N. R. Pillai, Synthesis, (1), 1 (1980), A.M. Abad et al., Tetrahedron Lett. , (47) 4555 (1971), D.M. H. R. Barton et al, J.A. Chem. Soc. , (C), 329 (1970), U.S. Pat. No. 3,779,778, European Patent No. 126,712, and the like, compounds that generate an acid by light can also be used.

  Preferred examples of the photocationic polymerization initiator that can be used in the present invention include compounds represented by the following formulas (b1), (b2), and (b3).

In the formula (b1), R ²⁰¹ , R ²⁰² and R ²⁰³ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably a sulfonate anion, a carboxylate anion, a bis (alkylsulfonyl) amide anion, a tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ or the following And the like, and BF ₄ ⁻ , PF ₆ ⁻ and SbF ₆ ⁻ are preferable.

  Preferable organic anions include organic anions represented by the following formula.

Rc ¹ represents an organic group.
Examples of the organic group in Rc ¹ include those having 1 to 30 carbon atoms, and preferably an alkyl group, a cycloalkyl group, an aryl group, or a plurality of these are a single bond, —O—, —CO ₂ —, —S—. , —SO ₃ —, —SO ₂ N (Rd ¹ ) — and the like.

Rd ¹ represents a hydrogen atom or an alkyl group.
Rc ³ , Rc ⁴ and Rc ⁵ each independently represents an organic group.
Preferred examples of the organic group for Rc ³ , Rc ⁴ , and Rc ⁵ include the same organic groups as those for Rc ¹ , and most preferably a perfluoroalkyl group having 1 to 4 carbon atoms.
Rc ³ and Rc ⁴ may combine to form a ring.
Examples of the group formed by combining Rc ³ and Rc ⁴ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group.

The organic group of Rc ¹ and Rc ^{3 to} Rc ⁵ is most preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved.

The carbon number of the organic group as R ²⁰¹ , R ²⁰² and R ²⁰³ is preferably 1-30, more preferably 1-20.
Two of R ^{201 to} R ²⁰³ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ²⁰¹ to R ^203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ²⁰¹ , R ²⁰² and R ²⁰³ include corresponding groups in the compounds (b1-1), (b1-2) and (b1-3) described later.

In addition, the compound which has two or more structures represented by Formula (b1) may be sufficient. For example, at least one of R ^{201 to} R ²⁰³ of the compound represented by the general formula (b1) is directly or linked to at least one of R ^{201 to} R ²⁰³ in the other compound represented by the formula (b1). It may be a compound having a structure bonded through a group.

  Further preferred examples of the component (b1) include compounds (b1-1), (b1-2), and (b1-3) described below.

Compound (b1-1) is in which at least one aryl group R ²⁰¹ to R ²⁰³ in formula (b1), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.

In the arylsulfonium compound, all of R ^{201 to} R ²⁰³ may be an aryl group, or a part of R ^{201 to} R ²⁰³ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldicycloalkylsulfonium compounds, and the like.

  The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

As the alkyl group that the arylsulfonium compound has as necessary, a linear or branched alkyl group having 1 to 15 carbon atoms is preferable. For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, sec -A butyl group, a t-butyl group, etc. can be mentioned.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ²⁰¹ to R ^203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and most preferred. Is an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. Substituents, of the three R ²⁰¹ to R ^203, may be substituted on any one, or may be substituted on all of three. When R ^{201 to} R ²⁰³ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (b1-2) will be described.
The compound (b1-2) is a compound in the case where R ^{201 to} R ²⁰³ in the formula (b1) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R ²⁰¹ to R ²⁰³ each independently, preferably an alkyl group, a cycloalkyl group, an allyl group, a vinyl group, more preferably a linear, branched or cyclic 2-oxoalkyl group, an alkoxycarbonylmethyl group, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ²⁰¹ to R ²⁰³ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, a butyl group, a pentyl group), and a linear, branched 2-oxoalkyl group, and an alkoxycarbonylmethyl group are more preferable.

The cycloalkyl group as R ²⁰¹ to R ²⁰³ is preferably a cycloalkyl group having 3 to 10 carbon atoms (a cyclopentyl group, a cyclohexyl group, a norbornyl group) can be exemplified, more preferably a cyclic 2-oxoalkyl group.

Linear R ²⁰¹ to R ^203, branched, or cyclic 2-oxoalkyl group, preferably, may be mentioned 2-position group having> C = O at the above-described alkyl or cycloalkyl group.
The alkoxy group in the alkoxycarbonylmethyl group as R ²⁰¹ to R ^203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R ^{201 to} R ²⁰³ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

  The compound (b1-3) is a compound represented by the following formula (b1-3) and is a compound having a phenacylsulfonium salt structure.

In formula (b1-3), R ^{1c to} R ^5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R ^6c and R ^7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R ^x and R ^y each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.
Any two or more of R ^{1c to} R ^5c , R ^6c and R ^7c , and R ^x and R ^y may be bonded to each other to form a ring structure.
Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (b1).

The alkyl group as R ^{1c to} R ^7c may be either linear or branched, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms (for example, Methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).

Preferred examples of the cycloalkyl group represented by R ^{1c to} R ^7c include a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).

The alkoxy group as R ^{1c to} R ^{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Examples of the group formed by combining any two or more of R ^{1c to} R ^5c , R ^6c and R ^7c , and R ^x and R ^y include a butylene group and a pentylene group. This ring structure may contain an oxygen atom, a sulfur atom, an ester bond, or an amide bond.

Preferably any one of R ^{1c to} R ^5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R ^1c to R ^5c is 2-15. Solvent solubility is further improved, and generation of particles during storage is suppressed, which is preferable.

^Examples of the alkyl group and cycloalkyl group as R ^x and R ^y include the same alkyl groups and cycloalkyl groups as R ^{1c to} R ^7c .
R ^x and R ^y are preferably a 2-oxoalkyl group or an alkoxycarbonylmethyl group.
Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R ^{1c to} R ^5c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R ^{1c to} R ^5c .

R ^x and R ^y are preferably an alkyl group or cycloalkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more alkyl groups or cycloalkyl groups.

Formula (b2), in (b3), R ²⁰⁴ ~R ²⁰⁷ each independently represents an aryl group, an alkyl group or a cycloalkyl group. X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (b1).

Phenyl group and a naphthyl group are preferred as the aryl group of R ²⁰⁴ to R ^207, more preferably a phenyl group.
The alkyl group as R ²⁰⁴ to R ²⁰⁷ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group). The cycloalkyl group as R ²⁰⁴ to R ²⁰⁷ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
The R ²⁰⁴ to R ²⁰⁷ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

  Examples of the compound that generates an acid upon irradiation with actinic rays or radiation that may be used further include compounds represented by the following formulas (b4), (b5), and (b6).

In formulas (b4) to (b6), Ar ³ and Ar ⁴ each independently represents an aryl group.
R ²⁰⁶ , R ²⁰⁷ and R ²⁰⁸ each independently represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

Preferable examples of the photoacid generator include compounds represented by formulas (b1) to (b3).
Preferred compound examples [(b-1) to (b-96)] of the cationic photopolymerization initiator that can be used in the present invention are listed below, but the present invention is not limited thereto.

Further, oxazole derivatives and s-triazine derivatives described in JP-A No. 2002-122994, paragraph numbers [0029] to [0030] are also preferably used.
The onium salt compounds and sulfonate compounds exemplified in JP-A-2002-122994, paragraphs [0037] to [0063] can also be suitably used in the present invention.

A photocationic polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
The content of the (b) photoacid generator in the ink composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably in terms of the total solid content of the ink composition. Is 1-7 mass%.

[Sensitizing dye]
The ink composition of the present invention can contain a sensitizing dye. Examples of the sensitizing dye include those belonging to the compounds listed below and having an absorption wavelength in a wavelength region of 350 nm to 450 nm.

  For example, polynuclear aromatics (for example, pyrene, perylene, triphenylene, 2-ethyl-9,10-dimethoxyanthracene, etc.), xanthenes (for example, fluorescein, eosin, erythrosine, rhodamine B, rose bengal, etc.), cyanine (Eg, thiacarbocyanine, oxacarbocyanine, etc.), merocyanines (eg, merocyanine, carbomerocyanine, etc.), thiazines (eg, thionine, methylene blue, toluidine blue, etc.), acridines (eg, acridine orange, chloroflavin, etc.) , Acriflavine, etc.), anthraquinones (eg, anthraquinone, etc.), squaliums (eg, squalium), and coumarins (eg, 7-diethylamino-4-methylcoumarin).

  Preferred examples of the sensitizing dye in the present invention include compounds represented by the following formulas (vi) to (xiv).

In formula (vi), A ¹ represents a sulfur atom or NR ⁵⁰ , and R ⁵⁰ represents an alkyl group or an aryl group. L ¹ represents a nonmetallic atomic group that forms a basic nucleus of a dye in cooperation with the adjacent A ¹ and the adjacent carbon atom. R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁵¹ and R ⁵² may be bonded to each other to form an acidic nucleus of the dye. W represents an oxygen atom or a sulfur atom.

In formula (vii), Ar ¹ and Ar ² each independently represent an aryl group and are linked via a bond with L ² . L ² represents —O— or —S—. W is synonymous with that shown in formula (vi).

In formula (viii), A ² represents a sulfur atom or NR ⁵⁹ , and R ⁵⁹ represents an alkyl group or an aryl group. L ³ represents a nonmetallic atomic group that forms a basic nucleus of a dye in cooperation 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.

In formula (ix), A ³ and A ⁴ each independently represent —S—, —NR ⁶² —, or —NR ⁶³ —, and R ⁶² and R ⁶³ each independently represent a substituted or unsubstituted group. An alkyl group or a substituted or unsubstituted aryl group is represented. L ⁴ and L ⁵ each independently represent a nonmetallic atomic group that forms a basic nucleus of a dye in cooperation with adjacent A ³ , A ⁴ and adjacent carbon atoms. R ⁶⁰ and R ⁶¹ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group. R ⁶⁰ and R ⁶¹ may be bonded to each other to form an aliphatic or aromatic ring.

In the formula (x), R ⁶⁶ represents an aromatic ring or a hetero ring which may have a substituent. A ⁵ denotes 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 nonmetallic atomic group. R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ may be bonded to each other to form an aliphatic or aromatic ring.

In the formula (xi), A ₂ represents a sulfur atom or NR ⁵⁹ , L ⁴ represents a nonmetallic atomic group that forms a basic nucleus of a 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 formula (xii), A ³ and A ⁴ each independently represent —S—, —NR ⁶² — or —NR ⁶³ —, wherein R ⁶² and R ⁶³ each independently represent a substituted or unsubstituted alkyl group, substituted or represents an unsubstituted aryl group, L to ^5, L ⁶ are each independently, together with the adjacent a ^3, a ⁴ and adjacent carbon atoms represents a nonmetallic atom group necessary for forming a basic nucleus of a dye, R ⁶⁰ , R ⁶¹ each independently represents a hydrogen atom or a monovalent non-metallic atomic group, or may be bonded to each other to form an aliphatic or aromatic ring.

In formula (xiii), R ⁶⁶ represents an aromatic ring or a hetero ring which 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 nonmetallic atomic group, and R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ each represent an aliphatic or aromatic ring. Can be combined to form.

In formula (xiv), R ₆₈ and R ₆₉ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group. R ₇₀ and R ₇₁ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and n represents an integer of 0 to 4. When n is 2 or more, R ₇₀ and R ₇₁ can be bonded to each other to form an aliphatic or aromatic ring.

  Specific preferred examples of the compounds represented by formulas (vi) to (xiv) include (C-1) to (C-26) shown below, but are not limited thereto. These sensitizing dyes are preferably used in combination with a photocationic polymerization initiator of a sulfonium salt, iodonium salt or pyridinium salt.

The content of the sensitizing dye in the ink composition of the present invention is preferably 0.01 to 20% by mass, and preferably 0.1 to 15% by mass with respect to the total solid content of the ink composition, from the viewpoint of ink colorability. Is more preferable, and still more preferably in the range of 0.5 to 10% by mass.
A sensitizing dye may be used individually by 1 type, and may use 2 or more types together.
The content ratio of the sensitizing dye and the photocationic polymerization initiator in the ink composition is a mass ratio of a / c = from the viewpoint of improving the decomposition rate of the polymerization initiator and transmitting light. 100-0.5 are preferable, a / c = 50-1 are more preferable, and a / c = 10-1.5 are still more preferable.

[Polymerization inhibitor]
In the present invention, it is preferable to use in combination with a polymerization inhibitor that inhibits the progress of polymerization other than cationic polymerization in order to effectively progress the polymerization by the photocationic polymerization initiator.
Suitable polymerization inhibitors include phenolic hydroxyl group-containing compounds and quinone compounds, N-oxide compounds, piperidine 1-oxyl free radical compounds, pyrrolidine 1-oxyl free radical compounds, N-nitrosophenylhydroxylamine compounds, and cationic dyes. A compound selected from the group consisting of Preferred polymerization inhibitors include haloquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, resorcinol, catechol, t-butylcatechol, hydroquinone, benzoquinone, 4,4-thiobis (3-methyl-6- t-butylphenol), 2,2′-methylenebis (4-methyl-6-t-butylphenol), 2,2,6,6-tetramethylpiperidine and its derivatives, di-t-butylnitroxide, 2,2,6 1,6-tetramethylpiperidine-N-oxide and its derivatives, such as piperidine 1-oxyl free radical, 2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-oxo-2,2,6,6 -Tetramethylpiperidine 1-oxyl free radical, 4-hydroxy-2,2,6,6-tetramethylpiperi 1-oxyl free radical, 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-maleimido-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4 -Phosphonoxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 3-carboxy-2,2,5,5-tetramethylpyrrolidine 1-oxyl free radical, N-nitrosophenylhydroxylamine cerium Salt, N-nitrosophenylhydroxylamine aluminum salt, crystal violet, methyl violet, ethyl violet and Victoria pure blue BOH. The addition amount of the polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the total solid content of the composition.

[Colorant]
A colorant can be preferably added to the ink composition of the present invention in order to form a visible image.
There is no restriction | limiting in particular in the coloring agent which can be used here, According to a use, well-known various color materials and (pigment, dye) can be selected suitably, and can be used. For example, when forming an image excellent in weather resistance, a pigment is preferable. As the dye, both water-soluble dyes and oil-soluble dyes can be used as long as they are soluble in the polymerizable compound. In the present invention, in order to form an image or characters, the ink composition of the present invention preferably contains a pigment or an oil-soluble dye as a colorant.
These colorants are preferably added in an amount of 0.5 to 20% by mass in the ink composition, more preferably 1 to 15% by mass, and still more preferably 5 to 15% by mass.

The pigment preferably used in the present invention will be described.
[Pigment]
The pigment is not particularly limited, and all commercially available organic and inorganic pigments or pigments dispersed in an insoluble resin or the like as a dispersion medium, or the resin is grafted onto the pigment surface Can be used. Moreover, what dye | stained the resin particle with dye can be used.
Examples of these pigments include, for example, “Spirit of Pigments” edited by Seijiro Ito (2000), W. Herbst, K. Hunger, “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A. Examples thereof include pigments described in JP-A No. 2003-26978 and JP-A No. 2003-342503.

  Specific examples of organic pigments and inorganic pigments that can be used in the present invention include 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) or the like 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 as necessary.

For dispersion of the pigment, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, or a wet jet mill is used. Can do.
It is also possible to add a dispersant when dispersing the pigment. Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a high molecular weight unsaturated acid ester, a high molecular weight copolymer, a modified polyacrylate, an aliphatic polyacrylate. Carboxylic acid, naphthalenesulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester, pigment derivative and the like. It is also preferable to use a commercially available polymer dispersant such as the Solsperse series from Zeneca.
Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment.

  In the ink composition, as a dispersion medium for various components such as pigments, a solvent may be added, and the cationic polymerizable compound that is a low molecular weight component without a solvent may be used as a dispersion medium. The ink composition of the invention is a radiation curable ink, and is preferably solvent-free in order to be cured after the ink is applied to a recording medium. This is because if the solvent remains in the cured ink image, the solvent resistance is deteriorated or a problem of VOC (Volatile Organic Compound) of the remaining solvent occurs. From such a viewpoint, it is preferable to use a cationically polymerizable compound as the dispersion medium, and in particular, to select a cationically polymerizable monomer having the lowest viscosity from the viewpoint of dispersion suitability and handling property of the ink composition.

The average particle diameter of the pigment is preferably 0.02 to 0.4 μm.
The average particle size of the pigment particles is preferably 0.08 to 0.5 μm, and the maximum particle size is 0.3 to 10 μm, preferably 0.3 to 3 μm. Set selection, dispersion conditions, and filtration conditions. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained.

[dye]
Next, the dyes preferably used as the colorant in the present invention will be described.
The dye can be appropriately selected from conventionally known compounds (dyes). Specific examples include the dyes described in paragraphs [0023] to [0089] of JP-A No. 2002-114930.

Examples of yellow dyes include, for example, phenols, naphthols, anilines, pyrazolones, pyridones, aryl or heteryl azo dyes having open-chain active methylene compounds as coupling components, for example, open-chain active methylene compounds as coupling components Azomethine dyes having, for example, methine dyes such as benzylidene dyes and monomethine oxonol dyes, for example, quinone dyes such as naphthoquinone dyes and anthraquinone dyes, and other dyes include quinophthalone dyes, nitro, Nitroso dyes, acridine dyes, acridinone dyes and the like can be mentioned. As the yellow dye, a compound having a structure represented by the general formula (Y-I) described in JP-A No. 2004-250483 is preferable.
Particularly preferred yellow dyes are dyes represented by the general formulas (Y-II) to (Y-IV) described in paragraph No. [0034] of JP-A No. 2004-250483. Examples include the compounds described in paragraph numbers [0060] to [0071] of 2004-250483. The oil-soluble dye of the general formula (Y-I) described in the publication may be used not only for yellow but also for any color ink such as black ink and red ink.

Examples of the magenta dye include phenols, naphthols, anilines, pyrazolones, pyridones, pyrazolotriazoles, and ring-closing active methylene compounds (for example, dimedone, barbituric acid, 4-hydroxycoumarin) as coupling components. Derivatives), electron-rich heterocycles (eg, pyrrole, imidazole, thiophene, thiazole derivatives), or aryl or heteryl azo dyes, eg, azomethine dyes having pyrazolones, pyrazolotriazoles as coupling components, eg, arylidene dyes, styryl Dyes, merocyanine dyes, methine dyes such as oxonol dyes, carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, such as naphthoquinone, anthraquinone, anthrone Quinone dyes such Rapiridon, can be mentioned condensed polycyclic dyes such as, for example, dioxazine dye.
The magenta dye is preferably a compound having a structure represented by the general formulas (3) and (4) described in JP-A No. 2002-114930. Specific examples thereof include paragraphs [0054] of JP-A No. 2002-114930. ] To [0073].
Particularly preferred magenta dyes are azo dyes represented by general formulas (M-1) to (M-2) described in paragraph numbers [0084] to [0122] of JP-A No. 2002-121414, Specific examples include the compounds described in JP-A No. 2002-121414, paragraph numbers [0123] to [0132]. The oil-soluble dyes represented by the general formulas (3), (4) and (M-1) to (M-2) described in the publication are used not only for magenta but also for any color ink such as black ink and red ink. May be.

Examples of cyan dyes include azomethine dyes such as indoaniline dyes and indophenol dyes, cyanine dyes, oxonol dyes, polymethine dyes such as merocyanine dyes, diphenylmethane dyes, triphenylmethane dyes, carbonium dyes such as xanthene dyes, Examples of phthalocyanine dyes and anthraquinone dyes include phenols, naphthols, anilines, pyrrolopyrimidin-one, aryl or heteryl azo dyes having pyrrolotriazin-one derivatives, and indigo / thioindigo dyes as coupling components.
Examples of cyan dyes include dyes represented by formulas (I) to (IV) described in JP-A No. 2001-181547, and paragraphs [0063] to [0078] of JP-A No. 2002-121414. The dyes represented by the general formulas (IV-1) to (IV-4) are preferable, and specific examples include paragraph numbers [0052] to [0066] of JP-A No. 2001-181547 and JP-A No. 2002. And the compounds described in paragraph Nos. [0079] to [0081] of JP-A-12414. Particularly preferred cyan dyes are phthalocyanine dyes represented by general formulas (CI) and (C-II) described in paragraph numbers [0133] to [0196] of JP-A No. 2002-121414, Furthermore, the phthalocyanine dye represented by general formula (C-II) is preferable. Specific examples thereof include compounds described in paragraphs [0198] to [0201] of JP-A No. 2002-121414. The oil-soluble dyes of the formulas (I) to (IV), (IV-1) to (IV-4), (CI) and (C-II) are not only cyan but also black ink or green ink. It may be used for inks of any color.

  Each of the dyes may exhibit yellow, magenta, and cyan colors only after a part of the chromophore is dissociated. In this case, the counter cation is an inorganic cation such as an alkali metal or ammonium. Alternatively, it may be an organic cation such as pyridinium, quaternary ammonium salt, or a cationic polymer having a partial structure thereof.

  The dye used in the present invention is preferably oil-soluble. Specifically, it means that the solubility in water at 25 ° C. (the mass of the dye dissolved in 100 g of water) is 1 g or less, preferably 0.5 g or less, more preferably 0.1 g or less. Therefore, a so-called water-insoluble oil-soluble dye is preferably used.

[Other ingredients]
Hereinafter, various additives that can be contained in the ink composition of the present invention as needed are described.
[Ultraviolet absorber]
From the viewpoint of improving the weather resistance of the image obtained, preventing discoloration, and preventing solidification of the nozzle, an ultraviolet absorber can be used.
Examples of the ultraviolet absorber are described in JP-A-58-185679, JP-A-61-190537, JP-A-2-782, JP-A-5-97075, JP-A-9-34057, and the like. Benzotriazole compounds, benzophenone compounds described in JP-A No. 46-2784, JP-A No. 5-194433, US Pat. No. 3,214,463, etc. Cinnamic acid compounds described in JP-A-10-88106, JP-A-4-298503, JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, JP The triazine compounds described in JP-A-8-501291, Research Disclosure No. Examples thereof include compounds described in No. 24239, compounds that emit ultraviolet light by absorbing ultraviolet rays typified by stilbene and benzoxazole compounds, so-called fluorescent brighteners, and the like.
The addition amount is appropriately selected according to the purpose, but is preferably 0.01 to 5% by mass of the ink composition. Addition of an ultraviolet absorber in an amount exceeding 5% by mass is not preferable because a problem of poor curing occurs.

〔Antioxidant〕
An antioxidant can be added to improve the stability of the ink composition. Examples of the antioxidant include European published patents, 223739, 309401, 309402, 310551, 310552, 359416, and 3435443. JP, 54-85535, 62-262417, 63-113536, 63-163351, JP-A-2-262654, JP-A-2-71262, Examples thereof include those described in Kaihei 3-121449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.
The addition amount is appropriately selected according to the purpose, but is generally about 0.001 to 1% by mass of the ink composition.

[Anti-fading agent]
In the ink composition of the present invention, various organic and metal complex anti-fading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Examples of the metal complex anti-fading agent include nickel complexes and zinc complexes. No. 17643, No. VII, I to J, ibid. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. It is possible to use the compounds described in the patent publication cited in No. 15162, or the compounds contained in the general formulas and compound examples of the representative compounds described on pages 127 to 137 of JP-A-62-215272. it can.
The addition amount is appropriately selected depending on the purpose, but is generally about 0.001 to 5% by mass of the ink composition.

[Conductive salts]
Conductive salts such as potassium thiocyanate, lithium nitrate, ammonium thiocyanate, and dimethylamine hydrochloride can be added to the ink composition of the present invention for the purpose of controlling ejection properties.
The addition amount is appropriately selected according to the purpose, but is generally about 0.001 to 1.0% by mass of the ink composition.

〔solvent〕
In order to improve the adhesion to the recording medium, it is also effective to add a very small amount of an organic solvent to the ink composition of the present invention.
Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone, alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol, and chlorine such as chloroform and methylene chloride. Solvents, aromatic solvents such as benzene and toluene, ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, glycols such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether And ether solvents.
In this case, it is effective to add the solvent within a range that does not cause the problem of solvent resistance and VOC, and the amount is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass with respect to the whole ink composition. % Range.

[Polymer compound]
Various polymer compounds can be added to the ink composition in order to adjust film properties. Examples of the polymer compound include styrene polymers, acrylic polymers, cyclic ether polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, and polyvinyl formal resins. Shellac, vinyl resin, acrylic resin, rubber resin, wax, and other natural resins can be used. Two or more of these may be used in combination. Of these, copolymerization of styrene monomers, acrylic monomers, and cyclic ethers is preferred. Furthermore, as a copolymer composition of the polymer binder, a copolymer containing “cyclic ether group-containing monomer” and “vinyl ether group-containing monomer” as a structural unit is also preferably used.
The addition amount is appropriately selected according to the purpose, but is generally about 0.01 to 10.0% by mass of the ink composition.

[Surfactant]
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. An organic fluoro compound may be used in place of the surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compounds include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). No. (columns 8 to 17) and those described in JP-A Nos. 62-135826.
The addition amount is appropriately selected according to the purpose, but is generally about 0.001 to 5.0% by mass of the ink composition.

In addition to this, if necessary, for example, leveling additives, matting agents, waxes for adjusting film physical properties, polymerization to inhibit the adhesion to recording media such as polyolefin and PET, and the like, The tackifier which does not do can be contained.
As a tackifier, specifically, a high molecular weight adhesive polymer described in JP-A-2001-49200, pages 5 to 6 (for example, (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms). A copolymer comprising an ester with an alcohol having a carboxylic acid, an ester of (meth) acrylic acid and an alicyclic alcohol having 3 to 14 carbon atoms, an ester of (meth) acrylic acid and an aromatic alcohol having 6 to 14 carbon atoms And low molecular weight tackifier resins having a polymerizable unsaturated bond.

  The ink composition of the present invention is preferably maintained at a substantially constant temperature in the range of 25 to 90 ° C. when ejected with an actual machine, and the viscosity at that time is preferably 2 to 35 mPa · s. It is preferable to adjust the composition ratio appropriately so as to be in the above range. The ink viscosity at 25 ° C. is 2 to 100 mPa · s, preferably 2 to 50 mPa · s.

  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.

[Inkjet recording method and inkjet recording apparatus]
The ink composition of the present invention thus prepared is suitably used as an ink for inkjet recording. When ink-jet recording is performed using the ink composition of the present invention, a step of ejecting the ink composition of the present invention onto a recording medium by an ink-jet printer and curing by irradiating the ejected ink composition with active energy rays Including the step of. As a result, characters and / or images are recorded on the recording medium using the ejected ink composition.
In the recorded matter obtained using the ink composition of the present invention, the image portion is cured by irradiation with radiation 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.

  Next, an ink jet recording method and an ink jet recording apparatus that can be suitably employed in the present invention will be described below.

  In the ink jet recording method of the present invention, recording is performed using the ink for ink jet recording, but there are no particular limitations on the ink nozzles and the like used at that time, and they can be appropriately selected according to the purpose. As a system for printing using the above ink, a form as shown in Japanese Patent Application Laid-Open No. 2002-11860 is given as an example, but the present invention is not limited to this, and other forms may be used.

  In the ink jet recording method, it is preferable that the ink composition is heated to 25 to 90 ° C. to lower the viscosity of the ink composition to 2 to 35 mPa · s and then ejected. Stability can be achieved. In general, radiation curable ink compositions generally have a higher viscosity than aqueous inks, so that the viscosity fluctuation range due to temperature fluctuations during printing is large. 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.

Next, energy beam irradiation conditions 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, a method using an optical fiber or a method of irradiating a recording unit with UV light by applying a collimated light source to a mirror surface provided on the side of the head unit is disclosed as an irradiation method. In the present invention, these irradiation methods can be used. As the active energy ray to be irradiated, a commonly used mercury lamp, metal halide lamp, or the like may be used, or a light source such as a light emitting diode (LED), a semiconductor laser, or a fluorescent lamp may be used. Further, a hot cathode tube, a cold cathode tube, an electron beam, an X-ray or the like, a light source that progresses a polymerization reaction of ink, electromagnetic waves, or the like can be used. In the present invention, it is preferable to use a light emitting diode as a light source.
When using a metal halide lamp, the lamp should be designed 10~1000W / cm ^2, it is preferable that the illuminance of 1mW / cm ² ~100W / cm ² at the media surface. The exposure energy is preferably 0.1 mJ / cm ^{2 to} 100 J / cm ² . When a light emitting diode is used, the maximum value of the emission wavelength is preferably 250 nm to 400 nm, the light emitting diode is preferably 1 mW / cm ^{2 to} 1000 W / cm ² , and 0.1 mW / cm ^{2 to} 100 W / cm in terms of media. An illuminance of cm ² is preferred. The exposure energy is preferably 0.1 mJ / cm ^{2 to} 10 J / cm ² .
Further, in a mercury lamp, a metal halide lamp, or the like that uses high-pressure discharge, ozone is generated due to discharge, and therefore it is preferable to have an exhaust means. The exhaust means is preferably arranged so as to also collect ink mist generated during ink ejection.
In the case of curing by radical polymerization, since the polymerization is inhibited by oxygen, it can be cured with low energy by exposure in a low oxygen concentration state, that is, in a gas atmosphere such as nitrogen.
When energy such as light for curing is applied to the ink discharge nozzle, the ink mist adhering to the surface of the nozzle may solidify, which may hinder ink discharge. In order to keep it to a minimum, it is preferable to take measures such as shading. Specifically, it is preferable to provide a partition that prevents the nozzle plate from being irradiated, or to provide a means for limiting the incident angle to the medium so as to reduce stray light.

  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, more preferably 0.01 to 0.3 seconds. More preferably, the irradiation is performed 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 inkjet recording method described above and the ink composition of the present invention in combination, a great synergistic effect is brought about. In particular, when an ink composition having an ink viscosity of 35 to 500 mP · s 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 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.

[Ink holding means]
As a means for holding ink, it is preferable to fill a known ink cartridge, and it is possible to store the ink in a deformable container and form a tank as disclosed in JP-A-5-16377. In addition, as disclosed in Japanese Patent Laid-Open No. 5-13882, when a sub tank is provided, the supply of ink to the head is further stabilized. Further, as disclosed in Japanese Patent Application Laid-Open No. 8-174860, it is also possible to use a cartridge that supplies ink by moving a valve when the pressure in the ink supply chamber decreases. As a negative pressure applying method for appropriately holding the meniscus in the head with these ink holding means, a method using the height of the ink holding means, that is, a water head pressure, or a method using a capillary force of a filter provided in the ink flow path In addition, a method of controlling the pressure with a pump or the like, and a method of holding the ink on the ink absorber and applying a negative pressure by this capillary force as disclosed in Japanese Patent Application Laid-Open No. 50-74341 are appropriate. It is.

[Ink supply path]
As a method of supplying ink from these ink holding means to the head, a method of directly connecting the holding means to the head unit or a method of connecting by a flow path such as a tube may be used. The ink holding means and the flow path are preferably made of a material having good wettability with respect to the ink or subjected to a surface treatment.

  As a method for ejecting ink, as disclosed in Japanese Patent Laid-Open No. 5-104725, whether or not ink droplets are ejected continuously and the droplets are deflected according to an image to land on a medium is determined. A selection control method may be used, or a so-called on-demand method may be used, in which ink droplets are ejected only to a portion necessary as an image. As disclosed in JP-A-5-16349, the on-demand system may be a system that generates and discharges ink pressure by deformation of a structure using a piezoelectric element or the like. As disclosed in Japanese Patent No. 234255, a method of discharging at a pressure generated by expansion accompanying vaporization by thermal energy may be used. Further, as disclosed in Japanese Patent Application Laid-Open No. 2001-277466, a method of controlling ejection to a medium by an electric field may be used.

For example, a form described in Japanese Patent Laid-Open No. 5-31908 can be applied to the nozzle.
At this time, in order to eject ink of a plurality of colors, the nozzles are configured in a plurality of rows as described in JP-A-2002-316420, so that a color image can be formed at a high speed. The speed can be further increased by arranging a plurality of head units having a plurality of nozzle rows.

Furthermore, as described in Japanese Patent Laid-Open No. 63-160849, the nozzles are arranged by a width equal to or greater than the width of the image, so-called line heads, and by moving the media simultaneously with droplet ejection from these nozzles Therefore, it is possible to form an image at high speed.
Further, the surface of the nozzle is subjected to a surface treatment as disclosed in Japanese Patent Application Laid-Open No. 5-116327, thereby preventing ink droplets from adhering to the nozzle surface and preventing ink droplets from adhering.
Even if such a treatment is performed, dirt may still adhere. Therefore, it is preferable to perform cleaning with a blade as disclosed in JP-A-6-71904.
In addition, the inks of the respective colors are not necessarily ejected from the nozzles uniformly, and specific inks may not be ejected for a long time. In such a case, in order to keep the meniscus stable, as disclosed in Japanese Patent Application Laid-Open No. 11-157102, ink is appropriately ejected outside the image area, and new ink is supplied to the head, thereby providing ink physical properties. Is preferably maintained at a suitable value.
Further, even if such treatment is performed, bubbles may enter the head or be generated in the head. In such a case, as described in Japanese Patent Application Laid-Open No. 11-334092, by forcibly sucking ink from outside the head, the ink whose physical properties have changed is discarded, and bubbles are also discharged outside the head. be able to. When droplets are not ejected for a long time, the nozzle surface can be protected by covering the nozzle surface with a cap, as disclosed in JP-A-11-138830. Even if these measures are taken, there is a case where the liquid is still not discharged.
If an image is printed in a state where some of the nozzles do not discharge, problems such as unevenness in the image occur. In order to avoid such a situation, it is effective to take a measure by detecting that no discharge has occurred, as disclosed in Japanese Patent Laid-Open No. 2000-343686.

In discharging the ink, it is preferable to keep the ink temperature constant with a predetermined accuracy in order to keep the viscosity constant. For this purpose, it is preferable to have an ink temperature detecting means, an ink heating means, and a control means for controlling heating according to the detected ink temperature.
It is also preferable to have a means for controlling energy applied to the means for ejecting ink according to the ink temperature.
When the head unit is mechanically moved as described in Japanese Patent Laid-Open No. 6-1515099 and the superimposed droplets are ejected by intermittently moving the medium in the orthogonal direction in synchronization with the head unit, This has the effect of making it difficult to see the unevenness caused by poor movement accuracy, and can achieve high image quality. At this time, the relationship between the image quality and the recording speed can be set to a preferable relationship by appropriately setting the relationship between the moving speed of the head, the moving amount of the medium, and the number of nozzles.
On the contrary, the same effect can be obtained by fixing the head and mechanically reciprocating the medium in a predetermined direction and intermittently moving the medium in a direction orthogonal thereto.

[System parameters]
In forming an image, the ink landing diameter on the medium is preferably between 10 and 500 μm, and for this purpose, the diameter of the ink droplets during ejection is preferably between 5 and 250 μm. The nozzle diameter is preferably 15 to 100 μm.
In order to form an image, the number of pixels per inch is preferably 50 to 2400 dpi, and for that purpose, the nozzle density of the head is preferably 10 to 2400 dpi. Here, even if the nozzle density of the head is low, it is possible to achieve high-density landing with a head with a large nozzle interval by tilting with respect to the media transport direction or by disposing a plurality of head units relative to each other. Is possible. In addition, by reciprocating the head or media as described above, each time the head moves at a low nozzle pitch, the media is transported by a predetermined amount, and ink droplets are landed at different positions, thereby realizing high-density image recording. Can do.
The amount of ink ejected onto the media is preferably controlled to an arbitrary amount between 0.05 and 25 g / m ² in order to express good gradation, and in order to realize this, the ink ejected from the head It is preferred to control the drop size and / or quantity.
If the distance between the head and the medium is too wide, the flying of the ink droplets is disturbed by the air flow accompanying the movement of the head or the medium, and the landing position accuracy is lowered. On the other hand, if the interval is narrow, there is a risk that the head and the medium come into contact with each other due to unevenness of the medium, vibration caused by the transport mechanism, and the like, and it is preferably maintained at about 0.5 to 2 mm.

[Ink set]
The ink may be a single color, may be cyan, magenta, or yellow, or may be four colors including black or a specific color other than these, called a special color. The coloring material may be a dye or a pigment. These inks may be ejected in order of landing in order of increasing lightness, may be landed in order of increasing lightness, or are preferably ejected in an order suitable for image recording quality.
The image signal to be recorded is preferably subjected to signal processing to obtain good color reproduction as described in, for example, Japanese Patent Laid-Open No. 6-210905.

[Recording medium]
The ink composition of the present invention can suitably perform recording such as printing on a known recording medium.
The recording medium to which the ink composition of the present invention can be applied is not particularly limited, and can be used for ordinary plain paper, uncoated paper, coated paper, inkjet special paper, electrophotographic co-paper, and so on, so-called soft packaging. Various non-absorbing resin materials used or resin films formed into films can be used. Examples of various plastic films include PET film, OPS film, OPP film, ONy film, PVC film, and PE film. TAC film and the like. In addition, examples of the plastic that can be used as a recording medium material include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers. Metals, glasses, fabrics, ceramics, etc. can also be used as recording media. As the recording material, those described in paragraph numbers (0228) to (0246) of JP-A Nos. 2001-181549 and 2001-279141 can also be used.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. Moreover,% in an Example is a mass reference | standard unless there is particular notice.

[Examples 1-6, Comparative Examples 1-3]
A polymerizable compound, a polymerization initiator, and a colorant were stirred and mixed in a quantity part (part by mass) in Table 2 to obtain a dye ink or a pigment ink.
The compounds in Table 2 are as follows.

* 5: 3,7-bis (3-oxetanyl) -5-oxa-nonane (OXT-221, trade name, manufactured by Toagosei Co., Ltd.)
* 6: 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate (Celoxide 2021A, trade name, manufactured by Daicel UC Corporation)
* 7: Photocationic polymerization initiator, triphenylsulfonium salt (UVI-6992, trade name, manufactured by Dow Chemical Company)
* 8: Sensitizing dye: 9,10-dibutoxyanthracene described in paragraph [0121] (C-26)
* 9: Pigment dispersion. 10 g of CI Pigment Yellow 12, 5 g of a polymeric dispersant (Solsprse series manufactured by Avecia), and a cationically polymerizable compound and a chemical compound, chemical compound 1, chemical compound 2, chemical compound 3, chemical compound or chemical compound in the proportions described in the corresponding Examples or Comparative Examples. 200 g of the solution mixed with 4 was dispersed using a known dispersing device so that the particle size of the pigment particles was in the range of 0.1 to 0.2 μm, and then filtered with a heating filter.

The obtained ink was ejected using a piezo-type head. The head has a nozzle density of 150 per 25.4 mm and has 318 nozzles with a diameter of 30 μm. By fixing these two nozzles in the nozzle row direction, the nozzle spacing is fixed by ½, and the nozzles are placed on the media. 300 drops per 25.4mm in the array direction. The head and ink were controlled so that the vicinity of the ejection portion was 50 ± 0.5 ° C. by circulating hot water in the head.
Ink ejection from the head is controlled by a piezo drive signal applied to the head, and ejection of 6 to 42 pl per drop is possible. In this embodiment, the medium was ejected from the head while being conveyed at a position 1 mm below the head. The conveyance speed can be set in the range of 50 to 200 mm / s. The piezo drive frequency can be up to 4.6 KHz, and the droplet ejection volume can be controlled by these settings. In this example, the ink ejection amount was controlled by setting the conveyance speed to 90 mm / s and the drive frequency to 4.3 KHz, and droplets were ejected up to a maximum of 23 g / m ² .
After ejecting the media, it was transported to the exposure section and exposed by an ultraviolet light emitting diode (UV-LED). In this example, NCCU033 (trade name) manufactured by Nichia Chemical was used as the UV-LED. This LED outputs ultraviolet light with a wavelength of 365 nm from one chip. When a current of about 500 mA is applied, about 100 mW of light is emitted from the chip. A plurality of these are arranged at intervals of 7 mm, and a power of 0.3 W / cm ² can be obtained on the media surface. The exposure time after the droplet ejection and the exposure time can be changed according to the transport speed of the medium and the distance between the head and the LED in the transport direction. In this embodiment, the exposure is performed about 0.5 seconds after landing.
Depending on the setting of the distance to the medium and the conveyance speed, the exposure energy on the medium can be adjusted between 0.01 and 15 J / cm ² . For measurement of the exposure power and the exposure energy, a spectroradiometer URS-40D (trade name) manufactured by USHIO ELECTRIC CO., LTD. Was used, and a value obtained by integrating between wavelengths 220 nm to 400 nm was used.

(Ink viscosity)
The viscosity of the prepared ink at 25 ° C. was measured using a viscometer RE-80 (trade name) manufactured by Toki Sangyo. A sample having a viscosity of 15 mPa · s or less was evaluated as A, a sample having a viscosity of 35 mPa · s or less as B, and a sample having a viscosity exceeding 35 mPa · s as C.
(Discharge stability)
When solid printing was performed on the A4 size by the above method, A was printed with no blurring until the end, B was evaluated for slight discharge unevenness, and C was evaluated for significant discharge unevenness. .
(Curable)
The printed surface was evaluated by a tack-free test. Irradiation light quantity until hardening without stickiness is 0.1 J / cm ² or less A, 0.1 J / cm ² to 0.50 J / cm ² or less B, 0.50 J / cm ² The thing was evaluated as C.
(Adhesion)
A solid film printed on a polyethylene terephthalate film (150 μm thick) is cut with a cutter in a grid pattern, and then an adhesive tape is applied to the surface, and then the adhesive tape is peeled off on the substrate. The remaining state of the cured film was visually observed. The case where peeling was not observed was evaluated as A, the case where partial peeling was observed was evaluated as B, the case where remarkable peeling was observed was evaluated as C, and the case where curing was insufficient and could not be evaluated was evaluated as D.
(Ink stability)
1 g of the adjusted ink was put in a test tube having a diameter of 5 ml and allowed to stand at room temperature for 2 weeks.
(Flexibility)
A film that has a solid print on a polyethylene terephthalate film (150 μm thick) and is folded 180 degrees so that the uncoated surface is aligned with the uncoated surface is A. The case where cracking was observed was evaluated as B, and the case where cracking and peeling occurred was evaluated as C.
(curl)
A pattern of 8 cm square and 10 μm thickness was solid printed on the center of a 10 cm square polyvinyl chloride film (50 μm thickness), and the curl of the sample was measured after drying for 2 hours at room temperature. When the sample was allowed to stand on a horizontal base, the sum of the heights from the horizontal surfaces of the four corners was evaluated as A, the sample having a height of 2 cm or more and less than 5 cm was evaluated as B, and the sample having a height of 5 cm or more was evaluated as C. In addition, what was hardened | cured was evaluated as D.

As shown in Table 2, when the ink composition of the present invention containing the compound represented by the general formula ( 2) is used, the ink viscosity is low and the ejection stability, curability and adhesion are all low. Good evaluations were all obtained regarding flexibility. Thus, by using the ink composition of the present invention, an ink for ink jet recording and an ink jet recording method that are excellent in ink stability, can form a good image, and have excellent curability and adhesion to a recording medium. I found that I could provide it.

Claims (12)

A compound represented by the following general formula (2), an ink composition characterized by a molecular weight containing more than 130 compounds.

In (formula ^(2), are each R 7 ~ ^{R 9} independently represents a hydrogen atom, an alkyl group, the alkoxycarbonyl Motoma other represents a group these oxirane ring is substituted. ^R 10 ^{to R 14} is Each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a group having an oxirane ring substituted thereon, provided that at least one of R ^{7 to} R ¹⁴ is a substituent other than a hydrogen atom. Wherein R ¹⁰ to R ¹⁴ is a hydrogen atom, an alkyl Motoma other ink composition according to claim 1, oxirane rings the alkyl group being a substituted group. Wherein R ⁷ or a group of to R ¹⁴ is an ink composition according to claim 1 or 2, characterized in that a substituted group oxirane ring. Wherein R ¹² is an ink composition according to any one of claims 1 to 3, wherein an alkyl group. Wherein R ⁹ is an ink composition according to any one of claims 1 to 4, characterized in that an alkyl group having 1 to 5 carbon atoms. The compound represented by the general formula ( 2) is contained in an ink composition in an amount of 2% by mass to 70% by mass, and further contains a photoacid generator and a cationically polymerizable compound. The ink composition according to any one of 5 to 5 . As the cationically polymerizable compound, further according to any one of claim 1 6, characterized in that it contains 25 wt% or less than 75 wt% of a monofunctional oxirane compound and / or a monofunctional oxetane compound in a total Ink composition. The ink composition according to any one of claims 1 to 7, characterized in that is used for inkjet. A radiation curable ink comprising the ink composition according to any one of claims 1 to 8 . A step of ejecting the ink composition according to any one of claims 1 to 8 onto a recording medium by an ink jet printer and a step of irradiating the cured ink composition with an active energy ray and curing the ink composition. An ink jet recording method. 11. The ink jet recording method according to claim 10 , wherein a light emitting diode is used as a light source of active energy rays to be irradiated. Recorded matter recorded using the ink composition according to any one of claims 1-8.