JP2009197194A - Ink composition, ink cartridge, inkjet recording method, and printed matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition excellent in curability and thermal stability with time over wide temperature range, an ink cartridge storing the ink composition, an inkjet recording method using the ink composition, and printed matter. <P>SOLUTION: The ink composition comprises a polymerizable compound, a polymerization inhibitor, and a polymerization initiator. In the ink composition, the polymerizable compound contains an N-vinyl compound, while the polymerization inhibitor contains a quinone methylide compound. The ink cartridge storing the ink composition, the inkjet recording method using the ink composition, and the printed matter are also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink composition, an ink cartridge, an inkjet recording method, and a printed matter.

As an image recording method for forming an image on a recording medium such as paper based on an image data signal, there are an electrophotographic method, a sublimation type and a melt type thermal transfer method, an ink jet method and the like. The electrophotographic system requires a process of forming an electrostatic latent image on a photosensitive drum by charging and exposure, and there is a problem that the system becomes complicated and consequently the manufacturing cost becomes high. In addition, although the thermal transfer system is inexpensive, there are problems such as high running costs and waste materials due to the use of ink ribbons.
On the other hand, the ink jet method is an inexpensive device and ejects ink only to the required image portion to form an image directly on the recording medium, so that the ink composition can be used efficiently and the running cost is low. . Furthermore, there is little noise and it is excellent as an image recording method.

Moreover, an ink composition containing N-vinyl lactams is disclosed as an ink composition (Patent Document 1).
Furthermore, a photocurable ink composition containing at least allyl glycol and / or an N-vinyl compound as a monofunctional monomer of the polymerizable compound and containing a hindered amine light stabilizer (HALS) and / or hydroquinone monomethyl ether as a polymerization inhibitor. A photocurable ink composition comprising 20 to 80% by mass of the monofunctional monomer and 0.05 to 0.5% by mass of the polymerization inhibitor in an ink composition. It is disclosed (Patent Document 2).

Japanese Patent No. 2880845 JP 2007-138084 A

  The problems to be solved by the present invention include an ink composition excellent in curability and thermal stability over time in a wide temperature range, an ink cartridge containing the ink composition, and an ink jet recording using the ink composition It is to provide a method and printed matter.

The above object has been achieved by the means described in <1>, <5>, <6> and <8> below. It is shown below with <2>-<4> and <7> which are preferable embodiments.
<1> An ink composition comprising a polymerizable compound, a polymerization inhibitor, and a polymerization initiator, wherein the polymerizable compound contains an N-vinyl compound, and the polymerization inhibitor contains a quinone methylide compound,
<2> The ink composition according to <1>, wherein the polymerization initiator includes an acylphosphine compound.
<3> The polymerizable compound is 2-acryloyloxyethyl monohydroxyphthalate, 2-acryloyloxypropyl monohydroxyphthalate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, isobornyl. <1> or <2>, comprising at least one monofunctional polymerizable compound selected from the group consisting of acrylate, tetrahydrofurfuryl acrylate, acryloylmorpholine, and 3,3,5-trimethylcyclohexyl acrylate An ink composition,
<4> The ink composition according to any one of <1> to <3>, which is for inkjet recording.
<5> An ink cartridge containing an oxygen-impermeable container filled with the ink composition according to any one of <1> to <4> above,
<6> (a ¹ ) A step of discharging the ink composition according to any one of the above <1> to <4> onto a recording medium, and (b ¹ ) active on the discharged ink composition Irradiating radiation to cure the ink composition, an inkjet recording method,
<7> The actinic radiation is irradiated by a light emitting diode that generates ultraviolet rays having an emission peak wavelength in a range of 350 to 420 nm and a maximum illuminance on a recording medium surface of 10 to 2,000 mW / cm ^2. The inkjet recording method according to <6>, wherein
<8> A printed matter recorded by the inkjet recording method according to <6> or <7>.

  According to the present invention, an ink composition excellent in curability and thermal stability over time in a wide temperature range, an ink cartridge containing the ink composition, an ink jet recording method using the ink composition, and a printed matter are provided. Could be provided.

  Hereinafter, the present invention will be described in detail.

(Ink composition)
The ink composition of the present invention includes a polymerizable compound, a polymerization inhibitor, and a polymerization initiator, wherein the polymerizable compound includes an N-vinyl compound, and the polymerization inhibitor includes a quinone methylide compound. .
In general, N-vinyl compounds tend to generate reactive species such as cation radicals at high temperatures, and therefore ink compositions containing N-vinyl compounds may have problems with stability over time at high temperatures. .
In the present invention, by using a quinone methylide compound as a polymerization inhibitor, even an ink composition containing an N-vinyl compound can be obtained which has excellent thermal stability over time in a wide temperature range. .

In addition, many common business ink cartridges contain an oxygen-impermeable container filled with an ink composition. Usually, after an ink composition is filled in an oxygen-impermeable container so that air does not enter during the manufacture of the ink cartridge, the oxygen-impermeable container is stored in the ink cartridge container.
The N-vinyl compound contained in the ink composition filled in the oxygen-impermeable container becomes a cation radical in the oxygen-impermeable container, polymerizes other monomers, and increases the viscosity of the ink composition. On the other hand, when using a container in which the ink composition is in contact with air, such as an open container, oxygen in the air is on the surface of the ink composition, and dissolved oxygen in the ink composition is in the ink composition. Since the cation radical is partially quenched, the ink composition has a slight suppression of thickening. However, since the ink composition does not come into contact with air in the oxygen-impermeable container, the cation generated in the container is not quenched by oxygen, and causes polymerization to increase the viscosity of the ink composition. It is done.
In the present invention, by using a quinone methylide compound as a polymerization inhibitor, it is possible to effectively suppress thickening of an ink composition containing an N-vinyl compound in an oxygen-free environment such as in an oxygen-impermeable container. I was able to.

<Quinone methylide compound>
The ink composition of the present invention contains a quinone methylide compound.
The quinone methylide compound is a compound in which one C═O bond of the quinone compound is replaced by a C═C bond, and may be a p-quinone methylide compound or an o-quinone methylide compound.
The quinone methylide compound that can be used in the present invention may be a compound having only one quinone methylide structure or a compound having two or more quinone methylide structures.
The compound having only one quinone methylide structure is preferably a compound represented by the following formula (1) or (2). In particular, the p-quinone methylide compound represented by the following formula (1) was able to reduce the initial viscosity.

In formula (1) and formula (2), R ^{1 to} R ⁴ each independently represents a hydrogen atom or a monovalent organic group, and R ⁵ and R ⁶ each independently represent a hydrogen atom or a double quinone methylide structure. The bond represents a monovalent organic group that does not cause isomerization to a phenol structure.
Moreover, the compound represented by Formula (1) and / or Formula (2) is, via at least one of R ^{1 to} R ⁶ , via a divalent or higher linking group (multivalent linking group), or , May be linked to other compounds represented by formula (1) and / or formula (2) by a single bond to form a multimer, and further, via one or more polyvalent linking groups, Alternatively, they may be linked by a single bond to form a multimer.

Examples of the monovalent organic group in R ^{1 to} R ⁴ include a halogen atom, a cyano group, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkenyloxy group, an alkynyloxy group, an aryloxy group, an alkylthio group, Examples include an alkenylthio group, an alkynylthio group, and an arylthio group.
The alkyl group, alkenyl group, alkynyl group, alkoxy group alkyl group, alkenyloxy group alkenyl group, alkynyloxy group alkynyl group, alkylthio group alkyl group, alkenylthio group alkenyl group, alkynylthio group alkynyl group are They may be linear, branched or have a ring structure.
The alkyl group, alkoxy group, alkenyloxy group, and alkylthio group preferably have 1 to 30 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 6 carbon atoms.
The alkyl group is preferably a tertiary alkyl group at the α-position.
The alkenyl group of the alkenyl group, alkenyloxy group, and alkenylthio group preferably has 2 to 30 carbon atoms, and more preferably 2 to 10 carbon atoms.
The alkynyl group, alkynyloxy group, and alkynylthio group preferably have 2 to 30 carbon atoms, and more preferably 2 to 10 carbon atoms.
The aryl group, aryloxy group, and arylthio group preferably have 6 to 30 carbon atoms, and more preferably 6 to 10 carbon atoms.

The alkyl group, aryl group, alkenyl group, alkynyl group, alkoxy group, alkenyloxy group, alkynyloxy group, aryloxy group, alkylthio group, alkenylthio group, alkynylthio group, arylthio group have a substituent. Also good.
Substituents include halogen atoms, cyano groups, alkyl groups, aryl groups, alkenyl groups, alkynyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups, aryloxy groups, alkylthio groups, alkenylthio groups, alkynylthio groups, arylthio groups. Examples include groups. Further, if possible, the substituent may further have a substituent.

Among these, the monovalent organic group in R ^{1 to} R ⁴ is preferably a t-butyl group, a t-pentyl group (1,1-dimethylpropyl group), a cyclohexyl group, or a methoxy group. A butyl group and a t-pentyl group are more preferable, and a t-butyl group is more preferable.

The monovalent organic group in which the double bond of the quinone methylide structure in R ⁵ and R ⁶ does not cause isomerization to the phenol structure is a halogen atom, a monovalent hydrocarbon group having no hydrogen atom at the α-position (alkyl group, Aryl group, alkenyl group, alkynyl group), preferably a halogen atom, an alkyl group having no hydrogen atom at the α-position, more preferably an aryl group, an alkyl group having no hydrogen atom at the α-position, An aryl group is more preferable, an aryl group is particularly preferable, and a phenyl group is most preferable.
The “α-position” is a carbon atom bonded to the carbon-carbon of the quinone methylide structure.
The alkyl group having no hydrogen atom at the α-position in R ⁵ and R ⁶ preferably has 4 to 30 carbon atoms, and more preferably 4 to 10 carbon atoms. The alkyl group having no hydrogen atom at the α-position has at least a branched and / or ring structure at the α-position.
The aryl group in R ⁵ and R ⁶ preferably has 6 to 30 carbon atoms, more preferably 6 to 10 carbon atoms, and particularly preferably a phenyl group.
The alkyl group and aryl group not having a hydrogen atom at the α-position may have a substituent.
Substituents include halogen atoms, cyano groups, alkyl groups, aryl groups, alkenyl groups, alkynyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups, aryloxy groups, alkylthio groups, alkenylthio groups, alkynylthio groups, arylthio groups. Examples include groups. Further, if possible, the substituent may further have a substituent.
Moreover, it is preferable that either one of R ⁵ and R ⁶ is a hydrogen atom.

The compound having two or more quinone methylide structures is preferably a multimer of the compounds represented by the formula (1) and / or (2), and is represented by the formula (1) or (2). It is more preferable that the compound is a dimer.
Moreover, as the polyvalent linking group for linking the compound represented by the formula (1) and / or the formula (2) and the compound represented by the other formula (1) and / or the formula (2), There is no particular limitation, and any polyvalent organic group may be used, and a group formed by one or more atoms selected from the group consisting of a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, and a sulfur atom. Preferably there is.
The dimer of the compound represented by the formula (1) or (2) is preferably a compound represented by the following formula (3) or formula (4).

In formula (3) and formula (4), R ^{1 to} R ⁴ and R ^{7 to} R ¹⁰ each independently represent a hydrogen atom or a monovalent organic group, and R ⁵ , R ⁶ , R ¹¹ and R ¹² are Independently, a hydrogen atom or a double bond of a quinone methylide structure represents a monovalent organic group that does not cause isomerization to a phenol structure, A represents a single bond or a divalent linking group, and A represents R ^1. any position to R ^6, and attached at any position of R ⁷ to R ^12.
R < ¹ > -R < ⁴ > in Formula (3) and Formula (4) is synonymous with R < ¹ > -R < ⁴ > in said Formula (1) and Formula (2), and its preferable range is also the same.
R ^{7 to} R ¹⁰ in formula (3) and formula (4) have the same meanings as R ^{1 to} R ⁴ in formula (1) and formula (2), and the preferred ranges are also the same.
R ⁵ and R ⁶ in Formula (3) and (4), the formula (1) and have the same meanings as R ⁵ and R ⁶ in Formula (2), and preferred ranges are also the same.
R ¹¹ and R ¹² in formula (3) and formula (4) have the same meanings as R ⁵ and R ⁶ in formula (1) and formula (2), and the preferred ranges are also the same.

Examples of the divalent linking group in A in Formula (3) and Formula (4) include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, an ether bond, a thioether bond, an ester bond (—CO—O—, —O—). CO-), an amide bond (-CO-NR'-, -NR'-CO-), and a group in which two or more of these are combined can be preferably exemplified. R ′ represents a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, or an alkynyl group.
Further, if the A is a single bond, in formula (3) or formula (4), and R ⁵ or R ^6, those with R ¹¹ or R ¹² are linked it is preferable.
In addition, the compound represented by the formula (3) or the formula (4) is preferably a symmetric compound having A as the center of line symmetry.

Specific examples of the quinone methylide compound that can be used in the present invention include the compounds represented by A-1 to A-21 shown below.
In the present invention, in some chemical formulas, the hydrocarbon chain may be described by a simplified structural formula in which symbols of carbon (C) and hydrogen (H) are omitted.

  Among these, as a quinone methylide compound, A-1, A-5, A-13, and A-15 are preferable, A-1 and A-5 are more preferable, and A-1 is especially preferable from the point of initial viscosity. .

In the ink composition of the present invention, the content of the quinone methylide compound is preferably 0.01 to 1% by weight and preferably 0.05 to 0.7% by weight with respect to the total weight of the ink composition. Is more preferable, and it is still more preferable that it is 0.1 to 0.5 weight%.
Within the above range, the temporal stability at high temperature is very excellent.

<N-vinyl compound>
The ink composition of the present invention contains an N-vinyl compound.
There is no restriction | limiting in particular as an N-vinyl compound, A well-known thing can be used.
The N-vinyl compound is preferably a compound in which the nitrogen atom to which the vinyl group is bonded is a ring member of the ring structure, and is an N-vinylcarbazole, 1-vinylimidazole, or N-vinyllactam. Are more preferable, and N-vinyl lactams are more preferable.
Preferable examples of N-vinyl lactams that can be used in the present invention include compounds represented by the following formula (A-1).

In formula (A-1), n represents an integer of 1 to 5, and n is 2 from the viewpoints of flexibility after the ink composition is cured, adhesion to a recording medium, and availability of raw materials. It is preferably an integer of ˜4, more preferably n is 2 or 4, and particularly preferably n is 4, that is, N-vinylcaprolactam. N-vinylcaprolactam is preferable since it is excellent in safety, is generally available and can be obtained at low cost, and provides particularly good ink curability and adhesion of a cured film to a recording medium.
The N-vinyllactams may have a substituent such as an alkyl group or an aryl group on the lactam ring, and may have an unsaturated ring structure in the lactam ring.

  The ink composition of the present invention preferably contains 5% by weight or more of the N-vinyl compound, more preferably 5 to 40% by weight, and further preferably 15 to 35% by weight of the total ink composition. The content is preferably 20 to 30% by weight. When the content of the N-vinyl compound is within the above range, the curability, the cured film flexibility, and the adhesion of the cured film to the recording medium are excellent. The N-vinyl compound is a compound having a relatively high melting point. When the content of the N-vinyl compound is 40% by weight or less, preferable solubility is exhibited even at a low temperature of 0 ° C. or less, and the temperature range in which the ink composition can be handled is widened. One type of N-vinyl compound may be contained in the ink composition, or two or more types may be contained.

<Other polymerizable compounds>
The ink composition of the present invention preferably contains another polymerizable compound in addition to the N-vinyl compound.
As the other polymerizable compound, a known polymerizable compound can be used, but an ethylenically unsaturated compound is preferably used.
The ethylenically unsaturated compound means a compound having at least one ethylenically unsaturated bond, preferably an addition polymerizable ethylenically unsaturated compound, and more preferably a radical polymerizable ethylenically unsaturated compound. .
As the ethylenically unsaturated compound, a monomer having a cyclic hydrocarbon group or an acyclic polyfunctional monomer can be preferably used.
In addition, the ink composition of the present invention includes 2-acryloyloxyethyl monohydroxyphthalate, 2-acryloyloxypropyl monohydroxyphthalate, dicyclopentanyl acrylate, among the compounds described later as other polymerizable monomers. At least one monofunctional polymerization selected from the group consisting of dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, isobornyl acrylate, tetrahydrofurfuryl acrylate, acryloylmorpholine, and 3,3,5-trimethylcyclohexyl acrylate It is preferable that an active compound is included.

(1) Monomer having a cyclic hydrocarbon group The ink composition of the present invention preferably contains a monomer having a cyclic hydrocarbon group represented by formula (I) or formula (II).

R ⁴⁰ in formula (I) or formula (II) represents a hydrogen atom, a methyl group or a halogen atom, and p R ^{40 s} may be the same or different.
In addition, R ⁴⁰ in formula (I) or formula (II) is preferably a hydrogen atom or a methyl group.
X ⁷ in Formula (I) or Formula (II) represents a divalent linking group, and is an ether group, carbonyl group, carbonyloxy group, oxycarbonyl group, amide group (—C (O) NR′—), nitrogen atom (—NR′—), an optionally substituted alkylene group having 1 to 15 carbon atoms, or a divalent linking group in which two or more thereof are combined is preferable. R ′ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. p X ⁷ may be the same or different.

Further, the end that binds to the vinyl group of X ⁷ in formula (I) or formula (II) is preferably an ester group or in which the carbonyl carbon and a vinyl group X ⁷ binds is an amide group, in which case, The other part of X ⁷ bonded to the adamantane skeleton or the norbornane skeleton may be a single bond or may be arbitrarily selected from the above groups.

The substitution number p of the vinyl moiety (H ₂ C═C (R ⁴⁰ ) —X ⁷ —) containing R ⁴⁰ and X ⁷ in formula (I) or formula (II) represents an integer of 1 to 6. Vinyl moieties including R ⁴⁰ and X ⁷ can be attached at any position on each alicyclic hydrocarbon structure. Note that “on each alicyclic hydrocarbon structure” refers to an adamantane structure in formula (I), a norbornane structure in formula (II), and a cyclic hydrocarbon structure including n.
Further, from the viewpoint of improving the affinity with the colorant, the end bonded to the alicyclic hydrocarbon structure of X ⁷ in formula (I) or formula (II) is preferably an oxygen atom, and ether X ⁷ in formula (I) or formula (II) is —C (O) O (CH ₂ CH ₂ O) _k — (k represents 1 or 2). More preferably.

R ⁴¹ and R ⁴² in formula (I) or formula (II) each independently represent a substituent, and can be bonded at any position on each alicyclic hydrocarbon structure. Further, q R ⁴¹ and r R ⁴² may be the same or different.
q R ⁴¹ and r R ⁴² may be each independently a monovalent or polyvalent substituent, and a monovalent substituent may be a hydrogen atom, a hydroxy group, a substituted or unsubstituted amino group. Group, thiol group, siloxane group, a hydrocarbon group or a heterocyclic group having a total carbon number of 30 or less which may have a substituent, or an oxy group (= O) as a divalent substituent. preferable.
The substitution number q of R ⁴¹ represents an integer of 0 to 5, and the substitution number r of R ⁴² represents an integer of 0 to 5.

N in the formula (II) represents a cyclic hydrocarbon structure, and both ends thereof may be substituted at any position of the norbornane skeleton, and may be a monocyclic structure or a polycyclic structure. In addition to the hydrocarbon bond, the cyclic hydrocarbon structure may contain a carbonyl bond (—C (O) —) and / or an ester bond (—C (O) O—).
Further, one carbon atom in the adamantane skeleton in the formula (I) may be substituted with a carbonyl bond (—C (O) —) and / or an ester bond (—C (O) O—). One carbon atom in the norbornane skeleton may be substituted with an ether bond (—O—) and / or an ester bond (—C (O) O—).

  As the monomer represented by formula (I) or formula (II), preferred specific examples of monofunctional acrylates are shown below.

  As the monomer represented by formula (I) or formula (II), preferred specific examples of monofunctional methacrylate are shown below.

  As the monomer represented by formula (I) or formula (II), preferred specific examples of monofunctional acrylamide are shown below.

  As the monomer represented by formula (I) or formula (II), preferred specific examples of monofunctional vinyl ethers are shown below.

  Preferred specific examples of the polyfunctional acrylate represented by the formula (I) or the formula (II) are shown below.

  Preferred specific examples of the polyfunctional methacrylate represented by the formula (I) or the formula (II) are shown below.

  Among these, monofunctional (meth) acrylate is preferable, monofunctional acrylate is more preferable, dicyclopentanyl acrylate (M-13), dicyclopentenyl acrylate (M-10), and dicyclopentenyloxyethyl acrylate ( M-11) is more preferred.

In addition to the monomers represented by the formulas (I) and (II), examples of the monomer having a cyclic hydrocarbon group that can be used in the present invention include cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, cycloheptyl ( (Meth) acrylate, cyclooctyl (meth) acrylate, cyclodecyl (meth) acrylate, dicyclodecyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, 2-benzyl (meth) acrylate, phenoxy Ethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxytriethylene glycol (meth) acrylate, ethylene oxide (EO) modified cresol (meth) acrylate, Ruphenoxypolyethylene glycol (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, paracumylphenoxyethylene glycol (meth) acrylate, N-cyclohexyl (meth) acrylamide, N- (1,1-dimethyl-2-phenyl) ethyl (Meth) acrylamide, N-diphenylmethyl (meth) acrylamide, 5- (meth) acryloyloxymethyl-5-ethyl-1,3-dioxacyclohexane, (poly) ethylene glycol (meth) acrylate phenyl ester, (poly) Propylene glycol mono (meth) acrylate phenyl ester, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl monohydroxyphthalate, 2 (Meth) acryloyloxy propyl monohydroxy phthalate, ethoxylated phenyl (meth) acrylate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, isobornyl (meth) acrylate.
Among them, trimethylcyclohexyl (meth) acrylate, 2- (meth) acryloyloxyethyl monohydroxyphthalate, 2- (meth) acryloyloxypropyl monohydroxyphthalate, isobornyl (meth) acrylate, and aromatic groups such as phenyl groups Are preferred, and trimethylcyclohexyl (meth) acrylate, 2- (meth) acryloyloxyethyl monohydroxyphthalate, 2- (meth) acryloyloxypropyl monohydroxyphthalate, isobornyl (meth) acrylate, and phenoxyethyl ( (Meth) acrylate is more preferable, 2-acryloyloxyethyl monohydroxyphthalate, 2-acryloyloxypropyl monohydroxyphthalate, 3,3,5-trimethylcyclohexyl Acrylate, and isobornyl acrylate is more preferred.

As the monomer having a cyclic hydrocarbon group, a monomer having a heterocyclic ring can also be preferably used. Among them, a compound having a heterocyclic ring and at least one ethylenically unsaturated bond is preferable, and (meth) acrylate having a heterocyclic ring and (meth) acrylamide having a heterocyclic ring are more preferable.
Of these, (meth) acrylate and (meth) acrylamide having a heterocyclic ring selected from the group consisting of a furan ring, a di- or tetrahydrofuran ring, a pyran ring, a di- or tetrahydropyran ring, a morpholine ring, and an imide ring are preferable.
Examples of the (meth) acrylate having a furan ring include furfuryl (meth) acrylate.
Examples of the (meth) acrylate having a di- or tetrahydrofuran ring include tetrahydrofuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, and the like.
Examples of the (meth) acrylate having a pyran ring include pyranyl (meth) acrylate.
Examples of the (meth) acrylate having a di- or tetrahydropyran ring include dihydropyranyl (meth) acrylate, tetrahydropyranyl (meth) acrylate, dimethyldihydropyranyl (meth) acrylate, dimethyltetrahydropyranyl (meth) acrylate and the like. it can.
As (meth) acrylate and (meth) acrylamide having a morpholine ring, (meth) acrylamide having a morpholine ring can be preferably exemplified, N- (meth) acryloylmorpholine can be more preferably exemplified, and N-acryloylmorpholine is further preferably exemplified. it can.
Examples include imide acrylate having an imide ring (Aronix TO-1428, manufactured by Toagosei Co., Ltd.).
Among these, tetrahydrofurfuryl (meth) acrylate, N- (meth) acryloylmorpholine, and Aronix TO-1428 (manufactured by Toagosei Co., Ltd.) are preferable, and tetrahydrofurfuryl (meth) acrylate and N- (meth) are preferred. Acryloylmorpholine is more preferable, and tetrahydrofurfuryl acrylate and N-acryloylmorpholine are more preferable.

  The content of the monomer having a cyclic hydrocarbon group excluding the N-vinyl compound in the ink composition of the present invention is preferably 65% by weight or less with respect to the total weight of the ink composition, and is 25 to 65% by weight. It is more preferable that it is 35 to 65% by weight. Within the above range, the curability is excellent and the viscosity is moderate.

(2) Acyclic polyfunctional monomer In addition to the N-vinyl compound and the monomer having a cyclic hydrocarbon group, an acyclic polyfunctional monomer is preferably used in combination. By containing an acyclic polyfunctional monomer, an ink composition having excellent curability and an image having high cured film strength can be obtained.

  Specific examples of non-cyclic polyfunctional monomers include neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, and 1,6-hexanediol di (Meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol diacrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaeryth Tall tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, tetramethylolmethanetetra (meth) Acrylate, tetramethylol methane tri (meth) acrylate, modified glycerin tri (meth) acrylate, modified bisphenol A di (meth) acrylate, propylene oxide (PO) adduct of bisphenol A di (meth) acrylate, EO adduct of bisphenol A Di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol di (meth) acrylate, caprolac Modified dipentaerythritol hexa (meth) acrylate, (poly) tetramethylene glycol di (meth) acrylate, EO modified pentaerythritol triacrylate, PO modified pentaerythritol tri (meth) acrylate, EO modified pentaerythritol tetra (meth) acrylate, PO-modified pentaerythritol tetra (meth) acrylate, EO-modified dipentaerythritol tetra (meth) acrylate, PO-modified dipentaerythritol tetra (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri ( (Meth) acrylate, EO-modified tetramethylolmethanetetra (meth) acrylate, PO-modified tetramethylolmethanetetra (meth) acrylate , Hydroxypivalate neopentyl glycol di (meth) acrylate, pentaerythritol triacrylate tolylene diisocyanate urethane prepolymer, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, bisphenol A diglycidyl ether acrylic acid adduct, etc. Propoxylated neopentyl glycol di (meth) acrylate and caprolactone-modified dipentaerythritol di (meth) acrylate are preferred.

(3) Other monomer In this invention, the following radically polymerizable compound may be contained as another monomer. Use of a radically polymerizable compound in combination is preferable because an ink composition having further excellent curability can be provided.
Examples of the radical polymerizable compound are described in JP-A-7-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, JP-A-9-80675, and the like. A photocurable material using a photopolymerizable composition is known.

The radical polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization, and may be any compound as long as it has at least one ethylenically unsaturated bond capable of radical polymerization in the molecule. , Oligomers, polymers and the like having a chemical form. The radical polymerizable compound may contain one kind at an arbitrary ratio in order to improve the desired properties, and may contain two or more kinds.
Examples of the polymerizable compound having an ethylenically unsaturated bond capable of radical polymerization include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and salts thereof, Preferred examples include an anhydride having a saturated bond, acrylonitrile, and styrene. Further, examples of various polymerizable compounds include unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, unsaturated urethane (meth) acrylic monomers or prepolymers, epoxy monomers or prepolymers, urethane monomers or prepolymers. (Meth) acrylic acid esters such as polymers are preferred.

Preferred examples of the other monomer include acyclic (meth) acrylate.
Specific examples of the acyclic (meth) acrylate include (poly) ethylene glycol mono (meth) acrylate, (poly) ethylene glycol (meth) acrylate methyl ester, (poly) ethylene glycol (meth) acrylate ethyl ester, (poly ) Propylene glycol mono (meth) acrylate, (poly) propylene glycol (meth) acrylate methyl ester, (poly) propylene glycol (meth) acrylate ethyl ester, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl-diglycol (meth) Acrylate, methyl (meth) acrylate, n-butyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, isooctyl (Meth) acrylate, n-lauryl (meth) acrylate, n-tridecyl (meth) acrylate, n-cetyl (meth) acrylate, n-stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (Meth) acrylate, butoxyethyl (meth) acrylate, oligoester (meth) acrylate, N-methylol (meth) acrylamide, diacetone (meth) acrylamide, epoxy (meth) acrylate, allyl (meth) acrylate, glycidyl (meth) acrylate , Dimethylaminomethyl (meth) acrylate, allyl glycidyl ether, diallyl phthalate, triallyl trimellitate, 2- (meth) acryloyloxyethyl succinic acid, lactone-modified flexible (meth) a Relate, butoxyethyl (meth) acrylate, methoxy dipropylene glycol acrylate.
More specifically, Yamashita Shinzo, “Crosslinking agent handbook” (1981, Taiseisha); Kato Kiyosumi, “UV / EB curing handbook (raw material)” (1985, Polymer publication society); Ed. "Application and Market of UV / EB Curing Technology", page 79 (1989, CMC); Eiichiro Takiyama, "Polyester Resin Handbook" (1988, Nikkan Kogyo Shimbun), etc. Radical polymerizable or crosslinkable monomers, oligomers and polymers can be used.

Furthermore, it is also preferable to use a vinyl ether compound as another monomer.
Suitable vinyl ether compounds include, for example, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, and cyclohexanedimethanol. Di- or trivinyl ether compounds such as divinyl ether, trimethylolpropane trivinyl ether, ethylene glycol monovinyl ether, triethylene glycol monovinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl Ether, 2-ethylhexyl vinyl ether, cyclohexanedimethanol monovinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, isopropenyl vinyl ether, dodecyl vinyl ether, diethylene glycol monovinyl ether, octadecyl vinyl ether, hydroxyethyl monovinyl ether, hydroxynonyl monovinyl ether, etc. Is mentioned.
Of these vinyl ether compounds, divinyl ether compounds and trivinyl ether compounds are preferable from the viewpoints of curability, adhesion, and surface hardness, and divinyl ether compounds are particularly preferable. A vinyl ether compound may be used individually by 1 type, and may be used in combination of 2 or more type as appropriate.

  In the present invention, oligomers or polymers can also be used as the polymerizable compound. Here, an oligomer means a compound having a molecular weight (weight average molecular weight for those having a molecular weight distribution) of 2,000 or more, and a polymer has a molecular weight (weight average molecular weight for those having a molecular weight distribution) of 10. Means more than 1,000 compounds. The oligomer or polymer may or may not have a radical polymerizable group. When the radically polymerizable group in one molecule of the oligomer or polymer is 4 or less (in terms of a compound having a molecular weight distribution, the average of the total number of molecules contained is 4 or less), an ink composition having excellent flexibility can be obtained. preferable. The ink composition can also be suitably used in the sense of adjusting the viscosity to be optimal for jetting.

The ink composition of the present invention can be used in combination with a cationically polymerizable compound as necessary. When a cationic polymerizable compound is used in combination, a cationic polymerization initiator is also preferably used as a polymerization initiator.
The cationically polymerizable compound that can be used in the present invention is not particularly limited as long as it is a compound that initiates a polymerization reaction with an acid generated from a photoacid generator and cures, and various known compounds known as photocationically polymerizable monomers. Cationic polymerizable monomers can be used. Examples of the cationic polymerizable monomer include JP-A-6-9714, JP-A-2001-31892, JP-A-2001-40068, JP-A-2001-55507, JP-A-2001-310938, JP-A-2001-310937, and 2001-2001. Examples thereof include epoxy compounds, vinyl ether compounds, oxetane compounds and the like described in each publication such as No. 220526.

  In addition, as the cationic polymerizable compound, for example, a polymerizable compound applied to a cationic polymerization type photocurable resin is known, and recently, a photo cationic polymerization type sensitized in a visible light wavelength region of 400 nm or more. Examples of the polymerizable compound applied to the photo-curable resin are disclosed in JP-A-6-43633 and JP-A-8-324137. These can also be applied to the ink composition of the present invention.

<Polymerization initiator>
The ink composition of the present invention contains a polymerization initiator.
Examples of the polymerization initiator include a radical polymerization initiator and a cationic polymerization initiator, but it is preferable to use at least a radical polymerization initiator. Moreover, you may use together a radical polymerization initiator and a cationic polymerization initiator.
The ink composition of the present invention preferably contains at least an acylphosphine compound described later as a polymerization initiator.

[Radical polymerization initiator]
There is no limitation in particular as a radical polymerization initiator which can be used for this invention, A well-known radical polymerization initiator can be used.
The radical polymerization initiator that can be used in the present invention may be used alone or in combination of two or more.

  The radical polymerization initiator that can be used in the present invention is a compound that absorbs external energy to generate radical polymerization initiating species. External energy used for initiating polymerization is roughly divided into heat and actinic radiation, and a thermal polymerization initiator and a photopolymerization initiator are used, respectively. Examples of the active radiation include γ rays, β rays, electron beams, ultraviolet rays, visible rays, and infrared rays.

  Examples of radical polymerization initiators that can be used in the present invention include (a) aromatic ketones, (b) acylphosphine compounds, (c) aromatic onium salt compounds, (d) organic peroxides, (e) thios. Compound, (f) hexaarylbiimidazole compound, (g) ketoxime ester compound, (h) borate compound, (i) azinium compound, (j) metallocene compound, (k) active ester compound, (l) carbon halogen bond And (m) an alkylamine compound. These radical polymerization initiators may use the above compounds (a) to (m) alone or in combination. The radical polymerization initiator in the present invention is preferably used alone or in combination of two or more.

  Preferable examples of (a) aromatic ketones and (e) thio compounds include “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” P. FOUASSIER J.M. F. RABEK (1993), pp. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in 77-117. More preferable examples of (a) aromatic ketones, (b) acylphosphine compounds, and (e) thio compounds include α-thiobenzophenone compounds described in JP-B-47-6416, and JP-B-47-3981. A benzoin ether compound described in Japanese Patent Publication No. 47-22326, an α-substituted benzoin compound described in Japanese Patent Publication No. 47-22326, a benzoin derivative described in Japanese Patent Publication No. 47-23664, an aroylphosphonic acid ester described in Dialkoxybenzophenone described in JP-B-60-26483, benzoin ethers described in JP-B-60-26403, JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318, 791, α-aminobenzophenones described in European Patent No. 0284561A1 P-di (dimethylaminobenzoyl) benzene described in JP-A-2-21152, thio-substituted aromatic ketone described in JP-A-61-194062, acylphosphine sulfide described in JP-B-2-9597, Examples include acylphosphine described in Japanese Patent Publication No. 2-9596, thioxanthones described in Japanese Patent Publication No. 63-61950, and coumarins described in Japanese Patent Publication No. 59-42864.

  (C) As aromatic onium salt compounds, elements of Groups 15, 16 and 17 of the periodic table, specifically N, P, As, Sb, Bi, O, S, Se, Te, or I fragrances Group onium salts are included. For example, iodonium salts described in European Patent No. 104143, US Pat. No. 4,837,124, Japanese Patent Laid-Open No. 2-150848, Japanese Patent Laid-Open No. 2-96514, European Patent Nos. 370693, 233567, and 297443 are disclosed. The diazonium salts described in the specifications of U.S. Pat. Nos. 2,974,279, 279210, and 422570, U.S. Pat. Nos. 3,902,144, 4,933,377, 4,760013, 4,734,444, and 2,833,827. Benzenediazonium which may have a substituent), diazonium salt resins (formaldehyde resin of diazodiphenylamine, etc.), N-alkoxypyridinium salts, etc. (for example, US Pat. No. 4,743,528, JP-A-63) -138345, JP-A-63 142345, JP-A-63-142346, and JP-B-46-42363, specifically 1-methoxy-4-phenylpyridinium tetrafluoroborate, etc. The compounds described in Japanese Patent Publication Nos. 52-147277, 52-14278, and 52-14279 are preferably used. Generates radicals and acids as active species.

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

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

  (G) Examples of the ketoxime ester compound include 3-benzoyloxyiminobutane-2-one, 3-acetoxyiminobutane-2-one, 3-propionyloxyiminobutane-2-one, and 2-acetoxyiminopentane-3. -One, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-p-toluenesulfonyloxyiminotan-2-one, 2-ethoxy And carbonyloxyimino-1-phenylpropan-1-one.

  (H) Examples of the borate compound include compounds described in US Pat. Nos. 3,567,453, 4,343,891, European Patents 109,772, and 109,773. Can be mentioned.

  (I) Examples of azinium compounds include those disclosed in JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, JP-A-63-143537, and JP-B-46-42363. The compound group which has NO bond of each gazette description can be mentioned.

  (J) Examples of metallocene compounds include titanocenes described in JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, and JP-A-2-4705. Examples thereof include compounds, and iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109.

  Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3. 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- -2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) phenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopenta And dienyl) bis [2,6-difluoro-3- (N-butylbialoylamino) phenyl] titanium.

  (K) Examples of the active ester compound include the specifications of European Patent Nos. 0290750, 046083, 156153, 271851, and 0388343, U.S. Pat. Nos. 3,901,710, and 4,181,531. Nitrobenzol ester compounds described in JP-A-60-198538 and JP-A-53-133022, European Patents 0199672, 84515, 199672, 0441115, and 0101122. No. 4,618,564, U.S. Pat. No. 4,371,605, and U.S. Pat. No. 4,431,774, JP-A 64-18143, JP-A 2-245756, and JP-A-4-365048. Iminosulfonate compound, Japanese Examined Patent Publication No. 62-6223, Japanese Examined Publication No. 63 No. 14340, and compounds, and the like described in the JP-A No. 59-174831.

  (L) Preferable examples of the compound having a carbon halogen bond include, for example, compounds described in Wakabayashi et al., Bull. Chem. Soc. Japan, 42, 2924 (1969), compounds described in British Patent No. 1388492, Examples thereof include compounds described in Japanese Utility Model Publication No. 53-133428, compounds described in German Patent No. 3337024, and the like.

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

(Cationic polymerization initiator)
In the ink composition of the present invention, a cationic polymerization initiator can be used as necessary.
As cationic polymerization initiators that can be used in the present invention, first, B (C ₆ F ₅ ) ₄ ⁻ , PF ₆ ⁻ , AsF ₆ of aromatic onium compounds such as diazonium, ammonium, iodonium, sulfonium, and phosphonium are used. ^- , SbF ₆ ^- and CF ₃ SO ₃ ^- salts. Secondly, sulfonated products that generate sulfonic acid can be mentioned. Thirdly, a halide that generates hydrogen halide can also be used. Fourthly, iron arene complexes can be mentioned.
Preferable specific examples of the cationic polymerization initiator that can be used in the present invention include compounds such as (b-1) to (b-96) described in JP-A-2007-224149.

The content of the polymerization initiator in the ink composition of the present invention is preferably 0.01 to 35% by weight, more preferably 5 to 20% by weight, and more preferably 10 to 15% by weight with respect to the weight of the entire ink composition. More preferably, it is the range. Within the above range, a cured film having a uniform degree of curing can be obtained.
In the present invention, when a sensitizer described later is used in the ink composition, the total amount of radical polymerization initiator used is preferably a radical polymerization initiator: sensitizer weight ratio with respect to the sensitizer. Is in the range of 200: 1 to 1: 200, more preferably 50: 1 to 1:50, and even more preferably 20: 1 to 1: 5.

<Colorant>
The ink composition of the present invention preferably contains a colorant in order to improve the visibility of the formed image portion.

  The colorant that can be used in the present invention is not particularly limited, but pigments and oil-soluble dyes that are excellent in weather resistance and excellent in color reproducibility are preferable, and are arbitrarily selected from known colorants such as soluble dyes. Can be used. From the viewpoint of not reducing the sensitivity of the curing reaction by actinic radiation, it is preferable to select a compound that does not function as a polymerization inhibitor in the polymerization reaction, which is a curing reaction, as the colorant that can be suitably used in the present invention.

[Pigment]
Although it does not necessarily limit as a pigment which can be used for this invention, For example, the organic or inorganic pigment of the following number described in a color index can be used.
Examples of red or magenta pigments include Pigment Red 3, 5, 19, 22, 31, 38, 42, 43, 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49: 1, 53. : 1, 57: 1, 57: 2, 58: 4, 63: 1, 81, 81: 1, 81: 2, 81: 3, 81: 4, 88, 104, 108, 112, 122, 123, 144 , 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13, 16, 20, 36,
Pigment Blue 1,15,15: 1,15: 2,15: 3,15: 4,15: 6,16,17-1,22,27,28,29,36,60 as a blue or cyan pigment ,
As a green pigment, Pigment Green 7, 26, 36, 50,
As yellow pigments, Pigment Yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 120, 137 , 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193,
As the black pigment, Pigment Black 7, 28, 26,
As a white pigment, Pigment White 6, 18, 21
Can be used according to the purpose.

[Oil-soluble dye]
The oil-soluble dye that can be used in the present invention will be described below.
The oil-soluble dye that can be used in the present invention means a dye that is substantially insoluble in water. Specifically, the solubility in water at 25 ° C. (the weight of the dye that can be 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, the oil-soluble dye means a so-called water-insoluble pigment or oil-soluble dye, and among these, an oil-soluble dye is preferable.

  Among the oil-soluble dyes that can be used in the present invention, any yellow dye can be used. For example, phenols, naphthols, anilines, pyrazolones, pyridones, aryl or heteryl azo dyes having open-chain active methylene compounds as coupling components; for example, azomethine dyes having open-chain active methylene compounds as coupling components; Examples include methine dyes such as benzylidene dyes and monomethine oxonol dyes; quinone dyes such as naphthoquinone dyes and anthraquinone dyes; and other dye species such as quinophthalone dyes, nitro / nitroso dyes, acridines And dyes and acridinone dyes.

  Of the oil-soluble dyes usable in the present invention, any magenta dye can be used. For example, aryl or heteryl azo dyes having phenols, naphthols, anilines as coupling components; for example, azomethine dyes having pyrazolones, pyrazolotriazoles as coupling components; for example arylidene dyes, styryl dyes, merocyanine dyes, oxonol dyes Methine dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes; quinone dyes such as naphthoquinone, anthraquinone, anthrapyridone; condensed polycyclic dyes such as dioxazine dyes, etc. Can be mentioned.

  Among the oil-soluble dyes applicable to the present invention, any cyan dye can be used. For example, indoaniline dyes, indophenol dyes or azomethine dyes having pyrrolotriazoles as coupling components; polymethine dyes such as cyanine dyes, oxonol dyes, merocyanine dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene dyes Phthalocyanine dyes; anthraquinone dyes; for example, aryl or heteryl azo dyes having phenols, naphthols and anilines as coupling components; indigo / thioindigo dyes;

  Each of the above dyes may exhibit yellow, magenta, and cyan colors only after a part of chromophore (chromogenic atomic group) is dissociated. In this case, the counter cation may be an alkali metal or ammonium. Such inorganic cations may be used, and organic cations such as pyridinium and quaternary ammonium salts may be used, and further, polymer cations having these in a partial structure may be used.

Although not limited to the following, preferred specific examples include C.I. I. Solvent Black 3, 7, 27, 29 and 34; C.I. I. Solvent Yellow 14, 16, 19, 29, 30, 56, 82, 93 and 162; C.I. I. Solvent Red 1, 3, 8, 18, 24, 27, 43, 49, 51, 72, 73, 109, 122, 132 and 218; I. Solvent Violet 3; C.I. I. Solvent Blue 2,11,25,35,38,67 and 70; I. Solvent Green 3 and 7; I. Solvent orange 2; and the like.
Particularly preferred among these are: Nubian Black PC-0850, Oil Black HBB, Oil Yellow 129, Oil Yellow 105, Oil Pink 312, Oil Red 5B, Oil Scallet 308, Vali Fast Blue chemistry 2606e B2 (Manufactured by Co., Ltd.), Aizen Spiron Blue GNH (manufactured by Hodogaya Chemical Co., Ltd.), Neopen Yellow 075, Neopen Magenta SE1378, Neopen Blue 808, Neopen Blue FF4012, and Neo42 Cy FF4012.
In the present invention, the oil-soluble dye may be used alone or in combination of several kinds.

Moreover, when using an oil-soluble dye as a colorant, other water-soluble dyes, disperse dyes, pigments, and other colorants may be used in combination as long as the effects of the present invention are not impaired.
In the present invention, a disperse dye can be used as long as it is soluble in a water-immiscible organic solvent. The disperse dye generally includes a water-soluble dye, but in the present invention, the disperse dye is preferably used as long as it is soluble in a water-immiscible organic solvent.
Preferable specific examples of the disperse dye include C.I. I. Disperse Yellow 5,42,54,64,79,82,83,93,99,100,119,122,124,126,160,184: 1,186,198,199,201,204,224 and 237 C. I. Disperse Orange 13, 29, 31: 1, 33, 49, 54, 55, 66, 73, 118, 119 and 163; I. Disperse Red 54, 60, 72, 73, 86, 88, 91, 92, 93, 111, 126, 127, 134, 135, 143, 145, 152, 153, 154, 159, 164, 167: 1,177 , 181, 204, 206, 207, 221, 239, 240, 258, 277, 278, 283, 311, 323, 343, 348, 356 and 362; I. Disperse Violet 33; C.I. I. Disperse Blue 56, 60, 73, 87, 113, 128, 143, 148, 154, 158, 165, 165: 1, 165: 2, 176, 183, 185, 197, 198, 201, 214, 224, 225 , 257, 266, 267, 287, 354, 358, 365 and 368; I. Disperse Green 6: 1 and 9;

  It is preferable that the colorant that can be used in the present invention is appropriately dispersed in the ink composition after being added to the ink composition. For dispersing the colorant, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, or a paint shaker can be used.

The colorant may be blended directly with each component when preparing the ink composition. However, in order to improve dispersibility, the colorant is added in advance to a dispersion medium such as a solvent or a polymerizable compound and uniformly dispersed or dissolved. After that, it can be blended.
In the present invention, in order to avoid deterioration of solvent resistance when the solvent remains in the cured image and the problem of VOC (Volatile Organic Compound) of the remaining solvent, the colorant is a radical polymerizable compound. It is preferable to add and mix in advance in such a dispersion medium. In consideration of only dispersibility, it is preferable to select a monomer having the lowest viscosity as the polymerizable compound used for the addition of the colorant.

  These colorants may be used by appropriately selecting one type or two or more types according to the purpose of use of the ink composition.

When using a colorant such as a pigment that remains solid in the ink composition, the average particle diameter of the colorant particles is preferably 0.005 to 0.5 μm, more preferably 0.01 to It is preferable to set the colorant, the dispersant, the dispersion medium, the dispersion conditions, and the filtration conditions so as to be 0.45 μm, more preferably 0.015 to 0.4 μm. This particle size control is preferable because clogging of the head nozzle can be suppressed and the storage stability, transparency, and curing sensitivity of the ink composition can be maintained.
The content of the colorant in the ink composition of the present invention is appropriately selected depending on the color and purpose of use, but is preferably 0.01 to 30% by weight based on the total weight of the ink composition.

<Dispersant>
It is preferable to add a dispersant when dispersing the colorant. The type of the dispersant is not particularly limited, but a polymer dispersant is preferably used.
Dispersor BYK-101, DisperBYK-102, DisperBYK-103, DisperBYK-106, DisperBYK-111, DisperBYK-161, DisperBYK-162, DisperBYK-164D, DisperBYK-164D, , DisperBYK-168, DisperBYK-170, DisperBYK-171, DisperBYK-174, DisperBYK-182 (manufactured by BYK Chemie), EFKA4010, EFKA4046, EFKA5080, EFKA5010, EFKA5010, EFKA5010, EFKA5010, EFKA5010, EFKA5010, EFKA5010 Polymer dispersing agents such as KA7462, EFKA7500, EFKA7570, EFKA7575, EFKA7580 (manufactured by Fuka Additive), Disperse Aid 6, Disperse Aid 8, Disperse Aid 15, Disperse Aid 9100 (Sannopco) Solsperse 3000, 5000, 9000, 12000, 13240, 13940, 17000, 24000, 26000, 28000, 32000, 36000, 39000, 41000, 71000, etc. (Abyssia); Adeka Pluronic L31 , F38, L42, L44, L61, L64, F68, L72, P95, F77, P84, F87, P94, L101, P103, F108, L121, -123 (manufactured by ADEKA Co., Ltd.) and Isonet S-20 (manufactured by Sanyo Kasei Kogyo Co., Ltd.), “Disparon KS-860, 873SN, 874 (polymer dispersing agent), # 2150 (fat) Group polyvalent carboxylic acid), # 7004 (polyether ester type) ”.
In addition, pigment derivatives such as a phthalocyanine derivative (trade name: EFKA-745 (manufactured by Efka)), Solsperse 5000, 12000, Solsperse 22000 (manufactured by Avicia) can also be used.
The content of the dispersant in the ink composition of the present invention is preferably 0.01 to 5% by weight with respect to the weight of the whole ink composition.

<Surfactant>
A surfactant is preferably added to the ink composition of the present invention in order to impart stable ejection properties for a long time.
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.
Further, an organic fluoro compound or a polysiloxane compound may be used as 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 polysiloxane compound is preferably a modified polysiloxane compound in which an organic group is introduced into part of the methyl group of dimethylpolysiloxane.
Examples of modification include polyether modification, methylstyrene modification, alcohol modification, alkyl modification, aralkyl modification, fatty acid ester modification, epoxy modification, amine modification, amino modification, mercapto modification, etc. is not. These modification methods may be used in combination. Among these, polyether-modified polysiloxane compounds are preferred from the viewpoint of improving ejection stability in ink jet.
Examples of the polyether-modified polysiloxane compound include, for example, SILWET L-7604, SILWET L-7607N, SILWET FZ-2104, SILWET FZ-2161 (manufactured by Nippon Unicar Co., Ltd.), BYK-306, BYK-307, BYK. -331, BYK-333, BYK-347, BYK-348 and the like (manufactured by BYK Chemie), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-6020, X-22-6191, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (Shin-Etsu Chemical Co., Ltd.) Manufactured).
The content of the surfactant in the ink composition of the present invention is preferably 0.0001 to 1% by weight with respect to the total weight of the ink composition.
These surfactants may be contained alone or in combination of two or more.

<Other ingredients>
In the ink composition of the present invention, other components other than the above components can be added as necessary. Examples of other components include other polymerization inhibitors, sensitizers, co-sensitizers, ultraviolet absorbers, anti-fading agents, conductive salts, solvents, polymer compounds, basic compounds, and the like.

[Other polymerization inhibitors]
The ink composition of the present invention may be used in combination with another polymerization inhibitor other than the quinone methylide compound.
As other polymerization inhibitors, known polymerization inhibitors can be used, for example, nitroso polymerization inhibitors, hindered amine polymerization inhibitors, hydroquinone, benzoquinone, p-methoxyphenol, TEMPO, TEMPOL, Cuperon Al, etc. Is mentioned.

[Sensitizer]
A sensitizer may be added to the ink composition of the present invention to absorb specific actinic radiation and promote decomposition of the polymerization initiator, particularly when used for ink jet recording.
The sensitizer absorbs specific actinic radiation and enters an electronically excited state. The sensitizer in an electronically excited state comes into contact with the polymerization initiator, and effects such as electron transfer, energy transfer, and heat generation occur. As a result, the polymerization initiator undergoes a chemical change and decomposes to generate polymerization initiation species such as radicals, acids, and bases.
Examples of preferred sensitizers include those belonging to the following compounds and having an absorption wavelength of 350 to 450 nm.
Specifically, polynuclear aromatics (for example, pyrene, perylene, triphenylene), xanthenes (for example, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (for example, thiacarbocyanine, oxacarbocyanine) ), Merocyanines (eg merocyanine, carbomerocyanine), thiazines (eg thionine, methylene blue, toluidine blue), acridines (eg acridine orange, chloroflavin, acriflavine), anthraquinones (eg anthraquinone), squalium (Eg, squalium), coumarins (eg, 7-diethylamino-4-methylcoumarin), and the like.
Preferable specific examples of the sensitizer that can be used in the present invention include (E-1) to (E-20) shown below.

  The content of the sensitizer in the ink composition of the present invention is appropriately selected depending on the purpose of use, but generally it is preferably 0.05 to 4% by weight based on the weight of the whole ink composition. .

[Co-sensitizer]
The ink composition of the present invention preferably contains a co-sensitizer.
In the present invention, the co-sensitizer has functions such as further improving the sensitivity of the sensitizer to actinic radiation or suppressing polymerization inhibition of the polymerizable compound by oxygen.
Examples of such a co-sensitizer include amines such as MR Sander et al., “Journal of Polymer Society”, Vol. Publication, JP 52-134692, JP 59-138205, JP 60-84305, JP 62-18537, JP 64-33104, Research Disclosure 33825 Specifically, triethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like can be mentioned.

  Other examples of co-sensitizers include thiols and sulfides such as thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, No. 56-75643, such as 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercapto. And naphthalene.

Other examples include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), and hydrogen described in Japanese Patent Publication No. 55-34414. Donors, sulfur compounds described in JP-A-6-308727 (eg, trithiane), phosphorus compounds described in JP-A-6-250387 (diethyl phosphite, etc.), Si-- described in JP-A-8-54735 H, Ge-H compound, etc. are mentioned.
The content of the co-sensitizer in the ink composition of the present invention is appropriately selected depending on the purpose of use, but is preferably 0.05 to 4% by weight with respect to the weight of the entire ink composition.

[Ultraviolet absorber]
In the present invention, an ultraviolet absorber can be used from the viewpoint of improving the weather resistance of the obtained image and preventing discoloration.
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. 5-194843, US Pat. No. 3,214,463, etc., JP-B Nos. 48-30492 and 56-21141 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 US Pat. No. 24239, stilbene-based and benzoxazole-based compounds that absorb ultraviolet rays and emit fluorescence, so-called fluorescent brighteners.
The addition amount is appropriately selected according to the purpose, but is preferably 0.5 to 15% by weight in terms of solid content.

[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 antifading agent include nickel complexes and zinc complexes.
Specifically, Research Disclosure No. No. 17643, VII, I to J, No. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of representative compounds described in JP-A-62-215272, pages 127 to 137 can be used. .
Although the addition amount is appropriately selected according to the purpose, it is preferably 0.1 to 8% by weight in terms of solid content.

[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.

〔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 Examples include 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. % Is more preferable.

[Polymer compound]
Various polymer compounds can be added to the ink composition of the present invention in order to adjust film physical properties.
High molecular compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylic resins. Rubber resins, waxes and other natural resins can be used. Two or more of these may be used in combination. Of these, vinyl copolymers obtained by copolymerization of acrylic monomers are preferred. Furthermore, as a copolymer composition of the polymer compound, a copolymer containing a carboxyl group-containing monomer, a methacrylic acid alkyl ester, or an acrylic acid alkyl ester as a structural unit is also preferably used.

[Basic compounds]
The basic compound can be added from the viewpoint of improving the storage stability of the ink composition.
As the basic compound that can be used in the present invention, known basic compounds can be used. For example, basic inorganic compounds such as inorganic salts, and basic organic compounds such as amines can be preferably used. .

In addition to this, for example, leveling additives, matting agents, waxes for adjusting film properties, polyolefins, polyethylene terephthalate (PET) and the like to improve adhesion to recording media In addition, a tackifier that does not inhibit the polymerization can be contained.
As the tackifier, specifically, a high molecular weight adhesive polymer described in JP-A-2001-49200, 5-6p (for example, (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms). An ester with an alcohol having, an ester of (meth) acrylic acid with an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer comprising an ester of (meth) acrylic acid with an aromatic alcohol having 6 to 14 carbon atoms) And a low molecular weight tackifier resin having a polymerizable unsaturated bond.

<Ink physical properties>
The ink composition of the present invention has a viscosity at 25 ° C. of preferably 40 mPa · s or less, more preferably 5 to 40 mPa · s, and more preferably 7 to 30 mPa · s in consideration of dischargeability. Further preferred. Moreover, it is preferable that the viscosity in discharge temperature (Preferably 25-80 degreeC, More preferably, 25-50 degreeC) is 3-15 mPa * s, and it is more preferable that it is 3-13 mPa * s. It is preferable that the composition ratio of the ink composition of the present invention is appropriately adjusted so that the viscosity is in the above range. By setting the viscosity at room temperature high, even when a porous recording medium is used, penetration of the ink composition into the recording medium can be avoided, and uncured monomers can be reduced. Furthermore, it is preferable because ink bleeding at the time of ink droplet landing can be suppressed, and as a result, the image quality is improved.

  In the present invention, the surface tension of the ink composition at 25 ° C. is preferably 20 to 35 mN / m, and more preferably 23 to 33 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 35 mN / m or less is preferable in terms of wettability.

(ink cartridge)
The ink cartridge of the present invention is an ink cartridge containing the ink composition of the present invention, and is preferably an ink cartridge containing an oxygen-impermeable container filled with the ink composition of the present invention. Hereinafter, the “oxygen-impermeable container” is also simply referred to as “ink container”.
In the present invention, the ink container is formed of an oxygen-impermeable material. Further, examples of the ink container include a configuration having a plastic case or a bag-like body, and a configuration having a bag-like body is preferable. Furthermore, it is more preferable that the ink container includes a bag-like body formed of a film and a supply unit capable of deriving the ink composition from the bag-like body. Here, an ink container including a bag-like body formed of a film and a supply unit capable of deriving an ink composition from the bag-like body is referred to as an ink pack.

In the present invention, it is particularly preferable that the ink container does not transmit oxygen, that is, the oxygen permeability coefficient of the ink container is 0, but the oxygen permeability coefficient of the ink container is substantially 1 × 10 ⁻¹⁴ (cm ^3). · Cm) / (cm ² · sec · Pa) is preferable.

The oxygen permeability coefficient can be measured by a differential pressure type gas chromatography method described in JIS K 7126A.
In the present invention, the oxygen transmission coefficient P (cm ³ · cm) / (cm ² · sec · Pa) of the ink container is calculated as follows.

X ₀ : Oxygen composition ratio in ink container before test X ₁ : Oxygen composition ratio in ink container after test X _air : Oxygen composition ratio in _air (0.21)
V: Inner volume of the ink container (cm ³ )
l: Ink container wall thickness (cm)
A: Ink container inner surface area (cm ² )
t: Time (sec)
P ₀ : total pressure (atmospheric pressure: 1.013 × 10 ⁵ Pa)

The ink container that can be used in the present invention can be produced according to a conventional method, and a commercially available product can also be used. Among these, the ink container is preferably an ink container, that is, an ink pack including a bag-like body formed of a film and a supply unit capable of deriving the ink composition from the bag-like body.
The bag-like body can be typically manufactured by a method of sealing a peripheral edge of a polyolefin film and molding it into a bag shape according to a conventional method. The film used here preferably has a thickness of 50 to 300 μm from the viewpoint of mechanical strength.

  The material of the ink container and the ink pack is not limited to polyolefin, such as polyethylene, ethylene vinyl acetate copolymer, polypropylene, or the like, but is a polymer obtained by blending or laminating the above polymers at an appropriate ratio, or a film thereof. Also good. In particular, the material of the plastic ink pack is preferably a heat-sealable thermoplastic polymer such as high-density, low-density or linear low-density polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, and polystyrene.

The ink pack may be composed of, for example, a multilayer film in which a suitable resin layer is further formed on the outside of the polyolefin, in addition to the above-mentioned polyolefin single layer film, laminate film, and the like.
Examples of the resin for forming an appropriate resin layer include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyacrylonitrile, polyamide (nylon), polycarbonate, polyfluorinated ethylene (Teflon (registered trademark)), and cyclic. Examples include olefin copolymers and polystyrene.
Some of these resins are generally difficult to heat-seal, but when they are heat-sealed using them and formed into a bag shape, a multilayer film in which polyolefin is arranged in the innermost layer is used. Good.
Specific examples of the multilayer film include a three-layer film in which the inner layer is polyethylene, the intermediate layer is nylon, and the outer layer is polyester, the inner and outer layers are polyethylene and the intermediate layer is polypropylene + polystyrene, and the inner and outer layers are polyethylene and polypropylene. And a three-layer film in which the intermediate layer is a cyclic olefin copolymer.
Here, as the cyclic olefin copolymer, commercially available products such as an ethylene-tetracyclododecene copolymer can be used.

FIG. 1 is an exploded perspective view showing an example of an ink cartridge that can be suitably used in the present invention.
The ink cartridge 130 contains an ink container (ink pack) 133 as a bag-like body in a space surrounded by a plastic case body 132 and a case upper lid 131. The ink container (ink pack) 133 is configured by attaching a supply unit 134 that is a cylindrical member to one end of a bag-like body 141 in which a film is formed in a bag shape, and the inside of the ink container (ink pack) 133. Contains an ink composition.
The front end of the supply unit 134 is exposed to the outside of the case from a notch 140 provided on the front wall of the case main body 132, and the ink cartridge 130 is attached to the cartridge holder (not shown) through the supply unit 134. Ink is supplied to the printer body. When the ink cartridge 130 is not attached, the opening of the supply unit 134 is preferably closed by a valve provided inside.

  The ink pack 133 is formed in a flat shape sandwiched between an upper surface 137 and a bottom surface 138, and one end side to which the supply unit 134 is attached and the other end side with respect to the one end side are thermally welded to a front end welded portion 135 and a rear end, respectively. An end weld portion 136 is formed. A fold line 147 is formed on the side surface 139 between the upper surface 137 and the bottom surface 138, and the side surface 139 is configured to be folded inward of the ink pack 133.

Here, the external configuration of the ink pack 133 will be described in detail by comparing FIG. 2 with FIG. 1.
FIG. 2 is a schematic development view of the ink pack 133 shown in FIG.
In FIG. 2, the boundary between the top surface 137 and the side surface 139, the boundary between the bottom surface 138 and the side surface 139, and the fold line 147 of the side surface 139 are indicated by two-dot chain lines, and the hatched region indicates a portion to be thermally welded. The supply unit 134 and the ink composition inside are not shown.
As shown in FIG. 2, the ink pack 133 is formed by heat-welding four sides of a film 160 cut into a substantially rectangular shape. The long side of the four sides corresponds to the front end welded portion 135 and the rear end welded portion 136 shown in FIG. 1, and the central welded portions 148a and 148b on the short side are joined together and thermally welded. The bottom surface 138 shown in FIG.

  In addition, although the example which uses an ink pack as an ink container was explained in full detail, this invention is not limited to this, For example, it is an ink container comprised from a plastic case, and all or one part is oxygen. It may be formed of a permeable material.

(Inkjet recording method, inkjet recording apparatus, and printed matter)
The ink composition of the present invention can be suitably used as an ink composition for inkjet recording.
In the inkjet recording method of the present invention, the ink composition of the present invention is ejected onto a recording medium (support, recording material, etc.), and the ink composition ejected onto the recording medium is irradiated with actinic radiation. It is a method of forming an image by curing a composition.

More specifically, the inkjet recording method of the present invention comprises (a ¹ ) a step of ejecting the ink composition of the present invention onto a recording medium, and (b ¹ ) irradiating the ejected ink composition with active radiation. And a step of curing the ink composition.
By including the steps (a ¹ ) and (b ¹ ), the ink jet recording method of the present invention forms an image with the ink composition cured on the recording medium.
The printed matter of the present invention is a printed matter recorded by the inkjet recording method of the present invention.

In the step (a ¹ ) in the ink jet recording method of the present invention, an ink jet recording apparatus described in detail below can be used.
There is no restriction | limiting in particular as an inkjet recording device used for the inkjet recording method of this invention, The well-known inkjet recording device which can achieve the target resolution can be selected arbitrarily and can be used. That is, any known inkjet recording apparatus including a commercially available product can eject the ink composition onto the recording medium in the step (a ¹ ) of the inkjet recording method of the present invention.
In the present invention, the recording medium is not particularly limited, and a known recording medium can be used as a support or a recording material. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which the above-mentioned metal is laminated or deposited. In addition, as the recording medium in the present invention, a non-absorbable recording medium can be preferably used.
Examples of the ink jet recording apparatus that can be used in the present invention include an apparatus including an ink supply system, a temperature sensor, and an actinic radiation source.
The ink supply system includes, for example, an ink cartridge containing an ink composition therein, a supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. The piezo-type inkjet head preferably has a multi-size dot of 1 to 100 pl, more preferably 8 to 30 pl, preferably 320 × 320 to 4,000 × 4,000 dpi, more preferably 400 × 400 to 1,600 ×. It can be driven so that it can discharge at a resolution of 1,600 dpi, more preferably 720 × 720 dpi. In the present invention, dpi represents the number of dots per 2.54 cm.

As described above, since the radiation curable ink composition such as the ink composition of the present invention desirably has a constant temperature for the ink composition to be ejected, from the ink composition supply tank to the inkjet head portion. Insulation and heating can be performed. 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 flow rate of the ink composition and the environmental temperature. The temperature sensor can be provided in the vicinity of the nozzle of the ink composition supply tank and the inkjet head. Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside air. In order to shorten the printer start-up time required for heating or to reduce the loss of thermal energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.
An embodiment in which the ink jet recording apparatus includes the ink cartridge of the present invention is also preferable.

In the ink jet recording method of the present invention, the ink composition is discharged preferably by heating the ink composition to 25 to 80 ° C., more preferably 25 to 50 ° C., thereby increasing the viscosity of the ink composition, preferably 3 to 3. It is preferable to carry out after lowering to 15 mPa · s, more preferably 3 to 13 mPa · s. In particular, it is preferable to use an ink composition having an ink viscosity of 50 mPa · s or less at 25 ° C. because it can be discharged satisfactorily. By using this method, high ejection stability can be realized.
A radiation curable ink composition such as the ink composition of the present invention generally has a higher viscosity than a water-based ink usually used in an ink composition for ink jet recording, and therefore has a large viscosity fluctuation due to temperature fluctuations during ejection. The ink viscosity fluctuation has a great influence on the change of the droplet size and the change of the droplet discharge speed, and causes the image quality deterioration. Therefore, it is necessary to keep the temperature of the ink composition during ejection as constant as possible. Therefore, in the present invention, the temperature control range of the ink composition is preferably set to ± 5 ° C. of the set temperature, more preferably ± 2 ° C. of the set temperature, and further preferably set temperature ± 1 ° C. .

Next, (b ¹ ) a step of curing the ink composition by irradiating the discharged ink composition with active radiation will be described.
The ink composition ejected on the recording medium is cured by irradiation with actinic radiation. This is because the polymerization initiator contained in the ink composition is decomposed by irradiation with actinic radiation to generate starting species such as radicals, acids, bases, etc., and the polymerization reaction of the radical polymerizable compound is a function of the starting species. This is because it is created and promoted. At this time, if a sensitizer is present together with the polymerization initiator in the ink composition, the sensitizer in the system absorbs actinic radiation to be in an excited state, and promotes decomposition of the polymerization initiator by contacting with the polymerization initiator. And a more sensitive curing reaction can be achieved.

  Here, examples of the active radiation used include α rays, γ rays, electron beams, X rays, ultraviolet rays, visible light, and infrared light. Although the peak wavelength of actinic radiation is based also on the absorption characteristic of a sensitizer, it is preferable that it is 200-600 nm, for example, it is more preferable that it is 300-450 nm, and it is further more preferable that it is 350-420 nm.

In addition, the polymerization initiation system in the ink composition of the present invention preferably has sufficient sensitivity even with a low output actinic radiation. Therefore, the illumination intensity on the exposed surface, preferably preferably be cured by 10~4,000mW / cm ^2, and more preferably cured at 20 to 2,500 mW / cm ^2.

Mercury lamps and gas / solid lasers are mainly used as actinic radiation sources, and mercury lamps and metal halide lamps are widely known as light sources used for curing ink compositions for ultraviolet light curable ink jet recording. It has been. However, from the viewpoint of environmental protection, mercury-free is strongly desired, and replacement with a GaN-based semiconductor ultraviolet light-emitting device is very useful industrially and environmentally. Furthermore, LED (UV-LED) and LD (UV-LD) are small, have a long lifetime, high efficiency, and low cost, and are expected as light sources for photo-curable ink jets.
Further, a light emitting diode (LED) and a laser diode (LD) can be used as the active radiation source. In particular, when an ultraviolet light source is required, an ultraviolet LED and an ultraviolet LD can be used. For example, Nichia Corporation has introduced a purple LED whose main emission spectrum has a wavelength between 365 nm and 420 nm. When even shorter wavelengths are required, US Pat. No. 6,084,250 discloses an LED that can emit actinic radiation centered between 300 nm and 370 nm. Other ultraviolet LEDs are also available and can emit radiation in different ultraviolet bands. In the present invention, the actinic radiation source is preferably a UV-LED, and more preferably a UV-LED having a peak wavelength at 350 to 420 nm.
The maximum illumination intensity of the LED on a recording medium is preferably 10 to 2,000 mW / cm ^2, more preferably 20 to 1,000 mW / cm ^2, at 50 to 800 mW / cm ² It is particularly preferred.

The ink composition of the present invention is preferably irradiated with such actinic radiation for 0.01 to 120 seconds, and more preferably for 0.1 to 90 seconds.
Actinic radiation irradiation conditions and a basic irradiation method are disclosed in JP-A-60-132767. Specifically, the light source is provided on both sides of the head unit including the ink ejection device, and the head unit and the light source are scanned by a so-called shuttle method. Irradiation with actinic radiation is performed for a certain time (preferably 0.01 to 0.5 seconds, more preferably 0.01 to 0.3 seconds, still more preferably 0.01 to 0.15 seconds) after the ink composition has landed. ). In this way, by controlling the time from landing to irradiation of the ink composition to an extremely short time, it is possible to prevent the ink composition that has landed on the recording medium from spreading before curing. In addition, since the ink composition can be exposed to a porous recording medium before the ink composition penetrates to a deep portion where the light source does not reach, it is preferable because residual unreacted monomers can be suppressed.
Further, the curing may be completed by another light source that is not driven. International Publication No. 99/54415 pamphlet discloses 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 as an irradiation method. Such a curing method can also be applied to the ink jet recording method of the present invention.

By adopting the ink jet recording method as described above, the dot diameter of the landed ink can be kept constant even on various recording media having different surface wettability, and the image quality is improved. In addition, in order to obtain a color image, it is preferable to superimpose in order from the color with the lowest brightness. By superimposing the inks in the order of low lightness, it becomes easier for the irradiation line to reach the lower ink, and good curing sensitivity, reduction of residual monomers, and improvement in adhesion can be expected. In addition, irradiation can be performed by discharging all colors and collectively exposing, but exposure for each color is preferable from the viewpoint of promoting curing.
Thus, the ink composition of the present invention can form an image on the surface of a recording medium by being cured with high sensitivity by irradiation with actinic radiation.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to these examples. In the following description, “parts” means “parts by weight” unless otherwise specified.

The materials used in the present invention are as shown below.
・ IRGALITETE BLUE GLVO (Cyan pigment, manufactured by Ciba Specialty Chemicals (CSC))
・ CINQUASIA MAGENTA RT-335 D (Magenta pigment, manufactured by Ciba Specialty Chemicals)
・ NOVOPERM YELLOW H2G (yellow pigment, manufactured by Clariant)
SPECIAL BLACK 250 (black pigment, manufactured by Ciba Specialty Chemicals)
・ KRONOS2300 (white pigment, manufactured by KRONOS)
・ Fancrill 512A (manufactured by Hitachi Chemical Co., Ltd.)
・ Fankrill 513A (manufactured by Hitachi Chemical Co., Ltd.)
・ Funkrill 512M (manufactured by Hitachi Chemical Co., Ltd.)
・ Isobornyl acrylate (SR506, manufactured by Satomer)
・ 3,3,5-trimethylcyclohexyl acrylate (CD420, manufactured by Satomer)
N-vinylcaprolactam (NVC, manufactured by Aldrich)
-Actilane 421 (propoxylated neopentyl glycol diacrylate, manufactured by Akcros)
・ KAYARAD DPCA-60 (DPCA, caprolactone-modified dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.)
-Solsperse 32000 (Noveon's dispersant)
Disper BYK-168 (polymer dispersing agent manufactured by BYK Chemie)
・ NK ester AMP-10G (PEA, phenoxyethyl acrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ THFA (tetrahydrofurfuryl acrylate, manufactured by Aldrich)
・ Rapi-Cure DVE-3 (triethylene glycol divinyl ether, manufactured by ISP Europe)
FIRSTCURE ST-1 (Tris (N-Nitroso-N-Phenylhydroxylamine) Aluminum Salt, nitroso polymerization inhibitor, 10 wt% phenoxyethyl acrylate solution, manufactured by Chem First)
TINUVIN 770 DF (Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, HALS polymerization inhibitor, manufactured by Ciba Specialty Chemicals)
TINUVIN 292 (bis (1,2,2,6,6-Pentamethyl-4-piperidinyl) sebacate and Methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate mixture, HALS polymerization) Inhibitor, manufactured by Ciba Specialty Chemicals)
・ MEHQ (hydroquinone monomethyl ether, phenol polymerization inhibitor, manufactured by Wako Chemical Co., Ltd.)
・ BHT (dibutylhydroxytoluene (2,6-di-t-butyl-4-methylphenol), phenol polymerization inhibitor, manufactured by Wako Chemical Co., Ltd.)
・ Lucirin TPO (Photoinitiator manufactured by BASF)
・ Benzophenone (Photoinitiator, Wako Pure Chemical Industries, Ltd.)
IRGACURE 184 (photoinitiator, manufactured by Ciba Specialty Chemicals)
-BYK-307 (surfactant, manufactured by BYK Chemie)
・ KF-353 (silicone surfactant, manufactured by Shin-Etsu Chemical Co., Ltd.)
-FIRSTCURE ITX (sensitizer, manufactured by Chem First)

(Preparation of cyan mill base A)
300 parts by weight of IRGALITETE BLUE GLVO, 500 parts by weight of Actylene 421 (Akcros acrylate monomer), and 200 parts by weight of Solsperse 32000 were mixed with stirring to obtain cyan mill base A. Cyan mill base A was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of magenta mill base B)
300 parts by weight of CINQUASIA MAGENTA RT-335 D, 300 parts by weight of Rapi-Cure DVE-3, and 400 parts by weight of Solsperse 32000 were mixed with stirring to obtain magenta mill base B. The magenta mill base B was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 10 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base C)
300 parts by weight of NOVOPERM YELLOW H2G, 300 parts by weight of Actylene 421 (Akcros acrylate monomer), and 400 parts by weight of Solsperse 32000 were mixed with stirring to obtain Yellow Mill Base C. The yellow mill base C was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 10 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of black mill base D)
300 parts by weight of SPECIAL BLACK 250, 300 parts by weight of Actylene 421 (Akcros acrylate monomer), and 400 parts by weight of Solsperse 32000 were mixed with stirring to obtain a black mill base D. The black mill base D was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 7 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of white mill base E)
A white mill base E was obtained by stirring and mixing 500 parts by weight of KRONOS 2300, 400 parts by weight of Actirane 421 (Akcros acrylate monomer) and 100 parts by weight of Solsperse 32000. The white mill base E was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of cyan mill base A-2)
300 parts by weight of IRGALITETE BLUE GLVO, 650 parts by weight of NK ester AMP-10G, and 50 parts by weight of Solsperse 32000 were stirred and mixed to obtain cyan mill base A-2. Cyan mill base A-2 was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 2 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of magenta mill base B-2)
300 parts by weight of CINQUASIA MAGENTA RT-335 D, 640 parts by weight of NK ester AMP-10G, and 60 parts by weight of Solsperse 32000 were stirred and mixed to obtain magenta mill base B-2. Magenta mill base B-2 was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 7 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base C-2)
300 parts by weight of NOVOPERM YELLOW H2G, 640 parts by weight of NK ester AMP-10G, and 60 parts by weight of Solsperse 32000 were stirred and mixed to obtain yellow mill base C-2. The yellow mill base C-2 was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 5 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of black mill base D-2)
300 parts by weight of SPECIAL BLACK 250, 650 parts by weight of NK ester AMP-10G, and 50 parts by weight of Solsperse 32000 were mixed with stirring to obtain a black mill base D-2. Black mill base D-2 was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 3 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

<Inkjet image recording method>
Next, recording on a recording medium was performed using an inkjet recording apparatus having a piezoelectric inkjet nozzle. The ink composition supply system consists of an original tank, supply piping, an ink composition supply tank just before the inkjet head, a filter, and a piezo-type inkjet head, and performs heat insulation and heating from the ink composition supply tank to the inkjet head part. It was. The temperature sensors were provided near the ink composition supply tank and the nozzle of the inkjet head, respectively, and temperature control was performed so that the nozzle portion was always 45 ° C. ± 2 ° C. The piezo-type inkjet head was driven so that 8 to 30 pl multi-size dots could be ejected at a resolution of 720 × 720 dpi. After landing, UV light is condensed to an exposure surface illuminance of 1,630 mW / cm ² , and the exposure system, main scanning speed and emission frequency are set so that irradiation starts 0.1 seconds after the ink composition has landed on the recording medium. It was adjusted. Further, the integrated light amount irradiated to the image was set to 12,000 mJ / cm ² . As an ultraviolet lamp, a HAN250NL high-cure mercury lamp (manufactured by GS Yuasa Corporation) was used. In the present invention, dpi represents the number of dots per 2.54 cm. As a recording medium, an ester film E5000 (thickness 125 μm, manufactured by Toyobo Co., Ltd.) was used.

[Measurement of curing sensitivity]
A solid image having an average film thickness of 12 μm was drawn, and the image surface after ultraviolet irradiation was evaluated by palpation. The amount of exposure energy (mJ / cm ² ) at which the sticky feeling disappears on the image surface after ultraviolet irradiation was defined as the curing sensitivity. The smaller the value, the higher the sensitivity.

[Method of measuring viscosity]
In this example, the viscosity was measured using a B-type viscometer: Brookfield LVDV-I (manufactured by Brookfield) at 25 ° C. and a rotor rotation speed of 20 rpm.

[Thermal stability evaluation]
-The viscosity of the ink stored in an aluminum-deposited multilayer structure oxygen-impermeable pack at 35 ° C for 3 months was measured, and the rate of increase / decrease from the initial viscosity was evaluated (forced aging test under normal storage conditions (at room temperature)).
Thermal stability (35 ° C.) = ((Ink viscosity after storage at 35 ° C. for 3 months) − (initial ink viscosity)) / (initial ink viscosity) × 100
・ Measured the viscosity of ink stored in an aluminum-deposited multilayer oxygen non-permeable pack for 1 month at 60 ° C., and evaluated the rate of increase / decrease from the initial viscosity (in the ink tank or in the inkjet head (heating at about 45 ° C.) Time) forced aging test).
Thermal stability (60 ° C.) = ((Ink viscosity after 1 month storage at 60 ° C.) − (Initial ink viscosity)) / (initial ink viscosity) × 100
In addition, the aluminum vapor deposition multilayer structure oxygen impermeable pack used above has an ink capacity of 250 ml and is a laminated form of polyethylene, nylon and polyester, and has an oxygen permeability coefficient of 9 × 10 ⁻¹⁴ (cm ³ · cm) / (cm ² · sec · Pa).

Example 1
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 19 mPa · s.
<Cyan ink composition>
・ Cyan Mill Base A 6.0 parts ・ N-vinylcaprolactam 25.0 parts ・ Fancryl 512A 35.0 parts ・ NK ester AMP-10G 20.0 parts ・ Compound (A-1) 0.5 part ・ Lucirin TPO ( BASF photoinitiator) 8.45 parts Benzophenone (photoinitiator) 3.0 parts IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 2)
The following components were stirred with a high-speed water-cooled stirrer to obtain a magenta UV inkjet ink. The initial viscosity was 20 mPa · s.
<Magenta ink composition>
・ Magenta mill base B 12.0 parts ・ N-vinylcaprolactam 25.0 parts ・ Fancryl 512A 35.0 parts ・ NK ester AMP-10G 14.0 parts ・ Compound (A-1) 0.5 part ・ Lucirin TPO ( BASF photoinitiator) 8.45 parts Benzophenone (photoinitiator) 3.0 parts IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 3)
The following components were stirred with a high-speed water-cooled stirrer to obtain a yellow UV inkjet ink. The initial viscosity was 19 mPa · s.
<Yellow color ink composition>
・ Yellow mill base C 12.0 parts ・ N-vinylcaprolactam 25.0 parts ・ Fancryl 512A 35.0 parts ・ NK ester AMP-10G 14.0 parts ・ Compound (A-1) 0.5 part ・ Lucirin TPO ( BASF photoinitiator) 8.45 parts Benzophenone (photoinitiator) 3.0 parts IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

Example 4
The following components were stirred with a high-speed water-cooled stirrer to obtain a black UV inkjet ink. The initial viscosity was 19 mPa · s.
<Black ink composition>
Black mill base D 6.0 parts N-vinylcaprolactam 25.0 parts Fancrail 512A 35.0 parts NK ester AMP-10G 20.0 parts Compound (A-1) 0.5 parts Lucirin TPO ( BASF photoinitiator) 8.45 parts Benzophenone (photoinitiator) 3.0 parts IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 5)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 18 mPa · s.
<Cyan ink composition>
-Cyan mill base A-2 6.0 parts-DisperBYK-168 2.0 parts-N-vinylcaprolactam 26.0 parts-Funkrill 512A 36.5 parts-NK ester AMP-10G 9.5 parts-KAYARAD DPCA-60 2.0 parts · Rapi-Cure DVE-3 3.0 parts · Compound (A-1) 0.3 parts · Lucirin TPO (BASF photoinitiator) 9.0 parts · Benzophenone (photoinitiator) 2 parts IRGACURE 184 (CSC photoinitiator) 2.44 parts KF353 0.06 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 6)
The following components were stirred with a high-speed water-cooled stirrer to obtain a magenta UV inkjet ink. The initial viscosity was 20 mPa · s.
<Magenta ink composition>
・ Magenta mill base B-2 13.0 parts ・ DisperBYK-168 2.0 parts ・ N-vinylcaprolactam 28.04 parts ・ Fancrill 512A 32.0 parts ・ NK ester AMP-10G 8.0 parts ・ KAYARAD DPCA-60 1.4 parts-Rapi-Cure DVE-3 3.0 parts-Compound (A-1) 0.3 parts-Lucirin TPO 9.0 parts-Benzophenone 3.5 parts-KF353 0.06 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 7)
The following components were stirred with a high-speed water-cooled stirrer to obtain a yellow UV inkjet ink. The initial viscosity was 18 mPa · s.
<Yellow color ink composition>
・ Yellow mill base C-2 13.0 parts ・ DisperBYK-168 2.0 parts ・ N-vinylcaprolactam 24.0 parts ・ Fancrill 512A 35.0 parts ・ NK ester AMP-10G 9.0 parts ・ KAYARAD DPCA-60 1.44 parts · Rapi-Cure DVE-3 3.0 parts · Compound (A-1) 0.3 parts · Lucirin TPO 9.0 parts · Benzophenone 3.5 parts · KF353 0.06 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 8)
The following components were stirred with a high-speed water-cooled stirrer to obtain a black UV inkjet ink. The initial viscosity was 18 mPa · s.
<Black ink composition>
Black mill base D-2 6.0 parts DisperBYK-168 2.0 parts N-vinylcaprolactam 26.0 parts Funkrill 512A 36.5 parts NK ester AMP-10G 9.5 parts KAYARAD DPCA-60 2.0 parts · Rapi-Cure DVE-3 3.0 parts · Compound (A-1) 0.3 parts · Lucirin TPO (BASF photoinitiator) 9.0 parts · Benzophenone (photoinitiator) 5 parts IRGACURE 184 (CSC photoinitiator) 2.44 parts KF353 0.06 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

Example 9
The following components were stirred with a high-speed water-cooled stirrer to obtain a white UV inkjet ink. The initial viscosity was 20 mPa · s.
<White ink composition>
・ White mill base E 31.0 parts ・ N-vinylcaprolactam 19.0 parts ・ Fancrill 512A 26.05 parts ・ NK ester AMP-10G 10.0 parts ・ TINUVIN 770 DF (HALS polymerization inhibitor, manufactured by CSC) 0.1 part ・ Compound (A-1) 0.3 part ・ Lucirin TPO (BASF Photoinitiator) 8.5 parts ・ Benzophenone (Photoinitiator) 3.0 parts ・ IRGACURE 184 (CSC Photoinitiator) Agent) 2.0 parts BYK-307 (surfactant manufactured by BYK Chemie) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 10)
The following components were stirred with a high-speed water-cooled stirrer to obtain a clear UV inkjet ink. The initial viscosity was 17 mPa · s.
<Clear color ink composition>
-N-vinyl caprolactam 25.0 parts-51.15 parts of fancryl 512A-10.0 parts of NK ester AMP-10G-0.3 parts of compound (A-1)-Lucirin TPO (photoinitiator manufactured by BASF) 8 .5 parts-Benzophenone (photoinitiator) 3.0 parts-IRGACURE 184 (CSC photoinitiator) 2.0 parts-BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

Example 11
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 24 mPa · s.
<Cyan ink composition>
-Cyan mill base A 6.0 parts-N-vinyl caprolactam 25.0 parts-Fancril 512A 35.15 parts-NK ester AMP-10G 20.0 parts-Compound (A-5) 0.3 part-Lucirin TPO ( BASF photoinitiator) 8.5 parts benzophenone (photoinitiator) 3.0 parts IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

Example 12
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 19 mPa · s.
<Cyan ink composition>
・ Cyan Mill Base A 6.0 parts ・ N-vinylcaprolactam 30.0 parts ・ Fancrile 513M 30.15 parts ・ Fancryl 512M 20.0 parts ・ Compound (A-1) 0.3 part ・ Lucirin TPO (BASF Corporation) 8.5 parts-Benzophenone (photoinitiator) 3.0 parts-IRGACURE 184 (CSC photoinitiator) 2.0 parts-BYK-307 (BYK Chemie surfactant) 0. 05 copies

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 13)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 18 mPa · s.
<Cyan ink composition>
-Cyan mill base A 6.0 parts-N-vinyl caprolactam 25.0 parts-NK ester AMP-10G 55.1 parts-Compound (A-1) 0.3 parts-Lucirin TPO (Photoinitiator manufactured by BASF) 8 .55 parts ・ Benzophenone (photoinitiator) 3.0 parts ・ IRGACURE 184 (CSC photoinitiator) 2.0 parts ・ BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 14)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 19 mPa · s.
<Cyan ink composition>
-Cyan mill base A 6.0 parts-Isobornyl acrylate 15.4 parts-N-vinylcaprolactam 15.0 parts-NK ester AMP-10G 50.0 parts-Compound (A-1) 0.3 part-Lucirin TPO (BASF photoinitiator) 8.25 parts benzophenone (photoinitiator) 3.0 parts IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) ) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 15)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 18 mPa · s.
<Cyan ink composition>
-Cyan mill base A 6.0 parts-Fancril 513A 20.4 parts-N-vinylcaprolactam 25.0 parts-NK ester AMP-10G 35.0 parts-Compound (A-1) 0.3 part-Lucirin TPO ( BASF photoinitiator) 8.25 parts benzophenone (photoinitiator) 3.0 parts IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 16)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 18 mPa · s.
<Cyan ink composition>
-Cyan mill base A 6.0 parts-N-vinyl caprolactam 26.0 parts-3,3,5- trimethylcyclohexyl acrylate 35.4 parts-NK ester AMP-10G 19.0 parts-Compound (A-1) 0. 3 parts · Lucirin TPO (BASF photoinitiator) 8.25 parts · Benzophenone (photoinitiator) 3.0 parts · IRGACURE 184 (CSC photoinitiator) 2.0 parts · BYK-307 (BYK Chemie) 0.05 parts surfactant)

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Example 17)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 24 mPa · s.
<Cyan ink composition>
-Cyan mill base A 6.0 parts-N-vinyl caprolactam 25.0 parts-Fancryl 512A 35.15 parts-NK ester AMP-10G 20.0 parts-Compound (A-5) 0.3 part-FIRSTCURE ST- 1 (nitroso polymerization inhibitor, 10 wt% solution, manufactured by Chem First) 0.3 part ・ Lucirin TPO (photoinitiator manufactured by BASF) 8.2 parts ・ benzophenone (photoinitiator) 3.0 parts ・ IRGACURE 184 (CSC photoinitiator) 2.0 parts BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Comparative Example 1)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 17 mPa · s.
<Cyan ink composition>
・ Cyan mill base A 6.0 parts ・ N-vinylcaprolactam 25.0 parts ・ Fancrill 512A 35.15 parts ・ NK ester AMP-10G 20.0 parts ・ FIRSTCURE ST-1 0.3 part ・ Lucirin TPO (BASF Corporation) 8.5 parts-Benzophenone (photoinitiator) 3.0 parts-IRGACURE 184 (CSC photoinitiator) 2.0 parts-BYK-307 (BYK Chemie surfactant) 0. 05 copies

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Comparative Example 2)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 18 mPa · s.
<Cyan ink composition>
・ Cyan mill base A 6.0 parts ・ N-vinylcaprolactam 25.0 parts ・ Fancryl 512A 35.0 parts ・ NK ester AMP-10G 20.0 parts ・ MEHQ (aromatic antioxidant, Wako Chemicals, Inc.) 0.5 parts ・ Lucirin TPO (photoinitiator manufactured by BASF) 8.45 parts ・ benzophenone (photoinitiator) 3.0 parts ・ IRGACURE 184 (photoinitiator manufactured by CSC) 2.0 parts ・ BYK- 307 (surfactant manufactured by BYK Chemie) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Comparative Example 3)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 18 mPa · s.
<Cyan ink composition>
・ Cyan mill base A 6.0 parts ・ N-vinylcaprolactam 25.0 parts ・ Fancryl 512A 35.0 parts ・ NK ester AMP-10G 20.0 parts ・ BHT (aromatic antioxidant, Wako Chemicals, Inc.) 0.5 parts ・ Lucirin TPO (photoinitiator manufactured by BASF) 8.45 parts ・ benzophenone (photoinitiator) 3.0 parts ・ IRGACURE 184 (photoinitiator manufactured by CSC) 2.0 parts ・ BYK- 307 (surfactant manufactured by BYK Chemie) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Comparative Example 4)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 18 mPa · s.
<Cyan ink composition>
・ Cyan mill base A 6.0 parts ・ N-vinylcaprolactam 25.0 parts ・ Fancrill 512A 35.25 parts ・ NK ester AMP-10G 20.0 parts ・ TINUVIN 770 DF 0.2 part ・ Lucirin TPO (manufactured by BASF) 8.5 parts · Benzophenone (photoinitiator) 3.0 parts · IRGACURE 184 (CSC photoinitiator) 2.0 parts · BYK-307 (BYK Chemie surfactant) 0.05 Part

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

(Comparative Example 5)
The following components were stirred with a high-speed water-cooled stirrer to obtain a cyan UV inkjet ink. The initial viscosity was 17 mPa · s.
<Cyan ink composition>
・ Cyan Mill Base A 6.0 parts ・ N-Vinylcaprolactam 25.0 parts ・ Fancrill 512A 35.3 parts ・ NK ester AMP-10G 20.0 parts ・ TINUVIN 292 0.15 parts ・ Lucirin TPO (manufactured by BASF) Initiator) 8.5 parts ・ Benzophenone (photoinitiator) 3.0 parts ・ IRGACURE 184 (CSC photoinitiator) 2.0 parts ・ BYK-307 (BYK Chemie surfactant) 0.05 parts

<Evaluation of ink composition>
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability and thermal stability.

FIG. 3 is an exploded perspective view showing an example of an ink cartridge that can be suitably used in the present invention. FIG. 2 is a schematic development view of the ink pack 133 shown in FIG. 1.

Explanation of symbols

130 Ink cartridge 131 Case upper lid 132 Case main body 133 Ink container (ink pack)
134 Supply portion 135 Front end weld portion 136 Rear end weld portion 137 Upper surface 138 Bottom surface 139 Side surface 140 Notch portion 141 Bag-like body 147 Creases 148a, 148b Central weld portion 160 Film

Claims (8)

Polymerizable compounds,
Polymerization inhibitors, and
Including a polymerization initiator,
The polymerizable compound includes an N-vinyl compound;
The ink composition, wherein the polymerization inhibitor contains a quinone methylide compound.   The ink composition according to claim 1, wherein the polymerization initiator includes an acylphosphine compound.   The polymerizable compound is 2-acryloyloxyethyl monohydroxyphthalate, 2-acryloyloxypropyl monohydroxyphthalate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, isobornyl acrylate, tetrahydro The ink composition according to claim 1 or 2, comprising at least one monofunctional polymerizable compound selected from the group consisting of furfuryl acrylate, acryloylmorpholine, and 3,3,5-trimethylcyclohexyl acrylate.   The ink composition according to claim 1, wherein the ink composition is for inkjet recording.   An ink cartridge containing an oxygen-impermeable container filled with the ink composition according to claim 1. Step (a ¹⁾ of discharging the ink composition according to any one of claims 1 to 4 onto a recording medium and,
(B ¹⁾ The ink composition discharged with actinic radiation is irradiated, the step of curing the ink composition, inkjet recording method comprising. The actinic radiation is ultraviolet light irradiated by a light emitting diode that generates ultraviolet light having an emission peak wavelength in the range of 350 to 420 nm and a maximum illuminance on the surface of the recording medium of 10 to 2,000 mW / cm ^2. The inkjet recording method according to claim 6.   Printed matter recorded by the ink jet recording method according to claim 6 or 7.

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