JP2012177061A - Ink composition, image forming method, and printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition that is excellent in storage stability, wherein an image obtained by using the ink composition is excellent in punchability and stretchability; and to provide an image forming method using the same.SOLUTION: The ink composition is used which comprises: a compound (component A) that does not have an ethylenically unsaturated double bond but has a silsesquioxane structure, and has a molecular weight of 300 to 3,000; a monofunctional polymerizable compound (component B); a polymerization initiator (component C); and a colorant (component D), wherein the content of the monofunctional polymerizable compound (component B) to the total of all polymerizable compounds is 80 mass% or more.

Description

  The present invention relates to an ink composition, an image forming 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. Among these, the ink jet method can be implemented with an inexpensive apparatus, and the ink can be efficiently used because the image is directly formed on the recording medium by ejecting the ink only to the required image portion. Running cost is low.

  As one of the ink jet methods, there is a recording method using an ink for ink jet recording that can be cured by irradiation with active energy rays. According to this method, by curing the ink droplets, the productivity of printing can be improved and a sharp image can be formed. It is also possible to mold a printed material on which an image is formed by such an ink jet method.

  For example, Patent Document 1 discloses a radiation curable ink composition containing an initiator and a polyhedral oligomeric silsesquioxane for the purpose of improving curability and sensitivity.

  Patent Document 2 discloses an optical nanoprint containing a polymerization initiator, a polymerizable compound, and silsesquioxane for the purpose of improving imprintability after heating and curing, substrate adhesion, heat resistance and surface hardness. A composition is disclosed.

JP 2004-339480 A JP 2010-13514 A

By the way, when the image-formed printed material is slowly stretched by heating to be molded, if the stretchability is insufficient, cracks or the like may occur on the molded image surface.
In addition, when a molded product is punched into individual molded products and cut, if the impact resistance (impact resistance) is insufficient, cracks (peripheral cracks) may occur on the cut surface or in the vicinity thereof. There's a problem. A product with such a low punching property has a reduced product value.

  None of the above documents discloses any improvement in punching characteristics and stretchability of an image formed. Further, there is still room for improvement regarding the storage stability of the ink composition.

  The present invention has been made in view of the above, and provides an ink composition having good storage stability, excellent punching characteristics and stretchability of an image obtained, an image forming method using the same, and a printed matter. It is an object to achieve this purpose.

Means for solving the above-mentioned problems are as follows.
Item 1. (Component A) a compound having no ethylenically unsaturated double bond and having a silsesquioxane structure and having a molecular weight of 300 to less than 3000, (Component B) a monofunctional polymerizable compound, (Component C) a polymerization initiator, and (Component D) An ink composition containing a colorant, wherein the content of (Component B) monofunctional polymerizable compound relative to the total content of all polymerizable compounds is 80% by mass or more.

  Item 2. Item 2. The ink composition according to Item 1, wherein the silsesquioxane structure is a structure represented by Structural Formula (A).

(In the structural formula (A), R ^x is a halogen atom, a cyano group, a thiol group, -PR ^a ₂ (R ^a is an aryl group), -SiR ^c ₃ (R ^c is an alkyl group), an amino group, an aryl group. Or R ^y is a single bond, —COO—, an alkylene group, an arylene group, an alkyleneoxy group, —SO ₂ —, —O—, —SiR ^b ₂ — (R ^b is an alkyl group) or —NH -Represents a group, * represents a bonding position.

Item 3. In the structural formula (A), R ^x is a thiol group, -PR ^a ₂ (R ^a is an aryl group), -SiR ^c ₃ (R ^c is an alkyl group), an alkyl group or an aryl group, and R ^y is an alkylene group. Item 3. The ink composition according to Item 2, which is an alkyleneoxy group or a single bond.
Item 4. Item 3. The ink composition according to Item 2, wherein R ^x in the structural formula (A) is an aryl group or an alkyl group, and R ^y is a single bond.
Item 5. Item 5. The ink composition according to any one of Items 1 to 4, wherein the silsesquioxane structure is a cage type.
Item 6. Item 6. The ink composition according to any one of Items 1 to 5, wherein the (Component A) compound is represented by the following General Formula (A-2).

(In the general formula (A-2), ^{R x} represents a halogen atom, a cyano group, a thiol ^group, _-PR ^a 2 ^(R a is an aryl _{^{group), - SiR c 3 (R}} c is an alkyl group), an amino group, Represents an aryl group or an alkyl group, and R ^y represents a single bond, —COO—, an alkylene group, an arylene group, an alkyleneoxy group, —SO ₂ —, —O—, —SiR ^b ₂ — (R ^b represents an alkyl group) or And represents a —NH— group, wherein a plurality of R ^x and R ^y may be the same or different from each other.

Item 7. Item 7. The ink composition according to Item 6, wherein R ^x in the general formula (A-2) is an aryl group or an alkyl group, and R ^y is a single bond.
Item 8. Item 8. The ink composition according to any one of Items 1 to 7, comprising an N-vinyl compound or a (meth) acrylamide compound as the monofunctional polymerizable compound.
Item 9. Item 9. The ink composition according to Item 8, wherein the N-vinyl compound is represented by the following formula (V).

  (In formula (V), m represents an integer of 1 to 5.)

  Item 10. Item 9. The ink composition according to Item 8, wherein the (meth) acrylamide compound is represented by the following formula (M-1).

(In General Formula (M-1), Q ¹ represents a single bond, an alkyleneoxy group or an alkylene group.
Q ² represents a hydrogen atom, an alkyl group, an aryl group, an amino group, a hydroxyl group, a sulfo group or an acyl group. Q ³ represents a hydrogen atom or an alkyl group. Q ² and Q ³ may be bonded to each other to form a ring. R ^m represents a hydrogen atom or a methyl group. )

Item 11. Item 11. The ink composition according to any one of Items 1 to 10, comprising 80 to 99 mass% of (Component B) a monofunctional polymerizable compound with respect to the total amount of the ink composition.
Item 12. Item 12. The ink composition according to any one of Items 1 to 11, comprising 0.1 to 20% by mass of the (Component A) compound with respect to the total amount of the ink composition.
Item 13. Item 13. The ink composition according to any one of Items 1 to 12, which is for inkjet recording.
Item 14. An ink application step of applying the ink composition according to any one of Items 1 to 13 onto a recording medium;
And an irradiation step of irradiating the ink composition with active energy rays.
Item 15. Item 15. The image forming method according to Item 14, wherein the ink application step is a step of applying the ink composition by an inkjet method.
Item 16. Item 14. A printed matter formed using the ink composition according to any one of Items 1 to 13.

  According to the present invention, an ink composition having good storage stability can be provided. In addition, an ink composition having excellent punching characteristics and stretchability can be provided.

Ink Composition The ink composition of the present invention comprises (Component A) a compound having no ethylenically unsaturated double bond and having a silsesquioxane structure and having a molecular weight of 300 to less than 3000, and (Component B) monofunctional polymerization. The content of the (component B) monofunctional polymerizable compound with respect to the total content of all polymerizable compounds is 80% by mass or more, including the functional compound, (component C) polymerization initiator and (component D) colorant. Features. Hereinafter, it is also simply referred to as “(component A)”, “(component B)”, “(component C)”, and “(component D)”. The ink composition of the present invention is preferably for inkjet recording.

Hereinafter, the ink composition of the present invention will be described in detail.
((Component A) Compound having no ethylenically unsaturated double bond and having a silsesquioxane structure and having a molecular weight of 300 or more and less than 3000)
The ink composition of the present invention contains (Component A) a compound having no ethylenically unsaturated double bond and having a silsesquioxane structure and having a molecular weight of 300 or more and less than 3000 as an essential component.

The compound having a silsesquioxane structure in the present invention is not limited as long as it is a siloxane compound formed by the structure of Si (O _1/2 ) ₃ having a substituent. In the present invention, a silsesquioxane structure having any structure such as a cage type, a ladder type, or a random type may be used, and a cage-type silsesquioxane structure is more preferable. The "cage type", "ladder type", and "random type" refer to structures described in, for example, the chemistry and application development of silsesquioxane materials (CMC Publishing).

  The silsesquioxane structure in the present invention is preferably a structure represented by the following structural formula (A).

(In the structural formula (A), R ^x is a halogen atom, a cyano group, a thiol group, -PR ^a ₂ (R ^a is an aryl group), -SiR ^c ₃ (R ^c is an alkyl group), an amino group, an aryl group. Or R ^y is a single bond, —COO—, an alkylene group, an arylene group, an alkyleneoxy group, —SO ₂ —, —O—, —SiR ^b ₂ — (R ^b is an alkyl group) or —NH -Represents a group, * represents a bonding position.

When R ^x in the structural formula (A) is a halogen atom, examples of the halogen atom include F, Cl, Br, I and the like. When R ^x is a halogen atom, R ^y is not a combination with a single bond, —COO—, —SO ₂ — or —NH—.

The ^{R a} when ^{R x} in the structural formula (A) is (are ^{R a} aryl group) ^-PR _a 2 is preferably an aryl group having 6 to 20 carbon atoms, an aryl group having 6 to 16 carbon atoms Is more preferable, and an aryl group having 6 to 10 carbon atoms is particularly preferable. Specific examples of the aryl group include a phenyl group and a naphthyl group. A plurality of ^Ra may be the same or different from each other. Note that when R ^x is —PR ^a ₂ (R ^a is an aryl group), R ^y is not a single bond, —COO—, —SO ₂ — or —NH—.

As ^{R c} is when ^{R x} in the structural formula (A) is ^{(R c} is an alkyl group) -SiR ^c ₃ is preferably an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 8 carbon atoms Is particularly preferred. The alkyl group may have a linear structure, a branched structure, or a cyclic structure. Specific examples of the alkyl group include a methyl group. A plurality of R ^c may be the same or different.

When R ^x in the structural formula (A) is an amino group, the amino group may be any of a primary amino group, a secondary amino group, or a tertiary amino group. For example, —NH ₂ , —NHR Or it represents with -NR < ₂ > (R is a substituent). The substituents represented by R of the amino group may be different from each other, for example, a linear or branched alkyl group having 1 to 8 carbon atoms (preferably having 1 to 4 carbon atoms), aryl having 6 to 20 carbon atoms. Group (preferably phenyl group) and the like. Specific examples of the amino group include a primary amino group and a dimethylamino group. These groups may or may not have a substituent, but preferably do not have a substituent. When R ^x is an amino group, R ^y is not a combination with a single bond, —COO—, —SO ₂ — or —NH—.

When R ^x in the structural formula (A) is an aryl group, the aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 16 carbon atoms, and an aryl group having 6 to 10 carbon atoms. Aryl groups are particularly preferred. Specific examples of the aryl group include a phenyl group and a naphthyl group, and a phenyl group is particularly preferable. These groups may or may not have a substituent, but preferably do not have a substituent.

When R ^x in Structural Formula (A) is an alkyl group, the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and 3 to 8 carbon atoms. The alkyl group is more preferable. The alkyl group may be a linear structure, a branched structure or a cyclic structure, but is preferably a chain, and particularly preferably a chain alkyl group having 3 to 8 carbon atoms. An epoxy group may be contained in the chain or cyclic alkyl group. In addition, when including an epoxy group, two carbons which comprise an epoxy group shall be included in the number of the above-mentioned carbon number. Specific examples of the alkyl group include a 3,4-epoxy-cyclohexyl group, a glycidyl group, a methyl group, an ethyl group, an isobutyl group, an isooctyl group, and a t-butyl group, and the isobutyl group and the isooctyl group include Particularly preferred. These groups may or may not have a substituent, but preferably do not have a substituent.

R ^x in the structural formula (A) is preferably an aryl group, an alkyl group, a thiol group, or an amino group, more preferably an alkyl group or an aryl group, an aryl group having 6 to 10 carbon atoms, or a 3 to 8 carbon atoms. A chain alkyl group is particularly preferred.

When ^Ry in Structural Formula (A) is an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms. Specific examples of the alkylene group include a methylene group. These groups may or may not have a substituent, but preferably do not have a substituent.

When R ^y in the structural formula (A) is an arylene group, the arylene group preferably has 6 to 18 carbon atoms, more preferably 6 to 14 carbon atoms, and 6 to 10 carbon atoms. It is particularly preferred that Specific examples of the arylene group include a phenylene group. These groups may or may not have a substituent, but preferably do not have a substituent.

When R ^y in the structural formula (A) is an alkyleneoxy group (—R—O—, R is an alkylene group), the alkyleneoxy group preferably has 1 to 10 carbon atoms, and further has 1 to 6 carbon atoms. Preferably, C1-C3 is especially preferable. Specific examples of the alkyleneoxy group include an ethoxy group. These groups may or may not have a substituent. The alkyleneoxy group is bonded to Si in the structural formula (A) in any direction of ** — R—O— and ** — O—R— (** represents a bonding position). Also good.

^{R y} in the structural formula (A) is -SiR ^b ₂ - The ^{R b} when (the ^{R b} alkyl group), preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, carbon atoms 1 to 3 is particularly preferable. Specific examples of the alkyl group include a methyl group. These groups may or may not have a substituent, but preferably do not have a substituent.

R ^y in the structural formula (A) is preferably a single bond, an alkylene group, or an arylene group, and more preferably a single bond.

In Structural Formula (A), a combination in which R ^x is a thiol group, —PR ^a ₃ group, —SiR ^c ₃ group, an alkyl group or an aryl group, and R ^y is an alkylene group, an alkyleneoxy group, or a single bond is preferable. , R ^x is an alkyl group or an aryl group, and a combination in which R ^y is a single bond is particularly preferable.

The compound having a silsesquioxane structure represented by the structural formula (A) is preferably a compound represented by the following general formula (A-1).
( ^{Rx- Ry-} SiO3 _{/ 2} ) _m General formula (A-1)
(In General Formula (A-1), R ^x represents a halogen atom, a cyano group, a thiol group, —PR ^a ₂ (R ^a is an aryl group), an amino group, an aryl group, or an alkyl group, and R ^y is a single bond. , -COO-, alkylene group, an arylene group, an alkylene _{group, -SO 2 -, - O -} , - SiR b 2 - (R b is an alkyl group) ^{R x} and represents more exist, or -NH- group. R ^y may be the same or different from each other, and m represents an integer of 6 to 10.)

R ^x in the general formula (A-1) is the same, including defined as the preferred ranges of R ^x in the structural formula of the above (A).

R ^y in the general formula (A-1) is the same including the definition and preferred range of R ^y in the structural formula (A).

In the general formula (A-1), R ^x is a thiol group, -PR ^a ₃ group, -SiR ^c ₃ group, an alkyl group or an aryl group, and R ^y is an alkylene group, an alkyleneoxy group or a single bond. A combination is preferable, and a combination in which R ^x is an alkyl group or an aryl group and R ^y is a single bond is particularly preferable.

  M in the general formula (A-1) is an integer of 6 to 10, and m is preferably 8. When m = 8, (Component A) is represented by the structure of the following general formula (A-2).

  The compound having a silsesquioxane structure represented by the structural formula (A) is preferably a compound represented by the following general formula (A-2).

(In the general formula (A-2), ^{R x} represents a halogen atom, a cyano group, a thiol ^group, _-PR ^a 2 ^(R a is an aryl _{^{group), - SiR c 3 (R}} c is an alkyl group), an amino group, Represents an aryl group or an alkyl group, and R ^y represents a single bond, —COO—, an alkylene group, an arylene group, an alkyleneoxy group, —SO ₂ —, —O—, —SiR ^b ₂ — (R ^b represents an alkyl group) or And represents a —NH— group, wherein a plurality of R ^x and R ^y may be the same or different from each other.

R ^x in the general formula (A-2) are the same, including defined as the preferred ranges of R ^x in the structural formula of the above (A).

R ^y in the general formula (A-2) is the same as the definition of R ^y in the structural formula (A) and the preferable range.

In the general formula (A-2), R ^x is a thiol group, -PR ^a ₃ group, -SiR ^c ₃ group, an alkyl group or an aryl group, and R ^y is an alkylene group, an alkyleneoxy group or a single bond. A combination is preferable, and a combination in which R ^x is an alkyl group or an aryl group and R ^y is a single bond is particularly preferable.

  The content of (Component A) with respect to the total amount of the ink composition in the present invention is preferably 0.1 to 20% by mass, more preferably 0.5 to 5% by mass, and particularly preferably 1 to 5% by mass. %.

  (Component A) of the present invention has a molecular weight of 300 or more and less than 3000, preferably 300 to 2500, more preferably 600 to 2000, and particularly preferably 800 to 1400.

  Specific examples (A-1-1) to (A-1-17) of (Component A) in the present invention are listed, but the present invention is not limited to these specific examples.

  As (Component A) in the present invention, for example, known compounds such as silsesquioxane (completely condensed series) manufactured by Sigma-Aldrich Japan, silsesquioxane series manufactured by Hybrid Plastic, and the like can be used. Moreover, a well-known compound can also be suitably synthesize | combined and used by a synthesis method.

((Component B) monofunctional polymerizable compound)
The ink composition of the present invention contains a monofunctional polymerizable compound as an essential component, and the content of (Component B) monofunctional polymerizable compound relative to the total content of all polymerizable compounds in the ink composition is 80 mass. % Or more is essential.

The content of the (component B) monofunctional polymerizable compound in the total polymerizable compound of the ink composition of the present invention is 80% by mass or more, preferably 80 to 99% by mass, and 95 to 99% by mass. More preferably it is. In addition, the total polymerizable compound in the present invention refers to the total content of (Component B) a monofunctional polymerizable compound and a polyfunctional polymerizable compound (described later) added as necessary.
The monofunctional polymerizable compound used in the ink composition of the present invention is not limited as long as it is a polymerizable compound having one polymerizable group.
As the monofunctional polymerizable compound used in the ink composition of the present invention, a radical polymerizable compound is preferable, and a compound having an ethylenically unsaturated bond capable of radical polymerization is exemplified. More specifically, any compound having at least one ethylenically unsaturated bond capable of radical polymerization in the molecule may be used.

  Examples of polymerizable monomers 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, unsaturated carboxylic acid esters, and the like. A salt having an ethylenically unsaturated group; acrylonitrile; styrene and the like. Further, various macromonomers such as various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides and unsaturated polyurethanes are also included.

  As such a monofunctional compound, for example, preferably 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, tridecyl acrylate, 2-phenoxyethyl acrylate, epoxy acrylate , Isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethylphthalic acid, methoxy-polyethylene glycol acrylate, 2 -Acryloyloxyethyl-2-hydroxyethylphthalic acid, cyclic trimethylolpropane Lumar acrylate, 2- (2-ethoxyethoxy) ethyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxylated phenyl acrylate, 2-acryloyloxyethyl succinic acid, nonylphenol EO adduct acrylate, phenoxy-polyethylene Acrylate compounds such as glycol acrylate, 2-acryloyloxyethyl hexahydrophthalic acid, lactone-modified acrylate, stearyl acrylate, isoamyl acrylate, isomyristyl acrylate, isostearyl acrylate, lactone-modified acrylate; methyl methacrylate, n-butyl methacrylate, allyl methacrylate , Glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate Methacrylate compounds such as chromatography preparative; allyl compounds such as allyl glycidyl ether.

  Also suitable are monofunctional vinyl ether compounds. Specific examples of the monofunctional vinyl ether compound include, for example, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, n-octadecyl vinyl ether, 2-ethylhexyl vinyl ether, n -Nonyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, 4-methylcyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, Butoxyethylbi Ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol mono Vinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxy polyethylene glycol vinyl ether, cyclohexanedimethanol monovinyl ether, isopropenyl ether-O-pro Ren carbonate, and the like.

  A (meth) acrylamide compound is also preferably exemplified. A preferred example of (meth) acrylamide is represented by the following general formula (M-1).

(In General Formula (M-1), Q ¹ represents a single bond, an alkyleneoxy group or an alkylene group.
Q ² represents a hydrogen atom, an alkyl group, an aryl group, an amino group, a hydroxyl group, a sulfo group or an acyl group. Q ³ represents a hydrogen atom or an alkyl group. Q ² and Q ³ may be bonded to each other to form a ring. R ^m represents a hydrogen atom or a methyl group. )

When Q ¹ in the general formula (M-1) is an alkyleneoxy group, the alkyleneoxy group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms. . Specific examples of the alkyleneoxy group include an ethoxy group. These groups may or may not have a substituent. The alkyleneoxy group is bonded to Q ² in the structural formula (M-1) in any direction of ** — R—O— and ** — O—R— (** represents a bonding position). You may do it.

When to ^{Q 1} in the general formula (M-1) is an alkylene group preferably has 1 to 10 carbon atoms as the alkylene group, more preferably 1 to 6 carbon atoms, 1 to 3 carbon atoms are particularly preferred. Specific examples of the alkylene group include a methylene group. These groups may or may not have a substituent, but preferably do not have a substituent.

Q ¹ in the general formula (M-1) is preferably a single bond.

When Q ² in the general formula (M-1) is an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms as the alkyl group, more preferably an alkyl group having 1 to 8 carbon atoms, 3 carbon More preferred is an alkyl group of 8. The alkyl group may have a linear structure, a branched structure, or a cyclic structure. Specific examples of the alkyl group include a methyl group, an ethyl group, an isobutyl group, an isopropyl group, an isooctyl group, a t-butyl group, and a cyclohexyl group. These groups may or may not have a substituent, but preferably have a substituent.

The substituent when the alkyl group represented by the general formula (M-1) in Q ² has a substituent group, and a hydroxyl group.

When Q ² in the general formula (M-1) is an aryl group, as the aryl group, preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 16 carbon atoms, 6 carbon atoms An aryl group of 10 to 10 is particularly preferred. Specific examples of the aryl group include a phenyl group and a naphthyl group, and a phenyl group is particularly preferable. These groups may or may not have a substituent, but preferably do not have a substituent.

When Q ² in the general formula (M-1) is an amino group, the amino group may be any of a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium group. It is represented by —NH ₂ , —NHR, —NR ₂ , —NH ₃ ⁺ or —NR ₃ ⁺ (R is a substituent). The substituents represented by R of the amino group may be different from each other, for example, a linear or branched alkyl group having 1 to 8 carbon atoms (preferably having 1 to 4 carbon atoms), aryl having 6 to 20 carbon atoms. Group (preferably phenyl group) and the like. Specific examples of the amino group include a primary amino group and a dimethylamino group. These groups may or may not have a substituent, but preferably do not have a substituent.

When Q ² in the general formula (M-1) is a sulfo group, examples of the sulfo group include a sulfo group or a salt of the sulfo group (—SO ₃ X, X is an alkali metal salt). Examples of the salt of the sulfo group include —SO ₃ Li, —SO ₃ Na, —SO ₃ K and the like, —SO ₃ Na is preferable.

When Q ² in the general formula (M-1) is an acyl group (R—CO—, R is an alkyl group), the acyl group preferably has 1 to 10 carbon atoms, and further has 1 to 5 carbon atoms. Preferably, C1-C3 is especially preferable. Examples of the acyl group, _{-COCH 3,} and the like.

Q ² in the general formula (M-1) is preferably an alkyl group, an amino group, or a hydroxyl group.

When the general formula (M-1) Q ³ being an alkyl group, the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms as the alkyl group, further the alkyl group having 1 to 8 carbon atoms An alkyl group having 3 to 8 carbon atoms is more preferable. The alkyl group may have a linear structure, a branched structure, or a cyclic structure. Specific examples of the alkyl group include a methyl group, an ethyl group, an isobutyl group, an isooctyl group, and a t-butyl group. These groups may or may not have a substituent, but preferably do not have a substituent.

Q ³ in the general formula (M-1) represents a hydrogen atom or an alkyl group, and preferably a hydrogen atom.

R ^m in the general formula (M-1) represents a hydrogen atom or a methyl group, and preferably a hydrogen atom.

When Q ² and Q ³ in the general formula (M-1) are bonded to each other to form a ring, the formed ring may be a ring composed of an atom selected from a carbon atom and an oxygen atom. preferable. Specific examples of the ring formed include a pyrrolidine ring, a piperidine ring, an oxazine ring and the like, and an oxazine ring is particularly preferable. These groups may or may not have a substituent, but preferably do not have a substituent.

  Specific examples of the (meth) acrylamide compound in the general formula (M-1) may be any monofunctional polymerizable compound having a (meth) acrylamide group, and may be an N-substituted (meth) acrylamide compound. . For example, (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-sec -Butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N-phenyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 1- (meth) acryloylpyrrolidine N-methylol (meth) acrylamide, N- (methoxyethyl) (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- [3- (dimethylamino) propyl] (meth) acrylamide, N -(1,1-dimension Le 3-oxobutyl) (meth) acrylamide, 4- (meth) acryloyl morpholine, diacetone acrylamide preferred. Among these, N-isopropylacrylamide, N-tert-butylacrylamide, N, N-dimethylacrylamide, N-methylolacrylamide, N- (2-hydroxyethyl) acrylamide, N- [3- (dimethylamino) propyl] acrylamide N- (1,1-dimethyl-3-oxobutyl) acrylamide and 4-acryloylmorpholine are more preferable, and N-isopropylacrylamide, N, N-dimethylacrylamide and 4-acryloylmorpholine are particularly preferable.

  As the (meth) acrylamide compound, those having a high glass transition temperature are preferable. Thereby, it is excellent in the point of the said drawability and the durability after a heating. The glass transition temperature is preferably 60 ° C to 180 ° C, and particularly preferably 70 ° C to 160 ° C.

  When the ink composition of the present invention contains the (meth) acrylamide compound, the content of the (meth) acrylamide compound is preferably 0.1% by mass to 75% by mass with respect to the total amount of the ink composition. 5 mass%-50 mass% are more preferable, and 10 mass%-40 mass% are especially preferable.

  In addition, N-vinyl compounds such as N-vinyl lactams and N-vinylformamide are also preferable. Preferred examples of N-vinyl lactams are represented by the following formula.

  In the general formula (V), m represents an integer of 1 to 5, m is preferably an integer of 2 to 4, m is more preferably 2 or 4, and m is 4. N-vinylcaprolactam is particularly preferable.

  When the ink composition of the present invention contains the N-vinyl compound, the content of the N vinyl compound is preferably 0.1% by mass to 50% by mass with respect to the total amount of the ink composition, and 5% by mass. % To 40% by mass is more preferable, and 10% to 35% by mass is particularly preferable.

  In the present invention, the (component B) monofunctional polymerizable compound preferably contains an N-vinyl compound or a (meth) acrylamide compound from the viewpoint of stretchability of the resulting image and indentation curing sensitivity, and (meth) acrylamide. It is particularly preferable to contain a compound.

  In the present invention, the molecular weight of the monofunctional polymerizable compound is preferably 130 to 3000, and more preferably 130 to 500.

(Polyfunctional polymerizable compound)
The ink composition of the present invention may contain a bifunctional or higher polyfunctional polymerizable compound.

  Examples of the radically polymerizable polyfunctional compound that may be possessed by the present invention include bis (4-acryloxypolyethoxyphenyl) propane, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, and dipentaerythritol. Tetraacrylate, trimethylolpropane (PO-modified) triacrylate, oligoester acrylate, hydroxypivalate neopentyl glycol diacrylate, tetramethylol methane triacrylate, dimethylol tricyclodecane diacrylate, modified glycerin triacrylate, bisphenol A diglycidyl ether Acrylic acid adduct, modified bisphenol A diacrylate, PO adduct diacrylate of bisphenol A, Sphenol A EO adduct diacrylate, dipentaerythritol hexaacrylate, propylene glycol diglycidyl ether acrylic acid adduct, acrylate compounds such as ditrimethylolpropane tetraacrylate; polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate 2,2-bis And methacrylate compounds such as (4-methacryloxypolyethoxyphenyl) propane. Other examples include allyl compounds such as diallyl phthalate and triallyl trimellitate. PO represents propylene oxide, and EO represents ethylene oxide. More specifically, Shinzo Yamashita, “Crosslinker Handbook”, (1981 Taiseisha); Kato Kiyosumi, “UV / EB Curing Handbook (Materials)” (1985, Polymer Publications); Radtech Study Group, “Application and Market of UV / EB Curing Technology”, p. 79, (1989, CMC); Eiichiro Takiyama, “Polyester Resin Handbook”, (1988, Nikkan Kogyo Shimbun) Commercially available products or radically polymerizable or crosslinkable compounds known in the industry can be used.

  Moreover, polyfunctional vinyl ether is also mentioned. Examples of the polyfunctional vinyl ether include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butylene glycol divinyl ether, butanediol divinyl ether, Divinyl ethers such as hexanediol divinyl ether, cyclohexane dimethanol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether; trimethylol ethane trivinyl ether, trimethylol propane trivinyl ether, ditrimethylol propane tetrabi Ether, glycerol trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, Propylene oxide addition ditrimethylolpropane tetravinyl ether, ethylene oxide addition pentaerythritol tetravinyl ether, propylene oxide addition pentaerythritol tetravinyl ether, ethylene oxide addition dipentaerythritol hexavinyl ether, propylene oxide addition dipe Polyfunctional vinyl ethers such as data hexavinyl ether, and the like.

  Examples of the radically polymerizable compound include JP-A-7-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, JP-A-9-134011, and JP-T-2004. Photo-curable polymerizable compounds used in the photopolymerizable compositions described in each publication such as 5114014 are known, and these can also be applied to the ink composition of the present invention.

  In the present invention, the molecular weight of the polyfunctional polymerizable compound is preferably 130 to 3000, and more preferably 130 to 500, as the molecular weight.

  When the ink composition of the present invention contains a polyfunctional polymerizable compound, the content of the polyfunctional polymerizable compound in the total polymerizable compound is preferably 0.1 to 20% by mass, and 1 to 10% by mass. More preferably, 1-5 mass% is especially preferable.

((Component C) polymerization initiator)
The ink composition of the present invention contains a polymerization initiator.
The polymerization initiator of the present invention may be either a thermal polymerization initiator or a photopolymerization initiator, but in the present invention, a photopolymerization initiator is preferably mentioned. As the photopolymerization initiator, a known photopolymerization initiator can be appropriately selected and used according to the kind of the polymerizable compound and the purpose of use of the ink composition.
The photopolymerization initiator used in the ink composition of the present invention is a compound that absorbs external energy (light) and generates radicals that are polymerization initiation species. In the photopolymerization initiator, the light for initiating polymerization indicates active irradiation rays, that is, γ rays, β rays, electron beams, ultraviolet rays, visible rays, infrared rays, and the like, and preferably ultraviolet rays.

  As the photopolymerization initiator, known compounds can be used. Preferred photopolymerization initiators that can be used in the present invention include α-amino ketones, aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic compounds. Examples thereof include peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  These photopolymerization initiators may be used alone or in combination. The photopolymerization initiator in the present invention is preferably used alone or in combination of two or more.

  Preferable examples of aromatic ketones, acylphosphine oxide compounds, and thio compounds include “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY”, J. Am. P. FOUASSIER, J.A. F. RABEK (1993), pp. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in 77-117. More preferable examples include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, α-substituted benzoin compounds described in JP-B-47-22326, Benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, JP-B-60-26403, JP-A Benzoin ethers described in JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, α-aminobenzophenones described in European Patent 0284561A1, JP-A-2-21152 P-Di (dimethylaminobenzoyl) benze Thio-substituted aromatic ketones described in JP-A-61-194062, acylphosphine sulfides described in JP-B-2-9597, acylphosphines described in JP-B-2-9596, and JP-B-63-61950 Thioxanthones, and coumarins described in JP-B-59-42864. Moreover, the polymerization initiators described in JP 2008-105379 A and JP 2009-114290 A are also preferable.

  Among these, in the present invention, it is preferable to use an aromatic ketone or an acylphosphine oxide compound as a photopolymerization initiator, and p-phenylbenzophenone (manufactured by Wako Pure Chemical Industries, Ltd.), Irgacure 819 (bis (2, 4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by BASF Japan), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphenylphosphine oxide, 2,4,6-trimethylbenzoyl -Diphenyl-phosphine oxide (Darocur TPO: BASF Japan Ltd., Lucirin TPO: BASF Japan Ltd.), Irg907 (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one , BAS Japan Co., Ltd.) and the like are preferable.

A polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
The content of the polymerization initiator in the ink composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass, and further preferably 1 to 10% by mass with respect to the ink composition. .

((Component D) Colorant)
The ink composition of the present invention contains a colorant. By adding a colorant to the ink composition, the ink composition can form a visible image (colored image).
The colorant that can be used in the ink composition of the present invention is not particularly limited, and various known colorants (pigments and dyes) can be appropriately selected and used depending on the application. For example, when forming an image excellent in weather resistance, a pigment is preferable. As the dye, both water-soluble dyes and oil-soluble dyes can be used, but oil-soluble dyes are preferred.

-Pigment-
First, a pigment that is preferably used as a colorant in the ink composition of the present invention will be described.
The pigment is not particularly limited, and all commercially available organic pigments and inorganic pigments or pigments dispersed in an insoluble resin or the like as a dispersion medium, or a resin is grafted on the pigment surface. Can be used. Moreover, what dye | stained the resin particle with dye can be used.
Examples of these pigments include, for example, “Pigment Dictionary” (2000), edited by Seijiro Ito. Herbst, K.M. Hunger “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A, JP 2003-26978 A, and JP 2003-342503 A3.

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

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

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

  As a pigment exhibiting green, C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. And azo metal complex pigments such as CI Pigment Green 8 (Nitroso Green).

  As a pigment exhibiting an orange color, C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. And anthraquinone pigments such as CI Pigment Orange 51 (dichloropyrantron orange).

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

Specific examples of the white pigment include basic lead carbonate (2PbCO ₃ Pb (OH) ₂ , so-called silver white), zinc oxide (ZnO, so-called zinc white), titanium oxide (TiO ₂ , so-called titanium white), Strontium titanate (SrTiO ₃ , so-called titanium strontium white) or the like can be used.

  For dispersion of the pigment, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, or a wet jet mill is used. Can do.

It is also possible to add a dispersant when dispersing the pigment. Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a high molecular weight unsaturated acid ester, a high molecular weight copolymer, a modified polyacrylate, an aliphatic polyacrylate. Carboxylic acid, naphthalenesulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester, pigment derivative and the like. It is also preferable to use a commercially available polymer dispersant such as Solsperse series manufactured by Lubrizol.
Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment.

  In the ink composition, as a dispersion medium for various components such as pigments, a solvent may be added, and the polymerizable compound that is a low molecular weight component may be used as a dispersion medium. The product is suitable as an active energy ray-curable ink, and is preferably solvent-free because it is cured after the ink is applied to the recording medium.

  The volume average particle size of the pigment particles in the ink composition is preferably 0.02 μm to 0.60 μm, more preferably 0.02 μm to 0.10 μm. Further, the maximum particle size is preferably 3 μm or less, more preferably 1 μm or less, and the selection of the pigment, dispersant, dispersion medium, dispersion conditions, and filtration conditions are set so as to be in such a range. The volume average particle diameter is measured using a laser diffraction / scattering particle size distribution analyzer (LA920, manufactured by Horiba, Ltd.) using tripropylene glycol methyl ether as a measurement solvent.

-Dye-
Next, the dyes preferably used as the colorant in the present invention will be described.
The dye can be appropriately selected from conventionally known compounds (dyes). Specific examples include compounds described in paragraph numbers [0023] to [0089] of JP-A No. 2002-114930 and paragraph numbers [0136] to [0140] of JP-A No. 2008-13646. These can also be applied to the present invention.

  The colorant is preferably added in an amount of 0.05% by mass to 20% by mass with respect to the total mass of the ink composition, and more preferably 0.2% by mass to 10% by mass. When an oil-soluble dye is used as the colorant, the content is particularly preferably 0.2% by mass to 6% by mass with respect to the total mass of the ink composition.

(water)
The ink composition of the present invention is preferably a non-aqueous ink composition containing substantially no water. Specifically, it is preferably 3% by mass or less, more preferably 2% by mass or less, and particularly preferably 1% by mass or less with respect to the total amount of the ink composition.

<Other ingredients>
Furthermore, components other than those described above can be added to the ink composition of the present invention. This will be sequentially described below.

(Chain transfer agent)
The ink composition of the present invention may further contain a chain transfer agent.
The chain transfer agent can be used without particular limitation as long as it is a substance that moves the active site of the reaction by a chain transfer reaction in the polymerization reaction.

  Specific examples of the chain transfer agent that can be used in the present invention include, for example, halogen compounds such as carbon tetrachloride and carbon tetrabromide; alcohols such as isopropyl alcohol and isobutyl alcohol; 2-methyl-1-butene, 2,4 -Olefins such as diphenyl-4-methyl-1-pentene; sulfur-containing compounds; and the like, but are not limited thereto.

  The molecular weight of the chain transfer agent is preferably 250 or more, particularly preferably 250 or more and 100,000 or less, more preferably 500 or more and 80,000 or less, and particularly preferably 3,000 or more and 80,000 or less.

Only 1 type may be used for a chain transfer agent and it may use 2 or more types together.
The addition amount of the chain transfer agent to the ink composition of the present invention is preferably 0.1% by mass to 15% by mass, and preferably 0.5% by mass to 10% by mass with respect to the total solid mass of the ink composition. More preferably, it is more preferably 1% by mass to 10% by mass.

(Sensitizing dye)
A sensitizing dye can be added to the ink composition of the present invention in order to promote decomposition of the polymerization initiator by irradiation with active energy rays.

As the sensitizing dye, a compound corresponding to the wavelength of the active energy ray that generates an initiation species in the polymerization initiator used in the ink composition may be used, but it is used for a curing reaction of a general ink composition. Considering this, examples of preferable sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region.
Polynuclear aromatics (for example, anthracene, pyrene, perylene, triphenylene), thioxanthones (for example, isopropylthioxanthone), xanthenes (for example, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (for example, thiaxene) Carbocyanine, oxacarbocyanine), merocyanines (eg, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones ( For example, anthraquinone), squalium (for example, squalium), coumarins (for example, 7-diethylamino-4-methylcoumarin), DETX (2,4-diethylthioxyl). Cantonal, Sun Chemical Co.), ITX (2-isopropyl thioxanthone, include Tokyo Chemical Industry Ltd.), polynuclear aromatic compounds and thioxanthones as preferred class.
Further, sensitizing dyes described in JP-A-2008-95086 are also suitable.

(Co-sensitizer)
The ink composition of the present invention can also contain a co-sensitizer.

  Examples of co-sensitizers include amines such as M.I. R. Sander et al., “Journal of Polymer Science”, Vol. 10, page 3173 (1972), Japanese Patent Publication No. 44-20189, Japanese Patent Publication No. 51-82102, Japanese Patent Publication No. 52-134692, Japanese Patent Publication No. 59-138205. No. 60-84305, JP-A 62-18537, JP-A 64-33104, Research Disclosure 33825, and the like. Specific examples include triethanolamine. P-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like.

  Other examples 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 of the co-sensitizer include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in JP-B-48-42965 (eg, tributyltin acetate), JP-B 55- No. 34414, a hydrogen donor described in JP-A-6-308727 (eg, trithiane), a phosphorus compound described in JP-A-6-250387 (eg diethylphosphite), JP-A-8-65779 Si-H and Ge-H compounds described in the above No.

(UV absorber)
An ultraviolet absorber can be used in the ink composition of the present invention.
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 No. 24239, compounds that emit ultraviolet light by absorbing ultraviolet rays typified by stilbene and benzoxazole compounds, so-called fluorescent brighteners, and the like.

(Antioxidant)
An antioxidant can be added to the ink composition of the present invention.
Examples of the antioxidant include European published patents, 223739, 309401, 309402, 310551, 310552, 359416, and 3435443. JP, 54-85535, 62-262417, 63-113536, 63-163351, JP-A-2-262654, JP-A-2-71262, Examples thereof include those described in Kaihei 3-121449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.

(Anti-fading agent)
In the ink composition of the present invention, various organic and metal complex anti-fading agents can be used. Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, and the like.
In addition, examples of the metal complex anti-fading agent include nickel complexes and zinc complexes. No. 17643, No. VII, I to J, ibid. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. 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. .

(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)
The ink composition of the present invention preferably contains no solvent, but may contain a very small amount of a non-curable organic solvent. The content of the solvent in the ink composition is preferably 1% by mass or less with respect to the total amount of the ink composition.
Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone, alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol, and chlorine such as chloroform and methylene chloride. Solvents, aromatic solvents such as benzene and toluene, ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, glycols such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether And ether solvents.

(Polymer compound)
Various oil-soluble polymer compounds can be added to the ink composition of the present invention in order to adjust film physical properties.
Examples of oil-soluble polymer compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylics. Resins, rubber resins, waxes, and other natural resins can be used. Two or more of these may be used in combination.
In addition, when the ink composition of the present invention is used as a film, a polymer compound that easily segregates on the surface for the purpose of improving tackiness or the like is also suitable. These polymer compounds contain Si and F atoms described in paragraph numbers [0017] to [0037] of JP-A-2008-248119, paragraph numbers [0015] to [0034] of JP-A-2005-250890, and the like. A polymer, a polymer having a long-chain alkyl group in the side chain, and the like can be used.

(Surfactant)
A surfactant may be added to the ink composition of the present invention.
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts.
An organic fluoro compound may be used in place of the surfactant.
The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compound include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). (Columns 8 to 17) and those described in JP-A Nos. 62-135826.

In addition, in order to improve the adhesion to recording media such as polymerization inhibitors, leveling additives, matting agents, waxes for adjusting film physical properties, polyolefins, PET, etc. A tack fire (tackifier) that does not inhibit the polymerization can be contained.
Examples of the polymerization inhibitor include hydroquinone, methoxybenzoquinone, methoxyphenol, phenothiazine, t-butylcatechol, mercaptobenzimidazole, alkyldithiocarbamates, alkylphenols, alkylbisphenols, salicylates, thiodipropionates, phosphines Phytes, nitroxide aluminum complexes and the like. Specific examples include Gerrad 16, 18, 20, 21, 22, (Rahn).
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 tackifying resin having a polymerizable unsaturated bond.

(Preferred physical properties of ink composition)
In the present invention, it is preferable to use an ink composition having a viscosity at 25 ° C. of 40 mPa · s or less. More preferably, it is 5-40 mPa * s, More preferably, it is 7-30 mPa * s. 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, the penetration of the ink composition into the recording medium can be avoided and the uncured monomer can be reduced. Furthermore, ink bleeding at the time of landing of the ink composition droplets can be suppressed, and as a result, the image quality is improved, which is preferable. The viscosity is measured under the condition of 25 ° C. using VISCOMETER TV-22 (manufactured by TOKI SANGYOCO. LTD).

  The surface tension of the ink composition of the present invention 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 uncoated 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. The surface tension is measured under the condition of 25 ° C. using an Automatic Surface Tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

  The ink composition of the present invention is suitably used for ink jet recording. When applied to ink jet recording, the ink composition of the present invention is ejected onto a recording medium by an ink jet recording apparatus, and then the ejected ink composition is irradiated with an energy ray and cured to perform recording.

The present inventors have (Component A) a compound having no ethylenically unsaturated double bond and having a silsesquioxane structure and having a molecular weight of 300 to less than 3000, (Component B) a monofunctional polymerizable compound, (Component The effect of the present invention is such that the content of the (component B) monofunctional polymerizable compound is 80% by mass or more with respect to the total content of all polymerizable compounds, including C) a polymerization initiator and (component D) colorant. Found to improve. Although it is not clear about this mechanism, the present inventors speculate as follows.
That is, since (Component A) does not have an ethylenically unsaturated double bond, (Component A) and the polymerizable compound do not react, and a phase separation structure (sea-island structure) is formed in the cured ink composition film. It is inferred that it has formed. Compared with a cured film of an ink composition that does not have a phase separation structure (sea-island structure) because the phase-separated structure formed by a compound having a silsesquioxane structure disperses impact propagation due to punching of the formed image. It is considered that the transmitted impact is weakened. As a result, it is considered that the punching characteristics are improved. Furthermore, by setting the content of (Component B) to 80% by mass or more with respect to the total content of all polymerizable compounds in the ink composition, moderate flexibility is imparted to the film, and stretchability is improved. It is considered.
In addition, the said mechanism is inference and this invention is not limited to the said mechanism.

2. Image forming method and printed matter The image forming method of the present invention includes an ink applying step of applying the ink composition of the present invention onto a recording medium, and an irradiation step of irradiating the ink composition with active energy rays. . In the ink application step, an image is preferably formed by ejecting ink by an ink jet method including a commercially available apparatus. The ink application process can be used for various printing applications such as lithographic printing applications and screen printing applications. Furthermore, the image forming method may include a step of obtaining a printed matter having a cured image on the recording medium.

  The recording medium (base material) that can be applied to the image forming method of the present invention is not particularly limited, and various non-absorbent resin materials used for ordinary non-coated paper, coated paper, and other so-called soft packaging or Resin films formed into films can be used, and various plastic films include, for example, PET film, OPS film, OPP film, ONy film, PVC film, PE film, TAC film, vinyl chloride sheet, etc. Can be mentioned. In addition, examples of the plastic that can be used as the recording medium material include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers. Metals and glasses can also be used as a recording medium. Furthermore, examples of the recording material applicable to the present invention include a support for a lithographic printing plate.

Examples of active energy rays applied to the image forming method of the present invention include α rays, γ rays, X rays, ultraviolet rays, visible rays, infrared rays, and electron beams. The peak wavelength of the active energy ray is preferably 200 nm to 600 nm, more preferably 300 nm to 450 nm, and still more preferably 350 nm to 420 nm. The output of the active energy rays, is preferably 2,000 mW / cm ² or less, more ^preferably at ^{10mW / cm 2 ~2,000mW / cm 2} , more preferably, 20 mW / ^cm 2 to 1 a 000mW / cm ^2, particularly ^{preferably 50mW / cm 2 ~800mW / cm 2} .

In particular, in the image forming method of the present invention, the active energy ray irradiation, emission wavelength peak is 350Nm～420nm, and maximum illuminance of the recording medium surface is 10mW ^/ cm ² ~2,000mW ^/ cm 2 The light is preferably emitted from a light emitting diode that generates ultraviolet rays. The ink composition of the present invention can be cured with high sensitivity even with low exposure light such as light emitted from a light emitting diode.

  In the image forming method of the present invention, the active energy rays can be exposed collectively after ejecting all colors, but it is preferable to perform exposure for each color.

  Further, as described above, the ink composition of the present invention is suitably used for image formation of general prints, and also suitable for a mode in which an image is formed on a recording medium such as a support and then processed. Can be used.

A printed matter molded body may be processed and molded using the printed matter. The printed product is formed by ejecting the ink composition of the present invention onto a recording medium by an inkjet method to form an image, and irradiating the obtained image with active energy rays to cure the ink composition. And a step of obtaining a print having a cured image on the recording medium, and a step of obtaining the print product by molding the print and obtaining a print product by the method for producing a print product of the present invention. Manufactured.
As the recording medium used for the production of the printed matter molded body, a recording medium made of a moldable resin material is used, and examples thereof include PET, polycarbonate, polystyrene and the like.

  As a processing method for producing the printed matter molded body, vacuum forming, pressure forming, or vacuum / pressure forming is particularly suitable. In principle, vacuum forming pre-heats a flat support to a temperature at which it can be thermally deformed, sucks it into the mold by decompression, and cools it by crimping to the mold. Pressure is applied from the opposite side to the mold and cooled by pressure. In vacuum / pressure forming, the pressure reduction and pressurization are performed simultaneously.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. Unless otherwise specified, “%” and “parts” are based on mass.

<Preparation of pigment dispersion>
The pigment, monofunctional polymerizable compound and dispersant shown in the table below were mixed with stirring to prepare pigment dispersions (Y1, M1, C1, K1, and W1) for each color. The pigment dispersion was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed using zirconia beads having a diameter of 0.65 mm at a peripheral speed of 9 m / s for the time shown in the table below.

-Example 1
The following components were stirred with a Silverson rotor / stator type high shear mixer to prepare an ink composition of Example 1.
Magenta Pigment Dispersion (M1) 13 parts (A-1-1) (Trade name Isostatic POSS Cage Mixture, MS0805, (Component A), manufactured by Hybrid Plastic Co., Ltd.), 0.1 parts, NVC (Component) B) Monofunctional polymerizable compound, N-vinylcaprolactam) 33 parts FA513AS ((Component B) monofunctional polymerizable compound, dicyclopentanyl acrylate) 23.9 parts NIPAM ((Component B) monofunctional polymerizable compound) , N-isopropylacrylamide, Tokyo Chemical Industry Co., Ltd.) 20 parts HDDA (polyfunctional polymerizable compound, 1,6-hexanediol diacrylate) 1 part Irg819 (BASF Japan Ltd., (Component C) polymerization initiator) ) 3 parts · Irg907 (BASF Japan, (component C) polymerization initiator) 2 parts · D ETX (2,4-diethylthioxanthone, Sun Chemical Co., Ltd., (Component C) polymerization initiator) 3 parts FIRSTCURE ST-1 (Tris (N-nitroso-N-phenylhydroxyamine) aluminum salt, Chem First, Polymerization Inhibitor) 1 part

-Examples 2 to 34, Comparative Examples 1 to 2
The same procedure as in Example 1 was conducted except that the pigment dispersion, the polymerizable compound (monofunctional polymerizable compound and polyfunctional polymerizable compound), and (Component A) were changed as shown in Tables 2 and 3. Examples 2 to 34 and Comparative Examples 1 to 2 were prepared.
Abbreviations in the table represent the following.

((Component A) Silsesquioxane Compound)
(A-1-2) Product name Phenyl Isobutyl POSS, MS0813 (manufactured by Hybrid Plastic, following structure)

  (A-1-3) Product name Phenyl Isotopic POSS, MS0814 (manufactured by Hybrid Plastic, following structure)

  (A-1-4) Product name Isotactic Phenyl POSS, MS0815 (manufactured by Hybrid Plastic, following structure)

  (A-1-5) Trade name OctaIsobutylPOSS, MS0825 (manufactured by Hybrid Plastic, following structure)

  (A-1-6) Trade name Octaphenyl POSS, MS0840 (Hybrid Plastic, following structure)

  (A-1-7) Trade name PSS-octahexyl substitution, 534412 (manufactured by Sigma-Aldrich, following structure)

  (A-1-8) Trade name Trans-Cyclohexanediol Isobutyl POSS, AL0125 (Hybrid Plastic, following structure)

  (A-1-9) Product name AminopropylIsobutyl POSS, AM0265, (manufactured by Hybrid Plastic, following structure)

  (A-1-10) Trade name Epoxycyclohexyl Isobytyl POSS, EP0402 (Hybrid Plastic, following structure)

  (A-1-11) Trade name GlycylylIsobutyl POSS, EP0418 (Hybrid Plastic, following structure)

  (A-1-12) Trade name Chlorobenzyl Isobutyl POSS, HA0605 (Hybrid Plastic, following structure)

  (A-1-13) Product name Mercaptopropyl Isobutyl POSS, TH1550 (Hybrid Plastic, following structure)

  (A-1-14) Trade name PSS-2- (diphenylphosphino) substitution, 477656 (manufactured by Sigma-Aldrich, following structure)

  (A-1-15) Product name OCtaTrimethylsilyl POSS, MS0865 (Hybrid Plastic, following structure)

  (A-1-16) Dodeca Phenyl POSS, MS0802 (Hybrid Plastic, following structure)

  (A-1-17) OctaMethylPOSS, MS0830 (manufactured by Hybrid Plastic, following structure)

(Comparative Compound 1)
Product name Acrylo POSS Cage Mixture, MA0736 (manufactured by Hybrid Plastic, following structure, comparative compound)

((Component B) monofunctional polymerizable compound)
PEA: 2-phenoxyethyl acrylate NVC: N-vinylcaprolactam IBOA: isobornyl acrylate FA-513AS: dicyclopentanyl acrylate NIPAM: N-isopropylacrylamide (Tokyo Chemical Industry Co., Ltd.)
ACMO: acryloyl morpholine (manufactured by Kojinsha)

(Polyfunctional polymerizable compound)
HDDA (1,6-hexanediol diacrylate, Shin-Nakamura Chemical Co., Ltd.)

[Evaluation]
<Image forming method>
First, the prepared ink composition was filtered with a filter having an absolute filtration accuracy of 2 μm.
Next, an image was formed on a recording medium using an inkjet recording experimental apparatus having a piezo-type inkjet nozzle (trade name LuxJet UV350GTW, manufactured by FUJIFILM Corporation). The ink supply system was composed of an original tank, a supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. The ink supply tank to the inkjet head portion were insulated and heated. Temperature sensors were provided near the ink supply tank and the nozzle of the ink jet 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 multi-size dots of 8 to 30 pl could be ejected at a resolution of 720 × 720 dpi, and a solid image was formed. After landing, UV light was condensed to an exposure surface illuminance of 2,100 mW / cm ² , and the exposure system, main scanning speed, and ejection frequency were adjusted so that irradiation started 0.1 seconds after ink landed on the recording medium. Further, the integrated light amount irradiated to the image was set to 3,000 mJ / cm ² . A HAN250NL high-cure mercury lamp (manufactured by GS Yuasa Corporation) was used as the ultraviolet lamp. In the present invention, dpi represents the number of dots per 2.54 cm. As a recording medium, Panlite PC-1151 (film thickness: 500 μm, polycarbonate sheet, manufactured by Teijin Chemicals Ltd.) was used. Each sample was drawn so that the average film thickness of the cured film of the ink composition was 12 μm.

  Under the above conditions, an image used for evaluation of punching suitability and stretchability was formed. The results are shown in Tables 2 and 3. In addition, the measurement / evaluation method of each evaluation item in Table 2 and Table 3 is as follows.

(Evaluation of storage stability)
The filtered ink was placed in a light-shielding bottle and allowed to stand at 45 ° C. for 1 month, and then a solid image (5 cm × 5 cm) was recorded on the recording medium by the above image recording method. Thereafter, the obtained solid image was observed. The observed images were visually evaluated according to the following evaluation criteria.
5: No dot dropout due to whiteout or the like was observed, and a good image was obtained.
4: The occurrence of missing dots due to the occurrence of white spots or the like was slightly observed, but it was of a level that would not hinder practical use.
3: Although dot missing occurred due to white spots, etc., the image was not unusable.
2: Many dots were missing due to white spots, etc., and the image was not practical.
1: Not discharged at all.

(Punching property evaluation)

A printed material was produced by the same method as the image forming method described above.
Under the condition of 25 ° C., the printed material produced was punched with a large punch for manual OA No. Drilling was performed using 200N (manufactured by Lion Corporation). The image was observed with a 100 × optical microscope for cracks around the perforated portion of the image, and visually observed for light transmission.
4: Cracks around punch holes and no light transmission.
3: There was a crack around the punch hole, but no light was transmitted.
2: There were cracks and light transmission around the punch hole, but the level was satisfactory.
1: Cracks were generated around the punch hole and light was transmitted, which was unsuitable as a product.

(Indentation hardness evaluation)
Using the sample formed by the image forming method, the indentation method was used. A Fischer Instruments HM-500 manufactured by Fischer Instruments was used as the apparatus, the indenter was Belkovic (triangular pyramid having a tip opening angle of 144 ° 34 ′), the load was 0.05 mN, and the indentation depth was 0.3 μm. The film hardness was determined from the load at the time of pressing and the contact area between the sample and the indenter. The hardness is preferably 80 N / mm ² or more.

(Extension evaluation)
In the production of the printed materials of Examples 1 to 34 and Comparative Examples 1 to 2, a solid image having an average film thickness of 12 μm was drawn according to the image forming method. The solid image was cut into a width of 2.5 cm and a length of 5.0 cm, and 50 mm / min using Shimadzu Corporation precision universal testing machine (Autograph AGS-J) and thermostatic chamber TCR2W-200P. A tensile test was performed under the conditions of 180 ° C. and the elongation ratio with respect to the length was measured. The state of elongation from the initial length to twice the length was defined as 100% elongation. The allowable range of the stretching ratio is 150% or more, and preferably 300% or more.

* Numerical values in the above table that do not have units are the content (parts by mass).
** Blanks in the above table indicate that they are not contained.

* Numerical values in the above table that do not have units are the content (parts by mass).
** Blanks in the above table indicate that they are not contained.

Claims (16)

(Component A) a compound having no ethylenically unsaturated double bond and having a silsesquioxane structure and having a molecular weight of 300 or more and less than 3000,
(Component B) Monofunctional polymerizable compound,
(Component C) including a polymerization initiator and (Component D) a colorant,
An ink composition wherein the content of the (component B) monofunctional polymerizable compound with respect to the total content of all polymerizable compounds is 80% by mass or more. The ink composition according to claim 1, wherein the silsesquioxane structure is a structure represented by the structural formula (A).

(In the structural formula (A), R ^x is a halogen atom, a cyano group, a thiol group, -PR ^a ₂ (R ^a is an aryl group), -SiR ^c ₃ (R ^c is an alkyl group), an amino group, an aryl group. Or R ^y is a single bond, —COO—, an alkylene group, an arylene group, an alkyleneoxy group, —SO ₂ —, —O—, —SiR ^b ₂ — (R ^b is an alkyl group) or —NH -Represents a group, * represents a bonding position. In the structural formula (A), R ^x is a thiol group, —PR ^a ₂ (R ^a is an aryl group), —SiR ^c ₃ (R ^c is an alkyl group), an alkyl group or an aryl group, and R ^y is an alkylene group. The ink composition according to claim 2, which is an alkyleneoxy group or a single bond. The ink composition according to claim 2, wherein R ^x in the structural formula (A) is an aryl group or an alkyl group, and R ^y is a single bond. The ink composition according to any one of claims 1 to 4, wherein the silsesquioxane structure is a cage type. The ink composition according to claim 1, wherein the (component A) compound is represented by the following general formula (A-2).

(In the general formula (A-2), ^{R x} represents a halogen atom, a cyano group, a thiol ^group, _-PR ^a 2 ^(R a is an aryl _{^{group), - SiR c 3 (R}} c is an alkyl group), an amino group, Represents an aryl group or an alkyl group, and R ^y represents a single bond, —COO—, an alkylene group, an arylene group, an alkyleneoxy group, —SO ₂ —, —O—, —SiR ^b ₂ — (R ^b represents an alkyl group) or And represents a —NH— group, wherein a plurality of R ^x and R ^y may be the same or different from each other. The ink composition according to claim 6, wherein R ^x in the general formula (A-2) is an aryl group or an alkyl group, and R ^y is a single bond.   The ink composition according to any one of claims 1 to 7, comprising an N-vinyl compound or a (meth) acrylamide compound as the monofunctional polymerizable compound. The ink composition according to claim 8, wherein the N-vinyl compound is represented by the following formula (V).
(In formula (V), m represents an integer of 1 to 5.) The ink composition according to claim 8, wherein the (meth) acrylamide compound is represented by the following formula (M-1).

(In General Formula (M-1), Q ¹ represents a single bond, an alkyleneoxy group or an alkylene group.
Q ² represents a hydrogen atom, an alkyl group, an aryl group, an amino group, a hydroxyl group, a sulfo group or an acyl group. Q ³ represents a hydrogen atom or an alkyl group. Q ² and Q ³ may be bonded to each other to form a ring. R ^m represents a hydrogen atom or a methyl group. )   The ink composition according to any one of claims 1 to 10, comprising 80 to 99% by mass of (Component B) a monofunctional polymerizable compound with respect to the total amount of the ink composition.   The ink composition according to any one of claims 1 to 11, comprising 0.1 to 20% by mass of the (Component A) compound with respect to the total amount of the ink composition.   The ink composition according to any one of claims 1 to 12, which is for inkjet recording. An ink application process for applying the ink composition according to any one of claims 1 to 13 onto a recording medium;
And an irradiation step of irradiating the ink composition with active energy rays.   The image forming method according to claim 14, wherein the ink application step is a step of applying the ink composition by an inkjet method.   A printed matter formed using the ink composition according to any one of claims 1 to 13.