WO2021065151A1 - Ink composition for inkjet recording, and image recording method - Google Patents

Abstract

Provided are: an ink composition for inkjet recording comprising an infrared light absorbing coloring matter, polymer particles having a polymerizable group, and water; and an image recording method.

Description

Inkjet recording ink composition and image recording method

The present disclosure relates to an ink composition for inkjet recording and an image recording method.

In general, securities such as stock certificates, bonds, checks, gift certificates, lottery tickets, and commuter passes are often provided with a code pattern that allows information to be read optically. As a code pattern, barcodes are widely used mainly in logistics management systems. In recent years, data codes that enable larger data capacity and high-density printing, VeriCode (registered trademark), CodeOne, MaxiCode, and two-dimensional bar codes (QR code) Two-dimensional codes such as Do (registered trademark) are also becoming widespread.

As a code pattern, a visible code pattern is common. However, the visible code pattern may impair the design of the image recording. Further, when recording a visible code pattern, it is necessary to secure a recording area. Therefore, there is an increasing demand for invisibility of code patterns.

Also, in recent years, code patterns have been recorded on a wide variety of substrates. Depending on the properties of the surface of the base material, the adhesion of the cord pattern to the base material may be insufficient, and the cord pattern may not be readable after rubbing. Therefore, it is required that the code pattern can be read even after rubbing.

As a method for obtaining an invisible ink image, a method using an ink having no absorption band in the visible light region, for example, an ink that mainly absorbs infrared rays is known (for example, Japanese Patent Application Laid-Open No. 2008-144004, JP. (See 2013-189596, International Publication No. 2017/056760, and International Publication No. 2018/0343447).

However, invisible ink images are obtained with the inks disclosed in JP-A-2008-144004, JP-A-2013-189596, International Publication No. 2017/056760, and International Publication No. 2018/0343447, respectively. Although it is possible, we do not pay attention to the readability after scratch resistance.

The present disclosure has been made in view of such circumstances, and according to the present disclosure, an ink composition for inkjet recording capable of recording an ink image having excellent invisibility and readability after rubbing, and an ink composition for inkjet recording. , An image recording method is provided.

The present disclosure includes the following aspects.
<1> An ink composition for inkjet recording containing an infrared absorbing dye, polymer particles having a polymerizable group, and water.
<2> The ink composition for inkjet recording according to <1>, wherein the infrared absorbing dye is a dye or a pigment capable of forming a J-aggregate.
<3> The inkjet recording according to <2>, wherein the dye capable of forming a J-aggregate is at least one selected from the group consisting of dyes represented by the following general formulas 1-1 and 1-2. Ink composition for.

In the general formula 1-1, Y ¹ and Y ² independently represent a group of non-metal atoms forming an aliphatic ring or a hetero ring, and M ⁺ is a proton, a monovalent alkali metal cation, or an organic cation. L ¹ represents a methine chain consisting of 5 or 7 methine groups, and the methine group in the center of the methine chain has a substituent represented by the following formula A.
* ^{-S A} -T A formula A
Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a group consisting of a combination of at least two of these, where ^RL1 represents a hydrogen atom, a halogen atom, It represents an alkyl group, an aryl group, or a monovalent heterocyclic group, R ^L2 is an alkylene group, an arylene group, or a divalent heterocyclic group, T ^a is a halogen atom, an alkyl group, a cycloalkyl group, an aryl Group, monovalent heterocyclic group, cyano group, hydroxy group, formyl group, carboxy group, amino group, thiol group, sulfo group, phosphoryl group, boryl group, vinyl group, ethynyl group, trialkylsilyl group, or trialkyl a silyl group, a S ^a is a single bond or an alkylene group, and, if T ^a represents an alkyl group, and a total number of carbon atoms included in the S ^a and T ^a is 3 or more, * the methine chain Represents the binding site with the methine group in the center of.
In the Formula 1-2, ring A and ring B each independently represent an aromatic ring or a heteroaromatic ring, it represents a monovalent substituent X ^A and X ^B are each independently, G ^A and G ^B is each independently represent a monovalent substituent, kA is _{0 ~} n a, kB represents an integer of 0 ~ _{n B, n a} and _{n B} respectively ring a or ring B can be substituted to a ^{G a} and ^{G B} Represents an integer, which is the maximum number of
X ^A and G ^A may be bonded to each other to form a ring, X ^B and G ^B may be bonded to each other to form a ring, if G ^A and G ^B are present in plural is, G ^a and between G ^B together may be bonded to form a ring structure.
<4> The ink composition for inkjet recording according to <3>, wherein the dye represented by the general formula 1-1 is a dye represented by the following general formula 3.

In the general formula 3, M ⁺ represents a proton, a monovalent alkali metal cation, or an organic cation, L ¹ represents a methine chain consisting of 5 or 7 methine groups, and the methine group in the center of the methine group is as follows. It has a substituent represented by the formula A and has a substituent.
* ^{-S A} -T A formula A
Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a group consisting of a combination of at least two of these, where ^RL1 represents a hydrogen atom, a halogen atom, It represents an alkyl group, an aryl group, or a monovalent heterocyclic group, R ^L2 is an alkylene group, an arylene group, or a divalent heterocyclic group, T ^a is a halogen atom, an alkyl group, an aryl group, one Heterocyclic group, cyano group, hydroxy group, formyl group, carboxy group, amino group, thiol group, sulfo group, phosphoryl group, boryl group, vinyl group, ethynyl group, trialkylsilyl group, or trialkoxysilyl group. represents represents S ^a is a single bond or an alkylene group, and, if T ^a represents an alkyl group, and a total number of carbon atoms included in the S ^a and T ^a is 3 or more, * the methine chain central Represents a binding site with a methine group
R ⁵ and R ⁷ independently represent a hydrogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group, and R ⁶ and R ⁸ independently represent an alkyl group, a halogen atom, an alkenyl group, and an aryl group, respectively. , monovalent heterocyclic group, a nitro group, a cyano ^{group, -OR L3, -C (= O} ) R L3, -C (= O) OR L3, -OC (= O) R L3, -N (R L3 _{^{) 2, -NHC (= O)}} R L3, -C (= O) N (R L3) 2, -NHC (= O) OR L3, -OC (= O) N (R L3) 2, -NHC ( _{^{= O) N (R L3)}} 2, -SR L3, -S (= O) 2 R L3, -S (= O) 2 oR L3, -NHS (= O) 2 R L3, or, -S (= O) ₂ N ( ^RL3 ) ₂ represents, ^RL3 independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a monovalent heterocyclic group, and n represents 1 to 5 independently, respectively. Represents an integer of, and X independently represents an O atom, an S atom, or a Se atom.
<5> The ink composition for inkjet recording according to <4>, wherein at least one selected from the group consisting of ^{R 5} , R ⁶ , R ⁷ , and R ⁸ in the general formula 3 is a hydrogen-bonding group. ..
<6> The ink composition for inkjet recording according to any one of <1> to <5>, wherein the polymer particles having a polymerizable group are polyurethane particles having a polymerizable group.
<7> The ink jet recording ink according to any one of <1> to <6>, wherein the content of the infrared absorbing dye is 0.5% by mass to 2.5% by mass with respect to the total amount of the ink composition. Composition.
<8> The inkjet recording according to any one of <1> to <7>, wherein the ratio of the content of the polymer particles having a polymerizable group to the content of the infrared absorbing dye is 2 to 20 on a mass basis. Ink composition.
<9> The ink composition for inkjet recording according to any one of <1> to <8>, which further contains a water-soluble photopolymerization initiator.
<10> The ink composition for inkjet recording according to any one of <1> to <9>, which further contains a water-soluble sensitizer having an absorption range in the wavelength range of 350 nm to 400 nm.
<11> The step of applying the inkjet recording ink composition according to any one of <1> to <10> onto a substrate by an inkjet recording method to record an ink image, and drying the ink image. An image recording method including a step and a step of irradiating a dried ink image with active energy rays.
<12> The image recording method according to <11>, wherein the active energy ray is ultraviolet rays.
<13> The image recording method according to <11> or <12>, wherein the active energy ray is irradiated using a light emitting diode light source.
<14> The image recording method according to <11>, wherein the active energy ray is an electron beam.

According to the present disclosure, it is possible to provide an ink composition for inkjet recording capable of recording an ink image having excellent invisibility and readability after rubbing, and an image recording method.

Hereinafter, the ink composition of the present disclosure and the image recording method will be described in detail.

The numerical range indicated by using "-" in the present specification means a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. Further, in the numerical range described in the present specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.

In the present specification, the amount of each component in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means.
In the present specification, a combination of two or more preferred embodiments is a more preferred embodiment.
In the present specification, the term "process" is included in this term as long as the intended purpose of the process is achieved, not only in an independent process but also in the case where it cannot be clearly distinguished from other processes. Is done.

As used herein, "(meth) acrylate" is a concept that includes both acrylate and methacrylate. In addition, "(meth) acrylic" is a concept that includes both acrylic and methacrylic.
In the present specification, the "alkyl group" may be linear or have a branched structure, and a part or all of the carbon atoms contained in the alkyl group may form a cyclic structure. ..
In the present specification, the monovalent heterocyclic group means a group obtained by removing one hydrogen atom from the heterocyclic compound, and the divalent heterocyclic group means two hydrogen atoms from the heterocyclic compound. It means the excluded group.

[Ink composition for inkjet recording]
The ink composition for inkjet recording of the present disclosure (hereinafter, simply referred to as "ink composition") includes an infrared absorbing dye, polymer particles having a polymerizable group, and water.

Since the ink composition of the present disclosure contains polymer particles having a polymerizable group, a film is formed when the ink composition is landed on a substrate and then dried. Then, by irradiating with active energy rays, the polymers having a polymerizable group are polymerized in the film to form a high molecular weight polymer, and a strong ink film is formed. Therefore, when the ink composition of the present disclosure is used, an ink image having excellent readability after rubbing can be obtained.

In order to form a strong ink film, it is conceivable to use an ink composition containing high molecular weight polymer particles. However, when an ink composition is applied onto a substrate by an inkjet recording method, it is difficult to use an ink composition containing high molecular weight polymer particles from the viewpoint of ejection stability. On the other hand, the ink composition of the present disclosure contains polymer particles having a polymerizable group, can be applied by an inkjet recording method, and further, after landing on a substrate, becomes a high molecular weight polymer. It is excellent in that it can be done.

Further, in the case of an ultraviolet curable ink containing a polymerizable monomer, when cured, an ink film is formed on the base material in an uneven shape, so that there is a high possibility that a person will notice the image by touching it, and the image is invisible. Even if there is, it is highly likely that you will notice it visually because of the haze. On the other hand, since the ink composition of the present disclosure contains an infrared absorbing dye and water together with polymer particles having a polymerizable group, an ink having excellent invisibility when the ink composition of the present disclosure is used. You can get an image.

Hereinafter, each component contained in the ink composition of the present disclosure will be described.

<Infrared absorbing pigment>
The ink composition of the present disclosure contains an infrared absorbing dye. The infrared absorbing dye is not particularly limited as long as it is a dye having an absorption maximum in the infrared region. From the viewpoint of invisibility, the maximum absorbance of the infrared absorbing dye in the visible region is preferably 0.1 or less when the maximum absorbance in the infrared region is 1. Absorbance is measured using a spectrophotometer, for example, by the following method.

To determine whether or not the above conditions are satisfied, the ink composition is dried and measured as an ink dried product as follows. For the dried ink, the ink composition is placed on OK top-coated paper (manufactured by Oji Paper Co., Ltd.) with a drip amount of 7 pL to 10 pL and a resolution of 600 dpi (dot per inch) x 600 dpi, with a halftone dot ratio of 1% to 100%. It is obtained by printing and drying with warm air at 100 ° C. for 1 minute.

The maximum absorption wavelength of the ink composition of the present disclosure in the case of a dried ink is a spectrophotometer UV-3100PC (manufactured by Shimadzu Corporation) equipped with a 150 mmφ large integrating sphere accessory device LISR-3100 (manufactured by Shimadzu Corporation). It is obtained by measuring the reflection spectrum using.

From the viewpoint of invisibility and readability of the obtained infrared absorption image, the ink composition of the present disclosure may have a maximum absorption wavelength in the range of 700 nm to 1000 nm in the range of 400 nm to 1000 nm when it is a dried ink product. preferable.

By measuring the optical density in the range of 400 nm to 1000 nm by the same method as the measurement of the maximum absorption wavelength of the ink composition of the present disclosure in the case of the above-mentioned dried ink, the maximum of the above-mentioned ink composition of the present disclosure is obtained. It is possible to measure the value of the absorption wavelength.

The optical density is measured using a spectrophotometer UV-3100PC (manufactured by Shimadzu Corporation) equipped with a 150 mmφ large integrating sphere accessory device LISR-3100 (manufactured by Shimadzu Corporation).

In the present disclosure, the infrared region means a wavelength region of more than 800 nm and 2500 nm or less. The visible region means a wavelength region of 380 nm to 800 nm.

Examples of infrared absorbing pigments include cyanine pigments, phthalocyanine pigments, squarylium pigments, oxonor pigments, and pigments. Above all, from the viewpoint that it is difficult to be decomposed by radicals in the polymerization reaction, the infrared absorbing dye is preferably a dye or a pigment capable of forming a J-aggregate.

(Pigment)
The pigment may be an inorganic pigment or an organic pigment.
Examples of the organic pigment include a phthalocyanine compound and a cyanine compound.

Examples of the inorganic pigment include LaB ₆ (lanthanum hexaboride), CWO (tungsten cesium oxide), ITO (indium tin oxide) and ATO (antimony tin oxide). Among them, CWO (Tungsten Cesium Oxide) is preferable as the inorganic pigment from the viewpoint of dispersibility in water.

(Dyes that can form J-aggregates)
A state in which dye chromogens are fixed to a specific spatial arrangement by covalent bonds, coordinate bonds, or various intermolecular forces (for example, hydrogen bonds, van der Waals forces, Coulomb forces, etc.). Is generally referred to as an association (or aggregation) state. From the viewpoint of the absorption wavelength of the aggregate, the aggregate whose absorption shifts to a short wavelength with respect to the monomer absorption is an H aggregate (among others, the dimer is specially called a dimer), and the aggregate whose absorption shifts to a long wavelength is defined as an aggregate. Called the J assembly.

The dye in the J-association state forms a so-called J band, and thus exhibits a sharp absorption spectrum peak. Dye associations and J-bands are described in detail in the literature (eg, Photographic Science and Engineering Vol 18, No. 323-335 (1974)).

The maximum absorption wavelength of the dye in the J-association state moves to the longer wave side than the maximum absorption wavelength of the dye in the solution state. Therefore, whether the dye is in the J-association state or the non-association state can be determined by measuring the maximum absorption wavelength in the range of 400 nm to 1,000 nm.

In the present disclosure, the maximum absorption wavelength in the range of 700 nm to 1,000 nm when the ink composition is used as an image recording material and the infrared absorbing dye contained in the ink composition are dissolved in N, N-dimethylformamide (DMF). If the difference from the maximum absorption wavelength of the resulting solution is 30 nm or more, it is determined that the infrared absorbing dye in the case of an image recording is a J-aggregate. From the viewpoint of improving the invisibility of the ink image, the above difference is preferably 50 nm or more, more preferably 70 nm or more, and further preferably 100 nm or more.

Further, the infrared absorbing dye may form J-aggregates in the ink composition, or may not form J-aggregates in the ink composition, but may form droplets and reach the substrate. Alternatively, a J-aggregate may be formed in the ink image after landing on the substrate. Further, it is not necessary that all the infrared absorbing dyes form J-aggregates on the substrate, and the infrared absorbing dyes in the J-aggregated state and the molecularly dispersed state may be mixed.

Examples of pigments that can form J-aggregates include oxonor pigments and cyanine pigments (including squarylium pigments).

The dye capable of forming the J-aggregate is preferably at least one selected from the group consisting of the dyes represented by the following general formulas 1-1 and 1-2, and is represented by the general formula 1-1. More preferably, it is a dye to be used.

In the general formula 1-1, Y ¹ and Y ² independently represent a group of non-metal atoms forming an aliphatic ring or a hetero ring, and M ⁺ is a proton, a monovalent alkali metal cation, or an organic cation. L ¹ represents a methine chain consisting of 5 or 7 methine groups, and the methine group in the center of the methine chain has a substituent represented by the following formula A.
* ^{-S A} -T A formula A
Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - It represents a group consisting of C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a combination of at least two of these. ^RL1 represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group. ^RL2 represents an alkylene group, an arylene group, or a divalent heterocyclic group. T ^A is a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, monovalent heterocyclic group, cyano group, hydroxy group, formyl group, carboxyl group, an amino group, a thiol group, a sulfo group, a phosphoryl group, a boryl group, Represents a vinyl group, an ethynyl group, a trialkylsilyl group, or a trialkoxysilyl group. S ^A represents a single bond or an alkylene group, and, if T ^A represents an alkyl group, is the total number of carbon atoms included in the S ^A and T ^A is 3 or more. * Represents the binding site with the methine group in the center of the methine chain.

[Y ¹ and Y ² ]
Y ¹ and Y ² may be the same non-metal atom group or different non-metal atom groups, but are preferably the same non-metal atom group in terms of synthetic suitability.
Examples of the aliphatic ring formed by Y ¹ and Y ² include an aliphatic ring having 5 to 10 carbon atoms. The aliphatic ring may have a substituent and may form a fused ring with an aliphatic ring, an aromatic ring, or another heterocycle.
Examples of the aliphatic ring formed by Y ¹ and Y ² include a 1,3-indandion ring, a 1,3-benzoindandion ring, and a 2,3-dihydro-1H-phenalene-1,3-dione ring. Can be mentioned.
The hetero ring Y ¹ and Y ² form, for example, heterocyclic is a 5- or 6-membered ring. Examples of the hetero atom contained in the hetero ring include a nitrogen atom (N atom), an oxygen atom (O atom), a sulfur atom (S atom), and the like, and the N atom is preferable. The aliphatic ring may have a substituent and may form a fused ring with an aliphatic ring, an aromatic ring, or another heterocycle.
In the general formula 1-1, Y ¹ and Y ² are preferably non-metal atom groups that independently form a heterocycle, and more preferably non-metal atom groups that form the same heterocycle.
The hetero ring Y ¹ and Y ² form, for example, 5-pyrazolone ring, isooxazolone ring, barbituric acid ring, and pyridone ring, rhodanine ring, pyrazolidinedione ring, pyrazolopyridone ring, and Meldrum's acid ring .. Heterocycle Y ¹ and Y ² are formed, from the viewpoint of invisibility, barbituric acid ring.

[M ⁺ ]
M ⁺ represents a proton, a monovalent alkali metal cation, or an organic cation. From the viewpoint of improving the light resistance and moist heat resistance of the obtained ink image, M ⁺ is preferably a monovalent alkali metal cation.
Examples of the monovalent alkali metal cation include lithium ion (Li ⁺ ), sodium ion (Na ⁺ ), potassium ion (K ⁺ ), rubidium ion (Rb ⁺ ), cesium ion (Cs ⁺ ), and francium ion. (Fr ^+). Among them, an alkali metal cation ^{monovalent, Li +, Na +, K} +, Rb +, or Cs ⁺ is ^{preferably, Li +, Na +, K} +, Rb +, or Cs ⁺ Is more preferred, and Li ⁺ , Na ⁺ , or K ⁺ is even more preferred.
The organic cation may be a monovalent organic cation or a polyvalent organic cation, but a monovalent organic cation is preferable.
Examples of the organic cations include tetraalkylammonium ion, trialkylammonium ion, pyridinium ion, N-methylpyridinium ion, and N-ethylpyridinium ion. The organic cation is preferably trialkylammonium ion, more preferably triethylammonium ion.
Further, as the organic cation, a polyvalent organic cation can also be used from the viewpoint of ease of dispersion. Examples of the polyvalent organic cation include N, N, N', N'-tetramethylethylenediammonium, and cation master PD-7 (manufactured by Yokkaichi Chemical Company Limited).
M ⁺ is a counter cation, and the ^{presence of M +} makes the entire compound represented by the general formula 1-1 electrically neutral.

[L ¹ ]
L ¹ represents a methine chain consisting of 5 or 7 methine groups, and the methine group in the center of the methine chain has a substituent represented by the formula A.
L ¹ represents a methine chain consisting of 5 or 7 methine groups, and preferably represents a methine chain consisting of 5 methine groups.
The methine group other than the methine group in the center of the methine chain may be substituted, but it is preferable that the methine group is not substituted.
The methine chain may have a crosslinked structure at any position. For example, the carbons on both sides of the methine group may be crosslinked to form a ring structure. By introducing a ring structure, it is possible to control the light resistance and the like of an ink image obtained by using the ink composition of the present disclosure. The ring structure may be appropriately determined according to the intended use of the ink composition. The ring structure is not particularly limited, but an aliphatic ring is preferable, and a 5-membered aliphatic ring or a 6-membered aliphatic ring is preferable.
Specifically, L ¹ is preferably a group represented by the following formula L1-1, L1-2, L2-1, or L2-2, and is represented by the following formula L1-1 or formula L1-2. It is more preferable that it is a group.

In the formulas L1-1, L1-2, L2-1, and L2-2, A represents a substituent represented by the formula A, and the wavy line portions are independently in the general formula 1-1. It represents the bonding position of the structure other than L ¹ of each.
Y ^L represents a group of non-metal atoms forming an aliphatic ring or a heterocycle, and preferably represents a group of non-metal atoms representing an aliphatic ring. The Y ^L is preferably an alkyl group, and examples of the alkyl group include -CH ₂ CH _2- and -CH ₂ C (Z) _2- CH _2- . The aliphatic ring is preferably a 5-membered aliphatic ring or a 6-membered aliphatic ring.
The group represented by the above formula L2-1 or L2-2 is preferably a group represented by the following formulas L3-1 to L3-4.

Among the above formula L3-1 ~ formula L3-4, A represents a substituent of the formula A, wavy line portions independently, a bond positions of the ^{L 1} other than the structure of the general formula 1-1 Represent each.
Z independently represents a hydrogen atom or an alkyl group, and a hydrogen atom or an alkyl group having 1 to 8 carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable. The two Zs may be combined to form a ring structure.

-Substituent represented by formula A-
Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - It represents a group consisting of C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a combination of at least two of these. S ^A, from the viewpoint of improvement invisibility of the resulting ink image, a single bond, an alkylene group, preferably an alkenylene group, or alkynylene group, more preferably a single bond.
The alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and even more preferably a methylene group or an ethylene group.
The alkenylene group is preferably an alkenylene group having 2 to 10 carbon atoms, more preferably an alkenylene group having 2 to 4 carbon atoms, and even more preferably an alkenylene group having 2 or 3 carbon atoms.
The alkynylene group is preferably an alkynylene group having 2 to 10 carbon atoms, more preferably an alkynylene group having 2 to 4 carbon atoms, and even more preferably an alkynylene group having 2 or 3 carbon atoms.
The alkylene group, the alkenylene group, and the alkynylene group may be linear or have a branched structure, and a part or all of the carbon atoms contained in each group form a cyclic structure. You may. The above contents are the same unless otherwise specified in the description of the alkylene group, the alkenylene group, and the alkynylene group in the present disclosure.
The -C (= O) O-, the carbon atoms located in the binding side of L ^1, and, to an oxygen atom may be bonded side of the T ^A, or vice versa.
The -C (= O) NR L1 ^- the carbon atom located in the binding side of L ^1, and, to the nitrogen atom may be located on the coupling side of the T ^A, and vice versa May be good.

Wherein A, ^{S A} is -C (= O) ^{NR L1} - if it ^{is, R L1} represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group. ^RL1 is preferably a hydrogen atom, an alkyl group, or an aryl group, and more preferably a hydrogen atom.
Examples of the halogen atom include a fluorine atom (F atom), a chlorine atom (Cl atom), a bromine atom (Br atom), and an iodine atom (I atom). The halogen atom is preferably a Cl atom or a Br atom, and more preferably a Cl atom.
The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably an alkyl group having 1 or 2 carbon atoms.
The aryl group is preferably an aryl group having 6 to 20 carbon atoms, and more preferably a phenyl group or a naphthyl group.
The heterocycle in the monovalent heterocyclic group is preferably a 5-membered ring or a 6-membered ring. Further, the heterocycle may form a fused ring with an aliphatic ring, an aromatic ring, or another heterocycle.
Examples of the hetero atom in the hetero ring include N atom, O atom, and S atom, and N atom is preferable.
Examples of the heterocycle include a pyridine ring, a piperidine ring, a furan ring, a furfuran ring, a thiophene ring, a pyrrole ring, a quinoline ring, a morpholine ring, an indole ring, an imidazole ring, a pyrazole ring, a carbazole ring, a phenothiazine ring, a phenoxazine ring, and an indole ring. Examples include a ring, a pyrrolidone ring, a thiazole ring, a pyrazine ring, a thiadiazine ring, a benzoquinoline ring, and a thiazizole ring.

Wherein A, ^{S A} is ^{-OR L2} - if it ^{is, R L2} is an alkylene group, an arylene group, or a divalent heterocyclic group is preferably an alkylene group.
The alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and even more preferably an alkylene group having 1 or 2 carbon atoms.
The arylene group is preferably an arylene group having 6 to 20 carbon atoms, more preferably a phenylene group or a naphthylene group, and even more preferably a phenylene group.
The divalent heterocyclic group refers to the structure except for yet another hydrogen from heterocyclic monovalent radical in R ^L1 is preferable.

Wherein A, T ^A is a halogen atom, an alkyl group, an aryl group, monovalent heterocyclic group, cyano group, hydroxy group, formyl group, carboxyl group, an amino group, a thiol group, a sulfo group, a phosphoryl group, a boryl group , Vinyl group, ethynyl group, trialkylsilyl group, or trialkoxysilyl group, preferably aryl group, monovalent heterocyclic group, or trialkylsilyl group.
Examples of the halogen atom include a fluorine atom (F atom), a chlorine atom (Cl atom), a bromine atom (Br atom), and an iodine atom (I atom). The halogen atom is preferably a Cl atom or a Br atom, and more preferably a Cl atom.
The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably an alkyl group having 1 or 2 carbon atoms.
Wherein A, if T ^A represents an alkyl group, T ^A may form another carbon atom and the ring structure in the methine chain. The ring structure is preferably a 5-membered ring or a 6-membered ring.
The aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or a naphthyl group, and even more preferably a phenyl group. The aryl group may further have a substituent. Substituents that can be introduced into the aryl group include alkyl groups, halogen atoms, alkenyl groups, aryl groups, monovalent heterocyclic groups, nitro groups, cyano groups, -OR ^L3 , -C (= O) ^RL3 , and-. _{^{C (= O) OR L3,}} -OC (= O) R L3, -N (R L3) 2, -NHC (= O) R L3, -C (= O) N (R L3) 2, -NHC ( _{^{= O) OR L3, -OC (}} = O) N (R L3) 2, -NHC (= O) N (R L3) 2, -SR L3, -S (= O) 2 R L3, -S (= O) ₂ OR ^L3 , -NHS (= O) ₂ R ^L3 , and -S (= O) ₂ N ( ^RL3 ) ₂ . Among them, the substituent is an alkyl group, an aryl group, monovalent heterocyclic group, a nitro group, a cyano _{^{group, -OR L3, -N (R L3}} ) 2, -NHC (= O) R L3, -C (= _{^{O) N (R L3) 2}} , -NHC (= O) oR L3, or ^{-NHC (= O) N (R} L3) 2 is preferred.
The heterocycle in the monovalent heterocyclic group is preferably a 5-membered ring or a 6-membered ring. Further, the heterocycle may form a fused ring with an aliphatic ring, an aromatic ring, or another heterocycle.
Examples of the hetero atom in the hetero ring include N atom, O atom, and S atom, and N atom is preferable.
Examples of the heterocycle include a pyridine ring, a triazine ring, a piperidine ring, a furan ring, a furfuran ring, a merdrum acid ring, a carbazole ring, a succinimide ring, a thiophene ring, a pyrrole ring, a quinoline ring, a morpholine ring, a thiomorpholin ring, and an indole. Examples thereof include a ring, an imidazole ring, a pyrazole ring, a carbazole ring, a phenothiazine ring, a phenoxazine ring, an indole ring, a pyrrolidone ring, a thiazole ring, a pyrazine ring, a thiaziazine ring, a benzoquinoline ring, and a thiazizole ring.
The heterocycle may form a salt structure. For example, the pyridine ring may form a pyridinium salt or may exist as a pyridinium ion.
The aryl group or monovalent heterocyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an alkenyl group, an alkynyl group, an aryl group, a monovalent heterocyclic group, a nitro group, a cyano group, -OR ^T , and -C (= O) ^RT. , -C (= O) OR ^T , -OC (= O) ^RT , -N ( ^RT ) ₂ , -NHC (= O) ^RT , -C (= O) N ( ^RT ) ₂ ,- NHC (= O) OR ^T , -OC (= O) N ( ^RT ) ₂ , -NHC (= O) N ( ^RT ) ₂ , -SR ^T , -S (= O) ₂ ^RT , -S Examples thereof include (= O) ₂ OR ^T , -NHS (= O) ₂ ^RT , and -S (= O) ₂ N ( ^RT ) _2.

^{Each of RT} independently represents a hydrogen atom, an alkyl group, an aryl group or a monovalent heterocyclic group, and a hydrogen atom, an alkyl group or an aryl group is preferable.
^{The alkyl group in RT} is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably a methyl group or an ethyl group.
^{The aryl group in RT} is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or a naphthyl group, and even more preferably a phenyl group.
^{The heterocycle in the monovalent heterocyclic group in RT} is preferably a 5-membered ring or a 6-membered ring. Further, the heterocycle may form a fused ring with an aliphatic ring, an aromatic ring, or another heterocycle.
Examples of the hetero atom in the hetero ring include N atom, O atom, and S atom, and N atom is preferable.
Examples of the heterocycle include a pyridine ring, a piperazine ring, a piperazine ring, a pyrrolidine ring, a furan ring, a tetrahydrofuran ring, a tetrahydropyran ring, a thiophene ring, a pyrrole ring, a quinoline ring, a morpholine ring, an indole ring, an imidazole ring, a pyrazole ring, and a carbazole ring. Examples thereof include a ring, a phenothiazine ring, a phenoxazine ring, an indolin ring, a pyrrolidone ring, a thiazole ring, a pyrazine ring, a thiadiazine ring, a benzoquinoline ring, and a thiazizole ring.
The monovalent heterocyclic group may further have a substituent. Examples of the substituent include ^{a group represented by RT} , and the same applies to preferred embodiments.

Examples of the amino group include an unsubstituted amino group and a substituted amino group, and a diarylamino group or a diheteroarylamino group is preferable.
Substituents in the substituted amino group include alkyl groups, aryl groups, and monovalent heterocyclic groups. The alkyl group, aryl group, or a monovalent heterocyclic group, an alkyl group of T ^A, has the same meaning as the aryl group, or a monovalent heterocyclic group, the trialkylsilyl group is the same preferred embodiment, A trialkylsilyl group having 1 to 10 carbon atoms of the alkyl group is preferable, and a trialkylsilyl group having 1 to 4 carbon atoms of the alkyl group is more preferable. For example, a trimethylsilyl group, a dimethylbutylsilyl group, a triethylsilyl group, and a triisopropylsilyl group can be mentioned.
The trialkoxysilyl group is preferably a trialkoxysilyl group having 1 to 10 carbon atoms in the alkoxy group, and more preferably a trialkoxysilyl group having 1 to 4 carbon atoms in the alkoxy group. Examples of the trialkoxysilyl group having 1 to 4 carbon atoms in the alkoxy group include a trimethoxysilyl group and a triethoxysilyl group.

S ^A represents a single bond or an alkylene group, and, if T ^A represents an alkyl group, the total number of carbon atoms included in the S ^A and T ^A, from the viewpoint of invisibility of the resulting ink image, at least 3 It is preferably 4 or more, and more preferably 5 or more.
Further, the total number of carbon atoms is preferably 20 or less, and more preferably 10 or less, from the viewpoint of ease of dispersion.
Among them, from the viewpoint of dispersibility, wherein A, T ^A is a heterocyclic group containing a nitrogen atom is preferably an aryl group, or a halogen atom.

Specific examples of the substituent (substituent A) represented by the above formula A include the following substituents A-1 to A-48. However, the substituent A in the present disclosure is not limited to these. Among the following substituents A-1 to A-48, i-C ₁₀ represents an isodecyl group, i-C ₈ represents an isooctyl group, and * indicates a binding site with ^{L 1 in the general formula 1-1.} ..
Of the following substituents A-1 to A-48, the substituent represented by the formula A is A-1, A-2, A-4, A-7, A-8, A from the viewpoint of dispersibility. -12, A-13, A-14, A-15, A-16, A-20, A-26, A-28, A-29, A-30, A-31, A-32, A-34 , A-39, A-41, A-42, A-43, A-44, A-45, A-47, or A-48, preferably A-1, A-2, A-4, A. -7, A-8, A-13, A-14, A-15, A-26, A-28, A-29, A-30, A-31, A-32, A-34, A-39 , Or A-42 is more preferable.
Further, the substituent represented by the formula A is A-1, A-2, A-4, A-5, A-6, A from the viewpoint that the absorption wavelength of the infrared absorbing dye is on the longer wavelength side. -7, A-8, A-20, A-34, A-39, A-41, A-42, A-45, or A-48 is preferable, and A-1, A-2, A-4. , A-8, A-39, or A-42 are more preferred.

Further, the dye capable of forming the J-aggregate may be a dye represented by the following general formula 1-2.

In the Formula 1-2, ring A and ring B each independently represent an aromatic ring or a heteroaromatic ring, it represents a monovalent substituent X ^A and X ^B are each independently, G ^A and G ^B is each independently represent a monovalent substituent, kA is _{0 ~} n a, kB represents an integer of 0 ~ _{n B, n a} and _{n B} respectively ring a or ring B can be substituted to a ^{G a} and ^{G B} Represents an integer that is the maximum number of.
X ^A and G ^A may be bonded to each other to form a ring, X ^B and G ^B may be bonded to each other to form a ring, if G ^A and G ^B are present in plural is, G ^a and between G ^B together may be bonded to form a ring structure.

G ^A and ^{G B} represents a monovalent substituent independently. The monovalent substituent includes a halogen atom, a cyano group, a nitro group, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an aralkyl group, -OR ¹⁰ , -COR ¹¹ , -COOR ¹² , and -OCOR. ¹³ , -NR ¹⁴ R ¹⁵ , -NHCOR ¹⁶ , -CONR ¹⁷ R ¹⁸ , -NHCONR ¹⁹ R ²⁰ , -NHCOOR ²¹ , -SR ²² , -SO ₂ R ²³ , -SO ₂ OR ²⁴ , -NHSO ₂ R ²⁵ , Alternatively, SO ₂ NR ²⁶ R ²⁷ can be mentioned.
R ¹⁰ to R ²⁷ each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. When R ^{12 of -COOR 12} is hydrogen (that is, a carboxyl group), the hydrogen atom may be dissociated (that is, a carbonate group), or it may be in a salt state. Further, when R ^{24 of} _{-SO 2} OR ²⁴ is a hydrogen atom (that is, a sulfo group), the hydrogen atom may be dissociated (that is, a sulfonate group) or may be in a salt state.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 8. The alkyl group may be linear, branched or cyclic, and is preferably linear or branched.
The alkenyl group preferably has 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms. The alkenyl group may be linear, branched or cyclic, and is preferably linear or branched.
The alkynyl group preferably has 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 to 25 carbon atoms. The alkynyl group may be linear, branched or cyclic, and is preferably linear or branched.
The aryl group preferably has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and even more preferably 6 to 12 carbon atoms.
The alkyl moiety of the aralkyl group is the same as the above alkyl group. The aryl moiety of the aralkyl group is the same as that of the above aryl group. The carbon number of the aralkyl group is preferably 7 to 40, more preferably 7 to 30, and even more preferably 7 to 25.

The heteroaryl group is preferably a monocyclic ring or a condensed ring, preferably a monocyclic ring or a condensed ring having a condensed number of 2 to 8, and more preferably a monocyclic ring or a condensed ring having a condensed number of 2 to 4. The number of heteroatoms constituting the ring of the heteroaryl group is preferably 1 to 3. The hetero atom constituting the ring of the heteroaryl group is preferably a nitrogen atom, an oxygen atom, or a sulfur atom. The heteroaryl group is preferably a 5-membered ring or a 6-membered ring. The number of carbon atoms constituting the ring of the heteroaryl group is preferably 3 to 30, more preferably 3 to 18, and even more preferably 3 to 12. Examples of heteroaryl groups include pyridine ring, piperidine ring, furan ring group, furfuran ring, thiophene ring, pyrrole ring, quinoline ring, morpholine ring, indole ring, imidazole ring, pyrazole ring, carbazole ring, phenothiazine ring, phenoxazine. Examples thereof include a ring, an indole ring, a thiazole ring, a pyrazole ring, a thiadiazine ring, a benzoquinoline ring, and a thiazizole ring.

The alkyl group, alkenyl group, alkynyl group, aralkyl group, aryl group and heteroaryl group may have a substituent or may be unsubstituted.
Examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, an aromatic heterocyclic oxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group and an acyloxy group. , Acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, aromatic heterocyclic thio group, sulfonyl group, sulfinyl group, ureido group, phosphate amide. Examples include groups, hydroxy groups, mercapto groups, halogen atoms, cyano groups, sulfo groups, carboxyl groups, nitro groups, hydroxamic acid groups, sulfino groups, hydrazino groups, imino groups, and silyl groups, and these substituents are further substituted. May be done.

X ^A and X ^B each independently represent a monovalent substituent. Substituent is preferably a group having an active _{^{hydrogen, -OH, -SH, -COOH, -SO}} 3 H, -NR X1 R X2, -NHCOR X1, -CONR X1 R X2, -NHCONR X1 R X2, -NHCOOR ^X1 , -NHSO ₂ R ^X1 , -B (OH) ₂ and PO (OH) ₂ are more preferred, and -OH, -SH, and NR ^X1 R ^{X 2} are even more preferred.

^RX1 and ^RX2 independently represent a hydrogen atom or a monovalent substituent. Substituents include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, and heteroaryl groups. Of these, the substituent is preferably an alkyl group. The alkyl group is preferably linear or branched. Alkyl group, an alkenyl group, an alkynyl group, an aryl group and, for details of the heteroaryl group, is as defined and ranges described for the G ^A and G ^B.

Ring A and ring B each independently represent an aromatic ring or a heteroaromatic ring.
The aromatic ring and the heteroaromatic ring may be a monocyclic ring or a condensed ring.
Specific examples of the aromatic ring and the heteroaromatic ring include a benzene ring, a naphthalene ring, a pentalene ring, an inden ring, an azulene ring, a heptalene ring, an indecene ring, a perylene ring, a pentacene ring, an acetaphthalene ring, a phenanthrene ring, an anthracene ring, and a naphthalene ring. , Chrysen ring, triphenylene ring, fluorene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, indridin ring, indole ring, Benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthylidine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenanthrene ring, aclysin ring, phenanthrene ring, thianthrene ring, chromene. Examples thereof include a ring, a xanthene ring, a phenoxatiin ring, a phenothiazine ring, and a phenazine ring. Among them, the aromatic ring and the heteroaromatic ring are preferably a benzene ring or a naphthalene ring.
The aromatic ring may be unsubstituted or may have a substituent. Examples of the substituent include the substituents described in G ^A and G ^B.

X ^A and G ^A may be bonded to each other to form a ring, X ^B and G ^B may be bonded to each other to form a ring, if G ^A and G ^B are present in plural is, G ^a and between G ^B together may be bonded to each other to form a ring.
The ring is preferably a 5-membered ring or a 6-membered ring. The ring may be a single ring or a double ring.
X ^A and ^G A, ^{X B} and ^G B, when forming a ^{G A} together, or ^{G B} are bonded to each other rings, it may be they are attached directly to form a ring, an alkylene group, -CO- , -O-, -NH-, -BR-, and combinations thereof may be bonded via a divalent linking group selected from the group to form a ring. X ^A and ^G A, ^{X B} and ^G B, ^{G A} together, or ^{G B} each other, it is preferable to form a ring via -BR-.
R represents a hydrogen atom or a monovalent substituent. Examples of the substituent include the substituents described in G ^A and G ^B. The substituent is preferably an alkyl group or an aryl group.
kA represents an integer from 0 to n _A , kB represents an integer from 0 to n _B , n _A represents the largest integer substitutable for the A ring, and n _B represents the largest substitutable for the ring B. Represents an integer.
As for kA and kB, 0 to 4 is preferable, 0 to 2 is more preferable, and 0 to 1 is particularly preferable, respectively.

A preferable embodiment of the compound represented by the general formula 1-2 is a compound represented by the following general formula (6). The compound represented by the following general formula (6) has a property of being excellent in light resistance as an infrared absorbing dye.

In the general formula (6), R ¹ and R ² each independently represent a monovalent substituent, and R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group. Examples of the substituent include the substituents described in G ^A and G ^B.
X ¹ and X ² independently represent an oxygen atom or -N (R ⁵ )-, and X ³ and X ⁴ independently represent a carbon atom or a boron atom, respectively.
t and u ^{represent 1 when X 3} and X ⁴ are boron atoms, and represent 2 when X ³ and X ⁴ are carbon atoms.
R ⁵ represents a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group, and Y ¹ , Y ² , Y ³ , and Y ⁴ each independently represent a monovalent substituent, Y ¹ and Y. ² may be bonded to each other to form a ring, and Y ³ and Y ⁴ may be bonded to each other to form a ring.
When a ^{plurality of Y 1} , Y ² , Y ³ , and Y ⁴ are present, they may be combined with each other to form a ring. Examples of the substituent include the substituents described in G ^A and G ^B.
p and s each independently represent an integer of 0 to 3, and q and r each independently represent an integer of 0 to 2.
^{R 1, R 2, Y 1} , Y 2, Y 3, and ^{substituents Y 4} represents a substituted group described for ^{G A} and ^{G B} are mentioned as well.

R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group. The alkyl group of R ³ has, for example, 1 to 4, preferably 1 or 2. The alkyl group may be linear or branched. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group. R ³ is preferably a hydrogen atom, a methyl group, or an ethyl group, particularly preferably hydrogen or a methyl group, and most preferably hydrogen.
X ¹ and X ² independently represent an oxygen atom (-O-) or -N (R ⁵ )-. X ¹ and X ² may be the same or different, but are preferably the same.
R ⁵ represents a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group.
R ⁵ is preferably a hydrogen atom, an alkyl group or an aryl group, and more preferably a hydrogen atom or an alkyl group. The alkyl group, aryl group and heteroaryl group represented by ^{R 5 may be unsubstituted or have a monovalent substituent.} The monovalent substituent include the monovalent substituent described in G ^A and G ^B described above.
The number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 10, further preferably 1 to 4, and particularly preferably 1 to 2. The alkyl group may be linear or branched.
The aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms.
The heteroaryl group may be monocyclic or polycyclic. The number of heteroatoms constituting the ring of the heteroaryl group is preferably 1 to 3. The hetero atom constituting the ring of the heteroaryl group is preferably a nitrogen atom, an oxygen atom, or a sulfur atom. The number of carbon atoms constituting the ring of the heteroaryl group is preferably 3 to 30, more preferably 3 to 18, and even more preferably 3 to 12.

The molecular weight of the compound represented by the general formula 1-2 is preferably 100 to 2,000, more preferably 150 to 1,000.

The compound represented by the general formula 1-2 and the compound represented by the general formula (6), which is a preferred embodiment thereof, are described in detail in Japanese Patent Application Laid-Open No. 2011-2008101. The compounds described in JP-A-2011-2008101 can be suitably used as the infrared absorbing dye in the present disclosure. Specific examples of the compound represented by the general formula 1-2 and the compound represented by the general formula (6), which is a preferred embodiment thereof, include, for example, the compound described in JP-A-2011-208101 and the compound described in JP-A-2011-208101. Examples thereof include the compounds described in paragraph Nos. 0076 and 0077 of JP-A-2018-154672. However, specific examples of the compounds represented by the general formula 1-2 are not limited to these descriptions.

Specific examples (B-1 to B-40) of the compounds represented by the above general formula 1-2 are shown below. However, the infrared absorbing dye in the present disclosure is not limited to the following compounds. In the formula, "Me" represents a methyl group and "Ph" represents a phenyl group.

Among the above specific examples, as more preferable compounds, compounds B-1, B-3, B-4, B-6, B-9, B-11, B-21, B-24, B-30, B -31, B-37, and B-38 can be mentioned.

<Dye represented by general formula 2>
The dye represented by the general formula 1-1 is preferably a dye represented by the following general formula 2. When the ink composition of the present disclosure contains a dye represented by the general formula 2, an ink image having better invisibility can be obtained.

In the general formula 2, M ⁺ represents a proton, a monovalent alkali metal cation, or an organic cation, L ¹ represents a methine chain consisting of 5 or 7 methine groups, and the methine group in the center of the methine group is as follows. It has a substituent represented by the formula A.
* ^{-S A} -T A formula A
Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - It represents a group consisting of C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a combination of at least two of these. ^RL1 represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group. ^RL2 represents an alkylene group, an arylene group, or a divalent heterocyclic group. T ^A is a halogen atom, an alkyl group, an aryl group, monovalent heterocyclic group, cyano group, hydroxy group, formyl group, carboxyl group, an amino group, a thiol group, a sulfo group, a phosphoryl group, a boryl group, a vinyl group, Represents an ethynyl group, a trialkylsilyl group, or a trialkoxysilyl group. S ^A represents a single bond or an alkylene group, and, if T ^A represents an alkyl group, is the total number of carbon atoms included in the S ^A and T ^A is 3 or more. * Represents the binding site with the methine group in the center of the methine chain.
R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group. Each X independently represents an O atom, an S atom or a Se atom.

[L ¹ and M ⁺ ]
In the Formula 2, ^{L 1} and ^{M +} have the same meanings as defined in formula 1-1 in ^{L 1} and ^{M +,} preferable embodiments thereof are also the same.

[R ¹ , R ² , R ³ and R ⁴ ]
In General Formula 2, R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group, respectively, and the light resistance and invisibleness of the obtained ink image. From the viewpoint of properties, a hydrogen atom or an aryl group is preferable, and a hydrogen atom or a phenyl group is preferable.
The alkyl group in R ¹ , R ² , R ³ and R ⁴ is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably a methyl group or an ethyl group.
The alkyl group preferably has a substituent. Examples of the substituent include groups other than the alkyl group, the nitro group, and the cyano group from the examples of the substituent in the aryl group described later, and the preferred embodiment is also the same.

The aryl group in R ¹ , R ² , R ³ and R ⁴ is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or a naphthyl group, and even more preferably a phenyl group.
The aryl group may be unsubstituted, but preferably has a substituent. From the viewpoint of dispersibility and association stability, the position of introduction of the substituent is preferably a meta position or a para position, and more preferably a meta position with respect to the binding site with another structure in the general formula 2. Above all, the embodiment having a polar group at the meta position is more preferable.
Examples of the substituent that can be introduced into the aryl group include an alkyl group, a halogen atom, an alkenyl group, an aryl group, a monovalent heterocyclic group, a nitro group, a cyano group, -OR ^L3 , and -C (= O) ^{RL3. _{, -C (= O) OR L3}} , -OC (= O) R L3, -N (R L3) 2, -NHC (= O) R L3, -C (= O) N (R L3) 2, - _{^{NHC (= O) OR L3,}} -OC (= O) N (R L3) 2, -NHC (= O) N (R L3) 2, -SR L3, -S (= O) 2 R L3, -S Examples thereof include (= O) ₂ OR ^L3 , -NHS (= O) ₂ R ^L3 , and -S (= O) ₂ N ( ^RL3 ) _2.

The substituent is preferably a polar group from the viewpoint of further improving the dispersibility and association stability of the infrared absorbing dye. Examples of the polar group include a nitro group, a cyano group, -OR ^L3 , -C (= O) R ^L3 , -C (= O) OR ^L3 , and -OC (= O) R ^{L3 among the above-exemplified substituents. _{, -N (R L3) 2,}} -NHC (= O) R L3, -C (= O) N (R L3) 2, -NHC (= O) OR L3, -OC (= O) N (R L3 ) ₂ , -NHC (= O) N ( ^RL3 ) ₂ , -SR ^L3 , -S (= O) ₂ R ^L3 , -S (= O) ₂ OR ^L3 , -NHS (= O) ₂ R ^L3 , And -S (= O) ₂ N ( ^RL3 ) ₂ . Among these, polar _{^{groups, -NHC (= O) R L3}} , -C (= O) N (R L3) 2, -NHC (= O) OR L3, -OC (= O) N (R L3) 2, -NHC (= O) N ( ^RL3 ) ₂ , -NHS (= O) ₂ ^RL3 , or -S (= O) ₂ N ( ^RL3 ) ₂ is more preferable.

From the viewpoint of light resistance and moisture heat resistance of the ink image, the substituent is preferably a hydrogen bonding group. A hydrogen-bonding group is a group that interacts with a hydrogen atom. Among the above-exemplified substituents, the hydrogen-bonding groups include -OH, -C (= O) OH, -NHC (= O) ^RL3 , -C (= O) N (RL3) ₂ , ^{and-. _{NHC (= O) oR L3,}} -OC (= O) N (R L3) 2, -NHC (= O) N (R L3) 2, -NHS (= O) 2 R L3 and,, -S (= O) ₂ N ( ^RL3 ) ₂ can be mentioned. Of these, -NHC (= O) OR ^L3 is more preferable as the hydrogen-bonding group.

^RL3 independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a monovalent heterocyclic group, and a hydrogen atom, an alkyl group, or an aryl group is preferable.
The alkyl group in R ^L3 is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
Alkenyl group for R ^L3 is preferably an alkenyl group having 2 to 10 carbon atoms, more preferably an alkenyl group having 2 to 4 carbon atoms, more preferably an alkenyl group having 2 or 3 carbon atoms.
Aryl group in R ^L3 is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or a naphthyl group, more preferably a phenyl group.
Heterocycle in the heterocyclic group of monovalent in R ^L3 is preferably a 5- or 6-membered ring. Further, the heterocycle may form a fused ring with an aliphatic ring, an aromatic ring, or another heterocycle.
Examples of the hetero atom in the hetero ring include N atom, O atom, and S atom, and N atom is preferable.
Examples of the heterocycle include a pyridine ring, a piperidine ring, a furan ring, a furfuran ring, a thiophene ring, a pyrrole ring, a quinoline ring, a morpholine ring, an indole ring, an imidazole ring, a pyrazole ring, a carbazole ring, a phenothiazine ring, a phenoxazine ring, and an indole ring. Examples include a ring, a pyrrolidone ring, a thiazole ring, a pyrazine ring, a thiadiazine ring, a benzoquinoline ring, and a thiazizole ring.
The monovalent heterocyclic group may further have a substituent. Examples of the substituent include ^{a group represented by RL3} , and the preferred embodiment is also the same.

Heterocycle in monovalent heterocyclic group in R ^{1, R} 2, ^{R 3} and ^{R 4} is preferably a 5- or 6-membered ring. Further, the heterocycle may form a fused ring with an aliphatic ring, an aromatic ring, or another heterocycle.
Examples of the hetero atom in the hetero ring include N atom, O atom, and S atom, and N atom is preferable.
Examples of the heterocycle include a pyridine ring, a piperidine ring, a furan ring, a furfuran ring, a thiophene ring, a pyrrole ring, a quinoline ring, a morpholine ring, an indole ring, an imidazole ring, a pyrazole ring, a carbazole ring, a phenothiazine ring, a phenoxazine ring, and an indole ring. Examples include a ring, a pyrrolidone ring, a thiazole ring, a pyrazine ring, a thiadiazine ring, a benzoquinoline ring, and a thiazizole ring.
The monovalent heterocyclic group preferably has a substituent. Examples of the substituent include the same group as the substituent when R ¹ , R ² , R ³ , and R ⁴ are aryl groups, and the preferred embodiment is also the same.

Further, from the viewpoint of improving the light resistance and moisture heat resistance of the obtained ink image, it is preferable that at least one selected from the group consisting of ^{R 1} , R ² , R ³ , and R ^{4 is a hydrogen atom, and R 1} , It is more preferable that at least two selected from the group consisting of R ² , R ³ , and R ^{4 are hydrogen atoms, and two selected from the group consisting of R 1} , R ² , R ³ , and R ⁴ are hydrogen. It is more preferably an atom.
When ^{two selected from the group consisting of R 1} , R 2, R ³ , and R ⁴ are hydrogen atoms, one of R ¹ and R ² and one of R ³ and R ⁴ are hydrogen atoms. Is preferable.
Further, from the viewpoint of invisibility of the obtained ink image, ^one of R 1 and R ² and one of R ³ and R ⁴ are hydrogen atoms, and the other ^one of R ^{1 and R 2 and R 3} and It is more preferable that the other one of R ^{4 is a phenyl group.} As described above, the phenyl group more preferably has a substituent.

Specific examples of the above R ¹ , R ² , R ³ and R ⁴ include the following substituents R-1 to R-79. ^{However, R 1, R 2, R} 3 in the present disclosure, and ^{R 4} are not limited thereto. Among the following substituents R-1 to R-79, the wavy line portion indicates a binding site with another structure in the general formula 2.
Of the following substituents R-1 to R-79, from the viewpoint of light resistance, R-1, R-2, R-3, R-4, R-5, R-7, R-11, R-13 , R-14, R-15, R-18, R-19, R-20, R-22, R-50, R-51, R-52, R-53, R-56, R-57, R -60, R-61, R-62, R-63, R-64, R-65, R-66, R-67, R-68, R-69, R-70, R-71, R-72 , R-73, R-74, R-75, R-76, R-77, R-78, or R-79, preferably R-1, R-2, R-4, R-7, R. -11, R-13, R-14, R-15, R-18, R-19, R-51, R-52, R-53, R-56, R-57, R-60, R-61 , R-62, R-63, R-64, or R-79 are more preferred.
In the structure of the substituent below, Me represents a methyl group.

[X]
In the general formula 2, X independently represents an O atom, an S atom, or a Se atom, and is preferably an O atom or an S atom, and more preferably an O atom.

<Dye represented by general formula 3>
The dye represented by the general formula 1-1 is preferably a dye represented by the following general formula 3. When the ink composition of the present disclosure contains a dye represented by the general formula 3, an excellent ink image can be obtained due to invisibility and readability after scraping.

In General Formula 3, M ⁺ represents a proton, a monovalent alkali metal cation, or an organic cation. L ¹ represents a methine chain consisting of 5 or 7 methine groups. The methine group in the center of the methine chain has a substituent represented by A.
* ^{-S A} -T A formula A
Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - It represents a group consisting of C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a combination of at least two of these. ^RL1 represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group. ^RL2 represents an alkylene group, an arylene group, or a divalent heterocyclic group. T ^A is a halogen atom, an alkyl group, an aryl group, monovalent heterocyclic group, cyano group, hydroxy group, formyl group, carboxyl group, an amino group, a thiol group, a sulfo group, a phosphoryl group, a boryl group, a vinyl group, Represents an ethynyl group, a trialkylsilyl group, or a trialkoxysilyl group. S ^A represents a single bond or an alkylene group, and, if T ^A represents an alkyl group, and a total number of carbon atoms included in the S ^A and T ^A is 3 or more, * the central methine group of the methine chain Represents the binding site with.
R ⁵ and R ⁷ each independently represent a hydrogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group. R ⁶ and R ⁸ are independently alkyl group, halogen atom, alkenyl group, aryl group, monovalent heterocyclic group, nitro group, cyano group, -OR ^L3 , -C (= O) R ^L3 , -C, respectively. _{^{(= O) OR L3, -OC}} (= O) R L3, -N (R L3) 2, -NHC (= O) R L3, -C (= O) N (R L3) 2, -NHC (= _{^{O) OR L3, -OC (=}} O) N (R L3) 2, -NHC (= O) N (R L3) 2, -SR L3, -S (= O) 2 R L3, -S (= O ) ₂ OR ^L3 , -NHS (= O) ₂ R ^L3 , or -S (= O) ₂ N ( ^RL3 ) ₂ . ^RL3 independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a monovalent heterocyclic group, n independently represents an integer of 1 to 5, and X independently represents O. Represents an atom, S atom or Se atom.

[L ¹ , M ⁺ , and X]
In the Formula ^3, L 1, ^{M +} and X have the same meanings as commonly ^L 1 of formula 2, ^{M +} and X, preferable embodiments thereof are also the same.

[R ⁵ , R ⁶ , R ⁷ and R ⁸ ]
R ⁵ and R ⁷ each independently represent a hydrogen atom, an alkyl group, an aryl group, or a monovalent heterocyclic group, and a hydrogen atom is preferable.
The alkyl group, aryl group, or monovalent heterocyclic group in R ⁵ and R ⁷ is the same as the alkyl group, aryl group, or monovalent heterocyclic group in R ¹ and R ³ , and the preferred embodiment is also the same. Is.
R ⁶ and R ⁸ are independently alkyl group, halogen atom, alkenyl group, aryl group, monovalent heterocyclic group, nitro group, cyano group, -OR ^L3 , -C (= O) R ^L3 , -C, respectively. _{^{(= O) OR L3, -OC}} (= O) R L3, -N (R L3) 2, -NHC (= O) R L3, -C (= O) N (R L3) 2, -NHC (= _{^{O) OR L3, -OC (=}} O) N (R L3) 2, -NHC (= O) N (R L3) 2, -SR L3, -S (= O) 2 R L3, -S (= O ) ₂ OR ^L3 , -NHS (= O) ₂ R ^L3 , or -S (= O) ₂ N ( ^RL3 ) ₂
The ^{R L3 has} the same meaning as ^{R L3} in R 1 ~ ^{R 4,} preferable embodiments thereof are also the same.
R ⁶ and R ⁸ are each independently preferably a hydrogen-bonding group. The hydrogen bonding group, for ^{example, -OH, -C (= O)} OH, -NHC (= O) R L3, -C (= O) N (R L3) 2, -NHC (= O) OR L3 _{^{, -OC (= O) N (}} R L3) 2, -NHC (= O) N (R L3) 2, -NHS (= O) 2 R L3, _{and, -S (= O) 2 N} (R L3 ) ₂ , and -NHC (= O) OR ^L4 is preferable.
The ^{R L3 has} the same meaning as ^{R L3} in R 1 ~ ^{R 4,} preferable embodiments thereof are also the same.
The ^RL4 represents an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

From the viewpoint of ink storage stability, the dye represented by the general formula 3 preferably has one group represented by ^{R 6 and one group represented by R 8.} In that case, groups represented by R ^6, or the bonding position of the group represented by R ^8, in the benzene ring group represented by R ⁶ or R ⁸ is attached, bonding position of the barbituric acid ring It is preferable that it is a meta position with respect to.

In general formula ^3, it is preferable that ^{R 5, R 6, R 7} , and at least one selected from the group consisting of ^{R 8} is a hydrogen bonding ^{group, R 5, R 6, R 7} , and from ^{R 8} More preferably, at least two selected from the group are hydrogen-bonding groups.
Further, from the viewpoint of synthetic suitability, ^{it is preferable that R 5} and R ⁷ and R ⁶ and R ⁸ are the same group, respectively.
Further, ^{it is preferable that R 5} and R ⁷ are hydrogen atoms, respectively, and R ⁶ and R ⁸ are the same hydrogen-bonding group.

[N]
n represents an integer of 1 to 5 independently, and is preferably an integer of 1 to 3 from the viewpoint of ease of dispersion, more preferably 1 or 2, and even more preferably 1.

<Manufacturing method of infrared absorbing pigment>
The dyes represented by any of the general formula 1-1, the general formula 2, or the general formula 3 are, for example, JP-A-2002-20648 and FM Harmer, “Hetero). Cyclic Compounds Cyanine Dies and Related Compounds, John Wiley & Sons, 19th, 19th, London, 19th, London, 19th, London It is possible to synthesize by referring to it.

Hereinafter, specific examples of the infrared absorbing dye will be described based on the general formula 2. A, R ¹ , R ² , R ³ , R ⁴ , X, and M ^{+ in L 1} , L ¹ in the general formula 2 are specifically described. However, the infrared absorbing dye in the present disclosure is not limited to these.

In the present disclosure, the content of the infrared absorbing dye in the ink composition is preferably 0.5% by mass to 2.5% by mass, more preferably 0.8% by mass, based on the total mass of the ink composition. % To 2.0% by mass, more preferably 1.0% by mass to 1.5% by mass.

The ink composition of the present disclosure may contain one kind of infrared absorbing dye alone, or may contain two or more kinds of infrared absorbing dyes.

<Polymer particles with polymerizable groups>
The ink composition of the present disclosure contains polymer particles having a polymerizable group. The polymer particles having a polymerizable group may have only one type of polymerizable group, or may have two or more types of polymerizable groups. The fact that the polymer particles have a polymerizable group can be confirmed by, for example, Fourier transform infrared spectroscopy (FT-IR) analysis. The polymerizable group is preferably a photopolymerizable group or a thermopolymerizable group.

The polymerizable group may or may not be covalently bonded to the polymer. The fact that the polymer particles having a polymerizable group contain a polymerizable group that is not covalently bonded to the polymer means that the particles contain a compound having a polymerizable group (that is, a polymerizable compound). On the other hand, the fact that the polymer particles having a polymerizable group contain a polymerizable group covalently bonded to the polymer means that the polymer has a polymerizable group.

The photopolymerizable group is preferably a radically polymerizable group, more preferably a group containing an ethylenic double bond, and even more preferably a group containing at least one of a vinyl group and a 1-methylvinyl group. As the radically polymerizable group, a (meth) acryloyl group is particularly preferable from the viewpoint of radical polymerization reactivity and the hardness of the film to be formed.

The thermopolymerizable group is preferably an epoxy group, an oxetanyl group, an aziridinyl group, an azetidinyl group, a ketone group, an aldehyde group, or a blocked isocyanate group.

The weight average molecular weight of the polymer particles having a polymerizable group is preferably 100,000 or less, more preferably 50,000 or less, and further preferably 30,000 or less. The weight average molecular weight is a value measured by gel permeation chromatography (GPC). Specifically, the product name "HLC-8020 GPC" manufactured by Toso Co., Ltd. was used as the GPC, and the product names "TSKgel GMHHR-H" and "TSKgel MHHR-M" manufactured by Tetrasolute Co., Ltd. were used as the columns. THF (tetrahydrofuran) is used as the eluent. The measurement is performed using a differential refractive index (RI) detector with a sample concentration of 0.45% by mass, a flow rate of 1.0 ml / min, a sample injection amount of 100 μl, and a measurement temperature of 40 ° C. The calibration curve is prepared from polystyrene / THF (1090000, 427000, 37900, 18700, 6200, 2500, 1010, 495). Hereinafter, the weight average molecular weight of the other components is also measured by the same method.

Examples of the polymer particles having a polymerizable group include polyurethane particles having a polymerizable group and polyester particles having a polymerizable group. From the viewpoint of further improving the flexibility of the ink image and the adhesion of the ink image to the substrate, the polymer particles having a polymerizable group are preferably polyurethane particles having a polymerizable group.

Further, the polymer having a polymerizable group is preferably a polymer having a (meth) acryloyl group from the viewpoint of dispersion stability.

The polymer having a (meth) acryloyl group is preferably urethane acrylate, epoxy acrylate, acrylic acrylate, or polyester acrylate, and more preferably urethane acrylate. Urethane acrylate is an aspect of polyurethane having a polymerizable group, and polyester acrylate is an aspect of polyester having a polymerizable group.

The polymer particles having a polymerizable group may be contained in the form of an aqueous dispersion when preparing the ink composition of the present disclosure. An aqueous dispersion of polymer particles having a polymerizable group is available as a commercially available product. Commercially available products of the aqueous dispersion containing urethane acrylate particles include, for example, Rio Duras (registered trademark) AQ2016 and Rio Duras AQ2017 (all manufactured by Toyo Chem Co., Ltd.);
Hydran (registered trademark) 100A, Hydran 100B, Hydran 100S (all manufactured by DIC Corporation);
Takelac (registered trademark) WR-620, Takelac WR-640 (all manufactured by Mitsui Chemicals, Inc.);
UT7019, UT7119 (all manufactured by Mitsubishi Chemical Corporation);
UCECOAT® 7571, UCECOAT7849, UCECOAT7655, UCECOAT7770, UCECOAT7773 (all manufactured by Daicel Ornex);
Beam set (registered trademark) EM90, beam set EM94 (all manufactured by Arakawa Chemical Industry Co., Ltd.); and WBR-832DA (manufactured by Taisei Fine Chemical Co., Ltd.) can be mentioned.

Further, in the present disclosure, the polymer constituting the polymer particles having a polymerizable group is a chain polymer containing the following structural unit (1), structural unit (2), and hydrophilic group (hereinafter, "specific chain polymer"). ) Is preferable.

-Structural unit (1), structural unit (2)-
The structural unit (1) and the structural unit (2) are as follows.

In the structural unit (1) and the structural unit (2),
Cy ¹ and Cy ² each independently represent a divalent organic group having 3 to 30 carbon atoms including a cyclic structure.
Y ¹ and Y ² independently represent an oxygen atom, a sulfur atom, or a −NR ¹ − group, and R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.
* 1 in the structural unit (1) represents the connection position with the structural unit other than the structural unit (1), and * 2 in the structural unit (2) is the connection with the structural unit other than the structural unit (2). Represents a position.

Here, "* 1 in the structural unit (1) represents a bonding position with a structural unit other than the structural unit (1)" means that the structural units (1) are directly bonded to each other in the specific chain polymer. It means that there is no such thing.
The structural unit other than the structural unit (1) bonded to the position of * 1 in the structural unit (1) may be only one type or two or more types.
The structural unit other than the structural unit (1) is not particularly limited, and examples thereof include a structural unit (2). When the specific chain polymer contains a structural unit (3) described later, a structural unit (3) can also be mentioned as a structural unit other than the structural unit (1). Further, when the specific chain polymer contains a structural unit derived from a diol compound, a structural unit derived from a diamine compound, or a structural unit derived from a dithiol compound other than the structural unit (2) and the structural unit (3). Can also be mentioned as a structural unit other than the structural unit (1).

Further, "* 2 in the structural unit (2) represents a bonding position with a structural unit other than the structural unit (2)" means that the structural units (2) are directly bonded to each other in the specific chain polymer. Means there is no.
The structural unit other than the structural unit (2) bonded to the position of * 2 in the structural unit (2) may be only one type or two or more types.
The structural unit other than the structural unit (2) is not particularly limited, and examples thereof include a structural unit (1). When the specific chain polymer contains a structural unit derived from an isocyanate compound other than the structural unit (1), the structural unit other than the structural unit (2) may be an isocyanate compound other than the structural unit (1). The structural unit from which it is derived is also mentioned.

Y ¹ and Y ² independently represent an oxygen atom, a sulfur atom, or a −NR ¹ − group, and R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.
As R ¹ , a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms is preferable, and a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms is more preferable.
Y ¹ and Y ² are each independently ^{preferably an oxygen atom or an −NR 1} − group, and more preferably an oxygen atom.

The "cyclic structure" in Cy ¹ and Cy ² means an aliphatic ring, an aromatic ring, or a heterocycle. That is, the ^{divalent organic group represented by Cy 1} and Cy ² contains at least one of an aliphatic ring, an aromatic ring, and a heterocycle.
The concept of "including cyclic structure" in Cy ¹ and Cy ^{2 includes}
Containing at least one single ring,
Containing at least one fused ring containing two or more monocycles,
Include at least one bridging ring containing two or more single rings, and
Any of including at least one spiro ring containing two or more monocycles is included.

The ^{divalent organic group represented by Cy 1} or Cy ² has 3 to 30 carbon atoms, preferably 5 to 30 carbon atoms.

The hetero atom in the heterocycle is preferably an oxygen atom, a sulfur atom, or a nitrogen atom, and more preferably a nitrogen atom.

The cyclic structure in Cy ¹ and Cy ² may be substituted with at least one substituent.
Substituents include halogen atoms, alkyl halides, alkyl groups, and heteroatom-containing groups.
The halogen atom as the substituent is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and more preferably a fluorine atom, a chlorine atom, or a bromine atom.
The alkyl halide group as the substituent is preferably an alkyl group having at least one halogen atom and having 1 to 6 carbon atoms. The preferred range of halogen atoms in the alkyl halide group is similar to the preferred range of halogen atoms as substituents.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms.
The heteroatom-containing group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms.

Further, from the viewpoint that the effect of improving the curability of the ink composition with time is more effectively exhibited, it is preferable that at least one of ^{Cy 1} and Cy ^{2 contains two or more cyclic structures.}

As used herein, the number of cyclic structures means the number of rings (ie, monocyclic).
Therefore, the concept of "containing two or more cyclic structures" includes not only two or more fused rings, bridged rings, and monocycles that are not part of the spiro ring, but also one fused ring. , Containing one bridging ring, and including one spiro ring are also included.

Further, from the viewpoint that the effects of dispersion stability and adhesion are more effectively exhibited, it is preferable that at least one of ^{Cy 1} and Cy ^{2 contains an aliphatic ring.}

Further, from the viewpoint that the effects of dispersion stability and adhesion are more effectively ^{exhibited, at least one of Cy 1} and Cy ² has a 5- or 6-membered cyclic structure (preferably an aliphatic ring or an aromatic ring, Particularly preferably, it contains an aliphatic ring).
Here, the concept of "including a 5- or 6-membered cyclic structure" includes a fused ring containing a 5- or 6-membered monocycle, and a bridging ring including a 5- or 6-membered monocyclic ring. It also includes including and including a spiro ring containing a 5- or 6-membered monocycle.

^{Examples of Cy 1} in the structural unit (1) include the following groups (C1-1) to (C1-16), but Cy ¹ is not limited to the following groups. In the group (C1-1) to the group (C1-16), * represents a bonding position.

　

From the viewpoint of further improving the adhesion between the ink image and the base material, the Cy ¹ in the structural unit (1) is more preferably any one of the groups (C1-1) to the groups (C1-7). Any one of the group (C1-1) to the group (C1-3) and the group (C1-5) is particularly preferable.

Further, from the viewpoint of further improving the water resistance and alcohol resistance of the ink image, Cy ¹ in the structural unit (1) is a group (C1-6), a group (C1-13), a group (C1-14), Alternatively, the group (C1-15) is preferable.

^{Examples of Cy 2} in the structural unit (2) include the following groups (C2-1) to (C2-22), but Cy ² is not limited to the following groups. In the group (C2-1) to the group (C2-22), * represents a bonding position.

^{Cy 2} in the structural unit (2) is used from the viewpoint of further improving the water resistance and alcohol resistance of the ink image.
Group (C2-10), Group (C2-11), Group (C2-12), Group (C2-13), Group (C2-15), Group (C2-16), Group (C2-18), Group (C2-19), group (C2-20), or group (C2-21) is preferable.
A group (C2-10), a group (C2-11), a group (C2-12), or a group (C2-19) is more preferable.
Group (C2-10) or group (C2-11) is particularly preferred.

-Unit (1) Compound for formation-
The structural unit (1) can be formed by using a diisocyanate compound.
Hereinafter, specific examples of compounds for forming the structural unit (1) (hereinafter, also referred to as “unit (1) forming compound” or “unit (1) compound”) (exemplified compounds (1-1) to Although (1-20)) is shown, the compound for forming the unit (1) is not limited to the following specific examples.

-Unit (2) Compound for formation-
The structural unit (2) can be formed by using, for example, a diol compound, a diamine compound, or a dithiol compound.
Hereinafter, specific examples of compounds for forming the structural unit (2) (hereinafter, also referred to as “unit (2) forming compound” or “unit (2) compound”) (exemplified compounds (2-1) to Although (2-24)) is shown, the compound for forming the unit (2) is not limited to the following specific examples.

　

The total amount of the structural unit (1) and the structural unit (2) with respect to the total amount of the specific chain polymer is preferably 50% by mass or more. As a result, the proportion of the cyclic structure in the characteristic chain polymer is increased, and as a result, the above-mentioned effects of dispersion stability and adhesion are more effectively exhibited.
From the viewpoint of more effectively exerting the effects of dispersion stability and adhesion, the total amount of the structural unit (1) and the structural unit (2) with respect to the total amount of the specific chain polymer should be 60% by mass or more. It is preferably 70% by mass or more.
The upper limit of the total amount of the structural unit (1) and the structural unit (2) with respect to the total amount of the specific chain polymer is not particularly limited, but is, for example, 98% by mass, preferably 95% by mass.

When the total number of millimoles of the cyclic structure contained in the structural unit (1) and the structural unit (2) in 1 g of the specific chain polymer is taken as the ring value of the specific chain polymer, the ring value of the specific chain polymer is 3. It is preferably 0.00 mmol / g or more. As a result, the effects of dispersion stability and adhesion are more effectively achieved.
The valence of the specific chain polymer is more preferably 4.00 mmol / g or more.
The upper limit of the ring value of the specific chain polymer is, for example, 9.00 mmol / g.
The ring value of the specific chain polymer can also be calculated by the following formula.

Ring value of specific chain polymer (mmol / g)
= (((Content of structural unit (1) with respect to total amount of specific chain polymer (mass%) / 100) × number of cyclic structures in structural unit (1) / molecular weight of structural unit (1)) + (( Content of structural unit (2) with respect to the total amount of the specific chain polymer (mass%) / 100) × number of cyclic structures in structural unit (2) / molecular weight of structural unit (2))) × 1000

Further, from the viewpoint of further improving the water resistance and alcohol resistance of the image, ^{it is preferable that at least one of Cy 1} and Cy ² in the specific chain polymer contains the following bisaryl structure (A).

In the bisaryl structure (A), Ar ¹ and Ar ² each independently represent an arylene group. L represents a single bond or a divalent linking group, and two *'s represent the bonding positions, respectively.

When the bisaryl structure (A) is included in the structural unit (1), the bisaryl structure (A) may be directly bonded to the nitrogen atom in the structural unit (1) or may be bonded via a linking group. You may be doing it. The linking group is **-OCH _2- CH _2- * group (where ** represents the bonding position with the arylene group in the bisaryl structure (A), and * is the nitrogen atom in the structural unit (1). (Representing the bonding position with) is preferable.
When the bisaryl structure (A) is included in the structural unit (2), the bisaryl structure (A) ^{may be directly bonded to Y 1} or Y ² in the structural unit (2), or may have a linking group. It may be connected via. The linking group is **-OCH ₂ CH _2- * group (where ** represents the bonding position with the arylene group in the bisaryl structure (A), and * is Y ^{1 in the structural unit (2).} Alternatively, it represents the bonding position with ^{Y 2).}

In the bisaryl structure (A), the ^{arylene groups represented by Ar 1} and Ar ² may be unsubstituted arylene groups, respectively, or may be arylene groups substituted with at least one substituent. ..
Substituents include halogen atoms, alkyl halides, alkyl groups, and heteroatom-containing groups.
The halogen atom as the substituent is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and more preferably a fluorine atom, a chlorine atom, or a bromine atom.
The alkyl halide group as the substituent is preferably an alkyl group having at least one halogen atom and having 1 to 6 carbon atoms. The preferred range of halogen atoms in the alkyl halide group is similar to the preferred range of halogen atoms as substituents.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms.
The heteroatom-containing group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms, more preferably a methoxy group or an ethoxy group, and particularly preferably a methoxy group.

^{At least one of Ar 1} and Ar ^{2 in} the bisaryl structure (A) is an unsubstituted arylene group, an arylene group substituted with at least one halogen atom, and an arylene group substituted with at least one alkyl halide group. , Or an arylene group substituted with at least one alkoxy group having 1 to 6 carbon atoms (preferably a methoxy group or an ethoxy group, particularly preferably a methoxy group).
An arylene group substituted with at least one halogen atom, an arylene group substituted with at least one alkyl halide group, or at least one alkoxy group having 1 to 6 carbon atoms (preferably a methoxy group or an ethoxy group). , Particularly preferably an arylene group substituted with a methoxy group), more preferably.
It is particularly preferred that it is an arylene group substituted with at least one halogen atom.

In the bisaryl structure (A), the ^{arylene group represented by Ar 1} and Ar ² is preferably a phenylene group or a naphthylene group, and a phenylene group is more preferable from the viewpoint of further improving the water resistance and alcohol resistance of the image.

In the bisaryl structure (A), the divalent linking group represented by L is preferably a linking group that can be contained in the bisphenol structure, and specifically, a sulfonyl group (-SO _2- group) and 1 to 10 carbon atoms. A divalent hydrocarbon group of 1 to 10 or a divalent halogenated hydrocarbon group having 1 to 10 carbon atoms is more preferable.

Divalent hydrocarbon group having 1 to 10 carbon atoms as L, the methylene group (-CH ₂ - group), a methylmethylene group (-CHCH ₃ - group), a dimethylmethylene group (-C _{(CH 3) 2} - Group), ethylmethylmethylene group (-C (CH ₃ ) (C ₂ H ₅ ) -group), diethyl methylene group (-C (CH ₃ ) _2- group), phenyl methylene group (-CH (C ₆ H ₅₎ ) - group), a phenyl methyl methylene group _{(-C (C 6 H 5)} (CH 3) - group), diphenylmethylene group _{(-C (C 6 H 5)} 2 - group), or, listed below based on Any one of (* represents the bonding position) is preferable.

The divalent halogenated hydrocarbon group having 1 to 10 carbon atoms as L is preferably any one of the groups listed below (* indicates the bond position).

L, from the viewpoint of improving the water resistance and alcohol resistance of an image, a sulfonyl group (-SO ₂ - group) or a dimethylmethylene group (-C _{(CH 3) 2} - group) are preferred, a sulfonyl group (-SO ₂ -Group) is more preferable.

The bisaryl structure (A) is preferably the following bisaryl structure (A2) from the viewpoint of further improving the water resistance and alcohol resistance of the image.

In the bisaryl structure (A2), R ¹⁰ to R ¹⁷ independently represent a hydrogen atom or a substituent, L represents a single bond or a divalent linking group, and two * represent the bond positions, respectively. ..

^{The substituents represented by R 10} to R ¹⁷ in the bisaryl structure (A2) are synonymous with the substituents that can be contained in ^{Ar 1} and Ar ² in the bisaryl structure (A).
Of R ¹⁰ to R ¹⁷ , at least one is a halogen atom, an alkyl halide group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms (preferably a methoxy group or an ethoxy group, particularly preferably a methoxy group). Is more preferable, and a halogen atom is particularly preferable.

L in the bisaryl structure (A2) is synonymous with L in the bisaryl structure (A), and preferred embodiments of L in the bisaryl structure (A2) are similar to preferred embodiments of L in the bisaryl structure (A). is there.

From the viewpoint of achieving both the adhesion of the image to the plastic substrate and the water resistance and alcohol resistance of the image, ^one of Cy ^{1 and Cy 2} contains an aliphatic ring, and Cy ¹ And ^{the other of Cy 2} preferably contains a bisaryl structure (A).
A particularly preferred embodiment in this case is ^{one in} which Cy 1 contains an aliphatic ring and Cy ² contains a bisaryl structure (A).

Further, when ^one of Cy 1 and Cy ² contains an aliphatic ring and the other of Cy ¹ and Cy ² contains a bisaryl structure (A), the viewpoint of further improving the water resistance and alcohol resistance of the image. Therefore, the molar ratio of the structural unit containing the bisaryl structure (A) to the structural unit containing the aliphatic ring in the specific chain polymer is preferably 0.10 to 1.00, preferably 0.10 to 0.80. Is more preferable, 0.10 to 0.70 is further preferable, and 0.10 to 0.60 is particularly preferable.

When ^one of Cy 1 and Cy ² contains an aliphatic ring and the other of Cy ¹ and Cy ² contains a bisaryl structure (A), a structural unit containing an aliphatic ring in the specific chain polymer. The content of is preferably 10% by mass to 80% by mass, more preferably 20% by mass to 60% by mass, still more preferably 30% by mass to 50% by mass, based on the total amount of the specific chain polymer.

-Hydrophilic group-
The specific chain polymer contains a hydrophilic group.
The hydrophilic groups contained in the specific chain polymer contribute to the dispersion stability of the ink.
As the hydrophilic group, an anionic group or a nonionic group is preferable, and an anionic group is preferable from the viewpoint of being excellent in the effect of improving dispersion stability.
For example, when comparing an anionic group and a nonionic group having the same molecular weight, the anionic group is more effective in improving the dispersion stability. That is, the anionic group (particularly preferably at least one selected from the group consisting of a carboxy group and a salt of the carboxy group) can sufficiently exert the effect of improving the dispersion stability even when its molecular weight is small. ..

Examples of the nonionic group include a group having a polyether structure, and a monovalent group containing a polyalkyleneoxy group is preferable.

The anionic group may be an unneutralized anionic group or a neutralized anionic group.
Examples of the unneutralized anionic group include a carboxy group, a sulfo group, a sulfate group, a phosphonic acid group, and a phosphoric acid group.
Neutralized anionic groups include carboxy group salts, sulfo group salts, sulfate group salts, phosphonic acid group salts, and phosphoric acid group salts.

In the present specification, "the carboxy group is neutralized" means that the carboxy group as an anionic group is in the form of "salt" (for example, "-COONa"). The same applies to the sulfo group, sulfate group, phosphonic acid group, and phosphoric acid group as anionic groups.
Neutralization can be carried out using, for example, an alkali metal hydroxide (for example, sodium hydroxide, potassium hydroxide, etc.) or an organic amine (for example, triethylamine, etc.).

The anionic groups that can be contained in the specific chain polymer are carboxy group, carboxy group salt, sulfo group, sulfo group salt, sulfate group, sulfate group salt, phosphonic acid group and phosphonic acid from the viewpoint of dispersion stability. At least one selected from the group consisting of a salt of a group, a phosphoric acid group, and a salt of a phosphoric acid group is preferable, and at least one selected from the group consisting of a carboxy group and a salt of a carboxy group is more preferable. ..
As the "salt" in the above-mentioned carboxy group salt, sulfo group salt, sulfate group salt, phosphonic acid group salt, and phosphoric acid group salt, an alkali metal salt or an organic amine salt is preferable, and an alkali metal salt is preferable. More preferred.
The alkali metal in the alkali metal salt is preferably K or Na.

Further, when the specific chain polymer contains an anionic group (for example, at least one selected from the group consisting of a carboxy group and a salt of a carboxy group) as a hydrophilic group, the anionic group in 1 g of the specific chain polymer. (For example, the total number of millimoles of the carboxy group and the salt of the carboxy group) is defined as the acid value of the specific chain polymer, and the acid value of the specific chain polymer is 0.10 mmol from the viewpoint of dispersion stability. It is preferably / g to 2.00 mmol / g, and more preferably 0.30 mmol / g to 1.50 mmol / g.

When the specific chain polymer has an anionic group as a hydrophilic group, the degree of neutralization of the anionic group of the specific chain polymer is preferably 50% to 100%, more preferably 70% to 90%.
Here, the degree of neutralization means "the number of unneutralized anionic groups (for example, carboxy groups) and the neutralized anionic groups (for example, salts of carboxy groups) in the specific chain polymer contained in the ink. The ratio of "the number of neutralized anionic groups" to "the sum of the number of)" (ie, the ratio [the number of neutralized anionic groups / (the number of unneutralized anionic groups + neutralization) The number of anionic groups formed)]).
The degree of neutralization (%) of the specific chain polymer is measured by neutralization titration.

In the present specification, the degree of neutralization (%) of the specific chain polymer is determined as follows.
First, an aqueous dispersion (for example, ink) of polymer particles having a polymerizable group containing a specific chain polymer to be measured is prepared.
50 g of the prepared aqueous dispersion is centrifuged at 80,000 rpm (revolutions per minute; the same applies hereinafter) under the conditions of 40 minutes. The supernatant produced by centrifugation is removed, and the precipitate (polymer particles having a polymerizable group) is collected.
Approximately 0.5 g of the recovered polymer particles having a polymerizable group are weighed in the container 1, and the weighed value W1 (g) is recorded. Next, a mixed solution of 54 mL of tetrahydrofuran (THF) and 6 mL of distilled water is added to dilute the weighed polymer particles having a polymerizable group to obtain a sample 1 for measuring the degree of neutralization.
The obtained sample 1 for measuring the degree of neutralization was titrated using a 0.1 N (= 0.1 mol / L) sodium hydroxide aqueous solution as a titrant, and the amount of the titrate required up to the equivalence point was F1 (. Record as mL). If multiple equivalence points are obtained in the titration, the value of the equivalence point in the maximum titration is used. Here, "maximum titration F1 (mL)" corresponds to the amount of unneutralized anionic groups (for example, -COOH) among the anionic groups contained in the polymer particles having a polymerizable group.
Further, about 0.5 g of the recovered polymer particles having a polymerizable group are weighed in the container 2, and the weighed value W2 (g) is recorded. Next, 60 mL of acetic acid is added to dilute the weighed polymer particles having a polymerizable group to obtain a sample 2 for measuring the degree of neutralization.
The obtained sample 2 for measuring the degree of neutralization was titrated using a 0.1 N (= 0.1 mol / L) acetic acid perchlorate solution as a titrant, and the amount of the titrate required up to the equivalence point was F2. Record as (mL). If multiple equivalence points are obtained in the titration, the value of the equivalence point in the maximum titration is used. Here, "maximum titration F2 (mL)" corresponds to the amount of neutralized anionic groups (for example, -COONa) among the anionic groups contained in the polymer particles having a polymerizable group.
Based on the measured values of "F1 (mL)" and "F2 (mL)", the degree of neutralization (%) of the anionic group is determined according to the following formula.
F1 (mL) × Normality of sodium hydroxide aqueous solution (0.1 mol / L) / W1 (g) + F2 (mL) × Normality of acetic acid perchlorate solution (0.1 mol / L) / W2 (g) = Total amount of anionic groups contained in polymer particles having polymerizable groups (total amount of neutralized anionic groups and unneutralized anionic groups) (mmol / g) ... (1)
F2 (mL) × Normality of acetic acid perchlorate solution (0.1 mol / L) / W2 (g) = Neutralized anionic groups among the anionic groups contained in the polymer particles having a polymerizable group Amount (mmol / g) ・ ・ ・ (2)
Neutralization degree (%) = (2) / (1) x 100

Further, as the nonionic group as the hydrophilic group, a group having a polyether structure is preferable, and a monovalent group containing a polyalkyleneoxy group is preferable.

-Structural unit with hydrophilic group-
The specific chain polymer preferably contains a structural unit having a hydrophilic group.
The structural unit having a hydrophilic group is preferably formed from a compound for introducing a hydrophilic group, which will be described later, as a raw material.
The structural unit having a hydrophilic group is particularly preferably the following structural unit (3), which is a structural unit having an anionic group.

In the structural unit (3), ^RX1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, A represents an anionic group, and * 3 is a bond with a structural unit other than the structural unit (3). Represents a position.

Here, "* 3 represents a bonding position with a structural unit other than the structural unit (3)" means that the structural units (3) do not directly bond to each other in the specific chain polymer. ..
The structural unit other than the structural unit (3) bonded to the position of * 3 in the structural unit (3) may be only one type or two or more types.
The structural unit other than the structural unit (3) is not particularly limited, and examples thereof include a structural unit (1). When the specific polymer contains a structural unit derived from an isocyanate compound other than the structural unit (1), it is derived from an isocyanate compound other than the structural unit (1) as a structural unit other than the structural unit (3). Structural units can also be mentioned.

Examples of the anionic group represented by A are the same as those of the above-mentioned anionic example.
The anionic group represented by A is preferably a carboxy group or a salt of a carboxy group.
The specific chain polymer may contain a structural unit (3) in an embodiment in which A is a carboxy group and a structural unit (3) in an embodiment in which A is a salt of a carboxy group.

The content of the structural unit having a hydrophilic group (for example, structural unit (3)) with respect to the total amount of the specific chain polymer is preferably 3% by mass to 30% by mass, more preferably 5% by mass to 20% by mass. is there.
The content of the structural unit having an anionic group with respect to the total amount of the specific chain polymer may be adjusted in consideration of the acid value (mmol / g) of the specific chain polymer.

-Compounds for introducing hydrophilic groups-
The introduction of the hydrophilic group into the specific chain polymer can be carried out by using the compound for introducing the hydrophilic group.
Among the compounds for introducing hydrophilic groups, the compounds for introducing anionic groups include α-amino acids (specifically, lysine, alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamine, glycine, histidine, isoleucine, etc. Amino acids such as leucine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine) can be mentioned.
Examples of the anionic group-introducing compound include the following specific examples in addition to the above-mentioned α-amino acids.

As the compound for introducing an anionic group, an inorganic base such as sodium hydroxide or potassium hydroxide; an organic base such as triethylamine; or the like may be used to neutralize at least a part of the anionic group.

Among the compounds for introducing a hydrophilic group, the compound for introducing a nonionic group is preferably a compound having a polyether structure, and more preferably a compound having a polyoxyalkylene group.

-Compounds for introducing polymerizable groups-
When the specific chain polymer contains a polymerizable group, the polymerizable group can be introduced into the specific chain polymer by using a compound for introducing a polymerizable group.
As the compound for introducing a polymerizable group, a compound having a polymerizable group and an active hydrogen group can be used. Here, the active hydrogen group refers to a hydroxy group, an amino group, or a thiol group.
As the compound for introducing a polymerizable group, it is preferable to use a compound having one or more polymerizable groups and two or more active hydrogen groups.

The method for introducing the polymerizable group into the specific chain polymer is not particularly limited, but when synthesizing the specific chain polymer, a unit (1) forming compound (for example, a diisocyanate compound) and a unit (2) forming are used. A method of reacting a compound (for example, a diol compound) with a compound for introducing a polymerizable group and (a compound for introducing a hydrophilic group if necessary) is particularly preferable.

As the compound for introducing a polymerizable group, for example, the compound described in paragraphs 0075 to 0089 of International Publication No. 2016/052053 can also be used.

The compound for introducing a polymerizable group is preferably a compound represented by the following formula (ma).
L ¹ Lc _m Z _n (ma)

In formula (ma), L ¹ represents an m + n-valent linking group, m and n are integers independently selected from 1 to 100, and Lc represents a monovalent ethylenically unsaturated group. Z represents an active hydrogen group.
L ¹ is a divalent or higher aliphatic group, a divalent or higher aromatic group, a divalent or higher heterocyclic group, -O-, -S-, -NH-, -N <, -CO-, -SO. -, -SO _2- , or a combination thereof is preferable.
m and n are each independently preferably 1 to 50, more preferably 2 to 20, further preferably 3 to 10, and particularly preferably 3 to 5.
Examples of the monovalent ethylenically unsaturated group represented by Lc include an allyl group, a vinyl group, an acryloyl group, and a methacryloyl group.
Z is preferably OH, SH, NH or NH ₂ , more preferably OH or NH ₂ , and even more preferably OH.

Hereinafter, examples of the compound for introducing a polymerizable group will be shown, but the compound for introducing a polymerizable group is not limited to these structures. In addition, n in the compound (a-3) and (a-12) represents an integer selected from 1 to 90, for example.

The monomer for introducing a polymerizable group may be used alone or in combination of two or more.

In the production of an isocyanate compound into which a polymerizable group has been introduced, polyisocyanate (that is, a trifunctional or higher functional isocyanate compound) and a polymerizable group-introduced monomer are used, and the number of moles of active hydrogen groups in the polymerizable group-introduced monomer is polyisocyanate. The reaction can be carried out at a ratio of 0.01 to 0.3 times (more preferably 0.02 to 0.25 times, still more preferably 0.03 to 0.2 times) the number of moles of the isocyanate group. preferable.

The polymer particles having a polymerizable group may contain a polymer other than the specific chain polymer as long as the effect of the ink of the present disclosure is not impaired.
Examples of other polymers include chain polymers other than specific chain polymers and polymers having a three-dimensional crosslinked structure.
However, from the viewpoint of more effectively exerting the effect of the ink of the present disclosure, the ratio of the specific chain polymer to all the polymer components in the polymer particles having a polymerizable group is 80% by mass to 100% by mass. It is more preferably 90% by mass to 100% by mass, further preferably 95% by mass to 100% by mass, and particularly preferably 100% by mass.

(Polymerizable compound)
The polymer particles having a polymerizable group include a polymerizable compound (for example, a photopolymerizable compound or a thermally polymerizable compound) as a compound having a polymerizable group (for example, a photopolymerizable group or a thermally polymerizable group). May be good. According to this aspect, the curing sensitivity of the ink film and the hardness of the ink film are further improved.
When the polymer particles having a polymerizable group contain a polymerizable compound, the polymerizable compound contained in the polymer particles having a polymerizable group may be only one kind or two or more kinds. When the polymer particles having a polymerizable group contain a polymerizable compound, the polymerizable group of the polymerizable compound functions as a polymerizable group of the polymer particles having a polymerizable group.
In addition, in the embodiment in which the polymer particles having a polymerizable group contain a polymerizable compound, the specific chain polymer may have a polymerizable group.

As the polymerizable compound that can be contained in the polymer particles having a polymerizable group, the compounds described in paragraphs 097 to 0105 of International Publication No. 2016/052053 may be used.

The polymerizable compound that can be contained in the polymer particles having a polymerizable group is preferably a photopolymerizable compound that polymerizes by irradiation with light, or a thermopolymerizable compound that polymerizes by irradiation with heating or infrared rays. As the photopolymerizable compound, a radically polymerizable compound having a radically polymerizable ethylenic double bond is preferable.
The polymerizable compound that can be contained in the polymer particles having a polymerizable group may be any of a polymerizable monomer, a polymerizable oligomer, and a polymerizable polymer. From the viewpoint of improving the curing sensitivity of the ink film and the hardness of the ink film, the polymerizable compound is preferably a polymerizable monomer. Among them, more preferable polymerizable compounds are a photopolymerizable monomer included in the concept of a photopolymerizable compound and a thermopolymerizable monomer included in the concept of a thermopolymerizable compound.

When the polymer particles having a polymerizable group contain a photopolymerizable compound as a polymerizable compound, it is preferable that the polymer particles having a polymerizable group further contain a photopolymerization initiator described later.
When the polymer particles having a polymerizable group contain a heat-polymerizable compound as the polymerizable compound, the polymer particles having a polymerizable group are further subjected to a photothermal converter, a thermosetting accelerator, or a photothermal converter. It is preferable to include a thermosetting accelerator.

The content of the polymerizable compound (preferably a polymerizable monomer; the same applies hereinafter) that can be contained in the polymer particles having a polymerizable group (the total amount when two or more kinds are contained) determines the curing sensitivity of the film and the hardness of the film. From the viewpoint of improvement, 10% by mass to 90% by mass is preferable, 20% by mass to 80% by mass is more preferable, and 30% by mass to 70% by mass is further preferable with respect to the solid content of the polymer particles having a polymerizable group. ..

From the viewpoint of further improving the adhesion of the image to the substrate, at least one of the polymerizable compounds (for example, photopolymerizable compounds) that can be contained in the polymer particles having a polymerizable group is a polymerizable compound having a cyclic structure (for example, a photopolymerizable compound). Hereinafter, it is also preferably referred to as “cyclically polymerizable compound”).

From the viewpoint of further improving the adhesion of the ink image to the substrate, at least one type of polymerizable compound (for example, a photopolymerizable compound) that can be contained in the polymer particles having a polymerizable group is one in one molecule. A polymerizable compound containing the above cyclic structure and two or more (meth) acryloyl groups (hereinafter, also referred to as “bifunctional or higher functional cyclic polymerizable compound”) is preferable.
As a bifunctional or higher cyclic polymerizable compound,
Tricyclodecanedimethanol di (meth) acrylate, bisphenol A ethylene oxide (EO) adduct di (meth) acrylate, bisphenol A propylene oxide (PO) adduct di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, Examples thereof include alkoxylated dimethylol tricyclodecanedi (meth) acrylate, alkoxylated cyclohexanone dimethanol di (meth) acrylate, and cyclohexanone dimethanol di (meth) acrylate.

When the polymer particles having a polymerizable group contain a polymerizable compound, the ratio of the bifunctional or higher functional cyclic polymerizable compound to the entire polymerizable compound is preferably 10% by mass to 100% by mass, preferably 30% by mass to 100% by mass. % Is more preferable, and 40% by mass to 100% by mass is particularly preferable.

Further, the polymer particles having a polymerizable group are a bifunctional or lower polymerizable compound (preferably a bifunctional or lower polymerizable monomer; the same applies hereinafter) and a trifunctional or higher functional polymerizable compound (preferably a trifunctional or higher functional polymerization). Sexual monomers; the same shall apply hereinafter) and may be included.
When the polymer particles having a polymerizable group contain a polymerizable compound having a bifunctionality or less and a polymerizable compound having a trifunctionality or more, the polymerizable compound having a bifunctionality or less contributes to the adhesion of the film to the substrate. However, it is considered that the trifunctional or higher-functional polymerizable compound contributes to the improvement of the hardness of the film.

The molecular weight of the polymerizable compound (weight average molecular weight when the molecular weight is 1000 or more) is preferably 100 to 100,000, more preferably 100 to 30,000, still more preferably 100 to 10,000, still more preferably. Is 100 to 4000, more preferably 100 to 2000, still more preferably 100 to 1000, still more preferably 100 to 900, still more preferably 100 to 800, and particularly preferably 150 to 750. is there.

-Polymerizable monomer-
Examples of the polymerizable monomer that can be contained in the polymer particles having a polymerizable group include a photopolymerizable monomer that is polymerized and cured by irradiation with light, and a thermopolymerizable monomer that is polymerized and cured by irradiation with heating or infrared rays.
When a photopolymerizable monomer is contained as the polymerizable compound, it is preferable to include a photopolymerization initiator described later. When a thermally polymerizable monomer is contained as the polymerizable compound, it is preferable to include a photothermal converter or a thermosetting accelerator, which will be described later, or a photothermal converter and a thermosetting accelerator.

<Photopolymerizable monomer>
The photopolymerizable monomer includes a polymerizable monomer having a radically polymerizable ethylenically unsaturated bond (that is, a radically polymerizable monomer) and a polymerizable monomer having a cationically polymerizable cationically polymerizable group (that is, a cationically polymerizable monomer). It can be selected from the group consisting of.

Examples of the radically polymerizable monomer include acrylate compounds, methacrylate compounds, styrene compounds, vinyl naphthalene compounds, N-vinyl heterocyclic compounds, unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.
The radically polymerizable monomer is preferably a compound having an ethylenically unsaturated group.
When the polymer particles having a polymerizable group contain a radically polymerizable monomer, the polymer particles having a polymerizable group may contain only one kind of radically polymerizable monomer or may contain two or more kinds of radically polymerizable monomers.

Examples of the acrylate compound include 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, tridecyl acrylate, 2-phenoxyethyl acrylate (PEA), and bis (4-acryloxypoly). Ethoxyphenyl) propane, oligoester acrylate, epoxy acrylate, isobornyl acrylate (IBOA), dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, cyclic trimethylolpropaneformal acrylate, 2- (2) -Ethoxyethoxy) ethyl acrylate, 2- (2-vinyloxyethoxy) ethyl acrylate, octyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, 3,3,5-trimethylcyclohexyl acrylate, 4-t-butylcyclohexyl acrylate, Isoamyl acrylate, stearyl acrylate, isostearyl acrylate, 2-ethylhexyl diglycol acrylate, 2-hydroxybutyl acrylate, 2-acryloyloxyethyl hydrophthalic acid, ethoxydiethylene glycol acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxypropylene glycol acrylate, 2-Hydroxy-3-phenoxypropyl acrylate, vinyl ether acrylate, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyphthalic acid, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, lactone-modified acrylate, acryloylmorpholine, acrylamide, And monofunctional acrylate compounds such as substituted acrylamides (eg, N-methylol acrylamide and diacetone acrylamide);

Polyethylene glycol diacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate (HDDA), 1,9 -Nonandiol diacrylate (NDDA), 1,10-decanediol diacrylate (DDDA), 3-methylpentadiol diacrylate (3MPDDA), neopentyl glycol diacrylate, tricyclodecanedimethanol diacrylate, bisphenol A ethylene oxide ( EO) adduct diacrylate, bisphenol A propylene oxide (PO) adduct diacrylate, ethoxylated bisphenol A diacrylate, hydroxyneopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, alkoxylated dimethylol tricyclodecanediacrylate , Polytetramethylene glycol diacrylate, alkoxylated cyclohexanone dimethanol diacrylate, alkoxylated hexanediol diacrylate, dioxane glycol diacrylate, cyclohexanone dimethanol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, Bifunctional acrylate compounds such as dipropylene glycol diacrylate, tripropylene glycol diacrylate (TPGDA), and neopentyl glycol propylene oxide adduct diacrylate; and

Trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol tetraacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate, dimethylolpropane tetraacrylate, dipentaerythritol penta Acrylate, dipentaerythritol hexaacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxytetraacrylate, glycerin propoxytriacrylate, ethoxylated Examples thereof include trifunctional or higher functional acrylate compounds such as dipentaerythritol hexaacrylate, caprolactam-modified dipentaerythritol hexaacrylate, propoxylated glycerin triacrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane triacrylate.

Examples of the methacrylate compound include methyl methacrylate, n-butyl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, methoxypolyethylene glycol methacrylate, methoxytriethylene glycol methacrylate, hydroxyethyl methacrylate, phenoxyethyl methacrylate, cyclohexyl methacrylate and the like. Monofunctional methacrylate compound; and

Examples thereof include bifunctional methacrylate compounds such as polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, and tetraethylene glycol dimethacrylate.

Examples of the styrene compound include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, and p-methoxy-β-methylstyrene.

Examples of the vinylnaphthalene compound include 1-vinylnaphthalene, methyl-1-vinylnaphthalene, β-methyl-1-vinylnaphthalene, 4-methyl-1-vinylnaphthalene, and 4-methoxy-1-vinylnaphthalene.

Examples of the N-vinyl heterocyclic compound include N-vinylcarbazole, N-vinylpyrrolidone, N-vinylethylacetamide, N-vinylpyrrole, N-vinylphenothiazine, N-vinylacetanilide, N-vinylethylacetamide, and N-vinylsuccinic acid. Examples include imide, N-vinylphthalimide, N-vinylcaprolacttam, and N-vinylimidazole.

Examples of other radically polymerizable monomers include allyl glycidyl ether, diallyl phthalate, triallyl trimellitate, and N-vinylamide such as N-vinylformamide.

Among these radically polymerizable monomers, the less than bifunctional radically polymerizable monomers are 1,6-hexanediol diacrylate (HDDA), 1,9-nonanediol diacrylate (NDDA), and 1,10-decanediol di. Acrylate (DDDA), 3-Methylpentadiol diacrylate (3MPDDA), neopentyl glycol diacrylate, tricyclodecanedimethanol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol di. At least one selected from the group consisting of acrylate (TPGDA), cyclohexanone dimethanol diacrylate, alkoxylated hexanediol diacrylate, polyethylene glycol diacrylate, and polypropylene glycol diacrylate is preferable.
The trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol tetraacrylate, dimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ethoxylated triacrylate are the trifunctional or higher functional monomer. Methylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxytetraacrylate, glycerin propoxytriacrylate, ethoxylated dipentaerythritol hexaacrylate, caprolactam-modified dipentaerythritol At least one selected from the group consisting of hexaacrylate, propoxylated glycerin triacrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane triacrylate is preferable.

As a combination of a bifunctional or lower functional radical polymerizable monomer and a trifunctional or higher functional radical polymerizable monomer, a combination of a bifunctional acrylate compound and a trifunctional acrylate compound, a bifunctional acrylate compound and a pentafunctional acrylate compound Examples thereof include a combination with and a combination of a monofunctional acrylate compound and a tetrafunctional acrylate compound.

The radically polymerizable monomer is preferably a monomer having a cyclic structure;
Preferred compounds of the above-mentioned bifunctional or higher functional cyclic polymerizable compounds, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, ethoxy Isocyanuric acid triacrylate or ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate is more preferred;
The preferred compound group of the above-mentioned bifunctional or higher functional cyclic polymerizable compounds, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, or dicyclopentanyl acrylate is more preferable;
The preferred compound group of the above-mentioned bifunctional or higher functional cyclic polymerizable compounds is particularly preferable.

In addition to the radically polymerizable monomers listed above, Shinzo Yamashita, "Handbook of Crosslinking Agents" (1981, Taiseisha); Kiyomi Kato, "UV / EB Curing Handbook (Raw Materials)" (1985, Polymer Publications); Radtech Study Group, "Applications and Markets of UV / EB Curing Technology", p. 79, (1989, CMC); Eiichiro Takiyama, "Polyester Resin Handbook", (1988, Nikkan Kogyo) Commercially available products described in (Newspaper) and the like, and radically polymerizable and crosslinkable monomers known in the industry can be used.

Examples of cationically polymerizable monomers include epoxy compounds, vinyl ether compounds, and oxetane compounds.
The cationically polymerizable monomer is preferably a compound having at least one olefin, thioether, acetal, thioxane, thietan, aziridine, N heterocycle, O heterocycle, S heterocycle, P heterocycle, aldehyde, lactam, or cyclic ester group. ..

Examples of cationically polymerizable monomers include "Advances in Polymer Science" by J. V. Crivello et al., 62, pages 1 to 47 (1984), "Handbook of Epoxy Resins" by Lee et al., McGraw Hill Book Company, New York (1967). ), And the compounds described in "Epoxy Resin Technology", (1968) by P. F. Bruins et al. May be used.

Examples of the photopolymerizable monomer include JP-A-7-159883, JP-A-7-31399, JP-A-8-224982, JP-A-10-863, JP-A-9-134011, and Japanese Patent Application Laid-Open No. Photocurable polymerizable monomers used in the photopolymerizable compositions described in each publication such as Table 2004-514014 are known, and these are also polymerizable monomers that can be contained in the polymer particles having a polymerizable group. Can be applied as.

As the photopolymerizable monomer, a commercially available product on the market may be used.
Examples of commercially available photopolymerizable monomers include AH-600 (bifunctional), AT-600 (bifunctional), UA-306H (six-functional), UA-306T (six-functional), and UA-306I (six-functional). ), UA-510H (10 functional), UF-8001G (bifunctional), DAUA-167 (bifunctional), light acrylate NPA (bifunctional), light acrylate 3EG-A (bifunctional) (above, Kyoeisha Chemical Co., Ltd. )), SR339A (PEA, monofunctional), SR506 (IBOA, monofunctional), CD262 (bifunctional), SR238 (HDDA, bifunctional), SR341 (3MPDDDA, bifunctional), SR508 (bifunctional), SR306H (2) (Functional), CD560 (2 functional), SR833S (2 functional), SR444 (3 functional), SR454 (3 functional), SR492 (3 functional), SR499 (3 functional), CD501 (3 functional), SR502 (3 functional) , SR9020 (3 functional), CD9021 (3 functional), SR9035 (3 functional), SR494 (4 functional), SR399E (5 functional) (above, Sartmer), A-NOD-N (NDDA, 2 functional), A -DOD-N (DDDA, bifunctional), A-200 (bifunctional), APG-400 (bifunctional), A-BPE-10 (bifunctional), A-BPE-20 (bifunctional), A-9300 (Trifunctional), A-9300-1CL (Trifunctional), A-TMPT (Trifunctional), A-TMM-3L (Trifunctional), A-TMMT (4 Functional), AD-TMP (4 Functional) (End) , Shin Nakamura Chemical Industry Co., Ltd., UV-7510B (trifunctional) (Nippon Synthetic Chemistry Co., Ltd.), KAYARAD DPCA-30 (six-functional), and KAYARAD DPEA-12 (six-functional) (above, Nippon Kayaku) Co., Ltd.).
Other polymerizable monomers include NPGPODA (neopentyl glycol propylene oxide adduct diacrylate), SR531, SR285, SR256 (above, Sartmer), A-DHP (dipentaerythritol hexaacrylate, Shin-Nakamura Chemical Industry Co., Ltd.) ), Aronix (registered trademark) M-156 (Toa Synthetic Co., Ltd.), V-CAP (BASF), Viscort # 192 (Osaka Organic Chemical Industry Co., Ltd.) and the like can be preferably used.
Among these commercially available products, SR506, SR833S, A-9300, or A-9300-CL, which are photopolymerizable monomers having a cyclic structure, are particularly preferable, and SR833S is particularly preferable.

<Thermopolymerizable monomer>
The thermopolymerizable monomer can be selected from the group of polymerizable monomers that can be polymerized by heating or irradiation with infrared rays. Thermopolymerizable monomers include, for example, epoxies, oxetane, aziridine, azetidine, ketones, aldehydes, and block isocyanates.

Among the above, the epoxy compounds include 1,4-butanediol diglycidyl ether, 3- (bis (glycidyloxymethyl) methoxy) -1,2-propanediol, limonene oxide, 2-biphenylglycidyl ether, 3,4. -Epoxycyclohexylmethyl-3', 4'-epoxycyclohexanecarboxylate, epoxide derived from epichlorohydrin-bisphenol S, epoxidized styrene, epoxide derived from epichlorohydrin-bisphenol F, derived from epichlorohydrin-bisphenol A Epoxy compounds such as epoxides, epoxidized novolaks, and alicyclic epoxides; and polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyols, polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyls of aromatic polyols. Examples thereof include trifunctional or higher functional epoxy compounds such as esters, urethane polyepoxy compounds, and polyepoxypolybutadienes.

Examples of the oxetane compound include 3-ethyl-3-hydroxymethyl-1-oxetane, 1,4 bis [3-ethyl-3-oxetanylmethoxy] methyl] benzene, 3-ethyl-3-phenoxymethyl-oxetane, and bis ([[]. 1-Ethyl (3-oxetanyl)] methyl) ether, 3-ethyl-3-[(2-ethylhexyloxy) methyl] oxetane, 3-ethyl-[(triethoxysilylpropoxy) methyl] oxetane, and 3,3- Examples include dimethyl-2- (p-methoxyphenyl) -oxetane.

Examples of the blocked isocyanate compound include a compound in which the isocyanate compound is inactivated with a blocking agent (active hydrogen-containing compound).
Examples of the isocyanate compound include hexamethylene diisocyanate, isophorone diisocyanate, toluyl diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate trimeric, trimethylhexylylene diisocyanate, diphenylmethane diisocyanate, and dicyclohexyl. Commercially available isocyanates such as methanediisocyanate, hydrogenated xylylene diisocyanate; Takenate (registered trademark; Mitsui Kagaku Co., Ltd.), Duranate (registered trademark; Asahi Kasei Co., Ltd.), Bayhydur (registered trademark; Bayer AG), or these. A combination of difunctional or higher isocyanates is preferred.

Examples of the blocking agent include lactams [eg, ε-caprolactam, δ-valerolactam, γ-butyrolactam, etc.], oximes [eg, acetoxime, methylethylketooxime (MEK oxime), methylisobutylketooxime (MIBK oxime), cyclohexanone oxime, etc.] , Amines [eg, aliphatic amines (dimethylamine, diisopyramine, di-n-propylamine, diisobutylamine, etc.), alicyclic amines (methylhexylamine, dicyclohexylamine, etc.), aromatic amines (aniline, diphenylamine, etc.)], Aliper alcohols [eg methanol, ethanol, 2-propanol, n-butanol, etc.], phenols and alkylphenols [eg phenol, cresol, ethylphenol, n-propylphenol, isopropylphenol, n-butylphenol, octylphenol, nonylphenol, xylenol, diisopropyl Phenol, di-t-butylphenol, etc.], imidazole [eg, imidazole, 2-methylimidazole, etc.], pyrazole [eg, pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, etc.], imine [eg, ethyleneimine, polyethyleneimine, etc.] ], Active oxime [for example, dimethyl malate, diethyl malonate, diisopropyl malate, acetylacetone, methyl acetoacetate, ethyl acetoacetate, etc.], Blocking described in JP-A-2002-309217 and JP-A-2008-239890. Agents, as well as mixtures of two or more of these. Of these, the blocking agent is preferably oxime, lactam, pyrazole, active methylene, or amine.

As the block isocyanate compound, a commercially available product on the market may be used, for example, Trixene (registered trademark) BI7982, BI7641, BI7462, BI7950, BI7960, BI9791 (Baxenden Chemicals LTD), Bayer (registered trademark; Bayer) AG) is preferably used. In addition, the compound group described in paragraph 0064 of International Publication No. 2015/158654 is also preferably used.

Polymer particles having a polymerizable group containing a polymerizable monomer can be produced, for example, by emulsifying a mixture of an oil phase component containing a specific chain polymer and a polymerizable monomer and an aqueous phase component.

The molecular weight of the polymerizable monomer (weight average molecular weight when the molecular weight is 1000 or more) is preferably 100 to 4000, more preferably 100 to 2000, still more preferably 100 to 1000, still more preferable. Is 100 to 900, more preferably 100 to 800, and particularly preferably 150 to 750.

In the ink composition of the present disclosure, the content of the polymer particles having a polymerizable group is preferably 1% by mass to 50% by mass, and 3% by mass to 40% by mass, based on the total mass of the ink composition. Is more preferable, and 3% by mass to 30% by mass is further preferable.
When the content of the polymer particles having a polymerizable group is 1% by mass or more, the adhesion between the ink image and the substrate is further improved. When the content of the polymer particles having a polymerizable group is 50% by mass or less, the dispersion stability of the ink composition is further improved.

The ratio of the content of the polymer particles having a polymerizable group to the content of the infrared absorbing dye (that is, the content of the polymer particles having a polymerizable group / the content of the infrared absorbing dye) is 2 to 20 on a mass basis. It is preferable, and more preferably 2 to 10. When the ratio is 2 or more, sufficient abrasion resistance can be obtained. When the ratio is 20 or less, good discharge property can be obtained.

The volume average particle size of the polymer particles having a polymerizable group is not particularly limited, but from the viewpoint of dispersion stability, it is preferably 0.01 μm to 10.0 μm, more preferably 0.01 μm to 5 μm. It is more preferably 0.05 μm to 1 μm, further preferably 0.05 μm to 0.5 μm, and particularly preferably 0.05 μm to 0.3 μm.

The volume average particle size is measured by the light scattering method. The volume average particle size is measured by the light scattering method using, for example, LA-960 (manufactured by HORIBA, Ltd.).

<Water>
The ink composition of the present disclosure contains water. The content of water is not particularly limited, but is preferably 10% by mass to 99% by mass, more preferably 20% by mass to 95% by mass, and further preferably 30% by mass, based on the total mass of the ink composition. It is by mass% to 90% by mass, and particularly preferably 50% by mass to 90% by mass.

The ink composition of the present disclosure may contain an infrared absorbing dye, polymer particles having a polymerizable group, and other components other than water. Other components include, for example, water-soluble photopolymerization initiators, water-soluble sensitizers, water-soluble organic solvents, and surfactants.

<Water-soluble photopolymerization initiator>
The ink composition of the present disclosure preferably contains a water-soluble photopolymerization initiator.
Examples of the water-soluble photopolymerization initiator (hereinafter, simply referred to as “photopolymerization initiator”) include carbonyl compounds (for example, aromatic ketones; for example, IRGACURE® 369, 907, 1173, 2959 manufactured by BASF Corporation). etc),
Acylphosphine oxide compounds (eg, IRGACURE 819 manufactured by BASF, DAROCURE® TPO manufactured by BASF, etc.), and
Polymer-based photopolymerization initiators (eg, Omnipol TX, Omnipol 9210, manufactured by LAMBSON; SPEEDCURE 7005, 7010, 7040, manufactured by LAMBSON, etc.) can be mentioned.

Examples of the photopolymerization initiator include aromatic onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketooxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, and carbon halogen bonds. A compound having the above, and an alkylamine compound are also mentioned.

Regarding the photopolymerization initiator, for example, International Publication No. 2016/052053 (Paragraph 0090 to Paragraph 096, Paragraph 0131 to Paragraph 0132, and Paragraph 0139 to Paragraph 0147), International Publication No. 2018/042916 (Paragraph 0169 to Paragraph). Known documents such as 0179 and paragraphs 0182 to 0183) can be referred to as appropriate.

When the ink composition contains a photopolymerization initiator, the photopolymerization initiator in the ink composition may be present in a form of being encapsulated in polymer particles having a polymerizable group, or may contain a polymerizable group. It may exist in a form of being adsorbed on the surface of the polymer particles having the polymer particles, may exist in a form of forming particles other than the polymer particles having a polymerizable group, or may exist in a form of being dissolved in the ink composition. May exist in.

Further, the photopolymerization initiator in the ink composition may exist in a form satisfying two or more of the above-mentioned forms. The same applies to the existing forms of the components other than the water-soluble organic solvent among the components described later.

Further, the photopolymerization initiator is preferably a photopolymerization initiator represented by the following general formula (X).

In the general formula (X), ^RX1 , ^RX2 , ^RX3 , and ^RX4 each independently represent a hydrogen atom or a substituent. In the general formula (X), n represents an integer of 1 or more and 4 or less.

When n is 1 or more, the generation of precipitates in a low temperature environment is suppressed.
When n is 4 or less, the sensitivity is maintained high, and as a result, the scratch resistance of the ink image formed by the ink composition is improved and image unevenness is suppressed.
The n is more preferably 1 or more and 3 or less, and particularly preferably 1 or more and 2 or less.

Further, by using a photopolymerization initiator having a structure represented by the above general formula (X) as the polymerization initiator in the ink composition, a phenomenon in which polymer particles having a polymerizable group in the ink composition are aggregated, and a phenomenon that polymer particles having a polymerizable group are aggregated, and , The phenomenon that the ejection property is lowered due to this aggregation is suppressed.

In ^RX1 to ^RX4 , examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an alkylthio group, a mercapto group, an acyl group, and an amino group.

In ^RX1 to ^RX4 , as the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom is preferable, a chlorine atom or a bromine atom is more preferable, and a chlorine atom is particularly preferable.

In ^RX1 to ^RX4 , the number of carbon atoms of the alkyl group is preferably 1 to 6 and more preferably 1 to 3.
Further, in ^RX1 to ^RX4 , the alkyl group may be a straight chain alkyl group or a branched chain alkyl group. Further, the alkyl group may have an alicyclic structure.
^{Alkyl groups in RX1} to ^RX4 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, n-pentyl group, n-hexyl group, and the like. And cyclohexyl groups. Of these, the alkyl group is preferably a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

In ^RX1 to ^RX4 , the number of carbon atoms of the alkoxy group is preferably 1 to 6 and more preferably 1 to 3.
Further, in ^RX1 to ^RX4 , the alkoxy group may be a linear alkoxy group or a branched chain alkoxy group. Further, the alkoxy group may have an alicyclic structure.
^{The alkoxy groups in RX1} to ^RX4 include methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butoxy group, s-butoxy group, t-butoxy group, n-pentyloxy group and n-. Examples thereof include a hexyloxy group and a cyclohexyloxy group. Of these, the alkoxy group is preferably a methoxy group, an ethoxy group, an n-propyloxy group, or an isopropyloxy group.

In ^RX1 to ^RX4 , the number of carbon atoms of the alkylthio group is preferably 1 to 6 and more preferably 1 to 4.
Further, in ^RX1 to ^RX4 , the alkylthio group may be a straight chain alkylthio group or a branched chain alkylthio group. Further, the alkylthio group may have an alicyclic structure.
The alkylthio group in R ^X1 ~ ^{R X4,} methylthio group, ethylthio group, n- propylthio group, isopropylthio group, n- butylthio group, s- butylthio group, t-butylthio group, n- pentylthio group, n- hexylthio , And a cyclohexylthio group. Of these, the alkylthio group is preferably a methylthio group, an ethylthio group, an n-propylthio group, or an isopropylthio group.

In ^RX1 to ^RX4 , the number of carbon atoms of the acyl group is preferably 1 to 6 and more preferably 1 to 3.
Further, in ^RX1 to ^RX4 , the acyl group may be a linear acyl group or a branched chain acyl group.
The acyl group in R ^X1 ~ ^{R X4,} a formyl group, an acetyl group, Echiruashiru group, n- propyl acyl group, and isopropyl acyl group. Of these, the acyl group is preferably a formyl group, an acetyl group, or an ethyl acyl group.

^RX1 to ^RX4 are preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an alkylthio group, more preferably a hydrogen atom, an alkoxy group, or an alkylthio group, and most preferably a hydrogen atom.

As a preferred form of the general formula (X) compounds represented by, among R ^{X1 ~} R ^X4, 2 or more (preferably three or more, four in most preferred) and the like can form a hydrogen atom ..

Hereinafter, specific examples (exemplified compounds) of the compounds represented by the general formula (X) will be shown, but the compounds represented by the general formula (X) are not limited thereto.

The compound represented by the general formula (X) can be synthesized, for example, according to the methods described in paragraphs 0067 to 0071 and 0112 to 0115 of JP-A-2000-186242.

In addition to the photopolymerization initiator represented by the above formula (X), the ink composition of the present disclosure further comprises 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1. It preferably contains -propane-1-one. This compound is a photopolymerization initiator having excellent sensitivity.

In this case, the content ratio of 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one to the photopolymerization initiator represented by the formula (X). Is preferably 0.1 to 10.0 on a mass basis.

Examples of commercially available products on the market of 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one include Irgacure 2959 (manufactured by BASF Japan Ltd.). Can be mentioned.

Further, the ink composition of the present disclosure may further contain 2-hydroxy-2-methyl-1-phenyl-propane-1-one in addition to the photopolymerization initiator represented by the formula (X). ..
Examples of commercially available products on the market of 2-hydroxy-2-methyl-1-phenyl-propane-1-one include DaroCure 1173 (manufactured by BASF Japan Ltd.).

In this case, the content ratio of 2-hydroxy-2-methyl-1-phenyl-propane-1-one to the photopolymerization initiator represented by the formula (X) is 0.1 to 10.0 on a mass basis. It is preferable to have.

Further, the ink composition of the present disclosure includes a photopolymerization initiator represented by the formula (X) and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane. It may contain -1-one and 2-hydroxy-2-methyl-1-phenyl-propane-1-one.
In this case, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one and 2-one with respect to the photopolymerization initiator represented by the formula (X). The content ratio of hydroxy-2-methyl-1-phenyl-propane-1-one is preferably 0.1 to 10.0 on a mass basis.

The content of the photopolymerization initiator in the ink composition of the present disclosure is preferably 0.05% by mass to 10.0% by mass, and 0.2% by mass to 3.0% by mass, based on the total mass of the ink composition. The mass% is more preferable, and 0.5% by mass to 2.0% by mass is further preferable.

The ink composition of the present disclosure may contain one type of photopolymerization initiator alone, or may contain two or more types of photopolymerization initiators.

<Water-soluble sensitizer>
The ink composition of the present disclosure may contain a water-soluble sensitizer. Examples of the water-soluble sensitizer include benzophenone, thioxanthone, isopropylthioxanthone (ITX), anthraquinone, 3-acylcoumarin derivative, terphenyl, styryl ketone, 3- (aloyl methylene) thiazolin, succinoquinone, eosin, rhodamine, Eosin and the like can be mentioned. The water-soluble sensitizer preferably has an absorption range in the wavelength range of 350 nm to 400 nm.

The water-soluble sensitizer is represented by the compound represented by the general formula (i) described in JP-A-2010-24276 or the general formula (I) described in JP-A-6-107718. Compounds can also be preferably used. Among them, the water-soluble sensitizer is preferably the compound Y-1 shown below. Details of compound Y-1 are described in JETT, 39 [9], p.86 (1991), Kenichi Koshikawa.

The ink composition of the present disclosure may contain one type of water-soluble sensitizer alone, or may contain two or more types.

<Water-soluble organic solvent>
The ink composition of the present disclosure may contain a water-soluble organic solvent.

Specific examples of the water-soluble organic solvent are as follows.
-Alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc.),
-Polyhydric alcohols (eg ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, 2- Methylpropanediol, etc.),
-Polyhydric alcohol ethers (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, tripropylene Glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol monophenyl ether, propylene glycol monophenyl Ether etc.),
-Amines (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholin, N-ethylmorpholin, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, penta Methyldiethylenetriamine, tetramethylpropylenediamine, etc.),
Amides (eg formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.),
Heterocycles (eg, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, etc.),
-Sulfoxides (eg, dimethyl sulfoxide, etc.),
-Sulfones (eg, sulfolane, etc.),
・ Others (for example, urea, acetonitrile, acetone, etc.)

The content of the water-soluble organic solvent is preferably 1% by mass to 40% by mass, more preferably 5% by mass to 35% by mass, based on the total mass of the ink composition.

The ink composition of the present disclosure may contain one kind of water-soluble organic solvent alone, or may contain two or more kinds.

<Surfactant>
The ink composition of the present disclosure may contain a surfactant. The surfactant has a function as, for example, a surface tension adjusting agent for adjusting the surface tension of the ink composition.

Examples of the surfactant include compounds having a structure having both a hydrophilic part and a hydrophobic part in the molecule, and more specifically, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Examples include surfactants and betaine-based surfactants. Among them, the surfactant is preferably a nonionic surfactant or an anionic surfactant.

As a surfactant,
JP-A-59-157636, pp. 37-38 and Research Disclosure No. Compounds listed as surfactants in 308119 (1989);
Fluorine-based (alkyl fluoride-based) surfactants described in JP-A-2003-322926, JP-A-2004-325707, and JP-A-2004-309806; and silicone-based surfactants are also mentioned.

Further, as the surfactant, a fluorine-based surfactant or an acetylene glycol-based surfactant is preferable, and an acetylene glycol-based surfactant is more preferable.

The surfactant may be a commercially available product.
For example, as a commercially available product of an acetylene glycol-based surfactant, Orphine E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) can be mentioned.

The content of the surfactant is preferably 0.001% by mass to 5% by mass, more preferably 0.005 to 3% by mass, and further preferably 0, based on the total mass of the ink composition. It is 0.01% by mass to 2% by mass.

The ink composition of the present disclosure may contain one type of surfactant alone, or may contain two or more types of surfactants.

<Additives>
The ink compositions of the present disclosure include anti-fading agents, emulsion stabilizers, penetration promoters, UV absorbers, preservatives, fungicides, pH regulators, surface tension regulators, defoamers, viscosity regulators, dispersants. , Dispersion stabilizers, rust preventives, chelating agents and the like may be included. Examples of the additive include the compounds described in paragraphs 0044 to 0050 of JP-A-2008-144004.

<Physical characteristics of ink composition>
[PH]
The pH of the ink composition is preferably 7 to 10, more preferably 7.5 to 9.5, from the viewpoint of ejection stability.
When the pH is within the above range, the dispersibility of the polymer particles having a polymerizable group is excellent, so that it is considered that the dot shape of the ink image and the ejection stability of the ink composition are improved.
The pH of the ink is a value measured at 25 ° C. using a pH meter (model number: HM-31, manufactured by Toa DKK Corporation).

〔viscosity〕
The viscosity of the ink composition is preferably 0.5 mPa · s to 30 mPa · s, more preferably 2 mPa · s to 20 mPa · s, preferably 2 mPa · s to 15 mPa · s, and 3 mPa · s to 10 mPa · s. Is more preferable.
The viscosity is measured under the condition of 30 ° C. using VISCOMETER TV-22 (manufactured by TOKI SANGYO CO. LTD).

〔surface tension〕
The surface tension of the ink composition at 25 ° C. is preferably 60 mN / m or less, more preferably 20 mN / m to 50 mN / m, and even more preferably 25 mN / m to 45 mN / m. When the surface tension of the ink is within the range, the occurrence of curl on the base material is suppressed, which is advantageous. The surface tension is measured by the plate method using an Automatic Surface Tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.).

[Image recording method]
The image recording method of the present disclosure includes a step of applying the above ink composition onto a substrate by an inkjet recording method to record an ink image, a step of drying the ink image, and a step of applying active energy rays to the dried ink image. Including the step of irradiating.

-A process of applying an ink composition onto a substrate by an inkjet recording method and recording an ink image-
In the image recording method of the present disclosure, first, an ink composition is applied onto a substrate by an inkjet recording method to record an ink image.

〔Base material〕
The base material is not particularly limited as long as it can form an ink image. Examples of the base material include paper, cloth, wood, metal plate, plastic film and the like.
As the paper, so-called high-quality paper, coated paper, art paper and other general printing paper mainly composed of cellulose, inkjet recording paper and the like, which are used for general offset printing and the like, can be used without particular limitation.
Further, as the base material, a non-permeable base material can also be used. When a non-permeable base material is used as the base material, it is preferable to include a step of applying the treatment liquid to the base material from the viewpoint of image forming property.
The "impermeable" of the impermeable substrate used in the present disclosure means that the water contained in the ink is absorbed little or not, and specifically, the amount of water absorbed is 10.0 g / g. It means a property of ^{m 2 or less.}
The non-permeable base material used in the present disclosure is not particularly limited, and examples thereof include a sheet-shaped base material and a film-shaped base material.
The non-permeable base material used in the present disclosure is a non-permeable base material in which a roll can be formed by winding a sheet-shaped or film-shaped non-permeable base material from the viewpoint of productivity of printed matter. Is preferable.

Examples of the impermeable substrate include metals (for example, aluminum foil, etc.) and plastic films (for example, polyvinyl chloride resin, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate. , Polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetate, etc.), plastics, and glass.
Among them, the non-permeable base material is preferably a base material containing a thermoplastic resin such as polyvinyl chloride, polyethylene terephthalate, or polypropylene.
The impermeable substrate may be surface-treated.
Examples of the surface treatment include, but are not limited to, corona treatment, plasma treatment, frame treatment, heat treatment, abrasion treatment, light irradiation treatment (UV treatment), and flame treatment. For example, if the surface of the impermeable substrate is subjected to corona treatment in advance before applying ink and recording an image, the surface energy of the impermeable substrate is increased and the surface of the impermeable substrate is wetted. And the adhesion of ink to the impermeable substrate is promoted. The corona treatment can be performed using, for example, a corona master (manufactured by Shinko Electric Meter Co., Ltd., PS-10S) or the like. The conditions for the corona treatment may be appropriately selected depending on the case, such as the type of impermeable base material and the composition of the ink. For example, the following processing conditions may be used.
-Processing voltage: 10 kV to 15.6 kV
-Processing speed: 30 mm / s to 100 mm / s

The ink image recorded in this step is not particularly limited, but an ink image composed of a plurality of element patterns (for example, a dot pattern, a line pattern, etc.), in other words, an ink image which is a set of a plurality of element patterns is preferable. ..
The diameter of each dot of the dot pattern is preferably 25 μm to 70 μm, more preferably 30 μm to 60 μm.

[Inkjet recording method]
The inkjet recording method is not particularly limited, and known methods such as a charge control method for ejecting ink by using an electrostatic attraction, a drop-on-demand method (pressure pulse method) using the vibration pressure of a piezo element, and the like. An acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the ink to eject the ink using radiation pressure, and a thermal inkjet method that heats the ink to form bubbles and uses the generated pressure (bubble jet (registered). It may be any of the trademark)) method and the like.
As an inkjet recording method, in particular, by the method described in JP-A-54-59936, the ink subjected to the action of thermal energy causes a rapid volume change, and the ink is ejected from the nozzle by the acting force due to this state change. The inkjet recording method for ejecting can be effectively used.
Further, regarding the inkjet recording method, the method described in paragraphs 093 to 0105 of JP-A-2003-306623 can also be referred to.

As the inkjet head used in the inkjet recording method, a short serial head is used, and a shuttle method in which recording is performed while scanning the head in the width direction of the base material and a recording element are arranged corresponding to the entire area of one side of the base material. An example is a line method using a line head that has been used.
In the line method, a pattern can be formed on the entire surface of the base material by scanning the base material in a direction intersecting the arrangement direction of the recording elements, and a transport system such as a carriage that scans a short head becomes unnecessary.
Further, since the movement of the carriage and the complicated scanning control with the base material are not required and only the base material moves, the recording speed can be increased as compared with the shuttle method.
The image recording method of the present disclosure can be applied to any of these, but the line method is preferable.

The amount of ink droplets ejected from the inkjet head is preferably 1 pL (picolitre) to 20 pL, more preferably 1.5 pL to 10 pL, from the viewpoint of obtaining a high-definition pattern.

In the ink images recorded in this step, the application amount per unit area of the infrared absorbing dye is preferably ^{0.0001g / m 2 ~ 1.0g / m} 2, 0.0001g / m 2 ~ 0. More preferably, it is 5 g / m ^2.

-The process of drying the ink image-
In the image recording method of the present disclosure, it is preferable to dry the ink image after recording the ink image.
The method for drying the ink image is not particularly limited, and a known method can be used. Examples of the drying means include known heating means such as a heater, known blowing means such as a dryer, and means combining these.

Examples of the method of drying the ink image include a method of applying heat with a heater or the like from the side opposite to the image recording surface of the base material, a method of applying warm air or hot air to the image recording surface of the base material, and an image recording of the base material. Examples thereof include a method of applying heat with an infrared heater from the side opposite to the surface or the image recording surface, and a method of combining these.

The heating temperature for heating is preferably 60 ° C. or higher, more preferably 65 ° C. or higher, and particularly preferably 70 ° C. or higher. The upper limit of the heating temperature is not particularly limited, but is preferably 150 ° C. or lower, for example.

The heating time for heating is not particularly limited, but is preferably 1 second to 300 seconds, more preferably 1 second to 30 seconds.

-The process of irradiating a dry ink image with active energy rays-
In the image recording method of the present disclosure, it is preferable to irradiate the dried ink image with active energy rays. In the ink image, the polymer particles having a polymerizable group are polymerized and cured by irradiation with active energy rays. Examples of the active energy ray include ultraviolet rays, visible rays, and electron beams. Among them, the active energy ray is preferably an ultraviolet ray (hereinafter, also referred to as “UV”) or an electron beam.

The peak wavelength of ultraviolet rays is, for example, preferably 200 nm to 405 nm, more preferably 220 nm to 390 nm, and even more preferably 220 nm to 380 nm.

^{UV, 20mJ / cm 2 ~ 5J /} cm 2, and preferably from being irradiated at an energy of ^{100mJ / cm 2 ~ 1,500mJ / cm} 2. The irradiation time is preferably 0.01 seconds to 120 seconds, more preferably 0.1 seconds to 90 seconds. As the irradiation conditions and the basic irradiation method, the irradiation conditions and the irradiation method disclosed in Japanese Patent Application Laid-Open No. 60-132767 can be applied. Specifically, the irradiation method is performed by providing light sources on both sides of the head unit including the ink composition ejection device and scanning the head unit and the light source by a so-called shuttle method, or by another light source that does not involve driving. The method is preferred.

Mercury lamps, gas lasers and solid-state lasers are mainly used as light sources for irradiating ultraviolet rays, and mercury lamps, metal halide lamps, and ultraviolet fluorescent lamps are widely known. In addition, replacement with a GaN (gallium nitride) -based semiconductor ultraviolet light emitting device is extremely useful industrially and environmentally, and UV-LED (light emitting diode) and UV-LD (laser diode) are compact and have a long life. It has high efficiency and low cost, and is expected as a light source for irradiating ultraviolet rays. Among them, the light source for ultraviolet irradiation is preferably a metal halide lamp, a high-pressure mercury lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, or a UV-LED.

When an electron beam is used as the active energy ray, the ink composition does not have to contain a photopolymerization initiator. Even if an ink composition containing no photopolymerization initiator is used, an ink image having excellent invisibility and readability after scraping can be recorded by irradiating the dried ink image with an electron beam.

Hereinafter, the present disclosure will be described in more detail with reference to Examples, but the present disclosure is not limited to the following Examples as long as the gist of the disclosure is not exceeded.

(Example 1)
[Preparation of ink composition]
4 parts by mass of the infrared absorbing dye (IR-1) described later was added to 96 parts by mass of ultrapure water and dispersed for 3 hours using a bead mill to obtain an aqueous dispersion A of the infrared absorbing dye (IR-1). ..

The following components so that the content of the infrared absorbing dye (IR-1) is 1% by mass with respect to the total mass of the ink composition and the content of the polymer particles is 4% by mass with respect to the total mass of the ink composition. Was mixed. The mixed solution was stirred for 1 hour and then filtered through a filter having a pore size of 5 μm to prepare an ink composition.
-Infrared absorbing dye (IR-1) aqueous dispersion A (solid content concentration 4% by mass)
・ ・ ・ 25 parts by mass, propylene glycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
... 20 parts by mass, surfactant (product name "Orfin E1010", manufactured by Nissin Chemical Industry Co., Ltd.)
・ ・ ・ 1 part by mass ・ Polymer particles having a polymerizable group (Product name “Riodurus AQ2017NPI”, manufactured by Toyo Chem Co., Ltd., solid content concentration 38% by mass) ・ ・ ・ 10.5 parts by mass ・ Water-soluble light shown in Table 1. Polymerization initiator X-1 (product name "L0290", manufactured by Tokyo Kasei Co., Ltd.) ・ ・ ・ 1 part by mass ・ Ion exchanged water ・ ・ ・ Remaining amount (parts by mass) when the total mass of the ink composition is 100 parts by mass )

(Examples 2 to 45, Comparative Examples 1 to 8)
The infrared absorbing dye, the polymer particles having a polymerizable group, and the water-soluble photopolymerization initiator used in the preparation of the ink composition of Example 1 were changed to the types and contents shown in Tables 1 to 3, and appropriately. An ink composition was prepared in the same manner as in Example 1 except that the water-soluble sensitizers shown in Tables 1 to 3 were added. In Comparative Examples 5 to 8, polymer particles having no polymerizable group were used instead of the polymer particles having a polymerizable group. In the table, the water-soluble photopolymerization initiator is described as "photopolymerization initiator", and the water-soluble sensitizer is described as "sensitizer". In addition, in the table, the content of the polymer particles with respect to the content of the infrared absorbing dye is described on a mass basis.

 

Hereinafter, the infrared absorbing dyes, polymer particles, water-soluble photopolymerization initiators, and water-soluble sensitizers shown in Tables 1 to 3 used for preparing the ink compositions of Examples and Comparative Examples will be described.

(Infrared absorbing pigment)
-Infrared absorbing pigments (IR-1) to (IR-9)
The infrared absorbing dyes (IR-1) to (IR-9) are compounds represented by the following general formula 2. ^{Details of L 1} , R ¹ , R ² , R ³ , R ⁴ , X, and M in the general formula 2 are shown in Table 4.

<L1-1>
L1-1 in Table 4 is represented by the following structural formula.

<A-1, A-4, A-8 and A-39>
A-1, A-4, A-8 and A-39 in Table 4 are represented by the following structural formulas.

<R-1, R-7, R-11, R-19, R-60 and R-72>
R-1, R-7, R-11, R-19, R-60 and R-72 in Table 4 are represented by the following structural formulas.

・ Infrared absorbing pigment (IR-S)
As the infrared absorbing dye (IR-S), B-1 described in paragraph No. 0076 of JP-A-2018-154672 was used. The infrared absorbing dye (IR-S) is a squarylium dye represented by the following structural formula. An aqueous dispersion of an infrared absorbing dye (IR-S) was prepared using sodium dodecylbenzenesulfonate as a dispersant according to the method described in paragraph 0139 of JP-A-2018-154672. An ink composition was prepared using the prepared aqueous dispersion of the infrared absorbing dye (IR-S).

-CWO: Tungsten cesium oxide aqueous dispersion (product name "YMW-D20", manufactured by Sumitomo Metal Mining Co., Ltd., solid content concentration 20% by mass)

-Cyanine pigment: A compound having the following structure (product name "T084511", manufactured by Tosco)

(Polymer particles)
-Polymer particles with polymerizable groups-
-Riodurus AQ2017NPI: Polyurethane particles having a polymerizable group (solid content concentration 38% by mass, volume average particle diameter 135 nm, manufactured by Toyo Chem Co., Ltd.)
WBR-832DA: Polyurethane particles having a polymerizable group (solid content concentration 35% by mass, volume average particle diameter 100 nm, manufactured by Taisei Fine Chemicals Co., Ltd.)
UT7019: Polyurethane particles having a polymerizable group (solid content concentration 40% by mass, volume average particle diameter 100 nm, manufactured by Mitsubishi Chemical Co., Ltd.)
UT7119: Polyurethane particles having a polymerizable group (solid content concentration 30% by mass, volume average particle diameter 100 nm, manufactured by Mitsubishi Chemical Co., Ltd.)
-Hydran UV100A: Polyurethane particles having a polymerizable group, solid content 33% by mass, volume average particle diameter 20 nm, manufactured by DIC Corporation)
Hydran UV100B: Polyurethane particles having a polymerizable group (solid content concentration 36.5% by mass, volume average particle diameter 75 nm, manufactured by DIC).
-Takelac WR-620: Polyurethane particles having a polymerizable group (solid content concentration 43% by mass, volume average particle diameter 110 nm, manufactured by Mitsui Chemicals, Inc.)
-Takelac WR-640: Polyurethane particles having a polymerizable group (solid content concentration 40% by mass, volume average particle diameter 110 nm, manufactured by Mitsui Chemicals, Inc.)
-Beam set EM94: Has a polymerizable group (solid content concentration 50% by mass, polyurethane particles, volume average particle diameter 100 nm, manufactured by Arakawa Chemical Industries, Ltd.)

・ P-1
P-1 used for the preparation of Example 18, Example 39 and Example 44 was prepared by the following method.
<Synthesis of polyurethane>
In a three-necked flask, isophorone diisocyanate (73.4 g), which is a unit (1) forming compound, dimethylolbutanoic acid (14.8 g), which is a hydrophilic group-introducing compound, and unit (2) forming compound 1, 6-Cyclohexanedimethanol (31.0 g) and ethyl acetate (100 g) were charged and heated to 70 ° C. To this, 0.2 g of an inorganic bismuth catalyst (product name "Neostan U-600", manufactured by Nitto Kasei Co., Ltd.) was added, and the mixture was stirred at 70 ° C. for 15 hours.
Next, isopropyl alcohol (83.3 g) and ethyl acetate (150 g) were added, and the mixture was stirred at 70 ° C. for 3 hours. After stirring for 3 hours, the reaction solution was allowed to cool to room temperature, and then the concentration was adjusted with ethyl acetate to obtain a 30% by mass solution of polyurethane (the solvent was a mixed solution of ethyl acetate / isopropyl alcohol).

<Preparation of aqueous dispersion>
-Preparation of oil phase components-
With ethyl acetate, a 30% by mass solution of polyurethane, tricyclodecanedimethanol diacrylate (product name "SR833S", manufactured by Sartmer), and dipentaerythritol pentaacrylate (product name "SR399E", manufactured by Sartmer). , Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (product name "Omnirad 819", manufactured by IGM Resins BV), which is a photopolymerization initiator, is mixed and stirred for 15 minutes. Obtained 45.7 g of an oil phase component having a solid content of 30% by mass.

In the preparation of the oil phase component, the amount of the polyurethane in a 30% by mass solution was set so that the content of polyurethane (% by mass) with respect to the solid content of the produced particles was the value shown in Table 1.

In the preparation of the oil phase component, the amounts of SR833S and SR399E used were set so that the respective contents of the produced particles with respect to the solid content were 28.5% by mass.

In the preparation of the oil phase component, the amount of the photopolymerization initiator used was set so that the content of the produced particles with respect to the solid content was 3.0% by mass.

-Preparation of aqueous phase components-
Distilled water (43.1 g) and sodium hydroxide as a neutralizing agent were mixed and stirred for 15 minutes to prepare an aqueous phase component.
The amount of sodium hydroxide used was adjusted so that the degree of neutralization of the produced particles was 90%.
The specific amount of sodium hydroxide was calculated by the following formula.
Amount of sodium hydroxide (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (mass%) / 100) × (content of polyurethane with respect to solid content of oil phase component (mass%)) / 100) × Acid value of polyurethane (mmol / g) × 0.9 × Molecular weight of sodium hydroxide (g / mol) / 1000

The oil phase component and the aqueous phase component were mixed, and the obtained mixture was emulsified at 12000 rpm for 10 minutes using a homogenizer at room temperature to obtain an emulsion. The obtained emulsion was added to distilled water (15.3 g), the obtained liquid was heated to 50 ° C., and the mixture was stirred at 50 ° C. for 5 hours to distill off ethyl acetate from the above liquid.
The liquid from which ethyl acetate was distilled off was diluted with distilled water so that the solid content was 20% by mass to obtain an aqueous dispersion of polymer particles P-1 containing polyurethane and a polymerizable monomer. ..

-Polymer particles without polymerizable groups-
・ P-2
P-2 used for the preparation of Comparative Examples 5 to 8 was prepared by the following method.
360.0 g of methyl ethyl ketone was charged into a 2-liter three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, and the temperature was raised to 75 ° C. Then, in another container, 72.0 g of isobornyl methacrylate, 252.0 g of methyl methacrylate, 36.0 g of methacrylic acid, 72 g of methyl ethyl ketone, and dimethyl 2,2'-azobis (2-methylpropionate) as a polymerization initiator. ) (Product name "V-601", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 1.44 g was mixed to prepare a mixed solution. While maintaining the temperature inside the flask charged with methyl ethyl ketone at 75 ° C., the mixed solution prepared above was added dropwise at a constant velocity so that the addition was completed in 2 hours. After completion of the dropping, a solution consisting of 0.72 g of "V-601" and 36.0 g of methyl ethyl ketone was added, and the mixture was stirred at 75 ° C. for 2 hours. Further, a solution consisting of 0.72 g of "V-601" and 36.0 g of isopropanol was added, and the mixture was stirred at 75 ° C. for 2 hours. Then, the temperature was raised to 85 ° C., and stirring was continued for 2 hours to obtain a polymer solution of an isobornyl methacrylate / methyl methacrylate / methacrylic acid (= 20/70/10 [mass ratio]) copolymer.
The weight average molecular weight (Mw) of the obtained copolymer was 60,000.

Next, 668.3 g of the obtained polymer solution was weighed, 388.3 g of isopropanol and 145.7 ml of a 1 mol / L sodium hydroxide aqueous solution were added to the polymer solution, and the temperature inside the reaction vessel was raised to 80 ° C. Next, 720.1 g of water was added dropwise at a rate of 20 ml / min, and after water dispersion, the temperature inside the reaction vessel was maintained at 80 ° C. for 2 hours, 85 ° C. for 2 hours, and 90 ° C. for 2 hours under atmospheric pressure. did. Then, the pressure inside the reaction vessel was reduced, and 913.7 g of isopropanol, methyl ethyl ketone and water were distilled off in total, and the solid content concentration (polymer particle concentration) of 28.0% by mass of the polymer particles P-2 having no polymerizable group was obtained. An aqueous dispersion was obtained.

(Water-soluble photopolymerization initiator)
The water-soluble photopolymerization initiators (X) -1 to (X) -5 are compounds represented by the following general formula (X).

^{Details of n and RX1} to ^{RX4 in} the water-soluble photopolymerization initiators (X) -1 to (X) -5 are as follows.

(Water-soluble sensitizer)
The water-soluble sensitizer Y-1 is a compound having an absorption range in the wavelength range of 350 nm to 400 nm and having the following structure.

[Recording of ink image (1)]
A base material to which topcoat varnish (product name "OP Top Varnish", manufactured by Tokyo Ink Co., Ltd.) is applied to paperboard (product name "Ivest W 310 g / m ^{2", manufactured by Nippon Paper Co., Ltd.) using an offset printing machine.} Using the prepared ink composition, an image was recorded by an inkjet printer (product name "DMP-2831 printer", manufactured by FUJIFILM Dimatix). Image recording was performed under the conditions of an image resolution of 600 dpi × 600 dpi and a dropping amount of 10 pl. A base material on which a screen code manufactured by Apollo Japan was recorded and a base material on which a solid image with a halftone dot ratio of 100% was recorded were obtained. As the ink composition, the ink compositions of Examples 1 to 34, Examples 40 to 45, and Comparative Examples 1 to 8 were used.

After recording the image, the ink film formed on the substrate by the ink composition was dried for 10 seconds using a dryer. Subsequently, an ultraviolet irradiation device (product name "CSOT-40", 1 4KW metal halide lamp, manufactured by GS Nippon Battery Co., Ltd.) was used at a transport speed of 10 m / min (exposure time 4 seconds) for the dried ink film. The exposure was performed four times to obtain an image recording object 1 and an image recording object 2.

The image recording material 1 is a recording of a screen code manufactured by Apollo Japan. The screen code is linked to a voice pen made by Apollo Japan, and when the code is read, the voice pen is set to play "collect".
Further, the image recording object 2 is a recording of a solid image having a halftone dot ratio of 100%.

Using the image recording material 1, the initial readability, the readability after scraping, and the invisibility were evaluated. The light resistance was evaluated using the image recording material 2. The evaluation method is as follows. The evaluation results are shown in Table 6.

<Initial readability>
For the image recording material 1, 10 places where the screen code was recorded were selected, and a reading test was performed using a voice pen manufactured by Apollo Japan. The evaluation criteria are as follows. A to D are practically acceptable levels.
A: I could read everything.
B: 8 or 9 places were read.
C: 3 to 7 places were read.
D: It was read once or twice.
E: I couldn't read it at all.

<Readability after rubbing>
An image recording material 1 was subjected to a 100-reciprocal friction test with a load of 500 g. After the friction test, 10 places where the screen code was recorded were selected for the image recording object 1, and a reading test was performed using a voice pen manufactured by Apollo Japan. The evaluation criteria are as follows. A to C are practically acceptable levels.
In Comparative Examples 1 to 4, the readability after rubbing could not be evaluated because the readability could not be read at all in the initial readability test. It is described as "-" in Table 6.
A: The number read after 100 round trip friction tests is the same as the initial number read.
B: The number read after the 50 round trip friction test was the same as the initial read number, but the number read after the 100 round trip friction test was less than the initial read number.
C: The number read after the 10 round trip friction test was the same as the initial read number, but the number read after the 50 round trip friction test was less than the initial read number.
D: The number read after the 10 round trip scraping test was less than the initial number read.
<Invisibility>
The image recording material 1 was presented to 10 people who did not know that the screen code was recorded on the image recording material 1, and a test was conducted to see if they noticed that the screen code was recorded. The smaller the number of people who notice, the better the invisibility. The evaluation criteria are as follows. A to C are practically acceptable levels.
In Comparative Examples 1 to 4, invisibility was not evaluated because it could not be read at all in the initial readability test. It is described as "-" in Table 6.
A: No one noticed B: 1 noticed C: 5 noticed D: All noticed <light resistance>
The image recording 2 was irradiated with xenon light (85,000 lux) for 6 days using a weather meter (Atlas CI65). The optical density at the maximum absorption wavelength of the image recording material 2 before and after the xenon light irradiation was measured, and the dye residual ratio was calculated by the following formula. The higher the dye residual ratio, the better the light resistance. The evaluation criteria are as follows. A to C are practically acceptable levels.
Dye residual rate (%) = (optical density after irradiation) / (optical density before irradiation) × 100.
The optical density was measured using a spectrophotometer UV-3100PC equipped with a 150 mmφ large integrating sphere accessory device LISR-3100 manufactured by Shimadzu Corporation.
In Comparative Examples 1 to 4, since no reading was possible in the initial readability test, the light resistance was not evaluated. It is described as "-" in Table 6.
A: The pigment residual rate is 90% or more.
B: The dye residual rate is 75% or more and less than 90%.
C: The dye residual rate is 60% or more and less than 75%.
D: The dye residual rate is less than 60%.

As shown in Table 6, the ink compositions of Examples 1 to 34 and Examples 40 to 45 contain an infrared absorbing dye, polymer particles having a polymerizable group, and water, and are initially read. It was found that an ink image having excellent properties, readability after scraping, invisibility, and light resistance can be recorded.

It was found that Example 1 contained an infrared absorbing dye represented by the general formula 1-1 and was superior in invisibility as compared with Example 19.

Since Example 1 contains an infrared absorbing dye represented by the general formula 1-1, it was found that it is superior in initial readability and readability after scraping as compared with Example 22.

In Example 1, the content of the infrared absorbing dye is 0.5% by mass to 2.5% by mass with respect to the total amount of the ink composition, and the initial readability and the reading after rubbing are compared with those of Example 23. It turned out to be excellent in sex.

In Example 1, the content of the infrared absorbing dye was 0.5% by mass to 2.5% by mass with respect to the total amount of the ink composition, and it was found that the invisibility was excellent as compared with Example 24.

In Example 1, the ratio of the content of the polymer particles having a polymerizable group to the content of the infrared absorbing dye is 2 to 20 on a mass basis, and the readability after rubbing is excellent as compared with Example 25. I found out.

In Example 1, the ratio of the content of the polymer particles having a polymerizable group to the content of the infrared absorbing dye is 2 to 20 on a mass basis, and the initial readability and after rubbing are compared with those of Example 28. It was found to be excellent in readability.

It was found that the content of the photopolymerization initiator in Example 1 was 0.3% by mass to 3.0% by mass, and the readability after rubbing was excellent as compared with Example 33.

In Example 1, the content of the photopolymerization initiator is 0.3% by mass to 3.0% by mass, and the initial readability, readability after scraping, and invisibility are excellent as compared with Example 34. I found out.

It was found that Comparative Examples 1 to 4 did not contain polymer particles having a polymerizable group and could not be read at all.

It was found that Comparative Examples 5 to 8 did not contain polymer particles having a polymerizable group, contained polymer particles having no polymerizable group, and were inferior in readability after rubbing.

[Recording of ink image (2)]
Ink image recording Image recording was performed using the prepared ink composition in the same manner as in (1). As the ink composition, the ink compositions of Example 1, Example 11, Example 13, Example 18, Example 19, and Examples 40 to 44 were used.
After recording the image, the ink film formed on the substrate by the ink composition was dried for 10 seconds using a dryer. Subsequently, using a UV-LED irradiation device (product name "GA5", LED light source having a wavelength of 385 nm, manufactured by Kyocera Corporation), the dried ink film is irradiated with ultraviolet rays, and the image recording material 1 and the image recording material 2 are irradiated. Got

The initial readability, readability after scraping, and invisibility were evaluated using the image recording object 1 in the same manner as in the ink image recording (1). In addition, the light resistance was evaluated using the image recording material 2. The evaluation results are shown in Table 7.

From Table 7, when the ink composition containing the sensitizer (Examples 40 to 44) was used, the ink composition containing no sensitizer (Example 1, Example 11, Example 13, Example). It was found that the readability after rubbing was superior to that in the case of using 18 and Example 19).

[Recording of ink image (3)]
Ink image recording Image recording was performed using the prepared ink composition in the same manner as in (1). As the ink composition, the ink compositions of Example 1, Example 11, Example 13, Example 18, Example 19, and Example 35 to 39 were used.
After recording the image, the ink film formed on the substrate by the ink composition was dried for 10 seconds using a dryer. Subsequently, an electron beam irradiation device (product name "standard EB experimental machine EC250 / 15 / 180L", manufactured by iElectron Beam Co., Ltd.) is used to irradiate the dried ink film with an electron beam, and the image recording material 1 And the image recording 2 was obtained.

The initial readability, readability after scraping, and invisibility were evaluated using the image recording object 1 in the same manner as in the ink image recording (1). In addition, the light resistance was evaluated using the image recording material 2. The evaluation results are shown in Table 8.

From Table 8, when an image recording material was prepared by irradiating an electron beam, even if an ink composition containing no polymerization initiator (Examples 35 to 39) was used, the ink composition containing the polymerization initiator (Example 35 to 39) was used. Similar to Example 1, Example 11, Example 13, Example 18 and Example 19), it was found to be excellent in initial readability, readability after scraping, invisibility, and light resistance.

From the above, the ink composition of the present disclosure contains an infrared absorbing dye, polymer particles having a polymerizable group, and water, and can record an ink image having excellent invisibility and readability after rubbing.

The disclosure of Japanese Patent Application No. 2019-180585 filed on September 30, 2019 is incorporated herein by reference in its entirety. Also, all documents, patent applications and technical standards described herein are to the same extent as if the individual documents, patent applications and technical standards were specifically and individually stated to be incorporated by reference. , Incorporated by reference herein.

Claims (14)

1. An ink composition for inkjet recording containing an infrared absorbing dye, polymer particles having a polymerizable group, and water.
2. The ink composition for inkjet recording according to claim 1, wherein the infrared absorbing dye is a dye or a pigment capable of forming a J-aggregate.
3. The ink jet recording ink according to claim 2, wherein the dye capable of forming the J-aggregate is at least one selected from the group consisting of dyes represented by the following general formulas 1-1 and 1-2. Composition.
   

   

   
   

   

   
   In the general formula 1-1, Y ¹ and Y ² independently represent a group of non-metal atoms forming an aliphatic ring or a hetero ring, and M ⁺ is a proton, a monovalent alkali metal cation, or an organic cation. ^{L 1} represents a methine chain consisting of 5 or 7 methine groups, and the methine group in the center of the methine chain has a substituent represented by the following formula A.
   * ^{-S A} -T A formula A
   Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a group consisting of a combination of at least two of these, where ^RL1 represents a hydrogen atom, a halogen atom, It represents an alkyl group, an aryl group or a monovalent heterocyclic group, R ^L2 is an alkylene group, an arylene group, or a divalent heterocyclic group, T ^a is a halogen atom, an alkyl group, a cycloalkyl group, an aryl group , Monovalent heterocyclic group, cyano group, hydroxy group, formyl group, carboxy group, amino group, thiol group, sulfo group, phosphoryl group, boryl group, vinyl group, ethynyl group, trialkylsilyl group, or trialkoxysilyl It represents a group, a S ^a is a single bond or an alkylene group, and, if T ^a represents an alkyl group, and a total number of carbon atoms included in the S ^a and T ^a is 3 or more, * is the methine chain Represents the binding site with the methine group in the center of.
   In the Formula 1-2, ring A and ring B each independently represent an aromatic ring or a heteroaromatic ring, it represents a monovalent substituent X ^A and X ^B are each independently, G ^A and G ^B is each independently represent a monovalent substituent, kA is _{0 ~} n a, kB represents an integer of 0 ~ _{n B, n a} and _{n B} respectively ring a or ring B can be substituted to a ^{G a} and ^{G B} Represents an integer, which is the maximum number of
   X ^A and G ^A may be bonded to each other to form a ring, X ^B and G ^B may be bonded to each other to form a ring, if G ^A and G ^B are present in plural is, G ^a and between G ^B together may be bonded to form a ring structure.
4. The ink composition for inkjet recording according to claim 3, wherein the dye represented by the general formula 1-1 is a dye represented by the following general formula 3.
   

   

   
   In the general formula 3, M ⁺ represents a proton, a monovalent alkali metal cation, or an organic cation, L ¹ represents a methine chain consisting of 5 or 7 methine groups, and the methine group in the center of the methine group is as follows. It has a substituent represented by the formula A and has a substituent.
   * ^{-S A} -T A formula A
   Wherein A, ^{S A} is a single bond, an alkylene group, an alkenylene group, an alkynylene ^{group, -O -, - S -,} - NR L1 -, - C (= O) -, - C (= O) O -, - C (= O) NR ^L1- , -S (= O) _2- , -OR ^L2- , or a group consisting of a combination of at least two of these, where ^RL1 represents a hydrogen atom, a halogen atom, It represents an alkyl group, an aryl group or a monovalent heterocyclic group, R ^L2 is an alkylene group, an arylene group, or a divalent heterocyclic group, T ^a is a halogen atom, an alkyl group, an aryl group, monovalent Represents a heterocyclic group, a cyano group, a hydroxy group, a formyl group, a carboxy group, an amino group, a thiol group, a sulfo group, a phosphoryl group, a boryl group, a vinyl group, an ethynyl group, a trialkylsilyl group, or a trialkoxysilyl group. represents S ^a is a single bond or an alkylene group, and, if T ^a represents an alkyl group, and a total number of carbon atoms included in the S ^a and T ^a is 3 or more, * the central methine methine chain Represents a binding site with a group
   R ⁵ and R ⁷ independently represent a hydrogen atom, an alkyl group, an aryl group or a monovalent heterocyclic group, and R ⁶ and R ⁸ independently represent an alkyl group, a halogen atom, an alkenyl group and an aryl group, respectively. Monovalent heterocyclic group, nitro group, cyano group, -OR ^L3 , -C (= O) R ^L3 , -C (= O) OR ^L3 , -OC (= O) R ^L3 , -N ( ^RL3 ) _{^{2, -NHC (= O) R}} L3, -C (= O) N (R L3) 2, -NHC (= O) OR L3, -OC (= O) N (R L3) 2, -NHC (= O) N ( ^RL3 ) ₂ , -SR ^L3 , -S (= O) ₂ R ^L3 , -S (= O) ₂ OR ^L3 , -NHS (= O) ₂ R ^L3 , or -S (= O) _{) 2} n ^(R L3) represents ^{_2, R L3} are each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a monovalent heterocyclic radical, n are each independently an integer of 1 to 5 Represents, and X independently represents an O atom, an S atom, or a Se atom.
5. The ink composition for inkjet recording according to claim 4, wherein at least one selected from the group consisting of ^{R 5} , R ⁶ , R ⁷ , and R ⁸ in the general formula 3 is a hydrogen-bonding group.
6. The ink composition for inkjet recording according to any one of claims 1 to 5, wherein the polymer particles having a polymerizable group are polyurethane particles having a polymerizable group.
7. The ink composition for inkjet recording according to any one of claims 1 to 6, wherein the content of the infrared absorbing dye is 0.5% by mass to 2.5% by mass with respect to the total amount of the ink composition. ..
8. The inkjet recording ink according to any one of claims 1 to 7, wherein the ratio of the content of the polymer particles having the polymerizable group to the content of the infrared absorbing dye is 2 to 20 on a mass basis. Composition.
9. The ink composition for inkjet recording according to any one of claims 1 to 8, further comprising a water-soluble photopolymerization initiator.
10. The ink composition for inkjet recording according to any one of claims 1 to 9, further comprising a water-soluble sensitizer having an absorption range in the wavelength range of 350 nm to 400 nm.
11. A step of applying the ink composition for inkjet recording according to any one of claims 1 to 10 onto a substrate by an inkjet recording method to record an ink image.
    The step of drying the ink image and
    An image recording method including a step of irradiating a dried ink image with active energy rays.
12. The image recording method according to claim 11, wherein the active energy ray is ultraviolet rays.
13. The image recording method according to claim 11 or 12, wherein the active energy ray is irradiated using a light emitting diode light source.
14. The image recording method according to claim 11, wherein the active energy ray is an electron beam.