JP2010202691A - Ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition which is excellent in the ink storage stability and dischargeability, is excellent in the curability when light-irradiated, and is excellent in the scratch resistance, flexibility and adhesion to a substrate of the film after cure. <P>SOLUTION: This ink composition contains a dispersant having an acid value larger than the amine value, a polymerizable compound, a polymerization initiator and an azo pigment expressed by formula (1), wherein Q is a non-metallic atomic group necessary for forming a five- to seven-membered heterocycle along with two carbon atoms bonding to Q; W is an alkoxy group, an amino group, an alkyl group or an aryl group; X<SB>1</SB>and X<SB>2</SB>are each independently a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group; R<SB>1</SB>is a hydrogen atom or a substituent group, and R<SB>2</SB>is a heterocycle group; and n is an integer of 1-4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radiation curable ink composition.

As an image recording method for forming an image on a recording medium such as paper based on an image data signal, there are an electrophotographic method, a sublimation type and a melt type thermal transfer method, an ink jet method and the like. In particular, the inkjet method can be implemented with an inexpensive device, and the ink composition is ejected only on the required image portion to form an image directly on the recording medium, so the ink composition is used efficiently. Yes, running costs are low. Furthermore, there is little noise and it is excellent as an image recording method.
In recent years, after drawing an ink composition (radiation curable ink jet recording ink composition) that can be cured by irradiation with radiation such as ultraviolet rays, the ink composition is cured by irradiation with radiation such as ultraviolet rays. A solventless ink jet recording system has attracted attention. In general, compared with a water-based ink composition containing water as a diluent and a solvent-type ink composition containing an organic solvent as a diluent, an inkjet recording method using a radiation curable ink composition is a glass, metal, plastic substrate, or the like. It is possible to draw on non-absorbent substrates, and the range of application of the substrate is wide, scratched images and solvent resistance are excellent, sensitivity is high, productivity is high, and volatile solvents are not included. Therefore, it has the merit that the influence on the human body such as odor and the load on the environment is small.

  As a colorant for the radiation curable ink composition for inkjet recording, a pigment is widely used because of its excellent light resistance and weather resistance. However, the pigment tends to cause aggregation, and the pigment tends to settle and the viscosity of the ink composition increases. These cause bending (deviation), mist generation or non-ejection (nozzle missing) of the ink composition when drawing by inkjet, and cause a large practical problem that good image quality cannot be obtained. For this reason, it is indispensable to stably disperse the pigment in the ink composition for a long period of time. Generally, for the purpose of improving such a problem, a polymer dispersant and / or a dispersion aid (also referred to as a synergist) are generally used. Pigment dispersion is carried out using a pigment derivative called

Conventionally, polar groups (for example, sulfonic acid groups) that interact with a pigment are used for the purpose of improving the dispersion stability of the pigment in the ink by increasing the adsorptivity of the polymer dispersant and / or the dispersion aid to the pigment. Attempts have been made to use compounds into which a carboxylic acid group or the like has been introduced.
For example, Patent Document 1 discloses C.I. I. Pigment Yellow 180, a polymeric dispersant having a basic adsorbing group, and C.I. I. An ultraviolet curable inkjet recording ink composition containing CI Pigment Yellow 151 is disclosed. Patent Document 2 discloses an active energy ray-curable inkjet ink containing a pigment, a pigment dispersant into which a functional group effective for pigment dispersion is introduced, and a monomer that can be polymerized with active energy rays. Patent Document 3 discloses an ultraviolet curable ink jet recording ink composition containing carbon black, a photopolymerizable compound, a photopolymerization initiator, a polymer dispersant having a basic adsorbing group, and a phthalocyanine sulfonic acid compound. Is disclosed. Patent Document 4 discloses an active energy ray-curable inkjet ink comprising a polymer dispersant, a monomer, a diketopyrrolopyrrole pigment, and a pigment derivative. Further, Patent Document 5 discloses an active energy ray-curable inkjet ink comprising a polymer dispersant, a monomer, a phthalocyanine pigment, and an amine salt of phthalocyanine sulfonic acid.

JP 2004-2528 A JP 2004-18656 A JP 2004-27211 A JP 2006-348200 A JP 2006-348201 A

  The present invention is an ink composition having good ink storage stability and ejection properties, excellent curability during light irradiation, and excellent scratch resistance, flexibility and adhesion to a substrate after curing. The purpose is to provide.

The above-described problems of the present invention have been solved by the means described in <1> below. It is described below together with <2> to <14> which are preferred embodiments.
<1> an ink composition comprising a dispersant having a larger acid value than the amine value, a polymerizable compound, a polymerization initiator, and an azo pigment represented by the following formula (1):

（式（１）中、Ｑは、Ｑが結合する２つの炭素原子と共に５〜７員のヘテロ環を形成するのに必要な非金属原子団を表し、Ｗはアルコキシ基、アミノ基、アルキル基又はアリール基を表し、Ｘ₁、Ｘ₂はそれぞれ独立に水素原子、アルキル基、アシル基、アルキルスルホニル基又はアリールスルホニル基を表し、Ｒ₁は水素原子又は置換基を表し、Ｒ₂はヘテロ環基を表し、ｎは１〜４の整数を表す。ｎ＝２〜４の場合、式（１）はＱ、Ｗ、Ｘ₁、Ｘ₂、Ｒ₁、又はＲ₂を介して結合した２〜４量体をそれぞれ表す。）

(In the formula (1), Q represents a nonmetallic atomic group necessary for forming a 5- to 7-membered heterocycle with two carbon atoms to which Q is bonded, and W represents an alkoxy group, an amino group, or an alkyl group. Or an aryl group, X ₁ and X ₂ each independently represent a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, R ₁ represents a hydrogen atom or a substituent, and R ₂ represents a heterocyclic ring. Represents a group, and n represents an integer of 1 to 4. In the case of n = 2 to 4, the formula (1) is ₂ to 2 bonded via Q, W, X ₁ , X ₂ , R ₁ , or R 2. Each represents a tetramer.)

<2> The ink composition according to <1>, wherein the dispersant is a polymer compound.
<3> The ink composition according to <1> or <2>, wherein the acid value of the dispersant is greater than the amine value, and the difference is 1 mgKOH / g or more and 120 mgKOH / g or less.
<4> The ink composition according to any one of <1> to <3>, wherein the azo pigment represented by the formula (1) is an azo pigment represented by the following formula (2):

（式（２）中、Ｑは、Ｑが結合する２つの炭素原子と共に５〜７員のヘテロ環を形成するのに必要な非金属原子団を表し、Ｗはアルコキシ基、アミノ基、アルキル基又はアリール基を表し、Ｘ₁はそれぞれ独立に水素原子、アルキル基、アシル基、アルキルスルホニル基又はアリールスルホニル基を表し、Ｒ₁は水素原子又は置換基を表し、Ｒ₂はヘテロ環基を表し、ｎは１〜４の整数を表す。ｎ＝２〜４の場合、式（２）はＱ、Ｗ、Ｘ₁、Ｒ₁、又はＲ₂を介して結合した２〜４量体をそれぞれ表す。）

(In the formula (2), Q represents a nonmetallic atomic group necessary for forming a 5- to 7-membered heterocycle with two carbon atoms to which Q is bonded, and W represents an alkoxy group, an amino group, or an alkyl group. Or an aryl group, X ₁ independently represents a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, R ₁ represents a hydrogen atom or a substituent, and R ₂ represents a heterocyclic group. , N represents an integer of 1 to 4. When n = 2 to 4, formula (2) represents a 2-tetramer bonded via Q, W, X ₁ , R ₁ , or R ₂ , respectively. .)

<5> The above <1> to <4>, wherein Q in the formula (1) is a nonmetallic atomic group necessary for forming a 5-membered nitrogen-containing heterocycle with two carbon atoms to which Q is bonded. An ink composition according to any one of
<6> The ink composition according to any one of <1> to <5>, wherein n in the formula (1) is 2.
<7> The ink composition according to <4>, wherein X ₁ in the formula (2) is a hydrogen atom.
<8> The ink composition according to any one of <1> to <3>, wherein the azo pigment represented by the formula (1) is an azo pigment represented by the following formula (3):

（式（３）中、Ｙは水素原子又は置換基を表し、Ｇは水素原子、アルキル基、シクロアルキル基、アラルキル基、アルケニル基、アルキニル基、アリール基又はヘテロ環基を表す。Ｗはアルコキシ基、アミノ基、アルキル基又はアリール基を表し、Ｘ₁、Ｘ₂はそれぞれ独立に水素原子、アルキル基、アシル基、アルキルスルホニル基又はアリールスルホニル基を表し、Ｒ₁は水素原子又は置換基を表し、Ｒ₂はヘテロ環基を表し、ｎは１〜４の整数を表す。ｎ＝２〜４の場合、式（３）はＧ、Ｙ、Ｗ、Ｘ₁、Ｘ₂、Ｒ₁、又はＲ₂を介して結合した２〜４量体をそれぞれ表す。）

(In Formula (3), Y represents a hydrogen atom or a substituent, G represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group. W represents an alkoxy group. A group, an amino group, an alkyl group or an aryl group, X ₁ and X ₂ each independently represents a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, and R ₁ represents a hydrogen atom or a substituent. R ₂ represents a heterocyclic group, and n represents an integer of 1 to 4. When n = 2 to 4, formula (3) is G, Y, W, X ₁ , X ₂ , R ₁ , or represents 2-4 dimer linked via R _2, respectively.)

<9> Any one of the above <1> to <8>, wherein W in the formula (1) is an alkoxy group having 3 or less carbon atoms, an amino group, or an alkylamino group having 3 or less total carbon atoms. The ink composition according to claim 1,
<10> The ink composition according to <8>, wherein G in the formula (3) is an alkyl group having 3 or less total carbon atoms,
<11> The ink composition according to <8>, wherein the azo pigment represented by the formula (3) is an azo pigment represented by the following formula (4):

（式（４）中、Ｚは５〜８員の含窒素ヘテロ環に由来する二価の基を表し、Ｙ₁、Ｙ₂、Ｒ₁₁、Ｒ₁₂は、それぞれ独立に水素原子又は置換基を表し、Ｇ₁、Ｇ₂は、それぞれ独立に水素原子、アルキル基、アラルキル基、アルケニル基、アルキニル基、アリール基、又はヘテロ環基を表し、Ｗ₁、Ｗ₂はそれぞれ独立にアルコキシ基、アミノ基、アルキル基又はアリール基を表す。）

(In formula (4), Z represents a divalent group derived from a 5- to 8-membered nitrogen-containing heterocycle, and Y ₁ , Y ₂ , R ₁₁ and R ₁₂ each independently represents a hydrogen atom or a substituent. G ₁ and G ₂ each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and W ₁ and W ₂ each independently represent an alkoxy group, amino Represents a group, an alkyl group or an aryl group.)

<12> W _1, W ₂ in the formula (4) in, respectively independently a total carbon number of 3 or less alkoxy group, according to the <11> is an amino group, or a total carbon number of 3 or less of an alkylamino group Ink composition,
<13> The ink composition according to the above <11> or <12>, wherein G ₁ and G ₂ in the formula (4) are each independently an alkyl group having 3 or less carbon atoms.
<14> The ink composition according to any one of <11> to <13>, wherein Z in the formula (4) is a 6-membered nitrogen-containing heterocycle.
Any of the ink compositions described in <1> to <14> above can be used as an inkjet ink composition.

  According to the present invention, the ink has excellent storage stability and dischargeability, excellent curability during light irradiation, excellent scratch resistance of the film after curing, flexibility, and adhesion to a substrate. A composition could be provided.

(Radiation curable ink composition)
The radiation curable ink composition of the present invention (also referred to simply as “ink composition” in the present invention) includes a dispersant, a polymerizable compound, a polymerization initiator having an acid value larger than the amine value, and the following formula (1): It contains the azo pigment represented by these.

（式（１）中、Ｑは、Ｑが結合する２つの炭素原子と共に５〜７員のヘテロ環を形成するのに必要な非金属原子団を表し、Ｗはアルコキシ基、アミノ基、アルキル基又はアリール基を表し、Ｘ₁、Ｘ₂はそれぞれ独立に水素原子、アルキル基、アシル基、アルキルスルホニル基又はアリールスルホニル基を表し、Ｒ₁は水素原子又は置換基を表し、Ｒ₂はヘテロ環基を表し、ｎは１〜４の整数を表す。ｎ＝２〜４の場合、式（１）はＱ、Ｗ、Ｘ₁、Ｘ₂、Ｒ₁、又はＲ₂を介して結合した２〜４量体をそれぞれ表す。）

(In the formula (1), Q represents a nonmetallic atomic group necessary for forming a 5- to 7-membered heterocycle with two carbon atoms to which Q is bonded, and W represents an alkoxy group, an amino group, or an alkyl group. Or an aryl group, X ₁ and X ₂ each independently represent a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, R ₁ represents a hydrogen atom or a substituent, and R ₂ represents a heterocyclic ring. Represents a group, and n represents an integer of 1 to 4. In the case of n = 2 to 4, the formula (1) is ₂ to 2 bonded via Q, W, X ₁ , X ₂ , R ₁ , or R 2. Each represents a tetramer.)

The ink composition of the present invention is an ink composition that can be cured by radiation, and is an oil-based ink composition.
The term “radiation” as used in the present invention is not particularly limited as long as it is actinic radiation that can impart energy capable of generating a starting species in the ink composition by the irradiation, and widely includes α rays, γ rays, X Among these, ultraviolet rays and electron beams are preferable, and ultraviolet rays are particularly preferable from the viewpoint of curing sensitivity and device availability. Therefore, the ink composition of the present invention is preferably an ink composition that can be cured by irradiating ultraviolet rays as radiation.
The ink composition of the present invention can be suitably used as an ink composition for inkjet recording.
Hereinafter, each component will be described.

(Dispersant with acid value greater than amine value)
The radiation curable ink composition of the present invention (hereinafter, also simply referred to as “the ink composition of the present invention”) is characterized in that a dispersant having a larger acid value than the amine value is used as the dispersant.
As the dispersant used in the present invention, any of a low molecular weight dispersant and a high molecular dispersant can be used as long as the conditions specified in the present invention are satisfied. preferable.

The ink composition of the present invention contains a dispersant having an acid value larger than the amine value.
Here, the “acid value” represents an acid value per 1 g of the solid content of the dispersant, and can be determined by potentiometric titration according to JIS K 0070. The amine value represents an amine value per 1 g of the solid content of the dispersant, and is a value converted to an equivalent of potassium hydroxide after being obtained by potentiometric titration using a 0.1N hydrochloric acid aqueous solution.
In the present invention, the step of mixing and dispersing the pigment is preferably performed in the presence of a dispersant having an acid value larger than the amine value.
The dispersant having an acid value greater than the amine value in the present invention is preferably a polymer dispersant. The polymer dispersant means a dispersant having a weight average molecular weight of 1,000 or more. The weight average molecular weight is preferably in the range of 2,000 to 300,000, more preferably 3,000 to 200,000, still more preferably 4,000 to 100,000, and particularly preferably 5,000 to 100,000. preferable. When the weight average molecular weight of the polymer dispersant is within the above range, the dispersibility of the pigment is improved, and the storage stability and dischargeability of the ink composition are improved.
The main chain skeleton of the polymer dispersant is not particularly limited, and examples thereof include a polyurethane skeleton, a polyacryl skeleton, a polyester skeleton, a polyamide skeleton, a polyimide skeleton, a polyurea skeleton, and the like, in terms of storage stability of the ink composition, A polyurethane skeleton, a polyacryl skeleton, and a polyester skeleton are preferable. The structure of the polymer dispersant is not particularly limited, and examples thereof include a random structure, a block structure, a comb structure, and a star structure. Similarly, in terms of storage stability, a block structure or a comb structure is used. preferable.

  As the dispersant having an acid value larger than the amine value, specifically, DisperBYK-101 (acid value 30 mgKOH / g, amine value: 0 mgKOH / g), DisperBYK-102 (acid value: 101 mgKOH / g, amine value: 0 mgKOH / g), DisperBYK-103 (acid value: 101 mgKOH / g, amine value: 0 mgKOH / g), DisperBYK-106 (acid value: 132 mgKOH / g, amine value: 74 mgKOH / g), DisperBYK-111 (acid value: 129 mgKOH / g) g, amine value: 0 mg KOH / g) (by BYK Chemie), EFKA4010 (acid value: 10-15 mg KOH / g, amine value: 4-84-8 mg KOH / g) (by Fuka Additive) Molecular dispersant; Solsperse 36000 (acid value 45 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 41000 (acid value: 50 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 3000 (acid value: 3000 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 21000 (Acid value: 72 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 26000 (acid value: 50 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 36600 (acid value: 23 mgKOH / g, amine value: 0 mgKOH / g) ), Solsperse 39000 (acid value: 33 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 41090 (acid value: 23 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 43000 (acid value: 8 mgKOH / g, amino Value: 0 mgKOH / g), Solsperse 44000 (acid value: 12 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 53095 (acid value: 47 mgKOH / g, amine value: 0 mgKOH / g), Solsperse 54000 (acid value: 47 mgKOH / G, amine value: 0 mgKOH / g) and the like, various Solsperse dispersants (manufactured by GENECA) can be exemplified.

In this invention, said dispersing agent may be used individually by 1 type, and can also use several types.
A small amount of other known dispersants can be used in combination. Specifically, DisperBYK-161 (amine value 11 mgKOH / g, acid value 0 mgKOH / g), DisperBYK-162 (amine value 13 mgKOH / g, acid value 0 mgKOH / g), DisperBYK-163 (amine value 10 mgKOH / g, acid value) Value 0 mgKOH / g), DisperBYK-164 (amine value 18 mgKOH / g, acid value 0 mgKOH / g), DisperBYK-166 (amine value 20 mgKOH / g, acid value 0 mgKOH / g), DisperBYK-167 (amine value 13 mgKOH / g, Acid value 0 mgKOH / g), DisperBYK-168 (amine value 10 mgKOH / g, acid value 0 mgKOH / g), DisperBYK-182 (amine value 13 mgKOH / g, acid value 0 mgKOH / g) (above BYK Chemi EFKA4046 (amine value 17 to 21 mgKOH / g, acid value 0 mgKOH / g), EFKA4060 (amine value 6 to 10 mgKOH / g, acid value 0 mgKOH / g), EFKA4080 (amine value 3.6 to 4.1 mgKOH / g) g, acid value 0 mgKOH / g), EFKA4800 (amine value 37 to 43 mgKOH / g, acid value 0 mgKOH / g), EFKA7462 (amine value 8 mgKOH / g, acid value 0 mgKOH / g) (manufactured by Efka Additives), Solsperse 13240 (basic dispersant), Solsperse 13940 (basic dispersant), Solsperse 24000 (amine value 47 mgKOH / g, acid value 24 mgKOH / g), Solsperse 28000 (basic dispersant), Solsperse 32000 (amine value 180 mgKOH / g) , Various Solsperse dispersants (manufactured by Zeneca), Disparon DA-234 (amine value 20 mgKOH / g, acid value 16 mgKOH / g), Disparon DA-325 (amine value 20 mgKOH / g, acid value 14 mgKOH) / G) (supplied by Enomoto Kasei Co., Ltd.).

  Among these polymer dispersants, the absolute value of the difference between the acid value and the amine value of the polymer dispersant is from 1 mgKOH / g to 120 mgKOH / g in terms of the balance between storage stability and curing speed. Is preferably 1 mgKOH / g or more and 60 mgKOH / g or less, more preferably 1 mgKOH / g or more and 30 mgKOH / g or less. The acid value represents an acid value per 1 g of the solid content of the polymer dispersant, and can be determined by potentiometric titration according to JIS K 0070. The amine value represents an amine value per gram of the solid content of the polymer dispersant, and is a value converted to an equivalent of potassium hydroxide after being obtained by a potentiometric titration method using a 0.1N hydrochloric acid aqueous solution. When a plurality of dispersants are used, it can be expressed as the weight average.

The content of the dispersant in the ink composition of the present invention is appropriately selected depending on the purpose of use, but is preferably 0.01 to 5% by weight with respect to the total weight of the ink composition.
Further, the preferable addition amount of the dispersant in the ink composition is such that the weight ratio (D / P) is P where the weight of the pigment in the ink composition is P and the weight of the dispersant in the ink composition is D. 0.01 ≦ D / P ≦ 1.5, more preferably 0.1 ≦ D / P ≦ 1.0, and 0.2 ≦ D / P ≦ 0.6. Is more preferable. Within the above range, pigment aggregation / sedimentation and ink viscosity increase do not occur, and an ink composition having excellent storage stability can be obtained, and an ink composition having low ink viscosity and excellent ejection stability can be obtained.

(Polymerizable compound)
As the polymerizable compound used in the ink composition of the present invention, either a cationic polymerizable compound or a radical polymerizable compound can be used.

<Cationically polymerizable compound>
The cationically polymerizable compound that can be used in the present invention is not particularly limited as long as it is a compound that initiates a polymerization reaction with an acid generated from a cationic polymerization initiator, which will be described later, and cures. Various known cationic photopolymerizable monomers Known cationic polymerizable monomers can be used. Examples of the cationic polymerizable monomer include JP-A-6-9714, JP-A-2001-31892, JP-A-2001-40068, JP-A-2001-55507, JP-A-2001-310938, JP-A-2001-310937, and 2001-2001. Examples thereof include epoxy compounds, vinyl ether compounds, oxetane compounds and the like described in each publication such as No. 220526.

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

As the alicyclic epoxide, cyclohexene oxide obtained by epoxidizing a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or peracid. Or a cyclopentene oxide containing compound is mentioned preferably.
Examples of aliphatic epoxides include dihydric polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, and typical examples thereof include diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol, or 1,6. -Diglycidyl ether of alkylene glycol such as diglycidyl ether of hexanediol, polyglycidyl ether of polyhydric alcohol such as di- or triglycidyl ether of glycerin or its alkylene oxide adduct, diglycidyl of polyethylene glycol or its alkylene oxide adduct Diglycidyl of polyalkylene glycol typified by diglycidyl ether of ether, polypropylene glycol or its alkylene oxide adduct Ether and the like. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

The monofunctional and polyfunctional epoxy compounds that can be used in the present invention are exemplified in detail.
Examples of monofunctional epoxy compounds include, for example, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene. Monooxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide, 3-vinylcyclohexene oxide, etc. Is mentioned.

  Examples of polyfunctional epoxy compounds include, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and brominated bisphenol. S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxy 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxy Hexylmethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ', 4'-epoxy- 6'-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate) ), Dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl Ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,1,3-tetradecadiene dioxide, limonene dioxide, 1,2,7,8 -Diepoxyoctane, 1,2,5,6-diepoxycyclooctane and the like.

  Among these epoxy compounds, aromatic epoxides and alicyclic epoxides are preferable from the viewpoint of excellent curing speed, and alicyclic epoxides are particularly preferable.

  Examples of the vinyl ether compound include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, and trimethylol. Di- or trivinyl ether compounds such as propane trivinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexane dimethanol monovinyl ether, n-pro Vinyl ether, isopropyl vinyl ether, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether.

Below, monofunctional vinyl ether and polyfunctional vinyl ether are illustrated in detail.
Examples of monofunctional vinyl ethers include, for example, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, 4 -Methylcyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl D Ter, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloro Examples thereof include ethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxy polyethylene glycol vinyl ether and the like.

Examples of polyfunctional vinyl ethers include ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, and bisphenol F. Divinyl ethers such as alkylene oxide divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol Hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, propylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, propylene oxide addition Examples thereof include polyfunctional vinyl ethers such as pentaerythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.
As the vinyl ether compound, a di- or trivinyl ether compound is preferable from the viewpoints of curability, adhesion to a recording medium, surface hardness of the formed image, and the like, and a divinyl ether compound is particularly preferable.

The oxetane compound that can be used in the present invention refers to a compound having at least one oxetane ring, and known oxetane as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217. A compound can be arbitrarily selected and used.
The compound having an oxetane ring that can be used in the ink composition of the present invention is preferably a compound having 1 to 4 oxetane rings in the structure. By using such a compound, it becomes easy to maintain the viscosity of the ink composition in a good handling property range, and it is possible to obtain high adhesion of the cured ink to the recording medium. .

  Examples of the compound having 1 to 2 oxetane rings in the molecule include compounds represented by the following formulas (1) to (3).

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

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

When R ^a3 is the above polyvalent group, R ^a4 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, a mercapto group, Represents a lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group.
R ^a5 represents an oxygen atom, a sulfur atom, a methylene group, NH, SO, SO ₂ , C (CF ₃ ) ₂ , or C (CH ₃ ) ₂ .
R ^a6 represents an alkyl group having 1 to 4 carbon atoms or an aryl group, and n is an integer of 0 to 2,000. R ^a7 represents an alkyl group having 1 to 4 carbon atoms, an aryl group, or a monovalent group having the following structure. In the following formula, R ^a8 is an alkyl group having 1 to 4 carbon atoms or an aryl group, and m is an integer of 0 to 100.

  As a compound represented by the formula (1), 3-ethyl-3-hydroxymethyloxetane (OXT-101: manufactured by Toagosei Co., Ltd.), 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (OXT) -212: manufactured by Toagosei Co., Ltd.) and 3-ethyl-3-phenoxymethyloxetane (OXT-211: manufactured by Toagosei Co., Ltd.). Examples of the compound represented by the formula (2) include 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene (OXT-121: manufactured by Toagosei Co., Ltd.). Examples of the compound represented by the formula (3) include bis (3-ethyl-3-oxetanylmethyl) ether (OXT-221: manufactured by Toagosei Co., Ltd.).

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

In the formula (4), R ^a1 has the same ^{meaning as} in the formula (1). Other examples of Ra ⁹ as a linking group include branched alkylene groups having 1 to 12 carbon atoms such as groups represented by the following A to C and branched poly ( An alkyleneoxy) group or a branched polysiloxy group such as a group represented by E below. j is 3 or 4.

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

  Another embodiment of the oxetane compound that can be suitably used in the present invention includes a compound represented by the following formula (5) having an oxetane ring in the side chain.

In the formula (5), R ^a8 has the same ^{meaning as} in the above formula. R ^a11 is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, or a trialkylsilyl group, and r is 1 to 4.

Such a compound having an oxetane ring is described in detail in JP-A No. 2003-341217, paragraphs 0021 to 0084, and the compounds described herein can be suitably used in the present invention.
Oxetane compounds described in JP 2004-91556 A can also be used in the present invention. This is described in detail in paragraphs 0022 to 0058.
Among the oxetane compounds used in the present invention, it is preferable to use a compound having one oxetane ring from the viewpoint of the viscosity and tackiness of the ink composition.

The cationically polymerizable compound that can be used in the present invention may be used alone or in combination of two or more. From the viewpoint of effectively suppressing shrinkage during ink curing, an oxetane compound. And at least one compound selected from epoxy compounds and a vinyl ether compound are preferably used in combination.
The content of the cationically polymerizable compound in the ink composition is preferably 10 to 95% by weight, more preferably 30 to 90% by weight, still more preferably 50 to 85% by weight, based on the total solid content of the composition. Range. It is preferable for the content of the cationically polymerizable compound in the ink composition to be within the above range because an ink composition having excellent curability can be obtained.
The content of the cationic polymerizable compound in the pigment dispersion and the cationic polymerizable compound to be added thereafter can be appropriately adjusted so that the content of the cationic polymerizable compound in the ink composition falls within the above range. preferable.

<Radically polymerizable compound>
The ink composition of the present invention contains a polymerizable compound, preferably a radically polymerizable compound.
The radical polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization, and may be any compound as long as it has at least one ethylenically unsaturated bond capable of radical polymerization in the molecule. , Oligomers, polymers and the like having a chemical form. Only one type of radically polymerizable compound may be used, or two or more types may be used in combination at any ratio in order to improve the desired properties, and the combination of two or more types may be used for reactivity, This is preferable for controlling the quality of printed matter.
The polymerizable compound is selected from the group consisting of aromatic monofunctional ethylenically unsaturated compounds, N-vinyl lactams, monofunctional ethylenically unsaturated compounds having an aliphatic cyclic structure, and polyfunctional ethylenically unsaturated compounds. More preferably, it contains at least one compound. Each will be described in detail below.

<Aromatic monofunctional ethylenically unsaturated compound and monofunctional ethylenically unsaturated compound having an aliphatic cyclic structure>
The monofunctional ethylenically unsaturated compound having an aliphatic cyclic structure and the aromatic monofunctional ethylenically unsaturated compound are preferably monofunctional ethylenically unsaturated compounds represented by the following formula (D1). The monofunctional ethylenically unsaturated compound having an aliphatic cyclic structure is a monofunctional ethylenically unsaturated compound having an alicyclic hydrocarbon group which may contain a hetero atom, and an aromatic monofunctional ethylenically unsaturated compound. The compound is a monofunctional ethylenically unsaturated compound having an aromatic group. The monofunctional ethylenically unsaturated compound is a radical polymerizable monomer and is a monomer having only one polymerizable ethylenically unsaturated bond. Preferred examples of the group having a polymerizable ethylenically unsaturated bond include acryloyloxy group, methacryloyloxy group, acrylamide group, methacrylamide group, vinyl group and vinyloxy group.
In the present invention, the radical polymerizable monomer having an aliphatic cyclic structure has an ethylenically unsaturated bond in addition to the aliphatic cyclic structure, and the ethylenic unsaturated bond in the aliphatic cyclic structure is: Not applicable to polymerizable ethylenically unsaturated bonds. The aromatic monofunctional ethylenically unsaturated compound is a compound having one ethylenically unsaturated bond in addition to the aromatic group.

In the above formula (D1), R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and X ¹ represents a single bond, an ether bond (—O—), an ester bond (—C (O) O- or -OC (O)-), amide bond (-C (O) NH- or -NHC (O)-), carbonyl bond (-C (O)-), branched An alkylene group having 20 or less carbon atoms which may be present, or a second divalent linking group obtained by combining these may be bonded, and only the first divalent linking group or the second divalent linking group may be bonded. When it has a group, those having an ether bond, an ester bond and an alkylene group having 20 or less carbon atoms are preferred.

  Y is an aromatic group or alicyclic hydrocarbon group containing a monocyclic aromatic group and a polycyclic aromatic group, and the aromatic group and alicyclic hydrocarbon group are a halogen atom, a hydroxy group, an amino group, It may have a siloxane group, a substituent having 30 or less carbon atoms, and the cyclic structure of the aromatic group or alicyclic hydrocarbon group may contain a heteroatom such as O, N, or S. .

In the above formula (D1), R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.
X ¹ preferably has an ester bond.
That is, in the present invention, the monofunctional ethylenically unsaturated compound and the aromatic monofunctional ethylenically unsaturated compound having an aliphatic cyclic structure are acrylates or methacrylates (hereinafter also referred to as “(meth) acrylates”). It is preferable.

<Aromatic monofunctional ethylenically unsaturated compound>
The aromatic monofunctional ethylenically unsaturated compound is preferably a polymerizable monomer represented by the following formula (D2).

In Formula (D2), R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, X ¹ represents a divalent linking group, R ⁵ represents a substituent, and u represents Represents an integer of 0 to 5, and u R ⁵ may be the same or different, and a plurality of R ⁵ may be bonded to each other to form a ring. May be an aromatic ring.

In formula (D2), R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and still more preferably a hydrogen atom.
X ¹ has the same meaning as X ¹ in Formula (D1). The end bonded to the vinyl group of X ¹ in Formula (D2) is preferably a carboxylic acid ester group or an amide group in which the carbonyl carbon of X ¹ and the vinyl group are bonded, and more preferably a carboxylic acid ester group. is there. In particular, it is preferable to have a structure of H ₂ C═C (R ¹ ) —C (O) O—. In that case, the other part of X ¹ bonded to the aromatic ring may be a single bond or may be arbitrarily selected from the aforementioned groups.

The vinyl moiety containing R ¹ and X ¹ (H ₂ C═C (R ¹ ) —X ¹ —) can be attached at any position of the aromatic ring. In addition, from the viewpoint of improving the affinity with (A) the pigment, the end bonded to the aromatic ring of X ¹ in Formula (D2) is preferably an oxygen atom, and is preferably an etheric oxygen atom. More preferably, X ¹ in the formula (D2) is more preferably —C (O) O (CH ₂ CH ₂ O) _p — (p represents 1 or 2).
Each of u ⁵ R ⁵ may be independently a monovalent or polyvalent substituent, and a monovalent substituent may be a hydrogen atom, a hydroxy group, a substituted or unsubstituted amino group, a thiol group, or a siloxane group. Or a hydrocarbon group or heterocyclic group having 30 or less total carbon atoms, which may further have a substituent.

In formula (D2), when a plurality of R ⁵ are bonded to each other to form a ring, it is preferable that an aromatic ring is formed.
That is, in the formula (D2), preferred as the aromatic group is a group obtained by removing one or more hydrogens from benzene which is a monocyclic aromatic group (phenyl group, phenylene group, etc.), as well as 2 to 4 rings. It is the polycyclic aromatic group which has, and is not limited. Specifically, naphthalene, anthracene, 1H-indene, 9H-fluorene, 1H-phenalene, phenanthrene, triphenylene, pyrene, naphthacene, tetraphenylene, biphenylene, as-indacene, s-indacene, acenaphthylene, fluoranthene, acephenanthrylene , Groups obtained by removing one or more hydrogen atoms from, for example, aceanthrylene, chrysene, preyandene and the like.

  These aromatic groups may be aromatic heterocyclic groups containing heteroatoms such as O, N, and S. Specifically, furan, thiophene, 1H-pyrrole, 2H-pyrrole, 1H-pyrazole, 1H-imidazole, isoxazole, isothiazole, 2H-pyran, 2H-thiopyran, pyridine, pyridazine, pyrimidine, pyrazine, 1,2 Group obtained by removing at least one hydrogen atom from a monocyclic aromatic heterocyclic compound such as 1,3-triazole or 1,2,4-triazole.

  Thianthrene, isobenzofuran, isochromene, 4H-chromene, xanthene, phenoxathiin, indolizine, isoindole, indole, indazole, purine, 4H-quinolidine, isoquinoline, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine , Carbazole, β-carboline, phenanthridine, acridine, perimidine, phenanthroline, phenazine, phenothiazine, phenoxazine, pyrrolidine, and the like, a group obtained by removing at least one hydrogen atom.

  The aromatic group may have one or more halogen atoms, hydroxy groups, amino groups, thiol groups, siloxane groups, and substituents having 30 or less carbon atoms. For example, you may form the cyclic structure containing hetero atoms, such as O, N, and S, by two or more substituents which an aromatic group has like phthalic anhydride and phthalimide anhydride.

  In the present invention, the polycyclic aromatic group is more preferably a polycyclic aromatic group having 2 to 3 rings, and particularly preferably a naphthyl group.

  Specific examples of the aromatic monofunctional ethylenically unsaturated compound include [L-1] to [L-71], but are not limited to the following.

<Monofunctional ethylenically unsaturated compound having an aliphatic cyclic structure>
The monofunctional ethylenically unsaturated compound having an aliphatic cyclic structure is more preferably a compound having a norbornene skeleton represented by the following formula (D3).

In formula (D3), R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, X ¹ represents a divalent linking group, an ether group (—O—), an ester group (—C (O) O— or —OC (O) —), an amide group (—C (O) NR′—), a carbonyl group (—C (O) —), a nitrogen atom (—NR′—), It is preferable that it is a C1-C15 alkylene group which may have a substituent, or a bivalent group which combined these 2 or more. R ′ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. R ² represents a substituent, r represents an integer of 0 to 5, q represents a cyclic hydrocarbon structure, and the cyclic hydrocarbon structure includes a carbonyl bond (—C (O) —) and / or a hydrocarbon bond in addition to the hydrocarbon bond. Alternatively, an ester bond (—C (O) O—) may be contained, and r ² R ^{2 s} may be the same or different from each other, and one carbon atom in the norbornene skeleton is substituted with an ether. A bond (—O—) and / or an ester bond (—C (O) O—) may be substituted.
In formula (D3), R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group.

The end bonded to the vinyl group of X ¹ in the formula (D3) is preferably an ester group or an amide group in which the carbonyl carbon of X ¹ and the vinyl group are bonded, and more preferably an ester bond. In particular, it is preferable to have a structure of H ₂ C═C (R ¹ ) —C (O) O—. In that case, the other part of X ¹ bonded to the norbornene skeleton may be a single bond or may be arbitrarily selected from the above groups.
The vinyl moiety (H ₂ C═C (R ¹ ) —X ¹ —) containing R ¹ and X ¹ can be bonded at any position on each alicyclic hydrocarbon structure. In addition, "on each alicyclic hydrocarbon structure" refers to the norbornene structure and the cyclic hydrocarbon structure containing q in Formula (D3).

Further, from the viewpoint of improving the affinity with (A) the pigment, the end bonded to the alicyclic hydrocarbon structure of X ¹ in formula (D3) is preferably an oxygen atom, and an etheric oxygen atom It is more preferable that X ¹ in formula (D3) is —C (O) O (CH ₂ CH ₂ O) _p — (p represents 1 or 2).

R ² in Formula (D3) independently represents a substituent, and can be bonded at any position on each alicyclic hydrocarbon structure. Also, r R ^{2 s} may be the same or different.
The R ² R ² may be each independently a monovalent or polyvalent substituent, and as a monovalent substituent, a hydrogen atom, a hydroxy group, a substituted or unsubstituted amino group, a thiol group, a siloxane group Further, a hydrocarbon group or heterocyclic group having 30 or less total carbon atoms which may have a substituent, or an oxy group (═O) as a divalent substituent is preferable.
The substitution number r of R ² represents an integer of 0 to 5.

  Q in the formula (D3) represents a cyclic hydrocarbon structure, and both ends thereof may be substituted at any position of the norbornene skeleton, and may be a monocyclic structure or a polycyclic structure; In addition to the hydrocarbon bond, the cyclic hydrocarbon structure may contain a carbonyl bond (—C (O) —) and / or an ester bond (—C (O) O—).

  The monomer represented by the formula (D3) is preferably a monomer represented by the formula (D4) or the formula (D5). The unsaturated bond in the cyclic hydrocarbon structure in formula (D5) has low radical polymerizability, and in the present invention, the compound represented by formula (D5) is a monofunctional ethylenically unsaturated compound. To do.

In Formula (D4) and Formula (D5), R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, X ¹ represents a divalent linking group, R ³ and R ⁴ Each independently represents a substituent, s and t each independently represent an integer of 0 to 5, and s R ³ and t R ⁴ are the same or different. Also good.

R ¹ and X ¹ in Formula (D4) or formula (D5) has the same meaning as R ¹ and X ¹ in Formula (D3), and preferred ranges are also the same.
The vinyl moiety containing R ¹ and X ¹ in formula (D4) or formula (D5) is bonded at any position on each alicyclic hydrocarbon structure shown below in formula (D4) or formula (D5). Can do.

R ³ and R ⁴ in Formula (D4) or Formula (D5) each independently represent a substituent, and are bonded at any position on each alicyclic hydrocarbon structure in Formula (D4) or Formula (D5). be able to. The substituent in R ³ and R ⁴ has the same meaning as the substituent in R ² of formula (D4), and the preferred range is also the same.
In formula (D4) or formula (D5), s and t each independently represents an integer of 0 to 5, and s R ³ and t R ⁴ are the same or different. May be.

As the monomer represented by the formula (D3), preferred specific examples of monofunctional acrylates are shown below.
In some of the following exemplary compounds, the hydrocarbon chain is described by a simplified structural formula in which symbols of carbon (C) and hydrogen (H) are omitted.

  As the monomer represented by the formula (D3), preferred specific examples of monofunctional methacrylate are shown below.

  As the monomer represented by the formula (D3), preferred specific examples of monofunctional acrylamide are shown below.

<N-vinyl lactams>
In the present invention, N-vinyl lactams can be used as the polymerizable compound. Preferable examples of N-vinyl lactams that can be used in the present invention include compounds represented by the following formula (D6).

  In formula (D6), m represents an integer of 1 to 5, and m is 2 to 4 from the viewpoints of flexibility after the ink composition is cured, adhesion to a recording medium, and availability of raw materials. It is preferable that m is 2 or 4, and m is 4, that is, N-vinylcaprolactam is particularly preferable. N-vinylcaprolactam is preferable because it is excellent in safety, is generally available and can be obtained at a relatively low price, and provides particularly good ink curability and adhesion of a cured film to a support.

  The N-vinyl lactams may have a substituent such as an alkyl group or an aryl group on the lactam ring, and may be linked with a saturated or unsaturated ring structure. The N-vinyl lactams may be included in the ink composition alone or in a plurality of types.

<Multifunctional monomer>
A radically polymerizable compound having two or more ethylenically unsaturated double bond groups selected from the group consisting of acryloxy group, methacryloxy group, acrylamide group, methacrylamide group, vinyloxy group, and N-vinyl group Functional monomers can also be used. By containing a polyfunctional monomer, an ink composition capable of providing an image having high cured film strength can be obtained.

  Specific examples of the polyfunctional monomer include bis (4-acryloxypolyethoxyphenyl) propane, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di ( (Meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di ( (Meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri ( Acrylate), pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methane tetra (meth) acrylate, tetramethylol methane tri (meth) acrylate, dimethylol Tricyclodecane di (meth) acrylate, modified glycerin tri (meth) acrylate, modified bisphenol A di (meth) acrylate, PO adduct di (meth) acrylate of bisphenol A, EO adduct di (meth) acrylate of bisphenol A, Examples include dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. Among these, an acyclic polyfunctional monomer having no cyclic structure is preferable.

  The total amount of the radical polymerizable compound with respect to the entire ink composition that can be used in the present invention is preferably 40 to 95% by weight, more preferably 50 to 90% by weight, and 60 to 85% by weight. More preferably. It is preferable for it to be in the above range since the curability is excellent and the viscosity is moderate.

  In the present invention, when an aromatic monofunctional ethylenically unsaturated compound is contained as the radical polymerizable compound, the content of the aromatic monofunctional ethylenically unsaturated compound is 80% by weight or less of the entire ink composition. It is preferably 5 to 70% by weight, more preferably 10 to 50% by weight. It is preferable for it to be within the above numerical value range because it can be adjusted to an appropriate viscosity and is excellent in ink jet discharge properties.

  In the present invention, when N-vinyl lactam is used, it is preferably contained in an amount of 50% by weight or less of the total ink composition, more preferably 5 to 45% by weight, and still more preferably 10 to 40% by weight. is there. Within the above range, an ink composition that exhibits good copolymerizability with other radically polymerizable compounds and is excellent in curability is preferable.

  Moreover, when using the monofunctional ethylenically unsaturated compound which has an aliphatic cyclic structure, it is preferable to contain 50 weight% or less of the whole ink composition, and it is more preferable to contain 5 to 45 weight%. More preferably, it is contained in an amount of ˜40 wt%. In the above range, an ink composition having excellent curability and scratch resistance is obtained, which is preferable.

  From the viewpoint of maintaining the adhesion of the cured film to the substrate (recording medium), the ratio of the polyfunctional monomer to the entire ink composition is preferably 70% by weight or less. More preferably, it is 0 to 60% by weight. In order to obtain a particularly flexible cured film, the content is preferably 0 to 40% by weight, and more preferably 1 to 30% by weight.

(Polymerization initiator)
The ink composition of the present invention contains a polymerization initiator.
A known polymerization initiator can be used as the polymerization initiator that can be used in the present invention. The polymerization initiator that can be used in the present invention may be used alone or in combination of two or more. Moreover, you may use together a cationic polymerization initiator and a radical polymerization initiator.
The polymerization initiator that can be used in the present invention is a compound that absorbs external energy and generates a polymerization initiating species. External energy used for initiating polymerization is roughly divided into heat and actinic radiation, and a thermal polymerization initiator and a photopolymerization initiator are used, respectively. Examples of the active radiation include γ rays, β rays, electron beams, ultraviolet rays, visible rays, and infrared rays.

<Cationic polymerization initiator>
In the ink composition of the present invention, when a cationic polymerizable compound is used, it is preferable to use a cationic polymerization initiator in combination.

First, B (C ₆ F ₅ ) ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , CF ₃ SO ₃ ⁻ salt of aromatic onium compounds such as diazonium, ammonium, iodonium, sulfonium, phosphonium, etc. be able to. Secondly, sulfonated products that generate sulfonic acid can be mentioned. Thirdly, a halide that generates hydrogen halide can also be used. Fourthly, an iron-arene complex can be mentioned.

  Further, for example, diazonium salts described in SI Schlesinger, Photogr. Sci. Eng., 18, 387 (1974), TS Bal et al, Polymer, 21, 423 (1980), etc., US Pat. No. 4,069,055 4, 069,056, Re 27,992, ammonium salts described in JP-A-3-140140, DC Necker et al, Macromolecules, 17, 2468 (1984), CS Wen et al, Tech, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055, 4,069,056, etc., JV Crivello et al, Macromolecules, 10 ( 6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent Nos. 104,143, 339,049, 410,201, JP-A-2- 150848, an iodonium salt described in JP-A-2-296514,

  JV Crivello et al, Polymer J. 17, 73 (1985), JV Crivello et al, J. Org. Chem., 43, 3055 (1978), WR Watt et al, J. Polymer Sci., Polymer Chem. Ed. , 22, 1789 (1984), JV Crivello et al, Polymer Bull., 14, 279 (1985), JV Crivello et al, Macromolecules, 14 (5), 1141 (1981), JV Crivello et al, J. Polymer Sci , Polymer Chem. Ed., 17, 2877 (1979), European Patent Nos. 370,693, 161,811, 410,201, 339,049, 233,567, 297, No. 443, No. 297,442, U.S. Pat.Nos. 3,902,114, 4,933,377, 4,760,013, 4,734,444, 2,833,827 And sulfonium salts described in German Patent Nos. 2,904,626, 3,604,580, 3,604,581, JP-A-7-28237, and 8-27102.

  Selenonium salts described in JV Crivello et al, Macromolecules, 10 (6), 1307 (1977), JV Crivello et al, J. Polymer Sci., Polymer Chem. Ed., 17, 1047 (1979), etc., CS Wen et Al, Tech, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), etc., onium salts such as arsonium salts, U.S. Pat. No. 3,905,815, Japanese Patent Publication No. 46-4605, JP JP 48-36281, JP 55-3070, JP 60-239736, JP 61-169835, JP 61-169837, JP 62-58241, JP 62 -212401, JP-A 63-70243, JP-A 63-298339 and the like, K. Meier et al, J. Rad. Curing, 13 (4), 26 (1986), TP Gill et al, Inorg. Chem., 19, 3007 (1980), D. Astruc, Acc. Chem. Res., 19 (12), 377 (1986), JP-A-2-161445, etc. Machine metal / organic halide,

  S. Hayase et al, J. Polymer Sci., 25, 753 (1987), E. Reichmanis et al, J. Polymer Sci., Polymer Chem. Ed., 23, 1 (1985), QQ Zhu et al, J Photochem., 36, 85, 39, 317 (1987), B. Amit et al, Tetrahedron Lett., (24) 2205 (1973), DHR Barton et al, J. Chem. Soc., 3571 (1965), PM Collins et al, J. Chem. Soc., Perkin I, 1695 (1975), M. Rudinstein et al, Tetrahedron Lett., (17), 1445 (1975), JW Walker et al, J. Am. Chem. Soc., 110, 7170 (1988), SC Busman et al, J. Imaging Technol., 11 (4), 191 (1985), HM Houlihan et al, Macromolecules, 21, 2001 (1988), PM Collins et al, J. Chem. Soc., Chem. Commun., 532 (1972), S. Hayase et al, Macromolecules, 18, 1799 (1985), E. Reichmanis et al, J. Electrochem. Soc., Solid State Sci. Technol ., 130 (6), FM Houlihan et al, Macromolcules, 21, 2001 (1988), European Patent Nos. 0290,750, 046,083, 156,535, 271,851, 0, 388,343, Polymerization initiators having an O-nitrobenzyl type protecting group described in U.S. Pat.Nos. 3,901,710, 4,181,531, JP-A-60-198538, JP-A-53-133022,

  M. TUNOOKA et al, Polymer Preprints Japan, 35 (8), G. Berner et al, J. Rad. Curing, 13 (4), WJ Mijs et al, Coating Technol., 55 (697), 45 (1983) Akzo H. Adachi et al, Polymer Preprints, Japan, 37 (3), European Patent Nos. 0199,672, 84515, 044,115, 618,564, 0101,122, USA Represented by imino sulfonates described in JP-A Nos. 4,371,605, 4,431,774, JP-A Nos. 64-18143, JP-A Nos. 2-245756, 3-140109, etc. Compounds that generate sulfonic acid upon photolysis, disulfone compounds described in JP-A Nos. 61-166544 and 2-71270, JP-A-3-103854, JP-A-3-103856, and JP-A-4-210960 The diazoketosulfone and diazodisulfone compounds described in the above be able to.

  Further, a group that generates an acid by these lights, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, ME Woodhouse et al, J. Am. Chem. Soc., 104, 5586 (1982), SP Pappas et al, J. Imaging Sci., 30 (5), 218 (1986), S. Kondo et al, Macromol. Chem., Rapid Commun., 9, 625 (1988), Y. Yamada et al, Macromol Chem., 152, 153, 163 (1972), JV Crivello et al, J. Polymer Sci., Polymer Chem. Ed., 17, 3845 (1979), US Pat. No. 3,849,137, German patent 3,914,407, JP 63-26653, JP 55-164824, JP 62-69263, JP 63-1446038, JP 63-163452, JP The compounds described in JP-A-62-153853 and JP-A-63-146029 can be used. For example, diazonium salt, ammonium salt, phosphonium salt, iodonium salt, sulfonium salt, selenonium salt, onium salt such as arsonium salt, organic halogen compound, organic metal / organic halide, polymerization initiator having o-nitrobenzyl type protecting group And compounds capable of generating a sulfonic acid by photolysis, such as iminosulfonate, disulfone compounds, diazoketosulfones, and diazodisulfone compounds.

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

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

  Preferable examples of (a) aromatic ketones, (b) acylphosphine compounds, and (e) thio compounds are “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY”, J. P. FOUASSIER, J. F. RABEK (1993), pp. 11-27. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in 77-117. More preferable examples include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, α-substituted benzoin compounds described in JP-B-47-22326, Benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, JP-B-60-26403, JP-A Benzoin ethers described in JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, α-aminobenzophenones described in European Patent 0284561A1, JP-A-2-21152 P-Di (dimethylaminobenzoyl) benze Thio-substituted aromatic ketones described in JP-A-61-194062, acylphosphine sulfides described in JP-B-2-9597, acylphosphines described in JP-B-2-9596, and JP-B-63-61950 Thioxanthones, and coumarins described in JP-B-59-42864.

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

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

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

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

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

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

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

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

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

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

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

The content of the polymerization initiator in the ink composition of the present invention is preferably 0.01 to 35% by weight, and preferably 0.5 to 20% by weight, based on the total content of the polymerizable compounds. More preferably, the content is 1.0 to 15% by weight. When the content is 0.01% by weight or more, the composition can be sufficiently cured, and when it is 35% by weight or less, a cured film having a uniform degree of curing can be obtained.
Moreover, when using the sensitizer mentioned later for the ink composition of this invention, the total usage-amount of a polymerization initiator is a weight ratio of a polymerization initiator: sensitizer with respect to a sensitizer, Preferably it is 200: It is 1-1: 200, More preferably, it is the range of 50: 1 to 1:50, More preferably, it is the range of 20: 1 to 1: 5.

(Azo pigment)
The azo pigment used in the present invention is typically represented by the formula (1), and the azo pigment may have a structure represented by the formula (1) or a tautomer thereof. Moreover, at least 1 sort (s) of those salts and hydrates may be sufficient.
Hereinafter, the azo pigment represented by the following formula (1) will be described.
The compound represented by the formula (1) easily forms an intermolecular interaction due to its specific structure, has low solubility in water or an organic solvent, and can be an azo pigment.
A pigment is used by being finely dispersed as solid particles such as molecular aggregates in a solvent, unlike a dye used by being dissolved in water or an organic solvent in a molecular dispersion state.

In formula (1), Q represents a non-metallic atomic group necessary for forming a 5- to 7-membered heterocycle with two carbon atoms to which it is bonded, and W represents an alkoxy group, an amino group, an alkyl group or an aryl group. X ₁ and X ₂ each independently represents a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, R ₁ represents a hydrogen atom or a substituent, and R ₂ represents a heterocyclic group. N represents an integer of 1 to 4. In the case of n = 2-4, it represents a 2-tetramer bonded via Q, W, X ₁ , X ₂ , R ₁ , or R ₂ , respectively.

When n is 1, the azo pigment represented by the formula (1) represents a mono-type azo pigment.
When n is 2, the azo pigment represented by the formula (1) is one of Q, W, X ₁ , X ₂ , R ₁ , and R _{2 when two} of the azo compounds shown in parentheses are Represents a bis-type azo pigment bonded to each other.

When n is 3, the azo pigment represented by the formula (1) has three azo compounds shown in parentheses through any one of Q, W, X ₁ , X ₂ , R ₁ , and R _2. Represents tris-type azo pigments bonded to each other. As the bonding mode of each azo compound, for example, two of Q, W, X ₁ , X ₂ , R ₁ and R ₂ in one of the azo compounds are divalent groups, Any one of Q, W, X ₁ , X ₂ , R ₁ , and R _{2 in} the two azo compounds is a divalent group, or Q, W, X ₁ , X _{2 in} one of the azo compounds , R ₁ and R ₂ are each a trivalent group, and any one of Q, W, X ₁ , X ₂ , R ₁ and R _{2 in} the other two azo compounds is divalent. It is the basis of.

When n is 4, the azo pigment represented by the formula (1) has four azo compounds shown in parentheses through any one of Q, W, X ₁ , X ₂ , R ₁ , and R _2. Represents a tetrakis-type azo pigment bonded to each other. As the bonding mode of each azo compound, for example, three of Q, W, X ₁ , X ₂ , R ₁ , and R ₂ in one of the azo compounds are divalent groups, Any one of Q, W, X ₁ , X ₂ , R ₁ , and R _{2 in} the three azo compounds is a divalent group, or Q, W, X ₁ , X _{2 in} one of the azo compounds , R ₁ , and R ₂ are divalent groups and the other is a trivalent group, and Q, W, X ₁ , X ₂ , R ₁ , in the other three azo compounds, Each of R ₂ and R _{2 is} a divalent group, or one of Q, W, X ₁ , X ₂ , R ₁ and R ₂ in one of the azo compounds is a tetravalent group, Any of Q, W, X ₁ , X ₂ , R ₁ , and R _{2 in} the other three azo compounds is a divalent group.

  In the present invention, n is preferably an integer of 1 to 3, more preferably 1 or 2, and most preferably 2 among them. By setting n to 2, solubility in water or an organic solvent is lowered (substantially hardly soluble), and this is preferable in terms of improving water resistance and chemical fastness.

In the formula (1), X ₁ and X ₂ each independently represent a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group.

Examples of the alkyl group represented by X ₁ and X ₂ include independently a linear, branched, or cyclic substituted or unsubstituted alkyl group, a cycloalkyl group, a bicycloalkyl group, and a tricyclo structure having many ring structures. Etc. are also included. An alkyl group (for example, an alkyl group of an alkoxy group, an alkylcarbonyl group, or an alkylsulfonyl group) in the substituents described below also represents such an alkyl group.
Specifically, the alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a t-butyl group, an n-octyl group, or an eicosyl group. , 2-chloroethyl group, 2-cyanoethyl group, 2-ethylhexyl group and the like. Preferred examples of the cycloalkyl group include substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, such as a cyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexyl group. The bicycloalkyl group is preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [ 1.2.2] heptan-2-yl group, bicyclo [2.2.2] octane-3-yl group and the like.

Preferable acyl groups represented by X ₁ and X ₂ are each independently a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, and a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms. A heterocyclic carbonyl group bonded to a carbonyl group with a substituted or unsubstituted carbon atom having 2 to 30 carbon atoms, such as an acetyl group, a pivaloyl group, a 2-chloroacetyl group, a stearoyl group, a benzoyl group, p- Examples include n-octyloxyphenylcarbonyl group, 2-pyridylcarbonyl group, 2-furylcarbonyl group and the like.

Preferred examples of the alkylsulfonyl group or arylsulfonyl group represented by X ₁ and X ₂ are each independently a substituted or unsubstituted alkylsulfonyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms. Examples thereof include a methylsulfonyl group, an ethylsulfonyl group, a phenylsulfonyl group, and a p-methylphenylsulfonyl group.

Among them, preferred X ₁ and X ₂ are each independently a hydrogen atom, an acyl group, or an alkylsulfonyl group, particularly preferably a hydrogen atom, and among them, both X ₁ and X ₂ are preferably hydrogen atoms. Most preferred.

  In the formula (1), W represents an alkoxy group, an amino group, an alkyl group or an aryl group.

  The alkoxy group represented by W is preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, such as a methoxy group, an ethoxy group, an isopropoxy group, a t-butoxy group, an n-octyloxy group, 2-methoxyethoxy group etc. are mentioned.

  The amino group represented by W includes an alkylamino group, an arylamino group, and a heterocyclic amino group, preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, and 6 to carbon atoms. 30 substituted or unsubstituted anilino groups, for example, methylamino group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group and the like can be mentioned.

The alkyl group represented by W has the same meaning as the alkyl group represented by X ₁ and X ₂ , and the preferred range is also the same.

  The aryl group represented by W is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as a phenyl group, a p-tolyl group, a naphthyl group, an m-chlorophenyl group, o-hexadecanoyl. An aminophenyl group etc. are mentioned.

Among them, W is preferably an alkoxy group, an amino group or an alkyl group, more preferably an alkoxy group or an amino group, and still more preferably an alkoxy group having 5 or less total carbon atoms, an amino group (—NH ₂ group). And an alkylamino group having a total carbon number of 5 or less, particularly preferably an alkoxy group having a total carbon number of 3 or less or an alkylamino group having a total carbon number of 3 or less, and among them, a methoxy group is most preferable.
When W is an alkoxy group having 5 or less carbon atoms, an amino group, or an alkylamino group having 5 or less carbon atoms, the dye molecule can easily form a strong interaction between the molecules and between the molecules, and is more stable. It is preferable in terms of good hue and high fastness (light resistance, gas, heat, water, chemicals) because it is easy to construct a pigment having a molecular arrangement.

In Formula (1), R ₁ represents a hydrogen atom or a substituent, and when R ₁ represents a substituent, the substituent is a linear or branched alkyl group having 1 to 12 carbon atoms, or 7 to 18 carbon atoms. A linear or branched aralkyl group, a linear or branched alkenyl group having 2 to 12 carbon atoms, a linear or branched alkynyl group having 2 to 12 carbon atoms, a linear or branched cycloalkyl group having 3 to 12 carbon atoms A straight or branched cycloalkenyl group having 3 to 12 carbon atoms (for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, 2-ethylhexyl, 2-methylsulfonylethyl, 3-phenoxypropyl, trifluoromethyl, cyclopentyl), halogen atom (for example, chlorine atom, bromine atom), aryl group (for example, phenyl, 4-t-butylphenyl) , 2,4-di-t-amylphenyl), heterocyclic groups (for example, imidazolyl, pyrazolyl, triazolyl, 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl), cyano group, hydroxy group, nitro Group, carboxy group, amino group, alkyloxy group (for example, methoxy, ethoxy, 2-methoxyethoxy, 2-methylsulfonylethoxy), aryloxy group (for example, phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 3-t-butyloxycarbonylphenoxy, 3-methoxycarbonylphenyloxy, acylamino group (eg, acetamide, benzamide, 4- (3-t-butyl-4-hydroxyphenoxy) butanamide), alkylamino group (Eg methylamino Butylamino, diethylamino, methylbutylamino), arylamino groups (eg, phenylamino, 2-chloroanilino), ureido groups (eg, phenylureido, methylureido, N, N-dibutylureido), sulfamoylamino groups (eg, N, N-dipropylsulfamoylamino), alkylthio group (for example, methylthio, octylthio, 2-phenoxyethylthio), arylthio group (for example, phenylthio, 2-butoxy-5-t-octylphenylthio, 2-carboxy) Phenylthio), alkyloxycarbonylamino groups (for example, methoxycarbonylamino), alkylsulfonylamino groups and arylsulfonylamino groups (for example, methylsulfonylamino, phenylsulfonylamino, p-toluenesulfonyl) Nylamino), carbamoyl group (for example, N-ethylcarbamoyl, N, N-dibutylcarbamoyl), sulfamoyl group (for example, N-ethylsulfamoyl, N, N-dipropylsulfamoyl, N-phenylsulfamoyl), A sulfonyl group (eg, methylsulfonyl, octylsulfonyl, phenylsulfonyl, p-toluenesulfonyl), an alkyloxycarbonyl group (eg, methoxycarbonyl, butyloxycarbonyl), a heterocyclic oxy group (eg, 1-phenyltetrazole-5-oxy) 2-tetrahydropyranyloxy), azo groups (for example, phenylazo, 4-methoxyphenylazo, 4-pivaloylaminophenylazo, 2-hydroxy-4-propanoylphenylazo), acyloxy groups (for example, acetoxy) B), carbamoyloxy group (for example, N-methylcarbamoyloxy, N-phenylcarbamoyloxy), silyloxy group (for example, trimethylsilyloxy, dibutylmethylsilyloxy), aryloxycarbonylamino group (for example, phenoxycarbonylamino), imide Group (for example, N-succinimide, N-phthalimide), heterocyclic thio group (for example, 2-benzothiazolylthio, 2,4-di-phenoxy-1,3,5-triazole-6-thio, 2-pyridylthio) ), Sulfinyl groups (eg 3-phenoxypropylsulfinyl), phosphonyl groups (eg phenoxyphosphonyl, octyloxyphosphonyl, phenylphosphonyl), aryloxycarbonyl groups (eg phenoxycarbonyl), acyl groups (eg , Acetyl, 3-phenylpropanoyl, benzoyl), ionic hydrophilic groups (e.g., carboxyl group, a sulfo group, a phosphono group and a quaternary ammonium group).

In the formula (1), preferred R ₁ is a substituted or unsubstituted acylamino group having 1 to 8 carbon atoms in total, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms in total, a substituted or unsubstituted total carbon number of 6 An aryl group having ˜18 or a substituted or unsubstituted heterocyclic group having 4 to 12 carbon atoms, more preferably a linear or branched alkyl group having 1 to 8 carbon atoms, and a methyl group Alternatively, a t-butyl group is preferable, and a t-butyl group is most preferable among them.

In the formula (1), R ₂ represents a heterocyclic group, which may be further condensed. R ₂ is preferably a 5- to 8-membered heterocyclic group, more preferably a 5- or 6-membered substituted or unsubstituted heterocyclic group, and particularly preferably a 6-membered nitrogen-containing nitrogen group having 3 to 10 carbon atoms. It is a heterocyclic group.

Examples of the heterocyclic group represented by R ₂ include, but are not limited to, the substitution position. , Thienyl, benzothienyl, pyrazolyl, imidazolyl, benzimidazolyl, triazolyl, oxazolyl, benzoxazolyl, thiazolyl, benzothiazolyl, isothiazolyl, benzisothiazolyl, thiadiazolyl, isoxazolyl, benzisoxazolyl, pyrrolidinyl, piperidinyl, piperazinyl , Thiazolinyl, sulfolanyl and the like.

Preferred examples of the heterocyclic group represented by R ₂ include pyridine ring, pyrimidine ring, S-triazine ring, pyridazine ring, pyrazine ring, 1,2,4-thiadiazole ring, 1,3,4-thiadiazole ring, A group derived from an imidazole ring, more preferably a group derived from a pyridine ring, a pyrimidine ring, an S-triazine ring, a pyridazine ring, or a pyrazine ring, and particularly preferably a group derived from a pyrimidine ring or an S-triazine ring. Among them, a group derived from a pyrimidine ring is most preferable.
Here, the group derived from a heterocycle means a group formed by removing one hydrogen atom from a heterocyclic compound, and the position at which the hydrogen atom is removed is not particularly limited.

In the formula (1), Q represents a nonmetallic atomic group necessary for forming a 5- to 7-membered heterocycle with two carbon atoms to which it is bonded. The heterocycle may be condensed with an aliphatic ring, an aromatic ring, or another heterocycle.
Examples of the 5- to 7-membered heterocycle formed by Q together with the carbon atom include a thiophene ring, a furan ring, a pyrrole ring, an indoline ring, an imidazole ring, a pyrazole ring, a thiazole ring, an isothiazole ring, an oxazole ring, and an isoxazole ring. , Triazine ring, pyridine ring, pyrazine ring, pyridazine ring, oxaazepine ring and the like. Each heterocycle may further have a substituent. The said substituent is synonymous with the substituent in R < ₁ > in Formula (1).

The 5- to 7-membered heterocycle formed by Q together with the carbon atom is preferably a 5-membered nitrogen-containing heterocycle, and particularly preferably any of the heterocycles represented by the following formulas (a) to (i) Most preferably.
In the following formulas (a) to (i), “*” represents the bonding position with the azo group in formula (1).

In the formulas (a) to (i), Ra represents a hydrogen atom or a substituent, and Rb and Rc each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group. Or represents a heterocyclic group.
W is synonymous with W in formula (1), and preferred ones are also the same.

  Ra is preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, or a substituted or unsubstituted total carbon number of 4 to 12 A heterocyclic group, more preferably a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms and / or a branched alkyl group, and particularly preferably a hydrogen atom or a linear alkyl group having 1 to 4 carbon atoms. And is preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

  Rb and Rc are preferably a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aralkyl group. , A substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, more preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group Particularly preferred is an alkyl group having a total carbon number of 3 or less, and a methyl group is most preferred among them.

In the present invention, when Q, W, X ₁ , X ₂ , R ₁ and R ₂ further have a substituent, the substituent may be referred to as the following substituent (hereinafter referred to as “substituent J”). ).

  For example, halogen atom, alkyl group, aralkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group, cyano group, hydroxy group, nitro group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group , Carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group , Mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl , An alkoxycarbonyl group, a carbamoyl group, an aryl or heterocyclic azo group, an imido group, a phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, a silyl group.

  Regarding the preferred combination of substituents of the pigment represented by the formula (1) of the present invention, a compound in which at least one of various substituents is the above preferred group is preferable, and more various substituents are the above preferred groups. Are more preferred, and compounds in which all substituents are the preferred groups are most preferred.

  Particularly preferred combinations of substituents for the azo pigment represented by the formula (1) of the present invention include the following (A) to (F).

(A) X ₁ and X ₂ are each independently a hydrogen atom, an alkyl group (for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, cyclopropyl group), acyl group (for example, formyl Group, acetyl group, pivaloyl group, benzoyl group), alkylsulfonyl group (for example, methylsulfonyl group or ethylsulfonyl group), and arylsulfonyl group (for example, phenylsulfonyl group) are preferable, among which hydrogen atom, acetyl group, methyl A sulfonyl group is preferred, and a hydrogen atom is particularly preferred. Among them, it is most preferred that both X ₁ and X ₂ are hydrogen atoms.

(B) W is an alkoxy group (eg, methoxy group, ethoxy group, isopropoxy group, t-butoxy group), amino group (eg, —NH ₂ group, methylamino group, dimethylamino group, anilino group), alkyl Group (for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, cyclopropyl group) or aryl group (for example, phenyl group, p-tolyl group, naphthyl group) is preferable. Group, amino group or alkyl group is preferred, and further alkoxy group and amino group are preferred, more preferably alkoxy group having 5 or less carbon atoms, amino group (-NH ₂ group), alkylamino group having 5 or less carbon atoms in total. , and particularly preferably having 3 or less carbon atoms of an alkoxy group, an amino group (-NH ₂ group), a total carbon number of 3 or less of an alkylamino group, its Inter alia a methoxy group (-OCH ₃ group) being most preferred.

(C) R ₁ is a hydrogen atom or a substituent (for example, a substituted or unsubstituted acylamino group having 1 to 8 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted group) Of the aryl group having 6 to 18 carbon atoms in total or a substituted or unsubstituted heterocyclic group having 4 to 12 carbon atoms in total, more preferably a linear or branched alkyl group having 1 to 8 carbon atoms in total. Further, a methyl group or a t-butyl group is preferable, and a t-butyl group is particularly preferable among them.

(D) R ₂ represents a heterocyclic group, which may be further condensed. R ₂ is preferably a 5- to 8-membered heterocyclic group, more preferably a 5- or 6-membered substituted or unsubstituted heterocyclic group, and particularly preferably a 6-membered nitrogen-containing heterocycle having 3 to 10 carbon atoms. It is a cyclic group. Examples of more preferred heterocycles are pyridine ring, pyrimidine ring, S-triazine ring, pyridazine ring, pyrazine ring, 1,2,4 thiadiazole ring, 1,3,4 thiadiazole ring, imidazole ring, more preferably A pyridine ring, a pyrimidine ring, an S-triazine ring, a pyridazine ring, and a pyrazine ring are preferable, and a pyrimidine ring and an S-triazine ring are particularly preferable, and among them, a pyrimidine ring is particularly preferable.

(E) Q represents a non-metallic atomic group necessary to form a 5- to 7-membered heterocycle with two carbon atoms to which it is bonded, and the heterocycle is an aliphatic ring, aromatic ring, or other The heterocycle may be condensed. Particularly preferred examples of the 5- to 7-membered heterocycle formed by Q together with carbon atoms include thiophene ring, furan ring, pyrrole ring, indole ring, imidazole ring, pyrazole ring, thiazole ring, isothiazole ring, oxazole ring, Examples thereof include an oxazole ring, a triazine ring, a pyridine ring, a pyrazine ring, a pyridazine ring, and an oxaazepine ring. Each heterocyclic ring may further have a substituent. In particular, the 5- to 7-membered heterocycle formed by Q together with the carbon atom is preferably a 5-membered nitrogen-containing heterocycle, and particularly preferably the heterocycle represented by the following formulas (a) to (i): preferable.

  In the formulas (a) to (i), Ra represents a hydrogen atom or a substituent, and Rb and Rc each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, a group, Represents an aryl group or a heterocyclic group. W is synonymous with W in formula (1), and preferred ones are also the same.

  Ra is preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, or a substituted or unsubstituted total carbon number of 4 to 12 A heterocyclic group, more preferably a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms and / or a branched alkyl group, and particularly preferably a hydrogen atom or a linear alkyl group having 1 to 4 carbon atoms. And is preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

  Rb and Rc are preferably a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aralkyl group. , A substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, more preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group Particularly preferred is an alkyl group having a total carbon number of 3 or less, and a methyl group is most preferred among them.

  Furthermore, the above formulas (a), (b) and (c) are particularly preferable as the 5-membered heterocycle formed by Q together with the carbon atom, and among these, the formula (a) is most preferable.

(F) n is preferably an integer of 1 to 3, more preferably 1 or 2, and most preferably n = 2.

The azo pigment represented by the above formula (1) is preferably an azo pigment represented by the following formula (2).
Hereinafter, the azo pigment represented by the formula (2) will be described in detail.

Q in formula _{(2), W, X 1} , R 1, R 2 and n are, Q in the formula (1), W, is synonymous with X _1, R _1, R ₂ and n. In the case of n = 2 to 4, 2 to 4 azo compounds shown in parentheses each represent a 2- to 4-mer bonded to each other through Q, W, X ₁ , R ₁ , or R ₂ .

The Q, W, X ₁ , R ₁ , R ₂ and n will be described in more detail below.
Examples of _{Q, W, X 1, R} 1, R 2, and n is the Q in the above formula _{(1), W, X 1} , R 1, R 2, and each in the example of n synonymous, preferably Each example is the same.

  Regarding the preferred combination of substituents of the pigment represented by the formula (2) of the present invention, a compound in which at least one of various substituents is the above preferred group is preferable, and more various substituents are the above preferred groups. Are more preferred, and compounds in which all substituents are the preferred groups are most preferred.

  Particularly preferred combinations of substituents as the azo pigment represented by the formula (2) of the present invention include combinations similar to (a) to (f) in the azo pigment represented by the above formula (1).

(A) X ₁ is a hydrogen atom, an alkyl group (for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, cyclopropyl group), acyl group (for example, formyl group, acetyl group, pivaloyl) Group, benzoyl group), alkylsulfonyl group (for example, methylsulfonyl group or ethylsulfonyl group), and arylsulfonyl group (for example, phenylsulfonyl group), among which hydrogen atom, acetyl group, and methylsulfonyl group are preferable, and hydrogen Most preferably it is an atom.

(B) to (f) are the same as (b) to (f) in the azo pigment represented by the above formula (1).

  The azo pigment in the present invention includes a tautomer of the azo pigment represented by the formula (1) or (2). Formulas (1) and (2) are shown in the form of one extreme structural formula among several tautomers that can be taken in terms of chemical structure, but tautomers other than those explicitly described Or a mixture containing a plurality of tautomers.

  For example, for the pigment represented by the formula (2), an azo-hydrazone tautomer represented by the following formula (2 ′) is considered, and the tautomerism of the azo pigment represented by the formula (2) is considered. The compounds represented by the following formula (2 ′) which are isomers are also included in the scope of the present invention.

Wherein _{(2 '), R 1,} R 2, Q, W, X 1, and _{n, R 1, R 2, Q} , W, X 1 in formula (2), and has the same meaning as n, The preferable range is also the same.

  The azo pigment represented by the above formula (1) in the present invention is more preferably an azo pigment represented by the following formula (3).

Y in Formula (3) represents a hydrogen atom or a substituent, G represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and W, X ₁ , X ₂ , R ₁ , R ₂ and n have the same meanings as W, X ₁ , X ₂ , R ₁ , R ₂ and n in the formula (1), respectively. When n = 2 to 4, a dimer in which 2 to 4 of the azo compounds shown in parentheses are bonded to each other through G, Y, W, X ₁ , X ₂ , R ₁ , or R ₂ to Each represents a tetramer.

Hereinafter, W, X ₁ , X ₂ , R ₁ , R ₂ , G, Y, and n will be described in more detail.
W, as examples of X _1, X _2, R _1, R ₂ and n are W in the above formula _{(1), X 1, X} 2, respectively, and examples of R _1, R ₂ and n synonymous, The preferred examples are also the same.

G represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and particularly preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group. Group, t-butyl group, cyclopropyl group, benzyl group, 2-phenethyl group, vinyl group, allyl group, ethynyl group, propargyl group, phenyl group, p-tolyl group, naphthyl group, pyridyl group, pyrimidinyl group, pyrazinyl group Further preferred are a hydrogen atom, a methyl group, a phenyl group, a pyridyl group, a pyrimidinyl group and a pyrazinyl group, and among them, a methyl group, a 2-pyridyl group, a 2,6-pyrimidinyl group and a 2,5-pyrazinyl group are preferred.
When G represents an alkyl group, it is preferably an alkyl group having a total carbon number of 5 or less, more preferably an alkyl group having a total carbon number of 3 or less, and most preferably a methyl group.

Examples of the case where Y represents a substituent include a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a cyano group, a hydroxyl group, a nitro group, an alkoxy group, an aryloxy group, Silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfa Moylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl , An aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an aryl or heterocyclic azo group, an imido group, a phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, a silyl group.
Y is particularly preferably a hydrogen atom, an alkyl group (for example, a methyl group), an aryl group (for example, a phenyl group), a heterocyclic group (for example, a 2-pyridyl group), an alkylthio group (for example, a methylthio group), and a hydrogen atom. An atom, a methyl group, a phenyl group, and a methylthio group, and among them, a hydrogen atom is most preferable.

  Regarding the preferred combination of substituents of the pigment represented by the formula (3) of the present invention, a compound in which at least one of various substituents is the above preferred group is preferable, and more various substituents are the above preferred groups. Are more preferred, and compounds in which all substituents are the preferred groups are most preferred.

  Particularly preferred combinations of substituents as the azo pigment represented by the formula (3) of the present invention include the following (A) to (G).

(A) X ₁ and X ₂ are each independently a hydrogen atom, an alkyl group (for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, cyclopropyl group), acyl group (for example, formyl Group, acetyl group, pivaloyl group, benzoyl group), alkylsulfonyl group (for example, methylsulfonyl group or ethylsulfonyl group), and arylsulfonyl group (for example, phenylsulfonyl group) are preferable, among which hydrogen atom, acetyl group, methyl A sulfonyl group is preferred, and a hydrogen atom is particularly preferred. Among them, at least one of X ₁ and X ₂ is more preferably a hydrogen atom, and most preferably both are hydrogen atoms.
When at least one of X ₁ and X ₂ is a hydrogen atom, not only the intermolecular interaction of the dye molecule but also the intramolecular interaction is easily formed, thereby forming a pigment with a more stable molecular arrangement. It is easy to use and preferable in terms of good hue and high fastness (light resistance, gas, heat, water, chemicals).

(B) to (D) are the same as (B) to (D) in the azo pigment represented by the above formula (1).

(E) G represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and particularly preferably a hydrogen atom, a methyl group, an ethyl group, or n-propyl. Group, isopropyl group, t-butyl group, cyclopropyl group, benzyl group, 2-phenethyl group, vinyl group, allyl group, ethynyl group, propargyl group, phenyl group, p-tolyl group, naphthyl group, pyridyl group, pyrimidinyl group A pyrazinyl group is preferable, and a hydrogen atom, a phenyl group, a pyridyl group, a pyrimidinyl group, and a pyrazinyl group are preferable, and among them, a 2-pyridyl group, a 2,6-pyrimidinyl group, and a 2,5-pyrazinyl group are preferable.
When G represents an alkyl group, it is preferably an alkyl group having 5 or less carbon atoms, preferably an alkyl group having 3 or less carbon atoms, and most preferably a methyl group.

(F) Y is a hydrogen atom, an alkyl group (for example, a methyl group), an aryl group (for example, a phenyl group), a heterocyclic group (for example, a 2-pyridyl group), an alkylthio group (for example, a methylthio group), and a hydrogen atom An atom, a methyl group, a phenyl group, and a methylthio group, and among them, a hydrogen atom is most preferable.

(G) n is preferably an integer of 1 to 3, more preferably 1 or 2, and most preferably n = 2.

  In the formulas (1), (2) and (3), preferable n is 2 or 3, and particularly preferable is when n is 2. When n is 2, the coloring power is high, the light resistance is excellent, and the chemical fastness is improved.

In the formulas (1), (2) and (3), the azo pigment in the case of n = 2 has two of the azo compounds shown in parentheses: Q, W, X ₁ , X ₂ , R ₁ , or R ₂ represents a dimer linked to each other via ₂ .

  When the azo pigment in the present invention represents a dimer, examples thereof include a connection mode represented by the following formulas (4), (5), (6), (7), (8) and (9).

In formula (4), G ₁ and G ₂ are each independently synonymous with G in formula (3). R ₁₁ and R ₁₂ are independently the same as R ₁ in the formula (3). W ₁ and W ₂ are each independently synonymous with W in the formula (3). Y ₁ and Y ₂ are independently the same as Y in the formula (3).

Z represents a divalent group derived from a 5- to 8-membered nitrogen-containing heterocycle.
The 5- to 8-membered nitrogen-containing heterocycle is synonymous with the nitrogen-containing heterocycle among the heterocycles listed as examples of the 5- to 8-membered heterocycle in R ₂ in Formula (3), and a preferred range is also included. It is the same.
The divalent group derived from a nitrogen-containing heterocyclic ring means a divalent group formed by removing two hydrogen atoms from a nitrogen-containing heterocyclic compound, and the position at which the hydrogen atom is removed is not particularly limited. .

In formula (5), G ₁ and G ₂ are each independently synonymous with G in formula (3). R ₁₁ and R ₁₂ are independently the same as R ₁ in the formula (3). W ₁ and W ₂ are each independently synonymous with W in the formula (3).
Z ₁ and Z ₂ are each independently synonymous with R ₂ in the formula (3).

Y ₅ represents a divalent group, and has the same meaning as a substituent that can be a divalent substituent among the substituents exemplified as Y in the formula (3). Specifically, Y ₅ is preferably a divalent group derived from an alkyl group, an aryl group, a heterocyclic group, or an alkylthio group.

In formula (6), G ₁ and G ₂ are each independently synonymous with G in formula (3). R ₁₁ and R ₁₂ are independently the same as R ₁ in the formula (3). W ₁ and W ₂ are each independently synonymous with W in the formula (3). Y ₁ and Y ₂ are independently the same as Y in the formula (3). Z ₁ and Z ₂ are each independently synonymous with R ₂ in the formula (3).

X ₆ represents a divalent group, and has the same meaning as a substituent that can be a divalent substituent among the substituents exemplified as X ₁ or X ₂ in the formula (3). Specifically, X ₆ is preferably a divalent group derived from an alkyl group, an acyl group, an alkylsulfonyl group, or an arylsulfonyl group.

In formula (7), G ₁ and G ₂ are each independently synonymous with G in formula (3). R ₁₁ and R ₁₂ are independently the same as R ₁ in the formula (3). Y ₁ and Y ₂ are independently the same as Y in the formula (3). Z ₁ and Z ₂ are each independently synonymous with R ₂ in the formula (3).

W ₇ represents a divalent group, and has the same meaning as a substituent that can be a divalent substituent among the substituents exemplified as W in the formula (3). Specifically, W ₇ is preferably a divalent group derived from an alkoxy group, an alkyl group, or an aryl group.

In formula (8), G ₁ and G ₂ are each independently synonymous with G in formula (3). W ₁ and W ₂ are each independently synonymous with W in the formula (3). Y ₁ and Y ₂ are independently the same as Y in the formula (3). Z ₁ and Z ₂ are each independently synonymous with R ₁ in the formula (3).

R ₈ represents a divalent group and is synonymous with a substituent that can be a divalent substituent among the substituents exemplified as R ₁ in the formula (3). Specifically, R ₈ is preferably a divalent group derived from an acylamino group, an alkyl group, an aryl group, or a heterocyclic group.

In formula (9), R ₁₁ and R ₁₂ are each independently synonymous with R ₁ in formula (3). W ₁ and W ₂ are each independently synonymous with W in the formula (3). Y ₁ and Y ₂ are independently the same as Y in the formula (3). Z ₁ and Z ₂ are each independently synonymous with R ₁ in the formula (3).

G ₉ represents a divalent group and is synonymous with a substituent that can be a divalent substituent among the substituents exemplified as G in the formula (3). Specifically, G ₉ is preferably a divalent group derived from an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group.

  In the present invention, the azo pigment represented by the formula (3) is particularly preferably an azo pigment represented by the above formulas (4), (5), (7), (8) and (9). Furthermore, the azo pigments represented by the above formulas (4), (5), (7) and (9) are more preferable, and among them, the azo pigments represented by the above formula (4) are particularly preferable. Particularly preferred.

  Hereinafter, the azo pigment represented by the formula (4) and tautomers thereof will be described in detail.

In formula (4), Z represents a divalent group derived from a 5- to 8-membered nitrogen-containing heterocycle, and Y ₁ , Y ₂ , R ₁₁ and R ₁₂ each independently represents a hydrogen atom or a substituent. , G ₁ and G ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and W ₁ and W ₂ each independently represent an alkoxy group. Represents an amino group, an alkyl group or an aryl group.

In the formula (4), Z represents a divalent group derived from a divalent 5- to 8-membered nitrogen-containing heterocycle. Examples of preferred nitrogen-containing heterocycles without limiting the substitution position include pyrrole ring, pyrazole ring, triazole ring, imidazole ring, thiazole ring, isothiazole ring, oxazole ring, isoxazole ring, thiadiazole ring, thiophene ring, furan A ring, a pyridine ring, a pyrimidine ring, a triazine ring, and a pyridane ring. More preferably, it is a 6-membered nitrogen-containing heterocycle, and examples thereof include a pyridine ring, a pyrimidine ring, and an S-triazine ring. Z is particularly preferably a divalent group derived from a pyrimidine ring.
When Z is a 6-membered nitrogen-containing heterocycle, the intramolecular and intermolecular action of the dye molecule is preferable in terms of easy improvement from the viewpoint of hydrogen bondability and molecular planarity.

In Formula (4), Y ₁ and Y ₂ have the same meaning as Y in Formula (3), and preferred examples are also the same. G ₁ and G ₂ are synonymous with G in the formula (3), and preferred examples are also the same. R ₁₁ and R ₁₂ have the same meaning as R ₁ in formula (3), and preferred examples are also the same. W ₁ and W ₂ are synonymous with W in the formula (1), and preferred examples are also the same.

The azo pigment in the present invention includes a tautomer of the azo pigment represented by the formula (4) within the range. Formula (4) is shown in the form of an ultimate structural formula among several tautomers that can be taken in terms of chemical structure, but may be a tautomer other than the described structure, You may use as a mixture containing the tautomer.
For example, the azo pigment represented by the formula (4) may be an azo-hydrazone tautomer represented by the following formula (4 ′).
The present invention includes in its scope a compound represented by the following formula (4 ′), which is a tautomer of the azo pigment represented by the formula (4).

In the formula (4 ′), R ₁₁ , R ₁₂ , W ₁ , W ₂ , Y ₁ , Y ₂ , G ₁ , G ₂ and Z are R ₁₁ , R ₁₂ , W ₁ , W in the formula (4). ₂ , Y ₁ , Y ₂ , G ₁ , G ₂ and Z have the same meanings.

  In addition, as for the preferable combination of substituents of the compound represented by the formula (4), a compound in which at least one of various substituents is the above preferable group is preferable, and more various substituents are the above preferable groups. Are more preferred, and compounds in which all substituents are the preferred groups are most preferred.

  A particularly preferred combination as the azo pigment represented by the formula (4) of the present invention includes the following (A) to (E).

(A) W ₁ and W ₂ are each independently an alkoxy group (eg, methoxy group, ethoxy group, isopropoxy group, t-butoxy group), amino group (eg, —NH ₂ group, methylamino group, dimethylamino). Group, anilino group), alkyl group (for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, cyclopropyl group) or aryl group (for example, phenyl group, p-tolyl group, naphthyl group) Among them, an alkoxy group, an amino group or an alkyl group is preferable, an alkoxy group or an amino group is more preferable, and an alkoxy group having 5 or less total carbon atoms, an amino group (—NH ₂ group), or a total carbon is more preferable. the number 5 is an alkyl group, particularly preferably a total carbon number of 3 or less alkoxy group, an amino group (-NH ₂ group), a total carbon number of 3 or less a A Kiruamino group, especially a methoxy group (-OCH ₃ group) is the most preferred among them.

(B) R ₁₁ and R ₁₂ are each independently a hydrogen atom or a substituent (for example, a substituted or unsubstituted acylamino group having 1 to 8 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms). Group, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms in total, or a substituted or unsubstituted heterocyclic group having 4 to 12 carbon atoms in total, more preferably a straight chain having 1 to 8 carbon atoms in total. It is an alkyl group or a branched alkyl group, more preferably a methyl group, an isopropyl group or a tert-butyl group, and among them, a tert-butyl group is most preferable.

(C) Z represents a divalent group derived from a 5- to 8-membered nitrogen-containing heterocyclic group, and they may be further condensed. The nitrogen-containing heterocycle in Z is a 5- or 6-membered substituted or unsubstituted nitrogen-containing heterocycle, such as a pyrrole ring, pyrazole ring, triazole ring, imidazole ring, thiazole ring, isothiazole ring, oxazole ring, isoxazole A ring, a thiadiazole ring, a thiophene ring, a furan ring, a pyridine ring, a pyrimidine ring, a triazine ring, and a pyridazine ring are preferable, and a 6-membered nitrogen-containing heterocyclic group having 3 to 10 carbon atoms is particularly preferable. Further preferred examples of the heterocyclic ring are a pyridine ring, a pyrimidine ring, an S-triazine ring, a pyridazine ring and a pyrazine ring, and more preferably a pyridine ring, a pyrimidine ring, an S-triazine ring, a pyridazine ring and a pyrazine ring. More preferred are a pyrimidine ring and an S-triazine ring, and among them, a pyrimidine ring is most preferred.

(D) G ₁ and G ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and particularly preferably a hydrogen atom or a methyl group. , Ethyl group, n-propyl group, isopropyl group, t-butyl group, cyclopropyl group, benzyl group, 2-phenethyl group, vinyl group, allyl group, ethynyl group, propargyl group, phenyl group, p-tolyl group, naphthyl Group, pyridyl group, pyrimidinyl group and pyrazinyl group are preferable, and further, hydrogen atom, methyl group, phenyl group, pyridyl group, pyrimidinyl group and pyrazinyl group are preferable, among which methyl group, 2-pyridyl group and 2,6-pyrimidinyl group are preferable. 2,5-pyrazinyl group is preferred.
Examples of the alkyl group represented by G _1, G _2, more preferably total alkyl group having 5 or less carbon atoms, more preferably alkyl group having a total carbon number of 3 or less, and most preferably a methyl group.

(E) Y ₁ and Y ₂ are each independently a hydrogen atom, an alkyl group (for example, a methyl group), an aryl group (for example, a phenyl group), a heterocyclic group (for example, a 2-pyridyl group), an alkylthio group (for example, a methylthio group) A hydrogen atom, a methyl group, a phenyl group, and a methylthio group, and among them, a hydrogen atom is most preferable.

  In the azo pigment of the present invention, preferred n in the formulas (1), (2) and (3) is 2 or 3, and particularly preferred is when n is 2. When n is 2, the coloring power is high, the light resistance is excellent, and the chemical fastness is improved.

  Of the azo pigments represented by the above formulas (1), (2), (3) and (4) in the present invention, preferably an azo pigment represented by any one of the following formulas (10) to (13): is there.

R _1, R _2, W and Q in the above formula (10) are respectively the same as R _1, R _2, W and Q in formula (2).
G in the above formula (11), R _1, R _2, W and Y are G in formula (3), respectively, and R _1, R _2, W and Y synonymous.

G _1, G _2, R ₁₁ in the formula _{(12), R 12, W} 1, W 2, Y 1 and Y _{2, G 1, G 2, R} 11 in the formula (4), R ₁₂ , W ₁ , W ₂ , Y ₁ and Y ₂ are synonymous with each other.
X ₁₁ and X ₁₂ each independently represent a hetero atom in a divalent group (Het.) Derived from a nitrogen-containing heterocycle represented by Z in the formula (4).

In said formula (13), G < ₁ >, G < ₂ > and G < ₃ > are synonymous with G in said formula (3) each independently. W ₁ , W ₂ and W ₃ are each independently synonymous with W in the above formula (3). The Y _1, Y ₂ and Y ₃ are as defined and Y each independently the above formula (3). R ₁₁ , R ₁₂ and R ₁₃ are each independently synonymous with R ₁ in the above formula (3).
Further, X ₁₁ , X ₁₂ and X ₁₃ are each independently in a trivalent heterocyclic group (Het.) Constituted by three R _{2 s} each of the azo compounds shown in parentheses in the above formula (3). Represents a hetero atom.

In the present invention, in the azo pigments represented by the above formulas (1), (2), (3) and (4), many tautomers can be considered.
In the present invention, the azo pigment represented by the formula (1) preferably has a substituent that forms an intramolecular hydrogen bond or an intramolecular cross-hydrogen bond. The azo pigment represented by the formula (1) in the present invention preferably has at least one or more substituents that form an intramolecular cross-hydrogen bond, and at least three or more substituents that form an intramolecular hydrogen bond. It is more preferable that it has a substituent that forms at least three intramolecular hydrogen bonds, and at least two of the hydrogen bonds have a substituent that forms an intramolecular cross-hydrogen bond. Particularly preferred.

  Among the azo pigments represented by the formulas (1), (2), (3) and (4), examples of particularly preferred azo pigments as described above include those represented by the above formulas (10) to (13). Mention may be made of the azo pigments represented.

These structures are preferable because the nitrogen atom, hydrogen atom, and hetero atom (azo group or a tautomer thereof) constituting the heterocyclic ring contained in the azo pigment structure as shown in the formulas (10) to (13). It is mentioned that a nitrogen atom of a certain hydrazone group and an oxygen atom of a carbonyl group or a nitrogen atom of an amino group) easily form at least one intramolecular hydrogen bond (intramolecular hydrogen bond).
The preferable factors for these structures include, as shown in the above formulas (10) and (11), a nitrogen atom, a hydrogen atom of an amino group, and a hetero atom (for example, an azo group) constituting the heterocyclic group contained in the azo pigment. Or a nitrogen atom of a hydrazone group which is a tautomer thereof, an oxygen atom of a carbonyl group, and a nitrogen atom of an amino group) can easily form at least one cross-hydrogen bond in the molecule.

More preferably, as shown in the above formulas (12) and (13), the nitrogen atom constituting the heterocyclic group contained in the azo pigment, the hydrogen atom of the amino group, and the hetero atom (for example, azo group or tautomerism thereof) A hydrazone group nitrogen atom, a carbonyl group oxygen atom or an amino group nitrogen atom) can easily form at least four intramolecular hydrogen bonds, and at least two intramolecular cross hydrogens. It is easy to form a bond easily.
As a result, the planarity of the molecule is increased, the intramolecular / intermolecular interaction is further improved, for example, the crystallinity of the azo pigment represented by the formula (12) is increased (higher-order structure is easily formed), This is the most preferred example because the required performance as a pigment, which is light fastness, heat stability, wet heat stability, water resistance, gas resistance and / or solvent resistance, is greatly improved.

In the azo pigment in the present invention, the formula (1) to isotopes into compounds of the formula (13) ^{(e.g., 2 H, 3 H, 13} C, 15 N) may contain.

  As specific examples of the azo pigments represented by the above formulas (1) to (13), Pig. -1 to Pig. Although −60 is shown below, the azo pigment used in the present invention is not limited to the following examples. In addition, the structures of the following specific examples are shown in the form of an ultimate structural formula among several tautomers that can be taken in terms of chemical structure. Needless to say, it may be.

  The azo pigments represented by the formulas (1) to (4) in the present invention may have chemical structural formulas of the formulas (1) to (4) or tautomers thereof, but the crystal form is also particularly limited. There is no. For example, the pigment may be any crystal form called polymorph (crystal polymorph).

Crystal polymorphs refer to crystals that have the same chemical composition but differ in the arrangement of building blocks (molecules or ions) in the crystal. In crystal polymorphs, the crystal structure determines the chemical and physical properties, and each crystal polymorph can be distinguished by its rheology, hue, and other color characteristics. Different crystal polymorphs are also known as X-Ray Diffraction.
It can also be confirmed by (powder X-ray diffraction measurement) or X-Ray Analysis (X-ray crystal structure analysis).
When crystal polymorphism exists in the azo pigments represented by the formulas (1) to (4) in the present invention, the crystal form may be any polymorph, or a mixture of two or more polymorphs. However, it is preferable that the main component is a single crystal type. That is, it is preferable that the polymorph is less mixed, and the content of the azo pigment having a single crystal type is 70% to 100%, preferably 80% to 100%, more preferably 90% to the entire azo pigment. 100%, more preferably 95% to 100, and particularly preferably 100%.

By using an azo pigment having a single crystal form as a main component, the regularity of the dye molecule arrangement is improved, the intramolecular / intermolecular interaction is strengthened, and a higher-order three-dimensional network is easily formed. . As a result, it is preferable in terms of performance required for pigments such as improvement of hue, light fastness, heat fastness, humidity fastness, oxidizing gas fastness and solvent resistance.
The mixing ratio of crystal polymorphs in azo pigments is based on solid physicochemical measurements such as single crystal X-ray crystal structure analysis, powder X-ray diffraction (XRD), crystal micrograph (TEM), IR (KBr method), etc. I can confirm.

  In the present invention, when the azo pigment represented by the formula (1) has an acid group, a part or all of the acid group may be a salt type, and a salt type pigment and a free acid type A pigment may be mixed. Examples of the salt type include salts of alkali metals such as Na, Li and K, ammonium salts optionally substituted with an alkyl group or hydroxyalkyl group, and organic amine salts. Examples of organic amines include lower alkyl amines, hydroxy-substituted lower alkyl amines, carboxy-substituted lower alkyl amines, and polyamines having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.

  Further, in the structure of the azo pigment used in the present invention, when a plurality of acid groups are contained in one molecule, the plurality of acid groups are each independently a salt type or an acid type and are different from each other. May be.

  In the present invention, the azo pigment represented by the formula (1) may be a hydrate containing water molecules in the crystal, and the number of water molecules contained in the crystal is not particularly limited.

  Next, an example of a method for producing the azo pigment represented by the above formula (1) will be described. For example, the heterocyclic amine represented by the following formula (A) is diazonium under acidic conditions, subjected to a coupling reaction with a compound represented by the following formula (B), and subjected to post-treatment by a conventional method to obtain the above formula (1 The azo pigment represented by this can be produced.

Each formula (A) and (B), W, Q, R 1, R 2, X 1, and X ₂ is W in formula _{(1), Q, R 1} , R 2, X 1, and X ₂ and It is synonymous.

The heterocyclic amine represented by the above formula (A) is generally a known and commonly used method, for example, Helv. Chim. Acta, 41, 1958, 1052 to 1056 and Helv. Chim. Acta, 42, 1959, 349 to 352, etc., and a method analogous thereto.
Moreover, the compound represented by the said Formula (B) can be manufactured by the method as described in the international publication 06/082669 and Unexamined-Japanese-Patent No. 2006-57076, and the method according to it.

The diazoniumation reaction of the heterocyclic amine represented by the above formula (A) can be carried out, for example, in an acidic solvent such as sulfuric acid, phosphoric acid, acetic acid, hydrochloric acid, methanesulfonic acid, sodium nitrite, nitrosyl sulfuric acid, isoamyl nitrite and the like. The reaction can be carried out by reacting the reagent at a temperature of 15 ° C. or lower for about 10 minutes to 6 hours.
The coupling reaction is performed by reacting the diazonium salt obtained by the above-described method and the compound represented by the above formula (B) at 40 ° C. or lower, preferably at 25 ° C. or lower for about 10 minutes to 12 hours. Can do.

  Crystals may be precipitated in the case of reaction in this way, but in general, water or an alcohol solvent is added to the reaction solution to precipitate crystals, and the crystals are collected by filtration. Can do. In addition, an alcohol solvent, water or the like can be added to the reaction solution to precipitate crystals, and the precipitated crystals can be collected by filtration. The crystal collected by filtration can be washed and dried as necessary to obtain an azo pigment represented by the formula (1).

  Although the azo pigment represented by the above formula (1) is obtained as a crude azo pigment (crude) by the above production method, when used as the pigment of the present invention, it is desirable to perform post-treatment. Examples of post-treatment methods include solvent salt milling, salt milling, dry milling, solvent milling, pigment particle control step by solvent heating treatment, resin particle, surfactant and dispersant. The surface treatment process by etc. is mentioned.

The azo pigment represented by the formula (1) of the present invention is preferably subjected to solvent heat treatment and / or solvent salt milling as a post-treatment.
Examples of the solvent used in the solvent heat treatment include water, aromatic hydrocarbon solvents such as toluene and xylene, halogenated hydrocarbon solvents such as chlorobenzene and o-dichlorobenzene, and alcohols such as isopropanol and isobutanol. Examples thereof include solvents, polar aprotic organic solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, glacial acetic acid, pyridine, and mixtures thereof. An inorganic or organic acid or base may be further added to the solvents mentioned above. The temperature of the solvent heat treatment varies depending on the desired primary particle size of the pigment, but is preferably 40 to 150 ° C, more preferably 60 to 100 ° C. The treatment time is preferably 30 minutes to 24 hours.

  As solvent salt milling, for example, a crude azo pigment, an inorganic salt, and an organic solvent that does not dissolve the crude azo pigment are charged into a kneader and kneaded and ground therein. As the inorganic salt, a water-soluble inorganic salt can be preferably used. For example, an inorganic salt such as sodium chloride, potassium chloride, sodium sulfate is preferably used. Moreover, it is more preferable to use an inorganic salt having an average particle size of 0.5 to 50 μm. The amount of the inorganic salt used is preferably 3 to 20 times by weight, more preferably 5 to 15 times by weight with respect to the crude azo pigment. As the organic solvent, a water-soluble organic solvent can be suitably used, but a high boiling point solvent is preferable from the viewpoint of safety because the solvent easily evaporates due to a temperature rise during kneading.

  Examples of such organic solvents include diethylene glycol, glycerin, ethylene glycol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2- (methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2 -(Hexyloxy) ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, Dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropy Glycol or mixtures thereof. The amount of the water-soluble organic solvent used is preferably 0.1 to 5 times by weight with respect to the crude azo pigment. The kneading temperature is preferably 20 to 130 ° C, particularly preferably 40 to 110 ° C. As a kneader, for example, a kneader or a mix muller can be used.

  The method for preparing the polymer vinyl polymer particles containing the styrene-acrylic acid copolymer in the present invention and the azo pigment represented by the formula (1) is not particularly limited. For example, it can be produced by the method for producing encapsulated pigments described in JP-A-10-140065. Specifically, after the styrene-acrylic acid copolymer and the azo pigment represented by the formula (1) are dispersed in an aqueous medium containing a water-soluble organic solvent, at least one of the water-soluble organic solvents is used. An aqueous dispersion of colored particles can be obtained by removing the portion.

(Other ingredients)

<Sensitizer>
If necessary, a sensitizer may be added to the ink composition for the purpose of improving the acid generation efficiency of a cationic polymerization initiator (preferably a photoacid generator) and increasing the photosensitive wavelength. Any sensitizer may be used as long as it sensitizes a cationic polymerization initiator (preferably a photoacid generator) with an electron transfer mechanism or an energy transfer mechanism. Preferably, aromatic polycondensed compounds such as anthracene, 9,10-dialkoxyanthracene, pyrene and perylene, aromatic ketone compounds such as acetophenone, benzophenone, thioxanthone and Michlerketone, heterocyclic compounds such as phenothiazine and N-aryloxazolidinone Is mentioned. The addition amount is appropriately selected according to the purpose, but is generally 0.01 to 1 mol%, preferably 0.1 to 0.5 mol%, based on the cationic polymerization initiator.

  More preferable examples of the sensitizer include compounds represented by the following formulas (IX) to (XIII).

In the formula (IX), A ¹ represents a sulfur atom or NR ⁵⁰ , R ⁵⁰ represents an alkyl group or an aryl group, and L ² forms a basic nucleus of the dye together with the adjacent A ¹ and the adjacent carbon atom. R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁵¹ and R ⁵² may be bonded to each other to form an acidic nucleus of the dye. Good. W represents an oxygen atom or a sulfur atom.

In formula (X), Ar ¹ and Ar ² each independently represent an aryl group and are linked via a bond with —L ³ —. Here, L ³ represents —O— or —S—. W is synonymous with that shown in Formula (IX).

In the formula (XI), A ₂ represents a sulfur atom or NR ⁵⁹ , L ⁴ represents a nonmetallic atomic group that forms a basic nucleus of the dye together with adjacent A ₂ and a carbon atom, R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ and R ⁵⁸ each independently represent a monovalent nonmetallic atomic group, and R ⁵⁹ represents an alkyl group or an aryl group.

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

In the formula (XIII), R ⁶⁶ represents an aromatic ring or a hetero ring which may have a substituent, and A ⁵ represents an oxygen atom, a sulfur atom or ═NR ⁶⁷ . R ⁶⁴ , R ⁶⁵ and R ⁶⁷ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ each represent an aliphatic or aromatic ring. Can be combined to form.

  Preferable specific examples of the compounds represented by formulas (IX) to (XIII) include (E-1) to (E-20) shown below.

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

<Co-sensitizer>
Furthermore, the ink composition of the present invention may contain a known compound having a function of further improving sensitivity or suppressing inhibition of polymerization by oxygen as a cosensitizer.
Such co-sensitizers include amines such as M.I. R. Sander et al., “Journal of Polymer Society”, Vol. 10, 3173 (1972), Japanese Patent Publication No. 44-20189, Japanese Patent Publication No. 51-82102, Japanese Patent Publication No. 52-134692, Japanese Patent Publication No. 59-138205. No. 60, No. 60-84305, No. 62-18537, No. 64-33104, Research Disclosure 33825, and the like. Examples include ethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like.

Other co-sensitizers include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, and JP-A-56- No. 75643, and more specifically, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene. Etc.
Other co-sensitizers include, for example, amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), Japanese Patent Publication No. 55-34414. Hydrogen donors described in JP-A-6-308727, sulfur compounds (e.g., trithiane) described in JP-A-6-308727, phosphorus compounds (such as diethyl phosphite) described in JP-A-6-250387, JP-A-8-54735 Examples include Si—H and Ge—H compounds described in the publication.

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

<Ultraviolet absorber>
In the present invention, an ultraviolet absorber can be used from the viewpoint of improving the weather resistance of the obtained image and preventing discoloration.
Examples of the ultraviolet absorber are described in JP-A-58-185679, JP-A-61-190537, JP-A-2-782, JP-A-5-97075, JP-A-9-34057, and the like. Benzotriazole compounds, benzophenone compounds described in JP-A No. 46-2784, JP-A No. 5-194843, US Pat. No. 3,214,463, etc., JP-B Nos. 48-30492 and 56-21141 Cinnamic acid compounds described in JP-A-10-88106, JP-A-4-298503, JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, JP The triazine compounds described in JP-A-8-501291, Research Disclosure No. Examples thereof include compounds described in No. 24239, compounds that emit ultraviolet light by absorbing ultraviolet rays typified by stilbene and benzoxazole compounds, so-called fluorescent brighteners, and the like.
The addition amount is appropriately selected according to the purpose, and is about 0.5 to 15% by weight in the ink composition.

<Antioxidant>
An antioxidant can be added to improve the stability of the ink composition. Examples of the antioxidant include European Published Patent Nos. 223739, 309401, 309402, 310551, 310552, 457416, and German Patent No. 3435443. JP-A-54-48535, JP-A-62-262047, JP-A-63-113536, JP-A-63-163351, JP-A-2-262654, JP-A-2-71262, and JP-A-3 No. 112449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.
The addition amount is appropriately selected according to the purpose, but is about 0.1 to 8% by weight in the ink composition.

<Anti-fading agent>
In the ink composition of the present invention, various organic and metal complex anti-fading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Examples of the metal complex anti-fading agent include nickel complexes and zinc complexes. No. 17643, Nos. VII to I, J. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in Japanese Patent No. 15162 and the compounds included in the formulas and compound examples of the representative compounds described on pages 127 to 137 of JP-A-62-215272 can be used.
The addition amount is appropriately selected according to the purpose, but is about 0.1 to 8% by weight in the ink composition.

<Conductive salts>
Conductive salts such as potassium thiocyanate, lithium nitrate, ammonium thiocyanate, and dimethylamine hydrochloride can be added to the ink composition of the present invention for the purpose of controlling ejection properties.

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

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

<Surfactant>
A surfactant may be added to the ink composition of the present invention.
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers and silicone oils, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. An organic fluoro compound may be used in place of the surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compounds include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). No. (columns 8 to 17) and those described in JP-A Nos. 62-135826.
The content of the surfactant in the ink composition is appropriately adjusted so as to match the surface tension suitable for ejection of the inkjet head, but is preferably 0 to 6% by weight, more preferably 0 to 4% by weight, Preferably it is the range of 0-2 weight%.

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

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

  The surface tension of the ink composition of the present invention at 25 ° C. is preferably 20 to 35 mN / m. More preferably, it is 23-33 mN / m. When recording on various recording media such as polyolefin, PET, coated paper, and non-coated paper, 20 mN / m or more is preferable from the viewpoint of bleeding and penetration, and 35 mN / m or less is preferable in terms of wettability.

(Inkjet recording method, inkjet recording apparatus and printed matter)
In the inkjet recording method of the present invention, the ink composition of the present invention is ejected onto a recording medium (support, recording material, etc.) for inkjet recording, and actinic radiation is applied to the ink composition ejected onto the recording medium. It is a method of forming an image by irradiating and curing the ink.

More specifically, the inkjet recording method of the present invention includes a step of ejecting the inkjet recording ink composition of the present invention onto a recording medium, and irradiating the ejected inkjet recording ink composition with active radiation. And the process of hardening the said ink composition for inkjet recording is characterized by the above-mentioned.
The ink jet recording method of the present invention includes the steps described above, whereby an image is formed from the ink composition cured on the recording medium.
The printed matter of the present invention is a printed matter recorded by the inkjet recording method of the present invention.

  In the ink jet recording method of the present invention, an ink jet recording apparatus described in detail below can be used.

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

Examples of the ink jet recording apparatus that can be used in the present invention include an apparatus including an ink supply system, a temperature sensor, and an actinic radiation source.
The ink supply system includes, for example, an original tank containing the ink composition of the present invention, a supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. The piezo-type inkjet head preferably has a multi-size dot of 1 to 100 pl, more preferably 8 to 30 pl, preferably 320 × 320 to 4,000 × 4,000 dpi, more preferably 400 × 400 to 1,600 ×. It can be driven so that it can discharge at a resolution of 1,600 dpi, more preferably 720 × 720 dpi. In the present invention, dpi represents the number of dots per 2.54 cm.

As described above, since it is desirable that the radiation curable ink, like the ink composition of the present invention, has a constant temperature for the ejected ink, the ink jet recording apparatus has a means for stabilizing the ink composition temperature. It is preferable to provide. The parts to be kept at a constant temperature are all the piping systems and members from the ink tank (intermediate tank if there is an intermediate tank) to the nozzle ejection surface. That is, heat insulation and heating can be performed from the ink supply tank to the inkjet head portion.
The temperature control method is not particularly limited, but for example, it is preferable to provide a plurality of temperature sensors at each piping site and perform heating control according to the ink flow rate and the environmental temperature. The temperature sensor can be provided near the ink supply tank and the nozzle of the inkjet head. Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside air. In order to shorten the printer start-up time required for heating or to reduce the loss of thermal energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

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

Next, a process of irradiating the ejected ink composition with radiation to cure the ink composition will be described.
The ink composition ejected on the recording medium is cured by irradiation with radiation. This is because the cationic polymerization initiator contained in the ink composition of the present invention is decomposed by irradiation with radiation to generate a cation, and the polymerization reaction of the cation polymerizable compound is caused and accelerated by the cation. . At this time, if a sensitizer is present together with the cationic polymerization initiator in the ink composition, the sensitizer in the system absorbs radiation to be in an excited state and comes into contact with the cationic polymerization initiator, thereby Degradation can be accelerated and a more sensitive curing reaction can be achieved.

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

Further, the ink composition of the present invention has sufficient sensitivity even with a low output actinic radiation. Therefore, it is appropriate to cure the exposed surface with an illuminance of 10 to 4,000 mW / cm ² , more preferably 20 to 2,500 mW / cm ² .

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

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

  By adopting the ink jet recording method as described above, the dot diameter of the landed ink can be kept constant even on various recording media having different surface wettability, and the image quality is improved.

The ink composition of the present invention can be used as an ink set by combining ink compositions of a plurality of colors. For example, it can be used in combination with a cyan ink composition and a magenta ink composition.
Further, it can be used as an ink set together with black and white ink compositions, and can also be used as an ink set together with ink compositions such as light magenta and light cyan. In order to obtain a color image, it is preferable to superimpose in order from the lightest color. By superimposing the inks in the order of low lightness, it becomes easier for the irradiation line to reach the lower ink, and good curing sensitivity, reduction of residual monomers, and improvement in adhesion can be expected. In addition, irradiation can be performed by discharging all colors and collectively exposing, but exposure for each color is preferable from the viewpoint of promoting curing.
Thus, the ink composition of the present invention can form an image on the surface of a recording medium by being cured with high sensitivity by irradiation with actinic radiation.

  In the ink jet recording method of the present invention, an ink set containing the ink composition of the present invention can be suitably used. The order of each colored ink composition to be ejected is not particularly limited, but it is preferably applied to a recording medium from a colored ink composition having low brightness, and when yellow, cyan, magenta, and black are used. Are preferably applied on the recording medium in the order of yellow → cyan → magenta → black. Furthermore, the present invention is not limited to this, and an ink set including at least a total of seven colors of light cyan and light magenta ink compositions and cyan, magenta, black, white and yellow dark ink compositions is used. In this case, it is preferable to apply the recording material in the order of white → light cyan → light magenta → yellow → cyan → magenta → black.

  In the present invention, the recording medium is not particularly limited, and a known recording medium can be used as a support or a recording material. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. In addition, as the recording medium in the present invention, a non-absorbable recording medium can be preferably used.

  The printed matter of the present invention can be obtained by printing the ink composition of the present invention on a recording medium using an ink jet printer, and then preferably irradiating the cured ink composition with actinic radiation and curing. Since the ink used for image formation is excellent in hue and sensitivity, the printed matter of the present invention has a high-quality image excellent in color developability and sharpness, and thus can be applied to a wide range of fields.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on weight.

[Synthesis Example 1]
-Synthesis of Exemplified Compound (Pig.-1)-
A synthesis scheme of the exemplary compound (Pig.-1) is shown below.

(1) Synthesis of intermediate (a) 29.7 g (0.3 mol) of methyl cyanoacetate, 42.4 g (0.4 mol) of trimethyl orthoformate, 20.4 g (0.2 mol) of acetic anhydride, p- Toluenesulfonic acid 0.5g was added and it heated at 110 degreeC (external temperature), and it stirred for 20 hours, distilling the low boiling point component produced from a reaction system. The reaction solution was concentrated under reduced pressure, and then purified on a silica gel column to obtain 14.1 g of the intermediate (a) (yellow powder, yield 30%). The NMR measurement result of the obtained intermediate (a) is as follows.
¹ H-NMR (300 MHz, CDCl ₃ ) δ = 7.96 (s, 1H), 4.15 (s, 3H), 3.81 (s, 3H)

(2) Synthesis of Intermediate (b) 150 mL of isopropanol was added to 7.4 mL (141 mmol) of methyl hydrazine and cooled to 15 ° C. (internal temperature), and 7.0 g (49. 6 mmol) was gradually added, and the mixture was heated to 50 ° C. and stirred for 1 hour and 40 minutes. After concentrating this reaction liquid under reduced pressure, silica gel column purification was performed to obtain 10.5 g of the intermediate (b) (white powder, yield 50%). The NMR measurement result of the obtained intermediate (b) is as follows.
¹ H-NMR (300 MHz, CDCl ₃ ) δ = 7.60 (s, 1H), 4.95 (brs, 2H), 3.80 (s, 3H), 3.60 (s, 3H)

(3) Synthesis of Intermediate (c) 100 mL of methanol was added to 130 mL of hydrazine monohydrate and cooled to 10 ° C. (internal temperature), and 50.0 g (336 mmol) of 4,6-dichloropyrimidine was added to this mixture. After gradually adding (internal temperature 20 ° C. or lower), the mixture was heated to 50 ° C. and stirred for 4 hours 30 minutes. Crystals precipitated from the reaction solution were collected by filtration, washed with isopropanol, and dried to obtain 43.1 g of the intermediate (c) (white powder, yield 92%). The NMR measurement result of the obtained intermediate (c) is as follows.
¹ H-NMR (300 MHz, d ₆ -DMSO) δ = 7.82 (s, 1H), 7.55 (s, 2H), 5.96 (s, 1H), 4.12 (s, 4H)

(4) Synthesis of Intermediate (d) 900 mL of water was added to 35.0 g (0.25 mol) of Intermediate (c) and 68.8 g (0.55 mol) of pivaloyl acetonitrile, and the mixture was stirred at room temperature. 1M aqueous hydrochloric acid was added dropwise to the suspension so that the pH was 3, and the mixture was heated to 50 ° C. and stirred for 8 hours. To this reaction solution, 8M aqueous potassium hydroxide solution is added dropwise to adjust the pH to 8. Further, 1M hydrochloric acid solution is added dropwise to adjust to pH 6, and the precipitated crystals are collected by filtration, washed with isopropanol, dried, and dried. 83.0 g (white powder, 94% yield) of (d) was obtained. The NMR measurement result of the obtained intermediate (d) is as follows.
¹ H-NMR (300 MHz, d ₆ -DMSO) δ = 8.73 (s, 1H), 7.97 (s, 1H), 6.88 (s, 4H), 5.35 (s, 2H)

(5) Synthesis of Exemplary Compound (Pig.-1) Acetic acid (18.5 mL) was added to concentrated sulfuric acid (4.1 mL), and the mixture was stirred with ice-cooling, and 40% nitrosylsulfuric acid (3.85 g, 12.1 mmol) was added dropwise. Intermediate (b) 1.71 g (11.0 mmol) was gradually added to the mixture (internal temperature of 0 ° C. or lower), and the mixture was stirred at 0 ° C. for 2 hours. 150 mg of urea was added to this reaction solution, and the mixture was further stirred at 0 ° C. for 15 minutes to prepare diazo solution A.
50 ml of methanol was added to 1.77 g (5 mmol) of the intermediate (d) and dissolved by heating, and then the diazo solution A was slowly added dropwise to an ice-cooled mixture (internal temperature of 10 ° C. or lower). After the reaction solution was stirred at room temperature for 2 hours, the precipitated crystals were collected by filtration and washed with methanol to obtain crude crystals of the exemplified compound (Pig.-1). Further, water was added to the crude crystals and stirred, and then the suspension was adjusted to pH 7 with an aqueous sodium hydroxide solution, and further 20 mL of dimethylacetamide was added and stirred at 80 ° C. for 2 hours. The precipitated crystals were collected by filtration and suspended and washed with methanol. The obtained crystals were collected by filtration and dried to obtain 2.0 g (yellow powder, yield 79%) of the exemplified compound (Pig.-1).
In addition, the exemplary compound (Pig.-18), the exemplary compound (Pig.-49), and the exemplary compound (Pig.-52) were synthesized in the same manner as in the above synthesis scheme.

The materials used in the present invention are as shown below.
・ NOVOPERM YELLOW H2G (yellow pigment, manufactured by Clariant)
・ New synthetic pigment (azo dye represented by formula (1))
・ Fancrill 512A (equivalent to exemplary compound M-11, manufactured by Hitachi Chemical Co., Ltd.)
・ N-vinylcaprolactam (manufactured by Aldrich)
-Actilane 421 (propoxylated neopentyl glycol diacrylate, manufactured by Akcros)
NK ester AMP-10G (phenoxyethyl acrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ Dimethylaminoethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
FIRSTCURE ST-1 (polymerization inhibitor, manufactured by Chem First)
・ Lucirin TPO (photoinitiator, manufactured by BASF)
・ Benzophenone (Photoinitiator, Wako Pure Chemical Industries, Ltd.)
IRGACURE 184 (photoinitiator, manufactured by Ciba Specialty Chemicals)
-BYK-307 (surfactant, manufactured by BYK Chemie)
・ RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP)
CELLOXIDE 2021P ((3 ′, 4′-epoxycyclohexane) methyl-3,4-epoxycyclohexanecarboxylate, manufactured by Daicel Cytec)
Aron oxetane OXT-221 (bis (3-ethyl-3-oxetanylmethyl) ether, manufactured by Toagosei Co., Ltd.)
UVI-6992 (Triarylsulfonium hexafluoroantimonate salts in propylene carbonate (mixed), manufactured by Dow Chemicals)
・ Anthracure UVS-1331 (9,10-dibutoxyanthracene, manufactured by Kawasaki Chemical Industry Co., Ltd.)
・ DisperBYK-101 (dispersant, manufactured by BYK Chemie)
・ DisperBYK-103 (dispersant, manufactured by BYK Chemie)
・ DisperBYK-106 (dispersant, manufactured by BYK Chemie)
EFKA4010 (dispersant, manufactured by Fuka Additive)
・ EFKA4800 (dispersant, manufactured by Fuka Additive)
・ Solsperse 36000 (dispersant, manufactured by Zeneca)
・ Solsperse 41000 (dispersant, manufactured by Zeneca)

(Preparation of yellow mill base A)
Exemplary compounds Pig. -1 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight DisperBYK-101 (acid value 30 mgKOH / g, amine value: 0 mgKOH / g) 200 parts by weight By mixing, a pigment ink was obtained. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base B)
Exemplary compounds Pig. -1 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight DisperBYK-103 (acid value: 101 mgKOH / g, amine number: 0 mgKOH / g) 200 parts by weight The mixture was stirred and mixed to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base C)
Exemplary compounds Pig. -1 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight DisperBYK-106 (acid value: 132 mgKOH / g, amine value: 74 mgKOH / g) 200 parts by weight The mixture was stirred and mixed to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base D)
Exemplary compounds Pig. -1 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight EFKA4010 (acid value: 10 to 15 mg KOH / g, amine value: 4 to 8 mg KOH / g) 200 parts by weight The components were mixed with stirring to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base E)
Exemplary compounds Pig. -1 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight Solsperse 36000 (acid value: 45 mgKOH / g, amine value: 0 mgKOH / g)
200 parts by weight The above components were mixed with stirring to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base F)
Exemplary compounds Pig. -1 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight Solsperse 41000 (acid value: 50 mgKOH / g, amine value: 0 mgKOH / g)
200 parts by weight The above components were mixed with stirring to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base G)
Exemplary compounds Pig. -18 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight Solsperse 36000 (acid value: 45 mgKOH / g, amine value: 0 mgKOH / g)
200 parts by weight The above components were mixed with stirring to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base H)
Exemplary compounds Pig. -49 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight Solsperse 36000 (acid value: 45 mgKOH / g, amine value: 0 mgKOH / g)
200 parts by weight The above components were mixed with stirring to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base I)
Exemplary compounds Pig. -52 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight Solsperse 36000 (acid value: 45 mg KOH / g, amine value: 0 mg KOH / g) 200 parts by weight By mixing, a pigment ink was obtained. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base J)
NOVOPERM YELLOW H2G 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight Solsperse 36000 (acid value: 45 mg KOH / g, amine value: 0 mg KOH / g 200 parts by weight) The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm. went.

(Preparation of yellow mill base K)
Exemplary compounds Pig. -1 300 parts by weight RAPI-CURE DVE-3 (triethylene glycol divinyl ether, manufactured by ISP) 500 parts by weight EFKA4800 (amine value 37-43 mg KOH / g, oxidation 0 mg KOH / g) 200 parts by weight A pigment ink was obtained. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

(Preparation of yellow mill base L)
Exemplary compounds Pig. -1 300 parts by weight Actilane 421 (acrylate monomer manufactured by Akcros) 500 parts by weight Solsperse 36000 (acid value: 45 mgKOH / g, amine value: 0 mgKOH / g)
200 parts by weight The above components were mixed with stirring to obtain a pigment ink. The pigment mill base was prepared in a disperser motor mill M50 (manufactured by Eiger) and dispersed for 4 hours at a peripheral speed of 9 m / s using zirconia beads having a diameter of 0.65 mm.

[Example 1]
The following components were stirred with a high-speed water-cooled stirrer to obtain a yellow UV inkjet ink. The viscosity was 19 mPa · s.
・ Yellow Mill Base A 10.0 parts ・ CELLOXIDE 2021P 30.0 parts ・ Aron Oxetane OXT-221 34.3 parts ・ RAPI-CURE DVE-3 13.6 parts ・ UVI-6922 9.0 parts ・ Anthracure UVS-1331 3 .0 part ・ BYK-307 0.1 part

(Evaluation of ink)
Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability, ink storage stability, and ejection performance. Table 1 shows the evaluation results of image flexibility and adhesion before and after storage.

[Examples 2-9, Comparative Examples 1-2]
An ink composition was prepared in the same manner as in Example 1 except that the yellow mill base used was changed from B to K.
Further, ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability, ink storage stability, and ejection performance. Table 1 shows the evaluation results of image flexibility and adhesion before and after storage.

Example 10
The following components were stirred with a high-speed water-cooled stirrer to obtain a yellow UV inkjet ink. The viscosity was 18.5 mPa · s.
・ Yellow mill base L 12.0 parts ・ Fancrile 512A 35.4 parts ・ N-vinylcaprolactam 25.0 parts ・ NK ester AMP-10G 14.0 parts ・ First cure ST-1 0.05 part ・ Lucirin TPO (BASF 8.5 parts ・ Benzophenone (photoinitiator) 3.0 parts ・ Irgacure 184 (CSC photoinitiator) 2.0 parts ・ Byk 307 (BYK Chemie surfactant) 0. 05 parts ・ Dimethylaminoethyl acrylate 1.0 part

  Ink jet recording was performed using the obtained ink composition. Table 1 shows the evaluation results of curability, ink storage stability, and ejection performance. Table 1 shows the evaluation results of image flexibility and adhesion before and after storage.

(Evaluation of ink composition)
These ink compositions were used to evaluate curability, ink storage stability, ejection properties, flexibility, and adhesion.

<Storage stability>
The ink composition was put in a glass vial and the rate of increase in viscosity after storage at 60 ° C. for 4 weeks was evaluated. The smaller the rate of increase, the better the storage stability. If it is approximately 20% or less, no practical problem will occur.
Rate of increase (%) = (viscosity after storage−viscosity before storage) / viscosity before storage × 100

<Inkjet image recording method>
Using the ink before aging and each ink composition after aging, recording on a recording medium was performed using an inkjet recording experimental apparatus having a piezo-type inkjet nozzle. The ink supply system was composed of an original tank, supply piping, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head, and heat insulation and heating were performed from the ink supply tank to the inkjet head portion. Temperature sensors were provided near the ink supply tank and the nozzle of the ink jet head, respectively, and temperature control was performed so that the nozzle portion was always 45 ° C. ± 2 ° C. The piezo-type inkjet head was driven so that 8 to 30 pl multi-size dots could be ejected at a resolution of 720 × 720 dpi. After landing, UV light was condensed to an exposure surface illuminance of 1,630 mW / cm ² , and the exposure system, main scanning speed, and ejection frequency were adjusted so that irradiation started 0.1 seconds after ink landed on the recording medium. . Further, the integrated light amount irradiated to the image was set to 4,500 mJ / cm ² . A HAN250NL high-cure mercury lamp (manufactured by GS Yuasa Corporation) was used as the ultraviolet lamp. In the present invention, dpi represents the number of dots per 2.54 cm. As a recording medium, an ester film E5000 (thickness 125 μm, manufactured by Toyobo Co., Ltd.) was used.

<Curing speed>
The ink composition was applied to the surface of polyvinyl chloride (thickness 220 μm) as a recording medium using a K hand coater (bar No. 2) so as to have a wet film thickness of 12 μm. Next, inside the UV conveyor device CSOT (manufactured by GS Yuasa Lighting) equipped with an ozone-less metal halide lamp MAN125L and set at a conveyor speed of 6 m / min and an exposure intensity of 1,800 W / cm ² until the adhesiveness of the coating surface disappears Repeated passage and radiation curing. The curing rate was evaluated according to the following criteria. The results are shown in Table 1.
A: Tack-free after one pass. The curing rate is extremely fast.
○: Tack-free after 2 passes. Cure speed is fast.
Δ: Tack-free after 3 passes. Curing time is somewhat slow.
X: It became tack-free when the number of passes was 4 or more. Curing time is slow.

<Abrasion resistance>
The ink composition was applied to the surface of polyvinyl chloride (thickness 220 μm) as a recording medium using a K hand coater (bar No. 2) so as to have a wet film thickness of 12 μm. Next, the inside of UV conveyor device CSOT (manufactured by GS Yuasa Lighting Co., Ltd.) equipped with an ozone-less metal halide lamp MAN125L and set at a conveyor speed of 6 m / min and an exposure intensity of 1,800 W / cm ² was used. It was repeatedly passed through until it disappeared, and was cured by radiation. The strength was evaluated according to the following criteria by ISO 15184 (scratch hardness-pencil method) using this cured coating film. The results are shown in Table 1.
A: 4H or more, scratch resistance is very good.
○: F or more and 3H or less, good scratch resistance.
(Triangle | delta): 3B or more and HB or less, and abrasion resistance are a little bad.
X: 4B or less, scratch resistance is poor.

<Inkjet ejection properties>
JetLyser (manufactured by Mimaki Engineering Co., Ltd.) equipped with an inkjet print head CA3 (manufactured by TOSHIBA TEC CO., LTD.) Is set to discharge voltage 22V, discharge drop number 7 drop, and the ink composition is continuously discharged at 45 ° C. for 60 minutes. The evaluation was based on the following criteria. The results are shown in Table 1.
(Double-circle): It was sprayed normally. Inkjet ejection is very good.
○: Slight mist generation was observed. Inkjet ejection is good.
Δ: Generation of mist was observed. Inkjet ejection properties are somewhat poor.
X: Severe mist generation was observed. Inkjet ejection properties are poor.

<Flexibility evaluation method: Bending test>
In this example, a bending test was performed as a method for evaluating the flexibility of the cured film before and after storage.
In accordance with the inkjet image recording method, an ester film E5000 (film thickness 125 μm, manufactured by Toyobo Co., Ltd.) was used as a recording medium, and three solid images having an average film thickness of 12 μm, 24 μm, and 36 μm were drawn. . In the bending test, the recording material on which the image was formed was bent once at 25 ° C. and evaluated by the presence or absence of cracks in the image area. In general, when the average film thickness is increased, distortion applied to the image portion when the image portion is bent increases, and cracks are likely to occur. That is, by testing whether the image portion is cracked with a thicker film thickness, a measure of flexibility can be obtained.
The evaluation criteria are as follows.
4: Cracks do not occur in samples having an average film thickness of 12 μm, 24 μm, and 36 μm.
3: Cracks do not occur in samples having an average film thickness of 12 μm and 24 μm.
2: Cracks do not occur in the sample having an average film thickness of 12 μm, but cracks occur in the bent portion of the image portion in the sample having an average film thickness of 24 μm.
1: In all samples having an average film thickness of 12 μm, 24 μm, and 36 μm, a crack occurs in the bent portion of the image portion.

<Base material adhesion evaluation method: cross hatch test (EN ISO 2409)>
Using PET (Ester film E5000, film thickness 125 μm, manufactured by Toyobo Co., Ltd.) as the recording medium, a solid image having an average film thickness of 12 μm was drawn on each substrate according to the inkjet image recording method. . Thereafter, a cross-hatch test (EN ISO 2409) was performed on each printed matter. In addition, evaluation was performed in six stages of 0 (excellent) to 5 (defect). Here, an evaluation of 0 means that the edges of the cut are completely smooth and there is no peeling in any grid eye.

<Viscosity measurement method>
In this example, the viscosity was measured using a B-type viscometer: Brookfield LVDV-I (manufactured by Brookfield) at 25 ° C. and a rotor rotation speed of 20 rpm.

  According to the present invention, the storage stability and ejection properties as ink are good, the curability during light irradiation is satisfactory, and the flexibility and substrate adhesion as a cured film (inkjet drawing image) are satisfied. A stable quality ink can be realized. On the other hand, as shown in Comparative Example 1, with pigments generally used as commercial products, it is difficult to ensure stability in pigment dispersion, storage stability is insufficient, and dischargeability deteriorates due to pigment aggregation and the like. It has become. In addition, as shown in Comparative Example 2, the use of the basic dispersant deteriorates the curability of the ink and reveals a defect in the cured film itself.

  According to the present invention, it is possible to obtain a printed image that is excellent in storage stability as an ink, has no problem with ejection properties, has good curability, and has excellent film characteristics after curing.

Claims (14)

A dispersant having an acid value greater than the amine value;
Polymerizable compounds,
A polymerization initiator, and
An ink composition comprising an azo pigment represented by the following formula (1).

(In the formula (1), Q represents a nonmetallic atomic group necessary for forming a 5- to 7-membered heterocycle with two carbon atoms to which Q is bonded, and W represents an alkoxy group, an amino group, or an alkyl group. Or an aryl group, X ₁ and X ₂ each independently represent a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, R ₁ represents a hydrogen atom or a substituent, and R ₂ represents a heterocyclic ring. Represents a group, and n represents an integer of 1 to 4. In the case of n = 2 to 4, the formula (1) is ₂ to 2 bonded via Q, W, X ₁ , X ₂ , R ₁ , or R 2. Each represents a tetramer.)   The ink composition according to claim 1, wherein the dispersant is a polymer compound.   3. The ink composition according to claim 1, wherein the acid value of the dispersant is larger than the amine value, and the difference is 1 mgKOH / g or more and 120 mgKOH / g or less. The ink composition according to any one of claims 1 to 3, wherein the azo pigment represented by the formula (1) is an azo pigment represented by the following formula (2).

(In the formula (2), Q represents a nonmetallic atomic group necessary for forming a 5- to 7-membered heterocycle with two carbon atoms to which Q is bonded, and W represents an alkoxy group, an amino group, or an alkyl group. Or an aryl group, X ₁ independently represents a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, R ₁ represents a hydrogen atom or a substituent, and R ₂ represents a heterocyclic group. , N represents an integer of 1 to 4. When n = 2 to 4, formula (2) represents a 2-tetramer bonded via Q, W, X ₁ , R ₁ , or R ₂ , respectively. .)   5. The compound according to claim 1, wherein Q in the formula (1) is a nonmetallic atomic group necessary for forming a 5-membered nitrogen-containing heterocycle with two carbon atoms to which Q is bonded. The ink composition as described.   The ink composition according to any one of claims 1 to 5, wherein n in the formula (1) is 2. The ink composition according to claim 4, wherein X ₁ in the formula (2) is a hydrogen atom. The ink composition according to any one of claims 1 to 3, wherein the azo pigment represented by the formula (1) is an azo pigment represented by the following formula (3).

(In Formula (3), Y represents a hydrogen atom or a substituent, G represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group. W represents an alkoxy group. A group, an amino group, an alkyl group or an aryl group, X ₁ and X ₂ each independently represents a hydrogen atom, an alkyl group, an acyl group, an alkylsulfonyl group or an arylsulfonyl group, and R ₁ represents a hydrogen atom or a substituent. R ₂ represents a heterocyclic group, and n represents an integer of 1 to 4. When n = 2 to 4, formula (3) is G, Y, W, X ₁ , X ₂ , R ₁ , or represents 2-4 dimer linked via R _2, respectively.)   The ink composition according to any one of claims 1 to 8, wherein W in the formula (1) is an alkoxy group having 3 or less carbon atoms, an amino group, or an alkylamino group having 3 or less total carbon atoms. .   The ink composition according to claim 8, wherein G in the formula (3) is an alkyl group having 3 or less carbon atoms. The ink composition according to claim 8, wherein the azo pigment represented by the formula (3) is an azo pigment represented by the following formula (4).

(In formula (4), Z represents a divalent group derived from a 5- to 8-membered nitrogen-containing heterocycle, and Y ₁ , Y ₂ , R ₁₁ and R ₁₂ each independently represents a hydrogen atom or a substituent. G ₁ and G ₂ each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and W ₁ and W ₂ each independently represent an alkoxy group, amino Represents a group, an alkyl group or an aryl group.) Formula (4) W _1, W ₂ in the ink composition according to claim 11 each independently having 3 or less carbon atoms of an alkoxy group, an amino group, or a total carbon number of 3 or less of an alkylamino group . The ink composition according to claim 11 or 12, wherein G ₁ and G ₂ in the formula (4) are each independently an alkyl group having a total carbon number of 3 or less.   14. The ink composition according to claim 11, wherein Z in the formula (4) is a 6-membered nitrogen-containing heterocycle.