JP2005350551A - Ink composition and method for ink-jet recording using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition having a high curing rate and to provide a method for ink-jet recording. <P>SOLUTION: The ink composition comprises at least a polymerizable compound, a colorant, a photopolymerization initiator and chain transfer agent. The method for ink-jet recording comprises using the ink composition. The chain transfer agent is preferably selected from the group consisting of o-quinonediazides, mercaptoazoles, N-aminomethyl group-substituted azoles, halogen-substituted 1,3,5-triazines and disulfonyldiazomethanes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  Water-based ink-jet inks have poor water resistance when printed on plain paper and are likely to bleed. In addition, when printed on non-water-absorbing recording materials such as plastic, ink droplets are poorly adhered. For this reason, image formation could not be performed, and drying of the solvent was extremely slow, so that it was necessary to dry without overlapping the recorded material immediately after printing, and the image was liable to blur.

  Ultraviolet curable inks using polyfunctional monomers with excellent adhesion to recording materials have been disclosed as suitable for printing on non-water-absorbing recording materials. However, it was slow and insufficient to form a full-color image. In order to solve the drying property, a method using a volatile organic solvent as the solvent of the ink has been carried out, but in order to dry quickly, it is highly flammable, such as methyl ethyl ketone and ethanol, and is also highly volatile. It was necessary to use a solvent.

In order to solve these problems, an inkjet ink that is cured and fixed by radiation rather than volatilization of the ink solvent is disclosed. For example, Patent Documents 1 to 3 disclose inks containing a monomer having a polymerizable group and an oil-soluble dye. Patent Document 4 discloses a photopolymerizable composition containing a photopolymerizable compound and a photopolymerization initiator.
However, these inks have a problem that the curing speed is insufficient.

JP 2003-221528 A JP 2003-221532 A JP 2003-221530 A JP 2001-222105 A

  The problem to be solved by the present invention is to provide an ink composition having a high curing rate. Another object of the present invention is to provide an ink jet recording method using an ink composition having a high curing rate.

  The above-mentioned problems to be solved by the present invention are solved by an ink composition comprising at least a polymerizable compound, a colorant, a photopolymerization initiator, and a chain transfer agent, and an ink jet recording method using the same. It was.

  According to the present invention, an ink composition having good curability can be obtained.

  The ink composition of the present invention contains at least a polymerizable compound, a colorant, a photopolymerization initiator, and a chain transfer agent.

(Polymerizable compound)
As the polymerizable compound that can be used in the present invention, a compound in which addition polymerization or ring-opening polymerization is initiated by a radical species or a cationic species generated from a photopolymerization initiator by ultraviolet irradiation to produce a polymer is preferably used. Examples of the polymerization mode of addition polymerization include radical, cation, anion, metathesis, and coordination polymerization. Examples of the ring-opening polymerization method include cation, anion, radical, metathesis, and coordination polymerization.
As the polymerization mode of the present invention, radical polymerization is preferably used, but it can also be used in combination with other polymerization modes, for example, a polymerizable compound that is cured by cationic polymerization. As the polymerizable compound, a compound that undergoes addition polymerization in a radical polymerization manner can be preferably used.

Examples of the addition polymerizable compound include compounds having at least one ethylenically unsaturated double bond. As the addition polymerizable compound, a compound having at least one, preferably two or more terminal ethylenically unsaturated bonds can be preferably used. Such terminal ethylenically unsaturated compounds are widely known in the industrial field. In the present invention, the ink composition can be used without particular limitation as long as it can be stably ejected from an inkjet nozzle.
The ethylenically unsaturated polymerizable compound has a chemical form of a monofunctional polymerizable compound and a polyfunctional polymerizable compound (ie, bifunctional, trifunctional and 4-6 functional), or a mixture thereof. Examples of the monofunctional polymerizable compound include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters thereof, and amides. As the polyfunctional polymerizable compound, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used.

  Also, addition reaction products, monofunctional or polyfunctional unsaturated carboxylic acid esters or amides having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group and the like with monofunctional or polyfunctional isocyanates and epoxies. A dehydration condensation reaction product with a functional carboxylic acid can also be used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, and a halogen group A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol can also be used.

  As a specific example of the radical polymerizable compound which is an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, a (meth) acrylic acid ester is representative, and at least one kind of a trifunctional or higher functional (meth) acrylate is used. It is preferable to use at least one of monofunctional and / or bifunctional (meth) acrylates.

  Specific examples of monofunctional (meth) acrylates include tolyloxyethyl (meth) acrylate, phenyloxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, isobornyl (meth) Examples thereof include acrylate and tetrahydrofurfuryl (meth) acrylate.

  Specific examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, Propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, Mention may be made of pentaerythritol di (meth) acrylate and dipentaerythritol di (meth) acrylate.

  Specific examples of trifunctional (meth) acrylates include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane alkylene oxide modified tri (meth) acrylate, pentaerythritol tri (meth) acrylate , Dipentaerythritol tri (meth) acrylate, trimethylolpropane tri ((meth) acryloyloxypropyl) ether, isocyanuric acid alkylene oxide modified tri (meth) acrylate, propionate dipentaerythritol tri (meth) acrylate, tri ((meta ) Acryloyloxyethyl) isocyanurate, hydroxypivalaldehyde modified dimethylolpropane tri (meth) acrylate, sorbitol tri (meth) acrylate Mention may be made of the rate.

  Specific examples of tetrafunctional (meth) acrylates include pentaerythritol tetra (meth) acrylate, sorbitol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate propionate, ethoxylated penta Mention may be made of erythritol tetra (meth) acrylate.

Specific examples of the pentafunctional (meth) acrylate include sorbitol penta (meth) acrylate and dipentaerythritol penta (meth) acrylate.
Specific examples of hexafunctional (meth) acrylate include dipentaerythritol hexa (meth) acrylate, sorbitol hexa (meth) acrylate, phosphazene alkylene oxide modified hexa (meth) acrylate, captolactone modified dipentaerythritol hexa (meth) acrylate Can be mentioned.

  Here, the above notation of (meth) acrylate is an abbreviated notation indicating that it can have both a methacrylate structure and an acrylate structure.

  Radical polymerizable compounds that are esters of various unsaturated carboxylic acids and aliphatic alcohol compounds are commercially available, PEG600 diacrylate (EB11: manufactured by Daicel UCB), KAYARAD DPCA-60 (caprolactone-modified dipentaerythritol hexa). Acrylate: Nippon Kayaku Co., Ltd.)

  In the present invention, it is preferable that the ink composition contains at least one polyfunctional (meth) acrylate as a polymerizable compound. The polymerizable compound preferably contains (a) at least one trifunctional or higher (meth) acrylate and (b) at least one monofunctional and / or bifunctional (meth) acrylate. Further, (a) the trifunctional or higher functional (meth) acrylate is more preferably a tetrafunctional, pentafunctional or hexafunctional (meth) acrylate.

In addition to (meth) acrylate, itaconic acid ester, crotonic acid ester, isocrotonic acid ester, maleic acid ester and the like can also be used as the polymerizable compound.
Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

  Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.

  Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

  Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

  Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, JP-A-59-5241. Those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 can be used.

  Specific examples of amide monomers of unsaturated carboxylic acid and aliphatic polyvalent amine compound include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.

  Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinylurethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following formula (I) to a polyisocyanate compound having two or more isocyanate groups. Etc.
Formula (I)
^{_{CH 2 = C (R 1)}} COOCH 2 CH (R 2) OH
(However, R ¹ and R ² represent H or CH _3. )

  In the present invention, a cationic ring-opening polymerizable compound having at least one cyclic ether group such as an epoxy group and / or an oxetane group in the molecule may be used as a UV curable ink composition together with a UV cationic polymerization initiator. it can.

The general cationic polymerizable compounds preferably used in the present invention will be described below. Examples of the cationic polymerizable compound include curable compounds containing a ring-opening polymerizable group, and among them, a heterocyclic group-containing curable compound is preferable. Examples of such a curable compound include epoxy derivatives, oxetane derivatives, tetrahydrofuran derivatives, cyclic lactone derivatives, cyclic carbonate derivatives, cyclic imino ethers such as oxazoline derivatives, vinyl ethers, etc., and particularly epoxy derivatives, oxetane derivatives, and vinyl ethers. preferable.
Examples of preferable epoxy derivatives are roughly classified into monofunctional glycidyl ethers, polyfunctional glycidyl ethers, monofunctional alicyclic epoxies, polyfunctional alicyclic epoxies, and the like.

  Specific examples of monofunctional and polyfunctional glycidyl ethers include diglycidyl ethers (for example, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether), trifunctional or higher glycidyl ethers (trimethylolethane triglycidyl ether) , Trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, triglycidyl trishydroxyethyl isocyanurate, etc.), tetra- or higher functional glycidyl ethers (sorbitol tetraglycidyl ether, pentaerythritol tetraglycyl ether, polyglycidyl ether of cresol novolac resin, Phenol novolac resin polyglycidyl ether, etc.), alicyclic epoxies (Celoxide 2021P, Celoxy Id 2081, epolide GT-301, epolide GT-401 (manufactured by Daicel Chemical Industries, Ltd.), EHPE (manufactured by Daicel Chemical Industries, Ltd.), phenol novolac resin polycyclohexyl epoxy methyl ether, etc.), oxetanes (OX-SQ, PNOX-1009 (manufactured by Toagosei Co., Ltd.)) and the like are included, but the present invention is not limited to these.

In the present invention, an alicyclic epoxy derivative can be preferably used. The “alicyclic epoxy group” refers to a partial structure obtained by epoxidizing a double bond of a cycloalkene ring such as a cyclopentene group or a cyclohexene group with an appropriate oxidizing agent such as hydrogen peroxide or peracid.
The alicyclic epoxy compound is preferably a polyfunctional alicyclic epoxy having two or more cyclohexene oxide groups or cyclopentene oxide groups in one molecule. Specific examples of the monofunctional or polyfunctional alicyclic epoxy compound include 4-vinylcyclohexene dioxide, (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexylcarboxylate, and di (3,4-epoxy). Cyclohexyl) adipate, di (3,4-epoxycyclohexylmethyl) adipate, bis (2,3-epoxycyclopentyl) ether, di (2,3-epoxy-6-methylcyclohexylmethyl) adipate, dicyclopentadiene dioxide Can be mentioned.
One type of alicyclic epoxy compound may be used, or a mixture of two or more types may be used.
Various alicyclic epoxy compounds are commercially available and can be obtained from Union Carbide Japan Co., Ltd., Daicel Chemical Industries, Ltd., and the like.

The glycidyl compound which has a normal epoxy group which does not have an alicyclic structure in a molecule | numerator can be used independently, or it can also use together with said alicyclic epoxy compound.
Examples of such normal glycidyl compounds include glycidyl ether compounds and glycidyl ester compounds, but it is preferable to use glycidyl ether compounds in combination.
Specific examples of the glycidyl ether compound include 1,3-bis (2,3-epoxypropyloxy) benzene, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy. Resin, aromatic glycidyl ether compound such as trisphenol methane type epoxy resin, aliphatic glycidyl ether compound such as 1,4-butanediol glycidyl ether, glycerol triglycidyl ether, propylene glycol diglycidyl ether, trimethylolpropane tritriglycidyl ether Can be mentioned. Examples of the glycidyl ester include glycidyl ester of linolenic acid dimer.
Glycidyl ethers can be obtained commercially from Yuka Shell Epoxy Co., Ltd.

  In the present invention, a compound having an oxetanyl group which is a 4-membered cyclic ether (hereinafter, also simply referred to as “oxetane compound”) can be used. An oxetanyl group-containing compound is a compound having one or more oxetanyl groups in one molecule. This oxetanyl group-containing compound is roughly classified into a monofunctional oxetane compound having one oxetanyl group in one molecule and a polyfunctional oxetane compound having two or more oxetanyl groups in one molecule.

  As the monofunctional oxetane compound, a compound represented by the following general formula (1) is preferable.

式（１）中、Ｒ₁はメチル基又はエチル基を示す。Ｒ₂は、炭素数６ないし１２の炭化水素基を示す。
Ｒ₂の炭化水素基としては、フェニル基やベンジル基も採りうるが、炭素数６ないし８のアルキル基が好ましく、２−エチルへキシル基等の分岐アルキル基が特に好ましい。Ｒ₂がフェニル基であるオキセタン化合物の例は、特開平１１−１４０２７９号公報に記載されている。Ｒ₂が置換されていても良い、ベンジル基であるオキセタン化合物の例は、特開平６−１６８０４号公報に記載されている。

In formula (1), R ₁ represents a methyl group or an ethyl group. R ₂ represents a hydrocarbon group having 6 to 12 carbon atoms.
The hydrocarbon group for R ₂ may be a phenyl group or a benzyl group, but is preferably an alkyl group having 6 to 8 carbon atoms, particularly preferably a branched alkyl group such as a 2-ethylhexyl group. Examples of oxetane compounds in which R ₂ is a phenyl group are described in JP-A No. 11-140279. An example of an oxetane compound which is a benzyl group, in which R ₂ may be substituted, is described in JP-A-6-16804.

  In this invention, although a polyfunctional oxetane compound can be used, a preferable compound group is represented by following General formula (2).

式（２）中、ｍは２、３又は４の自然数を示し、Ｚは酸素原子、硫黄原子、又はセレン原子を表す。Ｒ₃は水素原子、フッ素原子、炭素数が１ないし６の直鎖もしくは分岐状のアルキル基、炭素数が１ないし６のフルオロアルキル、アリル基、フェニル基又はフリル基である。Ｒ₄は、ｍ価の連結基であり、炭素数が１ないし２０の基であることが好ましく、１個以上の酸素原子、硫黄原子を含んでいても良い。
Ｚは酸素原子が好ましく、Ｒ₃はエチル基が好ましく、ｍは２が好ましく、Ｒ₄としては、炭素数が１ないし１６の線形又は分岐アルキレン基、線形又は分岐ポリ（アルキレンオキシ）基が好ましく、Ｒ₃、Ｒ₄、Ｚ、及びｍに対する好ましい例の内から任意の２つ以上を組み合わせた化合物は更に好ましい。

In formula (2), m represents a natural number of 2, 3 or 4, and Z represents an oxygen atom, a sulfur atom or a selenium atom. R ₃ is a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluoroalkyl having 1 to 6 carbon atoms, an allyl group, a phenyl group or a furyl group. R ₄ is an m-valent linking group, preferably a group having 1 to 20 carbon atoms, and may contain one or more oxygen atoms and sulfur atoms.
Z is preferably an oxygen atom, R ₃ is preferably an ethyl group, m is preferably 2, and R ₄ is preferably a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched poly (alkyleneoxy) group. , R ₃ , R ₄ , Z, and m are more preferably compounds obtained by combining any two or more of the preferred examples.

  As the ink composition of the present invention, it is also preferable to use a radical polymerizable ethylenically unsaturated compound and a cationic polymerizable cyclic ether (epoxy derivative and / or oxetane derivative) in combination. There is an advantage that a bonded body having a balanced physical property can be obtained due to the structure of an interpenetrating polymer network (IPN). In this case, it is preferable to use a radical photopolymerization initiator and a cationic photopolymerization initiator (such as an onium salt) in combination as the photopolymerization initiator.

  The volatile component after curing of the ultraviolet curable ink composition is preferably 5% by weight or less. Therefore, it is preferable to use a solvent-free formulation that does not use an organic solvent in the ink composition.

(Photopolymerization initiator)
The photopolymerization initiator used in the present invention refers to a compound that generates active radical species or cationic species by applying active light and initiates and accelerates the polymerization reaction of the ink composition. Ultraviolet rays are preferred as the active light. In addition, gamma rays, alpha rays, electron beams, etc., known as active energy rays, can be used in place of active rays.

Examples of the polymerization initiator that generates radicals by the action of light are preferably acetophenone compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, benzyl compounds, acylphosphine oxide compounds, and the like. Examples of the acetophenone compound include 2,2-diethoxyacetophenone, 2-hydroxymethyl-1-phenylpropan-1-one, 4′-isopropyl-2-hydroxy-2-methyl-propiophenone, 2-hydroxy -2-methyl-propiophenone, p-dimethylaminoacetone, p-tert-butyldichloroacetophenone, p-tert-butyltrichloroacetophenone, p-azidobenzalacetophenone, 1-hydroxycyclohexyl phenyl ketone and the like. Examples of the benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, and benzyldimethyl ketal. Examples of the benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, Michler's ketone, 4,4′-bisdiethylaminobenzophenone, 4,4′-dichlorobenzophenone, and the like. Examples of the thioxanthone compound include thioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, and the like. Examples of the benzyl compound include benzyl and benzyl-β-methoxyethyl acetal. Examples of the acyl phosphine oxide compound include bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) phosphine oxide, 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, and the like.
Since the sulfonium salt and iodonium salt, which are usually used as photocation generators described below, act as radical generators upon irradiation with ultraviolet rays, these may be used alone in the present invention. In addition to a polymerization initiator, a sensitizer may be used for the purpose of increasing sensitivity. Examples of the sensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone derivatives.

  As a photopolymerization initiator that generates an active cationic species by ultraviolet rays, an onium salt initiator such as an aromatic iodonium salt such as a triarylsulfonium salt or an aromatic iodonium salt such as a diaryliodonium salt is useful. Nonionic initiators such as nitrobenzyl esters can also be used. Among these, aromatic sulfonium salts and the like are preferable because they are thermally relatively stable. In addition, known photopolymerization initiators described in “Organic Materials for Imaging” published by Organic Electronics Materials Research Group (published in 1997), etc. can also be used.

When an aromatic sulfonium salt and an aromatic iodonium salt are used as an onium salt photoinitiator, the counter anions include BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ , PF ₆ ⁻ , B (C ₆ F ₅ ) _4- ^{and the} like. As the initiator, PF ₆ salt or SbF ₆ salt of aromatic sulfonium can be preferably used since it has solubility and moderate polymerization activity. In order to improve solubility, one or more alkyl groups or alkoxy groups having 1 to 10 carbon atoms are introduced into the aromatic group, usually phenyl group, of the aromatic group iodonium salt or aromatic sulfonium salt. A chemical structure is preferred.
PF ₆ salt or SbF ₆ salt of aromatic sulfonium salt is commercially available from Union Carbide Japan Co., Ltd. Asahi Denka Kogyo Co., Ltd. also sells PF ₆ salt of aromatic sulfonium under the trade name of Adekaoptomer SP series.
The aromatic sulfonium salt has an absorption up to about 360 nm, and the aromatic iodonium salt has an absorption up to about 320 nm. Therefore, for curing, it is preferable to irradiate ultraviolet rays including the spectral energy in this region.

  The addition amount of the photopolymerization initiator is preferably 0.05 to 10% by weight and more preferably 0.1 to 5% by weight with respect to the total amount of the polymerizable compound and the photopolymerization initiator.

(Polymer compound for viscosity adjustment)
In order to adjust the viscosity of the ink composition, a viscosity adjusting polymerizable compound may be added. As the polymerizable compound for adjusting viscosity, a compound having a low viscosity and copolymerizable with the polymerizable compound is used. For example, acrylate, methacrylate, acrylamides can be mentioned. Specifically, tolyloxyethyl (meth) acrylate, phenyloxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, ethylene glycol di (meth) acrylate, divinylbenzene, Methylene bisacrylamide, 1,6-di (meth) acryloyloxyhexane, etc., preferably, tolyloxyethyl (meth) acrylate, ethylene glycol di (meth) acrylate, 1,6-di (meth) acryloyloxyhexane, etc. It is done.
In ring-opening polymerizable cyclic ethers, bifunctional or higher cyclic ethers generally have high reactivity but high viscosity. Monofunctional cyclic ethers can be used in combination to adjust the viscosity to low.

(Chain transfer agent)
The ink composition of the present invention contains a chain transfer agent. Chain transfer agents include (1) o-quinonediazides, (2) mercaptoazoles, (3) N-aminomethyl group substituted azoles, (4) halogen substituted 1,3,5-triazines, and (6 ) A compound selected from the group consisting of disulfonyldiazomethanes. The compounds (1) to (6) will be described below.

(1) o-quinonediazides As the o-quinonediazides, compounds represented by the following general formula (1) are preferable.

In general formula (1), R ¹ represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a nitro group. The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, _{e.g., -CH 3, -C 6 H 13} , -C 8 H 17, -CH 2 CH (C 2 H 5) CH 2 CH 2 CH ₂ CH _{3 and the} like. As said aryl group, a C6-C30 aryl group is preferable, For example, the thing of the following structure etc. are mentioned.

R ² in the above formula represents an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a heterocyclic group, and examples of the substituent in the case of being substituted include —OCH ₃ , —Cl, —C _{6 H 5, -OC 6 H 5} , -NH 2 , and the like. The alkyl group is preferably an alkyl group having 1 to 15 carbon atoms, _{e.g., -CH 3, -C 6 H 13} , -C 8 H 17, -CH 2 CH (C 2 H 5) CH 2 CH 2 CH ₂ CH _{3 and the} like. The aryl group is preferably an aryl group having 6 to 30 carbon atoms, and examples thereof include those of the following group (i). Examples of the heterocyclic group include those of the following group (ii). It is done.

  Specific examples of the compound represented by the general formula (1) include the compounds shown below (Exemplary Compounds 1-1 to 1-10), but the invention is not limited thereto.

(2) Mercaptoazoles As the mercaptoazoles, compounds represented by the following general formula (2) are preferable.

In the general formula (2), X, NR ^3, an oxygen atom, a sulfur atom, a carbon atom, R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include —CH ₃ , —C ₂ H ₅ , —C ₃ H ₆ , —C ₄ H _{9 and the} like.

A in the general formula (2) forms a 5- or 6-membered heterocycle having a carbon atom together with the N═C—X moiety, and A is a N═C—X moiety by a single bond or a double bond. Two or three carbon atoms that are bonded to each other as part of an aromatic group, two nitrogen atoms that are bonded to each other, or one nitrogen atom that is bonded to one carbon atom Represent. Examples of A include CH ₂ CH ₂ , CHCH, N═N, or a CH ₂ CH ₂ CH ₂ portion constituting a part of a benzene ring or a naphthalene ring. Examples of the 5-membered or 6-membered heterocycle formed by including the A and N═C—X moieties include those having the following structures, among which the following (1) or (3) is preferable.

  Specific examples of the compound represented by the general formula (2) include the following compounds (Exemplary Compounds 2-1 to 2-15), but the present invention is not limited thereto.

(3) N-aminomethyl group-substituted azoles As the N-aminomethyl group-substituted azoles, compounds represented by the following general formula (3) are preferable.

In the general formula (3), X represents NR ⁴ , an oxygen atom, a sulfur atom, or a carbon atom, R ⁴ has the same meaning as R ³ in the general formula (2), and A is also the general formula (2). It is synonymous with the case of. D represents an oxygen atom or a sulfur atom. R ⁵ and R ⁶ in the formula represent a hydrogen atom, an alkyl group, or an aryl group, and the alkyl group and aryl group may be substituted. Examples of the substituent include —Cl, —OCH ₃ , —CH ₃ , —N (CH ₃ ) ₂ , —NH _{2 and the} like.

The alkyl group is preferably an alkyl group having 1 to 13 carbon atoms, _{e.g., -CH 3, -C 2 H 5} , -C 3 H 6, -C 4 H 9, -C 6 H 13 and the like . As said aryl group, a C6-C30 aryl group is preferable, For example, the thing of the following structure etc. are mentioned.

R ⁷ and R ⁸ in the above formulas represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. R ⁷ and R ⁸ may be bonded together to form a pyrrolidine, piperidine, morpholine or N-substituted piperazine nucleus together with the nitrogen atom.

  Specific examples of the compound represented by the general formula (3) include those described in JP-A-60-12543 and JP-A-60-15544, and the compounds shown below (Exemplary Compound 3-1). ~ 3-18). However, the present invention is not limited to these.

(4) Halogen-substituted 1,3,5-triazines As 1,3,5-triazines having a methyl group substituted with a halogen atom, compounds represented by the following general formula (4) are preferred.

In the general formula (4), Y represents a halogen atom, and among them, a chlorine atom is preferable. Z in the formula represents —CY ₃ , —NH ₂ , —NHR ⁹ , —N (R ⁹ ) ₂ , —OR ⁹ , and Y is as defined above.

R ⁹ represents an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group, and examples of the substituent in the case of substitution include —Cl, —NH ₂ , —N (CH ₃ ) ₂ , — COOC ₂ H _5, -OCH _3, include -OC ₂ H ₅ and the like. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, _{e.g., -CH 3, -C 2 H 5} , -C 3 H 6, -C 6 H 13 and the like. As said aryl group, a C6-C30 aryl group is preferable, For example, the thing of the following structure etc. are mentioned.

R ¹⁰ in the above formula represents —CY ₃ , an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, or a substituted alkenyl group, and Y has the same meaning as described above, and is a substituent when substituted. Examples thereof include —Cl, —CH ₃ , —OCH ₃ , —NH ₂ , —N (CH ₃ ) _{2 and the} like.

The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, _{e.g., -CH 3, -C 2 H 5} , -C 3 H 6, -C 6 H 13 and the like. As said aryl group, a C6-C20 aryl group is preferable, For example, the thing of the following structure etc. are mentioned.

Examples of the alkenyl group is preferably an alkenyl group having 2 to 10 carbon atoms, _{e.g., -CH = CHCH 3, -CH =} CHCH = CHCH 3 , and the like.

  Specific examples of the compound represented by the general formula (4) include the following compounds (Exemplary Compounds 4-1 to 4-18), but the invention is not limited thereto.

(6) Disulfonyldiazomethanes The disulfonyldiazomethanes are preferably compounds represented by the following general formula (6).

In the general formula (6), E ¹ and E ² each independently represent a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and E ¹ and E ² may be the same or different. Good. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

When E ¹ and / or E ² represents an aliphatic group, examples of the aliphatic group include an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group, or Examples thereof include a substituted aralkyl group, and among them, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group, or a substituted aralkyl group are preferable, and an alkyl group and a substituted alkyl group are particularly preferable. The aliphatic group may be a cyclic aliphatic group or a chain aliphatic group. The chain aliphatic group may have a branch.

  Examples of the alkyl group include linear, branched and cyclic alkyl groups, and the number of carbon atoms of the alkyl group is preferably 1 to 30, and more preferably 1 to 20. The preferred range of the number of carbon atoms in the alkyl part of the substituted alkyl group is the same as in the case of the alkyl group. Further, the alkyl group may be either a substituted alkyl group or an unsubstituted alkyl group. Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, decyl group, dodecyl group, octadecyl group, cyclohexyl group, cyclopentyl group, neopentyl group, An isopropyl group, an isobutyl group, etc. are mentioned.

  Examples of the substituent of the substituted alkyl group include a carboxyl group, a sulfo group, a cyano group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom), a hydroxy group, and an alkoxycarbonyl group having 30 or less carbon atoms (for example, methoxycarbonyl). Group, ethoxycarbonyl group, benzyloxycarbonyl group), alkylsulfonylaminocarbonyl group having 30 or less carbon atoms, arylsulfonylaminocarbonyl group, alkylsulfonyl group, arylsulfonyl group, acylaminosulfonyl group having 30 or less carbon atoms, carbon number 30 The following alkoxy groups (for example, methoxy group, ethoxy group, benzyloxy group, phenoxyethoxy group, phenethyloxy group, etc.), alkylthio groups having 30 or less carbon atoms (for example, methylthio group, ethylthio group, methylthioethylthioethyl group, etc.) An aryloxy group having 30 or less carbon atoms (for example, phenoxy group, p-tolyloxy group, 1-naphthoxy group, 2-naphthoxy group, etc.), nitro group, alkyl group having 30 or less carbon atoms, alkoxycarbonyloxy group, aryloxy A carbonyloxy group,

  Acyloxy group having 30 or less carbon atoms (for example, acetyloxy group, propionyloxy group, etc.), Acyl group having 30 or less carbon atoms (for example, acetyl group, propionyl group, benzoyl group, etc.), carbamoyl group (for example, carbamoyl group, N , N-dimethylcarbamoyl group, morpholinocarbonyl group, piperidinocarbonyl group, etc.), sulfamoyl group (for example, sulfamoyl group, N, N-dimethylsulfamoyl group, morpholinosulfonyl group, piperidinosulfonyl group, etc.), carbon An aryl group having a number of 30 or less (for example, phenyl group, 4-chlorophenyl group, 4-methylphenyl group, α-naphthyl group, etc.), substituted amino group (for example, amino group, alkylamino group, dialkylamino group, arylamino group) , Diarylamino group, acylamino group, etc.), substituted urea De group, a substituted phosphono group, and a heterocyclic group. Here, the carboxyl group, the sulfo group, the hydroxy group, and the phosphono group may be in a salt state.

Examples of the cation that forms a salt state include an organic cationic compound, a transition metal coordination complex cation (such as the compound described in Japanese Patent No. 2791143), or a metal cation (for example, Na ⁺ , K ⁺ , Li ⁺ , Ag). ⁺ , Fe ²⁺ , Fe ³⁺ , Cu ⁺ , Cu ²⁺ , Zn ²⁺ , Al ³⁺ , 1 / 2Ca ^2+, etc.) are preferred. Examples of the organic cationic compound include a quaternary ammonium cation, a quaternary pyridinium cation, a quaternary quinolinium cation, a phosphonium cation, an iodonium cation, a sulfonium cation, and a dye cation.

  Examples of the quaternary ammonium cation include a tetraalkylammonium cation (eg, tetramethylammonium cation, tetrabutylammonium cation), a tetraarylammonium cation (eg, tetraphenylammonium cation), and the quaternary pyridinium cation includes N -Alkyl pyridinium cations (eg N-methyl pyridinium cation), N-aryl pyridinium cations (eg N-phenyl pyridinium cation), N-alkoxy pyridinium cations (eg 4-phenyl-N-methoxy-pyridinium cation), N -Benzoylpyridinium cation, etc., and the quaternary quinolinium cation includes N-alkylquinolinium cation (for example, N-methyl cation). Li cation), N- aryl quinolinium cations (e.g., N- phenyl quinolinium cation), and examples of the phosphonium cation, tetra aryl phosphonium cations (for example, tetraphenylphosphonium cation) and the like. Examples of the iodonium cation include a diaryl iodonium cation (for example, a diphenyl iodonium cation), and examples of the sulfonium cation include a triaryl sulfonium cation (for example, a triphenyl sulfonium cation). In each of these cationic compounds, the alkyl group includes an alkyl group having 1 to 30 carbon atoms (for example, an unsubstituted alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, hexyl; 2-hydroxyethyl, 3- Hydroxy group alkyl group such as hydroxybutyl, etc.) is preferable, and an alkyl group having 1 to 12 carbon atoms is particularly preferable. Examples of the aryl group include phenyl group, halogen atom (for example, chlorine atom) -substituted phenyl group, alkyl ( For example, a methyl) substituted phenyl group and an alkoxy (for example, methoxy) substituted phenyl group are preferable. Further, specific examples of the cation include compounds described in paragraphs [0020] to [0038] of JP-A-9-188686.

  Examples of the alkenyl group include linear, branched, and cyclic alkenyl groups. The number of carbon atoms of the alkenyl group is preferably 2 to 30, and more preferably 2 to 20. The preferred range of the number of carbon atoms in the alkenyl part of the substituted alkenyl group is the same as in the case of the alkenyl group. The alkenyl group may be a substituted alkenyl group or an unsubstituted alkenyl group. Examples of the substituent of the substituted alkenyl group include the same substituents as those of the substituted alkyl group.

  Examples of the alkynyl group include linear, branched, and cyclic alkynyl groups, and the number of carbon atoms of the alkynyl group is preferably 2 to 30, and more preferably 2 to 20. The preferred range of the number of carbon atoms in the alkynyl part of the substituted alkynyl group is the same as in the case of the alkynyl group. Further, the alkynyl group may be either a substituted alkynyl group or an unsubstituted alkynyl group. Examples of the substituent for the substituted alkynyl group include the same substituents as those for the substituted alkyl group.

  Examples of the aralkyl group include linear, branched, and cyclic aralkyl groups. The number of carbon atoms in the aralkyl group is preferably 7 to 35, and more preferably 7 to 25. The preferred range of the number of carbon atoms in the aralkyl part of the substituted aralkyl group is the same as in the case of the aralkyl group. Further, the aralkyl group may be any of an aralkyl group having a substituent and an unsubstituted aralkyl group. Examples of the substituent for the substituted aralkyl group include the same substituents as those for the substituted alkyl group.

When E ¹ and / or E ² represent an aromatic group, examples of the aromatic group include an aryl group and a substituted aryl group. As a carbon atom number of an aryl group, 6-30 are preferable and 6-20 are more preferable. The preferable range of the number of carbon atoms in the aryl part of the substituted aryl group is the same as that of the aryl group. Examples of the aryl group include a phenyl group, an α-naphthyl group, a β-naphthyl group, and the like. Examples of the substituent for the substituted aryl group include the same substituents as those for the substituted alkyl group.

When E ¹ and / or E ² represents a heterocyclic group, examples of the heterocyclic group include a heterocyclic group having a substituent and an unsubstituted heterocyclic group, and the number of carbon atoms of the heterocyclic group Is preferably 4-13. Examples of the heterocyclic group include nitrogen-containing, oxygen-containing, and sulfur-containing heterocycles, and more specifically, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, quinoline ring, isoquinoline ring, quinoxaline. Ring, acridine ring, furan ring, pyrrole ring, pyrazole ring, imidazole ring, pyrroline ring, oxazole ring, thiazole ring, oxadiazole ring, thiazoline ring, thiophene ring, indole ring and the like. Examples of the substituent of the heterocyclic group having a substituent include the same substituents as in the case of the substituted alkyl group.

Among the above, as E ¹ and E ² , an unsubstituted alkyl group (for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, octyl group, An octadecyl group or the like) or a substituted alkyl group. Among the substituted alkyl groups, a substituted oxyalkyl group (for example, methoxyethyl group, phenoxyethyl group and the like) and a substituted oxycarbonylalkyl group (for example, butoxycarbonylmethyl group, phenoxyethoxycarbonylmethyl group and the like) are particularly preferable. E ¹ and E ² may be bonded to other adjacent substituents to form a ring, and examples of the ring include a 5-membered or 6-membered heterocycle. .

  Specific examples of the compound represented by the general formula (6) include the following compounds (Exemplary Compounds 6-1 to 6-11), but the present invention is not limited thereto.

  As the chain transfer agent, compounds represented by the general formulas (2), (3) and (6) are preferable, and the exemplified compounds 2-1, 2-5, 2-7, 3-1, and 6-2 include More preferred.

  The addition amount of the chain transfer agent is preferably from 0.1 to 40% by weight, more preferably from 1 to 10% by weight, based on the polymerizable compound.

(Coloring agent)
Colorants that can be used in the ink composition of the present invention are roughly classified into dyes and pigments, and dyes can be preferably used. The dye is preferably an oil-soluble dye.

<Dye>
By using yellow (Y), magenta (M) and cyan (C) dyes, which are the three primary colors of the subtractive color method, a wide range of hues can be reproduced with different saturations. In this invention, it is preferable to use the dye utilized for the color print of a color photograph. Details are described below.

As yellow dyes, U.S. Pat. Nos. 3,933,501, 4,022,620, 4,326,024, 4,401,752, 4,248,961, JP-B 58- 10739, British Patents 1,425,020, 1,476,760, U.S. Patents 3,973,968, 4,314,023, 4,511,649, European Patent 249,473A No., couplers represented by formulas (I) and (II) of No. 502,424A, couplers represented by formulas (1) and (2) of No. 513,496A (particularly Y-28 on page 18) A coupler represented by formula (I) in claim 1 of US Pat. No. 568,037A, a coupler represented by general formula (I) in columns 45 to 55 of column 1 of US Pat. No. 5,066,576, The general formula (I A coupler described in claim 1 on page 40 of European Patent No. 498,381A1 (particularly D-35 on page 18), a coupler represented by formula (Y) on page 4 of 447,969A1 (Especially Y-1 (page 17), Y-54 (page 41)), couplers represented by formulas (II) to (IV) in columns 7 to 58 of US Pat. No. 4,476,219, column 7. And ketimine type dyes obtained from (particularly II-17, 19 (column 17), II-24 (column 19)). Preferably, dyes described in JP 2001-294773 A, JP 2002-121414 A, JP 2002-105370 A, JP 2003-26974 A, JP 2003-73598 A, and the like are mentioned. Among these, a pyrazole compound represented by the general formula (Y-II) described in JP-A-2003-73598 is more preferably used.
Y-1 shown below can be preferably used as a yellow dye.

Examples of the magenta dye include dyes described in JP-A Nos. 2001-181549, 2002-121414, 2002-105370, 2003-12981, and 2003-26974. It is done.
Of these, a pyrazolotriazole azomethine compound represented by the general formula (III) described in JP-A No. 2002-121414 is preferably used.
M-1 shown below can be preferably used.

Examples of the cyan dye include dyes described in JP-A Nos. 2002-121414, 2002-105370, 2003-3109, and 2003-26974.
A pyrrolotriazole azomethine compound represented by the general formula (IV-1a) described in JP-A No. 2002-121414 and a phthalocyanine compound represented by the general formulas (C-II-1) and (C-II-2) Preferably used.
C-1 shown below can be preferably used as a cyan dye.

  If necessary, a black (black) dye may be used in combination with the three primary colors of CMY. The black dye can be made by mixing CMY3 dye.

As dyes other than those described above, those generally used in the technical field of printing (for example, color materials for copying or color proofing plates such as printing ink, thermal ink jet recording, and electrophotographic recording) can be used.
For example, “Organization of Organic Synthetic Chemistry” “Dye Handbook” Maruzen Co., Ltd. (published in 1970), Sadaharu Abeda, Kunihiko Imada “Commentary Dye Chemistry” Co., Ltd. Examples include dyes described in Kodansha (1986), Chemicals for Inkjet Printers-Material Development Trends and Perspective Survey-"CMC Co., Ltd. (1997), Takeshi Amari" Inkjet Printers-Technology and Materials ", etc. It is done.

  In the present invention, it is preferable to use an oil-soluble dye having an oxidation potential nobler than 1.0 V (SCE). The oxidation potential is more preferable as it is noble, the oxidation potential is more noble than 1.1 V (SCE), more preferably 1.2 V (SCE).

  A person skilled in the art can easily measure the value of the oxidation potential (Eox). Regarding this method, see, for example, P.I. Delahay, “New Instrumental Methods in Electrochemistry” (1954, published by Interscience Publishers) J. et al. "Electrochemical Methods" by Bard et al. (1980, published by John Wiley & Sons) and "Electrochemical Measurement Methods" by Akira Fujishima et al. (Published by Gihodo Publishing Co., 1984).

Specifically, the oxidation potential is 1 × 10 ⁻⁴ to 1 × 10 ⁻⁶ mol / in a solvent such as dimethylformamide or acetonitrile containing a supporting electrolyte such as sodium perchlorate or tetrapropylammonium perchlorate. Approximate the oxidization wave in a straight line by dissolving 1 liter and sweeping to the oxidation side (noble side) using carbon (GC) as the working electrode and rotating platinum electrode as the counter electrode by cyclic voltammetry and DC polarography equipment The intermediate potential of the line formed by the intersection of this straight line and the residual current / potential line and the intersection of the straight line and the saturation current line (or the intersection of the straight line parallel to the vertical axis passing through the peak potential value) Values are measured as values for SCE (saturated calomel electrode). Although this value may be deviated by several tens of mil volts due to the influence of the liquid potential difference or the liquid resistance of the sample solution, the reproducibility of the potential can be ensured by inserting a standard sample (for example, hydroquinone). The supporting electrolyte and solvent to be used can be selected appropriately depending on the oxidation potential and solubility of the test sample. The supporting electrolytes and solvents that can be used are described in Akira Fujishima et al., “Electrochemical measurement method” (published by Gihodo Publishing Co., Ltd., 1984), pages 101 to 118.
In the concentration range of the measurement solvent and the phthalocyanine compound sample, the oxidation potential in a non-association state is measured.

The value of Eox represents the ease of electron transfer from the sample to the electrode, and the greater the value (the higher the oxidation potential), the less electron transfer from the sample to the electrode, in other words, the less easily oxidized.
When a dye having a noble oxidation potential is used, there is almost no polymerization inhibition.

<Pigment>
The pigment is not particularly limited, and all commercially available organic and inorganic pigments or pigments dispersed in an insoluble resin or the like as a dispersion medium, or the resin is grafted onto the pigment surface Can be used. Moreover, what dye | stained the resin particle with dye can be used.

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

  Here, titanium oxide has a smaller specific gravity than other white pigments, a large refractive index, and is chemically and physically stable. Therefore, it has a high hiding power and coloring power as a pigment, and further, acid and alkali. Excellent durability against other environments. Therefore, it is preferable to use titanium oxide as the white pigment. Of course, other white pigments (may be other than the listed white pigments) may be used as necessary.

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

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

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

(Other additives)
In the range which does not impair the effect of this invention, the other component suitably selected according to the objective may be included. Examples of the other components include known additives such as solvents, polymers, surface tension adjusters, storage stabilizers, ultraviolet absorbers, antioxidants, anti-fading agents, conductive salts, and pH adjusters. .

  The preferred physical properties of the ink depend on the printing apparatus, but generally the viscosity is preferably 5 to 100 mPa · s (25 ° C.), more preferably 10 to 80 mPa · s (25 ° C.). The surface tension is preferably 20 to 60 mN / m, and more preferably 20 to 40 mN / m.

  The ink composition of the present invention is suitably used for an ink jet recording method. Hereinafter, an ink jet recording method using the ink composition of the present invention will be described.

  In the ink jet recording method of the present invention, the above ink composition is printed on a recording material by an ink jet printer (hereinafter referred to as “printing step”), and the printed ink composition is irradiated with actinic radiation and cured. Process (hereinafter referred to as “curing process”).

(Printing process)
There is no restriction | limiting in particular about the ink nozzle etc. which are used for an inkjet recording method, According to the objective, it can select suitably.
The ink composition of the present invention can be suitably printed on a known recording material. For example, plain paper, resin-coated paper, inkjet-only paper, film, electrophotographic co-paper, fabric, glass, metal, ceramics, and the like can be given. The recording material is described in Japanese Patent Application Laid-Open No. 2001-181549.
The ink of the present invention can be applied to any ink jet recording system. For example, a charge control system that ejects ink using electrostatic attraction, a drop-on-demand system (pressure pulse system) that uses vibration pressure of a piezo element , An acoustic ink jet method that converts electrical signals into acoustic beams, irradiates the ink with ink and ejects the ink using radiation pressure, thermal ink jet that heats the ink to form bubbles and uses the generated pressure (bubble jet (registered) Trademark)) system, etc. The ink jet recording method includes a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving the image quality using a plurality of inks having substantially the same hue and different concentrations, and a colorless and transparent type. A method using ink is included.

(Curing process)
The actinic radiation used in the present invention includes various types of radiation such as electron beams (β rays), ultraviolet rays, X rays, γ rays, and α rays. Among these, it is particularly preferable to use a binder that cures with ultraviolet rays (ultraviolet (UV) curable binder).
For UV exposure for curing the UV curable ink composition, generally used high pressure mercury lamps, low pressure mercury lamps, deep UV lamps, halogen lamps and the like can be used, and the exposure wavelength is 450 to 250 nm, preferably 400. It can be set to ˜300 nm. Exposure energy is preferably 500 mJ / cm ² or less, 10 to 400 mJ / cm ² is more preferable. UV light can be guided from the UV light source to the powder material surface using a UV transmissive optical fiber.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to an Example.
The materials used in the examples of the present invention are as follows.
DPHA: dipentaerythritol hexaacrylate, in-house synthesized product dipropylene glycol diacrylate: manufactured by Daicel UCB DPCA60: caprolactone modified dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd. M350: trimethylolpropane EO modified triacrylate, Tojo Synthetic Co., Ltd. TPGDA: Tripropylene glycol diacrylate, Daicel UCB 1-hydroxy-cyclohexyl-phenyl ketone: Ciba Specialty Chemicals 2-hydroxy-2-methylpropiophenone: Ciba Specialty Chemicals Lucirin TPO: Acyl The chemical structure of a phosphine oxide compound, Lucirin TPO manufactured by BASF is shown below.

Ｌｕｃｉｒｉｎ ＴＰＯ

Lucirin TPO

(Example I-1)
Polymerizable compound: DPHA 5 g
Polymerizable compound: 15 g of dipropylene glycol diacrylate
Photopolymerization initiator: Lucirin TPO 0.8g
Chain transfer agent: 0.6 g of Exemplified Compound 2-5
Coloring agent: Y-1 0.4 g
Y-1, the following M-1, and the following C-1 are as described in the best mode for carrying out the invention.
The above components were mixed by stirring to obtain a yellow ink.

(Example I-2)
A yellow ink was obtained in the same manner as in Example I-1, except that Exemplified Compound 2-7 was used instead of Exemplified Compound 2-5 as the chain transfer agent.

(Example I-3)
A yellow ink was obtained in the same manner as in Example I-1, except that Exemplified Compound 6-2 was used instead of Exemplified Compound 2-5 as the chain transfer agent.

(Comparative Example I-1)
A yellow ink was obtained in the same manner as in Example I-1 except that the chain transfer agent (Exemplary Compound 2-5) was not used.

Example II-1
Polymerizable compound: DPCA 60 8.0 g
Polymerizable compound: HDDA 12.0 g
Photopolymerization initiator: 1-hydroxy-cyclohexyl-phenyl ketone 0.5 g
Colorant: M-1 0.4 g
Chain transfer agent: 1.0 g of Exemplified Compound 2-7
The above components were mixed with stirring to obtain a magenta ink.

Example II-2
A magenta ink was obtained in the same manner as in Example II-1, except that the exemplified compound 6-2 was used instead of the exemplified compound 2-7 as the chain transfer agent.

Example II-3
A magenta ink was obtained in the same manner as in Example II-1, except that Exemplified Compound 3-1 was used instead of Exemplified Compound 2-7 as the chain transfer agent.

(Comparative Example II-1)
A magenta ink was obtained in the same manner as in Example II-1 except that the chain transfer agent (Exemplary Compound 2-7) was not used.

Example III-1
Polymerizable compound: M350 10.0 g
Polymerizable compound: TPGDA 10.0 g
Photopolymerization initiator: 0.6 g of 2-hydroxy-2-methylpropiophenone
Colorant: C-1 2.5g
Chain transfer agent: 0.8 g of Exemplified Compound 2-5
The above components were mixed with stirring to obtain a cyan ink.

(Example III-2)
A cyan ink was obtained in the same manner as in Example III-1, except that Exemplified Compound 2-7 was used instead of Exemplified Compound 2-5 as the chain transfer agent.

(Example III-3)
A cyan ink was obtained in the same manner as in Example III-1, except that Exemplified Compound 2-1 was used instead of Exemplified Compound 2-5 as the chain transfer agent.

(Comparative Example III-1)
A cyan ink was obtained in the same manner as in Example III-1, except that the chain transfer agent (Exemplary Compound 2-5) was not used.

The obtained ink composition was printed on art paper with an inkjet printer (printing density: 300 dpi, droplet ejection frequency: 4 kHz, number of nozzles: 64), and then 20 mj / cm with a Deep UV lamp (US-7, SP-7). ^The sample was exposed under the condition of energy of ² to obtain a print sample.

(Curable)
The seal screen was touched with a finger and evaluated according to the following criteria.
A: No stickiness B: Some stickiness C: Significant stickiness Table 1 shows the evaluation results.

Claims (6)

  An ink composition comprising at least a polymerizable compound, a colorant, a photopolymerization initiator, and a chain transfer agent.   The chain transfer agent is selected from the group consisting of o-quinonediazides, mercaptoazoles, N-aminomethyl group-substituted azoles, halogen-substituted 1,3,5-triazines, and disulfonyldiazomethanes. The ink composition as described.   The ink composition according to claim 1 or 2, wherein the colorant is an oil-soluble dye.   The ink composition according to claim 1, wherein the oxidation potential of the oil-soluble dye is 1.0 V (vs SCE) or more.   The ink composition according to any one of claims 1 to 4, which is used for inkjet. It includes a step of printing the ink composition according to any one of claims 1 to 5 on a recording material by an ink jet printer, and a step of irradiating the printed ink composition with an active radiation to cure the ink composition. Inkjet recording method.