JP2007197618A - Ink composition, inkjet recording method, print, method for producing lithographic printing plate and lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition which cures with high sensitivity by irradiation with active radiation, improves the wettability of a discharged ink on the cured ink, can form a high quality image, and excels in the discharge stability from an inkjet head, the adhesion on to a medium to be recorded, and storage stability, an inkjet recording method using the ink composition, a print obtained by using an ink composition which excels in the discharge stability from an inkjet head and storage stability, and can be cured by irradiation with ultraviolet rays with high sensitivity, a lithographic printing plate, and a method for producing a lithographic printing plate. <P>SOLUTION: The ink composition comprises (a) a polymerizable compound, (b) a polymerization initiator, (c) a colorant, and (d) an acetylene alcohol based surface active agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink composition suitably used for ink jet recording, an ink jet recording method, a printed material using the ink composition, a lithographic printing plate obtained using the ink, and a method for producing a lithographic printing plate. is there. Specifically, it can be cured with high sensitivity to radiation irradiation, can form high-quality images, and has excellent ejection stability from an inkjet head when the ink composition is used, and storage stability. The present invention relates to an ink composition suitable for inkjet recording with good properties, an inkjet recording method, a printed matter using the ink composition, a lithographic printing plate obtained using the ink, and a method for producing the lithographic printing plate.

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

  On the other hand, when the ink composition is a low-viscosity ink composition mainly composed of an aqueous solvent or a non-aqueous solvent, when printing on a recording medium, the dot diameter increases or the process of removing the residual solvent takes time. And there is a problem that heating drying is required.

On the other hand, when an ultraviolet curable ink composition that does not contain a solvent (see Patent Documents 1 and 2) is used, since there is substantially no solvent, the dispersibility of the pigment in the ink composition is inferior. Insufficient ejection stability when emitting light, and in particular, was not satisfactory in terms of print quality and adhesion on an ink non-absorbent recording medium.
It has been proposed to improve these problems by adding a surfactant, which is disclosed in Patent Document 3, for example. In this patent document, a nonionic, anionic, or fluorine group-containing surfactant having a specific structure is preferably described. In these ink compositions, when ink is ejected onto the cured ink, the cured ink is used. The wettability of the above ejected ink is insufficient, and the image quality is still not sufficient, such as the glossiness is lowered with the impression of unevenness on the printed matter.

Special Table 2000-504778 JP 2001-525479 A JP 2004-051881 A

The object of the present invention made in consideration of the above problems is to cure with high sensitivity by irradiation with actinic radiation, improve the wettability of the discharged ink on the cured ink, and form a high-quality image, Another object of the present invention is to provide an ink composition excellent in ejection stability from an ink jet head, adhesion to a recording medium, and storage stability, and an ink jet recording method using the ink composition.
Another object of the present invention is to provide a printed matter, a lithographic printing plate, and a printed matter obtained by using an ink composition that is excellent in ejection stability from an inkjet head and storage stability and can be cured with high sensitivity by ultraviolet irradiation. An object of the present invention is to provide a method for producing a lithographic printing plate.

The above object has been achieved by the following <1>, <4>, <7> and <8>. It is shown below together with <2>, <3>, <5> and <6> which are preferred embodiments.
<1> an ink composition comprising (a) a polymerizable compound, (b) a polymerization initiator, (c) a colorant, and (d) an acetylene alcohol surfactant,
<2> The ink composition according to <1>, wherein (a) the polymerizable compound is cationically polymerizable, and (b) the polymerization initiator is a photoacid generator,
<3> The ink composition according to <1> or <2>, which is for inkjet recording.
<4> An inkjet recording method comprising: (a) a step of discharging an ink composition onto a recording medium; and (b) a step of irradiating the discharged ink composition with active radiation to cure the ink composition. An ink jet recording method, wherein the ink composition is the ink composition according to any one of <1> to <3>,
<5> The actinic radiation is irradiated by a light emitting diode that generates ultraviolet rays having an emission peak wavelength in a range of 350 to 420 nm and a maximum illuminance on a recording medium surface of 10 to 2,000 mW / cm ^2. The inkjet recording method according to <4>, which is ultraviolet light,
<6> Printed matter recorded by the inkjet recording method according to <4> or <5>,
<7> (a) A step of discharging the ink composition according to any one of <1> to <3> onto a hydrophilic support, and (b) irradiating the discharged ink composition with actinic radiation. A method for producing a lithographic printing plate, comprising: a step of curing the ink composition to form a hydrophobic image formed by curing the ink composition on the hydrophilic support.
<8> A lithographic printing plate produced by the method for producing a lithographic printing plate according to <7>.

According to the present invention, the ink is cured with high sensitivity to radiation irradiation, the wettability of the ejected ink on the cured ink can be improved, and a high-quality image can be formed, and the inkjet head is clogged during ejection. Therefore, it is possible to provide an ink composition having a small amount, excellent adhesion to a recording medium and excellent storage stability, and an ink jet recording method using the ink composition.
In addition, there is little clogging of the inkjet head during ejection, excellent storage stability, printed matter obtained using an ink composition that can be cured with high sensitivity by ultraviolet irradiation has high image quality, and excellent image area strength. . Similarly, by using the ink composition of the present invention, it is possible to produce a lithographic printing plate with high printing durability and high image quality stably over a long period of time based on digital data.

  The ink composition of the present invention (hereinafter also simply referred to as “ink”) comprises (a) a polymerizable compound, (b) a polymerization initiator, (c) a colorant, and (d) an acetylene alcohol surfactant. It is characterized by containing

(1) Component essential to the present invention (a) Polymerizable compound The ink composition of the present invention comprises (a) a polymerizable compound. Examples of the polymerizable compound that can be used in the present invention include a cationic polymerizable compound or a radical polymerizable compound, and the cationic polymerizable compound and the radical polymerizable compound may be used in combination. Among these, it is preferable to use only a cationic polymerizable compound or to use a cationic polymerizable compound and a radical polymerizable compound in combination. As the cationic polymerizable compound, for example, a cationic polymerization type photo-curable resin is known, and recently, a photo cationic polymerization type photo-curable resin sensitized to a visible light wavelength region of 400 nm or more is also known, for example. It is disclosed in Japanese Laid-Open Patent Publication No. 6-43633 and Japanese Patent Laid-Open No. 8-324137. Examples of the radical polymerizable compound are described in JP-A-7-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, JP-A-7-231444, and the like. A photocurable material using a photopolymerizable composition is known.

(A-1) Cationic polymerizable compound The cationic polymerizable compound used in the present invention is not particularly limited as long as it is a compound that initiates a polymerization reaction with an acid generated from a photoacid generator described below and cures. Various known cationic polymerizable monomers known as 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, aliphatic epoxides, and the like. As the aromatic epoxide, a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof and epichlorohydrin are used. Di- or polyglycidyl ethers produced by reaction, for example, di- or polyglycidyl ethers of bisphenol A or its alkylene oxide adducts, di- or polyglycidyl ethers of hydrogenated bisphenol A or its alkylene oxide adducts, and novolaks Type epoxy resin. 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, 1,13-tetradecadiene dioxide, limonene dioxide, 1,2,7,8-di Examples thereof include epoxy octane, 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 vinyl ether compounds 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, cyclohexanedimethanol monovinyl ether, n-pro Vinyl ether, isopropyl vinyl ether, isopropenyl ether -O- propylene carbonate, dodecyl vinyl ether, and a monovinyl ether compounds such as diethylene glycol monovinyl 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. Therefore, it is preferable.

  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 in the molecule include compounds represented by the following formula (4).

In the formula (4), R ^a1 has the same ^{meaning as} in the formula (1). In addition, as R ^a9 which is a polyvalent linking group, for example, a branched polyalkylene group having 1 to 12 carbon atoms such as groups represented by the following A to C, a 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 ^a1 and R ^a8 have 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, paragraph numbers 0021 to 0084, and the compounds described therein 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. is there. In the present invention, the solid content in the ink composition is a component obtained by removing a volatile component such as a solvent described later from the ink composition.

(A-2) Radical polymerizable compound The radical polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization and having at least one ethylenically unsaturated bond capable of radical polymerization in the molecule. Any type may be used, including those having chemical forms such as monomers, oligomers, and polymers. Only one kind of radically polymerizable compound may be used, or two or more kinds thereof may be used in combination at an arbitrary ratio in order to improve desired properties. In addition, a polyfunctional compound having two or more functional groups is preferable to a monofunctional compound. More preferably, two or more polyfunctional compounds are used in combination for controlling performance such as reactivity and physical properties.

Examples of the polymerizable compound having an ethylenically unsaturated bond capable of radical polymerization include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and salts thereof, Examples thereof include radically polymerizable compounds such as anhydrides having a saturated group, acrylonitrile, styrene, various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.
Specifically, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, bis (4-acryloxypolyethoxyphenyl) propane, neopentyl glycol Diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol Tetraacrylate, dipentaery Acrylic acid derivatives such as lithol tetraacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, N-methylol acrylamide, diacetone acrylamide, epoxy acrylate, methyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate , Lauryl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylol Methacryl derivatives such as tan trimethacrylate, trimethylolpropane trimethacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, and other derivatives of allyl compounds such as allyl glycidyl ether, diallyl phthalate, triallyl trimellitate More specifically, Shinzo Yamashita, “Cross-linking agent handbook”, (1981 Taiseisha); Kato Kiyomi, “UV / EB curing handbook (raw material)” (1985, Polymer publication) ); Rad-Tech Study Group, “Application and Market of UV / EB Curing Technology”, p. 79, (1989, CMC); Eiichiro Takiyama, “Polyester Resin Handbook”, (1988, Nikkan Kogyo Shimbun) Commercially available products described in the above, or radically polymerizable or crosslinkable monomers known in the industry, Ligomers and polymers can be used.

(B) Polymerization initiator The ink composition of the present invention contains (b) a polymerization initiator. As the polymerization initiator, a known cationic polymerization initiator or a radical polymerization initiator can be used, but when a cationic polymerizable compound is used as the polymerizable compound, it is preferable to use a cationic polymerization initiator, When using a radical polymerization compound, it is preferable to use a radical polymerization initiator. When using a radical polymerization initiator, it is also preferable to use together with a cationic polymerization initiator. The said polymerization initiator may be used independently and may use 2 or more types together. Moreover, as a cationic polymerization initiator, it is preferable to use the photo-acid generator mentioned later.
The cationic polymerization initiator or radical polymerization initiator that can be used in the ink composition of 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. The photopolymerization initiator that can be used in the present invention is preferably a radiation-sensitive cationic polymerization initiator that is sensitive to actinic radiation, a so-called photoacid generator.

(B-1) Cationic Polymerization Initiator As a preferable cationic polymerization initiator that can be used in the present invention, for example, a chemically amplified photoresist or a compound used for photocationic polymerization is used (edited by Organic Electronics Materials Research Group). , "Organic Materials for Imaging", Bunshin Publishing (1993), pages 187-192). Examples of the cationic polymerization initiator suitable for the present invention are listed below.

  The cationic polymerization initiator that can be used in the present invention is preferably a compound that generates an acid upon irradiation with actinic radiation (hereinafter also referred to as a photoacid generator). Examples of the photoacid generator that can be used in the present invention include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, and microresists. Irradiation with light (400-200 nm ultraviolet light, far ultraviolet light, particularly preferably g-line, h-line, i-line, KrF excimer laser beam), ArF excimer laser beam, electron beam, X-ray, molecular beam or ion beam A compound that generates an acid can be appropriately selected and used.

  Examples of such photoacid generators include onium salt compounds such as diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones that decompose upon irradiation with actinic radiation to generate acids. And sulfonate compounds such as o-nitrobenzyl sulfonate.

  Further, as other compounds (photoacid generators) that generate an acid upon irradiation with actinic radiation used in the present invention, for example, S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Bal etal, Polymer, 21, 423 (1980), U.S. Pat. Nos. 4,069,055, 4,069,056, Re 27,992, JP-A-3-140140, etc. An ammonium salt according to claim 1, C. Necker et al., Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, The, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055, 4,069,056, and the like; V. 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, JP-A-2-296514 and the like,

  J. et al. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al. PolymerSci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al., Polymer Bull. 14, 279 (1985), J. Am. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patent Nos. 370,693, 161,811, 410,201, 339,049, 233,567, 297,443, and 297,442. U.S. Pat.Nos. 3,902,114, 4,933,377, 4,760,013, 4,734,444, 2,833,827, German Patent 2, Nos. 904, 626, 3,604, 580, 3,604, 581, JP-A-7-28237, 8-27102 and the like,

  J. et al. V. Crivello et al., Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al. PolymerSci. , Polymer Chem. Ed. , 17, 1047 (1979), etc., selenonium salts, C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988) and other onium salts such as arsonium salts, US Pat. No. 3,905,815, Japanese Examined Patent Publication No. 46-4605, Japanese Unexamined Patent Publication No. 48-36281, Japanese Unexamined Patent Publication No. 55-55. -32070, JP-A-60-239736, JP-A-61-169835, JP-A-61-169837, JP-A-62-58241, JP-A-62-212401, JP-A-63-70243 , Organic halogen compounds described in JP-A-63-298339 and the like; Meier et al, J.A. Rad. Curing, 13 (4), 26 (1986), T.A. P. Gill et al, Inorg. Chem. , 19, 3007 (1980), D.M. Astruc, Acc. Chem. Res. , 19 (12), 377 (1986), and organometallic / organic halides described in JP-A-2-161445, etc.

  S. Hayase et al. Polymer Sci. 25, 753 (1987), E.I. Reichmanis et al. Polymer Sci. , Polymer Chem. Ed. , 23, 1 (1985), Q.M. Q. Zhu etal, J. et al. Photochem. 36, 85, 39, 317 (1987), B.R. Amit etal, Tetrahedron Lett. , (24) 2205 (1973), D.M. H. R. Barton et al. Chem. Soc. , 3571 (1965), p. M.M. Collins et al. Chem. Soc. Perkin I, 1695 (1975), M .; Rudinstein et al., Tetrahedron Lett. , (17), 1445 (1975), J. MoI. W. Walker et al. Am. Chem. Soc. 110, 7170 (1988), S.A. C. Busman et al. Imaging Technol. 11 (4), 191 (1985), H. et al. M.M. Houlihan et al, Macormolecules, 21, 2001 (1988), p. M.M. Collins et al. Chem. Soc. , Chem. Commun. 532 (1972), S.A. Hayase et al., Macromolecules, 18, 1799 (1985), E.I. Reichmanis et al. Electrochem. Soc. , Solid State Sci. Technol. , 130 (6), F.M. M.M. Houlihan et al, Macromolecules, 21, 2001 (1988), European Patent Nos. 0,290,750, 046,083, 156,535, 271,851, 0,388,343, US Patents No. 3,901,710, 4,181,531, JP-A-60-198538, JP-A-53-133022 and the like, a photoacid generator having an O-nitrobenzyl type protecting group,

  M.M. TUNOOKA et al, Polymer Preprints Japan, 35 (8), G.M. Berner et al. Rad. Curing, 13 (4), W.M. J. et al. Mijs et al, Coating Technol. , 55 (697), 45 (1983), Akzo, H .; Adachi et al, Polymer Preprints, Japan, 37 (3), European Patent Nos. 0,199,672, 84515, 044,115, 618,564, 0,101,122, US Patents Nos. 4,371,605, 4,431,774, JP-A 64-18143, JP-A-2-245756, JP-A-3-140109, etc. Compounds that generate sulfonic acid upon photolysis, disulfone compounds described in JP-A-61-166544 and JP-A-2-71270, JP-A-3-103854, JP-A-3-103856, and JP-A-210960 And diazoketosulfone and diazodisulfone compounds described in the above.

  Further, a group in which an acid is generated by these lights, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, M.I. E. Woodhouse et al., J. MoI. Am. Chem. Soc. 104, 5586 (1982), S .; P. Pappas et al. Imaging Sci. , 30 (5), 218 (1986), S.A. Kondo et al, Makromol. Chem. , Rapid Commun. , 9, 625 (1988), Y. et al. Yamada et al, Makromol. Chem. 152, 153, 163 (1972), J. Am. V. Crivello et al, J.A. PolymerSci. , Polymer Chem. Ed. , 17, 3845 (1979), U.S. Pat. No. 3,849,137, German Patent 3,914,407, JP-A 63-26653, JP-A 55-164824, JP-A 62- 69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, and the like can be used. For example, diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, onium salts such as arsonium salts, organic halogen compounds, organic metal / organic halides, photoacid generators having o-nitrobenzyl type protecting groups Examples thereof include a compound capable of generating a sulfonic acid by photolysis represented by an agent, iminosulfonate, and the like, a disulfone compound, a diazoketosulfone, and a diazodisulfone compound.

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

  Preferred examples of the photoacid generator that can be used in the present invention include compounds represented by the following formulas (b1), (b2), and (b3).

In the formula (b1), R ²⁰¹ , R ²⁰² and R ²⁰³ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably a sulfonate anion, a carboxylate anion, a bis (alkylsulfonyl) amide anion, a tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ or the following The organic anion which has a carbon atom is preferable.

  Preferable organic anions include organic anions represented by the following formula.

Rc ¹ represents an organic group.
Examples of the organic group for Rc ¹ include those having ^{1 to} 30 carbon atoms, and preferably an alkyl group, a cycloalkyl group, an aryl group, or a plurality of these are a single bond, —O—, —CO ₂ —.
, —S—, —SO ₃ —, —SO ₂ N (Rd ¹ ) — and the like.

Rd ¹ represents a hydrogen atom or an alkyl group.
Rc ³ , Rc ⁴ and Rc ⁵ each independently represents an organic group.
Preferred examples of the organic group for Rc ³ , Rc ⁴ , and Rc ⁵ include the same organic groups as those for Rc ¹ , and most preferred are perfluoroalkyl groups having 1 to 4 carbon atoms.
Rc ³ and Rc ⁴ may combine to form a ring.
Examples of the group formed by combining Rc ³ and Rc ⁴ include an alkylene group and an arylene group. Preferably it is a C2-C4 perfluoroalkylene group.

The organic group of Rc ¹ and Rc ^{3 to} Rc ⁵ is most preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved.

The carbon number of the organic group as R ^201, R ²⁰² and R ²⁰³ is preferably 1 to 30, more preferably 1 to 20.
Two of R ^{201 to} R ²⁰³ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ²⁰¹ to R ^203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ²⁰¹ , R ²⁰² and R ²⁰³ include corresponding groups in the compounds (b1-1), (b1-2) and (b1-3) described later.

In addition, the compound which has two or more structures represented by Formula (b1) may be sufficient. For example, at least one of R ²⁰¹ to R ²⁰³ of a compound represented by the formula (b1) is at least one directly with R ²⁰¹ to R ²⁰³ of another compound represented by formula (b1), or a linking group It may be a compound having a structure bonded via

  Further preferred examples of the component (b1) include compounds (b1-1), (b1-2), and (b1-3) described below.

Compound (b1-1) is in which at least one aryl group R ²⁰¹ to R ²⁰³ in formula (b1), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.

In the arylsulfonium compound, all of R ^{201 to} R ²⁰³ may be an aryl group, or a part of R ^{201 to} R ²⁰³ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldicycloalkylsulfonium compounds, and the like.

  The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, and more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

As the alkyl group that the arylsulfonium compound has as necessary, a linear or branched alkyl group having 1 to 15 carbon atoms is preferable. For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, sec -A butyl group, a t-butyl group, etc. can be mentioned.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ²⁰¹ to R ^203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and most preferred. Is an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. Substituents, of the three R ²⁰¹ to R ^203, may be substituted on any one, or may be substituted on all of three. When R ^{201 to} R ²⁰³ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (b1-2) will be described.
The compound (b1-2) is a compound in the case where R ^{201 to} R ²⁰³ in the formula (b1) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ²⁰¹ to R ²⁰³ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R ²⁰¹ to R ²⁰³ each independently, preferably an alkyl group, a cycloalkyl group, an allyl group, a vinyl group, more preferably a linear, branched or cyclic 2-oxoalkyl group, an alkoxycarbonylmethyl group, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ²⁰¹ to R ²⁰³ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, a butyl group, a pentyl group), and a linear, branched 2-oxoalkyl group, and an alkoxycarbonylmethyl group are more preferable.

The cycloalkyl group as R ²⁰¹ to R ²⁰³ is preferably a cycloalkyl group having 3 to 10 carbon atoms (a cyclopentyl group, a cyclohexyl group, a norbornyl group) can be exemplified, more preferably a cyclic 2-oxoalkyl group.

Linear R ²⁰¹ to R ^203, branched, or cyclic 2-oxoalkyl group, preferably, may be mentioned 2-position group having> C = O at the above-described alkyl or cycloalkyl group.
The alkoxy group in the alkoxycarbonylmethyl group as R ²⁰¹ to R ^203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R ^{201 to} R ²⁰³ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

  The compound (b1-3) is a compound represented by the following formula (b1-3) and is a compound having a phenacylsulfonium salt structure.

In formula (b1-3), R ^{1c to} R ^5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R ^6c and R ^7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R ^x and R ^y each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.
Any two or more of R ^{1c to} R ^5c , R ^6c and R ^7c , and R ^x and R ^y may be bonded to each other to form a ring structure.
Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (b1).

The alkyl group as R ^{1c to} R ^7c may be either linear or branched, and is preferably a linear and branched alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms. (For example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group).

Preferred examples of the cycloalkyl group represented by R ^{1c to} R ^7c include a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).

The alkoxy group as R ^{1c to} R ^{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Examples of the group formed by combining any two or more of R ^{1c to} R ^5c , R ^6c and R ^7c , and R ^x and R ^y include a butylene group and a pentylene group. This ring structure may contain an oxygen atom, a sulfur atom, an ester bond, or an amide bond.

Preferably any one of R ^{1c to} R ^5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R ^1c to R ^5c is 2-15. This is preferable because solvent solubility is further improved and generation of particles is suppressed during storage.

^Examples of the alkyl group and cycloalkyl group as R ^x and R ^y include the same alkyl groups and cycloalkyl groups as R ^{1c to} R ^7c .
R ^x and R ^y are preferably a 2-oxoalkyl group or an alkoxycarbonylmethyl group.
Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R ^{1c to} R ^5c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R ^{1c to} R ^5c .

R ^x and R ^y are preferably an alkyl group or cycloalkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more alkyl groups or cycloalkyl groups.

Formula (b2), in (b3), R ²⁰⁴ ~R ²⁰⁷ each independently represents an aryl group, an alkyl group or a cycloalkyl group. X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (b1).

Phenyl group and a naphthyl group are preferred as the aryl group of R ²⁰⁴ to R ^207, more preferably a phenyl group.
The alkyl group as R ²⁰⁴ to R ²⁰⁷ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group). The cycloalkyl group as R ²⁰⁴ to R ²⁰⁷ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
The R ²⁰⁴ to R ²⁰⁷ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
R ²⁰⁴ and R ²⁰⁵ , R ²⁰⁶ and R ²⁰⁷ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The group R ²⁰⁴ and R ^205, R ²⁰⁶ and R ²⁰⁷ is formed by bonding, there can be mentioned an alkylene group (e.g., butylene, pentylene).
In addition, the compound which has two or more structures represented by Formula (b2) or (b3) may be sufficient. For example, R ²⁰⁴ or R ²⁰⁵ of the compound represented by the formula (b2) is bonded to R ²⁰⁴ or R ²⁰⁵ in the other compound represented by the formula (b2) directly or via a linking group. It may be a compound.

  Examples of the compound that generates an acid upon irradiation with actinic rays or radiation that may be used further include compounds represented by the following formulas (b4), (b5), and (b6).

In formulas (b4) to (b6), Ar ³ and Ar ⁴ each independently represents an aryl group.
R ²⁰⁶ , R ²⁰⁷ and R ²⁰⁸ each independently represents an alkyl group, a cycloalkyl group, an aryl group or a cyano group.
A represents an alkylene group, an alkenylene group or an arylene group.
Ar ³ and Ar ⁴ , R ^{206 to} R ^{208 and} A may have a substituent, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), aryl Examples include a group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.
In addition, the compound which has two or more structures represented by Formula (b4)-(b6) may be sufficient. For example, the formula (b6) at least one of R ²⁰⁶ to R ²⁰⁸ of a compound represented are in direct at least one of R ²⁰⁶ to R ²⁰⁸ in another compound represented by Formula (b6), or the linking group It may be a compound having a structure bonded via

Preferable examples of the photoacid generator include compounds represented by formulas (b1) to (b3).
Although the preferable compound example [(b-1)-(b-96)] of the photo-acid generator which can be used for this invention is given below, this invention is not limited to these.

Further, oxazole derivatives and s-triazine derivatives described in JP-A No. 2002-122994, paragraph numbers [0029] to [0030] are also preferably used.
The onium salt compounds and sulfonate compounds exemplified in JP-A-2002-122994, paragraphs [0037] to [0063] can also be suitably used in the present invention.

A cationic polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
The content of the polymerization initiator in the ink composition is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, and still more preferably 1 to 7% in terms of the total solid content of the ink composition. % By weight.

(B-2) Radical polymerization initiator Preferred radical polymerization initiators that can be used in the present invention include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, ( d) thio compound, (e) hexaarylbiimidazole compound, (f) ketoxime ester compound, (g) borate compound, (h) azinium compound, (i) metallocene compound, (j) active ester compound, (k) Examples thereof include a compound having a carbon halogen bond, and (l) an alkylamine compound. 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.

(C) Colorant The (c) colorant that can be used in the present invention is not particularly limited, but pigments and oil-soluble dyes that are excellent in weather resistance and excellent in color reproducibility are preferable, such as soluble dyes. Any known colorant can be selected and used. The colorant that can be suitably used in the ink composition of the present invention or the ink composition for inkjet recording preferably does not function as a polymerization inhibitor in a polymerization reaction that is a curing reaction. This is because the sensitivity of the curing reaction by actinic radiation is not reduced.

(C-1) Pigment The pigment that can be used in the present invention is not particularly limited. For example, organic or inorganic pigments having the following numbers described in the color index can be used.

  That is, as red or magenta pigment, Pigment Red 3, 5, 19, 22, 31, 38, 43, 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49: 1, 53 : 1, 57: 1, 57: 2, 58: 4, 63: 1, 81, 81: 1, 81: 2, 81: 3, 81: 4, 88, 104, 108, 112, 122, 123, 144 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13, 16, 20, 36, blue or cyan pigments include Pigment Blue 1, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16 17-1, 22, 27, 28, 29, 36, 60, as green pigment, Pigment Green 7, 26, 36, 50, as yellow pigment, Pigment Yellow 1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193, Pigment Black 7, 28, 26 as the black pigment, and Pigment White 6, 18, 21, etc. as the white pigment can be used according to the purpose.

(C-2) Oil-soluble dye The oil-soluble dye that can be used in the present invention is described below.
The oil-soluble dye that can be used in the present invention means a dye that is substantially insoluble in water. Specifically, the solubility in water at 25 ° C. (the mass of the dye that can be dissolved in 100 g of water) is 1 g or less, preferably 0.5 g or less, more preferably 0.1 g or less. Accordingly, the oil-soluble dye means a so-called water-insoluble pigment or oil-soluble dye, and among these, an oil-soluble dye is preferable.

  In the present invention, the oil-soluble dye may be used alone or in combination of several kinds. In addition, other water-soluble dyes, disperse dyes, pigments, and other colorants may be contained as necessary as long as the effects of the present invention are not impaired.

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

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

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

  Each of the above dyes may exhibit yellow, magenta, and cyan colors only after part of the chromophore is dissociated. In this case, the counter cation is an alkali metal or an inorganic cation such as ammonium. Alternatively, it may be an organic cation such as pyridinium or quaternary ammonium salt, and may further be a polymer cation having these in a partial structure.

The colorant that can be used in the present invention is preferably added to the ink composition of the present invention or the ink composition for inkjet recording and then appropriately dispersed in the ink. For dispersing the colorant, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, or a paint shaker can be used.
It is also possible to add a dispersant when dispersing the colorant. The type of the dispersant is not particularly limited, but a polymer dispersant is preferably used, and examples of the polymer dispersant include Solsperse series manufactured by Zeneca. Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. In the present invention, these dispersant and dispersion aid are preferably added in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the colorant.
The colorant may be added directly to the ink composition of the present invention, but may be added in advance to a dispersion medium such as a solvent or a polymerizable compound used in the present invention in order to improve dispersibility. In the present invention, in order to avoid the problem of deterioration of solvent resistance when the solvent remains in the cured image and the problem of VOC (Volatile Organic Compound) of the remaining solvent, the colorant is added to the polymerizable compound. It is preferable to add. Further, as the polymerizable compound to be used, it is preferable in view of dispersion suitability to select a monomer having the lowest viscosity.

  In the present invention, the colorant particles have an average particle diameter of preferably 0.005 to 0.5 μm, more preferably 0.01 to 0.45 μm, and still more preferably 0.015 to 0.3 μm. It is preferable to select a dispersant, a dispersion medium, dispersion conditions, and filtration conditions. This particle size control is preferable because clogging of the head nozzle can be suppressed and ink storage stability, ink transparency, and curing sensitivity can be maintained.

(D) Acetylene alcohol-based surfactant The (d) acetylene alcohol-based surfactant used in the present invention is represented by the formula (I) or (II).

In the formula, R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ and R ⁵⁵ are each independently a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, and x and y are , Each independently represents an integer of 0 to 30, and the sum of x and y is 40 or less.
Examples of the linear, branched or cyclic alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, 2-butyl group, t-butyl group, and hexyl group. , A cyclohexyl group, an octyl group, and the like.

  The above acetylene alcohol surfactants are commercially available and can be used. Surfinol 61, Surfinol 82, Surfinol 104, Surfinol 104E, Surfinol 104H, Surfinol 104A, Surfinol TG, Surfinol PC, Surfinol 420, Surfinol 440, Surfinol 465, Surfinol are preferable commercially available products. Nord 485 (available from Air Products and Chemicals Inc.), Surfynol E1004 (available from Nissin Chemical Industry Co., Ltd.) and the like. Some specific examples are shown below.

Also supplied by Kawaken Fine Chemicals (trade name: acetylenol), Dow Chemicals, General Aniline.
These can be used singly or in combination of two or more. Furthermore, in addition to the above acetylene-based surface activity, other surfactants can be used in combination.

  By using a surfactant having a specific structure, not only the dispersibility of the colorant can be improved, but also the ejection properties can be improved by exhibiting defoaming properties for the ink composition. Conceivable. In addition, the ink composition of the present invention can improve the familiarity of the ink composition to the coating agent of the inkjet head, and can improve the discharge property.

.
The blending amount of the acetylene alcohol derivative is preferably 0.01 to 2% by weight, more preferably 0.02 to 1% by weight in the ink composition (excluding the solvent). The content of 0.01% by weight or more is preferable because the effects of the present invention can be sufficiently obtained. Moreover, it is preferable that it is 2% by weight or less because the resolution of the ink composition is good.

  In the ink composition of the present invention, various additives can be used in combination with the essential components according to the purpose. These optional components will be described.

(E) Sensitizing dye When the ink composition of the present invention is used particularly for ink jet recording, a sensitizing dye may be added to absorb specific actinic radiation and promote decomposition of the polymerization initiator. Good. A sensitizing dye absorbs specific actinic radiation and enters an electronically excited state. The sensitizing dye in an electronically excited state comes into contact with the polymerization initiator, and effects such as electron transfer, energy transfer, and heat generation occur. As a result, the polymerization initiator undergoes a chemical change and decomposes to generate radicals, acids or bases.
Examples of preferred sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region.
Polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine), merocyanines ( For example, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones (eg, anthraquinone), squalium (eg, squalium) ), Coumarins (eg 7-diethylamino-4-methylcoumarin).

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

In 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 in cooperation with the adjacent A ² 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, and in cooperation with the adjacent a ^3, A4 ^及 beauty adjacent carbon atoms represent a non-metallic atomic group forming a basic nucleus of a dye, R ⁶⁰ and R ⁶¹ are each independently a hydrogen atom or a monovalent nonmetallic atomic group, or can be bonded to each other to form an aliphatic or aromatic ring.

In 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 those shown below.

(F) Co-sensitizer The ink composition of the present invention preferably contains a co-sensitizer. In the present invention, the co-sensitizer has functions such as further improving the sensitivity of the sensitizing dye to actinic radiation or suppressing polymerization inhibition of the polymerizable compound by oxygen.
Examples of such co-sensitizers include amines such as MR Sander et al., “Journal of Polymer Society”, Vol. 10, page 3173 (1972), Japanese Examined Patent Publication No. 44-20189, Japanese Patent Laid-Open No. 51-82102. Publication, JP 52-134692, JP 59-138205, JP 60-84305, JP 62-18537, JP 64-33104, Research Disclosure 33825 Specifically, triethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like can be mentioned.

  Other examples of co-sensitizers include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142773, and JP-A-56. And the like. Specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzoimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene. Etc.

  Other examples include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), and hydrogen described in Japanese Patent Publication No. 55-34414. Donors, sulfur compounds described in JP-A-6-308727 (eg, trithiane), phosphorus compounds described in JP-A-6-250387 (diethylphosphite, etc.), Si described in Japanese Patent Application No. 6-191605 -H, Ge-H compounds and the like.

If necessary, other components can be added to the ink composition of the present invention. Examples of other components include (g) radical polymerization inhibitor, (h) cationic polymerization inhibitor, and (I) solvent.
A radical polymerization inhibitor and a cationic polymerization inhibitor can be added from the viewpoint of enhancing the storage stability. Further, when the ink composition of the present invention is used as an ink composition for ink jet recording, it is preferably discharged at a temperature in the range of 40 to 80 ° C. with a reduced viscosity, and also for preventing head clogging due to thermal polymerization. It is preferable to add a polymerization inhibitor. The polymerization inhibitor is preferably added in an amount of 200 to 20,000 ppm based on the total amount of the ink composition of the present invention. Examples of the radical polymerization inhibitor include hydroquinone, benzoquinone, p-methoxyphenol, TEMPO, TEMPOL, and cuperon Al. The cationic polymerization inhibitor is a basic nitrogen-containing compound, preferably a compound having a tertiary amine structure. Examples of the pKa value of these compounds include aliphatic amines, aromatic amines, nitrogen-containing heterocyclic compounds having 4 or more, preferably 5 or more, and more preferably 7 to 13.

In view of the fact that the ink composition of the present invention and the ink composition for ink jet recording are radiation curable ink compositions, it is preferable that no solvent is contained so that the ink composition can react quickly and be cured immediately after landing of the ink composition. However, a predetermined solvent can be included as long as the curing rate of the ink composition is not affected. In the present invention, an organic solvent or water can be used as the solvent. In particular, an organic solvent can be added in order to improve the adhesion with a recording medium (support such as paper). The addition of an organic solvent is effective because the VOC problem can be avoided. The amount of the organic solvent is, for example, in the range of 0.1 to 5% by weight, preferably 0.1 to 3% by weight, based on the total weight of the ink composition of the present invention.
As a means for preventing a decrease in sensitivity due to the light-shielding effect of the colorant that can be used in the ink composition, in addition to a combination of a cationic polymerizable compound and a cationic polymerization initiator, and a combination of a radical polymerizable compound and a radical polymerization initiator Also, a radical-cation hybrid type curable ink using these polymerizable compounds and a polymerization initiator in combination may be used.

  In addition to this, a known compound can be added to the ink composition of the present invention as necessary. For example, surfactants (cationic, anionic, nonionic, fluorine, silicon), leveling additives, matting agents, polyester resins for adjusting film properties, polyurethane resins, vinyl resins, acrylics Resins, rubber-based resins, waxes and the like can be appropriately selected and added. In order to improve the adhesion to a recording medium such as polyolefin or PET, it is also preferable to contain a tackifier that does not inhibit the polymerization. Specifically, a high molecular weight adhesive polymer described in JP-A-2001-49200, pages 5 to 6 (for example, (meth) acrylic acid and an alcohol having an alkyl group having 1 to 20 carbon atoms). Ester, (meth) acrylic acid and a C3-14 alicyclic alcohol ester, (meth) acrylic acid and a C6-14 aromatic alcohol ester copolymer), and polymerizability Examples thereof include a low molecular weight tackifying resin having an unsaturated bond.

(2) Properties of ink composition As described above, the ink composition of the present invention contains a polymerizable compound, a polymerization initiator, and a colorant. These components are preferably 1 to 97% by weight of a polymerizable compound, more preferably 30 to 95% by weight, and preferably 0.01 to 20% by weight of a polymerization initiator based on the total weight of the ink composition. More preferably, the amount is 0.1 to 20% by weight, the colorant is preferably 1 to 10% by weight, more preferably 2 to 8% by weight, and the total weight% of each component is 100% by weight. It is appropriate to contain as follows.

  When the obtained ink composition is used for inkjet recording, the viscosity of the ink composition is determined at a temperature at the time of discharge (for example, 25 to 80 ° C., preferably 25 to 50 ° C.) in consideration of dischargeability. , Preferably 5 to 30 mPa · s, more preferably 7 to 15 mPa · s. For example, the viscosity of the ink composition of the present invention at room temperature (25 to 30 ° C.) is preferably 8 to 300 mPa · s, more preferably 10 to 100 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. When the viscosity at room temperature is set high, ink penetration into the recording medium can be avoided even when a porous recording medium is used, and uncured monomers can be reduced and odors can be reduced. Furthermore, ink bleeding at the time of ink droplet landing can be suppressed, and as a result, the image quality is improved. When the viscosity at room temperature is set low, heating during ink ejection is unnecessary or the heating temperature can be set to a relatively low temperature, so that the range of usable inkjet heads is expanded as the load on the inkjet device is reduced. Have advantages.

  The surface tension of the ink composition of the present invention is, for example, preferably 20 to 30 mN / m, more preferably 23 to 28 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 the wettability is preferably 30 mN / m or less.

(3) Inkjet recording method and apparatus The ink composition of the present invention is preferably used for inkjet recording.
An ink jet recording method that can be suitably employed in the present invention will be described below.

(3-1) Inkjet recording method The present invention ejects the ink composition onto a recording medium (support, recording material, etc.) and irradiates the ink composition ejected onto the recording medium with active radiation. Thus, a method for forming an image by curing ink is provided. That is, the present invention
(A) a step of discharging the ink composition onto a recording medium; and (b) a step of irradiating the discharged ink composition with active radiation to cure the ink composition;
An inkjet recording method comprising:
The present invention relates to an ink jet recording method in which the ink composition is the ink composition of the present invention.
The cured ink composition forms an image on the recording medium.
The peak wavelength of the active radiation is preferably 200 to 600 nm, more preferably 300 to 450 nm, and more preferably 350 to 420 nm. The output of active radiation is preferably 2,000 mJ / cm ² or less, more preferably from 10 to 2,000 mJ / cm ^2, more preferably, be 20 to 1,000 mJ / cm ² Particularly preferably, it is 50 to 800 mJ / cm ² .

Further, the ink jet recording method of the present invention will be described by taking as an example a method for producing a lithographic printing plate including forming an image by discharging an ink composition onto the lithographic printing plate.
The lithographic printing plate of the present invention has a hydrophilic support and a hydrophobic image formed on the hydrophilic support. The method for producing the lithographic printing plate comprises the following steps:
(A) a step of discharging the ink composition of the present invention onto a hydrophilic support; and (b) irradiating the discharged ink composition with actinic radiation to cure the ink composition. Forming a hydrophobic image formed by curing the composition on the hydrophilic support;
including.

(3-1-1) Hydrophilic support used for lithographic printing plate Here, the lithographic printing plate has a support and an image formed on the support.
Conventionally, so-called PS plates having a configuration in which a lipophilic photosensitive resin layer is provided on a hydrophilic support have been widely used as lithographic printing plates. As a method for producing the PS plate, a desired printing plate is usually obtained by performing mask exposure (surface exposure) through a lith film and then dissolving and removing the non-exposed portion. However, in recent years, digitization technology that electronically processes, stores, and outputs image information using a computer has become widespread, and a new image output method corresponding to the technology has been demanded. In particular, computer-to-plate (CTP) technology has been developed that scans highly-preferred light such as laser light according to digitized image information without using a lithographic film, and directly produces a printing plate. Yes.
Examples of a method for obtaining a lithographic printing plate that enables such scanning exposure include a method of directly producing a lithographic printing plate using an ink composition or an ink composition for ink jet recording. This is because ink is ejected onto a support, preferably a hydrophilic support, by an ink jet method or the like, and exposed to actinic radiation, whereby the ink composition or the ink for ink jet recording is exposed to a desired portion. A printing plate having an image (preferably a hydrophobic image) is obtained. An ink composition or ink jet recording ink suitable for such a system is the ink composition or ink jet recording ink of the present invention.
The support (recording medium) onto which the ink composition or ink for ink jet recording of the present invention is discharged is not particularly limited as long as it is a dimensionally stable plate-like support. The support is preferably a hydrophilic support. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which the above-mentioned metal is laminated or deposited. A preferable support includes a polyester film and an aluminum plate. Among these, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

  The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic laminated on a thin film of aluminum or aluminum alloy. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is preferably 10% by weight or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element. The composition of the aluminum plate is not specified, and a known material can be used as appropriate.

The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm.
Prior to using the aluminum plate, it is preferable to perform surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it is easy to improve hydrophilicity and secure adhesion between the image recording layer and the support. Prior to roughening the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like for removing rolling oil on the surface is performed as desired.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment for dissolving the surface electrochemically), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Also, a transfer method in which the uneven shape is transferred with a roll provided with unevenness in the aluminum rolling step may be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.
The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The conditions for anodizing treatment vary depending on the electrolyte used and cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. dm ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2. Within this range, good printing durability and good scratch resistance of the non-image area of the planographic printing plate can be obtained, which is preferable.

  As the support used in the present invention, a substrate that has been surface-treated as described above and has an anodized film may be used as it is, but it has adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation, etc. In order to further improve, if necessary, the micropore enlargement treatment or sealing treatment of the anodized film described in JP-A-2001-253181 and JP-A-2001-322365, and a hydrophilic compound are contained. A surface hydrophilization treatment immersed in an aqueous solution to be performed can be selected as appropriate. Of course, these enlargement processing and sealing processing are not limited to those described above, and any conventionally known method can be performed.

[Sealing treatment]
Sealing treatment includes vapor sealing, single treatment with zirconic fluoride, treatment with an aqueous solution containing an inorganic fluorine compound such as treatment with sodium fluoride, vapor sealing with addition of lithium chloride, sealing with hot water. Hole processing is also possible.
Of these, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing treatment with hot water are preferable. Each will be described below.

<Sealing treatment with an aqueous solution containing an inorganic fluorine compound>
As the inorganic fluorine compound used for the sealing treatment with an aqueous solution containing an inorganic fluorine compound, a metal fluoride is preferably exemplified.
Specifically, for example, sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, sodium fluoride zirconate, potassium fluoride zirconate, sodium fluoride titanate, potassium fluoride titanate, zircon fluoride Ammonium acid, ammonium fluoride titanate, potassium fluoride titanate, fluorinated zirconate, fluorinated titanate, hexafluorosilicic acid, nickel fluoride, iron fluoride, phosphor fluoride, ammonium fluoride phosphate It is done. Of these, sodium fluorinated zirconate, sodium fluorinated titanate, fluorinated zirconic acid, and fluorinated titanic acid are preferable.

The concentration of the inorganic fluorine compound in the aqueous solution is preferably 0.01% by weight or more, and more preferably 0.05% by weight or more in terms of sufficiently sealing the micropores of the anodized film. Further, in terms of stain resistance, the content is preferably 1% by weight or less, and more preferably 0.5% by weight or less.
It is preferable that the aqueous solution containing the inorganic fluorine compound further contains a phosphate compound. When the phosphate compound is contained, the hydrophilicity of the surface of the anodized film is improved, so that on-machine developability and stain resistance can be improved, which is preferable.

Suitable examples of the phosphate compound include phosphates of metals such as alkali metals and alkaline earth metals.
Specifically, for example, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, monoammonium phosphate, monopotassium phosphate, monosodium phosphate, dihydrogen phosphate Potassium, dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium hydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, hydrogen phosphate Disodium, lead phosphate, diammonium phosphate, calcium dihydrogen phosphate, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate, sodium phosphite , Tripolyphosphate Potassium, and sodium pyrophosphate. Of these, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are preferable.
The combination of the inorganic fluorine compound and the phosphate compound is not particularly limited, but the aqueous solution contains at least sodium zirconate fluoride as the inorganic fluorine compound and contains at least sodium dihydrogen phosphate as the phosphate compound. Is preferred.
The concentration of the phosphate compound in the aqueous solution is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, from the viewpoint of improving on-press developability and stain resistance. Further, in terms of solubility, it is preferably 20% by weight or less, and more preferably 5% by weight or less.

The ratio of each compound in the aqueous solution is not particularly limited, but the weight ratio of the inorganic fluorine compound and the phosphate compound is preferably 1/200 to 10/1, and preferably 1/30 to 2/1. Is more preferable.
The temperature of the aqueous solution is preferably 20 ° C. or higher, more preferably 40 ° C. or higher, preferably 100 ° C. or lower, more preferably 80 ° C. or lower.
The aqueous solution preferably has a pH of 1 or more, more preferably has a pH of 2 or more, preferably has a pH of 11 or less, and more preferably has a pH of 5 or less.
The method for sealing with an aqueous solution containing an inorganic fluorine compound is not particularly limited, and examples thereof include an immersion method and a spray method. These may be used alone or in combination, or may be used in combination of two or more.
Of these, the dipping method is preferred. When the treatment is performed using the dipping method, the treatment time is preferably 1 second or longer, more preferably 3 seconds or longer, and preferably 100 seconds or shorter, and 20 seconds or shorter. More preferred.

<Sealing treatment with water vapor>
Examples of the sealing treatment with water vapor include a method of bringing pressurized or normal pressure water vapor into contact with the anodized film continuously or discontinuously.
The temperature of the water vapor is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and preferably 105 ° C. or lower.
The water vapor pressure is preferably in the range (1.008 × 10 ^{5 to} 1.043 × 10 ⁵ Pa) from (atmospheric pressure−50 mmAq) to (atmospheric pressure + 300 mmAq).
Further, the time for which the water vapor is contacted is preferably 1 second or longer, more preferably 3 seconds or longer, 100 seconds or shorter, more preferably 20 seconds or shorter.

<Sealing treatment with hot water>
Examples of the sealing treatment with water vapor include a method in which an aluminum plate on which an anodized film is formed is immersed in hot water.
The hot water may contain an inorganic salt (for example, phosphate) or an organic salt.
The temperature of the hot water is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and preferably 100 ° C. or lower.
Further, the time of immersion in hot water is preferably 1 second or longer, more preferably 3 seconds or longer, more preferably 100 seconds or shorter, and even more preferably 20 seconds or shorter.
Examples of the hydrophilization treatment used in the present invention include US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There is an alkali metal silicate method as described in the book. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, And a method of treating with polyvinylphosphonic acid as described in each specification of No.272.
In the present invention, the support preferably has a center line average roughness of 0.10 to 1.20 μm. Within this range, good adhesion to the image recording layer, good printing durability and good stain resistance are obtained, which is preferable.

(3-1-2) Step of discharging the ink composition onto the hydrophilic support When the ink composition of the present invention or the ink composition for inkjet recording is discharged onto the surface of the hydrophilic support, the ink composition The ink composition or the ink composition for inkjet recording is preferably heated to 40 to 80 ° C., more preferably 25 to 30 ° C., and the viscosity of the ink composition is preferably 5 to 30 mPa · s, more preferably 7 to 15 mPa · s. It is preferable that the ink is discharged after being lowered. In particular, it is preferable to use an ink composition having an ink viscosity of 8 to 500 mP · s at 25 ° C. because a great effect can be obtained. By using this method, high ejection stability can be realized. A radiation curable ink composition such as the ink composition of the present invention generally has a higher viscosity than a water-based ink that is usually used in an ink composition or an ink for inkjet recording. Viscosity fluctuation of the ink has a great influence on the change of the droplet size and the change of the droplet discharge speed, and consequently causes the image quality deterioration. Therefore, it is necessary to keep the temperature of the ink at the time of ejection as constant as possible. Therefore, in the present invention, it is appropriate that the temperature control range is set to ± 5 ° C. of the set temperature, preferably ± 2 ° C. of the set temperature, more preferably set temperature ± 1 ° C.

(3-1-3) Irradiating actinic radiation to the ejected ink composition to cure the ink composition, whereby a hydrophobic image formed by curing the ink composition is formed on the hydrophilic support. Step of forming the ink composition ejected on the surface of the hydrophilic support is cured by irradiation with actinic radiation. This is because the sensitizing dye in the polymerization initiation system contained in the ink composition of the present invention absorbs actinic radiation to be in an excited state, and the polymerization initiator is decomposed by contact with the polymerization initiator in the polymerization initiation system. This is because the polymerizable compound is cured by radical polymerization.
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. The peak wavelength of the actinic radiation is, for example, from 200 to 600 nm, preferably from 300 to 450 nm, more preferably from 350 to 450 nm, although it depends on the absorption characteristics of the sensitizing dye. In the present invention, the polymerization initiation system has sufficient sensitivity even with a low-power active radiation. Thus, the output of the actinic radiation is, for example, 2,000 mJ / cm ² or less, preferably, 10 to 2,000 mJ / cm ^2, more preferably, 20 to 1,000 mJ / cm ^2, more preferably, 50 to 800 mJ An irradiation energy of / cm ² is appropriate. The active radiation, the illumination intensity on the exposed surface is, for example, 10 to 2,000 mW / cm ^2, preferably, it is suitable to be irradiated at 20 to 1,000 mW / cm ^2.

The ink composition of the present invention is appropriately irradiated with such actinic radiation, for example, for 0.01 to 120 seconds, and 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 time (for example, 0.01 to 0.5 seconds, preferably 0.01 to 0.3 seconds, 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. Further, since the ink can be exposed to a porous recording medium before the ink penetrates to a deep part where the light source does not reach, residual unreacted monomer can be suppressed, and as a result, odor can be reduced. .
Further, the curing may be completed by another light source that is not driven. In WO99 / 54415, as an irradiation method, a method using an optical fiber or a method in which a collimated light source is applied to a mirror surface provided on the side surface of the head unit to irradiate the recording unit with UV light is disclosed.

By adopting the ink jet recording method as described above, the dot diameter of the landed ink can be kept constant even on various recording media having different surface wettability, and the image quality is improved. In addition, in order to obtain a color image, it is preferable to superimpose in order from the color with the lowest brightness. By superimposing the inks in the order of low lightness, the irradiation line can easily reach the lower ink, and good curing sensitivity, reduction of residual monomers, reduction of odor, and improvement of 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 is cured by irradiation with actinic radiation to form a hydrophobic image on the surface of the hydrophilic support.

(3-2) Inkjet recording apparatus There is no restriction | limiting in particular as an inkjet recording apparatus used for this invention, A commercially available inkjet recording apparatus can be used. That is, in the present invention, recording can be performed on a recording medium using a commercially available inkjet recording apparatus.
Examples of the ink jet recording apparatus that can be used in the present invention include 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 has a multi-size dot of 1 to 100 pl, preferably 8 to 30 pl, for example, 320 × 320 to 4,000 × 4,000 dpi, preferably 400 × 400 to 1,600 × 1,600 dpi. More preferably, it can be driven so as to discharge at a resolution of 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 has a constant temperature for the ejected ink, 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.

As the active radiation source, a mercury lamp, a gas / solid laser or the like is mainly used, and a mercury lamp and a metal halide lamp are widely known as the ultraviolet light curable ink jet. 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 life, have high efficiency, and are low in cost, and are expected as light sources for photocurable 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.
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, particularly preferably 50 to 800 mW / cm ² .

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples.
IRGACURE 184, IRGACURE 819, IRGACURE 250, IRGACURE 907, and Darocur ITX (polymerization initiator) used in the present invention are commercial products manufactured by Ciba Specialty Chemicals (CSC).

Example 1
<< Preparation of pigment dispersion >>
Yellow, magenta, cyan, and black pigment dispersions 1 were prepared according to the method described below. The dispersion conditions are appropriately adjusted using a known dispersion device so that the average particle diameter of each pigment particle is in the range of 0.2 to 0.3 μm, and then the filter is heated under the filter. Prepared by filtration.

(Yellow pigment dispersion 1)
(C) C.I. I. 20 parts by weight of Pigment Yellow 13 / polymer dispersant (Solsperse series manufactured by Zeneca) 20 parts by weight / (a) 60 parts by weight of diethylene glycol divinyl ether (manufactured by BASF)

(Magenta pigment dispersion 1)
(C) C.I. I. Pigment Red 57: 1 20 parts by weight Polymer dispersing agent (Solsperse series manufactured by Zeneca) 20 parts by weight (a) Diethylene glycol divinyl ether (manufactured by BASF) 60 parts by weight

(Cyan pigment dispersion 1)
(C) C.I. I. Pigment Blue 15: 3 20 parts by weight Polymer dispersing agent (Solsperse series manufactured by Zeneca) 20 parts by weight (a) Diethylene glycol divinyl ether (manufactured by BASF) 60 parts by weight

(Black pigment dispersion 1)
(C) C.I. I. 20 parts by weight of Pigment Black 7 / polymer dispersant (Solsperse series manufactured by Zeneca) 20 parts by weight / (a) 60 parts by weight of diethylene glycol divinyl ether (manufactured by BASF)

<Preparation of ink>
The following components were mixed and filtered through a filter to prepare each color ink 1.
<Yellow ink 1>
(Containing (c)) 5 parts by weight of the yellow pigment dispersion 1 (a) Polymerizable compound A: Dipropylene glycol diacrylate (a bifunctional monomer manufactured by Daicel UCB) 60 parts by weight (a) Polymerizable compound B: ODA (Daicel Chemical Monofunctional Monomer) 20 parts by weight (b) Polymerization initiator 1 (CSC, IRGACURE 184) 5 parts by weight (b) Polymerization initiator 2 (CSC, IRGACURE 819) 5 parts by weight Polymerization inhibitor Benzoquinone 0.3 part by weight (d) Surfynol 420 (manufactured by Air Products and Chemicals) 1 part by weight

<Magenta ink 1>
(Containing (c)) 5 parts by weight of the magenta pigment dispersion 1 (a) Polymerizable compound A: 60 parts by weight of dipropylene glycol diacrylate (a) Polymerizable compound B: 20 parts by weight of ODA (b) Polymerization initiator 1 (CSC, IRGACURE 184) 5 parts by weight (b) Polymerization initiator 2 (CSC, IRGACURE 819) 5 parts by weight Polymerization inhibitor; benzoquinone 0.3 parts by weight (d) Surfynol 420 (manufactured by Air Products and Chemicals) 1 part by weight

<Cyan ink 1>
(Containing (c)) 5 parts by weight of the cyan pigment dispersion 1 (a) Polymerizable compound A: 60 parts by weight of dipropylene glycol diacrylate (a) Polymerizable compound B: 20 parts by weight of ODA (b) Polymerization initiator 1 (CSC, IRGACURE 184) 5 parts by weight (b) Polymerization initiator 2 (CSC, IRGACURE 819) 5 parts by weight Polymerization inhibitor: 0.3 parts by weight of benzoquinone (d) Surfynol 420 (manufactured by Air Products and Chemicals) 1 part by weight

<Black ink 1>
(Containing (c)) 5 parts by weight of the black pigment dispersion 1 (a) Polymerizable compound A: 60 parts by weight of dipropylene glycol diacrylate (a) Polymerizable compound B: 20 parts by weight of ODA (b) Polymerization initiator 1 (CSC, IRGACURE 184) 5 parts by weight (b) Polymerization initiator 2 (CSC, IRGACURE 819) 5 parts by weight Polymerization inhibitor: benzoquinone 0.3 parts by weight (d) Surfynol 420 (manufactured by Air Products and Chemicals) 1 part by weight

<Inkjet image recording>
Next, recording on a recording medium was performed using a commercially available inkjet recording apparatus having a piezoelectric 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 nozzles of the ink jet head, respectively, and temperature control was performed so that the nozzle portions were always 70 ° 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 100 mW / cm ² , and the exposure system, main scanning speed, and ejection frequency were adjusted so that irradiation started 0.1 seconds after ink landed on the recording medium. Further, the exposure time was variable, and exposure energy was irradiated. In the present invention, dpi represents the number of dots per 2.54 cm.

Each color ink prepared above was emitted in the order of black → cyan → magenta → yellow at an environmental temperature of 25 ° C., and ultraviolet rays were irradiated for each color by a metal halide lamp Vzero085 manufactured by Integration Technology. In order to eliminate tackiness by palpation, the exposure was performed with a total exposure energy per color of 300 mJ / cm ² as the energy for complete curing. As recording media, each color image was recorded on a grained aluminum support, a transparent biaxially stretched polypropylene film having a printability, a soft vinyl chloride sheet, cast coated paper, and commercially available recycled paper. However, in both cases, a high-resolution image without dot bleeding was obtained. Furthermore, even on high-quality paper, the ink was sufficiently cured without causing the ink to turn around, and there was almost no odor due to unreacted monomers. Further, the ink recorded on the film had sufficient flexibility, and the ink was not cracked even when it was bent, and there was no problem in the adhesion test by peeling the cello tape (registered trademark).

(Examples 2 to 10)
<Preparation of ink>
Magenta inks 2 to 10 were prepared according to the method described below.

<Magenta ink 2-5>
Magenta inks 2 to 5 were prepared in the same manner as the magenta ink 1 except that Surfynol 420 (produced by Air Products and Chemicals) was used as an acetylene alcohol surfactant shown in the following table.

The following components were mixed and filtered through a filter to prepare magenta ink 6.
<Magenta ink 6>
(Containing (c)) 5 parts by weight of the magenta pigment dispersion (a) Polymerizable compound C: Celoxide 2021
(Epoxy compound: manufactured by Daicel UCB) 35 parts by weight (a) Polymerizable compound D: OXT-221
(Oxetane compound: manufactured by Toagosei Co., Ltd.) 55 parts by weight (b) Polymerization initiator 3 (CSC, IRGACURE 250) 5 parts by weight (b) Polymerization initiator 4 (CSC, Darocur ITX) 5 parts by weight Polymerization inhibitor: Diethylaniline 0.2 parts by weight (d) Surfynol 420 (produced by Air Products and Chemicals) 1 part by weight

<Magenta ink 7-10>
Magenta inks 7 to 10 were prepared in the same manner as magenta ink 6 except that Surfynol 420 (produced by Air Products and Chemicals) of magenta ink 6 was used as an acetylene alcohol surfactant shown in the following table. .

<Magenta ink 11: Comparative example 1>
Magenta ink 11 was prepared in the same manner as magenta ink 1 except that (d) the acetylene alcohol surfactant (Surfinol 420) of magenta ink 1 was not used.

<Magenta ink 12: Comparative example 2>
Magenta ink 12 was prepared in exactly the same manner except that (d) the acetylene alcohol surfactant (Surfinol 420) of magenta ink 6 was not used.
<Magenta ink 13: Comparative example 3>
In place of (d) acetylene alcohol surfactant (1 part by weight of Surfynol 420 (Air Products and Chemicals)) in magenta ink 1, (d) nonionic surfactant: polyoxyethylene polyoxypropylene copolymer Magenta ink 13 was prepared in the same manner as magenta ink 1 except that 1 part by weight (oxypropylene block molecular weight of about 1,800, oxyethylene content of about 40%, average molecular weight of about 3,000) was used.
<Magenta ink 14: Comparative example 4>
Instead of (d) acetylene alcohol surfactant (Surfinol 420 (Air Products and Chemicals) 1 part by weight) of magenta ink 1 (d) Fluorine surfactant: Fluorard FC-430 (Sumitomo 3M Limited) Magenta ink 14 was prepared in the same manner as magenta ink 1 except that 0.3 part by weight was used.

<Inkjet image recording>
Using the magenta inks 2 to 14 prepared as described above and the magenta ink 1 prepared in Example 1, a magenta image was produced in the same manner as in the method described in Example 1.

<Evaluation of inkjet image>
Next, for each formed image, in accordance with the method described below, sensitivity required for curing, permeability in commercially available recycled paper, ink bleeding on a grained aluminum support, adhesion, printing durability, storage The stability was evaluated. The results are shown in Table 3.

(Measurement of curing sensitivity)
The amount of exposure energy (mJ / cm ² ) at which the sticky feeling disappears on the image surface after ultraviolet irradiation was defined as the curing sensitivity. The smaller the value, the higher the sensitivity.

(Permeability evaluation for commercial recycled paper)
For images printed on commercially available recycled paper, permeability was evaluated according to the following criteria.
○: Almost no penetration and no residual monomer odor △: Slight penetration and slight residual monomer odor X: Clearly the ink penetrates the back side and the residual monomer odor is strong

(Evaluation of ink bleeding on grained aluminum support)
For images printed on a grained aluminum support, ink bleeding was evaluated according to the following criteria.
○: No blur between adjacent dots Δ: Slightly blur dots ×: Dot blurs and the image is clearly blurred

(Evaluation of adhesion in grained aluminum support)
For the printed image created above, in accordance with JIS K 5400, a sample that does not scratch the printed surface at all, and has 11 cuts on the printed surface at 1 mm intervals vertically and horizontally. 100 samples were prepared, and a cellophane tape was affixed on each printing surface, quickly peeled off at an angle of 90 degrees, and the state of printed images or grids remaining without peeling was evaluated according to the following criteria.
○: No peeling of the printed image was observed even in the cross cut test. Δ: Some ink peeling was observed in the cross cut test, but almost no peeling was observed unless the ink surface was scratched. Easy to peel off with cello tape (registered trademark)

(Evaluation of printing durability)
The image printed on the grained aluminum support prepared above was used as a printing plate, and after printing with a Heidel KOR-D machine, the number of finished sheets was compared relative to each other as an index of printing durability (Example 1 was set to 100). ). A larger numerical value is preferable because it has a higher printing durability.

(Evaluation of storage stability)
The prepared ink was stored at 75% RH and 60 ° C. for 3 days, then the ink viscosity at the ejection temperature was measured, and the increase in the ink viscosity was expressed as the viscosity ratio after storage / before storage. When the viscosity does not change and is close to 1.0, the storage stability is good, and when it exceeds 1.5, clogging may occur at the time of injection, which is not preferable.

(Evaluation of ejection stability)
After continuous discharge for 30 minutes, the presence or absence of defects due to nozzle clogging (presence / absence of unprinted portions) and fine dots (satellite) not set around the print dots on the printed matter were evaluated.
○: No nozzle defect or satellite is generated.
Δ: Nozzle defects or satellites are slightly generated.
X: Nozzle defects or satellites are remarkably generated.

(Evaluation of print quality (image quality))
The printed matter after curing was evaluated for matte feeling (concaveness), glossiness, and saturation.
○: Less matte feeling, good glossiness and saturation.
Δ: Matte feeling, glossiness and saturation slightly decreased.
X: Matte feeling is large and glossiness and saturation are greatly reduced. Banding (streak-like defect) occurs in part.

(Example 11)
A magenta image was produced using the magenta ink 6 in the same manner as described in Example 6 except that an ultraviolet light emitting diode (UV-LED) was used instead of the metal halide lamp Vzero085 manufactured by Integration Technology.
In this example, NCCU033 manufactured by Nichia Chemical was used as the UV-LED. The LED outputs ultraviolet light having a wavelength of 365 nm from one chip. When a current of about 500 mA is applied, light of about 100 mW is emitted from the chip. A plurality of these are arranged at intervals of 7 mm, and a power of 0.3 W / cm ² can be obtained on the surface of a recording medium (hereinafter also referred to as a medium). The exposure time after the droplet ejection and the exposure time can be changed according to the transport speed of the medium and the distance between the head and the LED in the transport direction. In this embodiment, the exposure is performed about 0.5 seconds after landing.
Depending on the setting of the distance to the medium and the conveyance speed, the exposure energy on the medium can be adjusted between 0.01 and 15 J / cm ² .

As a result, the energy for complete curing was 110 mJ / cm ² so that tackiness disappeared by palpation. As recording media, each color image was recorded on a grained aluminum support, a transparent biaxially stretched polypropylene film having a printability, a soft vinyl chloride sheet, cast coated paper, and commercially available recycled paper. However, in both cases, a high-resolution image without dot bleeding was obtained. Furthermore, even on high-quality paper, the ink was sufficiently cured without causing the ink to turn around, and there was almost no odor due to unreacted monomers. Further, the ink recorded on the film had sufficient flexibility, and the ink was not cracked even when it was bent, and there was no problem in the adhesion test by peeling the cello tape (registered trademark).

From the above results, the ink composition using the acetylene alcohol-based surfactant in the present invention is highly sensitive to radiation irradiation, and can form a high-quality image in terms of image formation on paper. It can be seen that the ejection stability and the storage stability are also good, and even when used for the production of a printing plate, it is possible to form an image with high printing durability and high image quality.

Claims (8)

(A) a polymerizable compound,
(B) a polymerization initiator,
An ink composition comprising: (c) a colorant; and (d) an acetylene alcohol surfactant.   The ink composition according to claim 1, wherein (a) the polymerizable compound is cationically polymerizable, and (b) the polymerization initiator is a photoacid generator.   The ink composition according to claim 1 or 2, which is for inkjet recording. (A) a step of discharging the ink composition onto a recording medium; and (b) a step of irradiating the discharged ink composition with active radiation to cure the ink composition;
An inkjet recording method comprising:
The ink composition according to claim 1, wherein the ink composition is the ink composition according to claim 1. The active radiation is ultraviolet light emitted by a light emitting diode that generates ultraviolet light having an emission peak wavelength in the range of 350 to 420 nm and a maximum illuminance on the surface of the recording medium of 10 to 2,000 mW / cm ^2. The ink jet recording method according to claim 4.   Printed matter recorded by the inkjet recording method according to claim 4 or 5. (A) a step of discharging the ink composition according to any one of claims 1 to 3 onto a hydrophilic support; and (b) irradiating the discharged ink composition with actinic radiation to form the ink composition. A step of forming a hydrophobic image on the hydrophilic support by curing the product, by curing the ink composition;
A method for producing a lithographic printing plate comprising   A lithographic printing plate produced by the method for producing a lithographic printing plate according to claim 7.